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Sample records for anticoagulant activity induced

  1. Anticoagulant-induced pseudothrombocytopenia and pseudoleucocytosis.

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    Schrezenmeier, H; Müller, H; Gunsilius, E; Heimpel, H; Seifried, E

    1995-03-01

    Pseudothrombocytopenia (PTP) is the phenomenon of falsely low platelet counts due to in vitro platelet clumping in the presence of platelet autoantibodies and anticoagulants. We assessed anticoagulant-dependence, time course of platelet counts and impact of different counter devices on the phenomenon. Blood of 10 persons with previously recognized pronounced EDTA-dependent PTP was collected into 7 different anticoagulants and counted after different intervals in parallel in a Coulter T540 and a Coulter STKS counter and by phase contrast microscopy. With the Coulter T540 model PTP was most pronounced in blood samples anticoagulated with EDTA, Na-oxalate or Na-citrate. In the STKS counter EDTA, heparin and oxalate presented as the worst anticoagulants. The time course of platelet counts was significantly different between the two counters. Our results demonstrate that PTP is not restricted to EDTA, but is also present with other anticoagulants. In contrast, pseudoleucocytosis was observed only in EDTA-anticoagulated blood in the Coulter T540 device. We investigated the expression of platelet integrins and activation antigens on platelets of persons with anticoagulant-dependent PTP and in healthy controls without PTP. In the presence of EDTA the expression of GpIIb/IIIa was significantly reduced in the PTP subjects compared to control. Activation antigens CD62, CD63 and thrombospondin-antigen were upregulated in the presence of EDTA. These alterations in the expression of platelet antigens could also be induced on platelets of normal donors by incubation with sera of PTP subjects and EDTA.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Does plasmin have anticoagulant activity?

    Directory of Open Access Journals (Sweden)

    Jane Hoover-Plow

    2010-03-01

    Full Text Available Jane Hoover-PlowJoseph J Jacobs Center for Thrombosis and Vascular Biology, Departments of Cardiovascular Medicine and Molecular Cardiology, Lerner Research Institute Cleveland Clinic, Ohio, USAAbstract: The coagulation and fibrinolytic pathways regulate hemostasis and thrombosis, and an imbalance in these pathways may result in pathologic hemophilia or thrombosis. The plasminogen system is the primary proteolytic pathway for fibrinolysis, but also has important proteolytic functions in cell migration, extracellular matrix degradation, metalloproteinase activation, and hormone processing. Several studies have demonstrated plasmin cleavage and inactivation of several coagulation factors, suggesting plasmin may be not only be the primary fibrinolytic enzyme, but may have anticoagulant properties as well. The objective of this review is to examine both in vitro and in vivo evidence for plasmin inactivation of coagulation, and to consider whether plasmin may act as a physiological regulator of coagulation. While several studies have demonstrated strong evidence for plasmin cleavage and inactivation of coagulation factors FV, FVIII, FIX, and FX in vitro, in vivo evidence is lacking for a physiologic role for plasmin as an anticoagulant. However, inactivation of coagulation factors by plasmin may be useful as a localized anticoagulant therapy or as a combined thrombolytic and anticoagulant therapy.Keywords: thrombosis, anticoagulant, cardiovascular disease, plasminogen’s protease, blood

  3. Anticoagulant activities of persicarin and isorhamnetin.

    Science.gov (United States)

    Ku, Sae-Kwang; Kim, Tae Hoon; Bae, Jong-Sup

    2013-04-01

    Persicarin and isorhamnetin were isolated from Oenanthe javanica and their anticoagulant activities were examined by monitoring activated partial thromboplastin time (aPTT), prothrombin time (PT), and the activities of cell-based thrombin and activated factor X (FXa). In addition, the effects of persicarin and isorhamnetin on the expressions of plasminogen activator inhibitor type 1 (PAI-1) and tissue-type plasminogen activator (t-PA) were tested in tumor necrosis factor-α (TNF-α) activated human umbilical vein endothelial cells (HUVECs). The data obtained showed that persicarin and isorhamnetin both prolonged aPTT and PT significantly and inhibited the activities of thrombin and FXa. In addition, they both inhibited the generations of thrombin and FXa in HUVECs. In accordance with these anticoagulant activities, persicarin and isorhamnetin prolonged in vivo bleeding time and inhibited TNF-α induced PAI-1 production. Furthermore, PAI-1/t-PA ratio was significantly decreased by persicarin. Interestingly, the anticoagulant and profibrinolytic effects of persicarin were greater than those of isorhamnetin, which suggest that the sulfonate group of persicarin positively regulates its anticoagulatory function. Accordingly, our results suggest that persicarin and isorhamnetin possess antithrombotic activities and that they could provide bases for the development of new anticoagulant agents.

  4. Cystamine preparations exhibit anticoagulant activity.

    Science.gov (United States)

    Aleman, Maria M; Holle, Lori A; Stember, Katherine G; Devette, Christa I; Monroe, Dougald M; Wolberg, Alisa S

    2015-01-01

    Transglutaminases are a superfamily of isoenzymes found in cells and plasma. These enzymes catalyze the formation of ε-N-(γ-glutamyl)-lysyl crosslinks between proteins. Cystamine blocks transglutaminase activity and is used in vitro in human samples and in vivo in mice and rats in studies of coagulation, immune dysfunction, and inflammatory disease. These studies have suggested cystamine blocks fibrin crosslinking and has anti-inflammatory effects, implicating transglutaminase activity in the pathogenesis of several diseases. We measured the effects of cystamine on fibrin crosslinking, tissue factor-triggered plasma clot formation and thrombin generation, and coagulation factor enzymatic activity. At concentrations that blocked fibrin crosslinking, cystamine also inhibited plasma clot formation and reduced thrombin generation. Cystamine inhibited the amidolytic activity of coagulation factor XI and thrombin towards chromogenic substrates. These findings demonstrate that cystamine exhibits anticoagulant activity during coagulation. Given the close relationship between coagulation and inflammation, these findings suggest prior studies that used cystamine to implicate transglutaminase activity in disease pathogenesis warrant re-examination.

  5. Cystamine preparations exhibit anticoagulant activity.

    Directory of Open Access Journals (Sweden)

    Maria M Aleman

    Full Text Available Transglutaminases are a superfamily of isoenzymes found in cells and plasma. These enzymes catalyze the formation of ε-N-(γ-glutamyl-lysyl crosslinks between proteins. Cystamine blocks transglutaminase activity and is used in vitro in human samples and in vivo in mice and rats in studies of coagulation, immune dysfunction, and inflammatory disease. These studies have suggested cystamine blocks fibrin crosslinking and has anti-inflammatory effects, implicating transglutaminase activity in the pathogenesis of several diseases. We measured the effects of cystamine on fibrin crosslinking, tissue factor-triggered plasma clot formation and thrombin generation, and coagulation factor enzymatic activity. At concentrations that blocked fibrin crosslinking, cystamine also inhibited plasma clot formation and reduced thrombin generation. Cystamine inhibited the amidolytic activity of coagulation factor XI and thrombin towards chromogenic substrates. These findings demonstrate that cystamine exhibits anticoagulant activity during coagulation. Given the close relationship between coagulation and inflammation, these findings suggest prior studies that used cystamine to implicate transglutaminase activity in disease pathogenesis warrant re-examination.

  6. Heterofucans from Dictyota menstrualis have anticoagulant activity.

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    Albuquerque, I R L; Queiroz, K C S; Alves, L G; Santos, E A; Leite, E L; Rocha, H A O

    2004-02-01

    Fucan is a term used to denote a family of sulfated L-fucose-rich polysaccharides which are present in the extracellular matrix of brown seaweed and in the egg jelly coat of sea urchins. Plant fucans have several biological activities, including anticoagulant and antithrombotic, related to the structural and chemical composition of polysaccharides. We have extracted sulfated polysaccharides from the brown seaweed Dictyota menstrualis by proteolytic digestion, followed by separation into 5 fractions by sequential acetone precipitation. Gel electrophoresis using 0.05 M 1,3-diaminopropane-acetate buffer, pH 9.0, stained with 0.1% toluidine blue, showed the presence of sulfated polysaccharides in all fractions. The chemical analyses demonstrated that all fractions are composed mainly of fucose, xylose, galactose, uronic acid, and sulfate. The anticoagulant activity of these heterofucans was determined by activated partial thromboplastin time (APTT) using citrate normal human plasma. Only the fucans F1.0v and F1.5v showed anticoagulant activity. To prolong the coagulation time to double the baseline value in the APTT, the required concentration of fucan F1.0v (20 g/ml) was only 4.88-fold higher than that of the low molecular weight heparin Clexane (4.1 g/ml), whereas 80 g/ml fucan 1.5 was needed to obtain the same effect. For both fucans this effect was abolished by desulfation. These polymers are composed of fucose, xylose, uronic acid, galactose, and sulfate at molar ratios of 1.0:0.8:0.7:0.8:0.4 and 1.0:0.3:0.4:1.5:1.3, respectively. This is the fist report indicating the presence of a heterofucan with higher anticoagulant activity from brown seaweed.

  7. Heterofucans from Dictyota menstrualis have anticoagulant activity

    Directory of Open Access Journals (Sweden)

    I.R.L. Albuquerque

    2004-02-01

    Full Text Available Fucan is a term used to denote a family of sulfated L-fucose-rich polysaccharides which are present in the extracellular matrix of brown seaweed and in the egg jelly coat of sea urchins. Plant fucans have several biological activities, including anticoagulant and antithrombotic, related to the structural and chemical composition of polysaccharides. We have extracted sulfated polysaccharides from the brown seaweed Dictyota menstrualis by proteolytic digestion, followed by separation into 5 fractions by sequential acetone precipitation. Gel electrophoresis using 0.05 M 1,3-diaminopropane-acetate buffer, pH 9.0, stained with 0.1% toluidine blue, showed the presence of sulfated polysaccharides in all fractions. The chemical analyses demonstrated that all fractions are composed mainly of fucose, xylose, galactose, uronic acid, and sulfate. The anticoagulant activity of these heterofucans was determined by activated partial thromboplastin time (APTT using citrate normal human plasma. Only the fucans F1.0v and F1.5v showed anticoagulant activity. To prolong the coagulation time to double the baseline value in the APTT, the required concentration of fucan F1.0v (20 µg/ml was only 4.88-fold higher than that of the low molecular weight heparin Clexane® (4.1 µg/ml, whereas 80 µg/ml fucan 1.5 was needed to obtain the same effect. For both fucans this effect was abolished by desulfation. These polymers are composed of fucose, xylose, uronic acid, galactose, and sulfate at molar ratios of 1.0:0.8:0.7:0.8:0.4 and 1.0:0.3:0.4:1.5:1.3, respectively. This is the fist report indicating the presence of a heterofucan with higher anticoagulant activity from brown seaweed.

  8. Monitoring Oral Anticoagulant Therapy: Measuring Coagulant Activity

    DEFF Research Database (Denmark)

    Attermann, Jorn

    daily anticoagulant therapy. The therapy necessitates close monitoring of coagulant activity, since excess doses of anticoagulant medicine may lead to life-threatening bleedings. Traditionally, patients on OAT are required to pay regular visits to a physician, who decides on drug dosage adjustments...... of the new concept is the training and continuous support and monitoring of the patients, and a center with these purposes has been established at Skejby Sygehus. The main instrument for monitoring the coagulant activity is the prothrombin time (PT). This is the time until clotting can be observed...... central aspects of the INR system, such as the inaccuracy of INR estimates based on a given path of calibrations. The main result states that, under weak regularity conditions, log (log (estimated INR)) is approximately normally distributed with mean log (log (true INR)). The variance is a function...

  9. Anticoagulants

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    ... Receptor Blockers Angiotensin-Converting Enzyme (ACE) Inhibitors Antiarrhythmics Antiplatelet Therapy Aspirin Beta-Blockers Blood Thinners Calcium Channel Blockers Digitalis Medicines Diuretics Inotropic Agents Nitrates Statins, Cholesterol-Lowering Medicines Anticoagulants Related terms: ...

  10. [Heparin induced thrombocytopenia and anticoagulation in renal replacemant therapy].

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    Steinfeldt, Thorsten; Rolfes, Caroline

    2008-04-01

    The decision for an anticoagulant for renal replacement therapy (RRT) in patients with acute renal failure and heparin-induced thrombocytopenia (HIT) has to be made carefully. Based on results from the literature argatroban is favoured in patients without hepatic dysfunction, referring to its short halftime and easy feasable monitoring. In the case of coexsisting hepatic disorder, danaparoid provides a safe alternative therapy. However, long halftime and the difficult elimination of the substance are unfavourable. Lepirudin represents another possible anticoagulant therapy. Bleeding complications and monitoring of the ecarin clotting time imposes limitations. Experiences with bivalirudin, fondaparinux and prostaglandines are limited and future trials will have to determine the significance of their application in RRT in HIT patients. Furthermore it has to be proven whether the combination of alternative anticoagulants with citrate prolongates circuit halftime of CVVH.

  11. Anticoagulants influence the in vitro activity and composition of shock lymph but not its in vivo activity.

    Science.gov (United States)

    Deitch, Edwin A; Qin, Xiaofa; Sheth, Sharvil U; Tiesi, Gregory; Palange, David; Dong, Wei; Lu, Qi; Xu, Dazhong; Feketeova, Eleonora; Feinman, Rena

    2011-08-01

    Many models of trauma-hemorrhagic shock (T/HS) involve the reinfusion of anticoagulated shed blood. Our recent observation that the anticoagulant heparin induces increased mesenteric lymph lipase activity and consequent in vitro endothelial cell cytotoxicity prompted us to investigate the effect of heparin-induced lipase activity on organ injury in vivo as well as the effects of other anticoagulants on mesenteric lymph bioactivity in vitro and in vivo. To investigate this issue, rats subjected to trauma-hemorrhage had their shed blood anticoagulated with heparin, the synthetic anticoagulant arixtra (fondaparinux sodium), or citrate. Arixtra, in contrast to heparin, did not increase lymph lipase activity or result in high levels of endothelial cytotoxicity. Yet, the arixtra-treated rats subjected to T/HS still manifested lung injury, neutrophil priming, and red blood cell dysfunction, which was totally abrogated by lymph duct ligation. Furthermore, the injection of T/HS mesenteric lymph, but not sham-shock lymph, collected from the arixtra rats into control mice recreated the pattern of lung injury, polymorphonucleocyte (PMN) priming, and red blood cell dysfunction observed after actual shock. Consistent with these observations, citrate-anticoagulated rats subjected to T/HS developed lung injury, and the injection of mesenteric lymph from the citrate-anticoagulated T/HS rats into control mice also resulted in lung injury. Based on these results, several conclusions can be drawn. First, heparin-induced increased mesenteric lymph lipase activity is not responsible for the in vivo effects of T/HS mesenteric lymph. Second, heparin should be avoided as an anticoagulant when studying the biology or composition of mesenteric lymph because of its ability to cause increases in lymph lipase activity that increase the in vitro cytotoxicity of these lymph samples.

  12. Complement inhibitory and anticoagulant activities of fractionated heparins

    NARCIS (Netherlands)

    Hennink, W.E.; Klerx, J.P.A.M.; Dijk, H. van; Feijen, J.

    1984-01-01

    Almost monodisperse heparin fractions (w/n < 1.1) were obtained by gel filtration of a commercial heparin. These fractions were assayed for anticoagulant activity (thrombin times and APTT), chromogenic anti-factor Xa activity, inhibitory activity for the human classical complement pathway, carboxyl

  13. Anticoagulant activities of piperlonguminine in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Wonhwa Lee

    2013-10-01

    Full Text Available Piperlonguminine (PL, an important component of Piperlongum fruits, is known to exhibit anti-hyperlipidemic, antiplateletand anti-melanogenic activities. Here, the anticoagulantactivities of PL were examined by monitoring activatedpartial-thromboplastin-time (aPTT, prothrombin-time (PT, andthe activities of thrombin and activated factor X (FXa. Theeffects of PL on the expressions of plasminogen activatorinhibitor type 1 (PAI-1 and tissue-type plasminogen activator(t-PA were also tested in tumor necrosis factor-α (TNF-αactivated HUVECs. The results showed that PL prolonged aPTTand PT significantly and inhibited the activities of thrombin andFXa. PL inhibited the generation of thrombin and FXa inHUVECs. In accordance with these anticoagulant activities, PLprolonged in vivo bleeding time and inhibited TNF-α inducedPAI-1 production. Furthermore, PAI-1/t-PA ratio was significantlydecreased by PL. Collectively, our results suggest that PLpossesses antithrombotic activities and that the current studycould provide bases for the development of new anticoagulantagents. [BMB Reports 2013; 46(10: 484-489

  14. The enhanced anticoagulation for graphene induced by COOH(+) ion implantation.

    Science.gov (United States)

    Liu, Xiaoqi; Cao, Ye; Zhao, Mengli; Deng, Jianhua; Li, Xifei; Li, Dejun

    2015-01-01

    Graphene may have attractive properties for some biomedical applications, but its potential adverse biological effects, in particular, possible modulation when it comes in contact with blood, require further investigation. Little is known about the influence of exposure to COOH(+)-implanted graphene (COOH(+)/graphene) interacting with red blood cells and platelets. In this paper, COOH(+)/graphene was prepared by modified Hummers' method and implanted by COOH(+) ions. The structure and surface chemical and physical properties of COOH(+)/graphene were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and contact angle measurement. Systematic evaluation of anticoagulation, including in vitro platelet adhesion assays and hemolytic assays, proved that COOH(+)/graphene has significant anticoagulation. In addition, at the dose of 5 × 10(17) ions/cm(2), COOH(+)/graphene responded best on platelet adhesion, aggregation, and platelet activation.

  15. Coagulant and anticoagulant activities in Jatropha curcas latex.

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    Osoniyi, Omolaja; Onajobi, Funmi

    2003-11-01

    Jatropha curcas Linn. (Euphorbiaceae), a medicinal plant commonly grown in the Tropics, is traditionally used as a haemostatic. Investigation of the coagulant activity of the latex of Jatropha curcas showed that whole latex significantly (Platex, however, prolonged the clotting time: at high dilutions, the blood did not clot at all. This indicates that Jatropha curcas latex possesses both procoagulant and anticoagulant activities. Prothrombin time (PT) and activated partial thromboplastin time (APTT) tests on plasma confirm these observations. Solvent partitioning of the latex with ethyl acetate and butanol led to a partial separation of the two opposing activities: at low concentrations, the ethyl acetate fraction exhibited a procoagulant activity, while the butanol fraction had the highest anticoagulant activity. The residual aqueous fraction had no significant effect on the clotting time of blood and the PT but slightly prolonged the APTT.

  16. Anticoagulant activity of Moon jellyfish (Aurelia aurita) tentacle extract.

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    Rastogi, Akriti; Biswas, Sumit; Sarkar, Angshuman; Chakrabarty, Dibakar

    2012-10-01

    Moon jellyfish (Aurelia aurita) tentacle extract was studied for its anticoagulant activity in vitro. The Jellyfish Tentacle Extract (JFTE) showed very strong fibrinogenolytic activity by cleaving Aα and Bβ chain of fibrinogen molecule. The fibrinogenolytic activity was found to be stronger than some snake venom derived anticoagulants. JFTE also completely liquefied fibrin clots in 24 h. JFTE was found to contain both high and low molecular weight proteins/peptides. The fibrinogenolysis appears to be caused by high molecular weight fractions of the extract. It has been also noted that PMSF significantly reduced fibrinogenolytic activity and heating totally abolished it. Autolytic degradation of the high molecular weight protein was also noted. Autolysis slowed down, but did not abolish the fibrinogenolytic activity of the extract.

  17. Improvements of anticoagulant activities of silk fibroin films with fucoidan

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Fucoidan (FC),an effective anticoagulant constituent extracted from brown algae,was introduced into silk fibroin (SF) for improving its blood compatibility.The SF and SF/FC blend films were characterized by attenuated total reflectance Fourier-transform infrared (ATR-FTIR),X-ray photoelectron spectroscopy (XPS),scanning electron microscopy (SEM) and dynamic contact angle determinator (CA).The in vitro anticoagulant activities of the films were evaluated by activated partial thromboplastin time (APTT),thrombin time (TT) and prothrombin time (PT) measurements.The endothelial cell attachment and proliferation viability on the film were assessed by micropipette aspiration technique and MTT assay,respectively.The testing results indicated that the introduction of FC increased the roughness,hydrophilicity and sulfate component of the film surface without impeding the formation of β-sheet conformation in SF.More important,FC brought excellent anticoagulant activity and better endothelial cell affinity to SF.The SF/FC blend film was hopeful to be used as blood-contacting biomaterials.

  18. High antiangiogenic and low anticoagulant efficacy of orally active low molecular weight heparin derivatives.

    Science.gov (United States)

    Park, Jin Woo; Jeon, Ok Cheol; Kim, Sang Kyoon; Al-Hilal, Taslim Ahmed; Jin, Shun Ji; Moon, Hyun Tae; Yang, Victor C; Kim, Sang Yoon; Byun, Youngro

    2010-12-20

    Heparin, an anticoagulant that is widely used clinically, is also known to bind to several kinds of proteins through electrostatic interactions because of its polyanionic character. These interactions are mediated by the physicochemical properties of heparin such as sequence composition, sulfation patterns, charge distribution, overall charge density, and molecular size. Although this electrostatic character mediates its binding to many proteins related with tumor progression, thereby providing its antiangiogenic property, the administration of heparin for treating cancer is limited in clinical applications due to several drawbacks, such as its low oral absorption, unsatisfactory therapeutic effects, and strong anticoagulant activity which induces hemorrhaging. Here, we evaluated novel, orally active, low molecular weight heparin (LMWH) derivatives (LHD) conjugated with deoxycholic acid (DOCA) that show reduced anticoagulant activity and enhanced antiangiogenic activity. The chemical conjugate of LMWH and DOCA was synthesized by conjugating the amine group of N-deoxycholylethylamine (EtDOCA) with the carboxylic groups of heparin at various DOCA conjugation ratios. The LMWH-DOCA conjugate series (LHD1, LHD1.5, LHD2, and LHD4) were further formulated with poloxamer 407 as a solubilizer for oral administration. An in vitro endothelial tubular formation and in vivo Matrigel plug assay were performed to verify the antiangiogenic potential of LHD. Finally, we evaluated tumor growth inhibition of oral LHD administration in a SCC7 model as well as in A549 human cancer cell lines in a mouse xenograft model. Increasing DOCA conjugation ratios showed decreased anticoagulant activity, eventually to zero. LHD could block angiogenesis in the tubular formation assay and the Matrigel plug assay. In particular, oral administration of LHD4, which has 4 molecules of DOCA per mole of LMWH, inhibited tumor growth in SCC7 mice model as well as A549 mice xenograft model. LHD4 was orally

  19. In-vitro anticoagulant activity of fucoidan derivatives from brown seaweed Laminaria japonica

    Institute of Scientific and Technical Information of China (English)

    WANG Jing; ZHANG Quanbin; ZHANG Zhongshan; HOU Yun; ZHANG Hong

    2011-01-01

    Fucoidan, a group of sulfated heteropolysaccharides, was extracted from Laminariajaponica,an important economic alga species in China. The anticoagulant activity of fucoidan and its derivatives (including sulfated, phosphorylated, and aminated fucoidan) was examined using in-vitro anticoagulant systems. The correlation between chemical variations within the fucoidan group and anticoagulant activity was determined. The in-vitro anticoagulant properties of fucoidan and its derivatives were determined by measuring activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT).The results indicate anticoagulant activity in all samples using APTT and TT assays; however, only the fucoidan derivatives affected the PT assay. Thus, the fucoidan derivatives were able to inhibit both intrinsic and extrinsic blood coagulants. Fucoidan (FPS) and its derivatives presented better anticoagulant activity than low molecular weight fucoidan (DFPS) and its derivatives, suggesting that molecular weight and proper conformation are contributing factors for anticoagulant activity of polysaccharides. Amino groups have a positive charge and can thus change the charge density of fucoidan. Accordingly, among the tested samples, aminated fucoidan (NF) was the most active reflecting the importance of charge density for anticoagulant activity. Available data obtained using in-vitro models suggest that the sulfate content,sulfate/total-sugar ratio, molecular weight, and the substituted group of fucoidan are important factors for anticoagulant activity but that the influence of sulfate, phosphate and amino groups on anticoagulant activity was different.

  20. In-vitro anticoagulant activity of fucoidan derivatives from brown seaweed Laminaria japonica

    Science.gov (United States)

    Wang, Jing; Zhang, Quanbin; Zhang, Zhongshan; Hou, Yun; Zhang, Hong

    2011-05-01

    Fucoidan, a group of sulfated heteropolysaccharides, was extracted from Laminaria japonica, an important economic alga species in China. The anticoagulant activity of fucoidan and its derivatives (including sulfated, phosphorylated, and aminated fucoidan) was examined using in-vitro anticoagulant systems. The correlation between chemical variations within the fucoidan group and anticoagulant activity was determined. The in-vitro anticoagulant properties of fucoidan and its derivatives were determined by measuring activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT). The results indicate anticoagulant activity in all samples using APTT and TT assays; however, only the fucoidan derivatives affected the PT assay. Thus, the fucoidan derivatives were able to inhibit both intrinsic and extrinsic blood coagulants. Fucoidan (FPS) and its derivatives presented better anticoagulant activity than low molecular weight fucoidan (DFPS) and its derivatives, suggesting that molecular weight and proper conformation are contributing factors for anticoagulant activity of polysaccharides. Amino groups have a positive charge and can thus change the charge density of fucoidan. Accordingly, among the tested samples, aminated fucoidan (NF) was the most active reflecting the importance of charge density for anticoagulant activity. Available data obtained using in-vitro models suggest that the sulfate content, sulfate/total-sugar ratio, molecular weight, and the substituted group of fucoidan are important factors for anticoagulant activity but that the influence of sulfate, phosphate and amino groups on anticoagulant activity was different.

  1. The protein C omega-loop substitution Asn2Ile is associated with reduced protein C anticoagulant activity.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2012-02-01

    We report a kindred with heritable protein C (PC) deficiency in which two siblings with severe thrombosis showed a composite type I and IIb PC deficiency phenotype, identified using commercial PC assays (proband: PC antigen 42 u\\/dl, amidolytic activity 40 u\\/dl, anticoagulant activity 9 u\\/dl). The independent PROC nucleotide variations c.669C>A (predictive of Ser181Arg) and c.131C>T (predictive of Asn2Ile) segregated with the type I and type IIb PC deficiency phenotypes respectively, but co-segregated in the siblings with severe thrombosis. Soluble thrombomodulin (sTM)-mediated inhibition of plasma thrombin generation from an individual with PC-Asn2Ile was lower (endogenous thrombin potential (ETP) 56 +\\/- 1% that of ETP determined without sTM) than control plasma (ETP 15 +\\/- 2%) indicating reduced PC anticoagulant activity. Recombinant APC-Asn2Ile exhibited normal amidolytic activity but impaired anticoagulant activity. Protein S (PS)-dependent anticoagulant activity of recombinant APC-Asn2Ile and binding of recombinant APC-Asn2Ile to endothelial protein C receptor (EPCR) were reduced compared to recombinant wild-type APC. Asn2 lies within the omega-loop of the PC\\/APC Gla domain and this region is critical for calcium-induced folding and subsequent interactions with anionic phospholipids, EPCR and PS. The disruption of these interactions in this naturally-occurring PC variant highlights their collective importance in mediating APC anticoagulant activity in vivo.

  2. Relationship between lupus anticoagulant (LAC) and pregnancy-induced hypertension.

    Science.gov (United States)

    Matsumoto, T; Sagawa, N; Ihara, Y; Kobayashi, F; Itoh, H; Mori, T

    1995-01-01

    Lupus anticoagulant (LAC), a serum antiphospholipid autoantibody, is believed to be one of the causes of infertility or fetal loss. The purpose of the present study was to evaluate the role of LAC in the pathogenesis of hypertension during pregnancy. In this study, 20 pregnant women with hypertension were classified into two groups: 14 patients who did not have hypertension before the pregnancy but developed it during the pregnancy (pregnancy-induced hypertension; Group A) and 6 patients who had hypertensive or renal disease before the pregnancy, and developed further hypertension during the pregnancy (pregnancy-aggravated hypertension; Group B). A LAC coagulation assay was performed, and the presence of LAC in each group was compared. All 14 patients in group A were LAC-negative. In contrast, 3 of the 6 patients in group B were LAC-positive, and had clinical autoimmune diseases. The incidence of pregnancy-induced hypertension was also examined in 15 pregnancies from 9 LAC-positive women who had a history of repeated fetal loss but no systemic autoimmune disease (Group C). None of these 15 pregnancies had hypertensive complications, even when they reached term. In the placentas of LAC-positive women, no characteristic changes other than fibrinoid degeneration and microscopic infarction were observed upon histological examination. These results suggest that LAC does not relate with the onset of hypertension during pregnancy.

  3. [Glucosamine and chondroitin sulfate do not enhance anticoagulation activity of warfarin in mice in vivo].

    Science.gov (United States)

    Yokotani, Kaori; Nakanishi, Tomoko; Chiba, Tsuyoshi; Sato, Yoko; Umegaki, Keizo

    2014-01-01

    As an adverse event, it has been reported that anticoagulation activity of warfarin was enhanced by simultaneous intakes of glucosamine and chondroitin sulfate. However, it is unclear whether these is a causative relation. Therefore, in the present study, we evaluated whether glucosamine and chondroitin sulfate enhanced the anticoagulant action of warfarin in mice in vivo, focusing on hepatic cytochrome P450 (CYPs)-mediated mechanisms. Mice were fed a diet containing various doses of glucosamine or chondroitin sulfate (0, 0.3, 1% (w/w)) for 2 weeks, and given warfarin by gavage on the last 2 days of the treatment regimen. Doses of glucosamine and chondroitin sulfate were 443 mg/kg and 464 mg/kg in the 0.3% diet groups, and 1523 mg/kg and 1546 mg/kg in the 1% diet groups. We found that 1% glucosamine significantly shortened prothrombin time and thrombotest Owen in animals given warfarin. However, the two ingredients did not induce or inhibit hepatic CYPs, including (S)-warfarin hydroxylase. These findings suggest that glucosamine and chondroitin sulfate do not affect the anticoagulation activity of warfarin through hepatic CYP mediated-mechanisms.

  4. A non-anticoagulant heterofucan has antithrombotic activity in vivo.

    Science.gov (United States)

    Barroso, Edjane M A; Costa, Leandro S; Medeiros, Valquíria P; Cordeiro, Sara L; Costa, Mariana S S P; Franco, Célia R C; Nader, Helena B; Leite, Edda L; Rocha, Hugo A O

    2008-06-01

    Fucan is a term used to denominate a family of sulfated L-fucose-rich polysaccharides. The brown alga Spatoglossum schröederi (Dictyotaceae) has three heterofucans namely fucan A, B and C. The 21 kDa fucan A is composed of a core of a beta (1-3) glucuronic acid-containing oligosaccharide of 4.5 kDa with branches at C4 of the fucose chains alpha (1-3) linked. The fucose is mostly substituted at C4 with a sulfate group and at C2 with chains of beta (1-4) xylose. This fucan has neither anticoagulant (from from 0.1 to 100 microg) nor hemorrhagic activities (from 50 to 800 microg/mL). The antithrombotic test in vivo showed that fucan A has no activity in any of the concentrations (from 0.2 to 20 microg/g/day) tested 1 h after polysaccharide administration. However, when fucan A was injected endovenously 24 h before the ligature of the venae cavae, we observed a dose-dependent effect, reaching saturation at around 20 microg/g of rat weight. In addition, this effect is also time-dependent, reaching saturation around 16 h after fucan administration. In addition, regardless of the administration route, fucan A displayed antithrombotic activity. The exception was the oral pathway. Of particular importance was the finding that fucan A stimulates the synthesis of an antithrombotic heparan sulfate from endothelial cells like heparin. The hypothesis has been raised that the in vivo antithrombotic activity of fucan A is related to the increased production of this heparan. Taken together with the fact that the compound is practically devoid of anticoagulant and hemorrhagic activity, the data suggest that it may be an ideal antithrombotic agent in vivo.

  5. Anticoagulant-induced hemarthrosis presenting as anterior shoulder dislocation.

    Science.gov (United States)

    Davis, Christine B; Nowak, Richard M

    2014-12-01

    This is a case of nontraumatic shoulder pain initially diagnosed on x-ray as an anterior dislocation. The patient was on anticoagulants and, in actuality, had severe hemarthrosis that caused the subluxation. Attempts to reduce the dislocation in this situation might have resulted in worsening of the intra-articular bleed. There has been only 1 similar reported case in the European Journal of Emergency Medicine in 2013 of a 53-year-old woman who was thought to have a nontraumatic anterior shoulder dislocation, and attempts were unsuccessful at reduction. Definitive therapy involved hemarthrosis aspiration. Others have reported spontaneous hemarthrosis due to anticoagulants; however, only 1 has reported an initial mistaken joint dislocation diagnosis. Nontraumatic hemarthrosis do occur in patients on anticoagulant therapy, and it is important to recognize that this can be misdiagnosed as a joint dislocation requiring reduction. In a patient who is on anticoagulants presenting with nontraumatic joint pain and anterior shoulder or possibly other dislocations on plain radiographs, it is pertinent to consider hemarthrosis.

  6. Synthesis, anticoagulant and PIVKA-II induced by new 4-hydroxycoumarin derivatives.

    Science.gov (United States)

    Abdelhafez, Omaima M; Amin, Kamelia M; Batran, Rasha Z; Maher, Timothy J; Nada, Somaia A; Sethumadhavan, Shalini

    2010-05-15

    The action of the coumarin-type drugs and related compounds is reviewed to their VKOR antagonistic effects. In our study, twenty 3-pyridinyl, pyrimidinyl and pyrazolyl-4-hydroxycoumarin derivatives were synthesized. A comparative in vivo (CT, PT determination) and in vitro (measurement of PIVKA-II levels) anticoagulant study with respect to warfarin showed that the synthesized compounds have different anticoagulant activities, the most prospective compounds were the 3-pyrazolyl-4-hydroxycoumarin derivatives.

  7. Comparative Assessment of the Anticoagulant Activity of Rivaroxaban and Dabigatran in Patients With Nonvalvular Atrial Fibrillation: A Noninterventional Study.

    Science.gov (United States)

    Tsantes, Argirios E; Kyriakou, Elias; Ikonomidis, Ignatios; Katogiannis, Konstantinos; Papadakis, Ioannis; Douramani, Panagiota; Kopterides, Petros; Kapsimali, Violetta; Lekakis, John; Tsangaris, Iraklis; Bonovas, Stefanos

    2016-04-01

    There is a shortage of data in everyday clinical practice about the anticoagulant effects caused by the new oral anticoagulants (NOAs). Our aim was to estimate the intensity of anticoagulant activity induced by rivaroxaban 20 mg qd and dabigatran 110 mg bid among patients with nonvalvular atrial fibrillation (NV-AF).We studied 20 patients with NV-AF treated with dabigatran, and 20 patients treated with rivaroxaban. We performed conventional coagulation tests, thrombin generation (TG) test, thromboelastometry (ROTEM), and epinephrine-induced light transmission aggregometry (LTA) in all 40 patients and 20 controls. Hemoclot Thrombin Inhibitors (HTI) and Factor Xa Direct Inhibitor (DiXaI) assay were used to measure dabigatran and rivaroxaban plasma levels, respectively.Measurements of all assays estimating anticoagulant activity across the 2 patient groups were similar, except for aPTT. Patients on dabigatran exhibited statistically significantly prolonged aPTT values (P dabigatran also showed decreased aggregation compared to those on rivaroxaban (P = 0.045). Regarding the TG test, there was no association between endogenous thrombin potential (ETP) and rivaroxaban plasma levels (P = 0.33) as opposed to dabigatran levels (P dabigatran as compared to rivaroxaban.

  8. Comparison of Physicochemical Characteristics and Anticoagulant Activities of Polysaccharides from Three Sea Cucumbers

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    Shengmin Wang

    2013-02-01

    Full Text Available In order to search for sulfated polysaccharides in different invertebrate connective tissues and to examine their biological activities, we have isolated three types of polysaccharides from the body wall of the three sea cucumbers Holothuria edulis, Apostichopus japonicas and Holothuria nobilis. The physicochemical properties and anticoagulant activities of these polysaccharides were examined and compared. The chemical composition analysis and nuclear magnetic resonance (NMR analysis indicate that two types of polysaccharides, sulfated fucan and fucosylated chondroitin sulfate (FuCS, were found in all of the three species and in addition a neutral glycan was observed in H. edulis. The neutral α-glucan was firstly obtained from sea cucumber. The same type of polysaccharides from different species of sea cucumbers have similar physicochemical properties and anticoagulant activities, but those of different types of glycans are significantly different, possibly due to their different monosaccharide compositions, electric charges and average molecular weights. The FuCSs have stronger anticoagulant activities than the sulfated fucans, although the molecular sizes of the FuCSs are lower than those of the sulfated fucans, whereas the neutral glucan has no activity, as expected from the absence of sulfate. Thus, anticoagulant activities of the different type of polysaccharides are likely to relate to monosaccharide composition and sulfate content. Preliminary analysis suggests that the sulfation patterns of the FuCSs may result in the difference in anticoagulant activities. Our data could help elucidate the structure-activity relationship of the sea cucumber polysaccharides.

  9. Comparison of physicochemical characteristics and anticoagulant activities of polysaccharides from three sea cucumbers.

    Science.gov (United States)

    Luo, Lan; Wu, Mingyi; Xu, Li; Lian, Wu; Xiang, Jingying; Lu, Feng; Gao, Na; Xiao, Chuang; Wang, Shengmin; Zhao, Jinhua

    2013-02-05

    In order to search for sulfated polysaccharides in different invertebrate connective tissues and to examine their biological activities, we have isolated three types of polysaccharides from the body wall of the three sea cucumbers Holothuria edulis, Apostichopus japonicas and Holothuria nobilis. The physicochemical properties and anticoagulant activities of these polysaccharides were examined and compared. The chemical composition analysis and nuclear magnetic resonance (NMR) analysis indicate that two types of polysaccharides, sulfated fucan and fucosylated chondroitin sulfate (FuCS), were found in all of the three species and in addition a neutral glycan was observed in H. edulis. The neutral α-glucan was firstly obtained from sea cucumber. The same type of polysaccharides from different species of sea cucumbers have similar physicochemical properties and anticoagulant activities, but those of different types of glycans are significantly different, possibly due to their different monosaccharide compositions, electric charges and average molecular weights. The FuCSs have stronger anticoagulant activities than the sulfated fucans, although the molecular sizes of the FuCSs are lower than those of the sulfated fucans, whereas the neutral glucan has no activity, as expected from the absence of sulfate. Thus, anticoagulant activities of the different type of polysaccharides are likely to relate to monosaccharide composition and sulfate content. Preliminary analysis suggests that the sulfation patterns of the FuCSs may result in the difference in anticoagulant activities. Our data could help elucidate the structure-activity relationship of the sea cucumber polysaccharides.

  10. Platelet factor 4 impairs the anticoagulant activity of activated protein C.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2012-02-01

    Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated. In this study we demonstrate that PF4 significantly inhibits APC anti-coagulant activity. PF4 inhibited both protein S-dependent APC anticoagulant function in plasma and protein S-dependent factor Va (FVa) proteolysis 3- to 5-fold, demonstrating that PF4 impairs protein S cofactor enhancement of APC anticoagulant function. Using recombinant factor Va variants FVa-R506Q\\/R679Q and FVa-R306Q\\/R679Q, PF4 was shown to impair APC proteolysis of FVa at position Arg(306) by 3-fold both in the presence and absence of protein S. These data suggest that PF4 contributes to the poorly understood APC resistance phenotype associated with activated platelets. Finally, despite PF4 binding to the APC Gla domain, we show that APC in the presence of PF4 retains its ability to initiate PAR-1-mediated cytoprotective signaling. In summary, we propose that PF4 acts as a critical regulator of APC generation, but also differentially targets APC toward cytoprotective, rather than anticoagulant function at sites of vascular injury with concurrent platelet activation.

  11. Platelet factor 4 impairs the anticoagulant activity of activated protein C.

    LENUS (Irish Health Repository)

    Preston, Roger J S

    2009-02-27

    Platelet factor 4 (PF4) is an abundant platelet alpha-granule chemokine released following platelet activation. PF4 interacts with thrombomodulin and the gamma-carboxyglutamic acid (Gla) domain of protein C, thereby enhancing activated protein C (APC) generation by the thrombin-thrombomodulin complex. However, the protein C Gla domain not only mediates protein C activation in vivo, but also plays a critical role in modulating the diverse functional properties of APC once generated. In this study we demonstrate that PF4 significantly inhibits APC anti-coagulant activity. PF4 inhibited both protein S-dependent APC anticoagulant function in plasma and protein S-dependent factor Va (FVa) proteolysis 3- to 5-fold, demonstrating that PF4 impairs protein S cofactor enhancement of APC anticoagulant function. Using recombinant factor Va variants FVa-R506Q\\/R679Q and FVa-R306Q\\/R679Q, PF4 was shown to impair APC proteolysis of FVa at position Arg(306) by 3-fold both in the presence and absence of protein S. These data suggest that PF4 contributes to the poorly understood APC resistance phenotype associated with activated platelets. Finally, despite PF4 binding to the APC Gla domain, we show that APC in the presence of PF4 retains its ability to initiate PAR-1-mediated cytoprotective signaling. In summary, we propose that PF4 acts as a critical regulator of APC generation, but also differentially targets APC toward cytoprotective, rather than anticoagulant function at sites of vascular injury with concurrent platelet activation.

  12. Sulfation, anticoagulant and antioxidant activities of polysaccharide from green algae Enteromorpha linza.

    Science.gov (United States)

    Wang, Xiaomei; Zhang, Zhongshan; Yao, Zhiyun; Zhao, Mingxing; Qi, Huimin

    2013-07-01

    Sulfated polysaccharides exerted potent biological property which was relative to degree of sulfation, molecular weight, substitution position and chain conformation. In present study, the polysaccharide with low molecular weight (LEP) from Enteromorpha linza was sulfated with chlorosulfuric acid in formamide. The obtained polysaccharide sulfate was selected to evaluate their antioxidant activities and the anticoagulant activity in the coagulation assays, activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT). The data obtained in vitro models indicated that high DS and moderate Mw showed the best anticoagulant and antioxidant activities.

  13. A New Route of Fucoidan Immobilization on Low Density Polyethylene and Its Blood Compatibility and Anticoagulation Activity

    Science.gov (United States)

    Ozaltin, Kadir; Lehocký, Marián; Humpolíček, Petr; Pelková, Jana; Sáha, Petr

    2016-01-01

    Beside biomaterials’ bulk properties, their surface properties are equally important to control interfacial biocompatibility. However, due to the inadequate interaction with tissue, they may cause foreign body reaction. Moreover, surface induced thrombosis can occur when biomaterials are used for blood containing applications. Surface modification of the biomaterials can bring enhanced surface properties in biomedical applications. Sulfated polysaccharide coatings can be used to avoid surface induced thrombosis which may cause vascular occlusion (blocking the blood flow by blood clot), which results in serious health problems. Naturally occurring heparin is one of the sulfated polysaccharides most commonly used as an anticoagulant, but its long term usage causes hemorrhage. Marine sourced sulfated polysaccharide fucoidan is an alternative anticoagulant without the hemorrhage drawback. Heparin and fucoidan immobilization onto a low density polyethylene surface after functionalization by plasma has been studied. Surface energy was demonstrated by water contact angle test and chemical characterizations were carried out by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Surface morphology was monitored by scanning electron microscope and atomic force microscope. Finally, their anticoagulation activity was examined for prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin time (TT). PMID:27294915

  14. A New Route of Fucoidan Immobilization on Low Density Polyethylene and Its Blood Compatibility and Anticoagulation Activity

    Directory of Open Access Journals (Sweden)

    Kadir Ozaltin

    2016-06-01

    Full Text Available Beside biomaterials’ bulk properties, their surface properties are equally important to control interfacial biocompatibility. However, due to the inadequate interaction with tissue, they may cause foreign body reaction. Moreover, surface induced thrombosis can occur when biomaterials are used for blood containing applications. Surface modification of the biomaterials can bring enhanced surface properties in biomedical applications. Sulfated polysaccharide coatings can be used to avoid surface induced thrombosis which may cause vascular occlusion (blocking the blood flow by blood clot, which results in serious health problems. Naturally occurring heparin is one of the sulfated polysaccharides most commonly used as an anticoagulant, but its long term usage causes hemorrhage. Marine sourced sulfated polysaccharide fucoidan is an alternative anticoagulant without the hemorrhage drawback. Heparin and fucoidan immobilization onto a low density polyethylene surface after functionalization by plasma has been studied. Surface energy was demonstrated by water contact angle test and chemical characterizations were carried out by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Surface morphology was monitored by scanning electron microscope and atomic force microscope. Finally, their anticoagulation activity was examined for prothrombin time (PT, activated partial thromboplastin time (aPTT, and thrombin time (TT.

  15. Antimicrobial and anticoagulant activities of the spine of stingray Himantura imbricata

    Institute of Scientific and Technical Information of China (English)

    Kaliyamoorthy Kalidasan; Velayudham Ravi; Sunil Kumar Sahu; Murugan Lakshmi Maheshwaran; Kathiresan Kandasamy

    2014-01-01

    Objective:To study the spine structure of stingray Himantura imbricata (H. imbricata) and to evaluate the anticoagulant properties of the spine extract obtained through various solvents extracts followed by antibacterial activity against human pathogens. Methods:Spines of H. imbricata were collected from Nagappattinam coast, Tamil Nadu, India and their spines were observed under the light microscope. The grounded spines were subjected to extraction of metabolites using methanol, ethanol, chloroform and acetone. Antibacterial activity was evaluated by disc diffusion technique against 10 human pathogens. Similarly, anticoagulant activity was also assessed by following United States Pharmacopeia method. Results:Light microscopic observation of spine revealed that the venom apparatus of the stingray H. imbricata consisted of two to three spines, glandular tissue and a sheath. The spine extract showed potent antibacterial activity against all tested pathogen. Maximum activity (14 mm) was found against Staphylococcus aureus. Crude extract showed 91.50 USP units/mg of anticoagulant activity. Conclusions: Microscopic observations gave new insight about the spine structure of the stingray. The spine extracts of H. imbricate showed potent activity against human pathogens revealed by the good zone of inhibition. Chloroform extracts conferred the most prominent antibacterial activity. The anticoagulant activity was also comparable with that of standard heparin.

  16. Antimicrobial and anticoagulant activities of the spine of stingray Himantura imbricata

    Directory of Open Access Journals (Sweden)

    Kaliyamoorthy Kalidasan

    2014-02-01

    Full Text Available Objective: To study the spine structure of stingray Himantura imbricata (H. imbricata and to evaluate the anticoagulant properties of the spine extract obtained through various solvents extracts followed by antibacterial activity against human pathogens. Methods: Spines of H. imbricata were collected from Nagappattinam coast, Tamil Nadu, India and their spines were observed under the light microscope. The grounded spines were subjected to extraction of metabolites using methanol, ethanol, chloroform and acetone. Antibacterial activity was evaluated by disc diffusion technique against 10 human pathogens. Similarly, anticoagulant activity was also assessed by following United States Pharmacopeia method. Results: Light microscopic observation of spine revealed that the venom apparatus of the stingray H. imbricata consisted of two to three spines, glandular tissue and a sheath. The spine extract showed potent antibacterial activity against all tested pathogen. Maximum activity (14 mm was found against Staphylococcus aureus. Crude extract showed 91.50 USP units/mg of anticoagulant activity. Conclusions: Microscopic observations gave new insight about the spine structure of the stingray. The spine extracts of H. imbricate showed potent activity against human pathogens revealed by the good zone of inhibition. Chloroform extracts conferred the most prominent antibacterial activity. The anticoagulant activity was also comparable with that of standard heparin.

  17. Maternal malaria induces a procoagulant and antifibrinolytic state that is embryotoxic but responsive to anticoagulant therapy.

    Directory of Open Access Journals (Sweden)

    John W Avery

    Full Text Available Low birth weight and fetal loss are commonly attributed to malaria in endemic areas, but the cellular and molecular mechanisms that underlie these poor birth outcomes are incompletely understood. Increasing evidence suggests that dysregulated hemostasis is important in malaria pathogenesis, but its role in placental malaria (PM, characterized by intervillous sequestration of Plasmodium falciparum, proinflammatory responses, and excessive fibrin deposition is not known. To address this question, markers of coagulation and fibrinolysis were assessed in placentae from malaria-exposed primigravid women. PM was associated with significantly elevated placental monocyte and proinflammatory marker levels, enhanced perivillous fibrin deposition, and increased markers of activated coagulation and suppressed fibrinolysis in placental plasma. Submicroscopic PM was not proinflammatory but tended to be procoagulant and antifibrinolytic. Birth weight trended downward in association with placental parasitemia and high fibrin score. To directly assess the importance of coagulation in malaria-induced compromise of pregnancy, Plasmodium chabaudi AS-infected pregnant C57BL/6 mice were treated with the anticoagulant, low molecular weight heparin. Treatment rescued pregnancy at midgestation, with substantially decreased rates of active abortion and reduced placental and embryonic hemorrhage and necrosis relative to untreated animals. Together, the results suggest that dysregulated hemostasis may represent a novel therapeutic target in malaria-compromised pregnancies.

  18. Anticoagulant activity of marine bivalve Donax incarnates Lin, 1758 Collected from Thazhanguda, Southeast coast of India

    Institute of Scientific and Technical Information of China (English)

    P. Bharathirajan

    2012-01-01

    Objective: Molluscs are highly delicious seafood and they are also very good source for biomedically imported products. Among the molluscs some have pronounced pharmacological activities or other properties which are useful in biomedical area. Methods: In the present study GAGs was isolated from the bivalve such as Donax incarnates. Results: The isolated GAGs were quantified in crude samples and they were estimated as 6.84 gm/kg crude GAGs in Donax incarnates. The bivalve showed the anticoagulant activity of the crude samples 124.53 USP units/mg in Donax incarnates. FTIR analysis reveals the presence of anticoagulant substance signals at different ranges. Conclusions: The determined in this research show that gastropod Donax incarnates tissue is value medicinal due to high quality of anticoagulant compounds.

  19. 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.

  20. Anticoagulation activity of salivary gland extract of oriental blackfly Simulium indicum

    Institute of Scientific and Technical Information of China (English)

    Subhalaxmi Borah; Ashok Naglot; Sewali Goswami; Imtiaz Rahman; Manab Deka

    2014-01-01

    Objective: To study the morphology of the salivary gland of the female blackfly of the speciesSimulium indicum gland extract.Methods:(S. indicum) along with protein profile and anticoagulant activity of the salivary protein profile of the salivary gland extract (SGE) and anticoagulant activities against thrombin, and the extrinsic and intrinsic coagulation pathways were found in S. indicum SGE in the TT, PT and APTT assays, respectively.Results:Sodium dodecyl sulphate polyacrylamide gel electrophoresis was used to analyze the and a more or less spherical reservoir. The protein contents of whole salivary glands were also quantified and the amount of salivary gland proteins in the adult female S. indicum was found out to be approximately 1.12±0.13 µg/female. At least 16 major and several minor protein bands Results revealed that each gland consisted of a cylindrical U-shaped secretory lobe were detected in the female salivary glands. The molecular masses of these major protein bands were estimated at 69, 65, 61, 58, 44, 42, 39, 33, 30, 28, 27, 26, 23, 21, 18 and 16 kDa, consecutively. Anticoagulant activities were found in S. indicum SGE in all the assays. It was found that SGE prolonged human plasma clotting time in a dose-dependent manner. Factor Xa inhibition was shown by the SGE of S. indicum. Percent inhibition value was 93.8. A positive correlation (r=0.89) was observed between total protein and percent inhibition of factor Xa. Conclusions: The present study demonstrated that the mode of action of the anticoagulant(s) is mainly on the inhibition of thrombin and factor Xa along with other target factors of the coagulation cascade.

  1. Trans-Resveratrol Enhances the Anticoagulant Activity of Warfarin in a Mouse Model

    Science.gov (United States)

    Kimura, Yuka; Suzuki, Sachina; Tatefuji, Tomoki; Umegaki, Keizo

    2016-01-01

    Aim: Resveratrol is a popular ingredient in dietary supplements. Some patients concomitantly use dietary supplements and medicines in Japan. In the present study, we determined whether trans-resveratrol and melinjo (Gnetum gnemon L.) seed extract (MSE), which contains resveratrol dimers, interacted with drugs using a mouse model. Methods: Male C57BL/6J mice were fed experimental diets containing 0.005%, 0.05%, or 0.5% (w/w) trans-resveratrol or MSE for 1 or 12 weeks. The expression of liver cytochrome P-450 (CYP) mRNA and activity of liver microsomal CYP were measured. To determine the influence of resveratrol or MSE on drug efficacy, the anticoagulant activity of warfarin was examined in mice that were fed diets containing trans-resveratrol or MSE for 12 weeks. Results: When the mice were fed experimental diets for 1 week, none of the doses of trans-resveratrol and MSE affected body weight, liver weight, or plasma AST and ALT levels. Trans-resveratrol also did not affect CYP1A1, CYP1A2, CYP2C, or CYP3A activities. In contrast, 0.5% MSE slightly increased CYP1A1 activity. When the mice were fed experimental diets for 12 weeks, 0.05% trans-resveratrol increased CYP1A1, CYP2C, and CYP3A activities, whereas 0.5% MSE suppressed CYP3A activity. Under these conditions, 0.5% trans-resveratrol enhanced the anticoagulant activity of warfarin, although CYP2C activity increased. However, MSE did not affect the anticoagulant activity of warfarin. Conclusion: The 0.05% trans-resveratrol did not interact with warfarin in a mouse model, whereas 0.5% trans-resveratrol may have enhanced the anticoagulant activity of warfarin. PMID:26947597

  2. Anticoagulant activity of native and partially degraded glycoglucuronomannan after chemical sulfation.

    Science.gov (United States)

    de Oliveira Barddal, Helyn Priscila; Gracher, Ana Helena Pereira; Simas-Tosin, Fernanda Fogagnoli; Iacomini, Marcello; Cipriani, Thales Ricardo

    2015-09-01

    Heparin has great clinical importance as anticoagulant and antithrombotic agent. However, because of its risks of causing bleeding and contamination by animal pathogens, several studies aim to obtain alternatives to heparin. In the search for anticoagulant and antithrombotic agents from a non-animal source, a glycoglucuronomannan from the gum exudate of the plant Vochysia thyrsoidea was partially hydrolyzed, and both native and partially degraded polysaccharides were chemically sulfated, yielding VThS and Ph-VThS respectively. Methylation analysis indicated that sulfation occurred preferentially at the O-5 position of arabinose units in the VThS and at the O-6 position of mannose units in Ph-VThS. In vitro aPTT assay showed that VThS and Ph-VThS have anticoagulant activity, which could be controlled by protamine, and ex vivo aPTT assay demonstrated that Ph-VThS is absorbed by subcutaneous route. Like heparin, they were able to inhibit α-thrombin and factor Xa by a serpin-dependent mechanism. In vivo, VThS and Ph-VThS reduced thrombus formation by approximately 50% at a dose of 40 IU/kg, similarly to heparin. The results demonstrated that the chemically sulfated polysaccharides are promising anticoagulant and antithrombotic agents.

  3. Structure-activity relationship of the pro- and anticoagulant effects of Fucus vesiculosus fucoidan.

    Science.gov (United States)

    Zhang, Z; Till, S; Jiang, C; Knappe, S; Reutterer, S; Scheiflinger, F; Szabo, C M; Dockal, M

    2014-03-03

    Fucoidan is a highly complex sulfated polysaccharide commonly extracted from brown seaweed. In addition to their many biological activities, fucoidans have recently been demonstrated to inhibit or increase coagulation at different concentration ranges. Their structural features, i.e. molecular weight (Mw), Mw distribution, degree of sulfation, monosaccharide composition, and different linkages, are known to affect these activities. Therefore, structure-activity relationship (SAR) analysis of fucoidan is crucial for its potential use as a procoagulant. In this study, Fucus vesiculosus (F.v.) fucoidan was fractionated by charge and size as well as over- and desulfated to different degrees to yield preparations with various structural properties. The fractions' pro- and anticoagulant activities were assessed by calibrated automated thrombography (CAT) and activated partial thromboplastin time(aPTT) assays. Binding to and inhibition of the anticoagulant protein tissue factor pathway inhibitor (TFPI) and the ability to activate coagulation via the contact pathway were also investigated. This paper discusses the impact of charge density, size, and sugar composition on fucoidan's pro- and anticoagulant activities. Fucoidan requires a minimal charge density of 0.5 sulfates per sugar unit and a size of 70 sugar units to demonstrate desired procoagulant activities for improvement of haemostasis in factor VIII/factor IX-deficient plasma.

  4. 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

    2016-08-01

    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 EC 50 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.

  5. An Antithrombin-Heparin Complex Increases the Anticoagulant Activity of Fibrin Clots

    Directory of Open Access Journals (Sweden)

    Lesley J. Smith

    2008-01-01

    Full Text Available Clotting blood contains fibrin-bound thrombin, which is a major source of procoagulant activity leading to clot extension and further activation of coagulation. When bound to fibrin, thrombin is protected from inhibition by antithrombin (AT + heparin but is neutralized when AT and heparin are covalently linked (ATH. Here, we report the surprising observation that, rather than yielding an inert complex, thrombin-ATH formation converts clots into anticoagulant surfaces that effectively catalyze inhibition of thrombin in the surrounding environment.

  6. Effects of sulfate group in red seaweed polysaccharides on anticoagulant activity and cytotoxicity.

    Science.gov (United States)

    Liang, Wanai; Mao, Xuan; Peng, Xiaohui; Tang, Shunqing

    2014-01-30

    In this paper, the structural effects of two main red seaweed polysaccharides (agarose and carrageenan) and their sulfated derivatives on the anticoagulant activity and cytotoxicity were investigated. The substitution position rather than the substitution degree of sulfate groups shows the biggest impact on both the anticoagulant activity and the cell proliferation. Among them, C-2 of 3,6-anhydro-α-d-Galp is the most favorable position for substitution, whereas C-6 of β-d-Galp is the most disadvantageous. Moreover, the secondary structures of glycans also play a key role in biological activities. These demonstrations warrant that the red seaweed polysaccharides should be seriously considered in biomedical applications after carefully tailoring the sulfate groups.

  7. Molecular design, synthesis and anticoagulant activity evaluation of fluorinated dabigatran analogues.

    Science.gov (United States)

    Wang, Fei; Ren, Yu-Jie; Dong, Ming-Hui

    2016-06-15

    In the present study, a series of unreported fluorinated dabigatran analogues, which were based on the structural scaffold of dabigatran, were designed by computer-aided simulation. Fifteen fluorinated dabigatran analogues were screened and synthesized. All target compounds were characterized by (1)H NMR, (13)C NMR, (19)F NMR and HRMS. According to the preliminary screening results of inhibition ratio, eleven analogues (inhibition ratio >90%) were evaluated for antithrombin activity in vitro (IC50). The test results expressed that all the analogues showed effective inhibitory activities against thrombin. Especially, compounds 8f, 8k and 8o, with IC50 values of 1.81, 3.21 and 2.16nM, respectively, showed remarkable anticoagulant activities which were in the range of reference drug dabigatran (IC50=1.23nM). Moreover, compounds 8k and 8o were developed to investigate their anticoagulant activities in vivo. In those part, compound 8o exhibited a fairly strong inhibitory action for arteriovenous thrombosis with inhibition ratio of 84.66%, which was comparable with that of dabigatran (85.07%). Docking simulations demonstrated that these compounds could act as candidates for further development of novel anticoagulant drugs.

  8. Green synthesis and nanotopography of heparin-reduced gold nanoparticles with enhanced anticoagulant activity.

    Science.gov (United States)

    Kim, Hyun-Seok; Jun, Sang Hui; Koo, Yean Kyoung; Cho, Seonho; Park, Youmie

    2013-03-01

    This paper reports on the green synthesis of heparin-reduced gold nanoparticles and their nanotopography as studied with atomic force microscopy. The study also evaluated the anticoagulant activity of the newly prepared gold nanoparticles. The heparin-reduced gold nanoparticles were homogeneous, showing characteristic surface plasmon resonance bands of approximately 523-527 nm, and their shapes were mostly spherical and amorphous. The average diameter of the nanoparticles measured from atomic force microscopic images was either 20.26 +/- 3.35 nm or 40.85 +/- 8.95 nm depending on the different precursor salts and heparin concentrations. Atomic force microscopic images revealed that the topography of the heparin polymer aggregated when deposited onto mica, resembling a chain of mountains. This characteristic nanotopography of the heparin disappeared after the synthesis of the gold nanoparticles was performed. Interestingly, prolonged prothrombin time, thrombin time, and activated partial thromboplastin time were observed in the heparin-reduced gold nanoparticles when compared to a control heparin, suggesting the enhancement of anticoagulant activity in heparin-reduced gold nanoparticles. Hence, the green synthesis of gold nanoparticles with heparin using a simple reaction step could be a viable procedure for enhancing heparin's anticoagulant activity.

  9. Structural analysis and anticoagulant activities of the novel sulfated fucan possessing a regular well-defined repeating unit from sea cucumber.

    Science.gov (United States)

    Wu, Mingyi; Xu, Li; Zhao, Longyan; Xiao, Chuang; Gao, Na; Luo, Lan; Yang, Lian; Li, Zi; Chen, Lingyun; Zhao, Jinhua

    2015-04-13

    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.

  10. Evaluation of optical coherence tomography for the measurement of the effects of activators and anticoagulants on the blood coagulation in vitro.

    Science.gov (United States)

    Xu, Xiangqun; Geng, Jinhai; Liu, Gangjun; Chen, Zhongping

    2013-08-01

    Optical properties of human blood during coagulation were studied using optical coherence tomography (OCT) and the parameter of clotting time derived from the 1/e light penetration depth (d(1/e)) versus time was developed in our previous work. In this study, in order to know if a new OCT test can characterize the blood-coagulation process under different treatments in vitro, the effects of two different activators (calcium ions and thrombin) and anticoagulants, i.e., acetylsalicylic acid (ASA, a well-known drug aspirin) and melagatran (a direct thrombin inhibitor), at various concentrations are evaluated. A swept-source OCT system with a 1300 nm center wavelength is used for detecting the blood-coagulation process in vitro under a static condition. A dynamic study of d1/e reveals a typical behavior due to coagulation induced by both calcium ions and thrombin, and the clotting time is concentration-dependent. Dose-dependent ASA and melagatran prolong the clotting times. ASA and melagatran have different effects on blood coagulation. As expected, melagatran is much more effective than ASA in anticoagulation by the OCT measurements. The OCT assay appears to be a simple method for the measurement of blood coagulation to assess the effects of activators and anticoagulants, which can be used for activator and anticoagulant screening.

  11. 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.

  12. Purification, characterization and in vitro anticoagulant activity of polysaccharides from Gentiana scabra Bunge roots.

    Science.gov (United States)

    Cai, Weirong; Xu, Huiling; Xie, Liangliang; Sun, Jian; Sun, Taotao; Wu, Xiaoyan; Fu, Qinbao

    2016-04-20

    Three water-soluble polysaccharide fractions (GSP-1, GSP-2 and GSP-3) were obtained from Gentiana scabra Bunge roots by DEAE-Sepharose CL-6B and Sepharose CL-6B column chromatography. Their chemical characterizations were determined by high performance gel permeation chromatography (HPGPC), high performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD) and Fourier transform infrared (FT-IR) spectrometer. Moreover, their in vitro anticoagulant activities were evaluated by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) assays. GSP-1 and GSP-2 were composed of rhamnose, arabinose, galactose, glucose and galacturonic acid, while GSP-3 consisted of rhamnose, arabinose, galactose and galacturonic acid with a weight-average molecular weight of 5.8×10(4)Da. In comparison with the control group (saline), GSP, GSP-1, GSP-2 and GSP-3 could prolong APTT and TT, but not PT. Overall, GSP-3 exhibited potent anticoagulant activity and would be expected to be a potential source of anticoagulant.

  13. 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.

  14. Anticoagulant screening of marine algae from Mexico, and partial characterization of the active sulfated polysaccharide from Eisenia arborea

    OpenAIRE

    Muñoz Ochoa, Mauricio; Murillo-Álvarez, Jesús Iván; Rodríguez Montesinos, Yoloxochilt Elizabeth; Hernández Carmona, Gustavo; Arvizu Higuera, Dora Luz; Peralta Cruz, Javier;; Lizardi Mendoza, Jaime

    2009-01-01

    The in vitro anticoagulant activity of 41 water extracts of various seaweeds from Baja California Sur, Mexico was evaluated. In this study, nine extracts exhibited anticoagulant activity in the prothrombin time assay, and 29 extracts were active in the activated partial thromboplastin time assay. The water extract obtained at 25°C from the brown seaweed Eisenia arborea was the most active in both assays, increasing the normal blood clotting-time over 300 s at 100 mg mL-1. The fractionation of...

  15. Chemical Characteristics and Anticoagulant Activities of Two Sulfated Polysaccharides from Enteromorpha linza(Chlorophyta)

    Institute of Scientific and Technical Information of China (English)

    QI Xiaohui; MAO Wenjun; CHEN Yin; CHEN Yanli; ZHAO Chunqi; LI Na; WANG Chunyan

    2013-01-01

    Two sulfated polysaccharides,designated MP and SP,were extracted from the marine green alga Enteromorpha linza using hot water and then purified using ion-exchange and size-exclusion chromatography.The anticoagulant activities of MP and SP were examined by determination of their activated partial thromboplastin time (APTT),thrombin time (TT) and prothrombin time (PT) using human plasma.Results showed that MP and SP were composed of abundant rhamnose with small amounts of xylose and glucuronic acid,whereas SP also contained a small amount of galactose.Approximate molecular weights of MP and SP were 535 and 502kDa,respectively.As compared with SP,MP had higher contents of sulfate ester (19.0%) and uronic acid (14.9%).The MP mainly consisted of (1→4)-linked rhamnose residues with partially sulfated groups at the C-3 position,and small amounts of (1→3,4)-linked rhamnose,(1→2,4)-linked rhamnose,(1→4)-linked glucuronic acid and (1→4)-linked xylose residues.The SP contained abundant (1→4)-linked rhamnose with minor amounts of (1→3)-linked rhamnose,(1→3,4)-linked rhamnose,(1→2,4)-linked rhamnose,(1→4)-linked glucuronic acid,(1→4)-linked xylose,and (1→3)-linked galactose residues.The sulfate groups were mainly located at C-3 of (1→4)-linked rhamnose residues.Both MP and SP,in particular the former,effectively prolonged APTT and TT.This work demonstrates that MP and SP have unique structural characteristics distinct from those of other sulfated polysaccharides from Enteromorpha.The MP is a potential source of anticoagulant,and the difference in anticoagulant activities of the two sulfated polysaccharides is directly linked to the discrepancy of their chemical features.

