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Sample records for anticoagulant activated protein

  1. A plasma coagulation assay for an activated protein C-independent anticoagulant activity of protein S

    NARCIS (Netherlands)

    van Wijnen, M.; van 't Veer, C.; Meijers, J. C.; Bertina, R. M.; Bouma, B. N.

    1998-01-01

    To study the physiological importance of the activated protein C (APC)-independent anticoagulant activity of protein S, we developed an assay specific for this activity. The ability of protein S to prolong the clotting time in an APC-independent way was expressed as the ratio of the clotting time in

  2. Anticoagulant activity of a natural protein purified from Hypomesus olidus.

    Science.gov (United States)

    Gou, Mengxing; Wang, Liyan; Liu, Xuejun

    2017-05-01

    A novel anticoagulant protein (E-II-1) was separated and purified from Hypomesus olidus, a unique freshwater fish in northern China. E-II-1 had a molecular mass of approximately 40 kDa with no subunits. The high content of hydrophobic amino acids and negatively charged amino acids in E-II-1 demonstrated that the amino acid compositions might contribute to the anticoagulant activity. E-II-1 contained α-helices 16.75%, β-sheets 42.67%, β-turn 25.58% and random coil 15.00%. In vitro blood coagulation time assay, E-II-1 significantly prolonged the activated partial thrombin time in a dose-dependent manner. Results indicated that E-II-1 acted as anticoagulants through the endogenous pathway with an inhibition of FXa. The specific activity of E-II-1 was 103.50 U/mg at a concentration of 1.00 mg/mL. Therefore, E-II-1 might be one of the promising anticoagulants originated from natural food sources with more safety and less side effects.

  3. 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.

  4. 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.

  5. 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.

  6. [Screening and identification of Bacillus pumilus producing double active protein of anticoagulation and thrombolysis].

    Science.gov (United States)

    Liu, Binghua; Luo, Yaxiong; Tao, Xuemei; Xie, Xiaoying; Ma, Xupan; Zhang, Lin

    2014-03-04

    The aim of this study was to screen bacteria that can produce antithrombotic. We screened the target bacteria on VY/4 plate and casein plate from more than 20 samples such as water, soil, rabbit manure, sheep manure and deadwood. We detected the antithrombotic activity by fibrin plate and fibrin tube. We identified the target bacteria by morphological characteristics, physical and chemical properties and 16S DNA sequence homology. We obtained 5 strains that can produce antithrombotic. We found that the extracellular protein of strain LDS33 shows both stronger fibrinolytic activity and stronger anticoagulation activity. According to the morphology, physiochemical properties, 16S DNA sequencing and phylogenetic tree, strain LDS33 is identified as Bacillus pumilus. Bacillus pumilus LDS33 can produce highly active anticoagulation and thrombolysis double active protein.

  7. Increased prothrombin activation in protein S-deficient plasma under flow conditions on endothelial cell matrix: an independent anticoagulant function of protein S in plasma

    NARCIS (Netherlands)

    van't Veer, C.; Hackeng, T. M.; Biesbroeck, D.; Sixma, J. J.; Bouma, B. N.

    1995-01-01

    Protein S is a vitamin K-dependent nonenzymatic coagulation factor involved in the regulation of activated protein C (aPC). In this study, we report an aPC-independent anticoagulant function of protein S in plasma under flow conditions. Plasma, anticoagulated with low-molecular-weight heparin

  8. Human Protein C produces anticoagulation and increased fibrinolytic activity in the cat

    International Nuclear Information System (INIS)

    Burdick, M.D.; Schaub, R.G.

    1986-01-01

    The effect of activated human Protein C (PCa) infusion on the coagulation and fibrinolytic systems of the Nembutal anesthetized cat was assessed. Human Protein C was activated by incubation with thrombin or by passage over a column of thrombin immobilized on CNBr Sepharose 4B. Cats were given bolus i.v. injections of either vehicle or PCa in a dose range of 3-16 μg/mL of calculated whole body volume. Citrated blood samples (9:1) were taken from a femoral vein prior to and at 5, 10, 20, 30, 60, 120, and 180 min. after PCa. Activated partial thromboplastin time (APTT), thrombin time (TT) euglobulin clot lysis (ECLT) and I-125 fibrin release (FR) was measured. Vehicle treated cats had no change in any parameter. PCa produced a dose and time dependent prolongation of APTT while TT was unchanged. Anticoagulation was evident immediately after PCa infusion and began to normalize within 20 min. Fibrinolytic activity measured by ECLT and FR was also stimulated by PCa but was not evident until 40-60 minutes after PCa injection. The results show that human PCa induces anticoagulation effects in the cat similar to other species. However, stimulation of fibrinolysis requires a longer period of time before expression. This delay of fibrinolytic stimulation should be considered when assessing the effects of human Protein C in other species

  9. 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

  10. The interaction between anticoagulant protein S and complement regulatory C4b-binding protein (C4BP)

    NARCIS (Netherlands)

    van de Poel, R. H.; Meijers, J. C.; Bouma, B. N.

    2000-01-01

    An important mechanism of regulation of blood coagulation is the anticoagulant protein C pathway. In this pathway, the anticoagulant activity of activated protein C is increased by its cofactor protein S. The cofactor activity of protein S can be regulated by binding to complement regulatory

  11. [Factors influenceing the activity of oral anticoagulants].

    Science.gov (United States)

    González Caamaño, A; Díaz Barreiro, L A

    1976-01-01

    Anticoagulants are drugs capable to retard or even cancell the process of blood coagulation. They are many factors who influences the intensity and duration of oral anticoagulant acitivity, such as drugs, body constitution, physical agents, diseases, etc. The oral anticoagulants interacts with other drugs at differents levels: at the gut, at the plasma, modiffing the protein binding or the metabolism of such drugs, at the enzimatic induction or inhibition, or at unknown places with many other drugs. These paper deals with the description of such interactions.

  12. Heparin mimetics with anticoagulant activity.

    Science.gov (United States)

    Nahain, Abdullah Al; Ignjatovic, Vera; Monagle, Paul; Tsanaktsidis, John; Ferro, Vito

    2018-02-15

    Heparin, a sulfated polysaccharide belonging to the glycosaminoglycan family, has been widely used as an anticoagulant drug for decades and remains the most commonly used parenteral anticoagulant in adults and children. However, heparin has important clinical limitations and is derived from animal sources which pose significant safety and supply problems. The ever growing shortage of the raw material for heparin manufacturing may become a very significant issue in the future. These global limitations have prompted much research, especially following the recent well-publicized contamination scandal, into the development of alternative anticoagulants derived from non-animal and/or totally synthetic sources that mimic the structural features and properties of heparin. Such compounds, termed heparin mimetics, are also needed as anticoagulant materials for use in biomedical applications (e.g., stents, grafts, implants etc.). This review encompasses the development of heparin mimetics of various structural classes, including synthetic polymers and non-carbohydrate small molecules as well as sulfated oligo- and polysaccharides, and fondaparinux derivatives and conjugates, with a focus on developments in the past 10 years. © 2018 Wiley Periodicals, Inc.

  13. The prevalence of poor anticoagulant response to activated protein C (APC resistance) among patients suffering from stroke or venous thrombosis and among healthy subjects.

    Science.gov (United States)

    Halbmayer, W M; Haushofer, A; Schön, R; Fischer, M

    1994-02-01

    A poor anticoagulant response to activated protein C (APC) in an activated partial thromboplastin time (aPTT) assay (APC resistance) was recently reported to be a cause of familial thrombophilia. The response to APC was measured in 30 patients suffering from juvenile or recurrent stroke, in 40 patients suffering from venous thromboembolism and in 50 healthy subjects. The prevalence of APC resistance was found to be significantly higher among patients with stroke (20%, P < 0.003) and venous thrombosis (17.5%, P < 0.02) compared with the prevalence of APC resistance among normal controls (2%). In one case of venous thrombosis, the proposita's family (A) could be investigated and in five out of nine investigated members (56%) a poor or borderline response to APC was detected. The family (B) of another APC-resistant patient revealed six subjects with poor coagulation response to APC out of eight family members studied (75%). Measuring protein S activity with an automated calcium-thromboplastin-based protein S activity assay, a significant correlation (P < 0.0001) between the results of this functional protein S assay and APC resistance (represented by the ratio (Rs value) of clotting time with and without addition of activated protein C) was observed. Nine out of 14 patients (64%) with poor APC response showed protein S activities below the normal range. Assessment of protein S activity with a second protein S clotting assay using factor Va as substrate confirmed only 47% of the decreased levels of the thromboplastin-based protein S clotting assay.(ABSTRACT TRUNCATED AT 250 WORDS)

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

    Science.gov (United States)

    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. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. 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....... There is general agreement that the quality of the therapy is too low, and often unexpected fluctuations in the coagulant activity are seen. Recently, OAT based on patient self-management has become a realistic alternative by the availability of small portable whole blood coagulometers. An important part...... 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...

  16. Anticoagulant activity of ginger ( Zingiber officinale Rosc ...

    African Journals Online (AJOL)

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

  17. Anticoagulants

    Science.gov (United States)

    ... they last a long time. You participate in sports or other activities that put you at risk for bleeding or bruising. What are the side effects? Sometimes a medicine causes unwanted effects. These are ...

  18. Fibrinolytic and anticoagulative activities from the earthworm Eisenia foetida.

    Science.gov (United States)

    Hrzenjak, T; Popović, M; Bozić, T; Grdisa, M; Kobrehel, D; Tiska-Rudman, L

    1998-04-01

    Biologically active glycolipoprotein complex (G-90) isolated from whole earthworm tissue extract shows anticoagulative and fibrinolytic activities. We isolated two tyrosine like serine peptidases with molecular masses of 34 kDa (P I) and 23 kDa (P II), respectively. P I peptidase is autocatalytically degraded to P II. Both peptidases exhibit fibrinolytic and anticoagulative activities. The activity of P I is much higher. P I in concentration of 10(5) ng ml-1 of plasma shortened the physiological time of fibrin clot lysis by 54% and completely inhibited blood clotting at a concentration of 10(3) ng ml-1 of venous blood.

  19. Antithrombotic/anticoagulant and anticancer activities of selected ...

    African Journals Online (AJOL)

    Nine plants available in the Eastern Cape Province of South Africa were tested for antithrombotic and/or anticoagulant activity. Organic (methanol) and aqueous (distilled water) extractions were performed on the various plant parts. The thrombin assay and clotting time assays (thrombin-induced and CaCl2-induced) were ...

  20. Synthesis and anticoagulant activity of the quaternary ammonium chitosan sulfates.

    Science.gov (United States)

    Fan, Lihong; Wu, Penghui; Zhang, Jinrong; Gao, Song; Wang, Libo; Li, Mingjia; Sha, Mingming; Xie, Weiguo; Nie, Min

    2012-01-01

    Quaternary ammonium chitosan sulfates with diverse degrees of substitution (DS) ascribed to sulfate groups between 0.52 and 1.55 were synthesized by reacting quaternary ammonium chitosan with an uncommon sulfating agent (N(SO(3)Na)(3)) that was prepared from sodium bisulfite (NaHSO(3)) through reaction with sodium nitrite (NaNO(2)) in the aqueous system homogeneous. The structures of the derivatives were characterized by FTIR, (1)H NMR and (13)C NMR. The factors affecting DS of quaternary ammonium chitosan sulfates which included the molar ratio of NaNO(2) to quaternary ammonium chitosan, sulfated temperature, sulfated time and pH of sulfated reaction solution were investigated in detail. Its anticoagulation activity in vitro was determined by an activated partial thromboplastin time (APTT) assay, a thrombin time (TT) assay and a prothrombin time (PT) assay. Results of anticoagulation assays showed quaternary ammonium chitosan sulfates significantly prolonged APTT and TT, but not PT, and demonstrated that the introduction of sulfate groups into the quaternary ammonium chitosan structure improved its anticoagulant activity obviously. The study showed its anticoagulant properties strongly depended on its DS, concentration and molecular weight. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  1. 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.

  2. Exogenous Magnesium Chloride Reduces the Activated Partial Thromboplastin Times of Lupus Anticoagulant-Positive Patients.

    Directory of Open Access Journals (Sweden)

    Takayoshi Tokutake

    Full Text Available The activated partial thromboplastin time (APTT assay is a basic hemostatic assay based on the time it takes for clots to form in plasma samples after the addition of calcium chloride. It is used to screen for various coagulation disorders. Several previous reports have suggested that magnesium (Mg might contribute to coagulation reactions by binding to specific coagulation proteins. We investigated the effects of Mg on the APTT. In healthy controls, the APTT was significantly prolonged in proportion to the increase in the concentration of magnesium chloride in the range from 2.1 to 16.7 mmol/L. Among eight samples from patients with various disorders that exhibited prolonged APTT, two samples demonstrated shorter APTT when Mg was added, both of which were from patients that were positive for lupus anticoagulant. When we examined 206 clinical APTT samples, we found that Mg shortened the APTT of two samples. These two samples were also from lupus anticoagulant-positive patients (p-value: <0.003. Our findings regarding the unique effects of exogenous Mg on the APTT of lupus anticoagulant-positive patients might shed light on the role of Mg in APTT assays and lead to the development of a novel screening method for lupus anticoagulant.

  3. Exogenous Magnesium Chloride Reduces the Activated Partial Thromboplastin Times of Lupus Anticoagulant-Positive Patients.

    Science.gov (United States)

    Tokutake, Takayoshi; Baba, Hisami; Shimada, Yuji; Takeda, Wataru; Sato, Keijiro; Hiroshima, Yuki; Kirihara, Takehiko; Shimizu, Ikuo; Nakazawa, Hideyuki; Kobayashi, Hikaru; Ishida, Fumihiro

    2016-01-01

    The activated partial thromboplastin time (APTT) assay is a basic hemostatic assay based on the time it takes for clots to form in plasma samples after the addition of calcium chloride. It is used to screen for various coagulation disorders. Several previous reports have suggested that magnesium (Mg) might contribute to coagulation reactions by binding to specific coagulation proteins. We investigated the effects of Mg on the APTT. In healthy controls, the APTT was significantly prolonged in proportion to the increase in the concentration of magnesium chloride in the range from 2.1 to 16.7 mmol/L. Among eight samples from patients with various disorders that exhibited prolonged APTT, two samples demonstrated shorter APTT when Mg was added, both of which were from patients that were positive for lupus anticoagulant. When we examined 206 clinical APTT samples, we found that Mg shortened the APTT of two samples. These two samples were also from lupus anticoagulant-positive patients (p-value: <0.003). Our findings regarding the unique effects of exogenous Mg on the APTT of lupus anticoagulant-positive patients might shed light on the role of Mg in APTT assays and lead to the development of a novel screening method for lupus anticoagulant.

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

    Science.gov (United States)

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

    2017-01-01

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

  5. The interaction of protein S with the phospholipid surface is essential for the activated protein C-independent activity of protein S

    NARCIS (Netherlands)

    van Wijnen, M.; Stam, J. G.; van't Veer, C.; Meijers, J. C.; Reitsma, P. H.; Bertina, R. M.; Bouma, B. N.

    1996-01-01

    Protein S is a vitamin-K dependent glycoprotein involved in the regulation of the anticoagulant activity of activated protein C (APC). Recent data showed a direct anticoagulant role of protein S independent of APC, as demonstrated by the inhibition of prothrombinase and tenase activity both in

  6. Susceptibility and resistance to experimental autoimmune encephalomyelitis and neuritis in the guinea pig correlate with the induction of procoagulant and anticoagulant activities.

    Science.gov (United States)

    Geczy, C L; Roberts, I M; Meyer, P; Bernard, C C

    1984-12-01

    Activation of macrophage procoagulant activity (MPCA) is involved in the manifestation of EAE and EAN in susceptible guinea pigs and provides a mechanism for the deposition of fibrin, which is a feature of histologic lesions of EAE. Peritoneal exudate cells (PEC) from susceptible (strain 13) guinea pigs immunized with either central or peripheral nervous tissue antigens produce procoagulant activity when incubated with the immunogen in vitro. The production of the procoagulant is quantitative and antigen-specific and is maximal at the time of clinical signs of the disease. After recovery, the production of procoagulant activity decreased. The MPCA test was able to discriminate the biochemical differences existing between chicken and mammalian peripheral nerve proteins, thus providing a quantitative and sensitive indicator of cell-mediated immunity in EAE and EAN. The autoimmune response to brain and nerve antigens in nonsusceptible (strain 2) guinea pigs was coincident with the antigen-specific production of a cell-bound anticoagulant activity by stimulated mononuclear cells. The production of anticoagulant activity followed the same sequence of time changes after immunization as that of the MPCA in susceptible guinea pigs, and high immunizing doses of nerve antigens induced high levels of anticoagulant activity. The same cells produced high levels of procoagulant when incubated with tuberculin or lipopolysaccharide. The recalcification time of normal plasma was prolonged by the anticoagulant, and the decreased clotting time of plasma induced by the procoagulant activity obtained by incubating sensitized strain 13 PEC with myelin basic protein was suppressed by the anticoagulant produced by culturing sensitized strain 2 PEC with myelin basic protein. Preliminary evidence indicates that the anticoagulant has properties similar to antithrombin III. The anticoagulant could play a role in the control of effector cell function, and therefore in recovery from clinical

  7. Anticoagulant drugs increase natural killer cell activity in lung cancer

    Czech Academy of Sciences Publication Activity Database

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

    2005-01-01

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

  8. A comparative study on anticoagulant activities of three Chinese herbal medicines from the genus Panax and anticoagulant activities of ginsenosides Rg1 and Rg2.

    Science.gov (United States)

    Li, C T; Wang, H B; Xu, B J

    2013-08-01

    Chemical compositions of three herbal plants from the family Araliaceae genus Panax [Panax ginseng C. A. Mey, P. quinquefolius L. and P. notoginseng (Burk.) F. H. Chen] are quite similar; however, their medicinal natures vary greatly. The reason for differences has been explained in traditional Chinese medicine theory and partially verified by modern pharmacological investigations, such as antiplatelet aggregation. Aside from platelet aggregation, a variety of plasma coagulation factors are also involved in blood coagulation. The anticoagulation profiles of three herbs have not been investigated. The current research compared the inhibitory effects of three herbal extracts from Panax spp. and the purified ginsenosides from P. ginseng on blood coagulation. Human plasma was mixed with the water extracts (0.05 and 0.1 mg/mL) from roots of P. ginseng, P. quinquefolius and P. notoginseng and ginsenosides Rg1 and Rg2 (0.05 and 0.1 mg/mL), the blood clotting time of activated partial thromboplastin, prothrombin and thrombin were measured by a biochemical analyzer. The water extracts (0.05 mg/mL) of P. ginseng, P. quinquefolius and P. notoginseng could significantly extend blood clotting time as compared to the control group. Among three herbal medicines, 0.05 mg/mL of water extract from P. ginseng exhibited the strongest anticoagulation effects, followed by P. notoginseng, while P. quinquefolius presented the weakest effects. Both ginsenosides Rg1 and Rg2 could significantly extend blood clotting time in all three tests; ginsenoside Rg2 exhibited relative stronger anticoagulation effects as compared to ginsenoside Rg1. Among three herbs tested, P. ginseng as well as its active component ginsenoside Rg2 shows the strongest anticoagulation activity; current results indicate that P. ginseng and ginsenoside Rg2 have great potential to be an anticoagulation drug.

  9. Sulfated modification and anticoagulant activity of pumpkin (Cucurbita pepo, Lady Godiva) polysaccharide.

    Science.gov (United States)

    Liang, Li; Ao, Le; Ma, Tao; Ni, Yuanying; Liao, Xiaojun; Hu, Xiaosong; Song, Yi

    2018-01-01

    Sulfated modification of pumpkin polysaccharide using CAS with pyridines as catalysts under different conditions was conducted to obtain different degrees of sulfation on a laboratory scale. Anticoagulant activities of pumpkin polysaccharide and its sulfated derivatives were also investigated employing various established in vitro systems. Results showed that addition of high ratio of CAS/pyridine under constant conditions could increase the degree of substitution. Sulfate substitution was further confirmed by the FT-IR and 13 C NMR analysis. The d f values between 2.11-2.73 indicated the relatively expanded conformation of the sulfated derivatives. The sulfated polysaccharides showed higher anticoagulant activities through activated partial thrombosis time (aPTT), thrombin time (TT), prothrombin time (PT) and anti-Xa activity assay, which revealed that better anticoagulant activities could be obtained when DS remained higher and M w maintained in a moderate range. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Sulfonation of papain-treated chitosan and its mechanism for anticoagulant activity.

    Science.gov (United States)

    Suwan, Jiraporn; Zhang, Zhenqing; Li, Boyangzi; Vongchan, Preeyanat; Meepowpan, Puttinan; Zhang, Fuming; Mousa, Shaker A; Mousa, Shaymaa; Premanode, Bhusana; Kongtawelert, Prachya; Linhardt, Robert J

    2009-07-06

    The novel low-molecular-weight chitosan polysulfate (MW 5120-26,200 Da) was prepared using the depolymerization of chitosan with papain (EC. 3.4.22.2). The sulfonation of depolymerized products was performed using chlorosulfonic acid in N,N-dimethylformamide under semi-heterogeneous conditions. The structures of the products were characterized by FTIR, (13)C NMR, and (1)H NMR (1D, 2D NMR) spectroscopy. The present study sheds light on the mechanism of anticoagulant activity of chitosan polysulfate. Anticoagulant activity was investigated by an activated partial thromboplastin assay, a thrombin time assay, a prothrombin time assay, and thrombelastography. Surface plasmon resonance also provided valuable data for understanding the relationship between the molecular binding of sulfated chitosan to two important blood clotting regulators, antithrombin III and heparin cofactor II. These results show that the principal mechanism by which this chitosan polysulfate exhibits anticoagulant activity is mediated through heparin cofactor II and is dependent on polysaccharide molecular weight.

  11. Physical activity and risk of bleeding in elderly patients taking anticoagulants.

    Science.gov (United States)

    Frey, P M; Méan, M; Limacher, A; Jaeger, K; Beer, H-J; Frauchiger, B; Aschwanden, M; Rodondi, N; Righini, M; Egloff, M; Osterwalder, J; Kucher, N; Angelillo-Scherrer, A; Husmann, M; Banyai, M; Matter, C M; Aujesky, D

    2015-02-01

    Although the possibility of bleeding during anticoagulant treatment may limit patients from taking part in physical activity, the association between physical activity and anticoagulation-related bleeding is uncertain. To determine whether physical activity is associated with bleeding in elderly patients taking anticoagulants. In a prospective multicenter cohort study of 988 patients aged ≥ 65 years receiving anticoagulants for venous thromboembolism, we assessed patients' self-reported physical activity level. The primary outcome was the time to a first major bleeding, defined as fatal bleeding, symptomatic bleeding in a critical site, or bleeding causing a fall in hemoglobin or leading to transfusions. The secondary outcome was the time to a first clinically relevant non-major bleeding. We examined the association between physical activity level and time to a first bleeding by using competing risk regression, accounting for death as a competing event. We adjusted for known bleeding risk factors and anticoagulation as a time-varying covariate. During a mean follow-up of 22 months, patients with a low, moderate, and high physical activity level had an incidence of major bleeding of 11.6, 6.3, and 3.1 events per 100 patient-years and an incidence of clinically relevant non-major bleeding of 14.0, 10.3, and 7.7 events per 100 patient-years, respectively. A high physical activity level was significantly associated with a lower risk of major bleeding (adjusted sub-hazard ratio 0.40, 95% confidence interval 0.22-0.72). There was no association between physical activity and non-major bleeding. A high level of physical activity is associated with a decreased risk of major bleeding in elderly patients receiving anticoagulant therapy. © 2014 International Society on Thrombosis and Haemostasis.

  12. Recombinant human activated protein C (Xigris)

    NARCIS (Netherlands)

    Levi, M. [=Marcel M.; de Jonge, E.; van der Poll, T.

    2002-01-01

    An impaired function of the protein C pathway plays a central role in the pathogenesis of sepsis. Administration of human recombinant activated protein C (Xigris) may restore the dysfunctional anticoagulant mechanism and prevent amplification and propagation of thrombin generation and formation of

  13. Anticoagulant activity of a dermatan sulfate from the skin of the shark Scyliorhinus canicula.

    Science.gov (United States)

    Dhahri, Manel; Mansour, Mohamed B; Bertholon, Isabelle; Ollivier, Véronique; Boughattas, Naceur A; Hassine, Mohsen; Jandrot-Perrus, Martine; Chaubet, Frédéric; Maaroufi, Raoui M

    2010-09-01

    A dermatan sulfate isolated from the shark Scyliorhinus canicula skin by enzymatic digestion followed by purification with anion exchange chromatography was identified by chondroitinase and nitrous acid treatment and partially characterized by Fourier-transform infrared spectroscopy. Dermatan sulfate was the major glycosaminoglycan and represented 75% of the polysaccharide fraction in the sharkskin. This dermatan sulfate had a 38.6 kDa average molecular weight and 23% sulfate content. The anticoagulant action of this dermatan sulfate was checked by several coagulometric and colorimetric assays such as the activated partial thromboplastin time, thrombin time, thrombin generation and heparin cofactor II and antithrombin-mediated inhibition of thrombin and compared with that of porcine intestinal mucosa dermatan sulfate. The effects on platelet activation and aggregation were investigated using flow cytometry and aggregometry, respectively. The dermatan sulfate prolonged activated partial thromboplastin time and thrombin time, delayed and inhibited thrombin generation in a concentration-dependent manner. The specific anticoagulant activity of the sharkskin dermatan sulfate was 43 UI/mg. The anticoagulant effect of sharkskin dermatan sulfate was higher than that of the porcine dermatan sulfate and was due to the potentiation of thrombin inhibition by heparin cofactor II. Moreover, it had no effect on platelet aggregation and activation induced by various agonists and thereby constitutes a potentially useful drug of interest in anticoagulant therapy.

  14. Synergistic inhibition of the intrinsic factor X activation by protein S and C4b-binding protein

    NARCIS (Netherlands)

    Koppelman, S. J.; van't Veer, C.; Sixma, J. J.; Bouma, B. N.

    1995-01-01

    The complement protein C4b-binding protein plays an important role in the regulation of the protein C anticoagulant pathway. C4b-binding protein can bind to protein S, thereby inhibiting the cofactor activity of protein S for activated protein C. In this report, we describe a new role for

  15. Anticoagulant Activity of Low-Molecular Weight Compounds from Heterometrus laoticus Scorpion Venom

    Directory of Open Access Journals (Sweden)

    Thien Vu Tran

    2017-10-01

    Full Text Available Scorpion venoms are complex polypeptide mixtures, the ion channel blockers and antimicrobial peptides being the best studied components. The coagulopathic properties of scorpion venoms are poorly studied and the data about substances exhibiting these properties are very limited. During research on the Heterometrus laoticus scorpion venom, we have isolated low-molecular compounds with anticoagulant activity. Determination of their structure has shown that one of them is adenosine, and two others are dipeptides LeuTrp and IleTrp. The anticoagulant properties of adenosine, an inhibitor of platelet aggregation, are well known, but its presence in scorpion venom is shown for the first time. The dipeptides did not influence the coagulation time in standard plasma coagulation tests. However, similarly to adenosine, both peptides strongly prolonged the bleeding time from mouse tail and in vitro clot formation in whole blood. The dipeptides inhibited the secondary phase in platelet aggregation induced by ADP, and IleTrp decreased an initial rate of platelet aggregation induced by collagen. This suggests that their anticoagulant effects may be realized through the deterioration of platelet function. The ability of short peptides from venom to slow down blood coagulation and their presence in scorpion venom are established for the first time. Further studies are needed to elucidate the precise molecular mechanism of dipeptide anticoagulant activity.

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

    Science.gov (United States)

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

    2016-02-01

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

  17. 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

    by a flexible single-strand linker, have been shown to possess anticoagulant activity. Here, we link multiple aptamers at programmed positions on DNA nanostructures to optimize spacing and orientation of the aptamers and thereby to maximize anticoagulant activity in functional assays. By judicious engineering...... of the DNA nanostructures, we have created a novel, functional DNA nanostructure, which is a multi-aptamer inhibitor with activity eightfold higher than free aptamer. Reversal of the thrombin inhibition was also achieved by the use of single-stranded DNA antidotes, thus enabling significant control over......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...

  18. [Dependence of the anticoagulant activity of starch and inulin on their degree of sulfonation].

    Science.gov (United States)

    Drozd, N N; Torlopov, M A; Kuzhim, A A; Makarov, V A

    2012-01-01

    We have studied a relationship between the degree of sulfonation and anticoagulant activity of starch from Solanum tuberosum (molecular weight, 25000-30000 Da; sulfonation degree, 0.4-2.5) and inulin from Helianthus tuberosus (molecular weight, 7000-8000 Da; sulfonation degree, 0.6-1.6). Starch and inulin sulfates (i) increased the time of appearance of fibrin clots in plasma in coagulometric tests and (ii) reduced (via antithrombin) the rate of thrombin-induced hydrolysis of a chromogen substrate. The antithrombin (aIIa) activity of starch sulfates reached 16.8-70.0 IU/mg and the activity against factor Xa (aXa activity) was 2.3-16.6 IU/mg. The antithrombin activity of inulin sulfates was within 5.5-11.4 IU/mg and the activity against factor Xa (aXa activity) was within 0-1.4 IU/mg. An increase in the degree of sulfonation led to a growth in the anticoagulant activity of starch sulfates. The anticoagulant activity of starch sulfates and inulin sulfate with sulfonation degree 1.0 is mediated by antithrombin, which is the plasma inhibitor of serine proteases.

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

    Science.gov (United States)

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

    2017-07-01

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

  20. 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.

  1. 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. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Sulfonation and anticoagulant activity of botryosphaeran from Botryosphaeria rhodina MAMB-05 grown on fructose.

    Science.gov (United States)

    Mendes, Simone Ferreira; dos Santos, Osvaldo; Barbosa, Aneli M; Vasconcelos, Ana Flora D; Aranda-Selverio, Gabriel; Monteiro, Nilson K; Dekker, Robert F H; Sá Pereira, Mariana; Tovar, Ana Maria F; Mourão, Paulo A de Souza; da Silva, Maria de Lourdes Corradi

    2009-10-01

    Botryosphaeran (EPS(FRU)), an exopolysaccharide of the beta-(1-->3,1-->6)-d-glucan type with 31% branching at C-6, is produced by the fungus Botryosphaeria rhodina MAMB-05 when grown on fructose as carbon source. Botryosphaeran was derivatized by sulfonation to induce anticoagulant activity. The effectiveness of the sulfonation reaction by chlorosulfonic acid in pyridine was monitored by the degree of substitution and FT-IR analysis of the sulfonated EPS(FRU) (once sulfonated, EPS(FRUSULF); and re-sulfonated, EPS(FRURESULF)). Activated partial thromboplastin time (APTT) and thrombin time (TT) tests of EPS(FRURESULF) indicated significant in vitro anticoagulant activity that was dose-dependent. EPS(FRU) did not inhibit any of the coagulation tests.

  3. Physicochemical properties and anticoagulant activity of polyphenols derived from Lachnum singerianum

    Directory of Open Access Journals (Sweden)

    Shuai Zong

    2017-10-01

    Full Text Available In this study, polyphenols (LSP were obtained from the fermentation broth of Lachnum singerianum. Two fractions were isolated by Sephadex LH-20 chromatographic column, and the primary fraction (LSP-1 was collected. The comprehensive physicochemical properties of phenolic acids and polyhydroxy phenolic compounds of LSP-1 were determined by UV-visible spectroscopy, Fourier transform infrared spectroscopy, and gas chromatography–mass spectrometry. Results of anticoagulant activity assay in vitro showed that LSP-1 could lengthen prothrombin time, activated partial thromboplastin time, and thrombin time of mouse plasma. In addition, anticoagulant activity results in vivo showed that high dose of LSP-1 could significantly prolong bleeding time, coagulation time, prothrombin time, activated partial thromboplastin time, and thrombin time of hypercoagulable mice induced by adrenaline, reduce the content of fibrinogen and enhance antithrombin III activity. All results indicated that the LSP-1 could serve well as an anticoagulant, and might be used as a potential natural drug candidate for thrombosis.

  4. Depolymerized glycosaminoglycan and its anticoagulant activities from sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Yang, Jie; Wang, Yuanhong; Jiang, Tingfu; Lv, Lv; Zhang, Boyuan; Lv, Zhihua

    2015-01-01

    A controlled Cu(2+) catalytic free-radical depolymerization process of fucosylated chondroitin sulfate from sea cucumber Apostichopus japonicus was established. The results showed a good linear relationship between 1/Mw and time during the depolymerization. A series of fractions with different molecular weight were obtained, and the physicochemical properties of them were investigated and compared utilizing the chemical method, IR spectra and NMR spectra. The results showed no significant variations of the backbone and branches structures during the depolymerization. Furthermore, the anticoagulant activities of the depolymerized fractions were evaluated by the activated partial thromboplastin time (APTT). The APTT decreases in proportion to the molecular weight following a linear relationship and the prolongation of APTT activity requires at least oligosaccharide of 4 trisaccharide units (about 4000 Da). Their anticoagulant activity of low molecular weight fraction (Mw = 24,755 Da) is similar to LMWH with significantly less bleeding risk. The results suggest that the low molecular weight fraction could be used as a novel anticoagulant with less undesired side effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Preparation of low molecular weight Sargassum fusiforme polysaccharide and its anticoagulant activity

    Science.gov (United States)

    Sun, Yuhao; Chen, Xiaolin; Liu, Song; Yu, Huahua; Li, Rongfeng; Wang, Xueqin; Qin, Yukun; Li, Pengcheng

    2017-10-01

    Heparin has been used as an anticoagulant drug for many years, but it has significant side effects. In the search for good substitutes, low molecular weight (MW) polysaccharides from Sargassum fusiforme have been examined and confirmed to possess biological activities. Here, S. fusiforme polysaccharides (SFP) were extracted and subjected to a hydrogen peroxide (H2O2) oxidation method for the preparation of low-MW SFP (LSFP). The effects of temperature, pH, and H2O2 concentration on the degradation process were also examined. Several LSFP of 36, 9, 5.7, and 2.7 kDa were obtained under different conditions, and their anticoagulant activities studied in vitro. The results showed that SFP and LSFP prolonged activated partial thromboplastin (APTT), prothrombin (PT) and thrombin times (TT) significantly, indicating that these low MW polysaccharides possessed anticoagulant activity in the intrinsic, extrinsic, and common coagulation pathways. As these effects were related to the MW of the polysaccharides in APTT and TT but not in PT, the contents of the monosaccharide fucose and sulfate and the polysaccharide MW could have exerted combined effects. The details of this mechanism require further verification.

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Science.gov (United States)

    Zhao, Jun; Yang, Jingfeng; Song, Shuang; Zhou, Dayong; Qiao, Weizhou; Zhu, Ce; Liu, Shuyin; Zhu, Beiwei

    2016-06-08

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

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

    Directory of Open Access Journals (Sweden)

    Jun Zhao

    2016-06-01

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

  9. Sulfonation and anticoagulant activity of fungal exocellular β-(1→6)-D-glucan (lasiodiplodan).

    Science.gov (United States)

    Vasconcelos, Ana Flora D; Dekker, Robert F H; Barbosa, Aneli M; Carbonero, Elaine R; Silveira, Joana L M; Glauser, Bianca; Pereira, Mariana Sá; Corradi da Silva, Maria de Lourdes

    2013-02-15

    An exocellular β-(1→6)-D-glucan (lasiodiplodan) produced by a strain of Lasiodiplodia theobromae (MMLR) grown on sucrose was derivatized by sulfonation to promote anticoagulant activity. The structural features of the sulfonated β-(1→6)-D-glucan were investigated by UV-vis, FT-IR and (13)C NMR spectroscopy, and the anticoagulant activity was investigated by the classical coagulation assays APTT, PT and TT using heparin as standard. The content of sulfur and degree of substitution of the sulfonated glucan was 11.73% and 0.95, respectively. UV spectroscopy showed a band at 261 nm due to the unsaturated bond formed in the sulfonation reaction. Results of FT-IR and (13)C NMR indicated that sulfonyl groups were inserted on the polysaccharide. The sulfonated β-(1→6)-D-glucan presented anticoagulant activity as demonstrated by the increase in dose dependence of APTT and TT, and these actions most likely occurred because of the inserted sulfonate groups on the polysaccharide. The lasiodiplodan did not inhibit the coagulation tests. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Sulfated Polysaccharides Isolated from Cloned Grateloupia filicina and Their Anticoagulant Activity

    Directory of Open Access Journals (Sweden)

    Xiaolin Chen

    2015-01-01

    Full Text Available Sulfated polysaccharides (GSP were isolated from the cloned Grateloupia filicina which was cultured in Jiaozhou Bay, Qingdao, China. The yield of GSP was 15.75%. The total sugar and sulfate were 40.90 and 19.89%, respectively. And the average molecular weight was 11.7 KDa. The results of neutral sugar analysis showed that GSP was mainly sulfated polysaccharides of galactose. The experiments for activated partial thromboplastin time (APTT, prothrombin time (PT, and thrombin time (TT anticoagulant assays in vitro indicated that GSP was a good potential anticoagulant. Therefore, this study supplied new thought for the cloned Grateloupia filicina exploitation of high-value products.

  12. Manipulating the surface active and anticoagulant properties of heparin through amphiphilic molecular constructs

    Science.gov (United States)

    Mintz, Rosita Candida

    Cardiovascular devices implanted within the vasculature are subjected to non-specific adsorption of plasma proteins. This initiates the blood coagulation cascade and platelet adhesion and activation, leading to thrombus formation. In this thesis Heparin Alkyl Diblock (HAD) surfactants were developed to improve the blood compatibility of cardiovascular biomaterials. The material designs involved using heparin, a natural anticoagulant, to inhibit coagulation pathway enzymes and mimic the cell glycocalyx to provide a repulsive force field to inhibit non-specific protein adsorption. Type AB linear (HAD Cn, n = 6,10,12,18) and branched (HAD nx 18, n = 2,3,4) heparin surfactants were synthesized by end point coupling primary and secondary alkyl amines to heparin via reductive amination. Surfactant yields (83--4%) and anticoagulant activity (149.8 +/- 3.7--39.6 +/- 0.6 IU/mg) decreased with increased branching and hydrocarbon number. Surfactant adsorption, self assembly and molecular packing of HAD surfactants at the air/liquid and liquid/solid interface were a function of the number of hydrocarbons in the surfactant alkyl segment and the presence or absence of an ionic liquid phase. Increased molecular packing was observed at the air/PBS and PBS/graphite interface, relative to aqueous interfaces, resulting from buffer cations shielding heparin's negatively charged sulfate and carboxyl groups. At the PBS/graphite interface, the surfactant's apparent heparin head group cross section decreased in diameter (1.84 to 1.05 nm) and increased in tilt angle (75.7 to 81.9°) with increasing alkyl carbon number (n = 6 to 18). The heparin head group reached a minimum diameter, equivalent to the surfactant's diameter at the air/PBS interface (0.57 nm) just prior to 36 hydrocarbons in the surfactant. For surfactants with 36 to 78 hydrocarbons, the surfactant's heparin head group oriented normal to the graphite surface and alkyl overlap or interdigitation increased (0.02 to 0.59 nm

  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. Protein S binding to human endothelial cells is required for expression of cofactor activity for activated protein C

    NARCIS (Netherlands)

    Hackeng, T. M.; Hessing, M.; van 't Veer, C.; Meijer-Huizinga, F.; Meijers, J. C.; de Groot, P. G.; van Mourik, J. A.; Bouma, B. N.

    1993-01-01

    An important feedback mechanism in blood coagulation is supplied by the protein C/protein S anticoagulant pathway. In this study we demonstrate that the binding of human protein S to cultured human umbilical vein endothelial cells (HUVECs) is required for the expression of cofactor activity of

  15. Dissociation of activated protein C functions by elimination of protein S cofactor enhancement.

    LENUS (Irish Health Repository)

    Harmon, Shona

    2008-11-07

    Activated protein C (APC) plays a critical anticoagulant role in vivo by inactivating procoagulant factor Va and factor VIIIa and thus down-regulating thrombin generation. In addition, APC bound to the endothelial cell protein C receptor can initiate protease-activated receptor-1 (PAR-1)-mediated cytoprotective signaling. Protein S constitutes a critical cofactor for the anticoagulant function of APC but is not known to be involved in regulating APC-mediated protective PAR-1 signaling. In this study we utilized a site-directed mutagenesis strategy to characterize a putative protein S binding region within the APC Gla domain. Three single amino acid substitutions within the APC Gla domain (D35T, D36A, and A39V) were found to mildly impair protein S-dependent anticoagulant activity (<2-fold) but retained entirely normal cytoprotective activity. However, a single amino acid substitution (L38D) ablated the ability of protein S to function as a cofactor for this APC variant. Consequently, in assays of protein S-dependent factor Va proteolysis using purified proteins or in the plasma milieu, APC-L38D variant exhibited minimal residual anticoagulant activity compared with wild type APC. Despite the location of Leu-38 in the Gla domain, APC-L38D interacted normally with endothelial cell protein C receptor and retained its ability to trigger PAR-1 mediated cytoprotective signaling in a manner indistinguishable from that of wild type APC. Consequently, elimination of protein S cofactor enhancement of APC anticoagulant function represents a novel and effective strategy by which to separate the anticoagulant and cytoprotective functions of APC for potential therapeutic gain.

  16. Recombinant nematode anticoagulant protein c2 inhibits cell invasion by decreasing uPA expression in NSCLC cells.

    Science.gov (United States)

    Tong, Yu; Yue, Jun; Mao, Meng; Liu, Qingqing; Zhou, Jing; Yang, Jiyun

    2015-04-01

    Nematode anticoagulant protein c2 (NAPc2) is an 85-residue polypeptide originally isolated from the hematophagous hookworm, Ancylostoma caninum. Several studies have shown that rNAPc2 inhibits the growth of primary and metastatic tumors in mice independently of its ability to initiate coagulation. We obtained bioactive recombinant rNAPc2 by splicing of the rNAPc2-intein-CBD fusion proteins expressed in E. coli ER2566. In the in vitro assay, rNAPc2 obviously inhibited the invasive ability of non-small cell lung cancer (NSCLC) cells in a dose-dependent manner. Furthermore, rNAPc2 suppressed tumor growth in vivo by daily intraperitoneal injection of rNAPc2 in an NSCLC cell xenograft model of nude mice. Respectively, rNAPc2 downregulated the production of urokinase plasminogen activator (uPA) (P<0.05) and suppressed nuclear factor-κB (NF-κB) activity. We also identified that inhibition of NF-κB activity impaired cell invasion and reduced the uPA production in NSCLC cells. Meanwhile, NF-κB was found to directly bind to the uPA promoter in vitro. These results demonstrated that rNAPc2 inhibits cell invasion at least in part through the downregulation of the NF-κB-dependent metastasis-related gene expression in NSCLC. Our results also suggest that uPA, a known metastasis-promoting gene, is indirectly regulated by rNAPc2 through NF-κB activation. These results indicate that rNAPc2 may be a potent agent for the prevention of NSCLC progression.

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

    Directory of Open Access Journals (Sweden)

    Subhalaxmi Borah

    2014-05-01

    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.

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

    Science.gov (United States)

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

    2018-01-31

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

  19. A heparin binding synthetic peptide from human HIP / RPL29 fails to specifically differentiate between anticoagulantly active and inactive species of heparin

    Science.gov (United States)

    Hoke, David E; Carson, Daniel D; Höök, Magnus

    2003-01-01

    Despite extensive progress in determining structures within heparin and heparan sulfate (Hp/HS) and the discovery of numerous proteinaceous binding partners for Hp/HS so far; the only detailed characterization of a specific protein-glycosaminoglycan interaction is antithrombin III (ATIII) binding to a Hp pentasaccharide containing a unique 3-O-sulfated glucosamine residue. Previously, it was reported from our laboratories that a 16 amino acid synthetic peptide derived from the C-terminus of human HIP/RPL29 (HIP peptide-1) enriched for ATIII-dependent anticoagulant activity, presumably by specifically binding the ATIII pentasaccharide. Herein, we demonstrate that HIP peptide-1 cannot enrich ATIII-dependent anticoagulant activity from a starting pool of porcine intestinal mucosa Hp through a bio-specific interaction. However, a HIP peptide-1 column can be used to enrich for anticoagulantly active Hp from a diverse pool of glycosaminoglycans known as Hp byproducts by a mechanism of nonspecific charge interactions. Thus, HIP peptide-1 cannot recognize Hp via bio-specific interactions but binds glycosaminoglycans by non-specific charge interactions. PMID:12659638

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

    NARCIS (Netherlands)

    Koppelman, S.J.

