Synthesis and biological activity of the novel indanedione anticoagulant rodenticides containing fluorine.

Science.gov (United States)

Chen, Feng; Liu, Liping; Bai, Zengguo; Zhang, Tianhua; Zhao, Keke

2017-01-02

Here, 3 fluorinated intermediates of drug were synthesized: (M1), (M2), (M3). Three new anticoagulant rodenticides were designed which were based on 4-hydroxycoumarin or 1,3-indandione, added acute toxicity groups containing fluorine. The structures of synthesized compounds were analyzed and proved by FT-IR spectroscopy and 1 H nuclear magnetic resonance ( 1 H-NMR). The compounds were also evaluated for their anticoagulant and acute biologic activity. In addition, both the acute orally toxicity and the feeding indexes of R 1 and R 2 were tested. The result of the experiment proved that the new synthesis of 1, 3 - indan diketone for maternal new anticoagulant rodenticide can replace the current 4 - hydroxyl coumarin as the mother of the second generation anticoagulant rodenticide and 1, 3 - indan diketone for maternal new anticoagulant rodenticides will have a good development prospect.

Inhibition of the intrinsic factor X activating complex by protein S: evidence for a specific binding of protein S to factor VIII

NARCIS (Netherlands)

Koppelman, S.J.

1995-01-01

Protein S is a vitamin K-dependent nonenzymatic anticoagulant protein that acts as a cofactor to activated protein C. Recently it was shown that protein S inhibits the prothrombinase reaction independent of activated protein C. In this study, we show that protein S can also inhibit the intrinsic

Bioassay-guided fractionation of Melastoma malabathricum Linn. leaf solid phase extraction fraction and its anticoagulant activity.

Science.gov (United States)

Khoo, Li Teng; Abdullah, Janna Ong; Abas, Faridah; Tohit, Eusni Rahayu Mohd; Hamid, Muhajir

2015-02-24

The aims of this study were to examine the bioactive component(s) responsible for the anticoagulant activity of M. malabathricum Linn. leaf hot water crude extract via bioassay-guided fractionation and to evaluate the effect of bioactive component(s) on the intrinsic blood coagulation pathway. The active anticoagulant fraction of F3 was subjected to a series of chromatographic separation and spectroscopic analyses. Furthermore, the effect of the bioactive component(s) on the intrinsic blood coagulation pathway was studied through immediate and time incubation mixing studies. Through Activated Partial Thromboplastin Time (APTT) assay-guided fractionation, Subfraction B was considered the most potent anticoagulant fraction. Characterisation of Subfraction B indicated that anticoagulant activity could partly be due to the presence of cinnamic acid and a cinnamic acid derivative. APTT assays for both the immediate and time incubation mixing were corrected back into normal clotting time range (35.4-56.3 s). In conclusion, cinnamic acid and cinnamic acid derivative from Subfraction B were the first such compounds to be discovered from M. malabathricum Linn. leaf hot water crude extract that possess anticoagulant activity. This active anticoagulant Subfraction B prolonged blood clotting time by causing factor(s) deficiency in the intrinsic blood coagulation pathway.

Protein C inhibitor acts as a procoagulant by inhibiting the thrombomodulin-induced activation of protein C in human plasma

NARCIS (Netherlands)

Elisen, M. G.; von dem Borne, P. A.; Bouma, B. N.; Meijers, J. C.

1998-01-01

Protein C inhibitor (PCI), which was originally identified as an inhibitor of activated protein C, also efficiently inhibits coagulation factors such as factor Xa and thrombin. Recently it was found, using purified proteins, that the anticoagulant thrombin-thrombomodulin complex was also inhibited

Laboratory Assessment of the Anticoagulant Activity of Direct Oral Anticoagulants: A Systematic Review.

Science.gov (United States)

Samuelson, Bethany T; Cuker, Adam; Siegal, Deborah M; Crowther, Mark; Garcia, David A

2017-01-01

Direct oral anticoagulants (DOACs) are the treatment of choice for most patients with atrial fibrillation and/or noncancer-associated venous thromboembolic disease. Although routine monitoring of these agents is not required, assessment of anticoagulant effect may be desirable in special situations. The objective of this review was to summarize systematically evidence regarding laboratory assessment of the anticoagulant effects of dabigatran, rivaroxaban, apixaban, and edoxaban. PubMed, Embase, and Web of Science were searched for studies reporting relationships between drug levels and coagulation assay results. We identified 109 eligible studies: 35 for dabigatran, 50 for rivaroxaban, 11 for apixaban, and 13 for edoxaban. The performance of standard anticoagulation tests varied across DOACs and reagents; most assays, showed insufficient correlation to provide a reliable assessment of DOAC effects. Dilute thrombin time (TT) assays demonstrated linear correlation (r 2  = 0.67-0.99) across a range of expected concentrations of dabigatran, as did ecarin-based assays. Calibrated anti-Xa assays demonstrated linear correlation (r 2  = 0.78-1.00) across a wide range of concentrations for rivaroxaban, apixaban, and edoxaban. An ideal test, offering both accuracy and precision for measurement of any DOAC is not widely available. We recommend a dilute TT or ecarin-based assay for assessment of the anticoagulant effect of dabigatran and anti-Xa assays with drug-specific calibrators for direct Xa inhibitors. In the absence of these tests, TT or APTT is recommended over PT/INR for assessment of dabigatran, and PT/INR is recommended over APTT for detection of factor Xa inhibitors. Time since last dose, the presence or absence of drug interactions, and renal and hepatic function should impact clinical estimates of anticoagulant effect in a patient for whom laboratory test results are not available. Copyright © 2016 American College of Chest Physicians. Published by Elsevier

Protein C activation during the initial phase of experimental acute pancreatitis in the rabbit

DEFF Research Database (Denmark)

Ottesen, L H; Bladbjerg, E-M; Osman, M

2000-01-01

activity), anticoagulant proteins (protein C, antithrombin) and fibrinolytic factors (tissue plasminogen activator, plasminogen activator inhibitor-1) were performed for 5 h. RESULTS: ANP was confirmed by elevated serum amylase, development of ascites, and histological changes of the pancreas. A moderate...

The endothelial protein C receptor and activated protein C play a limited role in host defense during experimental tuberculosis

NARCIS (Netherlands)

Kager, Liesbeth M.; Roelofs, Joris J. T. H.; de Vos, Alex F.; Wieland, Catharina W.; Schouten, Marcel; Meijers, Joost C. M.; Isermann, Berend; van't Veer, Cornelis; Esmon, Charles T.; van der Poll, Tom

2013-01-01

The protein C (PC) system is an important regulator of both coagulation and inflammation. Activated PC (APC), together with its receptor the endothelial protein C receptor (EPCR), has anticoagulant and anti-inflammatory properties. During tuberculosis (TB), a devastating chronic pulmonary disease

Anticoagulant activity of ginger ( Zingiber officinale Rosc ...

African Journals Online (AJOL)

Background: Herbal medicines with anticoagulant therapeutic claims could serve as veritable sources of new oral anticoagulant drugs with possible wider safety margins than the currently available ones. Objectives: This work was aimed at evaluating a Ginger Rhizome Methanolic Extract in vivo in rats for its potential ...

Sulfated polysaccharides with antioxidant and anticoagulant activity from the sea cucumber Holothuria fuscogliva

Science.gov (United States)

Li, Rongfeng; Yu, Huahua; Yue, Yang; Liu, Song; Xing, Rong'e.; Chen, Xiaolin; Li, Pengcheng

2017-07-01

Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China. Holothuria fuscogliva is a big sea cucumber with a rich of bioactive polysaccharides. To investigate the bioactivities of the polysaccharides from sea cucumber H. fuscogliva, we prepared the sulfated polysaccharides (HfP) from sea cucumber H. fuscogliva using a protease hydrolysis method. Antioxidant activities of HfP were investigated, including hydroxyl radical scavenging activity and superoxide radical scavenging activity. And, the anticoagulant activities of HfP were studied, including the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT). The average molecular weight was 1 867.1 Da, with a sulfate content of 20.7%. In addition, the molar ratio of monosaccharide composition of HfP was Man: Rha: Glc A: Glc: Gal: Xyl: Fuc=0.083 6: 0.437: 0.134: 0:1.182: 0.748: 1. It had a strong antioxidant activity, the hydroxyl and superoxide radical scavenging activity EC50 of HfP was 3.74 and 0.037 mg/mL, respectively. It also showed a good anticoagulant activity in our study. The APTT of HfP was much higher than that of heparin sodium, and the PT and TT of HfP was close to that of heparin sodium at a low concentration. Therefore, HfP shows a good antioxidant and anticoagulant activity and it may become a potential candidate of the natural antioxidant and anticoagulant and will have a good application future in health product or medicine industry.

The functional significance of the autolysis loop in protein C and activated protein C.

Science.gov (United States)

Yang, Likui; Manithody, Chandrashekhara; Rezaie, Alireza R

2005-07-01

The autolysis loop of activated protein C (APC) is five residues longer than the autolysis loop of other vitamin K-dependent coagulation proteases. To investigate the role of this loop in the zymogenic and anticoagulant properties of the molecule, a protein C mutant was constructed in which the autolysis loop of the protein was replaced with the corresponding loop of factor X. The protein C mutant was activated by thrombin with approximately 5-fold higher rate in the presence of Ca2+. Both kinetics and direct binding studies revealed that the Ca2+ affinity of the mutant has been impaired approximately 3-fold. The result of a factor Va degradation assay revealed that the anticoagulant function of the mutant has been improved 4-5-fold in the absence but not in the presence of protein S. The improvement was due to a better recognition of both the P1-Arg506 and P1-Arg306 cleavage sites by the mutant protease. However, the plasma half-life of the mutant was markedly shortened due to faster inactivation by plasma serpins. These results suggest that the autolysis loop of protein C is critical for the Ca(2+)-dependence of activation by thrombin. Moreover, a longer autolysis loop in APC is not optimal for interaction with factor Va in the absence of protein S, but it contributes to the lack of serpin reactivity and longer half-life of the protease in plasma.

Characterization of mini-protein S, a recombinant variant of protein S that lacks the sex hormone binding globulin-like domain

NARCIS (Netherlands)

van Wijnen, M.; Stam, J. G.; Chang, G. T.; Meijers, J. C.; Reitsma, P. H.; Bertina, R. M.; Bouma, B. N.

1998-01-01

Protein S is a vitamin K-dependent glycoprotein involved in the regulation of the anticoagulant activity of activated protein C (APC). Also, an anticoagulant role for protein S, independent of APC, has been described. Protein S has a unique C-terminal sex hormone binding globulin (SHBG)-like domain

Acquired activated protein C resistance is associated with lupus anticoagulants and thrombotic events in pediatric patients with systemic lupus erythematosus.

Science.gov (United States)

Male, C; Mitchell, L; Julian, J; Vegh, P; Joshua, P; Adams, M; David, M; Andrew, M E

2001-02-15

Acquired activated protein C resistance (APCR) has been hypothesized as a possible mechanism by which antiphospholipid antibodies (APLAs) cause thrombotic events (TEs). However, available evidence for an association of acquired APCR with APLAs is limited. More importantly, an association of acquired APCR with TEs has not been demonstrated. The objective of the study was to determine, in pediatric patients with systemic lupus erythematosus (SLE), whether (1) acquired APCR is associated with the presence of APLAs, (2) APCR is associated with TEs, and (3) there is an interaction between APCR and APLAs in association with TEs. A cross-sectional cohort study of 59 consecutive, nonselected children with SLE was conducted. Primary clinical outcomes were symptomatic TEs, confirmed by objective radiographic tests. Laboratory testing included lupus anticoagulants (LAs), anticardiolipin antibodies (ACLAs), APC ratio, protein S, protein C, and factor V Leiden. The results revealed that TEs occurred in 10 (17%) of 59 patients. Acquired APCR was present in 18 (31%) of 58 patients. Acquired APCR was significantly associated with the presence of LAs but not ACLAs. Acquired APCR was also significantly associated with TEs. There was significant interaction between APCR and LAs in the association with TEs. Presence of both APCR and LAs was associated with the highest risk of a TE. Protein S and protein C concentrations were not associated with the presence of APLAs, APCR, or TEs. Presence of acquired APCR is a marker identifying LA-positive patients at high risk of TEs. Acquired APCR may reflect interference of LAs with the protein C pathway that may represent a mechanism of LA-associated TEs. (Blood. 2001;97:844-849)

Polysaccharides and their depolymerized fragments from Costaria costata: Molecular weight and sulfation-dependent anticoagulant and FGF/FGFR signal activating activities.

Science.gov (United States)

Hou, Ningning; Zhang, Meng; Xu, Yingjie; Sun, Zhongmin; Wang, Jing; Zhang, Lijuan; Zhang, Quanbin

2017-12-01

Crude polysaccharides from Costaria costata were extracted by hot water and further fractionated by anion exchange chromatography into three polysaccharide fractions. Three low molecular weight fragments were then prepared by degradation of the polysaccharides with hydrogen peroxide and ascorbic acid. The structural features of the polysaccharides and their low molecular weight fragments were elucidated for the first time based on the HGPC, FT-IR, NMR, MS, monosaccharide composition, and other chemical analyses. Their anticoagulant and FGF-1, -2, -7, -8, -9, -10/FGFR1c signaling activation activities in BaF3 cells were also examined. Our studies showed that the polysaccharides were sulfated at different positions of galactose and fucose residues. The APTT-, PT- and TT-based anticoagulant assay results indicated that a high molecular weight and a higher degree of sulfation were essential for their anticoagulant activities. In contrast, not only the polysaccharides but also the depolymerized fragments showed significant FGF/FGFR signal activating activities in a FGF-, molecular weight-, and sulfation-dependent manner. The results presented in current study demonstrated the potential use of the polysaccharides and their fragments as anticoagulants and FGF signal regulators. Copyright © 2017 Elsevier B.V. All rights reserved.

Synthesis and biological activity of the novel indanedione anticoagulant rodenticides containing fluorine

OpenAIRE

Chen, Feng; Liu, Liping; Bai, Zengguo; Zhang, Tianhua; Zhao, Keke

2016-01-01

Here, 3 fluorinated intermediates of drug were synthesized: (M1), (M2), (M3). Three new anticoagulant rodenticides were designed which were based on 4-hydroxycoumarin or 1,3-indandione, added acute toxicity groups containing fluorine. The structures of synthesized compounds were analyzed and proved by FT-IR spectroscopy and 1H nuclear magnetic resonance (1H-NMR). The compounds were also evaluated for their anticoagulant and acute biologic activity. In addition, both the acute orally toxicity ...

Histones Differentially Modulate the Anticoagulant and Profibrinolytic Activities of Heparin, Heparin Derivatives, and Dabigatran.

Science.gov (United States)

Ammollo, Concetta Tiziana; Semeraro, Nicola; Carratù, Maria Rosaria; Colucci, Mario; Semeraro, Fabrizio

2016-02-01

The antithrombin activity of unfractionated heparin (UFH) is offset by extracellular histones, which, along with DNA, represent a novel mediator of thrombosis and a structural component of thrombi. Here, we systematically evaluated the effect of histones, DNA, and histone-DNA complexes on the anticoagulant and profibrinolytic activities of UFH, its derivatives enoxaparin and fondaparinux, and the direct thrombin inhibitor dabigatran. Thrombin generation was assessed by calibrated automated thrombinography, inhibition of factor Xa and thrombin by synthetic substrates, tissue plasminogen activator-mediated clot lysis by turbidimetry, and thrombin-activatable fibrinolysis inhibitor (TAFI) activation by a functional assay. Histones alone delayed coagulation and slightly stimulated fibrinolysis. The anticoagulant activity of UFH and enoxaparin was markedly inhibited by histones, whereas that of fondaparinux was enhanced. Histones neutralized both the anti-Xa and anti-IIa activities of UFH and preferentially blocked the anti-IIa activity of enoxaparin. The anti-Xa activity of fondaparinux was not influenced by histones when analyzed by chromogenic substrates, but was potentiated in a plasma prothrombinase assay. Histones inhibited the profibrinolytic activity of UFH and enoxaparin and enhanced that of fondaparinux by acting on the modulation of TAFI activation by anticoagulants. Histone H1 was mainly responsible for these effects. Histone-DNA complexes, as well as intact neutrophil extracellular traps, impaired the activities of UFH, enoxaparin, and fondaparinux. Dabigatran was not noticeably affected by histones and/or DNA, whatever the assay performed. In conclusion, histones and DNA present in the forming clot may variably influence the antithrombotic activities of anticoagulants, suggesting a potential therapeutic advantage of dabigatran and fondaparinux over heparins. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Activated protein C inhibits neutrophil migration in allergic asthma: a randomised trial

NARCIS (Netherlands)

de Boer, J. Daan; Berger, Marieke; Majoor, Christof J.; Kager, Liesbeth M.; Meijers, Joost C. M.; Terpstra, Sanne; Nieuwland, Rienk; Boing, Anita N.; Lutter, René; Wouters, Diana; van Mierlo, Gerard J.; Zeerleder, Sacha S.; Bel, Elisabeth H.; van't Veer, Cornelis; de Vos, Alex F.; van der Zee, Jaring S.; van der Poll, Tom

2015-01-01

Asthma patients show evidence of a procoagulant state in their airways, accompanied by an impaired function of the anticoagulant protein C system. We aimed to study the effect of recombinant human activated protein C (rhAPC) in allergic asthma patients.We conducted a randomised, double-blind,

Biological and Biochemical Potential of Sea Snake Venom and Characterization of Phospholipase A2 and Anticoagulation Activity.

Science.gov (United States)

Damotharan, Palani; Veeruraj, Anguchamy; Arumugam, Muthuvel; Balasubramanian, Thangavel

2016-03-01

This study is designed to isolate and purify a novel anti-clotting protein component from the venom of Enhydrina schistosa, and explore its biochemical and biological activities. The active protein was purified from the venom of E. schistosa by ion-exchange chromatography using DEAE-cellulose. The venom protein was tested by various parameters such as, proteolytic, haemolytic, phospholipase and anti-coagulant activities. 80 % purity was obtained in the final stage of purification and the purity level of venom was revealed as a single protein band of about 44 kDa in SDS-polyacrylamide electrophoresis under reducing conditions. The results showed that the Potent hemolytic activity was observed against cow, goat, chicken and human (A, B and O positive) erythrocytes. Furthermore, the clotting assays showed that the venom of E. schistosa significantly prolonged in activated partial thromboplastin time, thrombin time, and prothrombin time. Venomous enzymes which hydrolyzed casein and gelatin substrate were found in this venom protein. Gelatinolytic activity was optimal at pH 5-9 and (1)H NMR analysis of purified venom was the base line information for the structural determination. These results suggested that the E. schistosa venom holds good promise for the development of novel lead compounds for pharmacological applications in near future.

Silencing of Anticoagulant Protein C Evokes Low-Incident but Spontaneous Atherothrombosis in Apolipoprotein E-Deficient Mice-Brief Report

NARCIS (Netherlands)

Ouweneel, Amber B.; Heestermans, Marco; Verwilligen, Robin A. F.; Gijbels, Marion J. J.; Reitsma, Pieter H.; van Eck, Miranda; van Vlijmen, Bart J. M.

2017-01-01

Murine atherosclerosis models do not spontaneously develop atherothrombotic complications. We investigated whether disruption of natural anticoagulation allows preexisting atherosclerotic plaques to progress toward an atherothrombotic phenotype. On lowering of plasma protein C levels with small

[New oral anticoagulant drugs].

Science.gov (United States)

Berkovits, Alejandro; Aizman, Andrés; Zúñiga, Pamela; Pereira, Jaime; Mezzano, Diego

2011-10-01

Thromboembolic disease (TED) is the leading cause of morbidity and mortality worldwide. The hallmark of oral long-term anticoagulant therapy has been the use of vitamin K antagonists, whose anticoagulant effect is exerted inhibiting vitamin K epoxide reductase. Warfarin and acenocoumarol are the most commonly used. In the last five years several new drugs for long term anticoagulation have been developed, which can inhibit single clotting factors with the purpose of improving drug therapeutic range and, ideally, minimizing bleeding risks. This review addresses the state of the art on the clinical use of inhibitors of activated factor X and thrombin.

Structure and anticoagulant activity of a sulfated galactan from the red alga, Gelidium crinale. Is there a specific structural requirement for the anticoagulant action?

Science.gov (United States)

Pereira, Maria G; Benevides, Norma M B; Melo, Marcia R S; Valente, Ana Paula; Melo, Fábio R; Mourão, Paulo A S

2005-09-05

Marine red algae are an abundant source of sulfated galactans with potent anticoagulant activity. However, the specific structural motifs that confer biological activity remain to be elucidated. We have now isolated and purified a sulfated galactan from the marine red alga, Gellidium crinale. The structure of this polysaccharide was determined using NMR spectroscopy. It is composed of the repeating structure -4-alpha-Galp-(1-->3)-beta-Galp1--> but with a variable sulfation pattern. Clearly 15% of the total alpha-units are 2,3-di-sulfated and another 55% are 2-sulfated. No evidence for the occurrence of 3,6-anhydro alpha-galactose units was observed in the NMR spectra. We also compared the anticoagulant activity of this sulfated galactan with a polysaccharide from the species, Botryocladia occidentalis, with a similar saccharide chain but with higher amounts of 2,3-di-sulfated alpha-units. The sulfated galactan from G. crinale has a lower anticoagulant activity on a clotting assay when compared with the polysaccharide from B. occidentalis. When tested in assays using specific proteases and coagulation inhibitors, these two galactans showed significant differences in their activity. They do not differ in thrombin inhibition mediated by antithrombin, but in assays where heparin cofactor II replaces antithrombin, the sulfated galactan from G. crinale requires a significantly higher concentration to achieve the same inhibitory effect as the polysaccharide from B. occidentalis. In contrast, when factor Xa instead of thrombin is used as the target protease, the sulfated galactan from G. crinale is a more potent anticoagulant. These observations suggest that the proportion and/or the distribution of 2,3-di-sulfated alpha-units along the galactan chain may be a critical structural motif to promote the interaction of the protease with specific protease and coagulation inhibitors.

Synthesis and in Vitro and in Vivo Anticoagulant and Antiplatelet Activities of Amidino- and Non-Amidinobenzamides

Directory of Open Access Journals (Sweden)

Soo Hyun Lee

2016-05-01

Full Text Available Three amidino- and ten non-amidinobenzamides were synthesized as 3-aminobenzoic acid scaffold-based anticoagulant and antiplatelet compounds. The anticoagulant activities of thirteen synthesized compounds 1–13, and 2b and 3b as prodrugs were preliminary evaluated by screening the prolongation of activated partial thromboplastin time (aPTT and prothrombin time (PT in vitro. From the aPTT results obtained, two amidinobenzamides, N-(3′-amidinophenyl-3-(thiophen-2′′-ylcarbonylamino benzamide (1, 33.2 ± 0.7 s and N-(4′-amidinophenyl-3-(thiophen-2′′-ylcarbonylamino benzamide (2, 43.5 ± 0.6 s were selected to investigate the further anticoagulant and antiplatelet activities. The aPTT results of 1 (33.2 ± 0.7 s and 2 (43.5 ± 0.6 s were compared with heparin (62.5 ± 0.8 s in vitro at 30 μM. We investigated the effect of 1 and 2 on blood anticoagulant activity (ex vivo and on tail bleeding time (in vivo on mice. A tail cutting/bleeding time assay revealed that both 1 and 2 prolonged bleeding time in mice at a dose of 24.1 g/mouse and above. Compounds 1 and 2 dose-dependently inhibited thrombin-catalyzed fibrin polymerization and platelet aggregation. In addition, 1 and 2 were evaluated on the inhibitory activities of thrombin and FXa as well as the generation of thrombin and FXa in human umbilical vein endothelial cells (HUVECs. Collectively, 1 and 2 possess some antiplatelet and anticoagulant activities and offer a basis for development of a novel antithrombotic product.

A network-based multi-target computational estimation scheme for anticoagulant activities of compounds.

Directory of Open Access Journals (Sweden)

Qian Li

Full Text Available BACKGROUND: Traditional virtual screening method pays more attention on predicted binding affinity between drug molecule and target related to a certain disease instead of phenotypic data of drug molecule against disease system, as is often less effective on discovery of the drug which is used to treat many types of complex diseases. Virtual screening against a complex disease by general network estimation has become feasible with the development of network biology and system biology. More effective methods of computational estimation for the whole efficacy of a compound in a complex disease system are needed, given the distinct weightiness of the different target in a biological process and the standpoint that partial inhibition of several targets can be more efficient than the complete inhibition of a single target. METHODOLOGY: We developed a novel approach by integrating the affinity predictions from multi-target docking studies with biological network efficiency analysis to estimate the anticoagulant activities of compounds. From results of network efficiency calculation for human clotting cascade, factor Xa and thrombin were identified as the two most fragile enzymes, while the catalytic reaction mediated by complex IXa:VIIIa and the formation of the complex VIIIa:IXa were recognized as the two most fragile biological matter in the human clotting cascade system. Furthermore, the method which combined network efficiency with molecular docking scores was applied to estimate the anticoagulant activities of a serial of argatroban intermediates and eight natural products respectively. The better correlation (r = 0.671 between the experimental data and the decrease of the network deficiency suggests that the approach could be a promising computational systems biology tool to aid identification of anticoagulant activities of compounds in drug discovery. CONCLUSIONS: This article proposes a network-based multi-target computational estimation

A network-based multi-target computational estimation scheme for anticoagulant activities of compounds.

Science.gov (United States)

Li, Qian; Li, Xudong; Li, Canghai; Chen, Lirong; Song, Jun; Tang, Yalin; Xu, Xiaojie

2011-03-22

Traditional virtual screening method pays more attention on predicted binding affinity between drug molecule and target related to a certain disease instead of phenotypic data of drug molecule against disease system, as is often less effective on discovery of the drug which is used to treat many types of complex diseases. Virtual screening against a complex disease by general network estimation has become feasible with the development of network biology and system biology. More effective methods of computational estimation for the whole efficacy of a compound in a complex disease system are needed, given the distinct weightiness of the different target in a biological process and the standpoint that partial inhibition of several targets can be more efficient than the complete inhibition of a single target. We developed a novel approach by integrating the affinity predictions from multi-target docking studies with biological network efficiency analysis to estimate the anticoagulant activities of compounds. From results of network efficiency calculation for human clotting cascade, factor Xa and thrombin were identified as the two most fragile enzymes, while the catalytic reaction mediated by complex IXa:VIIIa and the formation of the complex VIIIa:IXa were recognized as the two most fragile biological matter in the human clotting cascade system. Furthermore, the method which combined network efficiency with molecular docking scores was applied to estimate the anticoagulant activities of a serial of argatroban intermediates and eight natural products respectively. The better correlation (r = 0.671) between the experimental data and the decrease of the network deficiency suggests that the approach could be a promising computational systems biology tool to aid identification of anticoagulant activities of compounds in drug discovery. This article proposes a network-based multi-target computational estimation method for anticoagulant activities of compounds by

Influence of novel oral anticoagulants on anticoagulation care management.

Science.gov (United States)

Janzic, Andrej; Kos, Mitja

2017-09-01

Anticoagulation treatment was recently improved by the introduction of novel oral anticoagulants (NOACs). Using a combination of qualitative and quantitative methods, this study explores the effects of the introduction of NOACs on anticoagulation care in Slovenia. Face-to-face interviews with key stakeholders revealed evolvement and challenges of anticoagulation care from different perspectives. Obtained information was further explored through the analysis of nationwide data of drug prescriptions and realization of health care services. Simplified management of anticoagulation treatment with NOACs and their high penetration expanded the capacity of anticoagulation clinics, and consequentially the treated population increased by more than 50 % in the last 5 years. The main challenge concerned the expenditures for medicines, which increased approximately 10 times in just a few years. At the same time, the anticoagulation clinics and their core organisation were not affected, which is not expected to change, since they are vital in delivering high-quality care.

Lupus anticoagulant, disease activity and low complement in the first trimester are predictive of pregnancy loss.

Science.gov (United States)

Mankee, Anil; Petri, Michelle; Magder, Laurence S

2015-01-01

Multiple factors, including proteinuria, antiphospholipid syndrome, thrombocytopenia and hypertension, are predictive of pregnancy loss in systemic lupus erythematosus (SLE). In the PROMISSE study of predictors of pregnancy loss, only a battery of lupus anticoagulant tests was predictive of a composite of adverse pregnancy outcomes. We examined the predictive value of one baseline lupus anticoagulant test (dilute Russell viper venom time) with pregnancy loss in women with SLE. From the Hopkins Lupus Cohort, there were 202 pregnancies from 175 different women after excluding twin pregnancies and pregnancies for which we did not have a first trimester assessment of lupus anticoagulant. We determined the percentage of women who had a pregnancy loss in groups defined by potential risk factors. The lupus anticoagulant was determined by dilute Russell viper venom time with appropriate mixing and confirmatory testing. Generalised estimating equations were used to calculate p values, accounting for repeated pregnancies in the same woman. The age at pregnancy was 40 (3%). 55% were Caucasian and 34% African-American. Among those with lupus anticoagulant during the first trimester, 6/16 (38%) experienced a pregnancy loss compared with only 16/186 (9%) of other pregnancies (p=0.003). In addition, those with low complement or higher disease activity had a higher rate of pregnancy loss than those without (p=0.049 and 0.005, respectively). In contrast, there was no association between elevated anticardiolipin in the first trimester and pregnancy loss. The strongest predictor of pregnancy loss in SLE in the first trimester is the lupus anticoagulant. In addition, moderate disease activity by the physician global assessment and low complement measured in the first trimester were predictive of pregnancy loss. These data suggest that treatment of the lupus anticoagulant could be considered, even in the absence of history of pregnancy loss.

Anticoagulant Activity and Structural Characterization of Polysaccharide from Abalone (Haliotis discus hannai Ino Gonad

Directory of Open Access Journals (Sweden)

Jun Zhao

2016-06-01

Full Text Available In this study, we aimed at characterizing the structure and the anticoagulant activity of a polysaccharide fraction (AGP33 isolated from the gonads of Haliotis discus hannai Ino. AGP33 was extracted by enzymatic hydrolysis and purified by ion-exchange and gel-filtration chromatography. The backbone fraction of AGP33 (BAGP33, which appeared to contain of mannose, glucose and galactose, was prepared by partial acid hydrolysis. According to methylation and nuclear magnetic resonance (NMR spectroscopy, the backbone of AGP33 was identified as mainly consisting of 1→3-linked, 1→4-linked, and 1→6-linked monosaccharides. AGP33 is a sulfated polysaccharide with sulfates occur at 3-O- and 4-O-positions. It prolonged thromboplastin time (APTT, thrombin time (TT and prothrombin time (PT compared to a saline control solution in a dosage-dependent manner. AGP33 exhibited an extension (p < 0.01 of APTT compared to the saline group at concentrations higher than 5 μg/mL. AGP33 exhibited higher anticoagulant activity than its desulfated product (AGP33-des and BAGP33. The results showed that polysaccharide with higher molecular weight and sulfate content demonstrated greater anticoagulant activity.

O-sulfated bacterial polysaccharides with low anticoagulant activity inhibit metastasis.

Science.gov (United States)

Borgenström, Marjut; Wärri, Anni; Hiilesvuo, Katri; Käkönen, Rami; Käkönen, Sanna; Nissinen, Liisa; Pihlavisto, Marjo; Marjamäki, Anne; Vlodavsky, Israel; Naggi, Annamaria; Torri, Giangiacomo; Casu, Benito; Veromaa, Timo; Salmivirta, Markku; Elenius, Klaus

2007-07-01

Heparin-like polysaccharides possess the capacity to inhibit cancer cell proliferation, angiogenesis, heparanase-mediated cancer cell invasion, and cancer cell adhesion to vascular endothelia via adhesion receptors, such as selectins. The clinical applicability of the antitumor effect of such polysaccharides, however, is compromised by their anticoagulant activity. We have compared the potential of chemically O-sulfated and N,O-sulfated bacterial polysaccharide (capsular polysaccharide from E. COLI K5 [K5PS]) species to inhibit metastasis of mouse B16-BL6 melanoma cells and human MDA-MB-231 breast cancer cells in two in vivo models. We demonstrate that in both settings, O-sulfated K5PS was a potent inhibitor of metastasis. Reducing the molecular weight of the polysaccharide, however, resulted in lower antimetastatic capacity. Furthermore, we show that O-sulfated K5PS efficiently inhibited the invasion of B16-BL6 cells through Matrigel and also inhibited the in vitro activity of heparanase. Moreover, treatment with O-sulfated K5PS lowered the ability of B16-BL6 cells to adhere to endothelial cells, intercellular adhesion molecule-1, and P-selectin, but not to E-selectin. Importantly, O-sulfated K5PSs were largely devoid of anticoagulant activity. These findings indicate that O-sulfated K5PS polysaccharide should be considered as a potential antimetastatic agent.

Fucosylated chondroitin sulfate oligosaccharides exert anticoagulant activity by targeting at intrinsic tenase complex with low FXII activation: Importance of sulfation pattern and molecular size.

Science.gov (United States)

Li, Junhui; Li, Shan; Yan, Lufeng; Ding, Tian; Linhardt, Robert J; Yu, Yanlei; Liu, Xinyue; Liu, Donghong; Ye, Xingqian; Chen, Shiguo

2017-10-20

Fucosylated chondroitin sulfates (fCSs) are structurally unusual glycosaminoglycans isolated from sea cucumbers that exhibit potent anticoagulant activity. These fCSs were isolated from sea cucumber, Isostichopus badionotus and Pearsonothuria graeffei. Fenton reaction followed by gel filtration chromatography afforded fCS oligosaccharides, with different sulfation patterns identified by mass and NMR spectroscopy, and these were used to clarify the relationship between the structures and the anticoagulant activities of fCSs. In vitro activities were measured by activated partial thromboplastin time (APTT), thrombin time (TT), thrombin and factor Xa inhibition, and activation of FXII. The results showed that free radicals preferentially acted on GlcA residues affording oligosaccharides that were purified from both fCSs. The inhibition of thrombin and factor X activities, mediated through antithrombin III and heparin cofactor II of fCSs oligosaccharides were affected by their molecular weight and fucose branches. Oligosaccharides with different sulfation patterns of the fucose branching had a similar ability to inhibit the FXa by the intrinsic factor Xase (factor IXa-VIIIa complex). Oligosaccharides with 2,4-O-sulfo fucose branches from fCS-Ib showed higher activities than ones with 3,4-O-disulfo branches obtained from fCS-Pg. Furthermore, a heptasaccharide is the minimum size oligosaccharide required for anticoagulation and FXII activation. This activity was absent for fCS oligosaccharides smaller than nonasaccharides. Molecular size and fucose branch sulfation are important for anticoagulant activity and reduction of size can reverse the activation of FXII caused by native fCSs. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Honey Bee Venom (Apis mellifera) Contains Anticoagulation Factors and Increases the Blood-clotting Time.

Science.gov (United States)

Zolfagharian, Hossein; Mohajeri, Mohammad; Babaie, Mahdi

2015-12-01

Bee venom (BV) is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera) on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50), and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Blood samples were obtained from 10 rabbits, and the prothrombin time (PT) and the partial thromboplastin time (PTT) tests were conducted. The approximate lethal dose (LD) values of BV were determined. Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs) = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa), respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2) and melittin, and that can increase the blood clotting times in vitro.

Honey Bee Venom (Apis mellifera Contains Anticoagulation Factors and Increases the Blood-clotting Time

Directory of Open Access Journals (Sweden)

Hossein Zolfagharian

2015-12-01

Full Text Available Objectives: Bee venom (BV is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50, and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Blood samples were obtained from 10 rabbits, and the prothrombin time (PT and the partial thromboplastin time (PTT tests were conducted. The approximate lethal dose (LD values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa, respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2 and melittin, and that can increase the blood clotting times in vitro.

Effects of oversulfated and fucosylated chondroitin sulfates on coagulation. Challenges for the study of anticoagulant polysaccharides.

Science.gov (United States)

Fonseca, Roberto J C; Oliveira, Stephan-Nicollas M C G; Pomin, Vitor H; Mecawi, André S; Araujo, Iracema G; Mourão, Paulo A S

2010-05-01

We report the effects of a chemically oversulfated chondroitin sulfate and a naturally fucosylated chondroitin sulfate on the coagulation system. The former has been recently identified as a contaminant of heparin preparations and the latter has been proposed as an alternative anticoagulant. The mechanism of action of these polymers on coagulation is complex and target different components of the coagulation system. They have serpin-independent anticoagulant activity, which preponderates in plasma. They also have serpin-dependent anticoagulant activity but differ significantly in the target coagulation protease and preferential serpin. Their anticoagulant effects differ even more markedly when tested as inhibitors of coagulation proteases using plasma as a source of serpins. It is possible that the difference is due to the high availability of fucosylated chondroitin sulfate whereas oversulfated chondroitin sulfate has strong unspecific binding to plasma protein and low availability for the binding to serpins. When tested using a venous thrombosis experimental model, oversulfated chondroitin sulfate is less potent as an antithrombotic agent than fucosylated chondroitin sulfate. These highly sulfated chondroitin sulfates activate factor XII in in vitro assays, based on kallikrein release. However, only fucosylated chondroitin sulfate induces hypotension when intravenously injected into rats. In conclusion, the complexity of the regulatory mechanisms involved in the action of highly sulfated polysaccharides in coagulation requires their analysis by a combination of in vitro and in vivo assays. Our results are relevant due to the urgent need for new anticoagulant drugs or alternative sources of heparin.

[The study of anticoagulants selection in platelet-rich plasma preparation].

Science.gov (United States)

Hua, Lei; Lai, Gui; Zhenjun, Liu; Guie, Ma

2015-07-01

To investigate the effect of the anticoagulants on PRP quality, so as to clarify the appropriate anticoagulant used in PRP production. The microstructure change of platelets collected via heparin, citrate, acid citrate dextrose (ACD) and citrate-theophylline-adenosine-dipyridamole ( CTAD) was observed by TEM following time course. The extent of spontaneous activation of platelets in four groups was detected by measuring sP-selectin in plasma. The TGF-β1 release amount of activated PRP of four groups was measured. CTAD is superior to other anticoagulants in maintaining the integrity of platelet structures for a long time and preventing platelet spontaneous activation. ACD slightly surpassed heparin and citrate in above two aspects. ACD-PRP and CTAD-PRP released significantly more TGF-β1 compared with heparin and citrate. The PRP quality and biological effects were strongly associated with the type of Anticoagulants. ACD and CTAD are optimal anticoagulants in PRP production for they can maintain platelet viability at a high level.

New Insights into the Pros and Cons of the Clinical Use of Vitamin K Antagonists (VKAs Versus Direct Oral Anticoagulants (DOACs

Directory of Open Access Journals (Sweden)

Rick H. van Gorp

2015-11-01

Full Text Available Vitamin K-antagonists (VKA are the most widely used anticoagulant drugs to treat patients at risk of arterial and venous thrombosis for the past 50 years. Due to unfavorable pharmacokinetics VKA have a small therapeutic window, require frequent monitoring, and are susceptible to drug and nutritional interactions. Additionally, the effect of VKA is not limited to coagulation, but affects all vitamin K-dependent proteins. As a consequence, VKA have detrimental side effects by enhancing medial and intimal calcification. These limitations stimulated the development of alternative anticoagulant drugs, resulting in direct oral anticoagulant (DOAC drugs, which specifically target coagulation factor Xa and thrombin. DOACs also display non-hemostatic vascular effects via protease-activated receptors (PARs. As atherosclerosis is characterized by a hypercoagulable state indicating the involvement of activated coagulation factors in the genesis of atherosclerosis, anticoagulation could have beneficial effects on atherosclerosis. Additionally, accumulating evidence demonstrates vascular benefit from high vitamin K intake. This review gives an update on oral anticoagulant treatment on the vasculature with a special focus on calcification and vitamin K interaction.

Dermatotoxicity of epicutaneously applied anticoagulant warfarin

International Nuclear Information System (INIS)

Kataranovski, Milena; Prokic, Vera; Kataranovski, Dragan; Zolotarevski, Lidija; Majstorovic, Ivana

2005-01-01

Dermatotoxic effects of epicutaneous application of a first-generation anticoagulant, warfarin (WF) were examined in rats. Selected parameters of skin activity were determined 24 h following warfarin application, including metabolic viability of skin explants, some aspects of oxidative activity in skin tissue homogenates and inflammatory/immune relevant activity of epidermal cells from warfarin-treated skin. No changes in skin metabolic viability (MTT reduction) were noted ex vivo following WF application, suggesting the absence of immediate toxicity for skin. In contrast, increased formation of malondialdehyde (MDA), with a decrease in protein and non-protein thiols in homogenates of warfarin-treated skin was demonstrated, pointing to prooxidant activity in warfarin-treated skin. Increased costimulatory activity of epidermal cells isolated from warfarin-exposed skin in Con-A-stimulated T-cell activation/proliferation assay was noted, reflecting proinflammatory and immune-modulating capacity of warfarin for epidermis. No evident differences in skin histology between control and warfarin-treated skin were found at that time point, while striking changes in tissue integrity, cellularity and appearance 72 h following WF application were noted. The observed histological picture probably reflects a regenerative/inflammatory program related to oxidant/inflammation-type warfarin-evoked injury to the skin. Presented data demonstrate the potential of epicutaneously applied warfarin to modulate local skin activity in rats

Effect of Sulfation and Molecular Weight on Anticoagulant Activity of Dextran.

Science.gov (United States)

Drozd, N N; Logvinova, Yu S; Torlopov, M A; Udoratina, E V

2017-02-01

Sulfation (to 2.8) of dextrans with molecular weight of 150 and 20 kDa was followed by the appearance of anticoagulant activity that increased with decreasing their molecular weight and did not depend on antithrombin, plasma inhibitor of serine proteases of the blood coagulation system. Antithrombin activity of dextran sulfate with a molecular weight of 20 kDa reached 12.6-15.3 U/mg. Dextran sulfates with molecular weights of 20 and 150 kDa did not potentiate ADP-induced human platelet aggregation.

Lupus anticoagulants and antiphospholipid antibodies

Science.gov (United States)

Blood clots - lupus anticoagulants; DVT - anticoagulants ... Most often, lupus anticoagulants and aPL are found in people with diseases such as systemic lupus erythematosus (SLE). Lupus anticoagulants and ...

Contributions of procoagulants and anticoagulants to the international normalized ratio and thrombin generation assay in patients treated with warfarin: potential role of protein Z as a powerful determinant of coagulation assays.

Science.gov (United States)

Choi, Qute; Kim, Ji-Eun; Hyun, Jungwon; Han, Kyou-Sup; Kim, Hyun Kyung

2013-07-01

The effects of warfarin are measured with the international normalized ratio (INR). However, the thrombin generation assay (TGA) may offer more information about global coagulation. We analyzed the monitoring performance of the TGA and INR and investigated the impact of procoagulants (fibrinogen, factor (F)II, FVII, FIX, and FX) and anticoagulants (proteins C, S, and Z) on them. The TGA was performed on a calibrated automated thrombogram, producing lag time, endogenous thrombin potential (ETP), and peak thrombin in 239 patients treated with warfarin. Pro- and anticoagulant levels were also measured. The INR was significantly and inversely correlated with ETP. The therapeutic range of ETP comparable to an INR range of 2.0-3.0 was 290.1-494.6. ETP showed comparable performance to the INR as a warfarin-monitoring parameter with respect to clinical complication rate. The median levels of FII, FVII, FIX, and FX and proteins C and Z tended to decrease gradually with increasing anticoagulation intensity according to the INR or ETP. Of note, protein Z levels decreased dramatically with increasing anticoagulation status. INRs were significantly determined by FII, FVII, and protein Z. ETP was significantly dependent on FVII, and proteins C and Z concentration. Protein Z significantly reduced the total amount of thrombin generation and prolonged PT value in vitro. The INR and ETP exhibit similar efficacy for warfarin monitoring according to the clinical complication rate. Protein Z is considered to be a significant determinant of INR and ETP in patients on warfarin therapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

Low-dose oral contraceptives and acquired resistance to activated protein C: a randomised cross-over study

NARCIS (Netherlands)

Rosing, J.; Middeldorp, S.; Curvers, J.; Christella, M.; Thomassen, L. G.; Nicolaes, G. A.; Meijers, J. C.; Bouma, B. N.; Büller, H. R.; Prins, M. H.; Tans, G.

1999-01-01

BACKGROUND: We have reported previously that, compared with use of second-generation oral contraceptives, the use of third-generation oral contraceptives is associated with increased resistance to the anticoagulant action of activated protein C (APC). Owing to the cross-sectional design of that

Anticoagulant effects of inhaled unfractionated heparin in the dog as determined by partial thromboplastin time and factor Xa activity.

Science.gov (United States)

Manion, Jill S; Thomason, John M; Langston, Vernon C; Claude, Andrew K; Brooks, Marjory B; Mackin, Andrew J; Lunsford, Kari V

2016-01-01

To evaluate the anticoagulant effects of inhaled heparin in dogs. This study was conducted in 3 phases. In phase 1, bronchoalveolar lavage fluid (BALf) was collected to generate an in vitro calibration curve to relate heparin concentration to the activated partial thromboplastin time (aPTT). In phase 2, heparin was administered via nebulization to determine the threshold dose needed to prolong systemic aPTT. In phase 3, the local anticoagulant activity of inhaled heparin was determined by measurement of BALf anti-Xa activity and aPTT. University teaching hospital. Six healthy intact female Walker Hounds were used in this study. Two dogs were used for each phase. Inhaled unfractionated sodium heparin was administered in doses ranging from 50,000 to 200,000 IU. In vitro addition of heparin to BALf caused a prolongation in aPTT. Inhaled heparin at doses as high as 200,000 IU failed to prolong systemic aPTT, and a threshold dose could not be determined. No significant local anticoagulant effects were detected. Even at doses higher than those known to be effective in people, inhaled heparin appears to have no detectable local or systemic anticoagulant effects in dogs with the current delivery method. © Veterinary Emergency and Critical Care Society 2015.

Characterization of cDNA encoding human placental anticoagulant protein (PP4): Homology with the lipocortin family

International Nuclear Information System (INIS)

Grundmann, U.; Abel, K.J.; Bohn, H.; Loebermann, H.; Lottspeich, F.; Kuepper, H.

1988-01-01

A cDNA library prepared from human placenta was screened for sequences encoding the placental protein 4 (PP4). PP4 is an anticoagulant protein that acts as an indirect inhibitor of the thromboplastin-specific complex, which is involved in the blood coagulation cascade. Partial amino acid sequence information from PP4-derived cyanogen bromide fragments was used to design three oligonucleotide probes for screening the library. From 10 6 independent recombinants, 18 clones were identified that hybridized to all three probes. These 18 recombinants contained cDNA inserts encoding a protein of 320 amino acid residues. In addition to the PP4 cDNA the authors identified 9 other recombinants encoding a protein with considerable similarity (74%) to PP4, which was termed PP4-X. PP4 and PP4-X belong to the lipocortin family, as judged by their homology to lipocortin I and calpactin I

Stabilization of the E* Form Turns Thrombin into an Anticoagulant

Energy Technology Data Exchange (ETDEWEB)

Bah, Alaji; Carrell, Christopher J.; Chen, Zhiwei; Gandhi, Prafull S.; Di Cera, Enrico; (WU-MED)

2009-07-31

Previous studies have shown that deletion of nine residues in the autolysis loop of thrombin produces a mutant with an anticoagulant propensity of potential clinical relevance, but the molecular origin of the effect has remained unresolved. The x-ray crystal structure of this mutant solved in the free form at 1.55 {angstrom} resolution reveals an inactive conformation that is practically identical (root mean square deviation of 0.154 {angstrom}) to the recently identified E* form. The side chain of Trp215 collapses into the active site by shifting >10 {angstrom} from its position in the active E form, and the oxyanion hole is disrupted by a flip of the Glu192-Gly193 peptide bond. This finding confirms the existence of the inactive form E* in essentially the same incarnation as first identified in the structure of the thrombin mutant D102N. In addition, it demonstrates that the anticoagulant profile often caused by a mutation of the thrombin scaffold finds its likely molecular origin in the stabilization of the inactive E* form that is selectively shifted to the active E form upon thrombomodulin and protein C binding.

Anticoagulant Resistance

DEFF Research Database (Denmark)

Heiberg, Ann-Charlotte

Although sewer rat control is carried out in more than 80 % of all Danish municipalities, with usage of large amounts of anticoagulant rodenticides, knowledge on anticoagulant resistance among rats living in the sewers is limited. As rat problems in urban areas are believed to be related to sewer...... problems (70-90 % in UK and DK) unawareness of resistance amongst these populations of Brown rats may constitute a future control problem and knowledge on this issue has become crucial. Rats were captured in sewers from seven different locations in the suburban area of Copenhagen. Locations was chosen...... to represent different sewer rat management strategies i) no anticoagulants for approx. 20 years ii) no anticoagulants for the last 5 years and iii) continuous control for many years. Animals were tested for resistance to bromadiolone by Blood-Clotting Response test, as bromadiolone is the most frequently used...

High endogenous activated protein C levels attenuates bleomycin-induced pulmonary fibrosis

NARCIS (Netherlands)

Lin, Cong; von der Thüsen, Jan; Isermann, Berend; Weiler, Hartmut; van der Poll, Tom; Borensztajn, Keren; Spek, Chris A.

2016-01-01

Coagulation activation accompanied by reduced anticoagulant activity is a key characteristic of patients with idiopathic pulmonary fibrosis (IPF). Although the importance of coagulation activation in IPF is well studied, the potential relevance of endogenous anticoagulant activity in IPF progression

Reversal of target-specific oral anticoagulants

Science.gov (United States)

Siegal, D.M.; Cuker, Adam

2014-01-01

Target-specific oral anticoagulants (TSOACs) provide safe and effective anticoagulation for the prevention and treatment of thrombosis in a variety of clinical settings by interfering with the activity of thrombin (dabigatran) or factor Xa (rivaroxaban, apixaban, edoxaban, betrixaban). Although TSOACs have practical advantages over vitamin K antagonists (VKAs), there are currently no antidotes to reverse their anticoagulant effect. Herein we summarize the available evidence for TSOAC reversal using nonspecific and specific reversal agents. We discuss important limitations of existing evidence, which is derived from studies in human volunteers, animal models and in vitro experiments. Studies evaluating the safety and efficacy of reversal agents on clinical outcomes such as bleeding and mortality in patients with TSOAC-associated bleeding are needed. PMID:24880102

Anticoagulant, antiplatelet and antianemic effects of Punica granatum (pomegranate) juice in rabbits.

Science.gov (United States)

Riaz, Azra; Khan, Rafeeq A

2016-04-01

Pomegranate (Punica granatum L., Punicaceae) is a good source of minerals and phytochemicals with diverse pharmacological activities such as anxiolytic, antidepressant, hypoglycemic, hypolipidemic, and anti-inflammatory activities. Effects of P. granatum on blood parameters and coagulation have, however, been little studied. The aim of the study was to assess the outcome of P. granatum on coagulation and anticoagulation factors at different doses on blood samples of healthy white rabbits. Blood samples of the animals were collected twice during the study and biochemical assays were performed to assess the effect on hematological, coagulation, anticoagulation, and platelet aggregation. Significant changes were observed in erythrocytes, hemoglobin, and mean corpuscular hemoglobin concentration, while bleeding and thrombin time were also prolonged significantly. There was significant increase in protein C, thrombin antithrombin complex levels, and decrease in platelet aggregation and fibrinogen concentration, in a dose-dependent manner. The results of hematological and coagulation assays lead to the speculation about a possible antianemic and cardioprotective effect of P. granatum.

Anticoagulant activity in salivary glands of the insect vector Culicoides variipennis sonorensis by an inhibitor of factor Xa.

Science.gov (United States)

Pérez de León, A A; Valenzuela, J G; Tabachnick, W J

1998-02-01

Blood feeding by the insect vector Culicoides variipennis sonorensis involves laceration of superficial host tissues, an injury that would be expected to trigger the coagulation cascade. Accordingly, the salivary glands of C.v. sonorensis were examined for the presence of an antihemostatic that prevents blood coagulation. Assays using salivary gland extracts showed a delay in the recalcification time of plasma devoid of platelets, indicating the presence of anticoagulant activity. Retardation in the formation of a fibrin clot was also observed after the addition of tissue factor to plasma that was preincubated with salivary gland extracts. Similarly, an inhibitory effect by salivary gland extracts was detected in assays that included factors of the intrinsic pathway. Inhibition of the catalytic activity of purified factor Xa toward its chromogenic substrate suggested that it was the target of the salivary anticoagulant of C.v. sonorensis. This was corroborated by the coincidence of anticoagulant and anti-FXa activities obtained by reverse-phase HPLC. The depletion of anti-FXa activity from salivary glands during blood feeding suggests that the FXa inhibitor functions as anticoagulant. Molecular sieving HPLC yielded an apparent molecular mass of 28 kDa for the salivary FXa inhibitor of C.v. sonorensis. Preventing the formation of thrombin through the inhibition of FXa likely facilitates blood feeding by maintaining the pool of blood fluid at the feeding site. The salivary FXa inhibitor of C.v. sonorensis could impair the network of host-defense mechanisms in the skin microenvironment by avoiding blood coagulation at the site of feeding.

Reversing anticoagulant effects of novel oral anticoagulants: role of ciraparantag, andexanet alfa, and idarucizumab

Directory of Open Access Journals (Sweden)

Hu TY

2016-02-01

Full Text Available Tiffany Y Hu,1 Vaibhav R Vaidya,2 Samuel J Asirvatham2,31Mayo Medical School, 2Division of Cardiovascular Diseases, Department of Internal Medicine, 3Department of Pediatrics and Adolescent Medicine, Mayo Clinic, Rochester, MN, USAAbstract: Novel oral anticoagulants (NOACs are increasingly used in clinical practice, but lack of commercially available reversal agents is a major barrier for mainstream use of these therapies. Specific antidotes to NOACs are under development. Idarucizumab (aDabi-Fab, BI 655075 is a novel humanized mouse monoclonal antibody that binds dabigatran and reverses its anticoagulant effect. In a recent Phase III study (Reversal Effects of Idarucizumab on Active Dabigatran, a 5 g intravenous infusion of idarucizumab resulted in the normalization of dilute thrombin time in 98% and 93% of the two groups studied, with normalization of ecarin-clotting time in 89% and 88% patients. Two other antidotes, andexanet alfa (PRT064445 and ciraparantag (PER977 are also under development for reversal of NOACs. In this review, we discuss commonly encountered management issues with NOACs such as periprocedural management, laboratory monitoring of anticoagulation, and management of bleeding. We review currently available data regarding specific antidotes to NOACs with respect to pharmacology and clinical trials.Keywords: novel oral anticoagulant, dabigatran, idarucizumab, reversal

Anti-protein C antibodies are associated with resistance to endogenous protein C activation and a severe thrombotic phenotype in antiphospholipid syndrome.

Science.gov (United States)

Arachchillage, D R J; Efthymiou, M; Mackie, I J; Lawrie, A S; Machin, S J; Cohen, H

2014-11-01

Antiphospholipid antibodies may interfere with the anticoagulant activity of activated protein C (APC) to induce acquired APC resistance (APCr). To investigate the frequency and characteristics of APCr by using recombinant human APC (rhAPC) and endogenous protein C activation in antiphospholipid syndrome (APS). APCr was assessed in APS and non-APS venous thromboembolism (VTE) patients on warfarin and normal controls with rhAPC or Protac by thrombin generation. IgG anti-protein C and anti-protein S antibodies and avidity were assessed by ELISA. APS patients showed greater resistance to both rhAPC and Protac than non-APS patients and normal controls (median normalized endogenous thrombin potential inhibition): APS patients with rhAPC, 81.3% (95% confidence interval [CI] 75.2-88.3%; non-APS patients with rhAPC, 97.7% (95% CI 93.6-101.8%; APS patients with Protac, 66.0% (95% CI 59.5-72.6%); and non-APS patients with Protac, 80.7 (95% CI 74.2-87.2%). APS patients also had a higher frequency and higher levels of anti-protein C antibodies, with 60% (15/25) high-avidity antibodies. High-avidity anti-protein C antibodies were associated with greater APCr and with a severe thrombotic phenotype (defined as the development of recurrent VTE while patients were receiving therapeutic anticoagulation or both venous and arterial thrombosis). Twelve of 15 (80%) patients with high-avidity anti-protein C antibodies were classified as APS category I. Thrombotic APS patients showed greater APCr to both rhAPC and activation of endogenous protein C by Protac. High-avidity anti-protein C antibodies, associated with greater APCr, may provide a marker for a severe thrombotic phenotype in APS. However, in patients with category I APS, it remains to be established whether anti-protein C or anti-β2 -glycoprotein I antibodies are responsible for APCr. © 2014 International Society on Thrombosis and Haemostasis.

Pharmacology of new oral anticoagulants: mechanism of action, pharmacokinetics, pharmacodynamics

Directory of Open Access Journals (Sweden)

Luca Masotti

2013-12-01

Full Text Available Due to their mechanism of action, the new oral anticoagulants are named direct oral anticoagulants (DOACs. Dabigatran is a selective, competitive, direct inhibitor of thrombin (Factor IIa while rivaroxaban, apixaban and edoxaban act by directly inhibiting the activated Factor X (FXa in a selective and competitive manner. DOACs have a relatively short half-life and almost immediate anticoagulant activity, and rapidly reach the plasma peak concentration. Therefore, they do not need a phase of overlapping with parenteral anticoagulants. After their withdrawal, their removal is sufficiently rapid, although influenced by renal function. Dabigatran is the only DOACs to be administered as a pro-drug and becomes active after drug metabolization. The route of elimination of dabigatran is primarily renal, whereas FXa inhibitors are mainly eliminated by the biliary-fecal route. The drug interactions of DOACs are mainly limited to drugs that act on P-glycoprotein for dabigatran and on P-glycoprotein and/or cytochrome P3A4 for anti-Xa. DOACs have no interactions with food. Given their linear pharmacodynamics, with a predictable dose/response relationship and anticoagulant effect, DOACs are administered at a fixed dose and do not require routine laboratory monitoring.

Structural Analysis and Anticoagulant Activities of the Novel Sulfated Fucan Possessing a Regular Well-Defined Repeating Unit from Sea Cucumber

Directory of Open Access Journals (Sweden)

Mingyi Wu

2015-04-01

Full Text Available Sulfated fucans, the complex polysaccharides, exhibit various biological activities. Herein, we purified two fucans from the sea cucumbers Holothuria edulis and Ludwigothurea grisea. Their structures were verified by means of HPGPC, FT-IR, GC–MS and NMR. As a result, a novel structural motif for this type of polymers is reported. The fucans have a unique structure composed of a central core of regular (1→2 and (1→3-linked tetrasaccharide repeating units. Approximately 50% of the units from L. grisea (100% for H. edulis fucan contain sides of oligosaccharides formed by nonsulfated fucose units linked to the O-4 position of the central core. Anticoagulant activity assays indicate that the sea cucumber fucans strongly inhibit human blood clotting through the intrinsic pathways of the coagulation cascade. Moreover, the mechanism of anticoagulant action of the fucans is selective inhibition of thrombin activity by heparin cofactor II. The distinctive tetrasaccharide repeating units contribute to the anticoagulant action. Additionally, unlike the fucans from marine alga, although the sea cucumber fucans have great molecular weights and affluent sulfates, they do not induce platelet aggregation. Overall, our results may be helpful in understanding the structure-function relationships of the well-defined polysaccharides from invertebrate as new types of safer anticoagulants.

Association between Oral Anticoagulation Knowledge ...

African Journals Online (AJOL)

Association between Oral Anticoagulation Knowledge, Anticoagulation Control, and Demographic Characteristics of Patients Attending an Anticoagulation Clinic in Saudi Arabia: A Cross-Sectional Prospective Evaluation.

Optimal duration of anticoagulation in patients with venous thromboembolism.

Science.gov (United States)

Prandoni, Paolo; Piovella, Chiara; Spiezia, Luca; Dalla Valle, Fabio; Pesavento, Raffaele

2011-07-01

The risk of recurrent venous thromboembolism (VTE) approaches 40 per cent of all patients after 10 yr of follow up. This risk is higher in patients with permanent risk factors of thrombosis such as active cancer, prolonged immobilization from medical diseases, and antiphospholipid syndrome; in carriers of several thrombophilic abnormalities, including deficiencies of natural anticoagulants; and in patients with unprovoked presentation. Patients with permanent risk factors of thrombosis should receive indefinite anticoagulation, consisting of subtherapeutic doses of low molecular weight heparin in cancer patients, and oral anticoagulants in all other conditions. Patients whose VTE is triggered by major surgery or trauma should be offered three months of anticoagulation. Patients with unprovoked VTE, including carriers of thrombophilia, and those whose thrombotic event is associated with minor risk factors (such as hormonal treatment, minor injuries, long travel) should receive at least three months of anticoagulation. The decision as to go on or discontinue anticoagulation after this period should be individually tailored and balanced against the haemorrhagic risk. Post-baseline variables, such as the D-dimer determination and the ultrasound assessment of residual thrombosis can help identify those patients in whom anticoagulation can be safely discontinued. As a few emerging anti-Xa and anti-IIa compounds seem to induce fewer haemorrhagic complications than conventional anticoagulation, while preserving at least the same effectiveness, these have the potential to open new scenarios for decisions regarding the duration of anticoagulation in patients with VTE.

Recombinant nematode anticoagulant protein c2, an inhibitor of tissue factor/factor VIIa, attenuates coagulation and the interleukin-10 response in human endotoxemia

NARCIS (Netherlands)

de Pont, A. C. J. M.; Moons, A. H. M.; de Jonge, E.; Meijers, J. C. M.; Vlasuk, G. P.; Rote, W. E.; Büller, H. R.; van der Poll, T.; Levi, M. [=Marcel M.

2004-01-01

The tissue factor-factor (F)VIIa complex (TF/FVIIa) is responsible for the initiation of blood coagulation under both physiological and pathological conditions. Recombinant nematode anticoagulant protein c2 (rNAPc2) is a potent inhibitor of TF/FVIIa. mechanistically distinct from tissue factor

A new peptide (Ruviprase) purified from the venom of Daboia russelii russelii shows potent anticoagulant activity via non-enzymatic inhibition of thrombin and factor Xa.

Science.gov (United States)

Thakur, Rupamoni; Kumar, Ashok; Bose, Biplab; Panda, Dulal; Saikia, Debashree; Chattopadhyay, Pronobesh; Mukherjee, Ashis K

2014-10-01

Compounds showing dual inhibition of thrombin and factor Xa (FXa) are the subject of great interest owing to their broader specificity for effective anticoagulation therapy against cardiovascular disorders. This is the first report on the functional characterization and assessment of therapeutic potential of a 4423.6 Da inhibitory peptide (Ruviprase) purified from Daboia russelii russelii venom. The secondary structure of Ruviprase is composed of α-helices (61.9%) and random coils (38.1%). The partial N-terminal sequence (E(1)-V(2)-X(3)-W(4)-W(5)-W(6)-A(7)-Q(8)-L(9)-S(10)) of Ruviprase demonstrated significant similarity (80.0%) with an internal sequence of apoptosis-stimulating protein reported from the venom of Ophiophagus hannah and Python bivittatus; albeit Ruviprase did not show sequence similarity with existing thrombin/FXa inhibitors, suggesting its uniqueness. Ruviprase demonstrated a potent in vitro anticoagulant property and inhibited both thrombin and FXa following slow binding kinetics. Ruviprase inhibited thrombin by binding to its active site via an uncompetitive mechanism with a Ki value and dissociation constant (KD) of 0.42 μM and 0.46 μM, respectively. Conversely, Ruviprase demonstrated mixed inhibition (Ki = 0.16 μM) of FXa towards its physiological substrate prothrombin. Furthermore, the biological properties of Ruviprase could not be neutralized by commercial polyvalent or monovalent antivenom. Ruviprase at a dose of 2.0 mg/kg was non-toxic and showed potent in vivo anticoagulant activity after 6 h of intraperitoneal treatment in mice. Because of the potent anticoagulant property as well as non-toxic nature of Ruviprase, the possible application of the peptide as an antithrombotic agent for combating thrombosis-associated ailments appears promising. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

The future of anticoagulation clinics.

Science.gov (United States)

Macik, B Gail

2003-01-01

Anticoagulation therapy is the foundation of treatment for thromboembolic disorders; and coumarin derivatives (warfarin in the United States) are the only orally administered anticoagulant medications currently available. Due to the expense and relative difficulties associated with this route of administration, parenteral drugs are not used routinely for long-term therapy, leaving warfarin as the anticoagulant of choice in the outpatient setting. The management of warfarin is problematic, however, due the nuances of its pharmacodynamic and pharmacokinetic profile and the requirement for frequent monitoring of blood levels. Although management by anticoagulation clinics is considered the gold standard for warfarin therapy, management by an anticoagulation clinic may not be the optimal option from a clinician's view and, in many cases, may not be an option at all. Anticoagulation clinics may impinge on the doctor-patient relationship. Difficulties of communication and reimbursement are not ameliorated by a specialty clinic. Innovations in warfarin management, including patient self-management and computerized dosing programs, are alternatives for improved care that are available with or without input by an anticoagulation service. New oral drugs on the horizon do not require the same intensity of monitoring and do not present the same pharmacodynamic problems associated with warfarin. Warfarin will become obsolete in the foreseeable future. If anticoagulation clinics continue, they must re-define their role as the major part of the workload, warfarin management, disappears. To adapt, clinics must strengthen and enhance their role as coordinators and educators, and less so, managers of anticoagulation therapy.

Human activated protein C variants in a rat model of arterial thrombosis

Directory of Open Access Journals (Sweden)

Dahlbäck Björn

2008-10-01

Full Text Available Abstract Background Activated protein C (APC inhibits coagulation by degrading activated factor V (FVa and factor VIII (FVIIIa, protein S (PS functioning as a cofactor to APC. Methods By mutagenesis of the vitamin K-dependent Gla domain of APC, we have recently created an APC variant having enhanced anticoagulant activity due to increased affinity for negatively charged phospholipid membranes. In the present study, the potential antithrombotic effects of this APC variant, and of a variant APC that is additionally mutated in the serine protease domain, have been evaluated in a blind randomized study in a rat model of arterial thrombosis. In this model, we have previously found the combination of bovine APC and PS to be highly antithrombotic. Four treatment groups each containing 10 rats were, in a blind random fashion, given intravenous bolus injections of wild-type or mutant variants of APC (0.8 mg/kg together with human PS (0.6 mg/kg or human PS (0.6 mg/kg alone. A control group with 20 animals where given vehicle only. Results A trend to increased patency rates was noted in a group receiving one of the APC variants, but it did not reach statistical significance. Conclusion In conclusion, administration of human APC variants having enhanced anticoagulant efficacy together with human PS in a rat model of arterial thrombosis did not give an efficient antithrombotic effect. The lack of effect may be due to species-specific differences between the human protein C system and the rat hemostatic system.

The practical management of bleedings during treatment with direct oral anticoagulants: the emergency reversal therapy

Directory of Open Access Journals (Sweden)

Luca Masotti

2013-12-01

Full Text Available Bleeding represents the most feared complication of the new oral anticoagulants, direct oral anticoagulants (DOACs, as well as all the antithrombotic therapies. During the acute phase of bleeding in patients taking anticoagulants, restoration of an effective hemostasis represents the cornerstone of practical management. While vitamin K antagonists are effectively and promptly reversed by specific antidotes such as prothrombin complex concentrates (PCCs, fresh frozen plasma or vitamin K, it is still not clear how to manage the urgent reversal of DOACs during life-threatening or major bleedings due to the lack of specific antidotes. However, in vitro and ex vivo studies have suggested some potential strategies to reverse DOACs in clinical practice, other than general support measures that are always recommended. Activated charcoal could be used in subjects with DOAC-related bleedings presenting to the emergency department within two hours of the last oral intake. Non-activated or activated PCCs (FEIBA and recombinant activated Factor VII (raFVII seem to be the optimal strategy for urgent reversal of dabigatran, while non-activated PCCs seem to have efficacy in reversing rivaroxaban. Due to its low plasma protein binding, dabigatran could be also dialyzed in urgent cases. Clinically relevant non-major bleedings and minor bleedings should be treated with general and local measures, respectively, and, when necessary, with dose delay or drug withdrawal. In this article, the Authors describe the practical approach to bleedings occurring during DOACs treatment.