  16. New parenteral anticoagulants in development.

    Science.gov (United States)

    Gómez-Outes, Antonio; Suárez-Gea, Maria Luisa; Lecumberri, Ramón; Rocha, Eduardo; Pozo-Hernández, Carmen; Vargas-Castrillón, Emilio

    2011-02-01

    The therapeutic armamentarium of parenteral anticoagulants available to clinicians is mainly composed by unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), fondaparinux, recombinant hirudins (i.e. bivalirudin, desirudin, lepirudin) and argatroban. These drugs are effective and safe for prevention and/or treatment of thromboembolic diseases but they have some drawbacks. Among other inconveniences, UFH requires regular anticoagulant monitoring as a result of variability in the anticoagulant response and there is a risk of serious heparin-induced thrombocytopaenia (HIT). LMWH, fondaparinux and recombinant hirudins are mainly cleared through the kidneys and their use in patients with severe renal insufficiency may be problematic. LMWH is only partially neutralized by protamine while fondaparinux and recombinant hirudins have no specific antidote. Novel anticoagulants in development for parenteral administration include new indirect activated factor Xa (FXa) inhibitors (idrabiotaparinux, ultra-low-molecular-weight heparins [semuloparin, RO-14], new LMWH [M118]), direct FXa inhibitors (otamixaban), direct FIIa inhibitors (flovagatran sodium, pegmusirudin, NU172, HD1-22), direct FXIa inhibitors (BMS-262084, antisense oligonucleotides targeting FXIa, clavatadine), direct FIXa inhibitors (RB-006), FVIIIa inhibitors (TB-402), FVIIa/tissue factor inhibitors (tifacogin, NAPc2, PCI-27483, BMS-593214), FVa inhibitors (drotrecogin alpha activated, ART-123) and dual thrombin/FXa inhibitors (EP217609, tanogitran). These new compounds have the potential to complement established parenteral anticoagulants. In the present review, we discuss the pharmacology of new parenteral anticoagulants, the results of clinical studies, the newly planned or ongoing clinical trials with these compounds, and their potential advantages and drawbacks over existing therapies.

  17. Anticoagulant-induced pseudothrombocytopenia occurring after transcatheter arterial embolization for hepatocellular carcinoma.

    Science.gov (United States)

    Yoshikawa, Takeshi; Nakanishi, Kayo; Maruta, Tsutomu; Takenaka, Daisuke; Hirota, Shozo; Matsumoto, Shinichi; Saigo, Katsuyasu; Ohno, Yoshiharu; Fujii, Masahiko; Sugimura, Kazuro

    2006-08-01

    Pseudothrombocytopenia (PTCP) is the in vitro phenomenon of anticoagulant-activated platelet agglutination that results in spuriously low platelet counts. We report the case of a 65-year-old man with EDTA- and sodium citrate-dependent PTCP occurring after transcatheter arterial embolization (TAE) for hepatocellular carcinoma (HCC) due to hepatitis C cirrhosis. Invasion of the portal and hepatic veins by HCC formed severe trans-tumoral arterio-venous shunts that were effectively treated by TAE. Two days after the therapy, PTCP was seen on blood count and continued for 4 months. The patient received unnecessary treatment for disseminated intravascular coagulation (DIC) until the diagnosis of PTCP was established. PTCP is a rare complication but should be considered after TAE for HCC; lack of recognition may lead the physician to misdiagnosis and patient mismanagement.

  18. Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora.

    Science.gov (United States)

    Silva, T M A; Alves, L G; de Queiroz, K C S; Santos, M G L; Marques, C T; Chavante, S F; Rocha, H A O; Leite, E L

    2005-04-01

    The brown algae Padina gymnospora contain different fucans. Powdered algae were submitted to proteolysis with the proteolytic enzyme maxataze. The first extract of the algae was constituted of polysaccharides contaminated with lipids, phenols, etc. Fractionation of the fucans with increasing concentrations of acetone produced fractions with different proportions of fucose, xylose, uronic acid, galactose, and sulfate. One of the fractions, precipitated with 50% acetone (v/v), contained an 18-kDa heterofucan (PF1), which was further purified by gel-permeation chromatography on Sephadex G-75 using 0.2 M acetic acid as eluent and characterized by agarose gel electrophoresis in 0.05 M 1,3 diaminopropane/acetate buffer at pH 9.0, methylation and nuclear magnetic resonance spectroscopy. Structural analysis indicates that this fucan has a central core consisting mainly of 3-beta-D-glucuronic acid 1-> or 4-beta-D-glucuronic acid 1 ->, substituted at C-2 with alpha-L-fucose or beta-D-xylose. Sulfate groups were only detected at C-3 of 4-alpha-L-fucose 1-> units. The anticoagulant activity of the PF1 (only 2.5-fold lesser than low molecular weight heparin) estimated by activated partial thromboplastin time was completely abolished upon desulfation by solvolysis in dimethyl sulfoxide, indicating that 3-O-sulfation at C-3 of 4-alpha-L-fucose 1-> units is responsible for the anticoagulant activity of the polymer.

  19. Structural characterization and anticoagulant activity of a sulfated polysaccharide from the green alga Codium divaricatum.

    Science.gov (United States)

    Li, Na; Mao, Wenjun; Yan, Mengxia; Liu, Xue; Xia, Zheng; Wang, Shuyao; Xiao, Bo; Chen, Chenglong; Zhang, Lifang; Cao, Sujian

    2015-05-05

    A sulfated polysaccharide, designated CP2-1, was isolated from the green alga Codium divaricatum by water extraction and purified by anion-exchange and size-exclusion chromatography. CP2-1 is a galactan which is highly sulfated and substituted with pyruvic acid ketals. On the basis of chemical and spectroscopic analyses, the backbone of CP2-1 was mainly composed of (1→3)-β-d-galactopyranose residues, branched by single (1→)-β-d-galactopyranose units attached to the main chain at C-4 positions. The degree of branching was estimated to be about 12.2%. Sulfate groups were at C-4 of (1→3)-β-d-galactopyranose and C-6 of non-reducing terminal galactose residues. In addition, the ketals of pyruvic acid were found at 3,4- of non-reducing terminal galactose residues forming a five-membered ring. CP2-1 possessed a high anticoagulant activity as assessed by the activated partial thromboplastin time and thrombin time assays. The investigation demonstrated that CP2-1 was an anticoagulant-active sulfated polysaccharide distinguishing from other sulfated polysaccharides from marine green algae.

  20. Partial characterization and anticoagulant activity of a heterofucan from the brown seaweed Padina gymnospora

    Directory of Open Access Journals (Sweden)

    Silva T.M.A.

    2005-01-01

    Full Text Available The brown algae Padina gymnospora contain different fucans. Powdered algae were submitted to proteolysis with the proteolytic enzyme maxataze. The first extract of the algae was constituted of polysaccharides contaminated with lipids, phenols, etc. Fractionation of the fucans with increasing concentrations of acetone produced fractions with different proportions of fucose, xylose, uronic acid, galactose, and sulfate. One of the fractions, precipitated with 50% acetone (v/v, contained an 18-kDa heterofucan (PF1, which was further purified by gel-permeation chromatography on Sephadex G-75 using 0.2 M acetic acid as eluent and characterized by agarose gel electrophoresis in 0.05 M 1,3 diaminopropane/acetate buffer at pH 9.0, methylation and nuclear magnetic resonance spectroscopy. Structural analysis indicates that this fucan has a central core consisting mainly of 3-ß-D-glucuronic acid 1-> or 4-ß-D-glucuronic acid 1 ->, substituted at C-2 with alpha-L-fucose or ß-D-xylose. Sulfate groups were only detected at C-3 of 4-alpha-L-fucose 1-> units. The anticoagulant activity of the PF1 (only 2.5-fold lesser than low molecular weight heparin estimated by activated partial thromboplastin time was completely abolished upon desulfation by solvolysis in dimethyl sulfoxide, indicating that 3-O-sulfation at C-3 of 4-alpha-L-fucose 1-> units is responsible for the anticoagulant activity of the polymer.

  1. Effect of anticoagulants on the protein corona-induced reduced drug carrier adhesion efficiency in human blood flow.

    Science.gov (United States)

    Sobczynski, Daniel J; Eniola-Adefeso, Omolola

    2017-01-15

    Plasma proteins rapidly coat the surfaces of particulate drug carriers to form a protein corona upon their injection into the bloodstream. The high presence of immunoglobulins in the corona formed on poly(lactic-co-glycolic acid) (PLGA) vascular-targeted carrier (VTC) surfaces was recently shown to negatively impact their adhesion to activated endothelial cells (aECs) in vitro. Here, we characterized the influence of anticoagulants, or their absence, on the binding efficiency of VTCs of various materials via modulation of their protein corona. Specifically, we evaluated the adhesion of PLGA, poly(lactic acid) (PLA), polycaprolactone (PCL), silica, and polystyrene VTCs to aECs in heparinized, citrated, and non-anticoagulated (serum and whole) blood flows relative to buffer control. Particle adhesion is substantially reduced in non-anticoagulated blood flows regardless of the material type while only moderate to minimal reduction is observed for VTCs in anticoagulant-containing blood flow depending on the anticoagulant and material type. The substantial reduction in VTC adhesion in blood flows was linked to a high presence of immunoglobulin-sized proteins in the VTC corona via SDS-PAGE analysis. Of all the materials evaluated, PLGA was the most sensitive to plasma protein effects while PCL was the most resistant, suggesting particle hydrophobicity is a critical component of the observed negative plasma protein effects. Overall, this work demonstrates that anticoagulant positively alters the effect of plasma proteins in prescribing VTC adhesion to aECs in human blood flow, which has implication in the use of in vitro blood flow assays for functional evaluation of VTCs for in vivo use.

  2. Changes in coagulation and lytic activity of the blood and tissues at the pelvic trauma during anticoagulant therapy

    Directory of Open Access Journals (Sweden)

    A. P. Vlasov

    2014-01-01

    Full Text Available The purpose of our study was exploration of coagulation and lytic activity in blood and tissues during anticoagulation therapy in the early posttraumatic period in patients with pelvic bone fracture. The study was based on experiment researches using methods allowing to estimate coagulation activity in different tissues (skeletal muscles, liver, kidneys, heart, lungs and blood at pelvic trauma during anticoagulation therapy. It was established that at pelvic trauma using anticoagulation therapy (fraxiparine leads to hemostatic system modification in the early posttraumatic period. We observed fast decrease of a hypercoagulability in a blood plasma (organism level and growth fibrinolytic activity. In liver, kidneys, heart and lungs tissues (organ level we also registered correction the hemostatic disorders. However, the rate of these recovery processes in tissues is lower than in the blood. Especially low it was in skeletal muscles in the area of injury. Thus, it is proved that anticoagulant therapy at a pelvic trauma affects on the extrinsic coagulation pathway less than on the intrinsic coagulation pathway. The established regularity explains the risks of coagulation abnormalities in the early posttraumatic period during anticoagulation treatment.

  3. A sulfated fucan from the brown alga Laminaria cichorioides has mainly heparin cofactor II-dependent anticoagulant activity.

    Science.gov (United States)

    Yoon, Seon-Joo; Pyun, Yu-Ryang; Hwang, Jae-Kwan; Mourão, Paulo A S

    2007-11-05

    The major acidic polysaccharide from the brown alga Laminaria cichorioides is a complex and heterogeneous sulfated fucan. Its preponderant structure is a 2,3-disulfated, 4-linked alpha-fucose unit. The purified polysaccharide has a potent anticoagulant activity, as estimated by APTT assay ( approximately 40 IU/mg), which is mainly mediated by thrombin inhibition by heparin cofactor II. It also accelerates thrombin and factor Xa inhibition by antithrombin but at a lower potency. Sulfated fucan from L. cichorioides is a promising anticoagulant polysaccharide and a possible alternative for an antithrombotic compound due to its preferential heparin cofactor II-dependent activity.

  4. Anticoagulant and antithrombotic activities of modified xylofucan sulfate from the brown alga Punctaria plantaginea.

    Science.gov (United States)

    Ustyuzhanina, Nadezhda E; Bilan, Maria I; Gerbst, Alexey G; Ushakova, Natalia A; Tsvetkova, Eugenia A; Dmitrenok, Andrey S; Usov, Anatolii I; Nifantiev, Nikolay E

    2016-01-20

    Selectively and totally sulfated (1 → 3)-linked linear homofucans bearing ∼ 20 monosaccharide residues on average have been prepared from the branched xylofucan sulfate isolated from the brown alga Punctaria plantaginea. Anticoagulant and antithrombotic properties of the parent biopolymer and its derivatives were assessed in vitro. Highly sulfated linear fucan derivatives were shown to inhibit clot formation in APTT assay and ristocetin induced platelets aggregation, while the partially sulfated analogs were inactive. In the experiments with purified proteins, fucan derivatives with degree of sulfation of ∼ 2.0 were found to enhance thrombin and factor Xa inhibition by antithrombin III. The effect of sulfated fucans on thrombin inhibition, which was similar to those of heparinoid Clexane(®) (enoxaparin) and of a fucoidan from the brown alga Saccharina latissima studied previously, can be explained by the multicenter interaction and formation of a ternary complex thrombin-antithrombin III-polysaccharide. The possibility of such complexation was confirmed by computer docking study.

  5. Heparins with reduced anti-coagulant activity reduce myocardial reperfusion injury.

    Science.gov (United States)

    Barry, William H; Kennedy, Thomas P

    2011-05-01

    Heparin which is desulfated at the 2-O and 3-O positions (ODSH) has reduced anti-coagulant properties, and reduced interaction with heparin antibodies. Because of the reduced anti-coagulant effect, ODSH can be safely administered to animals and humans intravenously at doses up to 20 mg/kg, resulting in a serum concentration of up to 250µg/ml. Administration of ODSH causes a 35% reduction in infarct size in dogs and pigs subjected to coronary artery occlusion and reperfusion when given 5 min before reperfusion. ODSH has anti-inflamatory effects, manifest as a decrease in neutrophil infiltration into ischemic tissue at high doses, but this effect does not entirely account for the reduction in infarct size. ODSH decreases Na(+) and Ca(2+) loading in isolated cardiac myocytes subjected to simulated ischemia. This effect appears due to an ODSH-induced reduction in an enhanced Na(+) influx via the Na channel in the membrane of cardiac myocyes caused by oxygen radicals generated during ischemia and reperfusion. Reduction in Na(+) influx decreases Ca(2+) loading by reducing Ca2(+) influx via Na/Ca exchange, thus reducing Ca(2+) - dependent reperfusion injury. ODSH does not appear to interact with antibodies to the heparin/platelet factor 4 complex, and does not cause heparin-induced thrombocytopenia. Because of these therapeutic and safety considerations, ODSH would appear to be a promising heparin derivative for prevention of reperfusion injury in humans undergoing thrombolytic or catheter-based reperfusion for acute myocardial infarction. The review article discussed the use of heparin and the discussion of some of the important patents, including: US6489311; US7478358; PCTUS2008070836 and PCTUS2009037836.

  6. Sulfation of fucogalactan from Agaricus bisporus: Different patterns in the chemical structure and their effects on anticoagulant activity.

    Science.gov (United States)

    Román Ochoa, Yony; Iacomini, Marcello; Sassaki, Guilherme Lanzi; Cipriani, Thales Ricardo

    2017-04-01

    A fucogalactan from Agaricus bisporus was sulfated by two methodologies based on an optimized sulfation method. The direct action of chlorosulfonic acid and SO3-pyridine complex over the sulfation reaction and its effects on anticoagulant activity were evaluated. The products of chemical sulfations were two sulfated fucogalactans named E100 and ESL respectively. Clotting assays (APTT, PT and TT) showed that both sulfated polysaccharides have anticoagulant activity, and that ESL was more potent compared to E100. The FXa, T and FXIIa activities in the presence of the sulfated polysaccharides were determined. The better anticoagulant activity of ESL could be related to anti-FXIIa activity and also probably to its higher bioavailability. The HPSEC analysis showed similar Mw of 1.08×10(4)gmol(-1) and 1.00×10(4)gmol(-1) for E100 and ESL respectively. NMR and methylation analyses indicated a heterogeneous sulfation pattern for E100, whereas ESL showed conserved unsulfated (1→6)-linked α-d-Galp residues in the main-chain and a more homogeneous sulfation pattern. The DS values of ESL and E100 were 1.0 and 2.8 respectively, indicating that the sulfation pattern is more important for the anticoagulant activity than the amount of sulfate.

  7. An Anti-Coagulation Conundrum: Implantation of Total Artificial Heart in a Patient with Heparin-Induced Thrombocytopenia Type II

    Science.gov (United States)

    Cios, Theodore J.; Salamanca-Padilla, Yuliana; Guvakov, Dmitri

    2017-01-01

    Patient: Male, 44 Final Diagnosis: Heparin-induced thrombocytopenia Type II Symptoms: Congestive heart failure • short of breath Medication: — Clinical Procedure: LVAD explantation • TAH insertion Specialty: Anesthesiology Objective: Rare co-existance of disease or pathology Background: Heparin-induced thrombocytopenia (HIT) is a rare but life-threatening complication of heparin administration. It can present a major clinical dilemma for physicians caring for patients requiring life-saving urgent or emergent cardiac surgery. Studies have been published examining the use of alternative anticoagulants for patients undergoing cardiopulmonary bypass (CPB), however, evidence does not clearly support any particular approach. Presently, there are no large-scale, prospective randomized studies examining the impact of alternative anticoagulants on clinical outcomes for HIT-positive patients requiring cardiac surgery. Case Report: We present the case of a patient who underwent SynCardia Total Artificial Heart (TAH) implantation following a recent left ventricular assist device (LVAD) placement. The patient was receiving argatroban for type II HIT with anuric renal failure, and developed a thrombus which occluded the inflow cannula of the LVAD. Based on a published study and after establishing consensus with the surgical, anesthesiology, perfusion, and hematology teams, we decided to use tirofiban as an antiplatelet agent to inhibit the platelet aggregation induced by heparin, and ultimately used heparin as the anticoagulant for cardiopulmonary bypass. Conclusions: When selecting anticoagulation for a HIT-positive patient requiring CPB, so that benefits outweigh risks, it is of paramount importance that the decision be based on a multitude of factors. The team caring for the patient should have a shared mental model and be familiar with the pharmacology, devices used, and local practices. These three elements should be integrated with patient-specific comorbidities

  8. Optimization of chemical sulfation, structural characterization and anticoagulant activity of Agaricus bisporus fucogalactan.

    Science.gov (United States)

    Román, Yony; Iacomini, Marcello; Sassaki, Guilherme L; Cipriani, Thales R

    2016-08-01

    A fucogalactan (E) was isolated from aqueous extract of Agaricus bisporus. The monosaccharide composition, methylation, and NMR analyses showed it is constituted by a (1→6)-linked α-d-Galp main-chain, partially methylated at O-3, and partially substituted at O-2 by non-reducing end-units of α-l-Fucp or α-d-Galp. HPSEC analysis showed it had Mw of 1.28×10(4)gmol(-1). The polysaccharide was sulfated modifying reaction time, molar ratio of sulfation agent to hydroxyl group on the polysaccharide (ηClSO3H/OH ratio), and ratio of total reaction volume to weight of sample (VT/w ratio; μLmg(-1)). The degree of substitution (DS) was evaluated for all sulfated derivatives. The sulfated fucogalactan with the highest DS value (2.83) had the best anticoagulant activity on Activated Partial Thromboplastin Time (APTT) and Protrombin Time (PT) assays. This sulfated fucogalactan, named E100, was obtained with the optimal conditions of ηClSO3H/OH ratio of 18, VT/w ratio of 100, in 6h of reaction. The results showed that E100 produces a linear increment of APTT for concentrations of 15-45μgmL(-1), whereas PT was almost constant between 20 and 400μgmL(-1), suggesting an anticoagulant activity via inhibition of the intrinsic pathway of blood coagulation. NMR and methylation analyses showed that α-d-Galp units of the main chain were greatly sulfated on 2-O-, 3-O-, and 4-O-positions.

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

    Institute of Scientific and Technical Information of China (English)

    QI Huimin; LI Daxin; ZHANG Jingjing; LIU Li; ZHANG Quanbin

    2008-01-01

    Gelidium amansii agar was fractionated on DEAE-cellulose and four fractions were obtained sequentially.The yields of 1.0mol/L NaCl fraction and 2.5mol/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 400mg/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.

  10. 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.

  11. Anticoagulant-induced hemopericardium with tamponade: A case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Faruk Ertaş

    2013-06-01

    Full Text Available Acute cardiac tamponade requires urgent diagnosis andtreatment. We report a case of a 43-year-old man whowas receiving warfarin treatment for 8 months followingmitral valve replacement. The patient had complaint ofdyspnea and fatigue for a few days. Cardiac tamponadewas diagnosed, and the INR at that time was 10.4. Urgentpericardiocentesis were undertaken and 1400 ml of pericardialblood was drained. Following surgery the patient’srecovery was uneventful. An intravenous vitamin K injectionand fresh frozen plasma transfusion were administeredto reverse the patient’s over-anticoagulated state.The final pathology revealed chronic inflammation andthere was no malignancy, and no bacteria or mycobacteriumwere seen. Emergency physicians should rememberthat over-anticoagulation with warfarin may contribute tocertain complications, including hemopericardium, andthat strict control of target INR should be the goal for patientswho require continuous warfarin treatment. J ClinExp Invest 2013; 4 (2: 229-233Key words: Hemopericardium, tamponade, oral anticoagulation,warfarin, echocardiography

  12. Anticoagulant, antioxidant and antitumor activities of heterofucans from the seaweed Dictyopteris delicatula.

    Science.gov (United States)

    Magalhaes, Kaline Dantas; Costa, Leandro Silva; Fidelis, Gabriel Pereira; Oliveira, Ruth Medeiros; Nobre, Leonardo Thiago Duarte Barreto; Dantas-Santos, Nednaldo; Camara, Rafael Barros Gomes; Albuquerque, Ivan Rui Lopes; Cordeiro, Sara Lima; Sabry, Diego Araujo; Costa, Mariana Santana Santos Pereira; Alves, Luciana Guimaraes; Rocha, Hugo Alexandre Oliveira

    2011-01-01

    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.

  13. 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.

  14. 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...

  15. Antioxidant and anticoagulant activity of sulfated polysaccharide from Gracilaria debilis (Forsskal).

    Science.gov (United States)

    Sudharsan, Sadhasivam; Subhapradha, Namasivayam; Seedevi, Palaniappan; Shanmugam, Vairamani; Madeswaran, Perumal; Shanmugam, Annaian; Srinivasan, Alagiri

    2015-11-01

    Sulfated polysaccharide was isolated from Gracilaria debilis and purified through gel chromatography and their molecular weight was determined through AGE and PAGE. The total sugars in the crude, fractionated and purified polysaccharide were estimated as 52.65%, 59.70% and 67.60%, respectively. The ash and moisture content of crude and purified polysaccharide was found to be 14.2% and 23.5% and the polysaccharide was free from protein contamination. The sulfate and uronic acid contents in the crude, fractionated and purified were estimated as 14.08%, 15.33% and 16.01% and 10.12%, 13.56%, 16.70%. The elemental composition including carbon (crude - 23.12%, purified - 21.05%), hydrogen (crude - 3.4%, purified - 4.13%) and nitrogen (crude - 1.22%, purified - 0.56%) were also analyzed. The anticoagulant activity of the sulfated polysaccharide through APTT and PT was estimated at 14.11 and 8.23IU/mg. The purified polysaccharide with the molecular mass of 20kDa showed highest antioxidant activity (38.57%, 43.48% and 38.88%) in all the assays tested such as DPPH hydroxyl radical, superoxide radical, hydroxyl radical scavenging activities and the structural property was analyzed through FT-IR and (1)H NMR spectrum. The results together suggest that the isolated low molecular weight sulfated polysaccharide will demonstrate as a enormously available alternative natural source of antioxidant for industrial uses.

  16. Conformation of sulfated galactan and sulfated fucan in aqueous solutions: implications to their anticoagulant activities.

    Science.gov (United States)

    Becker, Camila F; Guimarães, Jorge A; Mourão, Paulo A S; Verli, Hugo

    2007-07-01

    The discovery of sulfated galactans and sulfated fucans in marine invertebrates with simple and ordered structures opened new perspectives to investigate the biological activity of these molecules and to determine whether different structures confer high affinity for a particular protein. We undertook a conformational analysis of a 2-sulfated, 3-linked alpha-L-galactan and of a alpha-L-fucan with similar structure. Through comparison between theoretical and NMR derived coupling constants, we observed that the pyranose rings are predominantly in the (1)C(4) conformation in these polysaccharides. Additionally, the geometry of the glycosidic linkages was determined based on force field calculations, indicating that the two polysaccharides have similar conformations in solution. Since the sulfated alpha-L-galactan, but not the alpha-L-fucan potentiates antithrombin (AT) inhibition of thrombin, the solution conformations of the compounds were docked into AT and the complexes obtained were refined through molecular dynamics calculations. The obtained results indicates extremely different orientations for the two polysaccharides, which well correlates and explain their distinct anticoagulant activities. Finally, the molecular mechanism of a selective 2-desulfation reaction, observed among sulfated fucans, was explained as a consequence of an intramolecular hydrogen bond capable of assisting in the removal of the charged group.

  17. Heterofucans from the brown seaweed Canistrocarpus cervicornis with anticoagulant and antioxidant activities.

    Science.gov (United States)

    Camara, Rafael Barros Gomes; Costa, Leandro Silva; Fidelis, Gabriel Pereira; Nobre, Leonardo Thiago Duarte Barreto; Dantas-Santos, Nednaldo; Cordeiro, Sara Lima; Costa, Mariana Santana Santos Pereira; Alves, Luciana Guimaraes; Rocha, Hugo Alexandre Oliveira

    2011-01-24

    Fucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated l-fucose. We extracted six fucans from Canistrocarpus cervicornis by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucuronic acid, galactose and sulfate. No polysaccharide was capable of prolonging prothrombin time (PT) at the concentration assayed. However, all polysaccharides prolonged activated partial thromboplastin time (aPTT). Four sulfated polysaccharides (CC-0.3/CC-0.5/CC-0.7/CC-1.0) doubled aPTT with only 0.1 mg/mL of plasma, only 1.25-fold less than Clexane, a commercial low molecular weight heparin. Heterofucans exhibited total antioxidant capacity, low hydroxyl radical scavenging activity, good superoxide radical scavenging efficiency (except CC-1.0), and excellent ferrous chelating ability (except CC-0.3). These results clearly indicate the beneficial effect of C. cervicornis polysaccharides as anticoagulants and antioxidants. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents.

  18. Heterofucans from the Brown Seaweed Canistrocarpus cervicornis with Anticoagulant and Antioxidant Activities

    Directory of Open Access Journals (Sweden)

    Hugo Alexandre Oliveira Rocha

    2011-01-01

    Full Text Available Fucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated L-fucose. We extracted six fucans from Canistrocarpus cervicornis by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucuronic acid, galactose and sulfate. No polysaccharide was capable of prolonging prothrombin time (PT at the concentration assayed. However, all polysaccharides prolonged activated partial thromboplastin time (aPTT. Four sulfated polysaccharides (CC-0.3/CC-0.5/CC-0.7/CC-1.0 doubled aPTT with only 0.1 mg/mL of plasma, only 1.25-fold less than Clexane®, a commercial low molecular weight heparin. Heterofucans exhibited total antioxidant capacity, low hydroxyl radical scavenging activity, good superoxide radical scavenging efficiency (except CC-1.0, and excellent ferrous chelating ability (except CC-0.3. These results clearly indicate the beneficial effect of C. cervicornis polysaccharides as anticoagulants and antioxidants. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents.

  19. 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.

  20. A novel prothrombin time assay for assessing the anticoagulant activity of oral factor Xa inhibitors.

    Science.gov (United States)

    Barrett, Yu Chen; Wang, Zhaoqing; Knabb, Robert M

    2013-09-01

    Conventional prothrombin time (PT) assays have limited sensitivity and dynamic range in monitoring the anticoagulant activity of direct factor Xa inhibitors. Hence, new assays are needed. We modified a PT assay by adding calcium chloride (CaCl2) to the thromboplastin reagent to increase assay dynamic range and improve sensitivity. Effects of calcium and sodium ion concentrations, and sample handling, were evaluated to optimize assay performance. Increasing concentrations of calcium ions produced progressive increases in PT across the factor Xa inhibitor concentrations of 0 to 2500 nmol/L for razaxaban and apixaban. The greatest effect was seen when the thromboplastin reagent was diluted 1:2.25 with 100 mmol/L CaCl2 (thus selected for routine use). The optimized assay showed an interassay precision of 1.5 to 9.3 percentage coefficient of variation (%CV) for razaxaban and 3.1 to 4.6 %CV for apixaban. We conclude that the modified PT assay is likely to be suitable as a pharmacodynamic marker for activity at therapeutic concentrations of factor Xa inhibitors.

  1. Depolymerization of Fucosylated Chondroitin Sulfate with a Modified Fenton-System and Anticoagulant Activity of the Resulting Fragments

    Science.gov (United States)

    Li, Jun-hui; Li, Shan; Zhi, Zi-jian; Yan, Lu-feng; Ye, Xing-qian; Ding, Tian; Yan, Lei; Linhardt, Robert John; Chen, Shi-guo

    2016-01-01

    Fucosylated chondroitin sulfate (fCS) from sea cucumber Isostichopus badionotus (fCS-Ib) with a chondroitin sulfate type E (CSE) backbone and 2,4-O-sulfo fucose branches has shown excellent anticoagulant activity although has also show severe adverse effects. Depolymerization represents an effective method to diminish this polysaccharide’s side effects. The present study reports a modified controlled Fenton system for degradation of fCS-Ib and the anticoagulant activity of the resulting fragments. Monosaccharides and nuclear magnetic resonance (NMR) analysis of the resulting fragments indicate that no significant chemical changes in the backbone of fCS-Ib and no loss of sulfate groups take place during depolymerization. A reduction in the molecular weight of fCS-Ib should result in a dramatic decrease in prolonging activated partial thromboplastin time and thrombin time. A decrease in the inhibition of thrombin (FIIa) by antithromin III (AT III) and heparin cofactor II (HCII), and the slight decrease of the inhibition of factor X activity, results in a significant increase of anti-factor Xa (FXa)/anti-FIIa activity ratio. The modified free-radical depolymerization method enables preparation of glycosaminoglycan (GAG) oligosaccharides suitable for investigation of clinical anticoagulant application. PMID:27657094

  2. Structure and anticoagulant activity of a fucosylated chondroitin sulfate from echinoderm. Sulfated fucose branches on the polysaccharide account for its high anticoagulant action.

    Science.gov (United States)

    Mourão, P A; Pereira, M S; Pavão, M S; Mulloy, B; Tollefsen, D M; Mowinckel, M C; Abildgaard, U

    1996-09-27

    A polysaccharide isolated from the body wall of the sea cucumber Ludwigothurea grisea has a backbone like that of mammalian chondroitin sulfate: [4-beta-D-GlcA-1-->3-beta-D-GalNAc-1]n but substituted at the 3-position of the beta--glucuronic acid residues with sulfated alpha--fucopyranosyl branches (Vieira, R. P., Mulloy, B., and Mourão, P. A. S. (1991) J. Biol. Chem. 266, 13530-13536). Mild acid hydrolysis removes the sulfated alpha--fucose branches, and cleaved residues have been characterized by 1H NMR spectroscopy; the most abundant species is fucose 4-O-monosulfate, but 2,4- and 3, 4-di-O-sulfated residues are also present. Degradation of the remaining polysaccharide with chondroitin ABC lyase shows that the sulfated alpha-L-fucose residues released by mild acid hydrolysis are concentrated toward the non-reducing end of the polysaccharide chains; enzyme-resistant polysaccharide material includes the reducing terminal and carries acid-resistant -fucose substitution. The sulfated alpha-L-fucose branches confer anticoagulant activity on the polysaccharide. The specific activity of fucosylated chondroitin sulfate in the activated partial thromboplastin time assay is greater than that of a linear homopolymeric alpha-L-fucan with about the same level of sulfation; this activity is lost on defucosylation or desulfation but not on carboxyl-reduction of the polymer. Assays with purified reagents show that the fucosylated chondroitin sulfate can potentiate the thrombin inhibition activity of both antithrombin and heparin cofactor II.

  3. Menthol reduces the anticoagulant effect of warfarin by inducing cytochrome P450 2C expression.

    Science.gov (United States)

    Hoshino, Motohiro; Ikarashi, Nobutomo; Tsukui, Makoto; Kurokawa, Asako; Naito, Rina; Suzuki, Midori; Yokobori, Kohsuke; Ochiai, Takumi; Ishii, Makoto; Kusunoki, Yoshiki; Kon, Risako; Ochiai, Wataru; Wakui, Nobuyuki; Machida, Yoshiaki; Sugiyama, Kiyoshi

    2014-06-02

    Recently, it was reported that the anticoagulant effect of warfarin was reduced when patients receiving warfarin also took menthol. The purpose of this study is to reveal the mechanism of this reduced anticoagulant effect of warfarin from the pharmacokinetic point of view. Warfarin was orally administered to mice 24h after the administration of menthol for 2 days, and the plasma warfarin concentration was measured. In the menthol administration group, the area under the blood concentration time curve of warfarin was decreased by approximately 25%, while total clearance was increased to 1.3-fold compared to the control group. The hepatic cytochrome P450 (CYP) 2C protein expression level in the menthol administration group was significantly increased compared to that in the control group. An increase in the nuclear translocation of constitutive androstane receptor (CAR) was also observed. The addition of menthol to human hepatic cells, HepaRG cells, caused an increase in the mRNA expression level of CYP2C9. The results of this study revealed that menthol causes an increase in CYP2C expression levels in the liver, which leads to an enhancement of warfarin metabolism, resulting in a decreased anticoagulant effect of warfarin. It was also suggested that menthol acted directly on the liver and increased the expression level of CYP2C by enhancing the nuclear translocation of CAR.

  4. The structure-anticoagulant activity relationships of sulfated lacquer polysaccharide: effect of carboxyl group and position of sulfation.

    Science.gov (United States)

    Yang, Jianhong; Du, Yumin; Huang, Ronghua; Wan, Yunyang; Wen, Yan

    2005-07-01

    Regiospecific oxidation of the primary hydroxyl groups in lacquer polysaccharide (LPL, Mw 6.85 x 10(4)) and its NaIO4 oxidation derivatives (LPLde) to C-6 carboxy groups was achieved with NaOCl in the presence of Tempo and NaBr. Sulfate groups were incorporated into the oxidated polysaccharides using Py.SO3 complex as a reagent. Reactivity of polysaccharide hydroxyl group was C-6 > C-2 > C-4. Sulfate groups were mainly linked to the second hydroxy at C-2 in the products. The results of APTT assay showed after incorporation of carboxyl groups into lacquer polysaccharides, the intrinsic coagulation pathway was promoted, and all sulfated polysaccharides had very weak anticoagulant activity within the scope of studied DS (0.39-1.11). These indicated that carboxyl groups and sulfate groups had the synergistic action. At the same time, the anticoagulant activity increased very slowly with the DS in the second hydroxy. This indicated that 6-O-SO3- in the side chains took an important role in the anticoagulant activity.

  5. Structure and anticoagulant activity of sulfated galactans. Isolation of a unique sulfated galactan from the red algae Botryocladia occidentalis and comparison of its anticoagulant action with that of sulfated galactans from invertebrates.

    Science.gov (United States)

    Farias, W R; Valente, A P; Pereira, M S; Mourão, P A

    2000-09-22

    We have characterized the structure of a sulfated d-galactan from the red algae Botryocladia occidentalis. The following repeating structure (-4-alpha-d-Galp-1-->3-beta-d-Galp-1-->) was found for this polysaccharide, but with a variable sulfation pattern. Clearly one-third of the total alpha-units are 2,3-di-O-sulfated and another one-third are 2-O-sulfated. The algal sulfated d-galactan has a potent anticoagulant activity (similar potency as unfractionated heparin) due to enhanced inhibition of thrombin and factor Xa by antithrombin and/or heparin cofactor II. We also extended the experiments to several sulfated polysaccharides from marine invertebrates with simple structures, composed of a single repeating structure. A 2-O- or 3-O-sulfated l-galactan (as well as a 2-O-sulfated l-fucan) has a weak anticoagulant action when compared with the potent action of the algal sulfated d-galactan. Possibly, the addition of two sulfate esters to a single alpha-galactose residue has an "amplifying effect" on the anticoagulant action, which cannot be totally ascribed to the increased charge density of the polymer. These results indicate that the wide diversity of polysaccharides from marine alga and invertebrates is a useful tool to elucidate structure/anticoagulant activity relationships.

  6. Successful Use of Alternative Anticoagulants in the Management of Heparin-induced Thrombocytopenia with Thrombotic Complications: Report of 5 cases and review of literature.

    LENUS (Irish Health Repository)

    Alkindi, Salam

    2011-08-01

    Heparin is one of the most frequently used anticoagulants. It is easy to use, but can be associated with life-threatening side effects. One of these is heparin-induced thrombocytopenia syndrome (HITS), which develops in about 3-5% of patients exposed to heparin and is associated with thrombosis in 1% of cases. We report here the successful treatment of five patients with HITS who were treated with alternative anticoagulants namely danaparoid or hirudin. The median time between their exposure to heparin and onset of symptoms and or signs was 10.2 days (range 7-14 days). Platelet counts decreased to a mean of 38.4 x 10(9) \\/l (12-82 x 10(9)\\/l). All five patients had evidence of thrombosis; four patients had clinical and radiological evidence of pulmonary emboli, one patient had confirmed deep vein thrombosis (DVT) and one patient had extensive skin necrosis of the thighs and abdomen. Platelet aggregation test were positive in two patients, inconclusive in one patient and negative in two patients. Two patients were anticoagulated with danaparoid and three with hirudin until their platelet counts returned to normal between 4 and 14 days (average 6 days) following the recognition of the syndrome. Our patients had significant morbidity, but no mortality. Immediate withdrawal of heparin is of paramount importance and introduction of alternative anticoagulant is necessary in the presence of thrombosis.

  7. Earthworm extracts utilized in the green synthesis of gold nanoparticles capable of reinforcing the anticoagulant activities of heparin

    Science.gov (United States)

    Kim, Hee Kyeong; Choi, Myung-Jin; Cha, Song-Hyun; Koo, Yean Kyoung; Jun, Sang Hui; Cho, Seonho; Park, Youmie

    2013-12-01

    Gold nanoparticles were obtained using a green synthesis approach with aqueous earthworm extracts without any additional reducing or capping agents. The gold nanoparticles were characterized using UV-visible spectrophotometry, high-resolution transmission electron microscopy, atomic force microscopy, field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma mass spectrometry. The anticoagulant activity of the gold nanoparticles was assessed using the activated partial thromboplastin time and was mildly enhanced by combining the gold nanoparticles with heparin. In addition to the generation of spherical nanoparticles with an average diameter of 6.13 ± 2.13 nm, cubic and block-shaped nanoparticles with an average aspect ratio, defined as the length divided by width, of 1.47 were also observed.

  8. Structure and anticoagulant activity of sulfated fucans. Comparison between the regular, repetitive, and linear fucans from echinoderms with the more heterogeneous and branched polymers from brown algae.

    Science.gov (United States)

    Pereira, M S; Mulloy, B; Mourão, P A

    1999-03-19

    Sulfated fucans are among the most widely studied of all the sulfated polysaccharides of non-mammalian origin that exhibit biological activities in mammalian systems. Examples of these polysaccharides extracted from echinoderms have simple structures, composed of oligosaccharide repeating units within which the residues differ by specific patterns of sulfation among different species. In contrast the algal fucans may have some regular repeating structure but are clearly more heterogeneous when compared with the echinoderm fucans. The structures of the sulfated fucans from brown algae also vary from species to species. We compared the anticoagulant activity of the regular and repetitive fucans from echinoderms with that of the more heterogeneous fucans from three species of brown algae. Our results indicate that different structural features determine not only the anticoagulant potency of the sulfated fucans but also the mechanism by which they exert this activity. Thus, the branched fucans from brown algae are direct inhibitors of thrombin, whereas the linear fucans from echinoderms require the presence of antithrombin or heparin cofactor II for inhibition of thrombin, as reported for mammalian glycosaminoglycans. The linear sulfated fucans from echinoderms have an anticoagulant action resembling that of mammalian dermatan sulfate and a modest action through antithrombin. A single difference of one sulfate ester per tetrasaccharide repeating unit modifies the anticoagulant activity of the polysaccharide markedly. Possibly the spatial arrangements of sulfate esters in the repeating tetrasaccharide unit of the echinoderm fucan mimics the site in dermatan sulfate with high affinity for heparin cofactor II.

  9. Selective cleavage and anticoagulant activity of a sulfated fucan: stereospecific removal of a 2-sulfate ester from the polysaccharide by mild acid hydrolysis, preparation of oligosaccharides, and heparin cofactor II-dependent anticoagulant activity.

    Science.gov (United States)

    Pomin, Vitor H; Pereira, Mariana S; Valente, Ana-Paula; Tollefsen, Douglas M; Pavão, Mauro S G; Mourão, Paulo A S

    2005-04-01

    A linear sulfated fucan with a regular repeating sequence of [3)-alpha-L-Fucp-(2SO4)-(1-->3)-alpha-L-Fucp-(4SO4)-(1-->3)-alpha-L-Fucp-(2,4SO4)-(1-->3)-alpha-L-Fucp-(2SO4)-(1-->]n is an anticoagulant polysaccharide mainly due to thrombin inhibition mediated by heparin cofactor II. No specific enzymatic or chemical method is available for the preparation of tailored oligosaccharides from sulfated fucans. We employ an apparently nonspecific approach to cleave this polysaccharide based on mild hydrolysis with acid. Surprisingly, the linear sulfated fucan was cleaved by mild acid hydrolysis on an ordered sequence. Initially a 2-sulfate ester of the first fucose unit is selectively removed. Thereafter the glycosidic linkage between the nonsulfated fucose residue and the subsequent 4-sulfated residue is preferentially cleaved by acid hydrolysis, forming oligosaccharides with well-defined size. The low-molecular-weight derivatives obtained from the sulfated fucan were employed to determine the requirement for interaction of this polysaccharide with heparin cofactor II and to achieve complete thrombin inhibition. The linear sulfated fucan requires significantly longer chains than mammalian glycosaminoglycans to achieve anticoagulant activity. A slight decrease in the molecular size of the sulfated fucan dramatically reduces its effect on thrombin inactivation mediated by heparin cofactor II. Sulfated fucan with approximately 45 tetrasaccharide repeating units binds to heparin cofactor II but is unable to link efficiently the plasma inhibitor and thrombin. This last effect requires chains with approximately 100 or more tetrasaccharide repeating units. We speculate that the template mechanism may predominate over the allosteric effect in the case of the linear sulfated fucan inactivation of thrombin in the presence of heparin cofactor II.

  10. MONITORING OF ANTICOAGULATION IN APROTININ-TREATED PATIENTS DURING HEART OPERATION

    NARCIS (Netherlands)

    TABUCHI, N; NJO, TL; TIGCHELAAR, [No Value; HUYZEN, RJ; BOONSTRA, PW; VANOEVEREN, W

    1994-01-01

    Since aprotinin has become extensively used during cardiopulmonary bypass the maintenance of safe anticoagulation is a concern. Aprotinin affects anticoagulation measurement by the activated clotting time. Therefore, a reliable new measurement is needed to monitor anticoagulation during cardiopulmon

  11. Annexin A5 anticoagulant activity in children with systemic lupus erythematosus and the association with antibodies to domain I of β2-glycoprotein I.

    Science.gov (United States)

    Wahezi, D M; Ilowite, N T; Wu, X X; Pelkmans, L; Laat, B; Schanberg, L E; Rand, J H

    2013-06-01

    Children with systemic lupus erythematosus (SLE) have a high prevalence of antiphospholipid (aPL) antibodies and are at increased risk for aPL-related thrombosis. We investigated the association between annexin A5 anticoagulant activity and antibodies to the domain I portion of β2-glycoprotein I (anti-DI antibodies), and propose a potential mechanism for the pathogenesis of aPL-related thrombosis. Using samples from 183 children with SLE collected during the Atherosclerosis Prevention in Pediatric Lupus Erythematosus (APPLE) trial, we examined resistance to the anticoagulant effects of annexin A5, using the annexin A5 resistance (A5R) assay, and evaluated for anti-DI IgG antibodies. Children with SLE had higher frequency of anti-D1 antibodies (p = 0.014) and significantly reduced A5R compared to pediatric controls: mean A5R = 172 ± 30% versus 242 ± 32% (p antibodies had significantly lower mean A5R levels compared to those with negative anti-DI antibodies: mean A5R = 155 ± 24% versus 177 ± 30% (p antibodies (p = 0.013) and lupus anticoagulant (LA) (p = 0.036) were both independently associated with reduced A5R. Children with SLE have significantly reduced annexin A5 anticoagulant activity that is associated with the presence of LA and anti-DI antibodies.

  12. Heparin-induced thrombocytopenia: reducing misdiagnosis via collaboration between an inpatient anticoagulation pharmacy service and hospital reference laboratory.

    Science.gov (United States)

    Burnett, Allison E; Bowles, Harmony; Borrego, Matthew E; Montoya, Tiffany N; Garcia, David A; Mahan, Charles

    2016-11-01

    Misdiagnosis of heparin-induced thrombocytopenia (HIT) is common and exposes patients to high-risk therapies and potentially serious adverse events. The primary objective of this study was to evaluate the impact of collaboration between an inpatient pharmacy-driven anticoagulation management service (AMS) and hospital reference laboratory to reduce inappropriate HIT antibody testing via pharmacist intervention and use of the 4T pre-test probability score. Secondary objectives included clinical outcomes and cost-savings realized through reduced laboratory testing and decreased unnecessary treatment of HIT. This was a single center, pre-post, observational study. The hospital reference laboratory contacted the AMS when they received a blood sample for an enzyme-linked immunosorbent HIT antibody (HIT Ab). Trained pharmacists prospectively scored each HIT Ab ordered by using the 4T score with subsequent communication to physicians recommending for or against processing and reporting of lab results. Utilizing retrospective chart review and a database for all patients with a HIT Ab ordered during the study period, we compared the incidence of HIT Ab testing before and after implementation of the pharmacy-driven 4T score intervention. Our intervention significantly reduced the number of inappropriate HIT Ab tests processed (176 vs. 63, p < 0.0001), with no increase in thrombotic or hemorrhagic events. Overall incidence of suspected and confirmed HIT was <3 and <0.005 %, respectively. Overall cost savings were $75,754 (US) or 62 % per patient exposed to heparin between the pre and post intervention groups. Collaboration between inpatient pharmacy AMS and hospital reference laboratories can result in reduction of misdiagnosis of HIT and significant cost savings with similar safety.

  13. Screening of the components with blood-anticoagulant activity from marine algae Sargassum fusiforme and Undaria pinnatifida%羊栖菜和裙带菜中抗凝血活性物质的初步筛选

    Institute of Scientific and Technical Information of China (English)

    刘承初; 周颖; 邬英睿; 甘建红; 周培根

    2004-01-01

    Components with blood-anticoagulant activity were fractionated from marine algae Sargassumfusiforrne and Undaria pinnatifida and the activity of the components was investigated by using the method of bioassay. It was found that the 80% ethanol soluble fraction of Sargassumfusiforme exhibited no blood-anticoagulant activity, while the components obtained from the 80 % ethanol insoluble fraction (hot water extract) gave obvious bloodanticoagulant activity. A further study suggests that the principal component in the hot water extract from Sargassumfusiforrne with high blood-anticoagulant activity should be sulfated polysaccharides, in which the activity was positively correlated with the content of total sugar and fucose in sulfated polysaccharides. As for Undaria pinnatifida, the n-butanol extract fractionated from the 80% ethanol soluble fraction had blood anticoagulant activity, while the petroleum ether, ether, ethyl acetate, or water extract showed no bloodanticoagulant activity.

  14. Venous Thromboembolism Anticoagulation Therapy

    Institute of Scientific and Technical Information of China (English)

    刘泽霖

    2009-01-01

    @@ VTE of the main treatment for anticoagulant thera-py, anticoagulant therapy drug of choice for low molecu-lar weight heparin (LMWH) for the overwhelming major-ity of clinicians agree that long-term oral anticoagulant therapy is still Vit. K antagonist (mainly warfarin).

  15. Impact of nonsynonymous mutations of factor X on the functions of factor X and anticoagulant activity of edoxaban.

    Science.gov (United States)

    Noguchi, Kengo; Morishima, Yoshiyuki; Takahashi, Shinichi; Ishihara, Hiroaki; Shibano, Toshiro; Murata, Mitsuru

    2015-03-01

    Edoxaban is an oral direct factor Xa (FXa) inhibitor and its efficacy as an oral anticoagulant is less subject to drug-food and drug-drug interaction than existing vitamin K antagonists. Although this profile of edoxaban suggests it is well suited for clinical use, it is not clear whether genetic variations of factor X influence the activity of edoxaban. Our aim was to investigate a possible impact of single-nucleotide polymorphisms (SNPs) in the factor X gene on the functions of factor X and the activity of edoxaban. Two nonsynonymous SNPs within mature factor X, Ala152Thr and Gly192Arg, were selected as possible candidates that might affect the functions of FXa and the activity of edoxaban. We measured catalytic activities of wild type and mutant FXas in a chromogenic assay using S-2222 and coagulation times including prothrombin time (PT) and activated partial thrombin time (aPTT) of plasma-containing recombinant FXs in the presence and absence of edoxaban. Michaelis-Menten kinetic parameters of FXas, Km and Vmax values, PT and aPTT were not influenced by either mutation indicating these mutations do not affect the FXa catalytic and coagulation activities. The Ki values of edoxaban for the FXas and the concentrations of edoxaban required to double PT and aPTT were not different between wild type and mutated FXas indicating that both mutations have little impact on the activity of edoxaban. In conclusion, these data suggest that edoxaban has little interpatient variability stemming from SNPs in the factor X gene.

  16. Neurotoxicity, anticoagulant activity and evidence of rhabdomyolysis in patients bitten by death adders (Acanthophis sp.) in southern Papua New Guinea.

    Science.gov (United States)

    Lalloo, D G; Trevett, A J; Black, J; Mapao, J; Saweri, A; Naraqi, S; Owens, D; Kamiguti, A S; Hutton, R A; Theakston, R D; Warrell, D A

    1996-01-01

    Thirty-two patients with enzyme-immunoassay-proven death adder (Acanthophis sp.) bites were studied in Port Moresby, Papua New Guinea. Eighteen were envenomed; local signs were rare and none had incoagulable blood, but all except one had signs of neurotoxicity. Five (27.7%) envenomed patients required intubation and ventilation. One patient developed renal failure, previously undescribed following death adder bites. Laboratory investigations showed mild prolongation of prothrombin and partial thromboplastin times in some patients. In vitro studies showed that the venom contains anticoagulant activity, but does not cause fibrinogenolysis. In contrast to taipan envenoming, neurotoxicity did not progress after antivenom administration, and there was reversal of neurotoxicity, evident within 6 h, in three severely envenomed patients treated less than 12 h after the bite. One patient treated with antivenom and anticholinesterases had the most dramatic response to treatment; the optimum management of bites by this species may include prompt treatment with both antivenom and anticholinesterases in addition to effective first aid.

  17. Daboxin P, a Major Phospholipase A2 Enzyme from the Indian Daboia russelii russelii Venom Targets Factor X and Factor Xa for Its Anticoagulant Activity.

    Directory of Open Access Journals (Sweden)

    Maitreyee Sharma

    Full Text Available In the present study a major protein has been purified from the venom of Indian Daboia russelii russelii using gel filtration, ion exchange and Rp-HPLC techniques. The purified protein, named daboxin P accounts for ~24% of the total protein of the crude venom and has a molecular mass of 13.597 kDa. It exhibits strong anticoagulant and phospholipase A2 activity but is devoid of any cytotoxic effect on the tested normal or cancerous cell lines. Its primary structure was deduced by N-terminal sequencing and chemical cleavage using Edman degradation and tandem mass spectrometry. It is composed of 121 amino acids with 14 cysteine residues and catalytically active His48 -Asp49 pair. The secondary structure of daboxin P constitutes 42.73% of α-helix and 12.36% of β-sheet. It is found to be stable at acidic (pH 3.0 and neutral pH (pH 7.0 and has a Tm value of 71.59 ± 0.46°C. Daboxin P exhibits anticoagulant effect under in-vitro and in-vivo conditions. It does not inhibit the catalytic activity of the serine proteases but inhibits the activation of factor X to factor Xa by the tenase complexes both in the presence and absence of phospholipids. It also inhibits the tenase complexes when active site residue (His48 was alkylated suggesting its non-enzymatic mode of anticoagulant activity. Moreover, it also inhibits prothrombinase complex when pre-incubated with factor Xa prior to factor Va addition. Fluorescence emission spectroscopy and affinity chromatography suggest the probable interaction of daboxin P with factor X and factor Xa. Molecular docking analysis reveals the interaction of the Ca+2 binding loop; helix C; anticoagulant region and C-terminal region of daboxin P with the heavy chain of factor Xa. This is the first report of a phospholipase A2 enzyme from Indian viper venom which targets both factor X and factor Xa for its anticoagulant activity.

  18. Increased anticoagulant activity of thrombin-binding DNA aptamers by nanoscale organization on DNA nanostructures

    DEFF Research Database (Denmark)

    Rangnekar, Abhijit; Zhang, Alex M.; Shiyuan Li, Susan;

    2012-01-01

    Control over thrombin activity is much desired to regulate blood clotting in surgical and therapeutic situations. Thrombin-binding RNA and DNA aptamers have been used to inhibit thrombin activity and thus the coagulation cascade. Soluble DNA aptamers, as well as two different aptamers tethered by...

  19. Distinct structures of the α-fucose branches in fucosylated chondroitin sulfates do not affect their anticoagulant activity.

    Science.gov (United States)

    Santos, Gustavo R C; Glauser, Bianca F; Parreiras, Luane A; Vilanova, Eduardo; Mourão, Paulo A S

    2015-10-01

    Fucosylated chondroitin sulfate (FCS) is a glycosaminoglycan found in sea cucumbers. It has a backbone like that of mammalian chondroitin sulfate (4-β-d-GlcA-1→3-β-d-GalNAc-1)n but substituted at the 3rd position of the β-d-glururonic acid residues with α-fucose branches. The structure of these branches varies among FCSs extracted from different species of sea cucumbers, as revealed by solution NMR spectroscopy. Some species (Isostichopus badionotus and Patalus mollis) contain branches formed by single α-fucose residues but with variable sulfation patterns (2,4-, 3,4- and 4-sulfation). FCS from Ludwigothurea grisea is distinguished because it contains preponderant branches formed by disaccharide units containing non-sulfated and 3-sulfated α-fucose units at the reducing and non-reducing ends, respectively. Despite the structural variability on their α-fucose branches, these FCSs have similar anticoagulant action on assays using purified reagents. They have serpin-dependent and serpin-independent effects. Pharmacological assays using experimental animals showed that the three types of FCSs have similar antithrombotic effect and bleeding tendency. They also activate factor XII on the same range of concentration. Based on these observations, we proposed that only few sulfated α-fucose branches along the FCS chain are enough to assure the binding of this glycosaminoglycan to proteins of the coagulation system. Substitution with additional sulfated α-fucose does not increase further the activity. Overall, the use of FCSs with marked variability on their branches of α-fucose allowed us to establish correlations between structures vs biological effects of these glycosaminoglycans on a more refined basis. It opens new avenues for therapeutic intervention using FCSs.

  20. The antiplatelet and anticoagulant activity of 7-O-gentiobiozide formononetin in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Ya. F. Zverev

    2016-01-01

    Full Text Available Aim. In experiments in vitro and in vivo it was investigated the effect of isoflavone 7-O-gentiobiozide formononetin (GBF isolated from the roots of the plant Maackia аmurensis (Maackia amurensis Rupr. et Maxim., on the processes of vascular-platelet and coagulation hemostasis.Materials and methods. In experiments using blood of healthy human plasma in concentrations of GBF 1,0–50,0 mM promoted dose-dependently ADP-induced weakening of platelet aggregation. Since the concentration of 10,0 mM GBF induced hypocoagulative changes in blood plasma, comparable with the effect of 0,2–0,5 IU/ml heparin. Revealed hypocoagulative effect was confirmed in the application thromboelastometry, showing pronounced hypocoagulation and a significant reduction in fibrin formation dynamics.Results. In chronic GBF oral administration to rats at a dose of 25 mg/kg was fixed almost a 10-fold reduction in ADP-induced platelet aggregation, with increased content of these cells in the peripheral blood. Furthermore, in these conditions, there was a pronounced effect of GBF’s hypocoagulation which was implemented in inhibiting reactions inner and outer tracks of blood clotting, reducing the rate of formation of fibrin and its mechanical density.Conclusion.Thus, in experiments in vitro and in vivo for the first time revealed the ability of isoflavone 7-O-gentiobiozideformononetin extracted from the roots Maackia amurensis, inhibit the processes of vascularplatelet and coagulation hemostasis. This fact is of great practical importance, because it opens the prospective of the development of a new drug that can reduce the risk of thrombosis in various cardiovascular diseases.

  1. Anticoagulation for Prosthetic Valves

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Kaneko

    2013-01-01

    Full Text Available Implantation of prosthetic valve requires consideration for anticoagulation. The current guideline recommends warfarin on all mechanical valves. Dabigatran is the new generation anticoagulation medication which is taken orally and does not require frequent monitoring. This drug is approved for treatment for atrial fibrillation and venous thromboembolism, but the latest large trial showed that this drug increases adverse events when used for mechanical valve anticoagulation. On-X valve is the new generation mechanical valve which is considered to require less anticoagulation due to its flow dynamics. The latest study showed that lower anticoagulation level lowers the incidence of bleeding, while the risk of thromboembolism and thrombosis remained the same. Anticoagulation poses dilemma in cases such as pregnancy and major bleeding event. During pregnancy, warfarin can be continued throughout pregnancy and switched to heparin derivative during 6–12 weeks and >36 weeks of gestation. Warfarin can be safely started after 1-2 weeks of discontinuation following major bleeding episode.

  2. Anticoagulation in the Elderly

    Directory of Open Access Journals (Sweden)

    Helia Robert-Ebadi

    2010-12-01

    Full Text Available Management of anticoagulation in elderly patients represents a particularly challenging issue. Indeed, this patient population is at high thromboembolic risk, but also at high hemorrhagic risk. Assessment of the benefit-risk balance of anticoagulation is the key point when decisions are made about introducing and/or continuing such treatments in the individual elderly patient. In order to maximise the safety of anticoagulation in the elderly, some specific considerations need to be taken into account, including renal insufficiency, modified pharmacodynamics of anticoagulants, especially vitamin K antagonists, and the presence of multiple comorbidities and concomitant medications. New anticoagulants could greatly simplify and possibly increase the safety of anticoagulation in the elderly in the near future.

  3. Sulfation modification and anticoagulant activity of the polysaccharides obtained from persimmon (Diospyros kaki L.) fruits.

    Science.gov (United States)

    Lu, Xiaoyun; Mo, Xiaoyan; Guo, Hui; Zhang, Yali

    2012-12-01

    The optimal conditions for sulfation of polysaccharides from persimmon fruits (PFP) with chlorosulfonic acid-pyridine (CSA-Pyr) method were determined by response surface methodology. Box-Behnken design was applied to evaluate the effects of three independent variables (volume ratio of Pyr to CSA, volume ratio of PFP to SO(3)Pyr and reaction time) on the degree of substitution (DS), molecular weight (MW) and activated partial thromboplastin time (APTT) of sulfated polysaccharides (PFP-S). The APTT activity of PFP-S could be improved by application of various volume ratio of Pyr to CSA, volume ratio of PFP to SO(3)Pyr and reaction time, which was possible due to the degradation of polysaccharides to different extent and increasing of DS. The optimal conditions to obtain the strongest APTT of PFP-S were the volume ratio of CSA to Pyr of 1:8, the volume ratio of SO(3)Pyr to PFP of 1:3.6 and the reaction time of 3 h, respectively.

  4. Antimicrobial and anticoagulant activities of N-chlorotaurine, N,N-dichloro-2,2-dimethyltaurine, and N-monochloro-2,2-dimethyltaurine in human blood.

    Science.gov (United States)

    Martini, C; Hammerer-Lercher, A; Zuck, M; Jekle, A; Debabov, D; Anderson, M; Nagl, M

    2012-04-01

    The aim of this study was to determine the potential application of N-chlorotaurine (NCT), N,N-dichloro-2,2-dimethyltaurine (NVC-422), and N-monochloro-2,2-dimethyltaurine (NVC-612) as catheter lock solutions for the prevention of catheter blockage and catheter-related bloodstream infections by testing their anticoagulant and broad-spectrum antimicrobial activities in human blood. NCT, NVC-422, NVC-612, and control compounds were serially diluted in fresh human blood to evaluate the effects on prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, and direct thrombin inhibition. Quantitative killing assays against pathogens, including methicillin-resistant Staphylococcus aureus, Escherichia coli, and Candida albicans, were performed in the presence of heparin and human blood. NCT and NVC-612 (1.38 mM each) and 1.02 mM NVC-422 prolonged prothrombin time (Quick value, 17 to 30%), activated partial thromboplastin time 3- to 4-fold to 76 to 125 s, and thrombin time 2- to 4-fold to 34 to 68 s. Fibrinogen decreased from 258 to 283 mg/dl (range of controls) to NVC-422 or NVC-612. Heparin did not influence the bactericidal activity of NCT. The microbicidal activities of NCT, NVC-422, and NVC-612 were maintained in diluted human blood. NCT, NVC-612, and NVC-422 have broad-spectrum antimicrobial activity in blood and anticoagulant activity targeting both intrinsic and extrinsic pathways of the coagulation system. These properties support their application as catheter lock solutions.

  5. Antimicrobial and Anticoagulant Activities of N-Chlorotaurine, N,N-Dichloro-2,2-Dimethyltaurine, and N-Monochloro-2,2-Dimethyltaurine in Human Blood

    OpenAIRE

    2012-01-01

    The aim of this study was to determine the potential application of N-chlorotaurine (NCT), N,N-dichloro-2,2-dimethyltaurine (NVC-422), and N-monochloro-2,2-dimethyltaurine (NVC-612) as catheter lock solutions for the prevention of catheter blockage and catheter-related bloodstream infections by testing their anticoagulant and broad-spectrum antimicrobial activities in human blood. NCT, NVC-422, NVC-612, and control compounds were serially diluted in fresh human blood to evaluate the effects o...

  6. Anticoagulation control in atrial fibrillation patients present to outpatient clinic of cardiology versus anticoagulant clinics

    Institute of Scientific and Technical Information of China (English)

    DU Xin; MA Chang-sheng; LIU Xiao-hui; DONG Jian-zeng; WANG Jun-nan; CHENG Xiao-jing

    2005-01-01

    @@ Nonvalvular atrial fibrillation (NVAF) is the most common sustained cardiac arrhythmia in clinical practice, which if untreated results in a doubling of cardiovascular morbidity and mortality. AF is an independent predictor of stroke, with an annual risk 5 to 6 times higher than patients in sinus rhythm.1 During recent years, several randomised clinical trials conducted by investigators around the world involving 13 843 participants with NVAF have demonstrated convincingly the value of warfarin therapies for stroke prevention in high risk patients.2-8 However, the dose response of warfarin is complex and its activity is easily altered by concurrent medications, food interactions, alcohol and illnesses. Adherence to medical advice and routine monitoring of the international normalized ratio (INR) is important, because low anticoagulant intensity predisposes the patients to thromboembolic complications and high intensity to haemorrhage. Studies suggested that anticoagulant clinics could improve the quality of anticoagulation control,9 and anticoagulant clinics are common in western countries. However, in China, most AF patients taking warfarin usually attend the outpatient clinic of cardiology, while the quality of anticoagulation control is never investigated. We therefore assessed anticoagulation control in the outpatient clinic of cardiology, and the quality of anticoagulation control since the establishment of anticoagulant clinics.

  7. The predictability of bleeding by prothrombin times sensitive or insensitive to PIVKA during intensive oral anticoagulation.

    Science.gov (United States)

    Arnesen, H; Smith, P

    1991-02-01

    To evaluate the effect of PIVKA (Proteins Induced by Vitamin K Absence or Antagonism) on the bleeding tendency during oral anticoagulation, we studied consecutive patients intensively treated with warfarin (INR greater than 4.8). The level of anticoagulation was measured with the PIVKA-insensitive Normotest (NT) as well as with the PIVKA-sensitive Thrombotest (TT), and the results are expressed as per cent coagulant activity. The NT/TT ratio was determined. Twenty patients with bleeding episodes had a mean NT/TT ratio of 2.06 as compared to 2.20 in 143 patients without bleeding episodes (p = 0.08). As the NT/TT ratio was not higher in patients with bleedings, we conclude that PIVKA are of no importance for bleeding during anticoagulation with vitamin K antagonists.