    1995-01-01

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

  1. Synthesis of New DNA G-Quadruplex Constructs with Anthraquinone Insertions and Their Anticoagulant Activity

    DEFF Research Database (Denmark)

    Gouda, Alaa S.; Amine, Mahasen S.; Pedersen, Erik Bjerregaard

    2016-01-01

    anthraquinone linker led to a significant stabilization of the G-quadruplex structure upon replacing a T in each of two neighboring lateral TT loops and a 26.28 increase in thermal melting temperature was found. CD Spectra of the modified quadruplexes confirmed anti-parallel conformations in all cases under...... potassium buffer conditions as previously observed for TBA. Although the majority of the anthraquinone modified TBA analogues showed a decrease in clotting times in a fibrinogen clotting assay when compared to TBA, modified aptamers containing a 1,8-disubstituted anthraquinone linker replacing G8 or T9...... in the TGT loop showed improved anticoagulant activities. Molecular modeling studies explained the increased thermal melting temperatures of anthraquinone-modified G-quadruplexes....

  2. An in vivo strategy to counteract post-administration anticoagulant activity of azido-Warfarin

    Science.gov (United States)

    Ursuegui, Sylvain; Recher, Marion; Krężel, Wojciech; Wagner, Alain

    2017-05-01

    Drugs, usually long acting and metabolically stable molecules, might be the source of adverse effects triggered by complex drug interactions, anaphylaxis and drug-induced coagulopathy. To circumvent this growing drug safety issue, we herein investigate the opportunity offered by bio-orthogonal chemistry for in vivo drug neutralization. We design a small-molecule anticoagulant drug (Warfarin) containing an azide group that acts as a safety pin. It allows drug deactivation and restoration of physiological coagulation via in vivo click reaction with a suitable cyclooctyne-based neutralizing agent. In this strategy, the new molecule formed by reaction of the drug and the antidote is deprived of biological activity and prone to fast renal clearance. This `Click & Clear' approach lays ground for new strategies in designing drugs with switchable biophysical properties.

  3. Novel branch patterns and anticoagulant activity of glycosaminoglycan from sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Yang, Jie; Wang, Yuanhong; Jiang, Tingfu; Lv, Zhihua

    2015-01-01

    A novel glucosidic pattern of fucose branches was found in the glycosaminoglycan from the sea cucumber Apostichopus japonicus in China. The methylation of desulfated/carboxyl-reduced polysaccharides and analysis of unsaturated disaccharides generated from the enzymolysis of the defucosed polysaccharides demonstrated that the branch is formed by one fucopyranosyl residue, 46.5% of which is linked through the O-3 position of β-D-glucuronic acid, while 8.7% and 43.9% are linked through the O-6 and O-4 positions of the N-acetylgalactosamine moiety. The β-D-glucuronic acid, N-acetyl-β-D-galactosamine, α-L-fucose and sulfate ester with the molecular ratio of 0.97:1.00:1.13:3.85 composed the backbone → 4)GlcUAβ(1 → 3)GalNAcβ(1 → and sulfated fucose branches. The sulfation patterns of fucose branches and the linkage pattern of the backbone structure were determined by 1/2 dimension NMR. The most abundant branch species were 2,4-di-O-sulfated and 3,4-di-O-sulfated fucose, but 4-mono-O-sulfated residue was also present. The structure of presently obtained glycosaminoglycan is different from that previously obtained from Stichopus japonicus (Kariya et al., Carbohyd. Res. 297 (1997) 273-279), which suggests that the structures of glycosaminoglycans from the same species of different regions somehow differ. The anticoagulant assay indicated that the polysaccharide possessed a high anticoagulant activity and the sulfated fucose branches were essential to the activity. Copyright © 2014 Elsevier B.V. All rights reserved.

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

    Czech Academy of Sciences Publication Activity Database

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

    2015-01-01

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

  5. 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.

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

    NARCIS (Netherlands)

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

    1998-01-01

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

  7. 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.

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

    Science.gov (United States)

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

    2018-01-05

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

  9. 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...

  10. The reversal effect of prothrombin complex concentrate (PCC), activated PCC and recombinant activated factor VII against anticoagulation of Xa inhibitor.

    Science.gov (United States)

    Schultz, Nina Haagenrud; Tran, Hoa Thi Tuyet; Bjørnsen, Stine; Henriksson, Carola Elisabeth; Sandset, Per Morten; Holme, Pål Andre

    2017-01-01

    An increasing number of patients are treated with direct-acting oral anticoagulants (DOACs), but the optimal way to reverse the anticoagulant effect is not known. Specific antidotes are not available and prothrombin complex concentrate (PCC), activated PCC (aPCC) and recombinant factor VIIa (rFVIIa) are variously used as reversal agents in case of a major bleeding. We aimed to determine the most effective haemostatic agent and dose to reverse the effect of rivaroxaban in blood samples from patients taking rivaroxaban for therapeutic reasons. Blood samples from rivaroxaban-treated patients ( n =  50) were spiked with PCC, aPCC and rFVIIa at concentrations imitating 80%, 100% and 125% of suggested therapeutic doses. The reversal effect was assessed by thromboelastometry in whole blood and a thrombin generation assay (TGA) in platelet-poor plasma. Samples from healthy subjects ( n =  40) were included as controls. In thromboelastometry measurements, aPCC and rFVIIa had a superior effect to PCC in reversing the rivaroxaban-induced lenghtening of clotting time (CT). aPCC was the only haemostatic agent that shortened the CT down to below the control level. Compared to healthy controls, patients on rivaroxaban also had a prolonged lag time and decreased peak concentration, velocity index and endogenous thrombin potential (ETP) in platelet-poor plasma. aPCC reversed these parameters more effectively than rFVIIa and PCC. There were no differences in efficacy between 80%, 100% and 125% doses of aPCC. aPCC seems to reverse the anticoagulant effect of rivaroxaban more effectively than rFVIIa and PCC by evaluation with thromboelastometry and TGA in vitro.

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

    Science.gov (United States)

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

    2015-03-01

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

  12. 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.

  13. 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.

  14. Fabrication of PP-g-PEGMA-g-heparin and its hemocompatibility: From protein adsorption to anticoagulant tendency

    Energy Technology Data Exchange (ETDEWEB)

    Jin Jing [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Jiang Wei, E-mail: wjiang@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Shi Qiang [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Zhao Jie [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Yin Jinghua, E-mail: yinjh@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Stagnaro, Paola [Istituto per Io Studio delle Macromolecole, Consiglio Nazionale delle Ricerche, Via de Marini 6, 16149 Genova (Italy)

    2012-05-15

    We described a two-step process to fabricate the heparinized polypropylene (PP) film using cyanuric chloride (CC) as a trifunctional reagent and poly (ethylene glycol) methacrylate (PEGMA) as a spacer. The modified PP films were characterized by attenuated total reflectance FT-IR and X-ray photoelectron spectroscopy; the content of PEGMA and heparin were determined by gravimetric method and a toluidine blue assay, respectively. For the PP-g-PEGMA films, it was found that small size protein BSA tended to adsorb on the surface of low molecular weight monomer grafted PP, whereas big spindle-shaped fibrinogen tended to adsorb on the surface of high molecular weight monomer grafted PP. We gave a definition of anti-protein adsorptive factor r with two model proteins, albumin and fibrinogen. The results by platelet adhesion and plasma recalcification time (PRT) experiments indicated that the factor r could be used to quantitatively evaluate the anticoagulant tendency of PP-g-PEGMA modified films. For the PP-g-PEGMA-g-heparin modified films, the surface was proved to have a high bioactivity by the adsorption of AT III assay and very low platelet adhesion. It indicated that immobilization of heparin on the PP film with PEGMA as a spacer was an effective way to improve the hemocompatibility of PP.

  15. New orally active anticoagulants in critical care and anesthesia practice: The good, the bad and the ugly

    Directory of Open Access Journals (Sweden)

    Vishal Sehgal

    2013-01-01

    Full Text Available With the adoption of dabigatran, rivaroxaban, and apixaban into clinical practice, a new era has arrived in the practice of oral anticoagulants. Venous thromboembolism (VTE has traditionally been underdiagnosed and under treated in Asia. With increasing longevity, the diagnosis and the need for management of atrial fibrillation (AF and VTE is likely to increase significantly. The new orally active anticoagulants (NOACs have reasonably filled the lacunae that clinicians traditionally faced when treating patients with vitamin K antagonist (VKA. Unlike VKA, NOACs do not need frequent monitoring. Therefore, more patients are likely to get therapeutic effects of anticoagulation and thus reduce morbidity and mortality associated with VTE and AF. However, the clinicians need to be circumspect and exercise caution in use of these medications. In particular (in geriatric population, the clinicians should look out for drug-drug interactions and underlying renal insufficiency. This would ensure therapeutic efficacy and minimize bleeding complications. Here, it is important to note that the antidote for NOACs is not available and is a major concern if emergency surgical procedure is required in their presence.

  16. Coagulation assays and anticoagulant monitoring.

    Science.gov (United States)

    Funk, Dorothy M Adcock

    2012-01-01

    Anticoagulant therapy, including conventional agents and a variety of new oral, fast-acting drugs, is prescribed for millions of patients annually. Each anticoagulant varies in its effect on routine and specialty coagulation assays and each drug may require distinct laboratory assay(s) to measure drug concentration or activity. This review provides an overview of the assorted assays that can measure anticoagulant drug concentration or activity and includes key assay interferences. The effect of these conventional and new anticoagulant agents on specialty coagulation assays used to evaluate for bleeding or clotting disorders, and whether this impact is physiological or factitious, is included. Also provided is a short review of superwarfarin poisoning and features distinguishing this from warfarin overdose. Knowledge of clinically significant pearls and pitfalls pertinent to coagulation assays in relation to anticoagulant therapy are important to optimize patient care.

  17. Recombinant human activated protein C: current insights into its mechanism of action

    NARCIS (Netherlands)

    Levi, Marcel; van der Poll, Tom

    2007-01-01

    Impairment of the protein C pathway plays a central role in the pathogenesis of sepsis. Administration of recombinant human activated protein C (rhAPC) may correct the dysregulated anticoagulant mechanism and prevent propagation of thrombin generation and formation of microvascular thrombosis.

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

    International Nuclear Information System (INIS)

    Liu Yun; Yang Yun; Wu Feng

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yun, E-mail: liuy@tgrc.org [Department of Chemistry, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Yang Yun [Department of Chemistry, School of Science, Xi' an Jiaotong University, Xi' an 710049 (China); Wu Feng [Research Centre of Blood, College of Medicine, Xi' an Jiaotong University, Xi' an 710065 (China)

    2010-04-01

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

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

    Science.gov (United States)

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

    2010-09-15

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

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

    Science.gov (United States)

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

    2005-07-01

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

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  3. Association between Oral Anticoagulation Knowledge ...

    African Journals Online (AJOL)

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

  4. Coagulation, Fibrinolysis and Inhibitors in Failing Filters during Continuous Venovenous Hemofiltration in Critically Ill Patients with Acute Kidney Injury: Effect of Anticoagulation Modalities.

    Science.gov (United States)

    Schilder, Louise; Nurmohamed, S Azam; ter Wee, Pieter M; Paauw, Nanne J; Girbes, Armand R J; Beishuizen, Albertus; Beelen, Robert H J; Groeneveld, A B Johan

    2015-01-01

    The mechanisms of early filter failure and clotting with different anticoagulation modalities during continuous venovenous hemofiltration (CVVH) are largely unknown. Citrate, heparin and no anticoagulation were compared. Blood was drawn pre- and post filter up to 720 min. Concentrations of the thrombin-antithrombin (TAT), activated protein C-protein C inhibitor (APC-PCI), and type I plasminogen activator inhibitor (PAI-1) were determined. In case of early filter failure (filter after 10 min in the heparin group than in other groups. In clotting filters, production of APC-PCI and PAI was also higher with heparin than citrate. Coagulation activation in plasma and inhibition of anticoagulation in plasma and filter may partly determine early CVVH filter failure due to clotting, particularly when heparin is used. Regional anticoagulation by citrate circumvents the inhibition of anticoagulation and fibrinolysis by platelet activation following heparin. © 2015 S. Karger AG, Basel.

  5. Recombinant activated protein C attenuates coagulopathy and inflammation when administered early in murine pneumococcal pneumonia

    NARCIS (Netherlands)

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

    2011-01-01

    Recombinant human activated protein C (APC), which has both anticoagulant and anti-inflammatory properties, improves survival of patients with severe sepsis. This beneficial effect is especially apparent in patients with pneumococcal pneumonia. Earlier treatment with APC in sepsis has been

  6. 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.

  7. 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

    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

  8. Recombinant human activated protein C inhibits local and systemic activation of coagulation without influencing inflammation during Pseudomonas aeruginosa pneumonia in rats

    NARCIS (Netherlands)

    Choi, Goda; Hofstra, Jorrit-Jan H.; Roelofs, Joris J. T. H.; Florquin, Sandrine; Bresser, Paul; Levi, Marcel; van der Poll, Tom; Schultz, Marcus J.

    2007-01-01

    OBJECTIVE: Alveolar fibrin deposition is a hallmark of pneumonia. It has been proposed that recombinant human activated protein C exerts lung-protective effects via anticoagulant and anti-inflammatory pathways. We investigated the role of the protein C system in pneumonia caused by Pseudomonas

  9. Recombinant human activated protein C inhibits local and systemic activation of coagulation without influencing inflammation during Pseudomonas aeruginosa pneumonia in rats

    NARCIS (Netherlands)

    Choi, Goda; Hofstra, Jorrit-Jan H; Roelofs, Joris J T H; Florquin, Sandrine; Bresser, Paul; Levi, Marcel; van der Poll, Tom; Schultz, Marcus J

    OBJECTIVE: Alveolar fibrin deposition is a hallmark of pneumonia. It has been proposed that recombinant human activated protein C exerts lung-protective effects via anticoagulant and anti-inflammatory pathways. We investigated the role of the protein C system in pneumonia caused by Pseudomonas

  10. Lupus anticoagulants and antiphospholipid antibodies

    Science.gov (United States)

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

  11. Isolation and characterization of anticoagulant compound from ...

    African Journals Online (AJOL)

    GIS

    2013-10-02

    Oct 2, 2013 ... The structural characterization of anticoagulant GAG was analyzed by Fourier transform infrared spectroscopy. Among the marine bivalve, D. faba purified showed more anticoagulant activity than that of crude sample. The results of this study suggest that the GAG from D. faba could be an alternative.

  12. 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

  13. THE ANTICOAGULANT AND ANTILYMPHOMA PROPERTIES OF ARSENIC AZOPROTEINS

    Science.gov (United States)

    Broome, J. D.; Kidd, John G.

    1964-01-01

    Experiments given in this paper have shown that 4-arsonophenylazoproteins possess marked anticoagulant activity both in vivo and in vitro. Mice and rabbits given moderate amounts of the arsenic azoprotein, for example, often bled to death from injuries that proved trivial in control animals, and their blood remained liquid during many hours' postmortem even when left in contact with transected tissues, fibrinolysis having no part in the outcome. So, too, the addition of minute amounts of 4-arsonophenylazoprotein to plasma procured from citrated rabbit or human blood greatly prolonged the time required for clotting after recalcification. Other arsenic-containing compounds,—for example, those in which arsenic See PDF for Structure was joined to amino acids or peptides through the azo linkage, or to proteins through couplings other than the azo linkage,—were largely devoid of anticoagulant and antilymphoma effects. The findings as a whole show clearly that the structural requirements for anticoagulant and antilymphoma effects are: (a) possession of negatively charged arsonic or arsinoso groups, (b) large molecular size (protein), and (c) linkage of arsenic-containing groups to protein through the azo bond. Two acidic azoproteins that were devoid of arsenic,—namely 4-carboxyphenylazoprotein and 4-sulfonophenylazoprotein,—were also found to have marked anticoagulant effects in vitro, but they had no inhibitory action against cells of Lymphoma 6C3HED in vivo, even when they were given to mice in maximum tolerated amounts. The essential part played by arsenic in the antilymphoma activity of arsenic azoproteins was further emphasized by the action of dimercaprol (BAL) in preventing the antilymphoma effects of 4-arsonophenylazoprotein on Lymphoma 6C3HED cells in vivo. In an associated paper the anticoagulant and antilymphoma effects of 4-arsonophenylazoproteins are studied further, and consideration is given to the ways in which these effects may be brought about

  14. Activated protein C resistance testing for factor V Leiden.

    Science.gov (United States)

    Kadauke, Stephan; Khor, Bernard; Van Cott, Elizabeth M

    2014-12-01

    Activated protein C resistance assays can detect factor V Leiden with high accuracy, depending on the method used. Factor Xa inhibitors such as rivaroxaban and direct thrombin inhibitors including dabigatran, argatroban, and bivalirudin can cause falsely normal results. Lupus anticoagulants can cause incorrect results in most current assays. Assays that include dilution into factor V-deficient plasma are needed to avoid interference from factor deficiencies or elevations, which can arise from a wide variety of conditions such as warfarin, liver dysfunction, or pregnancy. The pros and cons of the currently available assays are discussed. © 2014 Wiley Periodicals, Inc.

  15. Chemical structure and anticoagulant activity of highly pyruvylated sulfated galactans from tropical green seaweeds of the order Bryopsidales.

    Science.gov (United States)

    Arata, Paula X; Quintana, Irene; Canelón, Dilsia J; Vera, Beatriz E; Compagnone, Reinaldo S; Ciancia, Marina

    2015-05-20

    Sulfated and pyruvylated galactans were isolated from three tropical species of the Bryopsidales, Penicillus capitatus, Udotea flabellum, and Halimeda opuntia. They represent the only important sulfated polysaccharides present in the cell walls of these highly calcified seaweeds of the suborder Halimedineae. Their structural features were studied by chemical analyses and NMR spectroscopy. Their backbone comprises 3-, 6-, and 3,6-linkages, constituted by major amounts of 3-linked 4,6-O-(1'-carboxy)ethylidene-d-galactopyranose units in part sulfated on C-2. Sulfation on C-2 was not found in galactans from other seaweeds of this order. In addition, a complex sulfation pattern, comprising also 4-, 6-, and 4,6-disulfated galactose units was found. A fraction from P. capitatus, F1, showed a moderate anticoagulant activity, evaluated by general coagulation tests and also kinetics of fibrin formation was assayed. Besides, preliminary results suggest that one of the possible mechanisms involved is direct thrombin inhibition. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. HEEADSSS assessment for adolescents requiring anticoagulation therapy.

    Science.gov (United States)

    Jones, Sophie; Mertyn, Eliza; Alhucema, Paulina; Monagle, Paul; Newall, Fiona

    2012-05-01

    The care of adolescents with complex chronic illness needs to be developmentally appropriate to encourage adherence, knowledge retention and self-management. There has been an increase in the number of adolescents requiring long-term or lifelong anticoagulation therapy, related to either an underlying illness or idiopathic deep vein thrombosis. The burden of anticoagulant therapy, the associated risks and the required lifestyle changes can significantly impact on psychosocial well-being in the adolescent patient. This review identifies issues pertinent to adolescent anticoagulation management and discusses strategies to support optimal management. The HEEADSSS (Home, Education and employment, Eating, Activities with peers, Drugs, Sexual activity, Suicide and depression, and Safety) framework was used to provide guidance in undertaking a psychosocial assessment of adolescents requiring anticoagulant therapy in conjunction with a structured education strategy. Adolescent anticoagulant management strategies employing developmentally appropriate assessment and education will likely result in improved therapeutic outcomes for the patient and potentially facilitate transition to adult-based care.

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

    Science.gov (United States)

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

    2010-06-01

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

  18. In vitro anti-inflammatory and anti-coagulant effects of antibiotics towards Platelet Activating Factor and thrombin

    Science.gov (United States)

    2011-01-01

    properties of antibiotics used in sepsis suggest that apart from their general actions, these drugs may present additional beneficial anti-inflammatory and anti-coagulant effects against the onset and establishment of sepsis by inhibiting the PAF/PAF-receptor and/or the thrombin/protease-activated-receptor-1 systems, and/or by reducing PAF-levels through both PAF-biosynthesis inhibition and PAF-catabolism induction. These promising in vitro results need to be further studied and confirmed by in vivo tests, in order to optimize the efficacy of antibiotic treatment in sepsis. PMID:21736752

  19. Course of thrombin activation markers in patients implanted with Palmaz-Schatz stents: first experiences with a post-interventional anticoagulation regimen.

    Science.gov (United States)

    Haushofer, A; Halbmayer, W M; Dittel, M; Prachar, H; Mlczoch, J; Fischer, M

    1994-10-01

    Following implantation of coronary Palmaz-Schatz stents, 29 patients were anticoagulated with a combination of heparin, phenprocoumon and aspirin following a standard protocol. After removing the arterial and venous lines, post-interventional intravenous (i.v.) heparin treatment started with 1500 IU/h for patients > 80 kg and 1250 IU/h for patients < 80 kg. Heparin was monitored by the activated partial thromboplastin time (aPTT) and adjusted by increasing or reducing i.v. heparin by 250 IU/h to maintain the aPTT within the therapeutic range. Phenprocoumon therapy began the day after stent implantation (day 2) and lasted for 3 months. aPTT, Heptest, prothrombin fragment F1 and 2 (F1.2) and thrombin-antithrombin III complexes (TAT) were monitored at standard intervals for 10 days (mean monitoring time: 9.7 +/- 2.3 days). Anticoagulation was efficient with aPTT levels remaining within the therapeutic range on day 9 and the simultaneous, moderate-onset oral anticoagulation within the therapeutic range of the International Normalized Ratio (INR; 2.15-4.80) on day 8 on average, the mean INR being 2.43 +/- 0.76. On day 4, F1.2 levels were significantly higher than on the day of stenting (1.16 +/- 0.30 nmol/l vs 1.04 +/- 0.53 nmol/l; P < 0.005). F1.2 levels fell after day 5, the difference becoming significant from day 8 on (P < 0.05). F1.2 was negatively correlated with the Heptest (P < 0.05) and fell significantly as a function of the INR during phenprocoumon administration (P < 0.001). After phenprocoumon therapy was discontinued over 3 weeks, 25 patients were followed up by angiography. Despite adequate anticoagulation, mean F1.2 levels in patients showing restenosis at follow-up angiography were significantly higher (P < 0.005) than in those without restenosis. In one patient who developed subacute stent thrombosis, clotting factors were determined 20 min before stent occlusion. The levels of F1.2 and TAT were less than all other patients on this day (F1.2: 0.98 nmol

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

    NARCIS (Netherlands)

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

    1999-01-01

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

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

    Science.gov (United States)

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

    2013-07-01

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

  2. [Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complex(TAT) and thrombophilia parameters in orally anticoagulated patients with inferior vena cava filters].

    Science.gov (United States)

    Halbmayer, W M; Haushofer, A; Toth, E

    1993-01-01

    Prothrombin fragment 1 + 2 (F1 + 2) and thrombin-antithrombin-III-complex (TAT) levels were compared in 31 orally anticoagulated patients with inferior vena caval filters and a control group of 31 orally anticoagulated patients without caval filters and the incidence of markers of thrombophilia (deficiency of antithrombin-III, protein C, protein S and factor XII, presence of lupus anticoagulants) was determined. 8 of 31 patients (26%) from the group of caval filter carriers showed markers of thrombophilia (3 protein S deficiencies, 1 protein C deficiency, 2 factor XII deficiencies and 2 patients with lupus anticoagulants). In all orally anticoagulated patients a significant interdependence (p < 0.05) between F1 + 2- and TAT-levels and intensity (INR) of the oral anticoagulation could be observed. Comparison of F1 + 2- and TAT-levels of caval filter carriers and controls revealed no significant difference which leads to the conclusion that inferior vena caval filters do not induce detectable systemic activation of prothrombin under adequate oral anticoagulation therapy.

  3. [Effect on low-molecular-weight heparin obtained using a chitinolytic complex on the anticoagulant activity of plasma in rabbits and rats].

    Science.gov (United States)

    Drozd, N N; Tolstenkov, A S; Makarov, V A; Miftakhova, N T; Bannikova, G E; Sukhanova, P P; Varlamov, V P; Vikhoreva, G E

    2007-01-01

    The anticoagulant activity of low-molecular-weight heparin with an average molecular weight of 4.7 kD (LMWH-4.7) has been studied. This derivative was prepared from unfractionated heparin with the help of chitinolytic enzyme complex from Streptomyces kurssanovii. The antithrombin activity of LMWH-4.7 (aIla activity) was 72 +/- 9 IU/mg and the activity with respect to the blood coagulation factor Xa (aXa activity) was 200 +/- 33 IU/mg, which corresponded to an aXa/aIIa ratio of 2.8 (necessary for effective antithrombotic drugs). The aIIa and aXa activity exhibited a dose-dependent variation upon intravenous and subcutaneous injections in rabbits, so that a high aIIa/aXa ratio was retained: 5 min after the intravenous injection of a minimum dose (0.3 mg/kg), this ratio was 2, 7, and for a greater dose (3.0 mg/kg) it reached 3.8. Subcutaneous injections were followed by slow elimination of the anticoagulant within 24 h. LMWH-4.7 upon intraperitoneal injections produced a dose-dependent inhibition of a model thrombosis in rats. Complete inhibition was observed for a dose of 3 mg/kg. Thus, it is possible to obtain active LMW heparin with the help of chitinases.

  4. ORIGINAL ARTICLES Guideline for Prophylactic Anticoagulation

    African Journals Online (AJOL)

    situation. It is hoped that this will lead to improved anticoagulation practice in this country, which we believe will directly benefit patient outcome. S Afr Med J 2004; 94: 691-695. • Certain thrombophilic states (antithrombin/protein C/ protein S deficiency, antiphospholipid syndrome). • Inflammatory bowel disease. • Pregnancy.

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

    Science.gov (United States)

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

    2016-11-01

    Coagulation activation accompanied by reduced anticoagulant activity is a key characteristic of patients with idiopathic pulmonary fibrosis (IPF). Although the importance of coagulation activation in IPF is well studied, the potential relevance of endogenous anticoagulant activity in IPF progression remains elusive. We assess the importance of the endogenous anticoagulant protein C pathway on disease progression during bleomycin-induced pulmonary fibrosis. Wild-type mice and mice with high endogenous activated protein C APC levels (APC high ) were subjected to bleomycin-induced pulmonary fibrosis. Fibrosis was assesses by hydroxyproline and histochemical analysis. Macrophage recruitment was assessed immunohistochemically. In vitro, macrophage migration was analysed by transwell migration assays. Fourteen days after bleomycin instillation, APC high mice developed pulmonary fibrosis to a similar degree as wild-type mice. Interestingly, Aschcroft scores as well as lung hydroxyproline levels were significantly lower in APC high mice than in wild-type mice on day 28. The reduction in fibrosis in APC high mice was accompanied by reduced macrophage numbers in their lungs and subsequent in vitro experiments showed that APC inhibits thrombin-dependent macrophage migration. Our data suggest that high endogenous APC levels inhibit the progression of bleomycin-induced pulmonary fibrosis and that APC modifies pulmonary fibrosis by limiting thrombin-dependent macrophage recruitment. © 2016 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  6. Partial Purification and Characterization of Anticoagulant Factor from the Snake (Echis Carinatus) Venom

    Science.gov (United States)

    Amrollahi Byoki, Elham; Zare Mirakabadi, Abbas

    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 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: 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. Conclusion: The present study showed that the venom of E. carinatus contains at least one anticoagulant factor. PMID:24494065

  7. 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.

  8. Antithrombin III activity in healthy pregnant women seen at the ...

    African Journals Online (AJOL)

    Background: Antithrombin (AT III) is a glycoprotein synthesized by the liver. It has anticoagulant and antiinflammatory properties. Pregnancy is a hypercoagulable state due to increased synthesis of coagulation protein and depletion in the activity of natural anticoagulant due to consumption by activated coagulation proteins.

  9. Anticoagulant effect of marine algae.

    Science.gov (United States)

    Kim, Se-Kwon; Wijesekara, Isuru

    2011-01-01

    Recently, a great deal of interest has been developed in the nutraceutical and pharmaceutical industries to isolate natural anticoagulant compounds from marine resources. Among marine resources, marine algae are valuable sources of novel bioactive compounds with anticoagulant effect. Phlorotannins and sulfated polysaccharides such as fucoidans in brown algae, carrageenans in red algae, and ulvans in green algae have been recognized as potential anticoagulant agents. Therefore, marine algae-derived phlorotannins and SPs have great potential for developing as anticoagulant drugs in nutraceutical and pharmaceutical areas. This chapter focuses on the potential anticoagulant agents in marine algae and presents an overview of their anticoagulant effect. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Low anticoagulant heparin targets multiple sites of inflammation, suppresses heparin-induced thrombocytopenia, and inhibits interaction of RAGE with its ligands.

    Science.gov (United States)

    Rao, Narayanam V; Argyle, Brian; Xu, Xiaoyu; Reynolds, Paul R; Walenga, Jeanine M; Prechel, Margaret; Prestwich, Glenn D; MacArthur, Robert B; Walters, Bradford B; Hoidal, John R; Kennedy, Thomas P

    2010-07-01

    While heparin has been used almost exclusively as a blood anticoagulant, important literature demonstrates that it also has broad anti-inflammatory activity. Herein, using low anti-coagulant 2-O,3-O-desulfated heparin (ODSH), we demonstrate that most of the anti-inflammatory pharmacology of heparin is unrelated to anticoagulant activity. ODSH has low affinity for anti-thrombin III, low anti-Xa, and anti-IIa anticoagulant activities and does not activate Hageman factor (factor XII). Unlike heparin, ODSH does not interact with heparin-platelet factor-4 antibodies present in patients with heparin-induced thrombocytopenia and even suppresses platelet activation in the presence of activating concentrations of heparin. Like heparin, ODSH inhibits complement activation, binding to the leukocyte adhesion molecule P-selectin, and the leukocyte cationic granular proteins azurocidin, human leukocyte elastase, and cathepsin G. In addition, ODSH and heparin disrupt Mac-1 (CD11b/CD18)-mediated leukocyte adhesion to the receptor for advanced glycation end products (RAGE) and inhibit ligation of RAGE by its many proinflammatory ligands, including the advanced glycation end-product carboxymethyl lysine-bovine serum albumin, the nuclear protein high mobility group box protein-1 (HMGB-1), and S100 calgranulins. In mice, ODSH is more effective than heparin in reducing selectin-mediated lung metastasis from melanoma and inhibits RAGE-mediated airway inflammation from intratracheal HMGB-1. In humans, 50% inhibitory concentrations of ODSH for these anti-inflammatory activities can be achieved in the blood without anticoagulation. These results demonstrate that the anticoagulant activity of heparin is distinct from its anti-inflammatory actions and indicate that 2-O and 3-O sulfate groups can be removed to reduce anticoagulant activity of heparin without impairing its anti-inflammatory pharmacology.

  11. 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.

  12. ["Lupus anticoagulant" in immune hyperthyroidism].

    Science.gov (United States)

    Schuler, G; Alexopoulos, A; Hasler, K; Kerp, L

    1990-10-05

    A 56-year-old woman with autoimmune hyperthyroidism (Basedow) whose blood coagulation had at first been normal developed prolonged partial thromboplastin time (PTT) of 48 s and a fall in prothrombin time (Quick value) to 52%. At the same time, total activity of factor VIII was reduced to 18% and factor IX to 16%. These values not having changed after the addition of normal plasma, it is assumed that an acquired inhibitor of plasmatic coagulation was responsible. Such inhibitors were first described in lupus erythematodes and therefore called lupus anticoagulant, but later also demonstrated in other autoimmune diseases.

  13. lupus anticoagulants: pathophysiology, clinical

    African Journals Online (AJOL)

    2003-11-02

    Nov 2, 2003 ... report. East Afr. Med. J. 1998; 75:619-620. procainamide induced lupus anticoagulant. Acta Haematol. 13. Mateo, 1., Oliver, A., Borell, M. et al. Laboratory evaluation 1989; 82:50-52. and clinical characteristics of 2, 132 consecutive unselected 29. Rai, R., Cohen H., Dave M., and Regan, L. Randomised.

  14. Pharmacokinetics of activated protein C in guinea pigs

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  15. [A new deal with new anticoagulants?].

    Science.gov (United States)

    Godier, A; Samama, C-M

    2010-06-01

    The anticoagulant market has been very active recently with the development of new compounds including injectable anti-Xa such as fondaparinux, already available, and idraparinux, already replaced by its new biotynilateed form, and new oral drugs which can be divided into anti-IIa with dabigatran already available, and anti-Xa, such as the recently marketed rivaroxaban and apixaban still in the development stage. Others are coming forward. The competition is strong and the place for each drug remains to be determined. This review discusses these new anticoagulants in terms of efficacy and tolerance based on data in the literature. These recent reports mainly concern prophylaxis for orthopedic surgery but also consider treatment of deep venous thrombosis. The results of studies in heart patients have raised much curiosity since they will be determinant in the future use of innovating compounds, which could replace current oral anticoagulants. This will be upcoming but not yet for tomorrow.

  16. Reversal of target-specific oral anticoagulants

    Science.gov (United States)

    Siegal, D.M.; Cuker, Adam

    2014-01-01

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

  17. Anticoagulant property of sulphated polysaccharides extracted from ...

    African Journals Online (AJOL)

    The marine brown algae: Sargassum tenerrimum, Sargassum wightii, Turbinaria conoides, Turbinaria ornata and Padina tetrastromatica were collected from Mandapam Island, India. The crude sulphated polysaccharides (SPS) were extracted using hot water and examined for anticoagulation activity. The sugar, sulphate ...

  18. New Trends in Anticoagulation Therapy.

    Science.gov (United States)

    Smith, Margaret; Wakam, Glenn; Wakefield, Thomas; Obi, Andrea

    2018-04-01

    Anticoagulation pharmacy has been dramatically altered with US Food and Drug Administration (FDA) approval of 5 direct oral anticoagulants, 1 novel reversal agent and, a second designated for fast-track approval. Trial data surrounding current trends in anticoagulant choice for VTE, reversal, and bridging are constantly redefining practice. Extended therapy for unprovoked VTE has expanded to include low-dose direct oral anticoagulants, aspirin, and the use of the HERDOO2 system to identify women who can stop anticoagulant therapy without increased risk of recurrent VTE. Trends in thromboprophylaxis include extended duration low-dose direct oral anticoagulants to prevent VTE in high-risk patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Chronic kidney disease and anticoagulation

    DEFF Research Database (Denmark)

    Sciascia, Savino; Radin, Massimo; Schreiber, Karen

    2017-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  1. Stabilization of the E* Form Turns Thrombin into an Anticoagulant

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-31

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

  2. Direct oral anticoagulants: An update.

    Science.gov (United States)

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

    2017-12-30

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

  3. Effects of Chitosan Derivative N-[(2-Hydroxy-3-Trimethylammonium)Propyl]Chloride on Anticoagulant Activity of Guinea Pig Plasma.

    Science.gov (United States)

    Drozd, N N; Shagdarova, B Ts; Il'ina, A V; Varlamov, V P

    2017-07-01

    Intravenous injection of protamine sulfate or quarternized chitosan derivative to guinea pigs after injection of 70 aIIa U/kg non-fractionated heparin shortened plasma clotting time (shown by partial activated thromboplastin time, thrombin time, and prothrombin time). Intravenous injection of protamine sulfate or quarternized chitosan derivative to guinea pigs after injection of 1 mg/kg (100 aXa U/kg) low-molecular-weight heparin (clexane) led to shortening of plasma clotting time in the ReaClot Heparin test and to prolongation of plasma amidolytic activity in the factor Xa chromogenic substrate test.

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

    Science.gov (United States)

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

    2015-01-01

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

  5. [Activated protein C resistance and factor V Leiden: clinical interest].

    Science.gov (United States)

    Guermazi, S; Znazen, R

    2011-10-01

    Activated protein C resistance (APCR) is a coagulation abnormality often linked to FV Leiden mutation, a single nucleotide G1691A substitution resulting in arginine 506→glutamine missense factor V mutation. FV Leiden has a frequency of 20 to 30% in groups of patients with venous thrombosis while it is of 4 to 10% in normal subjects. FV Leiden is considered as a weak risk factor of thrombosis except in homozygote. FV Leiden is implicated in deep venous thrombosis occurrence. Duration of oral anticoagulant treatment is six months in patients developing a first venous thrombosis except in patients with combined defects or a clinical context suggesting a high risk of severe relapse. Detection of APCR by coagulation methods is often used in first intention with a high specificity if plasmas tested are diluted in factor V deficient plasma. Genotyping study is essential to establish the heterozygote or homozygote statute and certain teams perform it directly. Nevertheless, APCR not related to FV Leiden could be an independent thrombosis risk factor. APCR and FV Leiden are included in laboratory investigations of thrombophilic markers in patients less than 50 years with venous thrombosis. In arterial thrombosis, FV Leiden implication is weak or absent. FV Leiden increases the risk of thrombosis in other situations as in patients with cancer. An association with recurrent miscarriages and other vasculoplacental complications is also reported in many studies but the data concerning the efficacy of antithrombotic treatment to prevent recurrence are currently insufficient. Copyright © 2009 Elsevier Masson SAS. All rights reserved.

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

    LENUS (Irish Health Repository)

    Dillon, J P

    2012-02-03

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

  7. 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.

  8. 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.

  9. Chitin and stress induced protein kinase activation

    DEFF Research Database (Denmark)

    Kenchappa, Chandra Shekar; Azevedo da Silva, Raquel; Bressendorff, Simon

    2017-01-01

    The assays described here are pertinent to protein kinase studies in any plant. They include an immunoblot phosphorylation/activation assay and an in-gel activity assay for MAP kinases (MPKs) using the general protein kinase substrate myelin basic protein. They also include a novel in-gel peptide...... substrate assay for Snf1-related kinase family 2 members (SnRK2s). This kinase family-specific assay overcomes some limitations of in-gel assays and permits the identification of different types of kinase activities in total protein extracts....

  10. Anticoagulation Considerations for Travel to High Altitude.

    Science.gov (United States)

    DeLoughery, Thomas G

    2015-09-01

    DeLoughery, Thomas G. Anticoagulation considerations for travel to high altitude. High Alt Med Biol 16:181-185, 2015.-An increasing percentage of the population are on anticoagulation medicine for clinical reasons ranging from stroke prevention in atrial fibrillation to long term prevention of deep venous thrombosis. In recent years, several new direct oral anticoagulants have entered the market. The key questions that should be kept in mind when approaching a potential traveler on anticoagulation are: 1) why is the patient on anticoagulation? 2) do they need to stay on anticoagulation? 3) what are the choices for their anticoagulation? 4) will there be any drug interactions with medications needed for travel? and 5) how will they monitor their anticoagulation while traveling? Knowing the answers to these questions then can allow for proper counseling and planning for the anticoagulated traveler's trip.

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

    Directory of Open Access Journals (Sweden)

    Dahlbäck Björn

    2008-10-01

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

  12. Dietary protein considerations to support active aging.

    Science.gov (United States)

    Wall, Benjamin T; Cermak, Naomi M; van Loon, Luc J C

    2014-11-01

    Given our rapidly aging world-wide population, the loss of skeletal muscle mass with healthy aging (sarcopenia) represents an important societal and public health concern. Maintaining or adopting an active lifestyle alleviates age-related muscle loss to a certain extent. Over time, even small losses of muscle tissue can hinder the ability to maintain an active lifestyle and, as such, contribute to the development of frailty and metabolic disease. Considerable research focus has addressed the application of dietary protein supplementation to support exercise-induced gains in muscle mass in younger individuals. In contrast, the role of dietary protein in supporting the maintenance (or gain) of skeletal muscle mass in active older persons has received less attention. Older individuals display a blunted muscle protein synthetic response to dietary protein ingestion. However, this reduced anabolic response can largely be overcome when physical activity is performed in close temporal proximity to protein consumption. Moreover, recent evidence has helped elucidate the optimal type and amount of dietary protein that should be ingested by the older adult throughout the day in order to maximize the skeletal muscle adaptive response to physical activity. Evidence demonstrates that when these principles are adhered to, muscle maintenance or hypertrophy over prolonged periods can be further augmented in active older persons. The present review outlines the current understanding of the role that dietary protein occupies in the lifestyle of active older adults as a means to increase skeletal muscle mass, strength and function, and thus support healthier aging.

  13. 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

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

    Science.gov (United States)

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

    2014-02-01

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

  15. Safety and tolerability of a modified filter-type device for leukocytapheresis using ACD-A as anticoagulant in patients with mild to moderately active ulcerative colitis. Results of a pilot study.

    Science.gov (United States)

    Muratov, Vladislaw; Lundahl, Joachim; Mandic-Havelka, Aleksandra; Elvin, Kerstin; Ost, Ake; Shizume, Yasumasa; Furuya, Kaoru; Löfberg, Robert

    2010-01-01

    Cellsorba™ is a medical device for leukocytapheresis (LCAP) treatment of ulcerative colitis (UC). Cellsorba™ EX Global type has been developed from Cellsorba E for intended use with ACD-A as anticoagulant. We evaluated safety and efficacy of the modified Cellsorba using ACD-A in a pilot trial comprising patients with active UC, despite receiving 5-ASA. A total of 10 LCAP treatments/patients were administered. Safety assessment focused on clinical signs and symptoms, hematological variables, as well as levels of bradykinin and IL-6. Efficacy was determined using the Mayo clinical/endoscopic scoring index as well histological assessment of biopsies. Additional aim was to evaluate the impact of apheresis system lines and filter on selected regulatory molecules. All six subjects completed the trial without any serious adverse events. WBC, platelet counts, and levels of bradykinin and IL-6 were not significantly affected. The median Mayo score decreased from 8.0 to 3.5 at week 8 (and to 2 at week 16 for the responders). Four patients were responders, of whom two patients went into remission. Median histological scores decreased from 3.5 to 2.0 in these four patients. Concentration of LL-37 increased within the apheresis system lines. LCAP with Cellsorba EX using ACD-A as anticoagulant was found to be a safe and well-tolerated procedure in patients with active UC. The positive impact on efficacy parameters merits further evaluation in a controlled fashion.

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

    DEFF Research Database (Denmark)

    Ngo, HT; Pham, Long; Kim, JW

    2013-01-01

    and protein levels of MAPKAPK3 were elevated in both HCV subgenomic replicon cells and cell culture-derived HCV (HCVcc)-infected cells. Silencing of MAPKAPK3 expression resulted in decreases in both protein and HCV infectivity levels but not in the intracellular HCV RNA level. We showed that MAPKAPK3......Hepatitis C virus (HCV) is highly dependent on cellular proteins for its own propagation. In order to identify the cellular factors involved in HCV propagation, we performed protein microarray assays using the HCV core protein as a probe. Of ~9,000 host proteins immobilized in a microarray......, approximately 100 cellular proteins were identified as HCV core-interacting partners. Of these candidates, mitogen-activated protein kinase-activated protein kinase 3 (MAPKAPK3) was selected for further characterization. MAPKAPK3 is a serine/threonine protein kinase that is activated by stress and growth...