Pathology consultation on anticoagulation monitoring: factor X-related assays.

Science.gov (United States)

Wool, Geoffrey D; Lu, Chuanyi M

2013-11-01

To review various anticoagulation therapies and related laboratory monitoring issues, with a focus on factor X-related chromogenic assays. A case-based approach is used to review pertinent published literatures and product inserts of anticoagulation drugs and to look back on clinical use of factor X-related chromogenic assays. The number of anticoagulants available to clinicians has increased greatly in the past decade. Whether and how these anticoagulants should be monitored are areas of uncertainty for clinicians, which can lead to misuse of laboratory assays and suboptimal patient management. Factor X-related assays are of particular concern because of the similar and often confusing test names. Based on a common clinical case scenario and literature review regarding anticoagulant monitoring, an up-to-date discussion and review of the various factor X-related assays are provided, focusing on the differences in test designs and clinical utilities between the chromogenic anti-Xa and chromogenic factor X activity assays. Anticoagulation therapy and related laboratory monitoring are rapidly evolving areas of clinical practices. A good knowledge of relevant laboratory assays and their clinical applications is necessary to help optimize patient care.

Molecular dynamics and docking simulation of a natural variant of Activated Protein C with impaired protease activity: implications for integrin-mediated antiseptic function.

Science.gov (United States)

D'Ursi, Pasqualina; Orro, Alessandro; Morra, Giulia; Moscatelli, Marco; Trombetti, Gabriele; Milanesi, Luciano; Rovida, Ermanna

2015-01-01

Activated Protein C (APC) is a multifunctional serine protease, primarily known for its anticoagulant function in the coagulation system. Several studies have already elucidated its role in counteracting apoptosis and inflammation in cells, while significant effort is still ongoing for defining its involvement in sepsis. Earlier literature has shown that the antiseptic function of APC is mediated by its binding to leukocyte integrins, which is due to the presence of the integrin binding motif Arg-Gly-Asp at the N-terminus of the APC catalytic chain. Many natural mutants have been identified in patients with Protein C deficiency diagnosis including a variant of specificity pocket (Gly216Asp). In this work, we present a molecular model of the complex of APC with αVβ3 integrin obtained by protein-protein docking approach. A computational analysis of this variant is hereby presented, based on molecular dynamics and docking simulations, aiming at investigating the effects of the Gly216Asp mutation on the protein conformation and inferring its functional implications. Our study shows that such mutation is likely to impair the protease activity while preserving the overall protein fold. Moreover, superposition of the integrin binding motifs in wild-type and mutant forms suggests that the interaction with integrin can still occur and thus the mutant is likely to retain its antiseptic function related to the neutrophyl integrin binding. Therapeutic applications could result in this APC mutant which retains antiseptic function without anticoagulant side effects.

Single-Molecular Imaging of Anticoagulation Factor I from Snake Venom by Atomic Force Microscopy

Institute of Scientific and Technical Information of China (English)

XU,Xiao-Long(徐小龙); ZHOU,Yun-Shen(周云申); LIU,Qing-Liang(刘清亮); HOU,Jian-Guo(侯建国); YANG,Jing-Long(杨金龙); XIE,Yong-Shu(解永树)

2002-01-01

Anticoagulation factor I (ACF I) from the venom of Agkistrodon acutus is a binding protein to activated coagulation factor X (FXa) and possesses marked anticoagulant activity. Single ACF I molecule has been successfully imaged in air by tapping mode atomic force microscopy (AFM) with high-resolution using glutaraldehyde as a coupling agent. The physical adsorption and covalent binding of ACF I onto the mica show very different surface topographies. The former exhibits the characteristic strand-like structure with much less reproducibility, the latter displays a elliptic granular structure with better reproducibility, which suggests that the stability of ACF I molecules on the mica is enhanced by covalent bonding in the presence of glutaraldehyde. A small-scale AFM amplitude-mode image clearly shows that the covalently bonded ACF I molecule by glutaraldehyde has olive shape structure with an average size of 7.4 nm× 3.6 nm × 3.1 nm, which is very similar to the size determined from the crystal structure of ACF I.

Assessment of Heparin Anticoagulation Measured Using i-STAT and Hemochron Activated Clotting Time.

Science.gov (United States)

Maslow, Andrew; Chambers, Alison; Cheves, Tracey; Sweeney, Joseph

2018-01-31

Adequate anticoagulation, measured using activated clotting time (ACT), is important during vascular and cardiac surgeries. Unfractionated heparin is the most common anticoagulant used. The purpose of this analysis was to compare the i-STAT ACT (iACT) to the Hemochron ACT (hACT), both of which were then compared to anti-factor Xa (anti-Xa) assay, a representation of heparin level and activity. Prospective study. Tertiary care cardiovascular center. Eleven consecutive elective adult cardiac surgical patients. Prior to cardiopulmonary bypass, ACTs were measured using i-STAT and Hemochron technologies and compared to each other and to anti-Xa assay prior to and during a cumulative administration of heparin. Data were compared using bias analyses. Heparin (300 U/kg) was administered in quarterly doses. Coagulation labs were collected prior to and 3 minutes after each quarterly dose of heparin. The baseline ACTs for i-STAT and Hemochron were 147 and 142 seconds, respectively. A significant association was found between iACT and hACT (p = 0.002). The iACT measurements underestimated hACT at ACT levels >180 seconds or anti-Xa levels >0.75 U/mL. No significant difference was found between ACT data at anti-Xa levels 0.75 U/mL. Copyright © 2018 Elsevier Inc. All rights reserved.

Differential expression of cytochrome P450 genes between bromadiolone-resistant and anticoagulant-susceptible Norway rats:

DEFF Research Database (Denmark)

Markussen, Mette Drude; Heiberg, Ann-Charlotte; Fredholm, Merete

2008-01-01

Anticoagulant resistance in Norway rats (Rattus norvegicus) has been suggested to be due to mutations in the VKORC1 gene, encoding the target protein of anticoagulant rodenticides such as warfarin and bromadiolone. Other factors, e.g. pharmacokinetics, may however also contribute to resistance. We...... that bromadiolone resistance in Norway rats involves enhanced anticoagulant clearance and metabolism catalyzed by specific cytochrome P450 enzymes, such as Cyp2e1, Cyp3a2 and Cyp3a3. This pharmacokinetically based resistance varies to some extend between the genders....

Differential expression of cytochrome P450 genes between bromadiolone-resistant and anticoagulant-susceptible Norway rats

DEFF Research Database (Denmark)

Markussen, Mette Drude Kjær; Heiberg, Ann-Charlotte; Fredholm, Merete

2008-01-01

Background: Anticoagulant resistance in Norway rats, Rattus norvegicus (Berk.), has been suggested to be conferred by mutations in the VKORC1 gene, encoding the target protein of anticoagulant rodenticides. Other factors, e.g. pharmacokinetics, may also contribute to resistance, however. To examine......, Cyp3a2 and Cyp3a3 genes. On exposure to bromadiolone, females had higher Cyp2e1 expression than males, which possibly explains why female rats are generally more tolerant to anticoagulants than male rats. Conclusion: results suggest that bromadiolone resistance in a Danish strain of Norway rats...

[Drug compliance of patients on anticoagulant treatment].

Science.gov (United States)

Gadó, Klára; Kocsis, Eszter; Zelkó, Romána; Hankó, Balázs; Kovácsné Balogh, Judit; Forczig, Mónika; Domján, Gyula

2015-08-09

Despite several therapeutic possibilities the morbidity and mortality of thromboembolic disorders remain high. Improving drug compliance - i. e. keeping up the doctor's prescriptions - may be an effective tool to reach better results. To improve patients' compliance, the risk factors of non-compliance should be recognized. Among these patients' fear of adverse effects of drugs, their lack of knowledge about their illness and medication, forgetfulness, and other social, economic factors may be the most important. Furthermore, adherence may be worsened when the patient feels that the decision has been made over his/her head. Sustained medical adherence is important because anticoagulation may be a life-long treatment. The new oral anticoagulants make the matter of compliance to be current. These new type of drugs do not need regular laboratory monitoring and, therefore, compliance cannot be strictly followed. There are several studies concerning drug compliance to anticoagulant medications. Improvement of adherence is based on regular patient education after reviewing the factors of non-compliance, which needs teamwork with important roles of doctors, pharmacists, dietetics and nurses. Careful and accurate work of the participants of primary care might be complemented by the activity of anticoagulant clinics.

Activated protein C ameliorates coagulopathy but does not influence outcome in lethal H1N1 influenza: a controlled laboratory study

NARCIS (Netherlands)

Schouten, Marcel; van der Sluijs, Koenraad F.; Gerlitz, Bruce; Grinnell, Brian W.; Roelofs, Joris J. T. H.; Levi, Marcel M.; van 't Veer, Cornelis; van der Poll, Tom

2010-01-01

Introduction: Influenza accounts for 5 to 10% of community-acquired pneumonias and is a major cause of mortality. Sterile and bacterial lung injuries are associated with procoagulant and inflammatory derangements in the lungs. Activated protein C (APC) is an anticoagulant with anti-inflammatory

Effect of lysine clonixinate on the pharmacokinetics and anticoagulant activity of phenprocoumon.

Science.gov (United States)

Russmann, S; Dilger, K; Trenk, D; Nagyivanyi, P; Jähnchen, E

2001-11-01

The effect of the non-steroidal anti-inflammatory drug lysine clonixinate ([2-(3-chloro-o-toluidino)nicotinic acid]-L-lysinate, CAS 55837-30-4) on the pharmacokinetics and anticoagulant activity of phenprocoumon (4-hydroxy-3-(1-phenylpropyl)-coumarin, CAS 435-97-2) was investigated in an open, randomised, two-fold, cross-over study in 12 healthy male volunteers. These subjects received a single dose of 18 mg phenprocoumon without or with concomitant treatment with lysine clonixinate (125 mg five times a day for 3 days before and 13 days after ingestion of a single dose of phenprocoumon). Pharmacokinetic parameters of phenprocoumon following oral administration were: CL/f: 0.779 +/- 0.157 ml/min, half-life of elimination: 147.2 +/- 19.9 h; free fraction in serum: 0.51 +/- 0.20%. These parameters were not significantly altered by concomitant treatment with lysine clonixinate. Prothrombin time increased from 13.3 +/- 1.3 s (at time 0) to 17.7 +/- 2.7 s following phenprocoumon and from 13.3 +/- 1.2 s to 18.0 +/- 2.2 s following combined administration. Prothrombin time returned to the pretreatment values 240 h after administration of phenprocoumon. The integrated effect (AUEC0-288 h) was identical following both treatments (4.303 +/- 461 and 4.303 +/- 312 s x h for phenprocoumon alone and phenprocoumon with lysine clonixinate, respectively). Thus, lysine clonixinate administered in therapeutic doses does not affect the pharmacokinetics and anticoagulant activity of phenproxoumon.

Activated protein C attenuates acute ischaemia reperfusion injury in skeletal muscle.

LENUS (Irish Health Repository)

Dillon, J P

2012-02-03

Activated protein C (APC) is an endogenous anti-coagulant with anti-inflammatory properties. The purpose of the present study was to evaluate the effects of activated protein C in the setting of skeletal muscle ischaemia reperfusion injury (IRI). IRI was induced in rats by applying rubber bands above the levels of the greater trochanters bilaterally for a period of 2h followed by 12h reperfusion. Treatment groups received either equal volumes of normal saline or activated protein C prior to tourniquet release. Following 12h reperfusion, muscle function was assessed electrophysiologically by electrical field stimulation. The animals were then sacrificed and skeletal muscle harvested for evaluation. Activated protein C significantly attenuated skeletal muscle reperfusion injury as shown by reduced myeloperoxidase content, wet to dry ratio and electrical properties of skeletal muscle. Further in vitro work was carried out on neutrophils isolated from healthy volunteers to determine the direct effect of APC on neutrophil function. The effects of APC on TNF-alpha stimulated neutrophils were examined by measuring CD18 expression as well as reactive oxygen species generation. The in vitro work demonstrated a reduction in CD18 expression and reactive oxygen species generation. We conclude that activated protein C may have a protective role in the setting of skeletal muscle ischaemia reperfusion injury and that this is in part mediated by a direct inhibitory effect on neutrophil activation.

Direct oral anticoagulants: An update.

Science.gov (United States)

Franco Moreno, Ana Isabel; Martín Díaz, Rosa María; García Navarro, María José

2017-12-30

Vitamin K antagonists were the only choice for chronic oral anticoagulation for more than half a century. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In randomised controlled trials comparing direct oral anticoagulants with traditional vitamin K antagonists, the direct oral anticoagulants all showed a favourable benefit-risk balance in their safety and efficacy profile, in prevention of thromboembolic events in patients with atrial fibrillation and in the prevention and treatment of venous thromboembolism and acute coronary syndrome. In 2008, dabigatran was the first direct oral anticoagulant approved by the European Medicine Agency. Subsequently, rivaroxaban, apixaban and edoxaban were also authorised. This article reviews the evidence related to the use of these drugs. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Comparative study of anticoagulant and procoagulant properties of 28 snake venoms from families Elapidae, Viperidae, and purified Russell's viper venom-factor X activator (RVV-X).

Science.gov (United States)

Suntravat, Montamas; Nuchprayoon, Issarang; Pérez, John C

2010-09-15

Snake venoms consist of numerous molecules with diverse biological functions used for capturing prey. Each component of venom has a specific target, and alters the biological function of its target. Once these molecules are identified, characterized, and cloned; they could have medical applications. The activated clotting time (ACT) and clot rate were used for screening procoagulant and anticoagulant properties of 28 snake venoms. Crude venoms from Daboia russellii siamensis, Bothrops asper, Bothrops moojeni, and one Crotalus oreganus helleri from Wrightwood, CA, had procoagulant activity. These venoms induced a significant shortening of the ACT and showed a significant increase in the clot rate when compared to the negative control. Factor X activator activity was also measured in 28 venoms, and D. r. siamensis venom was 5-6 times higher than those of B. asper, B. moojeni, and C. o. helleri from Wrightwood County. Russell's viper venom-factor X activator (RVV-X) was purified from D. r. siamensis venom, and then procoagulant activity was evaluated by the ACT and clot rate. Other venoms, Crotalus atrox and two Naja pallida, had anticoagulant activity. A significant increase in the ACT and a significant decrease in the clot rate were observed after the addition of these venoms; therefore, the venoms were considered to have anticoagulant activity. Venoms from the same species did not always have the same ACT and clot rate profiles, but the profiles were an excellent way to identify procoagulant and anticoagulant activities in snake venoms.

Activated Protein C Drives the Hyperfibrinolysis of Acute Traumatic Coagulopathy.

Science.gov (United States)

Davenport, Ross A; Guerreiro, Maria; Frith, Daniel; Rourke, Claire; Platton, Sean; Cohen, Mitchell; Pearse, Rupert; Thiemermann, Chris; Brohi, Karim

2017-01-01

Major trauma is a leading cause of morbidity and mortality worldwide with hemorrhage accounting for 40% of deaths. Acute traumatic coagulopathy exacerbates bleeding, but controversy remains over the degree to which inhibition of procoagulant pathways (anticoagulation), fibrinogen loss, and fibrinolysis drive the pathologic process. Through a combination of experimental study in a murine model of trauma hemorrhage and human observation, the authors' objective was to determine the predominant pathophysiology of acute traumatic coagulopathy. First, a prospective cohort study of 300 trauma patients admitted to a single level 1 trauma center with blood samples collected on arrival was performed. Second, a murine model of acute traumatic coagulopathy with suppressed protein C activation via genetic mutation of thrombomodulin was used. In both studies, analysis for coagulation screen, activated protein C levels, and rotational thromboelastometry (ROTEM) was performed. In patients with acute traumatic coagulopathy, the authors have demonstrated elevated activated protein C levels with profound fibrinolytic activity and early depletion of fibrinogen. Procoagulant pathways were only minimally inhibited with preservation of capacity to generate thrombin. Compared to factors V and VIII, proteases that do not undergo activated protein C-mediated cleavage were reduced but maintained within normal levels. In transgenic mice with reduced capacity to activate protein C, both fibrinolysis and fibrinogen depletion were significantly attenuated. Other recognized drivers of coagulopathy were associated with less significant perturbations of coagulation. Activated protein C-associated fibrinolysis and fibrinogenolysis, rather than inhibition of procoagulant pathways, predominate in acute traumatic coagulopathy. In combination, these findings suggest a central role for the protein C pathway in acute traumatic coagulopathy and provide new translational opportunities for management of

Anti-Coagulant and Anti-Thrombotic Properties of Blacklip Abalone (Haliotis rubra): In Vitro and Animal Studies.

Science.gov (United States)

Suleria, Hafiz Ansar Rasul; Masci, Paul P; Zhao, Kong-Nan; Addepalli, Rama; Chen, Wei; Osborne, Simone A; Gobe, Glenda C

2017-08-04

Sulphated polysaccharides with anti-thrombotic and anti-coagulant activities have been found in various marine biota. In this study, a previously characterised anti-thrombotic and anti-coagulant extract from blacklip abalone was fractionated by anion exchange chromatography (AEC), pooled (on a sulphated polysaccharide basis) and administered to Wistar rats via oral gavage (N = 8) for assessment as an oral therapeutic. To ensure that the preparation had anti-coagulant activity prior to oral administration, it was assessed in rat blood by thromboelastography (TEG) significantly increasing reaction (R) time (or time until clot formation). Following in vitro confirmation of anti-coagulant activity, 40 mg of the preparation was orally administered to rats with blood samples collected at 2, 4, and 6 h post-gavage. Assessment of all blood samples by TEG showed some prolongation of R time from 355 to 380 s after 4 h. Dosing of the post-gavage blood samples with the abalone preparation to confirm anti-thrombotic activity in vitro revealed residual anti-coagulant activity, further suggesting that oral administration did increase anti-coagulant potential in the collected blood but that bioavailability was low. Assessment of tissues and haematological parameters showed no obvious harmful effects of the abalone preparation in animals. In summary, even though oral administration of fractionated and pooled blacklip abalone extract to rats delayed clotting after 4 h, bioavailability of the preparation appeared to be low and may be more appropriate for intravenous administration as an anti-thrombotic or anti-coagulant therapeutic.

Structural Features and Anti-coagulant Activity of the Sulphated Polysaccharide SPS-CF from a Green Alga Capsosiphon fulvescens

Czech Academy of Sciences Publication Activity Database

Synytsya, A.; Choi, D. J.; Pohl, Radek; Na, Y. S.; Capek, P.; Lattová, E.; Taubner, T.; Choi, J. W.; Lee, C. W.; Park, J. K.; Kim, W. J.; Kim, S. M.; Lee, J.; Park, Y. I.

2015-01-01

Roč. 17, č. 6 (2015), s. 718-735 ISSN 1436-2228 Institutional support: RVO:61388963 Keywords : alga Maesaengi (Capsosiphon fulvescens) * ulvan * monosaccharide composition * structure * anti-coagulant activity Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.062, year: 2015

Improved circulating microparticle analysis in acid-citrate dextrose (ACD) anticoagulant tube.

Science.gov (United States)

György, Bence; Pálóczi, Krisztina; Kovács, Alexandra; Barabás, Eszter; Bekő, Gabriella; Várnai, Katalin; Pállinger, Éva; Szabó-Taylor, Katalin; Szabó, Tamás G; Kiss, Attila A; Falus, András; Buzás, Edit I

2014-02-01

Recently extracellular vesicles (exosomes, microparticles also referred to as microvesicles and apoptotic bodies) have attracted substantial interest as potential biomarkers and therapeutic vehicles. However, analysis of microparticles in biological fluids is confounded by many factors such as the activation of cells in the blood collection tube that leads to in vitro vesiculation. In this study we aimed at identifying an anticoagulant that prevents in vitro vesiculation in blood plasma samples. We compared the levels of platelet microparticles and non-platelet-derived microparticles in platelet-free plasma samples of healthy donors. Platelet-free plasma samples were isolated using different anticoagulant tubes, and were analyzed by flow cytometry and Zymuphen assay. The extent of in vitro vesiculation was compared in citrate and acid-citrate-dextrose (ACD) tubes. Agitation and storage of blood samples at 37 °C for 1 hour induced a strong release of both platelet microparticles and non-platelet-derived microparticles. Strikingly, in vitro vesiculation related to blood sample handling and storage was prevented in samples in ACD tubes. Importantly, microparticle levels elevated in vivo remained detectable in ACD tubes. We propose the general use of the ACD tube instead of other conventional anticoagulant tubes for the assessment of plasma microparticles since it gives a more realistic picture of the in vivo levels of circulating microparticles and does not interfere with downstream protein or RNA analyses. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of L-arginine immobilization on the anticoagulant activity and hemolytic property of polyethylene terephthalate films

International Nuclear Information System (INIS)

Liu Yun; Yang Yun; Wu Feng

2010-01-01

Surface modification of polyethylene terephthalate (PET) films was performed with L-arginine (L-Arg) to gain an improved anticoagulant surface. The surface chemistry changes of modified films were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The in vitro anticoagulant activities of the surface-modified PET films were evaluated by blood clotting test, hemolytic test, and the measurement of clotting time including plasma recalcification time (PRT), activated partial thromboplastin time (APTT), and prothrombin time (PT). The data of blood coagulation index (BCI) for L-arginine modified PET films (PET-Arg) was larger than that for PET at the same blood-sample contact time. The hemolysis ratio for PET-Arg was less than that for PET and within the accepted standard for biomaterials. The PRT and APTT for PET-Arg were significantly prolonged by 189 s and 25 s, respectively, compared to those for the unmodified PET. All results suggested that the currently described modification method could be a possible candidate to create antithrombogenic PET surfaces which would be useful for further medical applications.

The N-terminal-truncated recombinant fibrin(ogen)olytic serine protease improves its functional property, demonstrates in vivo anticoagulant and plasma defibrinogenation activity as well as pre-clinical safety in rodent model.

Science.gov (United States)

Bora, Bandana; Gogoi, Debananda; Tripathy, Debabrata; Kurkalang, Sillarine; Ramani, Sheetal; Chatterjee, Anupam; Mukherjee, Ashis K

2018-05-01

An N-terminal truncated fibrino(geno)lytic serine protease gene encoding a ~42kDa protein from Bacillus cereus strain AB01 was produced by error prone PCR, cloned into pET19b vector, and expressed in E5 coli BL21 DE3 cells. The deletion of 24 amino acid residues from N-terminal of wild-type Bacifrinase improves the catalytic activity of [Bacifrinase (ΔN24)]. The anticoagulant potency of [Bacifrinase (ΔN24)] was comparable to Nattokinase and Warfarin and results showed that its anticoagulant action is contributed by progressive defibrinogenation and antiplatelet activities. Nonetheless, at the tested concentration of 2.0μM [Bacifrinase (ΔN24)] did not show in vitro cytotoxicity or chromosomal aberrations on human embryonic kidney cells-293 (HEK-293) and human peripheral blood lymphocytes (HPBL) cells. [Bacifrinase (ΔN24)], at a dose of 2mg/kg, did not show toxicity, adverse pharmacological effects, tissue necrosis or hemorrhagic effect after 72h of its administration in Swiss albino mice. However, at the tested doses of 0.125 to 0.5mg/kg, it demonstrated significant in anticoagulant effect as well as defibrinogenation after 6h of administration in mice. We propose that [Bacifrinase (ΔN24)] may serve as prototype for the development of potent drug to prevent hyperfibrinogenemia related disorders. Copyright © 2018 Elsevier B.V. All rights reserved.

Optical sensing of anticoagulation status: Towards point-of-care coagulation testing.

Directory of Open Access Journals (Sweden)

Diane M Tshikudi

Full Text Available Anticoagulant overdose is associated with major bleeding complications. Rapid coagulation sensing may ensure safe and accurate anticoagulant dosing and reduce bleeding risk. Here, we report the novel use of Laser Speckle Rheology (LSR for measuring anticoagulation and haemodilution status in whole blood. In the LSR approach, blood from 12 patients and 4 swine was placed in disposable cartridges and time-varying intensity fluctuations of laser speckle patterns were measured to quantify the viscoelastic modulus during clotting. Coagulation parameters, mainly clotting time, clot progression rate (α-angle and maximum clot stiffness (MA were derived from the clot viscoelasticity trace and compared with standard Thromboelastography (TEG. To demonstrate the capability for anticoagulation sensing in patients, blood samples from 12 patients treated with warfarin anticoagulant were analyzed. LSR clotting time correlated with prothrombin and activated partial thromboplastin time (r = 0.57-0.77, p<0.04 and all LSR parameters demonstrated good correlation with TEG (r = 0.61-0.87, p<0.04. To further evaluate the dose-dependent sensitivity of LSR parameters, swine blood was spiked with varying concentrations of heparin, argatroban and rivaroxaban or serially diluted with saline. We observed that anticoagulant treatments prolonged LSR clotting time in a dose-dependent manner that correlated closely with TEG (r = 0.99, p<0.01. LSR angle was unaltered by anticoagulation whereas TEG angle presented dose-dependent diminution likely linked to the mechanical manipulation of the clot. In both LSR and TEG, MA was largely unaffected by anticoagulation, and LSR presented a higher sensitivity to increased haemodilution in comparison to TEG (p<0.01. Our results establish that LSR rapidly and accurately measures the response of various anticoagulants, opening the opportunity for routine anticoagulation monitoring at the point-of-care or for patient self-testing.

Anticoagulant drugs increase natural killer cell activity in lung cancer

Czech Academy of Sciences Publication Activity Database

Bobek, M.; Boubelík, Michael; Fišerová, Anna; Luptovcová, Martina; Vannucci, Luca; Kacprzak, G.; Kolodzej, J.; Majewski, A.M.; Hoffman, R. M.

2005-01-01

Roč. 47, č. 2 (2005), s. 215-223 ISSN 0169-5002 Institutional research plan: CEZ:AV0Z5052915 Keywords : anticoagulant drugs * lung cancer * NK cells Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.172, year: 2005

Anticoagulation period in idiopathic venous thromboembolism

International Nuclear Information System (INIS)

Farraj, Rami S.

2004-01-01

The period of anticoagulation of a first episode of idiopathic venous thromboembolism has been 6 months. It is unclear if such patients would benefit from longer treatment, as there appears to be an increased risk of recurrence after anticoagulation is stopped. In a randomized prospective study of 64 patients admitted to King Hussein Medical city, Amman, Jordan, who developed a first episode of venous thromboembolism, 32 patients were given warfarin for 24-months, while 32 patients stopped anticoagulation after completion of 6-months of therapy. Our goal was to determine the effects of extended anticoagulation on rates of recurrence of symptomatic venous thromboembolism and bleeding. The patients were followed for 12-months after stopping anticoagulation. After 24-months, 7 of the 32 patients (21%) who had standard anticoagulation for 6-months had a recurrent episode of thromboembolism compared to one of the 32 patients who received anticoagulation for 24 months (3%). Extended warfarin therapy for 24-months has resulted in an absolute risk reduction of 0.1% (p<0.05). This translates into 8 patients having to be treated for 24-months to avoid one recurrence without increasing the risk of major bleeding. Two patients in each group (6%) had major nonfatal bleeding, all 4 bleeding episodes occurring within the first 3-months of anticoagulation. After 36-months of follow up, the recurrence rate of extended warfarin therapy was only 3 patients (9%), which is a 43% relative reduction in recurrence of thromboembolism compared to standard therapy for 6-months. Patients with first episodes of idiopathic venous thromboembolism have an increased risk of recurrent venous thromboembolism and should be treated with oral anticoagulants for longer than 6-months, probably 24-months. (author)

Chronic kidney disease and anticoagulation

DEFF Research Database (Denmark)

Sciascia, Savino; Radin, Massimo; Schreiber, Karen

2017-01-01

Anticoagulation in patients with impaired kidney function can be challenging since drugs' pharmacokinetics and bioavailability are altered in this setting. Patients with chronic kidney disease (CKD) treated with conventional anticoagulant agents [vitamin K antagonist (VKA), low-molecular weight...... are eliminated via the kidneys pose additional challenges. More recently, two classes of direct oral anticoagulant agents (DOACs) have been investigated for the prevention and management of venous thromboembolic events: the direct factor Xa inhibitors rivaroxaban, apixaban and edoxaban, and the direct thrombin...

Direct oral anticoagulants and venous thromboembolism

Directory of Open Access Journals (Sweden)

Massimo Franchini

2016-09-01

Full Text Available Venous thromboembolism (VTE, consisting of deep vein thrombosis and pulmonary embolism, is a major clinical concern associated with significant morbidity and mortality. The cornerstone of management of VTE is anticoagulation, and traditional anticoagulants include parenteral heparins and oral vitamin K antagonists. Recently, new oral anticoagulant drugs have been developed and licensed, including direct factor Xa inhibitors (e.g. rivaroxaban, apixaban and edoxaban and thrombin inhibitors (e.g. dabigatran etexilate. This narrative review focusses on the characteristics of these direct anticoagulants and the main results of published clinical studies on their use in the prevention and treatment of VTE.

[Effects of sodium ethamsylate on anticoagulant and anti-aggregation activity of vascular endothelium in hemorrhagic fever patients with renal syndrome].

Science.gov (United States)

Davidovich, I M; Sirotin, B Z; Parshina, T A

1999-01-01

To elucidate effects of sodium ethamsylate (SE) on anticoagulant and antiaggregation activity of vascular endothelium in patients suffering from hemorrhagic fever with renal syndrome (HFRS). A trial of SE enrolled 70 HFRS patients (58 males, 12 females aged under 30 years) compatible by the disease severity. They were divided into two groups. 42 patients of the control group received standard therapy, 28 patients of the study group received adjuvant 12% solution of SE in daily dose 1500-2000 mg in the course of HFRS oliguria period. Hemostatic parameters were measured before and after the cuff test to investigate the condition of vascular wall with calculation of the athrombogenicity index (the ratio of the relevant indices before and after the cuff test). SE effects on vascular endothelium was assessed by a blind method. In oliguria, both groups had baseline antiaggregation indices significantly higher than in the control. After the cuff test, control patients' indices tended to an increase while in the study group there was a marked decrease. The trend in anticoagulant activity of microvascular endothelium did not differ much with the groups. This picture persisted also in polyuria. In convalescence hemostasis was similar in both groups. SE enhances antiaggregant activity of vascular endothelium in oliguria period of HFRS without affecting its anticoagulant properties. This is explained by a direct effect of SE on vascular endothelium.

Anticoagulant Medicine: Potential for Drug-Food Interactions

Science.gov (United States)

... Medications Anticoagulants and Drug-Food Interactions Anticoagulants and Drug-Food Interactions Make an Appointment Ask a Question Refer Patient ... Jewish Health wants you to be aware these drug-food interactions when taking anticoagulant medicine. Ask your health care ...

Use of anticoagulants in elderly patients: practical recommendations

Directory of Open Access Journals (Sweden)

Helia Robert-Ebadi

2009-04-01

Full Text Available Helia Robert-Ebadi, Grégoire Le Gal, Marc RighiniDivision of Angiology and Hemostasis (HRE, MR, Department of Internal Medicine, Geneva University Hospital and Faculty of Medicine, Geneva, Switzerland, and Department of Internal Medicine and Chest Diseases, EA 3878 (GETBO, Brest University Hospital, Brest, France (GLGAbstract: Elderly people represent a patient population at high thromboembolic risk, but also at high hemorrhagic risk. There is a general tendency among physicians to underuse anticoagulants in the elderly, probably both because of underestimation of thromboembolic risk and overestimation of bleeding risk. The main indications for anticoagulation are venous thromboembolism (VTE prophylaxis in medical and surgical settings, VTE treatment, atrial fibrillation (AF and valvular heart disease. Available anticoagulants for VTE prophylaxis and initial treatment of VTE are low molecular weight heparins (LMWH, unfractionated heparin (UFH or synthetic anti-factor Xa pentasaccharide fondaparinux. For long-term anticoagulation vitamin K antagonists (VKA are the first choice and only available oral anticoagulants nowadays. Assessing the benefit-risk ratio of anticoagulation is one of the most challenging issues in the individual elderly patient, patients at highest hemorrhagic risk often being those who would have the greatest benefit from anticoagulants. Some specific considerations are of utmost importance when using anticoagulants in the elderly to maximize safety of these treatments, including decreased renal function, co-morbidities and risk of falls, altered pharmacodynamics of anticoagulants especially VKAs, association with antiplatelet agents, patient education. Newer anticoagulants that are currently under study could simplify the management and increase the safety of anticoagulation in the future.Keywords: anticoagulation, elderly patients, venous thromboembolism, hemorrhagic risk, atrial fibrillation, thrombin inhibitors, factor Xa

Characterization and structural analysis of a potent anticoagulant phospholipase A2 from Pseudechis australis snake venom.

Science.gov (United States)

Du, Qianyun Sharon; Trabi, Manuela; Richards, Renée Stirling; Mirtschin, Peter; Madaras, Frank; Nouwens, Amanda; Zhao, Kong-Nan; de Jersey, John; Lavin, Martin F; Guddat, Luke W; Masci, Paul P

2016-03-01

Pseudechis australis is one of the most venomous and lethal snakes in Australia. Numerous phospholipase A2 (PLA2) isoforms constitute a major portion of its venom, some of which have previously been shown to exhibit not only enzymatic, but also haemolytic, neurotoxic and anticoagulant activities. Here, we have purified a potent anticoagulant PLA2 (identified as PA11) from P. australis venom to investigate its phospholipase, anticoagulant, haemolytic and cytotoxic activities and shown that addition of 11 nM PA11 resulted in a doubling of the clotting time of recalcified whole blood. We have also demonstrated that PA11 has high PLA2 enzymatic activity (10.9 × 10(4) Units/mg), but low haemolytic activity (0.6% of red blood cells hydrolysed in the presence of 1 nM PA11). PA11 at a concentration lower than 600 nM is not cytotoxic towards human cultured cells. Chemical modification experiments using p-bromophenacyl bromide have provided evidence that the catalytic histidine of PA11 is critical for the anticoagulant activity of this PLA2. PA11 that was subjected to trypsin digestion without previous reduction and alkylation of the disulfide bonds maintained enzymatic and anticoagulant activity, suggesting that proteolysis alone cannot abolish these properties. Consistent with these results, administration of PA11 by gavage in a rabbit stasis thrombosis model increased the clotting time of recalcified citrated whole blood by a factor of four. These data suggest that PA11 has potential to be developed as an anticoagulant in a clinical setting. Copyright © 2015. Published by Elsevier Ltd.

Anticoagulation and high dose liver radiation. A preliminary report

International Nuclear Information System (INIS)

Lightdale, C.J.; Wasser, J.; Coleman, M.; Brower, M.; Tefft, M.; Pasmantier, M.

1979-01-01

Two groups of patients were observed for evidence of acute radiation hepatitis during high dose radiation to the liver. The first group of 18 patients with metastatic liver disease received an average of 4,050 rad to the whole liver. Half received anticoagulation with warfarin. One patient on anticoagulation developed evidence of acute radiation hepatitis while 2 patients did so without anticoagulation. Eleven patients with Hodgkin's disease received 4,000 rad to the left lobe of the liver during extended field radiation. Four of these 11 patients were anticoagulated to therapeutic range. Only one of the fully anticoagulated patients showed changes on liver scan consistent with radiation hepatitis whereas three did so without anticoagulation. No serious sequelae from anticoagulation occurred in either group. These preliminary data suggest that anticoagulation may be safely administered with high dose hepatic radiation and that further trials with anticoagulation are warranted

Managing reversal of direct oral anticoagulants in emergency situations Anticoagulation Education Task Force White Paper

NARCIS (Netherlands)

Ageno, Walter; Büller, Harry R.; Falanga, Anna; Hacke, Werner; Hendriks, Jeroen; Lobban, Trudie; Merino, Jose; Milojevic, Ivan S.; Moya, Francisco; van der Worp, H. Bart; Randall, Gary; Tsioufis, Konstantinos; Verhamme, Peter; Camm, A. John

2016-01-01

Anticoagulation is the cornerstone of prevention and treatment of venous thromboembolism (VTE) and stroke prevention in patients with atrial fibrillation (AF). However, the mechanisms by which anticoagulants confer therapeutic benefit also increase the risk of bleeding. As such, reversal strategies

Fatal consequences of synergistic anticoagulation

Directory of Open Access Journals (Sweden)

Sen P

2018-05-01

Full Text Available Objective: Novel oral anticoagulants (NOACs are increasingly being preferred by clinicians (and patients because they have a wide therapeutic window and therefore do not require monitoring of anticoagulant effect. Herein, we describe the unfortunate case of a patient who had fatal consequences as a result of switching from warfarin to rivaroxaban. Case Summary: A 90-year-old Caucasian woman, with atrial fibrillation on chronic anticoagulation with warfarin, was admitted to the hospital for pneumonia. She was treated with levofloxacin. In the same admission, her warfarin was switched to rivaroxaban. On Day 3 after the switch, her INR was found to be 6, and she developed a cervical epidural hematoma from C2 to C7. She ultimately developed respiratory arrest, was put on comfort care and died. Discussion: Rivaroxaban and warfarin are known to have a synergistic anticoagulant effect, usually seen shortly after switching. Antibiotics also increase the effects of warfarin by the inhibition of metabolizing isoenzymes. It is hypothesized that these two effects led to the fatal cervical spinal hematoma. Conclusion: The convenience of a wide therapeutic window and no requirement of laboratory monitoring makes the NOACs a desirable option for anticoagulation. However, there is lack of data and recommendations on how to transition patients from Warfarin to NOACs or even how to transition from one NOAC to another. Care should be taken to ensure continuous monitoring of anticoagulation when stopping, interrupting or switching between NOACS to avoid the possibility of fatal bleeding and strokes.

Anticoagulant Effect of Sugammadex: Just an In Vitro Artifact.

Science.gov (United States)

Dirkmann, Daniel; Britten, Martin W; Pauling, Henning; Weidle, Juliane; Volbracht, Lothar; Görlinger, Klaus; Peters, Jürgen

2016-06-01

Sugammadex prolongs activated partial thromboplastin time (aPTT) and prothrombin time (PT) suggestive of anticoagulant effects. To pinpoint its presumed anticoagulant site of action, the authors assessed Sugammadex's impact on a panel of coagulation assays. Sugammadex, Rocuronium, Sugammadex and Rocuronium combined, or saline were added to blood samples from healthy volunteers and analyzed using plasmatic (i.e., aPTT, thrombin time, and fibrinogen concentration) (n = 8 each), PT (quick), activities of plasmatic coagulation factors, and whole blood (extrinsically and intrinsically activated thromboelastometry) assays (n = 18 each). Furthermore, dose-dependent effects of Sugammadex were also assessed (n = 18 each) in diluted Russel viper venom time (DRVVT) assays with low (DRVVT1) and high (DRVVT2) phospholipid concentrations and in a highly phospholipid-sensitive aPTT assay. Sugammadex increased PT (+9.1%; P Sugammadex dose-dependently prolonged both DRVVT1 and the highly phospholipid-sensitive aPTT assays, but additional phospholipids in the DRVVT2 assay almost abolished these prolongations. Thrombin time, a thromboelastometric thrombin generation assay, clot firmness, clot lysis, fibrinogen concentration, and activities of other coagulation factors were unaltered. Rocuronium, Sugammadex and Rocuronium combined, and saline exerted no effects. Sugammadex significantly affects various coagulation assays, but this is explainable by an apparent phospholipid-binding effect, suggesting that Sugammadex`s anticoagulant effects are likely an in vitro artifact.

Pharmacokinetics of activated protein C in guinea pigs

International Nuclear Information System (INIS)

Berger, H. Jr.; Kirstein, C.G.; Orthner, C.L.

1991-01-01

Protein C is a vitamin K-dependent zymogen of the serine protease, activated protein C (APC), an important regulatory enzyme in hemostasis. In view of the potential of human APC as an anticoagulant and profibrinolytic agent, the pharmacokinetics and tissue distribution of APC were studied in guinea pigs. The plasma elimination of a trace dose of 125 I-APC was biphasic following an initial rapid elimination of approximately 15% of the injected dose within 1 to 2 minutes. This rapid removal of 125 I-APC from the circulation was found to be a result of an association with the liver regardless of the route of injection. Essentially identical results were obtained with active site-blocked forms of APC generated with either diisopropylfluorophosphate or D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone, which indicates that the active site was not essential for the liver association. Accumulation of all three forms of APC in the liver peaked at 30 minutes and then declined as increasing amounts of degraded radiolabeled material appeared in the gastrointestinal tract and urine. Removal of the gamma-carboxyglutamic acid (gla) domain of diisopropylphosphoryl-APC resulted in a 50% reduction in the association with liver and an accumulation in the kidneys. Protein C and protein S were cleared from the circulation at rates approximately one-half and one-fourth, respectively, that of APC. Both in vitro and in vivo, APC was found to form complexes with protease inhibitors present in guinea pig plasma. Complex formation resulted in a more rapid disappearance of the enzymatic activity of APC than elimination of the protein moiety. These findings indicate two distinct mechanisms for the elimination of APC. One mechanism involves reaction with plasma protease inhibitors and subsequent elimination by specific hepatic receptors. (Abstract Truncated)

Comparison of hematologic values in blood samples with lithium heparin or dipotassium ethylenediaminetetraacetic acid anticoagulants in Hispaniolan Amazon parrots (Amazona ventralis).

Science.gov (United States)

Guzman, David Sanchez-Migallon; Mitchell, Mark A; Gaunt, Stephen D; Beaufrère, Hugues; Tully, Thomas N

2008-06-01

Blood samples were collected from 20 Hispaniolan Amazon parrots (Amazona ventralis) and were divided into tubes that contained dipotassium ethylenediaminetetraacetic acid (K2EDTA) and lithium heparin. Complete blood cell counts were determined in each sample within 2 hours of collection. The level of agreement in results was moderate for plasma protein, packed cell volume (PCV), and leukocyte, monocyte, and lymphocyte counts between the anticoagulants. Plasma protein and PCV values were significantly lower in samples with lithium heparin than in those with K2EDTA, whereas lymphocyte numbers were significantly higher in lithium heparin samples than in K2EDTA samples. The level of agreement was good for the other cell types (heterophils, eosinophils, and basophils) when comparing the different anticoagulants. The poor level of agreement between anticoagulants with the increase in thrombocyte clumping in lithium heparin samples indicates that the use of lithium heparin as anticoagulant may affect thrombocyte count. No negative effects on morphology and staining of blood cells were apparent in smears from heparin samples compared with K2EDTA samples. Within the different values compared, the limits of agreement are small enough to be confident that lithium heparin can be used for routine CBC counts in a clinical setting. The use of the same anticoagulant should be recommended to follow trends within the same patient, especially when considering plasma protein concentration, PCV, and lymphocyte count.

Anticoagulant, Antioxidant and Antitumor Activities of Heterofucans from the Seaweed Dictyopteris delicatula

Directory of Open Access Journals (Sweden)

Hugo Alexandre Oliveira Rocha

2011-05-01

Full Text Available In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%, whereas fucans F1.3v (0.5 mg/mL showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress.

Synthesis of Fucosylated Chondroitin Sulfate Glycoclusters: A Robust Route to New Anticoagulant Agents.

Science.gov (United States)

Zhang, Xiao; Yao, Wang; Xu, Xiaojiang; Sun, Huifang; Zhao, Jinhua; Meng, Xiangbao; Wu, Mingyi; Li, Zhongjun

2018-02-01

Fucosylated chondroitin sulfate (FuCS) is a structurally distinct glycosaminoglycan with excellent anticoagulant activity. Studies show that FuCS and its depolymerized fragments exhibit a different anticoagulant mechanism from that of heparin derivatives, with decreased risks of adverse effects and bleeding. However, further exploitation has been hindered by the scarcity of structurally defined oligosaccharides. Herein, facile method is reported for the synthesis of the repeating trisaccharide unit of FuCS based on the degradation of chondroitin sulfate polymers. A series of simplified FuCS glycomimetics that have highly tunable structures, controllable branches, and defined sulfation motifs were generated by copper-catalyzed alkyne-azide cycloaddition. Remarkable improvement in activated partial thromboplastin time (APTT) assay activities was observed as the branches increased, but no significant influences were observed for prothrombin time (PT) and thrombin time (TT) assay activities. Further FXase inhibition tests suggested that glycoclusters 33 b-40 b selectively inhibited intrinsic anticoagulant activities, but had little effect on the extrinsic and common coagulation pathways. Notably, glycoclusters with the 2,4-di-O-sulfated fucosyl residue displayed the most potency, which was in consistent with that of natural polysaccharides. These FuCS clusters demonstrated potency to mimic linear glycosaminoglycans and offer a new framework for the development of novel anticoagulant agents. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

The "Janus face" of the thrombin binding aptamer: Investigating the anticoagulant and antiproliferative properties through straightforward chemical modifications.

Science.gov (United States)

Esposito, Veronica; Russo, Annapina; Amato, Teresa; Vellecco, Valentina; Bucci, Mariarosaria; Mayol, Luciano; Russo, Giulia; Virgilio, Antonella; Galeone, Aldo

2018-02-01

The thrombin binding aptamer (TBA) is endowed with both anticoagulant and antiproliferative activities. Its chemico-physical and/or biological properties can be tuned by the site-specific replacement of selected residues. Four oligodeoxynucleotides (ODNs) based on the TBA sequence (5'-GGTTGGTGTGGTTGG-3') and containing 2'-deoxyuridine (U) or 5-bromo-2'-deoxyuridine (B) residues at positions 4 or 13 have been investigated by NMR and CD techniques. Furthermore, their anticoagulant (PT assay) and antiproliferative properties (MTT assay) have been tested and compared with two further ODNs containing 5-hydroxymethyl-2'-deoxyuridine (H) residues in the same positions, previously investigated. The CD and NMR data suggest that all the investigated ODNs are able to form G-quadruplexes strictly resembling that of TBA. The introduction of B residues in positions 4 or 13 increases the melting temperature of the modified aptamers by 7 °C. The replacement of thymidines with U in the same positions results in an enhanced anticoagulant activity compared to TBA, also at low ODN concentration. Although all ODNs show antiproliferative properties, only TBA derivatives containing H in the positions 4 and 13 lose the anticoagulant activity and remarkably preserve the antiproliferative one. All ODNs have shown antiproliferative activities against two cancer cell lines but only those with U and B are endowed with anticoagulant activities similar or improved compared to TBA. The appropriate site-specific replacement of the residues in the TT loops of TBA with commercially available thymine analogues is a useful strategy either to improve the anticoagulant activity or to preserve the antiproliferative properties by quenching the anticoagulant ones. Copyright © 2017 Elsevier Inc. All rights reserved.

Secondary poisoning of owls by anticoagulant rodenticides

Science.gov (United States)

Mendenhall, Vivian M.; Pank, L.F.

1980-01-01

Anticoagulants-compounds that prevent clotting of the blood-are extensively used for control of small mammal pests. The potential secondary hazards of 6 anticoagulant rodenticides to birds of prey were examined in this study. Whole rats or mice were killed with each anticoagulant and were fed to 1-3 species of owls. Owls died of hemorrhaging after feeding on rats killed with bromadiolone, brodifacoum, or diphacinone; sublethal hemorrhaging occurred in owls fed rats killed with difenacoum. These results demonstrate potential secondary hazards of 4 anticoagulants to avian predators. No abnormalities were observed in owls fed rats killed with fumarin and chlorophacinone

Effects of computer-assisted oral anticoagulant therapy

DEFF Research Database (Denmark)

Rasmussen, Rune Skovgaard; Corell, Pernille; Madsen, Poul

2012-01-01

: Patients randomized to computer-assisted anticoagulation and the CoaguChek® system reached the therapeutic target range after 8 days compared to 14 days by prescriptions from physicians (p = 0.04). Time spent in the therapeutic target range did not differ between groups. The median INR value measured...... prescribed by physicians, and the total time spent within the therapeutic target range was similar. Thus computer-assisted oral anticoagulant therapy may reduce the cost of anticoagulation therapy without lowering the quality. INR values measured by CoaguChek® were reliable compared to measurements......UNLABELLED: BACKGROUND: Computer-assistance and self-monitoring lower the cost and may improve the quality of anticoagulation therapy. The main purpose of this clinical investigation was to use computer-assisted oral anticoagulant therapy to improve the time to reach and the time spent within...

Developing an Anti-Xa-Based Anticoagulation Protocol for Patients with Percutaneous Ventricular Assist Devices.

Science.gov (United States)

Sieg, Adam; Mardis, B Andrew; Mardis, Caitlin R; Huber, Michelle R; New, James P; Meadows, Holly B; Cook, Jennifer L; Toole, J Matthew; Uber, Walter E

2015-01-01

Because of the complexities associated with anticoagulation in temporary percutaneous ventricular assist device (pVAD) recipients, a lack of standardization exists in their management. This retrospective analysis evaluates current anticoagulation practices at a single center with the aim of identifying an optimal anticoagulation strategy and protocol. Patients were divided into two cohorts based on pVAD implanted (CentriMag (Thoratec; Pleasanton, CA) / TandemHeart (CardiacAssist; Pittsburgh, PA) or Impella (Abiomed, Danvers, MA)), with each group individually analyzed for bleeding and thrombotic complications. Patients in the CentriMag/TandemHeart cohort were subdivided based on the anticoagulation monitoring strategy (activated partial thromboplastin time (aPTT) or antifactor Xa unfractionated heparin (anti-Xa) values). In the CentriMag/TandemHeart cohort, there were five patients with anticoagulation titrated based on anti-Xa values; one patient developed a device thrombosis and a major bleed, whereas another patient experienced major bleeding. Eight patients received an Impella pVAD. Seven total major bleeds in three patients and no thrombotic events were detected. Based on distinct differences between the devices, anti-Xa values, and outcomes, two protocols were created to guide anticoagulation adjustments. However, anticoagulation in patients who require pVAD support is complex with constantly evolving anticoagulation goals. The ideal level of anticoagulation should be individually determined using several coagulation laboratory parameters in concert with hemodynamic changes in the patient's clinical status, the device, and the device cannulation.

Bridging Anticoagulation

Science.gov (United States)

... clinical centers in the United States, Canada, and Brazil. A more detailed description of the study is ... Your Personal Message Send Message Share on Social Media Bridging Anticoagulation The BRIDGE Study Investigators Circulation. 2012; ...

Anticoagulant factor V: factors affecting the integration of novel scientific discoveries into the broader framework.

Science.gov (United States)

LaBonte, Michelle L

2014-09-01

Since its initial discovery in the 1940s, factor V has long been viewed as an important procoagulant protein in the coagulation cascade. However, in the later part of the 20th century, two different scientists proposed novel anticoagulant roles for factor V. Philip Majerus proposed the first anticoagulant function for factor V in 1983, yet ultimately it was not widely accepted by the broader scientific community. In contrast, Björn Dahlbäck proposed a different anticoagulant role for factor V in 1994. While this role was initially contested, it was ultimately accepted and integrated into the scientific framework. In this paper, I present a detailed historical account of these two anticoagulant discoveries and propose three key reasons why Dahlbäck's anticoagulant role for factor V was accepted whereas Majerus' proposed role was largely overlooked. Perhaps most importantly, Dahlbäck's proposed anticoagulant role was of great clinical interest because the discovery involved the study of an important subset of patients with thrombophilia. Soon after Dahlbäck's 1994 work, this patient population was shown to possess the factor V Leiden mutation. Also key in the ultimate acceptance of the second proposed anticoagulant role was the persistence of the scientist who made the discovery and the interest in and ability of others to replicate and reinforce this work. This analysis of two different yet similar discoveries sheds light on factors that play an important role in how new discoveries are incorporated into the existing scientific framework. Copyright © 2014 The Author. Published by Elsevier Ltd.. All rights reserved.

The mythology of anticoagulation therapy interruption for dental surgery.

Science.gov (United States)

Wahl, Michael J

2018-01-01

Continuous anticoagulation therapy is used to prevent heart attacks, strokes, and other embolic complications. When patients receiving anticoagulation therapy undergo dental surgery, a decision must be made about whether to continue anticoagulation therapy and risk bleeding complications or briefly interrupt anticoagulation therapy and increase the risk of developing embolic complications. Results from decades of studies of thousands of dental patients receiving anticoagulation therapy reveal that bleeding complications requiring more than local measures for hemostasis have been rare and never fatal. However, embolic complications (some of which were fatal and others possibly permanently debilitating) sometimes have occurred in patients whose anticoagulation therapy was interrupted for dental procedures. Although there is now virtually universal consensus among national medical and dental groups and other experts that anticoagulation therapy should not be interrupted for most dental surgery, there are still some arguments made supporting anticoagulation therapy interruption. An analysis of these arguments shows them to be based on a collection of myths and half-truths rather than on logical scientific conclusions. The time has come to stop anticoagulation therapy interruption for dental procedures. Copyright © 2018 American Dental Association. Published by Elsevier Inc. All rights reserved.

Regulation of human protein S gene (PROS1) transcription

NARCIS (Netherlands)

Wolf, Cornelia de

2006-01-01

This thesis describes the investigation of the transcriptional regulation of the gene for anticoagulant plasma Protein S, PROS1. Protein S is a cofactor for Protein C in the Protein C anticoagulant pathway. The coagulation cascade is negatively regulated by this pathway through inactivation of

Improved anticoagulant effect of fucosylated chondroitin sulfate orally administered as gastro-resistant tablets.

Science.gov (United States)

Fonseca, Roberto J C; Sucupira, Isabela D; Oliveira, Stephan Nicollas M C G; Santos, Gustavo R C; Mourão, Paulo A S

2017-04-03

Fucosylated chondroitin sulfate (FucCS) is a potent anticoagulant polysaccharide extracted from sea cucumber. Its anticoagulant activity is attributed to the presence of unique branches of sulfated fucose. Although this glycosaminoglycan exerts an antithrombotic effect following oral administration, high doses are necessary to achieve the maximum effect. The diminished activity of FucCS following oral administration is likely due to its degradation in the gastrointestinal tract and its limited ability to cross the intestinal cell membranes. The latter aspect is particularly difficult to overcome. However, gastro-resistant tablet formulation may help limit the degradation of FucCS in the gastrointestinal tract. In the present work, we found that the oral administration of FucCS as gastro-resistant tablets produces a more potent and prolonged anticoagulant effect compared with its administration as an aqueous solution, with no significant changes in the bleeding tendency or arterial blood pressure. Experiments using animal models of arterial thrombosis initiated by endothelial injury demonstrated that FucCS delivered as gastro-protective tablets produced a potent antithrombotic effect, whereas its aqueous solution was ineffective. However, there was no significant difference between the effects of FucCS delivered as gastro-resistant tablets or as aqueous solution in a venous thrombosis model, likely due to the high dose of thromboplastin used. New oral anticoagulants tested in these experimental models for comparison showed significantly increased bleeding tendencies. Our study provides a framework for developing effective oral anticoagulants based on sulfated polysaccharides from marine organisms. The present results suggest that FucCS is a promising oral anticoagulant.

Single—Molecular Imaging of Anticoagulation Factor I From Snake Venom by Atomic Force Microscopy

Institute of Scientific and Technical Information of China (English)

徐小龙; 刘清亮; 等

2002-01-01

Anticoagulation factor I( ACF I) from the venom of Agki-strodom acutus is a binding protein to activanted coagulation fac tor X(FXa) and possesses marked anticoagulant acivity,Single ACF I molecule has been successfully imaged in air by tapping mode atomic force microscopy(AFM) with high-resolu-tion using glutaraldehyde as a coupling agent.The physical adsoprtion and covalent binding of ACF I onto the mica show very different surface topographies,The former exhibits the characteristic strand-like structure with much less reproducibility,the latter displays a elliptic granular structure with better repro-ducibility,which sugests that the stability of ACF I molecules on the mica is enhanced by covalent bonding in the presence of glutaraldehyde.A small-scale AFM amplitude -mode impage clearly shows that the covalently bonded ACF I molecule by glutaraldehyde has olive shape structure with an average size of 7.4nm×3.6nm×3.1nm ,which is very similar to the size determined from the crystal structure of ACF I.

Implementation of a more physiological plasma rich in growth factor (PRGF) protocol: Anticoagulant removal and reduction in activator concentration.

Science.gov (United States)

Anitua, Eduardo; Prado, Roberto; Troya, María; Zalduendo, Mar; de la Fuente, María; Pino, Ander; Muruzabal, Francisco; Orive, Gorka

2016-07-01

Plasma rich in growth factors (PRGF) is a biological therapy that uses patient's own growth factors for promoting tissue regeneration. Given the current European regulatory framework in which anticoagulant solution in blood extraction tubes could be considered as a medicinal product, a new PRGF protocol has been developed. The actual protocol (PRGF-A) and the new one (PRGF-B) have been performed and compared under Good Laboratory Practices. PRGF-A protocol uses extraction tubes with 0.9 mL of trisodium citrate as anticoagulant and 50 μL of calcium chloride/mL PRGF to activate it. The PRGF-B reduces the amount of sodium citrate and calcium chloride to 0.4 mL and to 20 μL, respectively. Basic hematological parameters, platelet function, the scaffold obtaining process, growth factors content, and the biological effect were compared between both PRGF obtaining protocols. PRGF-B protocol led to a statistically significant higher enrichment and recovery of platelets regarding to the PRGF-A. Hypotonic stress response by platelets was significantly better in the new protocol. A statistically significant decrease in the basal platelet activation status of PRGF-B compared to PRGF-A was also observed. The duration of the lag phase in the platelet aggregation assay was statistically lower for the PRGF-B protocol. Both the clotting and the clot retraction time were significantly reduced in the B protocol. A higher growth factor concentration was detected in the plasma obtained using the PRGF-B protocol. The new PRGF obtaining protocol, with a reduction in the amount of anticoagulant and activator, has even improved the actual one.

The Evaluation of Protein C Activity and Some Inflammatory Markers in Synovia of Patients Undergoing Total Knee Arthroplasty

Directory of Open Access Journals (Sweden)

Ahmet Ata Alturfan

2011-06-01

Full Text Available Objective: Total knee arthroplasty (TKA is a major risk factor for thrombosis in patients over 40 years of age and this risk persists for several weeks after the surgery. Since inflammatory mechanisms affect coagulation and the natural anticoagulant system, we aimed to investigate protein C activities and inflammatory markers in patients undergoing TKA surgery.Material and Methods: We included 20 osteoarthritis patients and 20 healthy controls. Protein C activity and tumor necrosis factor-α (TNF-α levels in plasma and synovia were evaluated by ELISA technique. Results: In the patient group, protein C activities decreased and TNF-α levels increased significantly both in synovia and plasma when compared with the controls. Erythrocyte sedimentation rate of the patient group was found to be significantly elevated in comparison to the controls. On the other hand, serum C reactive protein values increased insignificantly when compared to controls.Conclusion: The decreased activity of protein C and increased levels of inflammatory markers in preoperative plasma and synovia of the patient group may enhance the risk for developing thrombosis.

Pulsed electric field extraction enhanced anti-coagulant effect of fungal polysaccharide from Jew's ear (Auricularia auricula).

Science.gov (United States)

Li, Changtian; Mao, Xinxin; Xu, Baojun

2013-01-01

As a Chinese herbal medicine, Jew's ear has been known for its anti-coagulant effects. Hence it is worthwhile developing an effective technique to extract active components. To find the optimal extraction condition and to identify the best strain to yield fungal polysaccharide with anti-coagulant activity. Three strains of Jew's ear from Jilin Province, named as 988, DY 18 and FS 02, and three extraction techniques, namely, high intensity pulsed electric fields (HIPEF), microwave-assisted extraction method (MAEM) and ultrasonic-assisted extraction method (UAEM), were applied to optimise the extraction conditions. The crude extracts and polysaccharides were further determined for anti-coagulant activities. All extracts prolonged blood clotting time as compared to reagent control. The HIPEF exhibited the most remarkable effect among the three extraction techniques. The anti-coagulant activities of extracts were enhanced with increasing electric field strength when the field strength reached 24 kV/cm. Current results suggest that the HIPEF technique will be an effective method in the manufacture of bioactive natural polysaccharide. Copyright © 2012 John Wiley & Sons, Ltd.

In vitro anti-thrombotic and anti-coagulant properties of blacklip abalone (Haliotis rubra) viscera hydrolysate.

Science.gov (United States)

Suleria, Hafiz Ansar Rasul; Masci, Paul P; Addepalli, Rama; Chen, Wei; Gobe, Glenda C; Osborne, Simone A

2017-07-01

Abalone viscera contain sulphated polysaccharides with anti-thrombotic and anti-coagulant activities. In this study, a hydrolysate was prepared from blacklip abalone (Haliotis rubra) viscera using papain and bromelain and fractionated using ion exchange and size exclusion chromatography. Hydrolysates and fractions were investigated for in vitro thrombin inhibition mediated through heparin cofactor II (HCII) as well as anti-coagulant activity in plasma and whole blood. On the basis of sulphated polysaccharide concentration, the hydrolysate inhibited thrombin through HCII with an inhibitor concentration at 50% (IC50) of 16.5 μg/mL compared with 2.1 μg/mL for standard heparin. Fractionation concentrated HCII-mediated thrombin inhibition down to an IC50 of 1.8 μg/mL and improved anti-coagulant activities by significantly delaying clotting time. This study confirmed the presence of anti-thrombotic and anti-coagulant molecules in blacklip abalone viscera and demonstrated that these activities can be enriched with a simple chromatography regime. Blacklip abalone viscera warrant further investigation as a source of nutraceutical or functional food ingredients. Graphical abstract Schematic showing preparation of bioactive extracts and fractions from blacklip abalone.

Large enhancement of functional activity of active site-inhibited factor VIIa due to protein dimerization: insights into mechanism of assembly/disassembly from tissue factor.

Science.gov (United States)

Stone, Matthew D; Harvey, Stephen B; Martinez, Michael B; Bach, Ronald R; Nelsestuen, Gary L

2005-04-26

Active site-inhibited blood clotting factor VIIa (fVIIai) binds to tissue factor (TF), a cell surface receptor that is exposed upon injury and initiates the blood clotting cascade. FVIIai blocks binding of the corresponding enzyme (fVIIa) or zymogen (fVII) forms of factor VII and inhibits coagulation. Although several studies have suggested that fVIIai may have superior anticoagulation effects in vivo, a challenge for use of fVIIai is cost of production. This study reports the properties of dimeric forms of fVIIai that are cross-linked through their active sites. Dimeric wild-type fVIIai was at least 75-fold more effective than monomeric fVIIai in blocking fVIIa association with TF. The dimer of a mutant fVIIai with higher membrane affinity was 1600-fold more effective. Anticoagulation by any form of fVIIai differed substantially from agents such as heparin and showed a delayed mode of action. Coagulation proceeded normally for the first minutes, and inhibition increased as equilibrium binding was established. It is suggested that association of fVIIa(i) with TF in a collision-dependent reaction gives equal access of inhibitor and enzyme to TF. Assembly was not influenced by the higher affinity and slower dissociation of the dimer. As a result, anticoagulation was delayed until the reaction reached equilibrium. Properties of different dissociation experiments suggested that dissociation of fVIIai from TF occurred by a two-step mechanism. The first step was separation of TF-fVIIa(i) while both proteins remained bound to the membrane, and the second step was dissociation of the fVIIa(i) from the membrane. These results suggest novel actions of fVIIai that distinguish it from most of the anticoagulants that block later steps of the coagulation cascade.

Assessing Bleeding Risk in Patients Taking Anticoagulants

Science.gov (United States)

Shoeb, Marwa; Fang, Margaret C.

2013-01-01

Anticoagulant medications are commonly used for the prevention and treatment of thromboembolism. Although highly effective, they are also associated with significant bleeding risks. Numerous individual clinical factors have been linked to an increased risk of hemorrhage, including older age, anemia, and renal disease. To help quantify hemorrhage risk for individual patients, a number of clinical risk prediction tools have been developed. These risk prediction tools differ in how they were derived and how they identify and weight individual risk factors. At present, their ability to effective predict anticoagulant-associated hemorrhage remains modest. Use of risk prediction tools to estimate bleeding in clinical practice is most influential when applied to patients at the lower spectrum of thromboembolic risk, when the risk of hemorrhage will more strongly affect clinical decisions about anticoagulation. Using risk tools may also help counsel and inform patients about their potential risk for hemorrhage while on anticoagulants, and can identify patients who might benefit from more careful management of anticoagulation. PMID:23479259

NP-184[2-(5-methyl-2-furyl) benzimidazole], a novel orally active antithrombotic agent with dual antiplatelet and anticoagulant activities.

Science.gov (United States)

Kuo, Heng-Lan; Lien, Jin-Cherng; Chung, Ching-Hu; Chang, Chien-Hsin; Lo, Shyh-Chyi; Tsai, I-Chun; Peng, Hui-Chin; Kuo, Sheng-Chu; Huang, Tur-Fu

2010-06-01

The established antiplatelet and anticoagulant agents show beneficial effects in the treatment of thromboembolic diseases; however, these drugs still have considerable limitations. The effects of NP-184, a synthetic compound, on platelet functions, plasma coagulant activity, and mesenteric venule thrombosis in mice were investigated. NP-184 concentration-dependently inhibited the human platelet aggregation induced by collagen, arachidonic acid (AA), and U46619, a thromboxane (TX)A(2) mimic, with IC(50) values of 4.5 +/- 0.2, 3.9 +/- 0.1, and 9.3 +/- 0.5 microM, respectively. Moreover, NP-184 concentration-dependently suppressed TXA(2) formations caused by collagen and AA. In exploring effects of NP-184 on enzymes involved in TXA(2) synthesis, we found that NP-184 selectively inhibited TXA(2) synthase activity with an IC(50) value of 4.3 +/- 0.2 microM. Furthermore, NP-184 produced a right shift of the concentration-response curve of U46619, indicating a competitive antagonism on TXA(2)/prostaglandin H(2) receptor. Intriguingly, NP-184 also caused a concentration-dependent prolongation of the activated partial thromboplastin time (aPTT) with no changes in the prothrombin and thrombin time, indicating that it selectively impairs the intrinsic coagulation pathway. Oral administration of NP-184 significantly inhibited thrombus formation of the irradiated mesenteric venules in fluorescein sodium-treated mice without affecting the bleeding time induced by tail transection. However, after oral administration, NP-184 inhibited the ex vivo mouse platelet aggregation triggered by collagen and U46619 and also prolonged aPTT. Taken together, the dual antiplatelet and anticoagulant activities of NP-184 may have therapeutic potential as an oral antithrombotic agent in the treatment of thromboembolic disorders.

Transcriptional correlates of disease outcome in anticoagulant-treated non-human primates infected with ebolavirus.

Directory of Open Access Journals (Sweden)

Sara Garamszegi

Full Text Available Ebola virus (EBOV infection in humans and non-human primates (NHPs is highly lethal, and there is limited understanding of the mechanisms associated with pathogenesis and survival. Here, we describe a transcriptomic analysis of NHPs that survived lethal EBOV infection, compared to NHPs that did not survive. It has been previously demonstrated that anticoagulant therapeutics increase the survival rate in EBOV-infected NHPs, and that the characteristic transcriptional profile of immune response changes in anticoagulant-treated NHPs. In order to identify transcriptional signatures that correlate with survival following EBOV infection, we compared the mRNA expression profile in peripheral blood mononuclear cells from EBOV-infected NHPs that received anticoagulant treatment, to those that did not receive treatment. We identified a small set of 20 genes that are highly confident predictors and can accurately distinguish between surviving and non-surviving animals. In addition, we identified a larger predictive signature of 238 genes that correlated with disease outcome and treatment; this latter signature was associated with a variety of host responses, such as the inflammatory response, T cell death, and inhibition of viral replication. Notably, among survival-associated genes were subsets of genes that are transcriptionally regulated by (1 CCAAT/enhancer-binding protein alpha, (2 tumor protein 53, and (3 megakaryoblastic leukemia 1 and myocardin-like protein 2. These pathways merit further investigation as potential transcriptional signatures of host immune response to EBOV infection.