  8. Review of Urgent Reversal Therapies for Oral Anticoagulation

    Directory of Open Access Journals (Sweden)

    John J. Mondin II

    2016-09-01

    Full Text Available Anticoagulation has proven to be one of the most essential breakthroughs in cardiology in the last 100 years. The first major oral anticoagulant, warfarin, is a 4-hydroxycourmarin first synthesized in the 1940s for use as a rodenticide. It was not until 1954 that warfarin was finally approved by the FDA for use in patients requiring systemic anticoagulation. For over 55 years, warfarin was the only oral anticoagulant available in the United States until the approval of dabigatran in 2010, ushering in the era of the direct oral anticoagulants. This article will review modalities of anticoagulation reversal including activated charcoal, hemodialysis, blood-derived products, and medications currently available as well as in development.

  9. Fondaparinux for intra and perioperative anticoagulation in patients with heparin-induced thrombocytopenia candidates for peripheral vascular surgery: Report of 4 cases

    Directory of Open Access Journals (Sweden)

    Giulio Illuminati, MD

    2016-01-01

    Conclusions: These preliminary results seem to justify the off-label use of fondaparinux for intra and perioperative anticoagulation in patients with HIT, candidates for peripheral vascular surgery interventions.

  10. Anti-inflammatory, anticoagulant and antioxidant effects of aqueous extracts from Moroccan thyme varieties

    Institute of Scientific and Technical Information of China (English)

    Tarik; Khouya; Mhamed; Ramchoun; Abdelbassat; Hmidani; Souliman; Amrani; Hicham; Harnafi; Mohamed; Benlyas; Younes; Filali; Zegzouti; Chakib; Alem

    2015-01-01

    Objective: To evaluate the anti-inflammatory, anticoagulant and antioxidant effects of aqueous extracts of thyme varieties from Moroccan.Methods: The aqueous extracts of tree medicinal plants [Thymus atlanticus(T. atlanticus), Thymus satureioides and Thymus zygis(T. zygis)] were screened for their antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl radical-scavenging, ferric reducing antioxidant power assay, radical scavenging activity method, the inhibition of 2,2’-azobis(2-amidinopropane) dihydrochloride that induces oxidative erythrocyte hemolysis and thiobarbituric acid reactive substances assay. The anti-inflammatory activity of aqueous extracts was evaluated in vivo using croton oil-induced ear edema and carrageenan-induced paw edema in mice and rats, respectively. This extracts were evaluated in vitro for their anticoagulant activity at the different concentrations by partial thromboplastin time and prothrombin time activated. Results: All thyme varieties were found to possess considerable antioxidant activity and potent anti-inflammatory activity in the croton oil-induced edema. Administration of aqueous extracts of two varieties(50 mg/kg)(T. zygis and T. atlanticus) reduced significantly the carrageenaninduced paw edema similar to non-steroidal anti-inflammatory drug(indomethacin, 10 mg/kg). In partial thromboplastin time and prothrombin time tests, T. atlanticus and T. zygis extracts showed the strongest anticoagulant activity. In contrast, Thymus satureioides did not show the anticoagulant activity in these tests. Conclusions: All aqueous extracts possess considerable antioxidant activity and are rich in total polyphenol and flavonoid but they act differently in the process of inflammatory and coagulation studied. This study shows great variability of biological activities in thyme varieties.

  11. Patient values and preferences when choosing anticoagulants

    Directory of Open Access Journals (Sweden)

    Palacio AM

    2015-01-01

    unexposed to anticoagulants reported that they would select a medication that has an antidote even if the risk of bleeding was very small. Twenty-three percent of the unexposed and 22% of the exposed groups reported that they would prefer the medication that gives the best quality of life.Conclusion: Our study found that patients who may be exposed to an anticoagulation decision prefer to actively participate in the decision-making process, and have individual values for making a decision that cannot be predicted or assumed by anyone in the health care system. Keywords: warfarin, oral anticoagulant, bleeding risk, atrial fibrillation, patient decision making, medication selection

  12. Lupus anticoagulants and antiphospholipid antibodies

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000547.htm Lupus anticoagulants and antiphospholipid antibodies To use the sharing features on this page, please enable JavaScript. Lupus anticoagulants are antibodies against substances in the lining ...

  13. 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.

  14. Perioperative anticoagulation management in antiphospholipid syndrome.

    Science.gov (United States)

    Ishida, Keiichi; Masuda, Masahisa; Kohno, Hiroki; Tamura, Yusaku; Matsumiya, Goro

    2015-09-01

    Patients with antiphospholipid syndrome are at increased risk of developing thrombotic and hemorrhagic complications after cardiac surgery, and may have abnormal coagulation tests and develop thrombocytopenia after invasive procedures, which can complicate the perioperative management of anticoagulant therapy. We describe a patient with chronic thromboembolic pulmonary hypertension and antiphospholipid syndrome, who presented with prolonged activated partial thromboplastin and activated clotting times, and developed thrombocytopenia after the catheterization workup. We performed pulmonary endarterectomy and successfully managed anticoagulation by restricting heparin use at the time of surgery and monitoring the heparin effect by measuring heparin concentrations during cardiopulmonary bypass.

  15. Discovery of anticoagulant drugs: a historical perspective.

    Science.gov (United States)

    Gómez-Outes, Antonio; Suárez-Gea, Ma Luisa; Calvo-Rojas, Gonzalo; Lecumberri, Ramón; Rocha, Eduardo; Pozo-Hernández, Carmen; Terleira-Fernández, Ana Isabel; Vargas-Castrillón, Emilio

    2012-06-01

    The history of the traditional anticoagulants is marked by both perseverance and serendipity. The anticoagulant effect of heparin was discovered by McLean in 1915, while he was searching for a procoagulant in dog liver. Link identified dicumarol from spoiled sweet clover hay in 1939 as the causal agent of the sweet clover disease, a hemorrhagic disorder in cattle. Hirudin extracts from the medicinal leech were first used for parenteral anticoagulation in the clinic in 1909, but their use was limited due to adverse effects and difficulties in achieving highly purified extracts. Heparins and coumarins (i.e.: warfarin, phenprocoumon, acenocoumarol) have been the mainstay of anticoagulant therapy for more than 60 years. Over the past decades, the drug discovery paradigm has shifted toward rational design following a target-based approach, in which specific proteins, or "targets", are chosen on current understandings of pathophysiology, small molecules that inhibit the target's activity may be identified by high-throughput screening and, in selected cases, these new molecules can be developed further as drugs. Despite the application of rational design, serendipity has still played a significant role in some of the new discoveries. This review will focus on the discovery of the main anticoagulant drugs in current clinical use, like unfractionated heparin, low-molecular-weight heparins, fondaparinux, coumarins (i.e.: warfarin, acenocoumarol, phenprocoumon), parenteral direct thrombin inhibitors (DTIs) (i.e.: argatroban, recombinant hirudins, bivalirudin), oral DTIs (i.e.: dabigatran) and oral direct factor Xa inhibitors (i.e.: rivaroxaban, apixaban).

  16. The new oral anticoagulants.

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2010-01-01

    In patients with nonvalvular atrial fibrillation oral anticoagulation with the vitamin K antagonists acenocoumarol, phenprocoumon and warfarin reduces the risk of stroke by more than 60%, whereas single or double antiplatelet therapy is much less effective and sometimes associated with a similar ble

  17. Cataract surgery and anticoagulants

    NARCIS (Netherlands)

    Koopmans, SA; VanRij, G

    1996-01-01

    A questionnaire was sent to 240 members of the Netherlands Intraocular implant Club (NIOIC) to register their policy followed in 1993 with regard to anticoagulant therapy (ACT) and the use of aspirin in patients having cataract surgery. Ninety-one (32%) forms were suitable for analysis. Most eye sur

  18. Isolation, purification, and characterization of fucose-containing sulfated polysaccharides from the brown seaweed Ecklonia kurome and their blood-anticoagulant activities.

    Science.gov (United States)

    Nishino, T; Yokoyama, G; Dobashi, K; Fujihara, M; Nagumo, T

    1989-02-15

    A sulfated polysaccharide fraction, obtained from the hot-water extract of the brown seaweed, Ecklonia kurome by removing laminaran and the major part of alginic acid, gave sulfated polysaccharides (B-I, B-II, C-I, and C-II) by both anion-exchange chromatography on a column of Ecteola-cellulose and by fractional precipitation with ethanol containing 0.3% calcium acetate, and then by gel-filtration chromatography on a Sepharose 4B column. B-I and B-II are composed of fucose, galactose, mannose, xylose, glucuronic acid, and ester sulfate in the approximate molar ratios of 1.00:0.36:0.48:1.08:1.85:2.35 and 1.00:0.81:0.18:0.45:0.61:2.00, respectively. C-I and C-II are composed of fucose, galactose, glucuronic acid, and ester sulfate in approximate molar ratios of 1.00:0.03:0.03:1.61 and 1.00:0.19:0.07:1.48, respectively. Blood-anticoagulant activities with respect to activated partial thromboplastin time (APTT) were approximately 24, 19, 81, and 85% of that of heparin for B-I, B-II, C-I, and C-II, respectively. All the polysaccharides showed slight antithrombin activity. No antifactor Xa activity was observed for any of the polysaccharides.

  19. 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

  20. Extraction and anticoagulant activity of sulfated polysaccharides from Caulerpa cupressoides var. lycopodium (Vahl C. Agardh (Chlorophyceae - doi: 10.4025/actascibiolsci.v33i2.6243 Extraction and anticoagulant activity of sulfated polysaccharides from Caulerpa cupressoides var. lycopodium (Vahl C. Agardh (Chlorophyceae - doi: 10.4025/actascibiolsci.v33i2.6243

    Directory of Open Access Journals (Sweden)

    Norma Maria Barros Benevides

    2011-05-01

    Full Text Available The reportedly low standard quality of heparin (HEP for use in cardiac surgeries has led to concern in the Brazilian and international markets. Sulfated polysaccharides (SPs from seaweeds have been regarded as promising substitutes for HEP. The aim of this study was to sequentially extract total SPs (TSPs from Caulerpa cupressoides (Chlorophyceae with papain in 100 mM sodium acetate buffer (pH 5.0 containing 5 mM cysteine and 5 mM EDTA, followed by fractionation by ion-exchange chromatography (DEAE-cellulose, and then evaluate the anticoagulant potential of SP fractions by activated partial thromboplastin time (APTT using normal human plasma and compare it to standard HEP (193 IU mg-1. The obtained fractions were chemically characterized by chemical composition and agarose gel electrophoresis. The yield was 4.61%, and three fractions of SP (F I, F II and F III eluted with 0.50, 0.75 and 1.00 M of NaCl, respectively, were observed on chromatography profiles; however, differences in charge densities patterns and degree of resolution among them were revealed by electrophoresis. SPs were capable of modifying APTT only in fractions eluted with 0.75 M of NaCl, whose activities were 23.37 and 25.76 IU mg-1, respectively, and the charge density was prerequisite to activity. Therefore, C. cupressoides is a source of SPs possessing low anticoagulant potential compared to HEP.The reportedly low standard quality of heparin (HEP for use in cardiac surgeries has led to concern in the Brazilian and international markets. Sulfated polysaccharides (SPs from seaweeds have been regarded as promising substitutes for HEP. The aim of this study was to sequentially extract total SPs (TSPs from Caulerpa cupressoides (Chlorophyceae with papain in 100 mM sodium acetate buffer (pH 5.0 containing 5 mM cysteine and 5 mM EDTA, followed by fractionation by ion-exchange chromatography (DEAE-cellulose, and then evaluate the anticoagulant potential of SP fractions by activated

  1. DABIGATRAN ETEXILATE: NEW DIRECT THROMBIN INHIBITORS ANTICOAGULANTS

    Directory of Open Access Journals (Sweden)

    Patel Kinjal B

    2011-04-01

    Full Text Available Thrombin plays a key role in thrombotic events, and therefore thrombin inhibition represents a therapeutic target for numerous thromboembolic diseases. Thrombin is responsible for the conversion of soluble fibrinogen to fibrin; clot stabilization through activation of factor XIII and the formation of cross-linkage among fibrin molecules; and the generation of additional thrombin through activation of factors V, VIII, and XI. Direct thrombin inhibitors are an innovative class of anticoagulants that bind directly to thrombin to inhibit its actions and impede the clotting process. Dabigatran is the first direct thrombin inhibitor, orally available first approval by US Food and Drugs Administration in 2010. Specifically and reversibly inhibits thrombin, so the duration of action is predictable. The anticoagulant effect correlates well with plasma drug concentrations, which implies an effective anticoagulation with low bleeding risk without major problems of interactions with other drugs. The predictable pharmacokinetics and pharmacodynamics characteristics of dabigatran may facilitate dental management of patients who until now have been in treatment with traditional anticoagulants, given that it doesn’t require routine laboratory monitoring in the vast majority of patients treated. They also present a profile of drug interactions very favorable.

  2. Response to anticoagulant drug withdrawal.

    Science.gov (United States)

    Mulligan, R

    1987-09-01

    This study evaluated 44 separate medication withdrawal periods in 17 subjects who were attending a hospital anticoagulation clinic for management of anticoagulation medication. The data suggest that when anticoagulant withdrawal is needed for particular dental procedures, a 2-day hold is an effective period of medication withdrawal. No thromboembolic events were observed after any of the withdrawal periods. Further, no posttreatment hemorrhagic episodes were observed when the anticoagulant medication was reinstituted after dental treatment. Prothrombin time blood levels should be determined in the immediate pretreatment period, however, because the prothrombin time can fluctuate even in the best maintained patients.

  3. Roll-to-roll, shrink-induced superhydrophobic surfaces for antibacterial applications, enhanced point-of-care detection, and blood anticoagulation

    Science.gov (United States)

    Nokes, Jolie McLane

    Superhydrophobic (SH) surfaces are desirable because of their unique anti-wetting behavior. Fluid prefers to bead up (contact angle >150°) and roll off (contact angle hysteresis air pockets. Fluid only adheres to the peaks of the structures, causing minimal adhesion to the surface. Here, shrink-induced SH plastics are fabricated for a plethora of applications, including antibacterial applications, enhanced point-of-care (POC) detection, and reduced blood coagulation. Additionally, these purely structural SH surfaces are achieved in a roll-to-roll (R2R) platform for scalable manufacturing. Because their self-cleaning and water resistant properties, structurally modified SH surfaces prohibit bacterial growth and obviate bacterial chemical resistance. Antibacterial properties are demonstrated in a variety of SH plastics by preventing gram-negative Escherichia coli (E. coli) bacterial growth >150x compared to flat when fluid is rinsed and >20x without rinsing. Therefore, a robust and stable means to prevent bacteria growth is possible. Next, protein in urine is detected using a simple colorimetric output by evaporating droplets on a SH surface. Contrary to evaporation on a flat surface, evaporation on a SH surface allows fluid to dramatically concentrate because the weak adhesion constantly decreases the footprint area. On a SH surface, molecules in solution are confined to a footprint area 8.5x smaller than the original. By concentrating molecules, greater than 160x improvements in detection sensitivity are achieved compared to controls. Utility is demonstrated by detecting protein in urine in the pre-eclampsia range (150-300microgmL -1) for pregnant women. Further, SH surfaces repel bodily fluids including blood, urine, and saliva. Importantly, the surfaces minimize blood adhesion, leading to reduced blood coagulation without the need for anticoagulants. SH surfaces have >4200x and >28x reduction of blood residue area and volume compared to the non

  4. Clinical Safety of a High Dose of Phycocyanin-Enriched Aqueous Extract from Arthrospira (Spirulina) platensis: Results from a Randomized, Double-Blind, Placebo-Controlled Study with a Focus on Anticoagulant Activity and Platelet Activation.

    Science.gov (United States)

    Jensen, Gitte S; Drapeau, Cassandra; Lenninger, Miki; Benson, Kathleen F

    2016-07-01

    The goal for this study was to evaluate safety regarding anticoagulant activity and platelet activation during daily consumption of an aqueous cyanophyta extract (ACE), containing a high dose of phycocyanin. Using a randomized, double-blind, placebo-controlled study design, 24 men and women were enrolled after informed consent, and consumed either ACE (2.3 g/day) or placebo daily for 2 weeks. The ACE dose was equivalent to ∼1 g phycocyanin per day, chosen based on the highest dose Generally Recognized as Safe (GRAS) by the U.S. Food and Drug Administration. Consuming ACE did not alter markers for platelet activation (P-selectin expression) or serum P-selectin levels. No changes were seen for activated partial thromboplastin time, thrombin clotting time, or fibrinogen activity. Serum levels of aspartate transaminase (AST) showed a significant reduction after 2 weeks of ACE consumption (P < .001), in contrast to placebo where no changes were seen; the difference in AST levels between the two groups was significant at 2 weeks (P < .02). Reduced levels of alanine transaminase (ALT) were also seen in the group consuming ACE (P < .08). Previous studies showed reduction of chronic pain when consuming 1 g ACE per day. The higher dose of 2.3 g/day in this study was associated with significant reduction of chronic pain at rest and when physically active (P < .05). Consumption of ACE showed safety regarding markers pertaining to anticoagulant activity and platelet activation status, in conjunction with rapid and robust relief of chronic pain. Reduction in AST and ALT suggested improvement in liver function and metabolism.

  5. DABIGATRAN ETEXILATE: NEW DIRECT THROMBIN INHIBITORS ANTICOAGULANTS

    OpenAIRE

    Patel Kinjal B; Galani Varsha; Patel Paresh B; Mehta Hiren R

    2011-01-01

    Thrombin plays a key role in thrombotic events, and therefore thrombin inhibition represents a therapeutic target for numerous thromboembolic diseases. Thrombin is responsible for the conversion of soluble fibrinogen to fibrin; clot stabilization through activation of factor XIII and the formation of cross-linkage among fibrin molecules; and the generation of additional thrombin through activation of factors V, VIII, and XI. Direct thrombin inhibitors are an innovative class of anticoagulant...

  6. Design, synthesis, anticoagulant activity evaluation and molecular docking studies of a class of N-ethyl dabigatran derivatives.

    Science.gov (United States)

    Ren, Weixin; Ren, Yujie; Wang, Shuai

    2016-09-14

    A class of N-ethyl dabigatran derivatives was designed based on pharmacological strategies for inhibition of thrombin activity and the structure-activity relationship studies of the previous dabigatran derivatives. Activities of these novel compounds were predicted based on CoMFA model, and most of the compounds had comparable predicted activity with dabigatran. All of screened compounds were synthesized and characterized by (1)H NMR, (13)C NMR and HRMS. Subsequently, these compounds were evaluated inhibitory activity on thrombin. Among these compounds, 9a-9e, 9h, 9l-9n and 9p exhibited comparable inhibitory activity to dabigatran (IC50 = 1.20 nM), additionally, compound 9p (IC50 = 0.96 nM) exhibited better inhibitory activity than dabigatran. Moreover, compound 9p also exhibited a fairly good inhibitory activity for arteriovenous thrombosis with inhibition rate of (85.35 ± 0.72) %, which was comparable to that of dabigatran (85.07 ± 0.61) %. These results, along with related molecular docking studies, could provide an important basis for further development of compound 9p as a potent thrombin inhibitor.

  7. 肝素诱导的血小板减少症患者体外循环抗凝管理%Anticoagulation Management in Patients with Heparin-induced Thrombocytopenia Undergoing Extracorporeal Circulation

    Institute of Scientific and Technical Information of China (English)

    周伯颐

    2012-01-01

    Patients with heparin-induced thrombocytopenia have a poor prognosis and high mortality, thus surgical risk under extracorporeal circulation increased. Early diagnosis, safe and effective alternative anticoagulation strategy are crucial for these patients to receive extracorporeal circulation surgery. This review focuses on the pathophysiology, laboratory examination, diagnosis and alternative anticoagulation strategy of extracorporeal circulation for patients with heparin-induced thrombocytopenia.%肝素诱导的血小板减少症患者预后差,病死率高,大大增加了体外循环手术的风险.对其早期诊断和选择一种安全有效的药物替代肝素抗凝是这类患者接受体外循环手术的关键.我们对肝素诱导的血小板减少症发病机制、实验室检查、诊断以及体外循环抗凝管理进行综述.

  8. Anticoagulation therapy in intra-aortic balloon counterpulsation:Does IABP really need anti-coagulation?

    Institute of Scientific and Technical Information of China (English)

    JIANG Chen-yang(蒋晨阳); ZHAO Li-li(赵莉莉); WANG Jian-an(王建安); SAN Jiang(单江); MOHAMMOD Balgaith

    2003-01-01

    Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoagulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were randomly assigned into two groups. Anticoagulation group(Group A) consisted of 71 patients who were given heparin intravenously with target aPTT 50-70 seconds. Non-anticoagulation group(Group B) consisted of 82 patients without intravenous heparin during balloon pumping. Hematological parameters including platelet count, D-dimer, Plasminogen activator inhibitor-1(PAI-1) and fibrinogen degradation products(FDP) were checked respectively at the point of baseline, 24 hours, 48 hours and 24 hours post IABP counterpulsation. Clot deposits on balloon surface, vascular complications from IABP including bleeding and limb ischemia were recorded. Results: Platelet count and PAI-1 level decreased at 24 hours and 48 hours in both groups (P0.05). Three patients in Group A and 2 patients in Group B developed minor limb ischemia(P>0.05). No major limb ischemia in either group. Two patients in Group A suffered major bleeding and required blood transfusion or surgical intervention, whereas no patient had major bleeding in Group B. Eight patients had minor bleeding in Group A, but only 2 patients in Group B(P<0.05). No clot deposit developed on IABP surface in either group. Conclusion: IABP is safe without routine anticoagulation therapy. Selecting appropriate artery approach and early detection intervention are key methods for preventing complications.

  9. 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

  10. Anticoagulation therapy in intra-aortic balloon counterpulsation: Does IABP really need anti-coagulation

    Institute of Scientific and Technical Information of China (English)

    蒋晨阳; 赵莉莉; 王建安; 单江; MOHAMMODBalgaith

    2003-01-01

    Objective: To investigate if intra-aortic balloon pump(IABP) is contraindicated without anticoag-ulation therapy. Methods: Some 153 IABP patients in the King Abdulaziz Cardiac Center(KSA) were random-ly assigned into two groups. Anticoagulation group( Group A) consisted of 71 patients who were given heparin intravenously with target aPTT 50 - 70 seconds. Non-anticoagulation group( Group B) consisted of 82 patients without intravenous heparin during balloon pumping. Hematological parameters including platelet count, D-dimer, Plasminogen activator inhibitor-1 (PAI-1) and fibrinogen degradation products(FDP) were checked respectively at the point of baseline, 24 hours, 48 hours and 24 hours post IABP counterpulsation. Clot deposits on balloon surface, vascular complications from IABP including bleeding and limb ischemia were recorded.Results: Platelet count and PAI-1 level decreased at 24 hours and 48 hours in both groups ( P 0.05) . Three patients in Group A and 2 patients in Group B developed minor limb ischemia( P > 0.05). No major limb ischemia in either group. Two patients in Group A suffered major bleeding and required blood transfusion or surgical intervention, whereas no patient had major bleeding in Group B. Eight patients had minor bleeding in Group A, but only 2 patients in Group B ( P <0.05). No clot deposit developed on IABP surface in either group. Conclusion: IABP is safe without routine anticoagulation therapy. Selecting appropriate artery approach and early detection intervention are key methods for preventing complications.

  11. The Active Metabolite of Warfarin (3'-Hydroxywarfarin) and Correlation with INR, Warfarin and Drug Weekly Dosage in Patients under Oral Anticoagulant Therapy: A Pharmacogenetics Study

    OpenAIRE

    2016-01-01

    Objectives Warfarin oral anticoagulant therapy (OAT) requires regular and frequent drug adjustment monitored by INR. Interindividual variability, drug and diet interferences, and genetics (VKORC1 and CYP2C9) make the maintenance/reaching of stable INR a not so easy task. HPLC assessment of warfarin/enantiomers was suggested as a valid monitoring-tool along with INR, but definite results are still lacking. We evaluated possible correlations between INR, warfarin/3’-hydroxywarfarin, and drug we...

  12. 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

  13. 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.

  14. 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......, and several coagulation factor levels were decreased. However, VWF activity and antigen were normal when analyzed by other methods. Also, coagulation factor levels were normal if an aPTT reagent with low lupus anticoagulant sensitivity or a chromogenic method was applied. Altogether, the initial findings were...... because of lupus anticoagulant interference and in fact, the patient had normal VWF activity and coagulation status. Interference of lupus anticoagulant in clot-based assays is well known but has not previously been described in VWF assays. This is furthermore the first report in which lupus anticoagulant...

  15. Colonoscopic polypectomy in anticoagulated patients

    Institute of Scientific and Technical Information of China (English)

    Shai Friedland; Daniel Sedehi; Roy Soetikno

    2009-01-01

    AIM: To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hundred and twenty five polypectomies were performed in 123 patients. Patients followed a standardized protocol that included stopping warfarin for 36 h to avoid supratherapeutic anticoagulation from the bowel preparation. Patients with lesions larger than 1 cm were generally rescheduled for polypectomy off warfarin. Endoscopic clips were routinely applied prophylactically.RESULTS: One patient (0.8%, 95% CI: 0.1%-4.5%)developed major post-polypectomy bleeding that required transfusion. Two others (1.6%, 95% CI:0.5%-5.7%) had self-limited hematochezia at home and did not seek medical attention. The average polyp size was 5.1 ± 2.2 mm.

  16. Preoperative management of anticoagulation and antiplatelet agents.

    Science.gov (United States)

    Gleason, Lauren Jan; Friedman, Susan M

    2014-05-01

    This article describes current literature and treatment plans for managing anticoagulation and antiplatelet agents in patients presenting with hip fractures. Indications for anticoagulation and antiplatelet agents are discussed, and management techniques for when patients present with hip fractures are reviewed.

  17. What Are Anticoagulants and Antiplatelet Agents?

    Science.gov (United States)

    ... by heart Treatments + Tests What Are Anticoagulants and Antiplatelet Agents? Anticoagulants and antiplatelet agents are medicines that reduce blood clotting in an artery, a vein or the heart. Blood clots can block the ...

  18. [Anticoagulation in atrial fibrillation - an update].

    Science.gov (United States)

    Antz, Matthias; Hullmann, Bettina; Neufert, Christian; Vocke, Wolfgang

    2008-12-01

    The correct anticoagulation regimen for prevention of thromboembolic events is essential in patients with atrial fibrillation. However, only a minority of patients receives anticoagulation according to the guidelines. The current guidelines are intended to make the indication for anticoagulation more simple and are summarized in the present article. This includes recommendations for chronic anticoagulation, prevention of thromboembolic events after cardioversion and in ablation of atrial fibrillation.

  19. Experimental arterial thrombosis in genetically or diet induced hyperlipidemia in rats--role of vitamin K-dependent clotting factors and prevention by low-intensity oral anticoagulation.

    Science.gov (United States)

    De Curtis, A; D'Adamo, M C; Amore, C; Polishchuck, R; Castelnuovo, A D; Donati, M B; Iacoviello, L

    2001-12-01

    To investigate the relationship among lipids, coagulation and thrombosis in the absence of atherosclerosis, spontaneous or dietary-induced hyperlipidemic (FHL) rats were studied. FHL showed higher levels of coagulation factors VII, IX, X, VIII and XII and a shortening of the occlusion time (OT) of an artificial arterial prosthesis as compared with normolipidemic (FNL) animals. Damage of abdominal aorta of FHL was followed by increased fibrin deposition in the vascular intima as compared to FNL. After 5 months of cholesterol-rich diet FNL showed increased cholesterol, triglycerides and factor II, VII, IX, X, XII levels. A significant shortening of the OT and increased fibrin deposition was also observed. Two-month diet withdrawal restored the initial condition. Warfarin treatment, at a dose decreasing vitamin K-dependent factor to levels found in FNL, prolonged the OT and reduced fibrin deposition, without modifying F XII or changing lipid profile. An increase in the activated form of F VII was observed. In contrast, no difference was found in F VII clearance. High lipid levels favour the process of thrombus formation by increasing the activation of vitamin K-dependent coagulation factors. Low-dose warfarin treatment reverts the prothrombotic effect of hyperlipidemia.

  20. Synthesis and Anticoagulant Activity of Quaternary Ammonium Cationic Starch Sulfates%阳离子淀粉硫酸酯的制备及其抗凝血活性

    Institute of Scientific and Technical Information of China (English)

    樊李红; 沈元; 徐咏梅; 江澜; 王晓东; 周月; 潘晓然

    2011-01-01

    Quaternary ammonium cationic starch sulfate(QACSS) was synthesized by chemical modification of quaternary ammonium cationic starch(QACS) with trisulfonated sodium amine(N(SO_3Na)_3).This sulfating agent was close to neutral,and synthesized by reaction of sodium bisulfite and sodium nitrite in aqueous solution.The reaction conditions for the sulfonation process were optimized through posttest-only control group design.The optimal pH value of the sulfating agent solution was 10.0,the optimal ratio of sulfating agent to QACS was 2.0/314.5(mol/g),the reaction temperature was 40 ℃,the reaction time was about 22 h,respectively.The DS of QACSS was measured by barium sulfate nephelometry method,and the biggest DS was 1.83.The molecular weight was determined as 2.51×104 by static light scattering.Anticoagulant activity of QACSS was investigated by APTT,TT and PT assays.The results showed that QACSS exhibited good anticoagulant activity.The results also showed that with the increase of DS and concentration,APTT increased significantly,but TT and PT do not increased obviously.APTT prolonged as the molecular weight rose firstly and then decreased slowly with further increase in molecular weight.The best molecular weight was around 2.51×104.In addition,the anticoagulant activity of QACSS was better than QACS.%采用由亚硫酸氢钠和亚硝酸钠在水溶液中合成的近似中性的酯化剂N(SO3Na)3在水溶液中对季铵型阳离子淀粉(QACS)进行改性处理,制备了季铵型阳离子淀粉硫酸酯(QACSS).通过单因素实验优化得到酯化反应的最佳反应条件:pH=10.0,酯化剂的摩尔量与QACS的质量之比2∶314.5(mol/g),反应温度40℃,反应时间为22 h.通过测定凝血酶原时间(PT)、凝血活酶时间(APTT)以及凝血酶时间(TT),证明了QACSS有较优的抗凝血活性.随着QACSS取代度和浓度的增加,APTT明显增长,而TT与

  1. Antiplatelet agents and Anticoagulants: from pharmacology to clinical practice.

    Science.gov (United States)

    Tsoumani, Maria E; Tselepis, Alexandros D

    2017-01-24

    Thrombosis is the formation of potentially deadly blood clots in the artery (arterial thrombosis) or vein (venous thrombosis). Since thrombosis is one of the main causes of death worldwide, the development of antithrombotic agents is a global medical priority. They are subdivided into antiplatelet agents and anticoagulants. Antiplatelet agents inhibit clot formation by preventing platelet activation and aggregation, while anticoagulants primarily inhibit the coagulation cascade and fibrin formation. Therapeutics within each category differs with respect to the mechanism of action, time to onset, duration of effect and route of administration. In this review, we critically discuss their main pharmacodynamic and pharmacokinetic characteristics as well as recent advances in daily clinical practice.

  2. 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.

  3. [Antiplatelet agents and anticoagulants: management of the anticoagulated surgical patient].

    Science.gov (United States)

    Llau, Juan V; Ferrandis, Raquel; López Forte, Cristina

    2009-06-01

    Among the drugs most widely consumed by patients are both antiplatelet agents (aspirin, clopidogrel, ticlopidine) and anticoagulants (acenocoumarol, warfarin, low molecular weight heparin, fondaparinux). The use of these drugs in the perioperative period is an essential concern in patient care due to the need to balance the risk of bleeding against thrombotic risk (arterial or venous), which is increased in surgical patients. The present review highlights three main aspects. Firstly, withdrawal of antiplatelet agents is recommended between 1 week and 10 days before surgery to minimize perioperative bleeding. However, this practice has been questioned because patients without the required antiplatelet coverage may be at greater risk of developing cardiac, cerebral or peripheral vascular complications. Therefore, the recommendation of systematic antiplatelet withdrawal for a specific period should be rejected. Currently, risks should be evaluated on an individual basis to minimize the time during which the patient remains without adequate antiplatelet protection. Secondly, thromboprophylaxis is required in most surgical patients due to the high prevalence of venous thromboembolic disease. This implies the use of anticoagulants and the practice of regional anesthesia has been questioned in these patients. However, with the safety recommendations established by the various scientific societies, this practice has been demonstrated to be safe. Finally, "bridge therapy" in patients anticoagulated with acenocoumarol should be performed on an individual basis rather than systematically without taking into account the thrombotic risks of each patient. The perioperative period involves high arterial and venous thrombotic risk and the optimal use of antiplatelet agents and anticoagulants should be a priority to minimize this risk without increasing hemorrhagic risk. Multidisciplinary consensus is essential on this matter.

  4. Self-titrating anticoagulant nanocomplexes that restore homeostatic regulation of the coagulation cascade.

    Science.gov (United States)

    Lin, Kevin Y; Lo, Justin H; Consul, Nikita; Kwong, Gabriel A; Bhatia, Sangeeta N

    2014-09-23

    Antithrombotic therapy is a critical portion of the treatment regime for a number of life-threatening conditions, including cardiovascular disease, stroke, and cancer; yet, proper clinical management of anticoagulation remains a challenge because existing agents increase the propensity for bleeding in patients. Here, we describe the development of a bioresponsive peptide-polysaccharide nanocomplex that utilizes a negative feedback mechanism to self-titrate the release of anticoagulant in response to varying levels of coagulation activity. This nanoscale self-titrating activatable therapeutic, or nanoSTAT, consists of a cationic thrombin-cleavable peptide and heparin, an anionic polysaccharide and widely used clinical anticoagulant. Under nonthrombotic conditions, nanoSTATs circulate inactively, neither releasing anticoagulant nor significantly prolonging bleeding time. However, in response to life-threatening pulmonary embolism, nanoSTATs locally release their drug payload and prevent thrombosis. This autonomous negative feedback regulator may improve antithrombotic therapy by increasing the therapeutic window and decreasing the bleeding risk of anticoagulants.

  5. Neonatal renal vein thrombosis: role of anticoagulation and thrombolysis--an institutional review.

    Science.gov (United States)

    Bidadi, Behzad; Nageswara Rao, Amulya A; Kaur, Dominder; Khan, Shakila P; Rodriguez, Vilmarie

    2016-02-01

    Neonatal renal vein thrombosis (NRVT) is a rare thromboembolic complication in the neonatal period, and sequelae from renal dysfunction can cause significant morbidity. The authors retrospectively reviewed 10 patients with NRVT treated at their institution. The majority of the cohort were male (n = 9), preterm (n = 6), and had unilateral NRVT (n = 6). Six patients received thrombolysis and/or anticoagulation, and 4 patients received supportive care only. Two of the 6 patients treated with anticoagulation who had bilateral NRVT and anuria received thrombolysis with low-dose tissue plasminogen activator. Thrombolysis was not associated with any major adverse events, and both patients had marked improvement of renal function. Eight patients subsequently developed renal atrophy (3 received anticoagulation, 2 received thrombolysis with anticoagulation, and 3 received supportive care). Anticoagulation/thrombolysis did not appear to prevent renal atrophy. The role of thrombolysis needs to be further studied and considered in the setting of bilateral NRVT and acute renal failure.

  6. Transitions of care in anticoagulated patients

    Directory of Open Access Journals (Sweden)

    Michota F

    2013-06-01

    Full Text Available Franklin Michota Department of Hospital Medicine, Cleveland Clinic, Cleveland, OH, USA Abstract: Anticoagulation is an effective therapeutic means of reducing thrombotic risk in patients with various conditions, including atrial fibrillation, mechanical heart valves, and major surgery. By its nature, anticoagulation increases the risk of bleeding; this risk is particularly high during transitions of care. Established anticoagulants are not ideal, due to requirements for parenteral administration, narrow therapeutic indices, and/or a need for frequent therapeutic monitoring. The development of effective oral anticoagulants that are administered as a fixed dose, have low potential for drug-drug and drug-food interactions, do not require regular anticoagulation monitoring, and are suitable for both inpatient and outpatient use is to be welcomed. Three new oral anticoagulants, the direct thrombin inhibitor, dabigatran etexilate, and the factor Xa inhibitors, rivaroxaban and apixaban, have been approved in the US for reducing the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation; rivaroxaban is also approved for prophylaxis and treatment of deep vein thrombosis, which may lead to pulmonary embolism in patients undergoing knee or hip replacement surgery. This review examines current options for anticoagulant therapy, with a focus on maintaining efficacy and safety during transitions of care. The characteristics of dabigatran etexilate, rivaroxaban, and apixaban are discussed in the context of traditional anticoagulant therapy. Keywords: hemorrhagic events, oral anticoagulation, parenteral anticoagulation, stroke, transitions of care

  7. Targeting Two Coagulation Cascade Proteases with a Bivalent Aptamer Yields a Potent and Antidote-Controllable Anticoagulant.

    Science.gov (United States)

    Soule, Erin E; Bompiani, Kristin M; Woodruff, Rebecca S; Sullenger, Bruce A

    2016-02-01

    Potent and rapid-onset anticoagulation is required for several clinical settings, including cardiopulmonary bypass surgery. In addition, because anticoagulation is associated with increased bleeding following surgery, the ability to rapidly reverse such robust anticoagulation is also important. Previously, we observed that no single aptamer was as potent as heparin for anticoagulating blood. However, we discovered that combinations of two aptamers were as potent as heparin. Herein, we sought to combine two individual anticoagulant aptamers into a single bivalent RNA molecule in an effort to generate a single molecule that retained the potent anticoagulant activity of the combination of individual aptamers. We created four bivalent aptamers that can inhibit Factor X/Xa and prothrombin/thrombin and anticoagulate plasma, as well as the combination of individual aptamers. Detailed characterization of the shortest bivalent aptamer indicates that each aptamer retains full binding and functional activity when presented in the bivalent context. Finally, reversal of this bivalent aptamer with a single antidote was explored, and anticoagulant activity could be rapidly turned off in a dose-dependent manner. These studies demonstrate that bivalent anticoagulant aptamers represent a novel and potent approach to actively and reversibly control coagulation.

  8. Current Controversies in Lupus Anticoagulant Detection

    Directory of Open Access Journals (Sweden)

    Gary W. Moore

    2016-12-01

    Full Text Available Antiphospholipid syndrome is an autoimmune, acquired thrombophilia diagnosed when vascular thrombosis or pregnancy morbidity are accompanied by persistent antiphospholipid antibodies. Lupus anticoagulants (LA are one of the criteria antibodies but calibration plasmas are unavailable and they are detected by inference based on antibody behaviour in a medley of coagulation-based assays. Elevated screening tests suggest the presence of a LA, which is confirmed with mixing tests to evidence inhibition and confirmatory tests to demonstrate phospholipid-dependence. At least two screening tests of different principle must be used to account for antibody heterogeneity and controversy exists on whether assays, in addition to dilute Russell’s viper venom time and activated partial thromboplastin time, should be employed. A variety of approaches to raw data manipulation and interpretation attract debate, as does inclusion or exclusion of mixing studies in circumstances where the presence of a LA is already evident from other results. Therapeutic anticoagulation compromises coagulation-based assays but careful data interpretation and use of alternative reagents can detect or exclude LA in specific circumstances, and this aspect of LA detection continues to evolve. This review focuses on the main areas of debate in LA detection.

  9. New Type of Oral Anticoagulants

    Institute of Scientific and Technical Information of China (English)

    刘泽霖

    2012-01-01

    Since 1960,so far,has half a century,long-term oral vitamin K antagonists (VKA) for anticoagulation main plan,but the shortcomings of the VKA but not allow to ignore:( 1 ) the VKA effect to be slow,VKA after diagnosis should be immediate treatment,this plan have to start with unfractionated heparin (UFH),low molecular weight heparin (LMWH) and fondaparinux injection,use 5 ~ 10 d transition again after oral VKA,this plan for outpatient greatly inconvenience;(2) in the use of heparin drugs there is also monitoring problem during or the occurrence of heparin induction thrombocytopenic thrombosis disease (HITT) risk;(3) VKA treatment vulnerable to food,drugs,to VKA considerations of the interference of the individual differences are of great reaction;(4)VKA treatment window,need to narrow in close monitoring of adjusting dosage benefits under,but the present survey indicates that at least a third of patients with clinically failed to control the INR within the scope of the treatment.So send development new anticoagulants,especially oral anticoagulants listed was imminent

  10. 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 BACKGROUND: 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. PRINCIPAL FINDINGS: 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. CONCLUSION/SIGNIFICANCE: In order to develop peptide

  11. Antiplatelet and Anticoagulant Effects of Diterpenes Isolated from the Marine Alga, Dictyota menstrualis

    Directory of Open Access Journals (Sweden)

    Laura de Andrade Moura

    2014-04-01

    Full Text Available Cardiovascular diseases represent a major cause of disability and death worldwide. Therapeutics are available, but they often have unsatisfactory results and may produce side effects. Alternative treatments based on the use of natural products have been extensively investigated, because of their low toxicity and side effects. Marine organisms are prime candidates for such products, as they are sources of numerous and complex substances with ecological and pharmacological effects. In this work, we investigated, through in vitro experiments, the effects of three diterpenes (pachydictyol A, isopachydictyol A and dichotomanol from the Brazilian marine alga, Dictyota menstrualis, on platelet aggregation and plasma coagulation. Results showed that dichotomanol inhibited ADP- or collagen-induced aggregation of platelet-rich plasma (PRP, but failed to inhibit washed platelets (WP. In contrast, pachydictyol A and isopachydictyol A failed to inhibit the aggregation of PRP, but inhibited WP aggregation induced by collagen or thrombin. These diterpenes also inhibited coagulation analyzed by the prothrombin time and activated partial thromboplastin time and on commercial fibrinogen. Moreover, diterpenes inhibited the catalytic activity of thrombin. Theoretical studies using the Osiris Property Explorer software showed that diterpenes have low theoretical toxicity profiles and a drug-score similar to commercial anticoagulant drugs. In conclusion, these diterpenes are promising candidates for use in anticoagulant therapy, and this study also highlights the biotechnological potential of oceans and the importance of bioprospecting to develop medicines.

  12. Anticoagulant Therapy In Ischemic Stroke Or TIA

    Directory of Open Access Journals (Sweden)

    Kaveh Mehrvar

    2017-02-01

    Full Text Available Stroke is the leading cause of disability and the third leading cause of death  . Anticoagulants   have been used to treat patients with acute ischemic stroke for many years. Despite their widespread use, the usefulness of emergency anticoagulation is a subject of debate. Disagreements exist about the best agent to administer, the route of administration, the use of a bolus dose to start treatment, the level of anticoagulation required, and the duration of treatment. There are 2 types of anticoagulants: Parenteral and oral. Heparin is an anticoagulant that used parenteral. Oral anticoagulants are including Warfarin and new anticoagulants such as Dabigatrn,Rivaroxaban ,Apixaban and other newer drugs. In patients with noncardioembolic  ischemic stroke or TIA antiplatelet agents are treatment of choice and preferred to anticoagulants. In cardioembolic  ischemic stroke or TIA with high risk of reembolization  anticoagulants  are considered as preferred treatment.  Warfarin, apixaban10mg/d ,Rivaroxaban20mg/d, and dabigatran 150 mg/d are all indicated for the prevention of recurrent stroke in patients with nonvalvular AF, whether paroxysmal or permanent.Also anticoagulant therapy is recommended for ischemic stroke or TIA patients in the setting of acute MI, atrial or ventricular thrombosis or dilated and restricted cardiomyopathy. Some valvular heart diseases are other indication for anticoagulant therapy in ischemic stroke or TIA patients. Ischemic  Stroke or TIA in patients with Cerebral vein thrombosis and  known hypercoagulable state specially anti phospholipid antibody syndrome are other indications for anticoagulant treatment.

  13. Effect of magnetic bracelets on the coagulation and anticoagulation systems of the blood of patients with hypertension

    Science.gov (United States)

    Bublis, V. V.; Zabrodina, L. V.; Platonova, A. T.; Meyerova, Y. A.

    1974-01-01

    The data which have been obtained on the influence of magnetic bracelets on the coagulation and anticoagulation systems of the blood indicate that the wearing of magnetic bracelets results in a decrease in the coagulation activity of the blood and an increase in the activity of the anticoagulation system. These changes must be viewed as favorable for patients with cardiovascular pathology.

  14. 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.

  15. 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.

  16. Management of the anticoagulated dental patient.

    Science.gov (United States)

    Ball, J H

    1996-11-01

    An understanding of the primary mechanisms of hemostasis, including the coagulation pathways and the intrinsic, extrinsic, and common systems, is the basis for treating the anticoagulated patient. Two major anticoagulants are used for treating those who may be at risk for thromboembolic crisis. These drugs include Coumadin, which is an oral anticoagulant, and heparin, a parenteral anticoagulant, which is often used for acute thromboembolic episodes or for hospitalization protocols that include significant surgical procedures. The practitioner should be familiar with common dental drugs that can interact with anticoagulants and should consult with the patient's physician before administering any such drugs. By placing the patient into one of three dental treatment categories, appropriate anticoagulation therapy can be rendered to each patient according to his or her needs. Low-risk procedures require no change in anticoagulation medication. For moderate-risk procedures, withdrawal of anticoagulation medication 2 days before the procedure and verified with the PT the day of the procedure is indicated. For high-risk dental procedures, using a heparin protocol should be strongly considered. In all instances of dental treatment, the oral tissues should be treated atraumatically using local hemostatic measures for control of hemorrhage. Treating medically compromised patients who are on a variety of medications is becoming more common in dentistry today. Understanding the underlying disease and the appropriate protocol for treatment of anticoagulated patients reduces the risk of thromboembolism and hemorrhagic complications.

  17. Anticoagulant therapy in pregnant patients with metabolic syndrome: a review.

    Science.gov (United States)

    Mierzynski, Radzisław; Poniedzialek-Czajkowska, Elzbieta; Kimber-Trojnar, Zaneta; Leszczynska-Gorzelak, Bozena; Oleszczuk, Jan

    2014-01-01

    Pregnancy is a specific state of heightened coagulability related to the increase in procoagulant agents and to the reduced fibrinolysis. Pregnancy is associated with a 4-fold increased risk of developing venous thromboembolism (VTE) and this risk still increases to 14-fold during puerperium. A correlation between the metabolic syndrome and development of cardiovascular events and cerebrovascular incidents has been described. Such a relationship is referred to a hypercoagulable state due to increased serum levels of the plasminogen activator inhibitor-1 (PAI-1), fibrinogen, factor (F) VII and VIII, von Willebrand factor and from endothelial activation, caused by increased circulating adhesion molecules. As to the risk of VTE, the probability for its association with cardiovascular incidents is increased by common underlying mechanisms such as the activation of platelets and the blood coagulation. A correlation between idiopathic VTE and the metabolic syndrome has been reported. The anticoagulant therapy may be recommended during the pregnancy for the treatment or the prophylaxis of VTE and, in women with artificial heart valves, for the prevention of the valve thrombosis and systemic embolisation. There are also specific conditions during pregnancy which benefit from anticoagulant use, such as recurrent fetal loss, thrombophilia and assisted reproductive technology. There are no published specific data about using of anticoagulant agents in pregnant patients with the metabolic syndrome except for a few articles addressing reproductive problems. The mechanisms of anticoagulant action were studied with the focus on heparinoids, because of their safety not only for the patient but also for the fetus. The new oral anticoagulants were also shortly described although they have been contraindicated during the pregnancy.

  18. Partial Purification and Characterization of Anticoagulant Factor from the Snake (Echis carinatus) Venom

    OpenAIRE

    2013-01-01

    Objective(s): Snake venoms contain complex mixture of proteins with biological activities. Some of these proteins affect blood coagulation and platelet function in different ways. Snake venom toxin may serve as a starting material for drug design to combat several pathophysiological problems such as cardiovascular disorders. In the present study, purification of anticoagulation factor from venom of snake (Echis carinatus) was studied. Materials and Methods: Anticoagulation activity of crude v...

  19. Changing trends in anti-coagulant therapies. Are heparins and oral anti-coagulants challenged?

    Science.gov (United States)

    Fareed, J; Iqbal, O; Cunanan, J; Demir, M; Wahi, R; Clarke, M; Adiguzel, C; Bick, R

    2008-06-01

    The conventional management of thrombotic and cardiovascular disorders is based on the use of heparin, oral anticoagulants and aspirin. Despite progress in the sciences, these drugs still remain a challenge and mystery. The development of low molecular weight heparins (LMWHS) and the synthesis of heparinomimetics represent a refined use of heparin. Additional drugs will continue to develop. However, none of these drugs will ever match the polypharmacology of heparin. Aspirin still remains the leading drug in the management of thrombotic and cardiovascular disorders. The newer antiplatelet drugs such as adenosine diphosphate receptor inhibitors, GPIIb/IIIa inhibitors and other specific inhibitors have limited effects and have been tested in patients who have already been treated with aspirin. Warfarin provides a convenient and affordable approach in the long-term outpatient management of thrombotic disorders. The optimized use of these drugs still remains the approach of choice to manage thrombotic disorders. The new anticoagulant targets, such as tissue factor, individual clotting factors, recombinant forms of serpins (antithrombin, heparin co-factor II and tissue factor pathway inhibitors), recombinant activated protein C, thrombomodulin and site specific serine proteases inhibitors complexes have also been developed. There is a major thrust on the development of orally bioavailable anti-Xa and IIa agents, which are slated to replace oral anticoagulants. Both the anti-factor Xa and anti-IIa agents have been developed for oral use and have provided impressive clinical results. However, safety concerns related to liver enzyme elevations and thrombosis rebound have been reported with their use. For these reasons, the US Food and Drug Administration did not approve the orally active antithrombin agent Ximelagatran for several indications. The synthetic pentasaccharide (Fondaparinux) has undergone clinical development. Unexpectedly, Fondaparinux also produced major

  20. Transient pseudothrombocytopenia in a neonate: transmission of a maternal EDTA-dependent anticoagulant.

    Science.gov (United States)

    Ohno, Norioki; Kobayashi, Masao; Hayakawa, Seiichi; Utsunomiya, Akari; Karakawa, Shuhei

    2012-01-01

    EDTA-dependent pseudothrombocytopenia (PTCP) is characterised by a low platelet count caused by autoantibodies in the serum reacting with EDTA-anticoagulated blood. EDTA-dependent PTCP is caused by a factor that retains EDTA anticoagulation activity in the serum. We report here that a neonate from a mother with PTCP presented with transient low platelet counts when EDTA was used as an anticoagulant. To confirm the transmission of a maternal serum factor to the neonate, we examined to add the maternal serum into the normal blood. Platelet count decreased significantly after adding maternal serum. Clumped platelets were also observed in the smears of mixed samples.

  1. [New oral anticoagulants - influence on coagulation tests].

    Science.gov (United States)

    Simeon, L; Nagler, M; Wuillemin, W A

    2014-01-01

    The new oral anticoagulants (NOACs) represent alternative antithrombotic agents for prophylaxis and therapy of thromboembolic diseases. They act either by inhibition of the clotting factor Xa or IIa (thrombin). As a consequence, they influence several coagulation assays (for example prothrombin time, activated partial thromboplastin time). Because of the short half-life of these new agents, these changes show great variations in the course of 24 hours. Furthermore, there are significant differences of laboratory results depending on the used reagents. We explain the influence of apixaban, rivaroxaban (factor Xa inhibitors) and dabigatran (thrombin inhibitor) on the most commonly used coagulation assays. Besides we show that this influence depends on the way of action of the drug as well as on the principle of the coagulation assay. Being aware of this relationships helps to interpret the results of coagulation assays under influence of NOACs correctly.

  2. A Retrospective Study of Continuous Renal Therapy and Anticoagulation in Patients with Hemorrhagic Fever with Renal Syndrome

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    Objective To observe the application of continuous renal replacement therapy(CRRT) and heparin anticoagulation in patients with HFRS, and to explore a more suitable anticoagulant strategy. MethodsEighty-five severe-type patients (severe group) and 71 critical-type patients (critical group) were enrolled in this study. The frequency of CRRT was compared between the two groups; the frequency of CRRT treated with and without heparin anticoagulation and the frequency of hemorrhage and channel blood clotting induced by the two anticoagulant strategies were observed. ResultsThe frequency of CRRT in the critical group was higher than thatin the severe group (P<0.001). The frequency of CRRT initiated during the overlapping phases in the critical group was signiifcantly higher than that of the severe group (P=0.032). The total times of CRRT was 103, and 70 of them were treated with heparin anticoagulation. The frequencies of hemorrhage induced by heparin anticoagulation and no heparinization were 16 and 0, respectively, and the frequencies of channel blood clotting were 2 and 4, respectively. Conclusions CRRT has been used extensively in the critical-type patients with HFRS. The heparin anticoagulation and no anticoagulant strategies should be used more rationally in patients treated with CRRT, according to the clinical characteristics of the disease.

  3. [Dental extractions in patients taking anticoagulants: is alteration of the anticoagulant regime necessary?].

    Science.gov (United States)

    Madrid, Carlos

    2005-05-25

    A major concern in the management of patients under anticoagulants is the potential for excessive bleeding after dental procedures. Recommendations for the administration of oral anticoagulants in conjunction with oral surgery range from complete withdrawal of anticoagulants to the maintenance of an unchanged therapy. Rising evidences show that the alteration of anticoagulation is not necessary for patients with INR of 4 or less previous to tooth extractions. Topical antifibrinolytics as tranexamic acid control successfully alveolar bleeding. It is time to stop interrupting anticoagulant therapy for oral surgery. A theoretical risk of hemorrhage after dental surgery in patients at therapeutic levels of anticoagulation exists but it is minimal and is greatly overweighed by the risk of thromboembolism after alteration of the anticoagulant therapy.

  4. Safety of anticoagulation after hemorrhagic infarction.

    Science.gov (United States)

    Pessin, M S; Estol, C J; Lafranchise, F; Caplan, L R

    1993-07-01

    Cerebral hemorrhagic infarction visualized on CT, secondary to embolic stroke in an anticoagulated individual, is usually associated with clinically stable or improving neurologic signs; fear of transforming the hemorrhagic infarction into a hematoma, however, usually prompts cessation of anticoagulation until the blood has cleared on CT, despite the recognized risk of recurrent embolism during this non-anticoagulated period. We now report our experience with 12 patients with hemorrhagic infarction who remained anticoagulated. Eleven men and one woman, ages 33 to 77, developed hemorrhagic infarction while on heparin, warfarin, or both, for prevention of recurrent embolism. Patients were either continued on uninterrupted anticoagulation from stroke onset (n = 6), or anticoagulation was withheld for several days and then resumed (n = 4), or it was withheld for 5 and 14 days (n = 2) after stroke onset and then continued uninterrupted despite the CT appearance of hemorrhagic infarction. Eleven patients had a definite cardioembolic source for stroke (atrial fibrillation, seven; ventricular thrombus, two; and ventricular dyskinesia, two). One patient had carotid occlusion with local intra-arterial embolism. Hemorrhagic infarcts varied in size and were located in the middle cerebral artery territory in 11 patients and posterior cerebral artery territory in one. All patients remained clinically stable or improved on anticoagulation. Serial CTs showed fading hemorrhagic areas. When the risk of recurrent embolism is high, anticoagulation may be safely used in some patients with hemorrhagic infarction.

  5. Anticoagulation management in the ambulatory surgical setting.

    Science.gov (United States)

    Eisenstein, Diana Hill

    2012-04-01

    Many people receiving maintenance anticoagulation therapy require surgery each year in ambulatory surgery centers. National safety organizations focus attention toward improving anticoagulation management, and the American College of Chest Physicians has established guidelines for appropriate anticoagulation management to balance the risk of thromboembolism when warfarin is discontinued with the risk of bleeding when anticoagulation therapy is maintained. The guidelines recommend that patients at high or moderate risk for thromboembolism should be bridged with subcutaneous low-molecular-weight heparin or IV unfractionated heparin with the interruption of warfarin, and low-risk patients may require subcutaneous low-molecular-weight heparin or no bridging with the interruption of warfarin. The guidelines recommend the continuation of warfarin for patients who are undergoing minor dermatologic or dental procedures or cataract removal. The literature reveals, however, that there is not adequate adherence to these recommendations and guidelines. Management of anticoagulation therapy by a nurse practitioner may improve compliance and safety in ambulatory surgery centers.

  6. Anticoagulation therapy for atrial fibrillation.

    Science.gov (United States)

    Hylek, Elaine M

    2013-03-01

    Atrial fibrillation (AF) is the most common significant cardiac rhythm disorder, and its prevalence is increasing worldwide. Atrial fibrillation confers a fivefold increased risk of stroke, and these strokes are associated with significant mortality and disability. The vitamin K antagonist, warfarin, has been the mainstay of anticoagulant therapy for patients with AF, reducing the risk of stroke by 65%. Despite its efficacy, warfarin remains underused in clinical practice because of its variable dose response, diet and medication interactions, and need for frequent monitoring. Stroke prevention in AF has entered an exciting therapeutic era with new classes of targeted anticoagulants that avoid the many pitfalls of the vitamin K antagonists. Dabigatran, an oral thrombin inhibitor, and the factor Xa inhibitors, rivaroxaban and apixaban, have demonstrated efficacy for stroke prevention and a reduced risk of intracranial hemorrhage relative to warfarin. Translating the efficacy of clinical trials into effective use of these novel agents in clinical practice will require an understanding of their pharmacokinetic profiles, dose selection, and management in select clinical situations.

  7. Antidotes for novel oral anticoagulants: current status and future potential.

    Science.gov (United States)

    Crowther, Mark; Crowther, Mark A

    2015-08-01

    The direct thrombin inhibitor dabigatran and the anti-Xa agents rivaroxaban, edoxaban, and apixaban are a new generation of oral anticoagulants. Their advantage over the vitamin K antagonists is the lack of the need for monitoring and dose adjustment. Their main disadvantage is currently the absence of a specific reversal agent. Dabigatran's, unlike the anti-Xa agents, absorption can be reduced by activated charcoal if administered shortly after ingestion and it can be removed from the blood with hemodialysis. Prothrombin complex concentrate, activated prothrombin complex concentrate, and recombinant factor VIIa all show some activity in reversing the anticoagulant effect of these drugs but this is based on ex vivo, animal, and volunteer studies. It is unclear, which, if any, of these drugs is the most suitable for emergency reversal. Three novel molecules (idarucizumab, andexanet, and PER977) may provide the most effective and safest way of reversal. These agents are currently in premarketing studies.

  8. Regional citrate anticoagulation in critically ill patients during continuous blood purification

    Institute of Scientific and Technical Information of China (English)

    龚德华; 季大玺; 徐斌; 谢红浪; 刘云; 黎磊石

    2003-01-01

    Objectives To evaluate the safety and define the contraindication of regional citrate anticoagulation treatment on various critically ill patients being treated by continuous blood purification, who also had bleeding tendencies. Methods Forty critically ill patients being treated by continuous blood purification (CBP) were involved in this study. Due to their bleeding tendencies, regional citrate anticoagulation treatment was given to all of them. Those with hepatic function impairment (n=10) were classified as Group A, those with hypoxemia were classified as Group B (n=10), and the others as Group C (n=20). Blood samples were collected before treatment, and at 4, 12, 24, 36, and 48 hour intervals during CBP. These samples then were used arterial blood gas analysis, whole blood activated clotting time (WBACT) pre- and post-filter, and serum ionized calcium examination. Results WBACT pre-filter showed little fluctuant through the 48hr period of CBP, and WBACT post-filter showed obvious prolongation than that of the pre-filter (P<0.05) at all time points. Metabolic acidosis was found in Group A patients before CBP, and improved during CBP. Normal acid-base conditions of patients were disturbed and deteriorated in Group B during CBP, but not in Group C. Serum ionized calcium was maintained at a normal range during CBP in Group A and C patients, but declined significantly in Group B patients (vs. pre-treatment, P<0.05). Conclusions Regional citrate anticoagulation can be safely used in conjunction with CBP treatment for patients with hepatic function impairment , but may induce acidosis and a decline in serum ionized calcium when used with hypoxemic patients.

  9. New anticoagulant and antiplatelet agents: a primer for the gastroenterologist.

    Science.gov (United States)

    Baron, Todd H; Kamath, Patrick S; McBane, Robert D

    2014-02-01

    A large number of patients worldwide receive anticoagulant and antiplatelet agents, collectively known as antithrombotic agents. Several new anticoagulants and antiplatelet agents recently were approved for use. Gastroenterologists may be unfamiliar with the mechanism of action, indications for use, and pharmacokinetics of these newer drugs. In patients undergoing elective and urgent endoscopic procedures, clinicians must be familiar with these medications to optimize outcomes. When the decision is made to continue the newer antithrombotic agents for elective procedures, the clinician must understand the risk that these agents may impart on procedural-induced bleeding. Finally, it is important to understand how to manage these agents in the presence of acute gastrointestinal bleeding. In this article the use of newer antithrombotic agents is reviewed.

  10. Specific sulfation and glycosylation - a structural combination for the anticoagulation of marine carbohydrates

    OpenAIRE

    Vitor Hugo Pomin; Paulo Antonio De Souza Mourão

    2014-01-01

    Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans...

  11. Specific sulfation and glycosylation—a structural combination for the anticoagulation of marine carbohydrates

    OpenAIRE

    Pomin, Vitor H.; Mourão, Paulo A. S.

    2014-01-01

    Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans...

  12. Calpain Activator Dibucaine Induces Platelet Apoptosis

    Directory of Open Access Journals (Sweden)

    Jun Liu

    2011-03-01

    Full Text Available Calcium-dependent calpains are a family of cysteine proteases that have been demonstrated to play key roles in both platelet glycoprotein Ibα shedding and platelet activation and altered calpain activity is associated with thrombotic thrombocytopenic purpura. Calpain activators induce apoptosis in several types of nucleated cells. However, it is not clear whether calpain activators induce platelet apoptosis. Here we show that the calpain activator dibucaine induced several platelet apoptotic events including depolarization of the mitochondrial inner transmembrane potential, up-regulation of Bax and Bak, down-regulation of Bcl-2 and Bcl-XL, caspase-3 activation and phosphatidylserine exposure. Platelet apoptosis elicited by dibucaine was not affected by the broad spectrum metalloproteinase inhibitor GM6001. Furthermore, dibucaine did not induce platelet activation as detected by P-selectin expression and PAC-1 binding. However, platelet aggregation induced by ristocetin or α-thrombin, platelet adhesion and spreading on von Willebrand factor were significantly inhibited in platelets treated with dibucaine. Taken together, these data indicate that dibucaine induces platelet apoptosis and platelet dysfunction.

  13. Stresslets induced by active swimmers

    CERN Document Server

    Lauga, Eric

    2016-01-01

    Active particles disturb the fluid around them as force dipoles, or stresslets, which govern their collective dynamics. Unlike swimming speeds, the stresslets of active particles are rarely determined due to the lack of a suitable theoretical framework for arbitrary geometry. We propose a general method, based on the reciprocal theorem of Stokes flows, to compute stresslets as integrals of the velocities on the particle's surface, which we illustrate for spheroidal chemically-active particles. Our method will allow tuning the stresslet of artificial swimmers and tailoring their collective motion in complex environments.

  14. Compatibility of Injectable Anticoagulant Agents in Ethanol; In Vitro Antibiofilm Activity and Impact on Polyurethane Catheters of Enoxaparin 400 U/mL in 40% v/v Ethanol.

    Directory of Open Access Journals (Sweden)

    Damien Balestrino

    Full Text Available Interdialytic lock solutions should maintain catheter patency and prevent catheter infections. We aimed to determine in which conditions injectable anticoagulant agents (IAAs combined with ethanol are compatible and to assess the antibiofilm activity of the selected combination and its effects on dialysis catheters (DC.The solubility and compatibility of unfractionated heparin (UFH, low molecular weight heparins (LMWHs, heparinoids and fondaparinux (50 to 2,500 U/mL in 30 to 70% ethanol were determined by visual observation. The stability of enoxaparin in ethanol and the ethanol content were assessed by high performance liquid chromatography (HPLC and titrimetric control, respectively. The bactericidal effect was determined on 24h-old biofilms embedded in silicone-DC. The integrity of polyurethane-DC immersed in anticoagulant-ethanol was assessed by gas chromatography-mass spectrometry (GC-MS and compared with previously published results.The compatibility of IAAs and ethanol varied according to IAA type and concentration, and ethanol content. UFH in 40% ethanol was not compatible, whatever the UFH concentration used. Established limits of compatibility of enoxaparin, nadroparin, dalteparin and tinzaparin in 40% ethanol were 1350, 575, 307 and 207 U/ml, respectively, and up to 300 U/ml for danaparoid and 1 mg/mL for fondaparinux. Enoxaparin 400 U/mL in 40% ethanol (Enox/Eth eradicated biofilm after 4 hours of exposure for Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans and after 24 hours for Klebsiella pneumoniae and S. aureus. Aliphatic carbonate and alcohol compounds were released by polyurethane-DC after Enox/Eth exposure, as after 40% ethanol or saline exposure. There was no significant difference between the amounts released after 30 minutes of exposure to Enox/Eth and 15 days to saline.A 40% ethanol solution can be combined with all IAAs but UFH. Enox/Eth was effective as an anti-biofilm agent with minor impacts on

  15. Compatibility of Injectable Anticoagulant Agents in Ethanol; In Vitro Antibiofilm Activity and Impact on Polyurethane Catheters of Enoxaparin 400 U/mL in 40% v/v Ethanol

    Science.gov (United States)

    Charbonnel, Nicolas; Forestier, Christiane; Lartigue, Claire; Souweine, Bertrand

    2016-01-01

    Background and Objectives Interdialytic lock solutions should maintain catheter patency and prevent catheter infections. We aimed to determine in which conditions injectable anticoagulant agents (IAAs) combined with ethanol are compatible and to assess the antibiofilm activity of the selected combination and its effects on dialysis catheters (DC). Methods The solubility and compatibility of unfractionated heparin (UFH), low molecular weight heparins (LMWHs), heparinoids and fondaparinux (50 to 2,500 U/mL) in 30 to 70% ethanol were determined by visual observation. The stability of enoxaparin in ethanol and the ethanol content were assessed by high performance liquid chromatography (HPLC) and titrimetric control, respectively. The bactericidal effect was determined on 24h-old biofilms embedded in silicone-DC. The integrity of polyurethane-DC immersed in anticoagulant-ethanol was assessed by gas chromatography-mass spectrometry (GC-MS) and compared with previously published results. Results The compatibility of IAAs and ethanol varied according to IAA type and concentration, and ethanol content. UFH in 40% ethanol was not compatible, whatever the UFH concentration used. Established limits of compatibility of enoxaparin, nadroparin, dalteparin and tinzaparin in 40% ethanol were 1350, 575, 307 and 207 U/ml, respectively, and up to 300 U/ml for danaparoid and 1 mg/mL for fondaparinux. Enoxaparin 400 U/mL in 40% ethanol (Enox/Eth) eradicated biofilm after 4 hours of exposure for Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans and after 24 hours for Klebsiella pneumoniae and S. aureus. Aliphatic carbonate and alcohol compounds were released by polyurethane-DC after Enox/Eth exposure, as after 40% ethanol or saline exposure. There was no significant difference between the amounts released after 30 minutes of exposure to Enox/Eth and 15 days to saline. Conclusions A 40% ethanol solution can be combined with all IAAs but UFH. Enox/Eth was effective as

  16. The Anticoagulation Effects of Glycosaminoglycan from Mactra veneriformis

    Directory of Open Access Journals (Sweden)

    Yue Wang

    2015-07-01

    Full Text Available In this study, the anticoagulation effect of glycosaminoglycan from Mactra veneriformis was studied. The results showed that glycosaminoglycan mainly exerted anticoagulation via antithrombin III. Glycosaminoglycan could passivate the function of heparin cofactor II inhibiting thrombin activity. Glycosaminoglycan significantly reduced the activities of coagulation factor II, V, VII, X, VIII, IX, XI, XII as well as fibrinogen content in the plasma (p<0.05, p<0.01. Besides, glycosaminoglycan could extend blood recalcification time in rats by shielding Ca2+ in plasma and significantly reduced Ca2+ concentration in rats and mice serum (p<0.05, p<0.01. Glycosaminoglycan reduced the Ca2+ concentration in serum in a more intensive way than that of heparin sodium (p<0.05, p<0.01.