  17. PHARMACOGENETIC ASPECTS OF NEW ORAL ANTICOAGULANTS APPLICATION

    Directory of Open Access Journals (Sweden)

    A. V. Kryukov

    2017-01-01

    Full Text Available The aim of this review is to assess the effect of genetic factors on the pharmacokinetic parameters of new oral anticoagulants. The review presents data from studies investigating the effect of gene polymorphisms that encode biotransformation enzymes and transporter proteins of new oral anticoagulants on the pharmacokinetics of these drugs. RE-LY study showed a 15% decrease in trough dabigatran concentration and 27% lower risk of bleeding in carriers of CES1 gene rs2244613 polymorphism, there was also a tendency to reduce the risk of major bleeding. Further study of CES1 gene rs8192935 polymorphism showed a 3% decrease in trough dabigatran concentration in heterozygotes and 11% in homozygotes. There was found a 2% and 3% decrease in trough concentrations in hetero- and homozygotes for the minor allele of CES1 gene rs2244613 polymorphism, respectively. There was no significant effect of ABCB1 gene rs2032582 and rs1045642 polymorphisms on dabigatran pharmacokinetics. It is known the case of gastrointestinal bleeding in the carrier of allelic variants of ABCB1 gene rs2032582 and rs1045642 polymorphisms. However, there was no significant effect of genotype on rivaroxaban pharmacokinetics in the study involving the carriers of ABCB1 gene rs2032582 and rs1045642 polymorphisms. ABCB1 gene rs4148738 polymorphism was associated with higher apixaban peak concentration. But groups of patients with acute cardioembolic stroke showed no statistically significant difference of apixaban peak concentration depending on ABCB1 gene rs1045642 polymorphism genotype. ABCB1 gene rs1045642 and SLCO1B1 gene rs4149056 polymorphisms have no effect on edoxaban pharmacokinetics. Elevation of edoxaban metabolite concentration in carriers of SLCO1B1 gene allelic variants was not clinically significant because the proportion of metabolite is about 10% of the concentration of the main substance. It is necessary to provide large population studies with control of treatment

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

    Science.gov (United States)

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

    2014-11-01

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

  19. Acquired Activated Protein C Resistance, Thrombophilia and Adverse Pregnancy Outcomes: A Study Performed in an Irish Cohort of Pregnant Women

    Directory of Open Access Journals (Sweden)

    Sara Sedano-Balbás

    2011-01-01

    Full Text Available The combination of thrombophilia and pregnancy increases the risk of thrombosis and the potential for adverse outcomes during pregnancy. The most significant common inherited risk factor for thrombophilia is activated protein C resistance (APCR, a poor anticoagulant response of APC in haemostasis, which is mainly caused by an inherited single-nucleotide polymorphism (SNP, factor V G1691A (FV Leiden (FVL, referred as inherited APCR. Changes in the levels of coagulation factors: FV, FVIII, and FIX, and anticoagulant factors: protein S (PS and protein C (PC can alter APC function causing acquired APCR. Prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR C677T are prothrombotic SNPs which in association with APCR can also increase the risk of thrombosis amongst Caucasians. In this study, a correlation between an acquired APCR phenotype and increased levels of factors V, VIII, and IX was demonstrated. Thrombophilic mutations amongst our acquired APCR pregnant women cohort are relatively common but do not appear to exert a severe undue adverse effect on pregnancy.

  20. Coagulation inhibitors and activated protein C resistance in recurrent pregnancy losses in Indian women

    Directory of Open Access Journals (Sweden)

    P Lalita Jyotsna

    2011-01-01

    Full Text Available Background: Thrombophilias, both acquired and inherited, have been investigated in the etiopathogenesis of unexplained recurrent pregnancy loss. Aim: To study coagulation inhibitors and activated protein C resistance (APCR in recurrent pregnancy losses (RPL occurring in second and third trimesters. Materials and Methods: A total of 30 pregnant women (group A with two or more recurrent unexplained fetal loses were evaluated for APCR, protein C deficiency, protein S deficiency, antithrombin deficiency, and antiphospholipid antibodies (APLA. Thirty age-matched controls were taken (group B comprising of pregnant women with at least one live issue. Statistical Analysis: Comparisons between two group frequencies and group means were made using Chi square test and Student′s t test, respectively. Results: Protein C and protein S levels were reduced in group A compared with group B and the difference was statistically significant (P=0.005 and P=0.032, respectively. The mean value of antithrombin was slightly reduced in group A compared with group B. APCR was observed in 16.6% cases and 3.3% controls. However, the difference was not statistically significant. APLA was observed in 20% cases and none of the controls. Of these, lupus anticoagulant was positive in 16.6% cases and anticardiolipin antibodies in 10% cases. Combined defects were seen in seven patients. Conclusion: There is a significant risk of RPL in pregnant women with thrombophilias. Therefore, screening for thrombophilias may be justified in pregnant women with unexplained recurrent fetal wastage, especially in second and third trimester.

  1. Efficiency of three anti-coagulant rodenticides on commensal rodents.

    Science.gov (United States)

    Mikhail, M W; Kamilia; Allam, A M; Soliman, M I

    2007-08-01

    Susceptibiliy level to bromadilone, difencoum and coumtertraly anticoagulants were studied in different species of Norway rat Rattus norvegicus and roof rat Rattus rattus trapped from El-Qualyobia Governorate in which the anticoagulant rodenticides were used to control rodents for long periods in some rural regions at Qualyobia. Complete mortality was showed for both species and sex within a standard feeding period (6 days) indicated to be susceptible to the three anticoagulant rodenticides. The bait eaten and corresponding active ingredient showed a noticeable more intake for R. rattus than R. norvegicus for the three compounds. The time to death showed highest mean values for R. rattus comparison to R. norvegicus. Difencoum recorded highest values of time to death compare with bromadilone and coumatetralyl.

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

    Science.gov (United States)

    Cedrone, Edward; Neun, Barry W; Rodriguez, Jamie; Vermilya, Alison; Clogston, Jeffrey D; McNeil, Scott E; Barenholz, Yechezkel; Szebeni, Janos; Dobrovolskaia, Marina A

    2017-12-21

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

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

    Directory of Open Access Journals (Sweden)

    Edward Cedrone

    2017-12-01

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

  4. 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

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    Anticoagulant resistance in Norway rats (Rattus norvegicus) has been suggested to be due to mutations in the VKORC1 gene, encoding the target protein of anticoagulant rodenticides such as warfarin and bromadiolone. Other factors, e.g. pharmacokinetics, may however also contribute to resistance. We...

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    Background: Anticoagulant resistance in Norway rats, Rattus norvegicus (Berk.), has been suggested to be conferred by mutations in the VKORC1 gene, encoding the target protein of anticoagulant rodenticides. Other factors, e.g. pharmacokinetics, may also contribute to resistance, however. To examine...

  7. Oral anticoagulation in primary care.

    Science.gov (United States)

    Altirriba, J; Aparicio, P

    2017-06-01

    Oral anticoagulant therapy is currently widespread in the population and primary care plays an important role in its control in Spain. Younger populations, such as those in prisons, often require this treatment for reasons other than atrial fibrillation, often in relation to valvular or congenital or acquired hypercoagulability situations. The possibility of obtaining the INR by portable coagulometers has allowed primary care physicians to tackle the indication of this therapy and the control of these patients in coordination with haematology services. The emergence of new therapeutic alternatives (Dabigatran, Rivaroxaban, Apixaban and Edoxaban, the so called "ACOD") has permitted the expansion of options for oral anticoagulation in some cases, since they do not require systematic monitoring of their effect and interact with far fewer drugs than their predecessors, although there are still restrictions by the health authorities on their widespread use. This article reviews the different indications of oral anticoagulant therapy according to the new recommendations as well as the clinical scenarios in which it should be used.

  8. Anticoagulant rodenticides and wildlife: Introduction

    Science.gov (United States)

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

    2018-01-01

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

  9. Tribomechanical micronization and activation of whey protein ...

    Indian Academy of Sciences (India)

    Tribomechanics is a part of physics that is concerned with the study of phenomena that appear during milling under dynamic conditions. Tribomechanical micronization and activation (TMA) of whey protein concentrates (WPC) and zeolites (type clinoptilolite) were carried out. Samples of powdered WPC and zeolite were ...

  10. 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)

    Balestrino, Damien; Quintana, Mercédès; Charbonnel, Nicolas; Forestier, Christiane; Lartigue, Claire; Souweine, Bertrand

    2016-01-01

    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 DC

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  12. 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.

  13. 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.

  14. Raman optical activity of proteins and glycoproteins

    International Nuclear Information System (INIS)

    Smyth, E.

    2000-03-01

    Raman optical activity (ROA), measured in this project as a small difference in the intensity of Raman scattering from chiral molecules in right- and left-circularly polarised incident laser light, offers the potential to provide more information about the structure of biological molecules in aqueous solution than conventional spectroscopic techniques. Chapter one contains a general discussion of the relative merits of different spectroscopic techniques for structure determination of biomolecules, as well as a brief introduction to ROA. In Chapter two a theoretical analysis of ROA is developed, which extends the discussion in chapter one. The spectrometer setup and sample preparation is then discussed in chapter three. Instrument and sample conditions are monitored to ensure that the best results are obtained. As with any experimental project problems occur, which may result in a degradation of the spectra obtained. The cause of these problems was explored and remedied whenever possible. Chapter four introduces a brief account of protein, glycoprotein and carbohydrate structure and function, with a particular emphasis on the structure of proteins. In the remaining chapters experimental ROA results on proteins and glycoproteins, with some carbohydrate samples, from a wide range of sources are examined. For example, in chapter five some β-sheet proteins are examined. Structural features in these proteins are examined in the extended amide III region of their ROA spectra, revealing that ROA is sensitive to the rigidity or flexibility inherent in proteins. Chapter six concentrates on a group of proteins (usually glycoproteins) known as the serine proteinase inhibitors (serpins). Medically, the serpins are one of the most important groups of proteins of current interest, with wide-ranging implications in conditions such as Down's syndrome, Alzheimer's disease, and emphysema with associated cirrhosis of the liver. With favourable samples and conditions ROA may offer the

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

    Directory of Open Access Journals (Sweden)

    Diane M Tshikudi

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

  16. De Novo Construction of Redox Active Proteins.

    Science.gov (United States)

    Moser, C C; Sheehan, M M; Ennist, N M; Kodali, G; Bialas, C; Englander, M T; Discher, B M; Dutton, P L

    2016-01-01

    Relatively simple principles can be used to plan and construct de novo proteins that bind redox cofactors and participate in a range of electron-transfer reactions analogous to those seen in natural oxidoreductase proteins. These designed redox proteins are called maquettes. Hydrophobic/hydrophilic binary patterning of heptad repeats of amino acids linked together in a single-chain self-assemble into 4-alpha-helix bundles. These bundles form a robust and adaptable frame for uncovering the default properties of protein embedded cofactors independent of the complexities introduced by generations of natural selection and allow us to better understand what factors can be exploited by man or nature to manipulate the physical chemical properties of these cofactors. Anchoring of redox cofactors such as hemes, light active tetrapyrroles, FeS clusters, and flavins by His and Cys residues allow cofactors to be placed at positions in which electron-tunneling rates between cofactors within or between proteins can be predicted in advance. The modularity of heptad repeat designs facilitates the construction of electron-transfer chains and novel combinations of redox cofactors and new redox cofactor assisted functions. Developing de novo designs that can support cofactor incorporation upon expression in a cell is needed to support a synthetic biology advance that integrates with natural bioenergetic pathways. © 2016 Elsevier Inc. All rights reserved.

  17. Outpatient management of oral anticoagulation treatment (OAT in general practice: the “Medicina di Gruppo di Masate” experience

    Directory of Open Access Journals (Sweden)

    Fiorenzo Massimo Corti

    2017-04-01

    Full Text Available Outpatient management of oral anticoagulation treatment (OAT in general practice: the “Medicina di Gruppo di Masate” experienceOral anticoagulants are used for prophylaxis in thromboembolic conditions. Vitamin K antagonists (VKAs such as warfarin, are commonly employed. The anticoagulation activity induced by VKAs is monitored by the prothrombin time test to determine the International Normalized Ratio (INR. Point-of-care testing (POCT devices can be used to monitor anticoagulant therapy improving the quality of oral anticoagulation. This paper aims at describing the relevant experience of the “Medicina di Gruppo di Masate” in general practice. We also put this experience into the general context of the international evidence on the impact of POCT. Both our experience and the international evidence may support anticoagulant therapy management by GPs (General Practitioners.

  18. 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

  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

    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

  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

    International Nuclear Information System (INIS)

    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.

    2016-01-01

    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. Cranberry Proanthocyanidins - Protein complexes for macrophage activation.

    Science.gov (United States)

    Carballo, Sergio M; Haas, Linda; Krueger, Christian G; Reed, Jess D

    2017-09-20

    In this work we characterize the interaction of cranberry (Vaccinium macrocarpon) proanthocyanidins (PAC) with bovine serum albumin (BSA) and hen egg-white lysozyme (HEL) and determine the effects of these complexes on macrophage activation and antigen presentation. We isolated PAC from cranberry and complexed the isolated PAC with BSA and HEL. The properties of the PAC-protein complexes were studied by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS), gel electrophoresis and zeta-potential. The effects of PAC-BSA complexes on macrophage activation were studied in RAW 264.7 macrophage like cells after treatment with lipopolysaccharide (LPS). Fluorescence microscopy was used to study the endocytosis of PAC-BSA complexes. The effects of the PAC complexes on macrophage antigen presentation were studied in an in vitro model of HEL antigen presentation by mouse peritoneal mononuclear cells to a T-cell hybridoma. The mass spectra of the PAC complexes with BSA and HEL differed from the spectra of the proteins alone by the presence of broad shoulders on the singly and doubly charged protein peaks. Complexation with PAC altered the electrophoretic mobility shift assay in native agarose gel and the electrophoretic mobility (ζ-potential) values. These results indicate that the PAC-protein complexes are stable and alter the protein structure without precipitating the protein. Fluorescence microscopy showed that the RAW 264.7 macrophages endocytosed BSA and PAC-BSA complexes in discrete vesicles that surrounded the nucleus. Macrophages treated with increasing amounts of PAC-BSA complexes had significantly reduced COX-2 and iNOS expression in response to treatment with lipopolysaccharide (LPS) in comparison to the controls. The PAC-HEL complexes modulated antigen uptake, processing and presentation in murine peritoneal macrophages. After 4 h of pre-incubation, only trace amounts of IL-2 were detected in the co-cultures treated with HEL

  2. Anticoagulant Control Results among Patients with Mechanical ...

    African Journals Online (AJOL)

    Background: Patients with mechanical heart valves receive life long, oral anticoagulant therapy to prevent thromboembolic complications, but this treatment is associated with an increased risk of bleeding (1). However no study in Tanzania has been done to review the adequacy of anticoagulation monitoring and risk factors ...

  3. Anticoagulation

    Science.gov (United States)

    ... be hazardous. These medicines include most antibiotics, several pain medicines (e.g., non-steroidal anti-inflammatory drugs) and medications for acid reflux such as cimetidine (Tagamet). If you're taking warfarin and start a new prescription or over-the-counter medication, check with ...

  4. [Antioxidant activity of cationic whey protein isolate].

    Science.gov (United States)

    titova, M E; Komolov, S A; Tikhomirova, N A

    2012-01-01

    The process of lipid peroxidation (LPO) in biological membranes of cells is carried out by free radical mechanism, a feature of which is the interaction of radicals with other molecules. In this work we investigated the antioxidant activity of cationic whey protein isolate, obtained by the cation-exchange chromatography on KM-cellulose from raw cow's milk, in vitro and in vivo. In biological liquids, which are milk, blood serum, fetal fluids, contains a complex of biologically active substances with a unique multifunctional properties, and which are carrying out a protective, antimicrobial, regenerating, antioxidant, immunomodulatory, regulatory and others functions. Contents of the isolate were determined electrophoretically and by its biological activity. Cationic whey protein isolate included lactoperoxidase, lactoferrin, pancreatic RNase, lysozyme and angeogenin. The given isolate significantly has an antioxidant effect in model experimental systems in vitro and therefore may be considered as a factor that can adjust the intensity of lipid oxidation. In model solutions products of lipid oxidation were obtained by oxidation of phosphatidylcholine by hydrogen peroxide in the presence of a source of iron. The composition of the reaction mixture: 0,4 mM H2O2; 50 mcM of hemin; 2 mg/ml L-alpha-phosphatidylcholine from soybean (Sigma, German). Lipid peroxidation products were formed during the incubation of the reaction mixture for two hours at 37 degrees C. In our studies rats in the adaptation period immediately after isolation from the nest obtained from food given orally native cationic whey protein isolate at the concentration three times higher than in fresh cow's milk. On the manifestation of the antioxidant activity of cationic whey protein isolate in vivo evidence decrease of lipid peroxidation products concentration in the blood of rats from the experimental group receipt whey protein isolate in dos 0,6 mg/g for more than 20% (pisolate has an antioxidant

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    Joseph H. McMordie, MD

    2018-03-01

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

  7. Complement activation by ceramide transporter proteins.

    Science.gov (United States)

    Bode, Gerard H; Losen, Mario; Buurman, Wim A; Veerhuis, Robert; Molenaar, Peter C; Steinbusch, Harry W M; De Baets, Marc H; Daha, Mohamed R; Martinez-Martinez, Pilar

    2014-02-01

    C1q is the initiator of the classical complement pathway and, as such, is essential for efficient opsonization and clearance of pathogens, altered self-structures, and apoptotic cells. The ceramide transporter protein (CERT) and its longer splicing isoform CERTL are known to interact with extracellular matrix components, such as type IV collagen, and with the innate immune protein serum amyloid P. In this article, we report a novel function of CERT in the innate immune response. Both CERT isoforms, when immobilized, were found to bind the globular head region of C1q and to initiate the classical complement pathway, leading to activation of C4 and C3, as well as generation of the membrane attack complex C5b-9. In addition, C1q was shown to bind to endogenous CERTL on the surface of apoptotic cells. These results demonstrate the role of CERTs in innate immunity, especially in the clearance of apoptotic cells.

  8. Clinical significance of acquired activated protein C resistance in patients with systemic lupus erythematosus.

    Science.gov (United States)

    Muñoz-Rodríguez, F J; Reverter, J C; Font, J; Tàssies, D; Espinosa, G; Cervera, R; Carmona, F; Balsch, J; Ingelmo, M; Ordinas, A

    2002-01-01

    Antiphospholipid antibodies (aPL) may induce acquired activated protein C resistance (acquired APCR). The role of acquired APCR in patients with systemic lupus erythematosus (SLE) is not well known. To evaluate the prevalence of acquired APCR and its association with clinical manifestations we studied 103 consecutive SLE patients and 103 matched controls. APCR in the undiluted test and after dilution in factor V deficient plasma, factor V Leiden, protein C and S, lupus anticoagulant, and anti-cardiolipin, anti-beta2-glycoprotein I and anti-prothrombin antibodies were determined. Factor V Leiden was found in 4% in both patients and controls. The prevalence of acquired APCR was 22% for the undiluted assay and 17% in the diluted test. In SLE patients, acquired APCR was associated with aPL (39 vs 13% in undiluted assay, P = 0.007; and 33 vs 7% in the diluted test, P = 0.001). Arterial thromboses were found in 24% of patients with acquired APCR and in 6% of patients without (P = 0.04). However, no relationship was found with venous thrombosis. Acquired APCR was also associated with pregnancy losses: miscarriages in 70% of women with acquired APCR vs 32% in those without (P=0.03). Thus, in SLE patients acquired APCR seems to be associated with increased prevalence of arterial thrombosis and pregnancy losses.

  9. Receptor activity-modifying proteins; multifunctional G protein-coupled receptor accessory proteins.

    Science.gov (United States)

    Hay, Debbie L; Walker, Christopher S; Gingell, Joseph J; Ladds, Graham; Reynolds, Christopher A; Poyner, David R

    2016-04-15

    Receptor activity-modifying proteins (RAMPs) are single pass membrane proteins initially identified by their ability to determine the pharmacology of the calcitonin receptor-like receptor (CLR), a family B G protein-coupled receptor (GPCR). It is now known that RAMPs can interact with a much wider range of GPCRs. This review considers recent developments on the structure of the complexes formed between the extracellular domains (ECDs) of CLR and RAMP1 or RAMP2 as these provide insights as to how the RAMPs direct ligand binding. The range of RAMP interactions is also considered; RAMPs can interact with numerous family B GPCRs as well as examples of family A and family C GPCRs. They influence receptor expression at the cell surface, trafficking, ligand binding and G protein coupling. The GPCR-RAMP interface offers opportunities for drug targeting, illustrated by examples of drugs developed for migraine. © 2016 Authors; published by Portland Press Limited.

  10. Antioxidative Activity of Tobacco Leaf Protein Hydrolysates

    Directory of Open Access Journals (Sweden)

    Guohua Rao

    2007-01-01

    Full Text Available Discarded tobacco leaf protein hydrolysate (DTLPH was prepared by enzymatic hydrolysis using papain and then separated using ultrafiltration (UF membranes with molecular mass cut-off (MMCO of 10, 5, 3 and 1 kDa. Four permeate fractions including 10-K, 5-K, 3-K and 1-K (the permeate fractions from 10, 5, 3 and 1 kDa hydrolysate fractions were obtained. The 5-K hydrolysate fraction had high oxidation inhibilitory ratio (42.62 %, which was about twofold higher than the original hydrolysate and as high as that of vitamin E (α-tocopherol. The fractionated hydrolysates were superior to the original hydrolysate in the antioxidative activity tested. Moreover, these separated hydrolysates showed the enhanced functional property. The amino acid composition of 5-K hydrolysate was analyzed and the results show that the high antioxidative activity of 5-K hydrolysate was derived from high content of histidine, methionine, cystine and tryptophan.

  11. 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

  12. Marine pharmacology in 2001--2002: marine compounds with anthelmintic, antibacterial, anticoagulant, antidiabetic, antifungal, anti-inflammatory, antimalarial, antiplatelet, antiprotozoal, antituberculosis, and antiviral activities; affecting the cardiovascular, immune and nervous systems and other miscellaneous mechanisms of action.

    Science.gov (United States)

    Mayer, Alejandro M S; Hamann, Mark T

    2005-01-01

    During 2001--2002, research on the pharmacology of marine chemicals continued to be global in nature involving investigators from Argentina, Australia, Brazil, Canada, China, Denmark, France, Germany, India, Indonesia, Israel, Italy, Japan, Mexico, Netherlands, New Zealand, Pakistan, the Philippines, Russia, Singapore, Slovenia, South Africa, South Korea, Spain, Sweden, Switzerland, Thailand, United Kingdom, and the United States. This current article, a sequel to the authors' 1998, 1999 and 2000 marine pharmacology reviews, classifies 106 marine chemicals derived from a diverse group of marine animals, algae, fungi and bacteria, on the basis of peer-reviewed preclinical pharmacology. Anthelmintic, antibacterial, anticoagulant, antifungal, antimalarial, antiplatelet, antiprotozoal, antituberculosis or antiviral activities were reported for 56 marine chemicals. An additional 19 marine compounds were shown to have significant effects on the cardiovascular, immune and nervous system as well as to possess anti-inflammatory and antidiabetic effects. Finally, 31 marine compounds were reported to act on a variety of molecular targets and thus may potentially contribute to several pharmacological classes. Thus, during 2001--2002 pharmacological research with marine chemicals continued to contribute potentially novel chemical leads for the ongoing global search for therapeutic agents for the treatment of multiple disease categories.

  13. Egg yolk proteins and peptides with biological activity

    Directory of Open Access Journals (Sweden)

    Aleksandra Zambrowicz

    2014-12-01

    Full Text Available Many proteins of food reveal biological activity. In the sequence of these proteins also numerous biologically active peptides are encrypted. These peptides are released during proteolysis naturally occurring in the gastrointestinal tract, food fermentation or during designed enzymatic hydrolysis in vitro. Biopeptides may exert multiple activities, affecting the cardiovascular, endocrine, nervous and immune systems. An especially rich source of bioactive proteins and biopeptides is egg. Bioactive peptides released from egg white proteins have been well described, whereas egg yolk proteins as precursors of biopeptides are less well characterized. This manuscript describes biologically active proteins and peptides originating from egg yolk and presents their potential therapeutic role.

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

    Directory of Open Access Journals (Sweden)

    Hossein Zolfagharian

    2015-12-01

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

  15. Arabinogalactan proteins: focus on carbohydrate active enzymes

    Directory of Open Access Journals (Sweden)

    Eva eKnoch

    2014-06-01

    Full Text Available Arabinogalactan proteins (AGPs are a highly diverse class of cell surface proteoglycans that are commonly found in most plant species. AGPs play important roles in many cellular processes during plant development, such as reproduction, cell proliferation, pattern formation and growth, and in plant-microbe interaction. However, little is known about the molecular mechanisms of their function. Numerous studies using monoclonal antibodies that recognize different AGP glycan epitopes have shown the appearance of a slightly altered AGP glycan in a specific stage of development in plant cells. Therefore, it is anticipated that the biosynthesis and degradation of AGP glycan is tightly regulated during development. Until recently, however, little was known about the enzymes involved in the metabolism of AGP glycans. In this review, we summarize recent discoveries of carbohydrate active enzymes (CAZy; http://www.cazy.org/ involved in the biosynthesis and degradation of AGP glycans, and we discuss the biological role of these enzymes in plant development.

  16. Tamoxifen induces resistance to activated protein C.

    Science.gov (United States)

    Rühl, Heiko; Schröder, Lars; Müller, Jens; Fimmers, Rolf; Sukhitashvili, Shorena; Welz, Julia; Kuhn, Walther C; Oldenburg, Johannes; Rudlowski, Christian; Pötzsch, Bernd

    2014-05-01

    The estrogen antagonist tamoxifen (TAM) increases the thrombotic risk similar to estrogen containing oral contraceptives (OC). In OC users this risk is attributed to alterations of hemostasis resulting in acquired resistance to activated protein C (APC). TAM-induced APC resistance has not been reported yet. Blood samples were collected prospectively from women with breast cancer before (n=25) and monthly after start of adjuvant TAM treatment (n=75). APC resistance was evaluated on basis of the effect of APC on the endogenous thrombin generation potential. To detect increased in vivo APC generation APC plasma levels were measured using a highly sensitive oligonucleotide-based enzyme capture assay. Routine hemostasis parameters were measured additionally. APC sensitivity decreased by 41% (p=0.001) compared to baseline after one month of TAM application and remained significantly decreased during the study period. Free protein S increased (p=0.008) while other analyzed procoagulant factors, inhibitors, and activation markers of coagulation decreased or did not change significantly. In five patients the APC concentration increased to non-physiological levels but an overall significant increase of APC was not observed. This is the first study showing acquired APC resistance under TAM therapy. Acquired APC resistance might explain the increased thrombotic risk during TAM treatment. Observed changes of hemostasis parameters suggest different determinants of TAM-induced APC resistance than in OC-induced APC resistance. The presence of acquired APC resistance in TAM patients warrants further evaluation if these patients may benefit from antithrombotic prophylaxis in the presence of additional thrombotic risk factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Direct Oral Anticoagulants: An Overview for the Interventional Radiologist

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-03-15

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

  18. A rapid pro-hemostatic approach to overcome direct oral anticoagulants.

    Science.gov (United States)

    Thalji, Nabil K; Ivanciu, Lacramioara; Davidson, Robert; Gimotty, Phyllis A; Krishnaswamy, Sriram; Camire, Rodney M

    2016-08-01

    Direct inhibitors of coagulation factor Xa (FXa) or thrombin are promising oral anticoagulants that are becoming widely adopted. The ability to reverse their anticoagulant effects is important when serious bleeding occurs or urgent medical procedures are needed. Here, using experimental mouse models of hemostasis, we show that a variant coagulation factor, FXa(I16L), rapidly restores hemostasis in the presence of the anticoagulant effects of these inhibitors. The ability of FXa(I16L) to reverse the anticoagulant effects of FXa inhibitor depends, at least in part, on the ability of the active site inhibitor to hinder antithrombin-dependent FXa inactivation, paradoxically allowing uninhibited FXa to persist in plasma. Because of its inherent catalytic activity, FXa(I16L) is more potent (by >50-fold) in the hemostasis models tested than a noncatalytic antidote that is currently in clinical development. FXa(I16L) also reduces the anticoagulant-associated bleeding in vivo that is induced by the thrombin inhibitor dabigatran. FXa(I16L) may be able to fill an important unmet clinical need for a rapid, pro-hemostatic agent to reverse the effects of several new anticoagulants.

  19. Overview of a pharmacist anticoagulation certificate program.

    Science.gov (United States)

    Kirk, Julienne K; Edwards, Rebecca; Brewer, Andrew; Miller, Cathey; Bray, Bryan; Groce, James B

    2017-07-01

    To describe the design of an ongoing anticoagulation certificate program and annual renewal update for pharmacists. Components of the anticoagulation certificate program include home study, pre- and posttest, live sessions, case discussions with evaluation and presentation, an implementation plan, and survey information (program evaluation and use in practice). Clinical reasoning skills were assessed through case work-up and evaluation prior to live presentation. An annual renewal program requires pharmacists to complete home study and case evaluations. A total of 361 pharmacists completed the anticoagulation certificate program between 2002 and 2015. Most (62%) practiced in ambulatory care and 38% in inpatient care settings (8% in both). In the past four years, 71% were working in or starting anticoagulation clinics in ambulatory and inpatient settings. In their evaluations of the program, an average of 90% of participants agreed or strongly agreed the lecture material was relevant and objectives were met. Pharmacists are able to apply knowledge and skills in management of anticoagulation. This structured practice-based continuing education program was intended to enhance pharmacy practice and has achieved that goal. The certificate program in anticoagulation was relevant to pharmacists who attended the program. Copyright © 2017. Published by Elsevier Inc.

  20. Rapid kinetic BRET measurements to monitor G protein activation by GPCR and non-GPCR proteins.

    Science.gov (United States)

    Maziarz, Marcin; Garcia-Marcos, Mikel

    2017-01-01

    Heterotrimeric G proteins are central hubs of signal transduction whose activity is controlled by G protein-coupled receptors (GPCRs) as well as by a complex network of regulatory proteins. Recently, bioluminescence resonance energy transfer (BRET)-based assays have been used to monitor real-time activation of heterotrimeric G proteins in cells. Here we describe the use of a previously established BRET assay to monitor G protein activation upon GPCR stimulation and its adaptation to measure G protein activation by non-GPCR proteins, such as by cytoplasmic guanine nucleotide exchange factors (GEFs) like GIV/Girdin. The BRET assay monitors the release of free Gβγ from Gα-Gβγ heterotrimers as a readout of G protein activation, which is readily observable upon agonist stimulation of GPCRs. To control the signal input for non-GPCR activators, we describe the use of a chemically induced dimerization strategy to promote rapid membrane translocation of proteins containing the Gα-binding and -activating (GBA) motif found in some nonreceptor GEFs. The assay described here allows the kinetic measurement of G protein activation with subsecond temporal resolution and to compare the levels of activation induced by GPCR agonists vs those induced by the membrane recruitment of nonreceptor G protein signaling activators. © 2017 Elsevier Inc. All rights reserved.

  1. Non-Anticoagulant Heparins Are Hepcidin Antagonists for the Treatment of Anemia.

    Science.gov (United States)

    Poli, Maura; Asperti, Michela; Ruzzenenti, Paola; Naggi, Annamaria; Arosio, Paolo

    2017-04-08

    The peptide hormone hepcidin is a key controller of systemic iron homeostasis, and its expression in the liver is mainly regulated by bone morphogenetic proteins (BMPs), which are heparin binding proteins. In fact, heparins are strong suppressors of hepcidin expression in hepatic cell lines that act by inhibiting the phosphorylation of SMAD1/5/8 proteins elicited by the BMPs. The inhibitory effect of heparins has been demonstrated in cells and in mice, where subcutaneous injections of non-anticoagulant heparins inhibited liver hepcidin expression and increased iron bioavailability. The chemical characteristics for high anti-hepcidin activity in vitro and in vivo include the 2O-and 6O-sulfation and a molecular weight above 7 kDa. The most potent heparins have been found to be the super-sulfated ones, active in hepcidin suppression with a molecular weight as low as 4 kDa. Moreover, the alteration of endogenous heparan sulfates has been found to cause a reduction in hepcidin expression in vitro and in vivo, indicating that heparins act by interfering with the interaction between BMPs and components of the complex involved in the activation of the BMP/SMAD1/5/8 pathway. This review summarizes recent findings on the anti-hepcidin activity of heparins and their possible use for the treatment of anemia caused by hepcidin excess, including the anemia of chronic diseases.

  2. Vascular graft thrombosis secondary to activated protein C resistance: a case report and literature review.

    Science.gov (United States)

    Pejkic, Sinisa; Savic, Nebojsa; Paripovic, Miroslav; Sladojevic, Milos; Doric, Predrag; Ilic, Nikola

    2014-02-01

    Hypercoagulability is a well-documented and prominent risk factor for venous thromboembolism. The role of thrombophilia in arterial thrombotic events is less well defined. A 52-year-old male patient with multiple atherogenic risk factors was admitted for non-healing pedal ulcer and absent distal pulses. Based on the clinical presentation, Doppler ultrasound and angiography findings, the patient underwent elective in situ bypass arterial reconstruction. The saphenous vein graft was of satisfactory quality and the procedure went routinely. Acute graft thrombosis on postoperative day 0 was recognized immediately and prompted an emergent surgical revision. No technical errors or anatomical/mechanical causes for failed reconstruction were found and the graft was successfully thrombectomized using a Fogarty balloon-catheter. Graft rethrombosis, however, ensued after several hours. Considering the absence of threatening limb ischemia and the idiopathic recurrent thrombosis, raising suspicion of prothrombotic state, conservative treatment was pursued. Postoperative thrombophilia testing proved positive for activated protein C resistance, mandating introduction of chronic oral anticoagulation. Six months later, the operated extremity is viable. Inexplicable vascular graft thrombosis, particularly if early and recurrent, should raise suspicion of underlying thrombophilia. If confirmed by laboratory testing, long-term secondary antithrombotic prophylaxis may be required.

  3. Reduction of circulating annexin A5 levels and resistance to annexin A5 anticoagulant activity in women with recurrent spontaneous pregnancy losses.

    NARCIS (Netherlands)

    Rand, J.H.; Arslan, A.A.; Wu, X.X.; Wein, R.; Mulholland, J.; Shah, M.; Heerde, W.L. van; Reutelingsperger, C.P.M.; Lockwood, C.J.; Kuczynski, E.

    2006-01-01

    OBJECTIVE: We investigated whether levels of annexin A5, evidence for resistance to annexin A5 activity, and levels anti-annexin A5 antibodies might be altered in women with a history of recurrent spontaneous pregnancy losses. STUDY DESIGN: These annexin A5 parameters were assayed in 70 nonpregnant

  4. Thromboembolic and bleeding risks in patients undergoing atrial fibrillation ablation: oral anticoagulation perspectives.

    Science.gov (United States)

    Briceño, David F; Madan, Nidhi; Romero, Jorge; Londoño, Alejandra; Villablanca, Pedro A; Natale, Andrea; Di Biase, Luigi

    2017-07-01

    Atrial fibrillation (AF) is a cause of significant morbidity and mortality. Catheter ablation for AF (CAAF) has emerged as an effective treatment option of rhythm control for patients with symptomatic AF. However, the risk of thromboembolism and bleeding in the periprocedural period represent a worrisome complication of this therapy. The reported incidence of thromboembolic and bleeding events associated with CAAF varies from 0.9% to 5% depending on the CAAF strategy and the anticoagulation regimen used in the periprocedural period. Areas covered: The different anticoagulation regimens used prior to, during, and after CAAF to minimize the risk of thromboembolic and bleeding events are reviewed. The use of uninterrupted oral anticoagulation and appropriate heparin dosing to achieve safe activated clotting time levels are also detailed. A comprehensive approach with assessment of individual risk for thromboembolic and bleeding complications, and understanding the pharmacokinetics of the anticoagulant agents available is also reviewed. Expert opinion: The key advances done in the periprocedural anticoagulation field include the use of uninterrupted anticoagulation strategies in patients undergoing AF ablation and efforts to simplify the selection of patients who need LAA thrombus screening prior to ablation.

  5. Sulfated glycopeptide nanostructures for multipotent protein activation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sungsoo S.; Fyrner, Timmy; Chen, Feng; Álvarez, Zaida; Sleep, Eduard; Chun, Danielle S.; Weiner, Joseph A.; Cook, Ralph W.; Freshman, Ryan D.; Schallmo, Michael S.; Katchko, Karina M.; Schneider, Andrew D.; Smith, Justin T.; Yun, Chawon; Singh, Gurmit; Hashmi, Sohaib Z.; McClendon, Mark T.; Yu, Zhilin; Stock, Stuart R.; Hsu, Wellington K.; Hsu, Erin L.; Stupp , Samuel I. (NWU)

    2017-06-19

    Biological systems have evolved to utilize numerous proteins with capacity to bind polysaccharides for the purpose of optimizing their function. A well-known subset of these proteins with binding domains for the highly diverse sulfated polysaccharides are important growth factors involved in biological development and tissue repair. We report here on supramolecular sulfated glycopeptide nanostructures, which display a trisulfated monosaccharide on their surfaces and bind five critical proteins with different polysaccharide-binding domains. Binding does not disrupt the filamentous shape of the nanostructures or their internal β-sheet backbone, but must involve accessible adaptive configurations to interact with such different proteins. The glycopeptide nanostructures amplified signalling of bone morphogenetic protein 2 significantly more than the natural sulfated polysaccharide heparin, and promoted regeneration of bone in the spine with a protein dose that is 100-fold lower than that required in the animal model. These highly bioactive nanostructures may enable many therapies in the future involving proteins.

  6. Combination of lenalidomide and low-dose dexamethasone therapy promotes the anticoagulant activity of warfarin in patients with immunoglobulin light-chain amyloidosis.

    Science.gov (United States)

    Kitazawa, Fumiaki; Fuchida, Shin-Ichi; Ise, Fumitaka; Kado, Yoko; Ueda, Kumi; Kokufu, Takatoshi; Okano, Akira; Hatsuse, Mayumi; Murakami, Satoshi; Nakayama, Yuko; Takara, Kohji; Shimazaki, Chihiro

    2017-07-01

    The present study aimed to evaluate the drug interactions between warfarin and combination chemotherapy with lenalidomide and low-dose dexamethasone in immunoglobulin light-chain (AL) amyloidosis patients with unstable international normalized ratios (INR). The changes to INR values over time in 3 AL amyloidosis patients treated with warfarin and a combination of lenalidomide and low-dose dexamethasone between March 2011 and February 2015 were analyzed retrospectively. The mean INR value was 1.52 prior to the combination chemotherapy, and the value increased 1.7-fold during treatment. The median time to reach maximum values was 17 days. Horn's drug Interaction Probability Scale indicated a possible interaction between lenalidomide and warfarin. These patients exhibited no marked alterations in hepatic function or serum albumin concentrations prior to and following combination chemotherapy and no additional administration of CYP2C9 inhibitors or vitamin K supplements was conducted. In addition, no patient experienced chemotherapy-induced nausea or appetite loss. These findings suggest that the total clearance or protein binding of warfarin remained unchanged. Therefore, the combination of warfarin and lenalidomide may cause a pharmacodynamic interaction, more likely by inhibiting the production of interleukin-6. In conclusion, clinically important interactions between warfarin and lenalidomide and low-dose dexamethasone therapy were observed in AL amyloidosis patients, where INR values signi ficantly increased. Therefore, close and regular monitoring of patients during the course of treatment is important, and the dose of warfarin should be reduced if required.

  7. Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles.

    Science.gov (United States)

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

    2012-06-01

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

  8. Exploring potential anticoagulant drug formulations using thrombin generation test

    Directory of Open Access Journals (Sweden)

    Elena Zavyalova

    2016-03-01

    The thrombin generation test was used to assess the whole coagulation cascade in normal and factor-deficient human blood plasma. Potential therapeutic windows were estimated for coagulation factors, ranking them as targets for anticoagulant drugs. Thrombin and factor Xa have been revealed as the most promising targets, which fully agrees with the current drug development strategy. Inhibitors of factors Va and VIIa are expected to have narrow therapeutic windows. Inhibitors of factors VIIIa and IXa are expected to have a moderate anticoagulant effect. Factors XI and XII are poor targets for anticoagulant drugs. Compared with plasma that is deficient in factor II, the thrombin inhibitors bivalirudin and aptamer HD1 had increased activity. Both inhibitors were tested in deficient plasma providing a model of potential drug combination. The most promising combinations were anti-thrombin with anti-V/Va and also anti-thrombin with anti-IX/IXa. Each combination had an incremental dose-effect dependence that is promising from the standpoint of the therapeutic window.

  9. Anticoagulant and antimicrobial finishing of non-woven polypropylene textiles

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  10. Endoplasmic reticulum stress activates transglutaminase 2 leading to protein aggregation.

    Science.gov (United States)

    Lee, Jin-Haeng; Jeong, Jaeho; Jeong, Eui Man; Cho, Sung-Yup; Kang, Jeong Wook; Lim, Jisun; Heo, Jinbeom; Kang, Hyunsook; Kim, In-Gyu; Shin, Dong-Myung

    2014-04-01

    Aberrant activation of transglutaminase 2 (TGase2) contributes to a variety of protein conformational disorders such as neurodegenerative diseases and age-related cataracts. The accumulation of improperly folded proteins in the endoplasmic reticulum (ER) triggers the unfolded protein response (UPR), which promotes either repair or degradation of the damaged proteins. Inadequate UPR results in protein aggregation that may contribute to the development of age-related degenerative diseases. TGase2 is a calcium-dependent enzyme that irreversibly modifies proteins by forming cross-linked protein aggregates. Intracellular TGase2 is activated by oxidative stress which generates large quantities of unfolded proteins. However, the relationship between TGase2 activity and UPR has not yet been established. In the present study, we demonstrated that ER stress activated TGase2 in various cell types. TGase2 activation was dependent on the ER stress-induced increase in the intracellular calcium ion concentration but not on the TGase2 protein expression level. Enzyme substrate analysis revealed that TGase2-mediated protein modification promoted protein aggregation concurrently with decreasing water solubility. Moreover, treatment with KCC009, a TGase2 inhibitor, abrogated ER stress-induced TGase2 activation and subsequent protein aggregation. However, TGase2 activation had no effect on ER stress-induced cell death. These results demonstrate that the accumulation of misfolded proteins activates TGase2, which further accelerates the formation of protein aggregates. Therefore, we suggest that inhibition of TGase2 may be a novel strategy by which to prevent the protein aggregation in age-related degenerative diseases.

  11. Specific antidotes against direct oral anticoagulants: A comprehensive review of clinical trials data.

    Science.gov (United States)

    Tummala, Ramyashree; Kavtaradze, Ana; Gupta, Anjan; Ghosh, Raktim Kumar

    2016-07-01

    The Vitamin K antagonist warfarin was the only oral anticoagulant available for decades for the treatment of thrombosis and prevention of thromboembolism until Direct Oral Anticoagulants (DOACs); a group of new oral anticoagulants got approved in the last few years. Direct thrombin inhibitor: dabigatran and factor Xa inhibitors: apixaban, rivaroxaban, and edoxaban directly inhibit the coagulation cascade. DOACs have many advantages over warfarin. However, the biggest drawback of DOACs has been the lack of specific antidotes to reverse the anticoagulant effect in emergency situations. Activated charcoal, hemodialysis, and activated Prothrombin Complex Concentrate (PCC) were amongst the nonspecific agents used in a DOAC associated bleeding but with limited success. Idarucizumab, the first novel antidote against direct thrombin inhibitor dabigatran was approved by US FDA in October 2015. It comprehensively reversed dabigatran-induced anticoagulation in a phase I study. A phase III trial on Idarucizumab also complete reversal of anticoagulant effect of dabigatran. Andexanet alfa (PRT064445), a specific reversal agent against factor Xa inhibitors, showed a complete reversal of anticoagulant activity of apixaban and rivaroxaban within minutes after administration without adverse effects in two recently completed parallel phase III trials ANNEXA-A and ANNEXA-R respectively. It is currently being studied in ANNEXA-4, a phase IV study. Aripazine (PER-977), the third reversal agent, has shown promising activity against dabigatran, apixaban, rivaroxaban, as well as subcutaneous fondaparinux and LMWH. This review article summarizes pharmacological characteristics of these novel antidotes, coagulation's tests affected, available clinical and preclinical data, and the need for phase III and IV studies. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Antioxidant activity of black bean (Phaseolus vulgaris L. protein hydrolysates

    Directory of Open Access Journals (Sweden)

    Jarine Amaral do EVANGELHO

    2016-01-01

    Full Text Available Abstract The objective of this work was to study the effect of enzymatic hydrolysis of black bean protein concentrate using different enzymes. Bean proteins were extracted and hydrolyzed over a period of 120 min using the enzymes pepsin or alcalase. The protein hydrolysates’ molecular weight was assayed by electrophoresis and the antioxidant activity was evaluated by the capturing methods of free radicals ABTS●+ and DPPH. Electrophoretic results showed that the bands above 50 kDa disappeared, when the beans protein was subjected to hydrolysis with pepsin. The bean protein hydrolysate obtained by hydrolysis with alcalase enzyme, showed higher antioxidant activity for inhibition of the radical ABTS●+. However, the hydrolysates obtained by hydrolysis with pepsin had higher antioxidant activity for inhibition of the radical DPPH. The use of pepsin and alcalase enzymes, under the same reaction time, produced black bean protein hydrolysates with different molecular weight profiles and superior antioxidant activity than the native bean protein.