Anticoagulants Influence the Performance of In Vitro Assays Intended for Characterization of Nanotechnology-Based Formulations

Directory of Open Access Journals (Sweden)

Edward Cedrone

2017-12-01

Full Text Available The preclinical safety assessment of novel nanotechnology-based drug products frequently relies on in vitro assays, especially during the early stages of product development, due to the limited quantities of nanomaterials available for such studies. The majority of immunological tests require donor blood. To enable such tests one has to prevent the blood from coagulating, which is usually achieved by the addition of an anticoagulant into blood collection tubes. Heparin, ethylene diamine tetraacetic acid (EDTA, and citrate are the most commonly used anticoagulants. Novel anticoagulants such as hirudin are also available but are not broadly used. Despite the notion that certain anticoagulants may influence assay performance, a systematic comparison between traditional and novel anticoagulants in the in vitro assays intended for immunological characterization of nanotechnology-based formulations is currently not available. We compared hirudin-anticoagulated blood with its traditional counterparts in the standardized immunological assay cascade, and found that the type of anticoagulant did not influence the performance of the hemolysis assay. However, hirudin was more optimal for the complement activation and leukocyte proliferation assays, while traditional anticoagulants citrate and heparin were more appropriate for the coagulation and cytokine secretion assays. The results also suggest that traditional immunological controls such as lipopolysaccharide (LPS are not reliable for understanding the role of anticoagulant in the assay performance. We observed differences in the test results between hirudin and traditional anticoagulant-prepared blood for nanomaterials at the time when no such effects were seen with traditional controls. It is, therefore, important to recognize the advantages and limitations of each anticoagulant and consider individual nanoparticles on a case-by-case basis.

MARINE LEECH ANTICOAGULANT DIVERSITY AND EVOLUTION.

Science.gov (United States)

Tessler, Michael; Marancik, David; Champagne, Donald; Dove, Alistair; Camus, Alvin; Siddall, Mark E; Kvist, Sebastian

2018-03-16

Leeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and feed on host groups (e.g., sharks) not encountered by their freshwater and terrestrial counterparts. Moreover, some species of Ozobranchidae feed on endangered marine turtles and have been implicated as potential vectors for the tumor-associated turtle herpesvirus. In spite of their ecological importance and unique host associations, there is a distinct paucity of data regarding the salivary transcriptomes of either of these families. Using next generation sequencing, we profiled transcribed, putative anticoagulants and other salivary bioactive compounds that have previously been linked to bloodfeeding from 7 piscicolid species (3 elasmobranch-feeders; 4 non-cartilaginous fish-feeders) and 1 ozobranchid species (2 samples). In total, 149 putative anticoagulants and bioactive loci were discovered in varying constellations throughout the different samples. The putative anticoagulants showed a broad spectrum of described antagonistic pathways, such as inhibition of factor Xa and platelet aggregation, that likely have similar bioactive roles in marine fish and turtles. A transcript with homology to ohanin, originally isolated from king cobras, was found in Cystobranchus vividus but is otherwise unknown from leeches. Estimation of selection pressures for the putative anticoagulants recovered evidence for both positive and purifying selection along several isolated branches in the gene trees and positive selection was also estimated for a few select codons in a variety of marine species. Similarly, phylogenetic analyses of the amino acid sequences for several anticoagulants indicated divergent evolution.

In Vitro Antioxidant, Anticoagulant and Antimicrobial Activity and in Inhibition of Cancer Cell Proliferation by Xylan Extracted from Corn Cobs

Science.gov (United States)

Melo-Silveira, Raniere Fagundes; Fidelis, Gabriel Pereira; Costa, Mariana Santana Santos Pereira; Telles, Cinthia Beatrice Silva; Dantas-Santos, Nednaldo; de Oliveira Elias, Susana; Ribeiro, Vanessa Bley; Barth, Afonso Luis; Macedo, Alexandre José; Leite, Edda Lisboa; Rocha, Hugo Alexandre Oliveira

2012-01-01

Xylan is one of most abundant polymer after cellulose. However, its potential has yet to be completely recognized. Corn cobs contain a considerable reservoir of xylan. The aim of this work was to study some of the biological activities of xylan obtained from corn cobs after alkaline extraction enhanced by ultrasonication. Physical chemistry and infrared analyses showed 130 kDa heteroxylan containing mainly xylose:arabinose: galactose:glucose (5.0:1.5:2.0:1.2). Xylan obtained exhibited total antioxidant activity corresponding to 48.5 mg of ascorbic acid equivalent/g of xylan. Furthermore, xylan displayed high ferric chelating activity (70%) at 2 mg/mL. Xylan also showed anticoagulant activity in aPTT test. In antimicrobial assay, the polysaccharide significantly inhibited bacterial growth of Klebsiella pneumoniae. In a test with normal and tumor human cells, after 72 h, only HeLa tumor cell proliferation was inhibited (p < 0.05) in a dose-dependent manner by xylan, reaching saturation at around 2 mg/mL, whereas 3T3 normal cell proliferation was not affected. The results suggest that it has potential clinical applications as antioxidant, anticoagulant, antimicrobial and antiproliferative compounds. PMID:22312261

Antibacterial, cytotoxicity and anticoagulant activities from Hypnea esperi and Caulerpa prolifera marine algae.

Science.gov (United States)

Selim, Samy; Amin, Abeer; Hassan, Sherif; Hagazey, Mohamed

2015-03-01

Extracts from 2 algal species (Hypnea esperi and Caulerpa prolifera) from Suez Canal region, Egypt were screened for the production of antibacterial compounds against some pathogenic bacteria. The bacteria tested included Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Aeromonas hydrophila, Bacillus subtilis and Staphylococcus aureus. Algal species displayed antibacterial activity. The methanolic extracts showed variable response by producing various zones of inhibition against studied bacteria. The tested Gram-negative bacteria were less affected by studied algal extracts than Gram-positive bacteria. We determined some biopotentials properties such as cytotoxicity and anticoagulant activity of most potent algal active extracts. The secondary metabolites of only Hypnea esperi algal extract effectively prevented the blood clotting to the extent of 120 seconds. Minimum inhibitory concentration (MIC) indicated that all potent tested algal extract C inhibits Bacillus subtilis and Staphylococcus aureus. Minimum bactericidal concentration (MBC) was between 1 and 1.4mg/ml. The algal isolates from Egypt have been found showing promising results against infectious bacteria instead of some synthetic antibiotics.

Anticoagulated patient's perception of their illness, their beliefs about the anticoagulant therapy prescribed and the relationship with adherence: impact of novel oral anticoagulant therapy - study protocol for The Switching Study: a prospective cohort study.

Science.gov (United States)

Auyeung, Vivian; Patel, Jignesh P; Abdou, John K; Vadher, Bipin; Bonner, Lynda; Brown, Alison; Roberts, Lara N; Patel, Raj K; Arya, Roopen

2016-01-01

Anticoagulant therapy is prescribed for millions of patients worldwide for the prevention and treatment of both arterial and venous thrombosis. Historically, only vitamin K antagonists have been available for clinicians to prescribe. The anticoagulation landscape is changing. The recent availability of the novel oral anticoagulants overcome many of the disadvantages associated with vitamin K antagonists. However the lack of formal monitoring and clinic follow-up is a concern for clinicians, as medication adherence is being assumed, which is known to decline in patients prescribed medications for chronic conditions. The switching study is a programme of work investigating the association between medication adherence and patient's beliefs about anticoagulation therapy (warfarin and subsequently novel oral anticoagulants), together with beliefs about their illness and anticoagulation related quality of life. The anticoagulation database at King's College Hospital will be interrogated and two groups of patients will be identified; those with a time in therapeutic range on warfarin of ≥75 % and those beliefs about medications compared. Those patients in the time in therapeutic range beliefs about medications, re-evaluated on the novel agent. The results from these sub-studies, will inform a clinical pathway to support patients on these novel agents, which will be evaluated in an independent group of patients. The results from the switching study will be used to develop a clinical pathway to support patient's prescribed novel oral anticoagulant therapy long-term.

Survey of Botulinum Toxin Injections in Anticoagulated Patients: Korean Physiatrists' Preference in Controlling Anticoagulation Profile Prior to Intramuscular Injection.

Science.gov (United States)

Jang, Yongjun; Park, Geun-Young; Park, Jihye; Choi, Asayeon; Kim, Soo Yeon; Boulias, Chris; Phadke, Chetan P; Ismail, Farooq; Im, Sun

2016-04-01

To evaluate Korean physiatrists' practice of performing intramuscular botulinum toxin injection in anticoagulated patients and to assess their preference in controlling the bleeding risk before injection. As part of an international collaboration survey study, a questionnaire survey was administered to 100 Korean physiatrists. Physiatrists were asked about their level of experience with botulinum toxin injection, the safe international normalized ratio range in anticoagulated patients undergoing injection, their tendency for injecting into deep muscles, and their experience of bleeding complications. International normalized ratio injection by 41% of the respondents. Thirty-six respondents replied that the international normalized ratio should be lowered to sub-therapeutic levels before injection, and 18% of the respondents reported that anticoagulants should be intentionally withheld and discontinued prior to injection. In addition, 20%-30% of the respondents answered that they were uncertain whether they should perform the injection regardless of the international normalized ratio values. About 69% of the respondents replied that they did have any standardized protocols for performing botulinum toxin injection in patients using anticoagulants. Only 1 physiatrist replied that he had encountered a case of compartment syndrome. In accordance with the lack of consensus in performing intramuscular botulinum toxin injection in anticoagulated patients, our survey shows a wide range of practices among many Korean physiatrists; they tend to avoid botulinum toxin injection in anticoagulated patients and are uncertain about how to approach these patients. The results of this study emphasize the need for formulating a proper international consensus on botulinum toxin injection management in anticoagulated patients.

The pharmacology of recombinant hirudin, a new anticoagulant ...

African Journals Online (AJOL)

A new anticoagulant, recombinant hirudin, was given to healthy volunteers (5 per test dose) in single .intravenous doses of 0,01, 0,02, 0,04, 0,07 and 0,1 mg/kg to study its anticoagulant effects, how it was tolerated and its pharmacokinetics. Hirudin proved to be a potent anticoagulant with important effects on thrombin ...

Improvement in long-term ECMO by detailed monitoring of anticoagulation: a case report.

Science.gov (United States)

Sievert, Alicia; Uber, Walter; Laws, Stacey; Cochran, Joel

2011-01-01

The use of unfractionated heparin (UFH) as an anticoagulant during long-term extracorporeal support presents a unique challenge for the clinician in balancing the amount of anticoagulant to maintain adequate anticoagulation without causing excessive bleeding. Activated clotting times (ACT) and activated partial thromboplastin times (aPTT) are the most common modality to monitor UFH on extracorporeal membrane oxygenation (ECMO). Limitations to these tests include consumptive coagulopathies, clotting factor deficiencies, platelet dysfunction, and fibrinolysis. The following case report describes the use of alternative monitoring strategies to assess more accurately anticoagulation during ECMO. A 20-month-old female presented to the emergency department with a 5-6 day history of cough, fever, tachypnea, and respiratory distress. She was diagnosed with influenza A and B with pneumonia. The patient was placed on veno-venous ECMO (V-V ECMO) after mechanical ventilation failed. On ECMO day eight, the patient developed a thrombus in her inferior vena cava and pleural effusions, obstructing cannula flow. Laboratory tests revealed the ACT was within range, yet the aPTT was dropping, despite increased heparin. Heparin levels were low and antithrombin-III (AT) concentrations were 40%. Recombinant AT was given and subsequent aPTTs were within the therapeutic range. Later, the aPTT decreased to 475 mg/ dL, and Factor VIII >150 IU/dL, suggesting an acute phase reaction or ongoing systemic inflammation, increasing the risk for thrombosis. We maintained heparin assays between 0.5-0.7 IU/mL and AT >60% to assure heparin's effect. The patient showed no signs of excess bleeding, blood product administration, or clots in the circuit, suggesting proper anticoagulation. The patient was successfully weaned on day 33 and is currently alive and at home. Monitoring of anti-Xa UFH and AT proved effective for measuring anticoagulation and detecting inconsistencies in other anticoagulation

Activated protein C (APC) can increase bone anabolism via a protease-activated receptor (PAR)1/2 dependent mechanism.

Science.gov (United States)

Shen, Kaitlin; Murphy, Ciara M; Chan, Ben; Kolind, Mille; Cheng, Tegan L; Mikulec, Kathy; Peacock, Lauren; Xue, Meilang; Park, Sang-Youel; Little, David G; Jackson, Chris J; Schindeler, Aaron

2014-12-01

Activated Protein C (APC) is an anticoagulant with strong cytoprotective properties that has been shown to promote wound healing. In this study APC was investigated for its potential orthopedic application using a Bone Morphogenetic Protein 2 (rhBMP-2) induced ectopic bone formation model. Local co-administration of 10 µg rhBMP-2 with 10 µg or 25 µg APC increased bone volume at 3 weeks by 32% (N.S.) and 74% (pAPC are largely mediated by its receptors endothelial protein C receptor (EPCR) and protease-activated receptors (PARs). Cultured pre-osteoblasts and bone nodule tissue sections were shown to express PAR1/2 and EPCR. When pre-osteoblasts were treated with APC, cell viability and phosphorylation of ERK1/2, Akt, and p38 were increased. Inhibition with PAR1 and sometimes PAR2 antagonists, but not with EPCR blocking antibodies, ameliorated the effects of APC on cell viability and kinase phosphorylation. These data indicate that APC can affect osteoblast viability and signaling, and may have in vivo applications with rhBMP-2 for bone repair. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles

International Nuclear Information System (INIS)

Degoutin, S; Jimenez, M; Casetta, M; Bellayer, S; Chai, F; Blanchemain, N; Neut, C; Kacem, I; Traisnel, M; Martel, B

2012-01-01

The aim of this work is to prepare non-woven polypropylene (PP) textile functionalized with bioactive molecules in order to improve its anticoagulation and antibacterial properties. This paper describes the optimization of the grafting process of acrylic acid (AA) on low-pressure cold-plasma pre-activated PP, the characterization of the modified substrates and the effect of these modifications on the in vitro biological response towards cells. Then, the immobilization of gentamicin (aminoglycoside antibiotic) and heparin (anticoagulation agent) has been carried out on the grafted samples by either ionic interactions or covalent linkages. Their bioactivity has been investigated and related to the nature of their interactions with the substrate. For gentamicin-immobilized AA-grafted samples, an inhibition radius and a reduction of 99% of the adhesion of Escherichia coli have been observed when gentamicin was linked by ionic interactions, allowing the release of the antibiotic. By contrast, for heparin-immobilized AA-grafted PP samples, a strong increase of the anticoagulant effect up to 35 min has been highlighted when heparin was covalently bonded on the substrate, by contact with the blood drop. (paper)

Anti-thrombin III, Protein C, and Protein S deficiency in acute coronary syndrome

Directory of Open Access Journals (Sweden)

Dasnan Ismail

2002-06-01

Full Text Available The final most common pathway for the majority of coronary artery disease is occlusion of a coronary vessel. Under normal conditions, antithrombin III (AT III, protein C, and protein S as an active protein C cofactor, are natural anticoagulants (hemostatic control that balances procoagulant activity (thrombin antithrombin complex balance to prevent thrombosis. If the condition becomes unbalanced, natural anticoagulants and the procoagulants can lead to thrombosis. Thirty subjects with acute coronary syndrome (ACS were studied for the incidence of antithrombin III (AT III, protein C, and protein S deficiencies, and the result were compare to the control group. Among patients with ACS, the frequency of distribution of AT-III with activity < 75% were 23,3% (7 of 30, and only 6,7% ( 2 of 30 in control subject. No one of the 30 control subject have protein C activity deficient, in ACS with activity < 70% were 13,3% (4 of 30. Fifteen out of the 30 (50% control subjects had protein S activity deficiency, while protein S deficiency activity < 70% was found 73.3.% (22 out of 30. On linear regression, the deterministic coefficient of AT-III activity deficiency to the development ACS was 13,25 %, and the deterministic coefficient of protein C activity deficient to the development of ACS was 9,06 %. The cut-off point for AT-III without protein S deficiency expected to contribute to the development of vessel disease was 45%. On discriminant analysis, protein C activity deficiency posed a risk for ACS of 4,5 greater than non deficient subjects, and AT-III activity deficiency posed a risk for ACS of 3,5 times greater than non deficient subjects. On binary logistic regression, protein S activity acted only as a reinforcing factor of AT-III activity deficiency in the development of ACS. Protein C and AT III deficiency can trigger ACS, with determinant coefficients of 9,06% and 13,25% respectively. Low levels of protein C posed a greater risk of

D-dimer: a useful tool in gauging optimal duration of oral anticoagulant therapy?

Directory of Open Access Journals (Sweden)

M. Silingardi

2013-05-01

Full Text Available BACKGROUND AND AIM OF THE STUDY Optimal duration of oral anticoagulant therapy (OAT in idiopathic venous thromboembolism (VTE is unknown. Indefinite OAT carries an unacceptable risk of major bleeding and prospective studies have demonstrated that OAT is no longer protective after its withdrawal. How to identify the patients at risk for recurrence? D-dimer is a marker of thrombin activity. Early prospective studies showed that elevated D-dimer levels after anticoagulation had a highly predictive value for a recurrent episode. Does D-dimer assay have a role in gauging the appropriate duration of anticoagulant therapy? The PROLONG study tries to answer this question. METHOD D-dimer assay was performed one month after stopping anticoagulation. Patiens with normal D-dimer levels did not resume anticoagulation while patients with elevated D-dimer levels were randomized to discontinue or resume anticoagulation. Study end-points was the composite of recurrent VTE and major bleeding during an average follow-up of 1.4 years. RESULTS The rate of recurrence is significantly higher in patients with elevated D-dimer levels who discontinued anticoagulation. Resuming anticoagulation in this cohort of patients markedly reduces recurrent events without increasing major bleeding. DISCUSSION AND CONCLUSIONS PROLONG study is provocative, because D-dimer assay is simple, thus not requiring dedicated laboratory facilities. D-dimer test has otherwise high sensitivity but low specificity in VTE diagnosis. Aspecifically elevated D-dimer levels are available in the elderly and the majority of patients included in the study were > 65 years old, thus introducing a possible selection bias. Nonetheless the results of the study are useful for the clinician. Prolongation of vitamin K antagonists in patients with elevated D-dimer levels one month after discontinuation of OAT for a first unprovoked episode of VTE results in a favourable risk-benefit relationship. Probably this

Direct Oral Anticoagulants: An Overview for the Interventional Radiologist

Energy Technology Data Exchange (ETDEWEB)

Kumar, Pradesh, E-mail: pradeshkumar@doctors.org.uk; Ravi, Rajeev, E-mail: rajeev.ravi@aintree.nhs.uk; Sundar, Gaurav, E-mail: gaurav.sundar@aintree.nhs.uk [Aintree University Hospitals NHS Foundation Trust, Radiology Department (United Kingdom); Shiach, Caroline, E-mail: caroline.shiach@aintree.nhs.uk [Aintree University Hospitals NHS Foundation Trust, Haematology Department (United Kingdom)

2017-03-15

The direct oral anticoagulants (DOACs) have emerged as a good alternative for the treatment of thromboembolic diseases, and their use in clinical practice is increasing rapidly. The DOACs act by blocking the activity of one single step in the coagulation cascade. These drugs act downstream in the common pathway of the coagulation cascade by directly antagonising the action of thrombin or factor Xa. The development of DOACs represents a paradigm shift from the oral vitamin K antagonists such as warfarin. This article aims to describe the properties of the currently available DOACs including pharmacology and dosing. We also address the strategies for periprocedural management and reversal of anticoagulation of patients treated with these agents.

Direct Oral Anticoagulants: An Overview for the Interventional Radiologist

International Nuclear Information System (INIS)

Kumar, Pradesh; Ravi, Rajeev; Sundar, Gaurav; Shiach, Caroline

2017-01-01

The direct oral anticoagulants (DOACs) have emerged as a good alternative for the treatment of thromboembolic diseases, and their use in clinical practice is increasing rapidly. The DOACs act by blocking the activity of one single step in the coagulation cascade. These drugs act downstream in the common pathway of the coagulation cascade by directly antagonising the action of thrombin or factor Xa. The development of DOACs represents a paradigm shift from the oral vitamin K antagonists such as warfarin. This article aims to describe the properties of the currently available DOACs including pharmacology and dosing. We also address the strategies for periprocedural management and reversal of anticoagulation of patients treated with these agents.

The lectin-like domain of thrombomodulin confers protection from neutrophil-mediated tissue damage by suppressing adhesion molecule expression via nuclear factor kappaB and mitogen-activated protein kinase pathways

NARCIS (Netherlands)

Conway, Edward M.; van de Wouwer, Marlies; Pollefeyt, Saskia; Jurk, Kerstin; van Aken, Hugo; de Vriese, Astrid; Weitz, Jeffrey I.; Weiler, Hartmut; Hellings, Peter W.; Schaeffer, Paul; Herbert, Jean-Marc; Collen, Désiré; Theilmeier, Gregor

2002-01-01

Thrombomodulin (TM) is a vascular endothelial cell (EC) receptor that is a cofactor for thrombin-mediated activation of the anticoagulant protein C. The extracellular NH(2)-terminal domain of TM has homology to C-type lectins that are involved in immune regulation. Using transgenic mice that lack

Evaluation of hematuria in anticoagulated patients

International Nuclear Information System (INIS)

Cuttino, J.T.; Clark, R.L.

1986-01-01

To determine the efficacy of investigating hematuria in anticoagulated patients the authors examined records of 25 consecutive patients with hematuria who were on an anticoagulation regimen with sodium warfarin (Coumadin) for various thromboembolic disorders. All had undergone intravenous urography (IVU) and 12 had undergone cystoscopy. Potential bleeding sources were discovered in 14 patients by IVU and in seven patients by cystoscopy. Disorders found were renal stones (4), transitional carcinoma (1), lymphoma (1), retroperitoneal hematoma (1), bladder tumors (2), calcified renal mass (1), hemorrhagic cystitis (2), and enlarged prostate (7). In 18 (72%) patients, the findings on IVU and/or cystoscopy were abnormal. Hematuria is a serious symptom that warrants investigation in anticoagulated as well as nonanticoagulated patients

Aneurysmal subarachnoid hemorrhage in patients taking direct oral anticoagulants: A case series and discussion of management

Directory of Open Access Journals (Sweden)

Joseph H. McMordie, MD

2018-03-01

Full Text Available Direct oral anticoagulants are becoming more commonplace for the treatment of nonvalvular atrial fibrillation and deep vein thrombosis. Unfortunately, effective reversal agents are not widely available limiting options for neurosurgical intervention during active anticoagulation. We report a case series of 3 patients treated for aneurysmal subarachnoid hemorrhage while taking direct oral anticoagulants. All three underwent open surgical clipping after adequate time was allowed for drug metabolism. Decision-making must take into account timing of intervention, drug half-life, and currently available reversal agents.

Anticoagulation knowledge in patients with atrial fibrillation: An Australian survey.

Science.gov (United States)

Obamiro, Kehinde O; Chalmers, Leanne; Lee, Kenneth; Bereznicki, Bonnie J; Bereznicki, Luke R E

2018-03-01

Atrial fibrillation (AF) is the most commonly diagnosed arrhythmia in clinical practice, and is associated with a significant medical and economic burden. Anticoagulants reduce the risk of stroke and systemic embolism by approximately two-thirds compared with no therapy. Knowledge regarding anticoagulant therapy can influence treatment outcomes in patients with AF. To measure the level of anticoagulation knowledge in patients with AF taking oral anticoagulants (OACs), investigate the association between patient-related factors and anticoagulation knowledge, and compare these results in patients taking warfarin and direct-acting oral anticoagulant (DOACs). Participants were recruited for an online survey via Facebook. Survey components included the Anticoagulation Knowledge Tool, the Perception of Anticoagulant Treatment Questionnaires (assessing treatment expectations, convenience and satisfaction), a modified Cancer Information Overload scale and the Morisky Medication Adherence Scale. Treatment groups were compared and predictors of OAC knowledge were identified. Participants taking warfarin had a higher knowledge score compared with those taking DOACs (n = 386, 73% ± 13% vs 66% ± 14%, Pcounselling sessions to help identify and resolve knowledge deficits. © 2018 John Wiley & Sons Ltd.

Evidence-Based Management of Anticoagulant Therapy

Science.gov (United States)

Schulman, Sam; Witt, Daniel M.; Vandvik, Per Olav; Fish, Jason; Kovacs, Michael J.; Svensson, Peter J.; Veenstra, David L.; Crowther, Mark; Guyatt, Gordon H.

2012-01-01

Background: High-quality anticoagulation management is required to keep these narrow therapeutic index medications as effective and safe as possible. This article focuses on the common important management questions for which, at a minimum, low-quality published evidence is available to guide best practices. Methods: The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement. Results: Most practical clinical questions regarding the management of anticoagulation, both oral and parenteral, have not been adequately addressed by randomized trials. We found sufficient evidence for summaries of recommendations for 23 questions, of which only two are strong rather than weak recommendations. Strong recommendations include targeting an international normalized ratio of 2.0 to 3.0 for patients on vitamin K antagonist therapy (Grade 1B) and not routinely using pharmacogenetic testing for guiding doses of vitamin K antagonist (Grade 1B). Weak recommendations deal with such issues as loading doses, initiation overlap, monitoring frequency, vitamin K supplementation, patient self-management, weight and renal function adjustment of doses, dosing decision support, drug interactions to avoid, and prevention and management of bleeding complications. We also address anticoagulation management services and intensive patient education. Conclusions: We offer guidance for many common anticoagulation-related management problems. Most anticoagulation management questions have not been adequately studied. PMID:22315259

Anticoagulant activity of sulfated polysaccharides fractions from an aqueous extract obtained from the red seaweed Halymenia floresia (Clemente C. Agardh - doi: 10.4025/actascitechnol.v33i4.9143

Directory of Open Access Journals (Sweden)

José Ariévilo Gurgel Rodrigues

2011-09-01

Full Text Available Heparin (HEP is known due to their side effects and the red seaweed Halymenia floresia (Hf sulfated polysaccharides (SP are heparinoids. In this study we purified the Hf-SP obtained from an aqueous extract and evaluated their anticoagulant activities. Hf-SP1 (25°C, Hf-SP2 (80°C and Hf-SP3 (80°C were sequentially isolated. Hf-SP3 had the highest sulfate content (37.45%. Hf-SP3 was fractionated by ion exchange chromatography on a DEAE-cellulose column using a NaCl gradient. Fractions were lyophilized and submitted to 0.5% agarose gel electrophoresis. The anticoagulant activity was evaluated by the activated partial thromboplastin time using rabbits plasma and expressed in international units per mg of SP using standard HEP (193 IU mg-1. The chromatographic procedure separated into four different SP fractions (F I, F II, F III and F IV eluted at concentrations of 0.50, 0.75, 1.00 and 1.25 M of NaCl, respectively, reveling among them different marked on charge density, when compared by electrophoresis. F III had the highest anticoagulant activity (10.72 IU mg-1, suggesting that the sulfate is important in this process. In conclusion, our results suggest that sequential extractions of Hf-SP are an important biotechnological tool for identification of novel anticoagulants and studies of structural characterization are already in progress.

Andexanet alfa effectively reverses edoxaban anticoagulation effects and associated bleeding in a rabbit acute hemorrhage model

Science.gov (United States)

Lu, Genmin; Pine, Polly; Leeds, Janet M.; DeGuzman, Francis; Pratikhya, Pratikhya; Lin, Joyce; Malinowski, John; Hollenbach, Stanley J.; Curnutte, John T.

2018-01-01

Introduction Increasing use of factor Xa (FXa) inhibitors necessitates effective reversal agents to manage bleeding. Andexanet alfa, a novel modified recombinant human FXa, rapidly reverses the anticoagulation effects of direct and indirect FXa inhibitors. Objective To evaluate the ability of andexanet to reverse anticoagulation in vitro and reduce bleeding in rabbits administered edoxaban. Materials and methods In vitro studies characterized the interaction of andexanet with edoxaban and its ability to reverse edoxaban-mediated anti-FXa activity. In a rabbit model of surgically induced, acute hemorrhage, animals received edoxaban vehicle+andexanet vehicle (control), edoxaban (1 mg/kg)+andexanet vehicle, edoxaban+andexanet (75 mg, 5-minute infusion, 20 minutes after edoxaban), or edoxaban vehicle+andexanet prior to injury. Results Andexanet bound edoxaban with high affinity similar to FXa. Andexanet rapidly and dose-dependently reversed the effects of edoxaban on FXa activity and coagulation pharmacodynamic parameters in vitro. In edoxaban-anticoagulated rabbits, andexanet reduced anti-FXa activity by 82% (from 548±87 to 100±41 ng/ml; P<0.0001), mean unbound edoxaban plasma concentration by ~80% (from 100±10 to 21±6 ng/ml; P<0.0001), and blood loss by 80% vs. vehicle (adjusted for control, 2.6 vs. 12.9 g; P = 0.003). The reduction in blood loss correlated with the decrease in anti-FXa activity (r = 0.6993, P<0.0001) and unbound edoxaban (r = 0.5951, P = 0.0035). Conclusion These data demonstrate that andexanet rapidly reversed the anticoagulant effects of edoxaban, suggesting it could be clinically valuable for the management of acute and surgery-related bleeding. Correlation of blood loss with anti-FXa activity supports the use of anti-FXa activity as a biomarker for assessing anticoagulation reversal in clinical trials. PMID:29590221

Study on extraction of agaropectin from Gelidium amansii and its anticoagulant activity

Science.gov (United States)

Qi, Huimin; Li, Daxin; Zhang, Jingjing; Liu, Li; Zhang, Quanbin

2008-05-01

Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially. The yields of 1.0 mol/L NaCl fraction and 2.5 mol/L NaCl fraction were 2.80% and 2.03%. They are highly sulfated agar, and named as agaropectin with sulfate content being 22.8% and 32.5%, respectively. The anticoagulant experiment results show that agaropectin could effectively prolong the coagulation time in a dose-dependent manner in vitro. Agaropection could be absorbed and effectively prolong the plasma coagulation time in vivo. After intragastric administration at the doses of 100, 200, and 400 mg/kg·d in rats for 15 days, TT (thrombin time), CT (coagulation time), PT (prothrombin time), and APTT (activated partial thromboplastin time) could be effectively prolonged and the plasma Fib level could be significantly lowered.

Fabrication of anticoagulation layer on titanium surface by sequential immobilization of poly (ethylene glycol) and albumin.

Science.gov (United States)

Pan, Chang-Jiang; Hou, Yan-Hua; Zhang, Bin-Bin; Zhang, Lin-Cai

2014-01-01

This paper presents a simple method to sequentially immobilize poly (ethylene glycol) (PEG) and albumin on titanium surface to enhance the blood compatibility. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis indicated that PEG and albumin were successfully immobilized on the titanium surface. Water contact angle results showed a better hydrophilic surface after the immobilization. The immobilized PEG or albumin can not only obviously prevent platelet adhesion and activation but also prolong activated partial thromboplastin time (APTT), leading to the improved anticoagulation. Moreover, immobilization of albumin on PEG-modified surface can further improve the anticoagulation. The approach in the present study provides an effective and efficient method to improve the anticoagulation of blood-contact biomedical devices such as coronary stents.

Percutaneous Occlusion of the Left Atrial Appendage with the Watchman Device in an Active Duty Sailor with Atrial Fibrillation and Recurrent Thromboembolism Despite Appropriate Use of Oral Anticoagulation.

Science.gov (United States)

Cox, Justin M; Choi, Anthony J; Oakley, Luke S; Francisco, Gregory M; Nayak, Keshav R

2018-05-23

Atrial fibrillation is the most common significant cardiac arrhythmia and is associated with a five-fold increased risk of stroke from thromboembolism. Over 94% of these emboli arise from the left atrial appendage. Systemic embolic phenomena are rare, accounting for less than 1 out of 10 of all embolic events, but have a similar prevention strategy. Anticoagulation significantly reduces the risk of these events, and thus forms the cornerstone of therapy for most patients with atrial fibrillation. Left atrial appendage occlusion with the Watchman device is a recently approved alternative for stroke prevention in selected patients. We present a case of an active duty U.S. Navy sailor at low risk for thromboembolism who nonetheless suffered recurrent thromboembolic events despite appropriate anticoagulation, and thus underwent Watchman implantation. The therapy in this case will ideally provide a lifetime of protection from recurrent systemic embolization while allowing the patient to continue his active duty military career without restriction due to oral anticoagulation.

Risk of gastrointestinal bleeding during anticoagulant treatment.

Science.gov (United States)

Lanas-Gimeno, Aitor; Lanas, Angel

2017-06-01

Gastrointestinal bleeding (GIB) is a major problem in patients on oral anticoagulation therapy. This issue has become even more pressing since the introduction of direct oral anticoagulants (DOACs) in 2009. Areas covered: Here we review current evidence related to GIB associated with oral anticoagulants, focusing on randomized controlled trials, meta-analyses, and post-marketing observational studies. Dabigatran 150 mg twice daily and rivaroxaban 20 mg once daily increase the risk of GIB compared to warfarin. The risk increase with edoxaban is dose-dependent, while apixaban shows apparently, no increased risk. We summarize what is known about GIB risk factors for individual anticoagulants, the location of GIB in patients taking these compounds, and prevention strategies that lower the risk of GIB. Expert opinion: Recently there has been an important shift in the clinical presentation of GIB. Specifically, upper GIB has decreased with the decreased incidence of peptic ulcers due to the broad use of proton pump inhibitors and the decreased prevalence of H. pylori infections. In contrast, the incidence of lower GIB has increased, due in part to colonic diverticular bleeding and angiodysplasia in the elderly. In this population, the addition of oral anticoagulation therapy, especially DOACs, seems to increase the risk of lower GIB.

Anticoagulant activity of a sulfated polysaccharide isolated from the green seaweed Caulerpa cupressoides

Directory of Open Access Journals (Sweden)

José Ariévilo Gurgel Rodrigues

2011-08-01

Full Text Available The aim of this study was to evaluate certain molecular characteristics of a sulfated polysaccharide (SPs with anticoagulant properties, isolated from Caulerpa cupressoides (Chlorophyta. Crude SPs were extracted by proteolytic digestion (papain, followed by ion-exchange chromatography on a DEAE-cellulose column. The fractions obtained were analyzed for molecular mass, 0.5% agarose gel electrophoresis and chemical composition. The activated partial thromboplastin time (APTT test was applied using normal human plasma and standard heparin (HEP (193 IU mg-1. The yield was ~ 3%, and the chromatography procedure separated the material into three different SP fractions (F I, F II and F III, eluted at the concentrations of 0.50, 0.75 and 1.00 M of NaCl, respectively. Only fraction F II was active (24.62 IU mg-1, with high sulfate content (23.79% and number of molecular mass peaks. Therefore, the APTT of a fraction isolated from C. cupressoides was less potent than HEP.

[Pathogenesis and Laboratory Findings in Antiphospholipid Syndrome, Especially Associated with Lupus Anticoagulant].

Science.gov (United States)

Ieko, Masahiro; Naito, Sumiyoshi; Yoshida, Mika; Takahashi, Nobuhiko

2015-10-01

Antiphospholipid syndrome (APS), an acquired thrombotic condition, is a complex clinical state characterized by the presence of circulating antiphospholipid antibodies in patients with thrombosis or pregnancy morbidity. Revised APS classification criteria are used for diagnosis, which include at least one clinical criterion (thrombosis or pregnancy loss) and at least one of the laboratory criteria [anticardiolipin antibodies, anti-β2GPI antibodies, lupus anticoagulant (LA)]. LA is also an independent risk factor for developing thrombosis, though some LA-positive cases have been reported to have a bleeding symptom. Lupus anticoagulant-hypoprothrombinemia syndrome (LAHPS) is a rare disorder characterized by a bleeding tendency due to low prothrombin activity in patients with LA, and has recently been reported not only in children but also in adults We have encountered LA cases with bleeding and low coagulation factor activities except for prothrombin. Based on our findings, we propose that LA-positive cases with a bleeding symptom and characterized by low coagulation factor activity including prothrombin be termed lupus anticoagulant-associated coagulopathy (LAAC). Furthermore, coagulation factor autoantibodies are often detected in LAAC patients; thus, correct measurement of LA is important to distinguish LAAC patients from those possessing an inhibitor to coagulation factors such as acquired hemophilia A as well as to select the optimal therapeutic strategy.

Postpartum wound and bleeding complications in women who received peripartum anticoagulation.

Science.gov (United States)

Limmer, Jane S; Grotegut, Chad A; Thames, Elizabeth; Dotters-Katz, Sarah K; Brancazio, Leo R; James, Andra H

2013-07-01

The objective of this study was to compare wound and bleeding complications between women who received anticoagulation after cesarean delivery due to history of prior venous thromboembolic disease, arterial disease, or being a thrombophilia carrier with adverse pregnancy outcome, to women not receiving anticoagulation. Women in the Duke Thrombosis Center Registry who underwent cesarean delivery during 2003-2011 and received postpartum anticoagulation (anticoagulation group, n=77), were compared with a subset of women who delivered during the same time period, but did not receive anticoagulation (no anticoagulation group, n=77). The no anticoagulation group comprised women who were matched to the anticoagulation group by age, body mass index, type of cesarean (no labor vs. labor), and date of delivery. Bleeding and wound complications were compared between the two groups. A multivariable logistic regression model was constructed to determine if anticoagulation was an independent predictor of wound complication. Women who received anticoagulation during pregnancy had a greater incidence of wound complications compared to those who did not (30% vs. 8%, p<0.001). Using multivariable logistic regression, while controlling for race, diabetes, chorioamnionitis, and aspirin use, anticoagulation predicted the development of any wound complication (OR 5.8, 95% CI 2.2, 17.6), but there were no differences in the mean estimated blood loss at delivery (782 vs. 778 ml, p=0.91), change in postpartum hematocrit (5.4 vs. 5.2%, p=0.772), or percent of women receiving blood products (6.5 vs. 1.3%, p=0.209) between the two groups. Anticoagulation following cesarean delivery is associated with an increased risk of post-cesarean wound complications, but not other postpartum bleeding complications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modulation of protein C activation by histones, platelet factor 4, and heparinoids: new insights into activated protein C formation.

Science.gov (United States)

Kowalska, M Anna; Zhao, Guohua; Zhai, Li; David, George; Marcus, Stephen; Krishnaswamy, Sriram; Poncz, Mortimer

2014-01-01

Histones are detrimental in late sepsis. Both activated protein C (aPC) and heparin can reverse their effect. Here, we investigated whether histones can modulate aPC generation in a manner similar to another positively charged molecule, platelet factor 4, and how heparinoids (unfractionated heparin or oxygen-desulfated unfractionated heparin with marked decrease anticoagulant activity) may modulate this effect. We measured in vitro and in vivo effects of histones, platelet factor 4, and heparinoids on aPC formation, activated partial thromboplastin time, and murine survival. In vitro, histones and platelet factor 4 both affect thrombin/thrombomodulin aPC generation following a bell-shaped curve, with a peak of >5-fold enhancement. Heparinoids shift these curves rightward. Murine aPC generation studies after infusions of histones, platelet factor 4, and heparinoids supported the in vitro data. Importantly, although unfractionated heparin and 2-O, 3-O desulfated heparin both reversed the lethality of high-dose histone infusions, only mice treated with 2-O, 3-O desulfated heparin demonstrated corrected activated partial thromboplastin times and had significant levels of aPC. Our data provide a new contextual model of how histones affect aPC generation, and how heparinoid therapy may be beneficial in sepsis. These studies provide new insights into the complex interactions controlling aPC formation and suggest a novel therapeutic interventional strategy.

Direct oral anticoagulants: what can we learn?

Science.gov (United States)

Marongiu, Francesco; Barcellona, Doris

2018-03-02

Direct oral anticoagulants (DOACs) represent an innovation because they avoid periodic laboratory monitoring, and also reduce cerebral bleeding. An examination of the performance of DOACs versus warfarin in randomized clinical trials dedicated to atrial fibrillation would reveal the poor performance of warfarin because the percentage of major bleeding is always above 3%; however, the percentage of major bleeding is less than half of that when the management is done in anticoagulation clinics (ACs). Several years ago, a common opinion was that ACs would disappear as soon as DOACs enter the market. We proposed then that ACs could be transformed into thrombosis centres (TCs) because we envisaged many new activities in terms of diagnostic tools and therapeutic choices. After the introduction of DOACs, the role of the ACs has been re-evaluated because their role may be crucial in selecting both the most appropriate diagnostic approach and the best therapeutic option (including anti-vitamin K drugs) for the single patient. TCs can organize a regular follow-up to improve patient adherence to DOACs. Marketing might have a role in the decision making of the single doctor. Efforts should be made for limiting the relationships between doctors and pharmaceutical companies. It seems reasonable to better prepare doctors, during their university courses, for them to develop a greater scientific culture that would enable them to critically read clinical studies and acquire an independent opinion. Ideally, an expert in haemostasis and thrombosis should handle new and old anticoagulants.

Excessive anticoagulation with warfarin or phenprocoumon may have multiple causes

DEFF Research Database (Denmark)

Meegaard, Peter Martin; Holck, Line H V; Pottegård, Anton

2012-01-01

Excessive anticoagulation with vitamin K antagonists is a serious condition with a substantial risk of an adverse outcome. We thus found it of interest to review a large case series to characterize the underlying causes of excessive anticoagulation.......Excessive anticoagulation with vitamin K antagonists is a serious condition with a substantial risk of an adverse outcome. We thus found it of interest to review a large case series to characterize the underlying causes of excessive anticoagulation....

Citrate Anticoagulation during Continuous Renal Replacement Therapy.

Science.gov (United States)

Ricci, Davide; Panicali, Laura; Facchini, Maria Grazia; Mancini, Elena

2017-01-01

During extracorporeal dialysis, some anticoagulation strategy is necessary to prevent the coagulation of blood. Heparin has historically been used as an anticoagulant because of its efficacy combined with low cost. However, a variable incidence of hemorrhagic complications (5-30%) has been documented in patients undergoing continuous renal replacement therapy (CRRT) with heparin as an anticoagulant. Citrate has anticoagulation properties secondary to its ability to chelate calcium, which is necessary for the coagulation cascade. Citrate may thus be used in a regional anticoagulation (RCA), limited to the extracorporeal circuit of CRRT, to avoid systemic anticoagulation. Recent meta-analysis confirmed the advantage of RCA over heparin in terms of incidence of bleeding during CRRT. Moreover, an increase in filter lifespan is documented, with a secondary advantage in reaching the prescribed dialysis dose. In our experience, we could confirm this positive effect. In fact, with a progressive increase in the proportion of CRRT with citrate as RCA, we obtained a reduction in the number of filters used for every 72 h of treatment (from 2.4 in 2011 to 1.3 in 2015), and most importantly, a reduction in the difference between the prescribed and delivered dialysis doses (from 22 to 7%). Citrate has an intense effect on the acid-base balance as well, if fully metabolized through the Krebs cycle, due to the production of bicarbonate. Even more severely ill patients, such as those with liver dysfunction, may be treated with RCA without severe complications, because modern machines for CRRT are equipped with simple systems that are able to manage the citrate infusion and control the calcium levels, with minimal risks of metabolic derangements. © 2017 S. Karger AG, Basel.

Anticoagulant therapy and its impact on dental patients: a review.

Science.gov (United States)

Thean, D; Alberghini, M

2016-06-01

Several new oral anticoagulants have been studied in the past decade, and have now started to enter the market. These drugs are reported to be as effective as, or more effective than, warfarin. In Australia, the Therapeutic Goods Administration has approved dabigatran, rivaroxaban and apixaban. The use of these newer anticoagulants is likely to increase in time, and it is important for dentists to have a sound understanding of the mechanisms of action, reversal strategies, and management guidelines for patients taking oral anticoagulants. This article discusses the process of coagulation, available anticoagulants and their monitoring and reversal, and provides clinical advice on the management of patients on anticoagulants who require dental treatment. © 2016 Australian Dental Association.

Diagnostic imaging of severe rectus sheath hematoma complicating anticoagulant therapy

International Nuclear Information System (INIS)

Blum, A.; Bui, P.; Boccaccini, H.; Bresler, L.; Claudon, M.; Boissel, P.; Regent, D.

1995-01-01

CT were performed in thirteen patients (12 women, 1 man) aged from 53 to 90 (mean age, 74) with severe RSH. Five patients also underwent ultrasound examination and three MR examination. Nine patients (69%) were receiving subcutaneous injection of heparin, three (23%) oral anticoagulant therapy and one continuous IV infusion of heparin. Clinical diagnosis was reached in 6 cases. Excessive activity of anticoagulant therapy was noted in 4 cases. The location of the RSH, their densities and their signals were analysed. All the RSH were mostly developed in the lower third of the abdominal wall, had a large spreading into the Retzius space and compressed the bladder and/or the bowels. RSH were all hyperdense and in 8 cases (61%) a fluid-fluid level due to the hematocrit effect was noted. In one case, a retroperitoneal hematoma was discovered. The extension of the RSH was well delineated with MRI. The RSH showed itself with heterogeneous signal intensities with areas of high-signal-intensity on T1-weighted images. Fluid-fluid levels and a concentric ring sign were also noted. Older women with subcutaneous injection of heparin are especially prone to RSH even though there is no overall excessive activity of anticoagulant therapy. Clinical and biological diagnosis may be difficult. CT scan is the exam of choice to reach a precise and acute diagnosis of RSH. (authors). 34 refs., 8 figs

Purification, structural characterization and anticoagulant properties of fucosylated chondroitin sulfate isolated from Holothuria mexicana.

Science.gov (United States)

Mou, Jiaojiao; Wang, Cong; Li, Wenjing; Yang, Jie

2017-05-01

A novel fucosylated chondroitin sulfate (HmG) was isolated from sea cucumber Holothuria mexicana, the structure of which was characterized by monosaccharide composition, disaccharide composition, IR, 1 H and 13 C NMR spectrum, additionally with two dimensional NMR spectrum of degraded HmG (DHmG). The backbone of HmG was identified as chondroitin 6-O sulfate, while the major O-4 sulfated fucose branches linked to O-3 position of glucuronic acid in almost every disaccharide unit. The anticoagulant activities of HmG and DHmG were assessed and compared with heparin and low molecular weight heparin. The results indicated that HmG and DHmG both could significantly prolong the activated partial thrombo-plastin time, and the properties were well related to its molecular weight. DHmG showed similar anticoagulant properties to low molecular weight heparin with less bleeding risks, making it a safer anticoagulant drug. Copyright © 2017 Elsevier B.V. All rights reserved.

Anticoagulant rodenticide toxicity to non-target wildlife under controlled exposure conditions

Science.gov (United States)

Rattner, Barnett A.; Mastrota, F. Nicholas; van den Brink, Nico; Elliott, J.; Shore, R.; Rattner, B.

2018-01-01

Much of our understanding of anticoagulant rodenticide toxicity to non-target wildlife has been derived from molecular through whole animal research and registration studies in domesticated birds and mammals, and to a lesser degree from trials with captive wildlife. Using these data, an adverse outcome pathway identifying molecular initiating and anchoring events (inhibition of vitamin K epoxide reductase, failure to activate clotting factors), and established and plausible linkages (coagulopathy, hemorrhage, anemia, reduced fitness) associated with toxicity, is presented. Controlled exposure studies have demonstrated that second-generation anticoagulant rodenticides (e.g., brodifacoum) are more toxic than first- and intermediate-generation compounds (e.g., warfarin, diphacinone), however the difference in potency is diminished when first- and intermediate-generation compounds are administered on multiple days. Differences in species sensitivity are inconsistent among compounds. Numerous studies have compared mortality rate of predators fed prey or tissue containing anticoagulant rodenticides. In secondary exposure studies in birds, brodifacoum appears to pose the greatest risk, with bromadiolone, difenacoum, flocoumafen and difethialone being less hazardous than brodifacoum, and warfarin, coumatetralyl, coumafuryl, chlorophacinone and diphacinone being even less hazardous. In contrast, substantial mortality was noted in secondary exposure studies in mammals ingesting prey or tissue diets containing either second- or intermediate-generation compounds. Sublethal responses (e.g., prolonged clotting time, reduced hematocrit and anemia) have been used to study the sequelae of anticoagulant intoxication, and to some degree in the establishment of toxicity thresholds or toxicity reference values. Surprisingly few studies have undertaken histopathological evaluations to identify cellular lesions and hemorrhage associated with anticoagulant rodenticide exposure in non

Na2EDTA anticoagulant impaired blood samples from the teleost Piaractus mesopotamicus

Directory of Open Access Journals (Sweden)

Thaís Heloisa Vaz Farias

2016-05-01

Full Text Available Abstract: The present study aimed to evaluate the effects of Na heparin and Na2EDTA on blood of Piaractus mesopotamicus (360.7±42.4g, 26.4±1.0cm. Twenty fishes were sampled in two experiment trials, ten for erythrocyte fragility analysis and ten for hematologic and plasma biochemical study. The blood collected by venous-caudal puncture was fractioned and stored in anticoagulants solution: Na2EDTA 10%, Na2EDTA 3%, Na heparin 5000 IU and Na heparin 100 IU. Plasmatic levels of calcium presented in the Na2EDTA stored samples were about 80% lower than both heparin groups. Blood samples of P. mesopotamicus stored with Na2EDTA demonstrated increase in the hematocrit and MCV, and decrease in MCHC. The dose-response effect was observed in this study. The results are reinforced by the higher levels of plasmatic protein and hemolysis presented in the Na2EDTA 10% stored blood, confirming the deleterious effect of this anticoagulant treatment on the quality of blood samples. Na2EDTA is not indicated to store P. mesopotamicus blood samples, but sodium heparin at 100 IU is the most recommended anticoagulant, since this treatment presented the lower rate of alterations in the stored blood.

[Secondary osteoporosis induced by anticoagulants?].

Science.gov (United States)

Riess, H; Loew, A; Himmelreich, G

2001-07-01

Generalized osteoporosis is a result of different causes and pathogenic mechanisms, which often combine forces to become clinically relevant. Among the different exogenic factors, drugs play an important role, frequently in connection with other factors such as immobilization or pregnancy. It has been suggested that anticoagulation therapy with heparins or coumarins may induce osteoporotic changes or enhance the development of osteoporosis for other reasons. According to in vitro experiments, preclinical trials, and clinical investigations, it seems reasonable to assume that heparins induce increased bone loss in a time- and dose-related manner. Low-molecular-weight heparins most likely have less effect on bone turnover when compared to unfractionated heparin. Oral anticoagulation therapy with vitamin K-antagonists is believed to have a weak effect on induction of osteoporosis, but clinical studies are contradictory. In spite of the fact that a relevant effect of these drugs on the induction of osteoporosis is questionable, it must be taken into consideration that anticoagulant drugs may enhance the negative effects on bone density of other risk factors capable of inducing osteoporosis such as immobilization, pregnancy, or endocrinological disorders.

Evaluation of Oral Anticoagulant-Associated Intracranial Parenchymal Hematomas Using CT Findings.

Science.gov (United States)

Gökçe, E; Beyhan, M; Acu, B

2015-06-01

Intracranial hemorrhage (ICH) is one of the most serious and lethal complications of anticoagulants with a reported incidence of 5-18.5 %. Computed tomographic (CT) findings, should be carefully studied because early diagnosis and treatment of oral anticoagulant use-associated hematomas are vitally important. In the present study, CT findings of intraparenchymal hematomas associated with anticoagulant and antihypertensive use are presented. This study included 45 patients (25 men, 20 women) under anticoagulant (21 patients) or antihypertensive (24 patients) treatment who had brain CT examinations due to complaints and findings suggesting cerebrovascular disease during July 2010-October 2013 period. CT examinations were performed to determine hematoma volumes and presence of swirl sign, hematocrit effect, mid-line shift effect, and intraventricular extension. The patients were 40-89 years of age. In four cases, a total of 51 intraparenchymal hematomas (42 cerebral, 7 cerebellar and 2 brain stem) were detected in multiple foci. Hematoma volumes varied from 0.09 to 284.00 ml. Swirl sign was observed in 87.5 and 63.0 % of OAC-associated ICHs and non-OAC-associated ICHs, respectively. In addition, hematocrit effect was observed in 41.6 % of OAC-associated and in 3.7 % of non-OAC-associated ICHs. Volume increases were observed in all 19 hematomas where swirl sign was detected, and follow-up CT scanning was conducted. Mortality of OAC-associated ICHs was correlated with initial volumes of hematoma, mid-line shift amount, and intraventricular extension. Detection of hematocrit effect by CT scanning of intracranial hematomas should be cautionary in oral anticoagulant use, while detection of swirl sign should be suggestive of active hemorrhage.

Structural analysis and anticoagulant activities of two sulfated polysaccharides from the sea cucumber Holothuria coluber.

Science.gov (United States)

Yang, Wenjiao; Cai, Ying; Yin, Ronghua; Lin, Lisha; Li, Zhongkun; Wu, Mingyi; Zhao, Jinhua

2018-05-01

Sulfated polysaccharides such as fucosylated glycosaminoglycan and fucan sulfate from echinoderm possess complex chemical structure and various biological activities. The two sulfated polysaccharides were purified from the low-value sea cucumber Holothuria coluber. Their physicochemical properties and chemical structures were analyzed and characterized by chemical and instrumental methods. Structural analysis clarified that the sea cucumber fucosylated glycosaminoglycan contains a chondroitin sulfate-like backbone and fucosyl branches with four various sulfation patterns. The fucan sulfate with molecular weight of 64.6 kDa comprises a central core of regular α(1 → 4)-linked tetrasaccharide repeating units, each of which is linked by a 4-O-sulfated fucose residue. Anticoagulant assays indicated that these sulfated polysaccharides possessed strong APTT prolonging activities and intrinsic factor Xase inhibitory activities, both of which decreased with the reduction of their molecular weights. Our results expand knowledge on the structural types of sulfated polysaccharides from sea cucumbers and further illustrate their functionality. Copyright © 2018. Published by Elsevier B.V.

Cost effectiveness of novel oral anticoagulants for stroke prevention in atrial fibrillation depending on the quality of warfarin anticoagulation control.

Science.gov (United States)

Janzic, Andrej; Kos, Mitja

2015-04-01

Vitamin K antagonists, such as warfarin, are standard treatments for stroke prophylaxis in patients with atrial fibrillation. Patient outcomes depend on quality of warfarin management, which includes regular monitoring and dose adjustments. Recently, novel oral anticoagulants (NOACs) that do not require regular monitoring offer an alternative to warfarin. The aim of this study was to evaluate whether cost effectiveness of NOACs for stroke prevention in atrial fibrillation depends on the quality of warfarin control. We developed a Markov decision model to simulate warfarin treatment outcomes in relation to the quality of anticoagulation control, expressed as percentage of time in the therapeutic range (TTR). Standard treatment with adjusted-dose warfarin and improved anticoagulation control by genotype-guided dosing were compared with dabigatran, rivaroxaban, apixaban and edoxaban. The analysis was performed from the Slovenian healthcare payer perspective using 2014 costs. In the base case, the incremental cost-effectiveness ratio for apixaban, dabigatran and edoxaban was below the threshold of €25,000 per quality-adjusted life-years compared with adjusted-dose warfarin with a TTR of 60%. The probability that warfarin was a cost-effective option was around 1%. This percentage rises as the quality of anticoagulation control improves. At a TTR of 70%, warfarin was the preferred treatment in half the iterations. The cost effectiveness of NOACs for stroke prevention in patients with nonvalvular atrial fibrillation who are at increased risk for stroke is highly sensitive to warfarin anticoagulation control. NOACs are more likely to be cost-effective options in settings with poor warfarin management than in settings with better anticoagulation control, where they may not represent good value for money.

Net clinical benefit of combination anticoagulant and antiplatelet therapy versus anticoagulation alone in atrial fibrillation patients: Results from the amadeus trial

NARCIS (Netherlands)

Lane, Deirdre; Kamphuisen, Pieter; Minini, Pascal; De Peuter, Olaf R.; Buller, Harry R.; Lip, Gregory Y. H.

2010-01-01

Background: To compare the effect of combination anticoagulant and antiplatelet (AP) therapy with anticoagulation alone on stroke and bleeding risk in atrial fibrillation (AF) patients and examine predictors of clinically relevant bleeding. Methods: Post-hoc analysis of 4576 AF patients [mean (SD)

Prevalence of serious bleeding events and intracranial hemorrhage in patients receiving activated protein C: a systematic review and meta-analysis.

Science.gov (United States)

Khan, Ajmal; Agarwal, Ritesh; Aggarwal, Ashutosh N; Gupta, Dheeraj

2010-07-01

Activated protein C reduces 28-day mortality in patients with severe sepsis, but its anticoagulant properties entail a risk of bleeding. The aim of this systematic review was to evaluate the prevalence of serious bleeding events in patients receiving activated protein C. We searched the MEDLINE and EMBASE databases for studies that described the prevalence of serious bleeding events and intracranial hemorrhage in patients receiving activated protein C. We calculated the bleeding rates by calculating proportions and 95% CIs for each study, and then pooled the data to derive a pooled proportion and 95% CI. Our search yielded 17 studies, which included 10,679 patients. The occurrence of serious bleeding events in patients receiving activated protein C ranged from 0.5% to 9.6%, and the pooled prevalence was 3.3% (95% CI 2.4-4.4%) by the random effects model. The occurrence of intracranial hemorrhage ranged from 0% to 1.4%, and the pooled prevalence was 0.44% (95% CI 0.31-0.6%). Sensitivity analysis showed a higher prevalence of bleeding in the observational studies than in the randomized controlled trials. There was substantial clinical and statistical heterogeneity, but no evidence of publication bias. Activated protein C is associated with significant risk of bleeding, so strict inclusion and exclusion criteria should be set prior to administering activated protein C.

Oral Anticoagulant Use After Bariatric Surgery: A Literature Review and Clinical Guidance.

Science.gov (United States)

Martin, Karlyn A; Lee, Craig R; Farrell, Timothy M; Moll, Stephan

2017-05-01

Bariatric surgery may alter the absorption, distribution, metabolism, or elimination (disposition) of orally administered drugs via changes to the gastrointestinal tract anatomy, body weight, and adipose tissue composition. As some patients who have undergone bariatric surgery will need therapeutic anticoagulation for various indications, appropriate knowledge is needed regarding anticoagulant drug disposition and resulting efficacy and safety in this population. We review general considerations about oral drug disposition in patients after bariatric surgery, as well as existing literature on oral anticoagulation after bariatric surgery. Overall, available evidence on therapeutic anticoagulation is very limited, and individual drug studies are necessary to learn how to safely and effectively use the direct oral anticoagulants. Given the sparsity of currently available data, it appears most prudent to use warfarin with international normalized ratio monitoring, and not direct oral anticoagulants, when full-dose anticoagulation is needed after bariatric surgery. Copyright © 2017 Elsevier Inc. All rights reserved.

Underuse of Anticoagulation in Older Patients with Atrial Fibrillation and CHADS2 Score ≥ 2: Are We Doing Better Since the Marketing of Direct Oral Anticoagulants?

Science.gov (United States)

Henrard, Séverine; Vandenabeele, Caroline; Marien, Sophie; Boland, Benoit; Dalleur, Olivia

2017-11-01

Our objectives were to (1) describe the evolution of the underuse of anticoagulants in older people with atrial fibrillation (AF) and a CHADS 2 score ≥ 2 since direct oral anticoagulants (DOACs) were introduced to the market and (2) describe factors associated with this underuse. We conducted a retrospective cross-sectional study including geriatric patients admitted during the pre-DOAC (2008-2011) and post-DOAC (2013-2015) periods in an academic hospital in Belgium. Five inclusion criteria were met: age ≥ 75 years, diagnosis of AF, indication for anticoagulation (CHADS 2 score ≥ 2), risk of functional decline (Identification of Seniors At Risk [ISAR] score ≥ 2), and comprehensive geriatric assessment. The use of anticoagulants and antiplatelets at home before admission was recorded. Risks of stroke and bleeding were calculated using CHADS 2 and HEMORR 2 HAGES scores, respectively. Three different logistic regression models were performed to describe the evolution of and factors associated with the underuse of anticoagulants after DOAC marketing. Anticoagulant underuse, present in 209 of 614 (34%) geriatric patients with AF, was lower in patients with a history of stroke (28.5%) or congestive heart failure (26.9%) but higher in those receiving antiplatelets (56.2%) and in older individuals. Anticoagulant underuse decreased significantly from the pre-DOAC (37.3%) to the post-DOAC (29.7%) era, as shown by two analyses using propensity scores. In older patients with AF, anticoagulant underuse was mainly associated with antiplatelet use. Anticoagulant underuse and antiplatelet use have both decreased since DOAC marketing. Underuse of anticoagulants was still a concern for three in ten geriatric patients with AF at high risk of stroke (CHADS 2 score ≥ 2).

Anticoagulant Preferences and Concerns among Venous Thromboembolism Patients.

Science.gov (United States)

Lutsey, Pamela L; Horvath, Keith J; Fullam, Lisa; Moll, Stephan; Rooney, Mary R; Cushman, Mary; Zakai, Neil A

2018-03-01

 Warfarin and direct oral anticoagulants (DOACs) are used for the initial treatment and secondary prevention of venous thromboembolism (VTE), and have similar efficacy. Patient concerns and preferences are important considerations when selecting an anticoagulant, yet these are not well studied.  VTE patients ( n  = 519) were surveyed from online sources (clotconnect.org, stoptheclot.org and National Blood Clot Alliance Facebook followers [ n  = 495]) and a haematology clinic in Vermont ( n  = 24).  Patients were 83% females and on average (±standard deviation [SD]) 45.7 ± 13.1 years; 65% self-reported warfarin as their initial VTE treatment and 35% a DOAC. Proportions reporting being extremely concerned about the following outcomes were as follows: recurrent VTE 33%, major bleeding 21%, moderate bleeding 16% and all-cause death 29%. When asked about oral anticoagulant characteristics, patients strongly preferred anticoagulants that are reversible (53%), and for which blood drug levels can be monitored (30%). Lower proportions agreed with statements that regular blood testing is inconvenient (18%), that they are comfortable using the newest drug versus an established drug (15%) and that it is difficult to change their diet to accommodate their anticoagulant (17%). In multivariable-adjusted models, patients tended to have had as their initial treatment, and to currently be taking, the oral anticoagulant option they personally preferred.  Patients held the greatest concern for recurrent VTE and mortality, regardless of which treatment they were prescribed. Potential weaknesses of warfarin (e.g., dietary restrictions, regular monitoring) were generally not considered onerous, while warfarin's advantages (e.g., ability to monitor) were viewed favourably. Schattauer GmbH Stuttgart.

Evaluating the efficacy of citrate anticoagulation during CRRT in cardiac patients

Directory of Open Access Journals (Sweden)

А. М. Караськов

2015-10-01

Full Text Available Systemic anticoagulation during renal replacement therapy in cardiac patients increases the risk of postoperative complications. Citrate anticoagulation is a promising alternative. The objective of our study was to evaluate the efficacy of citrate anticoagulation and its influence on the parameters of hemostasis and complications.

Syndecans: synergistic activators of cell adhesion

DEFF Research Database (Denmark)

Woods, A; Couchman, J R

1998-01-01

Cell-surface proteoglycans participate in cell adhesion, growth-factor signalling, lipase activity and anticoagulation. Until recently, only the roles of the glycosaminoglycan chains were investigated. Now, with molecular characterization of several core proteins, the roles of each individual...... molecules modulating integrin-based adhesion....

Idarucizumab for Reversing Dabigatran-Induced Anticoagulation: A Systematic Review.

Science.gov (United States)

Thibault, Nathan; Morrill, Amanda M; Willett, Kristine C

The approval of the oral direct thrombin inhibitor, dabigatran etexilate, gave patients an alternative to oral anticoagulation with warfarin. Like all anticoagulants, the primary adverse event (AE) associated with dabigatran is bleeding. Until the FDA approval of idarucizumab, there had been no reversal agent for dabigatran-induced anticoagulation in patients with life-threatening or uncontrollable bleeding, or those requiring emergent procedures. The primary purpose of this review is to summarize the safety and efficacy of idarucizumab, a monoclonal antibody fragment, and its use as a reversal agent for dabigatran. A literature search was conducted through MEDLINE (1946 to November week 1 2015) and Embase (1980-2015 week 46) using the search term idarucizumab. Clinicaltrials.gov was consulted for a comprehensive list of ongoing and completed studies. Additional studies were identified through bibliographical citations. Clinical trials in animals and humans published in English evaluating the safety and efficacy of idarucizumab for reversal of anticoagulant treatment with dabigatran were included for review. Idarucizumab has been shown to significantly reverse the anticoagulant effects of dabigatran in both healthy volunteers and patients requiring a reversal agent because of either overt bleeding or an emergency surgery or invasive procedure. The most common AEs were headache, nasopharyngitis, back pain, skin irritation, hypokalemia, delirium, constipation, pyrexia, and pneumonia. Deaths reported in idarucizumab studies were attributed to either the index event or a preexisting comorbidity. Most adverse effects were minor, but 21 serious AEs have been reported in the published data including thrombotic events. Given the increased use of direct oral anticoagulants, such as dabigatran, a need for specific reversal agents exists. Idarucizumab has been shown to be safe and effective in the reversal of dabigatran-induced anticoagulation in patients requiring emergent

Interference from lupus anticoagulant on von Willebrand factor measurement in splenic marginal zone lymphoma

DEFF Research Database (Denmark)

Vinholt, Pernille J; Nybo, Mads

2015-01-01

We present a case concerning a patient with splenic marginal zone lymphoma (SMZL) and isolated prolonged activated partial thromboplastin time (aPTT) caused by lupus anticoagulant. Von Willebrand factor (VWF) activity and antigen were immeasurable by latex particle immunoturbidimetric assays...

[Retrospective analysis of correlative factors between digestive system injury and anticoagulant or antiplatelet-agents].

Science.gov (United States)

Cui, Ning; Luo, Hesheng

2014-05-27

To explore the correlative factors and clinical characteristics of digestive system injury during the treatment of anticoagulant and (or) antiplatelet-agents. A total of 1 443 hospitalized patients on anticoagulant and (or) antiplatelet-agents from January 2010 to December 2013 at Renmin Hospital of Wuhan University were analyzed retrospectively. Their length of hospital stay was from 5 to 27 days. Most of them were elderly males (n = 880, 61.0%) with an average age of (62 ± 6) years. 1 138 patients (78.9%) were farmers, workers or someone without a specific occupation. During the treatment of anticoagulant/antiplatelet-agents, statistical difference existed (P = 0.01) between positively and negatively previous digestive disease groups for actively newly occurring digestive system injury (16.0% (41/256) vs 15.9% (189/1 187)). After the dosing of anticoagulant and (or) antiplatelet-agents, 57 (66.3%, 57/86) patients were complicated by hemorrhage of digestive tract, taking 62.9% (61/97) of all positive result patients for Helicobacter pylori test. Comparing preventive PPI group with no PPI group, there was no marked statistical differences (P = 2.67) for digestive system complication (including hemorrhage of digestive tract) while receiving anticoagulant and (or) antiplatelet-agents (13.9% (74/533) vs 17.1% (156/910)). During anticoagulant and/or antiplatelet-agent therapy, 185 patients (12.8%) were complicated by peptic ulcer or peptic ulcer with bleeding, 40 patients (2.8%) had erosive gastritis and 5 (0.3%) developed acute gastric mucosal lesions. And 42 of 76 patients complicated by hemorrhage of digestive tract underwent endoscopic hemostasis while 2 patients were operated. Ninety-seven patients (6.7%) died, including 61 (62.9%, 61/97) from hemorrhage of digestive tract. The remainder became cured, improved and discharged. Moreover, no significant statistical differences existed (P = 2.29) among three combination group (aspirin, clopidogrel, warfarin), two

New oral anticoagulant-induced bleeding: clinical presentation and management

NARCIS (Netherlands)

Levy, Jerrold H.; Levi, Marcel

2014-01-01

Bleeding is a significant complication of anticoagulant therapy. With the emergence of new oral anticoagulants (NOACs; ie, direct factor IIa or Xa inhibitors), this risk is further compounded by the lack of validated reversal strategies for these agents. Emerging postmarketing evidence suggests that

Protein Z efficiently depletes thrombin generation in disseminated intravascular coagulation with poor prognosis.