  17. Perioperative management of the chronically anticoagulated patient.

    Science.gov (United States)

    Heit, J A

    2001-09-01

    Common indications for chronic anticoagulation include mechanical prosthetic heart valve, non-rheumatic atrial fibrillation, and venous thromboembolism. Perioperative management of the chronically anticoagulated patient is a complex medical problem, and includes the following issues: urgency of surgery, risk of thromboembolism in the absence of anticoagulation, bleeding risk, consequences of bleeding, ability to control bleeding physically, and duration of bleeding risk after the procedure. Most patients can be managed safely by stopping oral anticoagulants 4-5 days before surgery and restarting anticoagulation after the procedure at the patient's usual daily dose. In general, dental procedures and cataract extraction can be performed without interrupting anticoagulation. Most other procedures can be safely performed with an INR patients with double-wing prosthetic valves (e.g., St. Jude, Carbomedics) in the aortic position, uncomplicated atrial fibrillation, or a remote (>3 months) history of venous thromboembolism, oral anticoagulants can be stopped 4-5 days before surgery and restarted at the usual daily dose immediately after surgery. For other patients at higher risk of thrombosis, "bridging therapy" with outpatient low molecular weight heparin is safe and effective. For urgent procedures, a small dose of oral vitamin K usually will reduce the INR within 24-36 hours to a level sufficient for surgery and avoids exposure to transfused blood products.

  18. [Hypoprothrombinemia--lupus anticoagulant syndrome].

    Science.gov (United States)

    Campos, Maria Manuel; Reis Santos, Isabel

    2011-12-01

    Diagnosis criteria, pathogenic mechanisms, incidence and prevalence of the Antiphospholipid Syndrome are focused in a brief review. Hypoprothrombinemia (HPT) may be hereditary or acquired; the first is rare and with recessive autossomic transmission. We report the case of a 66-year-old white woman with Systemic Lupus Erythematosus (SLE), autoimmune haemolytic anaemia, periostitis, haematomas, bleeding leg ulcer and rectal haemorrhages; she had decreased levels of the prothrombin. Haemorrhagic episodes were related with the anti-prothrombin specificity of Lupus Anticoagulant (LA) detected. The SLE/LA/HPT association is less frequent than the correlated to SLE/LA/anti- ß2Glycoprotein I antibodies and was first reported in 1960 by Rapaport et al, in an 11-year- -old girl with severe haemorrhagic manifestations.

  19. Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

    Science.gov (United States)

    Navaneetha Pandiyaraj, K.; Ram Kumar, M. C.; Arun Kumar, A.; Padmanabhan, P. V. A.; Deshmukh, R. R.; Bah, M.; Ismat Shah, S.; Su, Pi-Guey; Halleluyah, M.; Halim, A. S.

    2016-05-01

    Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as Osbnd Cdbnd O, Cdbnd O, Csbnd N and Ssbnd S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was found that the anti-thrombogenic properties of the PP films are effectively controlled by the CAPP grafting of AAc and PEG followed by immobilization of biomolecules of heparin, chitosan and insulin. The grafting and immobilization was confirmed by FTIR and XPS through the recognition of specific functional groups such as COOH, Csbnd O, Ssbnd S and Csbnd N. on the surface of PP film. Furthermore, the surface morphology and hydrophilic nature of the PP films also tailored

  20. Tailoring the surface properties of polypropylene films through cold atmospheric pressure plasma (CAPP) assisted polymerization and immobilization of biomolecules for enhancement of anti-coagulation activity

    Energy Technology Data Exchange (ETDEWEB)

    Navaneetha Pandiyaraj, K., E-mail: dr.knpr@gmail.com [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T By Pass, Chinniyam Palayam (Post), Coimbatore 641062 (India); Ram Kumar, M.C.; Arun Kumar, A. [Surface Engineering Laboratory, Department of Physics, Sri Shakthi Institute of Engineering and Technology, L& T By Pass, Chinniyam Palayam (Post), Coimbatore 641062 (India); Padmanabhan, P.V.A. [PSN College of Engineering and Technology, Tirunelveli 627 152 (India); Deshmukh, R.R. [Department of Physics, Institute of Chemical Technology, Matunga, Mumbai 400 019 (India); Bah, M.; Ismat Shah, S. [Department of Physics and Astronomy, Department of Materials Science and Engineering, University of Delaware, 208 Dupont Hall, Newark (United States); Su, Pi-Guey [Department of Chemistry, Chinese Culture University, Taipei 111, Taiwan (China); Halleluyah, M.; Halim, A.S. [School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

    2016-05-01

    Graphical abstract: - Highlights: • Developed low cost cold atmospheric plasma reactor for plasma polymerization technique. • Surface of the PP film was modified by grafting of AAc and PEG by CAPP polymerization. • Biomolecules of chitosan, insulin and heparin were immobilized on surface of PEG-AAc grafted PP films. • The surface modified PP films were characterized by various techniques. • The plasma polymerized and immobilized film reveals substantial blood compatibility. - Abstract: Enhancement of anti-thrombogenic properties of polypropylene (PP) to avert the adsorption of plasma proteins (fibrinogen and albumin), adhesion and activation of the platelets are very important for vast biomedical applications. The cold atmospheric pressure plasma (CAPP) assisted polymerization has potential to create the specific functional groups such as O−C=O, C=O, C−N and S−S. on the surface of polymeric films using selective precursor in vapour phase to enhance anti-thrombogenic properties. Such functionalized polymeric surfaces would be suitable for various biomedical applications especially to improve the blood compatibility. The eventual aspiration of the present investigation is to develop the biofunctional coating onto the surface of PP films using acrylic acid (AAc) and polyethylene glycol (PEG) as a precursor in a vapour phase by incorporating specific functional groups for immobilization of biomolecules such as heparin (HEP), chitosan (CHI) and insulin (INS) on the surface of plasma modified PP films. The surface properties such as hydrophilicity, chemical composition, surface topography of the surface modified PP films were analyzed by contact angle (CA), Fourier transform infrared spectroscopy (FTIR), X-ray photo electron spectroscopy (XPS) and atomic force microscopy (AFM). Furthermore the anti-thrombogenic properties of the surface modified PP films were studied by in vitro tests which include platelet adhesion and protein adsorption analysis. It was

  1. Spontaneous Epiglottic Hematoma Secondary to Supratherapeutic Anticoagulation

    Directory of Open Access Journals (Sweden)

    Cody A. Koch

    2010-01-01

    Full Text Available Hemorrhage into the soft tissues of the airway represents a potentially life-threatening complication of long-term anticoagulation. We report the case of a chronically anticoagulated 37-year-old male who developed a spontaneous hematoma of the epiglottis secondary to a supra-therapeutic INR. Epiglottic hematoma should be considered in the differential of any anticoagulated patient presenting with upper airway compromise. The airway should be secured in a controlled fashion, and the coagulopathy should be rapidly corrected.

  2. Salvianolic acid B, a novel autophagy inducer, exerts antitumor activity as a single agent in colorectal cancer cells.

    Science.gov (United States)

    Jing, Zhao; Fei, Weiqiang; Zhou, Jichun; Zhang, Lumin; Chen, Liuxi; Zhang, Xiaomin; Liang, Xiao; Xie, Jiansheng; Fang, Yong; Sui, Xinbing; Han, Weidong; Pan, Hongming

    2016-09-20

    Salvianolic Acid B (Sal B), an active compound extracted from the Chinese herb Salvia miltiorrhiza, is attracting more and more attention due to its biological activities, including antioxidant, anticoagulant and antitumor effects. However, autophagy induction in cancer cells by Sal B has never been recognized. In this study, we demonstrated that Sal B induced cell death and triggered autophagy in HCT116 and HT29 cells in a dose-dependent manner. Specific inhibition of autophagy by 3-MA or shRNA targeting Atg5 rescued Sal B-induced cell death in vitro and in vivo, suggesting that Sal B-induced autophagy may play a pro-death role and contribute to the cell death of colorectal cancer cell lines. Furthermore, AKT/mTOR signaling pathway was demonstrated to be a critical mediator in regulating Sal B-induced cell death. Overexpression of AKT by the transfection with AKT plasmid or pretreatment with insulin decreased Sal B-induced autophagy and cell death. Inversely, inhibition of AKT by LY294002 treatment markedly enhanced Sal B-induced autophagy and cell death. Taken together, our results demonstrate, for the first time, that Sal B is a novel autophagy inducer and exerts its antitumor activity as a single agent in colorectal cancer cells through the suppression of AKT/mTOR pathway.

  3. Selection of an aptamer antidote to the anticoagulant drug bivalirudin.

    Science.gov (United States)

    Martin, Jennifer A; Parekh, Parag; Kim, Youngmi; Morey, Timothy E; Sefah, Kwame; Gravenstein, Nikolaus; Dennis, Donn M; Tan, Weihong

    2013-01-01

    Adverse drug reactions, including severe patient bleeding, may occur following the administration of anticoagulant drugs. Bivalirudin is a synthetic anticoagulant drug sometimes employed as a substitute for heparin, a commonly used anticoagulant that can cause a condition called heparin-induced thrombocytopenia (HIT). Although bivalrudin has the advantage of not causing HIT, a major concern is lack of an antidote for this drug. In contrast, medical professionals can quickly reverse the effects of heparin using protamine. This report details the selection of an aptamer to bivalirudin that functions as an antidote in buffer. This was accomplished by immobilizing the drug on a monolithic column to partition binding sequences from nonbinding sequences using a low-pressure chromatography system and salt gradient elution. The elution profile of binding sequences was compared to that of a blank column (no drug), and fractions with a chromatographic difference were analyzed via real-time PCR (polymerase chain reaction) and used for further selection. Sequences were identified by 454 sequencing and demonstrated low micromolar dissociation constants through fluorescence anisotropy after only two rounds of selection. One aptamer, JPB5, displayed a dose-dependent reduction of the clotting time in buffer, with a 20 µM aptamer achieving a nearly complete antidote effect. This work is expected to result in a superior safety profile for bivalirudin, resulting in enhanced patient care.

  4. Selection of an aptamer antidote to the anticoagulant drug bivalirudin.

    Directory of Open Access Journals (Sweden)

    Jennifer A Martin

    Full Text Available Adverse drug reactions, including severe patient bleeding, may occur following the administration of anticoagulant drugs. Bivalirudin is a synthetic anticoagulant drug sometimes employed as a substitute for heparin, a commonly used anticoagulant that can cause a condition called heparin-induced thrombocytopenia (HIT. Although bivalrudin has the advantage of not causing HIT, a major concern is lack of an antidote for this drug. In contrast, medical professionals can quickly reverse the effects of heparin using protamine. This report details the selection of an aptamer to bivalirudin that functions as an antidote in buffer. This was accomplished by immobilizing the drug on a monolithic column to partition binding sequences from nonbinding sequences using a low-pressure chromatography system and salt gradient elution. The elution profile of binding sequences was compared to that of a blank column (no drug, and fractions with a chromatographic difference were analyzed via real-time PCR (polymerase chain reaction and used for further selection. Sequences were identified by 454 sequencing and demonstrated low micromolar dissociation constants through fluorescence anisotropy after only two rounds of selection. One aptamer, JPB5, displayed a dose-dependent reduction of the clotting time in buffer, with a 20 µM aptamer achieving a nearly complete antidote effect. This work is expected to result in a superior safety profile for bivalirudin, resulting in enhanced patient care.

  5. The debate concerning oral anticoagulation: whether to suspend oral anticoagulants during dental treatment.

    Science.gov (United States)

    António, Natália; Castro, Graça; Ramos, Domingos; Machado, António; Gonçalves, Lino; Macedo, Tice; Providência, Luís A

    2008-04-01

    The management of patients taking long-term oral anticoagulants who require dental surgery is still highly controversial. The risk of bleeding associated with dental treatment under oral anticoagulants must be weighed against the risk of thromboembolism associated with suspension of antithrombotic therapy. Mortality and morbidity associated with thromboembolic events are higher than those associated with hemorrhagic events after minor oral surgery procedures. Evidence-based information does not support oral anticoagulant suspension before minor oral surgery. The authors propose a management protocol for chronically anticoagulated patients who require a dental procedure, to reduce both thromboembolic risk and the risk of bleeding.

  6. Dental management of the anticoagulated patient.

    Science.gov (United States)

    Purcell, C A

    1997-09-01

    Most anticoagulated patients can be safely managed for routine dental treatment in the outpatient setting by following appropriate guidelines. Management should be based on the present level of anticoagulation as assessed by tests, in particular the international normalised ratio (INR), which should be carried out as close to the intervention as possible. A philosophy of minimal, if any, alteration to the level of anticoagulation should be adopted. This is particularly true for procedures producing minimal bleeding such as scaling and cleaning which, in the past, have resulted in patients having their INR lowered, with its attendant risks. The patient's anticoagulation is potentially life-saving and, where at all possible, should be maintained at therapeutic levels when therapy for non-threatening conditions is planned.

  7. New antiplatelet drugs and new oral anticoagulants.

    Science.gov (United States)

    Koenig-Oberhuber, V; Filipovic, M

    2016-09-01

    In our daily anaesthetic practice, we are confronted with an increasing number of patients treated with either antiplatelet or anticoagulant agents. During the last decade, changes have occurred that make the handling of antithrombotic medication a challenging part of anaesthetic perioperative management. In this review, the authors discuss the most important antiplatelet and anticoagulant drugs, the perioperative management, the handling of bleeding complications, and the interpretation of some laboratory analyses related to these agents.

  8. The use of vitamin K in patients on anticoagulant therapy: a practical guide.

    Science.gov (United States)

    Hanslik, Thomas; Prinseau, Jacques

    2004-01-01

    Anticoagulation with antivitamin K (AVK) is very effective for primary and secondary prevention of thromboembolic events. However, questions persist about the risks and management of over-anticoagulation. For reversal of excessive anticoagulation by warfarin, AVK withdrawal, oral or parenteral vitamin K administration, prothrombin complex or fresh frozen plasma may be used, depending on the excess of anticoagulation, the existence and site of active bleeding, patient characteristics and the indication for AVK. In over-anticoagulated patients, vitamin K aims at rapid lowering of the international normalized ratio (INR) into a safe range to reduce the risk of major bleeding and therefore improving patient outcome without exposing the patient to the risk of thromboembolism due to overcorrection, resistance to AVK, or an allergic reaction to the medication. The risk of bleeding increases dramatically when the INR exceeds 4.0-6.0, although the absolute risk of bleeding remains fairly low, 10.0, a dose of 5mg may be more appropriate. Overcorrection of the INR or resistance to warfarin is unlikely if the above doses of vitamin K are used. Vitamin K is less effective for over-anticoagulation after treatment with acenocoumarol or phenprocoumon than after treatment with warfarin.

  9. Bleeding in patients using new anticoagulants or antiplatelet agents: risk factors and management.

    Science.gov (United States)

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

    2010-02-01

    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 reversed by various specific strategies. Heparin and heparin derivatives can be counteracted by protamine sulphate, whereas the anticoagulant effect of vitamin K antagonists may be neutralised by administration of vitamin K or prothrombin complex concentrates. The antihaemostatic effect of aspirin and other antiplatelet strategies can be corrected by the administration of platelet concentrate and/or desmopressin, if needed. Recently, a new generation of anticoagulants with a greater specificity towards activated coagulation factors has been introduced and most of these agents are currently being evaluated in clinical studies, showing promising results. The new-generation anticoagulants include specific inhibitors of factor IIa or factor Xa (including pentasaccharides) and antiplatelet agents belonging to the class of thienopyridine derivatives. A limitation of the new class of anti-IIa and anti-Xa agents may be the lack of an appropriate strategy to reverse the effect if a bleeding event occurs, although in some cases the administration of recombinant factor VIIa may be an option.

  10. New oral anticoagulants: clinical indications, monitoring and treatment of acute bleeding complications.

    Science.gov (United States)

    Fenger-Eriksen, C; Münster, A-M; Grove, E L

    2014-07-01

    New oral anticoagulants like the direct thrombin inhibitor, dabigatran (Pradaxa®), and factor Xa-inhibitors, rivaroxaban (Xarelto®) and apixaban (Eliquis®) are available for prophylaxis and treatment of thromboembolic disease. They are emerging alternatives to warfarin and provide equal or better clinical outcome together with reduced need for routine monitoring. Methods for measuring drug concentrations are available, although a correlation between plasma drug concentrations and the risk of bleeding has not been firmly established. Standard laboratory measures like prothrombin time and activated partial thromboplastin time are not sensitive enough to detect thrombin or factor Xa inhibition provided by new oral anticoagulants. Thus, these standard tests may only be used as a crude estimation of the actual anticoagulation status. Further challenges regarding patients receiving new oral anticoagulants who presents with major bleeding or need for emergency surgery pose a unique problem. No established agents are clinically available to reverse the anticoagulant effect, although preclinical data report prothrombin complex concentrate as more efficient than fresh frozen plasma or other prohaemostatic agents. This review summaries current knowledge on approved new oral anticoagulants and discusses clinical aspects of monitoring, with particular focus on the management of the bleeding patient.

  11. A sulfated polysaccharide, fucans, isolated from brown algae Sargassum vulgare with anticoagulant, antithrombotic, antioxidant and anti-inflammatory effects.

    Science.gov (United States)

    Dore, Celina Maria P Guerra; das C Faustino Alves, Monique Gabriela; Will, Luiza Sheyla E Pofírio; Costa, Thiago G; Sabry, Diego A; de Souza Rêgo, Leonardo Augusto R; Accardo, Camila M; Rocha, Hugo Alexandre O; Filgueira, Luciana Guimarães A; Leite, Edda Lisboa

    2013-01-02

    Fucan (SV1) sulfated polysaccharides from the brown algae Sargassum vulgare were extracted, fractionated in acetone and examined with respect to chemical composition, anticoagulant, anti-inflammatory, antithrombotic effects and cellular proliferation. These polysaccharides contain low levels of protein, high level of carbohydrate and sulfate. Monosaccharides analysis revealed that SV1 was composed of fucose, galactose, xylose, glucuronic acid and mannose. SV1 polysaccharide prolonged activated partial thromboplastin time (aPTT) and exhibited high antithrombotic action in vivo, with a concentration ten times higher than heparin activity. PSV1, a purified form in gel filtration showed very low biological activities. SV1 stimulated the enzymatic activity of FXa. Its action on DPPH radical scavenging activity was 22%. This polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different erythrocyte groups. It displays strong anti-inflammatory action at all concentrations tested in the carrageenan-induced paw edema model, demonstrated by reduced edema and cellular infiltration.

  12. Use of recombinant factor VIIa for emergency reversal of anticoagulation

    Directory of Open Access Journals (Sweden)

    Ingerslev J

    2007-01-01

    Full Text Available Context: There is limited data regarding the use of activated recombinant factor VII (rFVIIa in anticoagulated patients requiring reversal. Aims: To identify and describe characteristics of subjects who received rFVIIa as part of emergency treatment aimed at improving hemostasis. Settings and Design: Data was obtained from an international peer-reviewed registry haemostasis.com. This registry contains data reported by physicians, who had elected to use rFVIIa to control bleeding in an emergency clinical situation. The contributors′ approval for inclusion in the study was obtained and they were requested to validate and update information. Materials and Methods: Database review of cases receiving rFVIIa to manage bleeding coherent with the use of anticoagulant therapy. Statistical Analysis: The Wilcoxon signed rank test was used to compare requirements for blood products and crystalloids/colloids during the 24h preceding and following rFVIIa administration, as well as changes in the levels of clotting factors during that period. Results: Eighteen patients were treated with rFVIIa (median dose: 87.35 µg/kg; range: 20.0-106.0 µg/kg for bleeding. Anticoagulants requiring reversal included low-molecular-weight heparin (n = 6, unfractionated heparin (n =8, coumarin (n =3 and warfarin (n=1. All patients had failed to respond to traditional antidotes and blood products. Following administration, bleeding stopped in 10, markedly decreased in five and slowed in the remaining three. Amongst 12/16 patients, a response was observed within 2.0 h of first administration. The requirement for blood products and crystalloids/colloids decreased ( P < 0.05 after rFVIIa administration. rFVIIa was well tolerated. Conclusions: rFVIIa may play a role in control of untoward bleeding in subjects receiving anticoagulation therapy.

  13. Polysulfated Trehalose as a Novel Anticoagulant Agent with Dual Mode of Action

    Directory of Open Access Journals (Sweden)

    Qudsia Rashid

    2015-01-01

    Full Text Available Physiological hemostatic balance is a coordinated outcome of counteracting coagulation and fibrinolytic systems. An imbalance of procoagulant and anticoagulant factors may result in life threatening thromboembolism. Presently, anticoagulant administration is the first line of therapy for the treatment of these conditions and several anticoagulants have been approved, including various forms of heparin. However, the polyanionic nature and multispecificity of heparin pose several complications. Generally, the polysulfated compounds with antithrombotic potential are thought to have feasible synthetic procedures with much less bleeding, thus having favourable safety profiles. Here we report the synthesis of a novel compound, trehalose octasulfate and the assessment of its anticoagulation potential. Molecular docking of trehalose and trehalose octasulfate with antithrombin showed a specificity switch in binding affinity on sulfation, where trehalose octasulfate interacts with critical residues of AT that are either directly involved in heparin binding or in the conformational rearrangement of AT on heparin binding. An in vitro analysis of trehalose octasulfate demonstrated prolonged clotting time. Lead compound when intravenously injected in occlusion induced thrombotic rats showed remarkable reduction in the size and weight of the clot at a low dose. Delay in coagulation time was observed by analysing blood plasma isolated from rats preinjected with trehalose octasulfate. A decrease in Adenosine 5′-Diphosphate (ADP induced platelet aggregation indicated a probable dual anticoagulant and antiplatelet mechanism of action. To summarize, this study presents trehalose octasulfate as a novel, effective, dual acting antithrombotic agent.

  14. Activated protein C ameliorates Bacillus anthracis lethal toxin-induced lethal pathogenesis in rats

    Directory of Open Access Journals (Sweden)

    Kau Jyh-Hwa

    2012-11-01

    Full Text Available Abstract Background Lethal toxin (LT is a major virulence factor of Bacillus anthracis. Sprague Dawley rats manifest pronounced lung edema and shock after LT treatments, resulting in high mortality. The heart failure that is induced by LT has been suggested to be a principal mechanism of lung edema and mortality in rodents. Since LT-induced death occurs more rapidly in rats than in mice, suggesting that other mechanisms in addition to the heart dysfunction may be contributed to the fast progression of LT-induced pathogenesis in rats. Coagulopathy may contribute to circulatory failure and lung injury. However, the effect of LT on coagulation-induced lung dysfunction is unclear. Methods To investigate the involvement of coagulopathy in LT-mediated pathogenesis, the mortality, lung histology and coagulant levels of LT-treated rats were examined. The effects of activated protein C (aPC on LT-mediated pathogenesis were also evaluated. Results Fibrin depositions were detected in the lungs of LT-treated rats, indicating that coagulation was activated. Increased levels of plasma D-dimer and thrombomodulin, and the ameliorative effect of aPC further suggested that the activation of coagulation-fibrinolysis pathways plays a role in LT-mediated pathogenesis in rats. Reduced mortality was associated with decreased plasma levels of D-dimer and thrombomodulin following aPC treatments in rats with LT-mediated pathogenesis. Conclusions These findings suggest that the activation of coagulation in lung tissue contributes to mortality in LT-mediated pathogenesis in rats. In addition, anticoagulant aPC may help to develop a feasible therapeutic strategy.

  15. Anticoagulants versus antiplatelet drugs for cervical artery dissection: case for anticoagulants.

    Science.gov (United States)

    Norris, John W

    2013-02-01

    There are no reliable data from randomised trials to decide whether anticoagulants or antiplatelet agents are better to prevent further thromboembolic events after cervical arterial dissection. Most neurologists favour anticoagulants based on the underlying pathology and the likely course of acute post-dissection thromboembolism.

  16. Parenteral anticoagulation in patients with cancer who have no therapeutic or prophylactic indication for anticoagulation

    NARCIS (Netherlands)

    E.A. Akl; S. Gunukula; M. Barba; V.E.D. Yosuico; F.F. van Doormaal; S. Kuipers; S. Middeldorp; H.O. Dickinson; A. Bryant; H. Schuenemann

    2011-01-01

    Background Anticoagulation may improve survival in patients with cancer through an antitumor effect in addition to the perceived antithrombotic effect. Objectives To evaluate the efficacy and safety of parenteral anticoagulants in patients with cancer with no therapeutic or prophylactic indication f

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

    OpenAIRE

    Mingyi Wu; Li Xu; Longyan Zhao; Chuang Xiao; Na Gao; Lan Luo; Lian Yang; Zi Li; Lingyun Chen; Jinhua Zhao

    2015-01-01

    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...

  18. [Protein kinase C activation induces platelet apoptosis].

    Science.gov (United States)

    Zhao, Li-Li; Chen, Meng-Xing; Zhang, Ming-Yi; Dai, Ke-Sheng

    2013-10-01

    Platelet apoptosis elucidated by either physical or chemical compound or platelet storage occurs wildly, which might play important roles in controlling the numbers and functions of circulated platelets, or in the development of some platelet-related diseases. However, up to now, a little is known about the regulatory mechanisms of platelet apoptosis. Protein kinase C (PKC) is highly expressed in platelets and plays central roles in regulating platelet functions. Although there is evidence indicating that PKC is involved in the regulation of apoptosis of nucleated cells, it is still unclear whether PKC plays a role in platelet apoptosis. The aim of this study was to investigate the role of PKC in platelet apoptosis. The effects of PKC on mitochondrial membrane potential (ΔΨm), phosphatidylserine (PS) exposure, and caspase-3 activation of platelets were analyzed by flow cytometry and Western blot. The results showed that the ΔΨm depolarization in platelets was induced by PKC activator in time-dependent manner, and the caspase-3 activation in platelets was induced by PKC in concentration-dependent manner. However, the platelets incubated with PKC inhibitor did not results in ΔΨm depolarization and PS exposure. It is concluded that the PKC activation induces platelet apoptosis through influencing the mitochondrial functions and activating caspase 3. The finds suggest a novel mechanism for PKC in regulating platelet numbers and functions, which has important pathophysiological implications for thrombosis and hemostasis.

  19. Madagascine Induces Vasodilatation via Activation of AMPK

    Science.gov (United States)

    Chen, Dapeng; Lv, Bochao; Kobayashi, Sei; Xiong, Yongjian; Sun, Pengyuan; Lin, Yuan; Genovese, Salvatore; Epifano, Francesco; Hou, Shanshan; Tang, Fusheng; Ji, Yunyan; Yu, Dandan

    2016-01-01

    Madagascine (3-isopentenyloxyemodin) can be chemically synthesized or purified from several Rhamnus species, and it is found to have more potent biological activities than the parent compound emodin. The aim of this study is to characterize the vasodilatory effect of madagascine on vasoconstriction and sphingosylphosphorylcholine induced vasospasm in ex vivo and reveal the potential mechanisms in vitro. The effects of madagascine on vasoconstriction of rat mesenteric resistance arteries (MRAs) induced by K+, methoxamine, and endothelin-1 were, respectively, studied. The cholesterol-enriched porcine coronary vascular smooth muscle (VSM) strips were used to investigate the effects of madagascine on abnormal constriction induced by sphingosylphosphorylcholine (SPC) which has a pivotal role in vasospasm. The vasodilatory effect was induced by madagascine (0.3–100 μM) in isolated rat MRAs and the vasodilatory effect was blocked by NO synthase inhibitor L-NAME and AMPK inhibitor compound C. Madagascine (10 μM) also significantly relaxed the abnormal constriction in porcine VSM induced by SPC and the effect was abolished by compound C. Madagascine significantly increased the phosphorylation of endothelial nitric oxide synthase (eNOS) in endothelial cells while decreasing the phosphorylation of myosin phosphatase target subunit 1 (MYPT1) in VSM cells. Madagascine-induced vasodilatation was abrogated using small interfering RNA knockdown of AMPK. In summary, madagascine exerted vasodilatation through activating AMPK, leading to the activation of eNOS in endothelium and inhibition of ROCK/MYPT1 in VSM. This study suggests the potential value of madagascine in amelioration of vasospasm related cardiovascular diseases. PMID:27932979

  20. Ionic changes during experimentally induced seizure activity.

    Science.gov (United States)

    Lux, H D; Heinemann, U

    1978-01-01

    Changes in intra- and extracellular ionic activity and their relation to generation and termination of seizure phenomena can be studied with the help of ion-selective microelectrodes. Transient changes in extracellular potassium activity (aK) of the cortex regularly accompany paroxysmal activity induced by electrical stimulation and pentylenetetrazol injections or occur within active penicillin and aluminum foci. A rise of aK from baseline levels of about 3 mmoles/l up to ceiling levels of 8--12 mmoles/l, followed by subnormal K activity, is typically found during seizure discharge. Extracellular K accumulation during seizures facilitates the spread into extrafocal regions. Ceiling levels of extracellular aK are characterized by pronounced K reabsorption which is probably a limiting mechanism for the rise in extracellular aK. It may be a consequence of a simultaneous rise in intracellular Na activity that an electrogenic Na--K exchange process is involved in the termination of ictal activity. Seizures are also accompanied by significant reductions in extracellular Ca2+ activity (aCa) to as low as 0.7 mmoles/l (resting aCa 1.25 mmoles/l). There is no critical level of lowered aCa at which a seizure ultimately results. However, unlike changes in aK reductions in aCa can precede ictal activity. Thus, a fall of aCa occurs before the onset of paroxysmal periods during cyclical spike driving in a penicillin focus and before seizures induced by pentylenetetrazol. Ca2+-dependent mechanisms may contribute to seizure generation. In addition to changes in aK and aCa, intracellular chloride activity (aCl) can increase during seizure activity, as a result of an impaired chloride extrusion mechanism, which would lead to a reduced efficacy of inhibitory synaptic transmission and, therefore, to facilitation of seizure generation.

  1. Selection of anticoagulant solution to the hemolymph of Chlamys farreri by transmission electron microscropy and flow cytometry

    Institute of Scientific and Technical Information of China (English)

    Chen Muyan; Yang Hongsheng; Shi Fangfang

    2007-01-01

    Mixtures of hemolymph from Chlamys farreri with three different anticoagulant solutions were incubated for an hour in vitro , then the ultrastructural alterations of hemocytes were observed , and the aggregation rate was analyzed by using transmission electron microscropy and flow cytometry respectively. The results showed that Formula 3 (glucose 20. 8 g L-1; EDTA 20mM ; sodium chloride 20 g L-1 ; Tris-HCl 0.05M;pH 7. 4) was the desirable anticoagulant solution for C . Farreri hemocytes. Further phagocytosis assay showed that no obvious negative effect was given to the hemocyte phagocytic activity when using Formula 3 as the anticoagulant solution.

  2. Guidance for the practical management of the heparin anticoagulants in the treatment of venous thromboembolism.

    Science.gov (United States)

    Smythe, Maureen A; Priziola, Jennifer; Dobesh, Paul P; Wirth, Diane; Cuker, Adam; Wittkowsky, Ann K

    2016-01-01

    Venous thromboembolism (VTE) is a serious and often fatal medical condition with an increasing incidence. Despite the changing landscape of VTE treatment with the introduction of the new direct oral anticoagulants many uncertainties remain regarding the optimal use of traditional parenteral agents. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance based on existing guidelines and consensus expert opinion where guidelines are lacking. This specific chapter addresses the practical management of heparins including low molecular weight heparins and fondaparinux. For each anticoagulant a list of the most common practice related questions were created. Each question was addressed using a brief focused literature review followed by a multidisciplinary consensus guidance recommendation. Issues addressed included initial anticoagulant dosing recommendations, recommended baseline laboratory monitoring, managing dose adjustments, evidence to support a relationship between laboratory tests and meaningful clinical outcomes, special patient populations including extremes of weight and renal impairment, duration of necessary parenteral therapy during the transition to oral therapy, candidates for outpatient treatment where appropriate and management of over-anticoagulation and adverse effects including bleeding and heparin induced thrombocytopenia. This article concludes with a concise table of clinical management questions and guidance recommendations to provide a quick reference for the practical management of heparin, low molecular weight heparin and fondaparinux.

  3. Monitoring anticoagulant therapy with new oral agents

    Science.gov (United States)

    Ramos-Esquivel, Allan

    2015-01-01

    Thromboembolic disease is a major leading cause of mortality and morbidity in industrialized countries. Currently, the management of these patients is challenging due to the availability of new drugs with proven efficacy and security compared to traditional oral vitamin K antagonists. These compounds are characterized by a predictable pharmacokinetic profile for which blood monitoring is not routinely needed. Nevertheless, some data have suggested inter-patient variability in the anticoagulant effect of these drugs, raising concerns about their effectiveness and safety. Although mass-spectrometry is the gold standard to determine drug plasma concentrations, this method is not widely available in every-day practice and some coagulation assays are commonly used to determine the anticoagulant effect of these drugs. The present review aims to summarize the current knowledge regarding the clinical question of how and when to monitor patients with new anticoagulant oral agents. PMID:26713281

  4. [New oral anticoagulants for atrial fibrillation: a neurologist's view

    NARCIS (Netherlands)

    Dijk, E.J. van; Koudstaal, P.J.; Roos, Y.B.; Brouwers, P.J.; Kappelle, L.J.

    2012-01-01

    - Recent randomized controlled trials have shown that new oral anticoagulants (dabigatran, rivaroxaban en apixaban) in patients with atrial fibrillation are equally or more effective in preventing cerebral infarction than vitamin K antagonists (VKA).- New oral anticoagulants cause significant less i

  5. 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.

  6. Bosentan and oral anticoagulants in HIV patients: what we can learn of cases reported so far

    Directory of Open Access Journals (Sweden)

    José Antonio Morales-Molina

    2011-10-01

    Full Text Available Pulmonary arterial hypertension is an infrequent but nevertheless serious life-threatening severe complication of HIV infection. It can be treated with bosentan and oral anticoagulants. Bosentan could induce the acenocoumarol metabolism and it increases the INR values. Until now, no study of interaction between bosentan and oral anticoagulants in HIV patients has reported. So we present a case of this interaction between these drugs and we reviewed MEDLINE to identify all the papers published so far. In our case, several weeks after increasing dose of bosentan acenocoumarol dose had to be progressively increased to 70 mg/week (+33% without obtaining an adequate INR level (2.0-3.0. Forty-nine days later, we achieved a therapeutic INR with 90 mg/week of warfarin. The use of bosentan and oral anticoagulants together in these patients require a closer monitoring during first weeks of treatment, after increasing the bosentan dose and even during longer periods of time.

  7. Oral anticoagulant treatment with and without aspirin.

    Science.gov (United States)

    Altman, R; Rouvier, J; Gurfinkel, E

    1995-07-01

    For preventing thromboembolic events, the concurrent use of oral anticoagulant and antiplatelet drugs has been proposed. In prosthetic heart valves the use of moderate intensity anticoagulants [International Normalized Ratio (INR) 2-3] plus aspirin (100 mg/day) decreases the amount and severity of embolic episodes. The possibility that the same regimen could provide benefit in the prevention of thrombotic events in other arterial diseases is also indicated by the ATACS trial in unstable angina. The ongoing studies in ischemic heart diseases will also give the answer to this possibility.

  8. Pseudothrombocytopenia with multiple anticoagulant sample collection tubes

    Science.gov (United States)

    Kovacs, Ferenc; Varga, Marina; Pataki, Zsolt; Rigo, Erzsebet

    2016-01-01

    The knowledge of pseudothrombocytopenia (PTCP) is important for the accuracy of a clinical assessment and for avoiding unnecessary treatment. An elderly patient was hospitalized with left lung pneumonia. Severe thrombocytopenia [platelet (PLT) number: 18 × 109/L] without any clinical bleeding was found in ethylenediaminetetraacetic acid blood collection tube. PLT measurement was repeated in various anticoagulant [sodium citrate, lithium heparin, disodium oxalate, hirudin, and magnesium sulfate (Mg-sulfate)] sample collection tubes and all of them showed thrombocytopenia except with Mg-sulfate. To the best of our knowledge, PTCP with five anticoagulant sample collection tubes has not been reported earlier.

  9. Anticoagulated patient management in primary care service

    Directory of Open Access Journals (Sweden)

    Marco Antonio Zapata Sampedro

    2008-05-01

    Full Text Available Out-patients undergoing anticoagulant treatment are attended by nursing staff, working with doctors.To be able to provide adequate medical care, nurses must have the minimum knowledge and skills needed to work with the programme described in this article. These include basic and specific knowledge of anticoagulation. The correct functioning of the service will help provide an optimum control of the INR (International Normalized Ratio and reduce the complications of bleeding, both of which are the main objectives of the nursing care of these patients.

  10. Fatal pulmonary hemorrhage after taking anticoagulation medication

    Directory of Open Access Journals (Sweden)

    Samuel P. Hammar

    2015-01-01

    Full Text Available We describe a 64-year-old man with extensive diffuse acute lung hemorrhage, presumably as a result of anticoagulation therapy. We evaluated reports in the literature concerning acute exacerbation (acute lung injury of unknown cause in UIP and other forms of fibrotic interstitial pneumonias. We also evaluated autopsy tissue in this case in order to determine the cause of death in this 64-year-old man, who was initially thought to have an asbestos-related disease. Based on the autopsy findings, this man died as a result of anticoagulation therapy; specifically, the use of Xarelto® (rivaroxaban.

  11. Specific sulfation and glycosylation—a structural combination for the anticoagulation of marine carbohydrates

    Science.gov (United States)

    Pomin, Vitor H.; Mourão, Paulo A. S.

    2014-01-01

    Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans (SFs), sulfated galactans (SGs) and glycosaminoglycans (GAGs). The structural combinations necessary for the anticoagulant activities are the 2-sulfation in α-L-SGs, the 2,4-di-sulfation in α-L-fucopyranosyl units found as composing units of certain sea-urchin and sea-cucumber linear SFs, or as branching units of the fucosylated chondroitin sulfate, a unique GAG from sea-cucumbers. Another unique GAG type from marine organisms is the dermatan sulfate isolated from ascidians. The high levels of 4-sulfation at the galactosamine units combined with certain levels of 2-sulfation at the iduronic acid units is the anticoagulant structural requirements of these GAGs. When the backbones of red algal SGs are homogeneous, the anticoagulation is proportionally dependent of their sulfation content. Finally, 4-sulfation was observed to be the structural motif required to enhance the inhibition of thrombin via heparin cofactor-II by invertebrate SFs. PMID:24639954

  12. Management of the Bleeding Patient Receiving New Oral Anticoagulants: A Role for Prothrombin Complex Concentrates

    Directory of Open Access Journals (Sweden)

    Lisa M. Baumann Kreuziger

    2014-01-01

    Full Text Available Ease of dosing and simplicity of monitoring make new oral anticoagulants an attractive therapy in a growing range of clinical conditions. However, newer oral anticoagulants interact with the coagulation cascade in different ways than traditional warfarin therapy. Replacement of clotting factors will not reverse the effects of dabigatran, rivaroxaban, or apixaban. Currently, antidotes for these drugs are not widely available. Fortunately, withholding the anticoagulant and dialysis are freqnently effective treatments, particularly with rivaroxaban and dabigatran. Emergent bleeding, however, requires utilization of Prothrombin Complex Concentrates (PCCs. PCCs, in addition to recombinant factor VIIa, are used to activate the clotting system to reverse the effects of the new oral anticoagulants. In cases of refractory or emergent bleeding, the recommended factor concentrate in our protocols differs between the new oral anticoagulants. In patients taking dabigatran, we administer an activated PCC (aPCC [FELBA] due to reported benefit in human in vitro studies. Based on human clinical trial evidence, the 4-factor PCC (Kcentra is suggested for patients with refractory rivaroxaban- or apixaban-associated hemorrhage. If bleeding continues, recombinant factor VIIa may be employed. With all of these new procoagulant agents, the risk of thrombosis associated with administration of factor concentrates must be weighed against the relative risk of hemorrhage.

  13. Specific sulfation and glycosylation - a structural combination for the anticoagulation of marine carbohydrates

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Pomin

    2014-03-01

    Full Text Available Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans (SFs, sulfated galactans (SGs and glycosaminoglycans (GAGs. The structural combinations necessary for the anticoagulant activities are the 2-sulfation in α-L-SGs, the 2,4-di-sulfation in α-L-fucopyranosyl units found as composing units of certain sea-urchin and sea-cucumber linear SFs, or as branching units of the fucosylated chondroitin sulfate, a unique GAG from sea-cucumbers. Another unique GAG type from marine organisms is the dermatan sulfate isolated from ascidians. The high levels of 4-sulfation at the galactosamine units combined with certain levels of 2-sulfation at the iduronic acid units is the anticoagulant structural requirements of these GAGs. When the backbones of red algal SGs are homogeneous, the anticoagulation is proportionally dependent of their sulfation content. Finally, 4-sulfation was observed to be the structural motif required to enhance the inhibition of thrombin via heparin cofactor-II by invertebrate SFs.

  14. Specific sulfation and glycosylation-a structural combination for the anticoagulation of marine carbohydrates.

    Science.gov (United States)

    Pomin, Vitor H; Mourão, Paulo A S

    2014-01-01

    Based on considered achievements of the last 25 years, specific combinations of sulfation patterns and glycosylation types have been proved to be key structural players for the anticoagulant activity of certain marine glycans. These conclusions were obtained from comparative and systematic analyses on the structure-anticoagulation relationships of chemically well-defined sulfated polysaccharides of marine invertebrates and red algae. These sulfated polysaccharides are known as sulfated fucans (SFs), sulfated galactans (SGs) and glycosaminoglycans (GAGs). The structural combinations necessary for the anticoagulant activities are the 2-sulfation in α-L-SGs, the 2,4-di-sulfation in α-L-fucopyranosyl units found as composing units of certain sea-urchin and sea-cucumber linear SFs, or as branching units of the fucosylated chondroitin sulfate, a unique GAG from sea-cucumbers. Another unique GAG type from marine organisms is the dermatan sulfate isolated from ascidians. The high levels of 4-sulfation at the galactosamine units combined with certain levels of 2-sulfation at the iduronic acid units is the anticoagulant structural requirements of these GAGs. When the backbones of red algal SGs are homogeneous, the anticoagulation is proportionally dependent of their sulfation content. Finally, 4-sulfation was observed to be the structural motif required to enhance the inhibition of thrombin via heparin cofactor-II by invertebrate SFs.

  15. Efficacy of levonorgestrel releasing intrauterine system on menorrhagia induced by anticoagulant therapy in women after cardiac valve replacement%左炔诺孕酮宫内缓释系统用于治疗心脏瓣膜置换术后抗凝药物所致月经过多的疗效观察

    Institute of Scientific and Technical Information of China (English)

    莫小亮; 蒋晓莉; 郑晓宇; 孙燕

    2013-01-01

    目的:探讨左炔诺孕酮宫内缓释系统(levonorgestrel releasing intrauterine system,LNG-IUS)用于治疗心脏换瓣术后抗凝药物所致月经过多的有效性和安全性.方法:32例月经过多妇女,曾接受换瓣术,术后口服抗凝药物.将这32例患者随机分为观察组16例,月经1 ~5d放置LNG-IUS;对照组16例,未采取任何干预措施.记录活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)、国际标准化比值(INR)、纤维蛋白原、血红蛋白(Hb)、铁蛋白水平及月经改变.结果:观察组放置3个月后,月经量显著减少,子宫内膜显著变薄,Hb、铁蛋白升高(P<0.05),凝血指标两组比较差异无统计学意义(P>0.05).结论:LNG-IUS是治疗换瓣术后抗凝药物所致月经过多的有效方法.%Objective To evaluate the efficacy and safety of levonorgestrel releasing intrauterine system (LNG-IUS) on menorrhagia induced by anticoagulant therapy in women after cardiac valve replacement. Methods 32 women with menorrhagia induced by anticoagulant therapy after cardiac valve replacement were randomly divided into 2 groups: 16 patients in observation group received LNG-IUS replacement, 16 patients in control group received no intervention. APTT, PT, INR, Hb, ferritin levels and menstrual quantity in both groups were recorded. Results Menstrual blood volume was decreased, the endometrium became thinner, the levels of Hb and ferritin were increased in observation group 3 months after therapy (P < 0.05). Conclusion LNG-IUS was an effective method for menorrhagia induced by anticoagulant therapy in women after cardiac valve replacement.

  16. Expanding horizons of anticoagulant therapy: Dabigatran etexilate a novel oral anticoagulant

    Directory of Open Access Journals (Sweden)

    Pradeep Jadhav

    2013-10-01

    Full Text Available Thrombo-embolic disease is a major challenging clinical problem associated with significant mortality and morbidity. Anticoagulation with the existing heparin products and vitamin K antagonist (VKA anticoagulants are still the mainstay of management. However, due to the risk of bleeding and well-documented drawbacks, the quest for a novel oral anticoagulant has led to the clinical development of dabigatran etexilate. Dabigatran etexilate is a direct thrombin (IIa inhibitor which has recently been approved in India for prevention of venous thromboembolic events (VTE in patients who have undergone major orthopaedic (total knee or hip replacement surgery and for prevention of stroke, systemic embolism and reduction of vascular mortality in adult patients with atrial fibrillation. Thus dabigatran etexilate is a promising alternative to the current heparin products and VKAs in patients who require long-term oral anticoagulation. [Int J Basic Clin Pharmacol 2013; 2(5.000: 663-667

  17. Bleeding risk and reversal strategies for old and new anticoagulants and antiplatelet agents.

    Science.gov (United States)

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

    2011-09-01

    The most important adverse effect of antithrombotic treatment is the occurrence of bleeding. In the case of severe bleeding in a patient who uses anticoagulant agents or when a patient on anticoagulants needs to undergo an urgent invasive procedure, it may be useful to reverse anticoagulant treatment. Conventional anticoagulants such as vitamin K antagonists may be neutralized by administration of vitamin K or prothrombin complex concentrates, whereas heparin and heparin derivatives can be counteracted by protamine sulphate. The anti-hemostatic effect of aspirin and other antiplatelet strategies can be corrected by the administration of platelet concentrate and/or desmopressin, if needed. Recently, a new generation of anticoagulants with a greater specificity towards activated coagulation factors as well as new antiplatelet agents have been introduced and these drugs show promising results in clinical studies. A limitation of these new agents may be the lack of an appropriate strategy to reverse the effect if a bleeding event occurs, although experimental studies show hopeful results for some of these agents.

  18. Improving the quality of oral anticoagulant therapy

    NARCIS (Netherlands)

    Gadisseur, Alain Peter Anton

    2006-01-01

    Oral anticoagulant therapy has changed little since the development of the coumarin drugs after the Second World War. The basic nature of the therapy, i.e. the balancing between thrombosis and haemorrhage, makes it a therapy difficult to manage. Add to this the many influences from co-morbidity, c

  19. Modeling Exposure of Mammalian Predatorsto Anticoagulant Rodenticides

    DEFF Research Database (Denmark)

    Topping, Christopher John; Elmeros, Morten

    2016-01-01

    Anticoagulant rodenticides (AR) are a widespread and effective method of rodent control but there is concern about the impact these may have on non-target organisms, in particular secondary poisoning of rodent predators. Incidence and concentration of AR in free-living predators in Denmark is ver...

  20. Safety of anticoagulant treatment in cancer patients

    NARCIS (Netherlands)

    Wilts, Ineke Theodora; Bleker, Suzanne Mariella; Van Es, Nick; Buller, Harry Roger; Di Nisio, Marcello; Kamphuisen, Pieter Willem

    2015-01-01

    Introduction: Patients with cancer are at increased risk of (recurrent) venous thronnboembolism. They are also at increased risk of bleeding. This makes treatment of venous thromboembolisms (VTE) in cancer patients challenging. Areas covered: In this review, we will focus on the safety of anticoagul

  1. Anticoagulant management in the cardiovascular setting.

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2012-01-01

    Vitamin K antagonists have been used as oral anticoagulants (OACs) for over five decades, yet their use in real-world practice is problematic primarily because of their narrow therapeutic window, exacerbated by extensive food and drug interactions, necessitating regular coagulation monitoring and do

  2. 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.

  3. Heparin improves BMSC cell therapy: Anticoagulant treatment by heparin improves the safety and therapeutic effect of bone marrow-derived mesenchymal stem cell cytotherapy

    Science.gov (United States)

    Liao, Li; Shi, Bingzheng; Chang, Heran; Su, Xiaoxia; Zhang, Lichao; Bi, Chunsheng; Shuai, Yi; Du, Xiaoyan; Deng, Zhihong; Jin, Yan

    2017-01-01

    Systemic infusion of bone marrow-derived mesenchymal stem cells (BMSCs) has become a promising strategy for disease treatment and tissue regeneration. Strategies to enhance the efficiency of BMSC cell therapy are crucial to promote its clinical application. Here, we aimed to improve BMSC cell therapy by inhibiting the BMSC-induced coagulation reaction. Intravenous injection of gradient BMSCs into mice showed that BMSCs were not fully compatible with blood. Large doses of BMSCs induced a series of symptoms of respiratory failure and heart failure. Histological and homeostasis analysis confirmed that large doses of BMSCs induced disseminated intravascular thrombosis, exhaustion of platelets and coagulation factors, and prolonged prothrombin time (PT) and activated partial thromboplastin time (APTT). Similar to mouse BMSCs, goat and human BMSCs also induced coagulation reactions in vitro and in vivo. The coagulation was induced mostly by tissue factor, the overexpression of which enhanced the procoagulant activity of BMSCs during in vitro culture. Notably, clinical doses of BMSCs in cell therapy also induced mild and reversible coagulation, which increased BMSC lung embolism and clearance. Anticoagulation treatment by heparin (400 U/kg) prevented BMSC-induced coagulation and the acute adverse effects of large-dose BMSCs infusion efficiently. Importantly, heparin treatment led to decreased BMSC lung embolism and enhanced migration and maintenance of BMSCs to target organs in cell therapy. Based on an experimental colitis model, we confirmed that heparin treatment enhanced the effect of BMSC therapy efficiently to reduce mortality, prevent weight loss, suppress inflammation reaction and alleviate tissue injury. In conclusion, BMSCs possess procoagulant activity that could induce disseminated coagulation and thrombosis in recipients. Anticoagulation treatment by heparin is a practical strategy to improve both the safety and therapeutic effect of BMSC therapy. PMID

  4. Diagnosis and treatment of secondary anticoagulant rodenticide toxicosis in a red-tailed hawk (Buteo jamaicensis).

    Science.gov (United States)

    Murray, Maureen; Tseng, Florina

    2008-03-01

    Anticoagulant rodenticides inhibit the activation of vitamin K-ependent clotting factors, resulting in fatal hemorrhage. Nontarget species are exposed to these rodenticides primarily by direct consumption of baits or secondarily by consumption of poisoned prey. The diagnosis of anticoagulant rodenticide toxicosis is more challenging in birds than in mammals because of the limited availability of laboratory tests to evaluate avian coagulation. In addition, the presenting signs in birds may differ from those commonly seen in mammals. Treatment for acute blood loss and therapy with vitamin K1 can result in a favorable outcome in birds. This report describes the presenting signs, diagnosis, and successful treatment of a red-tailed hawk (Buteo jamaicensis) with secondary anticoagulant rodenticide toxicosis.

  5. 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.

  6. Lupus-anticoagulant testing at NOAC trough levels.

    Science.gov (United States)

    Ratzinger, Franz; Lang, Mona; Belik, Sabine; Jilma-Stohlawetz, Petra; Schmetterer, Klaus G; Haslacher, Helmuth; Perkmann, Thomas; Quehenberger, Peter

    2016-08-01

    Non-vitamin K antagonist oral anticoagulants (NOAC), including rivaroxaban, apixaban or dabigatran, regularly show relevant effects on coagulation tests, making the interpretation of results difficult. The aim of this study was to evaluate possible interferences of NOACs in trough level concentrations in lupus anticoagulant (LA) testing. Citrate plasma specimens of 30 healthy volunteers were spiked with rivaroxaban, apixaban or dabigatran in four plasma concentration levels at or below trough NOAC levels. The NOAC concentration was measured using dedicated surrogate concentration tests and a stepwise diagnostic procedure for LA-testing was applied using screening, mixing and confirmatory testing. Results were compared to NOAC-free specimens. Starting with a plasma concentration of 12.5 ng/ml, dabigatran-spiked specimens showed significant prolongations in the lupus anticoagulant-sensitive activated partial thromboplastin time (aPTT-LA) as well as in the Dilute Russell viper venom time (dRVVT), leading to 43.3 % false positives in confirmatory testing in the dRVVT. In contrast, rivaroxaban, beginning with 7.5 ng/ml, exclusively affected dRVVT-based tests. In confirmatory tests, 30.0 % of rivaroxaban-spiked specimens showed false positive results. Starting with 18.75 ng/ml apixaban, a significant prolongation of the dRVVT and up to 20.7 % false positives in confirmatory tests were found. In contrast to other NOACs tested, apixaban did not present with a dose-dependent increase of the dRVVT ratio. In conclusion, the rate of false positive results in LA-testing is unacceptably high at expected trough levels of NOACs. Even at plasma concentrations below the LLOQ of commercially available surrogate tests, LA testing is best avoided in patients with NOAC therapy.

  7. Selective sulfation of carrageenans and the influence of sulfate regiochemistry on anticoagulant properties.

    Science.gov (United States)

    de Araújo, Cristiano A; Noseda, Miguel D; Cipriani, Thales R; Gonçalves, Alan G; Duarte, Maria Eugênia R; Ducatti, Diogo R B

    2013-01-16

    Sulfated polysaccharides are recognized for their broad range of biological activities, including anticoagulant properties. The positions occupied by the sulfate groups are often related to the level of the inherent biological activity. Herein the naturally sulfated galactans, kappa-, iota- and theta-carrageenan, were additionally sulfated by regioselective means. The anticoagulant activity of the resulting samples was then studied using the aPTT in vitro assay. The influence of sulfate regiochemistry on the anticoagulant activity was evaluated. From kappa-carrageenan three rare polysaccharides were synthesized, one of them involved a synthetic route with an amphiphilic polysaccharide intermediate containing pivaloyl groups. Iota- and theta-carrageenan were utilized in a selective C6 sulfation at β-D-Galp units to produce different structures comprising trisulfated diads. All the samples were characterized by NMR (1D and 2D). The resulting aPPT measurements suggested that sulfation at C2 of 3,6-anhydro-α-D-Galp and C6 of β-D-Galp increased the anticoagulant activity.

  8. Procoagulants and anticoagulants in fetal blood. A literature survey.

    Directory of Open Access Journals (Sweden)

    Waldemar Uszyński

    2010-05-01

    Full Text Available In intrauterine life, hemostasis is maintained by the same components as in extrauterine life (blood platelets, coagulation and fibrinolysis systems, involvement of the vascular wall; in the fetus, however, these components show significant differences of a quantitative/qualitative nature. In the present study, we surveyed the literature on the coagulation system in the fetus. We focused on the velocity of development of the coagulation system, being reflected in the increased concentration of all procoagulants and anticoagulants (a rise from approximately 20% in the middle of pregnancy to about 60% or more in the period of labor; exceptions: factors V, VIII and XIII which in the labor period reach the adult level and screening test results (prothrombin time, aPTT - activated prothrombin time, and thrombin time. Reference values were given for the 19-38 weeks of pregnancy and the labor term. Biochemical features of fetal fibrinogen and PIVKA factors were also discussed. The role of activated protein C (APC in the maintenance of balance between procoagulants and anticoagulants was postulated as well as the role of APC in the formation of thrombin activatable fibrinolysis inhibitor (TAFI.

  9. A 2-sulfated, 3-linked alpha-L-galactan is an anticoagulant polysaccharide.

    Science.gov (United States)

    Pereira, Mariana S; Vilela-Silva, Ana-Cristina E S; Valente, Ana-Paula; Mourão, Paulo A S

    2002-11-19

    Marine alga is an abundant source of sulfated polysaccharides with potent anticoagulant activity. However, several attempts to identify the specific structural features in these compounds, which confer the biological activity, failed due to their complex, heterogeneous structure. We isolated and characterized several sulfated alpha-L-galactans and sulfated alpha-L-fucans from marine invertebrates. In contrast to the algal fucans and galactans, these invertebrate polysaccharides have a simple structure, composed of well-defined units of oligosaccharides. We employed two of these compounds to elucidate their structure-anticoagulant action relationship. Our results indicate that a 2-sulfated, 3-linked alpha-L-galactan, but not an alpha-L-fucan, is a potent thrombin inhibitor mediated by antithrombin or heparin cofactor II. The difference between the activities of these two polysaccharides is not very pronounced when factor Xa replaces thrombin. Thus, the anticoagulant activity of sulfated galactan and sulfated fucan is not merely a consequence of their charge density. The interaction of these polysaccharides with coagulation cofactors and their target proteases are specific. Identification of specific structural requirements in sulfated galactans and sulfated fucans necessary for interaction with coagulation cofactors is an essential step for a more rational approach to develop new anticoagulant and antithrombotic drugs.

  10. Structure and anticoagulant property of a sulfated polysaccharide isolated from the green seaweed Monostroma angicava.

    Science.gov (United States)

    Li, Na; Liu, Xue; He, Xiaoxi; Wang, Shuyao; Cao, Sujian; Xia, Zheng; Xian, Huali; Qin, Ling; Mao, Wenjun

    2017-03-01

    An anticoagulant-active polysaccharide PF2 was extracted with boiling water from the green seaweed Monostroma angicava, further purified by anion-exchange and size-exclusion chromatography. PF2 was a rhamnan-type sulfated polysaccharide with molecular weight of about 88.1kDa. Results of chemical and spectroscopic analyses demonstrated that PF2 consisted of→3)-α-l-Rhap-(1→ and →2)-α-l-Rhap-(1→residues, with partially branches at C-2 of→3)-α-l-Rhap-(1→residues. Sulfate groups were substituted at C-3 of →2)-α-l-Rhap-(1→ residues. The sulfated polysaccharide PF2 had a high anticoagulant action, and the mechanism of anticoagulant activity mediated by PF2 was mainly attributed to strong potentiation thrombin by heparin cofactor II. PF2 also exhibited weak effect on antithrombin-dependent thrombin or factor Xa inhibition. The fibrin(ogen)olytic activity and thrombolytic activity of PF2 were also evaluated. The investigation revealed that PF2 was a novel sulfated rhamnan differing from previously described sulfated polysaccharides from green seaweed and could be a potential anticoagulant polysaccharide.

  11. Monitoring of dabigatran anticoagulation and its reversal in vitro by thrombelastography

    DEFF Research Database (Denmark)

    Solbeck, Sacha; Meyer, Martin A S; Johansson, Pär I;

    2014-01-01

    may not sufficiently display the effect. Furthermore, no antidote exists and reversal of the anticoagulant effect is impossible or difficult. The present study investigated the in vitro effect of dabigatran on whole blood thromboelastography (TEG) and its reversal by recombinant activated factor VII...

  12. A simple method to discriminate between beta(2)-glycoprotein I- and prothrombin-dependent lupus anticoagulants

    NARCIS (Netherlands)

    Simmelink, MJA; Derksen, RHWM; Arnout, J; De Groot, PG

    2003-01-01

    Lupus anticoagulants (LAC) are a heterogeneous group of autoantibodies that prolong phospholipid-dependent clotting assays. The autoantibodies that cause LAC activity are predominantly directed against beta(2)-glycoprotein I (beta(2)GPI) or prothrombin. In the present study, we describe a method to

  13. 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.

  14. Specific antidotes in development for reversal of novel anticoagulants: a review.

    Science.gov (United States)

    Gomez-Outes, Antonio; Suarez-Gea, M L; Lecumberri, Ramon; Terleira-Fernandez, Ana I; Vargas-Castrillon, Emilio

    2014-01-01

    In the last decade, several direct oral anticoagulants (DOAC; dabigatran, rivaroxaban, apixaban, edoxaban) have been marketed for prophylaxis and/or treatment of thromboembolism without having specific antidotes available for their reversal. Current management of bleeding associated to DOAC includes the removal of all antithrombotic medications and supportive care. Non-specific procoagulant agents (prothrombin complex concentrates and activated factor VIIa) have been used in case of serious bleeding. Currently, some specific antidotes for the DOAC are under development. Idarucizumab (BI 655075; Boehringer Ingelheim) is a fragment of an antibody (Fab), which is a specific antidote to the oral direct thrombin inhibitor dabigatran. Andexanet alfa (r-Antidote, PRT064445; Portola Pharmaceuticals) is a truncated form of enzymatically inactive factor Xa, which binds and reverses the anticoagulant action of the factor Xa inhibitors (e.g.: rivaroxaban, apixaban and edoxaban). Aripazine (PER-977, ciraparantag; Perosphere Inc.) is a synthetic small molecule (~500 Da) that reverses oral dabigatran, apixaban, rivaroxaban, as well as subcutaneous fondaparinux and LMWH in vivo. These antidotes could provide an alternative for management of life-threatening bleeding events occurring with the above-mentioned anticoagulants. In addition, the specific antidote anivamersen (RB007; Regado Biosciences Inc.) is an RNA aptamer in clinical development to reverse the anticoagulant effect of the parenteral factor IXa inhibitor pegnivacogin, which is also in development. This anticoagulant-antidote pair may provide an alternative in situations in which a fast onset and offset of anticoagulation is needed, like in patients undergoing cardiac surgery with extracorporeal circulation, as an alternative to the heparin/protamine pair. This patent review includes a description of the pharmacological characteristics of the novel specific antidotes, the available results from completed non

  15. 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....... 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....... 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...

  16. New oral anticoagulants: their role and future.

    Science.gov (United States)

    Shapiro, Susie; Laffan, Mike

    2013-12-01

    After 60 years in which warfarin has been the only practical oral anticoagulant, a number of new oral anticoagulants are entering practice. These drugs differ in a several important respects from warfarin; most notably they have a reliable dose-response effect which means they can be given without the need for monitoring. Their simpler metabolism and mode of action also results in fewer interactions with other drugs and with diet. However, some of their other properties such as renal clearance (to varying degrees), short half-life and lack of an available antidote may slow their rate of introduction. Large trials have established their non-inferiority to warfarin in a number of indications and in some cases their superiority. To date they have been licensed for prophylaxis following high risk orthopaedic procedures, non-valvular atrial fibrillation and treatment of venous thromboembolism, but is not clear that they will supplant warfarin in all areas.

  17. Anticoagulation manager: development of a clinical decision support mobile application for management of anticoagulants.

    Science.gov (United States)

    Chih-Wen Cheng; Hang Wu; Thompson, Pamela J; Taylor, Julie R; Zehnbauer, Barbara A; Wilson, Karlyn K; Wang, May D

    2016-08-01

    Patients with certain clotting disorders or conditions have a greater risk of developing arterial or venous clots and downstream embolisms, strokes, and arterial insufficiency. These patients need prescription anticoagulant drugs to reduce the possibility of clot formation. However, historically, the clinical decision making workflow in determining the correct type and dosage of anticoagulant(s) is part science and part art. To address this problem, we developed Anticoagulation Manager, an intelligent clinical decision workflow management system on iOS-based mobile devices to help clinicians effectively choose the most appropriate and helpful follow-up clotting tests for patients with a common clotting profile. The app can provide physicians guidance to prescribe the most appropriate medication for patients in need of anticoagulant drugs. This intelligent app was jointly designed and developed by medical professionals in CDC and engineers at Georgia Tech, and will be evaluated by physicians for ease-of-use, robustness, flexibility, and scalability. Eventually, it will be deployed and shared in both physician community and developer community.