  13. APOLLO I: Anticoagulation control in atrial fibrillation.

    Science.gov (United States)

    Pinho-Costa, Luís; Moreira, Sónia; Azevedo, Cristiana; Azevedo, Pedro; Castro, Elisabete; Sousa, Hélder; Melo, Miguel

    2015-05-01

    Anticoagulation control as assessed by time in therapeutic range (TTR) correlates positively with the safety and efficacy of thromboprophylaxis in atrial fibrillation. We set out to assess TTR in our unit and to investigate determinants of better control. This was a case series study of atrial fibrillation patients anticoagulated with warfarin or acenocoumarol at the Family Health Unit of Fânzeres. Sociodemographic and clinical data were collected and TTR was calculated by the Rosendaal method, based on international normalized ratio tests performed in external laboratories in the preceding six months. SPSS 21.0 was used for the statistical analysis, with descriptive statistics, Spearman's correlation, and the Mann-Whitney U and Kruskal-Wallis tests. Of the 106 eligible patients, 70% participated in the study. Median TTR was 65.3% (P25=48.3%, P75=86.8%). We found a positive association between this variable and duration of atrial fibrillation (ρ=0.477, p0.05). Median TTR in our unit is similar to that in southern European countries and close to the good control threshold (70%) proposed by the European Society of Cardiology. The duration of atrial fibrillation and of anticoagulation explains only a small part of the measure's variability. Other determinants of anticoagulation control must be investigated in future studies and comparative studies should be carried out in family health units monitoring anticoagulation on the premises. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  14. Mini G protein probes for active G protein-coupled receptors (GPCRs) in live cells.

    Science.gov (United States)

    Wan, Qingwen; Okashah, Najeah; Inoue, Asuka; Nehmé, Rony; Carpenter, Byron; Tate, Christopher G; Lambert, Nevin A

    2018-03-09

    G protein-coupled receptors (GPCRs) are key signaling proteins that regulate nearly every aspect of cell function. Studies of GPCRs have benefitted greatly from the development of molecular tools to monitor receptor activation and downstream signaling. Here we show that mini G proteins are robust probes that can be used in a variety of assay formats to report GPCR activity in living cells. Mini G (mG) proteins are engineered GTPase domains of Gα subunits that were developed for structural studies of active state GPCRs. Confocal imaging revealed that mG proteins fused to fluorescent proteins were located diffusely in the cytoplasm, and translocated to sites of receptor activation at the cell surface and at intracellular organelles. Bioluminescence resonance energy transfer (BRET) assays with mG proteins fused to either a fluorescent protein or luciferase reported agonist, superagonist and inverse agonist activities. Variants of mG proteins (mGs, mGsi, mGsq and mG12) corresponding to the four families of Gα subunits displayed appropriate coupling to their cognate GPCRs, allowing quantitative profiling of subtype-specific coupling to individual receptors. BRET between luciferase-mG fusion proteins and fluorescent markers indicated the presence of active GPCRs at the plasma membrane, Golgi apparatus and endosomes. Complementation assays with fragments of NanoLuc luciferase fused to GPCRs and mG proteins reported constitutive receptor activity and agonist-induced activation with up to 20-fold increases in luminescence. We conclude that mG proteins are versatile tools for studying GPCR activation and coupling specificity in cells, and should be useful for discovering and characterizing G protein subtype-biased ligands. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Does current oral antiplatelet agent or subtherapeutic anticoagulation use have an effect on tissue-plasminogen-activator-mediated recanalization rate in patients with acute ischemic stroke?

    Science.gov (United States)

    Ibrahim, Mohamed M; Sebastian, Joseph; Hussain, Muhammad; Al-Hussain, Fawaz; Uchino, Ken; Molina, Carlos; Khan, Khurshid; Demchuk, Andrew M; Alexandrov, Andrei V; Saqqur, Maher

    2010-01-01

    Our goal is to assess if current antiplatelet (AP) use has an effect on recanalization rate and outcome in acute stroke patients. We conducted a retrospective analysis of acute stroke patients who received intravenous (IV) recombinant tissue plasminogen activator (rt-PA) and had transcranial Doppler examination within 3 h of symptom onset. The TCD findings were interpreted using the Thrombolysis in Brain Ischemia flow grading system as persistent arterial occlusion, reocclusion or complete recanalization. Complete recanalization was defined as established Thrombolysis in Brain Ischemia 4 or 5 within 2 h of IV rt-PA. The patients were divided based on their current use of AP agents. Comparisons were made between the different groups based on recanalziation rate, reocclusion and good long-term outcome (mRS ≤ 2) using χ(2) test. Multiple regression analysis was used to identify AP use as a predictor for recanalization and outcome including symptomatic intracranial hemorrhage after controlling for age, baseline NIHSS score, time to treatment, previous vascular event, hypertension and diabetes mellitus. Two hundred and eighty-four patients were included; 154 (54%) males, 130 (46%) females, with a mean age of 69.5 ± 13 years. The median baseline NIHSS score was 16 ± 5. The median time to TCD examination was 131 ± 38 min from symptom onset. The median time to IV rt-PA was 140 ± 34 min. One hundred eighty patients were not on AP prior to their stroke, 76 were on aspirin, 15 were on clopidogrel, 2 were on aspirin-dipyridamole combination, 2 were on both aspirin and clopidogrel, and 9 patients on subtherapeutic coumadin. In patients who were naïve to AP, 68/178 (38.2%) had complete recanalization, whereas in the AP group, 25/91 (28%) had complete recanalization. Patients on aspirin alone had a lower recanalization rate (16/72) as compared to those not on AP (22 vs. 39%) (p = 0.017), while those on clopidogrel had higher rates of complete recanalization (9/19, 60

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

    Science.gov (United States)

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

    2011-01-01

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

  17. Phospholipid transfer protein activity and incident type 2 diabetes mellitus

    NARCIS (Netherlands)

    Abbasi, Ali; Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.

    2015-01-01

    Background: The plasma activity of phospholipid transfer protein (PLTP), which has multifaceted functions in lipoprotein metabolism and in inflammatory responses, is elevated in insulin resistant conditions. We determined the association of plasma PLTP activity with incident type 2 diabetes mellitus

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

    Science.gov (United States)

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

    2015-07-01

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

  19. Citrate Anticoagulation during Continuous Renal Replacement Therapy.

    Science.gov (United States)

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

    2017-01-01

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

  20. Oxygen plasma modified P(3HB-4HB) used as anticoagulant materials

    Science.gov (United States)

    Zhan, Jiezhao; Tian, Xiaojun; Zhu, Yongjun; Wang, Lin; Ren, Li

    2013-09-01

    In this article, we report the modification of P(3HB-4HB) film with oxygen plasma. The results showed that both the chemical components and topography of the P(3HB-4HB) film changed after oxygen plasma modification. In addition, the decrease of contact angle and the increase of the surface oxygen content were observed. The results of BSA adsorption onto those films studied by QCM-D showed that the plasma treatment could improve the protein-resistant activity of the film. After 10-minute plasma treatment, the BSA-resistant activity of the film improved 27% in PBS buffer solution and 57.5% in aqueous solution. Platelet adhesion test showed that the platelet-resistant activity of the film improved 68.6%, 82.3%, 96.8% after treated for 2, 5 and 10 min, respectively. Also, the cck8 assay of L929 cells showed that there was no cytotoxicity for the sample treated with oxygen plasma. This film has the potential to be used as anticoagulant materials, which required high protein-resistant activity.

  1. Anticoagulant Effect of Sugammadex: Just an In Vitro Artifact.

    Science.gov (United States)

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

    2016-06-01

    Sugammadex prolongs activated partial thromboplastin time (aPTT) and prothrombin time (PT) suggestive of anticoagulant effects. To pinpoint its presumed anticoagulant site of action, the authors assessed Sugammadex's impact on a panel of coagulation assays. Sugammadex, Rocuronium, Sugammadex and Rocuronium combined, or saline were added to blood samples from healthy volunteers and analyzed using plasmatic (i.e., aPTT, thrombin time, and fibrinogen concentration) (n = 8 each), PT (quick), activities of plasmatic coagulation factors, and whole blood (extrinsically and intrinsically activated thromboelastometry) assays (n = 18 each). Furthermore, dose-dependent effects of Sugammadex were also assessed (n = 18 each) in diluted Russel viper venom time (DRVVT) assays with low (DRVVT1) and high (DRVVT2) phospholipid concentrations and in a highly phospholipid-sensitive aPTT assay. Sugammadex increased PT (+9.1%; P IX, XI, and XII decreased (-7%, P = 0.009; -7.8%, P < 0.0001; -6.9%, P < 0.0001; and -4.3%, P = 0.011, respectively). Sugammadex dose-dependently prolonged both DRVVT1 and the highly phospholipid-sensitive aPTT assays, but additional phospholipids in the DRVVT2 assay almost abolished these prolongations. Thrombin time, a thromboelastometric thrombin generation assay, clot firmness, clot lysis, fibrinogen concentration, and activities of other coagulation factors were unaltered. Rocuronium, Sugammadex and Rocuronium combined, and saline exerted no effects. Sugammadex significantly affects various coagulation assays, but this is explainable by an apparent phospholipid-binding effect, suggesting that Sugammadex`s anticoagulant effects are likely an in vitro artifact.

  2. 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.

  3. Current State of Anticoagulants to Treat Deep Venous Thrombosis

    OpenAIRE

    Vo, Timothy; Vazquez, Sara; Rondina, Matthew T.

    2014-01-01

    Anticoagulation remains the cornerstone of treatment in patients with deep vein thrombosis (DVT). While parenteral anticoagulants and oral vitamin K antagonists (e.g. warfarin) have been used for many decades, the recent development of novel oral anticoagulants have provided clinicians with an expanding set of therapeutic options for DVT. This review summarizes the pharmacology and clinical trial results of these new oral anticoagulants. Several practical considerations to the use of these or...

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

    Science.gov (United States)

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

    2016-03-01

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

  5. Anticoagulant effects of an antidiabetic drug on monocytes in vitro.

    Science.gov (United States)

    Henriksson, C E; Hellum, M; Haug, K B F; Aass, H C; Joø, G B; Øvstebø, R; Trøseid, A M; Klingenberg, O; Kierulf, P

    2011-11-01

    Monocyte- and microparticle (MP)-associated tissue factor (TF) is upregulated in diabetes. Lipopolysaccharide (LPS) induces expression of TF and alternatively spliced TF (asTF) and increases MP release from monocytes. Using LPS-stimulated TF-bearing human monocytes, we examined whether glibenclamide, a sulfonylurea used to treat diabetes type 2, might possess anticoagulant properties. We studied the effects of glibenclamide on cell- and supernatant-associated procoagulant activity (Factor Xa-generating assay and clot formation assay), on expression of TF and asTF (flow cytometry, RT-qPCR, western blot) and on cell viability and MP release (flow cytometry). Glibenclamide dose-dependently decreased procoagulant activity of cells and supernatants. The reduction in cellular procoagulant activity coincided with reduced expression of TF and asTF in cells, whereas cell viability remained almost unchanged. The glibenclamide-induced reduction in procoagulant activity of supernatants appeared to be associated with a decreased number of released MPs. Reduction of monocyte- and supernatant-associated procoagulant activity by glibenclamide is associated with decreased expression of TF and asTF and possibly with a reduced MP number. Our data indicate that glibenclamide reduces the prothrombotic state in LPS-stimulated monocytes in vitro. Glibenclamide might therefore also have an anticoagulant effect in vivo, but this needs to be further evaluated. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Outcomes during anticoagulation in patients with symptomatic vs. incidental splanchnic vein thrombosis.

    Science.gov (United States)

    Tufano, Antonella; Ageno, Walter; Di Micco, Pierpaolo; Niglio, Alferio; Rosa, Vladimir; Ballaz, Aitor; Braester, Andrei; Rubio, Carmen Mª; Isern, Virginia; Imbalzano, Egidio; Monreal, Manuel

    2018-02-27

    Current guidelines recommend the use of anticoagulant therapy in patients with symptomatic splanchnic vein thrombosis (SVT) and suggest no routine anticoagulation in those with incidental SVT. We used the RIETE (Registro Informatizado Enfermedad Trombo Embólica) registry to assess the rate and severity of symptomatic venous thromboembolism (VTE) recurrences and major bleeding events appearing during the course of anticoagulation in patients with symptomatic or incidental SVT. In March 2017, 521 patients with SVT were recruited. Of them, 212 (41%) presented with symptomatic SVT and 309 had incidental SVT. Most (93%) patients received anticoagulant therapy (median, 147 days). During the course of anticoagulation, 20 patients developed symptomatic VTE recurrences (none died) and 26 had major bleeding (fatal bleeding, 5). On multivariable analysis, patients with incidental SVT had a non-significantly higher risk for symptomatic VTE recurrences (adjusted hazard ratio [HR]: 2.04; 95%CI: 0.71-5.88) and a similar risk for major bleeding (HR: 1.12; 95%CI: 0.47-2.63) than those with symptomatic SVT. Active cancer was associated with at increased risk for VTE recurrences (HR: 3.06; 95%CI: 1.14-8.17) and anaemia (HR: 4.11; 95%CI: 1.45-11.6) or abnormal prothrombin time (HR: 4.10; 95%CI: 1.68-10.1) were associated with at increased risk for major bleeding. The rates of recurrent SVT and major bleeding were similar between patients with incidental or symptomatic SVT. Because the severity of bleeding complications during anticoagulation may outweigh the severity of VTE recurrences in both groups, further studies should identify those SVT patients who benefit from anticoagulant therapy. Copyright © 2018 Elsevier Ltd. All rights reserved.

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

    African Journals Online (AJOL)

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

  8. Anticoagulant Medicine: Potential for Drug-Food Interactions

    Science.gov (United States)

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

  9. Tribomechanical micronization and activation of whey protein ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Physical and structural properties of proteins sometimes can be altered by mechanical means. ... enters the equipment through the central part of the rotor system by ventilator air streaming. The particles are ... devised equipment, striking hammers and ventilation paddles placed on rotating discs pro- duce turbulent ...

  10. Activation of fluorescent protein chromophores by encapsulation.

    Science.gov (United States)

    Baldridge, Anthony; Samanta, Shampa R; Jayaraj, Nithyanandhan; Ramamurthy, V; Tolbert, Laren M

    2010-02-10

    Chromophores related to fluorescent proteins, when sequestered into the "octaacid" capsule, recover their fluorescence. The fluorescence recovery is related to the inhibition of torsional motions within the cavity, implicating the single-bond torsion as an important contributor to internal conversion within this important class of chromophores.

  11. Complement Activation by Ceramide Transporter Proteins

    NARCIS (Netherlands)

    Bode, G.H.; Losen, M.; Buurman, W.A.; Veerhuis, R.; Molenaar, P.C.; Steinbusch, H.W.M.; De Baets, M.H.; Daha, MR; Martinez-Martinez, P.

    2014-01-01

    C1q is the initiator of the classical complement pathway and, as such, is essential for efficient opsonization and clearance of pathogens, altered self-structures, and apoptotic cells. The ceramide transporter protein (CERT) and its longer splicing isoform CERTL are known to interact with

  12. Antimicrobial activity and molecular mechanism of the CRES protein.

    Directory of Open Access Journals (Sweden)

    Li Wang

    Full Text Available Cystatin-related epididymal spermatogenic (CRES protein, a member of the cystatin superfamily of cysteine protease inhibitors (also known as CST8, exhibits highly specific, age-dependent expression in mouse testis and epididymis. The CRES protein possesses four highly conserved cysteine residues which govern the overall conformation of the cystatins through the formation of two disulfide bonds. Previous studies have revealed that other cystatin family members, such as cystatin 3 and cystatin 11, show antibacterial activity in vitro. This prompted us to investigate the potential antimicrobial activity of the CRES protein. Colony forming assays and spectrophotometry were used to investigate the effects of recombinant CRES protein on Escherichia coli (E. coli and Ureaplasma urealyticum (Uu, respectively, in vitro. After incubation of E. coli with CRES recombinant protein fused with glutathione-S-transferase (GST, a substantial decrease in colony forming units was observed, and the effect was dose and time dependent. Furthermore, it took longer for Uu to grow to plateau stage when incubated with GST-CRES recombinant protein compared with the control GST. The antibacterial and Anti-Uu activities were not impaired when the cysteine residues of CRES protein were mutated, indicating that the antimicrobial effect was not dependent on its disulfide bonds. Functional analysis of three CRES polypeptides showed that the N-terminal 30 residues (N30 had no antimicrobial activity while N60 showed similar activity as full-length CRES protein. These results suggest that the active center of CRES protein resides between amino acid residues 31 and 60 of its N-terminus. Mechanistically, E. coli membrane permeabilization was increased in a dose-dependent manner, and macromolecular synthesis was inhibited on treatment with GST-CRES. Together, our data on the antimicrobial activities of CRES protein suggest that it is a novel and innate antimicrobial protein which

  13. 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,

  14. Periprocedural reversal and bridging of anticoagulant treatment

    NARCIS (Netherlands)

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

    2011-01-01

    Anticoagulants are effective agents in reducing the risk of thromboembolism but the most important adverse effect of these agents is the occurrence of bleeding. Bleeding complications may occur spontaneously but the risk of bleeding is particularly increased in case of trauma or around invasive

  15. Anticoagulation duration in heterozygous factor V Leiden: a decision analysis.

    Science.gov (United States)

    Donovan, Anna K; Smith, Kenneth J; Ragni, Margaret V

    2013-01-01

    Current anticoagulation guidelines suggest that optimal anticoagulation duration for unprovoked venous thromboembolism is determined by an individual risk assessment, balancing risks of anticoagulation bleeding with venous thromboembolism recurrence. Among individuals heterozygous for the factor V Leiden mutation, while venous thromboembolism recurrence risk is greater, the risk for bleeding is recognized to be lower, suggesting longer duration anticoagulation could be considered. The objective of this study was to compare standard vs. lifelong anticoagulation in 20-year-old factor V Leiden heterozygotes with unprovoked venous thromboembolism. A Markov state-transition model was used, incorporating risks of major, minor, and fatal anticoagulation bleeding, bleeding and thromboembolism morbidity and mortality, and quality of life utilities. Model parameter values favoring lifelong anticoagulation in factor V Leiden heterozygotes were determined in sensitivity analyses. Outcomes were in quality-adjusted life years, discounted at 3% per year. In general population groups with odds ratios for venous thromboembolism recurrence and anticoagulation bleeding of 1.0, a short-term anticoagulation strategy gained 0.09 quality-adjusted life years more than a lifelong anticoagulation strategy. By contrast, in factor V Leiden heterozygotes, lifetime anticoagulation was favored if their relative risk of venous thromboembolism was greater than 1.07 or their relative risk for bleeding was less than 0.91. Results were relatively insensitive to individual variation in other parameter values. Lifelong anticoagulation may benefit individuals heterozygous for factor V Leiden and previous idiopathic venous thromboembolism. Studies assessing bleeding risk with anticoagulation in factor V Leiden heterozygotes and the costs of indefinite anticoagulation are needed to determine if lifelong anticoagulation is the optimal strategy. © 2013 Elsevier Ltd. All rights reserved.

  16. Anticoagulant rodenticides and wildlife: Concluding remarks

    Science.gov (United States)

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

    2018-01-01

    Rodents are known to affect human society globally in various adverse ways, resulting in a widespread demand for their continuous control. Anticoagulant rodenticides (ARs) have been, and currently remain, the cornerstone of rodent control throughout the world. Although alternative control methods exist, they are generally less effective. ARs work by affecting vitamin K metabolism, thereby preventing the activation of blood clotting factors and eventual coagulopathy. Since ARs are non-selective, their undoubted benefits for rodent control have to be balanced against the environmental risks that these compounds pose. Although they have been used for decades, pharmacokinetic and toxicokinetic data are mainly available for laboratory mammals and have concentrated on acute effects. Limited information is available on chronic exposure scenarios and for wildlife species. Important gaps exist in our understanding of the large inter- and intra-species differences in sensitivity to ARs, especially for non-target species, and in our knowledge about the occurrence and importance of sub-lethal effects in wildlife. It is clear that mere presence of AR residues in the body tissues may not indicate the occurrence of effects, although unequivocal assessment of effects under field conditions is difficult. Ante-mortem symptoms, like lethargy, subdued behaviour and unresponsiveness are generally not very specific as is true for more generic post-mortem observations (e.g. pallor of the mucous membranes or occurrence of haemorrhages). It is only by combining ante or post-mortem data with information on exposure that effects in the field may be confirmed. We do know however that a wide variety of non-target species are directly exposed to ARs. Secondary exposure in predators is also widespread although there is limited information on whether this exposure causes actual effects. Exposure is driven by ecological factors and is context specific with respect to spatial habitat configuration

  17. Factors associated with availability of anticoagulation reversal agents in rural and community emergency departments.

    Science.gov (United States)

    Faine, Brett A; Amendola, Julie; Homan, Jordan; Ahmed, Azeemuddin; Mohr, Nicholas

    2018-01-15

    Results of a study of anticoagulation reversal agent availability in rural and community hospital emergency departments (EDs) are reported. A cross-sectional telephone survey was conducted to test the hypothesis that anticoagulation reversal agents are not commonly stocked in low-volume EDs. In phase 1 of the study, a physician, pharmacist, or nurse manager at a sample of EDs in 1 state was surveyed to characterize anticoagulation reversal agent availability and the presence or absence of reversal protocols; in phase 2, follow-up qualitative interviews were conducted with hospital pharmacists selected by purposive sampling to identify barriers to availability. Among the 103 EDs represented in the survey, 87 (84%) stocked fresh frozen plasma, 14 (14%) stocked 4-factor prothrombin complex concentrate (4F-PCC), and 2 (2%) stocked activated 4F-PCC. Forty-one EDs (40%) had a warfarin reversal protocol, but only 2 (2%) EDs had a protocol for direct oral anticoagulant reversal. ED volume and neurology coverage were significantly associated with reversal agent availability ( p = 0.014) and warfarin protocol availability ( p availability, and concerns about shelf life. An investigation of rural and community hospitals in 1 state revealed that the institutions rarely have specialized anticoagulation reversal drugs available. Cost and infrequency of utilization were 2 commonly cited reasons for reversal agent nonavailability. Copyright © 2018 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  18. Controlled Activation of Protein Rotational Dynamics Using Smart Hydrogel Tethering

    Energy Technology Data Exchange (ETDEWEB)

    Beech, Brenda M.; Xiong, Yijia; Boschek, Curt B.; Baird, Cheryl L.; Bigelow, Diana J.; Mcateer, Kathleen; Squier, Thomas C.

    2014-09-05

    Stimulus-responsive hydrogel materials that stabilize and control protein dynamics have the potential to enable a range of applications to take advantage of the inherent specificity and catalytic efficiencies of proteins. Here we describe the modular construction of a hydrogel using an engineered calmodulin (CaM) within a polyethylene glycol (PEG) matrix that involves the reversible tethering of proteins through an engineered CaM-binding sequence. For these measurements, maltose binding protein (MBP) was isotopically labeled with [13C] and [15N], permitting dynamic structural measurements using TROSY-HSQC NMR spectroscopy. Upon initial formation of hydrogels protein dynamics are suppressed, with concomitant increases in protein stability. Relaxation of the hydrogel matrix following transient heating results in the activation of protein dynamics and restoration of substrate-induced large-amplitude domain motions necessary for substrate binding.

  19. Mitogen-activated protein kinase signaling in plants

    DEFF Research Database (Denmark)

    Rodriguez, Maria Cristina Suarez; Petersen, Morten; Mundy, John

    2010-01-01

    Eukaryotic mitogen-activated protein kinase (MAPK) cascades have evolved to transduce environmental and developmental signals into adaptive and programmed responses. MAPK cascades relay and amplify signals via three types of reversibly phosphorylated kinases leading to the phosphorylation of subs...... the Arabidopsis thaliana MAPKs MPK3, 4, and 6 and MAP2Ks MKK1, 2, 4, and 5. Future work needs to focus on identifying substrates of MAPKs, and on understanding how specificity is achieved among MAPK signaling pathways.......Eukaryotic mitogen-activated protein kinase (MAPK) cascades have evolved to transduce environmental and developmental signals into adaptive and programmed responses. MAPK cascades relay and amplify signals via three types of reversibly phosphorylated kinases leading to the phosphorylation...... of substrate proteins, whose altered activities mediate a wide array of responses, including changes in gene expression. Cascades may share kinase components, but their signaling specificity is maintained by spaciotemporal constraints and dynamic protein-protein interactions and by mechanisms that include...

  20. Mitogen-activated protein kinases mediate Mycobacterium ...

    Indian Academy of Sciences (India)

    2012-01-19

    Jan 19, 2012 ... heat shock, UV irradiation and also to inflammatory cytokines. ERK is mainly activated by growth factors and phorbol esters. (Lewis et al. 1998; Cowan and Storey 2003). The activation of some MAPK family members by. M. tuberculosis H37Rv in human monocytes has already been reported. Song et al.

  1. The place of new oral anticoagulants in travel medicine.

    Science.gov (United States)

    Ringwald, Juergen; Grauer, Martin; Eckstein, Reinhold; Jelinek, Tomas

    2014-01-01

    New oral anticoagulants are increasingly used instead of vitamin K antagonists or low molecular weight heparins. Hence, more individuals treated with new oral anticoagulants will seek travel medicine advice. Travel medicine experts should therefore become familiar with new oral anticoagulants and with their impact and role in travel medicine. This review summarizes pharmacological characteristics and approved indications of dabigatran, rivaroxaban and apixaban, and highlights their relevance for travellers on permanent oral anticoagulation and for the prophylaxis of travellers' thrombosis. Compared to vitamin K antagonists, the new oral anticoagulants have many advantages: they do not have interactions with food, they have lower potential for drug-drug interactions and do not require regularly performed laboratory tests. The oral administration, obviating the need to carry needles and syringes during travel may give the new oral anticoagulants a further advantage over low molecular weight heparins. Clinical experience with the new oral anticoagulants, however, is still rather limited and there is concern regarding the clinical management of patients treated with new oral anticoagulants who suffer from severe bleeding or who need urgent invasive procedures. Overall, it remains an individual decision based on a risk/benefit analysis as to whether or not patients on long-term treatment with vitamin K antagonists should be switched to new oral anticoagulants for intended travel. Further caution is also indicated so that the availability of orally administered new anticoagulants should not lead to undifferentiated and unjustified prescription of anticoagulants for the prophylaxis of traveller's thrombosis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Antioxidant activities of protein hydrolysates obtained from the housefly larvae.

    Science.gov (United States)

    Zhang, Huan; Wang, Pan; Zhang, Ai-Jun; Li, Xuan; Zhang, Ji-Hong; Qin, Qi-Lian; Wu, Yi-Jun

    2016-09-01

    The housefly is an important resource insect and the housefly larvae are ideal source of food additives. The housefly larvae protein hydrolysates were obtained by enzymatic hydrolysis by alcalase and neutral proteinase. Their antioxidant activities were investigated, including the superoxide and hydroxyl radicalscavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, reducing power and metal chelating activity. The antioxidant activities of both hydrolysates increased with their increasing concentrations. The alcalase hydrolysate (AH) showed higher scavenging activities against hydroxyl radical and superoxide anion radical at low concentrations and higher metal-chelating activity than the neutral proteinase hydrolysate (NPH). The NPH exhibited higher scavenging activity against DPPH free radical and higher reducing power than the AH. Both hydrolysates showed more than 50% superoxide anion radical-scavenging activity at 10 μg/mL. These results indicate that both housefly larvae protein hydrolysates display high antioxidant activities and they could serve as potential natural antioxidant food additives.

  3. Modeling the SHG activities of diverse protein crystals

    International Nuclear Information System (INIS)

    Haupert, Levi M.; DeWalt, Emma L.; Simpson, Garth J.

    2012-01-01

    The origins of the diversity in the SHG signal from protein crystals are investigated and potential protein-crystal coverage by SHG microscopy is assessed. A symmetry-additive ab initio model for second-harmonic generation (SHG) activity of protein crystals was applied to assess the likely protein-crystal coverage of SHG microscopy. Calculations were performed for 250 proteins in nine point-group symmetries: a total of 2250 crystals. The model suggests that the crystal symmetry and the limit of detection of the instrument are expected to be the strongest predictors of coverage of the factors considered, which also included secondary-structural content and protein size. Much of the diversity in SHG activity is expected to arise primarily from the variability in the intrinsic protein response as well as the orientation within the crystal lattice. Two or more orders-of-magnitude variation in intensity are expected even within protein crystals of the same symmetry. SHG measurements of tetragonal lysozyme crystals confirmed detection, from which a protein coverage of ∼84% was estimated based on the proportion of proteins calculated to produce SHG responses greater than that of tetragonal lysozyme. Good agreement was observed between the measured and calculated ratios of the SHG intensity from lysozyme in tetragonal and monoclinic lattices

  4. A specific antidote for reversal of anticoagulation by direct and indirect inhibitors of coagulation factor Xa.

    Science.gov (United States)

    Lu, Genmin; DeGuzman, Francis R; Hollenbach, Stanley J; Karbarz, Mark J; Abe, Keith; Lee, Gail; Luan, Peng; Hutchaleelaha, Athiwat; Inagaki, Mayuko; Conley, Pamela B; Phillips, David R; Sinha, Uma

    2013-04-01

    Inhibitors of coagulation factor Xa (fXa) have emerged as a new class of antithrombotics but lack effective antidotes for patients experiencing serious bleeding. We designed and expressed a modified form of fXa as an antidote for fXa inhibitors. This recombinant protein (r-Antidote, PRT064445) is catalytically inactive and lacks the membrane-binding γ-carboxyglutamic acid domain of native fXa but retains the ability of native fXa to bind direct fXa inhibitors as well as low molecular weight heparin-activated antithrombin III (ATIII). r-Antidote dose-dependently reversed the inhibition of fXa by direct fXa inhibitors and corrected the prolongation of ex vivo clotting times by such inhibitors. In rabbits treated with the direct fXa inhibitor rivaroxaban, r-Antidote restored hemostasis in a liver laceration model. The effect of r-Antidote was mediated by reducing plasma anti-fXa activity and the non-protein bound fraction of the fXa inhibitor in plasma. In rats, r-Antidote administration dose-dependently and completely corrected increases in blood loss resulting from ATIII-dependent anticoagulation by enoxaparin or fondaparinux. r-Antidote has the potential to be used as a universal antidote for a broad range of fXa inhibitors.

  5. Antiproliferative activity of protein extracts from the black clam ...

    African Journals Online (AJOL)

    Hiessu

    2016-02-24

    Feb 24, 2016 ... 2F2 showed IC50 values of 67.46 µg/ml on HeLa cells. These results suggest that protein extracts from. C. fluctifraga might be potential anticancer agents. Key words: Protein extracts, clam, antiproliferative activity, breast cancer, cervical cancer. INTRODUCTION. Cancer is a worldwide health issue; it is not ...

  6. The contact activation proteins: a structure/function overview

    NARCIS (Netherlands)

    Meijers, J. C.; McMullen, B. A.; Bouma, B. N.

    1992-01-01

    In recent years, extensive knowledge has been obtained on the structure/function relationships of blood coagulation proteins. In this overview, we present recent developments on the structure/function relationships of the contact activation proteins: factor XII, high molecular weight kininogen,

  7. Plasma Renin Activity in Children with Protein Energy Malnutrition ...

    African Journals Online (AJOL)

    renin activity was significantly increased in children with kwashiorkor; and also that the activity was significantly higher in the patients who subsequently died in hospital, than in those who survived. Increased renin activity probably contributes to the retention of water characteris- tic of protein energy malnutrition. 5. Afr. Med.

  8. Direct oral anticoagulants in the management of venous thromboembolism--evidence from major clinical trials.

    Science.gov (United States)

    Holy, Erik W; Beer, Jürg H

    2014-04-01

    For decades the antithrombotic management of venous thromboembolism (VTE) was limited to parenteral heparin formulations and oral vitamin K antagonists. Even though both classes of anticoagulants are effective, they have several limitations, including a narrow therapeutic window and the need to monitor anticoagulant activity. Direct oral anticoagulants (DOACs) that specifically target factor IIa or Xa have emerged. Recent data suggest that they are at least as effective and as safe as conventional therapy and have practical advantages, such as fixed dose regimen and no need for laboratory monitoring. Hence, they represent a major step forward in the acute treatment and long-term prevention of VTE. In this review, we outline the use of DOACs in the management of VTE and provide an overview of recently published major trials. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Adenosine monophosphate-activated protein kinase from the mud ...

    Indian Academy of Sciences (India)

    2016-12-01

    Hochachka and Somero 2002). Therefore, some animals have to initiate anaerobic metabolism to meet part of energy needs (Costanzo et al. 2004; Colson-Proch et al. 2009). Adenosine monophosphate-activated protein kinase.

  10. Stress-induced activation of protein kinase CK2 by direct interaction with p38 mitogen-activated protein kinase

    DEFF Research Database (Denmark)

    Sayed, M; Kim, S O; Salh, B S

    2000-01-01

    Protein kinase CK2 has been implicated in the regulation of a wide range of proteins that are important in cell proliferation and differentiation. Here we demonstrate that the stress signaling agents anisomycin, arsenite, and tumor necrosis factor-alpha stimulate the specific enzyme activity of CK2...... to be an allosteric mechanism. Furthermore, we demonstrate that anisomycin- and tumor necrosis factor-alpha-induced phosphorylation of p53 at Ser-392, which is important for the transcriptional activity of this growth suppressor protein, requires p38 MAP kinase and CK2 activities....

  11. Gamma irradiation effect on soy protein modification, protein - phenolic interaction and antioxidant activity in soybean

    International Nuclear Information System (INIS)

    Kumari, Sweta; Dahuja, Anil; Vinutha, T.; Singh, Bhupinder

    2014-01-01

    Soy protein is one of the most important sources of protein to feed the world population in the future. Consumption of soybean quality protein and their texture is dependent on the protein modification. In the present study, four soybean genotypes PL5039 (black), EC 472143 (black), Pusa 9814 (yellow) and SL525 (yellow), differing in their seed coat colour were gamma irradiated at 0.5,1.0, 2.0 and 5.0 kGy and the extent of protein modification and parameters affecting it viz. free phenolics, bound phenolics, lip oxygenase and antioxidant activity were analysed. Modifications of soybean proteins were investigated by chemical analysis and electrophoresis. The irradiation dose of 1.0 kGy showed decreased turbidity, protein oxidation, surface hydrophobicity but increased solubility and sulfhydryl and disulfide contents in all the genotypes. Further, SDS PAGE profile of treated soybean seeds revealed remarkable difference in electrophoretic bands as compared to the untreated seeds. Lipoxygense activity in all the genotypes decreased with increased exposure of gamma irradiation, which produced peroxide products that changes the structural characteristics of soy protein. Free phenolics, bound phenolics and total antioxidant activity measured in terms of FRAP in all the genotypes increased significantly at a dose of 2.0 kGy and it declined at a dose of 5.0 kGy. Antioxidant potential measured in terms of 1,1-diphenyl-2- picrylhydrazyl (DPPH) scavenging activity showed an increasing trend with dose, indicating that radiation processing as a method of food preservation has a positive nutritional implication. Hence, it is suggested that, mild gamma irradiation upto 2.0 kGy may reduce the protein oxidation, enhance the antioxidant activity and improve the soybean protein quality compared to higher dose 5.0 kGy, which reduced the protein quality. (author)

  12. Protein expression, characterization and activity comparisons of wild type and mutant DUSP5 proteins

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, Jaladhi; Gastonguay, Adam J.; Talipov, Marat R.; Vakeel, Padmanabhan; Span, Elise A.; Kalous, Kelsey S.; Kutty, Raman G.; Jensen, Davin R.; Pokkuluri, Phani Raj; Sem, Daniel S.; Rathore, Rajendra; Ramchandran, Ramani

    2014-12-01

    Background: The mitogen-activated protein kinases (MAPKs) pathway is critical for cellular signaling, and proteins such as phosphatases that regulate this pathway are important for normal tissue development. Based on our previous work on dual specificity phosphatase-5 (DUSP5), and its role in embryonic vascular development and disease, we hypothesized that mutations in DUSP5 will affect its function. Results: In this study, we tested this hypothesis by generating full-length glutathione-S-transferase-tagged DUSP5 and serine 147 proline mutant (S147P) proteins from bacteria. Light scattering analysis, circular dichroism, enzymatic assays and molecular modeling approaches have been performed to extensively characterize the protein form and function. We demonstrate that both proteins are active and, interestingly, the S147P protein is hypoactive as compared to the DUSP5 WT protein in two distinct biochemical substrate assays. Furthermore, due to the novel positioning of the S147P mutation, we utilize computational modeling to reconstruct full-length DUSP5 and S147P to predict a possible mechanism for the reduced activity of S147P. Conclusion: Taken together, this is the first evidence of the generation and characterization of an active, full-length, mutant DUSP5 protein which will facilitate future structure-function and drug development-based studies.

  13. Measurement of GPCR-G protein activity in living cells.

    Science.gov (United States)

    Ratnayake, Kasun; Kankanamge, Dinesh; Senarath, Kanishka; Siripurapu, Praneeth; Weis, Nicole; Tennakoon, Mithila; Payton, John L; Karunarathne, Ajith

    2017-01-01

    G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors in eukaryotic genomes. They control a variety of cellular and physiological processes such as hormone secretion and heart rate, and therefore are associated with a majority of pathological conditions including cancer and heart diseases. Currently established assays to measure ligand-induced activation of GPCRs and G proteins possess limitations such as being time consuming, indirect, and expensive. Thus, an efficient method to measure GPCR-G protein activation is required to identify novel pharmacological modulators to control them and gain insights about molecular underpinnings of the associated pathways. Activation of GPCRs induces dissociation of G protein heterotrimers to form GαGTP and free Gβγ. Free Gβγ subunits have been shown to translocate reversibly from the plasma membrane to internal membranes. Gβγ translocation therefore represents the GPCR-G protein activation, and thus, imaging of this process can be used to quantify the kinetics and magnitude of the pathway activation-deactivation in real time in living cells. The objective of this chapter is to elaborate the protocols of (i) generation and optimization of the required sensor constructs; (ii) development of cell culture, transient transfection, imaging, and optogenetic procedures; (iii) imaging and data analysis methods; and (iv) stable cell line generation, pertaining to this assay to measure GPCR-G protein activation. © 2017 Elsevier Inc. All rights reserved.

  14. Anticoagulation in adults with congenital heart disease

    DEFF Research Database (Denmark)

    Jensen, A S; Idorn, L; Nørager, B

    2015-01-01

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

  15. Frontiers of anticoagulation therapy for atrial fibrillation.

    Science.gov (United States)

    Yamashita, Takeshi

    2011-07-01

    In the management of atrial fibrillation (AF), stroke prevention has been proved to play a pivotal role in addition to therapy for concomitant diseases. And, hitherto, anticoagulation by warfarin has been the only effective choice that is known to decrease the stroke rate with ∼70% risk reduction. Although the evidence has been rigid, there are many barriers not to make warfarin therapy pervasive. However, the principle of "KISS (keep it short and simple)" seems to alter our situations. Changing the complex pharmacology with warfarin into the simple pharmacology with new anticoagulants would lead us to a new paradigm, where the old book is now rewritten by a new language. Copyright © 2011 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  16. Anticoagulation in acute ischemic stroke: A systematic search

    Directory of Open Access Journals (Sweden)

    Nayara L. Froio

    Full Text Available Summary Introduction: Stroke is one of the most important diseases worldwide. Several clinical scenarios demand full dose of anticoagulants primary to stroke etiology or to the treatment of comorbidity. However, controversy exists over many issues regarding anticoagulation treatment in stroke such as time for initiation, efficacy according to stroke etiology, the ideal dose of anticoagulants, and whether novel anticoagulants should be used. Method: Computerized search for clinical trials and randomized controlled clinical trials was done to the present date at Medline, Scielo, Embase, PsychInfo, and Cochrane Library using MeSH terms and the keywords stroke, ischemic stroke, anticoagulation, anticoagulants, heparin, low-molecular-weight heparin, warfarin, dabigatran, rivaroxaban, apixaban. The PRISMA statement was used to evaluate clinical trials. Results: Fourteen clinical trials were selected based on inclusion criteria. No evidence was found supporting the early use of heparin, heparinoids or low-molecular-weight heparin (LMWH early after stroke. No consistent evidence for the use of warfarin and the newer oral anticoagulants were found. Argatroban was the only anticoagulant with significant positive results early after large-artery ischemic stroke. Conclusion: The ideal time for initiating anticoagulation remains undefined, requiring further investigation. Early anticoagulation for ischemic stroke is not recommended, with few exceptions, such as that of argatroban.

  17. New oral anticoagulants--a review.

    Science.gov (United States)

    Ghanima, Waleed; Atar, Dan; Sandset, Per Morten

    2013-10-01

    Dabigatran, rivaroxaban and apixaban are three new oral anticoagulants that have recently been approved in Norway. The aim of this article is to provide an overview of the mechanisms of action, the most important indications and practical advice on the use of these drugs. The review is based on published phase 3 studies, a literature search in PubMed and the authors' clinical experience. Indications for use of the new anticoagulants include thromboprophylaxis after total hip and knee replacement surgery (all three), prevention of stroke and systemic embolism in non-valvular atrial fibrillation (all three), treatment of acute venous thrombosis and secondary prophylaxis after venous thrombosis (currently only rivaroxaban). For the aforementioned indications, these drugs have proven to be non-inferior to standard established anticoagulation therapy. For atrial fibrillation, all three drugs have also shown a lower incidence of intracranial bleeding compared with standard treatment. It is important to limit the use of these drugs to approved indications, to select patients who show good compliance, to rule out contraindications and to identify drug interactions. Monitoring of coagulation is not required, but patients should be followed up regularly to detect conditions that may lead to changes in the expected efficacy or safety.

  18. Antiplatelet and Anticoagulant Drugs in Interventional Radiology

    International Nuclear Information System (INIS)

    Altenburg, Alexander; Haage, Patrick

    2012-01-01

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

  19. Depletion of WRN protein causes RACK1 to activate several protein kinase C isoforms

    DEFF Research Database (Denmark)

    Massip, L; Garand, C; Labbé, A

    2010-01-01

    Werner's syndrome (WS) is a rare autosomal disease characterized by the premature onset of several age-associated pathologies. The protein defective in patients with WS (WRN) is a helicase/exonuclease involved in DNA repair, replication, transcription and telomere maintenance. In this study, we...... show that a knock down of the WRN protein in normal human fibroblasts induces phosphorylation and activation of several protein kinase C (PKC) enzymes. Using a tandem affinity purification strategy, we found that WRN physically and functionally interacts with receptor for activated C-kinase 1 (RACK1......), a highly conserved anchoring protein involved in various biological processes, such as cell growth and proliferation. RACK1 binds strongly to the RQC domain of WRN and weakly to its acidic repeat region. Purified RACK1 has no impact on the helicase activity of WRN, but selectively inhibits WRN exonuclease...

  20. New constitutive latex osmotin-like proteins lacking antifungal activity.

    Science.gov (United States)

    Freitas, Cleverson D T; Silva, Maria Z R; Bruno-Moreno, Frederico; Monteiro-Moreira, Ana C O; Moreira, Renato A; Ramos, Márcio V

    2015-11-01

    Proteins that share similar primary sequences to the protein originally described in salt-stressed tobacco cells have been named osmotins. So far, only two osmotin-like proteins were purified and characterized of latex fluids. Osmotin from Carica papaya latex is an inducible protein lacking antifungal activity, whereas the Calotropis procera latex osmotin is a constitutive antifungal protein. To get additional insights into this subject, we investigated osmotins in latex fluids of five species. Two potential osmotin-like proteins in Cryptostegia grandiflora and Plumeria rubra latex were detected by immunological cross-reactivity with polyclonal antibodies produced against the C. procera latex osmotin (CpOsm) by ELISA, Dot Blot and Western Blot assays. Osmotin-like proteins were not detected in the latex of Thevetia peruviana, Himatanthus drasticus and healthy Carica papaya fruits. Later, the two new osmotin-like proteins were purified through immunoaffinity chromatography with anti-CpOsm immobilized antibodies. Worth noting the chromatographic efficiency allowed for the purification of the osmotin-like protein belonging to H. drasticus latex, which was not detectable by immunoassays. The identification of the purified proteins was confirmed after MS/MS analyses of their tryptic digests. It is concluded that the constitutive osmotin-like proteins reported here share structural similarities to CpOsm. However, unlike CpOsm, they did not exhibit antifungal activity against Fusarium solani and Colletotrichum gloeosporioides. These results suggest that osmotins of different latex sources may be involved in distinct physiological or defensive events. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. Phospholipid transfer protein activity and incident type 2 diabetes mellitus

    NARCIS (Netherlands)

    Abbasi, Ali; Dallinga-Thie, Geesje M.; Dullaart, Robin P. F.

    2015-01-01

    The plasma activity of phospholipid transfer protein (PLTP), which has multifaceted functions in lipoprotein metabolism and in inflammatory responses, is elevated in insulin resistant conditions. We determined the association of plasma PLTP activity with incident type 2 diabetes mellitus (T2DM).