Science.gov (United States)

Lee, Nuri; Kim, Ji-Eun; Gu, Ja-Yoon; Yoo, Hyun Ju; Kim, Inho; Yoon, Sung-Soo; Park, Seonyang; Han, Kyou-Sup; Kim, Hyun Kyung

2016-01-01

Disseminated intravascular coagulation (DIC) is characterized by consumption of coagulation factors and anticoagulants. Thrombin generation assay (TGA) gives useful information about global hemostatic status. We developed a new TGA system that anticoagulant addition can deplete thrombin generation in plasma, which may reflect defective anticoagulant system in DIC. TGAs were measured on the calibrated automated thrombogram with and without thrombomodulin or protein Z in 152 patients who were suspected of having DIC, yielding four parameters including lag time, endogenous thrombin potential, peak thrombin and time-to-peak in each experiment. Nonsurvivors showed significantly prolonged lag time and time-to-peak in TGA-protein Z system, which was performed with added protein Z. In multivariate Cox regression analysis, lag time and time-to-peak in TGA system were significant independent prognostic factors. In TGA-protein Z system, lag time and time-to-peak were revealed as independent prognostic factors of DIC. Protein Z addition could potentiate its anticoagulant effect in DIC with poor prognosis, suggesting the presence of defective protein Z system. The prolonged lag time and time-to-peak in both TGA and TGA-protein Z systems are expected to be used as independent prognostic factors of DIC.

Impact of Anticoagulation in Elderly Patients With Pulmonary Embolism That Undergo IVC Filter Placement: A Retrospective Cohort Study.

Science.gov (United States)

Falatko, John M; Dalal, Bhavinkumar; Qu, Lihua

2017-12-01

Anticoagulation is the primary treatment for pulmonary embolism (PE). Inferior vena cava (IVC) filters are an adjunctive intervention to prevent recurrent pulmonary embolism. Long-term outcomes in elderly patients with contraindications to anticoagulation after IVC filter placement for prevention of recurrent pulmonary embolism have yet to be assessed. Patients ≥60years of age, that had an IVC filter placed between 1 January, 2008 and 2 February, 2013, with a primary diagnosis of pulmonary embolism, were included. Patients that died during index hospitalisation, were discharged to hospice, or had active malignancy were excluded. The primary endpoint was overall survival. Patients were divided depending on whether they were treated with an approved anticoagulant for VTE or had no anticoagulant. Of the 152 patients identified, 55 were not anti-coagulated after IVC filter placement. The incidence of death was 0.4 per 1000 filter days and 0.7 per 1000 filter days in the anti-coagulated and untreated groups respectively (p-value=0.06). After statistical correction for co-morbid conditions, the effect of anticoagulation was not significant (HR 0.82 CI 0.49-1.37, p-value 0.46). Age was a significant confounder that was associated with death. Increased BMI was protective. Indications for IVC filter placement were numerous, but similar between the two groups. Treatment with an approved anticoagulant is recommended after IVC filter placement for prevention of recurrent PE, however its effect may be attenuated by advanced age. In elderly patients that have undergone IVC filter placement for prevention of recurrent PE, survival may be more dependent on age and co-morbid conditions than exposure to anticoagulation. Copyright © 2017 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Disadvantages of VKA and requirements for novel anticoagulants.

Science.gov (United States)

Shameem, Raji; Ansell, Jack

2013-06-01

Vitamin K antagonists have been in wide use for over 70 years. Warfarin, the most commonly used vitamin K antagonist, has been shown to be highly effective in treating and preventing thrombosis. Despite this, warfarin has many disadvantages, which has led to the development of a new class of oral anticoagulants targeted to specific coagulation factors designated as target-specific oral anticoagulants (TSOAs). TSOAs include the thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban, apixaban). This chapter reviews the disadvantages of warfarin and evaluates both the advantages and disadvantages of the new oral anticoagulants. © 2013 Elsevier Ltd. All rights reserved.

Hematometra secondary to anticoagulant rodenticide toxicity

International Nuclear Information System (INIS)

Padgett, S.L.; Stokes, J.E.; Tucker, R.L.; Wheaton, L.G.

1998-01-01

An adult, intact female Australian shepherd presented for frank vaginal bleeding of unknown duration. The only coagulation profile abnormality upon presentation was mild prolongation of the partial thromboplastin time (PTT). The uterus was removed at surgery and contained a large amount of coagulated blood. Clotting profiles were markedly abnormal48 hours postoperatively. Serum analysis was positive for brodifacoum, an anticoagulant rodenticide. Preoperative coagulation was most likely normalized by vitamin K-1 therapy administered prior to presentation. The only manifestation of anticoagulant rodenticide was hematometra. Rodenticide intoxication should be considered in the differential diagnosis list of hematometra or metrorrhagia

Standards of care issues with anticoagulation in real-world populations.

Science.gov (United States)

2015-01-01

Current guidelines recommend anticoagulants for reducing the risk of stroke in appropriate patients with nonvalvular atrial fibrillation (NVAF) and for the acute treatment of venous thromboembolism (VTE) and the prevention of recurrent VTE. Warfarin is the standard of care for both NVAF and VTE, yet International Normalized Ratio (INR) control remains suboptimal, even in the clinical trial setting. Maintaining INR within the recommended therapeutic range is associated with better outcomes in these distinct populations. In VTE, high rates of recurrence have been reported during the first few weeks of treatment, emphasizing the importance of surveillance during this time and of early optimization of anticoagulation therapy. The NVAF population tends to have more comorbidities and requires longer-term therapy. It is important to keep in mind that real-world patient populations are more complex than those in controlled studies. Patients with multiple comorbidities are particularly challenging, and physicians may focus on clinically urgent issues rather than anticoagulation optimization. Despite the many complexities associated with the use of warfarin, it remains a mainstay of anticoagulation therapy. Aligning financial incentives and improving care coordination are important factors in moving toward better outcomes for patients who need anticoagulation therapy. The increased focus on value-based care and evolving approaches to patient treatment could lead more physicians and payers to consider alternatives to warfarin, including the use of novel oral anticoagulants.

Vitamin K requirement in Danish anticoagulant-resistant Norway rats (Rattus norvegicus)

DEFF Research Database (Denmark)

Markussen, Mette D.; Heiberg, Ann-Charlotte; Nielsen, Robert

2003-01-01

Norway rats, Rattus norvegicus, Denmark, anticoagulant rodenticide resistance, vitamin K requirement......Norway rats, Rattus norvegicus, Denmark, anticoagulant rodenticide resistance, vitamin K requirement...

New anticoagulants for the prevention and treatment of venous thromboembolism

Directory of Open Access Journals (Sweden)

Simon J McRae

2005-04-01

Full Text Available Simon J McRae, Jeffrey S GinsbergDepartment of Medicine, McMaster University, Hamilton, ON, CanadaAbstract: Anticoagulant therapy is effective at preventing the development of venous thromboembolism in high-risk patients, and reduces morbidity and mortality in individuals with established thromboembolic disease. Vitamin K antagonists and heparins are currently the most commonly used anticoagulant drugs, but they have practical limitations. Therefore, new antithrombotic agents with predictable dose-responses (thereby decreasing the need for monitoring without compromising efficacy or safety, ideally available in an oral formulation and with a rapidly reversible anticoagulant effect, are needed. New drugs fulfilling some of the above criteria have been developed and have proven to be effective agents for the treatment and prevention of venous thromboembolism.Keywords: venous thromboembolism, anticoagulants, antithrombotic

New oral anticoagulants: key messages for clinicians

Directory of Open Access Journals (Sweden)

Matteo Giorgi-Pierfranceschi

2013-12-01

Full Text Available New oral anticoagulants are an effective and safe alternative to vitamin K antagonists in many fields of clinical practice. The use of the direct inhibitors of activated Factor II (dabigatran and activated Factor X (apixaban and rivaroxaban, both in patients with non-valvular atrial fibrillation (NVAF and those with acute venous thromboembolism (VTE, is of great interest for internal medicine physicians. This paper aims to give practical guidance on management (starting therapy, follow up and bleeding complications of patients treated with dabigatran, rivaroxaban or apixaban for NVAF or acute VTE providing practical tables concerning the phases of therapy, management of complications, drug interaction and dose adjustment if renal impairment occurs.

Adherence to a new oral anticoagulant treatment prescription: dabigatran etexilate

Directory of Open Access Journals (Sweden)

L Bellamy

2009-07-01

Full Text Available L Bellamy1, N Rosencher1, BI Eriksson21Anaesthesiology Department, Hôpital Cochin (AP-HP, René Descartes University, Paris 75014 France; 2Orthopaedic Department, University Hospital Sahlgrenska/Ostra, Gothenburg, SwedenAbstract: The recent development of new oral anticoagulants, of which dabigatran etexilate is currently at the most advanced stage of development, is the greatest advance in the provision of convenient anticoagulation therapy for many years. A new oral anticoagulation treatment, dabigatran etexilate, is already on the market in Europe. The main interest probably will be to improve the prescription and the adherence to an effective thromboprophylaxis in medical conditions such as atrial fibrillation without bleeding side effects, without the need for monitoring coagulation, and without drug and food interactions such as vitamin K anticoagulant (VKA treatment. Dabigatran is particularly interesting for extended thromboprophylaxis after major orthopedic surgery in order to avoid daily injection for a month. However, oral long-term treatments such as VKA are not systematically associated with a higher compliance level than injected treatments such as low-molecular-weight heparins. Indeed, adherence to an oral treatment, instead of the usual daily injection in major orthopedic surgery, is complex, and based not only on the frequency of dosing but also on patient motivation, understanding, and socio-economic status. New oral anticoagulants may be useful in this way but education and detection of risk factors of nonadherence to treatment are still essential.Keywords: oral anticoagulant, adherence, compliance, education, dabigatran

Scoring Systems for Estimating the Risk of Anticoagulant-Associated Bleeding.

Science.gov (United States)

Parks, Anna L; Fang, Margaret C

2017-07-01

Anticoagulant medications are frequently used to prevent and treat thromboembolic disease. However, the benefits of anticoagulants must be balanced with a careful assessment of the risk of bleeding complications that can ensue from their use. Several bleeding risk scores are available, including the Outpatient Bleeding Risk Index, HAS-BLED, ATRIA, and HEMORR 2 HAGES risk assessment tools, and can be used to help estimate patients' risk for bleeding on anticoagulants. These tools vary by their individual risk components and in how they define and weigh clinical factors. However, it is not yet clear how best to integrate bleeding risk tools into clinical practice. Current bleeding risk scores generally have modest predictive ability and limited ability to predict the most devastating complication of anticoagulation, intracranial hemorrhage. In clinical practice, bleeding risk tools should be paired with a formal determination of thrombosis risk, as their results may be most influential for patients at the lower end of thrombosis risk, as well as for highlighting potentially modifiable risk factors for bleeding. Use of bleeding risk scores may assist clinicians and patients in making informed and individualized anticoagulation decisions. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Site specific replacements of a single loop nucleoside with a dibenzyl linker may switch the activity of TBA from anticoagulant to antiproliferative.

Science.gov (United States)

Scuotto, Maria; Rivieccio, Elisa; Varone, Alessia; Corda, Daniela; Bucci, Mariarosaria; Vellecco, Valentina; Cirino, Giuseppe; Virgilio, Antonella; Esposito, Veronica; Galeone, Aldo; Borbone, Nicola; Varra, Michela; Mayol, Luciano

2015-09-18

Many antiproliferative G-quadruplexes (G4s) arise from the folding of GT-rich strands. Among these, the Thrombin Binding Aptamer (TBA), as a rare example, adopts a monomolecular well-defined G4 structure. Nevertheless, the potential anticancer properties of TBA are severely hampered by its anticoagulant action and, consequently, no related studies have appeared so far in the literature. We wish to report here that suitable chemical modifications in the TBA sequence can preserve its antiproliferative over anticoagulant activity. Particularly, we replaced one residue of the TT or TGT loops with a dibenzyl linker to develop seven new quadruplex-forming TBA based sequences (TBA-bs), which were studied for their structural (CD, CD melting, 1D NMR) and biological (fibrinogen, PT and MTT assays) properties. The three-dimensional structures of the TBA-bs modified at T13 (TBA-bs13) or T12 (TBA-bs12), the former endowed with selective antiproliferative activity, and the latter acting as potently as TBA in both coagulation and MTT assays, were further studied by 2D NMR restrained molecular mechanics. The comparative structural analyses indicated that neither the stability, nor the topology of the G4s, but the different localization of the two benzene rings of the linker was responsible for the loss of the antithrombin activity for TBA-bs13. © Crown copyright 2015.

Atrial Fibrillation in Embolic Stroke: Anticoagulant Therapy at UNTH ...

African Journals Online (AJOL)

Objective: The decision to commence anticoagulation in a patient with embolic stroke and atrial fibrillation (AF) is often a difficult one for many clinicians. The result can have significant impact on the patient. This study was therefore undertaken to review the use of anticoagulation in embolic stroke in the setting of atrial ...

Antithrombin deficiency and decreased protein C activity in a young man with venous thromboembolism: a case report.

Science.gov (United States)

Wang, Dong; Tian, Min; Cui, Guanglin; Wang, Dao Wen

2018-06-01

Antithrombin and protein C are two crucial members in the anticoagulant system and play important roles in hemostasis. Mutations in SERPINC1 and PROC lead to deficiency or dysfunction of the two proteins, which could result in venous thromboembolism (VTE). Here, we report a Chinese 22-year-old young man who developed recurrent and serious VTE in cerebral veins, visceral veins, and deep veins of the lower extremity. Laboratory tests and direct sequencing of PROC and SERPINC1 were conducted for the patient and his family members. Coagulation tests revealed that the patient presented type I antithrombin deficiency combined with decreased protein C activity resulting from a small insertion mutation c.848_849insGATGT in SERPINC1 and a short deletion variant c.572_574delAGA in PROC. This combination of the two mutations was absent in 400 healthy subjects each from southern and northern China. Then, we summarized all the mutations of the SERPINC1 and PROC gene reported in the Chinese Han population. This study demonstrates that the combination of antithrombin deficiency and decreased protein C activity can result in severe VTE and that the coexistence of different genetic factors may increase the risk of VTE.

Protein S is protective in pulmonary fibrosis.

Science.gov (United States)

Urawa, M; Kobayashi, T; D'Alessandro-Gabazza, C N; Fujimoto, H; Toda, M; Roeen, Z; Hinneh, J A; Yasuma, T; Takei, Y; Taguchi, O; Gabazza, E C

2016-08-01

Essentials Epithelial cell apoptosis is critical in the pathogenesis of idiopathic pulmonary fibrosis. Protein S, a circulating anticoagulant, inhibited apoptosis of lung epithelial cells. Overexpression of protein S in lung cells reduced bleomycin-induced pulmonary fibrosis. Intranasal therapy with exogenous protein S ameliorated bleomycin-induced pulmonary fibrosis. Background Pulmonary fibrosis is the terminal stage of interstitial lung diseases, some of them being incurable and of unknown etiology. Apoptosis plays a critical role in lung fibrogenesis. Protein S is a plasma anticoagulant with potent antiapoptotic activity. The role of protein S in pulmonary fibrosis is unknown. Objectives To evaluate the clinical relevance of protein S and its protective role in pulmonary fibrosis. Methods and Results The circulating level of protein S was measured in patients with pulmonary fibrosis and controls by the use of enzyme immunoassays. Pulmonary fibrosis was induced with bleomycin in transgenic mice overexpressing human protein S and wild-type mice, and exogenous protein S or vehicle was administered to wild-type mice; fibrosis was then compared in both models. Patients with pulmonary fibrosis had reduced circulating levels of protein S as compared with controls. Inflammatory changes, the levels of profibrotic cytokines, fibrosis score, hydroxyproline content in the lungs and oxygen desaturation were significantly reduced in protein S-transgenic mice as compared with wild-type mice. Wild-type mice treated with exogenous protein S showed significant decreases in the levels of inflammatory and profibrotic markers and fibrosis in the lungs as compared with untreated control mice. After bleomycin infusion, mice overexpressing human protein S showed significantly low caspase-3 activity, enhanced expression of antiapoptotic molecules and enhanced Akt and Axl kinase phosphorylation as compared with wild-type counterparts. Protein S also inhibited apoptosis of alveolar

Bleeding events associated with novel anticoagulants: a case series.

Science.gov (United States)

Mirzaee, Sam; Tran, Tara Thi Thien; Amerena, John

2013-12-01

Until lately warfarin was the only valuable oral anticoagulant in stroke reduction in high risk cases with non valvular atrial fibrillation (NVAF). Although with warfarin the rate of stroke reduced notably, the major concern is the risk of serious bleeding and difficulty of establishing and maintaining the international normalised ratio (INR) within the therapeutic range. With the development of the novel anticoagulants we now have for the first time since the innovation of Warfarin feasible alternatives to it to decrease stroke rates in high risk patients with NVAF. To diminish adverse bleeding events with the novel anticoagulant proper selection of patients prior starting treatment is essential. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Clinical impact of a pharmacist-led inpatient anticoagulation service: a review of the literature

Directory of Open Access Journals (Sweden)

Lee T

2016-05-01

Full Text Available Tiffany Lee, Erin Davis, Jason Kielly School of Pharmacy, Memorial University, St John's, NL, Canada Background: Anticoagulant therapies provide management options for potentially life-threatening thromboembolic conditions. They also carry significant safety risks, requiring careful consideration of medication dose, close monitoring, and follow-up. Inpatients are particularly at risk, considering the widespread use of anticoagulants in hospitals. This has prompted the introduction of safety goals for anticoagulants in Canada and the USA, which recommend increased pharmacist involvement to reduce patient harm. The goal of this review is to evaluate the efficacy and safety of pharmacist-led inpatient anticoagulation services compared to usual or physician-managed care. Methods: This narrative review includes articles identified through a literature search of PubMed, Embase, and International Pharmaceutical Abstracts databases, as well as hand searches of the references of relevant articles. Full publications of pharmacist-managed inpatient anticoagulation services were eligible if they were published in English and assessed clinical outcomes. Results: Twenty-six studies were included and further divided into two categories: 1 autonomous pharmacist-managed anticoagulation programs (PMAPs and 2 pharmacist recommendation. Pharmacist management of heparin and warfarin appears to result in improvements in some surrogate outcomes (international normalized ratio [INR] stability and time in INR goal range, while results for others are mixed (time to therapeutic INR, length of stay, and activated partial thromboplastin time [aPTT] measures. There is also some indication that PMAPs may be associated with reduced patient mortality. When direct thrombin inhibitors are managed by pharmacists, there seems to be a shorter time to therapeutic aPTT and a greater percentage of time in the therapeutic range, as well as a decrease in the frequency of medication

Bleeding in patients using new anticoagulants or antiplatelet agents: Risk factors and management

NARCIS (Netherlands)

Levi, M.M.; Eerenberg, E.; Löwenberg, E.; Kamphuisen, P.W.

2010-01-01

The most important adverse effect of antithrombotic treatment is the occurrence of bleeding. in case of serious or even life-threatening bleeding in a patient who uses anticoagulant agents or when patient on anticoagulants needs to undergo an urgent invasive procedure, anticoagulant treatment can be

In vitro anticoagulation monitoring of low-molecular-weight heparin

Institute of Scientific and Technical Information of China (English)

WANG Jian-qi; SHI Xu-bo; YANG Jin-gang; HU Da-yi

2009-01-01

Background Although low-molecular-weight heparin has replaced unfractionated heparin to become the primary anticoagulation drug for treatment of acute coronary syndrome, there is no convenient bedside monitoring method. We explored the best laboratory monitoring method of low-molecular-weight heparins (enoxapadn, dalteparin, and nadroparin) by use of the Sonoclot coagulation analyzer to monitor the activated clotting time.Methods Atotal of 20 healthy volunteers were selected and 15 ml of fasting venous blood samples were collected and incubated. Four coagulants, kaolin, diatomite, glass bead, and magnetic stick, were used to determine the activated clotting time of the low-molecular-weight heparins at different in vitro anti-Xa factor concentrations. A correlation analysis was made to obtain the regression equation. The activated clotting time of the different low-molecular-weight heparins with the same anti-Xa factor concentration was monitored when the coagulant glass beads were applied. Results The activated clotting time measured using the glass beads, diatomite, kaolin, and magnetic stick showed a linear correlation with the concentration of nadroparin (r= 0.964, 0.966, 0.970, and 0.947, respectively). The regression equation showed that the linear slopes of different coagulants were significantly different (glass beads 230.03 s/IU,diatomite 89.91 s/IU, kaolin 50.87 s/IU, magnetic stick could not be calculated). When the concentration of the anti-Xa factor was the same for different low-molecular-weight heparins, the measured activated clotting time was different after the application of the glass bead coagulant.Conclusions The glass bead coagulant is most feasible for monitoring the in vitro anticoagulation activity of nadroparin.The different effects of different low-molecular-weight heparins on the activated clotting time may be related to the different anti-Ila activities.

Anticoagulant rodenticides and wildlife: Introduction

Science.gov (United States)

van den Brink, Nico W.; Elliott, John E.; Shore, Richard F.; Rattner, Barnett A.; van den Brink, Nico W.; Elliott, John E.; Shore, Richard F.; Rattner, Barnett A.

2018-01-01

Rodents have interacted with people since the beginning of systematic food storage by humans in the early Neolithic era. Such interactions have had adverse outcomes such as threats to human health, spoiling and consumption of food sources, damage to human infrastructure and detrimental effects on indigenous island wildlife (through inadvertent anthropogenic assisted introductions). These socio/economic and environmental impacts illustrate the clear need to control populations of commensal rodents. Different methods have been applied historically but the main means of control in the last decades is through the application of rodenticides, mainly anticoagulant rodenticides (ARs) that inhibit blood clotting. The so-called First Generation Anticoagulant Rodenticides (FGARs) proved highly effective but rodents increasingly developed resistance. This led to a demand for more effective alternative compounds and paved the way to the development of Second Generation Anticoagulant Rodenticides (SGARs). These were more acutely toxic and persistent, making them more effective but also increasing the risks of exposure of non-target species and secondary poisoning of predatory species. SGARs often fail the environmental thresholds of different regulatory frameworks because of these negative side-effects, but their use is still permitted because of the overwhelming societal needs for rodent control and the lack of effective alternatives. This book provides a state-of-the-art overview of the scientific advancements in assessment of environmental exposure, effects and risks of currently used ARs. This is discussed in relation to the societal needs for rodent control, including risk mitigation and development of alternatives.

The effect of the amiodarone-warfarin interaction on anticoagulation quality in a single, high-quality anticoagulation center.

Science.gov (United States)

White, Ryan D; Riggs, Kyle W; Ege, Ed J; Petroski, Gregory F; Koerber, Scott M; Flaker, Greg

2016-03-01

Clinical trials have reported a low time in therapeutic range (TTR) in patients with atrial fibrillation treated with both warfarin andamiodarone. These trials included centers and countries with both high and low TTRs. What is the impact of amiodarone on the TTR in a single, high-quality anticoagulation clinic? TTR was assessed in amiodarone and nonamiodarone-treated patients from a University anticoagulation clinic. Baseline characteristics between patients ever-taking or never-taking amiodarone were similar, except more amiodarone patients were smokers (19.5 vs. 6.1%, P = 0.0031). The TTR calculated from 8901international normalized ratios (INRs) in 249 nonamiodarone patients with a mean follow-up of 34 ± 20 months (mean INR 36 ± 18) was 66 ± 16.6% compared with 61.3 ± 16.2% (P = 0.111) from 1455 INRs in 41 amiodarone-treated patients with a mean follow-up of 28 ± 20 months (mean INR 35 ± 22). Factors associated with a low TTR were male sex (P = 0.0013), smoker (P = 0.0048), and amiodarone use (P = 0.0374). A second on-treatment analysis, in which the TTR was calculated only during amiodarone therapy, resulted in similar findings; however, amiodarone did not emerge as a predictor of a low TTR. In 11 patients, the TTR prior to amiodarone (54.5 ± 22.2%) was not significantly different in the first 3 months (54.6 ± 33.4%) or after 3 months (67.2 ± 33.7%) of amiodarone. In a single high-quality anticoagulation center, anticoagulation quality, as measured by the TTR, can be comparable in amiodarone and nonamiodarone-treated patients.

Effect of an interactive voice response system on oral anticoagulant management.

Science.gov (United States)

Oake, Natalie; van Walraven, Carl; Rodger, Marc A; Forster, Alan J

2009-04-28

Monitoring oral anticoagulants is logistically challenging for both patients and medical staff. We evaluated the effect of adding an interactive voice response system to computerized decision support for oral anticoagulant management. We developed an interactive voice response system to communicate to patients the results of international normalized ratio testing and their dosage schedules for anticoagulation therapy. The system also reminded patients of upcoming and missed appointments for blood tests. We recruited patients whose anticoagulation control was stable after at least 3 months of warfarin therapy. We prospectively examined clinical data and outcomes for these patients for an intervention period of at least 3 months. We also collected retrospective data for each patient for the 3 months before study enrolment. We recruited 226 patients between Nov. 23, 2006, and Aug. 1, 2007. The mean duration of the intervention period (prospective data collection) was 4.2 months. Anticoagulation control was similar for the periods during and preceding the intervention (mean time within the therapeutic range 80.3%, 95% confidence interval [CI] 77.5% to 83.1% v. 79.9%, 95% CI 77.3% to 82.6%). The interactive voice response system delivered 1211 (77.8%) of 1557 scheduled dosage messages, with no further input required from clinic staff. The most common reason for clinic staff having to deliver the remaining messages (accounting for 143 [9.2%] of all messages) was an international normalized ratio that was excessively high or low, (i.e., 0.5 or more outside the therapeutic range). When given the option, 76.6% of patients (164/214) chose to continue with the interactive voice response system for management of their anticoagulation after the study was completed. The system reduced staff workload for monitoring anticoagulation therapy by 48 min/wk, a 33% reduction from the baseline of 2.4 hours. Interactive voice response systems have a potential role in improving the

Reproductive success of bromadiolone-resistant rats in absence of anticoagulant pressure

DEFF Research Database (Denmark)

Heiberg, Ann-Charlotte; Leirs, Herwig; Siegismund, Hans Redlef

2006-01-01

Resistance to anticoagulant rodenticides in brown rats (Rattus norvegicus Berk.) is associated with pleiotropic effects, notably with an increased dietary vitamin K requirement. Owing to this disadvantage, resistance is believed to be selected against if anticoagulant selection is absent. In small...... experimental populations of wild brown rats, an investigation was carried out to establish whether tolerance to anticoagulant exposure changed over a period of 2 years. In the same populations, DNA microsatellite markers were used to infer parentage, and this made it possible to estimate reproductive success...... of sensitive and resistant rats and estimate effective population size, Ne. Even though there was evidence for a selection against resistant rats with high vitamin K requirement, anticoagulant tolerance was not seen to be significantly influenced in the absence of bromadiolone selection. As the population size...

Utilization of oral anticoagulation in a teaching hospital in Nigeria ...

African Journals Online (AJOL)

The mean age of the patients was 53.4 years and more females than males were on anticoagulation and monitoring (F14:M12). The most common indications for anticoagulation include deep venous thrombosis/pulmonary embolism, congestive heart failure with atrial fibrillation and mitral valve disease with atrial fibrillation.

Enhancing anticoagulation and endothelial cell proliferation of titanium surface by sequential immobilization of poly(ethylene glycol) and collagen

International Nuclear Information System (INIS)

Pan, Chang-Jiang; Hou, Yan-Hua; Ding, Hong-Yan; Dong, Yun-Xiao

2013-01-01

In the present study, poly(ethylene glycol) (PEG) and collagen I were sequentially immobilized on the titanium surface to simultaneously improve the anticoagulation and endothelial cell proliferation. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy analysis confirmed that PEG and collagen I were successfully immobilized on the titanium surface. Water contact angle results suggested the excellent hydrophilic surface after the immobilization. The anticoagulation experiments demonstrated that the immobilized PEG and collagen I on the titanium surface could not only obviously prevent platelet adhesion and aggregation but also prolong activated partial thromboplastin time (APTT), leading to the improved blood compatibility. Furthermore, immobilization of collagen to the end of PEG chain did not abate the anticoagulation. As compared to those on the pristine and PEG-modified titanium surfaces, endothelial cells exhibited improved proliferative profiles on the surface modified by the sequential immobilization of PEG and collagen in terms of CCK-8 assay, implying that the modified titanium may promote endothelialization without abating the blood compatibility. Our method may be used to modify the surface of blood-contacting biomaterials such as titanium to promote endothelialization and improve the anticoagulation, it may be helpful for development of the biomedical devices such as coronary stents, where endothelializaton and excellent anticoagulation are required.

Isolamento, fracionamento e atividade anticoagulante de iota-carragenanas da Solieria filiformis Isolation, fractionation and anticoagulant activity of iota-carrageenans from Solieria filiformis

Directory of Open Access Journals (Sweden)

José Ariévilo Gurgel Rodrigues

2010-11-01

Full Text Available Este estudo teve como objetivo isolar, fracionar e avaliar o potencial anticoagulante de iota-carragenanas (i-CARs da rodofícea Solieria filiformis, quando obtidas por dois métodos de extração (M I e M II. As i-CARs foram isoladas com papaína bruta em tampão acetato de sódio 0,1M (pH 5,0, contendo cisteína 5mM e EDTA 5mM (M I ou água (80°C (M II e, em seguida, determinada sua composição química de carboidratos totais, sulfato livre (SL e proteínas contaminantes. As i-CARs foram submetidas à cromatografia de troca iônica (DEAE-celulose usando um gradiente de cloreto de sódio, sendo avaliado o tempo de tromboplastina parcial ativada (TTPA e tempo de protrombina das frações obtidas e comparadas à heparina (193UI mg-1. Uma fração anticoagulante também foi submetida ao procedimento de eletroforese em gel de agarose a 0,5%. A diferença no rendimento de i-CARs entre os métodos foi 10,14%. A composição química de SL (29,40% e o fracionamento, por DEAE-celulose, indicaram o M I mais eficiente na obtenção de i-CARs, comparado ao M II. O TTPA também foi somente alterado para as i-CARs do M I. Contudo, a atividade anticoagulante in vitro de uma fração rica (8,52UI mg-1 foi inferior à da heparina.This study aimed to isolate, fractionate and evaluate the anticoagulant potential of iota-carrageenans (i-CARs from Solieria filiformis when two extraction methods (M I and M II were used. i-CARs were isolated with papain in 0.1M sodium acetate (pH 5.0 containing 5mM cystein and 5mM EDTA (M I or water (80°C (M II, and then their chemical composition of total carbohydrates, free sulfate (FS and contaminant proteins were determined. i-CARs were submitted to anion-exchange chromatography (DEAE-cellulose using a sodium chloride gradient,being evaluated the activated partial thromboplastin time (APTT and prothrombin time of obtained fractions and compared to heparin (193IU mg-1. A rich fraction of anticoagulant was also submitted to 0

An Easy Method to Eliminate the Effect of Lupus Anticoagulants in the Coagulation Factor Assay.

Science.gov (United States)

Tang, Ning; Yin, Shiyu

2016-07-01

To build and evaluate intrinsic coagulation factor assays which can eliminate the effect of lupus anticoagulants (LAC). Commercial silica clotting time confirmatory (SCT-C) reagent containing sufficient synthetic phospholipid and routine activated partial thromboplastin time (APTT) reagent were each used for one-stage detection of FVIII, FIX, and FXI activities, in samples with or without LAC, and the results were compared. For samples without LAC, consistent results of FVIII, FIX, and FXI using both SCT-C reagent and APTT reagent were obtained. For samples with LAC, the assays with SCT-C reagent not only could eliminate the effect of strong lupus anticoagulants but also needed fewer dilutions than that with routine APTT reagent. The intrinsic factor detections by SCT-C reagent are credible and convenient to be used for samples with LAC.

Non-vitamin K antagonist oral anticoagulation agents in anticoagulant naïve atrial fibrillation patients

DEFF Research Database (Denmark)

Olesen, Jonas Bjerring; Sørensen, Rikke; Hansen, Morten Lock

2015-01-01

AIMS: Non-vitamin K antagonist oral anticoagulation (NOAC) agents have been approved for stroke prophylaxis in atrial fibrillation (AF). We investigated 'real-world' information on how these drugs are being adopted. METHODS AND RESULTS: Using Danish nationwide administrative registers, we identif...

Hemorrhagic stroke and oral anticoagulants: What is to be done?

Directory of Open Access Journals (Sweden)

M. A. Domashenko

2016-01-01

Full Text Available Hemorrhagic stroke (HS is associated with high mortality and disability rates. Due to the introduction of the current guidelines for the prevention of systemic thromboembolic events in patients with atrial fibrillations and to an increase in the number of older patients, there has been a rise in the incidence of intracranial hemorrhage (ICH associated with the use of oral anticoagulants. The paper discusses medical treatment in patients with HS during therapy with vitamin K antagonists (warfarin and novel oral anticoagulants (dabigatran. rivaroxaban, apixaban, as well as an anticoagulant resumption policy after prior ICH in patients at high risk for thromboembolic events.

Use of anticoagulant rodenticides in outdoor urban areas: considerations and proposals for the protection of public health and non-target species.

Science.gov (United States)

Dutto, M; Di Domenico, D; Rubbiani, M

2018-01-01

Rodent control operations represent an important tool for the prevention and management of infestations, in outdoor environments, by synanthropic rodents (Rattus rattus and R. norvegicus), which are a source of economic and environmental damage with significant sanitary implications. Although the use of anticoagulants is safer to humans and pets compared to the use of acute poisoning substances, an intrinsic hazard of the active ingredients exists, i.e. the possible poisoning of non-target organisms (e.g., children, pets and wildlife) following exposure. The risks arising from the use of anticoagulants for rodent control operations in anthropic contexts can therefore only be mitigated by a proper selection of the active ingredient, bait formulation and administration techniques, since an active ingredient with selective action towards non-target species does not currently exist on the market. This document lists practical proposals aimed at reducing the possibility of toxic exposure to anticoagulant rodenticides and mitigate the toxicological risk of human baits and non-target species.

APPLICATIONS OF PHARMACOGENETIC TESTING FOR PERSONALIZATION OF THERAPY WITH ORAL ANTICOAGULANTS IN RUSSIA

Directory of Open Access Journals (Sweden)

D. A. Sychev

2013-01-01

Full Text Available The clinical significance of the patient genetic characteristics in the individual pharmacological response to oral anticoagulants is considered. Possible tactics of warfarin dosing and new oral anticoagulants choice on the basis of pharmacogenetic testing as well as indications for this approach in clinical practice are discussed. It should increase efficacy and safety of anticoagulant therapy.

Direct Oral Anticoagulants and Women

NARCIS (Netherlands)

Cohen, Hannah; Arachchillage, Deepa R. J.; Beyer-Westendorf, Jan; Middeldorp, Saskia; Kadir, Rezan A.

2016-01-01

Direct oral anticoagulants (DOACs) provide an effective, safe, and convenient therapeutic alternative to warfarin and other vitamin K antagonists (VKAs), and are now established for a wide range of indications. The use of DOACs in women merits special consideration due to two main situations: first,

Anticoagulation Quality and Complications of using Vitamin K Antagonists in the Cardiac Surgery Outpatient Clinic

Directory of Open Access Journals (Sweden)

Mário Augusto Cray da Costa

Full Text Available ABSTRACT Introduction: In patients with mechanical prosthetic heart valves or atrial fibrillation requiring anticoagulation to prevent thromboembolic events, several factors influence adherence and anticoagulation complications. Objective: To evaluate the factors that interfere with the quality and complications of anticoagulation with vitamin K antagonists. Methods: A retrospective cohort study of 100 patients, in the period from 2011 to 2014, was performed. Anticoagulation conditions in the last year, regarding the presence of complications (embolisms/bleeding and inadequate treatment were assessed: achievement of less than 8 annual prothrombin times and International Normalized Ratio outside therapeutic target in more than 40% of prothrombin times. Results: There were 31 complications (22 minor bleeding without hospitalization and 9 major complications: 7 bleeding with hospitalization and two emboli; 70 were with International Normalized Ratio outside the target in more than 40% of the tests and 36 with insufficient number of prothrombin times. Socioeconomic factors, anticoagulant type and anticoagulation reason had no relationship with complications or with inadequate treatment. There were more complications in patients with longer duration of anticoagulation (P=0.001. Women had more International Normalized Ratio outside the target range (OR 2.61, CI:1.0-6.5; P=0.04. Patients with lower number of annual prothrombin times had longer times of anticoagulation (P=0.03, less annual consultations (P=0.02 and less dose adjustments (P=0.003. Patients with longer duration of anticoagulation have more complications (P=0.001. Conclusion: There was a high rate of major complications and International Normalized Ratio was outside the goal. Less annual prothrombin times was related to longer duration of anticoagulation, less annual consultations and less dose adjustments. More major complications occurred in patients with longer duration of

Fall risk and anticoagulation for atrial fibrillation in the elderly: A delicate balance.

Science.gov (United States)

Hagerty, Tracy; Rich, Michael W

2017-01-01

Guidelines for managing atrial fibrillation recommend systemic anticoagulation for almost all patients age 65 and older, but in practice up to 50% of older patients do not receive maintenance anticoagulation therapy. The most common reason physicians cite for withholding anticoagulation in older patients with atrial fibrillation is a perception of a high risk of falling and associated bleeding, especially intracranial hemorrhage. Copyright © 2017 Cleveland Clinic.

Hematin-derived anticoagulant. Generation in vitro and in vivo

OpenAIRE

1986-01-01

Prolongation of clotting times produced by hematin was investigated both in vitro and in vivo. Hematin-derived anticoagulant (HDA) was found to be due to a degradative product or derivative of hematin, and was generated in vitro in standing (aging) aqueous solutions of the parent compound. Generation of HDA in vitro was inhibited by antioxidants. The anticoagulant effect of HDA was inhibited by freshly prepared hematin, fresh Sn-protoporphyrin, imidazole, or the iron chelator desferrioxamine....

Contact activation: a revision.

Science.gov (United States)

Schmaier, A H

1997-07-01

In conclusion, a revised view of the contact system has been presented. This system has little to do with the initiation of hemostasis. Like lupus anticoagulants, deficiencies of contact proteins give prolonged APTTs but may be risk factors for thrombosis. BK from kininogens is a potent modulator of vascular biology inducing vasodilation, tissue plasminogen activator release, and prostacyclin liberation. Kininogens, themselves, are selective inhibitors of alpha-thrombin-induced platelet activation preventing alpha-thrombin from cleaving the cloned thrombin receptor after arginine41. Kininogens' alpha-thrombin inhibitory activity exists in intact kininogens, BK, and all of BK's breakdown products. HK also is the pivotal protein for contact protein assembly on endothelium. It is the receptor for prekallikrein which when bound to HK becomes activated to kallikrein by an endothelial cell enzyme system independent of activated forms of plasma factor XII. Prekallikrein activation on endothelial cells results in kinetically favorable single chain urokinase and plasminogen activation. Thus the "physiologic, negatively charged surface" for contact system activation is really the assembly of these proteins on cell membranes and activation by membrane-associated enzymes.

Oral Anticoagulation in Patients With Liver Disease.

Science.gov (United States)

Qamar, Arman; Vaduganathan, Muthiah; Greenberger, Norton J; Giugliano, Robert P

2018-05-15

Patients with liver disease are at increased risks of both thrombotic and bleeding complications. Many have atrial fibrillation (AF) or venous thromboembolism (VTE) necessitating oral anticoagulant agents (OACs). Recent evidence has contradicted the assumption that patients with liver disease are "auto-anticoagulated" and thus protected from thrombotic events. Warfarin and non-vitamin K-antagonist OACs have been shown to reduce thrombotic events safely in patients with either AF or VTE. However, patients with liver disease have largely been excluded from trials of OACs. Because all currently approved OACs undergo metabolism in the liver, hepatic dysfunction may cause increased bleeding. Thus, the optimal anticoagulation strategy for patients with AF or VTE who have liver disease remains unclear. This review discusses pharmacokinetic and clinical studies evaluating the efficacy and safety of OACs in patients with liver disease and provides a practical, clinically oriented approach to the management of OAC therapy in this population. Copyright © 2018 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

POST-NOAC: Portuguese observational study of intracranial hemorrhage on non-vitamin K antagonist oral anticoagulants.

Science.gov (United States)

Marques-Matos, Cláudia; Alves, José Nuno; Marto, João Pedro; Ribeiro, Joana Afonso; Monteiro, Ana; Araújo, José; Silva, Fernando; Grenho, Fátima; Viana-Baptista, Miguel; Sargento-Freitas, João; Pinho, João; Azevedo, Elsa

2017-08-01

Background There is a lower reported incidence of intracranial hemorrhage with non-vitamin K antagonist oral anticoagulants compared with vitamin K antagonist. However, the functional outcome and mortality of intracranial hemorrhage patients were not assessed. Aims To compare the outcome of vitamin K antagonists- and non-vitamin K antagonist oral anticoagulants-related intracranial hemorrhage. Methods We included consecutive patients with acute non-traumatic intracranial hemorrhage on oral anticoagulation therapy admitted between January 2013 and June 2015 at four university hospitals. Clinical and demographic data were obtained from individual medical records. Intracranial hemorrhage was classified as intracerebral, extra-axial, or multifocal using brain computed tomography. Three-month functional outcome was assessed using the modified Rankin Scale. Results Among 246 patients included, 24 (9.8%) were anticoagulated with a non-vitamin K antagonist oral anticoagulants and 222 (90.2%) with a vitamin K antagonists. Non-vitamin K antagonist oral anticoagulants patients were older (81.5 vs. 76 years, p = 0.048) and had intracerebral hemorrhage more often (83.3% vs. 63.1%, p = 0.048). We detected a non-significant trend for larger intracerebral hemorrhage volumes in vitamin K antagonists patients ( p = 0.368). Survival analysis adjusted for age, CHA 2 DS 2 VASc, HAS-BLED, and anticoagulation reversal revealed that non-vitamin K antagonist oral anticoagulants did not influence three-month mortality (hazard ratio (HR) = 0.83, 95% confidence interval (CI) = 0.39-1.80, p = 0.638). Multivariable ordinal regression for three-month functional outcome did not show a significant shift of modified Rankin Scale scores in non-vitamin K antagonist oral anticoagulants patients (odds ratio (OR) 1.26, 95%CI 0.55-2.87, p = 0.585). Conclusions We detected no significant differences in the three-month outcome between non-vitamin K antagonist oral anticoagulants

The effect anticoagulation status on geriatric fall trauma patients.

Science.gov (United States)

Coleman, Julia; Baldawi, Mustafa; Heidt, David

2016-12-01

This research study aims to identify the effect of anticoagulation status on hospital course, complications, and outcomes among geriatric fall trauma patients. The study design is a retrospective cohort study, looking at fall trauma among patients aged 60 to 80 years from 2009 to 2013 at a university hospital in the United States. The statistical analysis, conducted with SPSS software with a threshold for statistical significance of P patients included in this study was 1,121. Compared with patients not on anticoagulation, there was a higher LOS among patients on anticoagulation (6.3 ± 6.2 vs 4.9 ± 5.2, P = .001). A higher LOS (7.2 ± 6.8 vs 5.0 ± 5.3, P = .001) and days in the ICU (2.1 ± 5.4 vs 1.1 ± 3.8, P = .010) was observed in patients on warfarin. A higher mortality (7.1% vs 2.8%, P = .013), LOS (6.3 ± 6.2 vs 5.1 ± 5.396, P = .036), and complication rate (49.1 vs 36.7, P = .010) was observed among patients on clopidogrel. In this study, a higher mortality and complication rate were seen among clopidogrel, and a greater LOS and number of days in the ICU were seen in patients on warfarin. These differences are important, as they can serve as a screening tool for triaging the severity of a geriatric trauma patient's condition and complication risk. For patients on clopidogrel, it is essential that these patients are recognized early as high-risk patients who will need to be monitored more closely. For patients on clopidogrel or warfarin, bridging a patient's anticoagulation should be initiated as soon as possible to prevent unnecessary increased LOS. At last, these data also provide support against prescribing patients clopidogrel when other anticoagulation options are available. Published by Elsevier Inc.

Will NOACs become the new standard of care in anticoagulation therapy?

Directory of Open Access Journals (Sweden)

Ergene Oktay

2015-06-01

Full Text Available Atrial fibrillation is the most common cardiac arrhythmia in the general population, with a prevalence of 1–3%, which increases with age, reaching 15% in elderly people. Prophylaxis of ischemic stroke with warfarin was the gold standard of medical management for many years. On the other hand heparin and warfarin was the main pharmacologic agents for the prophylaxis/treatment of venous thromboembolism. In the last 5 years warfarin is getting replaced by non-vitamin K antagonist oral anticoagulants at least partly. In this article it is attempted to foresee whether new oral anticoagulants will become the new standard of care in anticoagulation therapy.

Citrate Anticoagulation for CRRT in Children: Comparison with Heparin

Directory of Open Access Journals (Sweden)

Sara Nicole Fernández

2014-01-01

Full Text Available Regional anticoagulation with citrate is an alternative to heparin in continuous renal replacement therapies, which may prolong circuit lifetime and decrease hemorrhagic complications. A retrospective comparative cohort study based on a prospective observational registry was conducted including critically ill children undergoing CRRT. Efficacy, measured as circuit survival, and secondary effects of heparin and citrate were compared. 12 patients on CRRT with citrate anticoagulation and 24 patients with heparin anticoagulation were analyzed. Median citrate dose was 2.6 mmol/L. Median calcium dose was 0.16 mEq/kg/h. Median heparin dose was 15 UI/kg/h. Median circuit survival was 48 hours with citrate and 31 hours with heparin (P=0.028. 66.6% of patients treated with citrate developed mild metabolic alkalosis, which was directly related to citrate dose. There were no cases of citrate intoxication: median total calcium/ionic calcium index (CaT/I of 2.16 and a maximum CaT/I of 2.33, without metabolic acidosis. In the citrate group, 45.5% of patients developed hypochloremia and 27.3% hypomagnesemia. In the heparin group, 27.8% developed hypophosphatemia. Three patients were moved from heparin to citrate to control postoperatory bleeding. In conclusion citrate is a safe and effective anticoagulation method for CRRT in children and it achieves longer circuit survival than heparin.

Adverse effects of anticoagulation treatment: clinically significant upper gastrointestinal hemorrhage

Directory of Open Access Journals (Sweden)

Pavel Skok

2006-12-01

Full Text Available Background: Over the last years, the use of oral anticoagulant treatment has increased dramatically, principally for the prevention of venous thrombosis and thrombembolic events. This treatment is demanding, especially among the elderly with concommitant diseases and different medication. Aim of the study to evaluate the rate of serious complications, clinically significant hemorrhage from upper gastointestinal tract in patients treated with oral antiocoagulants in a prospective cohort study.Patients and methods: Included were patients admitted to our institution between January 1, 1994 and December 31, 2003 due to gastrointestinal hemorrhage. Emergency endoscopy and laboratory testing was performed in all patients.Results: 6416 patients were investigated: 2452 women (38.2 % and 3964 men (61.8 %, mean age 59.1 years, SD 17.2. Among our patients, 55 % were aged over 60 years. In 86.4 % of patients the source of bleeding was confirmed in the upper gastrointestinal tract. In the last week prior to bleeding, 20.4 % (1309/6416 of all patients were regularly taking nonsteroidal anti-inflammatory drugs, anticoagulant therapy or antiplatelet agents in single daily doses at least. 6.3 % of patients (82/1309 with abundant hemorrhage from upper gastrointestinal tract were using oral anticoagulant therapy and had INR > 5 at admission, 25.6 % of them had INR > 10. The mortality of patients using oral anticoagulants and INR > 5 was 17.1 %.Conclusions: Upper gastrointestinal hemorrhage is a serious complication of different medications, particularly in elderly patients. Safe use of anticoagulant therapy is based on careful selection of patients and correct intake of the prescribed drugs.

Can we withdraw anticoagulation in patients with antiphospholipid syndrome after seroconvertion?

Science.gov (United States)

Sciascia, S; Coloma-Bazán, E; Radin, M; Bertolaccini, M L; López-Pedrera, C; Espinosa, Gerard; Meroni, P L; Cervera, R; Cuadrado, M J

2017-11-01

The current mainstay of treatment in patients with thrombotic antiphospholipid syndrome (APS) is long-term anticoagulation, mainly with Vitamin K antagonist agents. Some recently available studies have created new ground for discussion about the possible discontinuation of anticoagulation therapy in patients with a history of thrombotic APS in whom antiphospholipid antibodies (aPL) are not detected any longer (i.e. aPL seroconversion). We report the main points discussed at the last CORA Meeting regarding the issue whether or not anticoagulation can be stopped after aPL seroconversion. In particular, we systematically reviewed the available evidence investigating the clinical outcome of APS patients with aPL seroconversion in whom anticoagulation was stopped when compared to those in whom therapy was continued regardless the aPL profile. Furthermore, the molecular basis for the aPL pathogenicity, the available evidence of non-criteria aPL and their association with thrombosis are addressed. To date, available evidence is still limited to support the indication to stop oral anticoagulation therapy in patients with a previous diagnosis of thrombotic APS who subsequently developed a negative aPL profile. The identification of the whole risk profile for cardiovascular manifestations and possibly of a second level aPL testing in selected patients with aPL might support the eventual clinical decision but further investigation is warranted. Copyright © 2017 Elsevier B.V. All rights reserved.

A comparative assessment of efficacy of three anticoagulant rodenticides.

Science.gov (United States)

Renapurkar, D M

1982-01-01

Results are presented of feeding tests carried out with three common anticoagulant rodenticides viz., coumatetralyl, fumarin and warfarin on three common species of commensal rodents i.e., Rattus rattus, Rattus norvegicus and Bandicota bengalensis. All three species of rodents were susceptible to anticoagulant rodenticides. However, the action of these compounds in B. bengalensis was comparatively slow. Coumatetralyl was found to be the most effective rodenticide followed by fumarin and warfarin. Liquid baits of these compounds are more effective in comparison to food baits.

Acute management of stroke patients taking non-vitamin K antagonist oral anticoagulants Addressing Real-world Anticoagulant Management Issues in Stroke (ARAMIS) Registry: Design and rationale.

Science.gov (United States)

Xian, Ying; Hernandez, Adrian F; Harding, Tina; Fonarow, Gregg C; Bhatt, Deepak L; Suter, Robert E; Khan, Yosef; Schwamm, Lee H; Peterson, Eric D

2016-12-01

Non-vitamin K antagonist oral anticoagulants (NOACs, dabigatran, rivaroxaban, apixaban, and edoxaban) have been increasingly used as alternatives to warfarin for stroke prophylaxis in patients with atrial fibrillation. Yet there is substantial lack of information on how patients on NOACs are currently treated when they have an acute ischemic stroke and the best strategies for treating intracerebral hemorrhage for those on chronic anticoagulation with warfarin or a NOAC. These are critical unmet needs for real world clinical decision making in these emergent patients. The ARAMIS Registry is a multicenter cohort study of acute stroke patients who were taking chronic anticoagulation therapy prior to admission and are admitted with either an acute ischemic stroke or intracerebral hemorrhage. Built upon the existing infrastructure of American Heart Association/American Stroke Association Get With the Guidelines Stroke, the ARAMIS Registry will enroll a total of approximately 10,000 patients (5000 with acute ischemic stroke who are taking a NOAC and 5000 with anticoagulation-related intracerebral hemorrhage who are on warfarin or a NOAC). The primary goals of the ARAMIS Registry are to provide a comprehensive picture of current treatment patterns and outcomes of acute ischemic stroke patients on NOACs, as well as anticoagulation-related intracerebral hemorrhage in patients on either warfarin or NOACs. Beyond characterizing the index hospitalization, up to 2500 patients (1250 ischemic stroke and 1250 intracerebral hemorrhage) who survive to discharge will be enrolled in an optional follow-up sub-study and interviewed at 3 and 6 months after discharge to assess longitudinal medication use, downstream care, functional status, and patient-reported outcomes. The ARAMIS Registry will document the current state of management of NOAC treated patients with acute ischemic stroke as well as contemporary care and outcome of anticoagulation-related intracerebral hemorrhage. These

Abnormal uterine bleeding in women receiving direct oral anticoagulants for the treatment of venous thromboembolism.

Science.gov (United States)

Godin, Richard; Marcoux, Violaine; Tagalakis, Vicky

2017-08-01

Abnormal uterine bleeding (AUB) is a common complication of anticoagulant therapy in premenopausal women affected with acute venous thromboembolism. AUB impacts quality of life, and can lead to premature cessation of anticoagulation. There is increasing data to suggest that the direct oral anticoagulants when used for the treatment of venous thromboembolism differ in their menstrual bleeding profile. This article aims to review the existing literature regarding the association between AUB and the direct oral anticoagulants and make practical recommendations. Copyright © 2017 Elsevier Inc. All rights reserved.

Management of Periprocedural Anticoagulation: A Survey of Contemporary Practice.

Science.gov (United States)

Flaker, Greg C; Theriot, Paul; Binder, Lea G; Dobesh, Paul P; Cuker, Adam; Doherty, John U

2016-07-12

Interruption of oral anticoagulation (AC) for surgery or an invasive procedure is a complicated process. Practice guidelines provide only general recommendations, and care of such patients occurs across multiple specialties. The availability of direct oral anticoagulants further complicates decision making and guidance here is limited. To evaluate current practice patterns in the United States for bridging AC, a survey was developed by the American College of Cardiology Anticoagulation Work Group. The goal of the survey was to assess how general and subspecialty cardiologists, internists, gastroenterologists, and orthopedic surgeons currently manage patients who receive AC and undergo surgery or an invasive procedure. The survey was completed by 945 physicians involved in the periprocedural management of AC. The results provide a template for educational and research projects geared toward the development of clinical pathways and point-of-care tools to improve this area of health care. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Retroperitoneal Bleeding: An Experience During Prophylactic Anticoagulation in a Patient With Nephrotic Syndrome

Directory of Open Access Journals (Sweden)

Mari Okada

2017-07-01

Full Text Available The association between nephrotic syndrome (NS and a hypercoagulable state has been demonstrated. Controlling the blood clotting activity may therefore be attractive for patients with nephrosis in terms of thromboembolism prophylaxis. We herein report a 75-year-old woman with minimal change disease who developed pains in the right back, groin, and thigh because of retroperitoneal bleeding during prophylactic anticoagulation with unfractionated heparin. Although this procedure has not been accepted as the standard of care for patients with nephrosis, pharmacologic prophylaxis may already be practiced empirically, as in the present patient. We believe that our experience highlights the pitfalls of such a management in patients with nephrosis, implying the need for a diagnostic strategy for identifying those patients with NS who can benefit from prophylactic anticoagulation. Several concerns that emerged in this case are also discussed.

Two acidic, anticoagulant PLA2 isoenzymes purified from the venom of monocled cobra Naja kaouthia exhibit different potency to inhibit thrombin and factor Xa via phospholipids independent, non-enzymatic mechanism.

Directory of Open Access Journals (Sweden)

Ashis K Mukherjee

Full Text Available The monocled cobra (Naja kaouthia is responsible for snakebite fatality in Indian subcontinent and in south-western China. Phospholipase A2 (PLA2; EC 3.1.1.4 is one of the toxic components of snake venom. The present study explores the mechanism and rationale(s for the differences in anticoagulant potency of two acidic PLA2 isoenzymes, Nk-PLA2α (13463.91 Da and Nk-PLA2β (13282.38 Da purified from the venom of N. kaouthia.By LC-MS/MS analysis, these PLA2s showed highest similarity (23.5% sequence coverage with PLA2 III isolated from monocled cobra venom. The catalytic activity of Nk-PLA2β exceeds that of Nk-PLA2α. Heparin differentially regulated the catalytic and anticoagulant activities of these Nk-PLA2 isoenzymes. The anticoagulant potency of Nk-PLA2α was comparable to commercial anticoagulants warfarin, and heparin/antithrombin-III albeit Nk-PLA2β demonstrated highest anticoagulant activity. The anticoagulant action of these PLA2s was partially contributed by a small but specific hydrolysis of plasma phospholipids. The strong anticoagulant effect of Nk-PLA2α and Nk-PLA2β was achieved via preferential, non-enzymatic inhibition of FXa (Ki = 43 nM and thrombin (Ki = 8.3 nM, respectively. Kinetics study suggests that the Nk-PLA2 isoenzymes inhibit their "pharmacological target(s" by uncompetitive mechanism without the requirement of phospholipids/Ca(2+. The anticoagulant potency of Nk-PLA2β which is higher than that of Nk-PLA2α is corroborated by its superior catalytic activity, its higher capacity for binding to phosphatidylcholine, and its greater strength of thrombin inhibition. These PLA2 isoenzymes thus have evolved to affect haemostasis by different mechanisms. The Nk-PLA2β partially inhibited the thrombin-induced aggregation of mammalian platelets suggesting its therapeutic application in the prevention of unwanted clot formation.In order to develop peptide-based superior anticoagulant therapeutics, future application of Nk-PLA2

Use of antifibrinolytic mouthwash solution in anticoagulated oral surgery patients

OpenAIRE

Dimova, Cena; Evrosimovska, Biljana; Papakoca, Kiro; Georgiev, Zlatko; Angelovska, Bistra; Ristoska, Sonja

2012-01-01

Introduction:The ordinary treatment of anticoagulated patients includes the interruption of anticoagulant therapy for oral surgery interventions to prevent hemorrhage. However, this practice may logically increase the risk of a potentially life-threatening thromboembolism, so this issue is still controversial. The aim of the study was to evaluate the antifibrinolitic mouthwash solution (tranexamic acid) as a local haemostatic modality after oral surgery interventions. Methods:To realize the a...

Hemorrhagic transformation in patients with acute ischaemic stroke and an indication for anticoagulation.

Science.gov (United States)

Marsh, E B; Llinas, R H; Hillis, A E; Gottesman, R F

2013-06-01

Intracerebral hemorrhage (ICH) can occur in patients following acute ischaemic stroke in the form of hemorrhagic transformation, and results in significant long-term morbidity and mortality. Anticoagulation theoretically increases risk. We evaluated stroke patients with an indication for anticoagulation to determine the factors associated with hemorrhagic transformation. Three-hundred and forty-five patients with ICD-9 codes indicating: (i) acute ischaemic stroke; and (ii) an indication for anticoagulation were screened. One-hundred and twenty-three met inclusion criteria. Data were collected retrospectively. Neuroimaging was reviewed for infarct volume and evidence of ICH. Hemorrhages were classified as: hemorrhagic conversion (petechiae) versus intracerebral hematoma (a space occupying lesion); symptomatic versus asymptomatic. Using multivariable logistic regression, we determined the hypothesized factors associated with intracerebral bleeding. Age [odds ratio (OR) = 1.50 per 10-year increment, 95% confidence interval (CI) 1.07-2.08], infarct volume (OR = 1.10 per 10 ccs, 95% CI 1.06-1.18) and worsening category of renal impairment by estimated glomerular filtration rate (eGFR; OR = 1.95, 95% CI 1.04-3.66) were predictors of hemorrhagic transformation. Ninety- nine out of 123 patients were anticoagulated. Hemorrhage rates of patients on and off anticoagulation did not differ (25.3% vs. 20.8%; P = 0.79); however, all intracerebral hematomas (n = 7) and symptomatic bleeds (n = 8) occurred in the anticoagulated group. The risk of hemorrhagic transformation in patients with acute ischaemic stroke and an indication for anticoagulation is multifactorial, and most closely associated with an individual's age, infarct volume and eGFR. © 2013 The Author(s) European Journal of Neurology © 2013 EFNS.

Prediction of the risk of bleeding during anticoagulant treatment for venous thromboembolism

NARCIS (Netherlands)

Kuijer, P. M.; Hutten, B. A.; Prins, M. H.; Büller, H. R.

1999-01-01

OBJECTIVES: To construct and validate the bleeding risk prediction score, which is based on variables identified in the literature that can be easily obtained before the institution of anticoagulant therapy, in a large independent cohort of patients who were treated with anticoagulant therapy for

Effect of post-filter anticoagulation on mortality in patients with cancer-associated pulmonary embolism.

Science.gov (United States)

Kang, Jieun; Kim, Seon Ok; Oh, Yeon-Mok; Lee, Sang-Do; Lee, Jae Seung

2018-05-17

Malignancy is associated with an increased risk of venous thromboembolism. Inferior vena cava filters are a viable alternative when anticoagulation is infeasible because of the risk of bleeding. Although the current guidelines recommend that all patients with a vena cava filter be treated with anticoagulation treatment when the risk of bleeding is reduced, studies concerning the role of concomitant anticoagulation after vena cava filter insertion in high-risk patients are scarce. Since many cancer patients suffer from a high risk of hemorrhagic complications, we aimed to determine the effect of post-filter anticoagulation on mortality in patients with a malignant solid tumor. A retrospective cohort study of patients with pulmonary embolism was performed between January 2010 and May 2016. Patients with a solid tumor and vena cava filter inserted because of pulmonary embolism were included. Using Cox proportional hazards model, the prognostic effect of clinical variables was analyzed. A total of 180 patients were analyzed, with 143 patients receiving and 37 patients not receiving post-filter anticoagulation treatment. Mortality was not significantly different between the two groups. The presence of metastatic cancer and that of pancreatobiliary cancer were significant risk factors for mortality. However, post-filter anticoagulation did not show significant effect on mortality regardless of the stage of cancer. In patients with cancer-associated pulmonary embolism, the effect of post-filter anticoagulation on mortality may not be critical, especially in patients with a short life expectancy.

Evaluation of morning glory (Jacquemontia tamnifolia (L.) Griseb) leaves for antioxidant, antinociceptive, anticoagulant and cytotoxic activities.

Science.gov (United States)

Hossain, Mohammad Shahadat; Reza, A S M Ali; Rahaman, Md Masudur; Nasrin, Mst Samima; Rahat, Mohammed Rasib Uddin; Islam, Md Rabiul; Uddin, Md Josim; Rahman, Md Atiar

2018-01-05

The present study was planned to investigate the phytochemical, antioxidant, antinociceptive, anticoagulant and cytotoxic activities of the Jacquemontia tamnifolia (L.) Griseb leaf methanol extract (MExJT) in the laboratory using both in vitro and in vivo methods. Phytochemical values, namely, total phenolic and flavonoid contents, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging effect and FeCl3 reducing power effects, were studied by established methods. In vivo antinociceptive activity was performed by acidic acid-induced writhing test and formalin-induced pain test on Swiss albino mice at doses of 125, 250 and 500 mg/kg body weight. The clot lysis and brine shrimp lethality bioassay in vitro were used to evaluate the thrombolytic and cytotoxic activities of the plant extract, respectively. Phytochemical screening illustrates the presence of tannins, saponins, flavonoids, gums and carbohydrates, steroids, alkaloids and reducing sugars in the extract. The results showed the total phenolic content (146.33 g gallic acid equivalents/100 g extract) and total flavonoid content (133.33 g quercetin/100 g). Significant (pacetic acid-induced writhing test and formalin-induced pain models in Swiss albino mice with doses of 125, 250 and 500 mg/kg body weight. Significant (panalgesic activity. The results also demonstrate that MExJT has moderate thrombolytic and lower cytotoxic properties that may warrant further exploration.

Old and new oral anticoagulants for secondary stroke prevention in atrial fibrillation

Directory of Open Access Journals (Sweden)

Tommaso Sacquegna

2015-12-01

Full Text Available Vitamin K antagonists, such as warfarin, used in oral anticoagulation therapy currently represent the standard drugs for the primary and secondary prevention of stroke in non-valvular atrial fibrillation (AF, with a relative risk reduction close to 70%. Newer oral anticoagulants, such as direct thrombin inhibitors (i.e., dabigatran and direct factor Xa inhibitors (i.e., apixaban and rivaroxaban have been recently compared with warfarin in large randomized trials for stroke prevention in AF. The new oral anticoagulants showed, compared with warfarin, no statistically significant difference in the rate of stroke or systemic embolism in secondary prevention (patients with previous transient ischemic attack or stroke subgroups. With regard to safety, the risk of intracranial bleeding was reduced with new anticoagulants compared with warfarin. Indirect treatment comparisons of clinical trials on secondary prevention cohorts showed no significant difference in efficacy among apixaban, rivaroxaban, and dabigatran; but dabigatran 110 mg was associated with less intracranial bleedings than rivaroxaban.

Pathogenetic Substantiation of the Usability of the Natural Anticoagulant Sulodexide in a Combine Treatment of Pregnant Women with Premature Delivery

Directory of Open Access Journals (Sweden)

T. A. Mielikova

2017-05-01

Full Text Available Clinical effectiveness of the Natural Anticoagulant Sulodexide at violations in system of a hemostasis at pregnant women with threat of premature births is studied. 57 pregnant women with threat of premature births are examined. At 31 women in a combine of treatment applied Sulodexide, at 26 – a heparin, at 20 the physiological current of a gestation is noted. Conducted all-clinical examination of pregnant women, estimated a condition of system of a hemostasis before combine treatment. At patients at threat of premature births essential have significant changes in the hemostatic system, manifested in thrombocyte hyper-aggregation and hyper-coagulation in the plasma link of hemostasis, as well as appearance of markers of activating the intravascular blood coagulation. Use of the natural anticoagulant sulodexide for pregnant women provided the high antithrombotic potential  and moderate anti-coagulative activity, contributed to normalization of rheological behavior of blood by influence on all links of a hemostasis, to improvement of the course of the gestational period and the functional state of the fetus.

Synthesis of highly anti-HIV active sulfated poly- and oligo-saccharides and analysis of their action mechanisms by NMR [nuclear magnetic resonance] spectroscopy

International Nuclear Information System (INIS)

Uryu, Toshiyuki

1998-01-01

We have been synthesizing sulfated polysaccharides and oligosaccharides with highly anti-HIV (human immunodeficiency virus) activities. It has been known that sulfated polysaccharides such as dextran sulfate and pentosan polysulfate have biological activities such as anticoagulant activity and recently anti-HIV activity. Curdlan sulfate having 1,3-β-linked glucan backbone had high anti-HIV activity but low anticoagulant activity. Phase I/II test for the curdlan sulfate as an AIDS (acquired immunodeficiency syndrome) drug was carried out in the United States. In this study, regioselectivity sulfatec curdlan sulfates were prepared in order to study effects of sulfate groups and conformation of curdlan sulfates. In addition, action mechanisms of curdlan sulfate as anti-AIDS drug and of heparin as an anticoagulant were examined by means of NMR spectroscopy. 1. Structure dependence of anti-HIV and anticoagulant activities of sulfated polysaccharides. Curdlan with M n 9000 was regioselectively sulfated on its hydroxyl groups at 6, 4, and 2 positions. Those were a curdlan sulfate 62S in which 100% of 6-OH, and about 50% of 2-OH was sulfated, a curdlan sulfate 42S in which 4- and 2-OH's were sulfated, and a curdlan sulfate in which 6, 4, and 2-OH's were partially sulfated. All curdlan sulfates had very high anti-HIV activities exhibited by the drug concentration of 50% inhibition of infection, i.e., EC 50 of 0.04 - 0.25 μg/mL. However, there was almost no difference in the activity among the samples. Therefore, it was revealed that the degree of sulfation and putative conformation of the curdlan sulfates but not the position of sulfate groups have large effects on the anti-HIV activity. On the other hand, the anticoagulant activity increased with increasing molecular weight of the curdlan sulfates. As a result, it is assumed that the size of reaction sites of the virus protein reacting with curdlan sulfate is different from that of the proteins related to anticoagulant

Direct anticoagulants and nursing: an approach from patient's safety.

Science.gov (United States)

Romero Ruiz, Adolfo; Romero-Arana, Adolfo; Gómez-Salgado, Juan

In recent years, a new line of treatment for the prevention of stroke in non-valvular atrial fibrillation, the so-called direct anticoagulants or new anticoagulants has appeared. The proper management and follow-up of these patients is essential to minimize their side effects and ensure patient safety. In this article, a description of these drugs is given, analyzing their characteristics, functioning and interactions together with the most habitual nursing interventions, as well as a reflection on the implications for the practice. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Isolation and characterization of anticoagulant compound from ...

African Journals Online (AJOL)

GIS

2013-10-02

Oct 2, 2013 ... The structural characterization of anticoagulant GAG was analyzed by Fourier transform infrared ... for pharmaceutical use are currently not available. However ... methods and sold live in the market for human consump- tion.

Anticoagulation in adults with congenital heart disease

DEFF Research Database (Denmark)

Jensen, A S; Idorn, L; Nørager, B

2015-01-01

Adults with congenital heart disease are a growing population. One of the major challenges in the care of these patients is to prevent thromboembolic episodes. Despite relative young age and no typical cardiovascular risk factors, this cohort has a high prevalence of thrombotic events....... Furthermore, there is a lack of scientific evidence regarding how to prevent thromboembolic events with anticoagulation in adults with congenital heart disease. The aim of this paper is to review the current literature pertaining to anticoagulation in adults with congenital heart disease and hence enable....... It is difficult to use treatment algorithms from the general adult population with acquired heart disease in this heterogeneous population due to special conditions such as myocardial scarring after previous surgery, atypical atrial flutter, prothrombotic conditions and the presence of interatrial shunts...