  18. The anti-coagulants asis or apc do not protect against renal ischemia/ reperfusion injury

    Directory of Open Access Journals (Sweden)

    Sarah T.B.G. Loubele

    2014-06-01

    Full Text Available Renal ischemia/reperfusion (I/R injury is the main cause of acute renal failure. The severity of injury is determined by endothelial damage as well as inflammatory and apoptotic processes. The anticoagulants active site inhibited factor VIIa (ASIS and activated protein C (APC are besides their anticoagulant function also known for their cytoprotective properties. In this study the effect of ASIS and APC was assessed on renal I/R injury and this in relation to inflammation and apoptosis. Our results showed no effect of ASIS or APC on renal injury as determined by histopathological scoring as well as by blood urea nitrogen (BUN and creatinine levels. Furthermore, no effect on fibrin staining was detected but ASIS did reduce tissue factor activity levels after a 2-hr reperfusion period. Neither ASIS nor APC administration influenced overall inflammation markers, although some inflammatory effects of ASIS on interleukin (IL-1β and tumor necrosis factor (TNF-α were detectable after 2 hr of reperfusion. Finally, neither APC nor ASIS had an influence on cell signaling pathways or on the number of apoptotic cells within the kidneys. From this study we can conclude that the anticoagulants ASIS and APC do not have protective effects in renal I/R injury in the experimental setup as used in this study which is in contrast to the protective effects of these anticoagulants in other models of I/R.

  19. Partial Purification and Characterization of Anticoagulant Factor from the Snake (Echis carinatus Venom

    Directory of Open Access Journals (Sweden)

    Elham Amrollahi Byoki

    2013-11-01

    Full Text Available   Objective(s: Snake venoms contain complex mixture of proteins with biological activities. Some of these proteins affect blood coagulation and platelet function in different ways. Snake venom toxin may serve as a starting material for drug design to combat several pathophysiological problems such as cardiovascular disorders. In the present study, purification of anticoagulation factor from venom of snake (Echis carinatus was studied. Anticoagulation activity of crude venom, fractions and purified peptide were determined by using prothrombin time (PT and thrombin time (TT. Three fractions were partially purified from the venom of E. Carinatus by gel filtration on sephadex G-75 and final purification was performed by high-performance liquid chromatography (HPLC with C18 column. A purified anticoagulant factor was derived which showed a single protein band in SDS-PAGE electrophoresis under reducing condition. Results of PT and TT tests for purified peptide (EC217 were found to be 102±4.242 and < 5 min. respectively. Determination of molecular weight revealed that the active purified peptide (EC217 was about 30 KD. In conclusion, the present study showed that the venom of E. carinatus contains at least one anticoagulant factor.

  20. Perioperative Considerations and Management of Patients Receiving Anticoagulants

    Science.gov (United States)

    Shaikh, Safiya Imtiaz; Kumari, R. Vasantha; Hegade, Ganapati; Marutheesh, M.

    2017-01-01

    Anticoagulants remain the primary strategy for the prevention and treatment of thrombosis. Unfractionated heparin, low molecular weight heparin (LMWH), fondaparinux, and warfarin have been studied and employed extensively with direct thrombin inhibitors typically reserved for patients with complications or those requiring interventions. Novel oral anticoagulants have emerged from clinical development and are expected to replace older agents with their ease to use and more favorable pharmacodynamic profiles. Increasingly, anesthesiologists are being requested to anesthetize patients who are on some form of anticoagulants and hence it is important to have sound understanding of pharmacology, dosing, monitoring, and toxicity of anticoagulants. We searched the online databases including PubMed Central, Cochrane, and Google Scholar using anticoagulants, perioperative management, anesthetic considerations, and LMWH as keywords for the articles published between 1994 and 2015 while writing this review. In this article, we will review the different classes of anticoagulants and how to manage them in the perioperative settings.

  1. 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

  2. 降脂抗凝联合作用对兔激素性股骨头坏死骨细胞凋亡的影响%Impact of Lipid Lowering and Anti-coagulant Combined Application on the Femoral Bone Cell Apoptosis in Rabbit with Steroid-induced Osteonecrosis

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    李挺松; 肖增明; 黄秋嫔; 劳山; 杨劲松; 罗高斌

    2014-01-01

    Objective To investigate the combined effects of lipid lowering and anti-coagulant on the femoral bone cell apoptosis in rabbit with ste-roid-induced osteonecrosis. Methods A total of 44 female Japanese white rabbits were randomly divided into three groups:normal saline group (CTR group,12 rabbits),steroid-induced osteonecrois of femoral group(SIONF group,16 rabbits),and atorvastatin warfarin treated group(AW group,16 rabbits). Intravenous injection of endotoxin of E.coli(10μg·kg-1)and intramuscular injection of methylprednisolone(20 mg·kg-1)were used to establish the SIONF rabbit model in SIONF group and AW group. CTR group was only administrated with saline. AW group was given atorv-astatin 2.5 mg·kg-1·d-1 and warfarin 1.0 mg·kg-1·d-1 by oral. Random sampling of two animals before the experiment two,four,six weeks after the experiment,and at the end of experiment(the 8th week),the venous blood was collected for testing serum total cholesterol(Tch),low density lipo-protein(LDL),prothrombin time(PT),tissue-type plasminogen activation time(t-PA),and taken bilateral hip X-rays. Then,all animals were scarified,and the femoral head bone cell apoptosis was determined. Results From the sixth week to the end of the experiment,Tch and LDL were slightly increased in CTR group and AW group,but no significant difference was found between the two groups. Tch and LDL were significantly in-creased in SIONF group than CTR group and AW group(P0.05),而SIONF组Tch、LDL显著高于CTR组及AW组(P<0.05);从实验第4周开始,AW组PT及t-PA较CTR组和SIONF组显著延长(P<0.05),SIONF组与CTR组比较PT、t-PA缩短(P<0.05);实验终点CTR组股骨头X线摄片正常,而SIONF组股骨头表面粗糙,软骨面塌陷,发生率为44%,AW组股骨头有类似SIONF组改变,但显著减轻,发生率为25%。实验第4周开始AW组骨细胞凋亡发生率(AI)开始升高持续到实验终点高达39,较CTR组AI(23)增高(P<0.05

  3. Antiplatelet agents and anticoagulants in patients with chronic kidney disease - from pathophysiology to clinical practice.

    Science.gov (United States)

    Lutz, Jens; Jurk, Kerstin

    2016-12-05

    Progressive impairment of renal function can lead to uremia, which is associated with thus increasing the risk of bleeding as well as thrombosis. Furthermore, many patients with chronic kidney disease (CKD) have an indication for an anticoagulation or antiplatelet therapy due to atrial fibrillation, coronary artery disease, thromboembolic disease, or peripheral artery disease. The treatment usually includes vitamin-K antagonists (VKAs) and/or platelet aggregation inhibitors. The direct oral anticoagulants (DOACs) inhibiting factor Xa or thrombin activity represent an alternative for heparins and VKAs. However, DOACs can further aggravate the bleeding risk in CKD patients. This is related to a combination of an accumulation of the substance due to the reduced renal clearance, an inhibition of thrombin-mediated platelet activation, and uremia associated factors such as impaired coagulation, platelet function, and platelet-vessel wall. Furthermore, platelet aggregation inhibitors can also influence the bleeding risk, particularly if they are administered in combination with anticoagulants in patients with advanced CKD. In this review we discuss the different mechanisms leading to the increased risk of bleeding and thrombosis as well as the different options and problems related to an antiplatelet or anticoagulation therapy in CKD patients.

  4. Anticoagulant therapy for sepsis-associated disseminated intravascular coagulation: the view from Japan.

    Science.gov (United States)

    Iba, T; Gando, S; Thachil, J

    2014-07-01

    The current management of disseminated intravascular coagulation (DIC) is based on aggressive treatment of the underlying condition and resuscitation with appropriate blood products. Anticoagulant therapy has appeared and disappeared in the different guidelines and important documents detailing the treatment of DIC. For example, Surviving Sepsis Campaign (SSC) guidelines, the 'global standard' for the management of severe sepsis, had recombinant activated protein C highly recommended in the original version, but this was withdrawn in the latest version due to the lack of evidence. In contrast, recent international guidance released from the International Society on Thrombosis and Haemostasis has introduced the potential efficacy of other agents. In sepsis-related DIC, the basis for anticoagulant therapy comes from the mounting evidence for the anti-inflammatory effects which these agents possess and can prove beneficial in septic situations. Several studies have clearly shown the important cross-talk between coagulation and inflammation in patients with sepsis. More recently, neutrophil extracellular traps and damage-associated molecular patterns (DAMPs), especially histones, have been demonstrated to play a crucial role in the coagulopathy of sepsis. Once again, the natural anticoagulants have an important function in neutralizing the effects of DAMPs and histones. In this review, in addition to examining the important role of anticoagulants in the septic milieu, the clinical studies examining antithrombin, recombinant thrombomodulin and plasma-derived activated protein C are detailed. However, large-scale randomized controlled trials are yet to be performed, with important consideration of the timing, dosage and duration of treatment.

  5. Purification and characterization of an anticoagulant oligopeptide from Whitmania pigra Whitman

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    Xiaobei Zheng

    2015-01-01

    Full Text Available Background: Dried Whitmania pigra is used for the treatment of cardiovascular and cerebrovascular diseases in traditional Chinese medicine and hot water and alcohol extracts also have anticogulant activity. However, a lower molecular weight and more stable anticogulant is needed. Objective: The objective of the following study is to purify and characterize of an anticoagulant oligopeptide from Hirudo (Whitmania pigra Whitman. Materials and Methods: Gel filtration on Sephadex G 50, ion exchange on diethylaminoethyl cellulose, and semi prepared high performance liquid chromatography were used to purify Hirudo. Automated coagulation analyzer was used for evaluating anticoagulant activity. Molecular weight was measured by Matrix assisted laser desorption ionization time of flight mass spectrometry. Amino acid sequence of the oligopeptide was measured by amino acid sequence analyzer. Results: A new anticoagulant, named whitide, isolated from Hirudo was purified, with a molecular weight 1997.1 Da. Amino acid sequence of the oligopeptide was identified as Gly-Pro-ALa-Gly-Hyp-Val-Gly-Ala-Hyp-Gly-Gly-Hyp-Gly-Val-Arg-Gly-Leu-Hyp-Gly-Asp-Arg-Gly. The results revealed that its amino acid sequence had strong homology to various types of collagen. Conclusion: Whitide might be an orally anticoagulant for its hot and trypsin stable.

  6. Extraction of Anticoagulant Compound from Persian Gulf sea anemone Stichodactyla haddoni

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    Mahdeah Tahmasebi

    2015-07-01

    Full Text Available Background: The marine environment is anexceptional reservoir of bioactive natural products, many of them exhibit structural/chemical features that not found in terrestrial natural products.Glycosaminoglycans are one of this various bioactive compounds. Heparin, as a well known glycosaminoglycan, is a sulfated glycosaminoglycan that has natural anticoagulant properties. Heparin and heparin-like compounds are used as anticoagulants in many aspects of medicine. However, for two main reasons: 1. Contamination in heparin samples obtained from pig intestine or bovine lung pathogens and other pathogens, 2 .resource for use of heparin is limited and there are a lot of requirements for new compounds from natural resources. According to GAGs importance and widespread using of heparin in medicine, in the present study, GAGs compounds extracted from sea anemones and anticoagulant properties of the human blood is investigated. Materials and Methods: GAGs compound was extracted by using cetylpyridinium chloride. Anticoagulation activity of extracted GAGs (the extracted tentacle was tested in human blood plasma, using manual procedures, and assay system, prothrombin time (PT and activated partial thromboplastin time (APTT. Results: In this study the amount of the crude GAGs was 24 mg per gram of tentacle dry weight. The results ofanticoagulant activity extracted on human blood plasma showed that these compounds prolonged clotting time compared to the control. In APTT and PT assay of the extracted GAGs from the sea anemone also clotting time prolonged in compared to the control. Conclusion: The results demonstrated that anticoagulant compounds existed in the tentacle of the sea anemone, and although their effects is weaker than the heparin, but they can be substituted for heparin, at least in laboratory conditions.

  7. [Therapy education for patients receiving oral anti-coagulants vitamin K antagonists].

    Science.gov (United States)

    Satger, Bernadette; Blaise, Sophie; Fontaine, Michèle; Yver, Jacqueline; Allenet, Benoît; Baudrant, Magali; Pernod, Gilles; Bosson, Jean-Luc

    2009-12-01

    The vitamin K antagonists (VKA) remain to this day the only oral form of therapeutic anticoagulation. Approximately 1% of the French population, mainly elderly, is treated with these anticoagulants. Oral anticoagulants have significant risks of iatrogenic complications; indeed they are the leading cause of such drug-induced complications, predominantly hemorrhages. AFSSAPS (French Drug and Medical Products Agency) clinical practice recommendations, repeatedly disseminated, emphasize the education of patients receiving VKAs. Managing oral anticoagulant treatment is challenging, with a significant risk of under- or overdosing and consequently, thrombosis or hemorrhage. The therapeutic window is narrow, multiple drug-interactions are possible, and the specific dose required for a particular individual to achieve appropriate International Normalized Ratio (INR) levels is unpredictable. The literature contains few randomized controlled trials about the efficacy of education for patients treated with oral anticoagulants. These education programs are not standardized and are therefore varied and difficult to compare. Nevertheless, studies demonstrate the importance of patient education programs in reducing the risk of hemorrhage and achieving better treatment stability. The Grenoble region hospital-community network for vascular diseases (GRANTED) has developed an education program for these patients, consisting of individual sessions for the patient and/or a friend or family member (either at a health care facility or at the patient's home), telephone support and group sessions, and using educational tools and supports. There is also a link with the general practitioner who receives a report. This approach makes it possible to adapt the educational message to individual patients and their daily lives, as well as directly involving them in the management of their treatment.

  8. Reelin induces EphB activation

    Institute of Scientific and Technical Information of China (English)

    Elisabeth Bouché; Mario I Romero-Ortega; Mark Henkemeyer; Timothy Catchpole; Jost Leemhuis; Michael Frotscher; Petra May

    2013-01-01

    The integration of newborn neurons into functional neuronal networks requires migration of cells to their final position in the developing brain,the growth and arborization of neuronal processes and the formation of synaptic contacts with other neurons.A central player among the signals that coordinate this complex sequence of differentiation events is the secreted glycoprotein Reelin,which also modulates synaptic plasticity,learning and memory formation in the adult brain.Binding of Reelin to ApoER2 and VLDL receptor,two members of the LDL receptor family,initiates a signaling cascade involving tyrosine phosphorylation of the intracellular cytoplasmic adaptor protein Disabled-l,which targets the neuronal cytoskeleton and ultimately controls the positioning of neurons throughout the developing brain.However,it is possible that Reelin signals interact with other receptor-mediated signaling cascades to regulate different aspects of brain development and plasticity.EphB tyrosine kinases regulate cell adhesion and repulsion-dependent processes via bidirectional signaling through ephrin B transmembrane proteins.Here,we demonstrate that Reelin binds to the extracellular domains of EphB transmembrane proteins,inducing receptor clustering and activation of EphB forward signaling in neurons,independently of the ‘classical' Reelin receptors,ApoER2 and VLDLR.Accordingly,mice lacking EphB1 and EphB2 display a positioning defect of CA3 hippocampal pyramidal neurons,similar to that in Reelin-deficient mice,and this cell migration defect depends on the kinase activity of EphB proteins.Together,our data provide biochemical and functional evidence for signal integration between Reelin and EphB forward signaling.

  9. Critical temperature ranges of hypothermia-induced platelet activation: possible implications for cooling patients in cardiac surgery.

    Science.gov (United States)

    Straub, Andreas; Breuer, Melanie; Wendel, Hans P; Peter, Karlheinz; Dietz, Klaus; Ziemer, Gerhard

    2007-04-01

    Cooling of the patient is routinely applied in cardiac surgery to protect organs against ischemia. Hypothermia induces activation of platelets, but the effects of temperatures such as used during cardiac surgery are not well described. To investigate this in an in-vitro study heparinized whole blood was incubated at different temperatures (37 degrees C, 34.5 degrees C, 32 degrees C, 29.5 degrees C, 27 degrees C, 24.5 degrees C, 22 degrees C, 19.5 degrees C and 17 degrees C). The effect of these temperatures on aggregation, P-selectin expression, GP IIb/IIIa activation and platelet microparticle (PMP) formation of unstimulated and ADP-stimulated platelets of 36 subjects was evaluated in flow cytometry. A four-parametric logistic model was fitted to depict the temperature effect on platelet parameters. Lower temperatures increased aggregates, P-selectin expression, and GP IIb/IIIa activation. The number of PMPs decreases with hypothermia. Additional experiments revealed a slight influence of heparin on platelet P-selectin expression but excluded an effect of this anticoagulant on the other evaluated parameters. Threshold temperatures, which mark 5% changes of platelet parameters compared to values at 37 degrees C, were calculated. On ADP-stimulated platelets the thresholds for P-selectin expression and GP IIb/IIa activation are 34.0 degrees C and 36.4 degrees C, respectively, and lie in the temperature range routinely applied in cardiac surgery. Hypothermia-induced platelet activation may develop in most patients undergoing cardiac surgery, possibly resulting in thromboembolic events, coagulation defects, and proinflammatory leukocyte bridging by P-selectin bearing platelets and PMPs. These findings suggest that pharmacological protection of platelets against hypothermia-induced damage may be beneficial during cardiac surgery.

  10. The role of anticoagulation clinics in the era of new oral anticoagulants.

    Science.gov (United States)

    Testa, Sophie; Paoletti, Oriana; Zimmermann, Anke; Bassi, Laura; Zambelli, Silvia; Cancellieri, Emilia

    2012-01-01

    Anticoagulation Clinics (ACs) are services specialized in management of patients on anticoagulant treatment. At present, ACs manage patients chiefly on antivitamin K antagonists (AVKs), but patient population has already changed in the last few years, because of an increase of treatments with other anticoagulant drugs, which require different management systems. The strong increase in the number of patients at AC, mainly on long-term treatment, has determined the development of web management, through telemedicine systems, improving the quality of life and maintaining the same clinical quality levels. New oral anticoagulants (NOAs) have shown to be as effective as AVK antagonists in stroke prevention in atrial fibrillation and for treatment of venous thromboembolism in addition to VTE prophylaxis in orthopaedic surgery, when administered at a fixed dose, but patient adherence and compliance are crucial for good quality treatment. At present, lacking data from the real world, an oversimplification of treatment with NOAs could cause unjustified risks for patients and also a possible future underuse of good drugs. For these reasons the vigilance must be high and ACs can have a crucial role in defining which is the best management for NOA patients and how to do it, as it happened for AVKs.

  11. The Role of Anticoagulation Clinics in the Era of New Oral Anticoagulants

    Directory of Open Access Journals (Sweden)

    Sophie Testa

    2012-01-01

    Full Text Available Anticoagulation Clinics (ACs are services specialized in management of patients on anticoagulant treatment. At present, ACs manage patients chiefly on antivitamin K antagonists (AVKs, but patient population has already changed in the last few years, because of an increase of treatments with other anticoagulant drugs, which require different management systems. The strong increase in the number of patients at AC, mainly on long-term treatment, has determined the development of web management, through telemedicine systems, improving the quality of life and maintaining the same clinical quality levels. New oral anticoagulants (NOAs have shown to be as effective as AVK antagonists in stroke prevention in atrial fibrillation and for treatment of venous thromboembolism in addition to VTE prophylaxis in orthopaedic surgery, when administered at a fixed dose, but patient adherence and compliance are crucial for good quality treatment. At present, lacking data from the real world, an oversimplification of treatment with NOAs could cause unjustified risks for patients and also a possible future underuse of good drugs. For these reasons the vigilance must be high and ACs can have a crucial role in defining which is the best management for NOA patients and how to do it, as it happened for AVKs.

  12. Non-vitamin K antagonist oral anticoagulation agents in anticoagulant naive 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...

  13. Antithrombin Administration During Intravenous Heparin Anticoagulation in the Intensive Care Unit: A Single-Center Matched Retrospective Cohort Study.

    Science.gov (United States)

    Beyer, Jacob T; Schoeppler, Kelly E; Zanotti, Giorgio; Weiss, Gregory M; Mueller, Scott W; MacLaren, Robert; Fish, Douglas N; Kiser, Tyree H

    2016-09-13

    Unfractionated heparin (UFH) is a frequently utilized indirect anticoagulant that induces therapeutic effect by enhancing antithrombin (AT)-mediated procoagulant enzyme inhibition. In suspected heparin resistance (HR) during cardiopulmonary bypass, AT activity may be decreased and AT supplementation helps restore UFH responsiveness. The benefit of AT supplementation in HR over longer durations of UFH therapy is unclear. The objective of this study was to describe and evaluate the use of AT III concentrate in the intensive care units (ICUs) at our institution for improving UFH therapy response over 72 hours. A total of 44 critically ill patients were included in the analysis-22 patients received at least 1 dose of AT and 22 patients received no AT. Thirty (68.2%) of the 44 patients were receiving mechanical circulatory support. Baseline characteristics were similar between groups. The average AT activity prior to AT supplementation was 57.9% in the treatment group, and the median cumulative dose of AT was 786.5 U (9.26 U/kg) per patient. There were no significant differences observed in proportion of time spent in therapeutic range (31.9% vs 35.2%, P = .65), time to therapeutic goal (16.5 vs 15.5 hours, P = .97), or patients who experienced a bleeding event (5 vs 5, P = .99) between groups. In conclusion, AT supplementation had minimal impact on anticoagulant response in this cohort of ICU patients with mild to moderate HR receiving a prolonged UFH infusion. Additional research is needed to define AT activity targets and to standardize AT supplementation practices in patients receiving prolonged heparin infusion.

  14. Aromatic Amines Exert Contrasting Effects on the Anticoagulant Effect of Acetaldehyde upon APTT

    Directory of Open Access Journals (Sweden)

    La'Teese Hall

    2014-01-01

    Full Text Available The pharmacological effects of amphetamine, procaine, procainamide, DOPA, isoproterenol, and atenolol upon activated partial thromboplastin time in the absence and presence of acetaldehyde have been investigated. In the absence of acetaldehyde, amphetamine and isoproterenol exhibit a procoagulant effect upon activated partial thromboplastin time, whereas atenolol and procaine display anticoagulant effects upon activated partial thromboplastin time. DOPA and procainamide do not alter activated partial thromboplastin time. Premixtures of procaine with acetaldehyde produce an additive anticoagulant effect on activated partial thromboplastin time, suggesting independent action of these compounds upon clotting factors. Premixtures of amphetamine with acetaldehyde, as well as atenolol with acetaldehyde, generate a detoxication of the anticoagulant effect of acetaldehyde upon activated partial thromboplastin time. A similar statistically significant decrease in activated partial thromboplastin time is seen when procainamide is premixed with acetaldehyde for 20 minutes at room temperature. Premixtures of DOPA and isoproterenol with acetaldehyde do not affect an alteration in activated partial thromboplastin time relative to acetaldehyde alone. Hence, a selective interaction of atenolol, procaine, and amphetamine with acetaldehyde to produce detoxication of the acetaldehyde is suggested, undoubtedly due to the presence of amino, hydroxyl, or amide groups in these drugs.

  15. 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...

  16. Update of the guidelines for lupus anticoagulant detection

    NARCIS (Netherlands)

    Pengo, V.; Tripodi, A.; Reber, G.; Rand, J. H.; Ortel, T. L.; Galli, M.; de Groot, P. G.

    2009-01-01

    One of the conclusions of the subcommittee meeting on Lupus Anticoagulant/Phospholipid dependent antibodies, held in Geneva on 2007, was the need to update the guidelines on Lupus Anticoagulant (LA) detection. Particular emphasis was given to several aspects discussed in this official communication.

  17. Current perspectives on dental patients receiving coumarin anticoagulant therapy.

    Science.gov (United States)

    Herman, W W; Konzelman, J L; Sutley, S H

    1997-03-01

    Despite approximately 40 years of experience with oral anticoagulant drugs, controversy still exists about the safety of dental treatment in a patient receiving this therapy. The authors review the topic in depth and offer detailed recommendations for the dental management of patients receiving coumarin anticoagulant therapy.

  18. Genetic and environmental factors affecting the coumarin anticoagulant level

    NARCIS (Netherlands)

    L.E. Visser (Loes)

    2004-01-01

    textabstractThis introductory chapter has illustrated that various factors, such as genetic factors, drugs, diet and intercurrent diseases may affect anticoagulation levels. Most of the clinical and pharmacological data related to coumarin anticoagulants have so far been obtained from studying warfa

  19. Clinical considerations of anticoagulation therapy for patients with atrial fibrillation

    Institute of Scientific and Technical Information of China (English)

    Shu ZHANG

    2012-01-01

    Atrial fibrillation (AF) increases the risk of stroke.New anticoagulation agents have recently provided alternative and promising approaches.This paper reviews the current state of anticoagulation therapy in AF patients,focusing on various clinical scenarios and on comparisons,where possible,between western and eastern populations.

  20. Dental management of patients taking novel oral anticoagulants (NOAs): Dabigatran

    Science.gov (United States)

    Albaladejo, Alberto; Alvarado, Alfonso

    2017-01-01

    Background A new group of oral anticoagulants (dabigatran, rivaroxaban, apixaban and edoxaban) with clear advantages over classic dicoumarin oral anticoagulants (warfarin and acenocoumarol) has been developed in recent years. Patients being treated with oral anticoagulants are at higher risk for bleeding when undergoing dental treatments. Material and Methods A literature search was conducted through April 2016 for publications in the ISI Web of Knowledge, PubMed and Cochrane Library using the keywords “dabigatran”, “rivaroxaban”, “apixaban”, “edoxaban”, “new oral anticoagulants”, “novel oral anticoagulants”, “bleeding” and “dental treatment”. Results There is no need for regular coagulation monitoring of patients on dabigatran therapy. Whether or not to temporarily discontinue dabigatran must be assessed according to the bleeding risk involved in the dental procedure to be performed. Conclusions The number of patients under treatment with new oral anticoagulants will increase in the coming years. It is essential to know about the pharmacokinetics and pharmacodynamics of new oral anticoagulants and about their interactions with other drugs. It is necessary to develop clinical guidelines for the perioperative and postoperative management of these new oral anticoagulants in oral surgical procedures, and to carefully evaluate the bleeding risk of dental treatment, as well as the thrombotic risk of suppressing the new oral anticoagulant. Key words:Dabigatran, rivaroxaban, apixaban, edoxaban, novel oral anticoagulants, bleeding. PMID:28210451

  1. Anticoagulant response to Agkistrodon contortrix venom (ACV test): a new global test to screen for defects in the anticoagulant protein C pathway.

    Science.gov (United States)

    Robert, A; Eschwège, V; Hameg, H; Drouet, L; Aillaud, M F

    1996-04-01

    As specific assays used to identify defects in the protein C (PC) anticoagulant pathway are laborious and expensive, we describe here a global test to screen for these defects. This assay is expressed as the ratio of two activated partial thromboplastin times, one in the absence and one in the presence of 0,125 U/ml of the PC activator of Agkistrodon contortrix venom (ACV). Eight of the 168 healthy volunteers of the control group exhibited an ACV ratio below the lower normal limit of 3.37 [6 subjects with the mutation Arg 506 to Gln in their factor V gene (FV R506Q) and one with PS deficiency]. 128 patients who have had at least one episode of deep-vein thrombosis were retrospectively studied. All patients carrying FV Q506R (n = 48), PC deficiency (n = 14) or combined defects, i.e. FV Q506R and PC deficiency (n = 4) or FV Q506R and PS deficiency (n = 3), had ACV ratios ACV ratios which overlapped normal range. ACV ratios of one out of seven patients with antithrombin deficiency, and 10% of patients without identified defect in the PC anticoagulant pathway (n = 30) were ACV ratio raised to 3.70 could lead to a test identifying all patients with a defect in the PC anticoagulant pathway.

  2. Xiang-Qi-Tang and its active components exhibit anti-inflammatory and anticoagulant properties by inhibiting MAPK and NF-κB signaling pathways in LPS-treated rat cardiac microvascular endothelial cells.

    Science.gov (United States)

    He, Chang-Liang; Yi, Peng-Fei; Fan, Qiao-Jia; Shen, Hai-Qing; Jiang, Xiao-Lin; Qin, Qian-Qian; Song, Zhou; Zhang, Cui; Wu, Shuai-Cheng; Wei, Xu-Bin; Li, Ying-Lun; Fu, Ben-Dong

    2013-04-01

    Xiang-Qi-Tang (XQT) is a Chinese herbal formula containing Cyperus rotundus, Astragalus membranaceus and Andrographis paniculata. Alpha-Cyperone (CYP), astragaloside IV (AS-IV) and andrographolide (AND) are the three major active components in this formula. XQT may modulate the inflammatory or coagulant responses. We therefore assessed the effects of XQT on lipopolysaccharide (LPS)-induced inflammatory model of rat cardiac microvascular endothelial cells (RCMECs). XQT, CYP, AS-IV and AND inhibited the production of tumor necrosis factor alpha (TNF-α), intercellular cell adhesion molecule-1 (ICAM-1) and plasminogen activator inhibitor-1 (PAI-1), and up-regulated the mRNA expression of Kruppel-like factor 2 (KLF2). XQT and CYP inhibited the secretion of tissue factor (TF). To further explore the mechanism, we found that XQT, or its active components CYP, AS-IV and AND significantly inhibited extracellular signal-regulated kinase (ERK), c-jun NH2-terminal kinase (JNK) and p38 phosphorylation protein expression as well as decreased the phosphorylation levels of nuclear factor κB (NF-κB) p65 proteins in LPS-stimulated RCMECs. These results suggested that XQT and its active components inhibited the expression of inflammatory and coagulant mediators via mitogen-activated protein kinase (MAPKs) and NF-κB signaling pathways. These findings may contribute to future research on the action mechanisms of this formula, as well as therapy for inflammation- or coagulation-related diseases.

  3. Polissacarídeos sulfatados isolados das clorofíceas Caulerpa racemosa e Caulerpa cupressoides – extração, fracionamento e atividade anticoagulante =Sulfated polysaccharides isolated from Caulerpa racemosa and Caulerpa cupressoides (Chlorophyceaes – extraction, fractionation and anticoagulant activity

    Directory of Open Access Journals (Sweden)

    José Ariévilo Gurgel Rodrigues

    2010-04-01

    in 0.1 M sodium acetate buffer (pH 5.0 containing 5 mM cysteine and 5 mM EDTA, followed by fractionation on ion exchange DEAE-cellulose column with NaCl gradient. The obtained fractions were analyzed by 0.5% agarose gel electrophoresis and the anticoagulant activity measured by the activated partial thromboplastin time (APTT using normal human plasma, and compared to a standard heparin curve (193 IU mg-1. Similar chromatographic profiles of SP were shown on both species, butwith distinct mobility patterns, when the SP fractions were compared by electrophoresis. SP eluted with 0.75 M of NaCl modified the APTT, whose anticoagulant activities were only 21.23 and 24.36 IU mg-1 for C. racemosa and C. cupressoides, respectively. Therefore, anticoagulant SP isolated from chlorophyceaes showed effects inferior to heparin, and comparative studies of these molecules are also suggested as auxiliary tools in the identification of algae of the same genus.

  4. 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

  5. Management of oral anticoagulation in patients undergoing minor dental procedures.

    Science.gov (United States)

    Alaali, Yathreb; Barnes, Geoffrey D; Froehlich, James B; Kaatz, Scott

    2012-08-01

    Approximately 4.2 million patients in the United States are taking warfarin, making it the 11th most prescribed drug. Warfarin is primarily used for treatment of venous thromboembolic disease and stroke prevention in patients with atrial fibrillation and mechanical heart valves. Dentists frequently encounter anticoagulated patients and are faced with management decisions in these patients who require dental procedures. Observational studies suggest the risk of thrombosis if anticoagulation is suspended during dental procedures is higher than the risk of bleeding if anticoagulation is not suspended. Several groups now offer guidelines that recommend most minor dental procedures should be performed while on therapeutic warfarin. The recent approval of several new oral anticoagulants has introduced greater complexity to the management of the anticoagulated patient, and this narrative review will discuss current guidelines, the scientific underpinnings of the guidelines, and offer some practical suggestions for patients that are receiving the new agents.

  6. Potential role of new anticoagulants for prevention and treatment of venous thromboembolism in cancer patients.

    Science.gov (United States)

    Gómez-Outes, Antonio; Suárez-Gea, M Luisa; Lecumberri, Ramón; Terleira-Fernández, Ana Isabel; Vargas-Castrillón, Emilio; Rocha, Eduardo

    2013-01-01

    Venous thromboembolism (VTE), encompassing deep vein thrombosis and pulmonary embolism, represents a major cause of morbidity and mortality in patients with cancer. Low molecular weight heparins are the preferred option for anticoagulation in cancer patients according to current clinical practice guidelines. Fondaparinux may also have a place in prevention of VTE in hospitalized cancer patients with additional risk factors and for initial treatment of VTE. Although low molecular weight heparins and fondaparinux are effective and safe, they require daily subcutaneous administration, which may be problematic for many patients, particularly if long-term treatment is needed. Studying anticoagulant therapy in oncology patients is challenging because this patient group has an increased risk of VTE and bleeding during anticoagulant therapy compared with the population without cancer. Risk factors for increased VTE and bleeding risk in these patients include concomitant treatments (surgery, chemotherapy, placement of central venous catheters, radiotherapy, hormonal therapy, angiogenesis inhibitors, antiplatelet drugs), supportive therapies (ie, steroids, blood transfusion, white blood cell growth factors, and erythropoiesis-stimulating agents), and tumor-related factors (local vessel damage and invasion, abnormalities in platelet function, and number). New anticoagulants in development for prophylaxis and treatment of VTE include parenteral compounds for once-daily administration (ie, semuloparin) or once-weekly dosing (ie, idraparinux and idrabiotaparinux), as well as orally active compounds (ie, dabigatran, rivaroxaban, apixaban, edoxaban, betrixaban). In the present review, we discuss the pharmacology of the new anticoagulants, the results of clinical trials testing these new compounds in VTE, with special emphasis on studies that included cancer patients, and their potential advantages and drawbacks compared with existing therapies.

  7. Laser Induced Selective Activation For Subsequent Autocatalytic Electroless Plating

    DEFF Research Database (Denmark)

    Zhang, Yang

    The subject of this PhD thesis is “Laser induced selective activation for subsequent autocatalytic electroless plating.” The objective of the project is to investigate the process chains for micro structuring of polymer surfaces for selective micro metallization. Laser induced selective activation...

  8. 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.

  9. Systemic anticoagulation related to heparin locking of non-tunnelled venous dialysis catheters in intensive care patients.

    Science.gov (United States)

    Bong, Y C; Walsham, J

    2016-07-01

    Heparin locking of venous dialysis catheters is routinely performed in intensive care to maintain catheter patency when the catheters are not being used. Leakage of heparin into the circulation can potentially cause systemic anticoagulation and may present a risk to intensive care patients. To assess the effect of 5000 units per millilitre heparin locking of non-tunnelled dialysis catheters on systemic anticoagulation, we performed a prospective observational study of ten intensive care patients receiving heparin locking of dialysis catheters in an adult tertiary intensive care unit between July and September 2015. Activated partial thromboplastin time (APTT) was measured prior to, and three minutes after, heparin locking of catheter lumens with the manufacturer's recommended locking volume to assess the effect on systemic anticoagulation. Heparin locking of venous dialysis catheters resulted in a significant rise in APTT (P=0.002). The median rise was by 56 seconds (interquartile range 30-166.5). Following heparin locking, 80% of patients had APTT values within or above the range associated with therapeutic anticoagulation. Heparin locking of non-tunnelled venous dialysis catheters can cause systemic anticoagulation in intensive care patients and therefore poses a potential risk to patient safety.

  10. Perioperative management of anticoagulant users scheduled for glaucoma surgery: a survey among the Brazilian Glaucoma Society members

    Directory of Open Access Journals (Sweden)

    Marcos Balbino

    2013-12-01

    Full Text Available PURPOSE: To investigate and describe, among the members of the Brazilian Glaucoma Society (BGS, the practices regarding the perioperative management of anticoagulants (warfarin and aspirin use in patients scheduled for glaucoma surgery. METHODS: The active members of the Brazilian Glaucoma Society answered a questionnaire evaluating different aspects of their current perioperative management of glaucomatous patients taking warfarin or aspirin. RESULTS: A total of 52 participants returned a complete questionnaire. Warfarin or aspirin was routinely interrupted prior to glaucoma surgery by 82.7% of the respondents. The majority of the surgeons who discontinued these medications reported doing so 7 days prior to surgery and resumed their use the day after the procedure. Almost half of our interviewees reported hemorrhagic complications that could be related to anticoagulant therapy. A large number of the surgeons (86.5% preferred a particular surgical technique for anticoagulated patients; however, most of them (88.5% do not change the anesthetic planning in such patients. Finally, the majority of the participants (90.4% refer their anticoagulated patients to a preoperative appointment with a cardiologist or a general practitioner before the surgery. CONCLUSIONS: The majority of Brazilian Glaucoma Society members participating in this study interrupt either warfarin or aspirin prior to glaucoma surgery. Although there is scant information available in the literature to offer definitive guidance, most participants from the Brazilian Glaucoma Society seem to share the same opinion when it comes to perioperative management of anticoagulant users.

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

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chang-Jiang, E-mail: swjtupcj@163.com; Hou, Yan-Hua; Ding, Hong-Yan; Dong, Yun-Xiao

    2013-12-15

    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.

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

    Science.gov (United States)

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

    2013-12-01

    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.

  13. Management of antiplatelet and anticoagulant therapy for endoscopic procedures: Introduction to novel oral anticoagulants.

    Science.gov (United States)

    González Bárcenas, Martha L; Pérez Aisa, Ángeles

    2016-02-01

    The development of novel antithrombotic therapy in the past few years and its prescription in patients with cardiovascular and circulatory disease has widened the spectrum of drugs that need to be considered when performing an endoscopic procedure. The balance between the thrombotic risk patients carry due to their medical history and the bleeding risk involved in endoscopic procedures should be thoroughly analyzed by Gastroenterologists. New oral anticoagulants (NOACs) impose an additional task. These agents, that specifically target factor IIa or Xa, do not dispose of an anticoagulation monitoring method nor have an antidote to revert their effect, just as with antiplatelet agents. Understanding the fundamental aspects of these drugs provides the necessary knowledge to determine the ideal period the antithrombotic therapy should be interrupted in order to perform the endoscopic procedure, offering maximum safety for patients and optimal results.

  14. Management of antiplatelet and anticoagulant therapy for endoscopic procedures: introduction to novel oral anticoagulants

    Directory of Open Access Journals (Sweden)

    Martha L. González-Bárcenas

    Full Text Available The development of novel antithrombotic therapy in the past few years and its prescription in patients with cardiovascular and circulatory disease has widened the spectrum of drugs that need to be considered when performing an endoscopic procedure. The balance between the thrombotic risk patients carry due to their medical history and the bleeding risk involved in endoscopic procedures should be thoroughly analyzed by Gastroenterologists. New oral anticoagulants (NOACs impose an additional task. These agents, that specifically target factor IIa or Xa, do not dispose of an anticoagulation monitoring method nor have an antidote to revert their effect, just as with antiplatelet agents. Understanding the fundamental aspects of these drugs provides the necessary knowledge to determine the ideal period the antithrombotic therapy should be interrupted in order to perform the endoscopic procedure, offering maximum safety for patients and optimal results.

  15. Thromboembolism and anticoagulation after fontan surgery

    Directory of Open Access Journals (Sweden)

    Sangeetha Viswanathan

    2016-01-01

    Full Text Available This review attempts to answer the common questions faced by a clinician regarding thromboembolism and thromboprophylaxis in patients following Fontan surgery. The review is in an easy to understand question and answer format and discusses the currently available literature on the subject in an attempt to arrive at practical clinically relevant solutions. Patients who have undergone the Fontan operation are at a high risk for thromboembolism. Based on available evidence, there is a strong rationale for thromboprophylaxis. However, it is not clear as to which agent should be administered to prevent thromboembolic events. While the available evidence suggests that antiplatelet agents alone may be as good as oral anticoagulants, there is a need for a large multicenter randomized control trial comparing these two common strategies to deliver a clear verdict.

  16. [Antidotes to novel direct oral anticoagulants].

    Science.gov (United States)

    Khorev, N G; Momot, A P; Kon'kova, V O

    During the last 10 years, several novel direct oral anticoagulants (NOACs) have entered the clinical arena and were registered in the Russian Federation for use in patients presenting with atrial fibrillation, venous thrombosis, and pulmonary artery thromboembolism. NOACs are classified into two groups: direct thrombin inhibitor (notably dabigatran) and factor Xa inhibitors (including rivaroxaban, apixaban, and edoxaban). Their disadvantage is lack of specific antidotes in case of an emergency situation (injury, infarction, stroke requiring thrombolysis, urgent operation). The review contains the data on the existing therapeutic regimens of treating haemorrhage on the background of taking these coagulants. This is followed by analysing the present-day results of clinical trials aimed at working out pharmaceutical agents (andexanet alpha, idarucizumab, aripazine) being antidotes to direct thrombin inhibitor and the factor Xa inhibitors. Administration of these agents makes it possible to reverse coagulation and minimize the aftermaths of haemorrhage in patients taking these drugs, in emergency situations.

  17. Thromboembolism and anticoagulation after Fontan surgery.

    Science.gov (United States)

    Viswanathan, Sangeetha

    2016-01-01

    This review attempts to answer the common questions faced by a clinician regarding thromboembolism and thromboprophylaxis in patients following Fontan surgery. The review is in an easy to understand question and answer format and discusses the currently available literature on the subject in an attempt to arrive at practical clinically relevant solutions. Patients who have undergone the Fontan operation are at a high risk for thromboembolism. Based on available evidence, there is a strong rationale for thromboprophylaxis. However, it is not clear as to which agent should be administered to prevent thromboembolic events. While the available evidence suggests that antiplatelet agents alone may be as good as oral anticoagulants, there is a need for a large multicenter randomized control trial comparing these two common strategies to deliver a clear verdict.

  18. Therapeutic Dilemmas Regarding Anticoagulation: An Experience in a Patient with Nephrotic Syndrome, Pulmonary Embolism, and Traumatic Brain Injury

    Science.gov (United States)

    Akimoto, Tetsu; Yamazaki, Tomoyuki; Kusano, Eiji; Nagata, Daisuke

    2016-01-01

    Patients with active bleeding complications who concomitantly develop overt pulmonary embolism (PE) present distinct therapeutic dilemmas, since they are perceived to be at substantial risk for the progression of the embolism in the absence of treatment and for aggravation of the hemorrhagic lesions if treated with anticoagulants. A 76-year-old patient with nephrotic syndrome, which is associated with an increased risk of thromboembolism, concurrently developed acute PE and intracranial bleeding because of traumatic brain injury. In this case, we prioritized the treatment for PE with the intravenous unfractionated heparin followed by warfarinization. Despite the transient hemorrhagic progression of the brain contusion after the institution of anticoagulation, our patient recovered favorably from the disease without any signs of neurological compromise. Several conundrums regarding anticoagulation that emerged in this case are also discussed. PMID:27840582

  19. [Cardiovascular diseases, antiplatelet agents, anticoagulants and hemorrhagic risk].

    Science.gov (United States)

    Eusébio, Jorge; Reny, Jean-Luc; Fontana, Pierr; Nendaz, Mathieu

    2010-10-20

    If the benefits of antiplatelet and anticoagulant therapies are well established, bleeding complications appear underestimated in trials in comparison to their real-life incidence. Also, a large number of patients receive various associations of antiplatelet or anticoagulant treatments, while the benefit of some associations is not firmly established and data about their safety are missing. Identifying patients at high risk of bleeding is essential to define appropriate strategies. In this article we discuss the risk-benefit of various antiplatelet and anticoagulant molecules taken individually or in combination. An overview of the main clinical scores available to stratify the risk of bleeding is presented.

  20. Unplanned pregnancy on a direct oral anticoagulant (Rivaroxaban): A warning.

    Science.gov (United States)

    Myers, B; Neal, R; Myers, O; Ruparelia, M

    2016-03-01

    Direct oral anticoagulants (DOACs or NOACs -non-vitamin K oral anticoagulants), as the name suggests, are oral anticoagulants with a direct inhibitory action either against factor X or factor II (thrombin). Pregnant women were excluded from participating in all the large trials of the DOACs and they are considered contra-indicated in pregnancy and breast feeding. We present a case of inadvertent exposure to rivaroxaban in a woman who presented at 25 weeks' gestation. The management of her pregnancy and delivery is described, and the previous published case reports are reviewed with a discussion about the use of DOACs in woman of childbearing age.

  1. The management of dental patients taking new generation oral anticoagulants.

    Science.gov (United States)

    Scott, Alun; Gibson, John; Crighton, Alexander

    2014-11-01

    Recently, new oral anticoagulants have been introduced as alternatives to warfarin. While national guidelines for treatment of dental patients taking warfarin as an anticoagulant are well-established, no such information is available for these novel therapeutic agents. At present, the local guidance available is contradictory between different health boards/health planning units, and liaison with the medical practitioner managing the individual patient's anticoagulation is imperative if any invasive procedure is proposed. This paper examines the available evidence regarding these drugs and sets out proposals for clinical guidance of dental practitioners treating these patients in primary dental care.

  2. Emergency management of patients being treated with oral anticoagulants

    Directory of Open Access Journals (Sweden)

    Franco Manzato

    2013-12-01

    Full Text Available Vitamin K antagonists (VKA are among the most widely prescribed drugs in the industrialized world. In fact, for decades, VKA have been the only orally available anticoagulant for the primary and secondary prevention of venous and arterial thrombotic events. Their efficacy has been widely demonstrated in a series of studies carried out in the 1990s. Since the incidences of atrial fibrillation and venous thromboembolism increase exponentially with age, the number of anticoagulated patients is destined to increase. This paper examines anticoagulation therapy management with particular attention to the use of VKA.

  3. [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.

  4. Mass-transfer induced activity in galaxies

    Science.gov (United States)

    Shlosman, Isaac

    Current research on the origin and evolution of active galaxies is comprehensively surveyed in this collaborative volume. Both of the proposed types of central activity --- active galactic nuclei and nuclear starbursts --- are analyzed with a particular emphasis on their relationship to the large-scale properties of the host galaxy. The crucial question is what triggers and fuels nuclear activity now and at earlier epochs. The topics covered here are gas flows near to massive black holes, the circumnuclear galactic regions, and the large-scale bars in disk galaxies. Aspects of nuclear bursts of star formation and the relationship between central activity and the gas and stellar dynamics of the host galaxy are addressed as well. The contributors of this book for professionals and graduate students are world experts on galaxy evolution.

  5. Optimal duration of anticoagulation. Provoked versus unprovoked VTE and role of adjunctive thrombophilia and imaging tests.

    Science.gov (United States)

    Prandoni, Paolo; Barbar, Sofia; Milan, Marta; Campello, Elena; Spiezia, Luca; Piovella, Chiara; Pesavento, Raffaele

    2015-06-01

    Once anticoagulation is stopped, the risk of recurrent venous thromboembolism (VTE) over years after a first episode is consistently around 30%. This risk is higher in patients with unprovoked than in those with (transient) provoked VTE, and among the latter in patients with medical than in those with surgical risk factors. Baseline parameters that have been found to be related to the risk of recurrent VTE are the proximal location of deep-vein thrombosis, obesity, old age, male sex and non-0 blood group, whereas the role of inherited thrombophilia is controversial. The persistence of residual vein thrombosis at ultrasound assessment has consistently been shown to increase the risk, as do persistently high values of D-dimer and the early development of the post-thrombotic syndrome. Although the latest international guidelines suggest indefinite anticoagulation for most patients with the first episode of unprovoked VTE, strategies that incorporate the assessment of residual vein thrombosis and D-dimer have the potential to identify subjects in whom anticoagulation can be safely discontinued. Moreover, new opportunities are offered by a few emerging anti-Xa and anti-IIa oral compounds, which are likely to induce fewer haemorrhagic complications than vitamin K antagonists while preserving the same effectiveness; and by low-dose aspirin, which has the potential to prevent the occurrence of both venous and arterial thrombotic events.

  6. 湿法超微粉碎和水煎煮提取法对鼠妇蛋白溶栓抗凝活性的影响及机制初探%Comparison of Thrombolytic and Anticoagulant Activities of Proteins of Porcellio scaber Latreille Extracted by Wet Superfine Grinding Technology and Water Decoction and Exploration of Their Mechanisms

    Institute of Scientific and Technical Information of China (English)

    田周; 李博; 郭立玮; 吴勉华; 程海波; 朱华旭

    2015-01-01

    Objective To compare the active thrombolytic and anticoagulant proteins of Porcellio scaber Latreille extracted by wet superfine grinding technology and water decoction,and to study their thrombolytic and anticoagulant mechanisms. Methods We compared the difference of the yield of extract and the protein content extracted by wet superfine grinding technology and water decoction. Fractional precipitation method with ammonium sulfate was applied to purify the active proteins. The fibrinolysis activity and the mode of fibrinolyctia action of the active proteins were measured by agarose-fibrin plate. Moreover,prothrombin time(PT),thrombin time(TT),activated partial thromboplastin time(APTT)were measured by the automatic blood agglutination instrument. The effect of temperature on the obtained active proteins was also investigated. Results There were great differences in the yield of extract and the protein content extracted by water decoction and ultra-fine pulverization in wet processing. The extract obtained by water decoction had no thrombolytic activity,but the extract obtained by ultra-fine pulverization in wet processing could stimulate the secretion of plasminogen activator and dissolve fibrin. Besides,at the range of saturation from 60%to 80%,the active proteins extract obtained by wet ultra-fine pulverization had the higher thrombolytic activity;they could also delay APTT and TT,but had no effect on PT. However, the protein extracted by water decoction had no effect on TT, PT, and APTT. Conclusion The wet superfine grinding technology can maintain maximally the active components of Porcellio scaber Latreille,and the active proteins have obvious thrombolytic activity and anticoagulant function. However,the proteins obtained by water decoction have no thrombolytic and anticoagulant activities.%目的:比较湿法超微粉碎及水煎煮提取法对鼠妇溶栓抗凝活性蛋白的影响,并探究其溶栓抗凝活性的机理。方法比较两种不同提

  7. Mechanisms of macrophage activation in obesity-induced insulin resistance

    OpenAIRE

    Odegaard, Justin I.; Chawla, Ajay

    2008-01-01

    Chronic inflammation is now recognized as a key step in the pathogenesis of obesity-induced insulin resistance and type 2 diabetes mellitus. This low-grade inflammation is mediated by the inflammatory (classical) activation of recruited and resident macrophages that populate metabolic tissues, including adipose tissue and liver. These findings have led to the concept that infiltration and activation of adipose tissue macrophages is causally linked to obesity-induced insulin resistance. Studie...

  8. Lupus anticoagulant-hypoprothrombinemia syndrome: report of two cases and review of the literature.

    Science.gov (United States)

    Mulliez, S M N; De Keyser, F; Verbist, C; Vantilborgh, A; Wijns, W; Beukinga, I; Devreese, K M J

    2015-06-01

    Lupus anticoagulant-hypoprothrombinemia syndrome (LA-HPS) is a rare acquired disorder caused by prothrombin antibodies. The disease is most common in the pediatric age group (lupus erythematosus (SLE) and viral infections. The clinical manifestation of LA-HPS varies greatly in severity and it may cause severe life-threatening bleeding diathesis. LA-HPS is to be suspected when a patient presents with bleeding and a prolonged activated partial thromboplastin and prothrombin time, in combination with a lupus anticoagulant. The diagnosis is confirmed in the laboratory by identification of reduced prothrombin levels. There are no standardized recommendations for treatment of the hemorrhage associated with the syndrome; corticosteroids are used as first-line treatment. This review summarizes what is currently known about the pathogenesis, clinical features, diagnosis, treatment and prognosis of LA-HPS, and presents two case reports.

  9. Potential role of new anticoagulants for prevention and treatment of venous thromboembolism in cancer patients

    Directory of Open Access Journals (Sweden)

    Gómez-Outes A

    2013-05-01

    and treatment of VTE include parenteral compounds for once-daily administration (ie, semuloparin or once-weekly dosing (ie, idraparinux and idrabiotaparinux, as well as orally active compounds (ie, dabigatran, rivaroxaban, apixaban, edoxaban, betrixaban. In the present review, we discuss the pharmacology of the new anticoagulants, the results of clinical trials testing these new compounds in VTE, with special emphasis on studies that included cancer patients, and their potential advantages and drawbacks compared with existing therapies.Keywords: anticoagulants, venous thromboembolism, cancer, dabigatran, apixaban, rivaroxaban

  10. [Genetic predisposition to bleeding during oral anticoagulants treatment].

    Science.gov (United States)

    Montes Díaz, R; Nantes, O; Molina, E; Zozaya, J; Hermida, J

    2008-01-01

    The degree of anticoagulation obtained during oral anticoagulation therapy with vitamin K antagonists (VKA) varies among patients due to individual and environmental factors. The rate of anticoagulation influences the hemorrhagic risk. Therefore, it is plausible that patients specially sensitive to oral anticoagulants are at higher hemorrhagic risk, specially during the first weeks. The role of a series of polymorphisms of the enzymes involved in the metabolism of VKA or in the vitamin K cycle are reviewed. Three polymorphisms, two in the cytochrome P450 2C9 and one in the VKORC1 enzyme, are responsible for a high portion of the variability observed in the sensitivity to AVK. Although the available literature suggests that these genetic variants could increase the risk of severe hemorrhage, larger, well designed studies are needed to confirm this notion.

  11. How to manage new oral anticoagulants in case of surgery

    Directory of Open Access Journals (Sweden)

    Davide Imberti

    2013-12-01

    Full Text Available When a patient receiving new oral anticoagulants (NOACs requires an invasive procedure, the consequences of bleeding if anticoagulation is continued and the risk of thrombosis if it is omitted need to be carefully considered. In addition to the bleeding risk of the procedure, it is of paramount importance to evaluate the renal function, especially for dabigatran that is eliminated predominantly via the renal pathway. NOAC therapy should be stopped for at least 24 h before the intervention, and a longer interruption should be considered in cases of high bleeding risk procedures and/or renal failure. A base-line assessment of coagulation should be performed and intervention should be postponed (if possible if high levels of anticoagulation parameters are found. In the post-surgical period, if oral anticoagulant therapy cannot be re-started, patients should temporarily receive low molecular weight heparins and re-start NOACs as soon as possible.

  12. 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

  13. Effects of computer-assisted oral anticoagulant therapy

    DEFF Research Database (Denmark)

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

    2012-01-01

    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...... in a computer system by an algorithm specific to each group. The third group received traditional anticoagulation treatment by physicians. The obtained INR values were compared regarding the time to reach, and the time spent within, the therapeutic target range, corresponding to INR values from 2 to 3. RESULTS......: 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...

  14. Eculizumab in paroxysmal nocturnal hemoglobinuria with Budd-Chiari syndrome progressing despite anticoagulation

    Directory of Open Access Journals (Sweden)

    Brodsky Andrés

    2012-09-01

    Full Text Available Abstract Paroxysmal nocturnal hemoglobinuria (PNH is a progressive, life-threatening disorder characterized by chronic intravascular hemolysis caused by uncontrolled complement activation. Hepatic vein thrombosis (Budd-Chiari syndrome is common in PNH patients. This case report describes the response to eculizumab (a humanized monoclonal antibody that inhibits terminal complement activation in a 25-year-old male with progressive liver function deterioration despite standard anticoagulation therapy and transjugular intrahepatic porto-systemic shunt. The patient presented with anemia, severe thrombocytopenia, headache, abdominal pain, and distention. He was diagnosed with PNH, cerebral vein thrombosis, and Budd-Chiari syndrome. Despite adequate anticoagulation, diuretic administration, and placement of a transjugular shunt, additional thrombotic events and progressive liver damage were observed. Eculizumab therapy was initiated, resulting in rapid blockade of intravascular hemolysis, increased platelet counts, ascites resolution, and liver function recovery, all of which are presently sustained. Since starting eculizumab the patient has had no further thrombotic events and his quality of life has dramatically improved. This is the first report to confirm the role of complement-mediated injury in the progression of Budd-Chiari syndrome in a patient with PNH. This case shows that terminal complement blockade with eculizumab can reverse progressive thromboses and hepatic failure that is unresponsive to anticoagulation therapy and suggests that early initiation of eculizumab should be included in the therapeutic regimen of patients with PNH-related Budd-Chiari syndrome.

  15. EFFECTS OF ANTICOAGULATION PROTEIN DEFECT IN MATERNAL PLASMA ON SPONTANEOUS ABORTION

    Institute of Scientific and Technical Information of China (English)

    Chun-mei Bai; Shui-qing Ma; Ming-ying Gai; Lian-kai Fan; Feng-yan Ren; Guang-sheng Fan

    2004-01-01

    Objective To investigate the mechanism of anticoagulation protein defect in the pathogenesis of unexplained recurrent miscarriage.Methods Fifty-seven patients with a history of unexplained abortion were enrolled as the investigation group for tests of protein C, protein S, antithrombin Ⅲ (AT-Ⅲ), as well as activated protein C resistance (APC-R). The control group consisted of fifty healthy women with a history of hormal pregnancy and delivery. Blood samples were obtained for measuring serum activity of protein C, protein S, AT- Ⅲ, and APC-R. Patients with positive APC-R were tested for factor Ⅴ (FV) Leiden gene mutation by PCR-RFLP method.Results Of the 57 patients, 12 (21.1%), 1 (1.8%), and 5 (8.8%) cases were found with protein S, protein C, and AT-Ⅲdeficiency respectively, and 13 (22.8%) cases with positive results of APC-R. Of the control group, no protein C or AT-Ⅲdeficiency was ever found, whereas 2 (4.0%) volunteers were presented with protein S deficiency and 3 (6.0%) with positive results of APC-R. No FV Leiden gene mutation was identified in all the patients with positive APC-R results. Late spontaneous abortion cases had higher incidence of anticoagulation protein defect than the early cases.Conclusion Anticoagulation protein defect may play a role in the pathogenesis of fetal loss, especially for those occurring in late stage of pregnancy.

  16. TRAIL-Induced Caspase Activation Is a Prerequisite for Activation of the Endoplasmic Reticulum Stress-Induced Signal Transduction Pathways.

    Science.gov (United States)

    Lee, Dae-Hee; Sung, Ki Sa; Guo, Zong Sheng; Kwon, William Taehyung; Bartlett, David L; Oh, Sang Cheul; Kwon, Yong Tae; Lee, Yong J

    2016-05-01

    It is well known that tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis can be initially triggered by surface death receptors (the extrinsic pathway) and subsequently amplified through mitochondrial dysfunction (the intrinsic pathway). However, little is known about signaling pathways activated by the TRAIL-induced endoplasmic reticulum (ER) stress response. In this study, we report that TRAIL-induced apoptosis is associated with the endoplasmic reticulum (ER) stress response. Human colorectal carcinoma HCT116 cells were treated with TRAIL and the ER stress-induced signal transduction pathway was investigated. During TRAIL treatment, expression of ER stress marker genes, in particular the BiP (binding immunoglobulin protein) gene, was increased and activation of the PERK (PKR-like ER kinase)-eIF2α (eukaryotic initiation factor 2α)-ATF4 (activating transcription factor 4)-CHOP (CCAAT-enhancer-binding protein homologous protein) apoptotic signal transduction pathway occurred. Experimental data from use of a siRNA (small interfering RNA) technique, caspase inhibitor, and caspase-3-deficient cell line revealed that TRAIL-induced caspase activation is a prerequisite for the TRAIL-induced ER stress response. TRAIL-induced ER stress was triggered by caspase-8-mediated cleavage of BAP31 (B cell receptor-associated protein 31). The involvement of the proapoptotic PERK-CHOP pathway in TRAIL-induced apoptosis was verified by using a PERK knockout (PERK(-/-)) mouse embryo fibroblast (MEF) cell line and a CHOP(-/-) MEF cell line. These results suggest that TRAIL-induced the activation of ER stress response plays a role in TRAIL-induced apoptotic death.

  17. [Bridging: Perioperative management of chronic anticoagulation or antiplatelet therapy].

    Science.gov (United States)

    Nowak-Göttl, U; Langer, F; Limperger, V; Mesters, R; Trappe, R U

    2014-06-01

    Oral anticoagulants [Vitamin-K-Antagonists, Dabigatran, Rivaroxaban, Apixaban] or antiplatelet agents [Aspirin, Clopidogrel, Prasugrel, Ticagrelor] are effective in preventing thromboembolic diseases. In case of interventional of surgical procedures patients with indications for chronic anticoagulation [atrial fibrillation, valve prosthesis, venous thromboembolism] or use of antiplatelet agents [cerebrovascular events, cardiovascular events] will require interruption of antithrombotic/antiplatelet therapy with the need of replacement with a short-acting agent. Due to limited data available from randomized studies and meta-analyses the evidence level is low in the majority of recommendations. Therefore for each patient the bleeding and thrombosis risk depending on the individual patient constitution and the planned intervention must be weighted. In patients with an intermediate risk for thrombosis the bleeding risk of the scheduled intervention will influence the bridging recommendation: In patients with a low bleeding risk oral anticoagulation/antiplatelet therapy can be continued or reduced in intensity. In patients with an intermediate or high bleeding risk along with a low thrombosis risk a temporary interruption of the anticoagulation/antiplatelet therapy is feasible. In patients with a high thrombosis and bleeding risk anticoagulation should be bridged with unfractionated heparin [renal insufficiency] or low molecular weight heparin. In the latter risk situation, inhibition of platelet function can be achieved with short-lasting GPIIb-IIIa inhibitors [Eptifibatide, Tirofiban]. Prior to intervention patients treated with the new oral anticoagulants [Dabigatran; Rivaroxaban; Apixaban] are requested to temporary interrupt the anticoagulation depending on the individual drug half-life and their renal function. Bridging therapy with heparin prior to intervention is not necessary with the new oral anticoagulants.

  18. New oral anticoagulants in patients with chronic kidney disease.

    Science.gov (United States)

    Belmar Vega, Lara; de Francisco, A L M; Bada da Silva, Jairo; Galván Espinoza, Luis; Fernández Fresnedo, Gema

    2016-12-08

    Patients with chronic kidney disease (CKD) develop bleeding and thrombotic tendencies, so the indication of anticoagulation at the onset of atrial fibrillation (AF) is complex. AF is the most common chronic cardiac arrhythmia, and thromboembolism and ischemic stroke in particular are major complications. In recent years, new oral anticoagulant drugs have been developed, and they have shown superiority over the classical AVK in preventing stroke, systemic embolism and bleeding risk, constituting an effective alternative to those resources.

  19. New oral anticoagulants in thromboembolism prevention in nonvalvular atrial fibrillation

    OpenAIRE

    Sosa Rosado, José Manuel; Médico Cardiólogo, Clínica Internacional, Lima, Perú.

    2013-01-01

    Atrial fibrillation is the most frequent cardiac arrhythmia in clinical practice. The value of anticoagulation with vitamin K antagonists like warfarin in the prevention of embolic phenomena is widely demonstrated but managing is difficult because of its known interactions with other drugs and even food. Looking for the ideal anticoagulant in the last years new antithrombotic agents have appeared and others are in advanced phases of investigation. In the current review results of new anticoag...

  20. Management of anticoagulants and antiplatelet agents during colonoscopy.

    Science.gov (United States)

    Feagins, Linda Anne

    2017-03-23

    Colonoscopy frequently is performed for patients who are taking aspirin, NSAIDs, antiplatelet agents and other anticoagulants. These colonoscopies often involve polypectomy, which can be complicated by bleeding. The risks of precipitating thromboembolic complications if anticoagulants are stopped must be weighed against the risk of postpolypectomy bleeding if these agents are continued. This article systematically reviews the management of anticoagulation during elective and emergency colonoscopy. For patients undergoing colonoscopic polypectomy, the overall of risk of postpolypectomy bleeding is less than 0.5%. Risk factors for postpolypectomy bleeding include large polyp size and anticoagulant use, especially warfarin and thienopyridines. For patients who do not stop aspirin or other NSAIDs prior to colonoscopy, the rate of postpolypectomy bleeding is not significantly different than that for patients who do not take those medications. For patients who continue thienopyridines and undergo polypectomy, the risk of delayed postpolypectomy bleeding is approximately 2.4%. Even for patients who interrupt warfarin, the risk of postpolypectomy bleeding is increased. The direct oral anticoagulants (direct thrombin inhibitors and factor Xa inhibitors) have a rapid onset and offset of action, and periprocedural bridging generally is not necessary. For the thienopyridines, warfarin and the direct oral anticoagulants, the decision to interrupt or continue these agents for endoscopy will involve considerable exercise of clinical judgment.

  1. 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

  2. Adherence to oral anticoagulant therapy in patients with atrial fibrillation. Focus on non-vitamin K antagonist oral anticoagulants

    DEFF Research Database (Denmark)

    Raparelli, Valeria; Proietti, Marco; Cangemi, Roberto;

    2017-01-01

    and persistence. A multi-level approach, including patients' preferences, factors determining physicians' prescribing habits and healthcare system infrastructure and support, is warranted to improve initiation and adherence of anticoagulants. Adherence to NOACs is paramount to achieve a clinical benefit...

  3. Regulation of Activation Induced Deaminase (AID) by Estrogen.

    Science.gov (United States)

    Pauklin, Siim

    2016-01-01

    Regulation of Activation Induced Deaminase (AID) by the hormone estrogen has important implications for understanding adaptive immune responses as well as the involvement of AID in autoimmune diseases and tumorigenesis. This chapter describes the general laboratory techniques for analyzing AID expression and activity induced by estrogen, focusing on the isolation and preparation of cells for hormone treatment and the subsequent analysis of AID responsiveness to estrogen at the RNA level and for determining the regulation of AID activity via estrogen by analyzing Ig switch circle transcripts and mutations in switch region loci.

  4. Activating PTEN by COX-2 inhibitors antagonizes radiation-induced AKT activation contributing to radiosensitization

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Zhen [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Gan, Ye-Hua, E-mail: kqyehuagan@bjmu.edu.cn [Central Laboratory, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China); Department of Oral & Maxillofacial Surgery, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081 (China)

    2015-05-01

    Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can induce radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the radiation-induced inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with radiation alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked radiation-induced increase of PTEN phosphorylation, rescued radiation-induced decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize radiation-induced AKT activation. - Highlights: • COX-2 inhibitor, celecoxib, could enhance radiosensitization. • Radiation induced PTEN inactivation (phosphorylation) and AKT activation. • COX-2 inhibitor induced PTEN expression and activation, and inactivated AKT. • COX-2 inhibitor enhanced radiosensitization through activating PTEN.