  2. Energy transfer at the active sites of heme proteins

    International Nuclear Information System (INIS)

    Dlott, D.D.; Hill, J.R.

    1995-01-01

    Experiments using a picosecond pump-probe apparatus at the Picosecond Free-electron Laser Center at Stanford University, were performed to investigate the relaxation of carbon monoxide bound to the active sites of heme proteins. The significance of these experiments is two-fold: (1) they provide detailed information about molecular dynamics occurring at the active sites of proteins; and (2) they provide insight into the nature of vibrational relaxation processes in condensed matter. Molecular engineering is used to construct various molecular systems which are studied with the FEL. We have studied native proteins, mainly myoglobin obtained from different species, mutant proteins produced by genetic engineering using recombinant DNA techniques, and a variety of model systems which mimic the structures of the active sites of native proteins, which are produced using molecular synthesis. Use of these different systems permits us to investigate how specific molecular structural changes affect dynamical processes occurring at the active sites. This research provides insight into the problems of how different species needs are fulfilled by heme proteins which have greatly different functionality, which is induced by rather small structural changes

  3. Activated entomopathogenic nematode infective juveniles release lethal venom proteins.

    Directory of Open Access Journals (Sweden)

    Dihong Lu

    2017-04-01

    Full Text Available Entomopathogenic nematodes (EPNs are unique parasites due to their symbiosis with entomopathogenic bacteria and their ability to kill insect hosts quickly after infection. It is widely believed that EPNs rely on their bacterial partners for killing hosts. Here we disproved this theory by demonstrating that the in vitro activated infective juveniles (IJs of Steinernema carpocapsae (a well-studied EPN species release venom proteins that are lethal to several insects including Drosophila melanogaster. We confirmed that the in vitro activation is a good approximation of the in vivo process by comparing the transcriptomes of individual in vitro and in vivo activated IJs. We further analyzed the transcriptomes of non-activated and activated IJs and revealed a dramatic shift in gene expression during IJ activation. We also analyzed the venom proteome using mass spectrometry. Among the 472 venom proteins, proteases and protease inhibitors are especially abundant, and toxin-related proteins such as Shk domain-containing proteins and fatty acid- and retinol-binding proteins are also detected, which are potential candidates for suppressing the host immune system. Many of the venom proteins have conserved orthologs in vertebrate-parasitic nematodes and are differentially expressed during IJ activation, suggesting conserved functions in nematode parasitism. In summary, our findings strongly support a new model that S. carpocapsae and likely other Steinernema EPNs have a more active role in contributing to the pathogenicity of the nematode-bacterium complex than simply relying on their symbiotic bacteria. Furthermore, we propose that EPNs are a good model system for investigating vertebrate- and human-parasitic nematodes, especially regarding the function of excretory/secretory products.

  4. Activation of repair and checkpoints by double-strand breaks of DNA. Activational cascade of protein phosphorylation

    International Nuclear Information System (INIS)

    Koltovaya, N.A.

    2007-01-01

    Molecular mechanisms of double-strand breaks repair and checkpoints include phosphorylations of repair and checkpoint-proteins by protein kinases. Chemical modification of proteins has different consequences including activation, changing of affinity to proteins and localization

  5. Forkhead box protein A2 (FOXA2 protein stability and activity are regulated by sumoylation.

    Directory of Open Access Journals (Sweden)

    Narasimhaswamy S Belaguli

    Full Text Available The forkhead box protein A2 (FOXA2 is an important regulator of glucose and lipid metabolism and organismal energy balance. Little is known about how FOXA2 protein expression and activity are regulated by post-translational modifications. We have identified that FOXA2 is post-translationally modified by covalent attachment of a small ubiquitin related modifier-1 (SUMO-1 and mapped the sumoylation site to the amino acid lysine 6 (K6. Preventing sumoylation by mutating the SUMO acceptor K6 to arginine resulted in downregulation of FOXA2 protein but not RNA expression in INS-1E insulinoma cells. K6R mutation also downregulated FOXA2 protein levels in HepG2 hepatocellular carcinoma cells, HCT116 colon cancer cells and LNCaP and DU145 prostate cancer cells. Further, interfering with FOXA2 sumoylation through siRNA mediated knockdown of UBC9, an essential SUMO E2 conjugase, resulted in downregulation of FOXA2 protein levels. Stability of sumoylation deficient FOXA2K6R mutant protein was restored when SUMO-1 was fused in-frame. FOXA2 sumoylation and FOXA2 protein levels were increased by PIAS1 SUMO ligase but not a SUMO ligase activity deficient PIAS1 mutant. Although expressed at lower levels, sumoylation deficient FOXA2K6R mutant protein was detectable in the nucleus indicating that FOXA2 nuclear localization is independent of sumoylation. Sumoylation increased the transcriptional activity of FOXA2 on Pdx-1 area I enhancer. Together, our results show that sumoylation regulates FOXA2 protein expression and activity.

  6. Forkhead box protein A2 (FOXA2) protein stability and activity are regulated by sumoylation.

    Science.gov (United States)

    Belaguli, Narasimhaswamy S; Zhang, Mao; Brunicardi, F Charles; Berger, David H

    2012-01-01

    The forkhead box protein A2 (FOXA2) is an important regulator of glucose and lipid metabolism and organismal energy balance. Little is known about how FOXA2 protein expression and activity are regulated by post-translational modifications. We have identified that FOXA2 is post-translationally modified by covalent attachment of a small ubiquitin related modifier-1 (SUMO-1) and mapped the sumoylation site to the amino acid lysine 6 (K6). Preventing sumoylation by mutating the SUMO acceptor K6 to arginine resulted in downregulation of FOXA2 protein but not RNA expression in INS-1E insulinoma cells. K6R mutation also downregulated FOXA2 protein levels in HepG2 hepatocellular carcinoma cells, HCT116 colon cancer cells and LNCaP and DU145 prostate cancer cells. Further, interfering with FOXA2 sumoylation through siRNA mediated knockdown of UBC9, an essential SUMO E2 conjugase, resulted in downregulation of FOXA2 protein levels. Stability of sumoylation deficient FOXA2K6R mutant protein was restored when SUMO-1 was fused in-frame. FOXA2 sumoylation and FOXA2 protein levels were increased by PIAS1 SUMO ligase but not a SUMO ligase activity deficient PIAS1 mutant. Although expressed at lower levels, sumoylation deficient FOXA2K6R mutant protein was detectable in the nucleus indicating that FOXA2 nuclear localization is independent of sumoylation. Sumoylation increased the transcriptional activity of FOXA2 on Pdx-1 area I enhancer. Together, our results show that sumoylation regulates FOXA2 protein expression and activity.

  7. In vitro study of proteins surface activity by tritium probe

    International Nuclear Information System (INIS)

    Chernysheva, M.G.; Badun, G.A.

    2010-01-01

    A new technique for in vitro studies of biomacromolecules interactions, their adsorption at aqueous/organic liquid interfaces and distribution in the bulk of liquid/liquid systems was developed. The method includes (1) tritium labeling of biomolecules by tritium thermal activation method and (2) scintillation phase step with organic phase, which can be concerned as a model of cellular membrane. Two globular proteins lysozyme and human serum albumin tested. We have determined the conditions of tritium labeling when labeled by-products can be easy separated by means of dialysis and size-exclusion chromatography. Scintillation phase experiments were conducted for three types of organic liquids. Thus, the influences of the nature of organic phase on proteins adsorption and its distribution in the bulk of aqueous/organic liquid system were determined. It was found that proteins possess high surface activity at aqueous/organic liquid interface. Furthermore, values of hydrophobicity of globular proteins were found by the experiment. (author)

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

    Science.gov (United States)

    Cui, Ning; Luo, Hesheng

    2014-05-27

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

  9. [Activity of polygalacturonase-inhibiting protein of banana fruit tissues].

    Science.gov (United States)

    Bulantseva, E A; Thang, Nguen; Buza, N L; Krinitsyna, A A; Protsenko, M A

    2005-01-01

    The activity of polygalacturonase and the protein inhibiting this enzyme, which affected polygalacturonases of phytopathogenic fungi Verticillium dahliae and Gloesporium musarium, were detected in banana (Musa acumthata L.) fruit of cultivars Cavendish and Korolevskii. The polygalacturonase from banana fruit was inhibited by the preparations of the protein inhibitor not only from bananas but also from potato (Solanum tuberosum L.) tubers and pepper (Capsicum annuum L.) fruit.

  10. Beyond the zone: protein needs of active individuals.

    Science.gov (United States)

    Lemon, P W

    2000-10-01

    There has been debate among athletes and nutritionists regarding dietary protein needs for centuries. Although contrary to traditional belief, recent scientific information collected on physically active individuals tends to indicate that regular exercise increases daily protein requirements; however, the precise details remain to be worked out. Based on laboratory measures, daily protein requirements are increased by perhaps as much as 100% vs. recommendations for sedentary individuals (1.6-1.8 vs. 0.8 g/kg). Yet even these intakes are much less than those reported by most athletes. This may mean that actual requirements are below what is needed to optimize athletic performance, and so the debate continues. Numerous interacting factors including energy intake, carbohydrate availability, exercise intensity, duration and type, dietary protein quality, training history, gender, age, timing of nutrient intake and the like make this topic extremely complex. Many questions remain to be resolved. At the present time, substantial data indicate that the current recommended protein intake should be adjusted upward for those who are physically active, especially in populations whose needs are elevated for other reasons, e.g., growing individuals, dieters, vegetarians, individuals with muscle disease-induced weakness and the elderly. For these latter groups, specific supplementation may be appropriate, but for most North Americans who consume a varied diet, including complete protein foods (meat, eggs, fish and dairy products), and sufficient energy the increased protein needs induced by a regular exercise program can be met in one's diet.

  11. 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

  12. Antioxidant Activity of Coconut (Cocos nucifera L.) Protein Fractions.

    Science.gov (United States)

    Li, Yan; Zheng, Yajun; Zhang, Yufeng; Xu, Jianguo; Gao, Gang

    2018-03-20

    Coconut cake is an abundant and good potential edible protein source. However, until now it has not been extensively used in the food industry. To promote its usage, the characterization, nutrition value and antioxidant activity of coconut cake protein fractions (albumin, globulin, prolamine, glutelin-1 and glutelin-2) were studied. Results revealed that all the albumin, globulin, glutelin-1 and glutelin-2 fractions showed a high nutrition value. The prolamine, glutelin-1 and glutelin-2 all exhibited good radical scavenging activity and reducing power, and the globulin and prolamine showed high ion chelating ability (89.14-80.38%). Moreover, all the fractions except glutelin-2 could effectively protect DNA against oxidative damage. Several peptides containing five to eight amino acids with antioxidant activity were also identified by LC-MS/MS from the globulin and glutelin-2 fractions. The results demonstrated that the coconut cake protein fractions have potential usages in functional foods.

  13. Emerging Roles of AMP-Activated Protein Kinase

    DEFF Research Database (Denmark)

    Fritzen, Andreas Mæchel

    The cellular energy sensor AMP-activated protein kinase (AMPK) is activated, when the energy balance of the cell decreases. AMPK has been proposed to regulate multiple metabolic processes. However, much of the evidence for these general effects of AMPK relies on investigations in cell systems...... exercise appears to inhibit pyruvate dehydrogenase (PDH) activity by an immediate up-regulation of pyruvate dehydrogenase kinase 4 (PDK4) protein content. Consequently, this may inhibit glucose oxidation and thereby generate conditions for increased FA oxidation and glycogen resynthesis in skeletal muscle...... be of importance for prioritising energy dissipation, inhibition of lipid storage pathways and regulation of mitochondrial and metabolic proteins, but this needs further investigations. In addition, we provide evidence that AMPK is regulating autophagic signalling in skeletal muscle. Thus, in skeletal muscle AMPK...

  14. Citrate anticoagulation in the ICU: the Leeds experience.

    Science.gov (United States)

    Trumper, Charlotte

    2016-09-08

    Continuous renal replacement therapy (CRRT) is widely used in the management of critically ill patients with acute kidney injury. It requires effective anticoagulation of the extracorporeal blood circuit. Although heparin is the most commonly prescribed anticoagulant, there are issues associated with heparin, and there has been increasing interest in regional citrate anticoagulation as an alternative. In 2013, The Leeds Teaching Hospitals NHS Trust switched from heparin to citrate anticoagulant for CRRT in intensive care units (ICUs) across the Trust. This article examines the reasons for the switch, the implementation of citrate and the impact of this quality-improvement project in terms of patient outcome data and feedback from the ICU nursing team.

  15. The mythology of anticoagulation therapy interruption for dental surgery.

    Science.gov (United States)

    Wahl, Michael J

    2018-01-01

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

  16. Organizers and activators: Cytosolic Nox proteins impacting on vascular function.

    Science.gov (United States)

    Schröder, Katrin; Weissmann, Norbert; Brandes, Ralf P

    2017-08-01

    NADPH oxidases of the Nox family are important enzymatic sources of reactive oxygen species (ROS) in the cardiovascular system. Of the 7 members of the Nox family, at least three depend for their activation on specific cytosolic proteins. These are p47phox and its homologue NoxO1 and p67phox and its homologue NoxA1. Also the Rho-GTPase Rac is important but as this protein has many additional functions, it will not be covered here. The Nox1 enzyme is preferentially activated by the combination of NoxO1 with NoxA1, whereas Nox2 gains highest activity with p47phox together with p67phox. As p47phox, different to NoxO1 contains an auto inhibitory region it has to be phosphorylated prior to complex formation. In the cardio-vascular system, all cytosolic Nox proteins are expressed but the evidence for their contribution to ROS production is not well established. Most data have been collected for p47phox, whereas NoxA1 has basically not yet been studied. In this article the specific aspects of cytosolic Nox proteins in the cardiovascular system with respect to Nox activation, their expression and their importance will be reviewed. Finally, it will be discussed whether cytosolic Nox proteins are suitable pharmacological targets to tamper with vascular ROS production. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  17. Outer Membrane Protein 25 of Brucella Activates Mitogen-Activated Protein Kinase Signal Pathway in Human Trophoblast Cells

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2017-12-01

    Full Text Available Outer membrane protein 25 (OMP25, a virulence factor from Brucella, plays an important role in maintaining the structural stability of Brucella. Mitogen-activated protein kinase (MAPK signal pathway widely exists in eukaryotic cells. In this study, human trophoblast cell line HPT-8 and BALB/c mice were infected with Brucella abortus 2308 strain (S2308 and 2308ΔOmp25 mutant strain. The expression of cytokines and activation of MAPK signal pathway were detected. We found that the expressions of tumor necrosis factor-α, interleukin-1, and interleukin-10 (IL-10 were increased in HPT-8 cells infected with S2308 and 2308ΔOmp25 mutant. S2308 also activated p38 phosphorylation protein, extracellular-regulated protein kinases (ERK, and Jun-N-terminal kinase (JNK from MAPK signal pathway. 2308ΔOmp25 could not activate p38, ERK, and JNK branches. Immunohistochemistry experiments showed that S2308 was able to activate phosphorylation of p38 and ERK in BABL/c mice. However, 2308ΔOmp25 could weakly activate phosphorylation of p38 and ERK. These results suggest that Omp25 played an important role in the process of Brucella activation of the MAPK signal pathway.

  18. Chaperone activity of human small heat shock protein-GST fusion proteins.

    Science.gov (United States)

    Arbach, Hannah; Butler, Caley; McMenimen, Kathryn A

    2017-07-01

    Small heat shock proteins (sHsps) are a ubiquitous part of the machinery that maintains cellular protein homeostasis by acting as molecular chaperones. sHsps bind to and prevent the aggregation of partially folded substrate proteins in an ATP-independent manner. sHsps are dynamic, forming an ensemble of structures from dimers to large oligomers through concentration-dependent equilibrium dissociation. Based on structural studies and mutagenesis experiments, it is proposed that the dimer is the smallest active chaperone unit, while larger oligomers may act as storage depots for sHsps or play additional roles in chaperone function. The complexity and dynamic nature of their structural organization has made elucidation of their chaperone function challenging. HspB1 and HspB5 are two canonical human sHsps that vary in sequence and are expressed in a wide variety of tissues. In order to determine the role of the dimer in chaperone activity, glutathione-S-transferase (GST) was genetically linked as a fusion protein to the N-terminus regions of both HspB1 and HspB5 (also known as Hsp27 and αB-crystallin, respectively) proteins in order to constrain oligomer formation of HspB1 and HspB5, by using GST, since it readily forms a dimeric structure. We monitored the chaperone activity of these fusion proteins, which suggest they primarily form dimers and monomers and function as active molecular chaperones. Furthermore, the two different fusion proteins exhibit different chaperone activity for two model substrate proteins, citrate synthase (CS) and malate dehydrogenase (MDH). GST-HspB1 prevents more aggregation of MDH compared to GST-HspB5 and wild type HspB1. However, when CS is the substrate, both GST-HspB1 and GST-HspB5 are equally effective chaperones. Furthermore, wild type proteins do not display equal activity toward the substrates, suggesting that each sHsp exhibits different substrate specificity. Thus, substrate specificity, as described here for full-length GST

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. Detergent activation of the binding protein in the folate radioassay

    International Nuclear Information System (INIS)

    Hansen, S.I.; Holm, J.; Lyngbye, J.

    1982-01-01

    A minor cow's whey protein associated with β-lactoglobulin is used as binding protein in the competitive radioassay for serum and erythrocyte folate. Seeking to optimize the assay, we tested the performance of binder solutions of increasing purity. The folate binding protein was isolated from cow's whey by means of CM-Sepharose CL-6B cation-exchange chromatography, and further purified on a methotrexate-AH-Sepharose 4B affinity matrix. In contrast to β-lactoglobulin, the purified protein did not bind folate unless the detergents cetyltrimethylammonium (10 mmol/Ll) or Triton X-100 (1 g/L) were present. Such detergent activation was not needed in the presence of serum. There seems to be a striking analogy between these phenomena and the well-known reactivation of certain purified membrane-derived enzymes by surfactants

  2. Hepatic protein synthetic activity in vivo after ethanol administration

    International Nuclear Information System (INIS)

    Donohue, T.M. Jr.; Sorrell, M.F.; Tuma, D.J.

    1987-01-01

    Hepatic protein synthetic activity in vivo was measured by the incorporation of [ 3 H]puromycin into elongating nascent polypeptides of rat liver to form peptidyl-[ 3 H]puromycin. Our initial experiments showed that saturating doses of [ 3 H]puromycin were achieved at 3-6 mumol/100 g body weight, and that maximum labeling of nascent polypeptides was obtained 30 min after injection of the labeled precursor. Labeled puromycin was found to be suitable for measuring changes in the status of protein synthesis, since the formation of the peptidyl-[ 3 H]puromycin was decreased in fasted animals and was increased in rats pretreated with L-tryptophan. [ 3 H]Puromycin incorporation into polypeptides was then measured after acute ethanol administration as well as after prolonged consumption of ethanol which was administered as part of a liquid diet for 31 days. Acute alcohol treatment caused no significant change in [ 3 H]puromycin incorporation into liver polypeptides. In rats exposed to chronic ethanol feeding, peptidyl-[3H]puromycin formation, when expressed per mg of protein, was slightly lower compared to pair-fed controls, but was unchanged compared to chow-fed animals. When the data were expressed per mg of DNA or per 100 g body wt, no differences in protein synthetic activity were observed among the three groups. These findings indicate that neither acute nor chronic alcohol administration significantly affects protein synthetic activity in rat liver. They further suggest that accumulation of protein in the liver, usually seen after prolonged ethanol consumption, is apparently not reflected by an alteration of hepatic protein synthesis

  3. Heparin but not citrate anticoagulation of blood preserves platelet function for prolonged periods.

    Science.gov (United States)

    Truss, N J; Armstrong, P C J; Liverani, E; Vojnovic, I; Warner, T D

    2009-11-01

    Current guidelines state that platelet aggregation studies should be conducted within 4 h of venepuncture because of the decline in sensitivity to platelet agonists. This constrains studies of platelet activity in clinical situations where samples need to be transported or there are unavoidable delays prior to assessment. The aim of the present study was to compare systematically the responses of platelets stored in the presence of either citrate or heparin, the two most widely used anti-coagulants, using a range of standard techniques. Blood was taken from healthy volunteers and either assessed immediately or stored at ambient temperature (18-25 degrees C) for 24 h. Platelet reactivity to a range of agonists was determined by a combination of 96-well plate techniques; light transmission aggregometry, thrombi adhesion, ATP and ADP release, and TxA(2) release; by whole blood aggregometry; and by PFA-100. Testing using 96-well plate techniques allowed for the simultaneous measurement of responses to multiple concentrations of multiple agonists. The responses of platelets from blood anti-coagulated with heparin were predominantly preserved in all assays after 24 h storage, whereas, responses of platelets stored in blood anti-coagulated with citrate were greatly diminished. Consequently, anti-coagulation with heparin, but not citrate, preserves platelet responses for up to 24 h as determined by a range of techniques.

  4. Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID

    KAUST Repository

    Zourelidou, Melina

    2014-06-19

    The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the-in many cells-asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant.

  5. GTPase-activating protein oligophrenin 1 is a new partner of multifunctional adapter protein intersectin 1

    Directory of Open Access Journals (Sweden)

    Gasman S.

    2012-09-01

    Full Text Available Intersectin 1 (ITSN1 is a multifunctional adaptor protein which is involved in endocytosis, exocytosis and cellular signaling and it is also associated with such pathologies as Down syndrome and Alzheimer’s disease. The aim of this study was to identify new ITSN1 protein partners which are implicated in membrane trafficking. Methods. In silico analysis by Scansite online resource had identified a GTPase activating protein oligophrenin 1 (OPHN1 as a potential partner of ITSN1 SH3A domain. GST pull-down and immunoprecipitation were used to prove complex formation between ITSN1 and OPHN1. Subcellular protein localization was determined by immunofluorescence and confocal microscopy. Results. We have shown that brain-specific and ubiquitously expressed SH3A domain isoforms of ITSN1 interact with OPHN1. ITSN1 and OPHN1 form complexes in both resting and stimulated to exocytosis PC12 cell line. Conclusions. GTPase activating protein OPHN1 and adaptor protein ITSN1 interact in PC12 cell line independently of exocytosis stimulation.

  6. Increased Prevalence of Activated Protein C Resistance During ...

    African Journals Online (AJOL)

    centrifuged this time at 3000 gravitational under identical conditions. The resulting platelet poor plasma (PPP) was either tested immediately or stored in aliquots at in a -80oC freezer until testing. Protein C activity was measured using a clot-based assay.

  7. Fibroblast activation protein (FAP) as a novel metabolic target

    DEFF Research Database (Denmark)

    Sánchez-Garrido, Miguel Angel; Habegger, Kirk M; Clemmensen, Christoffer

    2016-01-01

    OBJECTIVE: Fibroblast activation protein (FAP) is a serine protease belonging to a S9B prolyl oligopeptidase subfamily. This enzyme has been implicated in cancer development and recently reported to regulate degradation of FGF21, a potent metabolic hormone. Using a known FAP inhibitor, talabostat...

  8. VHH Activators and Inhibitors for Protein Kinase C Epsilon

    NARCIS (Netherlands)

    Summanen, M.M.I.

    2012-01-01

    Protein kinase C epsilon (PKCε), which is one of the novel PKC isozymes, is widely expressed throughout the body and has important roles in the function of the nervous, cardiovascular and immune systems. In order to better understand PKCε regulated pathways, isozyme specific activity modulators are

  9. Adenosine monophosphate-activated protein kinase from the mud ...

    Indian Academy of Sciences (India)

    2016-12-01

    Dec 1, 2016 ... ... Journal of Genetics; Volume 95; Issue 4. Adenosine monophosphate-activated protein kinase from the mud crab, Scylla paramamosain: cDNA cloning and profiles under cold stress. CHENCUI HUANG KUN YU HUIYANG HUANG HAIHUI YE. RESEARCH ARTICLE Volume 95 Issue 4 December 2016 pp ...

  10. Adenosine monophosphate-activated protein kinase from the mud ...

    Indian Academy of Sciences (India)

    CHENCUI HUANG

    Adenosine monophosphate-activated protein kinase from the mud crab, Scylla paramamosain: cDNA cloning and profiles under cold stress. CHENCUI HUANG1, KUN YU1, HUIYANG HUANG1,2 and HAIHUI YE1,2∗. 1College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, People's Republic of China.

  11. Adenosine monophosphate-activated protein kinase from the mud ...

    Indian Academy of Sciences (India)

    2016-12-01

    Dec 1, 2016 ... to the understanding of the molecular mechanism of acclimation to cold hardiness in S. paramamosain. [Huang C., Yu K., Huang H. and Ye H. 2016 Adenosine monophosphate-activated protein kinase from the mud crab, Scylla paramamosain: cDNA cloning and profiles under cold stress. J. Genet.

  12. Activity-Based Protein Profiling of Rhomboid Proteases in Liposomes

    Czech Academy of Sciences Publication Activity Database

    Wolf, E. V.; Seybold, M.; Hadravová, Romana; Stříšovský, Kvido; Verhelst, S. H. L.

    2015-01-01

    Roč. 16, č. 11 (2015), s. 1616-1621 ISSN 1439-4227 R&D Projects: GA MŠk(CZ) LK11206; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : activity-based protein profiling * chemical probes * inhibitors * intramembrane proteases * liposomes Subject RIV: CE - Biochemistry Impact factor: 2.850, year: 2015

  13. The dopamine D2 receptor can directly recruit and activate GRK2 without G protein activation.

    Science.gov (United States)

    Pack, Thomas F; Orlen, Margo I; Ray, Caroline; Peterson, Sean M; Caron, Marc G

    2018-02-27

    The dopamine D2 receptor (D2R) is a G protein-coupled receptor (GPCR) that is critical for many central nervous system functions. The D2R carries out these functions by signaling through two transducers: G proteins and β-arrestins (βarrs). Selectively engaging either the G protein or βarr pathway may be a way to improve drugs targeting GPCRs. The current model of GPCR signal transduction posits a chain of events where G protein activation ultimately leads to βarr recruitment. GPCR kinases (GRKs), which are regulated by G proteins and whose kinase action facilitates βarr recruitment, bridge these pathways. Therefore βarr recruitment appears to be intimately tied to G protein activation via GRKs. Here, we sought to understand how GRK2 action at the D2R would be disrupted when G protein activation is eliminated and the effect of this on βarr recruitment. We used two recently developed biased D2R mutants that can preferentially interact either with G proteins or βarrs as well as a βarr-biased D2R ligand, UNC9994. With these functionally selective tools, we investigated the mechanism whereby the βarr-preferring D2R achieves βarr pathway activation in the complete absence of G protein activation. We describe how direct, G protein-independent recruitment of GRK2 drives interactions at the βarr-preferring D2R and also contributes to βarr recruitment at the WT D2R. Additionally, we found an additive interaction between the βarr-preferring D2R mutant and UNC9994. These results reveal that the D2R can directly recruit GRK2 without G protein activation and that this mechanism may have relevance to achieving βarr-biased signaling. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Structure and anticoagulant properties of sulfated glycosaminoglycans from primitive Chordates

    Directory of Open Access Journals (Sweden)

    MAURO S. G. PAVÃO

    2002-03-01

    Full Text Available Dermatan sulfates and heparin, similar to the mammalian glycosaminoglycans, but with differences in the degree and position of sulfation were previously isolated from the body of the ascidian Styela plicata and Ascidia nigra. These differences produce profound effects on their anticoagulant properties. S. plicata dermatan sulfate composed by 2-O-sulfatedalpha-L-iduronic acid and 4-O-sulfated N-acetyl-beta-D-galactosamine residues is a potent anticoagulant due to a high heparin cofactor II activity. Surprisingly, it has a lower potency to prevent thrombus formation on an experimental model and a lower bleeding effect in rats than the mammalian dermatan sulfate. In contrast, A. nigra dermatan sulfate, also enriched in 2-O-sulfated alpha-L-iduronic acid, but in this case sulfated at O-6 of the N-acetyl-beta-D-galactosamine units, has no in vitro or in vivo anticoagulant activity, does not prevent thrombus formation but shows a bleeding effect similar to the mammalian glycosaminoglycan. Ascidian heparin, composed by 2-O-sulfated alpha-L-iduronic acid, N- and 6-O-sulfated glucosamine (75% and alpha-L-iduronic acid, N- and 6-O-sulfated glucosamine (25% disaccharide units has an anticoagulant activity 10 times lower than the mammalian heparin, is about 20 times less potent in the inhibition of thrombin by antithrombin, but has the same heparin cofactor II activity as mammalian heparin.Dermatam sulfato e heparina semelhantes aos glicosaminoglicanos de mamíferos, mas apresentando diferenças no grau e posição de sulfatação foram previamente isolados do corpo das ascídias Styela plicata e Ascidia nigra. Estas diferenças produzem efeitos profundos nas suas propriedades anticoagulantes. O dermatam sulfato de S. plicata, composto por resíduos de ácido alfa-L-idurônico 2-O-sulfatados e N-acetilgalactosamina 4-O-sulfatados é um potente anticoagulante devido a sua alta atividade de cofator II da heparina. Surpreendentemente, este polímero possui uma

  15. Salt bridge integrates GPCR activation with protein trafficking.

    Science.gov (United States)

    Janovick, Jo Ann; Conn, P Michael

    2010-03-02

    G protein-coupled receptors (GPCRs) play central roles in almost all physiological functions; mutations in GPCRs are responsible for more than 30 disorders. There is a great deal of information about GPCR structure but little information that directly relates structure to protein trafficking or to activation. The gonadotropin releasing hormone receptor, because of its small size among GPCRs, is amenable to preparation of mutants and was used in this study to establish the relation among a salt bridge, protein trafficking, and receptor activation. This bridge, between residues E(90) [located in transmembrane segment (TM) 2] and K(121) (TM3), is associated with correct trafficking to the plasma membrane. Agonists, but not antagonists, interact with residue K(121), and destabilize the TM2-TM3 association of the receptor in the plasma membrane. The hGnRHR mutant E(90)K has a broken salt bridge, which also destabilizes the TM2-TM3 association and is typically retained in the endoplasmic reticulum. We show that this mutant, if rescued to the plasma membrane by either of two different means, has constitutive activity and shows modified ligand specificity, revealing a role for the salt bridge in receptor activation, ligand specificity, trafficking, and structure. The data indicate that destabilizing the TM2-TM3 relation for receptor activation, while requiring an intact salt bridge for correct trafficking, provides a mechanism that protects the cell from plasma membrane expression of constitutive activity.

  16. Cholesterol-Lowering Activity of Tartary Buckwheat Protein.

    Science.gov (United States)

    Zhang, Chengnan; Zhang, Rui; Li, Yuk Man; Liang, Ning; Zhao, Yimin; Zhu, Hanyue; He, Zouyan; Liu, Jianhui; Hao, Wangjun; Jiao, Rui; Ma, Ka Ying; Chen, Zhen-Yu

    2017-03-08

    Previous research has shown that Tartary buckwheat flour is capable of reducing plasma cholesterol. The present study was to examine the effect of rutin and Tartary buckwheat protein on plasma total cholesterol (TC) in hypercholesterolemia hamsters. In the first animal experiment, 40 male hamsters were divided into four groups fed either the control diet or one of the three experimental diets containing 8.2 mmol rutin, 8.2 mmol quercetin, or 2.5 g kg -1 cholestyramine, respectively. Results showed that only cholestyramine but not rutin and its aglycone quercetin decreased plasma TC, which suggested that rutin was not the active ingredient responsible for plasma TC-lowering activity of Tartary buckwheat flour. In the second animal experiment, 45 male hamsters were divided into five groups fed either the control diet or one of the four experimental diets containing 24% Tartary buckwheat protein, 24% rice protein, 24% wheat protein, or 5 g kg -1 cholestyramine, respectively. Tartary buckwheat protein reduced plasma TC more effectively than cholestyramine (45% versus 37%), while rice and wheat proteins only reduced plasma TC by 10-13%. Tartary buckwheat protein caused 108% increase in the fecal excretion of total neutral sterols and 263% increase in the fecal excretion of total acidic sterols. real-time polymerase chain reaction and Western blotting analyses showed that Tartary buckwheat protein affected the gene expression of intestinal Niemann-Pick C1-like protein 1 (NPC1L1), acyl CoA:cholesterol acyltransferase 2 (ACAT2), and ATP binding cassette transporters 5 and 8 (ABCG5/8) in a down trend, whereas it increased the gene expression of hepatic cholesterol-7α -hydroxylase (CYP7A1). It was concluded that Tartary buckwheat protein was at least one of the active ingredients in Tartary buckwheat flour to lower plasma TC, mainly mediated by enhancing the excretion of bile acids via up-regulation of hepatic CYP7A1 and also by inhibiting the absorption of dietary

  17. Acupuncture upregulates G protein coupled activity in SAMP8 mice.

    Science.gov (United States)

    Luo, Benhua; Zhao, Lan; Zhang, Xuezhu; Kan, Bohong; Liu, Yunhe; Jia, Yujie; Han, Jingxian; Yu, Jianchun

    2017-08-01

    Transmembrane and intracellular signal transduction of G protein is closely related to the pathophysiology of Alzheimer's disease (AD). To explore the effects of Sanjiao acupuncture on G protein signal transduction pathways in the pathogenesis of AD. 36 senescence-accelerated (SAM) prone 8 mice were divided into three groups that remained untreated (SAMP8, n=12) or received Sanjiao acupuncture (SAMP8+SA, n=12) or control acupuncture (SAMP8+CA, n=12). An additional control group of SAM resistant 1 mice was included (SAMR1 group, n=12). Morris water maze tests were used to investigate learning and memory abilities. Immunoprecipitation and Western blotting were used to study expression of G protein subunits and their activities in the cortex/hippocampus. Behavioural analysis showed that acupuncture attenuated the severe cognitive deficits observed in untreated/CA-treated SAMP8 mice. The findings of the G protein activation assays via immunoprecipitation and Western blots were that the physiologically coupled activation rate (PCAR) and maximal coupled activation rate (MCAR) of Gα s and Gα i were decreased in the cortex of SAMP8 vs SAMR1 mice. Sanjiao acupuncture induced an upregulation in the PCAR of Gα s and Gα i . In the hippocampus of untreated SAMP8 mice, the PCAR of Gα s and MCAR of both Gα s and Gα i declined, and Sanjiao acupuncture was associated with an upregulation in the MCAR of Gα s and Gα i . There were no significant differences in Gα s and Gα i expression between the groups. Sanjiao acupuncture attenuates cognitive deficits in a mouse model of AD via upregulation of G protein activity and stabilisation of the cellular signal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. In vitro antithrombotic activities of peanut protein hydrolysates.

    Science.gov (United States)

    Zhang, Shao Bing

    2016-07-01

    The antithrombotic activities of peanut protein hydrolysates were investigated using a microplates assay. When peanut proteins were hydrolyzed to a limited extent by various enzymes, their thrombin inhibitory abilities were significantly enhanced. However, the resultant hydrolysates showed significantly different activities even at the same degrees of hydrolysis. The hydrolysates generated by Alcalase 2.4L displayed the best antithrombotic activities and the hydrolysis process was further optimized by response surface methodology. The antithrombotic activities were increased to 86% based on a protein concentration of 50mg/ml under the optimal conditions: pH 8.5, enzyme concentration of 5000IU/g of peanut proteins, and 2h hydrolysis time at 50°C. The Alcalase 2.4L crude hydrolysates were then fractionated successively by preparative and semi-preparative reverse-phase high-performance liquid chromatography (RP-HPLC). The peptide fraction collected inhibited thrombin-catalyzed coagulation of fibrinogen completely at a concentration of 0.4mg/ml, with an antithrombotic activity close to that of heparin at quite a low concentration (0.2mg/ml). This peptide fraction was further analyzed by online reverse-phase ultra-performance liquid chromatography (RP-UPLC) coupled to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and three new peptides were identified as Ser-Trp-Ala-Gln-Leu, Gly-Asn-His-Glu-Ala-Gly-Glu and Cys-Phe-Asn-Glu-Tyr-Glu, respectively. This research provided an effective way to produce antithrombotic peptides from peanut proteins, and also helped to elucidate the structure-function relationships of peanut peptides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Reassessing the Potential Activities of Plant CGI-58 Protein.

    Directory of Open Access Journals (Sweden)

    Abdallah Khatib

    Full Text Available Comparative Gene Identification-58 (CGI-58 is a widespread protein found in animals and plants. This protein has been shown to participate in lipolysis in mice and humans by activating Adipose triglyceride lipase (ATGL, the initial enzyme responsible for the triacylglycerol (TAG catabolism cascade. Human mutation of CGI-58 is the cause of Chanarin-Dorfman syndrome, an orphan disease characterized by a systemic accumulation of TAG which engenders tissue disorders. The CGI-58 protein has also been shown to participate in neutral lipid metabolism in plants and, in this case, a mutation again provokes TAG accumulation. Although its roles as an ATGL coactivator and in lipid metabolism are quite clear, the catalytic activity of CGI-58 is still in question. The acyltransferase activities of CGI-58 have been speculated about, reported or even dismissed and experimental evidence that CGI-58 expressed in E. coli possesses an unambiguous catalytic activity is still lacking. To address this problem, we developed a new set of plasmids and site-directed mutants to elucidate the in vivo effects of CGI-58 expression on lipid metabolism in E. coli. By analyzing the lipid composition in selected E. coli strains expressing CGI-58 proteins, and by reinvestigating enzymatic tests with adequate controls, we show here that recombinant plant CGI-58 has none of the proposed activities previously described. Recombinant plant and mouse CGI-58 both lack acyltransferase activity towards either lysophosphatidylglycerol or lysophosphatidic acid to form phosphatidylglycerol or phosphatidic acid and recombinant plant CGI-58 does not catalyze TAG or phospholipid hydrolysis. However, expression of recombinant plant CGI-58, but not mouse CGI-58, led to a decrease in phosphatidylglycerol in all strains of E. coli tested, and a mutation of the putative catalytic residues restored a wild-type phenotype. The potential activities of plant CGI-58 are subsequently discussed.

  20. 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...

  1. The pharmacology of recombinant hirudin, a new anticoagulant

    African Journals Online (AJOL)

    1990-09-01

    Sep 1, 1990 ... The pharmacology of recombinant hirudin, a new anticoagulant. B. H. MEYER, H. G. LUUS, F. O. MULLER, P. N. BADENHORST, H.-J. ROTHIG. Summary. A new anticoagulant, recombinant hirudin, was given to hea"hy volunteers (5 per test dose) in single .intravenous doses of 0,01, 0,02, 0,04, 0,07 and 0 ...

  2. MRI screening for chronic anticoagulation in atrial fibrillation

    Directory of Open Access Journals (Sweden)

    Mark eFisher

    2013-10-01

    Full Text Available Anticoagulation is highly effective in preventing stroke due to atrial fibrillation, but numerous studies have demonstrated low utilization of anticoagulation for these patients. Assessment of clinicians’ attitudes on this topic indicate that fear of intracerebral hemorrhage (ICH, rather than appreciation of anticoagulant benefits, largely drives clinical decision-making for treatment with anticoagulation in atrial fibrillation. Risk stratification strategies have been used for anticoagulation benefits and hemorrhage risk, but ICH is not specifically addressed in the commonly used hemorrhage risk stratification systems. Cerebral microbleeds are cerebral microscopic hemorrhages demonstrable by brain MRI, indicative of prior microhemorrhages, and predictive of future risk of ICH. Prevalence of cerebral microbleeds increases with age; and cross-sectional and limited prospective studies generally indicate that microbleeds confer substantial risk of ICH in patients treated with chronic anticoagulation. MRI thus is a readily available and appealing modality that can directly assess risk of future ICH in patients receiving anticoagulants for atrial fibrillation. Incorporation of MRI into routine practice is, however, fraught with difficulties, including the uncertain relationship between number and location of microbleeds and ICH risk, as well as cost-effectiveness of MRI. A proposed algorithm is provided, and relevant advantages and disadvantages are discussed. At present, MRI screening appears most appropriate for a subset of atrial fibrillation patients, such as those with intermediate stroke risk, and may provide reassurance for clinicians whose concerns for ICH tend to outweigh benefits of anticoagulation.

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

    African Journals Online (AJOL)

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

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

    African Journals Online (AJOL)

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

  5. [Therapeutic equivalence of the new oral anticoagulants].

    Science.gov (United States)

    Moreno Villar, A; Nacle López, I; Barbero Hernández, M J; Lizan Tudela, L

    2015-10-01

    In an attempt to minimize the economic impact due to the incorporation of innovative drugs, health authorities have promoted and supported the evaluation and market positioning of drugs, as equivalent therapeutic alternatives. This issue has recently gained importance, possibly due to the current economic crisis. The equivalent therapeutic alternatives are justified by the need to compete on price, and by the authorities recommendation to establish therapeutic equivalence, price and financing of medicinal products at the same time. The establishment of the new oral anticoagulants and the equivalent therapeutic alternatives is a problematic issue if it is based on the absence of direct comparisons between different drugs and the questionable methodology used in the current indirect comparisons. Currently, it is difficult to determine when a new oral anticoagulant is more recommendable than others, but efforts are being made in order to propose alternatives for the decision based on patient characteristics. Copyright © 2015 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  6. Laboratory assessment of Activated Protein C Resistance/Factor V-Leiden and performance characteristics of a new quantitative assay.

    Science.gov (United States)

    Amiral, Jean; Vissac, Anne Marie; Seghatchian, Jerard

    2017-12-01

    Activated Protein C Resistance is mainly associated to a factor V mutation (RQ506), which induces a deficient inactivation of activated factor V by activated protein C, and is associated to an increased risk of venous and arterial thrombosis in affected individuals, caused by the prolonged activated factor V survival. Its prevalence is mainly in Caucasians (about 5%), and this mutation is absent in Africans and Asians. Presence of Factor V-Leiden is usually evidenced with clotting methods, using a two-step APTT assay performed without or with APC: prolongation of blood coagulation time is decreased if this factor is present. The R506Q Factor V-Leiden mutation is now usually characterized using molecular biology, and this technique tends to become the first intention assay for characterization of patients. Both techniques are qualitative, and allow classifying tested individuals as heterozygotes or homozygotes for the mutation, when present. A new quantitative assay for Factor V-Leiden, using a one-step clotting method, has been developed, and designed with highly purified human coagulation proteins. Clotting is triggered with human Factor Xa, in presence of calcium and phospholipids (mixture which favours APC action over clotting process). Diluted tested plasma, is supplemented with a clotting mixture containing human fibrinogen, prothrombin, and protein S at a constant concentration. APC is added, and clotting is initiated with calcium. Calibration is performed with a pool of plasmas from patients carrying the R506Q Factor V mutation, and its mixtures with normal plasma. Homozygous patients have clotting times of about 70sec. Factor V-Leiden concentration is usually >75% in homozygous patients, 30-60% in heterozygous patients and below 5% in normal. The assay is insensitive to clotting factor deficiencies (II, VII, VIII: C, IX, X), dicoumarol or heparin therapies, and has no interference with lupus anticoagulant (LA). This new assay for Factor V-Leiden can be

  7. Protein energy malnutrition increases arginase activity in monocytes and macrophages.

    Science.gov (United States)

    Corware, Karina; Yardley, Vanessa; Mack, Christopher; Schuster, Steffen; Al-Hassi, Hafid; Herath, Shanthi; Bergin, Philip; Modolell, Manuel; Munder, Markus; Müller, Ingrid; Kropf, Pascale

    2014-01-01

    Protein energy malnutrition is commonly associated with immune dysfunctions and is a major factor in susceptibility to infectious diseases. In this study, we evaluated the impact of protein energy malnutrition on the capacity of monocytes and macrophages to upregulate arginase, an enzyme associated with immunosuppression and increased pathogen replication. Our results show that monocytes and macrophages are significantly increased in the bone marrow and blood of mice fed on a protein low diet. No alteration in the capacity of bone marrow derived macrophages isolated from malnourished mice to phagocytose particles, to produce the microbicidal molecule nitric oxide and to kill intracellular Leishmania parasites was detected. However, macrophages and monocytes from malnourished mice express significantly more arginase both in vitro and in vivo. Using an experimental model of visceral leishmaniasis, we show that following protein energy malnutrition, the increased parasite burden measured in the spleen of these mice coincided with increased arginase activity and that macrophages provide a more permissive environment for parasite growth. Taken together, these results identify a novel mechanism in protein energy malnutrition that might contributes to increased susceptibility to infectious diseases by upregulating arginase activity in myeloid cells.