[Seronegative antiphospholipid syndrome, catastrophic syndrome, new anticoagulants: learning from a difficult case report].

Science.gov (United States)

Joalland, F; de Boysson, H; Darnige, L; Johnson, A; Jeanjean, C; Cheze, S; Augustin, A; Auzary, C; Geffray, L

2014-11-01

The diagnosis of the antiphospholipid syndrome (APS) is based on clinical and biological criteria including the persistent presence of antiphospholipid antibodies and thrombotic events or pregnancy morbidity. Heparins relayed by vitamin K antagonists (VKA) are the gold standard treatment for thrombosis. We report a 17-year-old man who presented with an initially seronegative antiphospholipid syndrome, in whom the diagnosis was late, only obtained after anticoagulation withdrawing, when a catastrophic antiphospholipid syndrome (CAPS) with cutaneous lesions and disseminated intravascular coagulation syndrome occurred. For personal convenience, this patient was initially treated with fondaparinux followed by a new oral anticoagulant (rivaroxaban) before to return to the conventional VKA treatment. The "seronegative" APS is a controversial concept reflecting the heterogeneity of antigenic targets for aPL. This diagnosis may be considered after a rigorous work-up, with the help of haemostasis laboratories testing new emerging aPL assays. In APS, the new anticoagulants represent an attractive option needing nevertheless prospective studies to evaluate their safety and efficacy. Lupus anticoagulant detection in patients treated by new oral anticoagulants is not easy by usually recommended coagulation tests. Copyright © 2014. Published by Elsevier SAS.

Control of anticoagulant therapy and quality of life of patients with atrial fibrillation (review

Directory of Open Access Journals (Sweden)

Shvarts Y.G.

2012-06-01

Full Text Available The review presents the published data on the relevance of the problem of thromboembolic complications in atrial fibrillation, the peculiarities of anticoagulant therapy for this disease. The relationship of clinical characteristics of patients with anticoagulant dose adjustment algorithms has been described. The problem of ethical issues of out of clinical trials patients and the dynamics of their quality of life against the background of long-term use of anticoagulant have been considered.

Tranexamic Acid Failed to Reverse the Anticoagulant Effect and Bleeding by an Oral Direct Factor Xa Inhibitor Edoxaban.

Science.gov (United States)

Honda, Yuko; Furugohri, Taketoshi; Morishima, Yoshiyuki

2018-01-01

Agents to reverse the anticoagulant effect of edoxaban, an oral direct factor Xa inhibitor, would be desirable in emergency situations. The aim of this study is to determine the effect of tranexamic acid, an antifibrinolytic agent, on the anticoagulant activity and bleeding by edoxaban in rats. A supratherapeutic dose of edoxaban (3 mg/kg) was intravenously administered to rats. Three minutes after dosing, tranexamic acid (100 mg/kg) was given intravenously. Bleeding was induced by making an incision with a blade on the planta 8 min after edoxaban injection and bleeding time was measured. Prothrombin time (PT) and clot lysis were examined. A supratherapeutic dose of edoxaban significantly prolonged PT and bleeding time. Tranexamic acid did not affect PT or bleeding time prolonged by edoxaban, although tranexamic acid significantly inhibited clot lysis in rat plasma. An antifibrinolytic agent tranexamic acid failed to reverse the anticoagulant effect and bleeding by edoxaban in rats. © 2017 S. Karger AG, Basel.

Does novel oral anticoagulant improve anticoagulation for non-valvular atrial fibrillation associated stroke: An inpatient registration study in Shanghai

Directory of Open Access Journals (Sweden)

Feng-Di Liu

2015-12-01

Full Text Available Abstracts: Objective: To summarize the use rate, safety, efficacy of antithrombotics in stroke/transient ischemic attack (TIA prevention, and reasons for not using dabigatran etexilate (DE in Shanghai, China. Methods: Non-valvular atrial fibrillation (NVAF-associated stroke patients were prospectively registered as an electronic database. Use rate of antithrombotics and reasons for not using DE were extracted during follow-up. Patients' baseline characteristics, recurrent ischemic stroke/TIA events and bleeding complications were analyzed. Patients: From April 2012 to August 2014, 110 inpatients with NVAF-associated stroke were studied in our hospital. NVAF was diagnosed by 12-lead electrocardiogram, 24 h Holter and echocardiography. Results: Before introduction of DE (April 2013, use rates of warfarin and antiplatelets were 28.9% (11/38 and 60.5% (23/38 respectively; after that, use rates of warfarin, DE, and antiplatelets were 20.8% (15/72, 12.5% (9/72, and 43.1% (31/72. The DE did not improve use of anticoagulants (P = 0.639. There were 19 (17.3% recurrent ischemic stroke events up to October 2015; two (9.5% in the non-user group, 10 (18.5% in the antiplatelet group, and seven (20.0% in the anticoagulants group (P = 0.570. Furthermore, recurrence rates were similar between the DE group (20.0% and the Warfarin group (20.0%, P = 1.000. The most common reason for not using DE was financial concerns (61.0%, followed by inconvenience to purchase (14.0% and hemorrhage concerns (11.0%. Two patients using warfarin found fecal occult blood so they stopped warfarin and began to use antiplatelet drugs. No bleeding event occurred in the other groups. Only one patient had side effects (dyspepsia and gastroesophageal reflux from DE. Conclusion: The use rate of either DE or warfarin in Shanghai was low; DE had not improved anticoagulation therapy for NVAF patients in Shanghai mainly because DE had not been covered by health insurance. Keywords

Site-selective conjugation of an anticoagulant aptamer to recombinant albumins and maintenance of neonatal Fc receptor binding

DEFF Research Database (Denmark)

Schmøkel, Julie; Voldum, Anders; Tsakiridou, Georgia

2017-01-01

-linked aptamer to that of aptamer alone was found using an anticoagulant activity assay measuring temporal levels of activated partial thrombin. Covalent albumin-aptamer conjugation, however, substantially compromized binding to hFcRn, to 10% affinity of that of non-conjugated WT, determined by biolayer......-life, predominately facilitated by engagement with the cellular recycling neonatal Fc receptor (FcRn), and ligand transport properties of albumin promote it as an attractive candidate to improve the pharmacokinetic profile of aptamers. This study investigates the effect of Cys34 site-selective covalent attachment...... of a factor IXa anticoagulant aptamer on aptamer functionality and human FcRn (hFcRn) engagement using recombinant human albumin (rHA) of either a wild type (WT) or an engineered human FcRn high binding variant (HB). Albumin-aptamer conjugates, connected covalently through a heterobifunctional succinimidyl 4...

Spontaneous pharyngo-laryngeal hematoma and anticoagulation. A case report

Directory of Open Access Journals (Sweden)

Marleny CASASOLA-GIRÓN

2016-03-01

Full Text Available Introduction and Objective: Spontaneous pharyngeal-laryngeal hematoma shows the importance of a complete ENT examination in the face of symptoms of banal appearance and a correct history that, in the case reported, unveiled the therapeutic use of anticoagulants. Case description: A 55 year old woman comes to emergency because of unexplained dysphagia. The inspection shows the presence of a hematoma in the pharyngeal-laryngeal region that, after the anticoagulant therapy was reversed, evolved favorably with conservative treatment. Discussion: In this case, apart from medical management performed by the hematology department, we focus our therapeutic approach in the protection of the airway and the prevention of a possible massive bleeding. Determining which patients require endotracheal intubation or tracheostomy and hemostatic surgery is the key to treatment. Conclusions: The anticoagulant therapy involves several complications that ENT specialists must consider in the face of clinical symptoms of dysphagia, dysphonia, dyspnea or signs of bleeding and they must know the possibilities of performance depending on the severity of each case.

Anticoagulant use for prevention of stroke in a commercial population with atrial fibrillation.

Science.gov (United States)

Patel, Aarti A; Lennert, Barb; Macomson, Brian; Nelson, Winnie W; Owens, Gary M; Mody, Samir H; Schein, Jeff

2012-07-01

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and patients with AF are at an increased risk for stroke. Thromboprophylaxis with vitamin K antagonists reduces the annual incidence of stroke by approximately 60%, but appropriate thromboprophylaxis is prescribed for only approximately 50% of eligible patients. Health plans may help to improve quality of care for patients with AF by analyzing claims data for care improvement opportunities. To analyze pharmacy and medical claims data from a large integrated commercial database to determine the risk for stroke and the appropriateness of anticoagulant use based on guideline recommendations for patients with AF. This descriptive, retrospective claims data analysis used the Anticoagulant Quality Improvement Analyzer software, which was designed to analyze health plan data. The data for this study were obtained from a 10% randomly selected sample from the PharMetrics Integrated Database. This 10% sample resulted in almost 26,000 patients with AF who met the inclusion criteria for this study. Patients with a new or existing diagnosis of AF between July 2008 and June 2010 who were aged ≥18 years were included in this analysis. The follow-up period was 1 year. Demographics, stroke risk level (CHADS2 and CHA2DS2-VASc scores), anticoagulant use, and inpatient stroke hospitalizations were analyzed through the analyzer software. Of the 25,710 patients with AF (CHADS2 score 0-6) who were eligible to be included in this study, 9093 (35%) received vitamin K antagonists and 16,617 (65%) did not receive any anticoagulant. Of the patients at high risk for stroke, as predicted by CHADS2, 39% received an anticoagulant medication. The rates of patients receiving anticoagulant medication varied by age-group-16% of patients aged <65 years, 22% of those aged 65 to 74 years, and 61% of elderly ≥75 years. Among patients hospitalized for stroke, only 28% were treated with an anticoagulant agent in the outpatient

Alkylation of phosphorothioated thrombin binding aptamers improves the selectivity of inhibition of tumor cell proliferation upon anticoagulation.

Science.gov (United States)

Yang, Xiantao; Zhu, Yuejie; Wang, Chao; Guan, Zhu; Zhang, Lihe; Yang, Zhenjun

2017-07-01

Recently, aptamers have been extensively researched for therapy and diagnostic applications. Thrombin-binding aptamer is a 15nt deoxyribonucleic acid screened by SELEX, it can specifically bind to thrombin and inhibit blood coagulation. Since it is also endowed with excellent antitumor activity, the intrinsic anticoagulation advantage converted to a main potential side effect for its further application in antiproliferative therapy. Site-specific alkylation was conducted through nucleophilic reaction of phosphorothioated TBAs using bromide reagents. Circular dichroism (CD) spectroscopy and surface plasmon resonance (SPR) measurements were used to evaluate anticoagulation activity, and a CCK-8 assay was used to determine cell proliferation activity. The CD spectra of the modified TBAs were weakened, and their affinity for thrombin was dramatically reduced, as reflected by the K D values. On the other hand, their inhibition of A549 cells was retained. Incorporation of different alkyls apparently disrupted the binding of TBA to thrombin while maintaining the antitumor activity. A new modification strategy was established for the use of TBA as a more selective antitumor agent. Copyright © 2017 Elsevier B.V. All rights reserved.

Graves’ Disease and Treatment Effects on Warfarin Anticoagulation

Directory of Open Access Journals (Sweden)

Amanda Howard-Thompson

2014-01-01

Full Text Available Background. Hyperthyroidism causes an increased hypoprothrombinemic response to warfarin anticoagulation. Previous studies have demonstrated that patients with hyperthyroidism require lower dosages of warfarin to achieve a therapeutic effect. As hyperthyroidism is treated and euthyroidism is approached, patients may require increasing warfarin dosages to maintain appropriate anticoagulation. We describe a patient’s varying response to warfarin during treatment of Graves’ disease. Case Presentation. A 48-year-old African American female presented to the emergency room with tachycardia, new onset bilateral lower extremity edema, gradual weight loss, palpable goiter, and generalized sweating over the prior 4 months. She was admitted with Graves’ disease and new onset atrial fibrillation. Primary stroke prophylaxis was started using warfarin; the patient developed a markedly supratherapeutic INR likely due to hyperthyroidism. After starting methimazole, her free thyroxine approached euthyroid levels and the INR became subtherapeutic. She remained subtherapeutic over several months despite steadily increasing dosages of warfarin. Immediately following thyroid radioablation and discontinuation of methimazole, the patient’s warfarin dose and INR stabilized. Conclusion. Clinicians should expect an increased response to warfarin in patients with hyperthyroidism and close monitoring of the INR is imperative to prevent adverse effects. As patients approach euthyroidism, insufficient anticoagulation is likely without vigilant follow-up, INR monitoring, and increasing warfarin dosages.

Unexpected disappearance of portal cavernoma on long-term anticoagulation.

Science.gov (United States)

Silva-Junior, Gilberto; Turon, Fanny; Hernandez-Gea, Virginia; Darnell, Anna; García-Criado, Ángeles; García-Pagán, Juan Carlos

2014-08-01

Idiopathic non-cirrhotic portal hypertension is a rare disease of unknown etiology. Patients with idiopathic non-cirrhotic portal hypertension have an increased risk of developing portal vein thrombosis and this is especially prevalent when HIV is also present. We describe a unique case of a patient with idiopathic non-cirrhotic portal hypertension associated to HIV, who developed acute portal vein thrombosis that despite anticoagulation transformed in portal cavernoma and disappeared completely after five years of follow-up on continuous anticoagulation. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Hematology of Nile tilapia (Oreochromis niloticus subjected to anesthesia and anticoagulation protocols

Directory of Open Access Journals (Sweden)

Nadia Cristine Weinert

2015-12-01

Full Text Available Clinical hematology facilitates the diagnosis of disease and can act as a prognostic indicator of pathological conditions in fish. The aim of the present study was to evaluate hematological parameters of Nile tilapia (Oreochromis niloticus subjected to different anesthetics and anticoagulants. Thirty apparently healthy fishes (average weight of 473 ± 35. 50 g and mean total length of 29. 33 ± 0. 37 cm, were selected from the local commercial fish farm in the Lages municipality (Santa Catarina, Brazil. The animals were randomly divided into three groups of 10. In two groups, anesthesia was induced with eugenol (70 mg·L- 1 (EG and Benzocaine hydrochloride (100 mg·L-1 (BG, respectively. Anesthesia was not administered to fish of the third group (CG/control group. Blood samples were obtained by venipuncture of the caudal vessels and placed into microtubes containing sodium heparin or Na2EDTA for further analysis. The results were analyzed by Sigma Stat for Windows, the paired t-test for significant differences between anticoagulants of the same group, and analysis of variance followed by the Tukey test for comparison of means between groups (p ? 0. 05. Most of the observed changes in the erythrogram were significantly higher for the anticoagulant heparin and benzocaine group in comparison to the control group. However, the values obtained for the leukogram were significantly higher for all groups subjected to the Na2EDTA anticoagulant, suggesting that heparin may cause cell clumping. The results suggest that the anesthetics under investigation effectively minimizes the effects of stress caused by handling and invasive procedures, and that the anticoagulant heparin causes less hemolysis in comparison to Na2EDTA for Nile tilapia. Thus, the hematological variations attributed to different anesthetic protocols and/or different anticoagulants should be considered for the species Oreochromis niloticus.

Optimizing the use of oral anticoagulant therapy for atrial fibrilation in primary care: a pharmacist-led intervention.

Science.gov (United States)

Virdee, Mandeep S; Stewart, Derek

2017-02-01

Background Updated evidence-based guidelines for the management of atrial fibrillation (AF) necessitate patient review, particularly with respect to oral anticoagulants, to ensure maximum health gain around stroke prophylaxis. Objective To quantify the level of anticoagulation utilisation in patients with a CHA 2 DS 2 -VASc ≥1/≥2 (male/female) according to evidence-based guidelines and to assess the impact of a pharmacist-led intervention to optimise therapy. Setting Fifteen general medical practices in Liverpool, North-West England with a practice population of 99,129. Method GRASP-AF software was employed to interrogate patient electronic medical records to identify and risk stratify AF patients (using CHA 2 DS 2 -VASc). A pharmacist then reviewed the medical records of those of patients not anticoagulated and with a CHA 2 DS 2 -VASc ≥1/≥2 (male/female). Recommendations were discussed with a general practitioner (GP) and those patients in whom the need for anticoagulation was agreed were invited for a consultation with either the pharmacist or GP and therapy optimised where appropriate. The GPs were responsible for managing those patients referred for diagnosis confirmation or further specialist opinion. Main outcome measure Proportion of patients eligible/not eligible for anticoagulation; proportions in whom anticoagulants initiated, refused, antiplatelets discontinued. Results Five hundred and twenty-three patients (31% of patients identified with AF and a CHA 2 DS 2 -VASc ≥1/≥2 (male/female)) were not receiving an anticoagulant (26 subsequently died or left the practice leaving 497). Three hundred and eighty-two (77%) pharmacist recommendations to a GP were agreed without modification. Following outcomes of diagnostic investigations and specialist referrals, 202 (41%) patients were candidates for anticoagulation, 251 (51%) were not eligible for anticoagulation, 103 (21%) were anticoagulated (56 warfarin, 47 DOAC). Conclusion A pharmacist

Recent developments in separation of low molecular weight heparin anticoagulants.

Science.gov (United States)

Sadowski, Radosław; Gadzała-Kopciuch, Renata; Buszewski, Bogusław

2017-10-05

The general function of anticoagulants is to prevent blood clotting and growing of the existing clots in blood vessels. In recent years, there has been a significant improvement in developing methods of prevention as well as pharmacologic and surgical treatment of thrombosis. For over the last two decades, low molecular weight heparins (LMWHs) have found their application in the antithrombotic diseases treatment. These types of drugs are widely used in clinical therapy. Despite the biological and medical importance of LMWHs, they have not been completely characterized in terms of their chemical structure. Due to both, the structural complexity of these anticoagulants and the presence of impurities, their structural characterization requires the employment of advanced analytical techniques. Since separation techniques play the key role in these endeavors, this review will focus on the presentation of recent developments in the separation of LMWH anticoagulants. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Subdural hematoma and oral anticoagulant therapy

NARCIS (Netherlands)

Wintzen, A. R.; Tijssen, J. G.

1982-01-01

In a retrospective study of the period 1959 to 1978, the role of anticoagulant therapy (ACT) in the development of subdural hematoma (SH) was investigated. Of 212 cases, 46 were receiving ACT, a proportion highly in excess of the frequency of ACT in the general population of the Leiden area. In this

In vivo examination of the anticoagulant effect of the Brassica oleracea methanol extract

Directory of Open Access Journals (Sweden)

Khan Rafeeq Alam

2015-01-01

Full Text Available The anticoagulant effect of the methanol extract of Brassica oleracea var. capitata (MEB was examined in rabbits. The animals were divided into five groups, each comprising seven animals. Three groups were administered increasing doses of MEB (200, 300, and 500 mg/kg, respectively; one group received warfarin (0.54 mg/kg; animals in the control group received saline (1 ml/day equivalent to the volume of doses applied to the treated and standard animals. Biochemical tests were performed on the 16th and 31st days of dosing. Animals that were administered MEB (500 mg MEB/kg 30 days displayed increases of 24.07 s, 28.79 s and 4.08 s in activated partial thromboplastin (aPTT, fibrinogen (Fg and thrombin time (TT. Compared to the control, the increase in aPTT and Fg was highly significant and the increase in TT was significant. The anticoagulant effect exhibited by MEB in rabbits may be due to inactivation or inhibition of factors affecting coagulation.

[Use of non-vitamin K antagonist oral anticoagulants in Primary Care: ACTUA study].

Science.gov (United States)

Barrios, V; Escobar, C; Lobos, J M; Polo, J; Vargas, D

2017-10-01

Approximately 40% of patients with non-valvular auricular fibrillation (NVAF) who receive vitamin K antagonists (VKA) in Primary Care in Spain have poor anticoagulation control. The objective of the study Actuación en antiCoagulación, Tratamiento y Uso de anticoagulantes orales de acción directa (ACOD) en Atención primaria (ACTUA) (Action in Coagulation, Treatment and Use of direct oral anticoagulants [DOACs]) in Primary Care) was to analyse the current situation regarding the use of VKA and non-vitamin K antagonist oral anticoagulants (NOACs) in patients with NVAF in Primary Care in Spain and the possible issues arising from it. An online survey was created covering various aspects of the use of oral anticoagulants in NAFV. A two-round modified Delphi approach was used. Results were compiled as a set of practical guidelines. Forty-four experts responded to the survey. Consensus was reached in 62% (37/60) of the items. Experts concluded that a considerable number of patients with NVAF who receive VKA do not have a well-controlled INR and that a substantial group of patients who could benefit from being treated with NOACs do not receive them. The use of NOACs increases the probability of having good anticoagulation control and decreases the risk of severe and intracranial haemorrhage. Current limitations to the use of NOACs include administrative barriers, insufficient knowledge about the benefits and risks of NOACs, limited experience of doctors in using them, and their price. Renal insufficiency influences the choice of a particular anticoagulant. The ACTUA study highlights the existing controversies about the use of oral anticoagulants for the treatment of NVAF in Primary Care in Spain, and provides consensus recommendations that may help to improve the use of these medications. Copyright © 2016 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

Statement on the safety of glucosamine for patients receiving coumarin anticoagulants

DEFF Research Database (Denmark)

Tetens, Inge

2011-01-01

The European Food Safety Authority (EFSA) asked the Panel on Dietetic Products, Nutrition and Allergies to provide a scientific statement on the safety of glucosamine for patients receiving coumarin anticoagulants. More than 40 case reports have been collected by drug-monitoring agencies...... cases haemorrhage occurred in a variety of organs, and in one case this resulted in a persistent vegetative state. The evidence for an interaction between glucosamine and coumarin anticoagulants is strengthened by the observation that in the majority of cases the INR began to fall to normal values when...... glucosamine intake was discontinued. There is insufficient information to conclude on a mechanism for an interaction between glucosamine and coumarin anticoagulants. There are also insufficient data in the case reports to derive a dose-response relationship for glucosamine and to assess the level of risk...

Oral anticoagulants for stroke prevention in atrial fibrillation.

Science.gov (United States)

Senoo, Keitaro; Lane, Deirdre A; Lip, Gregory Y H

2014-09-01

The availability of 4 non-vitamin K oral anticoagulants (NOACs), that is, dabigatran, rivaroxaban, apixaban, and edoxaban, has changed the landscape of stroke prevention in patients with atrial fibrillation. This review article provides an overview of the 4 phase III studies that have compared these NOACs, examining major outcomes of efficacy and safety. A range of practical questions relating to the NOACs have emerged, including topics such as patient selection, treating patients with renal impairment, treating elderly patients, and combining anticoagulant therapy with antiplatelet drugs. We also address the interaction of various patient characteristics with the treatments and suggest the features can assist the physician in the choice of a particular NOAC for a particular patient(s). Copyright © 2014 Elsevier B.V. All rights reserved.

Transportation cost of anticoagulation clinic visits in an urban setting.

Science.gov (United States)

Hwang, Jamie M; Clemente, Jennifer; Sharma, Krishna P; Taylor, Thomas N; Garwood, Candice L

2011-10-01

Patients being managed on warfarin make frequent or regular visits to anticoagulation monitoring appointments. International studies have evaluated transportation cost and associated time related to anticoagulation clinic visits. To our knowledge, no studies have evaluated the cost of transportation to such clinic visits in the United States. To describe the methods of transportation and estimate the average total cost of transportation to and from an anticoagulation clinic in an urban setting. We prospectively conducted a survey of patients treated at the Harper Anticoagulation Clinic located in Detroit, Michigan, during November 2010. The survey was given to patients while waiting at their regularly scheduled clinic appointments and included questions regarding mode of transportation, distance traveled in miles, parking payment, and time missed from work for clinic appointments. The mean distance traveled was translated into cost assuming 50 cents per mile based on 2010 estimates by the Internal Revenue Service. Sixty patients responded to the 11-item survey; response rates for individual items varied because participants were instructed to skip questions that did not pertain to them. Of the 47 participants responding to demographic questions, 70.2% were female, and 46.8% were older than 60 years. Transportation by private vehicle (80.0%), either driven by patients (41.7%) or someone else (38.3%), was the most common method reported. Use of private automobile translated into a cost of $11.19 per round trip. Other means of transportation identified include a ride from a medical transportation service (10.0%), bus (5.0%), walking (3.3%), and taxi (1.7%). The mean (SD) distance traveled to the clinic for all methods of transportation was 8.34 (7.7) miles. We estimated the average cost of round-trip transportation to be $10.78 weighted for all transportation modes. This is a direct nonmedical cost that is paid for by most patients out of pocket. However, 9 of 44 (20

Real life anticoagulation treatment of patients with atrial fibrillation in Germany

DEFF Research Database (Denmark)

Wilke, Thomas; Groth, Antje; Pfannkuche, Matthias

2015-01-01

Oral anticoagulation (OAC) with either new oral anticoagulants (NOACs) or Vitamin-K antagonists (VKAs) is recommended by guidelines for patients with atrial fibrillation (AF) and a moderate to high risk of stroke. Based on a claims-based data set the aim of this study was to quantify the stroke-r...... that both patient/disease characteristics and treatment environment/general prescribing behaviour of physicians may explain the OAC under-use in AF patients....

Non arteritic anterior ischemic optic neuropathy; does anticoagulation help?

International Nuclear Information System (INIS)

Aftab, A.M.; Iqbal, M.; Ali, A.; Rauf, A.

2017-01-01

Non Arteritic Anterior Ischemic Optic Neuropathy (NAION) is the most common acute optic neuropathy in patients over 50 years of age. This study was conducted to determine the beneficial effects of anticoagulation with Heparin and Warfarin in patients with NAION presenting within 4 weeks of onset of symptoms Methods: A prospective, interventional, pilot study was conducted in Eye- A unit of Khyber Teaching Hospital from July 2010 onwards on patients with NAION presenting within 4 weeks of onset of symptoms. Patients underwent complete ophthalmological examination including Snellen's visual acuity (latter converted to Log MAR), pupil examination, fundus examination and automated Humphrey visual field analysis. Hematologic tests, Thrombophilia screening, Echocardiography and carotid Doppler ultrasound were carried on patients. All patients were anticoagulated with Heparin and Warfarin after obtaining informed written consent. Patients were examined at 1 Month, 3 months and 6 months' time period. Primary parameter measured was improvement in visual acuity. Results: Total number of patients in our study was 24. Regarding visual outcome total number of patients having significant improvement of visual acuity in our study was 16 (66.6 percent), while 4 (16.7 percent) patients had marginal improvement of visual acuity. Three (12.5 percent) patients maintained stable visual acuity of 6/6 throughout the study period in presence of thrombophilic disorders. One patient (4.1 percent) suffered a decline in visual acuity compared to VA at baseline presentation. Conclusions: Anticoagulation using heparin and warfarin does benefit patients with NAION presenting within 4 weeks of onset of symptoms. In our study a higher proportion of patients experienced significant improvement of visual acuity following anticoagulation as compared to the highest reported spontaneous improvement in such patients. (author)

The role of heparin in sepsis: much more than just an anticoagulant.

Science.gov (United States)

Li, Xu; Ma, Xiaochun

2017-11-01

Despite progress in antibiotic treatment, mechanical ventilation, fluid resuscitation and blood glucose maintenance, sepsis remains a cause of high mortality in the intensive care unit to date, there are no proven treatment strategies for the routine management of septic patients. The extensive interaction between inflammation and coagulation contributes to the basic pathophysiology of sepsis. Thus, the agents that attenuate the activation of both inflammation and coagulation may improve the outcome in sepsis. Apart from the well-known anticoagulant effects of heparin, it also possesses various immunomodulatory properties and protects glycocalyx from shedding. Hence, heparin seems to be such an agent. Immunothrombosis plays an important role in early host defence against bacterial dissemination, thus the proper timing for anticoagulant therapy should be determined. We review the available experimental and clinical data supporting the use of heparin in sepsis. At this time the use of heparin in the treatment of sepsis is conflicting. Future trials of heparin therapy for sepsis should concentrate on the very severely ill patients, in whom benefit is most likely to be demonstrated. © 2017 John Wiley & Sons Ltd.

Prevalence of Lupus Anticoagulant in Women with Spontaneous ...

African Journals Online (AJOL)

2017-10-26

Oct 26, 2017 ... ... pregnancy. Presence of lupus anticoagulant (LA), one of the antiphospholipid antibodies, ... pregnancy outcomes such as preeclampsia/eclampsia and small for date deliveries. ... changes in a background of APL syndrome.

Are pharmacological properties of anticoagulants reflected in pharmaceutical pricing and reimbursement policy? Out-patient treatment of venous thromboembolism and utilization of anticoagulants in Poland.

Science.gov (United States)

Bochenek, T; Czarnogorski, M; Nizankowski, R; Pilc, A

2014-06-01

Pharmacotherapy with vitamin K antagonists (VKA) and low-molecular-weight heparins (LMWH) is a major cost driver in the treatment of venous thromboembolism (VTE). Major representatives of anticoagulants in Europe include: acenocoumarol and warfarin (VKA), enoxaparin, dalteparin, nadroparin, reviparin, parnaparin and bemiparin (LMWH). Aim of this report is to measure and critically assess the utilization of anticoagulants and other resources used in the out-patient treatment of VTE in Poland. To confront the findings with available scientific evidence on pharmacological and clinical properties of anticoagulants. The perspectives of the National Health Fund (NHF) and the patients were adopted, descriptive statistics methods were used. The data were gathered at the NHF and the clinic specialized in treatment of coagulation disorders. Non-pharmacological costs of treatment were for the NHF 1.6 times higher with VKA than with LMWH. Daily cost of pharmacotherapy with LMWH turned out higher than with VKA (234 times for the NHF, 42 times per patient). Within both LMWH and VKA the reimbursement due for the daily doses of a particular medication altered in the manner inversely proportional to the level of patient co-payment. Utilization of long-marketed and cheap VKA was dominated by LMWH, when assessed both through the monetary measures and by the actual volume of sales. Pharmaceutical reimbursement policy favored the more expensive equivalents among VKA and LMWH, whereas in the financial terms the patients were far better off when remaining on a more expensive alternative. The pharmaceutical pricing and reimbursement policy of the state should be more closely related to the pharmacological properties of anticoagulants.

Fluorogen-activating proteins: beyond classical fluorescent proteins

Directory of Open Access Journals (Sweden)

Shengnan Xu

2018-05-01

Full Text Available Fluorescence imaging is a powerful technique for the real-time noninvasive monitoring of protein dynamics. Recently, fluorogen activating proteins (FAPs/fluorogen probes for protein imaging were developed. Unlike the traditional fluorescent proteins (FPs, FAPs do not fluoresce unless bound to their specific small-molecule fluorogens. When using FAPs/fluorogen probes, a washing step is not required for the removal of free probes from the cells, thus allowing rapid and specific detection of proteins in living cells with high signal-to-noise ratio. Furthermore, with different fluorogens, living cell multi-color proteins labeling system was developed. In this review, we describe about the discovery of FAPs, the design strategy of FAP fluorogens, the application of the FAP technology and the advances of FAP technology in protein labeling systems. KEY WORDS: Fluorogen activating proteins, Fluorogens, Genetically encoded sensors, Fluorescence imaging, Molecular imaging

Treatment Changes among Users of Non-Vitamin K Antagonist Oral Anticoagulants in Atrial Fibrillation

DEFF Research Database (Denmark)

Poulsen, Maja Hellfritzsch; Husted, Steen Elkjær; Grove, Erik Lerkevang

2017-01-01

Patients with atrial fibrillation discontinuing anticoagulant therapy are left unprotected against ischaemic stroke. Further, switching between oral anticoagulants may be associated with a transiently increased risk of bleeding or thromboembolism. However, there is a paucity of real-life data on ...

Antiplatelet and Anticoagulant Drugs in Interventional Radiology

International Nuclear Information System (INIS)

Altenburg, Alexander; Haage, Patrick

2012-01-01

In treating peripheral arterial disease, a profound knowledge of antiplatelet and anticoagulative drug therapy is helpful to assure a positive clinical outcome and to anticipate and avoid complications. Side effects and drug interactions may have fatal consequences for the patient, so interventionalists should be aware of these risks and able to control them. Aspirin remains the first-line agent for antiplatelet monotherapy, with clopidogrel added where dual antiplatelet therapy is required. In case of suspected antiplatelet drug resistance, the dose of clopidogrel may be doubled; prasugrel or ticagrelor may be used alternatively. Glycoprotein IIb/IIIa inhibitors (abciximab or eptifibatide) may help in cases of hypercoagulability or acute embolic complications. Desmopressin, tranexamic acid, or platelet infusions may be used to decrease antiplatelet drug effects in case of bleeding. Intraprocedurally, anticoagulant therapy treatment with unfractionated heparin (UFH) still is the means of choice, although low molecular-weight heparins (LMWH) are suitable, particularly for postinterventional treatment. Adaption of LMWH dose is often required in renal insufficiency, which is frequently found in elderly patients. Protamine sulphate is an effective antagonist for UFH; however, this effect is less for LMWH. Newer antithrombotic drugs, such as direct thrombin inhibitors or factor X inhibitors, have limited importance in periprocedural treatment, with the exception of treating patients with heparin-induced thrombocytopenia (HIT). Nevertheless, knowing pharmacologic properties of the newer drugs facilitate correct bridging of patients treated with such drugs. This article provides a comprehensive overview of antiplatelet and anticoagulant drugs for use before, during, and after interventional radiological procedures.

Practical recommendations for the choice of anticoagulants in the management of patients with atrial fibrillation on ibrutinib.

Science.gov (United States)

Chai, Khai Li; Rowan, Gail; Seymour, John F; Burbury, Kate; Carney, Dennis; Tam, Constantine S

2017-12-01

The management of AF represents a major challenge in patients with CLL, especially in elderly patients with multiple comorbidities who are representative of the majority of patients with CLL. This is especially complex in the case of ibrutinib. Many anticoagulants have potential for pharmacological interaction with ibrutinib, and ibrutinib itself has antiplatelet properties. Use of ibrutinib therapy in these patients mandates review and revision of the need for anticoagulation and best anticoagulant to use. Herein, we review the current knowledge of the metabolism of common anticoagulants and how they may interact with ibrutinib.

The anticoagulant ability of ferulic acid and its applications for improving the blood compatibility of silk fibroin

Energy Technology Data Exchange (ETDEWEB)

Wang Song; Gao Zhen; Chen Xiaomeng; Lian Xiaojie; Zhu Hesun [School of Material Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China); Zheng Jun; Sun Lizhong [Department of Cardiac Surgery, Cardiovascular Institute and Fu Wai Hospital, CAMS and PUMC, Beijing 100037 (China)], E-mail: wangsongbit@hotmail.com

2008-12-15

The hemocompatibility of silk fibroin (SF) was improved with ferulic acid (FA) by graft polymerization. Ferulic acid is an active ingredient of many Chinese herbal medicines, such as Chuanxiong (Rhizoma ligustici wallichii), Danggui (Angelica sinensis) and Awei (Asafoetida giantfennel), which have been used to treat cardiovascular diseases by Chinese physicians for thousands of years. The inhibitory functions of FA on blood coagulation and erythrocyte agglutination were first characterized by a Lee-White test tube method and a micropipette technique, respectively. Then, FA was immobilized on SF by graft polymerization and the surface composition of modified SF was characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR), x-ray photoelectron spectroscopy (XPS) and optical microscopy. The anticoagulant activity of modified SF was assessed, respectively, by in vitro clotting time measurements on a photo-optical clot detection instrument and with the Lee-White test tube method. The test results indicated that in comparison to untreated SF, the anticoagulant activity of modified SF has been improved significantly. Moreover, the SF surface composition is altered by FA but its {beta}-sheet conformation is not disturbed.

A cost-analysis model for anticoagulant treatment in the hospital setting.

Science.gov (United States)

Mody, Samir H; Huynh, Lynn; Zhuo, Daisy Y; Tran, Kevin N; Lefebvre, Patrick; Bookhart, Brahim

2014-07-01

Rivaroxaban is the first oral factor Xa inhibitor approved in the US to reduce the risk of stroke and blood clots among people with non-valvular atrial fibrillation, treat deep vein thrombosis (DVT), treat pulmonary embolism (PE), reduce the risk of recurrence of DVT and PE, and prevent DVT and PE after knee or hip replacement surgery. The objective of this study was to evaluate the costs from a hospital perspective of treating patients with rivaroxaban vs other anticoagulant agents across these five populations. An economic model was developed using treatment regimens from the ROCKET-AF, EINSTEIN-DVT and PE, and RECORD1-3 randomized clinical trials. The distribution of hospital admissions used in the model across the different populations was derived from the 2010 Healthcare Cost and Utilization Project database. The model compared total costs of anticoagulant treatment, monitoring, inpatient stay, and administration for patients receiving rivaroxaban vs other anticoagulant agents. The length of inpatient stay (LOS) was determined from the literature. Across all populations, rivaroxaban was associated with an overall mean cost savings of $1520 per patient. The largest cost savings associated with rivaroxaban was observed in patients with DVT or PE ($6205 and $2742 per patient, respectively). The main driver of the cost savings resulted from the reduction in LOS associated with rivaroxaban, contributing to ∼90% of the total savings. Furthermore, the overall mean anticoagulant treatment cost was lower for rivaroxaban vs the reference groups. The distribution of patients across indications used in the model may not be generalizable to all hospitals, where practice patterns may vary, and average LOS cost may not reflect the actual reimbursements that hospitals received. From a hospital perspective, the use of rivaroxaban may be associated with cost savings when compared to other anticoagulant treatments due to lower drug cost and shorter LOS associated with

The Need for Anticoagulation Following Inferior Vena Cava Filter Placement: Systematic Review

International Nuclear Information System (INIS)

Ray, Charles E.; Prochazka, Allan

2008-01-01

Purpose. To perform a systemic review to determine the effect of anticoagulation on the rates of venous thromboembolism (pulmonary embolus, deep venous thrombosis, inferior vena cava (IVC) filter thrombosis) following placement of an IVC filter. Methods. A comprehensive computerized literature search was performed to identify relevant articles. Data were abstracted by two reviewers. Studies were included if it could be determined whether or not subjects received anticoagulation following filter placement, and if follow-up data were presented. A meta-analysis of patients from all included studies was performed. A total of 14 articles were included in the final analysis, but the data from only nine articles could be used in the meta-analysis; five studies were excluded because they did not present raw data which could be analyzed in the meta-analysis. A total of 1,369 subjects were included in the final meta-analysis. Results. The summary odds ratio for the effect of anticoagulation on venous thromboembolism rates following filter deployment was 0.639 (95% CI 0.351 to 1.159, p = 0.141). There was significant heterogeneity in the results from different studies [Q statistic of 15.95 (p = 0.043)]. Following the meta-analysis, there was a trend toward decreased venous thromboembolism rates in patients with post-filter anticoagulation (12.3% vs. 15.8%), but the result failed to reach statistical significance. Conclusion. Inferior vena cava filters can be placed in patients who cannot receive concomitant anticoagulation without placing them at significantly higher risk of development of venous thromboembolism

Healthcare resources and needs in anticoagulant therapy for patients with nonvalvular atrial fibrillation. SAMOA Study.

Science.gov (United States)

Barrios, V; Egocheaga-Cabello, M I; Gállego-Culleré, J; Ignacio-García, E; Manzano-Espinosa, L; Martín-Martínez, A; Mateo-Arranz, J; Polo-García, J; Vargas-Ortega, D

2017-05-01

To determine, in the various medical specialties, the healthcare process for anticoagulated patients with nonvalvular atrial fibrillation, to determine the available and necessary resources and to identify potential areas of improvement in the care of these patients. We performed a cross-sectional survey of primary care and specialised physicians involved in the care of anticoagulated patients. The questionnaires referred to the healthcare process, the indication and prescription of anticoagulant therapy and the barriers and deficiencies present for these patients. A total of 893 physicians participated in the study, 437 of whom worked in primary care and 456 of whom were specialists (mostly cardiologists). Forty-two percent of the family doctors indicated that they assessed and prescribed anticoagulant therapy, and 66% performed the regular follow-up of these patients. In both healthcare settings, the physicians noted the lack of standardised protocols. There was also a lack of quality control in the treatment. The role of primary care in managing anticoagulated patients has grown compared with previous reports. The responses of the participating physicians suggest marked gaps in the standardisation of the healthcare process and several areas for improvement in these patients' follow-up. The promotion of training in direct-acting anticoagulant drugs remains pivotal. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Could Some Geriatric Characteristics Hinder the Prescription of Anticoagulants in Atrial Fibrillation in the Elderly?

Directory of Open Access Journals (Sweden)

Paule Denoël

2014-01-01

Full Text Available Several studies have reported underprescription of anticoagulants in atrial fibrillation (AF. We conducted an observational study on 142 out of a total of 995 consecutive ≥75 years old patients presenting AF (14% when admitted in an emergency unit of a general hospital, in search of geriatric characteristics that might be associated with the underprescription of anticoagulation therapy (mostly antivitamin K at the time of the study. The following data was collected from patients presenting AF: medical history including treatment and comorbidities, CHADS2 score, ISAR scale (frailty, Lawton’s scale (ADL, GDS scale (mood status, MUST (nutrition, and blood analysis (INR, kidney function, and albumin. Among those patients for who anticoagulation treatment was recommended (73%, only 61% were treated with it. In the group with anticoagulation therapy, the following characteristics were observed more often than in the group without such therapy: a recent (≤6 months hospitalization and medical treatment including digoxin or based on >3 different drugs. Neither the value of the CHADS2 score, nor the geriatric characteristics could be correlated with the presence or the absence of an anticoagulation therapy. More research is thus required to identify and clarify the relative importance of patient-, physician-, and health care system-related hurdles for the prescription of oral anticoagulation therapy in older patients with AF.

Nonoclusive thrombosis of mechanical mitral valve prosthesis caused by inadequate treatment of anticoagulant therapy resistance

Directory of Open Access Journals (Sweden)

Ivanović Branislava

2008-01-01

Full Text Available Background. Oral anticoagulants have been used in the prevention of thromboembolic complications for over six decades. A rare, but possible problem in the application of these medications could be resistance to them. Case report. We presented a patient with nonocclusive thrombosis of the mechanical mitral prosthesis due to inadequately treated resistance to peroral anticoagulant therapy. Resistance to oral anticoagulant medications was proven by an increased dosage of warfarin up to 20 mg and, after that, acenokumarol to 15 mg over ten days which did not lead to an increase in the international normalized ratio (INR value over 1.2. On the basis of information that she did not take food rich in vitamin K or medications which could reduce effects of oral anticoagulants, and that she did not have additional illnesses and conditions that could cause an inadequate response to anticoagulant therapy, it was circumstantially concluded that this was a hereditary form of resistance. Because of the existing mechanical prosthetics on the mitral position, low molecular heparin has been introduced into the therapy. The patient reduced it on her own initiative, leading to nonocclusive valvular thrombosis. Conclusion. When associated complications like absolute arrhithmia does not exist, the finding of resistance to oral anticoagulant agents is an indication for the replacement of a mechanical prosthetic with a biological one which has been done in this patients.

Reversing the Effect of Oral Anticoagulant Drugs: Established and Newer Options.

Science.gov (United States)

Ansell, Jack E

2016-06-01

The vitamin K antagonists (VKAs) have been the standard (and only) oral anticoagulants used for the long-term treatment or prevention of venous thromboembolism or stroke in patients with atrial fibrillation. The coagulopathy induced by VKAs can be reversed with vitamin K, and in urgent situations, the vitamin K-dependent coagulation factors can be replaced by transfusion. In the last decade, a new class of oral anticoagulants has been developed, direct oral anticoagulants that bind to a specific coagulation factor and neutralize it. These compounds were shown to be effective and safe compared with the VKAs and were licensed for specific indications, but without a specific reversal agent. The absence of a reversal agent is a barrier to more widespread use of these agents. Currently, for the management of major life-threatening bleeding with the direct oral anticoagulants, most authorities recommend the use of four factor prothrombin complex concentrates. There are now three reversal agents in development and poised to enter the market. Idarucizumab is a specific antidote targeted to reverse the direct thrombin inhibitor, dabigatran, which was recently approved for use in the USA. Andexanet alfa is an antidote targeted to reverse the oral direct factor Xa inhibitors as well as the indirect inhibitor enoxaparin. Ciraparantag is an antidote targeted to reverse the direct thrombin and factor Xa inhibitors as well as the indirect inhibitor enoxaparin.

Efficacy and safety of a pharmacist-managed inpatient anticoagulation service for warfarin initiation and titration.

Science.gov (United States)

Wong, Y M; Quek, Y-N; Tay, J C; Chadachan, V; Lee, H K

2011-10-01

Anticoagulation consultations provided by a pharmacist-staffed inpatient service, similar to the experience reported in outpatient anticoagulation clinics, can potentially improve anticoagulation control and outcomes. At Tan Tock Seng Hospital, a 1200-bed acute care teaching hospital in Singapore, pharmacist-managed anticoagulation clinics have been in place since 1997. Pharmacist-managed services were extended to inpatient consultations in anticoagulation management from April 2006. Our objective was to assess the effect of implementing a pharmacist-managed inpatient anticoagulation service. This was a single-centre cohort study. Baseline data from 1 January 2006 to 31 March 2006 were collected and compared with post-implementation data from 1 April 2006 to 31 March 2007. Patients newly started on warfarin for deep vein thrombosis, pulmonary embolism or atrial fibrillation in general medicine and surgery departments were included. The three endpoints were as follows: (i) percentage of international normalized ratios (INRs) achieving therapeutic range within 5 days, (ii) INRs more than 4 during titration and (iii) subtherapeutic INRs on discharge. A total of 26 patients in the control period were compared with 144 patients who had received dosing consultations by a pharmacist during the initiation of warfarin. The provision of pharmacist consult resulted in 88% compared to 38% (P < 0·001) of INR values achieving therapeutic range within 5 days. There was a reduction in INR values of more than 4 during titration from 27% to 2% (P < 0·001), and subtherapeutic INR values on discharge without low molecular weight heparin from 15% to 0% (P < 0·001). The mean time to therapeutic INR was reduced from 6·5 to 3·9 days (P < 0·001) and mean length of stay after initiation of warfarin from 11 to 7·7 days (P = 0·004). Inpatient anticoagulation care and outcomes were significantly improved by a pharmacist-managed anticoagulation service. The time to therapeutic INR was

Trends in oral anticoagulant choice for acute stroke patients with nonvalvular atrial fibrillation in Japan: The SAMURAI‐NVAF Study

Science.gov (United States)

Arihiro, Shoji; Todo, Kenichi; Yamagami, Hiroshi; Kimura, Kazumi; Furui, Eisuke; Terasaki, Tadashi; Shiokawa, Yoshiaki; Kamiyama, Kenji; Takizawa, Shunya; Okuda, Satoshi; Okada, Yasushi; Kameda, Tomoaki; Nagakane, Yoshinari; Hasegawa, Yasuhiro; Mochizuki, Hiroshi; Ito, Yasuhiro; Nakashima, Takahiro; Takamatsu, Kazuhiro; Nishiyama, Kazutoshi; Kario, Kazuomi; Sato, Shoichiro; Koga, Masatoshi; Nagatsuka, K; Minematsu, K; Nakagawara, J; Akiyama, H; Shibazaki, K; Maeda, K; Shibuya, S; Yoshimura, S; Endo, K; Miyagi, T; Osaki, M; Kobayashi, J; Okata, T; Tanaka, E; Sakamoto, Y; Takizawa, H; Takasugi, J; Tokunaga, K; Homma, K; Kinoshita, N; Matsuki, T; Higashida, K; Shiozawa, M; Kanai, H; Uehara, S

2015-01-01

Background Large clinical trials are lack of data on non‐vitamin K antagonist oral anticoagulants for acute stroke patients. Aim To evaluate the choice of oral anticoagulants at acute hospital discharge in stroke patients with nonvalvular atrial fibrillation and clarify the underlying characteristics potentially affecting that choice using the multicenter Stroke Acute Management with Urgent Risk‐factor Assessment and Improvement‐NVAF registry (ClinicalTrials.gov NCT01581502). Method The study included 1192 acute ischemic stroke/transient ischemic attack patients with nonvalvular atrial fibrillation (527 women, 77·7 ± 9·9 years old) between September 2011 and March 2014, during which three nonvitamin K antagonist oral anticoagulant oral anticoagulants were approved for clinical use. Oral anticoagulant choice at hospital discharge (median 23‐day stay) was assessed. Results Warfarin was chosen for 650 patients, dabigatran for 203, rivaroxaban for 238, and apixaban for 25. Over the three 10‐month observation periods, patients taking warfarin gradually decreased to 46·5% and those taking nonvitamin K antagonist oral anticoagulants increased to 48·0%. As compared with warfarin users, patients taking nonvitamin K antagonist oral anticoagulants included more men, were younger, more frequently had small infarcts, and had lower scores for poststroke CHADS 2, CHA 2 DS 2‐VASc, and HAS‐BLED, admission National Institutes of Health stroke scale, and discharge modified Rankin Scale. Nonvitamin K antagonist oral anticoagulants were started at a median of four‐days after stroke onset without early intracranial hemorrhage. Patients starting nonvitamin K antagonist oral anticoagulants earlier had smaller infarcts and lower scores for the admission National Institutes of Health stroke scale and the discharge modified Rankin Scale than those starting later. Choice of nonvitamin K antagonist oral anticoagulants was independently associated with 20‐day or

Local hemostatic measures in anticoagulated patients undergoing oral surgery: a systematized literature review

Directory of Open Access Journals (Sweden)

Fábio Wildson Gurgel Costa

2013-01-01

Full Text Available PURPOSE: To conduct a systematized review of the literature about the main local hemostatic measures to control postoperative bleeding in anticoagulated patients. METHODS: A systematized review of literature was performed in the electronic database Medline (PubMed without restriction of the publication date. The eligibility criteria were studies involving maintenance of the anticoagulant therapy, prospective studies, retrospective studies, randomized clinical trials, controlled clinical studies, comparative studies, multicentric studies or case-control studies. Studies discontinuing anticoagulant therapy, case reports, literature reviews, in vitro studies, animal experiments and articles written in language not compatible with the search strategy adopted in this work were excluded. RESULTS: Twenty-four articles that met the adopted eligibility criteria were selected, enrolling 3891 subjects under anticoagulant therapy. A total of 171 cases of hemorrhage was observed. Tranexamic acid was the main local hemostatic measure used to controlling of postoperative bleeding. CONCLUSION: The local hemostatic measures proved to be effective according to previously published studies. Nevertheless, further clinical studies should be conducted to confirm this effectiveness.

SMART: self-management of anticoagulation, a randomised trial [ISRCTN19313375].

Science.gov (United States)

McCahon, Deborah; Fitzmaurice, David A; Murray, Ellen T; Fuller, Christopher J; Hobbs, Richard F D; Allan, Teresa F; Raftery, James P

2003-09-18

Oral anticoagulation monitoring has traditionally taken place in secondary care because of the need for a laboratory blood test, the international normalised ratio (INR). The development of reliable near patient testing (NPT) systems for INR estimation has facilitated devolution of testing to primary care. Patient self-management is a logical progression from the primary care model. This study will be the first to randomise non-selected patients in primary care, to either self-management or standard care. The study was a multi-centred randomised controlled trial with patients from 49 general practices recruited. Those suitable for inclusion were aged 18 or over, with a long term indication for oral anticoagulation, who had taken warfarin for at least six months. Patients randomised to the intervention arm attended at least two training sessions which were practice-based, 1 week apart. Each patient was assessed on their capability to undertake self management. If considered capable, they were given a near patient INR testing monitor, test strips and quality control material for home testing. Patients managed their own anticoagulation for a period of 12 months and performed their INR test every 2 weeks. Control patients continued with their pre-study care either attending hospital or practice based anticoagulant clinics. The methodology used in this trial will overcome concerns from previous trials of selection bias and relevance to the UK health service. The study will give a clearer understanding of the benefits of self-management in terms of clinical and cost effectiveness and patient preference.

SMART: Self-Management of Anticoagulation, a Randomised Trial [ISRCTN19313375

Directory of Open Access Journals (Sweden)

Murray Ellen T

2003-09-01

Full Text Available Abstract Background Oral anticoagulation monitoring has traditionally taken place in secondary care because of the need for a laboratory blood test, the international normalised ratio (INR. The development of reliable near patient testing (NPT systems for INR estimation has facilitated devolution of testing to primary care. Patient self-management is a logical progression from the primary care model. This study will be the first to randomise non-selected patients in primary care, to either self-management or standard care. Method The study was a multi-centred randomised controlled trial with patients from 49 general practices recruited. Those suitable for inclusion were aged 18 or over, with a long term indication for oral anticoagulation, who had taken warfarin for at least six months. Patients randomised to the intervention arm attended at least two training sessions which were practice-based, 1 week apart. Each patient was assessed on their capability to undertake self management. If considered capable, they were given a near patient INR testing monitor, test strips and quality control material for home testing. Patients managed their own anticoagulation for a period of 12 months and performed their INR test every 2 weeks. Control patients continued with their pre-study care either attending hospital or practice based anticoagulant clinics. Discussion The methodology used in this trial will overcome concerns from previous trials of selection bias and relevance to the UK health service. The study will give a clearer understanding of the benefits of self-management in terms of clinical and cost effectiveness and patient preference.

Anticoagulation therapy a risk factor for the development of chronic subdural hematoma

DEFF Research Database (Denmark)

Aspegren, Oskar P.; Åstrand, Ramona; Lundgren, Maria I.

2013-01-01

Chronic subdural hematoma (CSDH) is a common disease among the elderly and with increasing incidence we have chosen to focus on associations between development and recurrence of CSDH and anticoagulation and/or antiplatelet agent therapy.......Chronic subdural hematoma (CSDH) is a common disease among the elderly and with increasing incidence we have chosen to focus on associations between development and recurrence of CSDH and anticoagulation and/or antiplatelet agent therapy....

Altered Escherichia coli membrane protein assembly machinery allows proper membrane assembly of eukaryotic protein vitamin K epoxide reductase.

Science.gov (United States)

Hatahet, Feras; Blazyk, Jessica L; Martineau, Eugenie; Mandela, Eric; Zhao, Yongxin; Campbell, Robert E; Beckwith, Jonathan; Boyd, Dana

2015-12-08

Functional overexpression of polytopic membrane proteins, particularly when in a foreign host, is often a challenging task. Factors that negatively affect such processes are poorly understood. Using the mammalian membrane protein vitamin K epoxide reductase (VKORc1) as a reporter, we describe a genetic selection approach allowing the isolation of Escherichia coli mutants capable of functionally expressing this blood-coagulation enzyme. The isolated mutants map to components of membrane protein assembly and quality control proteins YidC and HslV. We show that changes in the VKORc1 sequence and in the YidC hydrophilic groove along with the inactivation of HslV promote VKORc1 activity and dramatically increase its expression level. We hypothesize that such changes correct for mismatches in the membrane topogenic signals between E. coli and eukaryotic cells guiding proper membrane integration. Furthermore, the obtained mutants allow the study of VKORc1 reaction mechanisms, inhibition by warfarin, and the high-throughput screening for potential anticoagulants.

Effects of citrate-enriched bicarbonate based dialysate on anticoagulation and dialyzer reuse in maintenance hemodialysis patients.

Science.gov (United States)

Rocha, Amanda D; Padua, Vanessa C; Oliveira, Esther; Guimaraes, Márcia M; Lugon, Jocemir R; Strogoff de Matos, Jorge P

2014-04-01

Systemic anticoagulation with unfractionated heparin is commonly used in maintenance hemodialysis (HD), but it increases the risk of bleeding complications. We investigated whether the use of citrate-enriched bicarbonate based dialysate (CD) would reduce systemic anticoagulation without compromising the efficacy of reprocessed dialyzers. This is a crossover study in which half of a total of 30 patients initially underwent HD with acetate-enriched bicarbonate based dialysate and a standard heparin dose of ∼ 100 IU/kg (Treatment A), whereas the remaining patients were treated with CD and a 30% reduced heparin dose (Treatment B). After 12 consecutive HD sessions in each treatment, the dialysate and heparin doses were reversed, then followed for another period of 12 HD sessions. The two treatment phases were split by a washout period of six HD sessions using acetate-enriched bicarbonate based dialysate and standard heparin dose. Systemic anticoagulation was higher in Treatment A. The activated partial thromboplastin time at the end of HD session was 68 ± 36 seconds in Treatment A and 47 ± 16 seconds in Treatment B (P = 0.005). Sixty-eight percent of the dialyzers remained adequate until the 12th use in Treatment A and 61% did so in Treatment B (P = 0.63). Patients had three and 24 cramps episodes during Treatment A and B, respectively (P < 0.001). Nine and 26 symptomatic intradialytic hypotension episodes were seen in Treatment A and B, respectively, (P = 0.003). In conclusion, the use of CD had a favorable effect on anticoagulation in the extracorporeal circuit in patients on maintenance HD, but it was also associated with more hypotension and cramps. © 2013 International Society for Hemodialysis.

Oral anticoagulation for stroke prevention amongst atrial fibrillation patients with valvular heart disease: an update.

Science.gov (United States)

Ha, Andrew C T; Verma, Atul; Verma, Subodh

2017-03-01

The majority of evidence on the safety and efficacy of oral anticoagulation for stroke prevention amongst patients with atrial fibrillation is derived from those without significant valvular heart disease. This article will review current knowledge, areas of uncertainty and controversy, and ongoing research on oral anticoagulation for stroke prevention amongst patients with valvular heart disease. The rates of stroke, systemic embolism, and major bleeding were similar for patients with and without significant native valvular disease when treated with direct oral anticoagulants (DOACs) or vitamin K antagonists. There are very limited prospective data on the safety and efficacy of DOAC use for patients with bioprosthetic valves or rheumatic mitral stenosis. Atrial fibrillation patients with concomitant valvulopathies constitute a group with high thromboembolic risk and should be treated with oral anticoagulation. There is good supportive evidence that DOAC is well tolerated and effective in preventing thromboembolism amongst patients with native valvular disease. Further research is underway to better define the risks and benefits of DOAC use among patients with bioprosthetic valves or rheumatic mitral stenosis in preventing thromboembolic events. Until then, vitamin K antagonists remain the oral anticoagulant of choice for these patient subsets.

INR targets and site-level anticoagulation control: results from the Veterans AffaiRs Study to Improve Anticoagulation (VARIA).

Science.gov (United States)

Rose, A J; Berlowitz, D R; Miller, D R; Hylek, E M; Ozonoff, A; Zhao, S; Reisman, J I; Ash, A S

2012-04-01

Not all clinicians target the same International Normalized Ratio (INR) for patients with a guideline-recommended target range of 2-3. A patient's mean INR value suggests the INR that was actually targeted. We hypothesized that sites would vary by mean INR, and that sites of care with mean values nearest to 2.5 would achieve better anticoagulation control, as measured by per cent time in therapeutic range (TTR). To examine variations among sites in mean INR and the relationship with anticoagulation control in an integrated system of care. We studied 103,897 patients receiving oral anticoagulation with an expected INR target between 2 and 3 at 100 Veterans Health Administration (VA) sites from 1 October 2006 to 30 September 2008. Key site-level variables were: proportion near 2.5 (that is, percentage of patients with mean INR between 2.3 and 2.7) and mean risk-adjusted TTR. Site mean INR ranged from 2.22 to 2.89; proportion near 2.5, from 30 to 64%. Sites' proportions of patients near 2.5, below 2.3 and above 2.7 were consistent from year to year. A 10 percentage point increase in the proportion near 2.5 predicted a 3.8 percentage point increase in risk-adjusted TTR (P < 0.001). Proportion of patients with mean INR near 2.5 is a site-level 'signature' of care and an implicit measure of targeted INR. This proportion varies by site and is strongly associated with site-level TTR. Our study suggests that sites wishing to improve TTR, and thereby improve patient outcomes, should avoid the explicit or implicit pursuit of non-standard INR targets. © 2012 International Society on Thrombosis and Haemostasis.

Multivariate relationships between international normalized ratio and vitamin K-dependent coagulation-derived parameters in normal healthy donors and oral anticoagulant therapy patients

Directory of Open Access Journals (Sweden)

Golanski Jacek

2003-11-01

Full Text Available Abstract Background and objectives International Normalized Ratio (INR is a world-wide routinely used factor in the monitoring of oral anticoagulation treatment (OAT. However, it was reported that other factors, e. g. factor II, may even better reflect therapeutic efficacy of OAT and, therefore, may be potentialy useful for OAT monitoring. The primary purpose of this study was to characterize the associations of INR with other vitamin K-dependent plasma proteins in a heterogenous group of individuals, including healthy donors, patients on OAT and patients not receiving OAT. The study aimed also at establishing the influence of co-morbid conditions (incl. accompanying diseases and co-medications (incl. different intensity of OAT on INR. Design and Methods Two hundred and three subjects were involved in the study. Of these, 35 were normal healthy donors (group I, 73 were patients on medication different than OAT (group II and 95 were patients on stable oral anticoagulant (acenocoumarol therapy lasting for at least half a year prior to the study. The values of INR and activated partial thromboplastin time (APTT ratio, as well as activities of FII, FVII, FX, protein C, and concentration of prothrombin F1+2 fragments and fibrinogen were obtained for all subjects. In statistical evaluation, the uni- and multivariate analyses were employed and the regression equations describing the obtained associations were estimated. Results Of the studied parameters, three (factors II, VII and X appeared as very strong modulators of INR, protein C and prothrombin fragments F1+2 had moderate influence, whereas both APTT ratio and fibrinogen had no significant impact on INR variability. Due to collinearity and low tolerance of independent variables included in the multiple regression models, we routinely employed a ridge multiple regression model which compromises the minimal number of independent variables with the maximal overall determination coefficient. The best

[Anticoagulation in the aged patient with atrial fibrillation: What are prescribing cardiologists, geriatricians and general practitioners?].

Science.gov (United States)

Fuchs, P; Vogel, T; Lang, P-O

2015-08-01

To assess prescribing of anticoagulants in atrial fibrillation (AF) in the elderly, both a quantitative point of view (rate of anticoagulation) and qualitative (type of anticoagulation). Determinants of prescribing and non-prescribing were also analysed. Prospective survey of practice, based on one clinical case and questionnaire conducted in 60 practitioners (20 cardiologists [C], 20 geriatricians [G] and 20 general practitioners [GP]). In reading the clinical case, 88.3% of physicians would have initiated a treatment; three types of treatments would have been chosen: AVK (68.3%), ODA (20.0%) and platelet antiaggregant (11.7%). Criteria taken into account to initiate anticoagulation varied according to the specialty. Cardiologists considered more the age criteria (C: 95.0%, G: 75.0%, MG: 60.0%; PC: 90.0%, G: 60.0%, MG: 55.0%; PC: 85.0%, G: 55.0%, MG: 60.0%; PC: 80.0%, G: 35.0%, MG: 25.0%; PC: 15.0%, G: 5.0%, MG: 0.0%; PC: 35.0%, G: 5.0%, MG: 45.0%; PC: 70.0%, G: 75.0%, MG: 85.0%; P<0.05). This survey confirms that the FA remains under anticoagulated in the elderly and the barriers to the prescription of oral anticoagulation are often without rational basis. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Quality of Life analysis of patients in chronic use of oral anticoagulant: an observational study

Directory of Open Access Journals (Sweden)

Almeida Geisa

2011-10-01

Full Text Available Abstract Background Treatment with oral anticoagulant may influence the quality of life perception as it promotes changes in the patient's life, not offering an evident symptomatic relief and presenting well defined risks, such as bleeding. In this trial, the influence of chronic use of anticoagulants on the quality of life perception has been analyzed in patients assisted at the anticoagulation outpatient unit. Methods The health related quality of life was evaluated through a cross-section study with a sample composed of 72 patients seen from July 23, 2009 to September 2, 2010 at the Anticoagulation Outpatient Unit of the Federal University of Bahia's University Hospital. The study's population was composed by patients with atrial fibrillation and mechanical heart valve. The patients were submitted to two quality of life evaluation questionnaires: a generic questionnaire - the Medical Outcomes Study SF-36 Health Survey (SF36 - and a specific questionnaire - the Duke Anticoagulation Satisfaction Scale (DASS. Results The quality of life perception of the patients studied, based on both the DASS and the SF36, was positive regarding the treatment with oral anticoagulant. The SF36 presented an average score of 62.2 (± 20.0. Among the SF36 evaluated domains, the physical-emotional aspect was the most compromised one regarding life quality perception. The DASS presented an average score of 67.1 (± 18.2 and the domain presenting a greater compromise was the one related to the treatment inconveniences (annoyances, burdens and obligations. Previous hemorrhagic event, comorbidities, drug interactions with medicines that increase the anticoagulant effect, lower education level in the SF36 and younger age group influence a more negative perception of the quality of life, whereas lower education level in the DASS and the duration of treatment for more than 1 year offer a more positive perception. Conclusion Patients seen at the anticoagulation outpatient

Anticoagulant and antithrombotic evaluation of native fucosylated chondroitin sulfates and their derivatives as selective inhibitors of intrinsic factor Xase.

Science.gov (United States)

Wu, Mingyi; Wen, Dandan; Gao, Na; Xiao, Chuang; Yang, Lian; Xu, Li; Lian, Wu; Peng, Wenlie; Jiang, Jianmin; Zhao, Jinhua

2015-03-06

Fucosylated chondroitin sulfate (FCS), a structurally unusual glycosaminoglycan, has distinct anticoagulant properties, and is an especially strong inhibitor of the intrinsic factor Xase (anti-Xase). To obtain a highly selective inhibitor of human Xase, we purified six native FCSs with various sulfation patterns, prepared a series of FCS derivatives, and then elucidated the relationship between the structures and the anticoagulant activities of FCSs. FCSs 1-3 containing higher Fuc2S4S exhibit stronger AT-dependent anti-IIa activities, whereas 4-6 containing more Fuc3S4S produce potent HCII-dependent anti-IIa activities. Saccharides containing a minimum of 6-8 trisaccharide units, free carboxyl groups, and full fucosylation of GlcA may be required for potent anti-Xase activity, and approximately six trisaccharide units and partial fucosylation of GlcA may contribute to potent HCII-dependent activity. Decreasing of the molecular weights markedly reduces their AT-dependent anti-IIa activities, and even eliminates human platelet and factor XII activation. Furthermore, in vitro and in vivo studies suggested that fractions of 6-12 kDa may be very promising compounds as putative selective intrinsic Xase inhibitors with antithrombotic action, but without the consequences of major bleeding and factor XII activation. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Cost Effectiveness of Implantable Cardiac Monitor-Guided Intermittent Anticoagulation for Atrial Fibrillation: An Analysis of the REACT.COM Pilot Study.

Science.gov (United States)

Steinhaus, Daniel A; Zimetbaum, Peter J; Passman, Rod S; Leong-Sit, Peter; Reynolds, Matthew R

2016-08-30

Anticoagulation guidelines for patients with atrial fibrillation (AF) disregard AF burden. A strategy of targeted anticoagulation with novel oral anticoagulants (NOACs) based on continuous rhythm assessment with an implantable cardiac monitor (ICM) has recently been explored. We evaluated the potential cost-effectiveness of this strategy versus projected outcomes with continuous anticoagulation. We developed a Markov model using data from the Rhythm Evaluation for AntiCoagulaTion With COntinuous Monitoring (REACT.COM) pilot study (N = 59) and prior NOAC trials to calculate the costs and quality-adjusted life years (QALYs) associated with ICM-guided intermittent anticoagulation for AF versus standard care during a 3-year time horizon. Health state utilities were estimated from the pilot study population using the SF-12. Costs were based on current Medicare reimbursement. Over 14 ± 4 months of follow-up, 18 of 59 patients had 35 AF episodes. The ICM-guided strategy resulted in a 94% reduction in anticoagulant use relative to continuous treatment. There were no strokes, 3 (5.1%) TIAs, 2 major bleeding events (on aspirin) and 3 minor bleeding events with the ICM-guided strategy. The projected total 3-year costs were $12,535 for the ICM-guided strategy versus $13,340 for continuous anticoagulation. Projected QALYs were 2.45 for both groups. Based on a pilot study, a strategy of ICM-guided anticoagulation with NOACs may be cost-saving relative to expected outcomes with continuous anticoagulation, with similar quality-adjusted survival. This strategy could be attractive from a health economic perspective if shown to be safe and effective in a rigorous clinical trial. © 2016 Wiley Periodicals, Inc.