  5. Increased mortality in patients with the lupus anticoagulant: the Vienna Lupus Anticoagulant and Thrombosis Study (LATS).

    Science.gov (United States)

    Gebhart, Johanna; Posch, Florian; Koder, Silvia; Perkmann, Thomas; Quehenberger, Peter; Zoghlami, Claudia; Ay, Cihan; Pabinger, Ingrid

    2015-05-28

    Data on the clinical course of lupus anticoagulant (LA)-positive individuals with or without thrombotic manifestations or pregnancy complications are limited. To investigate mortality rates and factors that might influence mortality, we conducted a prospective observational study of LA-positive individuals. In total, 151 patients (82% female) were followed for a median of 8.2 years; 30 of the patients (20%) developed 32 thromboembolic events (15 arterial and 17 venous events) and 20 patients (13%) died. In univariable analysis, new onset of thrombosis (hazard ratio [HR] = 8.76; 95% confidence interval [CI], 3.46-22.16) was associated with adverse survival. Thrombosis remained a strong adverse prognostic factor after multivariable adjustment for age and hypertension (HR = 5.95; 95% CI, 2.43-14.95). Concomitant autoimmune diseases, anticoagulant treatment at baseline, or positivity for anticardiolipin- or anti-β2-glycoprotein I antibodies were not associated with mortality. In a relative survival analysis, our cohort of LA positives showed a persistently worse survival in comparison with an age-, sex-, and study-inclusion-year-matched Austrian reference population. The cumulative relative survival was 95.0% (95% CI, 88.5-98.8) after 5 years and 87.7% (95% CI, 76.3-95.6) after 10 years. We conclude that occurrence of a thrombotic event is associated with higher mortality in patients with LA. Consequently, the prevention of thromboembolic events in LA positives might improve survival.

  6. No influence of dabigatran anticoagulation on hemorrhagic transformation in an experimental model of ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Ferdinand Bohmann

    Full Text Available BACKGROUND: Dabigatran etexilate (DE is a new oral direct thrombin inhibitor. Clinical trials point towards a favourable risk-to-benefit profile of DE compared to warfarin. In this study, we evaluated whether hemorrhagic transformation (HT occurs after experimental stroke under DE treatment as we have shown for warfarin. METHODS: 44 male C57BL/6 mice were pretreated orally with 37.5 mg/kg DE, 75 mg/kg DE or saline and diluted thrombin time (dTT and DE plasma concentrations were monitored. Ischemic stroke was induced by transient middle cerebral artery occlusion (tMCAO for 1 h or 3 h. We assessed functional outcome and HT blood volume 24 h and 72 h after tMCAO. RESULTS: After 1 h tMCAO, HT blood volume did not differ significantly between mice pretreated with DE 37.5 mg/kg and controls (1.5±0.5 µl vs. 1.8±0.5 µl, p>0.05. After 3 h tMCAO, DE-anticoagulated mice did also not show an increase in HT, neither at the dose of 37.5 mg/kg equivalent to anticoagulant treatment in the therapeutic range (1.3±0.9 µl vs. control 2.3±0.5 µl, p>0.05 nor at 75 mg/kg, clearly representing supratherapeutic anticoagulation (1.8±0.8 µl, p>0.05. Furthermore, no significant increase in HT under continued anticoagulation with DE 75 mg/kg could be found at 72 h after tMCAO for 1 h (1.7±0.9 µl vs. control 1.6±0.4 µl, p>0.05. CONCLUSION: Our experimental data suggest that DE does not significantly increase hemorrhagic transformation after transient focal cerebral ischemia in mice. From a translational viewpoint, this indicates that a continuation of DE anticoagulation in case of an ischemic stroke might be safe, but clearly, clinical data on this question are warranted.

  7. Feedback activation of neurofibromin terminates growth factor-induced Ras activation

    OpenAIRE

    Hennig, Anne; Markwart, Robby; Wolff, Katharina; Schubert, Katja; Cui, Yan; Ian A Prior; Manuel A Esparza-Franco; Ladds, Graham; Rubio, Ignacio

    2016-01-01

    This is the final published version. It first appeared at http://biosignaling.biomedcentral.com/articles/10.1186/s12964-016-0128-z. Background Growth factors induce a characteristically short-lived Ras activation in cells emerging from quiescence. Extensive work has shown that transient as opposed to sustained Ras activation is critical for the induction of mitogenic programs. Mitogen-induced accumulation of active Ras-GTP results from increased nucleotide exchange driven by the nucleo...

  8. Cold suppresses agonist-induced activation of TRPV1.

    Science.gov (United States)

    Chung, M-K; Wang, S

    2011-09-01

    Cold therapy is frequently used to reduce pain and edema following acute injury or surgery such as tooth extraction. However, the neurobiological mechanisms of cold therapy are not completely understood. Transient receptor potential vanilloid 1 (TRPV1) is a capsaicin- and heat-gated nociceptive ion channel implicated in thermosensation and pathological pain under conditions of inflammation or injury. Although capsaicin-induced nociception, neuropeptide release, and ionic currents are suppressed by cold, it is not known if cold suppresses agonist-induced activation of recombinant TRPV1. We demonstrate that cold strongly suppressed the activation of recombinant TRPV1 by multiple agonists and capsaicin-evoked currents in trigeminal ganglia neurons under normal and phosphorylated conditions. Cold-induced suppression was partially impaired in a TRPV1 mutant that lacked heat-mediated activation and potentiation. These results suggest that cold-induced suppression of TRPV1 may share a common molecular basis with heat-induced potentiation, and that allosteric inhibition may contribute, in part, to the cold-induced suppression. We also show that combination of cold and a specific antagonist of TRPV1 can produce an additive suppression. Our results provide a mechanistic basis for cold therapy and may enhance anti-nociceptive approaches that target TRPV1 for managing pain under inflammation and tissue injury, including that from tooth extraction.

  9. Hypertension and Atrial Fibrillation: Any Change with the New Anticoagulants.

    Science.gov (United States)

    Ghiadoni, Lorenzo; Taddei, Stefano; Virdis, Agostino

    2014-01-01

    Hypertension and atrial fibrillation are the most common cardiovascular risk factors and clinically significant arrhythmia, respectively. These conditions frequently coexist and their prevalence increases rapidly with aging. Despite several different risk factors and clinical conditions predisposing to hypertension for its high prevalence in the population is still the main risk factor for the development of atrial fibrillation. Several pathophysiologic mechanisms (such as structural changes at the level of left ventricle and or atrium, neurohormonal activation, arterial stiffness, etc.) can contribute to the onset of atrial fibrillation. Some antihypertensive treatments have been shown to contribute to reduce the risk of new-onset atrial fibrillation. Atrial fibrillation is a major risk factor for stroke, which is further increased in the presence of hypertension. For this reason, hypertension is included as a major risk factor in the available models for the risk stratification and the prevention of thromboembolism in patients with atrial fibrillation. In this article we will review the relationship between atrial fibrillation and hypertension, looking at the possible specific indications of the antithrombotic treatment with new classes of anticoagulants in the prevention of thromboembolic events in hypertensive patients with atrial fibrillation.

  10. Aldehyde-induced xanthine oxidase activity in raw milk.

    Science.gov (United States)

    Steffensen, Charlotte L; Andersen, Henrik J; Nielsen, Jacob H

    2002-12-04

    In the present study, the aldehyde-induced pro-oxidative activity of xanthine oxidase was followed in an accelerated raw milk system using spin-trap electron spin resonance (ESR) spectroscopy. The aldehydes acetaldehyde, propanal, hexanal, trans-2-hexenal, trans-2-heptenal, trans-2-nonenal, and 3-methyl-2-butenal were all found to initiate radical reactions when added to milk. Formation of superoxide through aldehyde-induced xanthine oxidase activity is suggested as the initial reaction, as all tested aldehydes were shown to trigger superoxide formation in an ultrahigh temperature (UHT) milk model system with added xanthine oxidase. It was found that addition of aldehydes to milk initially increased the ascorbyl radical concentration with a subsequent decay due to ascorbate depletion, which renders the formation of superoxide in milk with added aldehyde. The present study shows for the first time potential acceleration of oxidative events in milk through aldehyde-induced xanthine oxidase activity.

  11. Mucin-like peptides from Echinococcus granulosus induce antitumor activity.

    Science.gov (United States)

    Noya, Verónica; Bay, Sylvie; Festari, María Florencia; García, Enrique P; Rodriguez, Ernesto; Chiale, Carolina; Ganneau, Christelle; Baleux, Françoise; Astrada, Soledad; Bollati-Fogolín, Mariela; Osinaga, Eduardo; Freire, Teresa

    2013-09-01

    There is substantial evidence suggesting that certain parasites can have antitumor properties. We evaluated mucin peptides derived from the helminth Echinococcus granulosus (denominated Egmuc) as potential inducers of antitumor activity. We present data showing that Egmuc peptides were capable of inducing an increase of activated NK cells in the spleen of immunized mice, a fact that was correlated with the capacity of splenocytes to mediate killing of tumor cells. We demonstrated that Egmuc peptides enhance LPS-induced maturation of dendritic cells in vitro by increasing the production of IL-12p40p70 and IL-6 and that Egmuc-treated DCs may activate NK cells, as judged by an increased expression of CD69. This evidence may contribute to the design of tumor vaccines and open new horizons in the use of parasite-derived molecules in the fight against cancer.

  12. Experimental study on the anti-platelet aggregation and anti-coagulant activity of isoliensinine%异莲心碱抗血小板聚集和抗凝血作用

    Institute of Scientific and Technical Information of China (English)

    陈灵骏; 罗顺德

    2011-01-01

    目的:探讨异莲心碱(isoliensinine,IL)对大鼠体内血小板聚集和凝血功能的影响.方法:以二磷酸腺苷(ADP)诱导血小板聚集,采用比浊法观察IL对兔体内外血小板1,3,5 min聚集率和最大聚集率的影响,同时评价IL对大鼠凝血酶原时间(PT)、活化部分凝血激酶时间(APTT)及凝血酶时间(TT)的影响.结果:IL4 mg·L-1和8 mg·L-1能显著抑制ADP诱导的兔体外血小板1,3,5 min聚集率和最大聚集率,其抑制率为14.4%和27.9%;IL5 mg·kg-1和10 mg·kg-1能显著抑制ADP诱导的兔体内血小板1,3,5 min聚集率和最大聚集率,其抑制率为20.0%和32.6%; IL能显著延长大鼠PT,APTT和TT.结论:IL具有对抗血小板聚集和凝血作用.%OBJECTIVE To investigate the inhibitory effects of isoliensinine on platelet aggregation in rabbits and coagulation function in rats. METHODS Inhibition rates of platelet aggregation for isoliensinine in vivo and vitro were determined by the model of platelet aggregation induced by adenosine diphosphate. The effects of isoliensinine were also evaluated on pro-thrombin time (PT) , activated partial thromboplastin time (APTT) and thrombin time (TT). RESULTS Isoliensinine inhibited platelet aggregation in vitro at the concentration of 4 and 8 mg·L-1 , inhibition rates were 14. 4% and 27. 9%. Isoliensinine inhibited platelet aggregation in vivo at the concentration of 5 and 10 mg·kg-1 , inhibition rates were 20. 0% and 32. 6%. Isoliensinine also markedly prolonged PT, APTT and TT also. CONCLUSION Isoliensinine exerted remarkable effects against platelet aggregation and coagulation in animal study.

  13. Borrelia burgdorferi Spirochetes Induce Mast Cell Activation and Cytokine Release

    Science.gov (United States)

    Talkington, Jeffrey; Nickell, Steven P.

    1999-01-01

    The Lyme disease spirochete, Borrelia burgdorferi, is introduced into human hosts via tick bites. Among the cell types present in the skin which may initially contact spirochetes are mast cells. Since spirochetes are known to activate a variety of cell types in vitro, we tested whether B. burgdorferi spirochetes could activate mast cells. We report here that freshly isolated rat peritoneal mast cells or mouse MC/9 mast cells cultured in vitro with live or freeze-thawed B. burgdorferi spirochetes undergo low but detectable degranulation, as measured by [5-3H] hydroxytryptamine release, and they synthesize and secrete the proinflammatory cytokine tumor necrosis factor alpha (TNF-α). In contrast to findings in previous studies, where B. burgdorferi-associated activity was shown to be dependent upon protein lipidation, mast cell TNF-α release was not induced by either lipidated or unlipidated recombinant OspA. This activity was additionally shown to be protease sensitive and surface expressed. Finally, comparisons of TNF-α-inducing activity in known low-, intermediate-, and high-passage B. burgdorferi B31 isolates demonstrated passage-dependent loss of activity, indicating that the activity is probably plasmid encoded. These findings document the presence in low-passage B. burgdorferi spirochetes of a novel lipidation-independent activity capable of inducing cytokine release from host cells. PMID:10024550

  14. Proteases induce secretion of collagenase and plasminogen activator by fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Werb, Z.; Aggeler, J.

    1978-04-01

    We have observed that treatment of rabbit synovial fibroblasts with proteolytic enzymes can induce secretion of collagenase (EC 3.4.24.7) and plasminogen activator (EC 3.4.21.-). Cells treated for 2 to 24 hr with plasmin, trypsin, chymotrypsin, pancreatic elastase, papain, bromelain, thermolysin, or ..cap alpha..-protease but not with thrombin or neuraminidase secreted detectable amounts of collagenase within 16 to 48 hr. Treatment of fibroblasts with trypsin also induced secretion of plasminogen activator. Proteases initiated secretion of collagenase (up to 20 units per 10/sup 6/ cells per 24 hr) only when treatment produced decreased cell adhesion. Collagenase production did not depend on continued presence of proteolytic activity or on subsequent cell adhesion, spreading, or proliferation. Routine subculturing with crude trypsin also induced collagenase secretion by cells. Secretion of collagenase was prevented and normal spreading was obtained if the trypsinized cells were placed into medium containing fetal calf serum. Soybean trypsin inhibitor, ..cap alpha../sub 1/-antitrypsin, bovine serum albumin, collagen, and fibronectin did not inhibit collagenase production. Although proteases that induced collagenase secretion also removed surface glycoprotein, the kinetics of induction of cell protease secretion were different from those for removal of fibronectin. Physiological inducers of secretion of collagenase and plasminogen activator by cells have not been identified. These results suggest that extracellular proteases in conjunction with plasma proteins may govern protease secretion by cells.

  15. Low-dose effect of ethanol on locomotor activity induced by activation of the mesolimbic system.

    Science.gov (United States)

    Milton, G V; Randall, P K; Erickson, C K

    1995-06-01

    Four experiments were designed to study the ability of 0.5 g/kg ethanol (EtOH) intraperitoneally to modify locomotor activity induced by drugs that interact with different sites in the mesolimbic system (MLS) of male Sprague-Dawley rats. Locomotor activity was measured in a doughnut-shaped circular arena after various treatments. EtOH alone did not alter locomotor activity in any of the experiments. Amphetamine (AMP, intraperitoneally or intraaccumbens) increased locomotor activity in a dose-dependent manner, and the presence of EtOH attenuated AMP-induced locomotor activity. Bilateral infusion of GABAA antagonist picrotoxin (PIC) into the ventral tegmental area also increased locomotor activity in a dose-dependent manner, and the presence of EtOH attenuated PIC-induced locomotor activity. On the other hand, the interaction between bilateral infusion of mu-receptor agonist Tyr-D-Ala-Gly-NMe-Phe-Gly-ol (DAGO) and EtOH on locomotor activity is complex. The highest dose of DAGO that significantly increased locomotor activity was not affected by the presence of EtOH. But, with lower doses of DAGO that either had no effect or a small increase in locomotor activity, the combination of EtOH and DAGO increased and attenuated locomotor activity, respectively. Results from this study support our hypothesis that a low dose of EtOH that does not modify behavior can interact with neurotransmitter systems in the brain and modify drug-induced locomotor activity. Modification of this drug-induced locomotor activity by a low dose of EtOH is dependent on the rate of ongoing locomotor behavior induced by drug and the neurotransmitter substrate that the drug modified to induce locomotor behavior.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Factors Affecting Patients' Perception On, and Adherence To, Anticoagulant Therapy: Anticipating the Role of Direct Oral Anticoagulants.

    Science.gov (United States)

    Pandya, Ekta Y; Bajorek, Beata

    2017-04-01

    The role of the direct oral anticoagulants (DOACs) in practice has been given extensive consideration recently, albeit largely from the clinician's perspective. However, the effectiveness and safety of using anticoagulants is highly dependent on the patient's ability to manage and take these complex, high-risk medicines. This structured narrative review explores the published literature to identify the factors underpinning patients' non-adherence to anticoagulants in atrial fibrillation (AF), and subsequently contemplates to what extent the DOACs might overcome the known challenges with traditional warfarin therapy. This review comprised a two-tier search of various databases and search platforms (CINAHL, Cochrane, Current Contents Connect, EMBASE, MEDLINE Ovid, EBSCO, PubMed, Google, Google Scholar) to yield 47 articles reporting patients perspectives on, and patients adherence to, anticoagulant therapy. The findings from the literature were synthesised under five interacting dimensions of adherence: therapy-related factors, patient-related factors, condition-related factors, social-economic factors and health system factors. Factors negatively affecting patients' day-to-day lives (especially regular therapeutic drug monitoring, dose adjustments, dietary considerations) predominantly underpin a patient's reluctance to take warfarin therapy, leading to non-adherence. Other patient-related factors underpinning non-adherence include patients' perceptions and knowledge about the purpose of anticoagulation; understanding of the risks and benefits of therapy; socioeconomic status; and expectations of care from health professionals. In considering these findings, it is apparent that the DOACs may overcome some of the barriers to traditional warfarin therapy at least to an extent, particularly the need for regular monitoring, frequent dose adjustment and dietary considerations. However, their high cost, twice-daily dosing and gastrointestinal adverse effects may present

  17. New oral anticoagulants and their implications for dental patients.

    Science.gov (United States)

    O'Connell, John Edward; Stassen, Leo F A

    2014-01-01

    Anticoagulation therapy is used in several conditions to prevent or treat thromboembolism. Over the last 40 years, warfarin has been the oral anticoagulant of choice and has been considered the mainstay of treatment. However, its use is limited by a narrow therapeutic index and complex pharmacodynamics, necessitating regular monitoring and dose adjustments. Recently, two new oral anticoagulants--dabigatran etexilate (a direct thrombin inhibitor) and rivaroxiban (a factor Xa inhibitor)--have been approved for use in North America and Europe. Unlike warfarin, dabigatran and rivaroxiban are relatively small molecules that work as anticoagulants by targeting specific single steps of the coagulation cascade. Their advantages, relative to warfarin, include: predictable pharmacokinetics; limited food and drug interactions; rapid onset of action; and, short half-life. They require no monitoring. However, they lack a specific reversal agent. The number of patients taking dabigatran and rivaroxaban is increasing. Therefore, it is inevitable that dentists will be required to perform invasive procedures on this cohort of patients. This paper outlines the various properties of the new oral anticoagulants and the most recent guidelines regarding the management of these dental patients taking these medications.

  18. Dental procedures in patients receiving oral anticoagulation therapy.

    Science.gov (United States)

    Saour, J N; Ali, H A; Mammo, L A; Sieck, J O

    1994-05-01

    Over a 10-year period a uniform management plan for patients receiving long term oral anticoagulation therapy for prosthetic heart valves and needing dental procedures was instituted. Those undergoing dental extraction or gum hygiene in the presence of gross gum pathology (Group A) had their oral anticoagulation discontinued two days prior to the procedure which was carried out only if the INR was 1.5 or less on the day of the procedure. Patients who needed dental fillings or gum hygiene in the absence of gross gum pathology (Group B) continued their anticoagulation therapy and had these procedures completed provided the INR was 3.0 or less. The main outcome measured were valve thrombosis, thromboembolism and excessive bleeding requiring hospitalization and/or blood transfusion. In Group A, 240 procedures were carried out; 212 dental extractions and 28 dental hygiene in the presence of gross gum pathology. They had a brief period of under-anticoagulation (3-7 days) to an INR of 1.5 or less. In Group B, 156 procedures were performed. No patient developed valve thrombosis or thromboembolism. Two patients, both in Group A needed hospitalization for observation but no blood transfusion. This management plan was easy to implement. Patients needed one extra visit to the anticoagulation clinic within one week of the procedure. It was both safe and effective.

  19. Management of major bleedings during anticoagulant treatment with the oral direct thrombin inhibitor ximelagatran or warfarin.

    Science.gov (United States)

    Fernlöf, Gunilla; Sjöström, Britta M; Lindell, Klas M; Wall, Ulrika E

    2009-12-01

    Several new oral anticoagulants are currently investigated in phase III programmes, mainly with inhibition of factor Xa or thrombin as their pharmacological target. Advantages are expected with these new drugs compared with vitamin K antagonists, but one potential drawback is the lack of specific antidotes. During the clinical studies with ximelagatran, an oral direct thrombin inhibitor withdrawn due to hepatic side effects, investigators were instructed to manage bleedings with routine measures. We have retrospectively tried to assess whether this was sufficient or whether there was a need for reversal strategies. The study population consisted of patients with major bleedings in three long-term studies (104 ximelagatran, 155 warfarin). All individual patient narratives were reviewed with respect to management of the bleeding. Complementary data were retrieved from the data-based case report forms. Approximately, two of three of the patients in both groups were subject to some kind of treatment. One-third (1/3) in both groups had transfusions documented and/or received specific medication. Vitamin K was given more often to warfarin patients. Two ximelagatran patients received prothrombin complex (four-factor concentrate), but one was a patient with a severe hepatopathy suspected to be drug-induced. Overall, the case descriptions did not reveal any apparent differences in the course of events between groups. We found no indications that the lack of an antidote posed a clinical problem in patients treated with ximelagatran as compared with warfarin. The relatively short half-life of melagatran, the active metabolite of ximelagatran, may have contributed to these results.

  20. Protamine sulfate down-regulates thrombin generation by inhibiting factor V activation.

    LENUS (Irish Health Repository)

    Ni Ainle, Fionnuala

    2009-08-20

    Protamine sulfate is a positively charged polypeptide widely used to reverse heparin-induced anticoagulation. Paradoxically, prospective randomized trials have shown that protamine administration for heparin neutralization is associated with increased bleeding, particularly after cardiothoracic surgery with cardiopulmonary bypass. The molecular mechanism(s) through which protamine mediates this anticoagulant effect has not been defined. In vivo administration of pharmacologic doses of protamine to BALB\\/c mice significantly reduced plasma thrombin generation and prolonged tail-bleeding time (from 120 to 199 seconds). Similarly, in pooled normal human plasma, protamine caused significant dose-dependent prolongations of both prothrombin time and activated partial thromboplastin time. Protamine also markedly attenuated tissue factor-initiated thrombin generation in human plasma, causing a significant decrease in endogenous thrombin potential (41% +\\/- 7%). As expected, low-dose protamine effectively reversed the anticoagulant activity of unfractionated heparin in plasma. However, elevated protamine concentrations were associated with progressive dose-dependent reduction in thrombin generation. To assess the mechanism by which protamine mediates down-regulation of thrombin generation, the effect of protamine on factor V activation was assessed. Protamine was found to significantly reduce the rate of factor V activation by both thrombin and factor Xa. Protamine mediates its anticoagulant activity in plasma by down-regulation of thrombin generation via a novel mechanism, specifically inhibition of factor V activation.

  1. Activation-induced force enhancement in human adductor pollicis.

    Science.gov (United States)

    Oskouei, Ali E; Herzog, Walter

    2009-10-01

    It has been known for a long time that the steady-state isometric force after muscle stretch is bigger than the corresponding force obtained in a purely isometric contraction for electrically stimulated and maximal voluntary contractions (MVC). Recent studies using sub-maximal voluntary contractions showed that force enhancement only occurred in a sub-group of subjects suggesting that force enhancement for sub-maximal voluntary contractions has properties different from those of electrically-induced and maximal voluntary contractions. Specifically, force enhancement for sub-maximal voluntary contractions may contain an activation-dependent component that is independent of muscle stretching. To address this hypothesis, we tested for force enhancement using (i) sub-maximal electrically-induced contractions and stretch and (ii) using various activation levels preceding an isometric reference contraction at 30% of MVC (no stretch). All tests were performed on human adductor pollicis muscles. Force enhancement following stretching was found for all subjects (n=10) and all activation levels (10%, 30%, and 60% of MVC) for electrically-induced contractions. In contrast, force enhancement at 30% of MVC, preceded by 6s of 10%, 60%, and 100% of MVC was only found in a sub-set of the subjects and only for the 60% and 100% conditions. This result suggests that there is an activation-dependent force enhancement for some subjects for sub-maximal voluntary contractions. This activation-dependent force enhancement was always smaller than the stretch-induced force enhancement obtained at the corresponding activation levels. Active muscle stretching increased the force enhancement in all subjects, independent whether they showed activation dependence or not. It appears that post-activation potentiation, and the associated phosphorylation of the myosin light chains, might account for the stretch-independent force enhancement observed here.

  2. Antidiabetic activity of Rheum emodi in Alloxan induced diabetic rats.

    Directory of Open Access Journals (Sweden)

    Radhika.R

    2010-09-01

    Full Text Available The present study was carried out to evaluate the antidiabetic effect of Rheum emodi rhizome extract and to study the activities of hexokinase, aldolase and phosphoglucoisomerase, and gluconeogenic enzymes such as glucose-6- phosphatase and fructose 1,6-diphosphatase in liver and kidney of normal and alloxan induced diabetic rats. Oral administration of 75 % ethanolic extract of R. emodi (250 mg/kg body weight for 30 days, resulted in decrease inthe activities of glucose-6-phosphatase, fructose-1,6-disphosphatase, aldolase and an increase in the activity of phosphoglucoisomerase and hexokinase in tissues. The study clearly shows that the R.emodi possesses antidiabetic activity.

  3. Induced starburst and nuclear activity: Faith, facts, and theory

    Science.gov (United States)

    Shlosman, Isaac

    1990-01-01

    The problem of the origin of starburst and nuclear (nonstellar) activity in galaxies is reviewed. A physical understanding of the mechanism(s) that induce both types of activity requires one to address the following issues: (1) what is the source of fuel that powers starbursts and active galactic nuclei; and (2) how is it channeled towards the central regions of host galaxies? As a possible clue, the author examines the role of non-axisymmetric perturbations of galactic disks and analyzes their potential triggers. Global gravitational instabilities in the gas on scales approx. 100 pc appear to be crucial for fueling the active galactic nuclei.

  4. Antiplatelet and anticoagulant therapy for atherothrombotic disease: the role of current and emerging agents.

    Science.gov (United States)

    Angiolillo, Dominick J; Ferreiro, José Luis

    2013-08-01

    Coronary atherothrombotic disease, including chronic stable angina and acute coronary syndromes (ACS), is associated with significant global burden. The acute clinical manifestations of atherothrombotic disease are mediated by occlusive arterial thrombi that impair tissue perfusion and are composed of a core of aggregated platelets, generated by platelet activation, and a superimposed fibrin mesh produced by the coagulation cascade. Long-term antithrombotic therapies, namely oral antiplatelet agents and anticoagulants, have demonstrated variable clinical effects. Aspirin and P2Y12 adenosine diphosphate (ADP) receptor antagonists have been shown to reduce the risk for thrombosis and ischaemic events by blocking the thromboxane (Tx) A2 and platelet P2Y12 activation pathways, respectively, whereas the benefits of oral anticoagulants have not been consistently documented. However, even in the presence of aspirin and a P2Y12 receptor antagonist, the risk for ischaemic events remains substantial because platelet activation continues via pathways independent of TxA2 and ADP, most notably the protease-activated receptor (PAR)-1 platelet activation pathway stimulated by thrombin. Emerging antithrombotic therapies include those targeting the platelet, such as the new P2Y12 antagonists and a novel class of oral PAR-1 antagonists, and those inhibiting the coagulation cascade, such as the new direct factor Xa antagonists, the direct thrombin inhibitors, and a novel class of factor IX inhibitors. The role of emerging antiplatelet agents and anticoagulants in the long-term management of patients with atherothrombotic disease will be determined by the balance of efficacy and safety in large ongoing clinical trials.

  5. 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

  6. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, L.P.; Winther, A.; Dyhre-Poulsen, P.

    2009-01-01

    muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper...... in a way that protects the painful structure. Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load on the painful structures Udgivelsesdato: 2009/4...

  7. The influence of experimentally induced pain on shoulder muscle activity

    DEFF Research Database (Denmark)

    Diederichsen, Louise Pyndt; Winther, Annika; Dyhre-Poulsen, Poul

    2009-01-01

    . EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius...... the painful structure. Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load on the painful structures....

  8. Enhanced surface plasmon polariton propagation induced by active dielectrics

    OpenAIRE

    Athanasopoulos, C.; Mattheakis, M.; Tsironis, G. P.

    2013-01-01

    We present numerical simulations for the propagation of surface plasmon polaritons in a dielectric-metal-dielectric waveguide using COMSOL multiphysics software. We show that the use of an active dielectric with gain that compensates metal absorption losses enhances substantially plasmon propagation. Furthermore, the introduction of the active material induces, for a specific gain value, a root in the imaginary part of the propagation constant leading to infinite propagation of the surface pl...

  9. Nonpathogenic, environmental fungi induce activation and degranulation of human eosinophils.

    Science.gov (United States)

    Inoue, Yoshinari; Matsuwaki, Yoshinori; Shin, Seung-Heon; Ponikau, Jens U; Kita, Hirohito

    2005-10-15

    Eosinophils and their products are probably important in the pathophysiology of allergic diseases, such as bronchial asthma, and in host immunity to certain organisms. An association between environmental fungal exposure and asthma has been long recognized clinically. Although products of microorganisms (e.g., lipopolysaccharides) directly activate certain inflammatory cells (e.g., macrophages), the mechanism(s) that triggers eosinophil degranulation is unknown. In this study we investigated whether human eosinophils have an innate immune response to certain fungal organisms. We incubated human eosinophils with extracts from seven environmental airborne fungi (Alternaria alternata, Aspergillus versicolor, Bipolaris sorokiniana, Candida albicans, Cladosporium herbarum, Curvularia spicifera, and Penicillium notatum). Alternaria and Penicillium induced calcium-dependent exocytosis (e.g., eosinophil-derived neurotoxin release) in eosinophils from normal individuals. Alternaria also strongly induced other activation events in eosinophils, including increases in intracellular calcium concentration, cell surface expression of CD63 and CD11b, and production of IL-8. Other fungi did not induce eosinophil degranulation, and Alternaria did not induce neutrophil activation, suggesting specificity for fungal species and cell type. The Alternaria-induced eosinophil degranulation was pertussis toxin sensitive and desensitized by preincubating cells with G protein-coupled receptor agonists, platelet-activating factor, or FMLP. The eosinophil-stimulating activity in Alternaria extract was highly heat labile and had an M(r) of approximately 60 kDa. Thus, eosinophils, but not neutrophils, possess G protein-dependent cellular activation machinery that directly responds to an Alternaria protein product(s). This innate response by eosinophils to certain environmental fungi may be important in host defense and in the exacerbation of inflammation in asthma and allergic diseases.

  10. Lotus hairy roots expressing inducible arginine decarboxylase activity.

    Science.gov (United States)

    Chiesa, María A; Ruiz, Oscar A; Sánchez, Diego H

    2004-05-01

    Biotechnological uses of plant cell-tissue culture usually rely on constitutive transgene expression. However, such expression of transgenes may not always be desirable. In those cases, the use of an inducible promoter could be an alternative approach. To test this hypothesis, we developed two binary vectors harboring a stress-inducible promoter from Arabidopsis thaliana, driving the beta-glucuronidase reporter gene and the oat arginine decarboxylase. Transgenic hairy roots of Lotus corniculatus were obtained with osmotic- and cold-inducible beta-glucuronidase and arginine decarboxylase activities. The increase in the activity of the latter was accompanied by a significant rise in total free polyamines level. Through an organogenesis process, we obtained L. corniculatus transgenic plants avoiding deleterious phenotypes frequently associated with the constitutive over-expression of arginine decarboxylation and putrescine accumulation.

  11. Thrombotic and hemorrhagic complications in children with the lupus anticoagulant.

    Science.gov (United States)

    Bernstein, M L; Salusinsky-Sternbach, M; Bellefleur, M; Esseltine, D W

    1984-12-01

    Endogenous circulating anticoagulants are unusual in children without a congenital factor deficiency. In particular, the lupus anticoagulant has only rarely been reported in children. Despite its functioning in vitro to prolong the partial thromboplastin time, patients more frequently have problems with thrombosis than bleeding, unless there is a coexistent prothrombin deficiency or thrombocytopenia. We report the cases of three children with the lupus anticoagulant. Two children had associated thromboses. One had a thrombosis of the iliofemoral system and the other had a partial Budd-Chiari syndrome, a thrombosis of the deep calf veins and ureteric obstruction. The third child had a concomitant prothrombin deficiency and bleeding after tooth extraction. Associated findings in these patients included a positive antinuclear antibody test in two, a positive anti-DNA antibody test in two, a false-positive VDRL test in two, and an antiphospholipid antibody test in two.

  12. Nonhemostatic adverse effects of anticoagulants and antiplatelet agents.

    Science.gov (United States)

    Walenga, Jeanine M; Thethi, Indermohan; Lewis, Bruce E

    2012-11-01

    The topic of adverse effects of drugs is now receiving due attention in both the lay and medical communities. For drugs of the coagulation disorder class, such as anticoagulants and antiplatelet agents, the obvious adverse effects are bleeding from a dose too high and thrombosis from a dose too low. However, these drugs have other potential adverse effects that are not directly related to blood coagulation, yet cannot be dismissed due to their medical importance. There has been a recent advancement of several new drugs in this category and this number will soon grow as more drugs are reaching the end of their clinical trials. This article will discuss the nonhemostatic adverse effects of anticoagulants and antiplatelet drugs. As the adverse effects of bleeding and thrombosis will be excluded, this article will be in contrast to the typical discussions on the anticoagulant and antiplatelet drug classes.

  13. Prosthetic valve endocarditis 1976-1987. Antibiotics, anticoagulation, and stroke.

    Science.gov (United States)

    Davenport, J; Hart, R G

    1990-07-01

    We retrospectively reviewed the clinical characteristics and outcomes of 61 patients with 62 episodes of prosthetic valve endocarditis, paying particular attention to neurologic complications (stroke). Atypical features of the group included a benign outcome of early postoperative infection (18% mortality) and a high stroke morbidity and mortality rate with Staphylococcus epidermidis infections. Eleven patients (18%) suffered an embolic stroke, most less than or equal to 3 days after diagnosis and before the initiation of antimicrobial therapy; the rate of embolic stroke recurrence was low (9%). The risk of embolic stroke was lower with bioprosthetic than with mechanical valves. No protective effect of anticoagulation therapy with warfarin was observed. Six patients (8%) suffered brain hemorrhage due to septic arteritis, brain infarction, or undetermined causes; no specific risk of hemorrhagic stroke was evident with anticoagulation therapy. Antibiotic treatment appears to be more important than anticoagulation to prevent neurologic complications in patients with prosthetic valve endocarditis.

  14. NEW ORAL ANTICOAGULANTS IN THE THERAPY OF ANTIPHOSPHOLIPID SYNDROME

    Directory of Open Access Journals (Sweden)

    M. A. Satybaldyeva

    2016-01-01

    Full Text Available The vitamin K antagonist warfarin is an essential medicine from a group of anticoagulants, which is used to treat antiphospholipid syndrome (APS. However, it has a number of disadvantages especially in patients who need longterm and frequently lifetime prevention of thromboses. New oral anticoagulants, such as dabigatran etexilate (Pradaxa®, rivaroxaban (Xarelto®, apixaban (Eliquis and others, have been recently synthesized. Unlike warfarin, they are administered at fixed doses, require neither routine monitoring nor diet, and interact with drugs only in small amounts. The new oral anticoagulants have been approved for certain indications, but the data of performed trials are inapplicable to patients with APS. These medicines are expected to improve quality of life in patients with this condition. 

  15. Early autophagy activation inhibits podocytes from apoptosis induced by aldosterone

    Institute of Scientific and Technical Information of China (English)

    王文琰

    2013-01-01

    Objective To explore the protection of early autoph-agy activation on podocyte injury induced by aldosterone.Methods In vitro cultured mouse podocyte clones(MPC5) were treated with aldosterone for 6,12,24,48 hrespectively. Apoptosis of podocytes was detected by

  16. Caspase-9 mediates Puma activation in UCN-01-induced apoptosis.

    Science.gov (United States)

    Nie, C; Luo, Y; Zhao, X; Luo, N; Tong, A; Liu, X; Yuan, Z; Wang, C; Wei, Y

    2014-10-30

    The protein kinase inhibitor 7-hydroxystaurosporine (UCN-01) is one of the most potent and frequently used proapoptotic stimuli. The BH3-only molecule of Bcl-2 family proteins has been reported to contribute to UCN-01-induced apoptosis. Here we have found that UCN-01 triggers Puma-induced mitochondrial apoptosis pathway. Our data confirmed that Akt-FoxO3a pathway mediated Puma activation. Importantly, we elucidate the detailed mechanisms of Puma-induced apoptosis. Our data have also demonstrated that caspase-9 is a decisive molecule of Puma induction after UCN-01 treatment. Caspase-9 mediates apoptosis through two kinds of feedback loops. On the one hand, caspase-9 enhances Puma activation by cleaving Bcl-2 and Bcl-xL independent of caspase-3. On the other hand, caspase-9 directly activated caspase-3 in the presence of caspase-3. Caspase-3 could cleave XIAP in an another positive feedback loop to further sensitize cancer cells to UCN-01-induced apoptosis. Therefore, caspase-9 mediates Puma activation to determine the threshold for overcoming chemoresistance in cancer cells.

  17. Relationship between ascorbyl radical intensity and apoptosis-inducing activity.

    Science.gov (United States)

    Sakagami, H; Satoh, K; Ohata, H; Takahashi, H; Yoshida, H; Iida, M; Kuribayashi, N; Sakagami, T; Momose, K; Takeda, M

    1996-01-01

    Ascorbic acid and its related compounds were compared for their ascorbyl radical intensity and apoptosis-inducing activity. Sodium L-ascorbate, L-ascorbic acid, D-isoascorbic acid, sodium 6-beta-O-galactosyl-L-ascorbate and sodium 5,6-benzylidene-L-ascorbate, at the concentration of 1-10 mM, induced apoptotic cell death characterized by cell shrinkage, nuclear fragmentation and internucleosomal DNA cleavage in human promyelocytic leukemic HL-60 cells. On the other hand, L-ascorbic acid-2-phosphate magnesium salt and L-ascorbic acid 2-sulfate did not induce any of these apoptosis-associated characteristics. ESR measurements revealed that all the active compounds were progressively degraded, producing the ascorbyl radical (g = 2.0064, hfc = 0.17 mT) in culture medium, whereas the inactive compounds were stable and did not produce the ascorbyl radical. Cytotoxicity began to appear when the radical intensity exceeded a certain threshold level. In the presence of N-acetyl-L-cysteine, both ascorbyl radical intensity and apoptosis-inducing activity were significantly reduced. These data suggest the possible involvement of the ascorbyl radical in apoptosis induction by ascorbic acid-related compounds. Exposure of HL-60 cells to ascorbic acid or its active derivatives resulted in the rapid elevation of intracellular Ca2+ concentration, which might serve as the initial signal leading to the cell death pathway.

  18. [New pharmaceuticals in cardiology. Heart failure, anticoagulation, dyslipidemia].

    Science.gov (United States)

    Czepluch, F S; Hasenfuß, G; Jacobshagen, C

    2014-04-01

    Three innovative pharmaceuticals which might play an important role in the field of cardiology in the near future were recently tested in large clinical studies. Serelaxin, a vasoactive hormone peptide that is produced during pregnancy, reduces vessel resistance, increases cardiac output, and improves renal function. Lately, it was demonstrated that serelaxin significantly reduces congestion symptoms in patients with acute heart failure. As a secondary endpoint the mortality at day 180 was reduced. Therefore, serelaxin seems to be a promising new drug for the treatment of acute heart failure which might have a prognostic impact. Edoxaban is a selective factor Xa inhibitor, which inhibits thrombin production and thrombus formation. Two recently published studies reported that edoxaban is at least as effective as the vitamin K antagonist warfarin in prevention and treatment of venous thromboembolism and in the prevention of stroke and systemic embolism due to nonvalvular atrial fibrillation. Compared to warfarin, edoxaban significantly exhibited less frequent severe bleeding complications. Edoxaban will probably soon be the fourth new oral anticoagulant available for patients. The serine protease proprotein convertase subtilisin/kexin 9 (PCSK9) reduces the ability of the liver to bind low-density lipoprotein cholesterol (LDL-C) and to remove it from the circulation. Recently, a monoclonal antibody for PCSK9 was developed which induces a LDL-C plasma level reduction up to 73 % and also decreases lipoprotein(a) and apolipoprotein B. PCSK9 inhibition is a promising new mechanism for LDL-C reduction and the corresponding drug will be presumably approved soon by the regulatory authorities.

  19. Evaluating the impact of new anticoagulants in the hospital setting

    Directory of Open Access Journals (Sweden)

    Braidy N

    2011-03-01

    Full Text Available The short-comings of current anticoagulants have led to the development of newer, albeit more expensive, oral alternatives.Objective: To explore the potential impact the new anticoagulants dabigatran and rivaroxaban in the local hospital setting, in terms of utilisation and subsequent costing.Method: A preliminary costing analysis was performed based on a prospective 2-week clinical audit (29th June - 13th July 2009. Data regarding current anticoagulation management were extracted from the medical files of patients admitted to Ryde Hospital. To model potential costing implications of using the newer agents, the reported incidence of VTE/stroke and bleeding events were obtained from key clinical trials.Results: Data were collected for 67 patients treated with either warfarin (n=46 or enoxaparin (n=21 for prophylaxis of VTE/stroke. At least two-thirds of all patients were deemed suitable candidates for the use of newer oral anticoagulants (by current therapy: warfarin: 65.2% (AF, 34.8% (VTE; enoxaparin: 100%, (VTE. The use of dabigatran in VTE/stroke prevention was found to be more cost-effective than warfarin and enoxaparin due to significantly lower costs of therapeutic monitoring and reduced administration costs. Rivaroxaban was more cost-effective than warfarin and enoxaparin for VTE/stroke prevention when supplier-rebates (33% were factored into costing.Conclusion: This study highlights the potential cost-effectiveness of newer anticoagulants, dabigatran and rivaroxaban, compared to warfarin and enoxaparin. These agents may offer economic advantages, as well as clinical benefits, in the hospital-based management of anticoagulated patients.

  20. Personalized antiplatelet and anticoagulation therapy: applications and significance of pharmacogenomics

    Directory of Open Access Journals (Sweden)

    Beitelshees AL

    2015-02-01

    Full Text Available Amber L Beitelshees,1,* Deepak Voora,2,* Joshua P Lewis,1,* 1Program for Personalized and Genomic Medicine and Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD, USA; 2Center for Applied Genomics & Precision Medicine, Department of Medicine, Duke School of Medicine, Durham, NC, USA*All authors contributed equally to this work Abstract: In recent years, substantial effort has been made to better understand the influence of genetic factors on the efficacy and safety of numerous medications. These investigations suggest that the use of pharmacogenetic data to inform physician decision-making has great potential to enhance patient care by reducing on-treatment clinical events, adverse drug reactions, and health care-related costs. In fact, integration of such information into the clinical setting may be particularly applicable for antiplatelet and anticoagulation therapeutics, given the increasing body of evidence implicating genetic variation in variable drug response. In this review, we summarize currently available pharmacogenetic information for the most commonly used antiplatelet (ie, clopidogrel and aspirin and anticoagulation (ie, warfarin medications. Furthermore, we highlight the currently known role of genetic variability in response to next-generation antiplatelet (prasugrel and ticagrelor and anticoagulant (dabigatran agents. While compelling evidence suggests that genetic variants are important determinants of antiplatelet and anticoagulation therapy response, significant barriers to clinical implementation of pharmacogenetic testing exist and are described herein. In addition, we briefly discuss development of new diagnostic targets and therapeutic strategies as well as implications for enhanced patient care. In conclusion, pharmacogenetic testing can provide important information to assist clinicians with prescribing the most personalized and effective antiplatelet and

  1. Combined aspirin and anticoagulant therapy in patients with atrial fibrillation.

    Science.gov (United States)

    So, Charlotte H; Eckman, Mark H

    2017-01-01

    The combined use of aspirin and oral anticoagulant therapy in patients with atrial fibrillation (AF) and stable coronary artery disease (CAD) has been questioned due to an increased risk of major bleeding with little to no benefit in preventing ischemic events. (1) To better understand patterns and indications for combined antiplatelet and anticoagulant therapy and identify patients who might reasonably be treated with oral anticoagulant (OAC) therapy alone. (2) To perform an updated literature review regarding the use of combined antiplatelet and OAC therapy in patients with AF and stable CAD. Retrospective review. Patients within the University of Cincinnati Health System with a diagnosis of non-valvular AF, excluding those with acute coronary syndrome or revascularization within the last 12 months. Numbers and indications for combined antiplatelet and anticoagulant therapy and sequence of events leading to the initiation of each. Of 948 patients receiving OAC, 430 (45 %) were receiving concomitant OAC and aspirin. Among patients receiving combined antiplatelet and anticoagulant therapy, 49 and 42 % of patients respectively, had CAD or DM. In a more detailed analysis including chart review of 219 patients receiving combined OAC and aspirin, 27 % had a diagnosis of CAD and 14 % had a diagnosis of DM prior to the development of AF. These patients were initially treated with aspirin. Warfarin was added when they subsequently developed AF but aspirin wasn't discontinued. A surprisingly large proportion of patients (22.8 %) had no obvious indication for dual therapy. Prior myocardial infarction, CAD, vascular disease and DM (among others) increase the likelihood of receiving combined antiplatelet and anticoagulant therapy among patients with AF. A literature review suggests this may lead to increased major bleeding with little benefit in decreasing either AF-related stroke or cardiovascular events.

  2. 正常妊娠妇女血中活化的蛋白C抵抗、狼疮样抗凝物质与血栓前状态分子标志物测定%Measurement of activated protein C resistance, lupus-like anticoagulant and prethrombotic markers in normal gestation

    Institute of Scientific and Technical Information of China (English)

    徐勇; 霍梅; 余涟; 叶素丹; 谢康云

    2001-01-01

    目的 研究活化的蛋白C抵抗(Activated protein Cresistance,APC-R)在正常妊娠中的发生情况,探讨狼疮抗凝物质(Lupus-like anticoagulant,LA)对妊娠性APC-R的影响及二者与凝血酶生成、继发性纤溶的关系。方法 采用APTT-APC法检测APC-R、dRVVT 法测定LA水平,并用ELISA法测定了凝血酶原片段F1+2和D-二聚体(D-dimer,D-D)的含量。结果 检测30例正常妇女对照(NC)和50例正常妊娠妇女,NC组APC-R比率为2.88±0.37,NP组为2.04±0.31(APC-R阳性率为42%);NC组LA阳性率为0,NP组为36.7%;NC组F1+2为(0.734±0.42)nmol/L,NP组为(1.05±0.69)nmol/L;NC组D-D为(0.48±0.05)mg/L,NP组为(0.63±0.11)mg/L;NP组的APC比率、F1+2和D-D的测定结果均较NC组有显著性差异。结论 妊娠可能发生与LA升高有关的APC-R,并导致了凝血酶激活物生成增加以及凝血酶、纤溶酶的激活和继发性纤溶的发生。%Objective To investigate the activated proteinCresistance(APC-R)occurred in normal pregnancy women and the effect of lupus-like anticoagulant(LA) on it,as well as to discuss the relationships between them and coagulation / fibrinolysis activation.Methods APC sensitivity ratio was assessed using APTT-APC method, LA was measured using dRVVT method,prothrombin fragment F1+2and D-dimer were assayed using ELISA Kits.Results 30 normal women controls(NC group)and 50 normal pregnancy women at 28~32 week's gestation(NP group)were measured.We found lower APC sensitivity ratio in normal group(2.04±0.31)than that in normal group (2.88±0.37).None LA positive was found in normal group but there were 36% LA positive samples in normal group.The F1+2and D-dimer levels in normal group were (0.73±0.42)nmol/L and (0.48±0.05)mg/L respectively,whereas were significant increased in NP group(1.05±0.69)nmol/L and (0.63±0.11)mg/L,respectively.Conclusion Normal gestation is associated with a decreased APC sensitivity ratio,which may be related to the increase of LA level

  3. Jealousy increased by induced relative left frontal cortical activity.

    Science.gov (United States)

    Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

    2015-10-01

    Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed.

  4. [Preparation of patients on anticoagulant treatment for invasive surgery].

    Science.gov (United States)

    Brejcha, M; Gumulec, J; Penka, M; Klodová, D; Wróbel, M; Bogoczová, E

    2009-03-01

    The management of warfarin therapy in patients undergoing surgery or other invasive procedures involves a balance between the risk of hemorrhage, and the risk of thrombosis. Risk of hemorrhage and the trombosis depends on the type of procedure and on pre-existing conditions. Procedures with low risk of hemorrhage (dental, dermatologic or ophtalmologic procedures, endoscopy) can be provided with continuing anticoagulant therapy. Surgery with high hemorrhagic risk need stop warfarin and start bridging anticoagulant therapy, such as unfractionated heparin or low molecular weight heparin, prior and after surgery. In patients requiring emergency surgery, vitamin K, prothrombin complex concentrate or fresh frozen plasma can be used to improve coagulation.

  5. 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.

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

    Science.gov (United States)

    van Gorp, Rick H; Schurgers, Leon J

    2015-11-17

    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.

  7. New anticoagulants and antiplatelet agents: a primer for the clinical gastroenterologist.

    Science.gov (United States)

    Parekh, Parth J; Merrell, Jonathan; Clary, Meredith; Brush, John E; Johnson, David A

    2014-01-01

    The discovery of the first oral anticoagulant, warfarin, was a milestone in anticoagulation. Warfarin's well-known limitations, however, have led to the recent development of more effective anticoagulants. The rapidly growing list of these drugs, however, presents a challenge to endoscopists who must treat patients on these sundry medications. This review is intended to summarize the pharmacological highlights of new anticoagulants, with particular attention to suggested "best-practice" recommendations for the withholding of these drugs before endoscopic procedures.

  8. Characteristics of induced activity from medical linear accelerators.

    Science.gov (United States)

    Wang, Yi Zhen; Evans, Michael D C; Podgorsak, Ervin B

    2005-09-01

    A study of the induced activity in a medical linear accelerator (linac) room was carried out on several linac installations. Higher beam energy, higher dose rate, and larger field size generally result in higher activation levels at a given point of interest, while the use of multileaf collimators (MLC) can also increase the activation level at the isocenter. Both theoretical and experimental studies reveal that the activation level in the morning before any clinical work increases from Monday to Saturday and then decreases during the weekend. This weekly activation picture keeps stable from one week to another during standard clinical operation of the linac. An effective half-life for a given point in the treatment room can be determined from the measured or calculated activity decay curves. The effective half-life for points inside the treatment field is longer than that for points outside of the field in the patient plane, while a larger field and longer irradiation time can also make the effective half-life longer. The activation level reaches its practical saturation value after a 30 min continuous irradiation, corresponding to 12 000 MU at a "dose rate" of 400 MU/min. A "dose" of 300 MU was given 20 times in 15 min intervals to determine the trends in the activation level in a typical clinical mode. As well, a long-term (85 h over a long weekend) decay curve was measured to evaluate the long-term decay of room activation after a typical day of clinical linac use. A mathematical model for the activation level at the isocenter has been established and shown to be useful in explaining and predicting the induced activity levels for typical clinical and experimental conditions. The activation level for a 22 MeV electron beam was also measured and the result shows it is essentially negligible.

  9. Antimicrobial Activity of UV-Induced Phenylamides from Rice Leaves

    Directory of Open Access Journals (Sweden)

    Hye Lin Park

    2014-11-01

    Full Text Available Rice produces a wide array of phytoalexins in response to pathogen attacks and UV-irradiation. Except for the flavonoid sakuranetin, most phytoalexins identified in rice are diterpenoid compounds. Analysis of phenolic-enriched fractions from UV-treated rice leaves showed that several phenolic compounds in addition to sakuranetin accumulated remarkably in rice leaves. We isolated two compounds from UV-treated rice leaves using silica gel column chromatography and preparative HPLC. The isolated phenolic compounds were identified as phenylamide compounds: N-trans-cinnamoyltryptamine and N-p-coumaroylserotonin. Expression analysis of biosynthetic genes demonstrated that genes for arylamine biosynthesis were upregulated by UV irradiation. This result suggested that phenylamide biosynthetic pathways are activated in rice leaves by UV treatment. To unravel the role of UV-induced phenylamides as phytoalexins, we examined their antimicrobial activity against rice fungal and bacterial pathogens. N-trans-Cinnamoyltryptamine inhibited the growth of rice brown spot fungus (Bipolaris oryzae. In addition to the known antifungal activity to the blast fungus, sakuranetin had antimicrobial activity toward B. oryzae and Rhizoctonia solani (rice sheath blight fungus. UV-induced phenylamides and sakuranetin also had antimicrobial activity against rice bacterial pathogens for grain rot (Burkholderia glumae, blight (Xanthomonas oryzae pv. oryzae and leaf streak (X. oryzae pv. oryzicola diseases. These findings suggested that the UV-induced phenylamides in rice are phytoalexins against a diverse array of pathogens.

  10. Calciumreleasing activity induced by nuclei of mouse fertilized early embryos

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    At fertilization, repetitive transient rises of intracellular calcium concentration occur in all mammals studied so far. It has been shown that calcium rises could be induced when mouse fertilized 1-, 2-cell nuclei were transplanted into unfertilized eggs and that the reconstituted embryo could be activated. However, whether the capability of inducing calcium rises occurs in all stages of mammalian embryos remains unknown. In this study, by using the nuclear transplantation technique and measurement of intracellular calcium rises in living cells, we showed that only the nuclei from mouse fertilized 1-cell and 2-cell embryos, neither the nuclei from 4-, 8-cell and ethanol activated parthenogenetic embryos nor 2 or 3 nuclei of electrofused 4-cell stage syncytium, have calcium-releasing activity when they were transferred into unfertilized mature oocytes. Our results indicate that the calcium-releasing activity in nuclei of 1-, 2-cell embryos is produced during fertilization and exists at the special stage of fertilized early embryos. These suggested that the capacity of inducing calcium release activity in fertilized early embryos is important for normal embryonic development.

  11. Efficacy and safety of anticoagulation with heparin versus heparin plus epoprostenol in patients undergoing extracorporeal liver support with Prometheus.

    Science.gov (United States)

    Krisper, Peter; Tiran, Beate; Fliser, Danilo; Haditsch, Bernd; Stadlbauer, Vanessa; Otto, Ronald; Ernst, Thomas; Kretschmer, Ulrich; Stauber, Rudolf E; Haller, Hermann; Holzer, Herwig; Manns, Michael P; Rifai, Kinan

    2010-01-01

    Anticoagulation for extracorporeal liver support is delicate due to underlying coagulation disorders in patients with liver failure and to the associated elevated bleeding risk. To date, there has been no detailed report on anticoagulation issues in patients treated with Prometheus, a device based on the principle of fractionated plasma separation and adsorption. We studied 17 patients from two centers treated with Prometheus, comparing standard anticoagulation with heparin (15 treatments) and a combination of heparin and the synthetic prostacyclin epoprostenol (22 treatments). Standard coagulation tests, proteins C and S, and thrombin-antithrombin (TAT) complex were determined, and adverse events were recorded. All but two treatments could be completed as scheduled, although filter exchange due to filter clotting was required in 24% of the treatments. Three out of 17 patients developed severe bleeding complications within 24 h of treatment. There were no overt thrombotic events. Addition of epoprostenol neither reduced coagulation-related adverse events nor improved standard coagulation parameters. Protein C, but not protein S, showed a significant reduction (23 +/- 18%) after Prometheus treatments, but levels rebounded to baseline within 18 h. TAT levels--a measure for activation of coagulation--were only altered by Prometheus in patients where TAT was already elevated before treatment. In conclusion, anticoagulation of Prometheus with heparin is feasible but still associated with a relatively high frequency of filter clotting and a considerable risk of severe bleeding in this high-risk patient population. As addition of epoprostenol did not prove beneficial, other strategies, such as regional anticoagulation with citrate, should be further evaluated.

  12. Heparin-induced thrombocytopenia

    Directory of Open Access Journals (Sweden)

    Shaikh Nissar

    2011-01-01

    Full Text Available In the last 7 decades heparin has remained the most commonly used anticoagulant. Its use is increasing, mainly due to the increase in the number of vascular interventions and aging population. The most feared complication of heparin use is heparin-induced thrombocytopenia (HIT. HIT is a clinicopathologic hypercoagulable, procoagulant prothrombotic condition in patients on heparin therapy, and decrease in platelet count by 50% or to less than 100,000, from 5 to 14 days of therapy. This prothrombotic hypercoagulable state in HIT patient is due to the combined effect of various factors, such as platelet activation, mainly the formation of PF4/heparin/IgG complex, stimulation of the intrinsic factor, and loss of anticoagulant effect of heparin. Diagnosis of HIT is done by clinical condition, heparin use, and timing of thrombocytopenia, and it is confirmed by either serotonin release assay or ELISA assay. Complications of HIT are venous/arterial thrombosis, skin gangrene, and acute platelet activation syndrome. Stopping heparin is the basic initial treatment, and Direct Thrombin Inhibitors (DTI are medication of choice in these patients. A few routine but essential procedures performed by using heparin are hemodialysis, Percutaneous Coronary Intervention, and Cardiopulmonary Bypass; but it cannot be used if a patient develops HIT. HIT patients with unstable angina, thromboembolism, or indwelling devices, such as valve replacement or intraaortic balloon pump, will require alternative anticoagulation therapy. HIT can be prevented significantly by keeping heparin therapy shorter, avoiding bovine heparin, using low-molecular weight heparin, and stopping heparin use for flush and heparin lock.

  13. 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.

  14. 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

  15. Acupuncture inhibits cue-induced heroin craving and brain activation

    Institute of Scientific and Technical Information of China (English)

    Xinghui Cai; Xiaoge Song; Chuanfu Li; Chunsheng Xu; Xiliang Li; Qi Lu

    2012-01-01

    Previous research using functional MRI has shown that specific brain regions associated with drug dependence and cue-elicited heroin craving are activated by environmental cues.Craving is an important trigger of heroin relapse,and acupuncture may inhibit craving.In this study,we performed functional MRI in heroin addicts and control subjects.We compared differences in brain activation between the two groups during heroin cue exposure,heroin cue exposure plus acupuncture at the Zusanli point(ST36)without twirling of the needle,and heroin cue exposure plus acupuncture at the Zusanli point with twirling of the needle.Heroin cue exposure elicited significant activation in craving-related brain regions mainly in the frontal lobes and callosal gyri.Acupuncture without twirling did not significantly affect the range of brain activation induced by heroin cue exposure,but significantly changed the extent of the activation in the heroin addicts group.Acupuncture at the Zusanli.point with twirling of the needle significantly decreased both the range and extent of activation induced by heroin cue exposure compared with heroin cue exposure plus acupuncture without twirling of the needle.These experimental findings indicate that presentation of heroin cues can induce activation in craving-related brain regions,which are involved in reward,learning and memory,cognition and emotion.Acupuncture at the Zusanli point can rapidly suppress the activation of specific brain regions related to craving,supporting its potential as an intervention for drug craving.

  16. Multinational development of a questionnaire assessing patient satisfaction with anticoagulant treatment: the 'Perception of Anticoagulant Treatment Questionnaire' (PACT-Q©

    Directory of Open Access Journals (Sweden)

    Bousser Marie-Germaine

    2009-02-01

    Full Text Available Abstract Background The side effects and burden of anticoagulant treatments may contribute to poor compliance and consequently to treatment failure. A specific questionnaire is necessary to assess patients' needs and their perceptions of anticoagulant treatment. Methods A conceptual model of expectation and satisfaction with anticoagulant treatment was designed by an advisory board and used to guide patient (n = 31 and clinician (n = 17 interviews in French, US English and Dutch. Patients had either atrial fibrillation (AF, deep venous thrombosis (DVT, or pulmonary embolism (PE. Following interviews, three PACT-Q language versions were developed simultaneously and further pilot-tested by 19 patients. Linguistic validations were performed for additional language versions. Results Initial concepts were developed to cover three areas of interest: 'Treatment', 'Disease and Complications' and 'Information about disease and anticoagulant treatment'. After clinician and patient interviews, concepts were further refined into four domains and 17 concepts; test versions of the PACT-Q were then created simultaneously in three languages, each containing 27 items grouped into four domains: "Treatment Expectations" (7 items, "Convenience" (11 items, "Burden of Disease and Treatment" (2 items and "Anticoagulant Treatment Satisfaction" (7 items. No item was deleted or added after pilot testing as patients found the PACT-Q easy to understand and appropriate in length in all languages. The PACT-Q was divided into two parts: the first part to measure the expectations and the second to measure the convenience, burden and treatment satisfaction, for evaluation prior to and after anticoagulant treatment, respectively. Eleven additional language versions were linguistically validated. Conclusion The PACT-Q has been rigorously developed and linguistically validated. It is available in 14 languages for use with thromboembolic patients, including AF, PE and DVT patients

  17. Nrf2 activation prevents cadmium-induced acute liver injury

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  18. Identity, regulation, and activity of inducible diterpenoid phytoalexins in maize.

    Science.gov (United States)

    Schmelz, Eric A; Kaplan, Fatma; Huffaker, Alisa; Dafoe, Nicole J; Vaughan, Martha M; Ni, Xinzhi; Rocca, James R; Alborn, Hans T; Teal, Peter E

    2011-03-29

    Phytoalexins constitute a broad category of pathogen- and insect-inducible biochemicals that locally protect plant tissues. Because of their agronomic significance, maize and rice have been extensively investigated for their terpenoid-based defenses, which include insect-inducible monoterpene and sesquiterpene volatiles. Rice also produces a complex array of pathogen-inducible diterpenoid phytoalexins. Despite the demonstration of fungal-induced ent-kaur-15-ene production in maize over 30 y ago, the identity of functionally analogous maize diterpenoid phytoalexins has remained elusive. In response to stem attack by the European corn borer (Ostrinia nubilalis) and fungi, we observed the induced accumulation of six ent-kaurane-related diterpenoids, collectively termed kauralexins. Isolation and identification of the predominant Rhizopus microsporus-induced metabolites revealed ent-kaur-19-al-17-oic acid and the unique analog ent-kaur-15-en-19-al-17-oic acid, assigned as kauralexins A3 and B3, respectively. Encoding an ent-copalyl diphosphate synthase, fungal-induced An2 transcript accumulation precedes highly localized kauralexin production, which can eventually exceed 100 μg · g(-1) fresh weight. Pharmacological applications of jasmonic acid and ethylene also synergize the induced accumulation of kauralexins. Occurring at elevated levels in the scutella of all inbred lines examined, kauralexins appear ubiquitous in maize. At concentrations as low as 10 μg · mL(-1), kauralexin B3 significantly inhibited the growth of the opportunistic necrotroph R. microsporus and the causal agent of anthracnose stalk rot, Colletotrichum graminicola. Kauralexins also exhibited significant O. nubilalis antifeedant activity. Our work establishes the presence of diterpenoid defenses in maize and enables a more detailed analysis of their biosynthetic pathways, regulation, and crop defense function.

  19. Low standard oral anticoagulation therapy for Chinese patients with St.Jude mechanical heart valves

    Institute of Scientific and Technical Information of China (English)

    孙晓刚; 胡盛寿; 祁国奇; 周玉燕

    2003-01-01

    Objective To study the efficacy of the low standard oral anticoagulation therapy following St Jude Medical (SJM) valve implantation for Chinese patients.Methods Totally 805 patients with a mean age of 42.70±11.09 years, enrolled into this study. Among them, 230 underwent aortic valve replacements (AVR), 381 mitral valve replacements (MVR), 189 double valve replacements (DVR) and 5 tricuspid valve replacememts (TVR). All patients received postoperative oral anticoagulation therapy based on a low standard of international normalized ratio (INR, 2.0-2.5). Of the 805 patients, 710 were followed up for 0.25-13 years (a median, 4.15 years). Results Postoperatively, 17 adverse events occurred. Operative mortality was 2.11%. The most frequent cause of operative mortality was a low cardiac output. During follow-up, there were 47 anticoagulant-induced hemorrhages [1.59%/patient-year (pt-yr)], 10 cases of thromboembolism (0.34%/pt-yr), and 3 mechanical valve thromboses (0.19%/pt-yr). There were 44 late deaths and the linearized late mortality rates were 0.51%pt-yr. Estimates of actuarial survival for all patients at 5 and 10 years was 97.45% (0.70%) and 77.96% (17.44%), respectively.Conclusions A low target INR range of 2.0-2.5 is preferable for Chinese patients so as to reduce the severe bleeding complications in those with conventionally higher levels of INR. The long-term results were satisfactory in terms of the numbers of those who suffered thrombosis, embolism and bleeding.