  8. Activation of mitogen-activated protein kinase by heat shock treatment in Drosophila.

    OpenAIRE

    Chen, F; Torres, M; Duncan, R F

    1995-01-01

    Heat shock treatment of Drosophila melanogaster tissue culture cells causes increased tyrosine phosphorylation of several 44 kDa proteins, which are identified as Drosophila mitogen-activated protein (MAP) kinases. Tyrosine phosphorylation occurs within 5 min, and is maintained at high levels during heat shock. It decreases to basal levels during recovery, concurrent with the repression of heat shock transcription and heat-shock-protein synthesis. The increased MAP kinase tyrosine phosphoryla...

  9. Fungal aegerolysin-like proteins: distribution, activities, and applications.

    Science.gov (United States)

    Novak, Maruša; Kraševec, Nada; Skočaj, Matej; Maček, Peter; Anderluh, Gregor; Sepčić, Kristina

    2015-01-01

    The aegerolysin protein family (from aegerolysin of the mushroom Agrocybe aegerita) comprises proteins of ∼15-20 kDa from various eukaryotic and bacterial taxa. Aegerolysins are inconsistently distributed among fungal species, and variable numbers of homologs have been reported for species within the same genus. As such noncore proteins, without a member of a protein family in each of the sequenced fungi, they can give insight into different species-specific processes. Some aegerolysins have been reported to be hemolytically active against mammalian erythrocytes. However, some function as bi-component proteins that have membrane activity in concert with another protein that contains a membrane attack complex/perforin domain. The function of most of aegerolysins is unknown, although some have been suggested to have a role in development of the organism. Potential biotechnological applications of aegerolysins are already evident, despite the limited scientific knowledge available at present. Some mushroom aegerolysins, for example, can be used as markers to detect and label specific membrane lipids. Others can be used as biomarkers of fungal exposure, where their genes can serve as targets for detection of fungi and their progression during infectious diseases. Antibodies against aegerolysins can also be raised as immuno-diagnostic tools. Aegerolysins have been shown to serve as a species determination tool for fungal phytopathogen isolates in terms of some closely related species, where commonly used internal transcribed spacer barcoding has failed. Moreover, strong promoters that regulate aegerolysin genes can promote secretion of heterologous proteins from fungi and have been successfully applied in simultaneous multi-gene expression techniques.

  10. Novel condensation products having high activity to insolubilize proteins and protein-insolubilized products

    Energy Technology Data Exchange (ETDEWEB)

    Krasnobajew, V.; Boeniger, R.

    1980-01-01

    According to the invention a substantially more active product with respect to the fixing or insolubilization pf proteins, including enzymes, is obtained when 1,3 phenylenediamine is condensed with glutardialdehyde. One application of the process is the enzymatic hydrolysis of lactose in milk products by lactase.

  11. Activity Based Protein Profiling Leads to Identification of Novel Protein Targets for Nerve Agent VX.

    Science.gov (United States)

    Carmany, Dan; Walz, Andrew J; Hsu, Fu-Lian; Benton, Bernard; Burnett, David; Gibbons, Jennifer; Noort, Daan; Glaros, Trevor; Sekowski, Jennifer W

    2017-04-17

    Organophosphorus (OP) nerve agents continue to be a threat at home and abroad during the war against terrorism. Human exposure to nerve agents such as VX results in a cascade of toxic effects relative to the exposure level including ocular miosis, excessive secretions, convulsions, seizures, and death. The primary mechanism behind these overt symptoms is the disruption of cholinergic pathways. While much is known about the primary toxicity mechanisms of nerve agents, there remains a paucity of information regarding impacts on other pathways and systemic effects. These are important for establishing a comprehensive understanding of the toxic mechanisms of OP nerve agents. To identify novel proteins that interact with VX, and that may give insight into these other mechanisms, we used activity-based protein profiling (ABPP) employing a novel VX-probe on lysates from rat heart, liver, kidney, diaphragm, and brain tissue. By making use of a biotin linked VX-probe, proteins covalently bound by the probe were isolated and enriched using streptavidin beads. The proteins were then digested, labeled with isobarically distinct tandem mass tag (TMT) labels, and analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Quantitative analysis identified 132 bound proteins, with many proteins found in multiple tissues. As with previously published ABPP OP work, monoacylglycerol lipase associated proteins and fatty acid amide hydrolase (FAAH) were shown to be targets of VX. In addition to these two and other predicted neurotransmitter-related proteins, a number of proteins involved with energy metabolism were identified. Four of these enzymes, mitochondrial isocitrate dehydrogenase 2 (IDH2), isocitrate dehydrogenase 3 (IDH3), malate dehydrogenase (MDH), and succinyl CoA (SCS) ligase, were assayed for VX inhibition. Only IDH2 NADP+ activity was shown to be inhibited directly. This result is consistent with other work reporting animals exposed to OP compounds exhibit

  12. Mitogen Activated Protein kinase signal transduction pathways in the prostate

    Directory of Open Access Journals (Sweden)

    Koul Sweaty

    2004-06-01

    Full Text Available Abstract The biochemistry of the mitogen activated protein kinases ERK, JNK, and p38 have been studied in prostate physiology in an attempt to elucidate novel mechanisms and pathways for the treatment of prostatic disease. We reviewed articles examining mitogen-activated protein kinases using prostate tissue or cell lines. As with other tissue types, these signaling modules are links/transmitters for important pathways in prostate cells that can result in cellular survival or apoptosis. While the activation of the ERK pathway appears to primarily result in survival, the roles of JNK and p38 are less clear. Manipulation of these pathways could have important implications for the treatment of prostate cancer and benign prostatic hypertrophy.

  13. Anticoagulant rodenticide poisoning in animals of Apulia and Basilicata, Italy.

    Science.gov (United States)

    Muscarella, Marilena; Armentano, Antonio; Iammarino, Marco; Palermo, Carmen; Amorena, Michele

    2016-06-30

    This study evaluates the presence of anticoagulant rodenticides in animals with a diagnosis of suspected poisoning and in bait samples. The survey was carried out from 2010 to 2012, in 2 regions of South Italy (Puglia and Basilicata) on 300 organs of animals and 90 suspected bait samples. The qualitative and quantitative analyses were conducted using an analytical method based on high‑performance liquid chromatography (HPLC) with fluorimetric detection (FLD) for the simultaneous determination of 8 anticoagulant rodenticides (bromadiolone, brodifacoum, coumachlor, coumafuryl, coumatetralyl, difenacoum, flocoumafen, and warfarin). The presence of anticoagulant rodenticides was detected in 33 organs of animals (11% of the total) and 6 bait samples (7% of the total). The most commonly detected compound was coumachlor (47% of 39 positive samples) followed by bromadiolone (24%), and brodifacoum (11%). The species mostly involved in anticoagulant rodenticide poisoning were dogs and cats. This study emphasizes the relevance of the determinations of anticoagulant rodenticides in cases of suspected poisoning in veterinary practice.

  14. Effects of computer-assisted oral anticoagulant therapy

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  15. 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.

  16. Antifreeze Protein Mimetic Metallohelices with Potent Ice Recrystallization Inhibition Activity.

    Science.gov (United States)

    Mitchell, Daniel E; Clarkson, Guy; Fox, David J; Vipond, Rebecca A; Scott, Peter; Gibson, Matthew I

    2017-07-26

    Antifreeze proteins are produced by extremophile species to control ice formation and growth, and they have potential applications in many fields. There are few examples of synthetic materials which can reproduce their potent ice recrystallization inhibition property. We report that self-assembled enantiomerically pure, amphipathic metallohelicies inhibited ice growth at just 20 μM. Structure-property relationships and calculations support the hypothesis that amphipathicity is the key motif for activity. This opens up a new field of metallo-organic antifreeze protein mimetics and provides insight into the origins of ice-growth inhibition.

  17. 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

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

    Science.gov (United States)

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

    2018-01-01

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

  19. Acupuncture safety in patients receiving anticoagulants: a systematic review.

    Science.gov (United States)

    Mcculloch, Michael; Nachat, Arian; Schwartz, Jonathan; Casella-Gordon, Vicki; Cook, Joseph

    2015-01-01

    Theoretically, acupuncture in anticoagulated patients could increase bleeding risk. However, precise estimates of bleeding complication rates from acupuncture in anticoagulated patients have not been systematically examined. To critically evaluate evidence for safety of acupuncture in anticoagulated patients. We searched PubMed, EMBASE, the Physiotherapy Evidence Database, and Google Scholar. Of 39 potentially relevant citations, 11 met inclusion criteria: 2 randomized trials, 4 case series, and 5 case reports. Seven provided reporting quality sufficient to assess acupuncture safety in 384 anticoagulated patients (3974 treatments). Minor-moderate bleeding related to acupuncture in an anticoagulated patient occurred in one case: a large hip hematoma, managed with vitamin K reversal and warfarin discontinuation following reevaluation of its medical justification. Blood-spot bleeding, typical for any needling/injection and controlled with pressure/cotton, occurred in 51 (14.6%) of 350 treatments among a case series of 229 patients. Bleeding deemed unrelated to acupuncture during anticoagulation, and more likely resulting from inappropriately deep needling damaging tissue or from complex anticoagulation regimens, occurred in 5 patients. No bleeding was reported in 2 studies (74 anticoagulated patients): 1 case report and 1 randomized trial prospectively monitoring acupuncture-associated bleeding as an explicit end point. Altogether, 1 moderate bleeding event occurred in 3974 treatments (0.003%). Acupuncture appears to be safe in anticoagulated patients, assuming appropriate needling location and depth. The observed 0.003% complication rate is lower than the previously reported 12.3% following hip/knee replacement in a randomized trial of 27,360 anticoagulated patients, and 6% following acupuncture in a prospective study of 229,230 all-type patients. Prospective trials would help confirm our findings.

  20. Strategies for the recovery of active proteins through refolding of bacterial inclusion body proteins

    Directory of Open Access Journals (Sweden)

    Rinas Ursula

    2004-09-01

    Full Text Available Abstract Recent advances in generating active proteins through refolding of bacterial inclusion body proteins are summarized in conjunction with a short overview on inclusion body isolation and solubilization procedures. In particular, the pros and cons of well-established robust refolding techniques such as direct dilution as well as less common ones such as diafiltration or chromatographic processes including size exclusion chromatography, matrix- or affinity-based techniques and hydrophobic interaction chromatography are discussed. Moreover, the effect of physical variables (temperature and pressure as well as the presence of buffer additives on the refolding process is elucidated. In particular, the impact of protein stabilizing or destabilizing low- and high-molecular weight additives as well as micellar and liposomal systems on protein refolding is illustrated. Also, techniques mimicking the principles encountered during in vivo folding such as processes based on natural and artificial chaperones and propeptide-assisted protein refolding are presented. Moreover, the special requirements for the generation of disulfide bonded proteins and the specific problems and solutions, which arise during process integration are discussed. Finally, the different strategies are examined regarding their applicability for large-scale production processes or high-throughput screening procedures.

  1. Stimulation of DNA Glycosylase Activities by XPC Protein Complex: Roles of Protein-Protein Interactions

    Directory of Open Access Journals (Sweden)

    Yuichiro Shimizu

    2010-01-01

    Full Text Available We showed that XPC complex, which is a DNA damage detector for nucleotide excision repair, stimulates activity of thymine DNA glycosylase (TDG that initiates base excision repair. XPC appeared to facilitate the enzymatic turnover of TDG by promoting displacement from its own product abasic site, although the precise mechanism underlying this stimulation has not been clarified. Here we show that XPC has only marginal effects on the activity of E. coli TDG homolog (EcMUG, which remains bound to the abasic site like human TDG but does not significantly interacts with XPC. On the contrary, XPC significantly stimulates the activities of sumoylated TDG and SMUG1, both of which exhibit quite different enzymatic kinetics from unmodified TDG but interact with XPC. These results point to importance of physical interactions for stimulation of DNA glycosylases by XPC and have implications in the molecular mechanisms underlying mutagenesis and carcinogenesis in XP-C patients.

  2. Activated protein C induces the release of microparticle-associated endothelial protein C receptor.

    Science.gov (United States)

    Pérez-Casal, Margarita; Downey, Colin; Fukudome, Kenji; Marx, Gernot; Toh, Cheng Hock

    2005-02-15

    Activated protein C (APC) treatment is now used for patients with severe sepsis. We investigated its effect in vitro on primary, physiologically relevant cells and demonstrate a novel mechanism of endothelial protein C receptor (EPCR) release that is not inhibited by metalloproteinase inhibitors. Exposure of human umbilical vein endothelial cells or monocytes to APC (6.25-100 nM) results in the release of EPCR-containing microparticles, as demonstrated by confocal microscopy and characterized through flow cytometry, enzyme-linked immunosorbent assay quantitation of isolated microparticles, and Western blotting. The phenomenon is time- and concentration-dependent and requires the APC active site, EPCR, and protease activated receptor 1 (PAR1) on endothelial cells. Neither protein C nor boiled or D-Phe-Pro-Arg-chloromethylketone-blocked APC can induce microparticle formation and antibody blockade of EPCR or PAR1 cleavage and activation abrogates this APC action. Coincubation with hirudin does not alter the APC effect. The released microparticle bound is full-length EPCR (49 kDa) and APC retains factor V-inactivating activity. Although tumor necrosis factor-alpha (10 ng/mL) can also induce microparticle-associated EPCR release to a similar extent as APC (100 nM), it is only APC-induced microparticles that contain bound APC. This novel observation could provide new insights into the consequences of APC therapy in the septic patient.

  3. Forkhead Box Protein A2 (FOXA2) Protein Stability and Activity Are Regulated by Sumoylation

    OpenAIRE

    Belaguli, Narasimhaswamy S.; Zhang, Mao; Brunicardi, F. Charles; Berger, David H.

    2012-01-01

    The forkhead box protein A2 (FOXA2) is an important regulator of glucose and lipid metabolism and organismal energy balance. Little is known about how FOXA2 protein expression and activity are regulated by post-translational modifications. We have identified that FOXA2 is post-translationally modified by covalent attachment of a small ubiquitin related modifier-1 (SUMO-1) and mapped the sumoylation site to the amino acid lysine 6 (K6). Preventing sumoylation by mutating the SUMO acceptor K6 t...

  4. Calcium/phospholipid-dependent protein kinase (protein kinase C) phosphorylates and activates tyrosine hydroxylase.

    OpenAIRE

    Albert, K A; Helmer-Matyjek, E; Nairn, A C; Müller, T H; Haycock, J W; Greene, L A; Goldstein, M; Greengard, P

    1984-01-01

    Protein kinase C, purified to homogeneity, was found to phosphorylate and activate tyrosine hydroxylase that had been partially purified from pheochromocytoma PC 12 cells. These actions of protein kinase C required the presence of calcium and phospholipid. This phosphorylation of tyrosine hydroxylase reduced the Km for the cofactor 6-methyltetrahydropterine from 0.45 mM to 0.11 mM, increased the Ki for dopamine from 4.2 microM to 47.5 microM, and produced no change in the Km for tyrosine. Lit...

  5. Protein S is protective in pulmonary fibrosis.

    Science.gov (United States)

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

    2016-08-01

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

  6. C4b-binding protein inhibits the factor V-dependent but not the factor V-independent cofactor activity of protein S in the activated protein C-mediated inactivation of factor VIIIa

    NARCIS (Netherlands)

    van de Poel, R. H.; Meijers, J. C.; Bouma, B. N.

    2001-01-01

    Activated protein C (APC) is an important inactivator of coagulation factors Va and VIIIa. In the inactivation of factors Va and VIIIa, protein S serves as a cofactor to APC. Protein S can bind to C4b-binding protein (C4BP), and thereby loses its cofactor activity to APC. By modulating free protein

  7. Activation of G Proteins by Guanine Nucleotide Exchange Factors Relies on GTPase Activity.

    Science.gov (United States)

    Stanley, Rob J; Thomas, Geraint M H

    2016-01-01

    G proteins are an important family of signalling molecules controlled by guanine nucleotide exchange and GTPase activity in what is commonly called an 'activation/inactivation cycle'. The molecular mechanism by which guanine nucleotide exchange factors (GEFs) catalyse the activation of monomeric G proteins is well-established, however the complete reversibility of this mechanism is often overlooked. Here, we use a theoretical approach to prove that GEFs are unable to positively control G protein systems at steady-state in the absence of GTPase activity. Instead, positive regulation of G proteins must be seen as a product of the competition between guanine nucleotide exchange and GTPase activity--emphasising a central role for GTPase activity beyond merely signal termination. We conclude that a more accurate description of the regulation of G proteins via these processes is as a 'balance/imbalance' mechanism. This result has implications for the understanding of intracellular signalling processes, and for experimental strategies that rely on modulating G protein systems.

  8. Contractions activate hormone-sensitive lipase in rat muscle by protein kinase C and mitogen-activated protein kinase

    DEFF Research Database (Denmark)

    Donsmark, Morten; Langfort, Jozef; Holm, Cecilia

    2003-01-01

    Intramuscular triacylglycerol is an important energy store and is also related to insulin resistance. The mobilization of fatty acids from this pool is probably regulated by hormone-sensitive lipase (HSL), which has recently been shown to exist in muscle and to be activated by both adrenaline...... and contractions. Adrenaline acts via cAMP-dependent protein kinase (PKA). The signalling mediating the effect of contractions is unknown and was explored in this study. Incubated soleus muscles from 70 g male rats were electrically stimulated to perform repeated tetanic contractions for 5 min. The contraction...... of the inhibitors reduced adrenaline-induced HSL activation in soleus muscle. Both phorbol-12-myristate-13-acetate (PMA), which activates PKC and, in turn, ERK, and caffeine, which increases intracellular Ca2+ without eliciting contraction, increased HSL activity. Activated ERK increased HSL activity in supernatant...

  9. Peptidoglycan recognition proteins with amidase activity in early deuterostomes (Echinodermata).

    Science.gov (United States)

    Coteur, Geoffroy; Mellroth, Peter; De Lefortery, Coline; Gillan, David; Dubois, Philippe; Communi, David; Steiner, Håkan

    2007-01-01

    Despite the ecological and evolutionary importance of echinoderms, very little is known about the immune mechanisms in this group especially regarding humoral immunity. In this paper, we screened for proteins putatively involved in immunity in the common European seastar Asterias rubens using a mass spectrometry-based proteomic approach. Two proteins showed striking sequence similarities with peptidoglycan recognition proteins (PGRPs). The two seastar proteins were identified as a single protein, termed PGRP-S1a, occurring in two forms in the coelomic plasma, one of 20kDa and another of 22kDa. We also cloned and sequenced a second member of the PGRP family, termed PGRP-S2a. It has a calculated molecular mass of 21.3kDa and is expressed in circulating phagocytes. Both the S1a-cDNA from coelomic epithelium RNA and the S2a-cDNA from phagocytes code for the amino acid residues necessary for peptidoglycan degradation. PGRP-S1a did not affect the phagocytic activity of seastar immune cells towards Micrococcus luteus but inhibited their production of reactive oxygen species (ROS). A recombinant, His-tagged, PGRP-S2a degrades peptidoglycan and increases the phagocytosis of M. luteus cells by seastar phagocytes.

  10. Protective effects of soybean protein and egg white protein on the antibacterial activity of nisin in the presence of trypsin.

    Science.gov (United States)

    Pan, Dan; Zhang, Dong; Hao, Limin; Lin, Songyang; Kang, Qiaozhen; Liu, Xin; Lu, Laizheng; Lu, Jike

    2018-01-15

    The using of nisin to prevent foodborne pathogens (Staphylococcus aureus and Listeria monocytogenes) from contamination has received broad attentions during meat processing. However, the application of nisin has been limited because its antibacterial activity may be inhibited by trypsin. In this study, the protective effects of soybean protein and egg white protein on antibacterial activity of nisin were evaluated. It could be concluded that exogenous trypsin decreased the antibacterial activity of nisin, soybean protein and egg white protein could keep the nisin activity from enzymolysis of trypsin. Trypsin inhibitors in soybean protein and egg white protein could protect the antibacterial activity of nisin. Nisin with soybean protein or egg white protein in cooked meat product presented better quality preservation effects than nisin alone in the presence of trypsin. The total viable counts (TVC) and total volatile basic nitrogen (TVB-N) of nisin-treated group were significantly higher than these in nisin-soybean protein-treated and nisin-egg white protein-treated groups with trypsin. This study showed the potential of using soybean protein and egg white protein to stabilize the antibacterial activity of nisin under high trypsin conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Detection of expansin proteins and activity during tomato fruit ontogeny.

    Science.gov (United States)

    Rose, J K; Cosgrove, D J; Albersheim, P; Darvill, A G; Bennett, A B

    2000-08-01

    Expansins are plant proteins that have the capacity to induce extension in isolated cell walls and are thought to mediate pH-dependent cell expansion. J.K.C. Rose, H.H. Lee, and A.B. Bennett ([1997] Proc Natl Acad Sci USA 94: 5955-5960) reported the identification of an expansin gene (LeExp1) that is specifically expressed in ripening tomato (Lycopersicon esculentum) fruit where cell wall disassembly, but not cell expansion, is prominent. Expansin expression during fruit ontogeny was examined using antibodies raised to recombinant LeExp1 or a cell elongation-related expansin from cucumber (CsExp1). The LeExp1 antiserum detected expansins in extracts from ripe, but not preripe tomato fruit, in agreement with the pattern of LeExp1 mRNA accumulation. In contrast, antibodies to CsExp1 cross-reacted with expansins in early fruit development and the onset of ripening, but not at a later ripening stage. These data suggest that ripening-related and expansion-related expansin proteins have distinct antigenic epitopes despite overall high sequence identity. Expansin proteins were detected in a range of fruit species and showed considerable variation in abundance; however, appreciable levels of expansin were not present in fruit of the rin or Nr tomato mutants that exhibit delayed and reduced softening. LeExp1 protein accumulation was ethylene-regulated and matched the previously described expression of mRNA, suggesting that expression is not regulated at the level of translation. We report the first detection of expansin activity in several stages of fruit development and while characteristic creep activity was detected in young and developing tomato fruit and in ripe pear, avocado, and pepper, creep activity in ripe tomato showed qualitative differences, suggesting both hydrolytic and expansin activities.

  12. Mitogen-activated protein kinases in the acute diabetic myocardium

    Czech Academy of Sciences Publication Activity Database

    Strnisková, M.; Barančík, M.; Neckář, Jan; Ravingerová, T.

    2003-01-01

    Roč. 249, 1-2 (2003), s. 59-65 ISSN 0300-8177 R&D Projects: GA MŠk LN00A069 Grant - others:VEGA(SK) 2/2063/22 Institutional research plan: CEZ:AV0Z5011922 Keywords : experimental diabetes * ischemia * mitogen-activated protein kinases (MAPK) Subject RIV: ED - Physiology Impact factor: 1.763, year: 2003

  13. Initiation of anticoagulation in atrial fibrillation

    DEFF Research Database (Denmark)

    Gundlund, A.; Staerk, L.; Fosbøl, E. L.

    2017-01-01

    Background: The use of non-vitamin K antagonist oral anticoagulants (NOACs) for stroke prophylaxis in atrial fibrillation (AF) is increasing rapidly. We compared characteristics of AF patients initiated on NOACs versus vitamin K antagonists (VKAs). Methods: Using Danish nationwide registry data, we...... identified AF patients initiating either a VKA or a NOAC from 22 August 2011 until 30 September 2016. We compared patient characteristics including age, gender, comorbidities, concomitant pharmacotherapy and CHA2DS2-VASc and HAS-BLED scores in patients initiated on a VKA, dabigatran, rivaroxaban or apixaban....... Differences were examined using multivariable logistic regression models. Results: The study population comprised 51 981 AF patients of whom 19 989 (38.5%) were initiated on a VKA, 13 242 (25.5%) on dabigatran, 8475 (16.3%) on rivaroxaban and 10 275 (19.8%) on apixaban. Those patients initiated on apixaban...

  14. Activation of the Unfolded Protein Response Contributes toward the Antitumor Activity of Vorinostat

    Directory of Open Access Journals (Sweden)

    Soumen Kahali

    2010-01-01

    Full Text Available Histone deacetylase (HDAC inhibitors represent an emerging class of anticancer agents progressing through clinical trials. Although their primary target is thought to involve acetylation of core histones, several nonhistone substrates have been identified, including heat shock protein (HSP 90, which may contribute towards their antitumor activity. Glucose-regulated protein 78 (GRP78 is a member of the HSP family of molecular chaperones and plays a central role in regulating the unfolded protein response (UPR. Emerging data suggest that GRP78 is critical in cellular adaptation and survival associated with oncogenesis and may serve as a cancer-specific therapeutic target. On the basis of shared homology with HSP family proteins, we sought to determine whether GRP78 could serve as a molecular target of the HDAC inhibitor vorinostat. Vorinostat treatment led to GRP78 acetylation, dissociation, and subsequent activation of its client protein double-stranded RNA-activated protein-like endoplasmic reticulum kinase (PERK. Investigations in a panel of cancer cell lines identified that UPR activation after vorinostat exposure is specific to certain lines. Mass spectrometry performed on immunoprecipitated GRP78 identified lysine-585 as a specific vorinostat-induced acetylation site of GRP78. Downstream activation of the UPR was confirmed, including eukaryotic initiating factor 2α phosphorylation and increase in ATF4 and C/EBP homologous protein expression. To determine the biologic relevance of UPR activation after vorinostat, RNA interference of PERK was performed, demonstrating significantly decreased sensitivity to vorinostat-induced cytotoxicity. Collectively, these findings indicate that GRP78 is a biologic target of vorinostat, and activation of the UPR through PERK phosphorylation contributes toward its antitumor activity.

  15. Study on antibacterial activity of hydrogel from irradiated silk protein

    Energy Technology Data Exchange (ETDEWEB)

    Bunnak, J.; Chaisupakitsin, M. [King Mongkut' s Institute of Technology Lardkrabang, Bangkok (Thailand)

    2001-03-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N{sub 2} atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  16. Study on antibacterial activity of hydrogel from irradiated silk protein

    International Nuclear Information System (INIS)

    Bunnak, J.; Chaisupakitsin, M.

    2001-01-01

    Hydrogels for biomedical application were prepared from solution blends of 3% silk protein and 3%, 10% poly (vinyl alcohol) (PVA) and followed with irradiation. Mixture of hydrogels were gamma irradiated at 10, 20, 30, 40 and 50 kGy under N 2 atmosphere. To clarify anti-bacterial activity of hydrogels, modified of the Agar disk diffusion method and American Association of Textile Chemists and Colorists, AATCC Test Method 90-1977, were carried out. The four kinds of bacteria such as Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Staphylococcus epidermidis, were used. It was found that a 1:3 volume ratio of 3% silk protein and 3% PVA respectively, at 50 kGy irradiation, is suitable conditions for preparation hydrogels and trend to indicate the highest of an antibacterial activity against E. coli, B. subtilis and S. aureus. However the antibacterial activity of hydrogels against S. epidermidis was not clearly. These results are very useful to expand the application of hydrogel from irradiated silk protein to the medical products. (author)

  17. Dual regulation of G proteins and the G-protein-activated K+ channels by lithium.

    Science.gov (United States)

    Farhy Tselnicker, Isabella; Tsemakhovich, Vladimir; Rishal, Ida; Kahanovitch, Uri; Dessauer, Carmen W; Dascal, Nathan

    2014-04-01

    Lithium (Li(+)) is widely used to treat bipolar disorder (BPD). Cellular targets of Li(+), such as glycogen synthase kinase 3β (GSK3β) and G proteins, have long been implicated in BPD etiology; however, recent genetic studies link BPD to other proteins, particularly ion channels. Li(+) affects neuronal excitability, but the underlying mechanisms and the relevance to putative BPD targets are unknown. We discovered a dual regulation of G protein-gated K(+) (GIRK) channels by Li(+), and identified the underlying molecular mechanisms. In hippocampal neurons, therapeutic doses of Li(+) (1-2 mM) increased GIRK basal current (Ibasal) but attenuated neurotransmitter-evoked GIRK currents (Ievoked) mediated by Gi/o-coupled G-protein-coupled receptors (GPCRs). Molecular mechanisms of these regulations were studied with heterologously expressed GIRK1/2. In excised membrane patches, Li(+) increased Ibasal but reduced GPCR-induced GIRK currents. Both regulations were membrane-delimited and G protein-dependent, requiring both Gα and Gβγ subunits. Li(+) did not impair direct activation of GIRK channels by Gβγ, suggesting that inhibition of Ievoked results from an action of Li(+) on Gα, probably through inhibition of GTP-GDP exchange. In direct binding studies, Li(+) promoted GPCR-independent dissociation of Gαi(GDP) from Gβγ by a Mg(2+)-independent mechanism. This previously unknown Li(+) action on G proteins explains the second effect of Li(+), the enhancement of GIRK's Ibasal. The dual effect of Li(+) on GIRK may profoundly regulate the inhibitory effects of neurotransmitters acting via GIRK channels. Our findings link between Li(+), neuronal excitability, and both cellular and genetic targets of BPD: GPCRs, G proteins, and ion channels.

  18. Activated protein synthesis and suppressed protein breakdown signaling in skeletal muscle of critically ill patients.

    Directory of Open Access Journals (Sweden)

    Jakob G Jespersen

    Full Text Available BACKGROUND: Skeletal muscle mass is controlled by myostatin and Akt-dependent signaling on mammalian target of rapamycin (mTOR, glycogen synthase kinase 3β (GSK3β and forkhead box O (FoxO pathways, but it is unknown how these pathways are regulated in critically ill human muscle. To describe factors involved in muscle mass regulation, we investigated the phosphorylation and expression of key factors in these protein synthesis and breakdown signaling pathways in thigh skeletal muscle of critically ill intensive care unit (ICU patients compared with healthy controls. METHODOLOGY/PRINCIPAL FINDINGS: ICU patients were systemically inflamed, moderately hyperglycemic, received insulin therapy, and showed a tendency to lower plasma branched chain amino acids compared with controls. Using Western blotting we measured Akt, GSK3β, mTOR, ribosomal protein S6 kinase (S6k, eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1, and muscle ring finger protein 1 (MuRF1; and by RT-PCR we determined mRNA expression of, among others, insulin-like growth factor 1 (IGF-1, FoxO 1, 3 and 4, atrogin1, MuRF1, interleukin-6 (IL-6, tumor necrosis factor α (TNF-α and myostatin. Unexpectedly, in critically ill ICU patients Akt-mTOR-S6k signaling was substantially higher compared with controls. FoxO1 mRNA was higher in patients, whereas FoxO3, atrogin1 and myostatin mRNAs and MuRF1 protein were lower compared with controls. A moderate correlation (r2=0.36, p<0.05 between insulin infusion dose and phosphorylated Akt was demonstrated. CONCLUSIONS/SIGNIFICANCE: We present for the first time muscle protein turnover signaling in critically ill ICU patients, and we show signaling pathway activity towards a stimulation of muscle protein synthesis and a somewhat inhibited proteolysis.

  19. FAS activation induces dephosphorylation of SR proteins - Dependence on the de novo generation of ceramide and activation of protein phosphatase 1

    NARCIS (Netherlands)

    Chalfant, CE; Ogretmen, B; Galadari, S; Kroesen, BJ; Pettus, BJ; Hannun, YA

    2001-01-01

    The search for potential targets for ceramide action led to the identification of ceramide-activated protein phosphatases (CAPP). To date, two serine/threonine protein phosphatases, protein phosphatase 2A (PP2A) and protein phosphatase 1 (PP1), have been demonstrated to function as

  20. Delineation of protein structure classes from multivariate analysis of protein Raman optical activity data.

    Science.gov (United States)

    Zhu, Fujiang; Tranter, George E; Isaacs, Neil W; Hecht, Lutz; Barron, Laurence D

    2006-10-13

    Vibrational Raman optical activity (ROA), measured as a small difference in the intensity of Raman scattering from chiral molecules in right and left-circularly polarized incident light, or as the intensity of a small circularly polarized component in the scattered light, is a powerful probe of the aqueous solution structure of proteins. On account of the large number of structure-sensitive bands in protein ROA spectra, multivariate analysis techniques such as non-linear mapping (NLM) are especially favourable for determining structural relationships between different proteins. Here NLM is used to map a dataset of 80 polypeptide, protein and virus ROA spectra, considered as points in a multidimensional space with axes representing the digitized wavenumbers, into readily visualizable two and three-dimensional spaces in which points close to or distant from each other, respectively, represent similar or dissimilar structures. Discrete clusters are observed which correspond to the seven structure classes all alpha, mainly alpha, alphabeta, mainly beta, all beta, mainly disordered/irregular and all disordered/irregular. The average standardised ROA spectra of the proteins falling within each structure class have distinct features characteristic of each class. A distinct cluster containing the wheat protein A-gliadin and the plant viruses potato virus X, narcissus mosaic virus, papaya mosaic virus and tobacco rattle virus, all of which appear in the mainly alpha cluster in the two-dimensional representation, becomes clearly separated in the direction of increasing disorder in the three-dimensional representation. This suggests that the corresponding five proteins, none of which to date has yielded high-resolution X-ray structures, consist mainly of alpha-helix and disordered structure with little or no beta-sheet. This combination of structural elements may have functional significance, such as facilitating disorder-to-order transitions (and vice versa) and suppressing

  1. 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.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  3. Plasma Protein Turnover Rates in Rats Using Stable Isotope Labeling, Global Proteomics, and Activity-Based Protein Profiling

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Jordan N.; Tyrrell, Kimberly J.; Hansen, Joshua R.; Thomas, Dennis G.; Murphree, Taylor A.; Shukla, Anil K.; Luders, Teresa; Madden, James M.; Li, Yunying; Wright, Aaron T.; Piehowski, Paul D.

    2017-12-06

    Protein turnover is important for general health on cellular and organism scales providing a strategy to replace old, damaged, or dysfunctional proteins. Protein turnover also informs of biomarker kinetics, as a better understanding of synthesis and degradation of proteins increases the clinical utility of biomarkers. Here, turnover rates of plasma proteins in rats were measured in vivo using a pulse-chase stable isotope labeling experiment. During the pulse, rats (n=5) were fed 13C6-labeled lysine (“heavy”) feed for 23 days to label proteins. During the chase, feed was changed to an unlabeled equivalent feed (“light”), and blood was repeatedly sampled from rats over 10 time points for 28 days. Plasma samples were digested with trypsin, and analyzed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). MaxQuant was used to identify peptides and proteins, and quantify heavy:light lysine ratios. A system of ordinary differential equations was used to calculate protein turnover rates. Using this approach, 273 proteins were identified, and turnover rates were quantified for 157 plasma proteins with half-lives ranging 0.3-103 days. For the ~70 most abundant proteins, variability in turnover rates among rats was low (median coefficient of variation: 0.09). Activity-based protein profiling was applied to pooled plasma samples to enrich serine hydrolases using a fluorophosphonate (FP2) activity-based probe. This enrichment resulted in turnover rates for an additional 17 proteins. This study is the first to measure global plasma protein turnover rates in rats in vivo, measure variability of protein turnover rates in any animal model, and utilize activity-based protein profiling for enhancing measurements of targeted, low-abundant proteins, such as those commonly used as biomarkers. Measured protein turnover rates will be important for understanding of the role of protein turnover in cellular and organism health as well as increasing the utility of protein

  4. Fast calcium sensor proteins for monitoring neural activity.

    Science.gov (United States)

    Badura, Aleksandra; Sun, Xiaonan Richard; Giovannucci, Andrea; Lynch, Laura A; Wang, Samuel S-H

    2014-10-01

    A major goal of the BRAIN Initiative is the development of technologies to monitor neuronal network activity during active information processing. Toward this goal, genetically encoded calcium indicator proteins have become widely used for reporting activity in preparations ranging from invertebrates to awake mammals. However, slow response times, the narrow sensitivity range of Ca 2+ and in some cases, poor signal-to-noise ratio still limit their usefulness. Here, we review recent improvements in the field of neural activity-sensitive probe design with a focus on the GCaMP family of calcium indicator proteins. In this context, we present our newly developed Fast-GCaMPs, which have up to 4-fold accelerated off-responses compared with the next-fastest GCaMP, GCaMP6f. Fast-GCaMPs were designed by destabilizing the association of the hydrophobic pocket of calcium-bound calmodulin with the RS20 binding domain, an intramolecular interaction that protects the green fluorescent protein chromophore. Fast-GCaMP6f-RS06 and Fast-GCaMP6f-RS09 have rapid off-responses in stopped-flow fluorimetry, in neocortical brain slices, and in the intact cerebellum in vivo . Fast-GCaMP6f variants should be useful for tracking action potentials closely spaced in time, and for following neural activity in fast-changing compartments, such as axons and dendrites. Finally, we discuss strategies that may allow tracking of a wider range of neuronal firing rates and improve spike detection.

  5. When Heterotrimeric G Proteins Are Not Activated by G Protein-Coupled Receptors: Structural Insights and Evolutionary Conservation.

    Science.gov (United States)

    DiGiacomo, Vincent; Marivin, Arthur; Garcia-Marcos, Mikel

    2018-01-23

    Heterotrimeric G proteins are signal-transducing switches conserved across eukaryotes. In humans, they work as critical mediators of intercellular communication in the context of virtually any physiological process. While G protein regulation by G protein-coupled receptors (GPCRs) is well-established and has received much attention, it has become recently evident that heterotrimeric G proteins can also be activated by cytoplasmic proteins. However, this alternative mechanism of G protein regulation remains far less studied than GPCR-mediated signaling. This Viewpoint focuses on recent advances in the characterization of a group of nonreceptor proteins that contain a sequence dubbed the "Gα-binding and -activating (GBA) motif". So far, four proteins present in mammals [GIV (also known as Girdin), DAPLE, CALNUC, and NUCB2] and one protein in Caenorhabditis elegans (GBAS-1) have been described as possessing a functional GBA motif. The GBA motif confers guanine nucleotide exchange factor activity on Gαi subunits in vitro and activates G protein signaling in cells. The importance of this mechanism of signal transduction is highlighted by the fact that its dysregulation underlies human diseases, such as cancer, which has made the proteins attractive new candidates for therapeutic intervention. Here we discuss recent discoveries on the structural basis of GBA-mediated activation of G proteins and its evolutionary conservation and compare them with the better-studied mechanism mediated by GPCRs.

  6. Exactin: A specific inhibitor of Factor X activation by extrinsic tenase complex from the venom of Hemachatus haemachatus.

    Science.gov (United States)

    Girish, Vallerinteavide Mavelli; Kini, R Manjunatha

    2016-08-25

    Unwanted clots lead to heart attack and stroke that result in a large number of deaths. Currently available anticoagulants have some drawbacks including their non-specific actions. Therefore novel anticoagulants that target specific steps in the coagulation pathway are being sought. Here we describe the identification and characterization of a novel anticoagulant protein from the venom of Hemachatus haemachatus (African Ringhals cobra) that specifically inhibits factor X (FX) activation by the extrinsic tenase complex (ETC) and thus named as exactin. Exactin belongs to the three-finger toxin (3FTx) family, with high sequence identity to neurotoxins and low identity to the well-characterized 3FTx anticoagulants-hemextin and naniproin. It is a mixed-type inhibitor of ETC with the kinetic constants, Ki' and Ki determined as 30.62 ± 7.73 nM and 153.75 ± 17.96 nM, respectively. Exactin does not bind to the active site of factor VIIa and factor Xa based on its weak inhibition (IC50 ≫ 300 μM) to the amidolytic activities of these proteases. Exactin shows exquisite macromolecular specificity to FX activation as compared to factor IX activation by ETC. Exactin thus displays a distinct mechanism when compared to other anticoagulants targeting ETC, with its selective preference to ETC-FX [ES] complex.

  7. Rapamycin Induces Mitogen-activated Protein (MAP) Kinase Phosphatase-1 (MKP-1) Expression through Activation of Protein Kinase B and Mitogen-activated Protein Kinase Kinase Pathways*

    Science.gov (United States)

    Rastogi, Ruchi; Jiang, Zhongliang; Ahmad, Nisar; Rosati, Rita; Liu, Yusen; Beuret, Laurent; Monks, Robert; Charron, Jean; Birnbaum, Morris J.; Samavati, Lobelia

    2013-01-01

    Mitogen-activated protein kinase phosphatase-1 (MKP-1), also known as dual specificity phosphatase-1 (DUSP-1), plays a crucial role in the deactivation of MAPKs. Several drugs with immune-suppressive properties modulate MKP-1 expression as part of their mechanism of action. We investigated the effect of mTOR inhibition through rapamycin and a dual mTOR inhibitor (AZD2014) on MKP-1 expression. Low dose rapamycin led to a rapid activation of both AKT and ERK pathways with a subsequent increase in MKP-1 expression. Rapamycin treatment led to phosphorylation of CREB, transcription factor 1 (ATF1), and ATF2, three transcription factors that bind to the cyclic AMP-responsive elements on the Mkp-1 promoter. Inhibition of either the MEK/ERK or the AKT pathway attenuated rapamycin-mediated MKP-1 induction. AZD2014 did not activate AKT but activated the ERK pathway, leading to a moderate MKP-1 induction. Using bone marrow-derived macrophages (BMDMs) derived from wild-type (WT) mice or mice deficient in AKT1 and AKT2 isoforms or BMDM from targeted deficiency in MEK1 and MEK2, we show that rapamycin treatment led to an increased MKP1 expression in BMDM from WT but failed to do so in BMDMs lacking the AKT1 isoform or MEK1 and MEK2. Importantly, rapamycin pretreatment inhibited LPS-mediated p38 activation and decreased nitric oxide and IL-6 production. Our work provides a conceptual framework for the observed immune modulatory effect of mTOR inhibition. PMID:24126911

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

    Directory of Open Access Journals (Sweden)

    M. A. Domashenko

    2016-01-01

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

  9. Na2EDTA anticoagulant impaired blood samples from the teleost Piaractus mesopotamicus

    Directory of Open Access Journals (Sweden)

    Thaís Heloisa Vaz Farias

    2016-05-01

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

  10. Transcatheter Arterial Embolization of Concurrent Spontaneous Hematomas of the Rectus Sheath and Psoas Muscle in Patients Undergoing Anticoagulation

    International Nuclear Information System (INIS)

    Basile, Antonio; Medina, Jose Garcia; Mundo, Elena; Medina, Vicente Garcia; Leal, Rafael

    2004-01-01

    We report a case of concurrent rectus sheath and psoas hematomas in a patient undergoing anticoagulant therapy, treated by transcatheter arterial embolization (TAE) of inferior epigastric and lumbar arteries. Computed tomography (CT) demonstrated signs of active bleeding in two hematomas of the anterior and posterior abdominal walls. Transfemoral arteriogram confirmed the extravasation of contrast from the right inferior epigastric artery (RIEA). Indirect signs of bleeding were also found in a right lumbar artery (RLA). We successfully performed TAE of the feeding arteries. There have been few reports in the literature of such spontaneous hemorrhages in patients undergoing anticoagulation, successfully treated by TAE

  11. Fusion expression of Helicobacter pylori neutrophil-activating protein in E.coli

    OpenAIRE

    Kang, Qiao-Zhen; Duan, Guang-Cai; Fan, Qing-Tang; Xi, Yuan-Lin

    2005-01-01

    AIM: To produce a recombinant protein rMBP-NAP, which was fusionally expressed by Helicobacter pylori (H pylori) neutrophil-activating protein (NAP) and E. coli maltose-binding protein (MBP) and to evaluate its immunoreactivity and immunogenicity.

  12. [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.

  13. Interference of the new oral anticoagulant dabigatran with frequently used coagulation tests.

    Science.gov (United States)

    Halbmayer, Walter-Michael; Weigel, Guenter; Quehenberger, Peter; Tomasits, Josef; Haushofer, Alexander C; Aspoeck, Gerold; Loacker, Lorin; Schnapka-Koepf, Mirjam; Goebel, Georg; Griesmacher, Andrea

    2012-01-01

    Dabigatran etexilate is a new oral anticoagulant for the therapy and prophylaxis of venous thromboembolism and stroke prevention in patients with atrial fibrillation. To investigate the extent of interactions of this new anticoagulant with frequently used coagulation assays, we completed a multicenter in vitro trial with Conformité Européenne(CE)-labeled dabigatran-spiked plasma samples. Lyophilized plasma samples with dabigatran concentrations ranging from 0.00 to 0.48 μg/mL were sent to the coagulation laboratories of six major Austrian hospitals for evaluation. Coagulation assays were performed under routine conditions using standard reagents and analyzer. Dabigatran led to a dose-dependent prolongation of the clotting times in coagulometric tests and influenced the majority of the parameters measured. Statistically significant interference could be observed with the prothrombin time (PT), activated partial thromboplastin time (aPTT) and PT/aPTT-based assays (extrinsic/intrinsic factors, APC-resistance test) as well as lupus anticoagulant testing. Even non-clotting tests, such as the colorimetric factor XIII activity assay and to a minor extent the amidolytic antithrombin activity assay (via factor IIa) were affected. This multicenter trial confirms and also adds to existing data, demonstrating that laboratories should expect to observe strong interferences of coagulation tests with increasing concentrations of dabigatran. This finding might become particularly important in the elderly and in patients with renal impairment as well as patients whose blood is drawn at peak levels of dabigatran.