Impact of INR monitoring, reversal agent use, heparin bridging, and anticoagulant interruption on rebleeding and thromboembolism in acute gastrointestinal bleeding.

Directory of Open Access Journals (Sweden)

Naoyoshi Nagata

Full Text Available Anticoagulant management of acute gastrointestinal bleeding (GIB during the pre-endoscopic period has not been fully addressed in American, European, or Asian guidelines. This study sought to evaluate the risks of rebleeding and thromboembolism in anticoagulated patients with acute GIB.Baseline, endoscopy, and outcome data were reviewed for 314 patients with acute GIB: 157 anticoagulant users and 157 age-, sex-, and important risk-matched non-users. Data were also compared between direct oral anticoagulants (DOACs and warfarin users.Between anticoagulant users and non-users, of whom 70% underwent early endoscopy, no endoscopy-related adverse events or significant differences were found in the rate of endoscopic therapy need, transfusion need, rebleeding, or thromboembolism. Rebleeding was associated with shock, comorbidities, low platelet count and albumin level, and low-dose aspirin use but not HAS-BLED score, any endoscopic results, heparin bridge, or international normalized ratio (INR ≥ 2.5. Risks for thromboembolism were INR ≥ 2.5, difference in onset and pre-endoscopic INR, reversal agent use, and anticoagulant interruption but not CHA2DS2-VASc score, any endoscopic results, or heparin bridge. In patients without reversal agent use, heparin bridge, or anticoagulant interruption, there was only one rebleeding event and no thromboembolic events. Warfarin users had a significantly higher transfusion need than DOACs users.Endoscopy appears to be safe for anticoagulant users with acute GIB compared with non-users. Patient background factors were associated with rebleeding, whereas anticoagulant management factors (e.g. INR correction, reversal agent use, and drug interruption were associated with thromboembolism. Early intervention without reversal agent use, heparin bridge, or anticoagulant interruption may be warranted for acute GIB.

Effective management of venous thromboembolism in the community: non-vitamin K antagonist oral anticoagulants

Directory of Open Access Journals (Sweden)

Patel R

2016-05-01

Full Text Available Raj Patel Department of Haematological Medicine, King's Thrombosis Centre, King's College Hospital, London, UK Abstract: Anticoagulation therapy is essential for the effective treatment and secondary prevention of venous thromboembolism (VTE. For many years, anticoagulation for acute VTE was limited to the use of initial parenteral heparin, overlapping with and followed by a vitamin K antagonist. Although highly effective, this regimen has several limitations and is particularly challenging when given in an ambulatory setting. Current treatment pathways for most patients with deep-vein thrombosis typically involve initial hospital or community-based ambulatory care with subsequent follow-up in a secondary care setting. With the introduction of non-vitamin K antagonist oral anticoagulants (NOACs into routine clinical practice, it is now possible for the initial acute management of patients with deep-vein thrombosis to be undertaken by primary care. As hospital admissions associated with VTE become shorter, primary care will play an increasingly important role in the long-term management of these patients. Although the NOACs can potentially simplify patient management and improve clinical outcomes, primary care physicians may be less familiar with these new treatments compared with traditional therapy. To assist primary care physicians in further understanding the role of the NOACs, this article outlines the main differences between NOACs and traditional anticoagulation therapy and discusses the benefit–risk profile of the different NOACs in the treatment and secondary prevention of recurrent VTE. Key considerations for the use of NOACs in the primary care setting are highlighted, including dose transition, risk assessment and follow-up, duration of anticoagulant therapy, how to minimize bleeding risks, and the importance of patient education and counseling. Keywords: venous thromboembolism, oral anticoagulant, prevention, treatment, primary

Direct Oral Anticoagulants in Emergency Trauma Admissions.

Science.gov (United States)

Maegele, Marc; Grottke, Oliver; Schöchl, Herbert; Sakowitz, Oliver A; Spannagl, Michael; Koscielny, Jürgen

2016-09-05

Direct (non-vitamin-K-dependent) oral anticoagulants (DOAC) are given as an alternative to vitamin K antagonists (VKA) to prevent stroke and embolic disease in patients with atrial fibrillation that is not due to pathology of the heart valves. Fatal hemorrhage is rarer when DOACs are given (nonvalvular atrial fibrillation: odds ratio [OR] 0.68; 95% confidence interval [95% CI: 0.48; 0.96], and venous thromboembolism: OR 0.54; [0.22; 1.32]). 48% of emergency trauma patients need an emergency operation or early surgery. Clotting disturbances elevate the mortality of such patients to 43%, compared to 17% in patients without a clotting disturbance. This underscores the impor tance of the proper, targeted treatment of trauma patients who are aking DOAC. This review is based on articles retrieved by a selective search in PubMed and on a summary of expert opinion and the recommendations of the relevant medical specialty societies. Peak DOAC levels are reached 2-4 hours after the drug is taken. In patients with normal renal and hepatic function, no drug accumulation, and no drug interactions, the plasma level of DOAC 24 hours after administration is generally too low to cause any clinically relevant risk of bleeding. The risk of drug accumulation is higher in patients with renal dysfunction (creatinine clearance [CrCl] of 30 mL/min or less). Dabigatran levels can be estimated from the thrombin time, ecarin clotting time, and diluted thrombin time, while levels of factor Xa inhibitors can be estimated by means of calibrated chromogenic anti-factor Xa activity tests. Routine clotting studies do not reliably reflect the anticoagulant activity of DOAC. Surgery should be postponed, if possible, until at least 24-48 hours after the last dose of DOAC. For patients with mild, non-life threatening hemorrhage, it suffices to discontinue DOAC; for patients with severe hemorrhage, there are special treatment algorithms that should be followed. DOACs in the setting of hemorrhage are a

Lupus anticoagulant-hypoprothrombinemia syndrome and catastrophic antiphospholipid syndrome in a patient with antidomain I antibodies.

Science.gov (United States)

Galland, Joris; Mohamed, Shirine; Revuz, Sabine; de Maistre, Emmanuel; de Laat, Bas; Marie, Pierre-Yves; Zuily, Stéphane; Lévy, Bruno; Regnault, Véronique; Wahl, Denis

2016-07-01

Lupus anticoagulant-hypoprothrombinemia syndrome is a rare condition characterized by the association of acquired factor II deficiency and lupus anticoagulant. Contrary to classical antiphospholipid syndrome, it may cause severe life-threatening bleeding (89% of published cases). We report a patient, positive for antidomain I antibodies, with initially primary lupus anticoagulant-hypoprothrombinemia syndrome without previous clinical manifestation or underlying systemic disease. Five years later, he experienced the first systemic lupus erythematous flare. Within a few days, catastrophic antiphospholipid syndrome was diagnosed with heart, liver and kidney involvement. The patient recovered under pulse steroids, intravenous heparin and intravenous immunoglobulins.

New Direct Oral Anticoagulants (DOAC and Their Use Today

Directory of Open Access Journals (Sweden)

Heike Schwarb

2016-03-01

Full Text Available The ideal anticoagulant is oral, has a wide therapeutic range, predictable pharmacokinetics and pharmacodynamics, a rapid onset of action, an available antidote, minimal side effects and minimal interactions with other drugs or food. With the development of the novel direct oral anticoagulants (DOAC, we now have an alternative to the traditional vitamin K antagonists (VKA for the prevention and treatment of thrombosis. DOACs have limited monitoring requirements and very predictable pharmacokinetic profiles. They were shown to be non-inferior or superior to VKA in the prophylaxis or treatment of thromboembolic events. Particularly in terms of safety they were associated with less major bleeding, including intracranial bleeding, thus providing a superior benefit for the prevention of stroke in patients with atrial fibrillation. Despite these advantages, there are remaining limitations with DOACs: their dependence on renal and hepatic function for clearance and the lack of an approved reversal agent, whereas such antidotes are successively being made available. DOACs do not need regular monitoring to assess the treatment effect but, on the other hand, they interact with other drugs and interfere with functional coagulation assays. From a practical point of view, the properties of oral administration, simple dosing without monitoring, a short half-life allowing for the possibility of uncomplicated switching or bridging, and proven safety overwhelm the disadvantages, making them an attractive option for short- or long-term anticoagulation.

Rivaroxaban limits complement activation compared with warfarin in antiphospholipid syndrome patients with venous thromboembolism.

Science.gov (United States)

Arachchillage, D R J; Mackie, I J; Efthymiou, M; Chitolie, A; Hunt, B J; Isenberg, D A; Khamashta, M; Machin, S J; Cohen, H

2016-11-01

Essentials Complement activation has a pathogenic role in thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Complement activation markers were elevated in anticoagulated thrombotic APS patients. Complement activation decreased in APS patients switching from warfarin to rivaroxaban. Background Complement activation may play a major role in the pathogenesis of thrombotic antiphospholipid syndrome (APS). Coagulation proteases such as factor Xa can activate complement proteins. Aims To establish whether rivaroxaban, a direct factor Xa inhibitor, limits complement activation compared with warfarin in APS patients with previous venous thromboembolism (VTE). Methods A total of 111 APS patients with previous VTE, on warfarin target INR 2.5, had blood samples taken at baseline and at day 42 after randomization in the RAPS (Rivaroxaban in Antiphospholipid Syndrome) trial. Fifty-six patients remained on warfarin and 55 switched to rivaroxaban. Fifty-five normal controls (NC) were also studied. Markers of complement activation (C3a, C5a, terminal complement complex [SC5b-9] and Bb fragment) were assessed. Results APS patients had significantly higher complement activation markers compared with NC at both time-points irrespective of the anticoagulant. There were no differences between the two patient groups at baseline, or patients remaining on warfarin at day 42. In 55 patients randomized to rivaroxaban, C3a, C5a and SC5b-9 were lower at day 42 (median (ng mL -1 ) [confidence interval] 64 [29-125] vs. 83 [35-147], 9 [2-15] vs. 12 [4-18] and 171 [56-245] vs. 201 [66-350], respectively) but levels of Bb fragment were unchanged. There were no correlations between rivaroxaban levels and complement activation markers. Conclusions APS patients with previous VTE on warfarin exhibit increased complement activation, which is likely to occur via the classical pathway and is decreased by rivaroxaban administration

Activated protein C and its potential applications in prevention of islet β-cell damage and diabetes.

Science.gov (United States)

Xue, Meilang; Jackson, Christopher J

2014-01-01

Activated protein C (APC) is derived from its precursor, protein C (PC). Originally thought to be synthesized exclusively by the liver, recent reports have shown that PC is also produced by many other cells including pancreatic islet β cells. APC functions as a physiological anticoagulant with anti-inflammatory, anti-apoptotic, and barrier-stabilizing properties. APC exerts its protective effects via an intriguing mechanism requiring combinations of endothelial PC receptor, protease-activated receptors, epidermal growth factor receptor, Tie2 or CD11b, depending on cell types. Diabetes is a chronic condition resulted from the body's inability to produce and/or properly use insulin. The prevalence of diabetes has risen dramatically and has become one of the major causes of premature mortality and morbidity worldwide. Diabetes prevention is an ideal approach to reduce this burden. Type 1 and type 2 diabetes are the major forms of diabetes mellitus, and both are characterized by an autoimmune response, intraislet inflammation, β-cell apoptosis, and progressive β-cell loss. Protecting β-cell from damage is critical in both prevention and treatment of diabetes. Recent in vitro and animal studies show that APC's strong anti-inflammatory and anti-apoptotic properties are beneficial in preventing β-cell destruction and diabetes in the NOD mouse model of type 1 diabetes. Future preventive and therapeutic uses of APC in diabetes look very promising. © 2014 Elsevier Inc. All rights reserved.

Evaluation of computerized decision support for oral anticoagulation management based in primary care.

OpenAIRE

Fitzmaurice, D A; Hobbs, F D; Murray, E T; Bradley, C P; Holder, R

1996-01-01

BACKGROUND: Increasing indications for oral anticoagulation has led to pressure on general practices to undertake therapeutic monitoring. Computerized decision support (DSS) has been shown to be effective in hospitals for improving clinical management. Its usefulness in primary care has previously not been investigated. AIM: To test the effectiveness of using DSS for oral anticoagulation monitoring in primary care by measuring the proportions of patients adequately controlled, defined as with...

How to Invest in Getting Cost-effective Technologies into Practice? A Framework for Value of Implementation Analysis Applied to Novel Oral Anticoagulants.

Science.gov (United States)

Faria, Rita; Walker, Simon; Whyte, Sophie; Dixon, Simon; Palmer, Stephen; Sculpher, Mark

2017-02-01

Cost-effective interventions are often implemented slowly and suboptimally in clinical practice. In such situations, a range of implementation activities may be considered to increase uptake. A framework is proposed to use cost-effectiveness analysis to inform decisions on how best to invest in implementation activities. This framework addresses 2 key issues: 1) how to account for changes in utilization in the future in the absence of implementation activities; and 2) how to prioritize implementation efforts between subgroups. A case study demonstrates the framework's application: novel oral anticoagulants (NOACs) for the prevention of stroke in the National Health Service in England and Wales. The results suggest that there is value in additional implementation activities to improve uptake of NOACs, particularly in targeting patients with average or poor warfarin control. At a cost-effectiveness threshold of £20,000 per quality-adjusted life-year (QALY) gained, additional investment in an educational activity that increases the utilization of NOACs by 5% in all patients currently taking warfarin generates an additional 254 QALYs, compared with 973 QALYs in the subgroup with average to poor warfarin control. However, greater value could be achieved with higher uptake of anticoagulation more generally: switching 5% of patients who are potentially eligible for anticoagulation but are currently receiving no treatment or are using aspirin would generate an additional 4990 QALYs. This work can help health services make decisions on investment at different points of the care pathway or across disease areas in a manner consistent with the value assessment of new interventions.

Prevention of thromboembolic events in patients with atrial fibrillation - new anticoagulants.

Science.gov (United States)

Campos, Alexandre Holthausen; Cirenza, Cláudio

2011-09-01

The authors present alternatives for the treatment of cardiac arrhythmias. Its detection is based on the use of different methods that record the cardiac electrical activity. The treatment involves intervening in the underlying disorder, antiarrhythmic drugs, stimulation and cardiac defibrillation devices, and, less often, surgery. The technological advances in the last two decades have provided greater efficiency in diagnoses and therapy. Atrial fibrilation patients will benefit from a new set of anticoagulant drugs tested in the past three years. The potential advantages include greater safety and efficacy, as well as convenience for not requiring frequent laboratory controls.

The Italian START-Register on Anticoagulation with Focus on Atrial Fibrillation

Science.gov (United States)

2015-01-01

START-Register – Survey on anTicoagulated pAtients RegisTer – is an independent, inception-cohort, observational, collaborative database aimed at recording prospectively the clinical history of adult patients starting anticoagulant treatment for any reason and using whatever drug. In this article we present the START-Register and give cross section baseline data focusing on non valvular atrial fibrillation (NVAF). Participants are asked to insert prospectively consecutive patients recorded as electronic file on the web-site of the registry. Required data are: demographic and clinical characteristics of patients, associated risk factors for stroke and bleeding, laboratory routine data, clinical indication for treatment, expected therapeutic range (in cases of treatment with vitamin K antagonists -VKAs). The follow-up is carried out to record: quality of treatment (for patients on VKAs), bleeding complications, thrombotic events, and the onset of any type of associated disease. To date 5252 patients have been enrolled; 97.6% were on VKAs because direct oral anticoagulants (DOAC) have been available in Italy only recently. The median age was 74 years [interquartile range (IQR) 64-80]; males 53.7%. This analysis is focused on the 3209 (61.1%) NVAF patients. Mean CHADS2 score was 2.1±1.1, CHADSVASc score was 3.1±1.3;median age was 76 years (IQR 70-81); 168 patients (5.3%) had severe renal failure [Creatinine clearance (CrCl) START-Register data shows that two-third of patients who started chronic anticoagulant treatment had NVAF, one-third of them was > 80 years with high prevalence of renal failure. PMID:26001109

Generic switching of warfarin and risk of excessive anticoagulation

DEFF Research Database (Denmark)

Hellfritzsch, Maja; Rathe, Jette; Stage, Tore Bjerregaard

2016-01-01

PURPOSE: Generic switching of warfarin was recently repealed in Denmark, as adverse drug reaction (ADR) reports suggested risk of excessive anticoagulation following switches from branded to generic warfarin. We investigated this putative association in a formalized pharmacoepidemiological analysis....... METHODS: We conducted a nationwide cohort study based on Danish healthcare registries, including data from the introduction of generic warfarin until the repeal (January 2011-April 2015). We followed Danish warfarin users over time and compared the rate of incident hospitalizations due to excessive...... anticoagulation (i.e. increased INR or any bleeding requiring hospitalization) in periods following a recent switch to generic warfarin to the rate in periods without a recent switch. RESULTS: We included 105,751 warfarin users, filling a total of 1,539,640 prescriptions for warfarin (2.5% for generic warfarin...

Adherence to oral anticoagulant therapy in secondary stroke prevention – impact of the novel oral anticoagulants

Directory of Open Access Journals (Sweden)

Luger S

2015-11-01

Full Text Available Sebastian Luger,1 Carina Hohmann,2 Daniela Niemann,1 Peter Kraft,3 Ignaz Gunreben,3 Tobias Neumann-Haefelin,2 Christoph Kleinschnitz,3 Helmuth Steinmetz,1 Christian Foerch,1 Waltraud Pfeilschifter1 1Department of Neurology, University Hospital Frankfurt, Frankfurt am Main, 2Department of Neurology, Klinikum Fulda gAG, Fulda, 3Department of Neurology, University Hospital Würzburg, Würzburg, Germany Background: Oral anticoagulant therapy (OAT potently prevents strokes in patients with atrial fibrillation. Vitamin K antagonists (VKA have been the standard of care for long-term OAT for decades, but non-VKA oral anticoagulants (NOAC have recently been approved for this indication, and raised many questions, among them their influence on medication adherence. We assessed adherence to VKA and NOAC in secondary stroke prevention. Methods: All patients treated from October 2011 to September 2012 for ischemic stroke or transient ischemic attack with a subsequent indication for OAT, at three academic hospitals were entered into a prospective registry, and baseline data and antithrombotic treatment at discharge were recorded. At the 1-year follow-up, we assessed the adherence to different OAT strategies and patients’ adherence to their respective OAT. We noted OAT changes, reasons to change treatment, and factors that influence persistence to the prescribed OAT. Results: In patients discharged on OAT, we achieved a fatality corrected response rate of 73.3% (n=209. A total of 92% of these patients received OAT at the 1-year follow-up. We observed good adherence to both VKA and NOAC (VKA, 80.9%; NOAC, 74.8%; P=0.243 with a statistically nonsignificant tendency toward a weaker adherence to dabigatran. Disability at 1-year follow-up was an independent predictor of lower adherence to any OAT after multivariate analysis, whereas the choice of OAT did not have a relevant influence. Conclusion: One-year adherence to OAT after stroke is strong (>90% and patients

Comparing new anticoagulants.

Science.gov (United States)

Wooten, James M

2012-12-01

For years, the pharmaceutical industry has been trying to find a safe and effective drug to replace warfarin. Although warfarin is an effective anticoagulant, its pharmacology, adverse effects, and risk profiles dictate that patients taking this medication must be monitored judiciously. The US Food and Drug Administration has approved two drugs for commercial use, dabigatran and rivaroxaban, that will compete directly with warfarin for use in specific indications. Because of direct marketing to patients, physicians are being asked to comment on these new medications. This brief review illustrates the data available for the two new drugs when compared to warfarin for the specified indications. For some patients, these drugs may be highly beneficial and offer an excellent alternative to warfarin. For others, warfarin may still be the preferred drug.

Atrial fibrillation and stroke prevention practices in patients with candidacy for anticoagulation therapy

International Nuclear Information System (INIS)

Ullah, I.; Ahmad, S.; Hayat, Y.

2015-01-01

Background: Stroke secondary to Atrial Fibrillation is usually due to thrombi formed in the left atrium and left atrial appendage embolizing to cause ischemic stroke. Therefore, in patients with Atrial Fibrillation, antithrombotic therapy is recommended to prevent stroke. Vitamin K antagonist therapy is most widely used antithrombotic therapy for patients with valvular and non valvular AF. Aspirin is recommended only in low risk patients. This study was conducted to determine the stroke prevention practices in local patients with atrial fibrillation who were candidates for anticoagulation therapy. Method: This was descriptive cross sectional study conducted at Cardiovascular Department Lady Reading Hospital Peshawar and Cardiology Department Hayatabad Medical Complex Peshawar. Sampling technique was non probability consecutive. Patients visiting OPD of respective hospitals with EKG evidence of AF and having CHADES VASC score 2 or more or having mitral stenosis and AF were included in the study. Patients with additional indications for anticoagulation were excluded from the study. Results: A total of 205 patients with atrial fibrillation were studied. Mean age was 60.7±14.7 years. Male were 55.6 percentage (n=114) while 44.4 percentage (n=91) were female. Of these 149 (72.7 percentage) were candidates for anticoagulation based on CHA2DS2 VASc score of 2 and more or mitral stenosis with AF. Only 27.5 percentage (n=41) patients were adequately treated with anticoagulant therapy using VKA or novel oral anticoagulant drugs. Majority of them were getting dual antiplatelet therapy (DAPT). Conclusion: Most patients with AF and high risk characteristics for thromboembolism are not receiving proper stroke prevention therapies. (author)

Does small mammal prey guild affect the exposure of predators to anticoagulant rodenticides?

International Nuclear Information System (INIS)

Tosh, D.G.; McDonald, R.A.; Bearhop, S.; Lllewellyn, N.R.; Fee, S.; Sharp, E.A.; Barnett, E.A.; Shore, R.F.

2011-01-01

Ireland has a restricted small mammal prey guild but still includes species most likely to consume anticoagulant rodenticide (AR) baits. This may enhance secondary exposure of predators to ARs. We compared liver AR residues in foxes (Vulpes vulpes) in Northern Ireland (NI) with those in foxes from Great Britain which has a more diverse prey guild but similar agricultural use of ARs. Liver ARs were detected in 84% of NI foxes, more than in a comparable sample of foxes from Scotland and similar to that of suspected AR poisoned animals from England and Wales. High exposure in NI foxes is probably due to greater predation of commensal rodents and non-target species most likely to take AR baits, and may also partly reflect greater exposure to highly persistent brodifacoum and flocoumafen. High exposure is likely to enhance risk and Ireland may be a sentinel for potential effects on predator populations. - Highlights: → Exposure of a predator to anticoagulant rodenticides was compared in Britain and Ireland. → Exposure was higher in Ireland. → Differences driven by small mammal prey guilds. → Ireland a potential sentinel for predator exposure to anticoagulants. - Restriction of the small mammal prey guild is associated with enhanced exposure of predators to anticoagulant rodenticides.

Practical considerations in emergency management of bleeding in the setting of target-specific oral anticoagulants.

Science.gov (United States)

Miller, Michael P; Trujillo, Toby C; Nordenholz, Kristen E

2014-04-01

The recent arrival of the target-specific oral anticoagulants (TSOACs) offers potential advantages in the field of anticoagulation. However, there are no rapid and accurate and routinely available laboratory assays to evaluate their contribution to clinical bleeding. With the expanding clinical indications for the TSOACs, and the arrival of newer reversal agents on the market, the emergency clinician will need to be familiar with drug specifics as well as methods for anticoagulation reversal. This review offers a summary of the literature and some practical strategies for the approach to the patient taking TSOACs and the management of bleeding in these cases. Copyright © 2014 Elsevier Inc. All rights reserved.

Monitoring of anticoagulant therapy in heart disease: considerations for the current assays.

Science.gov (United States)

Boroumand, Mohammadali; Goodarzynejad, Hamidreza

2010-01-01

Clinicians should be aware of new developments to familiarize themselves with pharmacokinetic and pharmacodynamic characteristics of new anticoagulant agents to appropriately and safely use them. For the moment, cardiologists and other clinicians also require to master currently available drugs, realizing the mechanism of action, side effects, and laboratory monitoring to measure their anticoagulant effects. Warfarin and heparin have narrow therapeutic window with high inter- and intra-patient variability, thereby the use of either drug needs careful laboratory monitoring and dose adjustment to ensure proper antithrombotic protection while minimizing the bleeding risk. The prothrombin time (PT) and the activated partial thromboplastin time (aPTT) are laboratory tests commonly used to monitor warfarin and heparin, respectively. These two tests depend highly on the combination of reagent and instrument utilized. Results for a single specimen tested in different laboratories are variable; this is mostly attributable to the specific reagents and to a much lesser degree to the instrument used. The PT stands alone as the single coagulation test that has undergone the most extensive attempt at assay standardization. The international normalized ratio (INR) was introduced to "normalize" all PT reagents to a World Health Organization (WHO) reference thromboplastin preparation standard, such that a PT measured anywhere in the world would result in an INR value similar to that which would have been achieved had the WHO reference thromboplastin been utilized. However, INRs are reproducible between laboratories for only those patients who are stably anticoagulated with vitamin K antagonists (VKAs) (i.e., at least 6 weeks of VKA therapy), and are not reliable or reproducible between laboratories for patients for whom VKA therapy has recently been started or any other clinical conditions associated with a prolonged PT such as liver disease, disseminated intravascular coagulation

Synthesis of an endothelial cell mimicking surface containing thrombomodulin and endothelial protein C receptor

Science.gov (United States)

Kador, Karl Erich

Synthetic materials for use in blood contacting applications have been studied for many years with limited success. One of the main areas of need for these materials is the design of synthetic vascular grafts for use in the hundreds of thousands of patients who have coronary artery bypass grafting, many without suitable veins for autologous grafts. The design of these grafts is constrained by two common modes of failure, the formation of intimal hyperplasia (IH) and thrombosis. IH formation has been previously linked to a mismatching of the mechanical properties of the graft and has been overcome by creating grafts using materials whose compliance mimics that of the native artery. Several techniques and surface modification have been designed to limit thrombosis on the surface of synthetic materials. One which has shown the greatest promise is the immobilization of Thrombomodulin (TM), a protein found on the endothelial cell membrane lining native blood vessels involved in the activation of the anticoagulant Protein C (PC). While TM immobilization has been shown to arrest thrombin formation and limit fibrous formations in in-vitro and in-vivo experiments, it has shown to be transport limiting under arterial flow. On the endothelial cell surface, TM is co-localized with Endothelial Protein C Receptor (EPCR), which increases PC transport onto the cell surface and increases PC activation via TM between 20-100 fold. This dissertation will describe the chemical modification of medical grade polyurethane (PU), whose compliance has been shown to match that of native arteries. This modification will enable the immobilization of two proteins on an enzymatically relevant scale estimated at less than 10 nm. This dissertation will further describe the immobilization of the proteins TM and EPCR, and analyze the ability of a surface co-immobilized with these proteins to activate the anticoagulant PC. Finally, it will compare the ability of this co-immobilized surface to delay

Gaps in monitoring during oral anticoagulation: insights into care transitions, monitoring barriers, and medication nonadherence.

Science.gov (United States)

Rose, Adam J; Miller, Donald R; Ozonoff, Al; Berlowitz, Dan R; Ash, Arlene S; Zhao, Shibei; Reisman, Joel I; Hylek, Elaine M

2013-03-01

Among patients receiving oral anticoagulation, a gap of > 56 days between international normalized ratio tests suggests loss to follow-up that could lead to poor anticoagulation control and serious adverse events. We studied long-term oral anticoagulation care for 56,490 patients aged 65 years and older at 100 sites of care in the Veterans Health Administration. We used the rate of gaps in monitoring per patient-year to predict percentage time in therapeutic range (TTR) at the 100 sites. Many patients (45%) had at least one gap in monitoring during an average of 1.6 years of observation; 5% had two or more gaps per year. The median gap duration was 74 days (interquartile range, 62-107). The average TTR for patients with two or more gaps per year was 10 percentage points lower than for patients without gaps (P < .001). Patient-level predictors of gaps included nonwhite race, area poverty, greater distance from care, dementia, and major depression. Site-level gaps per patient-year varied from 0.19 to 1.78; each one-unit increase was associated with a 9.2 percentage point decrease in site-level TTR (P < .001). Site-level gap rates varied widely within an integrated care system. Sites with more gaps per patient-year had worse anticoagulation control. Strategies to address and reduce gaps in monitoring may improve anticoagulation control.

Risk scores and geriatric profile: can they really help us in anticoagulation decision making among older patients suffering from atrial fibrillation?

Science.gov (United States)

Maes, Frédéric; Dalleur, Olivia; Henrard, Séverine; Wouters, Dominique; Scavée, Christophe; Spinewine, Anne; Boland, Benoit

2014-01-01

Anticoagulation for the prevention of cardio-embolism is most frequently indicated but largely underused in frail older patients with atrial fibrillation (AF). This study aimed at identifying characteristics associated with anticoagulation underuse. A cross-sectional study of consecutive geriatric patients aged ≥75 years, with AF and clear anticoagulation indication (CHADS₂ [Congestive heart failure, Hypertension, Age >75, Diabetes mellitus, and prior Stroke or transient ischemic attack] ≥2) upon hospital admission. All patients benefited from a comprehensive geriatric assessment. Their risks of stroke and bleeding were predicted using CHADS₂ and HEMORR2HAGES (Hepatic or renal disease, Ethanol abuse, Malignancy, Older (age >75 years), Reduced platelet count or function, Rebleed risk, Hypertension (uncontrolled), Anemia, Genetic factors, Excessive fall risk, and Stroke) scores, respectively. Anticoagulation underuse was observed in 384 (50%) of 773 geriatric patients with AF (median age 85 years; female 57%, cognitive disorder 33%, nursing home 20%). No geriatric characteristic was found to be associated with anticoagulation underuse. Conversely, anticoagulation underuse was markedly increased in the patients treated with aspirin (odds ratio [OR] [95% confidence interval]: 5.3 [3.8; 7.5]). Other independent predictors of anticoagulation underuse were ethanol abuse (OR: 4.0 [1.4; 13.3]) and age ≥90 years (OR: 2.0 [1.2; 3.4]). Anticoagulation underuse was not inferior in patients with a lower bleeding risk and/or a higher stroke risk and underuse was surprisingly not inferior either in the AF patients who had previously had a stroke. Half of this geriatric population did not receive any anticoagulation despite a clear indication, regardless of their individual bleeding or stroke risks. Aspirin use is the main characteristic associated with anticoagulation underuse.

Best strategies for patient education about anticoagulation with warfarin: a systematic review

Directory of Open Access Journals (Sweden)

Singh Sonal

2008-02-01

Full Text Available Abstract Background Patient education is an essential component in quality management of the anticoagulated patient. Because it is time consuming for clinicians and overwhelming for patients, education of the anticoagulated patient is often neglected. We surveyed the medical literature in order to identify the best patient education strategies. Methods Study Selection: Two reviewers independently searched the MEDLINE and Google Scholar databases (last search March 2007 using the terms "warfarin" or "anticoagulation", and "patient education". The initial search identified 206 citations, A total of 166 citations were excluded because patients were of pediatric age (4, the article was not related to patient education (48, did not contain original data or inadequate program description (141, was focused solely on patient self-testing (1, was a duplicate citation (3, the article was judged otherwise irrelevant (44, or no abstract was available (25. Data Extraction: Clinical setting, study design, group size, content source, time and personnel involved, educational strategy and domains, measures of knowledge retention. Results Data Synthesis: A total of 32 articles were ultimately used for data extraction. Thirteen articles adequately described features of the educational strategy. Five programs used a nurse or pharmacist, 4 used a physician, and 2 studies used other personnel/vehicles (lay educators (1, videotapes (1. The duration of the educational intervention ranged from 1 to 10 sessions. Patient group size most often averaged 3 to 5 patients but ranged from as low as 1 patient to as much as 11 patients. Although 12 articles offered information about education content, the wording and lack of detail in the description made it too difficult to accurately assign categories of education topics and to compare articles with one another. For the 17 articles that reported measures of patient knowledge, 5 of the 17 sites where the surveys were

Scoring and psychometric validation of the Perception of Anticoagulant Treatment Questionnaire (PACT-Q©

Directory of Open Access Journals (Sweden)

Essers B

2009-04-01

Full Text Available Abstract Background The 'Perception of Anti-Coagulant Treatment Questionnaire' (PACT-Q was developed to assess patients' expectations of, and satisfaction with their anticoagulant treatment. This questionnaire needs to be finalised and psychometrically validated. Methods The PACT-Q was included in the United States, the Netherlands and France into three phase III multinational clinical trials conducted to evaluate efficacy and safety of a new long-acting anticoagulant drug (idraparinux compared to vitamin K antagonist (VKA. PACT-Q was administered to patients with deep venous thrombosis (DVT, atrial fibrillation (AF or pulmonary embolism (PE at Day 1, to assess patients' expectations, and at 3 and 6 months to assess patients' satisfaction and treatment convenience and burden. The final structure of the PACT-Q (Principal Component Analysis – PCA – with Varimax Rotation was first determined and its psychometric properties were then measured with validity of the structure (Multitrait analysis, internal consistency reliability (Cronbach's alpha coefficients and known-group validity. Results PCA and multitrait analyses showed the multidimensionality of the "Treatment Expectations" dimension, comprising 7 items that had to be scored independently. The "Convenience" and "Burden of Disease and Treatment" dimensions of the hypothesised original structure of the questionnaire were combined, thus resulting in 13 items grouped into the single dimension "Convenience". The "Anticoagulant Treatment Satisfaction" dimension remained unchanged and included 7 items. All items of the "Convenience" and "Anticoagulant Treatment Satisfaction" dimensions displayed good convergent and discriminant validity. The internal consistency reliability was good, with a Cronbach's alpha of 0.84 for the "Convenience" dimension, and 0.76 for the "Anticoagulant Treatment Satisfaction" dimension. Known-group validity was good, especially with regard to occurrence of

Using Artificial Intelligence to Reduce the Risk of Nonadherence in Patients on Anticoagulation Therapy.

Science.gov (United States)

Labovitz, Daniel L; Shafner, Laura; Reyes Gil, Morayma; Virmani, Deepti; Hanina, Adam

2017-05-01

This study evaluated the use of an artificial intelligence platform on mobile devices in measuring and increasing medication adherence in stroke patients on anticoagulation therapy. The introduction of direct oral anticoagulants, while reducing the need for monitoring, have also placed pressure on patients to self-manage. Suboptimal adherence goes undetected as routine laboratory tests are not reliable indicators of adherence, placing patients at increased risk of stroke and bleeding. A randomized, parallel-group, 12-week study was conducted in adults (n=28) with recently diagnosed ischemic stroke receiving any anticoagulation. Patients were randomized to daily monitoring by the artificial intelligence platform (intervention) or to no daily monitoring (control). The artificial intelligence application visually identified the patient, the medication, and the confirmed ingestion. Adherence was measured by pill counts and plasma sampling in both groups. For all patients (n=28), mean (SD) age was 57 years (13.2 years) and 53.6% were women. Mean (SD) cumulative adherence based on the artificial intelligence platform was 90.5% (7.5%). Plasma drug concentration levels indicated that adherence was 100% (15 of 15) and 50% (6 of 12) in the intervention and control groups, respectively. Patients, some with little experience using a smartphone, successfully used the technology and demonstrated a 50% improvement in adherence based on plasma drug concentration levels. For patients receiving direct oral anticoagulants, absolute improvement increased to 67%. Real-time monitoring has the potential to increase adherence and change behavior, particularly in patients on direct oral anticoagulant therapy. URL: http://www.clinicaltrials.gov. Unique identifier: NCT02599259. © 2017 American Heart Association, Inc.

Safety and efficacy of anticoagulation for secondary stroke prevention in atrial fibrillation patients: The AMADEUS trial

NARCIS (Netherlands)

Lane, D.A.; Kamphuisen, P.W.; Minini, P.; Buller, H.R.; Lip, G.Y.H.

2010-01-01

ackground: Patients with atrial fibrillation (AF) and previous ischemic stroke are at high risk of recurrent stroke, but are also perceived to be at increased bleeding risk while treated with anticoagulants. Methods: Post-hoc analyses examined the efficacy and safety of anticoagulation of 4576 AF

Avaliação do desempenho dos reagentes do tempo de tromboplastina parcial ativada utilizados para detectar o anticoagulante lúpico Assessment of the performance of reagents of activated partial thromboplastin time used to detect the lupus anticoagulant

Directory of Open Access Journals (Sweden)

Fernanda Chiuso

2005-06-01

Full Text Available INTRODUÇÃO: O anticoagulante lúpico é uma imunoglobulina pertencente à família dos anticorpos antifosfolípides. A sua ação in vitro é interferir nos testes de coagulação dependentes de fosfolípides. O tempo de tromboplastina parcial ativada (TTPA é um teste utilizado como screening na pesquisa do anticoagulante lúpico. Os reagentes utilizados neste teste apresentam grandes variações quanto à sensibilidade. OBJETIVO: Avaliar o desempenho dos reagentes do TTPA e detectar a presença do anticoagulante lúpico através de diferentes testes da coagulação. MATERIAL E MÉTODO: A pesquisa do anticoagulante lúpico foi realizada em 50 amostras plasmáticas de pacientes do sexo feminino através dos testes do TTPA, do tempo de coagulação do caulim (TCC, do tempo de tromboplastina parcial ativada diluída (TTPAd e do tempo do veneno da víbora de Russel diluído (TVVRd. Três cefalinas comerciais foram avaliadas pelos testes do TTPA e do TTPAd. Na comparação entre os reagentes estudados foi aplicado o cálculo do intervalo de confiança (95%. RESULTADOS: Os três reagentes avaliados apresentaram boa concordância e os métodos utilizados responderam bem à pesquisa do anticoagulante lúpico. DISCUSSÃO E CONCLUSÃO: As três cefalinas comerciais avaliadas podem ser utilizadas na rotina laboratorial para a pesquisa do anticoagulante lúpico.INTRODUCTION: The lupus anticoagulant is an immunoglobin which belongs to the antiphospholid antibodies family. Its in vitro function is to interfere with coagulation tests that are dependent on phospholipids. The activated partial thromboplastin time (APTT is a test used as screening on lupus anticoagulant research. Reagents used in this test demonstrate wide sensitivity ranges. OBJECTIVE: To assess the performance of APTT reagents and detect the presence of lupus anticoagulant through various coagulation tests. MATERIAL AND METHOD: The lupus anticoagulant research was performed in plasma from 50

Major cerebral events in Staphylococcus aureus infective endocarditis: is anticoagulant therapy safe?

DEFF Research Database (Denmark)

Rasmussen, Rasmus V; Snygg-Martin, Ulrika; Olaison, Lars

2009-01-01

OBJECTIVES: To study the impact of anticoagulation on major cerebral events in patients with left-sided Staphylococcus aureus infective endocarditis (IE). METHODS: A prospective cohort study; the use of anticoagulation and the relation to major cerebral events was evaluated separately at onset...... of admission and during hospitalization. RESULTS: Overall, 70 out of 175 patients (40%; 95% CI: 33-47%) experienced major cerebral events during the course of the disease, cerebral ischaemic stroke occured in 59 patients (34%; 95% CI: 27-41%), cerebral infection in 23 patients (14%; 95% CI: 9...

Lupus anticoagulants: first French interlaboratory Etalonorme survey.

Science.gov (United States)

Roussi, J; Roisin, J P; Goguel, A

1996-06-01

In 1994, the, French National Quality Control Group for Hematology, Etalonorme, conducted a large-scale interlaboratory survey concerning the detection of lupus anticoagulants (LA) involving all the 4,500 French laboratories. Each laboratory received the same batch of a lyophilized citrated plasma (94B3) prepared from a patient with LA that had been confirmed by all the techniques used in the intralaboratory study. In the interlaboratory survey, the screening test was activated partial thromboplastin time (APTT); mean APTT calculated from the results reported by 4,029 labs was prolonged (clotting ratio = 1.44) with a large dispersion (coefficients of variation = 18.8%). APTT of the mixture 94B3 + normal plasma were performed by 2,698 laboratories. No correction of APTT was obtained (R = 1.36, Rosner index = 24) with a wide variation between reagents (17 kaolin. This survey allowed Etalonorme to inform French biologists and draft an educational program for the biologic detection of LA and the identification of its mechanism of action.

The first pharmacist-managed anticoagulation clinic under a collaborative practice agreement in Qatar: clinical and patient-oriented outcomes.

Science.gov (United States)

Elewa, H F; AbdelSamad, O; Elmubark, A E; Al-Taweel, H M; Mohamed, A; Kheir, N; Mohamed Ibrahim, M I; Awaisu, A

2016-08-01

Optimal outpatient anticoagulation management requires a systematic and coordinated approach. Extensive evidence regarding the benefits of pharmacist-managed anticoagulation services has been reported in the literature. The quality and outcomes associated with pharmacist-managed anticoagulation clinics under collaborative practice agreements in the Middle East have rarely been reported. The first pharmacist-managed ambulatory anticoagulation clinic in Qatar was launched at Al-Wakrah Hospital in March 2013. The objectives of this study were to: (i) describe the practice model of the clinic, (ii) evaluate the quality of the clinic [i.e. the time in therapeutic range (TTR)] and the clinical outcomes (i.e. the efficacy and safety), and (iii) determine the patients' satisfaction and overall quality of life (QoL). Clinical outcome data were collected through a retrospective chart review of all patients managed from March 2013 to October 2014 at the pharmacist-managed anticoagulation clinic. Furthermore, the patient-oriented outcomes data were prospectively collected using the 24-item Duke Anticoagulation Satisfaction Scale (DASS). Each item was assessed using a 7-point Likert-type scale on which lower scores indicated better QoL and greater satisfaction. The clinical outcome data analyses included 119 patients who were enrolled at the clinic during the 19-month study period. The mean number of international normalized ratio (INR) tests/month was 65 ± 9, the average testing frequency was 2·7 ± 1·6 weeks, and the average %TTR was 76·8 ± 22·9%. There was one major bleeding event (0·67%/year), 12 minor bleeding events (8%/year) and two thromboembolic events (1·35%/year) recorded during the study period. Of the 119 patients, 50 participated in the satisfaction and QoL survey. The median (IQR) total QoL score of these subjects was 63 (48) (minimum-maximum achievable score: 24-168). Seventy-six per cent of the patients indicated 'a lot to very much' in terms of their

The risk of venous thromboembolism with aspirin compared to anticoagulants after hip and knee arthroplasty.

Science.gov (United States)

Chu, Janet N; Maselli, Judith; Auerbach, Andrew D; Fang, Margaret C

2017-07-01

Recent guidelines include aspirin as an option to prevent venous thromboembolism (VTE) in selected patients undergoing hip or knee replacement surgery. However, the efficacy of aspirin after arthroplasty has not been well-defined, particularly in more contemporary patient populations. We compared rates of post-operative VTE between patients who received aspirin-only versus anticoagulants after hip or knee arthroplasty, using data from a large US-based administrative database. We conducted a retrospective cohort study of 231,780 adults who underwent total knee arthroplasty and 110,621 who underwent total hip arthroplasty in 2009-2012 and who received pharmacologic VTE prophylaxis (aspirin or anticoagulant) within the first 7days after surgery. We compared the risk of post-operative VTE between patients receiving aspirin-only vs. anticoagulants, controlling for clinical and hospital characteristics using multivariable logistic regression with propensity score adjustment. Aspirin-only prophylaxis was administered to 7.5% of patients after knee arthroplasty and 8.0% after hip arthroplasty. Post-operative VTE was diagnosed in 2217 (0.96%) patients after knee arthroplasty and 454 (0.41%) after hip arthroplasty. Compared to anticoagulants, aspirin was not associated with a higher risk for post-operative VTE either after knee arthroplasty (adjusted odds ratio and 95% confidence interval [OR] 0.34 [0.24-0.48]) or hip arthroplasty (OR 0.82 [0.45-1.51]). Aspirin was uncommonly administered as the sole prophylactic agent after hip or knee arthroplasty in this study. However, patients who received aspirin-only had similar rates of post-operative VTE compared to patients who received anticoagulants. Further research should focus on distinguishing which patients benefit more from anticoagulants versus aspirin after arthroplasty. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is automated kinetic measurement superior to end-point for advanced oxidation protein product?

Science.gov (United States)

Oguz, Osman; Inal, Berrin Bercik; Emre, Turker; Ozcan, Oguzhan; Altunoglu, Esma; Oguz, Gokce; Topkaya, Cigdem; Guvenen, Guvenc

2014-01-01

Advanced oxidation protein product (AOPP) was first described as an oxidative protein marker in chronic uremic patients and measured with a semi-automatic end-point method. Subsequently, the kinetic method was introduced for AOPP assay. We aimed to compare these two methods by adapting them to a chemistry analyzer and to investigate the correlation between AOPP and fibrinogen, the key molecule responsible for human plasma AOPP reactivity, microalbumin, and HbA1c in patients with type II diabetes mellitus (DM II). The effects of EDTA and citrate-anticogulated tubes on these two methods were incorporated into the study. This study included 93 DM II patients (36 women, 57 men) with HbA1c levels > or = 7%, who were admitted to the diabetes and nephrology clinics. The samples were collected in EDTA and in citrate-anticoagulated tubes. Both methods were adapted to a chemistry analyzer and the samples were studied in parallel. In both types of samples, we found a moderate correlation between the kinetic and the endpoint methods (r = 0.611 for citrate-anticoagulated, r = 0.636 for EDTA-anticoagulated, p = 0.0001 for both). We found a moderate correlation between fibrinogen-AOPP and microalbumin-AOPP levels only in the kinetic method (r = 0.644 and 0.520 for citrate-anticoagulated; r = 0.581 and 0.490 for EDTA-anticoagulated, p = 0.0001). We conclude that adaptation of the end-point method to automation is more difficult and it has higher between-run CV% while application of the kinetic method is easier and it may be used in oxidative stress studies.

Fatal rebleeding following coil embolization of cerebral aneurysms: the role of long-term systemic anticoagulation

International Nuclear Information System (INIS)

Sinson, G.; Bagley, L.J.; Hurst, R.W.; Flamm, E.S.

2001-01-01

Embolization of cerebral aneurysms has become a common technique. Its impact on subsequent medical management of the patient is not well known. We report two patients who presented in a poor neurological grade after subarachnoid hemorrhage from posterior communicating artery aneurysms. Both were treated by coil embolization and both developed subclavian vein thrombosis, requiring systemic anticoagulation, initiated 11 and 21 days after embolization, respectively. Both developed a large, fatal intracranial hemorrhage adjacent to the embolized aneurysm in the fourth week of anticoagulation. Systemic anticoagulation of patients who have had a ruptured aneurysm treated by coil embolization may carry a significant risk of rebleeding. Alternate management strategies should be considered in these patients. (orig.)

Fatal rebleeding following coil embolization of cerebral aneurysms: the role of long-term systemic anticoagulation

Energy Technology Data Exchange (ETDEWEB)

Sinson, G. [Dept. of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Bagley, L.J.; Hurst, R.W. [Dept. of Radiology-Neuroradiology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Flamm, E.S. [Hyman-Newman Institute for Neurology and Neurosurgery, New York, NY (United States)

2001-05-01

Embolization of cerebral aneurysms has become a common technique. Its impact on subsequent medical management of the patient is not well known. We report two patients who presented in a poor neurological grade after subarachnoid hemorrhage from posterior communicating artery aneurysms. Both were treated by coil embolization and both developed subclavian vein thrombosis, requiring systemic anticoagulation, initiated 11 and 21 days after embolization, respectively. Both developed a large, fatal intracranial hemorrhage adjacent to the embolized aneurysm in the fourth week of anticoagulation. Systemic anticoagulation of patients who have had a ruptured aneurysm treated by coil embolization may carry a significant risk of rebleeding. Alternate management strategies should be considered in these patients. (orig.)

Intermittent vs. Continuous Anticoagulation theRapy in patiEnts with Atrial Fibrillation (iCARE-AF): a randomized pilot study.

Science.gov (United States)

Stavrakis, Stavros; Stoner, Julie A; Kardokus, Joel; Garabelli, Paul J; Po, Sunny S; Lazzara, Ralph

2017-01-01

We hypothesized that intermittent anticoagulation based on daily rhythm monitoring using the novel oral anticoagulants (NOACs) is feasible and safe among patients with paroxysmal atrial fibrillation (AF). Patients with paroxysmal AF and ≥1 risk factors for stroke were randomized to either intermittent or continuous anticoagulation. Those in the intermittent group were instructed to transmit a daily ECG using an iPhone-based rhythm monitoring device. If AF was detected, patients received one of the NOACs for 48 h-1 week. Patients who failed to transmit an ECG for three consecutive days or more than 7 days total were crossed over to continuous anticoagulation. Patients in the continuous group received one of the NOACs. Fifty-eight patients were randomized to either intermittent (n = 29) or continuous anticoagulation (n = 29). Over a median follow-up of 20 months, 20 patients in the intermittent group failed to submit a daily ECG at least once (median three failed submissions). Four patients (14 %) crossed over to continuous anticoagulation due to failure to submit an ECG for three consecutive days. One stroke (continuous group) occurred during the study. Major bleeding occurred in two patients in the continuous and one patient in the intermittent group, after crossing over to continuous anticoagulation. In a prespecified per-protocol analysis, gastrointestinal bleeding was more frequent in the continuous group (16 vs. 0 %; p = 0.047). Intermittent anticoagulation based on daily rhythm monitoring is feasible and may decrease bleeding in low-risk patients with paroxysmal AF. A larger trial, adequately powered to detect clinical outcomes, is warranted.

[Clinical scores for the risk of bleeding with or without anticoagulation].

Science.gov (United States)

Junod, Alain

2016-09-14

The assessment of hemorragic risk related to therapeutic anticoagulation is made difficult because of the variety of existing drugs, the heterogeneity of treatment strategies and their duration. Six prognostic scores have been analyzed. For three of them, external validations have revealed a marked decrease in the discrimination power. One British study, Qbleed, based on the data of more than 1 million of ambulatory patients, has repeatedly satisfied quality criteria. Two scores have also studied the bleeding risk during hospital admission for acute medical disease. The development of new and effective anticoagulants with fewer side-effects is more likely to solve this problem than the production of new clinical scores.

Influence of the sample anticoagulant on the measurements of impedance aggregometry in cardiac surgery

Directory of Open Access Journals (Sweden)

Cristina Solomon

2008-10-01

Full Text Available Cristina Solomon1, Michael Winterhalter1, Isabel Gilde1, Ludwig Hoy2, Andreas Calatzis3, Niels Rahe-Meyer11Department of Anesthesiology, Hannover Medical School, Hannover, Germany; 2Institute for Biometry, Hannover Medical School, Hannover, Germany; 3Department Hemostasis Transfusion Medicine, University Hospital Munich, Munich, GermanyBackground: The standard method of assessment of platelet function is represented by light transmission aggregometry (LTA, performed in citrated platelet-rich plasma (PRP. With LTA, decrease and subsequent post-cardiopulmonary bypass (CPB recovery of platelet function have been reported during cardiac surgery. Multiple electrode aggregometry (MEA may be used as point-of-care method to monitor perioperative changes in platelet function. Since MEA assesses macroaggregation which is influenced by the plasmatic levels of unbound calcium, citrate may be inadequate as anticoagulant for MEA. We used citrate and heparin for MEA samples, to see with which anticoagulant the intraoperative decrease and postoperative recovery in platelet function previously described with other aggregometric methods in cardiac surgery may be observed with MEA.Methods: Blood was obtained from 60 patients undergoing routine cardiac surgery and the samples were collected in standard tubes containing unfractionated heparin (50 U/mL or trisodium citrate (3.2%. The samples were obtained before CPB, at 30 minutes on CPB, end of CPB and on the first postoperative day. MEA was performed using the Multiplate® analyzer. Collagen (COLtest, 100 μg/mL and TRAP-6 (thrombin receptor activating peptide, TRAPtest, 1mM/mL were used as aggregation agonists.Results: Platelet aggregometric response decreased significantly during CPB. Platelet aggregation assessed using TRAP-6 as agonist on heparinized blood significantly correlated with the duration of CPB (r = −0.41, p = 0.001, 2-tailed Pearson test. The aggregometric analysis performed on the first

Bleeding complications during anticoagulant treatment in patients with cancer

NARCIS (Netherlands)

Kamphuisen, Pieter W.; Beyer-Westendorf, Jan

Patients with cancer have an increased risk of bleeding complications, of which some are fatal. This risk is influenced by chemotherapy, cancer type and stage, thrombocytopenia, renal function, and previous bleeding. Since many cancer patients receive anticoagulant treatment for prophylaxis or

Self-management of oral anticoagulant therapy in two centers

DEFF Research Database (Denmark)

Nilsson, Hanna; Grove, E; Larsen, Torben Bjerregaard

of Cardiology, Aarhus University Hospital, Aarhus; 3Department of Cardiology, Aalborg Hospital & Department of Health Science and Technology, Aalborg University, Aalborg, Denmark haana_86@hotmail.com Objectives: Patient-self-management (PSM) of oral anticoagulant therapy with vitamin K antagonists have...

Quality of Vitamin K Antagonist Anticoagulation in Spain: Prevalence of Poor Control and Associated Factors.

Science.gov (United States)

Anguita Sánchez, Manuel; Bertomeu Martínez, Vicente; Cequier Fillat, Ángel

2015-09-01

To study the prevalence of poorly controlled vitamin K antagonist anticoagulation in Spain in patients with nonvalvular atrial fibrillation, and to identify associated factors. We studied 1056 consecutive patients seen at 120 cardiology clinics in Spain between November 2013 and March 2014. We analyzed the international normalized ratio from the 6 months prior to the patient's visit, calculating the prevalence of poorly controlled anticoagulation, defined as < 65% time in therapeutic range using the Rosendaal method. Mean age was 73.6 years (standard deviation, 9.8 years); women accounted for 42% of patients. The prevalence of poorly controlled anticoagulation was 47.3%. Mean time in therapeutic range was 63.8% (25.9%). The following factors were independently associated with poorly controlled anticoagulation: kidney disease (odds ratio = 1.53; 95% confidence interval, 1.08-2.18; P = .018), routine nonsteroidal anti-inflammatory drugs (odds ratio = 1.79; 95% confidence interval, 1.20-2.79; P = .004), antiplatelet therapy (odds ratio = 2.16; 95% confidence interval, 1.49-3.12; P < .0001) and absence of angiotensin receptor blockers (odds ratio = 1.39; 95% confidence interval, 1.08-1.79; P = .011). There is a high prevalence of poorly controlled vitamin K antagonist anticoagulation in Spain. Factors associated with poor control are kidney disease, routine nonsteroidal anti-inflammatory drugs, antiplatelet use, and absence of angiotensin receptor blockers. Copyright © 2014 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

Vitamin K and stability of oral anticoagulant therapy

NARCIS (Netherlands)

Rombouts, Eva Karolien

2011-01-01

One of the causes of unstable anticoagulation is a variable vitamin K intake. The main objective of this thesis was to test the hypothesis that the INR is particularly sensitive to changes in vitamin K intake when vitamin K status is low, and that patients with a low vitamin K intake would therefore

Non-vitamin K antagonist oral anticoagulants (NOAC) in the treatment of venous thromboembolism

OpenAIRE

Sebastian Werth; Jan Beyer-Westendorf

2015-01-01

In case of venous thromboembolism (VTE) e ective anticoagulation is needed. The introduction of non-vitamin K antagonist oral anticoagulants (NOACs) for VTE therapy o ers new treatment options and, in general, simpli es VTE therapy compared to the concept of LMWH/ VKA. At the same time, NOACs may help to improve the clinical outcome of patients with VTE as trial results consistently indicated the reduction in major bleeding complications. There are several reasons to use NOAC in special p...

Renal Infarction during Anticoagulant Therapy after Living Donor Liver Transplantation

Directory of Open Access Journals (Sweden)

Shinji Onda

2018-04-01

Full Text Available Introduction: Liver transplant recipients are at risk for complications of vascular thrombosis. The reconstructed hepatic artery and portal vein thrombosis potentially result in hepatic failure and graft loss. Renal infarction is a rare clinical condition, but in severe cases, it may lead to renal failure. We herein report a case of renal infarction after living donor liver transplantation (LDLT during anticoagulant therapy. Case Presentation: A 60-year-old woman with end-stage liver disease due to primary biliary cholangitis underwent LDLT with splenectomy. Postoperatively, tacrolimus, mycophenolate mofetil, and steroid were used for initial immunosuppression therapy. On postoperative day (POD 5, enhanced computed tomography (CT revealed splenic vein thrombosis, and anticoagulant therapy with heparin followed by warfarin was given. Follow-up enhanced CT on POD 20 incidentally demonstrated right renal infarction. The patient’s renal function was unchanged and the arterial flow was good, and the splenic vein thrombosis resolved. At 4 months postoperatively, warfarin was discontinued, but she developed recurrent splenic vein thrombosis 11 months later, and warfarin was resumed. As of 40 months after transplantation, she discontinued warfarin and remains well without recurrence of splenic vein thrombosis or renal infarction. Conclusion: Renal infarction is a rare complication of LDLT. In this case, renal infarction was incidentally diagnosed during anticoagulant therapy and was successfully treated.

Emergency management of major bleeding in a case of maxillofacial trauma and anticoagulation: utility of prothrombin complex concentrates in the shock room

Directory of Open Access Journals (Sweden)

Alessandro Morotti

2015-03-01

Full Text Available Life-threatening bleeding in anticoagulation with Warfarin is an emergency challenging issue. Several approaches are available to treat bleeding in either over-anticoagulation or propeanticoagulation, including vitamin K, fresh frozen plasma and prothrombin complex concentrates (PCC administration. In coexisting trauma-induced bleeding and anticoagulation, reversal of anticoagulation must be a rapid and highly effective procedure. Furthermore the appropriate treatment must be directly available in each shock rooms to guarantee the rapid management of the emergency. PCC require a simple storage, rapid accessibility, fast administration procedures and high effectiveness. Here we report the utility of PCC in management of a craniofacial trauma in proper-anticoagulation.

Prevention of thromboembolic events in patients with atrial fibrillation – new anticoagulants

Directory of Open Access Journals (Sweden)

Alexandre Holthausen Campos

2011-09-01

Full Text Available The authors present alternatives for the treatment of cardiacarrhythmias. Its detection is based on the use of different methods that record the cardiac electrical activity. The treatment involves intervening in the underlying disorder, antiarrhythmic drugs, stimulation and cardiac defibrillation devices, and, less often, surgery. The technological advances in the last two decades have provided greater efficiency in diagnoses and therapy. Atrial fibrilation patients will benefit from a new set of anticoagulant drugs tested in the past three years. The potential advantages include greater safety and efficacy, as well as conveniencefor not requiring frequent laboratory controls.

Safety of percutaneous nephrolithotomy in patients on chronic anticoagulant or antiplatelet therapy.

Science.gov (United States)

Fernández-Baltar, C; Pérez-Fentes, D; Sánchez-García, J F; García-Freire, C

2018-01-22

In developed countries, the incidence of cardiovascular disease is increasing, therefore, anticoagulant and antiplatelet drugs are a widespread treatment nowadays. Percutaneous nephrolithotomy (PNL) is the first-line treatment for large or complex stones (> 2 cm) and remains an alternative for the smaller ones. The objective of this study is to analyze whether PNL surgery is a safe procedure in patients under a treatment discontinuation protocol for anticoagulant or antiplatelet therapies. We retrospectively studied 301 patients who underwent PNL in our hospital between 2008 and 2016 and identified 46 patients on chronic antiplatelet or anticoagulation treatment. With respect to PNL outcomes, the stone-free rate was similar (78 vs 74%, p = 0.762) in both groups, without any significant differences in the overall postoperative complications (17 vs 26%, p = 0.203). The incidence of hemorrhagic complications was similar between groups (12 vs 9%, p = 0.492), as demonstrated by the mean drop in hemoglobin (Hb), which was comparable in both cohorts (2.2 ± 1.3 vs 2.0 ± 1.4 p = 0.270) and the blood transfusion rate (14% in group A and 8% in group B, p = 0.205). No thromboembolic events were found within the year after the PNL procedure. PNL is a safe and effective intervention in patients under a treatment discontinuation protocol for anticoagulant or antiplatelet therapies. Although our study demonstrates the feasibility of this protocol, new scientific evidence aims to stratify the thromboembolic and bleeding risk of each patient to individualize the perioperative management thereafter.

Target specific oral anticoagulants in the management of thromboembolic disease in the elderly.

Science.gov (United States)

Maddula, Surekha; Ansell, Jack

2013-08-01

The elderly population represents a population at highest risk of thromboembolism, but also the most vulnerable to hemorrhage. In the community setting there is a general tendency to under- treat this patient group. Specific consideration must be taken with elderly patients because they have reduced renal function, co-morbidities and risk of falls, altered pharmacodynamics, and challenges with adherence. Vitamin K antagonists, most often warfarin, have been the first line choice of therapy for long-term anticoagulation and enjoyed an unopposed position in the market for the last 70 years. Recently several new oral anticoagulants have been developed and found to be equally effective as warfarin in phase III studies and may provide an optimal treatment option in the elderly population. In this review we explore the target-specific oral anticoagulants and the pharmacological differences between them with a focus on the elderly population in whom these new drugs would constitute a possible alternative to warfarin therapy.

Effect of vitamin K2 on the anticoagulant activity of warfarin during the perioperative period of catheter ablation: Population analysis of retrospective clinical data.

Science.gov (United States)

Zhou, Zhi; Yano, Ikuko; Odaka, Sumiko; Morita, Yosuke; Shizuta, Satoshi; Hayano, Mamoru; Kimura, Takeshi; Akaike, Akinori; Inui, Ken-Ichi; Matsubara, Kazuo

2016-01-01

Catheter ablation is a non-medication therapy for atrial fibrillation, and during the procedure, warfarin is withdrawn in the preoperative period to prevent the risk of bleeding. In case of emergency, vitamin K2 can be intravenously administered to antagonize the anticoagulant activity of warfarin. The aims of this study were to conduct population pharmacokinetic/pharmacodynamic modeling for retrospective clinical data and to investigate the effect of vitamin K2 on the anticoagulant activity of warfarin in the perioperative period of catheter ablation. A total of 579 international normalized ratio (INR) values of prothrombin time from 100 patients were analyzed using the nonlinear mixed-effects modeling program NONMEM. A 1-compartment model was adapted to the pharmacokinetics of warfarin and vitamin K2, and the indirect response model was used to investigate the relationship between plasma concentration and the pharmacodynamic response of warfarin and vitamin K2. Since no plasma concentration data for warfarin and vitamin K2 were available, 3 literally available pharmacokinetic parameters were used to simultaneously estimate 1 pharmacokinetic parameter and 5 pharmacodynamic parameters. The population parameters obtained not only successfully explained the observed INR values, but also indicated an increase in sensitivity to warfarin in patients with reduced renal function. Simulations using these parameters indicated that vitamin K2 administration of more than 20 mg caused a slight dose-dependent decrease in INR on the day of catheter ablation and a delayed INR elevation after warfarin re-initiation. A pharmacokinetic/pharmacodynamic model was successfully built to explain the retrospective INR data during catheter ablation. Simulation studies suggest that vitamin K2 should be administered with care and that more than 20 mg is unnecessary in the preoperative period of catheter ablation.

Medium intensity oral anticoagulants versus aspirin after cerebral ischaemia of arterial origin (ESPRIT): a randomised controlled trial.

Science.gov (United States)

Halkes, P H A; van Gijn, J; Kappelle, L J; Koudstaal, P J; Algra, A

2007-02-01

Oral anticoagulants are better than aspirin for secondary prevention after myocardial infarction and after cerebral ischaemia in combination with non-rheumatic atrial fibrillation. The European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) aimed to determine whether oral anticoagulation with medium intensity is more effective than aspirin in preventing future vascular events in patients with transient ischaemic attack or minor stroke of presumed arterial origin. In this international, multicentre trial, patients were randomly assigned within 6 months after a transient ischaemic attack or minor stroke of presumed arterial origin either anticoagulants (target INR range 2.0-3.0; n=536) or aspirin (30-325 mg daily; n=532). The primary outcome was the composite of death from all vascular causes, non-fatal stroke, non-fatal myocardial infarction, or major bleeding complication, whichever occurred first. In a post hoc analysis anticoagulants were compared with the combination of aspirin and dipyridamole (200 mg twice daily). Treatment was open, but auditing of outcome events was blinded. Primary analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial (number ISRCTN73824458) and with ClinicalTrials.gov (NCT00161070). The anticoagulants versus aspirin comparison of ESPRIT was prematurely ended because ESPRIT reported previously that the combination of aspirin and dipyridamole was more effective than aspirin alone. Mean follow-up was 4.6 years (SD 2.2). The mean achieved INR was 2.57 (SD 0.86). A primary outcome event occurred in 99 (19%) patients on anticoagulants and in 98 (18%) patients on aspirin (hazard ratio [HR] 1.02, 95% CI 0.77-1.35). The HR for ischaemic events was 0.73 (0.52-1.01) and for major bleeding complications 2.56 (1.48-4.43). The HR for the primary outcome event comparing anticoagulants with the combination treatment of aspirin and dipyridamole was 1.31 (0.98-1.75). Oral

Vitamin K-dependent proteins GAS6 and Protein S and TAM receptors in patients of systemic lupus erythematosus: correlation with common genetic variants and disease activity.

Science.gov (United States)

Recarte-Pelz, Pedro; Tàssies, Dolors; Espinosa, Gerard; Hurtado, Begoña; Sala, Núria; Cervera, Ricard; Reverter, Joan Carles; de Frutos, Pablo García

2013-03-12

Growth arrest-specific gene 6 protein (GAS6) and protein S (ProS) are vitamin K-dependent proteins present in plasma with important regulatory functions in systems of response and repair to damage. They interact with receptor tyrosine kinases of the Tyro3, Axl and MerTK receptor tyrosine kinase (TAM) family, involved in apoptotic cell clearance (efferocytosis) and regulation of the innate immunity. TAM-deficient mice show spontaneous lupus-like symptoms. Here we tested the genetic profile and plasma levels of components of the system in patients with systemic lupus erythematosus (SLE), and compare them with a control healthy population. Fifty SLE patients and 50 healthy controls with matched age, gender and from the same geographic area were compared. Genetic analysis was performed in GAS6 and the TAM receptor genes on SNPs previously identified. The concentrations of GAS6, total and free ProS, and the soluble forms of the three TAM receptors (sAxl, sMerTK and sTyro3) were measured in plasma from these samples. Plasma concentrations of GAS6 were higher and, total and free ProS were lower in the SLE patients compared to controls, even when patients on oral anticoagulant treatment were discarded. Those parameters correlated with SLE disease activity index (SLEDAI) score, GAS6 being higher in the most severe cases, while free and total ProS were lower. All 3 soluble receptors increased its concentration in plasma of lupus patients. The present study highlights that the GAS6/ProS-TAM system correlates in several ways with disease activity in SLE. We show here that this correlation is affected by common polymorphisms in the genes of the system. These findings underscore the importance of mechanism of regulatory control of innate immunity in the pathology of SLE.

Comparative Molecular Dynamics Simulations of Mitogen-Activated Protein Kinase-Activated Protein Kinase 5

Directory of Open Access Journals (Sweden)

Inger Lindin

2014-03-01

Full Text Available The mitogen-activated protein kinase-activated protein kinase MK5 is a substrate of the mitogen-activated protein kinases p38, ERK3 and ERK4. Cell culture and animal studies have demonstrated that MK5 is involved in tumour suppression and promotion, embryogenesis, anxiety, cell motility and cell cycle regulation. In the present study, homology models of MK5 were used for molecular dynamics (MD simulations of: (1 MK5 alone; (2 MK5 in complex with an inhibitor; and (3 MK5 in complex with the interaction partner p38α. The calculations showed that the inhibitor occupied the active site and disrupted the intramolecular network of amino acids. However, intramolecular interactions consistent with an inactive protein kinase fold were not formed. MD with p38α showed that not only the p38 docking region, but also amino acids in the activation segment, αH helix, P-loop, regulatory phosphorylation region and the C-terminal of MK5 may be involved in forming a very stable MK5-p38α complex, and that p38α binding decreases the residual fluctuation of the MK5 model. Electrostatic Potential Surface (EPS calculations of MK5 and p38α showed that electrostatic interactions are important for recognition and binding.