  20. Different activation signals induce distinct mast cell degranulation strategies

    Science.gov (United States)

    Sibilano, Riccardo; Marichal, Thomas; Reber, Laurent L.; Cenac, Nicolas; McNeil, Benjamin D.; Dong, Xinzhong; Hernandez, Joseph D.; Sagi-Eisenberg, Ronit; Hammel, Ilan; Roers, Axel; Valitutti, Salvatore; Tsai, Mindy

    2016-01-01

    Mast cells (MCs) influence intercellular communication during inflammation by secreting cytoplasmic granules that contain diverse mediators. Here, we have demonstrated that MCs decode different activation stimuli into spatially and temporally distinct patterns of granule secretion. Certain signals, including substance P, the complement anaphylatoxins C3a and C5a, and endothelin 1, induced human MCs rapidly to secrete small and relatively spherical granule structures, a pattern consistent with the secretion of individual granules. Conversely, activating MCs with anti-IgE increased the time partition between signaling and secretion, which was associated with a period of sustained elevation of intracellular calcium and formation of larger and more heterogeneously shaped granule structures that underwent prolonged exteriorization. Pharmacological inhibition of IKK-β during IgE-dependent stimulation strongly reduced the time partition between signaling and secretion, inhibited SNAP23/STX4 complex formation, and switched the degranulation pattern into one that resembled degranulation induced by substance P. IgE-dependent and substance P–dependent activation in vivo also induced different patterns of mouse MC degranulation that were associated with distinct local and systemic pathophysiological responses. These findings show that cytoplasmic granule secretion from MCs that occurs in response to different activating stimuli can exhibit distinct dynamics and features that are associated with distinct patterns of MC-dependent inflammation. PMID:27643442

  1. The influence of experimentally induced pain on shoulder muscle activity.

    Science.gov (United States)

    Diederichsen, Louise Pyndt; Winther, Annika; Dyhre-Poulsen, Poul; Krogsgaard, Michael R; Nørregaard, Jesper

    2009-04-01

    Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0 degrees -105 degrees) at a speed of approximately 120 degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows that acute pain both subacromially and in the supraspinatus muscle modulates coordination of the shoulder muscles during voluntary movements. During painful conditions, an increased activity was detected in the antagonist (latissimus), which support the idea that localized pain affects muscle activation in a way that protects the painful structure. Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load

  2. Is there a correlation between structure and anticoagulant action of sulfated galactans and sulfated fucans?

    Science.gov (United States)

    Pereira, Mariana S; Melo, Fábio R; Mourão, Paulo A S

    2002-10-01

    We attempted to identify the specific structural features in sulfated galactans and sulfated fucans that confer anticoagulant activity. For this study we employed a variety of invertebrate polysaccharides with simple structures composed of well-defined units of oligosaccharides. Our results indicate that a 2-O-sulfated, 3-linked alpha-L-galactan, but not a alpha-L-fucan with a similar molecular size, is a potent thrombin inhibitor mediated by antithrombin or heparin cofactor II. The difference between the activities of these two polysaccharides is not very pronounced when factor Xa replaced thrombin. The occurrence of 2,4-di-O-sulfated units is an amplifying motif for 3-linked alpha-fucan-enhanced thrombin inhibition by antithrombin. If we replace antithrombin by heparin cofactor II, then the major structural requirement for the activity becomes single 4-O-sulfated fucose units. The presence of 2-O-sulfated fucose residues always had a deleterious effect on anticoagulant activity. Overall, our results indicate that the structural requirements for interaction of sulfated galactans and sulfated fucans with coagulation cofactors and their target proteases are stereospecific and not merely a consequence of their charge density and sulfate content.

  3. Do we have to anticoagulated patients with cerebral venous thrombosis?

    DEFF Research Database (Denmark)

    Feher, G; Illes, Z; Hargroves, D

    2016-01-01

    INTRODUCTION: Cerebral venous thrombosis (CVT) is a rare form of venous thromboembolism (VTE). Although anticoagulation is recommended for the initial and long term treatment with regards to thrombotic risks for patients with CVT, the role of anticogalution has not been fully elucidated. The aim...... and the outcome of a second event as good as that of the first one irrespective of underlying risk factors....

  4. Novel oral anticoagulants in the treatment of cerebral venous thrombosis

    DEFF Research Database (Denmark)

    Feher, G; Illes, Z; Komoly, S;

    2015-01-01

    Cerebral venous thrombosis (CVT) is an uncommon cause of stroke with extremely diverse clinical features, predisposing factors, brain imaging findings, and outcome. Anticoagulation is the cornerstone of CVT management, however, it is not supported by high-quality evicence. Novel oral anticoagulan...

  5. Antiplatelet and anticoagulant therapy in elective percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Verheugt Freek WA

    2001-05-01

    Full Text Available Abstract Thrombosis plays a major role in acute vessel closure both after coronary balloon angioplasty and after stenting. This review will address the role of antiplatelet and anticoagulant therapy in preventing early thrombotic complications after percutaneous coronary intervention. The focus will be on agents that are routinely available and commonly used.

  6. Novel antiplatelet and anticoagulant agents in the cardiac care unit.

    Science.gov (United States)

    Garg, Vaani Panse; Halperin, Jonathan L

    2013-11-01

    This article reviews the pivotal studies of several novel antiplatelet (prasugrel and ticagrelor) and anticoagulant (dabigatran, rivaroxaban, and apixaban) agents. The clinical use of these drugs in cardiac intensive care is discussed, focusing on the management of acute coronary syndromes, ischemic stroke, atrial fibrillation, and venous thromboembolism.

  7. The new oral anticoagulants in atrial fibrillation: an update

    NARCIS (Netherlands)

    Verheugt, F.W.A.

    2013-01-01

    In patients with nonvalvular atrial fibrillation, oral anticoagulation with the vitamin K antagonists acenocoumarol, phenprocoumon and warfarin reduces the risk of stroke by more than 60 %, whereas single or double antiplatelet therapy is much less effective and sometimes associated with a similar b

  8. Personalised treatment with oral anticoagulant drugs : clinical and economic issues

    NARCIS (Netherlands)

    Verhoef, T.I.

    2013-01-01

    Coumarin derivatives such as acenocoumarol, phenprocoumon and warfarin are frequently used for the prevention of stroke and systemic embolism in patients with atrial fibrillation or for the treatment of venous thromboembolism. These oral anticoagulants have a narrow therapeutic range and a large var

  9. Laboratory monitoring of novel oral anticoagulants rivaroxaban and dabigatran

    NARCIS (Netherlands)

    Eerenberg, E.S.; Kamphuisen, P.W.; Sijpkens, M.K.; Meijers, J.C.; Büller, H.R.; Levi, M.

    2013-01-01

    Background: Rivaroxaban and dabigatran are new oral anticoagulants that both have been licensed worldwide for the treatment of atrial fibrillation and rivaroxaban also for venous thrombosis. Both drugs specifically inhibit one coagulation factor, factor Xa and thrombin, respectively, and both compou

  10. Maternal and fetal sequelae of anticoagulation during pregnancy.

    Science.gov (United States)

    Hall, J G; Pauli, R M; Wilson, K M

    1980-01-01

    Review of published cases of pregnancies in which coumarin derivatives or heparin were administered demonstrates that use of either class of anticoagulant carries substantial risks. Of 418 reported pregnancies in which coumarin derivatives were used, one-sixth resulted in abnormal liveborn infants, one-sixth in abortion or stillbirth and, at most, two-thirds in apparently normal infants. In addition to the expected hemorrhagic complications, fetal effects of coumarin derivative administration include a specific embryopathy and central nervous system abnormalities. All available cases (including unpublished ones) of warfarin embryopathy and central nervous system abnormalities following gestational exposure to coumarin derivatives are reviewed, various complications are tabulated, critical periods of teratogenesis are discussed and possible mechanisms proposed. The use of heparin during gestation does not result in a significantly better outcome of pregnancy. In 135 published cases, the infants in one-eighth were stillborn, in one-fifth premature (a third of whom died) and, again at most, in two-thirds apparently normal. Because of the substantial risks of both clases of anticoagulants, and the inherent risks of pregnancy complicated by the indications for anticoagulation, prevention of pregnancy is usually indicated. If pregnancy occurs, a relatively normal outcome can be anticipated in about two-thirds of the pregnancies regardless of the anticoagulant used. Heparin does not appear to be a clearly superior alternative to coumarin derivatives.

  11. 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.

  12. Use of Oral Anticoagulation Therapy in Atrial Fibrillation after Stroke

    DEFF Research Database (Denmark)

    Jespersen, Stine Funder; Christensen, Louisa M; Christensen, Anders;

    2013-01-01

    Background. The knowledge is still sparse about patient related factors, influencing oral anticoagulation therapy (OAC) rates, in stroke patients with atrial fibrillation (AF). Aims. To assess the use of OAC in ischemic stroke patients diagnosed with AF and to identify patient related factors...

  13. 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

  14. New oral anticoagulants for patients with nonvalvular atrial fibrillation.

    Science.gov (United States)

    Holden, Amber; Azimi, Nassir; Forest, Christopher P

    2015-11-01

    Four new oral anticoagulants have been approved for reducing stroke risk in patients with nonvalvular atrial fibrillation. Compared with warfarin, these agents offer a more predictable dose response with fewer food and drug interactions and no regular blood monitoring, although some of the drugs have an increased risk of major gastrointestinal bleeding. This article reviews the new drugs.

  15. Risk of bleeding after dentoalveolar surgery in patients taking anticoagulants

    NARCIS (Netherlands)

    Broekema, Ferdinand I.; van Minnen, Baucke; Jansma, Johan; Bos, Rudolf R. M.

    2014-01-01

    To avoid increasing the risk of thromboembolic events, it is recommended that treatment with anticoagulants should be continued during dentoalveolar operations. We have evaluated the incidence of bleeding after dentoalveolar operations in a prospective study of 206 patients, 103 who were, and 103 wh

  16. Bridging of oral anticoagulation therapy for invasive procedures.

    Science.gov (United States)

    Spyropoulos, Alex C

    2005-09-01

    The management of patients who need temporary interruption of chronic oral anticoagulant (OAC) therapy for an elective surgical or invasive procedure is problematic and complex. Patient and procedural risk factors for thrombosis and bleeding, anticoagulant-related risks of bleeding, and clinical consequences of a thrombotic or bleeding event need to be assessed and properly risk-stratified in the perioperative period. Certain procedures, such as dental, endoscopic, and cutaneous procedures, can be completed without discontinuing OAC, but most procedures with a high bleeding risk (including major surgeries) will necessitate temporary discontinuation of OAC. Bridging therapy with shorter-acting anticoagulants, such as heparin, for patients at intermediate to high risk of thromboembolism represents one strategy to maintain functional anticoagulation during this period. Large, prospective cohort studies and registries of patients on chronic OAC who underwent bridging therapy mostly with low-molecular-weight heparin have been completed recently. This paper reviews these clinical data on bridging therapy and provides an evidence-based perioperative management strategy for the at-risk patient on chronic OAC.

  17. Acetaminophen induces human neuroblastoma cell death through NFKB activation.

    Directory of Open Access Journals (Sweden)

    Inmaculada Posadas

    Full Text Available Neuroblastoma resistance to apoptosis may contribute to the aggressive behavior of this tumor. Therefore, it would be relevant to activate endogenous cellular death mechanisms as a way to improve neuroblastoma therapy. We used the neuroblastoma SH-SY5Y cell line as a model to study the mechanisms involved in acetaminophen (AAP-mediated toxicity by measuring CYP2E1 enzymatic activity, NFkB p65 subunit activation and translocation to the nucleus, Bax accumulation into the mitochondria, cytochrome c release and caspase activation. AAP activates the intrinsic death pathway in the SH-SY5Y human neuroblastoma cell line. AAP metabolism is partially responsible for this activation, because blockade of the cytochrome CYP2E1 significantly reduced but did not totally prevent, AAP-induced SH-SY5Y cell death. AAP also induced NFkB p65 activation by phosphorylation and its translocation to the nucleus, where NFkB p65 increased IL-1β production. This increase contributed to neuroblastoma cell death through a mechanism involving Bax accumulation into the mitochondria, cytochrome c release and caspase3 activation. Blockade of NFkB translocation to the nucleus by the peptide SN50 prevented AAP-mediated cell death and IL-1β production. Moreover, overexpression of the antiapoptotic protein Bcl-x(L did not decrease AAP-mediated IL-1β production, but prevented both AAP and IL-1β-mediated cell death. We also confirmed the AAP toxic actions on SK-N-MC neuroepithelioma and U87MG glioblastoma cell lines. The results presented here suggest that AAP activates the intrinsic death pathway in neuroblastoma cells through a mechanism involving NFkB and IL-1β.

  18. Evidence for Planet-induced Chromospheric Activity on HD 179949

    CERN Document Server

    Shkolnik, E; Bohlender, D A; Shkolnik, Evgenya; Walker, Gordon A.H.; Bohlender, David A.

    2003-01-01

    We have detected the synchronous enhancement of Ca II H & K emission with the short-period planetary orbit in HD 179949. High-resolution spectra taken on three observing runs extending more than a year show the enhancement coincides with phi ~ 0 (the sub-planetary point) of the 3.093-day orbit with the effect persisting for more than 100 orbits. The synchronous enhancement is consistent with planet-induced chromospheric heating by magnetic rather than tidal interaction. Something which can only be confirmed by further observations. Independent observations are needed to determine whether the stellar rotation is sychronous with the planet's orbit. Of the five 51 Peg-type systems monitored, HD 179949 shows the greatest chromospheric H & K activity. Three others show significant nightly variations but the lack of any phase coherence prevents us saying whether the activity is induced by the planet. Our two standards, tau Ceti and the Sun, show no such nightly variations.

  19. Antioxidant activity of simvastatin prevents ifosfamide-induced nephrotoxicity.

    Science.gov (United States)

    Mhaidat, Nizar Mahmoud; Ali, Reem Mustafa; Shotar, Ali Muhammad; Alkaraki, Almuthanna Khalaf

    2016-03-01

    Ifosfamide is an anticancer agent used largely in treatment of solid tumors. The mainstay dose-limiting toxicity of ifosfamide is nephrotoxicity. This is largely believde to be a result of ifosfamide-induced oxidative stress. In this study, we investigated the antioxidant activity of simvastatin and the possible protective role of simvastatin against ifosfamide induced nephrotoxicity. Thirty Sprague-Dawely rats were divided into five groups and given orally different drug combinations. Group I and II were regarded as control groups and received 0.1% DMSO and normal saline, respectively. Group III received ifosfamide at 50 mg/kg, group IV received simvastatin at 0.3 mg/kg and group V received both ifosfamide and simvastatin. All animals were decapitated 2 days after the last ifosfamide administration. Findings revealed that ifosfamide induced nephrotoxicity as indicated by a significant increase in plasma creatinine and lipid per oxidation. This increase was significantly inhibited in animals pretreated with simvastatin. Histopathological observations were in correlation with the biochemical parameters in that simvastatin minimized ifosfamide-induced renal tubular damage. The above results promote a future use of simvastatin in combination with ifosfamide in treatment of cancer patients to indicate that simvastatin protectics against ifosfamide-induced nephrotoxicity in terms of oxidative stress and might be given in combination.

  20. New Oral Anticoagulants in the Treatment of Pulmonary Embolism: Efficacy, Bleeding Risk, and Monitoring

    Directory of Open Access Journals (Sweden)

    Kelly M. Rudd

    2013-01-01

    Full Text Available Anticoagulation therapy is mandatory in patients with pulmonary embolism to prevent significant morbidity and mortality. The mainstay of therapy has been vitamin-K antagonist therapy bridged with parenteral anticoagulants. The recent approval of new oral anticoagulants (NOACs: apixaban, dabigatran, and rivaroxaban has generated significant interest in their role in managing venous thromboembolism, especially pulmonary embolism due to their improved pharmacokinetic and pharmacodynamic profiles, predictable anticoagulant response, and lack of required efficacy monitoring. This paper addresses the available literature, on-going clinical trials, highlights critical points, and discusses potential advantages and disadvantages of the new oral anticoagulants in patients with pulmonary embolism.

  1. Overinhibition of Mitogen-Activated Protein Kinase Inducing Tau Hyperphosphorylation

    Institute of Scientific and Technical Information of China (English)

    LI Hong-lian; CHEN Juan; LIU Shi-jie; ZHANG Jia-yu; WANG Qun; WANG Jian-zhi

    2005-01-01

    To reveal the relationship between mitogen-activated protein kinase (MAPK) and tau phosphorylation, we used different concentration of PD98059, an inhibitor of MEK (MAPK kinase), to treat mice neuroblastma (N2a) cell line for 6 h. It showed that the activity of MAPK decreased in a dose-dependent manner. But Western blot and immunofluorescence revealed that just when the cells were treated with 16 μmol/L PD98059, tau was hyperphosphorylated at Ser396/404 and Ser199/202 sites. We obtained the conclusion that overinhibited MAPK induced tau hyperphosphorylation at Ser396/404 and Ser199/202 sites.

  2. Activation-induced cell death in B lymphocytes

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Upon encountering the antigen (Ag), the immune system can either develop a specific immune response or enter a specific state of unresponsiveness, tolerance. The response of B cells to their specific Ag can be activation and proliferation, leading to the immune response, or anergy and activation-induced cell death (AICD), leading to tolerance. AICD in B lymphocytes is a highly regulated event initiated by crosslinking of the B cell receptor (BCR). BCR engagement initiates several signaling events such as activation of PLCγ, Ras, and PI3K, which generally speaking, lead to survival However, in the absence of survival signals (CD40 or IL-4R engagement), BCR crosslinking can also promote apoptotic signal transduction pathways such as activation of effector caspases, expression of pro-apoptotic genes, and inhibition of pro-survival genes. The complex interplay between survival and death signals determines the B cell fate and, consequently, the immune response.

  3. Characteristics of ambulatory anticoagulant adverse drug events: a descriptive study

    Directory of Open Access Journals (Sweden)

    Eckstrand Julie

    2010-02-01

    Full Text Available Abstract Background Despite the high frequency with which adverse drug events (ADEs occur in outpatient settings, detailed information regarding these events remains limited. Anticoagulant drugs are associated with increased safety concerns and are commonly involved in outpatient ADEs. We therefore sought to evaluate ambulatory anticoagulation ADEs and the patient population in which they occurred within the Duke University Health System (Durham, NC, USA. Methods A retrospective chart review of ambulatory warfarin-related ADEs was conducted. An automated trigger surveillance system identified eligible events in ambulatory patients admitted with an International Normalized Ratio (INR >3 and administration of vitamin K. Event and patient characteristics were evaluated, and quality/process improvement strategies for ambulatory anticoagulation management are described. Results A total of 169 events in 167 patients were identified from December 1, 2006-June 30, 2008 and included in the study. A median supratherapeutic INR of 6.1 was noted, and roughly half of all events (52.1% were associated with a bleed. Nearly 74% of events resulted in a need for fresh frozen plasma; 64.8% of bleeds were classified as major. A total of 59.2% of events were at least partially responsible for hospital admission. Median patient age was 68 y (range 36-95 y with 24.9% initiating therapy within 3 months prior to the event. Of events with a prior documented patient visit (n = 157, 73.2% were seen at a Duke clinic or hospital within the previous month. Almost 80% of these patients had anticoagulation therapy addressed, but only 60.0% had a follow-up plan documented in the electronic note. Conclusions Ambulatory warfarin-related ADEs have significant patient and healthcare utilization consequences in the form of bleeding events and associated hospital admissions. Recommendations for improvement in anticoagulation management include use of information technology to assist

  4. Interleukin-25 fails to activate STAT6 and induce alternatively activated macrophages.

    Science.gov (United States)

    Stolfi, Carmine; Caruso, Roberta; Franzè, Eleonora; Sarra, Massimiliano; De Nitto, Daniela; Rizzo, Angelamaria; Pallone, Francesco; Monteleone, Giovanni

    2011-01-01

    Interleukin-25 (IL-25), a T helper type 2 (Th2) -related factor, inhibits the production of inflammatory cytokines by monocytes/macrophages. Since Th2 cytokines antagonize classically activated monocytes/macrophages by inducing alternatively activated macrophages (AAMs), we here assessed the effect of IL-25 on the alternative activation of human monocytes/macrophages. The interleukins IL-25, IL-4 and IL-13 were effective in reducing the expression of inflammatory chemokines in monocytes. This effect was paralleled by induction of AAMs in cultures added with IL-4 or IL-13 but not with IL-25, regardless of whether cells were stimulated with lipopolysaccharide or interferon-γ. Moreover, pre-incubation of cells with IL-25 did not alter the ability of both IL-4 and IL-13 to induce AAMs. Both IL-4 and IL-13 activated signal transducer and activator of transcription 6 (STAT6), and silencing of this transcription factor markedly reduced the IL-4/IL-13-driven induction of AAMs. In contrast, IL-25 failed to trigger STAT6 activation. Among Th2 cytokines, only IL-25 and IL-10 were able to activate p38 mitogen-activated protein kinase. These results collectively indicate that IL-25 fails to induce AAMs and that Th2-type cytokines suppress inflammatory responses in human monocytes by activating different intracellular signalling pathways.

  5. Polissacarídeos sulfatados isolados das clorofíceas Caulerpa racemosa e Caulerpa cupressoides – extração, fracionamento e atividade anticoagulante - doi: 10.4025/actascibiolsci.v32i2.5923 Sulfated polysaccharides isolated from Caulerpa racemosa and Caulerpa cupressoides (Chlorophyceaes – extraction, fractionation and anticoagulant activity - doi: 10.4025/actascibiolsci.v32i2.5923

    Directory of Open Access Journals (Sweden)

    Norma Maria Barros Benevides

    2010-05-01

    papain in 0.1 M sodium acetate buffer (pH 5.0 containing 5 mM cysteine and 5 mM EDTA, followed by fractionation on ion exchange DEAE-cellulose column with NaCl gradient. The obtained fractions were analyzed by 0.5% agarose gel electrophoresis and the anticoagulant activity measured by the activated partial thromboplastin time (APTT using normal human plasma, and compared to a standard heparin curve (193 IU mg-1. Similar chromatographic profiles of SP were shown on both species, but with distinct mobility patterns, when the SP fractions were compared by electrophoresis. SP eluted with 0.75 M of NaCl modified the APTT, whose anticoagulant activities were only 21.23 and 24.36 IU mg-1 for C. racemosa and C. cupressoides, respectively. Therefore, anticoagulant SP isolated from chlorophyceaes showed effects inferior to heparin, and comparative studies of these molecules are also suggested as auxiliary tools in the identification of algae of the same genus.

  6. Non-Anticoagulant Fractions of Enoxaparin Suppress Inflammatory Cytokine Release from Peripheral Blood Mononuclear Cells of Allergic Asthmatic Individuals.

    Directory of Open Access Journals (Sweden)

    Madhur D Shastri

    Full Text Available Enoxaparin, a low-molecular-weight heparin, is known to possess anti-inflammatory properties. However, its clinical exploitation as an anti-inflammatory agent is hampered by its anticoagulant effect and the associated risk of bleeding.The aim of the current study was to examine the ability of non-anticoagulant fractions of enoxaparin to inhibit the release of key inflammatory cytokines in primed peripheral blood mononuclear cells derived from allergic mild asthmatics.Peripheral blood mononuclear cells from allergic asthmatics were activated with phytohaemag glutinin (PHA, concanavalin-A (ConA or phorbol 12-myristate 13-acetate (PMA in the presence or absence of enoxaparin fractions before cytokine levels were quantified using specific cytokine bead arrays. Together with nuclear magnetic resonance analysis,time-dependent and target-specific effects of enoxaparin fractions were used to elucidate structural determinants for their anti-inflammatory effect and gain mechanistic insights into their anti-inflammatory activity.Two non-anticoagulant fractions of enoxaparin were identified that significantly inhibited T-cell activation. A disaccharide fraction of enoxaparin inhibited the release of IL-4, IL-5, IL-13 and TNF-α by more than 57% while a tetrasaccharide fraction was found to inhibit the release of tested cytokines by more than 68%. Our data suggest that the observed response is likely to be due to an interaction of 6-O-sulfated tetrasaccharide with cellular receptor(s.The two identified anti-inflammatory fractions lacked anticoagulant activity and are therefore not associated with risk of bleeding. The findings highlight the potential therapeutic use of enoxaparin-derived fractions, in particular tetrasaccharide, in patients with chronic inflammatory disorders.

  7. DVT prophylaxis after TKA: routine anticoagulation vs risk screening approach - a randomized study.

    Science.gov (United States)

    Kulshrestha, Vikas; Kumar, Santhosh

    2013-12-01

    The American College of Chest Physicians (ACCP) recommended routine anticoagulation for thromboprophylaxis in patients undergoing lower limb arthroplasty. We compared results of routine anticoagulation Vs risk stratified approach for Deep Venous Thrombosis (DVT) prophylaxis after TKA in terms of symptomatic DVT and wound complications. Nine hundred TKAs done in 673 patients were randomized after DVT risk screening to routine anticoagulation (n = 450) or to risk stratification (n = 450) and selective anticoagulation. 194 patients in the risk screening group received only Aspirin. Primary outcome was symptomatic DVT and wound complication. This randomized study showed that the symptomatic DVT rates after TKA were similar whether patients were routinely anticoagulated or selectively anticoagulated after risk screening. However there was a significantly higher incidence of wound complications (P < 0.014) after routine anticoagulation.

  8. Upper gastrointestinal endoscopy in emergency setting for patients receiving oral anticoagulants – practice updates

    Science.gov (United States)

    Oprita, R; Oprita, B; Diaconescu, B; Bratu, MR; Berceanu, D

    2017-01-01

    Anticoagulants are frequently used medications in diverse cardiovascular diseases. Their uses highly increase the risk of bleeding from upper and lower gastrointestinal sources, whether there is a classic vitamin K antagonist or a novel oral anticoagulant. Their interruption can promote procoagulation status with different thromboembolic accidents. Discontinuation of oral anticoagulants before the elective procedures is standardized but there are no guidelines for managing bleeding lesions of upper gastrointestinal tract concomitant with anticoagulation. Also, because some of the anticoagulants are new comers, there is no specific antidote, and so their anticoagulation effect cannot be antagonized fast in order to reduce the bleeding. Therefore, the endoscopic hemostasis must be definitive and efficient. This is a short review of the current management for the bleeding lesions of the upper gastrointestinal tract in patients taking oral anticoagulants. PMID:28255372

  9. 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

  10. Creatine kinase activity in dogs with experimentally induced acute inflammation

    Directory of Open Access Journals (Sweden)

    Dimitrinka Zapryanova

    2013-01-01

    Full Text Available The main purpose of this study was to investigate the effect of acute inflammation on total creatine kinase (CK activity in dogs. In these animals, CK is an enzyme found predominantly in skeletal muscle and significantly elevated serum activity is largely associated with muscle damage. Plasma increases in dogs are associated with cell membrane leakage and will therefore be seen in any condition associated with muscular inflammation. The study was induced in 15 mongrel male dogs (n=9 in experimental group and n=6 in control group at the age of two years and body weight 12-15 kg. The inflammation was reproduced by inoculation of 2 ml turpentine oil subcutaneously in lumbar region. The plasma activity of creatine kinase was evaluated at 0, 6, 24, 48, 72 hours after inoculation and on days 7, 14 and 21 by a kit from Hospitex Diagnostics. In the experimental group, the plasma concentrations of the CK-activity were increased at the 48th hour (97.48±6.92 U/L and remained significantly higher (p<0.05 at the 72 hour (97.43±2.93 U/L compared to the control group (77.08±5.27 U/L. The results of this study suggest that the evaluation of creatine kinase in dogs with experimentally induced acute inflammation has a limited diagnostic value. It was observed that the creatine kinase activity is slightly affected by the experimentally induced acute inflammation in dogs.

  11. Activation-induced cytidine deaminase induces reproducible DNA breaks at many non-Ig Loci in activated B cells.

    Science.gov (United States)

    Staszewski, Ori; Baker, Richard E; Ucher, Anna J; Martier, Raygene; Stavnezer, Janet; Guikema, Jeroen E J

    2011-01-21

    After immunization or infection, activation-induced cytidine deaminase (AID) initiates diversification of immunoglobulin (Ig) genes in B cells, introducing mutations within the antigen-binding V regions (somatic hypermutation, SHM) and double-strand DNA breaks (DSBs) into switch (S) regions, leading to antibody class switch recombination (CSR). We asked if, during B cell activation, AID also induces DNA breaks at genes other than IgH genes. Using a nonbiased genome-wide approach, we have identified hundreds of reproducible, AID-dependent DSBs in mouse splenic B cells shortly after induction of CSR in culture. Most interestingly, AID induces DSBs at sites syntenic with sites of translocations, deletions, and amplifications found in human B cell lymphomas, including within the oncogene B cell lymphoma11a (bcl11a)/evi9. Unlike AID-induced DSBs in Ig genes, genome-wide AID-dependent DSBs are not restricted to transcribed regions and frequently occur within repeated sequence elements, including CA repeats, non-CA tandem repeats, and SINEs.

  12. Unfractionated and low-molecular-weight heparin and the phosphodiesterase inhibitors, IBMX and cilostazol, block ex vivo Equid Herpesvirus type-1-induced platelet activation

    Directory of Open Access Journals (Sweden)

    Tracy Stokol

    2016-11-01

    Full Text Available Equid herpes virus type-1 (EHV-1 is a major pathogen of horses, causing abortion storms and outbreaks of herpes virus myeloencephalopathy. These clinical syndromes are partly attributed to ischemic injury from thrombosis in placental and spinal vessels. The mechanism of thrombosis in affected horses is unknown. We have previously shown that EHV-1 activates platelets through virus-associated tissue factor-initiated thrombin generation. Activated platelets participate in thrombus formation by providing a surface to localize coagulation factor complexes that amplify and propagate thrombin generation. We hypothesized that coagulation inhibitors that suppress thrombin generation (heparins or platelet inhibitors that impede post-receptor thrombin signaling (phosphodiesterase [PDE] antagonists would inhibit EHV-1-induced platelet activation ex vivo. We exposed platelet-rich plasma collected from healthy horses to the RacL11 abortigenic and Ab4 neuropathogenic strains of EHV-1 at 1 plaque forming unit/cell in the presence or absence of unfractionated heparin (UFH, low-molecular-weight (LMWH heparin or the PDE inhibitors, 3-isobutyl-1methylxanthine (IBMX and cilostazol. We assessed platelet activation status in flow cytometric assays by measuring P-selectin expression. We found that all of the inhibitors blocked EHV-1- and thrombin-induced platelet activation in a dose-dependent manner. Platelet activation in PRP was maximally inhibited at concentrations of 0.05 U/mL UFH and 2.5 μg/mL LMWH. These concentrations represented 0.1 to 0.2 U/mL anti-Factor Xa activity measured in chromogenic assays. Both IBMX and cilostazol showed maximal inhibition of platelet activation at the highest tested concentration of 50 μM but inhibition was lower than that seen with UFH and LMWH. Our results indicate that heparin anticoagulants and strong non-selective (IBMX or isoenzyme-3 selective (cilostazol PDE antagonists inhibit ex vivo EHV-1-induced platelet activation

  13. The polyphosphate/factor XII pathway in cancer-associated thrombosis: novel perspectives for safe anticoagulation in patients with malignancies.

    Science.gov (United States)

    Nickel, Katrin F; Labberton, Linda; Long, Andrew T; Langer, Florian; Fuchs, Tobias A; Stavrou, Evi X; Butler, Lynn M; Renné, Thomas

    2016-05-01

    Cancer is an established risk factor for venous thromboembolism (VTE) and VTE is the second leading cause of death in patients with cancer. The incidence of cancer-related thrombosis is rising and is associated with worse outcomes. Despite our growing understanding on tumor-driven procoagulant mechanisms including cancer-released procoagulant proteases, expression of tissue factor on cancer cells and derived microvesicles, as well as alterations in the extracellular matrix of the cancer cell milieu, anticoagulation therapy in cancer patients has remained challenging. This review comments on a newly discovered cancer-associated procoagulant pathway. Experimental VTE models in mice and studies on patient cancer material revealed that prostate cancer cells and associated exosomes display the inorganic polymer polyphosphate on their plasma membrane. Polyphosphate activates blood coagulation factor XII and initiates thrombus formation via the intrinsic pathway of coagulation. Pharmacologic inhibition of factor XII activity protects mice from VTE and reduces thrombin coagulant activity in plasma of prostate cancer patients. Factor XII inhibitors provide thrombo-protection without impairing hemostatic mechanisms and thus, unlike currently used anticoagulants, do not increase bleeding risk. Interference with the polyphosphate/factor XII pathway may provide the novel opportunity for safe anticoagulation therapy in patients with malignancies.

  14. GP130 activation induces myeloma and collaborates with MYC

    Science.gov (United States)

    Dechow, Tobias; Steidle, Sabine; Götze, Katharina S.; Rudelius, Martina; Behnke, Kerstin; Pechloff, Konstanze; Kratzat, Susanne; Bullinger, Lars; Fend, Falko; Soberon, Valeria; Mitova, Nadya; Li, Zhoulei; Thaler, Markus; Bauer, Jan; Pietschmann, Elke; Albers, Corinna; Grundler, Rebekka; Schmidt-Supprian, Marc; Ruland, Jürgen; Peschel, Christian; Duyster, Justus; Rose-John, Stefan; Bassermann, Florian; Keller, Ulrich

    2014-01-01

    Multiple myeloma (MM) is a plasma cell neoplasm that results from clonal expansion of an Ig-secreting terminally differentiated B cell. Advanced MM is characterized by tissue damage that involves bone, kidney, and other organs and is typically associated with recurrent genetic abnormalities. IL-6 signaling via the IL-6 signal transducer GP130 has been implicated as an important driver of MM pathogenesis. Here, we demonstrated that ectopic expression of constitutively active GP130 (L-GP130) in a murine retroviral transduction-transplantation model induces rapid MM development of high penetrance. L-GP130–expressing mice recapitulated all of the characteristics of human disease, including monoclonal gammopathy, BM infiltration with lytic bone lesions, and protein deposition in the kidney. Moreover, the disease was easily transplantable and allowed different therapeutic options to be evaluated in vitro and in vivo. Using this model, we determined that GP130 signaling collaborated with MYC to induce MM and was responsible and sufficient for directing the plasma cell phenotype. Accordingly, we identified Myc aberrations in the L-GP130 MM model. Evaluation of human MM samples revealed recurrent activation of STAT3, a downstream target of GP130 signaling. Together, our results indicate that deregulated GP130 activity contributes to MM pathogenesis and that pathways downstream of GP130 activity have potential as therapeutic targets in MM. PMID:25384216

  15. Ginsenoside Rb1 attenuates activated microglia-induced neuronal damage

    Institute of Scientific and Technical Information of China (English)

    Lining Ke; Wei Guo; Jianwen Xu; Guodong Zhang; Wei Wang; Wenhua Huang

    2014-01-01

    The microglia-mediated inlfammatory reaction promotes neuronal damage under cerebral isch-emia/hypoxia conditions. We therefore speculated that inhibition of hypoxia-induced microglial activation may alleviate neuronal damage. To test this hypothesis, we co-cultured ginsenoside Rb1, an active component of ginseng, and cortical neurons. Ginsenoside Rb1 protected neuronal morphology and structure in a single hypoxic culture system and in a hypoxic co-culture system with microglia, and reduced neuronal apoptosis and caspase-3 production. The protective effect was observable prior to placing in co-culture. Additionally, ginsenoside Rb1 inhibited levels of tumor necrosis factor-αin a co-culture system containing activated N9 microglial cells. Ginse-noside Rb1 also signiifcantly decreased nitric oxide and superoxide production induced by N9 microglia. Our ifndings indicate that ginsenoside Rb1 attenuates damage to cerebral cortex neu-rons by downregulation of nitric oxide, superoxide, and tumor necrosis factor-αexpression in hypoxia-activated microglia.

  16. Copper is required for cobalt-induced transcriptional activity of hypoxia-inducible factor-1.

    Science.gov (United States)

    Qiu, Liying; Ding, Xueqin; Zhang, Zhen; Kang, Y James

    2012-08-01

    Cobalt inhibits prolyl hydroxylases, leading to the accumulation of hypoxia-inducible factor-1α (HIF-1α) and a concomitant increase in the transcriptional activity of HIF-1. Therefore, cobalt has been under development as a drug for activating HIF-1 under some disease conditions. However, it has been shown that ischemic conditions resulted in the loss of copper, and the activation of HIF-1 would not occur unless copper was supplemented. The present study was undertaken to test the hypothesis that copper is also required for the cobalt activation of HIF-1 transcriptional activity. Human umbilical vein endothelial cells subjected to treatment with cobalt chloride (CoCl(2)) at concentrations above 25 μM for 2 h resulted in an accumulation of HIF-1α, which was determined by Western blot analysis, and an increase in the expression of vascular endothelial growth factor (VEGF), which was determined by real-time reverse transcription-polymerase chain reaction analysis for mRNA levels and enzyme-linked immunosorbent assay analysis for protein levels. The copper chelator tetraethylenepentamine at 25 μM did not significantly affect the accumulation of HIF-1α but blocked increases in VEGF mRNA and protein levels, an effect that could be reversed by the addition of 25 μM copper sulfate (CuSO(4)). In addition, gene silencing of the copper chaperone for Cu,Zn-superoxide dismutase blocked VEGF expression with little effect on cobalt-induced HIF-1α accumulation. The present study thus demonstrates that copper was required for cobalt-activated transcriptional activity of HIF-1, although copper did not affect cobalt-induced accumulation of HIF-1α in the cells.

  17. Chemically Induced and Light-Independent Cryptochrome Photoreceptor Activation

    Institute of Scientific and Technical Information of China (English)

    Gesa Rosenfeldt; Rafael Mu(n)oz Viana; Henning D.Mootz; Albrecht G.Von Arnim; Alfred Batschauer

    2008-01-01

    The cryptochrome photoreceptors of higher plants are dimeric proteins. Their N-terminal photosensory domain mediates dimerization, and the unique C-terminal extension (CCT) mediates signaling. We made use of the human FK506-binding protein (FKBP) that binds with high affinity to rapamycin or rapamycin analogs (rapalogs). The FKBP-rapamycin complex is recognized by another protein, FRB, thus allowing rapamycin-induced dimerization of two target proteins. Here we demonstrate by bioluminescence resonance energy transfer (BRET) assays the applicability of this regulated dimerization system to plants. Furthermore, we show that fusion proteins consisting of the C-terminal domain of Arabidopsis cryptochrome 2 fused to FKBP and FRB and coexpressed in Arabidopsis cells specifically induce the expression of cryptochrome-controlled reporter and endogenous genes in darkness upon incubation with the rapalog. These results demonstrate that the activation of cryptochrome signal transduction can be chemically induced in a dose-dependent fashion and uncoupled from the light signal, and provide the groundwork for gain-of-function experiments to study specifically the role of photoreceptors in darkness or in signaling cross-talk even under light conditions that activate members of all photoreceptor families.

  18. Platelet-Activating Factor Induces Th17 Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Anne-Marie Drolet

    2011-01-01

    Full Text Available Th17 cells have been implicated in a number of inflammatory and autoimmune diseases. The phospholipid mediator platelet-activating factor (PAF is found in increased concentrations in inflammatory lesions and has been shown to induce IL-6 production. We investigated whether PAF could affect the development of Th17 cells. Picomolar concentrations of PAF induced IL-23, IL-6, and IL-1β expression in monocyte-derived Langerhans cells (LCs and in keratinocytes. Moreover, when LC were pretreated with PAF and then cocultured with anti-CD3- and anti-CD28-activated T cells, the latter developed a Th17 phenotype, with a significant increase in the expression of the transcriptional regulator RORγt and enhanced expression of IL-17, IL-21, and IL-22. PAF-induced Th17 development was prevented by the PAF receptor antagonist WEB2086 and by neutralizing antibodies to IL-23 and IL-6R. This may constitute a previously unknown stimulus for the development and persistence of inflammatory processes that could be amenable to pharmacologic intervention.

  19. CREB is activated in EPO induced HEL cells

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    cAMP response element binding protein (CREB) is a transcription factor in nucleus. The activating CREB can specifically bind to the cAMP response element (CRE). The present result showed that erythropoietin (EPO) could induce the phosphorylation of CREB on Serine133(Pser133), as detected by Western blot analysis. In addition, the EPO-dependent activation of CREB binding to CRE element was demonstrated by electrophoretic mobility shift assay. However, the binding of CREB to CRE element could be inhibited by anti-CREB-Pser133antibody. The data obtained suggested that the EPO-mediated CREB phosphorylation might be critical to both the binding of CREB to the CRE element and the activation of the CREB transcription factor.

  20. The tick-derived anticoagulant madanin is processed by thrombin and factor Xa.

    Directory of Open Access Journals (Sweden)

    Ana C Figueiredo

    Full Text Available The cysteine-less peptidic anticoagulants madanin-1 and madanin-2 from the bush tick Haemaphysalis longicornis are the founding members of the MEROPS inhibitor family I53. It has been previously suggested that madanins exert their functional activity by competing with physiological substrates for binding to the positively charged exosite I (fibrinogen-binding exosite of α-thrombin. We hereby demonstrate that competitive inhibition of α-thrombin by madanin-1 or madanin-2 involves binding to the enzyme's active site. Moreover, the blood coagulation factors IIa and Xa are shown to hydrolyze both inhibitors at different, although partially overlapping cleavage sites. Finally, the three-dimensional structure of the complex formed between human α-thrombin and a proteolytic fragment of madanin-1, determined by X-ray crystallography, elucidates the molecular details of madanin-1 recognition and processing by the proteinase. Taken together, the current findings establish the mechanism of action of madanins, natural anticoagulants that behave as cleavable competitive inhibitors of thrombin.

  1. 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.

  2. 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.

  3. Monitoring of Anticoagulant Therapy in Heart Disease: Considerations for the Current Assays

    Directory of Open Access Journals (Sweden)

    Hamidreza Goodarzynejad

    2010-05-01

    Full Text Available 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

  4. Electron beam induced surface activation of oxide surfaces for nanofabrication

    Energy Technology Data Exchange (ETDEWEB)

    Vollnhals, Florian; Seiler, Steffen; Walz, Marie-Madeleine; Steinrueck, Hans-Peter; Marbach, Hubertus [Lehrstuhl fuer Physikalische Chemie II and Interdisciplinary Center for Molecular Materials (ICMM), Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen (Germany); Woolcot, Tom; Thornton, Geoff [London Centre for Nanotechnology and Department of Chemistry, University College London (United Kingdom)

    2012-07-01

    The controlled fabrication of structures on the nanoscale is a major challenge in science and engineering. Direct-write techniques like Electron Beam Induced Deposition (EBID) were shown to be suitable tools in this context. Recently, Electron Beam Induced Surface Activation (EBISA) has been introduced as a new focused electron beam technique. In EBISA, a surface, e.g. SiO{sub 2}, is irradiated by a focused electron beam, resulting in an activation of the exposed area. The activated area can then react and decompose precursor gases like iron pentacarbonyl, Fe(CO){sub 5}. This leads to a primary deposit, which continues to grow autocatalytically as long as Fe(CO){sub 5} is supplied, resulting in pure (> 90 % at.), crystalline iron nanostructures. We expand the use of this concept by exploring EBISA to produce metallic nanostructures on TiO{sub 2}(110) in UHV; atomistic insight into the process is obtained via Scanning Tunneling Microscopy (STM) and chemical insight via Auger Electron Spectroscopy (AES).

  5. Sulfation pattern of citrus pectin and its carboxy-reduced derivatives: influence on anticoagulant and antithrombotic effects.

    Science.gov (United States)

    Maas, Nadiezda C; Gracher, Ana Helena P; Sassaki, Guilherme L; Gorin, Philip A J; Iacomini, Marcello; Cipriani, Thales R

    2012-08-01

    Citrus pectin (CP), a polysaccharide composed of [→4)-α-D-GalpA-(1→]n, was submitted to one or four carboxy-reduction cycles, resulting in CP-CR1 and CP-CR4, which had 40% and 2% of GalpA units, respectively. The polysaccharides were chemically sulfated and their anticoagulant and antithrombotic effects determined. Sulfated polysaccharides (CP-S, CP-CR1S and CP-CR4S) had different anticoagulant activities, doubling APTT at concentrations of 28.7, 13.2, and 4.9 μg/ml respectively. CP-CR1S and CP-CR4S also showed antithrombotic activity in vivo with ED50 of 3.01 and 1.70 mg/kg, respectively. Like heparin, they inhibited thrombin by a mechanism dependent on AT and HCII. Their hemorrhagic potential was also similar to that of heparin. According to methylation analysis, 91.1% and 50.2% of 6-O-position in CP-CR4S and CP-CR1S were sulfated, respectively. Therefore, substitution of carboxyl groups by sulfate esters in these polysaccharides increases the anticoagulant and antithrombotic effects.

  6. New classification of landslide-inducing anthropogenic activities

    Science.gov (United States)

    Michoud, C.; Jaboyedoff, M.; Derron, M.-H.; Nadim, F.; Leroi, E.

    2012-04-01

    Although landslides are usually considered typical examples of natural hazards, they can be influenced by human activities. Many examples can be found in the literature about slope instabilities induced by anthropogenic activities, ranging from small superficial landslides to rock avalanches. Research on this topic is of primary importance for understanding and mitigation of landslide risk. Indeed, slope stabilities influenced by human actions contribute significantly to the risk level because, by definition, they are located where elements at risk and people are present. Within the framework of the European project SafeLand "Living with Landslide Risk in Europe", the authors analyzed the landslides induced by anthropogenic factors in Europe and elsewhere (SafeLand deliverable D1.6). During the bibliographical research, it appeared that a complete and illustrated classification on human activities influencing slope stabilities does not yet exist. Therefore, a new classification was introduced by Michoud et al. (2011) about anthropogenic activities affecting slope stability conditions. This classification takes into account conceptual processes leading to landslides (Terzaghi, 1950; Jaboyedoff and Derron, 2005) and the distinction between destabilization factors and triggering factors (Vaunat et al., 1994; Leroueil et al., 1996). The classification was tested and improved through fifty-eight well-documented case studies, even lots of large landslides, such as Elm, Aberfan, Namsos and Rissa landslides, etc. Furthermore, the boundary between natural and "anthropogenic" landslide triggers (e.g. water run-off modified by new land-uses, creating landslides some km farther), and the time during which changes and reactions are to be considered as direct consequences of human activities were highlighted. Finally, anthropogenic influences can also be positive and examples of (non-voluntary) positive human impacts on slope stability are presented. Jaboyedoff, M. and Derron, M

  7. Activation-Induced Cell Death in T Cells and Autoimmunity

    Institute of Scientific and Technical Information of China (English)

    Jian Zhang; Xuemei Xu; Yong Liu

    2004-01-01

    Activation-induced cell death (AICD), which results from the interaction between Fas and Fas ligand, is responsible for maintaining tolerance to self-antigen. A defect in AICD may lead to development of autoimmunity. During the last several years, much progress has been made in understanding the mechanism(s) of AICD and its potential role in the pathogenesis of autoimmune diseases. In this review, we summarize the most recent progress on the regulation of the susceptibility of T cells to AICD and its possible involvement in autoimmune diseases.

  8. Terpenoids from Diplophyllum taxifolium with quinone reductase-inducing activity.

    Science.gov (United States)

    Wang, Xiao; Zhang, Jiao-Zhen; Zhou, Jin-Chuan; Shen, Tao; Lou, Hong-Xiang

    2016-03-01

    Two new ent-prenylaromadendrane-type diterpenoids, diplotaxifols A (1) and B (2), a new ent-eudesmol, ent-eudesma-4(15),11(13)-dien-6α,12-diol (3), eight new eudesmanolides enantiomers (4-11) of the corresponding compounds from higher plants along with four known ent-eudesmanolides (12-15) were isolated from the 95% EtOH extract of Chinese liverwort Diplophyllum taxifolium. Their structures were elucidated on the basis of MS, NMR and IR spectral data, and confirmed by single-crystal X-ray diffraction analysis. The quinone reductase-inducing activity of the compounds was evaluated.

  9. New oral anticoagulants in atrial fibrillation and acute coronary syndromes: ESC Working Group on Thrombosis-Task Force on Anticoagulants in Heart Disease position paper.

    NARCIS (Netherlands)

    Caterina, R. de; Husted, S.; Wallentin, L.; Andreotti, F.; Arnesen, H.; Bachmann, F.; Baigent, C.; Huber, K.; Jespersen, J.; Kristensen, S.D.; Lip, G.Y.; Morais, J.; Rasmussen, L.H.; Siegbahn, A.; Verheugt, F.W.A.; Weitz, J.I.

    2012-01-01

    Until recently, vitamin K antagonists were the only available oral anticoagulants, but with numerous limitations that prompted the introduction of new oral anticoagulants targeting the single coagulation enzymes thrombin (dabigatran) or factor Xa (apixaban, rivaroxaban, and edoxaban) and given in fi

  10. Genetic determinants of response and adverse effects following vitamin K antagonist oral anticoagulants

    Directory of Open Access Journals (Sweden)

    Parameshwar S.

    2016-06-01

    Full Text Available Background: Vitamin K antagonist anticoagulants (warfarin/acenocoumarol are commonly used anticoagulants that require careful clinical management to balance the risks of over anticoagulation and bleeding with those of under anticoagulation and clotting. Genetic variants of the enzyme that metabolizes vitamin K antagonist anticoagulant, cytochrome P-450 2C9 (CYP2C9, and of a key pharmacologic target of vitamin K antagonists anticoagulant, vitamin K epoxide reductase (VKORC1, contribute to differences in patients responses to various anticoagulant doses. Methods: In thirty patients on oral vitamin K antagonist anticoagulant therapy, presented with either clotting manifestations (valve thrombosis, pulmonary embolism and DVT or prolonged INR/bleeding manifestations, we assessed CYP2C9 genotypes, VKORC1 haplotypes, clinical characteristics, response to therapy (as determined by the international normalized ratio [INR], and bleeding events. Results: Of the thirty patients, thirteen patients INR was high and four patients presented with major bleeding and four with minor bleeding manifestations. Out of thirteen patients with high INR, ten patients showed CYP2C9 polymorphism ( 1/ 3 and 2/ 3 of poor metabolizer genotype. Most of the high INR patients were recently started on oral vitamin K antagonist anticoagulant. Most patients presented with clotting manifestations with below therapeutic INR are noncompliant with anticoagulants. Conclusions: The results of this study suggest that the CYP2C9 polymorphisms are associated with an increased risk of over anticoagulation and of bleeding events among patients on vitamin K antagonists' anticoagulant setting. Screening for CYP2C9 variants may allow clinicians to develop dosing protocols and surveillance techniques to reduce the risk of adverse drug reactions in patients receiving vitamin K antagonist anticoagulants. However the cost-effectiveness of genotyping of patients must be considered. [Int J Res Med Sci

  11. [Bilateral renal infarction after discontinuation of anticoagulant therapy].

    Science.gov (United States)

    Lavoignet, Charles-Éric; Le Borgne, Pierrick; Ugé, Sarah; Veneziano, Rinaldo; Brunhuber, Claudia; Kam, Claire; Bilbault, Pascal

    2016-07-01

    Acute renal infarction is an uncommon and often under diagnosed condition mostly because of misleading symptoms. Accurate data regarding clinical presentation, laboratory tests, diagnostic and treatment are lacking. Detection is often delayed or missed because of non-specific clinical presentation. The mechanisms of acute renal infarction are various, mainly embolic or thrombotic. Abdominal CT scan remains the most valuable exam to confirm the diagnosis. Therapeutic guidelines for the treatment of renal embolism have not been well established. The standard treatment strategy includes anticoagulation with or without thrombolysis. Despite the uncertainty regarding management, the renal outcome remains favorable. Some patients do develop some degree of renal insufficiency during the acute episode. We report here the case of a 73-year-old woman with bilateral acute renal infarction after discontinuation of anticoagulant therapy.

  12. Old and new applications of non-anticoagulant heparin.

    Science.gov (United States)

    Cassinelli, Giuseppe; Naggi, Annamaria

    2016-06-01

    The aim of this chapter is to provide an overview of non-anticoagulant effects of heparins and their potential use in new therapeutic applications. Heparin and heparin derivatives have been tested in inflammatory, pulmonary and reproductive diseases, in cardiovascular, nephro- and neuro-tissue protection and repair, but also as agents against angiogenesis, atheroschlerosis, metastasis, protozoa and viruses. Targeting and inhibition of specific mediators involved in the inflammatory process, promoting some of the above mentioned pathologies, are reported along with recent studies of heparin conjugates and oral delivery systems. Some reports from the institute of the authors, such as those devoted to glycol-split heparins are also included. Among the members and derivatives of this class, several are undergoing clinical trials as antimetastatic and antimalarial agents and for the treatment of labour pain and severe hereditary anaemia. Other heparins, whose therapeutic targets are non-anticoagulant such as nephropathies, retinopathies and cystic fibrosis are also under investigation.

  13. Generic switching of warfarin and risk of excessive anticoagulation

    DEFF Research Database (Denmark)

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

    2015-01-01

    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...

  14. Successful Anticoagulation Therapy for Antiphospholipid Syndrome with Mobile Aortic Thrombi

    Science.gov (United States)

    Park, Hyun Oh; Moon, Seong Ho; Kim, Jong Woo; Byun, Joung Hun; Kim, Sung Hwan; Yang, Jun Ho; Lee, Chung-Eun; Kim, Jong-Duk

    2016-01-01

    Hypercoagulable states have been associated with aortic thrombosis. Antiphospholipid syndrome (APS) is one of the commonest types of acquired thrombophilia. We report the case of successful anticoagulation management in an APS patient with mobile thrombi within the aorta. A 58-year-old male patient presented to the emergency department (ED) with right-sided hemiparesis. His first symptoms were noted approximately 12–16 hours before presentation to the ED. Magnetic resonance imaging of the brain showed acute embolic infarction of the left frontal and parietotemporal lobes. Transesophageal echocardiography (TEE) and computed tomography angiography (CTA) demonstrated mobile thrombi attached to the wall of the ascending aorta and aortic arch. The patient was diagnosed with APS based on positivity of anti-beta-2 glycoprotein 1 antibodies, and was initiated on anticoagulation therapy. Repeated TEE and CTA revealed complete resolution of the thrombi after 12 days of treatment; the patient was discharged well. PMID:28042559

  15. New antiplatelet and anticoagulant drugs. Considerations for dental patient management.

    Science.gov (United States)

    Cohen, Harold V; Quek, Samuel Y P; Subramanian, Gayathri; Abbas, Ali

    2013-01-01

    A recent occurrence in dental practice is the noting of new "blood thinners" when the clinician is reviewing a patient's medical history and medications. "Doc, I take Pradaxa or Effient or Xarelto" etc. After many years of the widespread use of aspirin and Coumadin there has appeared a new generation of medications focused on reducing thromboembolic events in patients at risk. This trend has been driven by a need for drugs providing better drug efficacy based on patient biologic processing of the medications and the frequency and cost factors associated with the monitoring the degree of anticoagulation. Guidelines for assessing bleeding risk and managing patients on these new medications in dental practice are not yet defined and are empirically based on medical practitioner experience. This paper will review these new medications and will discuss current considerations for dental patient care. (Note that not all new antiplatelet and anticoagulant medications will be reviewed in this paper.)

  16. New oral anticoagulants in non-valvular atrial fibrillation.

    Science.gov (United States)

    Francia, Pietro; Adduci, Carmen; Santini, Daria; Musumeci, Beatrice; Tocci, Giuliano

    2013-06-01

    Atrial fibrillation (AF) is associated with an increased risk of embolic stroke. Dose-adjusted vitamin K antagonists (VKAs) to a target international normalized ratio (INR) range of 2.0-3.0 reduce the risk of ischemic stroke and are currently recommended in all patients with AF at moderate-high risk for stroke or systemic embolism. However, VKAs have several drawbacks, including unpredictable anticoagulant response, food and drug interactions, need for regular laboratory monitoring and dose adjustment. These limitations prompted the introduction of new oral anticoagulants (NOA) that target thrombin and factor Xa, key-enzymes in the coagulation pathway. NOA have predictable pharmacodynamics, allowing fixed dosing without the need of laboratory monitoring, and have few drug and food interactions. The present review focuses on pharmacological properties, safety, and appropriate clinical use of dabigatran, rivaroxaban and apixaban.

  17. Opioid-Induced Glial Activation: Mechanisms of Activation and Implications for Opioid Analgesia, Dependence, and Reward

    Directory of Open Access Journals (Sweden)

    Mark R. Hutchinson

    2007-01-01

    Full Text Available This review will introduce the concept of toll-like receptor (TLR–mediated glial activation as central to all of the following: neuropathic pain, compromised acute opioid analgesia, and unwanted opioid side effects (tolerance, dependence, and reward. Attenuation of glial activation has previously been demonstrated both to alleviate exaggerated pain states induced by experimental pain models and to reduce the development of opioid tolerance. Here we demonstrate that selective acute antagonism of TLR4 results in reversal of neuropathic pain as well as potentiation of opioid analgesia. Attenuating central nervous system glial activation was also found to reduce the development of opioid dependence, and opioid reward at a behavioral (conditioned place preference and neurochemical (nucleus accumbens microdialysis of morphine-induced elevations in dopamine level of analysis. Moreover, a novel antagonism of TLR4 by (+- and (˗-isomer opioid antagonists has now been characterized, and both antiallodynic and morphine analgesia potentiating activity shown. Opioid agonists were found to also possess TLR4 agonistic activity, predictive of glial activation. Targeting glial activation is a novel and as yet clinically unexploited method for treatment of neuropathic pain. Moreover, these data indicate that attenuation of glial activation, by general or selective TLR antagonistic mechanisms, may also be a clinical method for separating the beneficial (analgesia and unwanted (tolerance, dependence, and reward actions of opioids, thereby improving the safety and efficacy of their use.

  18. Lumbar puncture in patients using anticoagulants and antiplatelet agents

    OpenAIRE

    Renan Domingues; Gustavo Bruniera; Fernando Brunale; Cristóvão Mangueira; Carlos Senne

    2016-01-01

    ABSTRACT The use of anticoagulants and antiplatelet agents has largely increased. Diagnostic lumbar puncture in patients taking these drugs represents a challenge considering the opposing risks of bleeding and thrombotic complications. To date there are no controlled trials, specific guidelines, nor clear recommendations in this area. In the present review we make some recommendations about lumbar puncture in patients using these drugs. Our recommendations take into consideration the pharmaco...

  19. Oral anticoagulant therapy related to oral surgery procedures

    OpenAIRE

    Knežević Milan; Petrović Dragan; Jović Nebojša; Bosch Carlos

    2011-01-01

    Today there must be established protocol in oral surgery treatment for the patients which are under anticoagulant treatment via oral (ATO). This is due to danger of the possible complications and also for increased demand for hospital treatment of these patients, which can be estimated now days as high as 8%. In the present study, the authors intent to define all the parameters for creation of one acting protocol applicable to this group of patients and concluding that there is no necessary n...

  20. [Novel oral anticoagulants and atrial fibrillation in the elderly].

    Science.gov (United States)

    Hanon, Olivier

    2013-12-01

    Atrial fibrillation treatment relies on anticoagulation therapy that reduces the risk of stroke. Vitamin K antagonists (VKA) were the only oral anticoagulant drugs for more than 50 years, but they are difficult to manage especially in the elderly. In France, VKA are the main cause of iatrogenic hospitalizations with about 17,000 hospitalizations per year and around 4,000 to 5,000 deaths per year. Pharmacologic properties of VKA, especially the narrow therapeutic margin explain the complexity of their management. Several studies have shown that patients treated with VKA were on average only 50% of the time with an INR in the therapeutic range. In other words, patients are, half of the time, either-under treated or over-treated. Within this framework, development of new oral anticoagulant drugs appeared necessary, in order to obtain drugs with larger therapeutic margin and a better risk/benefit profile than VKA. Three large randomized clinical trials including almost 50,000 patients with 20,000 subjects over 75 years old and 8,000 over 80 years old, show a better risk/benefit profile of the new oral anticoagulants (NOAC) than VKA, characterized by a 50% reduction of cerebral hemorrhages, 22% reduction of stroke and 12% reduction of total mortality. Meanwhile, their renal elimination and the lack of control of the biological efficacy need to be taken into account for their prescription. Renal failure (estimated glomerular filtration rate according to Cockcroft formula < 30 mL/min) contraindicates their use. Their half-life is shorter than that of VKA and the biological monitoring is not available, thus a good adherence to the treatment is important. Studies specifically conducted among geriatric older population with poly-pathologies and frail are therefore needed to evaluate tolerance of NOAC in real life conditions.

  1. Fission and spallation data evaluation using induced-activity method

    CERN Document Server

    Karapetyan, G S

    2015-01-01

    The induced-activity investigations in off-line analysis performed in different experiments, concerning pre-actinide and actinide nuclei, are here presented and discussed. Generalized expressions for the determination of independent yields/cross sections of radioactive nuclei, formed in the targets, are derived and analysed. The fragment mass distribution from U-238, Th-232 and Ta-181 photofission at the bremsstrahlung end-point energies of 50 and 3500 MeV, and from Am-241, U-238 and Np-237 fission induced by 660-MeV protons, are scrutinized from the point of view of the multimodal fission approach. The results of these studies are hence compared with theoretical model calculations using the CRISP code. We subsequently discuss the complex particle-induced reaction, such as heavy-ions and deuterons, by using the thick-target thick-catcher technique and the two-step vector model framework as well. This is accomplished in order to present the investigation of the main processes (fission, spallation and (multi)fr...

  2. 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.

  3. 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.

  4. Direct-acting oral anticoagulants: pharmacology, indications, management, and future perspectives.

    Science.gov (United States)

    Gómez-Outes, Antonio; Suárez-Gea, Ma Luisa; Lecumberri, Ramón; Terleira-Fernández, Ana Isabel; Vargas-Castrillón, Emilio

    2015-11-01

    In recent years, several direct-acting oral anticoagulants (DOAC) have become available for use in Europe and other regions in indications related to prophylaxis and treatment of venous and arterial thromboembolism. They include the oral direct thrombin inhibitor dabigatran etexilate (Pradaxa, Boehringer Ingelheim) and the oral direct FXa inhibitors rivaroxaban (Xarelto, Bayer HealthCare), apixaban (Eliquis, Bristol-Myers Squibb), and edoxaban (Lixiana/Savaysa, Daiichi-Sankyo). The new compounds have a predictable dose response and few drug-drug interactions (unlike vitamin k antagonists), and they do not require parenteral administration (unlike heparins). However, they accumulate in patients with renal impairment, lack widely available monitoring tests for measuring its anticoagulant activity, and no specific antidotes for neutralization in case of overdose and/or severe bleeding are currently available. In this review, we describe the pharmacology of the DOAC, the efficacy, and safety data from pivotal studies that support their currently approved indications and discuss the postmarketing experience available. We also summarize practical recommendations to ensure an appropriate use of the DOAC according to existing data. Finally, we discuss relevant ongoing studies and future perspectives.

  5. Stroke Prevention in Atrial Fibrillation: Understanding the New Oral Anticoagulants Dabigatran, Rivaroxaban, and Apixaban

    Directory of Open Access Journals (Sweden)

    Tan Ru San

    2012-01-01

    Full Text Available Unlike vitamin K antagonists (VKAs, the new oral anticoagulants (NOACs—direct thrombin inhibitor, dabigatran, and direct activated factor X inhibitors, rivaroxaban, and apixaban—do not require routine INR monitoring. Compared to VKAs, they possess relatively rapid onset of action and short halflives, but vary in relative degrees of renal excretion as well as interaction with p-glycoprotein membrane transporters and liver cytochrome P450 metabolic enzymes. Recent completed phase III trials comparing NOACs with VKAs for stroke prevention in atrial fibrillation (AF—the RE-LY, ROCKET AF, and ARISTOTLE trials—demonstrated at least noninferior efficacy, largely driven by significant reductions in haemorrhagic stroke. Major and nonmajor clinically relevant bleeding rates were acceptable compared to VKAs. Of note, the NOACs caused significantly less intracranial haemorrhagic events compared to VKAs, the mechanisms of which are not completely clear. With convenient fixed-dose administration, the NOACs facilitate anticoagulant management in AF in the community, which has hitherto been grossly underutilised. Guidelines should evolve towards simplicity in anticipation of greater use of NOACs among primary care physicians. At the same time, the need for caution with their use in patients with severely impaired renal function should be emphasised.

  6. 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.

  7. 8. Are nurse-led prosthetic valve anticoagulation clinics effective?

    Directory of Open Access Journals (Sweden)

    F. Obeid

    2016-07-01

    Full Text Available Valvular heart disease is a major and serious healthcare issue. There is an increasing evidence that Nurse-led anticoagulation clinics may improve patients’ management and care.This is a retrospective comparison study that included the first 94 patients enrolled in the Nurse Led Prosthetic Valve Anticoagulation Clinic (PVATC in King Abdul-Aziz Cardiac Centre between April and June 2013, and received Warfarin by General Cardiology Clinics for one year pre enrollment in PVATC, and one year after. Time in Therapeutic Range (TTR of the International Normalized Ratio (INR was calculated and compared between pre and post PVATC enrolment. Other data including demographics and comorbidities were collected and analyzed. Mean age of patients was 53 ± 12.5 years and males were 56%. Atrial fibrillation was found in 37%, Diabetes Mellitus in 28% and Hypertension in 34%. Mean TTR was 72% pre enrollment in PVATC as compared to 78.9% after (P < 0.006. Median TTR was 75% pre, and 81.5% after attending the PVATC (P < 0.0001. 56% of patients pre enrollment had TTR values above 70% threshold, compared to 75% after enrollment. Nurse-Led PVATC has significant impact on the care provided to patients receiving anticoagulation treatment.

  8. 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.

  9. New anticoagulants in the treatment of stroke:future promise

    Institute of Scientific and Technical Information of China (English)

    Emre Kumral; Tuba Cerraho(g)lu (S)irin

    2013-01-01

    Recent evidence is leading to the replacement of vitamin K antagonists,the efficacy of which in preventing stroke in patients with atrial fibrillation (AF) is well established,with better tolerated and more manageable new anticoagulant drugs,with a lower risk of intracranial bleeding,no clear interactions with food,fewer interactions with medications,and no need for frequent laboratory monitoring and dose adjustments.Among new anticoagulants,dabigatran etexilate is a direct,competitive inhibitor of thrombin.It was evaluated for patients with AF in the RE-LY trial,showing lower rates of stroke and systemic embolism at a dose of 150 mg twice daily with similar rates of major hemorrhage compared with warfarin; and non-inferiority compared with warfarin for the prevention of stroke and systemic embolism at a dose of 110 mg twice daily,with lower rates of major bleeding.Beside dabigatran,oral factor X a inhibitors are also emerging for the prevention of thromboembolic events in AF.Despite the obvious advantages of these new oral anticoagulants over vitamin K antagonists,further information is still needed on how to prioritize the patients deriving the greatest benefit from these novel agents on the basis of patient characteristics or drug pharmacokinetics.There is also a need for assessing their long-term efficacy and safety over decades in the real-world setting.

  10. 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.