  14. Refolding techniques for recovering biologically active recombinant proteins from inclusion bodies.

    Science.gov (United States)

    Yamaguchi, Hiroshi; Miyazaki, Masaya

    2014-02-20

    Biologically active proteins are useful for studying the biological functions of genes and for the development of therapeutic drugs and biomaterials in a biotechnology industry. Overexpression of recombinant proteins in bacteria, such as Escherichia coli, often results in the formation of inclusion bodies, which are protein aggregates with non-native conformations. As inclusion bodies contain relatively pure and intact proteins, protein refolding is an important process to obtain active recombinant proteins from inclusion bodies. However, conventional refolding methods, such as dialysis and dilution, are time consuming and, often, recovered yields of active proteins are low, and a trial-and-error process is required to achieve success. Recently, several approaches have been reported to refold these aggregated proteins into an active form. The strategies largely aim at reducing protein aggregation during the refolding procedure. This review focuses on protein refolding techniques using chemical additives and laminar flow in microfluidic chips for the efficient recovery of active proteins from inclusion bodies.

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

    Science.gov (United States)

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

    2008-06-01

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

  16. Cyclic AMP activates the mitogen-activated protein kinase cascade in PC12 cells

    DEFF Research Database (Denmark)

    Frödin, M; Peraldi, P; Van Obberghen, E

    1994-01-01

    Mitogen-activated protein (MAP) kinases are activated in response to a large variety of extracellular signals, including growth factors, hormones, and neurotransmitters, which activate distinct intracellular signaling pathways. Their activation by the cAMP-dependent pathway, however, has not been...... reported. In rat pheochromocytoma PC12 cells, we demonstrate here a stimulation of the MAP kinase isozyme extracellular signal-regulated kinase 1 (ERK1) following elevation of intracellular cAMP after exposure of the cells to isobutylmethylxanthine, cholera toxin, forskolin, or cAMP-analogues. cAMP acted...... synergistically with phorbol ester, an activator of protein kinase C, in the stimulation of ERK1. In accordance with this observation, the peptide neurotransmitter pituitary adenylate cyclase-activating polypeptide 38 (PACAP38), which stimulates cAMP production as well as phosphatidylinositol breakdown in PC12...

  17. Plasma cholesteryl ester transfer protein mass and phospholipid transfer protein activity are associated with leptin in type 2 diabetes mellitus

    NARCIS (Netherlands)

    Dullaart, R. P. F.; de Vries, R.; Dallinga-Thie, G. M.; van Tol, A.; Sluiter, W. J.

    Adipose tissue contributes to plasma levels of lipid transfer proteins and is also the major source of plasma adipokines. We hypothesized that plasma cholesteryl ester transfer protein (CETP) mass, phospholipid transfer protein (PLTP) activity and cholesteryl ester transfer (CET, a measure of CETP

  18. Metals in the active site of native protein phosphatase-1.

    Science.gov (United States)

    Heroes, Ewald; Rip, Jens; Beullens, Monique; Van Meervelt, Luc; De Gendt, Stefan; Bollen, Mathieu

    2015-08-01

    Protein phosphatase-1 (PP1) is a major protein Ser/Thr phosphatase in eukaryotic cells. Its activity depends on two metal ions in the catalytic site, which were identified as manganese in the bacterially expressed phosphatase. However, the identity of the metal ions in native PP1 is unknown. In this study, total reflection X-ray fluorescence (TXRF) was used to detect iron and zinc in PP1 that was purified from rabbit skeletal muscle. Metal exchange experiments confirmed that the distinct substrate specificity of recombinant and native PP1 is determined by the nature of their associated metals. We also found that the iron level associated with native PP1 is decreased by incubation with inhibitor-2, consistent with a function of inhibitor-2 as a PP1 chaperone. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Annotating activation/inhibition relationships to protein-protein interactions using gene ontology relations.

    Science.gov (United States)

    Yim, Soorin; Yu, Hasun; Jang, Dongjin; Lee, Doheon

    2018-04-11

    Signaling pathways can be reconstructed by identifying 'effect types' (i.e. activation/inhibition) of protein-protein interactions (PPIs). Effect types are composed of 'directions' (i.e. upstream/downstream) and 'signs' (i.e. positive/negative), thereby requiring directions as well as signs of PPIs to predict signaling events from PPI networks. Here, we propose a computational method for systemically annotating effect types to PPIs using relations between functional information of proteins. We used regulates, positively regulates, and negatively regulates relations in Gene Ontology (GO) to predict directions and signs of PPIs. These relations indicate both directions and signs between GO terms so that we can project directions and signs between relevant GO terms to PPIs. Independent test results showed that our method is effective for predicting both directions and signs of PPIs. Moreover, our method outperformed a previous GO-based method that did not consider the relations between GO terms. We annotated effect types to human PPIs and validated several highly confident effect types against literature. The annotated human PPIs are available in Additional file 2 to aid signaling pathway reconstruction and network biology research. We annotated effect types to PPIs by using regulates, positively regulates, and negatively regulates relations in GO. We demonstrated that those relations are effective for predicting not only signs, but also directions of PPIs. The usefulness of those relations suggests their potential applications to other types of interactions such as protein-DNA interactions.

  20. Steric effects in peptide and protein exchange with activated disulfides.

    Science.gov (United States)

    Kerr, Jason; Schlosser, Jessica L; Griffin, Donald R; Wong, Darice Y; Kasko, Andrea M

    2013-08-12

    Disulfide exchange is an important bioconjugation tool, enabling chemical modification of peptides and proteins containing free cysteines. We previously reported the synthesis of a macromer bearing an activated disulfide and its incorporation into hydrogels. Despite their ability to diffuse freely into hydrogels, larger proteins were unable to undergo in-gel disulfide exchange. In order to understand this phenomenon, we synthesized four different activated disulfide-bearing model compounds (Mn = 300 Da to 10 kDa) and quantified their rate of disulfide exchange with a small peptide (glutathione), a moderate-sized protein (β-lactoglobulin), and a large protein (bovine serum albumin) in four different pH solutions (6.0, 7.0, 7.4, and 8.0) to mimic biological systems. Rate constants of exchange depend significantly on the size and accessibility of the thiolate. pH also significantly affects the rate of reaction, with the faster reactions occurring at higher pH. Surprisingly, little difference in exchange rates is seen between macromolecular disulfides of varying size (Mn = 2 kDa - 10 kDa), although all undergo exchange more slowly than their small molecule analogue (MW = 300 g/mol). The maximum exchange efficiencies (% disulfides exchanged after 24 h) are not siginificantly affected by thiol size or pH, but somewhat affected by disulfide size. Therefore, while all three factors investigated (pH, disulfide size, and thiolate size) can influence the exchange kinetics and extent of reaction, the size of the thiolate and its accessibility plays the most significant role.

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

    Directory of Open Access Journals (Sweden)

    Dasnan Ismail

    2002-06-01

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

  2. Keap1-Independent Regulation of Nrf2 Activity by Protein Acetylation and a BET Bromodomain Protein.

    Science.gov (United States)

    Chatterjee, Nirmalya; Tian, Min; Spirohn, Kerstin; Boutros, Michael; Bohmann, Dirk

    2016-05-01

    Mammalian BET proteins comprise a family of bromodomain-containing epigenetic regulators with complex functions in chromatin organization and gene regulation. We identified the sole member of the BET protein family in Drosophila, Fs(1)h, as an inhibitor of the stress responsive transcription factor CncC, the fly ortholog of Nrf2. Fs(1)h physically interacts with CncC in a manner that requires the function of its bromodomains and the acetylation of CncC. Treatment of cultured Drosophila cells or adult flies with fs(1)h RNAi or with the BET protein inhibitor JQ1 de-represses CncC transcriptional activity and engages protective gene expression programs. The mechanism by which Fs(1)h inhibits CncC function is distinct from the canonical mechanism that stimulates Nrf2 function by abrogating Keap1-dependent proteasomal degradation. Consistent with the independent modes of CncC regulation by Keap1 and Fs(1)h, combinations of drugs that can specifically target these pathways cause a strong synergistic and specific activation of protective CncC- dependent gene expression and boosts oxidative stress resistance. This synergism might be exploitable for the design of combinatorial therapies to target diseases associated with oxidative stress or inflammation.

  3. A recyclable protein resource derived from cauliflower by-products: Potential biological activities of protein hydrolysates.

    Science.gov (United States)

    Xu, Yang; Li, Yuting; Bao, Tao; Zheng, Xiaodong; Chen, Wei; Wang, Jianxu

    2017-04-15

    Cauliflower by-products (CBP) are rich in leaf protein. Every year tons of CBP will lead to environmental pollution. Therefore, this study was conducted to extract leaf protein from CBP and investigate its biological activities. Our results showed that the optimal extraction parameters were: a liquid to solid ratio of 4mL/g, a pH of 11, an ultrasonic extraction lasting 15min, and at an applied power of 175W. Under these optimized conditions, 12.066g of soluble leaf protein (SLP) was obtained from 1000g of CBP and its extraction yield was 53.07%. The obtained SLP was further hydrolysed by Alcalase and the SLP hydrolysate (SLPH) showed a potent angiotensin I-converting enzyme (ACE) inhibitory activity with an IC 50 value of 138.545μg/mL in vitro. In addition, SLPH promoted the glucose consumption and enhanced the glycogen content in HepG2 cells. Overall, our results suggested that CBP may be recycled for designing future functional foods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. 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.

  5. 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...... of our literature based review was collect articles showing the benefit of anticoagulation in CVT and gathering the data of follow-up studies focusing on the recurrence of CVT and other thrombotic events. RESULTS: We have identified 15 follow-up studies studies with 2422 patients . The mean duration...... of follow up was 37,9 months. Death occured in 6,5% and 76,4 % of the patients had favourable outcome. 85,5 % received initial anticoagulation with ultrafractionated or low molecular weight heparin and 82,1 % received long-term anticoagulation. Recurent CVT occured in 3,7% and other thrombotic event occured...

  6. [Management of new oral anticoagulants in gastrointestinal bleeding and endoscopy].

    Science.gov (United States)

    del Molino, Fátima; Gonzalez, Isabel; Saperas, Esteve

    2015-10-01

    New oral direct anticoagulants agents are alternatives to warfarin for long-term anticoagulation in a growing number of patients that require long-term anticoagulation for atrial fibrillation, deep venous thrombosis and pulmonary embolism. These new agents with predictable pharmacokinetic and pharmacodynamics profiles offer a favorable global safety profile, but increased gastrointestinal bleeding compared to the vitamin K antagonists. Many gastroenterologists are unfamiliar and may be wary of these newer drugs, since Clinical experience is limited and no specific antidote is available to reverse their anticoagulant effect. In this article the risk of these new agents and, how to manage these agents in both the presence of acute gastrointestinal bleeding and in patients undergoing endoscopic procedures is reviewed. Copyright © 2014 Elsevier España, S.L.U. and AEEH y AEG. All rights reserved.

  7. Generic switching of warfarin and risk of excessive anticoagulation

    DEFF Research Database (Denmark)

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

    2016-01-01

    PURPOSE: Generic switching of warfarin was recently repealed in Denmark, as adverse drug reaction (ADR) reports suggested risk of excessive anticoagulation following switches from branded to generic warfarin. We investigated this putative association in a formalized pharmacoepidemiological analys...

  8. Utilization of Oral Anticoagulation in a Teaching Hospital in Nigeria

    African Journals Online (AJOL)

    : Anticoagulation, Barriers, Nigeria, .... Cardiovascular disease (thromboembolic stroke). 2/26 (7.7). Heart valve replacement. 2/26 (7.7) ... accounts for approximately 2% of the reported hemorrhagic complications of warfarin therapy and is ...

  9. Structural analyses of a constitutively active mutant of exchange protein directly activated by cAMP.

    Science.gov (United States)

    White, Mark A; Li, Sheng; Tsalkova, Tamara; Mei, Fang C; Liu, Tong; Woods, Virgil L; Cheng, Xiaodong

    2012-01-01

    Exchange proteins directly activated by cAMP (EPACs) are important allosteric regulators of cAMP-mediated signal transduction pathways. To understand the molecular mechanism of EPAC activation, we have combined site-directed mutagenesis, X-ray crystallography, and peptide amide hydrogen/deuterium exchange mass spectrometry (DXMS) to probe the structural and conformational dynamics of EPAC2-F435G, a constitutively active EPAC2 mutant. Our study demonstrates that conformational dynamics plays a critical role in cAMP-induced EPAC activation. A glycine mutation at 435 position shifts the equilibrium of conformational dynamics towards the extended active conformation.

  10. Structural analyses of a constitutively active mutant of exchange protein directly activated by cAMP.

    Directory of Open Access Journals (Sweden)

    Mark A White

    Full Text Available Exchange proteins directly activated by cAMP (EPACs are important allosteric regulators of cAMP-mediated signal transduction pathways. To understand the molecular mechanism of EPAC activation, we have combined site-directed mutagenesis, X-ray crystallography, and peptide amide hydrogen/deuterium exchange mass spectrometry (DXMS to probe the structural and conformational dynamics of EPAC2-F435G, a constitutively active EPAC2 mutant. Our study demonstrates that conformational dynamics plays a critical role in cAMP-induced EPAC activation. A glycine mutation at 435 position shifts the equilibrium of conformational dynamics towards the extended active conformation.

  11. Upper Airway Obstruction Secondary to Anticoagulant Rodenticide Toxicosis in Five Dogs.

    Science.gov (United States)

    Lawson, Corinne; O'Brien, Mauria; McMichael, Maureen

    Five dogs were presented with clinical signs compatible with upper airway obstruction, including stridor, stertor, coughing, gagging, and varying degrees of respiratory distress. All dogs had radiographic findings of soft tissue opacity in the area of the pharynx, larynx, or trachea, and several had narrowing of the tracheal lumen. Coagulation abnormalities (prolonged prothrombin time, activated partial thromboplastin time) were present in the four dogs that underwent testing. Four of five dogs were treated for the coagulopathy, presumably due to anticoagulant rodenticide toxicosis, and survived to discharge.Upper airway obstruction is an unusual presentation for anticoagulant rodenticide toxicosis in dogs. Raising the index of suspicion for this treatable condition may help clinicians to identify this sooner.

  12. Immersion freezing of ice nucleation active protein complexes

    Directory of Open Access Journals (Sweden)

    S. Hartmann

    2013-06-01

    Full Text Available Utilising the Leipzig Aerosol Cloud Interaction Simulator (LACIS, the immersion freezing behaviour of droplet ensembles containing monodisperse particles, generated from a Snomax™ solution/suspension, was investigated. Thereto ice fractions were measured in the temperature range between −5 °C to −38 °C. Snomax™ is an industrial product applied for artificial snow production and contains Pseudomonas syringae} bacteria which have long been used as model organism for atmospheric relevant ice nucleation active (INA bacteria. The ice nucleation activity of such bacteria is controlled by INA protein complexes in their outer membrane. In our experiments, ice fractions increased steeply in the temperature range from about −6 °C to about −10 °C and then levelled off at ice fractions smaller than one. The plateau implies that not all examined droplets contained an INA protein complex. Assuming the INA protein complexes to be Poisson distributed over the investigated droplet populations, we developed the CHESS model (stoCHastic modEl of similar and poiSSon distributed ice nuclei which allows for the calculation of ice fractions as function of temperature and time for a given nucleation rate. Matching calculated and measured ice fractions, we determined and parameterised the nucleation rate of INA protein complexes exhibiting class III ice nucleation behaviour. Utilising the CHESS model, together with the determined nucleation rate, we compared predictions from the model to experimental data from the literature and found good agreement. We found that (a the heterogeneous ice nucleation rate expression quantifying the ice nucleation behaviour of the INA protein complex is capable of describing the ice nucleation behaviour observed in various experiments for both, Snomax™ and P. syringae bacteria, (b the ice nucleation rate, and its temperature dependence, seem to be very similar regardless of whether the INA protein complexes inducing ice

  13. 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

  14. Biological activity and dimerization state of modified phytochrome A proteins.

    Directory of Open Access Journals (Sweden)

    Peng Liu

    Full Text Available To assess potential physical interactions of type I phyA with the type II phyB-phyE phytochromes in vivo, transgenes expressing fusion gene forms of phyA were introduced into the Arabidopsis phyA mutant background. When a single c-Myc (myc epitope is added to either the N- or C-terminus of phyA, the constructs completely complement phyA mutant phenotypes. However, addition of larger tags, such as six consecutive myc epitopes or the yellow fluorescent protein sequence, result in fusion proteins that show reduced activity. All the tagged phyA proteins migrate as dimers on native gels and co-immunoprecipitation reveals no binding interaction of phyA to any of the type II phys in the dark or under continuous far-red light. Dimers of the phyA 1-615 amino acid N-terminal photosensory domain (NphyA, generated in vivo with a yeast GAL4 dimerization domain and attached to a constitutive nuclear localization sequence, are expressed at a low level and, although they cause a cop phenotype in darkness and mediate a very low fluence response to pulses of FR, have no activity under continuous FR. It is concluded that type I phyA in its Pr form is present in plants predominantly or exclusively as a homodimer and does not stably interact with type II phys in a dimer-to-dimer manner. In addition, its activity in mediating response to continuous FR is sensitive to modification of its N- or C-terminus.

  15. Extractions without eliminating anticoagulant treatment : a literature review.

    OpenAIRE

    Rodríguez Cabrera, Manuel Alejandro; Barona Dorado, Cristina; Leco Berrocal, María Isabel; Gómez Moreno, Gerardo; Martínez González, José María

    2011-01-01

    To establish whether there is a high enough risk of bleeding in patients who take oral anticoagulants, such that it would justify not using oral anticoagulants when performing a dental extraction, as well as if the reason for and anatomical location of the extraction increases such risk. Study We performed a bibliographic search in order to carry out a meta-analytic study using descriptive statistics. We compiled a sample of 1194 patients from the articles selected. Of these patients, a total...

  16. [Risk and benefit of oral anticoagulants in atrial fibrillation].

    Science.gov (United States)

    Zotova, I V; Zateĭshchikov, D A

    2011-01-01

    Thromboembolism is the main cause of death and disability of patients with atrial fibrillation. Indirect anticoagulants are effective means of primary and secondary prevention of thromboembolic complications. However in a number of patients risk associated with therapy with indirect anticoagulants might exceed potential benefit. The principle problem requiring solution in a patient with atrial fibrillation is individual comparative assessment of risk of development of thromboembolic and hemorrhagic complications. Modern stratification scales which allow solving this problem are considered in this review.

  17. Lupus Anticoagulant and Anticardiolipin Antibodies in Unexplained Fetal Losses

    OpenAIRE

    ALPER, Gülinnaz

    2014-01-01

    Lupus anticoagulant (LA) and anti-cardiolipin antibodies (ACAs) are acquired antiphospholipid antibodies (APAs), which are considered to be important markers for pregnancy losses and intrauterine fetal demise. LA and ACAs have anticoagulant effects in vitro and thrombotic effects in vivo and are considered to be the cause of recur-rent pregnancy losses (RPLs), resulting from placental vascular thrombosis and infarction. The aim of this study was to identify the most sensitive and specific met...

  18. Redox regulation of the AMP-activated protein kinase.

    Directory of Open Access Journals (Sweden)

    Yingying Han

    2010-11-01

    Full Text Available Redox state is a critical determinant of cell function, and any major imbalances can cause severe damage or death.The aim of this study is to determine if AMP-activated protein kinase (AMPK, a cellular energy sensor, is activated by oxidants generated by Berberine in endothelial cells (EC.Bovine aortic endothelial cells (BAEC were exposed to Berberine. AMPK activity and reactive oxygen species were monitored after the incubation.In BAEC, Berberine caused a dose- and time-dependent increase in the phosphorylation of AMPK at Thr172 and acetyl CoA carboxylase (ACC at Ser79, a well characterized downstream target of AMPK. Concomitantly, Berberine increased peroxynitrite, a potent oxidant formed by simultaneous generation of superoxide and nitric oxide. Pre-incubation of BAEC with anti-oxidants markedly attenuated Berberine-enhanced phosphorylation of both AMPK and ACC. Consistently, adenoviral expression of superoxide dismutase and pretreatment of L-N(G-Nitroarginine methyl ester (L-NAME; a non-selective NOS inhibitor blunted Berberine-induced phosphorylation of AMPK. Furthermore, mitochondria-targeted tempol (mito-tempol pretreatment or expression of uncoupling protein attenuated AMPK activation caused by Berberine. Depletion of mitochondria abolished the effects of Berberine on AMPK in EC. Finally, Berberine significantly increased the phosphorylation of LKB1 at Ser307 and gene silencing of LKB1 attenuated Berberine-enhanced AMPK Thr172 phosphorylation in BAEC.Our results suggest that mitochondria-derived superoxide anions and peroxynitrite are required for Berberine-induced AMPK activation in endothelial cells.

  19. [Perioperative management of direct oral anticoagulant in emergency surgery and bleeding. Haemostasis monitoring and treatment].

    Science.gov (United States)

    Hidalgo, F; Gómez-Luque, A; Ferrandis, R; Llau, J V; de Andrés, J; Gomar, C; Sierra, P; Castillo, J; Torres, L M

    2015-10-01

    There is an almost unanimous consensus on the management of the direct new oral anticoagulants, dabigatran, rivaroxaban, and apixaban in elective surgery. However, this general consensus does not exist in relation with the direct new oral anticoagulants use in emergency surgery, especially in the bleeding patient. For this reason, a literature review was performed using the MEDLINE-PubMed. An analysis was made of the journal articles, reviews, systematic reviews, and practices guidelines published between 2000 and 2014 using the terms "monitoring" and "reversal". From this review, it was shown that the routine tests of blood coagulation, such as the prothrombin time and activated partial thromboplastin time, have a limited efficacy in the perioperative control of blood coagulation in these patients. There is currently no antidote to reverse the effects of these drugs, although the possibility of using concentrated prothrombin complex and recombinant activated factor vii has been suggested for the urgent reversal of the anticoagulant effect. Copyright © 2014 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Emergency Coagulation Assessment During Treatment With Direct Oral Anticoagulants: Limitations and Solutions.

    Science.gov (United States)

    Ebner, Matthias; Birschmann, Ingvild; Peter, Andreas; Härtig, Florian; Spencer, Charlotte; Kuhn, Joachim; Blumenstock, Gunnar; Zuern, Christine S; Ziemann, Ulf; Poli, Sven

    2017-09-01

    In patients receiving direct oral anticoagulants (DOACs), emergency treatment like thrombolysis for acute ischemic stroke is complicated by insufficient availability of DOAC-specific coagulation tests. Conflicting recommendations have been published concerning the use of global coagulation assays for ruling out relevant DOAC-induced anticoagulation. Four hundred eighty-one samples from 96 DOAC-treated patients were tested using prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT), DOAC-specific assays (anti-Xa activity, diluted TT), and liquid chromatography-tandem mass spectrometry. Sensitivity and specificity of test results to identify DOAC concentrations 95% specificity and a specific TT cutoff enhanced sensitivity for dabigatran to 84%. For apixaban, no cutoffs could be established. Even if highly DOAC-reactive reagents are used, normal results of global coagulation tests are not suited to guide emergency treatment: whereas normal PT and aPTT lack specificity to rule out DOAC-induced anticoagulation, the low sensitivity of normal TT excludes the majority of eligible patients from treatment. However, reagent-specific cutoffs for global coagulation tests ensure high specificity and optimize sensitivity for safe emergency decision making in rivaroxaban- and dabigatran-treated patients. URL: http://www.clinicaltrials.gov. Unique identifiers: NCT02371044 and NCT02371070. © 2017 American Heart Association, Inc.

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

    Science.gov (United States)

    Li, Changtian; Mao, Xinxin; Xu, Baojun

    2013-01-01

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

  2. Extended Physicochemical Characterization of the Synthetic Anticoagulant Pentasaccharide Fondaparinux Sodium by Quantitative NMR and Single Crystal X-ray Analysis

    NARCIS (Netherlands)

    Wildt, William de; Kooijman, Huub; Funke, Carel; Üstün, Bülent; Leika, Afranina; Lunenburg, Maarten; Kaspersen, Frans; Kellenbach, Edwin

    2017-01-01

    Fondaparinux sodium is a synthetic pentasaccharide representing the high affinity antithrombin III binding site in heparin. It is the active pharmaceutical ingredient of the anticoagulant drug Arixtra(®). The single crystal X-ray structure of Fondaparinux sodium is reported, unequivocally confirming

  3. 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

  4. PENURUNAN KADAR PROTEIN LIMBAH CAIR TAHU DENGAN PEMANFAATAN KARBON BAGASSE TERAKTIVASI (Protein Reduction of Tofu Wastewater Using Activated Carbon Bagasse

    Directory of Open Access Journals (Sweden)

    Candra Purnawan

    2014-10-01

    Full Text Available ABSTRAK Penurunan kadar protein limbah tahu telah dilakukan dengan pemanfaatan karbon Bagasse teraktivasi. Tujuan dari penelitian ini adalah untuk mengetahui kondisi optimum dari karbon teraktivasi NaOH dan H2SO4 dalam menurunkan kadar protein limbah cair tahu dan mengetahui jenis isoterm adsorpsi dari karbon aktif yang digunakan untuk menyerap protein limbah cair tahu. Hasil penelitian menunjukkan konsentrasi NaOH yang optimum untuk aktivasi karbon aktif 15%, massa optimum karbon bagasse teraktivasi NaOH adalah 2 g dan penurunan kadar proteinnya 71,95%, sedangkan massa optimum karbon bagasse teraktivasi H2SO4 adalah 1 g dengan penurunan kadar protein sebesar 38,19%. Waktu kontak optimum karbon bagasse teraktivasi  NaOH dan H2SO4 adalah 12 jam. Adsorpsi protein oleh karbon bagasse teraktivasi NaOH mengikuti isoterm adsorpsi Langmuir dan Freundlich sedangkan karbon bagasse teraktivasi H2SO4 dominan mengikuti isoterm Freundlich.   ABSTRACT The protein reduction of tofu wastewater using activated carbon from bagasse  had been conducted. The purposes of this research were to analysis optimum condition of activated carbon bagsse using NaOH and H2SO4 for reduction protein in tofu wastewater, and analysis adsorption isotherm of activated carbon with protein. The result showed that optimum mass of carbon bagasse activated NaOH was  2 g with 71.95% protein reduction, while carbon bagasse activated H2SO4 has 1 g with 38.19% protein reduction. The optimum contact time between protein and activated carbon (with NaOH and H2SO4 was happened in 12 hours. Adsorption protein with carbon bagasse activated NaOH had followed Langmuir and Freundlich adsorption isotherm, while adsorption with carbon bagasse activated H2SO4 dominantlyhad followed Freundlich adsorption isotherm

  5. Anticoagulant-free Genius haemodialysis using low molecular weight heparin-coated circuits.

    Science.gov (United States)

    Frank, Rolf Dario; Müller, Ute; Lanzmich, Regina; Groeger, Christian; Floege, Jürgen

    2006-04-01

    Regional citrate anticoagulation or saline flushes are often used in haemodialysis patients at high risk of bleeding. In an alternative approach we evaluated the effects of covalent circuit coating with low molecular weight heparin (LMWH) for intermittent haemodialysis. In vitro, we compared the thrombogenicity of an uncoated polyvinylchloride (PVC) tubing set with LMWH-coated tubing (AOThel) and a reference tubing with end-point attached heparin coating (Carmeda Bioactive surface) under dynamic blood contact. In vivo, five chronic haemodialysis patients were studied using the Genius dialysis system and F60S filters. Each patient underwent three dialysis sessions separated by a standard haemodialysis each: (1) standard dialysis (uncoated circuit and regular dalteparin dosage), (2) dialysis with LMWH-coated circuit and regular dalteparin dosage and (3) dialysis with a completely LMWH-coated circuit without anticoagulant use. In vitro, both coated tubings showed significantly reduced thrombin-antithrombin (TAT) complex levels compared with PVC. The reference coating (Carmeda) released substantial antifactor Xa (antiXa) activity into the plasma. The LMWH coating (AOThel) released low antiXa activity only during the initial rinsing. In vivo, all dialysis sessions were well tolerated and completed without major clotting. Antithrombin levels and platelet counts were similar in all groups. P-selectin and D-dimer levels increased similarly in all groups. TAT levels were comparable in all groups during the first 3 h and significantly increased in the anticoagulant-free group after the fourth hour. LMWH surface coating reduces thrombogenicity in vitro without releasing significant amounts of heparin from the surface. In vivo, anticoagulant-free haemodialysis using a completely LMWH-coated circuit is feasible and safe in stable chronic dialysis patients with normal coagulation.

  6. Activated Protein C-Resistance Determination and Vascular Access Thrombosis in Populations with High Prevalence of Factor V Leiden.

    Science.gov (United States)

    Androulakis, Nikolaos E; Tzenakis, Nikolaos; Nioti, Eleni; Spatharaki, Paraskevi; Vyzoukaki, Rodanthi; Papadopoulou, Anastasia; Kokonozaki, Maria; Alexandrakis, Michael G

    2015-01-01

    Factor V Leiden heterozygosity occurs in 3-8% of the general European and US populations. Activated protein C resistance (APC-R)--a non-molecular laboratory test--can efficiently demonstrate the presence of this mutation and can be performed on most coagulation analyzers. On the other hand, fistula or graft thrombosis is a common and costly complication in hemodialysis patients. Our aim was to establish the value of APC-R determination in hemodialysis patients by assessing the risk of access thrombosis in patients with increased APC-R. A total of 133 patients (81 men, mean age 64.5 ± 14.9 years and 52 women, mean age 63.6 ± 15 years) were selected. Participants were divided into 2 groups: those with access thrombosis (54 patients, 40.6%) and those with no access thrombosis (79 patients, 59.4%), and they were tested for the most common congenital or acquired thrombophilia risk factors. Overall, 12 patients (9%) had an increased APC-R and 10 of them had at least 1 episode of access thrombosis (83.3%). Univariate analysis to estimate crude odds ratio (OR) showed an OR of 8.8 (95% CI 1.8-41.8) times higher risk for access thrombosis in these patients. No significant differences were found after adjusting for age, hypertension, diabetes mellitus, coronary artery disease, cerebrovascular disease, peripheral arterial disease and malignancy. Sex was also a factor influencing thrombosis, presenting a higher OR for women (OR 2.2, 95% CI 1.1-4.4). This study revealed a significant association between access thrombosis and increased APC-R in hemodialysis patients. This indicates that the determination of APC-R should be considered--especially, in populations with a high prevalence of Factor V Leiden--as proper anticoagulant therapy in these patients may reduce the risk of access thrombosis. © 2015 S. Karger AG, Basel.

  7. Protein tyrosine kinase but not protein kinase C inhibition blocks receptor induced alveolar macrophage activation

    Directory of Open Access Journals (Sweden)

    K. Pollock

    1993-01-01

    Full Text Available The selective enzyme inhibitors genistein and Ro 31-8220 were used to assess the importance of protein tyrosine kinase (PTK and protein kinase C (PKC, respectively, in N-formyl-methionyl-leucyl-phenylalanine (FMLP induced generation of superoxide anion and thromboxane B2 (TXB2 in guinea-pig alveolar macrophages (AM. Genistein (3–100 μM dose dependently inhibited FMLP (3 nM induced superoxide generation in non-primed AM and TXB2 release in non-primed or in lipopolysaccharide (LPS (10 ng/ml primed AM to a level > 80% but had litle effect up to 100 μM on phorbol myristate acetate (PMA (10 nM induced superoxide release. Ro 31-8220 inhibited PMA induced superoxide generation (IC50 0.21 ± 0.10 μM but had no effect on or potentiated (at 3 and 10 μM FMLP responses in non-primed AM. In contrast, when present during LPS priming as well as during FMLP challenge Ro 31-8220 (10 μM inhibited primed TXB2 release by > 80%. The results indicate that PTK activation is required for the generation of these inflammatory mediators by FMLP in AM. PKC activation appears to be required for LPS priming but not for transducing the FMLP signal; rather, PKC activation may modulate the signal by a negative feedback mechanism.

  8. [Progress of anticoagulation therapy in atrial fibrillation].

    Science.gov (United States)

    Hernández Olmedo, Miguel; Suárez Fernández, Carmen

    2015-08-07

    Atrial fibrillation is currently a very prevalent disease and it represents one of the most common causes of disabling stroke. Antithrombotic therapies have reduced the incidence of this complication although they pose many limitations and difficulties. As a result, a large number of high risk patients do not receive an appropriate treatment. In recent years, four new oral anticoagulants (NOAC) with relevant advantages in comparison to vitaminK antagonists have been released. Four large phaseiii clinical trials have demonstrated that NOAC are at least as safe and efficacious as warfarin in stroke prevention in non-valve atrial fibrillation patients with moderate-high thrombotic risk, being their main advantage the reduction in intracranial hemorrhage. The arrival of these drugs has caused great expectations in the management of these patients but also new doubts. Lacking data in some subgroups of frail patients, the absence of specific antidotes available and specially their high cost represent nowadays the main limitations for their generalization. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  9. Novel oral anticoagulants in acute coronary syndrome.

    Science.gov (United States)

    Costopoulos, Charis; Niespialowska-Steuden, Maria; Kukreja, Neville; Gorog, Diana A

    2013-09-10

    Coronary artery disease (CAD) is a leading cause of morbidity and mortality worldwide with a prevalence that has now reached pandemic levels as a consequence of the rapid modernization of the developing world. Its presentation as an acute coronary syndrome (ACS) is a frequent reason for hospital admission and of profound implications for personal, societal and global health. Despite improvements in the management of ACS with anti-platelet and anticoagulant therapy and revascularization techniques, many patients continue to suffer recurrent ischemic events. The need to reduce future cardiovascular events has led to the development of novel therapies to prevent coronary thrombosis, targeting thrombin-mediated pathways. These include direct Xa inhibitors (apixaban, rivaroxaban and darexaban), direct thrombin inhibitors (dabigatran) and PAR 1 antagonists (vorapaxar and atopaxar). This article critically reviews the comparative mechanisms of action, the risks and benefits, together with the clinical evidence base for the use of these novel oral agents in the management of ACS patients. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  10. Small Molecule Inhibitors Targeting Activator Protein 1 (AP-1)

    Science.gov (United States)

    2015-01-01

    Activator protein 1 (AP-1) is a pivotal transcription factor that regulates a wide range of cellular processes including proliferation, apoptosis, differentiation, survival, cell migration, and transformation. Accumulating evidence supports that AP-1 plays an important role in several severe disorders including cancer, fibrosis, and organ injury, as well as inflammatory disorders such as asthma, psoriasis, and rheumatoid arthritis. AP-1 has emerged as an actively pursued drug discovery target over the past decade. Excitingly, a selective AP-1 inhibitor T-5224 (51) has been investigated in phase II human clinical trials. Nevertheless, no effective AP-1 inhibitors have yet been approved for clinical use. Despite significant advances achieved in understanding AP-1 biology and function, as well as the identification of small molecules modulating AP-1 associated signaling pathways, medicinal chemistry efforts remain an urgent need to yield selective and efficacious AP-1 inhibitors as a viable therapeutic strategy for human diseases. PMID:24831826

  11. Antistaphylococcal activity of bacteriophage derived chimeric protein P128

    Directory of Open Access Journals (Sweden)

    Vipra Aradhana A

    2012-03-01

    Full Text Available Abstract Background Bacterial drug resistance is one of the most significant challenges to human health today. In particular, effective antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA are urgently needed. A causal relationship between nasal commensal S. aureus and infection has been reported. Accordingly, elimination of nasal S. aureus reduces the risk of infection. Enzymes that degrade bacterial cell walls show promise as antibacterial agents. Bacteriophage-encoded bacterial cell wall-degrading enzymes exhibit intrinsic bactericidal activity. P128 is a chimeric protein that combines the lethal activity of the phage tail-associated muralytic enzyme of Phage K and the staphylococcal cell wall targeting-domain (SH3b of lysostaphin. Here we report results of in vitro studies evaluating the susceptibility of staphylococcal strains to this novel protein. Results Using the broth microdilution method adapted for lysostaphin, we found that P128 is effective against S. aureus clinical strains including MRSA, methicillin-sensitive S. aureus (MSSA, and a mupirocin-resistant S. aureus. Minimum bactericidal concentrations and minimum inhibitory concentrations of P128 (1-64 μg/mL were similar across the 32 S. aureus strains tested, demonstrating its bactericidal nature. In time-kill assays, P128 reduced colony-forming units by 99.99% within 1 h and inhibited growth up to 24 h. In an assay simulating topical application of P128 to skin or other biological surfaces, P128 hydrogel was efficacious when layered on cells seeded on solid media. P128 hydrogel was lethal to Staphylococci recovered from nares of healthy people and treated without any processing or culturing steps, indicating its in situ efficacy. This methodology used for in vitro assessment of P128 as an agent for eradicating nasal carriage is unique. Conclusions The novel chimeric protein P128 is a staphylococcal cell wall-degrading enzyme under development for

  12. Rivaroxaban Causes Missed Diagnosis of Protein S Deficiency but Not of Activated Protein C Resistance (Factor V Leiden).

    Science.gov (United States)

    Maryamchik, Elena; Rosenbaum, Matthew W; Van Cott, Elizabeth M

    2018-01-01

    - Rivaroxaban causes a false increase in activated protein C resistance (APCR) ratios and protein S activity. - To investigate whether this increase masks a diagnosis of factor V Leiden (FVL) or protein S deficiency in a "real-world" population of patients undergoing rivaroxaban treatment and hypercoagulation testing. - During a 2.5-year period, we compared 4 groups of patients (n = 60): FVL heterozygous (FVL-HET)/taking rivaroxaban, wild-type/taking rivaroxaban, FVL-HET/no rivaroxaban, and normal APCR/no rivaroxaban. Patients taking rivaroxaban were tested for protein S functional activity and free antigen (n = 32). - The FVL-HET patients taking rivaroxaban had lower APCR ratios than wild-type patients ( P < .001). For FVL-HET patients taking rivaroxaban, mean APCR was 1.75 ± 0.12, versus 1.64 ± 0.3 in FVL-HET patients not taking rivaroxaban ( P = .005). Activated protein C resistance in FVL-HET patients fell more than 3 SDs below the cutoff of 2.2 at which the laboratory reflexes FVL DNA testing. No cases of FVL were missed despite rivaroxaban. In contrast, rivaroxaban falsely elevated functional protein S activity, regardless of the presence or absence of FVL ( P < .001). A total of 4 of 32 patients (12.5%) had low free protein S antigen (range, 58%-67%), whereas their functional protein S activity appeared normal (range 75%-130%). Rivaroxaban would have caused a missed diagnosis of all cases of protein S deficiency during the study if testing relied on the protein S activity assay alone. - Despite rivaroxaban treatment, APCR testing can distinguish FVL-HET from normal patients, rendering indiscriminate FVL DNA testing of all patients on rivaroxaban unnecessary. Free protein S should be tested in patients taking rivaroxaban to exclude hereditary protein S deficiency.

  13. Validation of commercial ELISAs for quantifying anabolic growth factors and cytokines in canine ACD-A anticoagulated plasma.

    Science.gov (United States)

    Birdwhistell, Kate; Basinger, Robert; Hayes, Brian; Norton, Natalie; Hurley, David J; Franklin, Samuel P

    2017-03-01

    Platelet-rich plasma has been studied extensively in dogs, but validation of enzyme-linked immunosorbent assays (ELISAs) for quantifying anabolic growth factors and inflammatory cytokines in canine plasma prepared with citrate-based anticoagulants is not available. We performed a validation of commercial ELISAs for transforming growth factor-beta 1 (TGF-β1), platelet-derived growth factor-BB (PDGF-BB), vascular endothelial growth factor (VEGF), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) for use with canine plasma prepared with acid-citrate-dextrose, solution A (ACD-A). Platelet-poor plasma (PPP) anticoagulated with ACD-A as well as PPP anticoagulated with ACD-A and spiked with the relevant canine recombinant proteins were evaluated with each ELISA to calculate the efficiency of spike recovery. Replicates of the spiked PPP were also assessed in 2 additional assays to quantify intra-assay and interassay precision. The efficiency of spike recovery was within 75-125% of the expected concentration for the TGF-β1, PDGF-BB, and VEGF ELISAs. The intra- and interassay variability were ACD-A anticoagulated canine plasma.

  14. Development of antimicrobial active packaging materials based on gluten proteins.

    Science.gov (United States)

    Gómez-Heincke, Diana; Martínez, Inmaculada; Partal, Pedro; Guerrero, Antonio; Gallegos, Críspulo

    2016-08-01

    The incorporation of natural biocide agents into protein-based bioplastics, a source of biodegradable polymeric materials, manufactured by a thermo-mechanical method is a way to contribute to a sustainable food packaging industry. This study assesses the antimicrobial activity of 10 different biocides incorporated into wheat gluten-based bioplastics. The effect that formulation, processing, and further thermal treatments exert on the thermo-mechanical properties, water absorption characteristics and rheological behaviour of these materials is also studied. Bioplastics containing six of the 10 examined bioactive agents have demonstrated suitable antimicrobial activity at 37 °C after their incorporation into the bioplastic. Moreover, the essential oils are able to create an antimicrobial atmosphere within a Petri dish. Depending on the selected biocide, its addition may alter the bioplastics protein network in a different extent, which leads to materials exhibiting less water uptake and different rheological and thermo-mechanical behaviours. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  15. Stromal serine protein kinase activity in spinach chloroplasts

    International Nuclear Information System (INIS)

    Cortez, N.; Lucero, H.A.; Vallejos, R.H.

    1987-01-01

    At least twelve 32 P-labeled stromal proteins were detected by electrophoresis under denaturing conditions when intact chloroplasts were incubated with 32 Pi, in the light but only three were detected in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) or in the dark. Incubation of isolated stroma with [gamma- 32 P]ATP resulted in the preferential phosphorylation of one of them, a 70-kDa polypeptide, in serine residues. Thylakoid membranes in the dark promoted the phosphorylation of two additional stromal polypeptides of 55 and 40 kDa. Illumination during the phosphorylation of stroma in the presence of thylakoids stimulated severalfold the labeling of the 40-kDa polypeptide but not when DCMU was added. The protein kinase activity present in isolated stroma phosphorylated exogenous substrates like histone III, phosvitin, histone II, and casein with specific activities of 3, 1.8, 0.7, and 0.2 pmol X mg-1 X min-1. Histone III polypeptides were phosphorylated differently by stroma and by thylakoids in the dark. Moreover, histone III phosphorylated by thylakoids in the dark yielded a pattern of phosphopeptides after V8 protease treatment that was different from the pattern obtained when histone III was phosphorylated by stroma

  16. Modeling of human factor Va inactivation by activated protein C

    Directory of Open Access Journals (Sweden)

    Bravo Maria

    2012-05-01

    Full Text Available Abstract Background Because understanding of the inventory, connectivity and dynamics of the components characterizing the process of coagulation is relatively mature, it has become an attractive target for physiochemical modeling. Such models can potentially improve the design of therapeutics. The prothrombinase complex (composed of the protease factor (FXa and its cofactor FVa plays a central role in this network as the main producer of thrombin, which catalyses both the activation of platelets and the conversion of fibrinogen to fibrin, the main substances of a clot. A key negative feedback loop that prevents clot propagation beyond the site of injury is the thrombin-dependent generation of activated protein C (APC, an enzyme that inactivates FVa, thus neutralizing the prothrombinase complex. APC inactivation of FVa is complex, involving the production of partially active intermediates and “protection” of FVa from APC by both FXa and prothrombin. An empirically validated mathematical model of this process would be useful in advancing the predictive capacity of comprehensive models of coagulation. Results A model of human APC inactivation of prothrombinase was constructed in a stepwise fashion by analyzing time courses of FVa inactivation in empirical reaction systems with increasing number of interacting components and generating corresponding model constructs of each reaction system. Reaction mechanisms, rate constants and equilibrium constants informing these model constructs were initially derived from various research groups reporting on APC inactivation of FVa in isolation, or in the presence of FXa or prothrombin. Model predictions were assessed against empirical data measuring the appearance and disappearance of multiple FVa degradation intermediates as well as prothrombinase activity changes, with plasma proteins derived from multiple preparations. Our work integrates previously published findings and through the cooperative

  17. Regulation of mitogen-activated protein kinase 3/1 activity during meiosis resumption in mammals

    Czech Academy of Sciences Publication Activity Database

    Procházka, Radek; Blaha, Milan

    2015-01-01

    Roč. 61, č. 6 (2015), s. 495-502 ISSN 0916-8818 R&D Projects: GA MZe(CZ) QJ1510138 Institutional support: RVO:67985904 Keywords : cumulus oocyte complexes * meiosis resumption * mitogen-activated protein kinase 3/1 (MAPK3/1) Subject RIV: GI - Animal Husbandry ; Breeding Impact factor: 1.453, year: 2015

  18. Exercise in rats does not alter hypothalamic AMP-activated protein kinase activity

    DEFF Research Database (Denmark)

    Andersson, Ulrika; Treebak, Jonas Thue; Nielsen, Jakob Nis

    2005-01-01

    Recent studies have demonstrated that AMP-activated protein kinase (AMPK) in the hypothalamus is involved in the regulation of food intake. Because exercise is known to influence appetite and cause substrate depletion, it may also influence AMPK in the hypothalamus. Male rats that either rested o...