A survey of anticoagulation practice among German speaking microsurgeons – Perioperative management of anticoagulant therapy in free flap surgery [Erhebung über die antikoagulatorische Praxis unter deutschsprachigen Mikrochirurgen – Perioperatives Management der antikoagulatorischen Therapie bei freien Lappentransplantaten

Directory of Open Access Journals (Sweden)

Jokuszies, Andreas

2012-02-01

Full Text Available [english] Background: Anticoagulation is a crucial element in microsurgery. Although various clinical studies and international surveys have revealed that anticoagulation strategies can vary and result in similar outcomes, anticoagulative regimen are far away from standardization. In Germany and german speaking countries standardized anticoagulation protocols concerning free flap surgery do not exist so far. Methods: To evaluate the current practice of clinics in Germany, Austria and Switzerland with specialization in microsurgery we performed a questionnaire surveying the perioperative regimen of anticoagulant and antiplatelet therapy in free flap surgery. The microsurgeons were interrogated on several anticoagulant, rheologic and antiplatelet medications, their dosage and perioperative frequency of application pre-, intra- and postoperative.Results: The questionnaire revealed that the used antithrombotic and perioperative regimens varied from department to department presumably based on the personal experience of the surgeon. Multiple approaches are used with a wide range of anticoagulants used either alone or in combination, with different intervals of application and different dosages. Conclusion: Therefore consensus meetings should be held in future leading to conduct prospective multicenter studies with formulation of standardized anticoagulative and perioperative protocols in microsurgery reducing flap failure to other than pharmacologic reasons.[german] Hintergrund: Die Antikoagulation stellt ein zentrales Element in der Mikrochirurgie dar. Zahlreiche klinische Studien und internationale Erhebungen zu antikoagulatorischen Strategien weisen eine grosse Varianz bei vergleichbaren Resultaten nach, entbehren jedoch einer Standardisierung. Auch in Deutschland und deutschsprachigen Ländern fehlen bislang standardisierte Regime zur Antikoagulation in der Mikrochirurgie.Methodik: Zur Erhebung der antikoagulatorischen Praxis unter

Shifting to a non-vitamin K antagonist oral anticoagulation agent from vitamin K antagonist in atrial fibrillation

DEFF Research Database (Denmark)

Fosbøl, Emil L; Vinding, Naja Emborg; Lamberts, Morten

2017-01-01

Aims: After non-vitamin K antagonist (VKA) oral anticoagulation agents (NOAC) have been approved for thrombo-embolic prophylaxis in non-valvular atrial fibrillation (NVAF), utilization of oral anticoagulants (OAC) in NVAF has changed. Contemporary shifting from a VKA to a NOAC (dabigatran...

Standardisation of the Laboratory Control of Anticoagulant Therapy

African Journals Online (AJOL)

1974-09-11

Sep 11, 1974 ... Anticoagulant therapy with the coumarin group of drugs has been used in clinical practice for more than a quarter of a century. The most widely used form of laboratory control of the treatment is the Quick one-stage prothrom·- bin time. I. This simple test proved to be satisfactory in most cases, but discrepant ...

Factors Affecting Outcome in Treatment of Chronic Subdural Hematoma in ICU Patients: Impact of Anticoagulation.

Science.gov (United States)

Szczygielski, Jacek; Gund, Sina-Maria; Schwerdtfeger, Karsten; Steudel, Wolf-Ingo; Oertel, Joachim

2016-08-01

The use of anticoagulants and older age are the main risk factors for chronic subdural hematoma (CSDH). Because the age of the population and use of anticoagulants are increasing, a growing number of CSDH cases is expected. To address this issue, we analyzed the impact of anticoagulants on postsurgical outcome in patients in the intensive care unit (ICU). Demographic data, coagulation parameters, surgical details, radiologic appearance of hematoma, Glasgow Coma Scale (GCS) score on admission, and Glasgow Outcome Scale (GOS) score on discharge were retrieved and retrospectively analyzed in 98 patients with CSDH treated in the neurosurgical ICU using correlation coefficient tests and multivariate analysis test. Overall outcome was good (GOS score 4 and 5) in 55.1% of patients. Overall mortality was 9.1%. There was a correlation between GCS score on admission and GOS score. There was no correlation between hematoma thickness/radiologic appearance and impaired coagulation. Disturbance in thrombocyte function (usually resulting from aspirin intake) correlated with improved outcome, whereas warfarin-related coagulopathy correlated with poor recovery. Nevertheless, patients with thrombocytopathy presented with better initial GCS scores. Neither hematoma size nor recurrence rate affected the outcome. The size of CSDH was not associated with poor outcome and is not necessarily determined by the use of anticoagulants. Coagulopathy does not rule out a good outcome, but the impact of anticoagulation on treatment results in CSDH varies between the main groups of drugs (warfarin vs. antiplatelet drugs). Patients in good neurologic condition on ICU admission have better chances of recovery. Copyright © 2016 Elsevier Inc. All rights reserved.

Anticoagulant and Antiplatelet Prescribing Patterns for Patients with Atrial Fibrillation after Percutaneous Coronary Intervention.

Science.gov (United States)

Woods, Erin A; Ackman, Margaret L; Graham, Michelle M; Koshman, Sheri L; Boswell, Rosaleen M; Barry, Arden R

2016-01-01

Current guidelines recommend triple antithrombotic therapy (TAT), defined as acetylsalicylic acid (ASA), clopidogrel, and warfarin, for patients with nonvalvular atrial fibrillation who have undergone percutaneous coronary intervention with stent implantation. The choice of anticoagulant/antiplatelet therapy in this population is ambiguous and complex, and prescribing patterns are not well documented. To characterize local prescribing patterns for anticoagulant/antiplatelet therapy after percutaneous coronary intervention in patients with nonvalvular atrial fibrillation. A chart review was conducted at a single quaternary cardiology centre. Patients with nonvalvular atrial fibrillation were identified via medical records, and those who underwent percutaneous coronary intervention were identified using a local clinical patient registry. Adult inpatients with nonvalvular atrial fibrillation and a CHADS2 score (based on congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, prior stroke) of 1 or higher who underwent percutaneous coronary intervention from 2011 to 2013 were included. Patients undergoing cardiovascular surgery or transcatheter aortic valve replacement, those with mechanical devices requiring anticoagulation, and those with an allergy to any component of TAT were excluded. Seventy patients were included. The median age was 75 years, and 52 (74%) were men. At discharge, 30 (43%) were receiving TAT and 27 (39%) were receiving dual antiplatelet therapy (clopidogrel and ASA). No patients received the combination of warfarin and clopidogrel. Among those who received TAT, 90% (19 of 21) who received a bare metal stent had a recommended duration of 1 month, and 75% (6 of 8) who received a drug-eluting stent had a recommended duration of 1 year. Direct-acting oral anticoagulants with 2 antiplatelet drugs were prescribed for 9% (6 of 70) of the patients, and 10% (7 of 70) received ticagrelor and ASA with or without warfarin. Overall, the

The Anticoagulation of Calf Thrombosis (ACT project: study protocol for a randomized controlled trial

Directory of Open Access Journals (Sweden)

Horner Daniel

2012-04-01

Full Text Available Abstract Background Half of all lower limb deep vein thrombi (DVT in symptomatic ambulatory patients are located in the distal (calf veins. While proximal disease warrants therapeutic anticoagulation to reduce the associated risks, distal DVT often goes untreated. However, a proportion of untreated distal disease will undoubtedly propagate or embolize. Concern also exists that untreated disease could lead to long-term post thrombotic changes. Currently, it is not possible to predict which distal thrombi will develop such complications. Whether these potential risks outweigh those associated with unrestricted anticoagulation remains unclear. The Anticoagulation of Calf Thrombosis (ACT trial aims to compare therapeutic anticoagulation against conservative management for patients with acute symptomatic distal deep vein thrombosis. Methods ACT is a pragmatic, open-label, randomized controlled trial. Adult patients diagnosed with acute distal DVT will be allocated to either therapeutic anticoagulation or conservative management. All patients will undergo 3 months of clinical and assessor blinded sonographic follow-up, followed by 2-year final review. The project will commence initially as an external pilot study, recruiting over a 16-month period at a single center to assess feasibility measures and clinical event rates. Primary outcome measures will assess feasibility endpoints. Secondary clinical outcomes will be collected to gather accurate data for the design of a definitive clinical trial and will include: (1 a composite endpoint combining thrombus propagation to the popliteal vein or above, development of symptomatic pulmonary embolism or sudden death attributable to venous thromboembolic disease; (2 the incidence of major and minor bleeding episodes; (3 the incidence of post-thrombotic leg syndrome at 2 years using a validated screening tool; and (4 the incidence of venous thromboembolism (VTE recurrence at 2 years. Discussion The ACT trial

Coronary artery bypass grafting in a patient with protein S deficiency: Perioperative implications

Directory of Open Access Journals (Sweden)

Baskaran Balan

2014-01-01

Full Text Available Protein S (PS along with activated protein C plays an important role in the down-regulation of in vivo thrombin generation. Its deficiency can cause abnormal and inappropriate clot formation within the circulation necessitating chronic anticoagulation therapy. The risk of developing thrombotic complications is heightened in the perioperative period in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB. Heparin resistance is very rare in these patients, especially when antithrombin levels are near normal. Management of CPB in this scenario is quite challenging. We report the perioperative management, particularly the CPB management, of a patient with type I PS deficiency and incidentally detected heparin resistance, who underwent coronary artery bypass grafting with CPB.

On the variability of the salting-out curves of proteins of normal human plasma and serum

NARCIS (Netherlands)

Steyn-Parvé, Elizabeth P.; Hout, A.J. van den

1953-01-01

Salting-out curves of proteins of normal human plasma reflect the influence of a number of other factors besides the protein composition: the manner of obtaining the blood, the nature of the anti-coagulant used, the non-protein components of the plasma. Diagrams of serum and plasma obtained from

Combined administration of antibiotics and direct oral anticoagulants: a renewed indication for laboratory monitoring?

Science.gov (United States)

Lippi, Giuseppe; Favaloro, Emmanuel J; Mattiuzzi, Camilla

2014-10-01

The recent development and marketing of novel direct oral anticoagulants (DOACs) represents a paradigm shift in the management of patients requiring long-term anticoagulation. The advantages of these compounds over traditional therapy with vitamin K antagonists include a reportedly lower risk of severe hemorrhages and the limited need for laboratory measurements. However, there are several scenarios in which testing should be applied. The potential for drug-to-drug interaction is one plausible but currently underrecognized indication for laboratory assessment of the anticoagulant effect of DOACs. In particular, substantial concern has been raised during Phase I studies regarding the potential interaction of these drugs with some antibiotics, especially those that interplay with permeability glycoprotein (P-gp) and cytochrome 3A4 (CYP3A4). A specific electronic search on clinical trials published so far confirms that clarithromycin and rifampicin significantly impair the bioavailability of dabigatran, whereas clarithromycin, erythromycin, fluconazole, and ketoconazole alter the metabolism of rivaroxaban in vivo. Because of their more recent development, no published data were found for apixaban and edoxaban, or for potential interactions of DOACs with other and widely used antibiotics. It is noteworthy, however, that an online resource based on Food and Drug Administration and social media information, reports several hemorrhagic and thrombotic events in patients simultaneously taking dabigatran and some commonly used antibiotics such as amoxicillin, cephalosporin, and metronidazole. According to these reports, the administration of antibiotics in patients undergoing therapy with DOACs would seem to require accurate evaluation as to whether dose adjustments (personalized or antibiotic class driven) of the anticoagulant drug may be advisable. This might be facilitated by direct laboratory assessments of their anticoagulant effect ex vivo. Thieme Medical Publishers

Personalized prophylactic anticoagulation decision analysis in patients with membranous nephropathy

Science.gov (United States)

Lee, Taewoo; Biddle, Andrea K.; Lionaki, Sofia; Derebail, Vimal K.; Barbour, Sean J.; Tannous, Sameer; Hladunewich, Michelle A.; Hu, Yichun; Poulton, Caroline J.; Mahoney, Shannon L.; Jennette, J. Charles; Hogan, Susan L.; Falk, Ronald J.; Cattran, Daniel C.; Reich, Heather N.; Nachman, Patrick H.

2014-01-01

Primary membranous nephropathy is associated with increased risk of venous thromboembolic events, which are inversely correlated with serum albumin levels. To evaluate the potential benefit of prophylactic anticoagulation (venous thromboembolic events prevented) relative to the risk (major bleeds), we constructed a Markov decision model. The venous thromboembolic event risk according to serum albumin was obtained from an inception cohort of 898 patients with primary membranous nephropathy. Risk estimates of hemorrhage were obtained from a systematic literature review. Benefit-to-risk ratios were predicted according to bleeding risk and serum albumin. This ratio increased with worsening hypoalbuminemia from 4.5:1 for an albumin under 3 g/dl to 13.1:1 for an albumin under 2 g/dl in patients at low bleeding risk. Patients at intermediate bleeding risk with an albumin under 2 g/dl have a moderately favorable benefit-to-risk ratio (under 5:1). Patients at high bleeding risk are unlikely to benefit from prophylactic anticoagulation regardless of albuminemia. Probabilistic sensitivity analysis, to account for uncertainty in risk estimates, confirmed these trends. From these data, we constructed a tool to estimate the likelihood of benefit based on an individual’s bleeding risk profile, serum albumin level, and acceptable benefit-to-risk ratio (http://www.gntools.com). This tool provides an approach to the decision of prophylactic anticoagulation personalized to the individual’s needs and adaptable to dynamic changes in health status and risk profile. PMID:24336031

Electroconvulsive therapy and anticoagulation after pulmonary embolism: a case report

Directory of Open Access Journals (Sweden)

Julio Cesar Lazaro

2014-07-01

Full Text Available Introduction Electroconvulsive therapy (ECT is considered the most effective treatment for catatonia regardless its underlying condition. The rigid fixed posture and immobility observed in catatonia may lead to several clinical complications, of which, pulmonary embolism (PE is one of the most severe. The rapid improvement of the psychiatric condition in catatonia-related PE is essential, since immobility favors the occurrence of new thromboembolic events and further complications. In that scenario, ECT should be considered, based on a risk-benefit analysis, aiming at the faster resolution of the catatonia. Methods Case report and literature review. Results A 66-years-old woman admitted to the psychiatric ward with catatonia due to a depressive episode presented bilateral PE. Clinically stable, but still severely depressed after a trial of antidepressants, she was treated with ECT in the course of full anticoagulation with enoxaparin. After five ECT sessions, her mood was significantly better and she was walking and eating spontaneously. She did not present complications related either to PE or to anticoagulation. After the eighth ECT session, she evolved with hypomania, which was managed with oral medication adjustments. The patient was completely euthymic at discharge. Conclusion The case we presented provides further evidence to the anecdotal case reports on the safety of ECT in the course of concomitant full anticoagulant therapy after PE, and illustrates how, with the proper precautions, the benefits of ECT in such condition might outweigh its risks.

Extracellular matrix inspired surface functionalization with heparin, fibronectin and VEGF provides an anticoagulant and endothelialization supporting microenvironment

International Nuclear Information System (INIS)

Wang, Xue; Liu, Tao; Chen, Yuan; Zhang, Kun; Maitz, Manfred F.; Pan, Changjiang; Chen, Junying; Huang, Nan

2014-01-01

Highlights: • Surface modification with fibronectin, heparin and VEGF could selectively anticoagulant and promote endothelialization. • The bioactivity of biomolecules was more efficiently maintained via specific intermolecular interaction. • Poly-l-lysine interlayer was more feasible and the degradation product had no harm to human body. - Abstract: The biocompatibility of currently used coronary artery stent is still far from perfect, which closely related to insufficient endothelialization and thrombus formation. In this study, heparin, fibronectin and VEGF were immobilized on Ti surface to construct a multifunctional microenvironment with favorable properties to inhibit thrombosis formation and promote endothelialization simultaneously. The microenvironment on Ti surface was characterized in detail and demonstrated that the Hep/Fn/VEGF biofunctional coating was constructed successfully on Ti surface. The influence of surface properties such as chemical composition, roughness, hydrophilicity, and binding density of biomolecules on the performances of hemocompatibility and cytocompatibility was evaluated and discussed. Modified surface significantly enhanced the AT III binding density and prolonged the clotting time. In vitro platelet adhesion and activation assays further proved that the modified surface presented favorable anti-coagulant property. In addition, the proliferation of endothelial progenitor cells (EPCs) and endothelial cells (ECs) on the Hep/Fn/VEGF biofunctional coating was significantly promoted. In conclusion, the Hep/Fn/VEGF biofunctional coating was successfully constructed with desirable anticoagulant and endothelialization supporting properties. This work may provide a promising approach for biofunctional surface modification of coronary artery stent to acquire a desired multifunctional microenvironment

Self-monitoring and self-management of oral anticoagulation.

Science.gov (United States)

Heneghan, Carl J; Garcia-Alamino, Josep M; Spencer, Elizabeth A; Ward, Alison M; Perera, Rafael; Bankhead, Clare; Alonso-Coello, Pablo; Fitzmaurice, David; Mahtani, Kamal R; Onakpoya, Igho J

2016-07-05

The introduction of point-of-care devices for the management of patients on oral anticoagulation allows self-testing by the patient at home. Patients who self-test can either adjust their medication according to a pre-determined dose-INR (international normalized ratio) schedule (self-management), or they can call a clinic to be told the appropriate dose adjustment (self-monitoring). Increasing evidence suggests self-testing of oral anticoagulant therapy is equal to or better than standard monitoring. This is an updated version of the original review published in 2010. To evaluate the effects on thrombotic events, major haemorrhages, and all-cause mortality of self-monitoring or self-management of oral anticoagulant therapy compared to standard monitoring. For this review update, we re-ran the searches of the Cochrane Central Register of Controlled Trials (CENTRAL), 2015, Issue 6, the Cochrane Library, MEDLINE (Ovid, 1946 to June week 4 2015), Embase (Ovid, 1980 to 2015 week 27) on 1 July 2015. We checked bibliographies and contacted manufacturers and authors of relevant studies. We did not apply any language restrictions . Outcomes analysed were thromboembolic events, mortality, major haemorrhage, minor haemorrhage, tests in therapeutic range, frequency of testing, and feasibility of self-monitoring and self-management. Review authors independently extracted data and we used a fixed-effect model with the Mantzel-Haenzel method to calculate the pooled risk ratio (RR) and Peto's method to verify the results for uncommon outcomes. We examined heterogeneity amongst studies with the Chi(2) and I(2) statistics and used GRADE methodology to assess the quality of evidence. We identified 28 randomised trials including 8950 participants (newly incorporated in this update: 10 trials including 4227 participants). The overall quality of the evidence was generally low to moderate. Pooled estimates showed a reduction in thromboembolic events (RR 0.58, 95% CI 0.45 to 0

Monitoring the effectiveness of the natural anticoagulant sulodexide in pregnant women with autoimmune hyperthyroidism on the background of hyperhomocysteinemia

Directory of Open Access Journals (Sweden)

A.Yu. Scherbakov

2017-04-01

Full Text Available According to modern concepts, the occurrence of complications in utero-placental pool during pregnancy is a common cause of primary placental insufficiency, severe forms of late gestosis, recurrent miscarriage. It is obvious that the study of the nature of violations in the hemostatic system during pregnancy and the development of methods for timely correction will be the prevention of many obstetric diseases. Among the factors that affect hemostasis, thyroid hormones occupy a special place, they are able to influence not only the functional activity of platelets, but also adjust the intensity of the plasma and tissue fibrinolysis. Oppression of fibrinolytic activity is one of the pathogenetic factors of thrombosis development. The aim – to study the efficacy of natural anticoagulant sulodexide in pregnant women with autoimmune hyperthyroidism on the background of hyperhomocysteinemia. Materials and methods. The study involved 34 pregnant women with autoimmune hyperthyroidism complicated by hyperhomocysteinemia. A control group comprised 29 somatically healthy pregnant women. General clinical examination was carried out, the main indicators of all the links of the hemostatic system and the level of homocysteine were determined. Results. We determined that the main group of pregnant is characterized with chronometric and structural hypercoagulation, which manifests itself in the form of subclinical syndrome of disseminated intravascular coagulation, leading to complications of pregnancy, childbirth and the pathological condition of the fetus. Addition of anticoagulant sulodexide to the standard treatment led to the significant change in indices of all the components of hemostasis in pregnant women of the main group, in particular normalization of the total capacity of the coagulation and fibrinolytic systems. Decrease in activity of intravascular coagulation and platelet aggregation, the level of homocysteine was marked. Clinical indicators of

Congenital Malformations Associated with the Administration of Oral Anticoagulants During Pregnancy

Science.gov (United States)

Pettifor, J. M.; Benson, R.

1975-01-01

Reported are case histories of three infants with congenital malformations (including defective formation of the nose and hands) associated with ingestion of oral anticoagulants during the first trimester of pregnancy. (CL)

Utilization of Oral Anticoagulation in a Teaching Hospital in Nigeria

African Journals Online (AJOL)

optimal antithrombotic effect. The oral drugs ... vitamin K-dependent clotting factors, which include factors. II, VII, IX, and X, ... hyperthyroidism) and those that decrease INR (pharmacokinetic: Barbiturates ... of anticoagulation, drug dosing, treatment outcome and .... national guidelines, and performance on quality measures.

Upsetting the apple cart: a community anticoagulation clinic survey of life event factors that undermine safe therapy.

Science.gov (United States)

Edmundson, Sarah; Stuenkel, Diane L; Connolly, Phyllis M

2005-09-01

Anticoagulation therapy is a life-enhancing therapy for patients who are at risk for embolic events secondary to atrial fibrillation, valve replacement, and other comorbidities. Clinicians are motivated to decrease the amount of time that patients are either under- or over-anticoagulated, common conditions that decrease patient safety at either extreme. The primary purpose of this descriptive study was to examine the relationship between personal life event factors as measured by Norbeck's Life Events Questionnaire, core demographics such as age and income, and anticoagulation regulation. Although many factors affect anticoagulation therapy, the precise impact of life events, positive or negative, is unknown. The salient findings of this study (n = 202) showed a small, though statistically significant, inverse relationship (r = -0.184, P < .01) between negative life events and decreased time within therapeutic international normalized ratio. Total Life Event scores showed a statistically significant inverse relationship (r = -0.159, P < .05) to international normalized ratio time within therapeutic level. Lower income was inversely associated with higher negative Life Event scores (r = -0.192, P < .01). The findings demonstrate the need for strategies that address the potential impact of life events in conjunction with coexisting screening measures used in anticoagulation clinics. Implications for this study are limited by lack of methodology documenting concurrent social support factors and limitations of the research tool to reflect life event issues specific to outpatient seniors.

Current practice of antiplatelet and anticoagulation management in post-cardiac surgery patients: a national audit.

Science.gov (United States)

Hosmane, Sharath; Birla, Rashmi; Marchbank, Adrian

2012-04-01

The Audit and Guidelines Committee of the European Association for Cardio-Thoracic Surgery recently published a guideline on antiplatelet and anticoagulation management in cardiac surgery. We aimed to assess the awareness of the current guideline and adherence to it in the National Health Service through this National Audit. We designed a questionnaire consisting of nine questions covering various aspects of antiplatelet and anticoagulation management in post-cardiac surgery patients. A telephonic survey of the on-call cardiothoracic registrars in all the cardiothoracic centres across the UK was performed. All 37 National Health Service hospitals in the UK with 242 consultants providing adult cardiac surgical service were contacted. Twenty (54%) hospitals had a unit protocol for antiplatelet and anticoagulation management in post-cardiac surgery. Only 23 (62.2%) registrars were aware of current European Association for Cardio-Thoracic Surgery guidelines. Antiplatelet therapy is variable in the cardiac surgical units across the country. Low-dose aspirin is commonly used despite the recommendation of 150-300 mg. The loading dose of aspirin within 24 h as recommended by the guideline is followed only by 60.7% of surgeons. There was not much deviation from the guideline with respect to the anticoagulation therapy.

Modulation of mitogen-activated protein kinase-activated protein kinase 3 by hepatitis C virus core protein

DEFF Research Database (Denmark)

Ngo, HT; Pham, Long; Kim, JW

2013-01-01

Hepatitis C virus (HCV) is highly dependent on cellular proteins for its own propagation. In order to identify the cellular factors involved in HCV propagation, we performed protein microarray assays using the HCV core protein as a probe. Of ~9,000 host proteins immobilized in a microarray...... inducers. Binding of HCV core to MAPKAPK3 was confirmed by in vitro pulldown assay and further verified by coimmunoprecipitation assay. HCV core protein interacted with MAPKAPK3 through amino acid residues 41 to 75 of core and the N-terminal half of kinase domain of MAPKAPK3. In addition, both RNA...... increased HCV IRES-mediated translation and MAPKAPK3-dependent HCV IRES activity was further increased by core protein. These data suggest that HCV core may modulate MAPKAPK3 to facilitate its own propagation....

Educational Level, Anticoagulation Quality, and Clinical Outcomes in Elderly Patients with Acute Venous Thromboembolism: A Prospective Cohort Study.

Science.gov (United States)

Hofmann, Eveline; Faller, Nicolas; Limacher, Andreas; Méan, Marie; Tritschler, Tobias; Rodondi, Nicolas; Aujesky, Drahomir

2016-01-01

Whether the level of education is associated with anticoagulation quality and clinical outcomes in patients with acute venous thromboembolism (VTE) is uncertain. We thus aimed to investigate the association between educational level and anticoagulation quality and clinical outcomes in elderly patients with acute VTE. We studied 817 patients aged ≥65 years with acute VTE from a Swiss prospective multicenter cohort study (09/2009-12/2013). We defined three educational levels: 1) less than high school, 2) high school, and 3) post-secondary degree. The primary outcome was the anticoagulation quality, expressed as the percentage of time spent in the therapeutic INR range (TTR). Secondary outcomes were the time to a first recurrent VTE and major bleeding. We adjusted for potential confounders and periods of anticoagulation. Overall, 56% of patients had less than high school, 25% a high school degree, and 18% a post-secondary degree. The mean percentage of TTR was similar across educational levels (less than high school, 61%; high school, 64%; and post-secondary, 63%; P = 0.36). Within three years of follow-up, patients with less than high school, high school, and a post-secondary degree had a cumulative incidence of recurrent VTE of 14.2%, 12.9%, and 16.4%, and a cumulative incidence of major bleeding of 13.3%, 15.1%, and 15.4%, respectively. After adjustment, educational level was neither associated with anticoagulation quality nor with recurrent VTE or major bleeding. In elderly patients with VTE, we did not find an association between educational level and anticoagulation quality or clinical outcomes.

Cost evaluation of two methods of post tooth extraction hemostasis in patients on anticoagulant therapy.

Science.gov (United States)

Zusman, S P; Lustig, J P; Bin Nun, G

1993-06-01

The classical management of patients on oral anticoagulant therapy included hospitalisation, cessation of the anticoagulant agent, and extraction of teeth when the prothrombine levels rise. This method was substituted in the High Risk Dental Clinic at Barzilai Medical Center in Ashkelon by use of a tissue sealant (Tisseel) which does not need hospitalisation nor cessation of the anticoagulant therapy. In comparing the last 23 sessions employing the former method to the first 23 sessions using the new method there were significant differences in the cost effectiveness for the health system, provider, insurer and patient. Despite the fact that from the health system point of view the new method is much more cost effective, there is no financial incentive for the provider (hospital) nor awareness on the part of the insurer (General Sick Fund) to embrace it and 'market' it.

Anticoagulant Prairie Dog Bait Risk Mitigation Measures to Protect Endangered Species

Science.gov (United States)

This Web page contains information on how certified pesticide applicators can use anticoagulant prairie dog bait products such as Rozol and Kaput-D while minimizing exposure risks to listed and non-target species.

Use of Non-Vitamin K Antagonist Oral Anticoagulants 2008-2016

DEFF Research Database (Denmark)

Haastrup, Simone; Hellfritzsch, Maja; Rasmussen, Lotte

2018-01-01

We aimed to provide detailed utilization data on the total use of non-vitamin K antagonist oral anticoagulants (NOACs) since their introduction in 2008. Using the nationwide Danish National Prescription Registry, we identified all individuals filling prescriptions for NOACs 2008-2016. We reported...

Stratifying the risks of oral anticoagulation in patients with liver disease.

Science.gov (United States)

Efird, Lydia M; Mishkin, Daniel S; Berlowitz, Dan R; Ash, Arlene S; Hylek, Elaine M; Ozonoff, Al; Reisman, Joel I; Zhao, Shibei; Jasuja, Guneet K; Rose, Adam J

2014-05-01

Chronic liver disease presents a relative contraindication to warfarin therapy, but some patients with liver disease nevertheless require long-term anticoagulation. The goal is to identify which patients with liver disease might safely receive warfarin. Among 102 134 patients who received warfarin from the Veterans Affairs from 2007 to 2008, International Classification of Diseases-Ninth Revision codes identified 1763 patients with chronic liver disease. Specific diagnoses and laboratory values (albumin, aspartate aminotransferase, alanine aminotransferase, creatinine, and cholesterol) were examined to identify risk of adverse outcomes, while controlling for available bleeding risk factors. Outcomes included percent time in therapeutic range, a measure of anticoagulation control, and major hemorrhagic events, by International Classification of Diseases-Ninth Revision codes. Patients with liver disease had lower mean time in therapeutic range (53.5%) when compared with patients without (61.7%; P<0.001) and more hemorrhages (hazard ratio, 2.02; P<0.001). Among patients with liver disease, serum albumin and creatinine levels were the strongest predictors of both outcomes. We created a 4-point score system: patients received 1 point each for albumin (2.5-3.49 g/dL) or creatinine (1.01-1.99 mg/dL), and 2 points each for albumin (<2.5 g/dL) or creatinine (≥2 mg/dL). This score predicted both anticoagulation control and hemorrhage. When compared with patients without liver disease, those with a score of zero had modestly lower time in therapeutic range (56.7%) and no increase in hemorrhages (hazard ratio, 1.16; P=0.59), whereas those with the worst score (4) had poor control (29.4%) and high hazard of hemorrhage (hazard ratio, 8.53; P<0.001). Patients with liver disease receiving warfarin have poorer anticoagulation control and more hemorrhages. A simple 4-point scoring system using albumin and creatinine identifies those at risk for poor outcomes. © 2014 American

The recent clinical trials on use of the novel direct oral anticoagulants in patients with venous thromboembolism: a review

Directory of Open Access Journals (Sweden)

Gualtiero Palareti

2014-10-01

Full Text Available Venous thromboembolism (VTE, encompassing deep vein thrombosis and pulmonary embolism, requires an immediate anticoagulation, that has been carried out so far by administering a parenteral anticoagulant drug (heparin or derivatives overlapped with an oral vitamin K antagonist (VKA, more often warfarin. Several new direct oral anticoagulants (DOACs, with a mechanism of action completely different than VKA, have been developed in recent years. Recent clinical trials have investigated their use in VTE patients showing results at least equal for efficacy and safety, and sometime even better, as the standard anticoagulant treatment. There are differences in the design of the trials. In two cases the involved DOAC was administered immediately after VTE diagnosis as a single drug treatment (rivaroxaban and apixaban, whereas in the other trials (involving dabigatran and edoxaban the DOAC was administered after an initial course of approximately 7 days with heparin or derivatives. Some clinical trials have also investigated the use of DOACs for extended anticoagulant treatment after the acute phase. Aim of this article is to review the results of the currently available clinical trials that have compared the use of DOACs versus the standard of care in patients with VTE.

Consensus recommendations for preventing and managing bleeding complications associated with novel oral anticoagulants in singapore.

Science.gov (United States)

Ng, Heng Joo; Chee, Yen Lin; Ponnudurai, Kuperan; Lim, Lay Cheng; Tan, Daryl; Tay, Jam Chin; Handa, Pankaj Kumar; Akbar Ali, Mufeedha; Lee, Lai Heng

2013-11-01

Novel oral anticoagulants (NOACs) have at least equivalent efficacy compared to standard anticoagulants with similar bleeding risk. Optimal management strategies for bleeding complications associated with NOACs are currently unestablished. A working group comprising haematologists and vascular medicine specialists representing the major institutions in Singapore was convened to produce this consensus recommendation. A Medline and EMBASE search was conducted for articles related to the 3 available NOACs (dabigatran, rivaroxaban, apixaban), bleeding and its management. Additional information was obtained from the product monographs and bibliographic search of articles identified. The NOACs still has substantial interactions with a number of drugs for which concomitant administration should best be avoided. As they are renally excreted, albeit to different degrees, NOACs should not be prescribed to patients with creatinine clearance of factor VIIa and prothrombin complex may be considered although their effectiveness is currently unsupported by firm clinical evidence. The NOACs have varying effect on the prothrombin time and activated partial thromboplastin time which has to be interpreted with caution. Routine monitoring of drug level is not usually required. NOACs are an important advancement in antithrombotic management and careful patient selection and monitoring will permit optimisation of their potential and limit bleeding events.

Mitogen-activated protein kinases mediate Mycobacterium ...

Indian Academy of Sciences (India)

2012-01-19

Jan 19, 2012 ... CD44, an adhesion molecule, has been reported to be a binding site for ... receptors in mediating mitogen-activated protein kinase activation. ... surface expression and tumour necrosis factor-alpha levels, ... Abbreviations used: Abs, antibodies; ANOVA, analysis of variance; AP-1, activator protein -1; BCG, ...

Practice points in gynecardiology: Abnormal uterine bleeding in premenopausal women taking oral anticoagulant or antiplatelet therapy.

Science.gov (United States)

Maas, Angela H E M; Euler, Mia von; Bongers, Marlies Y; Rolden, Herbert J A; Grutters, Janneke P C; Ulrich, Lian; Schenck-Gustafsson, Karin

2015-12-01

A growing number of premenopausal women are currently using antithrombotic and/or (dual) antiplatelet therapy for various cardiovascular indications. These may induce or exacerbate abnormal uterine bleeding and more awareness and knowledge among prescribers is required. Heavy and irregular menstrual bleeding is common in women in their forties and may have a variety of underlying causes that require different treatment options. Thus using anticoagulants in premenopausal women demands specific expertise and close collaboration between cardiovascular physicians and gynecologists. In this article we summarize the scope of the problem and provide practical recommendations for the care for young women taking anticoagulants and/or (dual) antiplatelet therapy. We also recommend that more safety data on uterine bleeding with novel anticoagulants in premenopausal women should be obtained. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Management of anticoagulation in hip fractures: A pragmatic approach.

Science.gov (United States)

Yassa, Rafik; Khalfaoui, Mahdi Yacine; Hujazi, Ihab; Sevenoaks, Hannah; Dunkow, Paul

2017-09-01

Hip fractures are common and increasing with an ageing population. In the United Kingdom, the national guidelines recommend operative intervention within 36 hours of diagnosis. However, long-term anticoagulant treatment is frequently encountered in these patients which can delay surgical intervention. Despite this, there are no set national standards for management of drug-induced coagulopathy pre-operatively in the context of hip fractures.The aim of this study was to evaluate the management protocols available in the current literature for the commonly encountered coagulopathy-inducing agents.We reviewed the current literature, identified the reversal agents used in coagulopathy management and assessed the evidence to determine the optimal timing, doses and routes of administration.Warfarin and other vitamin K antagonists (VKA) can be reversed effectively using vitamin K with a dose in the range of 2 mg to 10 mg intravenously to correct coagulopathy.The role of fresh frozen plasma is not clear from the current evidence while prothrombin complex remains a reliable and safe method for immediate reversal of VKA-induced coagulopathy in hip fracture surgery or failed vitamin K treatment reversal.The literature suggests that surgery should not be delayed in patients on classical antiplatelet medications (aspirin or clopidogrel), but spinal or regional anaesthetic methods should be avoided for the latter. However, evidence regarding the use of more novel antiplatelet medications (e.g. ticagrelor) and direct oral anticoagulants remains a largely unexplored area in the context of hip fracture surgery. We suggest treatment protocols based on best available evidence and guidance from allied specialties.Hip fracture surgery presents a common management dilemma where semi-urgent surgery is required. In this article, we advocate an evidence-based algorithm as a guide for managing these anticoagulated patients. Cite this article: EFORT Open Rev 2017;2:394-402. DOI: 10.1302/2058-5241.2.160083.

Concurrent use of tramadol and oral vitamin K antagonists and the risk of excessive anticoagulation

DEFF Research Database (Denmark)

Pottegård, Anton; Meegaard, P. M.; Holck, L. H.

2013-01-01

.9-5.2). This corresponds to, on average, one excess case per 250 treatment years (CI 125-584). The result is potentially confounded by concomitant paracetamol use and the presence of acute illness. CONCLUSION: Caution is advised when using tramadol in patients using VKA, and if possible, an alternative pain......OBJECTIVES: The objective was to assess whether the concurrent use of tramadol and vitamin K antagonists (VKAs) leads to an increased risk of excessive anticoagulation. DESIGN: The study was designed as a case-control study, nested within users of VKA and with tramadol use as our main exposure. We...... anticoagulation attributable to the use of tramadol. RESULTS: A total of 178 patients were included, 30 of which were exposed to tramadol, along with 2643 controls, 114 of which were exposed to tramadol. The adjusted odds-ratio for experiencing excessive anticoagulation during use of tramadol was 3.1 (1...

Real-life Use of Anticoagulants in Venous Thromboembolism With a Focus on Patients With Exclusion Criteria for Direct Oral Anticoagulants.

Science.gov (United States)

Moustafa, Farès; Pesavento, Raffaele; di Micco, Pierpaolo; González-Martínez, José; Quintavalla, Roberto; Peris, Maria-Luisa; Porras, José Antonio; Falvo, Nicolas; Baños, Pilar; Monreal, Manuel

2018-04-01

We assessed the real-life use of direct oral anticoagulants (DOACs) in patients with venous thromboembolism (VTE) and exclusion criteria for randomized trials. From 2013 to 2016, 3,578 of 18,853 patients (19%) had exclusion criteria. Irrespective of which anticoagulant was chosen, they had more VTE recurrences (hazard ratio (HR): 3.10; 95% confidence interval (CI): 2.47-3.88), major bleeds (HR: 4.10; 95% CI: 3.38-4.96), and deaths (HR: 9.47; 95% CI: 8.46-10.6) than those without exclusion criteria. During initial therapy, no patient with exclusion criteria on DOACs (n = 115) recurred, but those on rivaroxaban bled less often (adjusted HR: 0.18; 95% CI: 0.04-0.79) than those on unfractionated heparin (n = 224) and similar to those (n = 3,172) on low-molecular-weight (LMWH) heparin. For long-term therapy, patients on rivaroxaban (n = 151) had nonsignificantly fewer VTE recurrences (adjusted HR: 0.74; 95% CI: 0.08-1.32) and major bleeds (adjusted HR: 0.41; 95% CI: 0.15-1.15) than those on LMWH (n = 2,071). The efficacy and safety of DOACs were similar to standard therapy. © 2017 American Society for Clinical Pharmacology and Therapeutics.

Anticoagulant use for the prevention of stroke in patients with atrial fibrillation: findings from a multi-payer analysis.

Science.gov (United States)

Lang, Kathleen; Bozkaya, Duygu; Patel, Aarti A; Macomson, Brian; Nelson, Winnie; Owens, Gary; Mody, Samir; Schein, Jeff; Menzin, Joseph

2014-07-28

Oral anticoagulation is recommended for stroke prevention in intermediate/high stroke risk atrial fibrillation (AF) patients. The objective of this study was to demonstrate the usefulness of analytic software tools for descriptive analyses of disease management in atrial AF; a secondary objective is to demonstrate patterns of potential anticoagulant undertreatment in AF. Retrospective data analyses were performed using the Anticoagulant Quality Improvement Analyzer (AQuIA), a software tool designed to analyze health plan data. Two-year data from five databases were analyzed: IMS LifeLink (IMS), MarketScan Commercial (MarketScanCommercial), MarketScan Medicare Supplemental (MarketScanMedicare), Clinformatics™ DataMart, a product of OptumInsight Life Sciences (Optum), and a Medicaid Database (Medicaid). Included patients were ≥ 18 years old with a new or existing diagnosis of AF. The first observed AF diagnosis constituted the index date, with patient outcomes assessed over a one year period. Key study measures included stroke risk level, anticoagulant use, and frequency of International Normalized Ratio (INR) monitoring. High stroke risk (CHADS2 ≥ 2 points) was estimated in 54% (IMS), 22% (MarketScanCommercial), 64% (MarketscanMedicare), 42% (Optum) and 62% (Medicaid) of the total eligible population. Overall, 35%, 29%, 38%, 39% and 16% of all AF patients received an anticoagulant medication in IMS, MarketScanCommercial, MarketScanMedicare, Optum and Medicaid, respectively. Among patients at high risk for stroke, 19% to 51% received any anticoagulant. The AQuIA provided a consistent platform for analysis across multiple AF populations with varying baseline characteristics. Analyzer results show that many high-risk AF patients in selected commercial, Medicare-eligible, and Medicaid populations do not receive appropriate thromboprophylaxis, as recommended by treatment guidelines.

Cross-cultural adaptation and psychometric properties of the Brazilian-Portuguese version of the Duke Anticoagulation Satisfaction Scale.

Science.gov (United States)

Pelegrino, Flávia M; Dantas, Rosana A S; Corbi, Inaiara S A; da Silva Carvalho, Ariana R; Schmidt, André; Pazin Filho, Antônio

2012-09-01

The aim of this study was to evaluate the internal reliability and validity of the Brazilian-Portuguese version of Duke Anticoagulation Satisfaction Scale (DASS) among cardiovascular patients. Oral anticoagulation is widely used to prevent and treat thromboembolic events in several conditions, especially in cardiovascular diseases; however, this therapy can induce dissatisfaction and reduce the quality of life. Methodological and cross-sectional research design. The cultural adaptation of the DASS included the translation and back-translation, discussions with healthcare professionals and patients to ensure conceptual equivalence, semantic evaluation and instrument pretest. The Brazilian-Portuguese version of the DASS was tested among subjects followed in a university hospital anticoagulation outpatient clinic. The psychometric properties were assessed by construct validity (convergent, known groups and dimensionality) and internal consistency/reliability (Cronbach's alpha). A total of 180 subjects under oral anticoagulation formed the baseline validation population. DASS total score and SF-36 domain correlations were moderate for General health (r=-0.47, pDASS score and most of the subscales, except Limitation (r=-0.375, pscale, and it ranged from 0.76 (hassles and burdens)-0.46 (psychological impact) among the domains, confirming the internal consistency reliability. The Brazilian-Portuguese version of the DASS has shown levels of reliability and validity comparable with the original English version. Healthcare practitioners and researchers need internationally validated measurement tools to compare outcomes of interventions in clinical management and research tools in oral anticoagulation therapy. © 2011 Blackwell Publishing Ltd.

Anticoagulation: Where have we come from and where are we going ...

African Journals Online (AJOL)

is its predictable renal excretion, with low inter- and intra-individual variability.[11] Clinically, this ... recent meta-analysis of 50 000 patients requiring anticoagulation ... data supporting the use of NOACs in secondary stroke prevention in. NVAF.

Initiation of anticoagulation in atrial fibrillation

DEFF Research Database (Denmark)

Gundlund, A.; Staerk, L.; Fosbøl, E. L.

2017-01-01

Background: The use of non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prophylaxis in atrial fibrillation (AF) is increasing rapidly. We compared characteristics of AF patients initiated on NOACs versus vitamin K antagonists (VKAs). Methods: Using Danish nationwide registry data, we...... compared with a VKA [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.28–1.43]. By contrast, patients with a history of myocardial infarction were less likely to be initiated on a NOAC compared with a VKA (OR 0.72, 95% CI 0.67–0.77). Conclusions: Atrial fibrillation patients who were initiated...

Impact of anticoagulation therapy on valve haemodynamic deterioration following transcatheter aortic valve replacement.

Science.gov (United States)

Del Trigo, María; Muñoz-García, Antonio J; Latib, Azeem; Auffret, Vincent; Wijeysundera, Harindra C; Nombela-Franco, Luis; Gutierrez, Enrique; Cheema, Asim N; Serra, Vicenç; Amat-Santos, Ignacio J; Kefer, Joelle; Benitez, Luis Miguel; Leclercq, Florence; Mangieri, Antonio; Le Breton, Hervé; Jiménez-Quevedo, Pilar; Garcia Del Blanco, Bruno; Dager, Antonio; Abdul-Jawad Altisent, Omar; Puri, Rishi; Pibarot, Philippe; Rodés-Cabau, Josep

2018-05-01

To evaluate the changes in transvalvular gradients and the incidence of valve haemodynamic deterioration (VHD) following transcatheter aortic valve replacement (TAVR), according to use of anticoagulation therapy. This multicentre study included 2466 patients (46% men; mean age 81±7 years) who underwent TAVR with echocardiography performed at 12-month follow-up. Anticoagulation therapy was used in 707 patients (28.7%) following TAVR (AC group). A total of 663 patients received vitamin K antagonists, and 44 patients received direct oral anticoagulants. A propensity score matching analysis was performed to adjust for intergroup (AC vs non-AC post-TAVR) differences. A total of 622 patients per group were included in the propensity-matched analysis. VHD was defined as a ≥10 mm Hg increase in the mean transprosthetic gradient at follow-up (vs hospital discharge). The mean clinical follow-up was 29±18 months. The mean transvalvular gradient significantly increased at follow-up in the non-AC group within the global cohort (P=0.003), whereas it remained stable over time in the AC group (P=0.323). The incidence of VHD was significantly lower in the AC group (0.6%) compared with the non-AC group (3.7%, P<0.001), and these significant differences remained within the propensity-matched populations (0.6% vs 3.9% in the AC and non-AC groups, respectively, P<0.001). The occurrence of VHD did not associate with an increased risk of all-cause death (P=0.468), cardiovascular death (P=0.539) or stroke (P=0.170) at follow-up. The lack of anticoagulation therapy post-TAVR was associated with significant increments in transvalvular gradients and a greater risk of VHD. VHD was subclinical in most cases and did not associate with major adverse clinical events. Future randomised trials are needed to determine if systematic anticoagulation therapy post-TAVR would reduce the incidence of VHD. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article

Evaluation of computerized decision support for oral anticoagulation management based in primary care.

Science.gov (United States)

Fitzmaurice, D A; Hobbs, F D; Murray, E T; Bradley, C P; Holder, R

1996-09-01

Increasing indications for oral anticoagulation has led to pressure on general practices to undertake therapeutic monitoring. Computerized decision support (DSS) has been shown to be effective in hospitals for improving clinical management. Its usefulness in primary care has previously not been investigated. To test the effectiveness of using DSS for oral anticoagulation monitoring in primary care by measuring the proportions of patients adequately controlled, defined as within the appropriate therapeutic range of International Normalised Ratio (INR). All patients receiving warfarin from two Birmingham inner city general practices were invited to attend a practice-based anticoagulation clinic. In practice A all patients were managed using DSS. In practice B patients were randomized to receive dosing advice either through DSS or through the local hospital laboratory. Clinical outcomes, adverse events and patient acceptability were recorded. Forty-nine patients were seen in total. There were significant improvements in INR control from 23% to 86% (P > 0.001) in the practice where all patients received dosing through DSS. In the practice where patients were randomized to either DSS or hospital dosing, logistic regression showed a significant trend for improvement in intervention patients which was not apparent in the hospital-dosed patients (P DSS through the full 12 months (24 days to 36 days) (P = 0.033). Adverse events were comparable between hospital and practice-dosed patients, although a number of esoteric events occurred. Patient satisfaction with the practice clinics was high. Computerized DSS enables the safe and effective transfer of anticoagulation management from hospital to primary care and may result in improved patient outcome in terms of the level of control, frequency of review and general acceptability.

Inhibition of adhesion breast cancer cells by anticoagulant drugs and cimetidine

Czech Academy of Sciences Publication Activity Database

Bobek, V.; Boubelík, Michael; Kovařík, J.; Taltynov, O.

2003-01-01

Roč. 50, č. 2 (2003), s. 148-151 ISSN 0028-2685 Institutional research plan: CEZ:AV0Z5052915 Keywords : cimetidine * breast cancer * anticoagulants Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.782, year: 2003

Percutaneous left atrial appendage occlusion in atrial fibrillation patients with a contraindication to oral anticoagulation: a focused review.

Science.gov (United States)

Nishimura, Marin; Sab, Shiv; Reeves, Ryan R; Hsu, Jonathan C

2017-12-08

Stroke is the most feared complication of atrial fibrillation (AF). Although oral anticoagulation with non-vitamin K antagonist and non-vitamin K antagonist oral anticoagulants (NOACs) have been established to significantly reduce risk of stroke, real-world use of these agents are often suboptimal due to concerns for adverse events including bleeding from both patients and clinicians. Particularly in patients with previous serious bleeding, oral anticoagulation may be contraindicated. Left atrial appendage occlusion (LAAO), mechanically targeting the source of most of the thrombi in AF, holds an immense potential as an alternative to OAC in management of stroke prophylaxis. In this focused review, we describe the available evidence of various LAAO devices, detailing data regarding their use in patients with a contraindication for oral anticoagulation. Although some questions of safety and appropriate use of these new devices in patients who cannot tolerate anticoagulation remain, LAAO devices offer a significant step forward in the management of patients with AF, including those patients who may not be able to be prescribed OAC at all. Future studies involving patients fully contraindicated to OAC are warranted in the era of LAAO devices for stroke risk reduction. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Hypoxia and the anticoagulants dalteparin and acetylsalicylic acid affect human placental amino acid transport.

Directory of Open Access Journals (Sweden)

Marc-Jens Kleppa

Full Text Available BACKGROUND: Anticoagulants, e.g. low-molecular weight heparins (LMWHs and acetylsalicylic acid (ASA are prescribed to women at risk for pregnancy complications that are associated with impaired placentation and placental hypoxia. Beyond their role as anticoagulants these compounds exhibit direct effects on trophoblast but their impact on placental function is unknown. The amino acid transport systems A and L, which preferably transfer essential amino acids, are well-described models to study placental nutrient transport. We aimed to examine the effect of hypoxia, LMWHs and ASA on the activity of the placental amino acid transport systems A and L and associated signalling mechanisms. METHODS: The uptake of C14-MeAIB (system A or H3-leucin (system L was investigated after incubation of primary villous fragments isolated from term placentas. Villous tissue was incubated at 2% O2 (hypoxia, 8% O2 and standard culture conditions (21% O2 or at 2% O2 and 21% O2 with dalteparin or ASA. Activation of the JAK/STAT or mTOR signalling pathways was determined by Western analysis of total and phosphorylated STAT3 or Raptor. RESULTS: Hypoxia decreased system A mediated MeAIB uptake and increased system L mediated leucine uptake compared to standard culture conditions (21% O2. This was accompanied by an impairment of STAT3 and a stimulation of Raptor signalling. System L activity increased at 8% O2. Dalteparin treatment reduced system A and system L activity under normoxic conditions and ASA (1 mM decreased system A and L transporter activity under normoxic and hypoxic conditions. CONCLUSIONS: Our data underline the dependency of placental function on oxygen supply. LMWHs and ASA are not able to reverse the effects of hypoxia on placental amino acid transport. These findings and the uncovering of the signalling mechanisms in more detail will help to understand the impact of LMWHs and ASA on placental function and fetal growth.

[Comparison of quality and hemorragic risk of oral anticoagulant therapy using acenocoumarol versus warfarin].

Science.gov (United States)

Oliva Berini, Elvira; Galán Alvarez, Pilar; Pacheco Onrubia, Ana María

2008-06-21

Long half life oral anticoagulants have shown a higher anticoagulation stability and a lower hemorragic risk than those of a short half life. We have compared therapeutic stability and hemorragic risk of acenocoumarol versus warfarin in 2 groups of patients on preventive anticoagulation because of atrial fibrilation (international normalised ratio [INR]: 2-3). Data on 120 patients treated with acenocoumarol and 120 on warfarin treatment who had started and continued treatment in our hospital for a minimum of a year was collected. The percentage of visits within the intended range of INR (2 to 3) was 65.5% with warfarin and 63.4% with acenocoumarol. Thirty percent of patients on warfarin had 75% or more of their controls within range, while for those treated with acenocoumarol this percentage was 22.5%. In the acenocoumarol group, 0.3 visits/patient/year presented an INR > or = 6 versus 0.07 in the warfarin group (p = 0.003). Patients treated with acenocoumarol show a higher risk of presenting with an INR > or = 6, but no statistically significant differences are observed in therapeutic stability.

Symptomatic type 1 protein C deficiency caused by a de novo Ser270Leu mutation in the catalytic domain

DEFF Research Database (Denmark)

Lind, B; Koefoed, P; Thorsen, S

2001-01-01

the intracellular content of mutant and wild-type protein was similar. Northern blot analysis of total mRNA from transfected cells showed no reduction of the mutant protein C mRNA compared with wild-type protein C mRNA. Collectively, these results indicate that the Ser270Leu mutation in the affected family caused......Heterozygosity for a C8524T transition in the protein C gene converting Ser270(TCG) to Leu(TTG) in the protease domain was identified in a family with venous thrombosis. The mutation was associated with parallel reduction in plasma levels of protein C anticoagulant activity and protein C antigen......, which is consistent with a type 1 deficiency. Transient expression of mutant protein C cDNA in human kidney 293 cells and analysis of protein C antigen in culture media and cell lysates showed that the secretion of mutant protein compared with wild-type protein was reduced by at least 97% while...

Anticoagulant resistance: a relevant issue in sewer rat (Rattus norvegicus) control?

DEFF Research Database (Denmark)

Heiberg, Ann-Charlotte

2009-01-01

the resistant rats, had resistance-related mutations in the VKORC1 gene. CONCLUSION: The results of this study suggest that the genetic background of anticoagulant resistance may have to be redefined in respect of resistance-related changes in the VKORC1 gene. Copyright © 2009 Society of Chemical Industry......BACKGROUND: The majority of rat problems in cities are thought to be related to defective sewers, and the use of anticoagulant rodenticides in such places is often implemented as part of regular urban rodent control. Knowledge pertaining to the resistance status of sewer rat populations is non......-existent, which may be leading to control problems in cities. It has become crucial to provide knowledge on the prevalence of resistance and how different control strategies have affected its prevalence among sewer rat populations. The prevalence of resistance was investigated in six sewer locations in Copenhagen...

Quantitative method for analysis of six anticoagulant rodenticides in faeces, applied in a case with repeated samples from a dog.

Science.gov (United States)

Seljetun, Kristin Opdal; Eliassen, Elin; Karinen, Ritva; Moe, Lars; Vindenes, Vigdis

2018-01-17

Accidental poisoning with anticoagulant rodenticides is not uncommon in dogs, but few reports of the elimination kinetics and half-lives in this species have been published. Our objectives were to develop and validate a new method for the quantification of anticoagulant rodenticides in canine blood and faeces using reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) and apply the method on a case of anticoagulant rodenticide intoxication. Sample preparation was liquid-liquid extraction. Six anticoagulant rodenticides were separated using a UPLC ® BEH C 18 -column with a mobile phase consisting of 5 mM ammonium formate buffer pH 10.2 and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. The limits of quantification were set at the levels of the lowest calibrator (1.5-2.7 ng/mL or ng/g). The method was successfully applied to a case from a dog accidentally poisoned with anticoagulant rodenticide. Coumatetralyl and brodifacoum concentrations were determined from serial blood and faecal samples. A terminal half-life of at least 81 days for coumatetralyl in blood was estimated, which is longer than previous reported in other species. A slow elimination of brodifacoum from the faeces was found, with traces still detectable in the faeces at day 513. This study offers a new method of detection and quantification of six frequently used anticoagulant rodenticides in canine faeces. Such drugs might cause serious health effects and it is important to be able to detect these drugs, to initiate proper treatment. The very long elimination half-lives detected in our study is important to be aware of in assessment of anticoagulant rodenticide burden to the environment.

Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants versus Vitamin K Antagonist Oral Anticoagulants in Patients Undergoing Radiofrequency Catheter Ablation of Atrial Fibrillation: A Meta-Analysis.

Directory of Open Access Journals (Sweden)

Giuseppe Santarpia

Full Text Available Use of the non-vitamin K antagonist oral anticoagulants (NOACs is endorsed by current guidelines for stroke prevention in patients with atrial fibrillation (AF. However efficacy and safety of NOACs in patients undergoing catheter ablation (RFCA of AF has not been well established yet.To perform a meta-analysis of all studies comparing NOACs and vitamin K antagonist oral anticoagulants (VKAs in patients undergoing RFCA.Studies were searched for in PubMed and Google Scholar databases.Studies were considered eligible if: they evaluated the clinical impact of NOACs versus VKAs; they specifically analyzed the use of anticoagulants during periprocedural phase of RFCA; they reported clinical outcome data.25 studies were selected, including 9881 cases. The summary measure used was the risk ratio (RR with 95% confidence interval (CI. The random-effects or the fixed effect model were used to synthesize results from the selected studies.There was no significant difference in thromboembolic complications (RR 1.39; p=0.13. Bleeding complications were significantly lower in the NOACs-treated arm as compared to VKAs (RR=0.67, p<0.001. Interestingly, a larger number of thromboembolic events was found in the VKAs-treated arm in those studies where VKAs had been interrupted during the periprocedural phase (RR=0.68; p=ns. In this same subgroup a significantly higher incidence of both minor (RR=0.54; p=0.002 and major bleeding (RR=0.41; p=0.01 events was recorded. Conversely, the incidence of thromboembolic events in the VKAs-treated arm was significantly lower in those studies with uninterrupted periprocedural anticoagulation treatment (RR=1.89; p=0.02.As with every meta-analysis, no patients-level data were available.The use of NOACs in patients undergoing RFCA is safe, given the lower incidence of bleedings observed with NOACs. On the other side, periprocedural interruption of VKAs and bridging with heparin is associated with a higher bleeding rate with no

Feasibility Study of a Mobile Health Intervention for Older Adults on Oral Anticoagulation Therapy

Directory of Open Access Journals (Sweden)

Jung-Ah Lee PhD, RN

2016-10-01

Full Text Available Background: Oral anticoagulation treatment (OAT such as warfarin therapy is recommended for older adults with atrial fibrillation, heart failure, or who are at risk for venous thromboembolism. Despite its proven benefits, older adults report both dissatisfaction with OAT and reduced quality of life that can potentially lead to low adherence to OAT and decreased treatment efficacy. Objective: To test the feasibility of Mobile Applications for Seniors to enhance Safe anticoagulation therapy (MASS, a mobile-based health technology intervention designed to promote independence and self-care. Method s: This pilot study used a single-arm experimental pre–post design to test the feasibility of a 3-month intervention using MASS in 18 older adults (male: n = 14; White: n = 9; Hispanic: n = 7; Other: n = 2; M age = 67. MASS was available in English or Spanish. Participants completed surveys about their OAT knowledge, attitudes, quality of life with OAT, and adherence at baseline and at a 3-month follow-up. Satisfaction with the MASS intervention was also assessed at follow-up. Results: Anticoagulation knowledge significantly improved from baseline to follow-up ( M base = 12.5 ± 5.51, M follow-up = 14.78 ± 3.93, p = .007. Other outcomes were not different, pre- and post-tests. Participants reported they were generally satisfied with MASS, its ease of use and its usefulness. Conclusion: The results showed use of MASS improved older adults’ knowledge of OAT. Using mHealth apps may enhance self-care among older adults with chronic conditions who are also taking oral anticoagulants.

Chitin and stress induced protein kinase activation

DEFF Research Database (Denmark)

Kenchappa, Chandra Shekar; Azevedo da Silva, Raquel; Bressendorff, Simon

2017-01-01

The assays described here are pertinent to protein kinase studies in any plant. They include an immunoblot phosphorylation/activation assay and an in-gel activity assay for MAP kinases (MPKs) using the general protein kinase substrate myelin basic protein. They also include a novel in-gel peptide...... substrate assay for Snf1-related kinase family 2 members (SnRK2s). This kinase family-specific assay overcomes some limitations of in-gel assays and permits the identification of different types of kinase activities in total protein extracts....

Discontinuation risk comparison among 'real-world' newly anticoagulated atrial fibrillation patients

DEFF Research Database (Denmark)

Lip, Gregory Y H; Pan, Xianying; Kamble, Shital

2018-01-01

Discontinuation of oral anticoagulants may expose non-valvular atrial fibrillation (NVAF) patients to an increased risk of stroke. This study describes the real-world discontinuation rates and compared the risk of drug discontinuation among NVAF patients initiating apixaban, warfarin, dabigatran,...

Recommendations for the anticoagulation of pregnant patients with mechanical heart valves

NARCIS (Netherlands)

Schapkaitz, Elise; Jacobson, Barry Frank; Manga, Pravin; Chitsike, Rufaro Saeed; Benade, Estee; Haas, Sylvia; Buller, Harry R.

2015-01-01

The management of pregnant patients with mechanical heart valves remains challenging because there are no large randomised studies to provide guidelines for effective anticoagulant therapy. Both vitamin K antagonists and heparins may be associated with maternal and foetal adverse events. The

Chaperone activity of human small heat shock protein-GST fusion proteins.

Science.gov (United States)

Arbach, Hannah; Butler, Caley; McMenimen, Kathryn A

2017-07-01

Small heat shock proteins (sHsps) are a ubiquitous part of the machinery that maintains cellular protein homeostasis by acting as molecular chaperones. sHsps bind to and prevent the aggregation of partially folded substrate proteins in an ATP-independent manner. sHsps are dynamic, forming an ensemble of structures from dimers to large oligomers through concentration-dependent equilibrium dissociation. Based on structural studies and mutagenesis experiments, it is proposed that the dimer is the smallest active chaperone unit, while larger oligomers may act as storage depots for sHsps or play additional roles in chaperone function. The complexity and dynamic nature of their structural organization has made elucidation of their chaperone function challenging. HspB1 and HspB5 are two canonical human sHsps that vary in sequence and are expressed in a wide variety of tissues. In order to determine the role of the dimer in chaperone activity, glutathione-S-transferase (GST) was genetically linked as a fusion protein to the N-terminus regions of both HspB1 and HspB5 (also known as Hsp27 and αB-crystallin, respectively) proteins in order to constrain oligomer formation of HspB1 and HspB5, by using GST, since it readily forms a dimeric structure. We monitored the chaperone activity of these fusion proteins, which suggest they primarily form dimers and monomers and function as active molecular chaperones. Furthermore, the two different fusion proteins exhibit different chaperone activity for two model substrate proteins, citrate synthase (CS) and malate dehydrogenase (MDH). GST-HspB1 prevents more aggregation of MDH compared to GST-HspB5 and wild type HspB1. However, when CS is the substrate, both GST-HspB1 and GST-HspB5 are equally effective chaperones. Furthermore, wild type proteins do not display equal activity toward the substrates, suggesting that each sHsp exhibits different substrate specificity. Thus, substrate specificity, as described here for full-length GST

Comparison on Anticoagulation and Antiplatelet Aggregation Effects of Puerarin with Heparin Sodium and Tirofiban Hydrochloride: An In Vitro Study.

Science.gov (United States)

Li, Si-Wei; Feng, Xue; Xu, Hao; Chen, Ke-Ji

2018-02-01

To detect the anticoagulation and antiplatelet effects of different concentrations of puerarin, heparin sodium and tirofiban hydrochloride on the blood samples of healthy volunteers by Sonoclot coagulation and platelet function analyzer. Peripheral blood samples were extracted from 20 healthy volunteers, followed by adding different concentrations of puerarin, heparin sodium and tirofiban hydrochloride. Samples were detected for activated clotting time (ACT), clot rate (CR) and platelet function (PF) by Sonoclot coagulation and platelet function analyzer instrument. For puerarin and heparin sodium, the values of ACT gradually increased, and the values of CR and PF gradually decreased with increasing in drug concentration. There was a linear (or log linear) relationship between ACT, CR, PF value and drug concentration (Phydrochloride, the values of ACT and CR had no significant changes, while PF values gradually decreased with concentration increasing. There was also a linear relationship between PF values and concentrations of tirofiban hydrochloride (Psodium. For high concentrations of puerarin (e.g. 3.8 mg/600 μL) and tirofiban hydrochloride (e.g. 0.8 μg/600 μL), PF values had no significant difference. However, PF values for high puerarin concentration had a larger variance. Puerarin has similar anticoagulant and antiplatelet effects with the heparin sodium, and may have a lower hemorrhage risk than heparin sodium when obtained the same anticoagulation effect in the concentration range of this experiment. In addition, for high concentration, puerarin had the same antiplatelet function as tirofiban hydrochloride but with a larger individual variability.

Outcome after discontinuing anticoagulant therapy in women with venous thromboembolism during hormonal use.

Science.gov (United States)

Blanco-Molina, Ángeles; Trujillo-Santos, Javier; Pesavento, Raffaele; Rosa, Vladimir; Falgá, Conxita; Tolosa, Carles; Mazzolai, Lucia; Sampériz, Ángel; Duce, Rita; Monreal, Manuel

2017-03-01

Whether women developing venous thromboembolism (VTE) while using hormonal therapy should be classified as having "unprovoked" or "provoked" VTE is controversial. We used the RIETE (Registro Informatizado Enfermedad TromboEmbólica) database to compare the rate of symptomatic VTE recurrences after discontinuing anticoagulation in 3 subgroups of women aged ≤50years without cancer, pregnancy or puerperium: (1) those with hormonal therapy and no additional risk factors (hormonal users only); (2) those with unprovoked VTE; and (3) those with additional risk factors, with or without hormonal therapy. As of March 2016, 1513 women had been followed-up for at least one month after discontinuing anticoagulation. Of these, 654 (43%) were hormonal users only, 390 (26%) had unprovoked VTE and 469 (31%) had transient risk factors with or without hormonal therapy. After discontinuing anticoagulation, the rate of VTE recurrences in women with hormonal use only (2.44 per 100 patient-years; 95% CI: 1.53-3.69) was significantly lower than in those with unprovoked VTE (6.03; 95% CI: 3.97-8.77) and similar to those with transient risk factors (2.58; 95% CI: 1.50-4.13). Interestingly, the rate of VTE recurrences presenting as pulmonary embolism in women with hormonal use only (0.55 per 100 patient-years; 95% CI: 0.18-1.29) was similar to those with transient risk factors (0.46; 95% CI: 0.09-1.33) and 4-fold lower than in women with unprovoked VTE (2.23; 95% CI: 1.07-4.10). After discontinuing anticoagulation, the rate of VTE recurrences in hormonal users only was significantly lower than in women with unprovoked VTE and similar to the rate in women with additional risk factors. © 2017 Elsevier Ltd. All rights reserved.

Tailoring of TiO2 films by H2SO4 treatment and UV irradiation to improve anticoagulant ability and endothelial cell compatibility.

Science.gov (United States)

Liao, Yuzhen; Li, Linhua; Chen, Jiang; Yang, Ping; Zhao, Ansha; Sun, Hong; Huang, Nan

2017-07-01

Surfaces with dual functions that simultaneously exhibit good anticoagulant ability and endothelial cell (EC) compatibility are desirable for blood contact materials. However, these dual functions have rarely been achieved by inorganic materials. In this study, titanium dioxide (TiO 2 ) films were treated by sulphuric acid (H 2 SO 4 ) and ultraviolet (UV) irradiation successively (TiO 2 H 2 SO 4 -UV), resulting in good anticoagulant ability and EC compatibility simultaneously. We found that UV irradiation improved the anticoagulant ability of TiO 2 films significantly while enhancing EC compatibility, though not significantly. The enhanced anticoagulant ability could be related to the oxidation of surface-adsorbed hydrocarbons and increased hydrophilicity. The H 2 SO 4 treatment improved the anticoagulant ability of TiO 2 films slightly, while UV irradiation improved the anticoagulant ability strongly. The enhanced EC compatibility could be related to the increased surface roughness and positive charges on the surface of the TiO 2 films. Furthermore, the time-dependent degradation of the enhanced EC compatibility and anticoagulant ability of TiO 2 H 2 SO 4 -UV was observed. In summary, TiO 2 H 2 SO 4 -UV expressed both excellent anticoagulant ability and good EC compatibility at the same time, which could be desirable for blood contact materials. However, the compatibility of TiO 2 H 2 SO 4 -UV with smooth muscle cells (SMCs) and macrophages was also improved. More effort is still needed to selectively improve EC compatibility on TiO 2 films for better re-endothelialization. Copyright © 2017 Elsevier B.V. All rights reserved.

The impact of pre-injury anticoagulation therapy in the older adult patient experiencing a traumatic brain injury: A systematic review.