  11. Dental management of patients receiving anticoagulation or antiplatelet treatment.

    Science.gov (United States)

    Pototski, Mariele; Amenábar, José M

    2007-12-01

    Antiplatelet and anticoagulant agents have been extensively researched and developed as potential therapies in the prevention and management of arterial and venous thrombosis. On the other hand, antiplatelet and anticoagulant drugs have also been associated with an increase in the bleeding time and risk of postoperative hemorrhage. Because of this, some dentists still recommend the patient to stop the therapy for at least 3 days before any oral surgical procedure. However, stopping the use of these drugs exposes the patient to vascular problems, with the potential for significant morbidity. This article reviews the main antiplatelet and anticoagulant drugs in use today and explains the dental management of patients on these drugs, when subjected to minor oral surgery procedures. It can be concluded that the optimal INR value for dental surgical procedures is 2.5 because it minimizes the risk of either hemorrhage or thromboembolism. Nevertheless, minor oral surgical procedures, such as biopsies, tooth extraction and periodontal surgery, can safely be done with an INR lower than 4.0.

  12. 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.

  13. Survival of heparins, oral anticoagulants, and aspirin after the year 2010.

    Science.gov (United States)

    Fareed, Jawed; Hoppensteadt, Debra A; Fareed, Daniel; Demir, Muzaffer; Wahi, Rakesh; Clarke, Melaine; Adiguzel, Cafer; Bick, Rodger

    2008-02-01

    The conventional management of thrombotic and cardiovascular disorders is based on the use of heparin, oral anticoagulants, and aspirin. Despite remarkable progress in life sciences, these drugs still remain a challenge and a mystery to us, and their use is far from optimized. The development of low-molecular-weight heparins and the synthesis of heparinomimetics, such as the chemically synthesized pentasaccharide, represent a refined use of heparin. Additional drugs from this knowledge will continue to develop; however, none of these drugs will ever match the polypharmacology of heparin. Aspirin still remains the leading drug in the management of thrombotic and cardiovascular disorders. The newer antiplatelet drugs such as adenosine diphosphate receptor inhibitors, glycoprotein IIb/IIIa inhibitors, and other specific inhibitors have limited effects and have been tested in patients who have already been treated with aspirin. Warfarin provides a convenient and affordable approach in the long-term outpatient management of thrombotic disorders. The optimized use of these drugs still remains as the approach of choice to manage thrombotic disorders. The new anticoagulant targets, including specific sites in the hemostatic network such as tissue factor, individual clotting factors (IIa, VIIa, IXa, Xa, XIIa, and XIIIa), recombinant forms of serpins (antithrombin, heparin cofactor II, and tissue factor pathway inhibitors), recombinant activated protein C, thrombomodulin, and site-specific serine protease inhibitor complexes have also been developed. There is a major thrust on the development of orally bioavailable anticoagulant drugs (anti-Xa and anti-IIa agents), which are slated to replace oral anticoagulants. Both the anti-factor Xa and antithrombin agents have been developed for oral use and have provided impressive clinical outcomes in sponsor trials for the postsurgical prophylaxis of venous thrombosis; however, safety concerns related to liver enzyme elevations and

  14. Clinical significance of the mixing test in laboratory diagnoses of lupus anticoagulant: the fate of the mixing test in integrated lupus anticoagulant test systems.

    Science.gov (United States)

    Hong, Sung Kuk; Hwang, Sang Mee; Kim, Ji-Eun; Kim, Hyun Kyung

    2012-12-01

    The mixing test is used to determine the presence of inhibitors in laboratory diagnoses of lupus anticoagulant. Updated international guidelines state that an integrated lupus anticoagulant test system does not require the mixing test; an appraisal of the mixing tests in integrated lupus anticoagulant test systems is, therefore, required. We investigated the clinical relevance of mixing tests by using the best cutoff value of the mixing test through thrombotic risk analysis. A retrospective analysis was performed on 525 specimens with positive screening tests by using two integrated lupus anticoagulant tests: diluted Russell's Viper venom (dRVVT) and silica clotting time. The diagnostic performance of two interpretation formulas (percentage correction, Rosner index) was assessed, and the thrombotic risk of a subgroup based on the mixing results was investigated. Finally, the thrombotic risk of lupus anticoagulant positivity based on the integrated lupus anticoagulant test system procedures was assessed for the appraisal of mixing test exclusion in integrated lupus anticoagulant test systems. The best cutoff values of mixing test interpretation methods based on dRVVT were as follows: 60.1% for percentage correction and 15.7 for Rosner index. There was no substantial difference in the thrombotic risk between percentage correction and the Rosner index. The mixing-positive group showed a higher lupus anticoagulant titer and higher thrombotic risk than the mixing-negative group. However, even the mixing-negative group carried a significant risk of thrombosis. Finally, lupus anticoagulant positivity determined by the updated two-step procedure (screening and confirmation tests) showed higher thrombotic risk than that determined by the traditional three-step procedure (screening, mixing, and confirmation tests). Although a positive mixing result can predict a high risk of thrombosis, negative mixing results are also associated with a substantial thrombotic risk. The

  15. Active Control Does Not Eliminate Motion-Induced Illusory Displacement

    Directory of Open Access Journals (Sweden)

    Ian M. Thornton

    2011-05-01

    Full Text Available When the sine-wave grating of a Gabor patch drifts to the left or right, the perceived position of the entire object is shifted in the direction of local motion. In the current work we explored whether active control of the physical position of the patch overcomes such motion induced illusory displacement. In Experiment 1 we created a simple computer game and asked participants to continuously guide a Gabor patch along a randomly curving path using a joystick. When the grating inside the Gabor patch was stationary, participants could perform this task without error. When the grating drifted to either left or right, we observed systematic errors consistent with previous reports of motion-induced illusory displacement. In Experiment 2 we created an iPad application where the built-in accelerometer tilt control was used to steer the patch through as series of “gates”. Again, we observed systematic guidance errors that depended on the direction and speed of local motion. In conclusion, we found no evidence that participants could adapt or compensate for illusory displacement given active control of the target.

  16. Hyaluronic acid induces activation of the κ-opioid receptor.

    Directory of Open Access Journals (Sweden)

    Barbara Zavan

    Full Text Available INTRODUCTION: Nociceptive pain is one of the most common types of pain that originates from an injury involving nociceptors. Approximately 60% of the knee joint innervations are classified as nociceptive. The specific biological mechanism underlying the regulation of nociceptors is relevant for the treatment of symptoms affecting the knee joint. Intra-articular administration of exogenous hyaluronic acid (HA in patients with osteoarthritis (OA appears to be particularly effective in reducing pain and improving patient function. METHODS: We performed an in vitro study conducted in CHO cells that expressed a panel of opioid receptors and in primary rat dorsal root ganglion (DRG neurons to determine if HA induces the activation of opioid peptide receptors (OPr using both aequorin and the fluorescent dye Fura-2/AM. RESULTS: Selective agonists and antagonists for each OPr expressed on CHO cells were used to test the efficacy of our in vitro model followed by stimulation with HA. The results showed that HA induces stimulatory effects on the κ receptor (KOP. These effects of HA were also confirmed in rat DRG neurons, which express endogenously the OPr. CONCLUSIONS: HA activates the KOP receptor in a concentration dependent manner, with a pEC(50 value of 7.57.

  17. Activation of phospholipase D activity in transforming growth factor—beta—induced cell growth inhibition

    Institute of Scientific and Technical Information of China (English)

    ZHOUBINGHONG; JUNSONGCHEN; 等

    2000-01-01

    Cells regulate phospholipase D(PLD) activity in response to numerous extracellular signals.Here,we investigated the involvement of PLD activity in transforming growth factor-β(TGF-β1)-mediated growth inhibition of epithelial cells.TGF-β1)-mediated growth inhibition of epithelial cells.TGF-β1 inhibits the growth of MDCK,Mv1Lu,and A-549 cells.In the presence of 0.4% butanol,TGF-β1 induces an increase in the formation of phosphatidylbutanol,a unique product catalyzed by PLD.TGF-β1 also induces an increase in phosphatidic acid (PA) level in A-549 and MDCK cells.TGF-β1 induces an increase in the levels of DAG labeled with [3H]-myristic acid in A-549 and MDCK cells but not in Mv1Lu cells.No increase of DAG was observed in cells prelabeled with [3H]-arachidonic acid.The data presented suggest that PLD activation is involved in the TGF-β1-induced cell growth inhibition.

  18. Lupus anticoagulant is significantly associated with inflammatory reactions in patients with suspected deep vein thrombosis

    DEFF Research Database (Denmark)

    Sidelmann, Johannes Jakobsen; Sjøland, Jonas A.; Gram, Jørgen

    2007-01-01

    OBJECTIVE: Lupus anticoagulant (LA) and antiphospholipid antibodies (aPL) are suggested as risk factors for development of deep vein thrombosis (DVT) among patients without systemic lupus erythematosus (SLE). Other conditions, e.g. inflammation, are reported to induce LA and it is uncertain whether...... of the International Society of Thrombosis and Haemostasis. The concentration of anticardiolipin (aCL) and beta(2)-glycoprotein I (anti-beta(2)-GPI) antibodies as well as C-reactive protein (CRP) was determined with sensitive and precise methods. RESULTS: LA was demonstrated in 8 patients with DVT and in 10 patients...... without DVT, relative risk 1.33 (CI: 0.55-3.18). No significant association was observed between aCL or anti-beta(2)-GPI and DVT. Patients suffering from DVT had significantly higher concentrations of CRP than patients without DVT. However, CRP was also significantly higher in patients positive for LA...

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

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xue [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Liu, Tao [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai’an (China); Chen, Yuan [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Zhang, Kun [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); School of Life Science, Zhengzhou University, Zhengzhou (China); Maitz, Manfred F. [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Leibniz Institute of Polymer Research Dresden, Max Bergmann Center of Biomaterials, Hohe Str. 06, 01069 Dresden (Germany); Pan, Changjiang [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai’an (China); Chen, Junying, E-mail: chenjy@263.net [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China); Huang, Nan [Key Laboratory of Advanced Technology for Materials of Chinese Education Ministry, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu (China)

    2014-11-30

    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.

  20. Safety and Efficacy of Underdosing Non-vitamin K Antagonist Oral Anticoagulants in Patients Undergoing Catheter Ablation for Atrial Fibrillation

    Science.gov (United States)

    Murakami, Takashi; Hina, Kazuyoshi; Higashiya, Shunichi; Kawamura, Hiroshi; Murakami, Masaaki; Kamikawa, Shigeshi; Komatsubara, Issei; Kusachi, Shozo

    2017-01-01

    Background: Some patients with atrial fibrillation (AF) received underdoses of non-vitamin K antagonist oral anticoagulants (NOACs) in the real world. Underdosing is defined as administration of a dose lower than the manufacturer recommended dose. Objectives: To identify the efficacy and safety of underdosing NOACs as perioperative anticoagulation for atrial fibrillation ablation. Methods: We retrospectively analyzed patients who received rivaroxaban or dabigatran etexilate according to dosage: adjusted low dosage (reduced by disturbed renal function; n = 30), underdosage (n = 307), or standard dosage (n = 683). Non-vitamin K antagonist oral anticoagulants and dosing decisions were at the discretion of treating cardiologists. Results: Patients who received underdosed NOACs were older, more often female, and had lower body weight and lower renal function than those who received standard dosages. Activated clotting time at baseline in patients who received adjusted low dosage or underdosages was slightly longer than that in patients receiving standard dosages (156 ± 23, 151 ± 224, and 147 ± 24 seconds, respectively). Meaningful differences were not observed in other coagulation parameters. Adjusted low-, under-, and standard-dosing regimens did not differ in perioperative thromboembolic complications (0/30, 0.0%; 1/307, 0.3%; and 0/683, 0%, respectively) or major (0/30, 0.0%; 2/307, 0.6%; 3/683, 0.4%) and minor (1/30, 3.3%; 13/307, 4.2%; 25/683, 3.6%) bleeding episodes. When comparisons were performed for each NOAC, similar results were observed. Conclusions: With consideration of patient condition, age, sex, body weight, body mass index, and renal function, underdosing NOACs was effective and safe as a perioperative anticoagulation therapy for atrial fibrillation ablation. The therapeutic range of NOACs is potentially wider than manufacturer recommendations. PMID:28170360

  1. Experimental autoimmune prostatitis induces microglial activation in the spinal cord

    Science.gov (United States)

    Wong, Larry; Done, Joseph D.; Schaeffer, Anthony J.; Thumbikat, Praveen

    2014-01-01

    Background The pathogenesis of chronic prostatitis/chronic pelvic pain syndrome is unknown and factors including the host’s immune response and the nervous system have been attributed to the development of CP/CPPS. We previously demonstrated that mast cells and chemokines such as CCL2 and CCL3 play an important role in mediating prostatitis. Here, we examined the role of neuroinflammation and microglia in the CNS in the development of chronic pelvic pain. Methods Experimental autoimmune prostatitis (EAP) was induced using a subcutaneous injection of rat prostate antigen. Sacral spinal cord tissue (segments S4–S5) was isolated and utilized for immunofluorescence or QRT-PCR analysis. Tactile allodynia was measured at baseline and at various points during EAP using Von Frey fibers as a function for pelvic pain. EAP mice were treated with minocycline after 30 days of prostatitis to test the efficacy of microglial inhibition on pelvic pain. Results Prostatitis induced the expansion and activation of microglia and the development of inflammation in the spinal cord as determined by increased expression levels of CCL3, IL-1β, Iba1, and ERK1/2 phosphorylation. Microglial activation in mice with prostatitis resulted in increased expression of P2X4R and elevated levels of BDNF, two molecular markers associated with chronic pain. Pharmacological inhibition of microglia alleviated pain in mice with prostatitis and resulted in decreased expression of IL-1β, P2X4R, and BDNF. Conclusion Our data shows that prostatitis leads to inflammation in the spinal cord and the activation and expansion of microglia, mechanisms that may contribute to the development and maintenance of chronic pelvic pain. PMID:25263093

  2. Curcumin attenuates diet-induced hepatic steatosis by activating AMP-activated protein kinase.

    Science.gov (United States)

    Um, Min Young; Hwang, Kwang Hyun; Ahn, Jiyun; Ha, Tae Youl

    2013-09-01

    Curcumin is a well-known component of traditional turmeric (Curcuma longa), which has been reported to prevent obesity and diabetes. However, the effect of curcumin on hepatic lipid metabolism remains unclear. The aim of this study was to examine the effects of curcumin on hepatic steatosis in high-fat/cholesterol diet (HFD)-induced obese mice. Male C57BL/6J mice were fed a normal diet (ND), HFD or HFD with 0.15% curcumin (HFD+C) for 11 weeks. We found that curcumin significantly lowered the body-weight and adipose tissue weight of mice in the HFD+C group compared with the findings for the HFD group (p cholesterol, fasting glucose and insulin in serum were decreased, and HFD-induced impairment of insulin sensitivity was improved by curcumin supplementation (p Curcumin protected against the development of hepatic steatosis by reducing hepatic fat accumulation. Moreover, curcumin activated AMP-activated protein kinase (AMPK) and elevated the gene expression of peroxisome proliferator-activated receptor alpha. By contrast, curcumin suppressed the HFD-mediated increases in sterol regulatory element-binding protein-1, acetyl-CoA carboxylase 1, fatty acid synthase and cluster of differentiation 36 expression. Taken together, these findings indicate that curcumin attenuates HFD-induced hepatic steatosis by regulating hepatic lipid metabolism via AMPK activation, suggesting its use as a therapeutic for hepatic steatosis.

  3. Photonic activation of plasminogen induced by low dose UVB.

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    Manuel Correia

    Full Text Available Activation of plasminogen to its active form plasmin is essential for several key mechanisms, including the dissolution of blood clots. Activation occurs naturally via enzymatic proteolysis. We report that activation can be achieved with 280 nm light. A 2.6 fold increase in proteolytic activity was observed after 10 min illumination of human plasminogen. Irradiance levels used are in the same order of magnitude of the UVB solar irradiance. Activation is correlated with light induced disruption of disulphide bridges upon UVB excitation of the aromatic residues and with the formation of photochemical products, e.g. dityrosine and N-formylkynurenine. Most of the protein fold is maintained after 10 min illumination since no major changes are observed in the near-UV CD spectrum. Far-UV CD shows loss of secondary structure after illumination (33.4% signal loss at 206 nm. Thermal unfolding CD studies show that plasminogen retains a native like cooperative transition at ~70 ºC after UV-illumination. We propose that UVB activation of plasminogen occurs upon photo-cleavage of a functional allosteric disulphide bond, Cys737-Cys765, located in the catalytic domain and in van der Waals contact with Trp761 (4.3 Å. Such proximity makes its disruption very likely, which may occur upon electron transfer from excited Trp761. Reduction of Cys737-Cys765 will result in likely conformational changes in the catalytic site. Molecular dynamics simulations reveal that reduction of Cys737-Cys765 in plasminogen leads to an increase of the fluctuations of loop 760-765, the S1-entrance frame located close to the active site. These fluctuations affect the range of solvent exposure of the catalytic triad, particularly of Asp646 and Ser74, which acquire an exposure profile similar to the values in plasmin. The presented photonic mechanism of plasminogen activation has the potential to be used in clinical applications, possibly together with other enzymatic treatments for the

  4. MANAGEMENT OF PATIENTS ON ANTICOAGULANT THERAPY UNDERGOING DENTAL SURGICAL PROCEDURES. Review Article.

    OpenAIRE

    Atanaska Dinkova; Donka G. Kirova; Delyan Delev

    2013-01-01

    Dental treatment performed in patients receiving oral anticoagulant drug therapy is becoming increasingly common in dental offices.The aim of oral anticoagulant therapy is to reduce blood coagulability to an optimal therapeutic range within which the patient is provided some degree of protection from thromboembolic events. This is achieved at the cost of a minor risk of haemorrhage. Frequently raised questions concern the safety and efficacy of the various anticoagulation regimens and their a...

  5. Differences between warfarin and new oral anticoagulants in dental clinical practice

    OpenAIRE

    Miranda, M; MARTINEZ, L.S.; De Franco, R.; FORTE, V.; BARLATTANI, A.; BOLLERO, P.

    2016-01-01

    The oral anticoagulant therapy is used for the cure and the prevention of thromboembolic diseases. In the last fifty years the warfarin has been considered the oral anticoagulant of choice. However, its use is limited by a narrow therapeutic index and by a complex pharmacodynamics, which requires regular adjustments and monitoring of the dose. Recently, three new oral anticoagulant – dabigatran etexilato (direct thrombin inhibitor), rivaroxaban and apixaban (Xa factor direct inhibitor) – have...

  6. Paclitaxel-induced activation of murine peritoneal macrophage in vitro

    Institute of Scientific and Technical Information of China (English)

    Li Zhongxiang; Wang Fufeng; Qiao Yuhuan

    2004-01-01

    Objective: To study the effects of paclitaxel on macrophage activation. Methods:Mouse macrophages were isolated by peritoneal lavage and cultured in RPMI 1640 medium according to the following groups: paclitaxel (5μmol/L) group, IFN-γ (5U/L) group, paclitaxel (5μmol/L) and IFN-γ (5U/L) combination group, and control group(without paclitaxel and IFNγ) .24 hours later, supematants were collected for nitric oxide(NO) assessment using the Griess reagent, and ttanor necrosis factor-α(TNF-α) assessment using the enzyme linked immunosorbent assay. Antibody-dependent cell-mediated cytotoxicity(ADCC) of the macrophages was assessed using the method of hemoglobin-enzyme release assay (Hb-ERA). Results: Paclitaxel induced the production of higher levels of NO(8.86 ± 1.16μmol/L) and TNF-α(120.2 ± 10.2pg/ml) ,and enhanced the ADCC of macrophages[ (20.61 + 1.13)% ]. The differences were significant compared with the control group[no NO and TNF-α detected,ADCC (15.37 + 1.93)% ](P < 0.01). Paclitaxel and IFN-γ in combination induced the production of higher levels of NO(22.85 ± 0.91μmol/L) and TNF-α(358.6 ± 27 .5pg/ml), and enhanced the ADCC of macrophages[ (42.49 + 3.09) % ]. The differences were significant compared with paclitaxel or IFN-γ[NO 8.09 ± 1.13μmol/L, TNF-α1 24.8 + 9.6pg/ml, ADCC(23.32 ± 2.63) % ] alone (P<0.01). Conclusion: These findings indicate that paclitaxel can promote NO and TNF-α production,enhance ADCC of macrophages, and induce macrophage activation. The active effects are more significant with paclitaxel and IFN-γcombination.

  7. Biological function of activation-induced cytidine deaminase (AID

    Directory of Open Access Journals (Sweden)

    Ritu Kumar

    2014-10-01

    Full Text Available Activation-induced Cytidine Deaminase (AID is an essential regulator of B cell diversification, but its full range of action has until recently been an enigma. Based on homology, it was originally proposed to be an RNA-editing enzyme, but so far, no RNA substrates are known. Rather, it functions by deaminating cytidine, and in this manner, coupled with base-excision repair or mismatch repair machinery, it is a natural mutator. This allows it to play a central role in adaptive immunity, whereby it initiates the processes of class switch recombination and somatic hypermutation to help generate a diverse and high-affinity repertoire of immunoglobulin isotypes. More recently, it has been appreciated that methylated cytidine, already known as a key epigenetic mark on DNA controlling gene expression, can also be a target for AID modification. Coupled with repair machinery, this can facilitate the active removal of methylated DNA. This activity can impact the process of cellular reprogramming, including transition of a somatic cell to pluripotency, which requires major reshuffling of epigenetic memory. Thus, seemingly disparate roles for AID in controlling immune diversity and epigenetic memory have a common mechanistic basis. However, the very activity that is so useful for B cell diversity and cellular reprogramming is dangerous for the integrity of the genome. Thus, AID expression and activity is tightly regulated, and deregulation is associated with diseases including cancer. Here, we review the range of AID functions with a focus on its mechanisms of action and regulation. Major questions remain to be answered concerning how and when AID is targeted to specific loci and how this impacts development and disease.

  8. Biological function of activation-induced cytidine deaminase (AID).

    Science.gov (United States)

    Kumar, Ritu; DiMenna, Lauren J; Chaudhuri, Jayanta; Evans, Todd

    2014-01-01

    Activation-induced Cytidine Deaminase (AID) is an essential regulator of B cell diversification, but its full range of action has until recently been an enigma. Based on homology, it was originally proposed to be an RNA-editing enzyme, but so far, no RNA substrates are known. Rather, it functions by deaminating cytidine, and in this manner, coupled with base-excision repair or mismatch repair machinery, it is a natural mutator. This allows it to play a central role in adaptive immunity, whereby it initiates the processes of class switch recombination and somatic hypermutation to help generate a diverse and high-affinity repertoire of immunoglobulin isotypes. More recently, it has been appreciated that methylated cytidine, already known as a key epigenetic mark on DNA controlling gene expression, can also be a target for AID modification. Coupled with repair machinery, this can facilitate the active removal of methylated DNA. This activity can impact the process of cellular reprogramming, including transition of a somatic cell to pluripotency, which requires major reshuffling of epigenetic memory. Thus, seemingly disparate roles for AID in controlling immune diversity and epigenetic memory have a common mechanistic basis. However, the very activity that is so useful for B cell diversity and cellular reprogramming is dangerous for the integrity of the genome. Thus, AID expression and activity is tightly regulated, and deregulation is associated with diseases including cancer. Here, we review the range of AID functions with a focus on its mechanisms of action and regulation. Major questions remain to be answered concerning how and when AID is targeted to specific loci and how this impacts development and disease.

  9. The role of prothrombin complex concentrates in reversal of target specific anticoagulants.

    Science.gov (United States)

    Babilonia, Katrina; Trujillo, Toby

    2014-01-01

    Over the past several years a new era for patients requiring anticoagulation has arrived. The approval of new target specific oral anticoagulants offers practitioners several advantages over traditionally used vitamin K antagonist agents including predictable pharmacokinetics, rapid onset of action, comparable efficacy and safety, all without the need for routine monitoring. Despite these benefits, hemorrhagic complicates are inevitable with any anticoagulation treatment. One of the major disadvantages of the new oral anticoagulants is lack of specific antidotes or reversal agents for patients with serious bleeding or need for urgent surgery. As use of the new target specific oral anticoagulants continues to increase, practitioners will need to understand both the pharmacodynamics and pharmacokinetic properties of the agents, as well as, the available literature with use of non-specific therapies to reverse anticoagulation. Four factor prothrombin complex concentrates have been available for several years in Europe, and recently became available in the United States with approval of Kcentra. These products have shown efficacy in reversing anticoagulation from vitamin K antagonists, however their usefulness with the new target specific oral anticoagulants is poorly understood. This article will review the properties of dabigatran, rivaroxaban and apixaban, as well as the limited literature available on the effectiveness of prothrombin complex concentrates in reversal of their anticoagulant effects. Additional studies are needed to more accurately define the role of prothrombin complex concentrates in patients with life threatening bleeding or who require emergent surgery, as current data is both limited and conflicting.

  10. A case of bilateral hemarthrosis due to pseudoaneurysms in a patient on anticoagulation therapy.

    Science.gov (United States)

    Son, Kyeong Min; Kim, Ja Kyung; Seo, Young Il; Kim, Hyun Ah

    2013-06-01

    Hemarthrosis can occur in patients with a predisposition to hemorrhage, such as hemophiliacs or patients on anticoagulation therapy. If hemarthrosis recurs after supportive treatment, however, other etiologies such as anatomical abnormalities should be considered. Spontaneous articular pseudoaneurysm associated with anticoagulation treatment has not been reported previously. We describe a patient on anticoagulation therapy with bilateral hemarthrosis due to pseudoaneurysms. After failing to respond to the correction of over-anticoagulation, magnetic resonance imaging led to the diagnosis of articular pseudoaneurysm. The patient was treated successfully by transarterial embolization.

  11. Thrombus precursor protein for monitoring anticoagulation in patients with mechanical valve prosthesis

    Institute of Scientific and Technical Information of China (English)

    Qin Chuan; Xiao Yingbin

    2009-01-01

    Objective: To evaluate the plasma concentration of thrombus precursor protein (TPP) in patients after mechanical heart valve replacement, and to explore whether it can be used as a marker for monitoring anticoagulation. Methods: Totally 60 patients who took warfarin after mitral valve replacement and 20 control patients with non-valvular heart diseases were subjected in this study. Their plasma TPP concentration and international normalized ratio (INR) were determined, and compared not only between the anticoagulant patients and the control patients, but also between the patients with atrial fibrillaiton (AF, n=37) and the patients with sinus rhythm (SR, n=23) after mechanical valve replacement. The relationship between plasma TPP concentration and INR in the 60 anticoagulant patients was analyzed with linear regression. Results: It was found that the anticoagulant therapy effectively decreased plasma TPP concentration and elevated INR. In the anticoagulant group, the patients with AF had higher plasma TPP concentration than the others with sinus rhythm (P0.05). No significant correlation was found between plasma TPP concentration and INR in the anticoagulant patients (P>0.05). INR did not accord with plasma TPP concentration in several patients. Conclusion: INR can't reflect the coagulation status and guide the anticoagulation correctly sometimes; TPP may be a valuable assistant marker for monitoring anticoagulation in patients with mechanical heart valve prothesis; Patients with AF may require higher density of anticoagulation and TPP is strongly suggested to be monitored in these patients.

  12. Safety and efficacy of bone wax in patients on oral anticoagulant therapy.

    Science.gov (United States)

    Krasny, Marta; Krasny, Kornel; Fiedor, Piotr

    2014-01-01

    Cardiovascular conditions, apart from neoplastic diseases, remain the major cause of death in developed countries; therefore, the number of patients receiving oral anticoagulants is constantly increasing. Anticoagulant therapy considerably reduced mortality in patients with history of myocardial infarction among others. Although many interventions may be performed without withdrawal of the anticoagulant and tooth extraction was qualified as a procedure of low hemorrhage risk, a majority of dentists refer the patient to a cardiologist several days before the elective tooth extraction to withdraw anticoagulants. The aim of the study was to evaluate the efficacy and safety of bone wax used to stop bleeding after dental procedures in a group of patients on chronic anticoagulant therapy and find an answer to a question, whether it is justified to temporarily withdraw anticoagulants for this type of procedures. The study involved 176 patients on chronic anticoagulant therapy undergoing tooth extraction (154 subjects) or surgical extraction of a retained tooth (48 subjects). After the procedure, in each case the alveolus was filled with bone wax to stop bleeding. In all patients involved in the study bleeding from the alveolus was successfully stopped during the procedure. None of the subjects reported increased bleeding from the operational site after coming back home. Bone wax is a good, efficient, and safe material to block bleeding from the alveolus following tooth extractions, also in patients on chronic anticoagulant therapy. The study demonstrated that withdrawal or adjustment of anticoagulant therapy is not necessary before an elective tooth extraction.

  13. Use of INR to assess degree of anticoagulation in patients who have dental procedures.

    Science.gov (United States)

    Steinberg, M J; Moores, J F

    1995-08-01

    Dental professionals frequently treat patients who are receiving anticoagulation therapy. Proper treatment may require adjustment of the anticoagulant dose usually on the basis of the patient's current prothrombin time. This test has been shown to be less accurate than previously thought. The international normalized ratio is another method that attempts to standardize the degree of anticoagulation and to improve reproducibility of results. This system is slowly being implemented in laboratories in the United States. Practitioners who treat patients taking anticoagulants need to be aware of this system in order to make appropriate management decisions.

  14. Cisplatin induces cytotoxicity through the mitogen-activated protein kinase pathways and activating transcription factor 3.

    Science.gov (United States)

    St Germain, Carly; Niknejad, Nima; Ma, Laurie; Garbuio, Kyla; Hai, Tsonwin; Dimitroulakos, Jim

    2010-07-01

    The mechanisms underlying the proapoptotic effect of the chemotherapeutic agent, cisplatin, are largely undefined. Understanding the mechanisms regulating cisplatin cytotoxicity may uncover strategies to enhance the efficacy of this important therapeutic agent. This study evaluates the role of activating transcription factor 3 (ATF3) as a mediator of cisplatin-induced cytotoxicity. Cytotoxic doses of cisplatin and carboplatin treatments consistently induced ATF3 expression in five tumor-derived cell lines. Characterization of this induction revealed a p53, BRCA1, and integrated stress response-independent mechanism, all previously implicated in stress-mediated ATF3 induction. Analysis of mitogen-activated protein kinase (MAPK) pathway involvement in ATF3 induction by cisplatin revealed a MAPK-dependent mechanism. Cisplatin treatment combined with specific inhibitors to each MAPK pathway (c-Jun N-terminal kinase, extracellular signal-regulated kinase, and p38) resulted in decreased ATF3 induction at the protein level. MAPK pathway inhibition led to decreased ATF3 messenger RNA expression and reduced cytotoxic effects of cisplatin as measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cell viability assay. In A549 lung carcinoma cells, targeting ATF3 with specific small hairpin RNA also attenuated the cytotoxic effects of cisplatin. Similarly, ATF3-/- murine embryonic fibroblasts (MEFs) were shown to be less sensitive to cisplatin-induced cytotoxicity compared with ATF3+/+ MEFs. This study identifies cisplatin as a MAPK pathway-dependent inducer of ATF3, whose expression influences cisplatin's cytotoxic effects.

  15. Load-Induced Confinement Activates Diamond Lubrication by Water

    Science.gov (United States)

    Zilibotti, G.; Corni, S.; Righi, M. C.

    2013-10-01

    Tribochemical reactions are chemical processes, usually involving lubricant or environment molecules, activated at the interface between two solids in relative motion. They are difficult to be monitored in situ, which leaves a gap in the atomistic understanding required for their control. Here we report the real-time atomistic description of the tribochemical reactions occurring at the interface between two diamond films in relative motion, by means of large scale ab initio molecular dynamics. We show that the load-induced confinement is able to catalyze diamond passivation by water dissociative adsorption. Such passivation decreases the energy of the contacting surfaces and increases their electronic repulsion. At sufficiently high coverages, the latter prevents surface sealing, thus lowering friction. Our findings elucidate effects of the nanoscale confinement on reaction kinetics and surface thermodynamics, which are important for the design of new lubricants.

  16. Active tunable plasmonically induced polarization conversion in the THz regime

    Science.gov (United States)

    Ling, Furi; Yao, Gang; Yao, Jianquan

    2016-01-01

    A plasmon-induced polarization conversion (PIPC) structure based on periodically patterned graphene was demonstrated in the THz regime. By varying the Fermi level of two connected T-shape graphene strips through the electrostatic gating, the peak frequency and the group index in the transparency window can be tuned, which is good agreement with the coupled Lorentz oscillator model. Due to interference between two polarization selective graphene plasmonic resonances coexisting in the planar metamaterial, polarization conversion can be achieved. The linearly polarized THz wave can be converted to elliptically and right circularly polarized THz wave through varying the relaxation time of electrons in graphene. This novel chip-scale active terahertz device promises essential application opportunities in terahertz sensing and terahertz communications. PMID:27734912

  17. Study on antithrombotic and antiplatelet activities of low molecular weight fucoidan from Laminaria japonica

    Science.gov (United States)

    Chen, Anjin; Zhang, Fang; Shi, Jie; Zhao, Xue

    2012-06-01

    The antithrombotic and antiplatelet effects of two fucoidan fractions with low molecular weight and different sulfate content from Laminaria japonica were compared in order to examine the influence of chemical character on their antithrombotic activity and the possible mechanism. Both LMW fucoidan fractions exhibited favorable antithrombotic activity in an Fecl3-induced arterial thrombosis. The antithrombotic activity of LMW fucoidan was related with decrease of TXB2 and whole blood viscosity and hematocrit. LMW fucoidan showed a correlation between anticoagulant, antiaggregant and antithrombotic effects in vivo. For LMW fucoidan, antithrombotic activity required high dose of 5-10 nmol kg-1, concomitantly with increase in anticoagulant activity and inhibition of platelet aggregation. Administration of LMW fucoidan significantly promoted the 6-keto-PGF1α content and decreased the TXB2 content, indicating its inhibition of tissue factor pathway and regulation of metabolism of arachidonic acid. By comparison, highly sulfated fucoidan LF2 with Mw 3900 seemed to be a more suitable choice for antithrombotic drug for its antithrombotic activity accompanied with specific inhibitory activity on platelet aggregation, low anticoagulant activity and low hemorrhagic risk in vivo.

  18. Activity deprivation induces neuronal cell death: mediation by tissue-type plasminogen activator.

    Directory of Open Access Journals (Sweden)

    Eldi Schonfeld-Dado

    Full Text Available Spontaneous activity is an essential attribute of neuronal networks and plays a critical role in their development and maintenance. Upon blockade of activity with tetrodotoxin (TTX, neurons degenerate slowly and die in a manner resembling neurodegenerative diseases-induced neuronal cell death. The molecular cascade leading to this type of slow cell death is not entirely clear. Primary post-natal cortical neurons were exposed to TTX for up to two weeks, followed by molecular, biochemical and immunefluorescence analysis. The expression of the neuronal marker, neuron specific enolase (NSE, was down-regulated, as expected, but surprisingly, there was a concomitant and striking elevation in expression of tissue-type plasminogen activator (tPA. Immunofluorescence analysis indicated that tPA was highly elevated inside affected neurons. Transfection of an endogenous tPA inhibitor, plasminogen activator inhibitor-1 (PAI-1, protected the TTX-exposed neurons from dying. These results indicate that tPA is a pivotal player in slowly progressing activity deprivation-induced neurodegeneration.

  19. Factor XI and contact activation as targets for antithrombotic therapy.

    Science.gov (United States)

    Gailani, D; Bane, C E; Gruber, A

    2015-08-01

    The most commonly used anticoagulants produce therapeutic antithrombotic effects either by inhibiting thrombin or factor Xa (FXa) or by lowering the plasma levels of the precursors of these key enzymes, prothrombin and FX. These drugs do not distinguish between thrombin generation contributing to thrombosis from thrombin generation required for hemostasis. Thus, anticoagulants increase bleeding risk, and many patients who would benefit from therapy go untreated because of comorbidities that place them at unacceptable risk for hemorrhage. Studies in animals demonstrate that components of the plasma contact activation system contribute to experimentally induced thrombosis, despite playing little or no role in hemostasis. Attention has focused on FXII, the zymogen of a protease (FXIIa) that initiates contact activation when blood is exposed to foreign surfaces, and FXI, the zymogen of the protease FXIa, which links contact activation to the thrombin generation mechanism. In the case of FXI, epidemiologic data indicate this protein contributes to stroke and venous thromboembolism, and perhaps myocardial infarction, in humans. A phase 2 trial showing that reduction of FXI may be more effective than low molecular weight heparin at preventing venous thrombosis during knee replacement surgery provides proof of concept for the premise that an antithrombotic effect can be uncoupled from an anticoagulant effect in humans by targeting components of contact activation. Here, we review data on the role of FXI and FXII in thrombosis and results of preclinical and human trials for therapies targeting these proteins.

  20. Ginger extract inhibits LPS induced macrophage activation and function

    Directory of Open Access Journals (Sweden)

    Bruch David

    2008-01-01

    Full Text Available Abstract Background Macrophages play a dual role in host defence. They act as the first line of defence by mounting an inflammatory response to antigen exposure and also act as antigen presenting cells and initiate the adaptive immune response. They are also the primary infiltrating cells at the site of inflammation. Inhibition of macrophage activation is one of the possible approaches towards modulating inflammation. Both conventional and alternative approaches are being studied in this regard. Ginger, an herbal product with broad anti inflammatory actions, is used as an alternative medicine in a number of inflammatory conditions like rheumatic disorders. In the present study we examined the effect of ginger extract on macrophage activation in the presence of LPS stimulation. Methods Murine peritoneal macrophages were stimulated by LPS in presence or absence of ginger extract and production of proinflammatory cytokines and chemokines were observed. We also studied the effect of ginger extract on the LPS induced expression of MHC II, B7.1, B7.2 and CD40 molecules. We also studied the antigen presenting function of ginger extract treated macrophages by primary mixed lymphocyte reaction. Results We observed that ginger extract inhibited IL-12, TNF-α, IL-1β (pro inflammatory cytokines and RANTES, MCP-1 (pro inflammatory chemokines production in LPS stimulated macrophages. Ginger extract also down regulated the expression of B7.1, B7.2 and MHC class II molecules. In addition ginger extract negatively affected the antigen presenting function of macrophages and we observed a significant reduction in T cell proliferation in response to allostimulation, when ginger extract treated macrophages were used as APCs. A significant decrease in IFN-γ and IL-2 production by T cells in response to allostimulation was also observed. Conclusion In conclusion ginger extract inhibits macrophage activation and APC function and indirectly inhibits T cell activation.

  1. [Seasonal changes in the blood coagulating and anticoagulating system indices in men at the preclinical stage of ischemic heart disease].

    Science.gov (United States)

    Andreenko, G V; Panchenko, V M; Liutova, L V; Lisina, A N; Karabasova, M A

    1980-03-01

    Examination of 52 males (aged 23 to 40 years) in the preclinical stage of ischemic heart disease revealed seasonal differences in the values of the blood coagulation and anticoagulation systems: in the spring, there was an increase in blood coagulation activity displayed by growth of the concentration of fibrinogen and soluble fibrin and a reduction in the amount of the plasminogen activator. The authors suggest conducting preventive treatment of patients in the spring, the most unfavourable season in respect of the effect of the pathogenetic factors.

  2. p38 Mitogen-Activated Protein Kinase in beryllium-induced dendritic cell activation.

    Science.gov (United States)

    Li, L; Huang, Z; Gillespie, M; Mroz, P M; Maier, L A

    2014-12-01

    Dendritic cells (DC) play a role in the regulation of immune responses to haptens, which in turn impact DC maturation. Whether beryllium (Be) is able to induce DC maturation and if this occurs via the MAPK pathway is not known. Primary monocyte-derived DCs (moDCs) models were generated from Be non-exposed healthy volunteers as a non-sensitized cell model, while PBMCs from BeS (Be sensitized) and CBD (chronic beryllium disease) were used as disease models. The response of these cells to Be was evaluated. The expression of CD40 was increased significantly (pBeSO₄-stimulation. BeSO₄ induced p38MAPK phosphorylation, while IκB-α was degraded in Be-stimulated moDCs. The p38 MAPK inhibitor SB203580 blocked Be-induced NF-κB activation in moDCs, suggesting that p38MAPK and NF-κB are dependently activated by BeSO₄. Furthermore, in BeS and CBD subjects, SB203580 downregulated Be-stimulated proliferation in a dose-dependent manner, and decreased Be-stimulated TNF-α and IFNγ cytokine production. Taken together, this study suggests that Be-induces non-sensitized Glu69+ DCs maturation, and that p38MAPK signaling is important in the Be-stimulated DCs activation as well as subsequent T cell proliferation and cytokine production in BeS and CBD. In total, the MAPK pathway may serve as a potential therapeutic target for human granulomatous lung diseases.

  3. Light-induced self-assembly of active rectification devices.

    Science.gov (United States)

    Stenhammar, Joakim; Wittkowski, Raphael; Marenduzzo, Davide; Cates, Michael E

    2016-04-01

    Self-propelled colloidal objects, such as motile bacteria or synthetic microswimmers, have microscopically irreversible individual dynamics-a feature they share with all living systems. The incoherent behavior of individual swimmers can be harnessed (or "rectified") by microfluidic devices that create systematic motions that are impossible in equilibrium. We present a computational proof-of-concept study showing that such active rectification devices could be created directly from an unstructured "primordial soup" of light-controlled motile particles, solely by using spatially modulated illumination to control their local propulsion speed. Alongside both microscopic irreversibility and speed modulation, our mechanism requires spatial symmetry breaking, such as a chevron light pattern, and strong interactions between particles, such as volume exclusion, which cause a collisional slowdown at high density. Together, we show how these four factors create a novel, many-body rectification mechanism. Our work suggests that standard spatial light modulator technology might allow the programmable, light-induced self-assembly of active rectification devices from an unstructured particle bath.

  4. Neuronal activity-induced regulation of Lingo-1.

    Science.gov (United States)

    Trifunovski, Alexandra; Josephson, Anna; Ringman, Andreas; Brené, Stefan; Spenger, Christian; Olson, Lars

    2004-10-25

    Axonal regeneration after injury can be limited in the adult CNS by the presence of inhibitory proteins such as Nogo. Nogo binds to a receptor complex that consists of Nogo receptor (NgR), p75NTR, and Lingo-1. Nogo binding activates RhoA, which inhibits axonal outgrowth. Here we assessed Lingo-1 and NgR mRNA levels after delivery of BDNF into the rat hippocampal formation, Lingo-1 mRNA levels in rats subjected to kainic acid (KA) and running in running wheels. Lingo-1 mRNA was not changed by running. However, we found that Lingo-1 mRNA was strongly up-regulated while NgR mRNA was down-regulated in the dentate gyrus in both the BDNF and the KA experiments. Our data demonstrate inverse regulation of NgR and Lingo-1 in these situations, suggesting that Lingo-1 up-regulation is one characteristic of activity-induced neural plasticity responses.

  5. Irregular persistent activity induced by synaptic excitatory feedback

    Directory of Open Access Journals (Sweden)

    Francesca Barbieri

    2007-11-01

    Full Text Available Neurophysiological experiments on monkeys have reported highly irregular persistent activity during the performance of an oculomotor delayed-response task. These experiments show that during the delay period the coefficient of variation (CV of interspike intervals (ISI of prefrontal neurons is above 1, on average, and larger than during the fixation period. In the present paper, we show that this feature can be reproduced in a network in which persistent activity is induced by excitatory feedback, provided that (i the post-spike reset is close enough to threshold , (ii synaptic efficacies are a non-linear function of the pre-synaptic firing rate. Non-linearity between presynaptic rate and effective synaptic strength is implemented by a standard short-term depression mechanism (STD. First, we consider the simplest possible network with excitatory feedback: a fully connected homogeneous network of excitatory leaky integrate-and-fire neurons, using both numerical simulations and analytical techniques. The results are then confirmed in a network with selective excitatory neurons and inhibition. In both the cases there is a large range of values of the synaptic efficacies for which the statistics of firing of single cells is similar to experimental data.

  6. RIP3 induces apoptosis independent of pronecrotic kinase activity.

    Science.gov (United States)

    Mandal, Pratyusha; Berger, Scott B; Pillay, Sirika; Moriwaki, Kenta; Huang, Chunzi; Guo, Hongyan; Lich, John D; Finger, Joshua; Kasparcova, Viera; Votta, Bart; Ouellette, Michael; King, Bryan W; Wisnoski, David; Lakdawala, Ami S; DeMartino, Michael P; Casillas, Linda N; Haile, Pamela A; Sehon, Clark A; Marquis, Robert W; Upton, Jason; Daley-Bauer, Lisa P; Roback, Linda; Ramia, Nancy; Dovey, Cole M; Carette, Jan E; Chan, Francis Ka-Ming; Bertin, John; Gough, Peter J; Mocarski, Edward S; Kaiser, William J

    2014-11-20

    Receptor-interacting protein kinase 3 (RIP3 or RIPK3) has emerged as a central player in necroptosis and a potential target to control inflammatory disease. Here, three selective small-molecule compounds are shown to inhibit RIP3 kinase-dependent necroptosis, although their therapeutic value is undermined by a surprising, concentration-dependent induction of apoptosis. These compounds interact with RIP3 to activate caspase 8 (Casp8) via RHIM-driven recruitment of RIP1 (RIPK1) to assemble a Casp8-FADD-cFLIP complex completely independent of pronecrotic kinase activities and MLKL. RIP3 kinase-dead D161N mutant induces spontaneous apoptosis independent of compound, whereas D161G, D143N, and K51A mutants, like wild-type, only trigger apoptosis when compound is present. Accordingly, RIP3-K51A mutant mice (Rip3(K51A/K51A)) are viable and fertile, in stark contrast to the perinatal lethality of Rip3(D161N/D161N) mice. RIP3 therefore holds both necroptosis and apoptosis in balance through a Ripoptosome-like platform. This work highlights a common mechanism unveiling RHIM-driven apoptosis by therapeutic or genetic perturbation of RIP3.

  7. An Engineered Herpesvirus Activates Dendritic Cells and Induces Protective Immunity

    Science.gov (United States)

    Ma, Yijie; Chen, Min; Jin, Huali; Prabhakar, Bellur S.; Valyi-Nagy, Tibor; He, Bin

    2017-01-01

    Herpes simplex viruses (HSV) are human pathogens that switch between lytic and latent infection. While attenuated HSV is explored for vaccine, the underlying event remains poorly defined. Here we report that recombinant HSV-1 with a mutation in the γ134.5 protein, a virulence factor, stimulates dendritic cell (DC) maturation which is dependent on TANK-binding kinase 1 (TBK1). When exposed to CD11+ DCs, the mutant virus that lacks the amino terminus of γ134.5 undergoes temporal replication without production of infectious virus. Mechanistically, this leads to sequential phosphorylation of interferon regulatory factor 3 (IRF3) and p65/RelA. In correlation, DCs up-regulate the expression of co-stimulatory molecules and cytokines. However, selective inhibition of TBK1 precludes phosphorylation of IRF3 and subsequent DC activation by the γ134.5 mutant. Herein, the γ134.5 mutant is immune-stimulatory and non-destructive to DCs. Remarkably, upon immunization the γ134.5 mutant induces protection against lethal challenge by the wild type virus, indicative of its vaccine potential. Furthermore, CD11+ DCs primed by the γ134.5 mutant in vivo mediate protection upon adoptive transfer. These results suggest that activation of TBK1 by engineered HSV is crucial for DC maturation, which may contribute to protective immunity. PMID:28150813

  8. Thioredoxin interacting protein inhibits hypoxia-inducible factor transcriptional activity

    Science.gov (United States)

    Farrell, Michael R; Rogers, Lynette K; Liu, Yusen; Welty, Stephen E; Tipple, Trent E

    2010-01-01

    Vascular endothelial growth factor (VEGF) is required for proper lung development and is transcriptionally regulated in alveolar epithelial cells by hypoxia inducible factor (HIF). Previous findings in a newborn mouse model of bronchopulmonary dysplasia (BPD) suggest that thioredoxin interacting protein (Txnip) is a novel regulator of VEGF expression. The present studies were designed to test the hypothesis that Txnip negatively regulates VEGF through effects on HIF-mediated gene expression. To test this hypothesis, we first examined the levels of VEGF and Txnip protein in the lungs of 1 day-old newborn and E19 embryos and detected a significant inverse correlation. To elucidate the mechanisms underlying this relationship, we studied the effects of Txnip overexpression on HIF-mediated transcription using murine lung epithelial (MLE-12) cells. Overexpression of Txnip inhibited HIF-mediated reporter activity in both hypoxia and room air. Suppression of HIF activity by Txnip appeared to be independent of the ability of Txnip to bind to thioredoxin. Thus, our studies support a model in which Txnip is a potentially critical regulator of HIF-mediated gene transcription in the murine lung. Alterations in Txnip expression could alter lung VEGF expression in prematurely born human infants and contribute to the development of BPD. PMID:20692333

  9. 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

  10. Methoxychlor induces atresia by altering Bcl2 factors and inducing caspase activity in mouse ovarian antral follicles in vitro.

    Science.gov (United States)

    Basavarajappa, Mallikarjuna S; Karman, Bethany N; Wang, Wei; Gupta, Rupesh K; Flaws, Jodi A

    2012-12-01

    Methoxychlor (MXC) is an organochlorine pesticide widely used in many countries against various species of insects that attack crops and domestic animals. MXC reduces fertility by increasing atresia (death) of antral follicles in vivo. MXC also induces atresia of antral follicles after 96 h in vitro. The current work tested the hypothesis that MXC induces morphological atresia at early time points (24 and 48 h) by altering pro-apoptotic (Bax, Bok, Casp3, and caspase activity) and anti-apoptotic (Bcl2 and Bcl-xL) factors in the follicles. The results indicate that at 24 h, MXC increased Bcl-xL and Bax mRNA levels and increased the ratio of Bax/Bcl2. At 48-96 h, MXC induced morphological atresia. At 24-96 h, MXC increased caspase activities. These data suggest that MXC may induce atresia by altering Bcl2 factors and inducing caspase activities in antral follicles.

  11. 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.

  12. [Pharmacogenetics of oral anticoagulants: individualized drug treatment for more efficacy and safety].

    Science.gov (United States)

    Loriot, Marie-Anne; Beaune, Philippe

    2007-06-30

    Oral anti-vitamin K (AVK) anticoagulants constitute the first cause of iatrogenic accidents in France because of narrow therapeutic index and bleeding risk. The wide interindividual variation in AVK response is partly genetically determined. The main enzyme responsible for the metabolism of AVK is the hepatic cytochrome P450 2C9 (CYP2C9). Vitamine K epoxide reductase complex subunit I (VKORC1) is a key enzyme in the vitamin K cycle, cofactor required for the activation of vitamin K-dependent clotting factors, and is the target enzyme of AVK inhibition. Genetic variations affecting both CYP2C9 and VKORC1 are associated with variability in drug response and may explain differences in dose requirements. Genotyping for CYP2C9 and VKORC1 variants before initiation of treatment may allow clinicians to develop dosing protocols and identify the patients at a higher risk for bleeding complications.

  13. Potential Use of Polysaccharides from the Brown Alga Undaria pinnatifida as Anticoagulants

    Directory of Open Access Journals (Sweden)

    Caterina Faggio

    2015-10-01

    Full Text Available Undaria pinnatifida (U. pinnatifida is a highly invasive species and has caused concern all over the world because it has invaded coastal environments, has the potential to displace native species, significantly alters habitat for associated fauna, and disturbs navigation. Any attempt to eradicate it would be futile, owing to the elusive, microscopic gametophyte, and because the alga thrives in sites rich in anthropic activities. Venice Lagoon is the largest Mediterranean transitional environment and the spot of the highest introduction of non-indigenous species, including U. pinnatifida, which is removed as a waste. We demonstrated that polysaccharide extracts from U. pinnatifida have an anticoagulant effect on human blood in vitro and are not cytotoxic. The results obtained by PT (normal values 70-120% and APTT (normal values 28-40s assays were significantly prolonged by the polysaccharide extracts of U. pinnatifida, therefore algal extracts are ideal candidates as antithrombotic agents.

  14. Clinical application of argatroban as an alternative anticoagulant for extracorporeal circulation.

    Science.gov (United States)

    Kawada, T; Kitagawa, H; Hoson, M; Okada, Y; Shiomura, J

    2000-04-01

    The authors attempted experimental and clinical use of argatroban as an alternative anticoagulant in left heart bypass with the centrifugal pump, percutaneous cardiopulmonary support (PCPS), and extracorporeal membrane oxygenation (ECMO) to determine if it has complementary effects in preventing thrombus formation without aggravating bleeding tendency. Its reversible binding to thrombin and its short half-life contributed to reduce the risk of excessive blood loss without clot formation within the extracorporeal circulation circuit during thoracic aortic surgery using left heart bypass. PCPS and ECMO were safely performed at doses ranging from 0.5 to 10 micrograms/kg/min to maintain activated clotting time at approximately 200 seconds. Although experimental studies showed argatroban to be advantageous in preserving platelet and fibrinogen, further clinical investigations are necessary.

  15. Pressure-related activation of inducible nitric oxide synthase

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A lot of reports suggested that inducible nitric oxide synthase (iNOS) has a very different nature from constitutive NOS including endothelial NOS (eNOS) and neural NOS (nNOS). When exposed to cytokines or bacterial products, iNOS could be greatly activated and produces hundreds or thousands fold more NO than it does usually. Whether iNOS activation is arterial pressure related is not clear. In the present experiment, we studied three groups(n=6) of Sprague Dawley (SD) rats with implanted aorta and venous catheters that were maintained on 1 mEq/d, 12.5 mEq/d and 25 mEq/d of sodium intake respectively. Pulsatile arterial pressure signals from the amplifier were sent to a digital computer and the urine samples were taken every other day for nitrate/nitrite excretion (UNOx) assay using Greiss Reaction. After 6 days infusion, the rats were euthanized with an overdose of sodium pentobarbital, and the renal medullas were rapidly removed and frozen on dry ice for iNOS activity assay. Morever separate groups of hypertensive rats including spontaneously hypertensive rat (SHR, n=6) and High NaCl-induced hypertensive rat (NaHR, n=6) were used to measure renal iNOS protein by Western Blotting. The results showed that the mean arterial pressure (MAP) were significantly increased with the increase intake of sodium, the MAP (mmHg) at day 6 were 99.6±3.5,116.65±4.2 and 125.43±4.5, and the iNOS activity (nmol*g-1 protein*min-1) were 122.3±23.4, 342.4±35.6 and 623.9±65.4 in 1 mEq/d, 12.5 mEq/d and 25 mEq/d of sodium intake-rats respectively. At the same time, UNOx at day 6 were also increased, in turn, to 5 865.6±343.0 (for 12.5 mEq/d intake-rats) and (9 642.8±1 045.3) (for 25 mEq/d sodium intake-rats) nmol/d from (3 834.9±234.8) nmol/d of 1 mEq/d sodium intake-rats respectively. Western blotting showed that the renal medullary iNOS protein in SHR and NaHR were increased by 178%±13% and 104%±9% of normal Wistar rats. The data indicates that elevated arterial pressure

  16. Inflammation is strongly associated with lupus anticoagulant positivity, indepentent of know autoimmune disease and recent venous or arterial thrombosis

    DEFF Research Database (Denmark)

    Just, Søren Andreas; Nybo, Mads; Laustrup, Helle;

    2014-01-01

    Inflammation is strongly associated with lupus anticoagulant positivity, indepentent of know autoimmune disease and recent venous or arterial thrombosis......Inflammation is strongly associated with lupus anticoagulant positivity, indepentent of know autoimmune disease and recent venous or arterial thrombosis...

  17. Damage-induced DNA replication stalling relies on MAPK-activated protein kinase 2 activity

    DEFF Research Database (Denmark)

    Köpper, Frederik; Bierwirth, Cathrin; Schön, Margarete;

    2013-01-01

    DNA damage can obstruct replication forks, resulting in replicative stress. By siRNA screening, we identified kinases involved in the accumulation of phosphohistone 2AX (γH2AX) upon UV irradiation-induced replication stress. Surprisingly, the strongest reduction of phosphohistone 2AX followed...... replication impaired by gemcitabine or by Chk1 inhibition. This rescue strictly depended on translesion DNA polymerases. In conclusion, instead of being an unavoidable consequence of DNA damage, alterations of replication speed and origin firing depend on MK2-mediated signaling....... knockdown of the MAP kinase-activated protein kinase 2 (MK2), a kinase currently implicated in p38 stress signaling and G2 arrest. Depletion or inhibition of MK2 also protected cells from DNA damage-induced cell death, and mice deficient for MK2 displayed decreased apoptosis in the skin upon UV irradiation...

  18. Enzyme-assisted extraction of anticoagulant polysaccharide from Liparis tessellatus eggs.

    Science.gov (United States)

    Ticar, Bernadeth F; Rohmah, Zuliyati; Ambut, Carmelo V; Choi, Yeung-Joon; Mussatto, Solange I; Choi, Byeong-Dae

    2015-03-01

    This study aimed to recover a heparin-like anticoagulant polysaccharide from Liparis tessellatus eggs (PLE) by using enzyme-assisted extraction technique. Extraction experiments were carried out using three different enzymes (Alcalase®2.4 L, Flavourzyme®500 MG, and Protamex®) under different conditions of temperature (45, 50, and 55°C), pH (6.5, 7.0, and 7.5), incubation time (24, 36, and 48 h), and enzyme to substrate ratio (E/S=0.5, 1.0, and 1.5%, w/w), which were combined according to a D-optimal design. Statistical analysis of extraction results allowed identifying the variables with greater influence on the extraction yield, and selecting the conditions that maximize the PLE extraction. The best extraction results were achieved when using the Protamex® enzyme in an E/S ratio of 1.34% (w/w), pH 6.60, 47.40°C, during 26.50 h. Under these conditions, a polysaccharide yield of 2.10% (w/w) was obtained. Clotting time measurements, activated partial thromboplastin time, and prothrombin time for evaluation of the anticoagulant properties of PLE were determined and showed increasing activities in correlation with the concentrations used. In the final step, the heparin-like nature of PLE was confirmed by digestion with heparinases I, II, and III, which showed ΔDiHS-0S, ΔDiHS-6S, ΔDiHS-diS1, and ΔDiHS-diS2 at compositions of 0.04, 0.03, 0.35, and 0.24 mol/g, respectively.

  19. Characteristics of Symptomatic Intracranial Hemorrhage in Patients Receiving Non-Vitamin K Antagonist Oral Anticoagulant Therapy.

    Directory of Open Access Journals (Sweden)

    Hisanao Akiyama

    Full Text Available The first non-vitamin K antagonist oral anticoagulant (NOAC introduced to the market in Japan was dabigatran in March 2011, and three more NOACs, rivaroxaban, apixaban, and edoxaban, have since become available. Randomized controlled trials of NOACs have revealed that intracranial hemorrhage (ICH occurs less frequently with NOACs compared with warfarin. However, the absolute incidence of ICH associated with NOACs has increased with greater use of these anticoagulants, and we wanted to explore the incidence, clinical characteristics, and treatment course of patients with NOACs-associated ICH.We retrospectively analyzed the characteristics of symptomatic ICH patients receiving NOACs between March 2011 and September 2014.ICH occurred in 6 patients (5 men, 1 woman; mean ± SD age, 72.8 ± 3.2 years. Mean time to onset was 146.2 ± 111.5 days after starting NOACs. Five patients received rivaroxaban and 1 patient received apixaban. None received dabigatran or edoxaban. Notably, no hematoma expansion was observed within 24 h of onset in the absence of infusion of fresh frozen plasma, activated prothrombin complex concentrate, recombinant activated factor VIIa or hemodialysis. When NOAC therapy was initiated, mean HAS-BLED and PANWARDS scores were 1.5 ± 0.5 and 39.5 ± 7.7, respectively. Mean systolic blood pressure was 137.8 ± 15.9 mmHg within 1 month before spontaneous ICH onset.Six symptomatic ICHs occurred early in NOAC therapy but hematoma volume was small and did not expand in the absence of infusion of reversal agents or hemodialysis. The occurrence of ICH during NOAC therapy is possible even when there is acceptable mean systolic blood pressure control (137.8 ± 15.9 mmHg and HAS-BLED score ≤ 2. Even stricter blood pressure lowering and control within the acceptable range may be advisable to prevent ICH during NOAC therapy.

  20. High platelet reactivity--the challenge of prolonged anticoagulation therapy after ACS

    NARCIS (Netherlands)

    Brouwer, M.A.; Jaspers Focks, J.; Verheugt, F.W.A.

    2013-01-01

    Despite dual antiplatelet therapy (DAPT), one-year event rates after acute coronary syndrome (ACS) vary from 9-12%. The development of novel oral anticoagulants (NOAC) without a need for monitoring has initiated renewed interest for prolonged adjunctive anticoagulation. Importantly, the cornerstone

  1. Recurrent venous thromboembolism in anticoagulated patients with cancer : management and short-term prognosis

    NARCIS (Netherlands)

    Schulman, S.; Zondag, M.; Linkins, L.; Pasca, S.; Cheung, Y. W.; De Sancho, M.; Gallus, A.; Lecumberri, R.; Molnar, S.; Ageno, W.; Le Gal, G.; Falanga, A.; Hulegardh, E.; Ranta, S.; Kamphuisen, P.; Debourdeau, P.; Rigamonti, V.; Ortel, T. L.; Lee, A.

    2015-01-01

    BackgroundRecommendations for management of cancer-related venous thromboembolism (VTE) in patients already receiving anticoagulant therapy are based on low-quality evidence. This international registry sought to provide more information on outcomes after a breakthrough VTE in relation to anticoagul

  2. Oral anticoagulants for stroke prevention in atrial fibrillation: current status, special situations, and unmet needs

    NARCIS (Netherlands)

    Verheugt, F.W.A.; Granger, C.B.

    2015-01-01

    In patients with non-valvular atrial fibrillation, oral anticoagulation with vitamin K antagonists reduces the risk of stroke by more than 60%. But vitamin K antagonists have limitations, including causing serious bleeding such as intracranial haemorrhage and the need for anticoagulation monitoring.

  3. Monitoring the Effects and Antidotes of the Non-vitamin K Oral Anticoagulants

    DEFF Research Database (Denmark)

    Rahmat, Nur A; Lip, Gregory Y H

    2015-01-01

    major challenges: the need for reliable laboratory assays to assess their anticoagulation effect, and the lack of approved antidotes to reverse their action. This article provides an overview of monitoring the anticoagulant effect of NOACs and their potential specific antidotes in development....

  4. Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation?

    Science.gov (United States)

    Numerous factors have been identified as risk factors for instability of oral anticoagulation, including variability in vitamin K intake. However few studies have directly tested the feasibility of manipulating dietary vitamin K to achieve stable oral anticoagulation. Recent findings from a rando...

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

    DEFF Research Database (Denmark)

    Hellfritzsch, Maja; Husted, Steen Elkjaer; Grove, Erik Lerkevang;

    2016-01-01

    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 ...

  6. Anticoagulant therapy in patients undergoing dental interventions: a critical review of the literature and current perspectives.

    Science.gov (United States)

    Isola, G; Matarese, G; Cordasco, G; Rotondo, F; Crupi, A; Ramaglia, L

    2015-02-01

    Patients treated with oral anticoagulant therapy (OAT) represent an issue to the dentist, as an increasing number of people are using anticoagulant drugs for cardiovascular disease. The choice of an eventual suspension or continuation of anticoagulant therapy is important when considering an efficient management of the patient. Patients in anticoagulant therapy and requiring dental procedures sometimes represent therapeutic concerns especially concerning the suspension of the anticoagulant treatment. At the moment there is no consensus among international experts of a possible discontinuation of therapy before invasive dental procedures. In this paper, the authors try to focus on this topic through a critical review of the literature. Most of the studies suggest the continuation of the anticoagulant treatment with heparin before invasive oral surgical interventions. Based on the data of the literature, two rules must be adopted in clinical practice: 1) maintenance of anticoagulation related to the international normalized ratio (INR); 2) local application of antifibrinolytic agents to ensure a proper hemostatic process. Given the widespread use of anticoagulant drugs in cardiovascular disease, dentists must often face the problem of the therapy and, since there is no consensus on the management of these patients, the authors propose, after a thorough critical review of the literature, the implementation of a multiphase protocol of surgical approach to be implemented with safety in daily clinical practice.

  7. Switching, Adverse Effects and Use of Over-the-Counter Analgesics among Users of Oral Anticoagulants

    DEFF Research Database (Denmark)

    Poulsen, Maja Hellfritzsch; Hyllested, Lea Maria Rønneberg; Meegaard, Line

    2017-01-01

    Oral anticoagulants are widely used but information on important aspects in that respect is not available from medical registers or clinical databases. Therefore, we conducted a survey including patients filling a prescription for oral anticoagulants at two large Danish community pharmacies. We...

  8. Lupus anticoagulants and the risk of a first episode of deep venous thrombosis

    NARCIS (Netherlands)

    De Groot, PG; Lutters, B; Derksen, RHWM; Lisman, T; Meijers, JCM; Rosendaal, FR

    2005-01-01

    We have determined lupus anticoagulants, anti-beta(2) glycoprotem I (beta(2)GPI) and antiprothrombin antibodies in the Leiden Thrombophilia Study, a population-based case-control study designed to determine risk factors for deep venous thrombosis (DVT). Lupus anticoagulant (LAC) was measured in 473

  9. 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...

  10. Mitogen-Activated Protein Kinases Regulate Susceptibility to Ventilator-Induced Lung Injury

    OpenAIRE

    2008-01-01

    BACKGROUND: Mechanical ventilation causes ventilator-induced lung injury in animals and humans. Mitogen-activated protein kinases have been implicated in ventilator-induced lung injury though their functional significance remains incomplete. We characterize the role of p38 mitogen-activated protein kinase/mitogen activated protein kinase kinase-3 and c-Jun-NH(2)-terminal kinase-1 in ventilator-induced lung injury and investigate novel independent mechanisms contributing to lung injury during ...

  11. Differential <