Science.gov (United States)

Smith, Karen; Weeks, Susan

2012-01-01

The objective of this systematic review is to synthesize the best available evidence on the impact of pre-injury anticoagulation therapy in the older adult patient who experiences a traumatic brain injury. Trauma in the elderly remains one of the most challenging problems for healthcare providers in the 21 century. The most recent United States (U.S.) census estimates that by the year 2020 more than 52 million Americans will be age 65 years or older, and one million of those will live to be over 100 years of age. In the older adult population, classified as age 65 years or greater, the two leading causes of injury were reported as motor vehicle crashes (MVC) and falls. We have become increasingly aware of the unique physiologic changes in this population that make them more susceptible to succumb to traumatic injuries than their younger counterparts. This is especially true in the anticoagulated patient with a traumatic brain injury.Traumatic brain injury (TBI) is defined as an injury occurring when an external force traumatizes the brain. It may also be known as an intracranial or head injury. TBI is classified depending on the mechanism of injury (blunt or penetrating), severity, and location of the assault. Damage to the brain, skull, and/or scalp transpires. TBI is the leading cause of death and disability in the U.S, and persons of all ages, races, ethnicities, and incomes are affected. In the past five to ten years, trauma services have recorded an increase in major trauma admissions of patients age 65 years and older. In review of the literature to date, it is recognized that outcomes following moderate to severe TBI in older adults are poor, with high rates of significant disability and mortality reported. A recent Australian study reported that 28% of older adults died in the hospital following a TBI and in Finland adults aged 75 years and older had the highest rates of TBI related hospitalizations and death. According to a systematic review of European

Anticoagulation and endothelial cell behaviors of heparin-loaded graphene oxide coating on titanium surface

Energy Technology Data Exchange (ETDEWEB)

Pan, Chang-Jiang, E-mail: panchangjiang@hyit.edu.cn [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an 223003 (China); Pang, Li-Qun [Department of General Surgery, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an 223300 (China); Gao, Fei [Zhejiang Zylox Medical Devices Co., Ltd., Hangzhou 310000 (China); Wang, Ya-Nan; Liu, Tao; Ye, Wei; Hou, Yan-Hua [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an 223003 (China)

2016-06-01

Owing to its unique physical and chemical properties, graphene oxide (GO) has attracted tremendous interest in many fields including biomaterials and biomedicine. The purpose of the present study is to investigate the endothelial cell behaviors and anticoagulation of heparin-loaded GO coating on the titanium surface. To this end, the titanium surface was firstly covered by the polydopamine coating followed by the deposition of the GO coating. Heparin was finally loaded on the GO coating to improve the blood compatibility. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that the heparin-loaded GO coating was successfully created on the titanium surface. The scanning electron microscopy (SEM) images indicated that a relative uniform GO coating consisting of multilayer GO sheets was formed on the substrate. The hydrophilicity of the titanium surface was enhanced after the deposition of GO and further improved significantly by the loading heparin. The GO coating can enhance the endothelial cell adhesion and proliferation as compared with polydopamine coating and the blank titanium. Loading heparin on the GO coating can significantly reduce the platelet adhesion and prolong the activated partial thromboplastin time (APTT) while not influence the endothelial cell adhesion and proliferation. Therefore, the heparin-loaded GO coating can simultaneously enhance the cytocompatibility to endothelial cells and blood compatibility of biomaterials. Because the polydopamine coating can be easily prepared on most of biomaterials including polymer, ceramics and metal, thus the approach of the present study may open up a new window of promising an effective and efficient way to promote endothelialization and improve the blood compatibility of blood-contact biomedical devices such as intravascular stents. - Highlights: • Heparin-loaded graphene oxide coating was

Venom Protein C activators as diagnostic agents for defects of protein C System.

Science.gov (United States)

Ramzan, Faiqah; Asmat, Andleeb

2018-06-18

Background Protein C is a vitamin K dependent plasma zymogen. It prevents clotting by inhibiting clotting by inactivating factor V and factor VIII. Protein C activation pathway involves three steps: (i) Activation of protein C; (ii) Inhibition of coagulation through inactivating factor V and VIII by activated protein C and (iii) Inhibition of activated protein C by plasma protease inhibitors specific for this enzyme. Proteinases converts the zymogen Protein C (PC) of vertebrates into activated PC, which has been detected in several snake venoms. Most PC activators have been purified from venom of snake species belonging to the genera of the Agkistrodon complex. Unlike the physiological thrombin-catalyzed PC activation reaction which requires thrombomodulin as a cofactor, most snake venom activators directly convert the zymogen PC into the catalytically active form which can easily be determined by means of coagulation or chromogenic substrate techniques. Conclusion The fast-acting PC activator Protac® from Agkistrodon contortrix (southern copperhead snake) venom has been found to have broad application in diagnostic practice for the determination of disorders in the PC pathway. Recently, screening assays for the PC pathway have been introduced, based on the observation that the PC pathway is probably the most important physiological barrier against thrombosis. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Dental Procedures in Patients with Atrial Fibrillation and New Oral Anticoagulants

Science.gov (United States)

2014-01-01

This review discusses the basic pharmacology of new oral anticoagulants that are used for prevention of thromboembolism in patients with atrial fibrillation. It presents available evidence, and provides recommendations for the management of patients requiring invasive procedures in dental practice. PMID:26835072

Managing direct oral anticoagulants in patients undergoing dentoalveolar surgery.

Science.gov (United States)

Patel, J P; Woolcombe, S A; Patel, R K; Obisesan, O; Roberts, L N; Bryant, C; Arya, R

2017-02-24

Our objective was to describe our experience of managing a cohort of adult patients prescribed direct oral anticoagulants (DOACs) undergoing dentoalveolar procedures between November 2012 and May 2016. Prior to conducting a procedure a formal assessment was made of each patient's anticoagulation treatment. A specific plan was then formulated, balancing the risk of bleeding with the risk of thrombosis. Patients received a telephone consultation one week following treatment to assess any post-operative bleeding. Eighty-two patients underwent 111 oral surgical procedures, the majority of which were dental extractions. In the case of 35 (32%) procedures, advice was given to omit the DOAC, either before or after treatment. There was no bleeding following the majority of procedures. Persistent bleeding followed 15 (13.5%) procedures, of which 7 (6.3%) procedures required specific intervention. The majority of patients prescribed DOACs can undergo dentoalveolar procedures safely. Important considerations when planning treatment are: (i) when the patient usually takes their dose of DOAC, (ii) the time the procedure is performed and, (iii) when the DOAC is taken post-procedure. In our experience, if these factors are considered carefully, omission of DOAC doses is unlikely to be required for most patients.

Antiphospholipid and antioangiogenic activity in females with recurrent miscarriage and antiphospholipid syndrome.

Science.gov (United States)

Pelusa, Hector F; Pezzarini, Eleonora; Basiglio, Cecilia L; Musuruana, Jorge; Bearzotti, Mariela; Svetaz, María J; Daniele, Stella M; Bottai, Hebe; Arriaga, Sandra Mm

2017-09-01

Background Antiphospholipid syndrome is an autoimmune disease characterized by thrombosis, fetal losses and thrombocytopenia associated to antiphospholipid antibodies. They are directed to phospholipids, such as cardiolipins (anticardiolipin) and lupus anticoagulant or to complexes formed by phospholipids and protein cofactors, such as β2 glycoprotein 1 (a-β2GP1) and annexin V (a-annexin V). These auto-antibodies may be considered as a family of antibodies involved in thrombotic events and antiphospholipid activity. On the other hand, some proangiogenic factors are involved in the normal development of placental vasculature, such as the vascular endothelial growth factor. Overexpression of vascular endothelial growth factor receptor in its soluble form (sVEGFR-1) has been associated to a higher antiangiogenic activity. Our aim was to analyse the association between anticardiolipin, lupus anticoagulant, a-β2GP1, a-annexin V and sVEGFR-1 with recurrent miscarriage before week 10 of gestation in females with antiphospholipid syndrome. Methods We studied 24 females (primary or secondary antiphospholipid syndrome), who were divided into two groups: females with recurrent miscarriage before week 10 of gestation (M; n = 12) and females with no history of fetal loss (NM; n = 12). Anticardiolipin, a-β2GP1, a-annexin V and sVEGF-R1 concentrations were assessed by ELISA, while lupus anticoagulant was assessed by screening and confirmatory tests. Results A significant association was observed between the number of positive biomarkers and the belonging group ( P antiphospholipid syndrome.

Haemorrhage in the labyrinth caused by anticoagulant therapy: case report

International Nuclear Information System (INIS)

Callonnec, F.; Gerardin, E.; Thiebot, J.; Marie, J.P.; Andrieu Guitrancourt, J.; Marsot-Dupuch, K.

1999-01-01

We report a patient who experienced a severe vertiginous episode with bilateral tinnitus and progressive right-sided hearing loss. She had Marfan's disease and was on anticoagulant treatment. The fluid in the labyrinth gave higher signal than cerebrospinal fluid on T1-weighted images, suggesting haemorrhage. The radiological follow-up is discussed. (orig.)

Portuguese Observational Study of Ischaemic Stroke in Patients Medicated with Non-Vitamin K Antagonist Oral Anticoagulants.

Science.gov (United States)

Beato-Coelho, José; Marto, João Pedro; Alves, José Nuno; Marques-Matos, Cláudia; Calado, Sofia; Araújo, José; Cunha, Luís; Pinho, João; Azevedo, Elsa; Viana-Baptista, Miguel; Sargento-Freitas, João

2018-01-01

Clinical trials and subsequent meta-analyses showed advantages of non-vitamin K antagonists oral anticoagulants (NOACs) over vitamin K antagonists (VKAs) in patients with non-valvular atrial fibrillation. The impact of preadmission anticoagulation in acute ischaemic stroke (AIS) has not been established. To compare functional outcome of patients with AIS with preadmission NOACs vs. VKAs. A retrospective analysis was conducted on consecutive AIS patients under oral anticoagulation (VKAs or NOACs) admitted in 4 Portuguese hospitals within a period of 30 months. Two primary outcomes were defined and compared between VKA and NOAC groups: symptomatic intracerebral hemorrhage transformation (sICH) and modified Rankin Scale (mRS) at 3 months. Four hundred sixty-nine patients were included, of whom 332 (70.8%) were treated with VKA and 137 (29.2%) with NOAC. Patients' median age was 78.0 and 234 (49.9%) were male. NOAC-treated patients had a higher median CHA2DS2-VASc score than those under VKA (5.0 vs. 4.0, p = 0.023). The two primary outcomes showed no statistical differences between the VKAs' group and the NOACs' group (sICH: 5.4 vs. 5.4% [p = 0.911]; mRS at 3 months: 3.0 vs. 3.0 [p = 0.646], respectively). Preadmission anticoagulation with NOACs in AIS has a functional impact similar to that of VKAs. © 2018 S. Karger AG, Basel.

Anticoagulation After Biological Aortic Valve Replacement: Is There An Optimal Regimen?

Science.gov (United States)

Owais, Tamer; Rouman, Mina; Breuer, Martin; Hüter, Lars; Fuchs, Jürgen; Lauer, Bernward; Kuntze, Thomas

2016-03-01

The anticoagulation of biological heart valves remains a 'hot spot' of discussion in various domains due to the risk of developing valve thrombosis and arterial thromboembolism. The situation has always been controversial, especially during the early postoperative phase. The American College of Cardiology/ American Heart Association and European Society of Cardiology guidelines recommend the use of warfarin for the first three months after biological aortic valve replacement (BAVR), although the American College of Chest Physicians guidelines suggest that these recommendations are experience-based and that the risk/benefit is unclear. The aim of the present study was to compare the efficacy of aspirin and warfarin in patients after BAVR. A total of 863 patients who underwent BAVR between 2008 and 2015 was allocated to two groups. Each group was managed with a specific anticoagulation regimen, with 430 patients receiving warfarin during the first three postoperative months, and 433 receiving aspirin. The major study end points were bleeding, cerebral ischemic events, and survival. In total, 10 and 15 postoperative cerebral ischemic events occurred between 24 h and three months after surgery in patients treated with aspirin and warfarin, respectively. After three months the incidence of cerebral ischemic events did not differ greatly between the two groups. The rate of major bleeding events and rates of stroke-free survival and overall survival were not statistically significant between the warfarin and aspirin groups. Plasma anticoagulation with warfarin during the early postoperative phase was shown statistically to be inferior to platelet aggregation inhibition by aspirin with regards to postoperative bleeding risk, cerebral ischemic events, and survival.

Choosing a particular oral anticoagulant and dose for stroke prevention in individual patients with non-valvular atrial fibrillation: part 1

NARCIS (Netherlands)

Diener, H.C.; Aisenberg, J.; Ansell, J.; Atar, D.; Breithardt, G.; Eikelboom, J.; Ezekowitz, M.D.; Granger, C.B.; Halperin, J.L.; Hohnloser, S.H.; Hylek, E.M.; Kirchhof, P.; Lane, D.A.; Verheugt, F.W.A.; Veltkamp, R.; Lip, G.Y.

2017-01-01

Patients with atrial fibrillation (AF) have a high risk of stroke and mortality, which can be considerably reduced by oral anticoagulants (OAC). Recently, four non-vitamin-K oral anticoagulants (NOACs) were compared with warfarin in large randomized trials for the prevention of stroke and systemic

Screening computer-assisted dosage programs for anticoagulation with warfarin and other vitamin K antagonists: minimum safety requirements for individual programs

DEFF Research Database (Denmark)

Poller, L; Roberts, C; Ibrahim, S

2009-01-01

Based on the results of the previous European Action on Anticoagulation (EAA) multicenter study, a simplified minimum procedure is described for screening the safety and effectiveness of marketed programs for dosage of oral anticoagulant drugs (vitamin K antagonists). The aim was to demonstrate non...

Outer Membrane Protein 25 of Brucella Activates Mitogen-Activated Protein Kinase Signal Pathway in Human Trophoblast Cells

Directory of Open Access Journals (Sweden)

Jing Zhang

2017-12-01

Full Text Available Outer membrane protein 25 (OMP25, a virulence factor from Brucella, plays an important role in maintaining the structural stability of Brucella. Mitogen-activated protein kinase (MAPK signal pathway widely exists in eukaryotic cells. In this study, human trophoblast cell line HPT-8 and BALB/c mice were infected with Brucella abortus 2308 strain (S2308 and 2308ΔOmp25 mutant strain. The expression of cytokines and activation of MAPK signal pathway were detected. We found that the expressions of tumor necrosis factor-α, interleukin-1, and interleukin-10 (IL-10 were increased in HPT-8 cells infected with S2308 and 2308ΔOmp25 mutant. S2308 also activated p38 phosphorylation protein, extracellular-regulated protein kinases (ERK, and Jun-N-terminal kinase (JNK from MAPK signal pathway. 2308ΔOmp25 could not activate p38, ERK, and JNK branches. Immunohistochemistry experiments showed that S2308 was able to activate phosphorylation of p38 and ERK in BABL/c mice. However, 2308ΔOmp25 could weakly activate phosphorylation of p38 and ERK. These results suggest that Omp25 played an important role in the process of Brucella activation of the MAPK signal pathway.

Dietary protein considerations to support active aging.

Science.gov (United States)

Wall, Benjamin T; Cermak, Naomi M; van Loon, Luc J C

2014-11-01

Given our rapidly aging world-wide population, the loss of skeletal muscle mass with healthy aging (sarcopenia) represents an important societal and public health concern. Maintaining or adopting an active lifestyle alleviates age-related muscle loss to a certain extent. Over time, even small losses of muscle tissue can hinder the ability to maintain an active lifestyle and, as such, contribute to the development of frailty and metabolic disease. Considerable research focus has addressed the application of dietary protein supplementation to support exercise-induced gains in muscle mass in younger individuals. In contrast, the role of dietary protein in supporting the maintenance (or gain) of skeletal muscle mass in active older persons has received less attention. Older individuals display a blunted muscle protein synthetic response to dietary protein ingestion. However, this reduced anabolic response can largely be overcome when physical activity is performed in close temporal proximity to protein consumption. Moreover, recent evidence has helped elucidate the optimal type and amount of dietary protein that should be ingested by the older adult throughout the day in order to maximize the skeletal muscle adaptive response to physical activity. Evidence demonstrates that when these principles are adhered to, muscle maintenance or hypertrophy over prolonged periods can be further augmented in active older persons. The present review outlines the current understanding of the role that dietary protein occupies in the lifestyle of active older adults as a means to increase skeletal muscle mass, strength and function, and thus support healthier aging.

Conservatively managed pineal apoplexy in an anticoagulated patient

International Nuclear Information System (INIS)

Werder, Gabriel M.; Razdan, Rahul S.; Gagliardi, Joseph A.; Chaddha, Shashi K.B.

2008-01-01

We present a case of pineal apoplexy in an anticoagulated and hypertensive 56-year-old Hispanic male. At presentation, the patient's international normalized ratio (INR) was 10.51 and his blood pressure was 200/130 mmHg. His presenting symptoms included acute onset of headache, chest pain, nausea, vomiting, vertigo, and visual disturbance. Neuroimaging demonstrated hemorrhage into a morphologically normal pineal gland. Under conservative management, the patient experienced gradual resolution of all symptoms excluding the disturbance of upward gaze

Economic evaluation of the new oral anticoagulants for the prevention of thromboembolic events: a cost-minimization analysis

Directory of Open Access Journals (Sweden)

Milena Soriano Marcolino

Full Text Available ABSTRACT CONTEXT AND OBJECTIVE: Randomized clinical trials have shown that the new oral anticoagulants have at least similar impact regarding reduction of thromboembolic events, compared with warfarin, with similar or improved safety profiles. There is little data on real costs within clinical practice. Our aim here was to perform economic analysis on these strategies from the perspective of Brazilian society and the public healthcare system. DESIGN AND SETTING: Cost-minimization analysis; anticoagulation clinic of Hospital Municipal Odilon Behrens, Belo Horizonte, MG, Brazil. METHODS: Patients at the anticoagulation clinic were recruited between August and October 2011, with minimum follow-up of four weeks. Operational and non-operational costs were calculated and corrected to 2015. RESULTS: This study included 633 patients (59% women of median age 62 years (interquartile range 49-73. The mean length of follow-up was 64 ± 28 days. The average cost per patient per month was $ 54.26 (US dollars. Direct costs accounted for 32.5% of the total cost. Of these, 69.5% were related to healthcare professionals. With regards to indirect costs, 52.4% were related to absence from work and 47.6% to transportation. Apixaban, dabigatran and rivaroxaban were being sold to Brazilian public institutions, on average, for $ 49.87, $ 51.40 and $ 52.16 per patient per month, respectively, which was lower than the costs relating to warfarin treatment. CONCLUSION: In the Brazilian context, from the perspective of society and the public healthcare system, the cumulative costs per patient using warfarin with follow-up in anticoagulation clinics is currently higher than the strategy of prescribing the new oral anticoagulants.

Traumatic events involving elderly patients treated with anticoagulants for atrial fibrillation: the downside of stroke prevention

Directory of Open Access Journals (Sweden)

Alessandro Riccardi

2016-08-01

Full Text Available A group of oral anticoagulant-treated patients affected by permanent atrial fibrillation was evaluated after their access to the emergency room as a result of a traumatic accident. In these patients, the re-evaluation of their risk of thromboembolism and bleeding was performed together with the evaluation of their risk of falling and institutionalization. Results show that the emergency department identifies a cohort of very elderly frail patients, who should be carefully reconsidered for anticoagulant therapy after a traumatic event.

3K3A-activated protein C stimulates postischemic neuronal repair by human neural stem cells in mice

DEFF Research Database (Denmark)

Wang, Yaoming; Zhao, Zhen; Rege, Sanket V

2016-01-01

-APC (Lys191-193Ala) mutant in which three Lys residues (KKK191-193) were replaced with alanine, and/or its other mutants with reduced (>90%) anticoagulant activity, engineered to reduce APC-associated bleeding risk while retaining normal cell-signaling activity, have shown benefits in preclinical models...... of ischemic stroke, brain trauma, multiple sclerosis, amyotrophic lateral sclerosis, sepsis, ischemic and reperfusion injury of heart, kidney and liver, pulmonary, kidney and gastrointestinal inflammation, diabetes and lethal body radiation. On the basis of proof-of-concept studies and an excellent safety...

Aspirin or anticoagulants for treating recurrent miscarriage in women without antiphospholipid syndrome

NARCIS (Netherlands)

Kaandorp, Stef; Di Nisio, Marcello; Goddijn, Mariette; Middeldorp, Saskia

2009-01-01

Background Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the live-birth rate in subsequent pregnancies in women with either inherited thrombophilia or unexplained recurrent miscarriage. Objectives To evaluate the efficacy and safety

Cellular reprogramming through mitogen-activated protein kinases

Directory of Open Access Journals (Sweden)

Justin eLee

2015-10-01

Full Text Available Mitogen-activated protein kinase (MAPK cascades are conserved eukaryote signaling modules where MAPKs, as the final kinases in the cascade, phosphorylate protein substrates to regulate cellular processes. While some progress in the identification of MAPK substrates has been made in plants, the knowledge on the spectrum of substrates and their mechanistic action is still fragmentary. In this focused review, we discuss the biological implications of the data in our original paper (Sustained mitogen-activated protein kinase activation reprograms defense metabolism and phosphoprotein profile in Arabidopsis thaliana; Frontiers in Plant Science 5: 554 in the context of related research. In our work, we mimicked in vivo activation of two stress-activated MAPKs, MPK3 and MPK6, through transgenic manipulation of Arabidopsis thaliana and used phosphoproteomics analysis to identify potential novel MAPK substrates. Here, we plotted the identified putative MAPK substrates (and downstream phosphoproteins as a global protein clustering network. Based on a highly stringent selection confidence level, the core networks highlighted a MAPK-induced cellular reprogramming at multiple levels of gene and protein expression – including transcriptional, post-transcriptional, translational, post-translational (such as protein modification, folding and degradation steps, and also protein re-compartmentalization. Additionally, the increase in putative substrates/phosphoproteins of energy metabolism and various secondary metabolite biosynthesis pathways coincides with the observed accumulation of defense antimicrobial substances as detected by metabolome analysis. Furthermore, detection of protein networks in phospholipid or redox elements suggests activation of downstream signaling events. Taken in context with other studies, MAPKs are key regulators that reprogram cellular events to orchestrate defense signaling in eukaryotes.

New oral anticoagulant and antiplatelet agents for neurosurgeons.

Science.gov (United States)

Kimpton, George; Dabbous, Bassam; Leach, Paul

2015-01-01

Until recently, warfarin, clopidogrel and aspirin have provided the mainstay for prevention of thrombotic disease in cardiac patients. However, new classes of drugs have recently emerged that promise better clinical outcomes and lower risks. Use of such agents has increased, but increased risk and severity of intra-cranial haemorrhage (ICH) still remain. These cases of intra-cranial bleeds present as emergencies to neurosurgical units. It is of paramount importance that neurosurgical practitioners are aware of those new drugs, useful monitoring tests and available emergency reversal options in case the patient needs emergency intervention. In this review we survey newly available agents in the U.K. at the time of publication. We look at the data provided by the manufacturers, related publications and international guidelines for their use and reversal. New anticoagulants offer a lower incidence of ICH compared with warfarin. Advanced and accurate monitoring tests are emerging, as are prospective data on reversal of anticoagulation in bleeding. Some standard coagulation tests may be of use, whilst reversal agents are available and being evaluated. The trial data shows that new antiplatelet agents have similar or increased incidence and severity of intra-cranial ICH compared with clopidogrel. There is currently limited data on monitoring or reversal. We suggest they may be managed similarly to clopidogrel by using platelet reactivity assays, optimising platelet count and using platelet transfusion with adjunctive agents.

Early Recurrence and Cerebral Bleeding in Patients With Acute Ischemic Stroke and Atrial Fibrillation: Effect of Anticoagulation and Its Timing: The RAF Study.

Science.gov (United States)

Paciaroni, Maurizio; Agnelli, Giancarlo; Falocci, Nicola; Caso, Valeria; Becattini, Cecilia; Marcheselli, Simona; Rueckert, Christina; Pezzini, Alessandro; Poli, Loris; Padovani, Alessandro; Csiba, Laszló; Szabó, Lilla; Sohn, Sung-Il; Tassinari, Tiziana; Abdul-Rahim, Azmil H; Michel, Patrik; Cordier, Maria; Vanacker, Peter; Remillard, Suzette; Alberti, Andrea; Venti, Michele; Scoditti, Umberto; Denti, Licia; Orlandi, Giovanni; Chiti, Alberto; Gialdini, Gino; Bovi, Paolo; Carletti, Monica; Rigatelli, Alberto; Putaala, Jukka; Tatlisumak, Turgut; Masotti, Luca; Lorenzini, Gianni; Tassi, Rossana; Guideri, Francesca; Martini, Giuseppe; Tsivgoulis, Georgios; Vadikolias, Kostantinos; Liantinioti, Chrissoula; Corea, Francesco; Del Sette, Massimo; Ageno, Walter; De Lodovici, Maria Luisa; Bono, Giorgio; Baldi, Antonio; D'Anna, Sebastiano; Sacco, Simona; Carolei, Antonio; Tiseo, Cindy; Acciarresi, Monica; D'Amore, Cataldo; Imberti, Davide; Zabzuni, Dorjan; Doronin, Boris; Volodina, Vera; Consoli, Domenico; Galati, Franco; Pieroni, Alessio; Toni, Danilo; Monaco, Serena; Baronello, Mario Maimone; Barlinn, Kristian; Pallesen, Lars-Peder; Kepplinger, Jessica; Bodechtel, Ulf; Gerber, Johannes; Deleu, Dirk; Melikyan, Gayane; Ibrahim, Faisal; Akhtar, Naveed; Mosconi, Maria Giulia; Bubba, Valentina; Silvestri, Ilenia; Lees, Kennedy R

2015-08-01

The best time for administering anticoagulation therapy in acute cardioembolic stroke remains unclear. This prospective cohort study of patients with acute stroke and atrial fibrillation, evaluated (1) the risk of recurrent ischemic event and severe bleeding; (2) the risk factors for recurrence and bleeding; and (3) the risks of recurrence and bleeding associated with anticoagulant therapy and its starting time after the acute stroke. The primary outcome of this multicenter study was the composite of stroke, transient ischemic attack, symptomatic systemic embolism, symptomatic cerebral bleeding and major extracranial bleeding within 90 days from acute stroke. Of the 1029 patients enrolled, 123 had 128 events (12.6%): 77 (7.6%) ischemic stroke or transient ischemic attack or systemic embolism, 37 (3.6%) symptomatic cerebral bleeding, and 14 (1.4%) major extracranial bleeding. At 90 days, 50% of the patients were either deceased or disabled (modified Rankin score ≥3), and 10.9% were deceased. High CHA2DS2-VASc score, high National Institutes of Health Stroke Scale, large ischemic lesion and type of anticoagulant were predictive factors for primary study outcome. At adjusted Cox regression analysis, initiating anticoagulants 4 to 14 days from stroke onset was associated with a significant reduction in primary study outcome, compared with initiating treatment before 4 or after 14 days: hazard ratio 0.53 (95% confidence interval 0.30-0.93). About 7% of the patients treated with oral anticoagulants alone had an outcome event compared with 16.8% and 12.3% of the patients treated with low molecular weight heparins alone or followed by oral anticoagulants, respectively (P=0.003). Acute stroke in atrial fibrillation patients is associated with high rates of ischemic recurrence and major bleeding at 90 days. This study has observed that high CHA2DS2-VASc score, high National Institutes of Health Stroke Scale, large ischemic lesions, and type of anticoagulant administered

Influence of the physicochemical and aromatic properties on the chemical reactivity and its relation with carcinogenic and anticoagulant effect of 17β-aminoestrogens

Energy Technology Data Exchange (ETDEWEB)

Soriano-Correa, Catalina, E-mail: socc@puma2.zaragoza.unam.mx [Química Computacional, FES-Zaragoza, Universidad Nacional Autónoma de México (UNAM), Iztapalapa, Mexico City (Mexico); Raya, Angélica [Unidad Profesional Interdisciplinaria de Ingeniería Campus Guanajuato, Instituto Politécnico Nacional (IPN), Silao de la Victoria, Guanajuato (Mexico); Barrientos-Salcedo, Carolina [Laboratorio de Química Médica y Quimiogenómica, Facultad de Bioanálisis Campus Veracruz - Boca del Río, Universidad Veracruzana, Veracruz (Mexico); Esquivel, Rodolfo O. [Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa (UAM-Iztapalapa), Mexico City (Mexico)

2014-06-25

Highlights: • The aromatic A-ring of 17β-aminoestrogens contribute to its anticoagulant effect. • The electron-donor substituent groups favored the basicity of 17β-aminoestrogens. • The physicochemical properties are important in the carcinogenic effect of anticoagulant molecules. - Abstract: Activity of steroid hormones is dependent upon a number of factors, as solubility, transport and metabolism. The functional differences caused by structural modifications could exert an influence on the chemical reactivity and biological effect. The goal of this work is to study the influence of the physicochemical and aromatic properties on the chemical reactivity and its relation with the carcinogenic risk that can associate with the anticoagulant effect of 17β-aminoestrogens using quantum-chemical descriptors at the DFT-B3LYP, BH and HLYP and M06-2X levels. The relative acidity of (H1) of the hydroxyl group increases with electron-withdrawing groups. Electron-donor groups favor the basicity. The steric hindrance of the substituents decreases the aromatic character and consequently diminution the carcinogenic effect. Density descriptors: hardness, electrophilic index, atomic charges, molecular orbitals, electrostatic potential and their geometric parameters permit analyses of the chemical reactivity and physicochemical features and to identify some reactive sites of 17β-aminoestrogens.

Preventive Strategies against Bleeding due to Nonvitamin K Antagonist Oral Anticoagulants

Directory of Open Access Journals (Sweden)

Lessire Sarah

2014-01-01

Full Text Available Dabigatran etexilate (DE, rivaroxaban, and apixaban are nonvitamin K antagonist oral anticoagulants (NOACs that have been compared in clinical trials with existing anticoagulants (warfarin and enoxaparin in several indications for the prevention and treatment of thrombotic events. All NOACs presented bleeding events despite a careful selection and control of patients. Compared with warfarin, NOACs had a decreased risk of intracranial hemorrhage, and apixaban and DE (110 mg BID had a decreased risk of major bleeding from any site. Rivaroxaban and DE showed an increased risk of major gastrointestinal bleeding compared with warfarin. Developing strategies to minimize the risk of bleeding is essential, as major bleedings are reported in clinical practice and specific antidotes are currently not available. In this paper, the following preventive approaches are reviewed: improvement of appropriate prescription, identification of modifiable bleeding risk factors, tailoring NOAC’s dose, dealing with a missed dose as well as adhesion to switching, bridging and anesthetic procedures.

Self-management of oral anticoagulant therapy for mechanical heart valve patients

DEFF Research Database (Denmark)

Christensen, Thomas D; Attermann, Jørn; Pilegaard, Hans K

2001-01-01

.4%–2.9%) for the control group. Conclusion: Self-management of OAT is a feasible and safe concept for selected patients with mechanical heart valve prostheses also on a long-term basis. It provides at least as good and most likely better quality of anticoagulant therapy than conventional management assessed by time within......Objective: Self-management of oral anticoagulant therapy (OAT) has shown good results on a short-term basis. We hypothesize that self-management of OAT provides a better quality of treatment than conventional management also on a long-term basis. The aim of this study was to assess the quality...... of conventionally managed heart valve patients (control group) was used as reference. Results: The median observation time was 1175 days (range: 174–1428 days). The self-managed patients were within therapeutic INR target range for a mean of 78.0% (range: 36.1%–93.9%) of the time compared with 61.0% (range 37...

Guideline-related barriers to optimal prescription of oral anticoagulants in primary care

NARCIS (Netherlands)

Beukenhorst, A. L.; Arts, D. L.; Lucassen, W.; Jager, K. J.; van der Veer, S. N.

2016-01-01

Guidelines provide recommendations for antithrombotic treatment to prevent stroke in people with atrial fibrillation, but oral anticoagulant prescriptions in Dutch primary care are often discordant with these recommendations. Suboptimal guideline features (i.e. format and content) have been

Risk of upper and lower gastrointestinal bleeding in patients taking nonsteroidal anti-inflammatory drugs, antiplatelet agents, or anticoagulants.

Science.gov (United States)

Lanas, Ángel; Carrera-Lasfuentes, Patricia; Arguedas, Yolanda; García, Santiago; Bujanda, Luis; Calvet, Xavier; Ponce, Julio; Perez-Aísa, Ángeles; Castro, Manuel; Muñoz, Maria; Sostres, Carlos; García-Rodríguez, Luis A

2015-05-01

Treatment with nonsteroidal anti-inflammatory drugs (NSAIDs) or low-dose aspirin is associated with increased risk of upper gastrointestinal bleeding. There is little evidence on the risk of lower gastrointestinal bleeding with NSAIDs, antiplatelet agents (APAs), or anticoagulants. We aimed to quantify the relative risk (RR) of upper and lower gastrointestinal bleeding associated with use of NSAIDs, APAs, or anticoagulants. We performed a case-control study that used data collected from consecutive patients hospitalized for gastrointestinal bleeding (563 upper, mean age, 63.6 ± 16.7 years and 415 lower, mean age, 70.8 ± 13.8 years), confirmed by endoscopy or other diagnostic procedures. Unhospitalized patients were used as controls (n = 1008) and matched for age, hospital, and month of admission. Drug use was considered current when taken within 7 days or less before hospitalization. RRs and 95% confidence intervals (CIs) were estimated by unconditional logistic regression analysis. Use of anticoagulants, low-dose aspirin, and other drugs (non-aspirin-APA, 82.3% thienopiridines) was associated with upper and lower gastrointestinal bleeding; the risk was 2-fold higher for anticoagulants (RR, 4.2; 95% CI, 2.9-6.2) than for low-dose aspirin (RR, 2.1; 95% CI, 1.4-3.3) or other non-aspirin-APA drugs (RR, 2.0; 95% CI, 1.6-2.6). NSAID use was also associated with increased risk of gastrointestinal bleeding and greater for upper (RR, 2.6; 95% CI, 2.0-3.5) than lower gastrointestinal bleeding (RR, 1.4; 95% CI, 1.0-1.9). Use of proton pump inhibitors was associated with reduced risk of upper, but not lower, gastrointestinal bleeding. Anticoagulants, low-dose aspirin, NSAIDs, and other non-aspirin-APA drugs are associated with increased risk of upper and lower gastrointestinal bleeding. Use of anticoagulants appears to be the strongest risk factor for gastrointestinal bleeding. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

Haemorrhage in the labyrinth caused by anticoagulant therapy: case report

Energy Technology Data Exchange (ETDEWEB)

Callonnec, F; Gerardin, E; Thiebot, J [Department of Radiology, Rouen University Hospital, 1 rue de Germont, F-76031 Rouen cedex (France); Marie, J P; Andrieu Guitrancourt, J [Department of Otolaryngology, Rouen University Hospital (France); Marsot-Dupuch, K [Department of Radiology, St. Antoine, Paris University Hospital (France)

1999-06-01

We report a patient who experienced a severe vertiginous episode with bilateral tinnitus and progressive right-sided hearing loss. She had Marfan`s disease and was on anticoagulant treatment. The fluid in the labyrinth gave higher signal than cerebrospinal fluid on T1-weighted images, suggesting haemorrhage. The radiological follow-up is discussed. (orig.) With 2 figs., 11 refs.

Impact of CHA2DS2VASc Score on Candidacy for Anticoagulation in Patients With Atrial Fibrillation: A Multi-payer Analysis.

Science.gov (United States)

Patel, Aarti A; Nelson, Winnie W; Schein, Jeff

2016-10-01

The purpose of this study is to report on the effect of using CHA 2 DS 2 VASc (congestive heart failure, hypertension, age ≥75 years [doubled], type 1 or type 2 diabetes mellitus, stroke or transient ischemic attack or thromboembolism [doubled], vascular disease [prior myocardial infarction, peripheral artery disease, or aortic plaque], age 65-75 years, sex category [female]) rather than CHADS 2 (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke) to determine candidacy for anticoagulant prophylaxis in insured patients with atrial fibrillation (AF). Six administrative claims databases that included medical and pharmacy claims for patients aged ≥18 years with a new or existing diagnosis of AF and patient outcomes assessed for 1 year after diagnosis were analyzed. Retrospective health plan data analyses were performed using a software tool (Anticoagulant Quality Improvement Analyzer). Study measures included stroke risk (identified by CHADS 2 and CHA 2 DS 2 VASc scores), bleeding risk (identified by the Anticoagulation and Risk Factors in Atrial Fibrillation score), and anticoagulant use. A total of 115,906 patients with AF (range of mean ages among the 6 databases, 56-79 years) met the inclusion criteria. All ranges reported represent the minimum and maximum values among the 6 databases. Using the CHA 2 DS 2 VASc compared with the CHADS 2 index to assess stroke risk resulted in a 23% to 32% increase in patients considered potential candidates for anticoagulant prophylaxis. This translated to a 38% to 114% increase in the number of ostensibly undertreated patients. Among patients with high stroke and low bleeding risk, 18% to 28% more patients were considered potential candidates for anticoagulation treatment using CHA 2 DS 2 VASc compared with CHADS 2 , or a 57% to 151% increase in the number of undertreated patients. Use of the CHA 2 DS 2 VASc score to determine the risk of stroke increased the number of AF patients for

Restarting Anticoagulant Treatment After Intracranial Hemorrhage in Patients With Atrial Fibrillation and the Impact on Recurrent Stroke, Mortality, and Bleeding: A Nationwide Cohort Study.

Science.gov (United States)

Nielsen, Peter Brønnum; Larsen, Torben Bjerregaard; Skjøth, Flemming; Gorst-Rasmussen, Anders; Rasmussen, Lars Hvilsted; Lip, Gregory Y H

2015-08-11

Intracranial hemorrhage is the most feared complication of oral anticoagulant treatment. The optimal treatment option for patients with atrial fibrillation who survive an intracranial hemorrhage remains unknown. We hypothesized that restarting oral anticoagulant treatment was associated with a lower risk of stroke and mortality in comparison with not restarting. Linkage of 3 Danish nationwide registries in the period between 1997 and 2013 identified patients with atrial fibrillation on oral anticoagulant treatment with incident intracranial hemorrhage. Patients were stratified by treatment regimens (no treatment, oral anticoagulant treatment, or antiplatelet therapy) after the intracranial hemorrhage. Event rates were assessed 6 weeks after hospital discharge and compared with Cox proportional hazard models. In 1752 patients (1 year of follow-up), the rate of ischemic stroke/systemic embolism and all-cause mortality (per 100 person-years) for patients treated with oral anticoagulants was 13.6, in comparison with 27.3 for nontreated patients and 25.7 for patients receiving antiplatelet therapy. The rate of ischemic stroke/systemic embolism and all-cause mortality (per 100 person-years) for recurrent intracranial hemorrhage, the rate of ischemic stroke/systemic embolism, and all-cause mortality (per 100 person-years) patients treated with oral anticoagulants was 8.0, in comparison with 8.6 for nontreated patients and 5.3 for patients receiving antiplatelet therapy. The adjusted hazard ratio of ischemic stroke/systemic embolism and all-cause mortality was 0.55 (95% confidence interval, 0.39-0.78) in patients on oral anticoagulant treatment in comparison with no treatment. For ischemic stroke/systemic embolism and for all-cause mortality, hazard ratios were 0.59 (95% confidence interval, 0.33-1.03) and 0.55 (95% confidence interval, 0.37-0.82), respectively. Oral anticoagulant treatment was associated with a significant reduction in ischemic stroke/all-cause mortality

Conservatively managed pineal apoplexy in an anticoagulated patient

Energy Technology Data Exchange (ETDEWEB)

Werder, Gabriel M. [William Beaumont Hospital, Department of Radiology, 3600 West Thirteen Mile Road, Royal Oak, MI 48073 (United States); St Christopher Iba Mar Diop College of Medicine, Luton (United Kingdom)], E-mail: gabriel_werder@yahoo.com; Razdan, Rahul S.; Gagliardi, Joseph A.; Chaddha, Shashi K.B. [St Vincent' s Medical Center, Bridgeport, CT (United States)

2008-02-15

We present a case of pineal apoplexy in an anticoagulated and hypertensive 56-year-old Hispanic male. At presentation, the patient's international normalized ratio (INR) was 10.51 and his blood pressure was 200/130 mmHg. His presenting symptoms included acute onset of headache, chest pain, nausea, vomiting, vertigo, and visual disturbance. Neuroimaging demonstrated hemorrhage into a morphologically normal pineal gland. Under conservative management, the patient experienced gradual resolution of all symptoms excluding the disturbance of upward gaze.

Recent developments in the use of oral anticoagulants

DEFF Research Database (Denmark)

Lassen, Michael R

2009-01-01

, such as their subcutaneous route of administration or the need for coagulation monitoring. Research was challenged to develop new drugs that would simplify thromboprophylaxis while showing equivalent or better efficacy. Rivaroxaban and dabigatran are now available in some countries for the prevention of venous......For many years, vitamin K antagonists, unfractionated heparins, low-molecular-weight heparins and a pentasaccharide were the only anticoagulant drugs available for the prevention of venous thromboembolism after surgery. However, their benefits were associated with disadvantages...

Protein C and antithrombin levels in patients with sickle cell anemia ...

African Journals Online (AJOL)

Background: Alterations in the components of hemostasis, namely platelet function, the procoagulant, anticoagulant, and the fibrinolytic systems, are observed in sickle cell anemia (SCA) and are in favor of a procoagulant phenotype. Therefore, study of protein C and antithrombin (AT) levels in patients with SCA in steady ...

Anticoagulant therapy for venous thromboembolism detected by Doppler ultrasound in patients with metastatic colorectal cancer receiving bevacizumab

Directory of Open Access Journals (Sweden)

Suenaga M

2015-01-01

Full Text Available Mitsukuni Suenaga, Nobuyuki Mizunuma, Eiji Shinozaki, Satoshi Matsusaka, Masato Ozaka, Mariko Ogura, Keisho Chin, Toshiharu Yamaguchi Department of Gastroenterology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan Background: Doppler ultrasound imaging is useful for management of venous thromboembolism associated with a subclavicular implantable central venous access system in patients receiving bevacizumab (Bev. We investigated the efficacy and safety of our anticoagulant regimen based on Doppler findings.Methods: Patients aged ≤75 years with metastatic colorectal cancer, no history of thromboembolism, and no prior use of Bev received chemotherapy plus Bev. Doppler ultrasound imaging of the deep venous system to detect thrombosis was performed after the first course of Bev and repeated after the third course in patients with asymptomatic thrombosis. Indications for anticoagulant therapy in patients with asymptomatic thrombosis were as follows: enlarging thrombus (E, thrombus >40 mm in diameter (S, thrombus involving the superior vena cava (C, and decreased blood flow (V.Results: Among 79 patients enrolled in this study, asymptomatic thrombosis was detected in 56 patients (70.9% by Doppler ultrasound imaging after the first course of Bev and there was no thrombus in 23 patients (29.1%. Of these 56 patients, 11 (19.6% received anticoagulant therapy with warfarin, including eight after the first course and three after follow-up imaging. S + V was observed in four of 11 patients (36.4%, as well as V in two (18.2%, S + V + C in one (9.1%, E + S + V in one (9.1%, E + C in one (9.1%, E in one (9.1%, and C in one (9.1%. All patients resumed chemotherapy, including seven who resumed Bev. Improvement or stabilization of thrombi was achieved in ten patients (90.9%. Only one patient had symptomatic thromboembolism. Mild bleeding due to anticoagulant therapy occurred in six patients (54.5%, but there were no treatment

Limited evidence on persistence with anticoagulants, and its effect on the risk of recurrence of venous thromboembolism: a systematic review of observational studies

Directory of Open Access Journals (Sweden)

Vora P

2016-08-01

Full Text Available Pareen Vora, Montse Soriano-Gabarró, Kiliana Suzart, Gunnar Persson Brobert Department of Epidemiology, Bayer Pharma AG, Berlin, Germany Purpose: The risk of venous thromboembolism (VTE recurrence is high following an initial VTE event, and it persists over time. This recurrence risk decreases rapidly after starting with anticoagulation treatment and reduces by ~80%–90% with prolonged anticoagulation. Nonpersistence with anticoagulants could lead to increased risk of VTE recurrence. This systematic review aimed to estimate persistence at 3, 6, and 12 months with anticoagulants in patients with VTE, and to evaluate the risk of VTE recurrence in nonpersistent patients.Methods: PubMed and Embase® were searched up to May 3, 2014 and the search results updated to May 31, 2015. Studies involving patients with VTE aged ≥18 years, treatment with anticoagulants intended for at least 3 months or more, and reporting data for persistence were included. Proportions were transformed using Freeman–Tukey double arcsine transformation and pooled using the DerSimonian–Laird random-effects approach.Results: In total, 12 observational studies (7/12 conference abstracts were included in the review. All 12 studies either reported or provided data for persistence. The total number of patients meta-analyzed to estimate persistence at 3, 6, and 12 months was 71,969 patients, 58,940 patients, and 68,235 patients, respectively. The estimated persistence for 3, 6, and 12 months of therapy was 83% (95% confidence interval [CI], 78–87; I2=99.3%, 62% (95% CI, 58–66; I2=98.1%, and 31% (95% CI, 22–40; I2=99.8%, respectively. Only two studies reported the risk of VTE recurrence based on nonpersistence – one at 3 months and the other at 12 months.Conclusion: Limited evidence showed that persistence was suboptimal with an estimated 17% patients being nonpersistent with anticoagulants in the crucial first 3 months. Persistence declined over 6 and 12 months

Determinants of the over-anticoagulation response during warfarin initiation therapy in Asian patients based on population pharmacokinetic-pharmacodynamic analyses.

Science.gov (United States)

Ohara, Minami; Takahashi, Harumi; Lee, Ming Ta Michael; Wen, Ming-Shien; Lee, Tsong-Hai; Chuang, Hui-Ping; Luo, Chen-Hui; Arima, Aki; Onozuka, Akiko; Nagai, Rui; Shiomi, Mari; Mihara, Kiyoshi; Morita, Takashi; Chen, Yuan-Tsong

2014-01-01

To clarify pharmacokinetic-pharmacodynamic (PK-PD) factors associated with the over-anticoagulation response in Asians during warfarin induction therapy, population PK-PD analyses were conducted in an attempt to predict the time-courses of the plasma S-warfarin concentration, Cp(S), and coagulation and anti-coagulation (INR) responses. In 99 Chinese patients we analyzed the relationships between dose and Cp(S) to estimate the clearance of S-warfarin, CL(S), and that between Cp(S) and the normal prothrombin concentration (NPT) as a coagulation marker for estimation of IC50. We also analyzed the non-linear relationship between NPT inhibition and the increase in INR to derive the non-linear index λ. Population analyses accurately predicted the time-courses of Cp(S), NPT and INR. Multivariate analysis showed that CYP2C9*3 mutation and body surface area were predictors of CL(S), that VKORC1 and CYP4F2 polymorphisms were predictors of IC50, and that baseline NPT was a predictor of λ. CL(S) and λ were significantly lower in patients with INR≥4 than in those with INR<4 (190 mL/h vs 265 mL/h, P<0.01 and 3.2 vs 3.7, P<0.01, respectively). Finally, logistic regression analysis revealed that CL(S), ALT and hypertension contributed significantly to INR≥4. All these results indicate that factors associated with the reduced metabolic activity of warfarin represented by CL(S), might be critical determinants of the over-anticoagulation response during warfarin initiation in Asians. ClinicalTrials.gov NCT02065388.

Determinants of the over-anticoagulation response during warfarin initiation therapy in Asian patients based on population pharmacokinetic-pharmacodynamic analyses.

Directory of Open Access Journals (Sweden)

Minami Ohara

Full Text Available To clarify pharmacokinetic-pharmacodynamic (PK-PD factors associated with the over-anticoagulation response in Asians during warfarin induction therapy, population PK-PD analyses were conducted in an attempt to predict the time-courses of the plasma S-warfarin concentration, Cp(S, and coagulation and anti-coagulation (INR responses. In 99 Chinese patients we analyzed the relationships between dose and Cp(S to estimate the clearance of S-warfarin, CL(S, and that between Cp(S and the normal prothrombin concentration (NPT as a coagulation marker for estimation of IC50. We also analyzed the non-linear relationship between NPT inhibition and the increase in INR to derive the non-linear index λ. Population analyses accurately predicted the time-courses of Cp(S, NPT and INR. Multivariate analysis showed that CYP2C9*3 mutation and body surface area were predictors of CL(S, that VKORC1 and CYP4F2 polymorphisms were predictors of IC50, and that baseline NPT was a predictor of λ. CL(S and λ were significantly lower in patients with INR≥4 than in those with INR<4 (190 mL/h vs 265 mL/h, P<0.01 and 3.2 vs 3.7, P<0.01, respectively. Finally, logistic regression analysis revealed that CL(S, ALT and hypertension contributed significantly to INR≥4. All these results indicate that factors associated with the reduced metabolic activity of warfarin represented by CL(S, might be critical determinants of the over-anticoagulation response during warfarin initiation in Asians.ClinicalTrials.gov NCT02065388.

Recurrent venous thromboembolism and abnormal uterine bleeding with anticoagulant and hormone therapy use.

Science.gov (United States)

Martinelli, Ida; Lensing, Anthonie W A; Middeldorp, Saskia; Levi, Marcel; Beyer-Westendorf, Jan; van Bellen, Bonno; Bounameaux, Henri; Brighton, Timothy A; Cohen, Alexander T; Trajanovic, Mila; Gebel, Martin; Lam, Phuong; Wells, Philip S; Prins, Martin H

2016-03-17

Women receiving vitamin K antagonists (VKAs) require adequate contraception because of the potential for fetal complications. It is unknown whether the use of hormonal therapy, especially those containing estrogens, is associated with recurrent venous thromboembolism (VTE) during anticoagulation. Despite the absence of data, World Health Organization guidelines state that use of estrogen-containing contraceptives confers an "unacceptable health risk" during established anticoagulation for VTE. We compared the incidences of recurrent VTE and abnormal uterine bleeding with and without concomitant hormonal therapy in women aged abnormal uterine bleeding. In total, 1888 women were included. VTE incidence densities on and off hormonal therapy were 3.7%/year and 4.7%/year (adjusted HR, 0.56; 95% confidence interval [CI], 0.23-1.39), respectively, and were 3.7%/year and 3.8%/year, respectively, for estrogen-containing and progestin-only therapy. The adjusted HR for all abnormal uterine bleeding (on vs off hormonal therapy) was 1.02 (95% CI, 0.66-1.57). Abnormal uterine bleeding occurred more frequently with rivaroxaban than with enoxaparin/VKA (HR, 2.13; 95% CI, 1.57-2.89). Hormonal therapy was not associated with an increased risk of recurrent VTE in women receiving therapeutic anticoagulation. The observed increased risk of abnormal uterine bleeding with rivaroxaban needs further exploration. © 2016 by The American Society of Hematology.

A single center retrospective cohort study comparing low-molecular-weight heparins to direct oral anticoagulants for the treatment of venous thromboembolism in patients with cancer - A real world experience.

Science.gov (United States)

Phelps, Megan K; Wiczer, Tracy E; Erdeljac, H Paige; Van Deusen, Kelsey R; Porter, Kyle; Philips, Gary; Wang, Tzu-Fei

2018-01-01

Introduction Low-molecular-weight heparins are the standard treatment for cancer-associated thrombosis. Recently, direct oral anticoagulants are a new option for thrombosis treatment; however, data supporting the use of direct oral anticoagulants for cancer-associated thrombosis are limited. Objectives The primary objective of this study was to determine the rate of recurrent cancer-associated thrombosis and major bleeding within 6 months of starting either low-molecular-weight heparin or direct oral anticoagulant for treatment of cancer-associated thrombosis. Secondary objectives were to determine the rates of clinically relevant-non-major bleeding and all-cause mortality. Patients/methods This is a retrospective cohort study including adults with cancer-associated thrombosis treated with low-molecular-weight heparin or direct oral anticoagulant between 2010 and 2016 at the Ohio State University. Medical records were reviewed for 6 months after initiation of anticoagulation or until the occurrence of recurrent cancer-associated thrombosis, major bleeding, cessation of anticoagulation of interest, or death, whichever occurred first. Results Four hundred and eighty patients were included (290 low-molecular-weight heparin and 190 direct oral anticoagulant). Patients treated with direct oral anticoagulant were found to carry "lower risk" features including cancer with lower VTE risk and lower rate of metastatic disease. After adjustment for baseline differences, there was no significant difference in the rate of recurrent cancer-associated thrombosis (7.2% low-molecular-weight heparin vs 6.3% direct oral anticoagulant, p = 0.71) or major bleeding (7.6% low-molecular-weight heparin vs 2.6% direct oral anticoagulant, p = 0.08). Conclusions Our study demonstrates that in a select population of cancer patients with VTE, direct oral anticoagulant use can be as effective and safe compared to the standard therapy with low-molecular-weight heparin.

Simultaneous antibacterial and anticoagulant properties of polypropylene non-woven textiles Elaboration d'un textile polypropylène non-tissé présentant simultanément des propriétés antibactériennes et anticoagulantes

Directory of Open Access Journals (Sweden)

Jimenez Maude

2013-11-01

Full Text Available The aim of this work was to prepare a non-woven Polypropylene (PP textile functionalized with bioactive molecules to improve simultaneously its anticoagulation and antibacterial properties. The immobilization of either heparin (anticoagulation agent or gentamicin (aminoglycoside antibiotic was already proven to be effective on non-woven PP textiles. This work details how we managed to immobilize both gentamicin and heparin on the textile [1]. The immobilization times were studied in order to determine the best compromise between cytocompatibility, anticoagulant effect and antimicrobial activity. Cetté étude décrit le procédé de fonctionnalisation d'un textile polypropylène (PP non-tissé afin d'améliorer à la fois ses propriétés antibactériennes et anticoagulantes. Dans des précédents travaux, l'immobilisation soit de l'héparine (agent anticoagulant, soit de la gentamicine (agent antibiotique aminoglycoside a déjà été reportée. Des effets respectivement anticoagulants et antibactériens ont été obtenus. Cette étude décrit la faç on d'immobiliser ces deux principes actifs sur un même textile. L'effet des temps d'imprégnation sur les propriétés antibactériennes et anticoagulantes a été étudié afin d'obtenir le meilleur compromis possible en termes de cytocompatibilité, effet anticoagulant et activité antimicrobienne.

Biochemical and Functional Characterization of Parawixia bistriata Spider Venom with Potential Proteolytic and Larvicidal Activities

Science.gov (United States)

Gimenez, Gizeli S.; Coutinho-Neto, Antonio; Kayano, Anderson M.; Simões-Silva, Rodrigo; Trindade, Frances; de Almeida e Silva, Alexandre; Marcussi, Silvana; da Silva, Saulo L.; Fernandes, Carla F. C.; Zuliani, Juliana P.; Calderon, Leonardo A.; Soares, Andreimar M.; Stábeli, Rodrigo G.

2014-01-01

Toxins purified from the venom of spiders have high potential to be studied pharmacologically and biochemically. These biomolecules may have biotechnological and therapeutic applications. This study aimed to evaluate the protein content of Parawixia bistriata venom and functionally characterize its proteins that have potential for biotechnological applications. The crude venom showed no phospholipase, hemorrhagic, or anti-Leishmania activities attesting to low genotoxicity and discrete antifungal activity for C. albicans. However the following activities were observed: anticoagulation, edema, myotoxicity and proteolysis on casein, azo-collagen, and fibrinogen. The chromatographic and electrophoretic profiles of the proteins revealed a predominance of acidic, neutral, and polar proteins, highlighting the presence of proteins with high molecular masses. Five fractions were collected using cation exchange chromatography, with the P4 fraction standing out as that of the highest purity. All fractions showed proteolytic activity. The crude venom and fractions P1, P2, and P3 showed larvicidal effects on A. aegypti. Fraction P4 showed the presence of a possible metalloprotease (60 kDa) that has high proteolytic activity on azo-collagen and was inhibited by EDTA. The results presented in this study demonstrate the presence of proteins in the venom of P. bistriata with potential for biotechnological applications. PMID:24895632

Current guidelines and prospects for using novel oral anticoagulants for nonvalvular atrial fibrillation

Directory of Open Access Journals (Sweden)

A. V. Fonyakin

2014-01-01

Full Text Available The capabilities of antithrombotic therapy to prevent systemic thromboembolic events in nonvalvular atrial fibrillation (AF are substantially extended after clinically introducing novel oral anticoagulants (NOACs, such as dabigatran, rivaroxaban, and apixaban. World clinical experience with NOACs in AF has confirmed their efficacy and safety in both primary and secondary stroke prevention. At the same time, apixaban additionally reduces the risk of fatal outcomes and it is the safest among the NOACs against hemorrhagic events. The low risks of intracranial hemorrhage typical of NOACs should be taken into account when choosing oral anticoagulant therapy after hemorrhagic stroke in patients athigh risk for thromboembolic events due to AF. Whether NOACs may be used in acute myocardial infarction and during coronary stenting in the presence of nonvalvular AF, left ventricular thromboses, and cardiomyopathies is considered. In real clinical practice, nonvalvular AF may be accompanied by different cardiovascular diseases, by creating the situations where there are no specific guidelines for the use of NOACs. The results of comparing the clinical efficiency of different antithrombotic therapy regimens, the subanalysis of randomized trials, and experts’ opinions may assist a physician to substantiate their decisions. Thus, just a few NOACs that are similar and/or superior to warfarin in efficacy and safety have emerged to date. There are grounds to believe that many physicians will prefer direct anticoagulants to warfarin not only because of their proven efficacy, but also the rapid onset of their anticoagulant effect, neither interaction with a number of foods or drugs, and above all, nor need for regular laboratory blood testing. World post-marketingsurveillance and new clinical tests will be helpful in better estimating the benefits and risks of treatment with NOACs and in expanding indications for their use, which will considerably

Economic evaluation of strategies for restarting anticoagulation therapy after a first event of unprovoked venous thromboembolism.

Science.gov (United States)

Monahan, M; Ensor, J; Moore, D; Fitzmaurice, D; Jowett, S

2017-08-01

Essentials Correct duration of treatment after a first unprovoked venous thromboembolism (VTE) is unknown. We assessed when restarting anticoagulation was worthwhile based on patient risk of recurrent VTE. When the risk over a one-year period is 17.5%, restarting is cost-effective. However, sensitivity analyses indicate large uncertainty in the estimates. Background Following at least 3 months of anticoagulation therapy after a first unprovoked venous thromboembolism (VTE), there is uncertainty about the duration of therapy. Further anticoagulation therapy reduces the risk of having a potentially fatal recurrent VTE but at the expense of a higher risk of bleeding, which can also be fatal. Objective An economic evaluation sought to estimate the long-term cost-effectiveness of using a decision rule for restarting anticoagulation therapy vs. no extension of therapy in patients based on their risk of a further unprovoked VTE. Methods A Markov patient-level simulation model was developed, which adopted a lifetime time horizon with monthly time cycles and was from a UK National Health Service (NHS)/Personal Social Services (PSS) perspective. Results Base-case model results suggest that treating patients with a predicted 1 year VTE risk of 17.5% or higher may be cost-effective if decision makers are willing to pay up to £20 000 per quality adjusted life year (QALY) gained. However, probabilistic sensitivity analysis shows that the model was highly sensitive to overall parameter uncertainty and caution is warranted in selecting the optimal decision rule on cost-effectiveness grounds. Univariate sensitivity analyses indicate variables such as anticoagulation therapy disutility and mortality risks were very influential in driving model results. Conclusion This represents the first economic model to consider the use of a decision rule for restarting therapy for unprovoked VTE patients. Better data are required to predict long-term bleeding risks during therapy in this

Hypercoagulability in end-stage liver disease: prevalence and its correlation with severity of liver disease and portal vein thrombosis.

Science.gov (United States)

Singhal, Ashish; Karachristos, Andreas; Bromberg, Michael; Daly, Ellen; Maloo, Manoj; Jain, Ashok Kumar

2012-11-01

Contrary to well-recognized bleeding diathesis in chronic liver disease, thrombotic events can occur in these patients due to reduction or loss of synthesis of anticoagulant proteins. Forty-seven consecutive patients with end-stage liver disease (ESLD) were investigated for activity of protein C, protein S, antithrombin, and factor V Leiden mutation. Forty-two (89.4%) patients had low levels of at least 1 while 33 (70.2%) patients were deficient for all anticoagulant proteins studied. Forty-six (97.9%) patients were negative for factor V Leiden mutation. The deficiencies were more marked in hepatitis C virus-positive patients and patients with model for end-stage liver disease (MELD) score >15. Six (12.8%) patients had portal vein thrombosis (PVT), and all had diminished protein S activity. In conclusions, deficiency of anticoagulant proteins occur in early phase of chronic liver disease. The severity of deficiency is proportional to the severity of liver disease. Despite the high prevalence of hypercoagulability, the incidence of PVT is low. Further studies with larger cohort of patients are needed to support these conclusions and to study other associated factors.

Simultaneous Determination of 13 Anticoagulant Rodenticidesin Human Blood by Liquid Chromatography-Tandem Mass Spectrometry and its Application in Three Poisoning Cases.

Science.gov (United States)

Qiao, Zheng; Xiang, Ping; Shen, Baohua; Shen, Min; Yan, Hui

2018-05-01

Anticoagulant rodenticides are widely used for rodent control around the world. A rapid and sensitive method was developed and validated for the simultaneous determination of 13 anticoagulant rodenticides (coumafuryl, pindone, valone, warfarin, coumatetralyl, coumachlor, diphacinone, dicumarol, chlorophacinone, bromadiolone, difenacoum, flocoumafen, and brodifacoum) in human blood by liquid chromatography-tandem mass spectrometry. After liquid-liquid extraction, the anticoagulant rodenticides were separated on an Eclipse Plus C18 column. Linearities were observed for each analyte in blood ranging from 0.5 to 50 ng/mL, with correlation coefficients over 0.99. The limits of detection ranged from 0.01 to 0.2 ng/mL, and the limits of quantification were 0.5 ng/mL for all analytes. The intraday and interday precisions were <15%, and accuracies ranged from 80.3% to 111.0%. This validated method with high sensitivity has been applied in three anticoagulant rodenticide poisoning cases and has been used successfully in monitoring blood concentrations for months. © 2017 American Academy of Forensic Sciences.

LPS-Toll-Like Receptor-Mediated Signaling on Expression of Protein S and C4b-Binding Protein in the Liver

Directory of Open Access Journals (Sweden)

Tatsuya Hayashi

2010-01-01

Full Text Available Protein S (PS, mainly synthesized in hepatocytes and endothelial cells, plays a critical role as a cofactor of anticoagulant activated protein C (APC. PS activity is regulated by C4b-binding protein (C4BP, structurally composed of seven α-chains (C4BPα and a β-chain (C4BPβ. In this paper, based primarily on our previous studies, we review the lipopolysaccharide (LPS-induced signaling which affects expression of PS and C4BP in the liver. Our in vivo studies in rats showed that after LPS injection, plasma PS levels are significantly decreased, whereas plasma C4BP levels first are transiently decreased after 2 to 12 hours and then significantly increased after 24 hours. LPS decreases PS antigen and mRNA levels in both hepatocytes and sinusoidal endothelial cells (SECs, and decreases C4BP antigen and both C4BPα and C4BPβ mRNA levels in hepatocytes. Antirat CD14 and antirat Toll-like receptor (TLR-4 antibodies inhibited LPS-induced NFκB activation in both hepatocytes and SECs. Furthermore, inhibitors of NFκB and MEK recovered the LPS-induced decreased expression of PS in both cell types and the LPS-induced decreased expression of C4BP in hepatocytes. These data suggest that the LPS-induced decrease in PS expression in hepatocytes and SECs and LPS-induced decrease in C4BP expression in hepatocytes are mediated by MEK/ERK signaling and NFκB activation and that membrane-bound CD14 and TLR-4 are involved in this mechanism.

Thromboembolic risk in 16 274 atrial fibrillation patients undergoing direct current cardioversion with and without oral anticoagulant therapy

DEFF Research Database (Denmark)

Hansen, Morten Lock; Jepsen, Rikke Malene H G; Olesen, Jonas Bjerring

2015-01-01

-time DC cardioversion for atrial fibrillation between 2000 and 2008. Use of oral anticoagulant therapy within 90 days prior and 360 days after DC cardioversion was obtained from the Danish Register of Medicinal Product Statistics. The risk of thromboembolism was estimated by calculating incidence rates......AIMS: To study the risk of thromboembolism in a nationwide cohort of atrial fibrillation patients undergoing direct current (DC) cardioversion with or without oral anticoagulant coverage. METHODS AND RESULTS: A retrospective study of 16 274 patients in Denmark discharged from hospital after a first...... and by multivariable adjusted Cox proportional-hazard models. During the initial 30 days following discharge, the thromboembolic incidence rate was 10.33 per 100 patient-years for the no prior oral anticoagulant therapy group [n = 5084 (31.2%)], as compared with 4.00 per 100 patient-years for the prior oral...

A dose-response study in animals to evaluate the anticoagulant effect of the stage 2 unfractionated heparin USP monograph change.

Science.gov (United States)

Honchel, R; Carraway, J; Gopee, N; Callicott, R; Chen, J; Patton, R; Xu, Q; Zalkkar, J; Laniyonu, A; Krefting, I; Cato, M; Robie-Suh, K; Rieves, R

2011-08-01

The United States Pharmacopeia (USP) monograph for unfractionated heparin (UFH) was revised in October 2009. This revision was anticipated, based upon in vitro tests, to reduce UFH potency by approximately 10%. To study the potential in vivo consequences of the monograph change, we evaluated activated partial thromboplastin time (aPTT) and activated clotting time (ACT) responses in animals. Female mini-pigs and monkeys (n=8/species) were administered intravenously 60, 54, 48, or 42 U/kg and 50, 45, 40, or 35 U/kg "old" (pre-USP revision) UFH, respectively, in a Williams 4×4 crossover design. Blood samples for aPTT and ACT were collected at 15 min after dosing. The same study design was then repeated using "new" (post-USP revision) UFH. Mean "new" UFH aPTT and ACT values were generally lower than those for "old" UFH although individual animal responses varied considerably. The aPTT and ACT response was generally dose-proportional for both "old" and "new" UFH. These studies indicate that the USP monograph alteration for UFH may result in a modest reduction in the anticoagulant response across a population, but the variability in animal responses underscores the importance of individualization of clinical UFH dosing and the importance of anticoagulant test monitoring. Published by Elsevier Inc.

Gc protein (vitamin D-binding protein): Gc genotyping and GcMAF precursor activity.

Science.gov (United States)

Nagasawa, Hideko; Uto, Yoshihiro; Sasaki, Hideyuki; Okamura, Natsuko; Murakami, Aya; Kubo, Shinichi; Kirk, Kenneth L; Hori, Hitoshi

2005-01-01

The Gc protein (human group-specific component (Gc), a vitamin D-binding protein or Gc globulin), has important physiological functions that include involvement in vitamin D transport and storage, scavenging of extracellular G-actin, enhancement of the chemotactic activity of C5a for neutrophils in inflammation and macrophage activation (mediated by a GalNAc-modified Gc protein (GcMAF)). In this review, the structure and function of the Gc protein is focused on especially with regard to Gc genotyping and GcMAF precursor activity. A discussion of the research strategy "GcMAF as a target for drug discovery" is included, based on our own research.

Self management of oral anticoagulant therapy in children with congenital heart disease

DEFF Research Database (Denmark)

Christensen, Thomas D; Attermann, Jørn; Hjortdal, Vibeke E.

2001-01-01

Objective: The concept of self – management of oral anticoagulation has been shown to entail better quality of treatment than conventional management when assessed in selected adults. We have extended the concept of self – management to include children with congenital cardiac disease......, hypothesizing self-management of oral anticoagulation is also possible in this subset of patients. Our aim was to assess the quality of self-management. Methods: We trained 14 children aged from 2.2 to 15.6 years, with a mean age of 9.7 years, and their parents, in domiciliary analysis of the International...... observed over a mean of 547 days, with a range from 214 to 953 days. The patients were within the therapeutic targetted range of the International Normalized Ratio for a median of 65.5% of the time, with a range from 17.6 % to 90.4 %. None of the patients experienced thromboembolic or bleeding...