  19. Pharmacy students provide care comparable to pharmacists in an outpatient anticoagulation setting.

    Science.gov (United States)

    Dalal, Kavita; McCall, Kenneth L; Fike, David S; Horton, Niambi; Allen, April

    2010-10-11

    To evaluate whether student participation in ambulatory clinics influenced the percentage of therapeutic international normalized ratio (INR) results among patients on chronic warfarin therapy. Medical records in outpatient anticoagulation clinics managed by pharmacists under physician protocol were reviewed retrospectively in 2 university-affiliated clinics in Amarillo and Lubbock, TX. Pharmacy student activities included patient interviews, vital sign measurements, fingersticks, counseling, and documentation. Patient visits were conducted by a precepted pharmacy student or a pharmacist without a student, and the INR was measured at the subsequent patient visit. Records of 1,958 anticoagulation patient visits were reviewed; 865 patients were treated by pharmacists, and 1093 were treated by precepted students. The follow-up INR was therapeutic for 48.5% of third-year (P3) students' patients, 45.6% of fourth-year (P4) students' patients, 51.2% of residents' patients, and 44.7% of pharmacists's patients (p = 0.23). Eight variables were associated with the follow-up INR (baseline INR, warfarin noncompliance, held warfarin doses, a warfarin dosage adjustment, diet change, alcohol use, tobacco use, and any medication changes). Student participation in the patient-care process did not compromise patient care and no significant difference in patient outcomes was found between patients in an anticoagulation clinic cared for by precepted students and those cared for by pharmacists.

  20. Do novel oral anticoagulants do better than standard therapy in the treatment of deep vein thrombosis?

    Science.gov (United States)

    Brodmann, M

    2013-08-01

    The focus of DVT treatment is the prevention of recurrence and thrombus migration by treatment with anticoagulants. The aim is to improve outcomes by reducing clot burden and by preventing thrombus propagation, in order to prevent PE and the development of long-term complication. Actually, initial therapy is parenteral anticoagulation, mainly with low molecular weight heparin followed by a vitamin K antagonist (VKA) for triggered and idiopathic DVT. The long term treatment suggestion with a VKA is for sure the most challenging therapeutic scenario, showing all the disadvantages of VKA especially in the onset phase when therapeutic levels of VKA are difficult to achieve. The difference between VKAs and NOACs is the fact, that NOACs target a specific factor in the coagulation cascade. At time now two pathways have been chosen for treatment options, the direct inhibition of active sites of thrombin and factor Xa. Routine monitoring is not required and the drugs can be administered in fixed doses, which should increase patient adherence to long term treatment. At time now, four novel anticoagulants are called to be options for DVT treatment. Rivaroxaban, apixaban and edoxaban are direct FXa inhibitors, whereas dabigtran etexilate is a direct thrombin inhibitor.

  1. The RecX protein interacts with the RecA protein and modulates its activity in Herbaspirillum seropedicae

    Directory of Open Access Journals (Sweden)

    C.W. Galvão

    2012-12-01

    Full Text Available DNA repair is crucial to the survival of all organisms. The bacterial RecA protein is a central component in the SOS response and in recombinational and SOS DNA repairs. The RecX protein has been characterized as a negative modulator of RecA activity in many bacteria. The recA and recX genes of Herbaspirillum seropedicae constitute a single operon, and evidence suggests that RecX participates in SOS repair. In the present study, we show that the H. seropedicae RecX protein (RecX Hs can interact with the H. seropedicaeRecA protein (RecA Hs and that RecA Hs possesses ATP binding, ATP hydrolyzing and DNA strand exchange activities. RecX Hs inhibited 90% of the RecA Hs DNA strand exchange activity even when present in a 50-fold lower molar concentration than RecA Hs. RecA Hs ATP binding was not affected by the addition of RecX, but the ATPase activity was reduced. When RecX Hs was present before the formation of RecA filaments (RecA-ssDNA, inhibition of ATPase activity was substantially reduced and excess ssDNA also partially suppressed this inhibition. The results suggest that the RecX Hs protein negatively modulates the RecA Hs activities by protein-protein interactions and also by DNA-protein interactions.

  2. The RecX protein interacts with the RecA protein and modulates its activity in Herbaspirillum seropedicae

    International Nuclear Information System (INIS)

    Galvão, C.W.; Souza, E.M.; Etto, R.M.; Pedrosa, F.O.; Chubatsu, L.S.; Yates, M.G.; Schumacher, J.; Buck, M.; Steffens, M.B.R.

    2012-01-01

    DNA repair is crucial to the survival of all organisms. The bacterial RecA protein is a central component in the SOS response and in recombinational and SOS DNA repairs. The RecX protein has been characterized as a negative modulator of RecA activity in many bacteria. The recA and recX genes of Herbaspirillum seropedicae constitute a single operon, and evidence suggests that RecX participates in SOS repair. In the present study, we show that the H. seropedicae RecX protein (RecX Hs ) can interact with the H. seropedicae RecA protein (RecA Hs ) and that RecA Hs possesses ATP binding, ATP hydrolyzing and DNA strand exchange activities. RecX Hs inhibited 90% of the RecA Hs DNA strand exchange activity even when present in a 50-fold lower molar concentration than RecA Hs . RecA Hs ATP binding was not affected by the addition of RecX, but the ATPase activity was reduced. When RecX Hs was present before the formation of RecA filaments (RecA-ssDNA), inhibition of ATPase activity was substantially reduced and excess ssDNA also partially suppressed this inhibition. The results suggest that the RecX Hs protein negatively modulates the RecA Hs activities by protein-protein interactions and also by DNA-protein interactions

  3. The RecX protein interacts with the RecA protein and modulates its activity in Herbaspirillum seropedicae

    Energy Technology Data Exchange (ETDEWEB)

    Galvão, C.W. [Departamento de Biologia Estrutural, Molecular e Genética, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR (Brazil); Souza, E.M. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil); Etto, R.M. [Departamento de Biologia Estrutural, Molecular e Genética, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR (Brazil); Pedrosa, F.O.; Chubatsu, L.S.; Yates, M.G. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil); Schumacher, J.; Buck, M. [Department of Life Sciences, Imperial College London, London (United Kingdom); Steffens, M.B.R. [Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, Curitiba, PR (Brazil)

    2012-10-15

    DNA repair is crucial to the survival of all organisms. The bacterial RecA protein is a central component in the SOS response and in recombinational and SOS DNA repairs. The RecX protein has been characterized as a negative modulator of RecA activity in many bacteria. The recA and recX genes of Herbaspirillum seropedicae constitute a single operon, and evidence suggests that RecX participates in SOS repair. In the present study, we show that the H. seropedicae RecX protein (RecX{sub Hs}) can interact with the H. seropedicae RecA protein (RecA{sub Hs}) and that RecA{sub Hs} possesses ATP binding, ATP hydrolyzing and DNA strand exchange activities. RecX{sub Hs} inhibited 90% of the RecA{sub Hs} DNA strand exchange activity even when present in a 50-fold lower molar concentration than RecA{sub Hs}. RecA{sub Hs} ATP binding was not affected by the addition of RecX, but the ATPase activity was reduced. When RecX{sub Hs} was present before the formation of RecA filaments (RecA-ssDNA), inhibition of ATPase activity was substantially reduced and excess ssDNA also partially suppressed this inhibition. The results suggest that the RecX{sub Hs} protein negatively modulates the RecA{sub Hs} activities by protein-protein interactions and also by DNA-protein interactions.

  4. The potent, indirect adenosine monophosphate-activated protein kinase activator R419 attenuates mitogen-activated protein kinase signaling, inhibits nociceptor excitability, and reduces pain hypersensitivity in mice

    Directory of Open Access Journals (Sweden)

    Galo L. Mejia

    2016-07-01

    Full Text Available Abstract. There is a great need for new therapeutics for the treatment of pain. A possible avenue to development of such therapeutics is to interfere with signaling pathways engaged in peripheral nociceptors that cause these neurons to become hyperexcitable. There is strong evidence that mitogen-activated protein kinases and phosphoinositide 3-kinase (PI3K/mechanistic target of rapamycin signaling pathways are key modulators of nociceptor excitability in vitro and in vivo. Activation of adenosine monophosphate-activated protein kinase (AMPK can inhibit signaling in both of these pathways, and AMPK activators have been shown to inhibit nociceptor excitability and pain hypersensitivity in rodents. R419 is one of, if not the most potent AMPK activator described to date. We tested whether R419 activates AMPK in dorsal root ganglion (DRG neurons and if this leads to decreased pain hypersensitivity in mice. We find that R419 activates AMPK in DRG neurons resulting in decreased mitogen-activated protein kinase signaling, decreased nascent protein synthesis, and enhanced P body formation. R419 attenuates nerve growth factor (NGF-induced changes in excitability in DRG neurons and blocks NGF-induced mechanical pain amplification in vivo. Moreover, locally applied R419 attenuates pain hypersensitivity in a model of postsurgical pain and blocks the development of hyperalgesic priming in response to both NGF and incision. We conclude that R419 is a promising lead candidate compound for the development of potent and specific AMPK activation to inhibit pain hypersensitivity as a result of injury.

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

    Science.gov (United States)

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

    2016-05-12

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

  6. Thrombin-Inhibiting Anticoagulant Liposomes: Development and Characterization.

    Science.gov (United States)

    Endreas, Wegderes; Brüßler, Jana; Vornicescu, Doru; Keusgen, Michael; Bakowsky, Udo; Steinmetzer, Torsten

    2016-02-04

    Many peptides and peptidomimetic drugs suffer from rapid clearance in vivo; this can be reduced by increasing their size through oligomerization or covalent conjugation with polymers. As proof of principle, an alternative strategy for drug oligomerization is described, in which peptidomimetic thrombin inhibitors are incorporated into the liposome surface. For this purpose, the inhibitor moieties were covalently coupled to a palmitic acid residue through a short bifunctionalized ethylene glycol spacer. These molecules were directly added to the lipid mixture used for liposome preparation. The obtained liposomes possess strong thrombin inhibitory potency in enzyme kinetic measurements and anticoagulant activity in plasma. Their strong potency and positive ζ potential indicate that large amounts of the benzamidine-derived inhibitors are located on the surface of the liposomes. This concept should be applicable to other drug molecules that suffer from rapid elimination and allow covalent modification with a suitable fatty acid residue. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Sustained mitogen-activated protein kinase activation reprograms defense metabolism and phosphoprotein profile in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Ines eLassowskat

    2014-10-01

    Full Text Available Mitogen-activated protein kinases (MAPKs target a variety of protein substrates to regulate cellular signaling processes in eukaryotes. In plants, the number of identified MAPK substrates that control plant defense responses is still limited. Here, we generated transgenic Arabidopsis thaliana plants with an inducible system to simulate in vivo activation of two stress-activated MAPKs, MPK3 and MPK6. Metabolome analysis revealed that this artificial MPK3/6 activation (without any exposure to pathogens or other stresses is sufficient to drive the production of major defense-related metabolites, including various camalexin, indole glucosinolate and agmatine derivatives. An accompanying (phosphoproteome analysis led to detection of hundreds of potential phosphoproteins downstream of MPK3/6 activation. Besides known MAPK substrates, many candidates on this list possess typical MAPK-targeted phosphosites and in many cases, the corresponding phosphopeptides were detected by mass spectrometry. Notably, several of these putative phosphoproteins have been reported to be associated with the biosynthesis of antimicrobial defense substances (e.g. WRKY transcription factors and proteins encoded by the genes from the PEN pathway required for penetration resistance to filamentous pathogens. Thus, this work provides an inventory of candidate phosphoproteins, including putative direct MAPK substrates, for future analysis of MAPK-mediated defense control. (Proteomics data are available with the identifier PXD001252 via ProteomeXchange, http://proteomecentral.proteomexchange.org.

  8. Strategies for the photo-control of endogenous protein activity.

    Science.gov (United States)

    Brechun, Katherine E; Arndt, Katja M; Woolley, G Andrew

    2017-08-01

    Photo-controlled or 'optogenetic' effectors interfacing with endogenous protein machinery allow the roles of endogenous proteins to be probed. There are two main approaches being used to develop optogenetic effectors: (i) caging strategies using photo-controlled conformational changes, and (ii) protein relocalization strategies using photo-controlled protein-protein interactions. Numerous specific examples of these approaches have been reported and efforts to develop general methods for photo-control of endogenous proteins are a current focus. The development of improved screening and selection methods for photo-switchable proteins would advance the field. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Exploring the active site structure of photoreceptor proteins by Raman optical activity

    Science.gov (United States)

    Unno, Masashi

    2015-03-01

    Understanding protein function at the atomic level is a major challenge in a field of biophysics and requires the combined efforts of structural and functional methods. We use photoreceptor proteins as a model system to understand in atomic detail how a chromophore and a protein interact to sense light and send a biological signal. A potential technique for investigating molecular structures is Raman optical activity (ROA), which is a spectroscopic method with a high sensitivity to the structural details of chiral molecules. However, its application to photoreceptor proteins has not been reported. Thus we have constructed ROA spectrometer using near-infrared (NIR) laser excitation at 785 nm. The NIR excitation enables us to measure ROA spectra for a variety of biological samples, including photoreceptor proteins, without fluorescence from the samples. In the present study, we have applied the NIR-ROA to bacteriorhodopsin (BR) and photoactive yellow protein (PYP). BR is a light-driven proton pump and contains a protonated Schiff base of retinal as a chromophore. PYP is a blue light receptor, and this protein has the 4-hydroxycinnamyl chromophore, which is covalently linked to Cys69 through a thiolester bond. We have successfully obtained the ROA spectra of the chromophore within a protein environment. Furthermore, calculations of the ROA spectra utilizing density functional theory provide detailed structural information, such as data on out-of-plane distortions of the chromophore. The structural information obtained from the ROA spectra includes the positions of hydrogen atoms, which are usually not detected in the crystal structures of biological samples.

  10. Inadvertent exaggerated anticoagulation following use of bismuth subsalicylate in an enterally fed patient receiving warfarin therapy.

    Science.gov (United States)

    Bingham, Angela L; Brown, Rex O; Dickerson, Roland N

    2013-12-01

    We report a case of an inadvertent increase in the international normalized ratio (INR) after the addition of bismuth subsalicylate for the treatment of diarrhea in an enterally fed patient receiving warfarin therapy. A 56-year-old Caucasian female presented to the trauma intensive care unit (ICU) with multiple lower extremity fractures. Warfarin was initiated for deep vein thrombosis prophylaxis due to the patient's inability to ambulate. The target INR was 2-3. Continuous intragastric enteral feeding was withheld 1 hour before and 1 hour after intragastric administration of warfarin. Bismuth subsalicylate 30 mL every 4 hours was prescribed for diarrhea. Within 3 days after starting bismuth subsalicylate therapy, the patient's INR increased from 2.56 to 3.54 and minor bleeding was noted from the patient's tracheostomy site. No significant change in warfarin dosage, variability in vitamin K intake, or medications that potentially alter warfarin metabolism were present during the unexpected rise in INR. When the bismuth subsalicylate was discontinued, the patient's INR stabilized into the target range on the same warfarin dose given at the time of the supratherapeutic INR. Salicylate displaces warfarin from plasma protein binding sites and may result in a significant increase in INR secondary to redistribution of warfarin to the free active form. Evaluation of this case report using the Drug Interaction Probability Scale and Naranjo Adverse Drug Reaction Probability Scale yielded scores consistent with a probable adverse drug interaction. Bismuth subsalicylate exaggerates warfarin's anticoagulant response and its concurrent use during warfarin therapy should be avoided.

  11. New Activity of a Protein from Canavalia ensiformis

    Directory of Open Access Journals (Sweden)

    Vanya Petkova BOGOEVA

    2014-06-01

    Full Text Available Concanavalin A is a legume lectin which preferentially agglutinates transformed cells and shows antitumor effects on human breast carcinoma cells in vitro and in vivo. It is considered as a new potential antineoplastic agent targeting apoptosis, autophagy, and anti-angiogenesis in preclinical or clinical trials for cancer therapeutics, which has recently become the object of intensive study. In the present investigation, we show the capacity of the lectin to bind manganese, gold, iron, and zinc porphyrins: all potential anticancer agents. The interaction of the legume lectin with the studied compounds has been investigated by tryptophan fluorescence, showing conformational changes within the quaternary and tertiary structures of the protein. The binding of Con A with manganese, gold, and iron porphyrins, as well as adenine, was studied by fluorescence quenching. In contrast, the interaction of Con A with zinc porphyrin caused an increase in Trp fluorescence and a red shift of 10 nm of the emission maximum position. However, the binding of Con A to iron porphyrin was accompanied by a 5 nm blue shift of the emission maximum, and a kD of 0.95 ± 0.13 μM was calculated, respectively. The sigmoidal shape of the curve showed cooperative interactions, which indicated the presence of more than one class of binding site within the Con A molecule for iron porphyrin, confirmed by the Hill slope (h = 1.89±0.46. We have found that the legume lectin interacts with porphyrins and adenine with an affinity (0.14–1.89 μM similar to that of the non-legume lectin, wheat germ agglutinin. In conclusion, the protein Con A shows new binding activity towards porphyrins with anticancer activities and could find prospective application as a drug delivery molecule that specifically targets cancer cells.

  12. Engineering Fluorogen Activating Proteins into Self-Assembling Materials

    Science.gov (United States)

    Saunders, Matthew J.; Liu, Wen; Szent-Gyorgyi, Christopher; Wen, Yi; Drennen, Zachary; Waggoner, Alan S.; Meng, Wilson S.

    2013-01-01

    We present herein characteristics of a conjugate in which dL5, a fluorogen-activating protein (FAP) and AEAEAKAK, an amphiphilic peptide are combined to form a solid-phase fluorescence-detection platform. The FAP dL5 is a covalently linked dimer of two identical light chain variable fragments which activates the fluorescence of the fluorogen malachite green (MG). The amphiphilic peptide of sequence AEAEAKAK is a building block of stimuli-responsive materials that undergoes sol-gel phase transition at high ionic strengths. We hypothesize that the novel bi-functional protein containing both the FAP and the amphiphile, termed dL5_EAK, co-assembles with the self-assembling peptide [AEAEAKAK]2 (EAK16-II) to form an insoluble membrane composite whereby the fluorescence enhancement function of the FAP domain remains intact. Denaturing polyacrylamide electrophoresis indicated that greater than 78% of dL5_EAK incorporates into the EAK16-II membrane. Conversely, less than 32% of dL5 without the EAK sequence associates with the insoluble fraction of EAK16-II in buffers. Membranes containing dL5_EAK and EAK16-II exhibited at least 4-fold higher fluorescence intensity compared to mixtures containing dL5 and EAK16-II. Scanning electron microscopy revealed the presence of particulates, presumably FAPs, scattering on the membrane fibrils. The evidence suggests a system of materials that can be developed into in situ-forming local sensors by immobilizing dL5 into coacervate, on which MG can be detected. It is envisioned that dL5 membranes can be established in diseased locales to monitor infiltration and migration of inflammatory cells marked with antibodies conjugated to MG. PMID:23573960

  13. Activation of AMP-activated protein kinase by tributyltin induces neuronal cell death

    International Nuclear Information System (INIS)

    Nakatsu, Yusuke; Kotake, Yaichiro; Hino, Atsuko; Ohta, Shigeru

    2008-01-01

    AMP-activated protein kinase (AMPK), a member of the metabolite-sensing protein kinase family, is activated by energy deficiency and is abundantly expressed in neurons. The environmental pollutant, tributyltin chloride (TBT), is a neurotoxin, and has been reported to decrease cellular ATP in some types of cells. Therefore, we investigated whether TBT activates AMPK, and whether its activation contributes to neuronal cell death, using primary cultures of cortical neurons. Cellular ATP levels were decreased 0.5 h after exposure to 500 nM TBT, and the reduction was time-dependent. It was confirmed that most neurons in our culture system express AMPK, and that TBT induced phosphorylation of AMPK. Compound C, an AMPK inhibitor, reduced the neurotoxicity of TBT, suggesting that AMPK is involved in TBT-induced cell death. Next, the downstream target of AMPK activation was investigated. Nitric oxide synthase, p38 phosphorylation and Akt dephosphorylation were not downstream of TBT-induced AMPK activation because these factors were not affected by compound C, but glutamate release was suggested to be controlled by AMPK. Our results suggest that activation of AMPK by TBT causes neuronal death through mediating glutamate release

  14. Extractions without eliminating anticoagulant treatment: a literature review.

    Science.gov (United States)

    Rodríguez-Cabrera, Manuel-Alejandro; Barona-Dorado, Cristina; Leco-Berrocal, Isabel; Gómez-Moreno, Gerardo; Martínez-González, José-Maria

    2011-09-01

    To establish whether there is a high enough risk of bleeding in patients who take oral anticoagulants, such that it would justify not using oral anticoagulants when performing a dental extraction, as well as if the reason for and anatomical location of the extraction increases such risk. We performed a bibliographic search in order to carry out a meta-analytic study using descriptive statistics. We compiled a sample of 1194 patients from the articles selected. Of these patients, a total of 2392 simple, serial surgical extractions were performed; none of the patients interrupted their anticoagulant treatment with warfarin sodium. Of the sample, 83 patients presented a certain degree of bleeding; in 77 of such cases, the bleeding was controlled with local hemostasis, whereas 6 patients required their dose of oral anticoagulants to be adjusted. There was a higher incidence of bleeding in patients presenting a periodontal pathology, compared to deep caries and pericoronitis. Patients being treated with oral anticoagulants represent a risk that we should be aware of, but local hemostasis has proven to be effective when performing extractions, provided that the INR value is less than 4. There is an increased incidence of bleeding in patients with periodontal problems, due to the greater presence of inflammation in the soft tissues. If the extraction is performed in the maxilla, the incidence of hemorrhagic complications is slightly higher than in the mandible, although this difference is considered to be insignificant.

  15. Protein implicated in nonsyndromic mental retardation regulates protein kinase A (PKA) activity

    KAUST Repository

    Altawashi, Azza

    2012-02-28

    Mutation of the coiled-coil and C2 domain-containing 1A (CC2D1A) gene, which encodes a C2 domain and DM14 domain-containing protein, has been linked to severe autosomal recessive nonsyndromic mental retardation. Using a mouse model that produces a truncated form of CC2D1A that lacks the C2 domain and three of the four DM14 domains, we show that CC2D1A is important for neuronal differentiation and brain development. CC2D1A mutant neurons are hypersensitive to stress and have a reduced capacitytoformdendritesandsynapsesinculture. Atthebiochemical level,CC2D1Atransduces signals to the cyclic adenosine 3?,5?-monophosphate (cAMP)-protein kinase A (PKA) pathway during neuronal cell differentiation. PKA activity is compromised, and the translocation of its catalytic subunit to the nucleus is also defective in CC2D1A mutant cells. Consistently, phosphorylation of the PKA target cAMP-responsive element-binding protein, at serine 133, is nearly abolished in CC2D1A mutant cells. The defects in cAMP/PKA signaling were observed in fibroblast, macrophage, and neuronal primary cells derived from the CC2D1A KO mice. CC2D1A associates with the cAMP-PKA complex following forskolin treatment and accumulates in vesicles or on the plasma membrane in wild-type cells, suggesting that CC2D1A may recruit the PKA complex to the membrane to facilitate signal transduction. Together, our data show that CC2D1A is an important regulator of the cAMP/PKA signaling pathway, which may be the underlying cause for impaired mental function in nonsyndromic mental retardation patients with CC2D1A mutation. 2012 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. 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

  17. Cyclic nucleotides and mitogen-activated protein kinases: regulation of simvastatin in platelet activation

    Directory of Open Access Journals (Sweden)

    Hou Ssu-Yu

    2010-06-01

    Full Text Available Abstract Background 3-Hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA reductase inhibitors (statins have been widely used to reduce cardiovascular risk. These statins (i.e., simvastatin may exert other effects besides from their cholesterol-lowering actions, including inhibition of platelet activation. Platelet activation is relevant to a variety of coronary heart diseases. Although the inhibitory effect of simvastatin in platelet activation has been studied; the detailed signal transductions by which simvastatin inhibit platelet activation has not yet been completely resolved. Methods The aim of this study was to systematically examine the detailed mechanisms of simvastatin in preventing platelet activation. Platelet aggregation, flow cytometric analysis, immunoblotting, and electron spin resonance studies were used to assess the antiplatelet activity of simvastatin. Results Simvastatin (20-50 μM exhibited more-potent activity of inhibiting platelet aggregation stimulated by collagen than other agonists (i.e., thrombin. Simvastatin inhibited collagen-stimulated platelet activation accompanied by [Ca2+]i mobilization, thromboxane A2 (TxA2 formation, and phospholipase C (PLCγ2, protein kinase C (PKC, and mitogen-activated protein kinases (i.e., p38 MAPK, JNKs phosphorylation in washed platelets. Simvastatin obviously increased both cyclic AMP and cyclic GMP levels. Simvastatin markedly increased NO release, vasodilator-stimulated phosphoprotein (VASP phosphorylation, and endothelial nitric oxide synthase (eNOS expression. SQ22536, an inhibitor of adenylate cyclase, markedly reversed the simvastatin-mediated inhibitory effects on platelet aggregation, PLCγ2 and p38 MAPK phosphorylation, and simvastatin-mediated stimulatory effects on VASP and eNOS phosphorylation. Conclusion The most important findings of this study demonstrate for the first time that inhibitory effect of simvastatin in platelet activation may involve activation of the cyclic AMP

  18. Xylazine Activates Adenosine Monophosphate-Activated Protein Kinase Pathway in the Central Nervous System of Rats.

    Directory of Open Access Journals (Sweden)

    Xing-Xing Shi

    Full Text Available Xylazine is a potent analgesic extensively used in veterinary and animal experimentation. Evidence exists that the analgesic effect can be inhibited using adenosine 5'-monophosphate activated protein kinase (AMPK inhibitors. Considering this idea, the aim of this study was to investigate whether the AMPK signaling pathway is involved in the central analgesic mechanism of xylazine in the rat. Xylazine was administrated via the intraperitoneal route. Sprague-Dawley rats were sacrificed and the cerebral cortex, cerebellum, hippocampus, thalamus and brainstem were collected for determination of liver kinase B1 (LKB1 and AMPKα mRNA expression using quantitative real-time polymerase chain reaction (qPCR, and phosphorylated LKB1 and AMPKα levels using western blot. The results of our study showed that compared with the control group, xylazine induced significant increases in AMPK activity in the cerebral cortex, hippocampus, thalamus and cerebellum after rats received xylazine (P < 0.01. Increased AMPK activities were accompanied with increased phosphorylation levels of LKB1 in corresponding regions of rats. The protein levels of phosphorylated LKB1 and AMPKα in these regions returned or tended to return to control group levels. However, in the brainstem, phosphorylated LKB1 and AMPKα protein levels were decreased by xylazine compared with the control (P < 0.05. In conclusion, our data indicates that xylazine alters the activities of LKB1 and AMPK in the central nervous system of rats, which suggests that xylazine affects the regulatory signaling pathway of the analgesic mechanism in the rat brain.

  19. Scaffold protein enigma homolog activates CREB whereas a short splice variant prevents CREB activation in cardiomyocytes.

    Science.gov (United States)

    Ito, Jumpei; Iijima, Masumi; Yoshimoto, Nobuo; Niimi, Tomoaki; Kuroda, Shun'ichi; Maturana, Andrés D

    2015-12-01

    Enigma Homolog (ENH1 or Pdlim5) is a scaffold protein composed of an N-terminal PDZ domain and three LIM domains at the C-terminal end. The enh gene encodes for several splice variants with opposing functions. ENH1 promotes cardiomyocytes hypertrophy whereas ENH splice variants lacking LIM domains prevent it. ENH1 interacts with various Protein Kinase C (PKC) isozymes and Protein Kinase D1 (PKD1). In addition, the binding of ENH1's LIM domains to PKC is sufficient to activate the kinase without stimulation. The downstream events of the ENH1-PKC/PKD1 complex remain unknown. PKC and PKD1 are known to phosphorylate the transcription factor cAMP-response element binding protein (CREB). We tested whether ENH1 could play a role in the activation of CREB. We found that, in neonatal rat ventricular cardiomyocytes, ENH1 interacts with CREB, is necessary for the phosphorylation of CREB at ser133, and the activation of CREB-dependent transcription. On the contrary, the overexpression of ENH3, a LIM-less splice variant, inhibited the phosphorylation of CREB. ENH3 overexpression or shRNA knockdown of ENH1 prevented the CREB-dependent transcription. Our results thus suggest that ENH1 plays an essential role in CREB's activation and dependent transcription in cardiomyocytes. At the opposite, ENH3 prevents the CREB transcriptional activity. In conclusion, these results provide a first molecular explanation to the opposing functions of ENH splice variants. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. PIAS proteins are involved in the SUMO-1 modification, intracellular translocation and transcriptional repressive activity of RET finger protein

    International Nuclear Information System (INIS)

    Matsuura, Tetsuo; Shimono, Yohei; Kawai, Kumi; Murakami, Hideki; Urano, Takeshi; Niwa, Yasumasa; Goto, Hidemi; Takahashi, Masahide

    2005-01-01

    Ret finger protein (RFP) is a nuclear protein that is highly expressed in testis and in various tumor cell lines. RFP functions as a transcriptional repressor and associates with Enhancer of Polycomb 1 (EPC1), a member of the Polycomb group proteins, and Mi-2β, a main component of the nucleosome remodeling and deacetylase (NuRD) complex. We show that RFP binds with PIAS (protein inhibitor of activated STAT) proteins, PIAS1, PIAS3, PIASxα and PIASy at their carboxyl-terminal region and is covalently modified by SUMO-1 (sumoylation). PIAS proteins enhance the sumoylation of RFP in a dose-dependent manner and induce the translocation of RFP into nuclear bodies reminiscent of the PML bodies. In addition, co-expression of PIAS proteins or SUMO-1 strengthened the transcriptional repressive activity of RFP. Finally, our immunohistochemical results show that RFP, SUMO-1 and PIASy localize in a characteristic nuclear structure juxtaposed with the inner nuclear membrane (XY body) of primary spermatocytes in mouse testis. These results demonstrate that the intracellular location and the transcriptional activity of RFP are modified by PIAS proteins which possess SUMO E3 ligase activities and suggest that they may play a co-operative role in spermatogenesis

  1. Site-specific incorporation of redox active amino acids into proteins

    Energy Technology Data Exchange (ETDEWEB)

    Alfonta, Lital; Schultz, Peter G.; Zhang, Zhiwen

    2017-10-10

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  2. Site-specific incorporation of redox active amino acids into proteins

    Science.gov (United States)

    Alfonta, Lital [San Diego, CA; Schultz, Peter G [La Jolla, CA; Zhang, Zhiwen [San Diego, CA

    2009-02-24

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  3. Metformin activates type I interferon signaling against HCV via activation of adenosine monophosphate-activated protein kinase.

    Science.gov (United States)

    Tsai, Wei-Lun; Chang, Tsung-Hsien; Sun, Wei-Chi; Chan, Hoi-Hung; Wu, Chun-Ching; Hsu, Ping-I; Cheng, Jin-Shiung; Yu, Ming-Lung

    2017-11-03

    Activation of the type I interferon (IFN) signaling pathway is essential for the eradication of hepatitis C virus (HCV). Metformin can activate adenosine monophosphate-activated protein kinase (AMPK) to reduce insulin resistance. Cross talks between AMPK and IFN signaling remain unclear. To understand the influence of metformin on the type I IFN signaling pathway and HCV infection, the full-length HCV replicon OR6 cells and the infectious HCV clones JFH1 were used to assess the anti-HCV effect of the insulin sensitizers, metformin and pioglitazone. Immunofluorescence staining and the immunoblotting of HCV viral protein demonstrated that metformin, but not pioglitazone, inhibited HCV replication in OR-6 and JFH-1-infected Huh 7.5.1 cells. Immunoblotting data showed that metformin activated the phosphorylation of STAT-1 and STAT-2 in OR-6 and JFH-1 infected Huh 7.5.1 cells. Metformin enhanced the phosphorylation of AMPK, and the metformin-activated IFN signaling was down-regulated by AMPK inhibitor. After treatment of AMPK inhibitor, the level of HCV core protein decreased by metformin can be rescued. In conclusion, metformin activates type I interferon signaling and inhibits the replication of HCV via activation of AMPK.

  4. Molecular mechanism by which AMP-activated protein kinase activation promotes glycogen accumulation in muscle

    DEFF Research Database (Denmark)

    Hunter, Roger W; Treebak, Jonas Thue; Wojtaszewski, Jørgen

    2011-01-01

    OBJECTIVE During energy stress, AMP-activated protein kinase (AMPK) promotes glucose transport and glycolysis for ATP production, while it is thought to inhibit anabolic glycogen synthesis by suppressing the activity of glycogen synthase (GS) to maintain the energy balance in muscle. Paradoxically......, chronic activation of AMPK causes an increase in glycogen accumulation in skeletal and cardiac muscles, which in some cases is associated with cardiac dysfunction. The aim of this study was to elucidate the molecular mechanism by which AMPK activation promotes muscle glycogen accumulation. RESEARCH DESIGN...... caused a modest inactivation of GS, it stimulated muscle glycogen synthesis that was accompanied by increases in glucose transport and intracellular [G6P]. These effects of AICAR required the catalytic activity of AMPK. Strikingly, AICAR-induced glycogen synthesis was completely abolished in G6P...

  5. Stimulation of Leishmania tropica protein kinase CK2 activities by platelet-activating factor (PAF).

    Science.gov (United States)

    Dutra, Patricia M L; Vieira, Danielle P; Meyer-Fernandes, Jose R; Silva-Neto, Mario A C; Lopes, Angela H

    2009-09-01

    Leishmania tropica is one of the causative agents of cutaneous leishmaniasis. Platelet-activating factor (PAF) is a phospholipid mediator in diverse biological and pathophysiological processes. Here we show that PAF promoted a three-fold increase on ecto-protein kinase and a three-fold increase on the secreted kinase activity of L. tropica live promastigotes. When casein was added to the reaction medium, along with PAF, there was a four-fold increase on the ecto-kinase activity. When live L. tropica promastigotes were pre-incubated for 30 min in the presence of PAF-plus casein, a six-fold increase on the secreted kinase activity was observed. Also, a protein released from L. tropica promastigotes reacted with polyclonal antibodies for the mammalian CK2 alpha catalytic subunit. Furthermore, in vitro mouse macrophage infection by L. tropica was doubled when promastigotes were pre-treated for 2 h with PAF. Similar results were obtained when the interaction was performed in the presence of purified CK2 or casein. TBB and DRB, CK2 inhibitors, reversed PAF enhancement of macrophage infection by L. tropica. WEB 2086, a competitive PAF antagonist, reversed all PAF effects here described. This study shows for the first time that PAF promotes the activation of two isoforms of CK2, secreted and membrane-bound, correlating these activities to infection of mouse macrophages.

  6. Protein Inhibitors of Activated STAT (Pias1 and Piasy) Differentially Regulate Pituitary Homeobox 2 (PITX2) Transcriptional Activity*

    Science.gov (United States)

    Wang, Jianbo; Sun, Zhao; Zhang, Zichao; Saadi, Irfan; Wang, Jun; Li, Xiao; Gao, Shan; Engle, Jamison J.; Kuburas, Adisa; Fu, Xueyao; Yu, Wenjie; Klein, William H.; Russo, Andrew F.; Amendt, Brad A.

    2013-01-01

    Protein inhibitors of activated STAT (Pias) proteins can act independent of sumoylation to modulate the activity of transcription factors and Pias proteins interacting with transcription factors can either activate or repress their activity. Pias proteins are expressed in many tissues and cells during development and we asked if Pias proteins regulated the pituitary homeobox 2 (PITX2) homeodomain protein, which modulates developmental gene expression. Piasy and Pias1 proteins are expressed during craniofacial/tooth development and directly interact and differentially regulate PITX2 transcriptional activity. Piasy and Pias1 are co-expressed in craniofacial tissues with PITX2. Yeast two-hybrid, co-immunoprecipitation and pulldown experiments demonstrate Piasy and Pias1 interactions with the PITX2 protein. Piasy interacts with the PITX2 C-terminal tail to attenuate its transcriptional activity. In contrast, Pias1 interacts with the PITX2 C-terminal tail to increase PITX2 transcriptional activity. The E3 ligase activity associated with the RING domain in Piasy is not required for the attenuation of PITX2 activity, however, the RING domain of Pias1 is required for enhanced PITX2 transcriptional activity. Bimolecular fluorescence complementation assays reveal PITX2 interactions with Piasy and Pias1 in the nucleus. Piasy represses the synergistic activation of PITX2 with interacting co-factors and Piasy represses Pias1 activation of PITX2 transcriptional activity. In contrast, Pias1 did not affect the synergistic interaction of PITX2 with transcriptional co-factors. Last, we demonstrate that Pias proteins form a complex with PITX2 and Lef-1, and PITX2 and β-catenin. Lef-1, β-catenin, and Pias interactions with PITX2 provide new molecular mechanisms for the regulation of PITX2 transcriptional activity and the activity of Pias proteins. PMID:23515314

  7. Protein inhibitors of activated STAT (Pias1 and Piasy) differentially regulate pituitary homeobox 2 (PITX2) transcriptional activity.

    Science.gov (United States)

    Wang, Jianbo; Sun, Zhao; Zhang, Zichao; Saadi, Irfan; Wang, Jun; Li, Xiao; Gao, Shan; Engle, Jamison J; Kuburas, Adisa; Fu, Xueyao; Yu, Wenjie; Klein, William H; Russo, Andrew F; Amendt, Brad A

    2013-05-03

    Protein inhibitors of activated STAT (Pias) proteins can act independent of sumoylation to modulate the activity of transcription factors and Pias proteins interacting with transcription factors can either activate or repress their activity. Pias proteins are expressed in many tissues and cells during development and we asked if Pias proteins regulated the pituitary homeobox 2 (PITX2) homeodomain protein, which modulates developmental gene expression. Piasy and Pias1 proteins are expressed during craniofacial/tooth development and directly interact and differentially regulate PITX2 transcriptional activity. Piasy and Pias1 are co-expressed in craniofacial tissues with PITX2. Yeast two-hybrid, co-immunoprecipitation and pulldown experiments demonstrate Piasy and Pias1 interactions with the PITX2 protein. Piasy interacts with the PITX2 C-terminal tail to attenuate its transcriptional activity. In contrast, Pias1 interacts with the PITX2 C-terminal tail to increase PITX2 transcriptional activity. The E3 ligase activity associated with the RING domain in Piasy is not required for the attenuation of PITX2 activity, however, the RING domain of Pias1 is required for enhanced PITX2 transcriptional activity. Bimolecular fluorescence complementation assays reveal PITX2 interactions with Piasy and Pias1 in the nucleus. Piasy represses the synergistic activation of PITX2 with interacting co-factors and Piasy represses Pias1 activation of PITX2 transcriptional activity. In contrast, Pias1 did not affect the synergistic interaction of PITX2 with transcriptional co-factors. Last, we demonstrate that Pias proteins form a complex with PITX2 and Lef-1, and PITX2 and β-catenin. Lef-1, β-catenin, and Pias interactions with PITX2 provide new molecular mechanisms for the regulation of PITX2 transcriptional activity and the activity of Pias proteins.

  8. Extended anticoagulation in venous thromboembolism disease. In favour.

    Science.gov (United States)

    Fernández Capitan, M C

    Venous thromboembolism disease can be considered a chronic disease because, after the first episode, there is a life-long risk of recurrence. Recurrence is a severe complication. Anticoagulation is effective while it is maintained, but when it is discontinued, the risk of new thrombotic events persists indefinitely. Clinical practice guidelines offer specific recommendations on the treatment duration for patients with provoked or recurrent disease but are not specific for those with a first unprovoked episode. The decision should be made after a careful individual assessment of the risk-benefit of anticoagulation. This article reviews the evidence in favour of extending the anticoagulation and the current therapeutic options. Copyright © 2017. Publicado por Elsevier España, S.L.U.

  9. [Tranexamic acid gel in patients treated with oral anticoagulants].

    Science.gov (United States)

    Ripollés-de Ramón, Jorge; Muñoz-Corcuera, Marta; Bravo-Llatas, Carmen; Bascones-Martínez, Antonio

    2014-12-09

    Patients treated with oral anticoagulants have increased susceptibility to bleeding, and therefore any surgical medical procedure and especially oral surgery requires a therapeutic approach that minimizes bleeding effects in these patients. The working hypothesis was based on studies of local application of tranexamic acid after maxillofacial interventions as effective therapeutic alternative for the prevention and control of bleeding. The aim was to assess the effectiveness of the application of a gel solution tranexamic acid after tooth extraction in anticoagulated patients in terms of healing time and degree of healing. The results indicate that application of tranexamic acid gel is very effective for consistency and maintenance in the place of action and shows its efficacy as a procoagulant material. The application of a gel solution of tranexamic acid in oral anticoagulants patients ameliorates healing time and the bleeding time within the first 48-72 h. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  10. [Novel anticoagulants for stroke prevention in atrial fibrillation].

    Science.gov (United States)

    Baumhäkel, M; Schirmer, S H; Böhm, M

    2010-11-01

    The most frequent cardiac arrhythmia and main cause for cardio-embolic stroke is atrial fibrillation. Prophylaxis for thrombembolic events is performed regarding individual risk of patients with either ASS or vitamin-K-antagonists. Efficacy and safety of oral anticoagulation is limited by a narrow therapeutical range as well as by inter- and intraindividual variability of INR-values due to genetic disposition, differences in alimentation, dosage errors, rare control of INR-levels and drug-interactions. New oral anticoagulants with different mechanisms of action may be a promising therapeutic option in future. This review addresses the new anticoagulants Apixaban, Rivaroxban and Dabigatranetexilat with the design and as available the results of the corresponding phase-III-trials in atrial fibrillation (ARISTOTLE, ROCKET-AF, RE-LY). © Georg Thieme Verlag KG Stuttgart · New York.

  11. Management of Periprocedural Anticoagulation: A Survey of Contemporary Practice.

    Science.gov (United States)

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

    2016-07-12

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

  12. Mechanical Prosthetic Valves and Pregnancy: A therapeutic dilemma of anticoagulation

    Directory of Open Access Journals (Sweden)

    Prashanth Panduranga

    2014-10-01

    Full Text Available Choosing the best anticoagulant therapy for a pregnant patient with a mechanical prosthetic valve is controversial and the published international guidelines contain no clear-cut consensus on the best approach. This is due to the fact that there is presently no anticoagulant which can reliably decrease thromboembolic events while avoiding damage to the fetus. Current treatments include either continuing oral warfarin or substituting warfarin for subcutaneous unfractionated heparin or low-molecular-weight heparin (LMWH in the first trimester (6–12 weeks or at any point throughout the pregnancy. However, LMWH, while widely-prescribed, requires close monitoring of the blood anti-factor Xa levels. Unfortunately, facilities for such monitoring are not universally available, such as within hospitals in developing countries. This review evaluates the leading international guidelines concerning anticoagulant therapy in pregnant patients with mechanical prosthetic valves as well as proposing a simplified guideline which may be more relevant to hospitals in this region.

  13. Chemical synthesis of biologically active monoglycosylated GM2-activator protein analogue using N-sulfanylethylanilide peptide.

    Science.gov (United States)

    Sato, Kohei; Shigenaga, Akira; Kitakaze, Keisuke; Sakamoto, Ken; Tsuji, Daisuke; Itoh, Kohji; Otaka, Akira

    2013-07-22

    Going to SEA(lide): Total chemical synthesis of a 162-residue glycoprotein analogue of the monoglycosylated human GM2-activator protein (GM2AP) was achieved. Key steps were the use of N-sulfanylethylanilide (SEAlide) peptides in the kinetic chemical ligation synthesis of a large peptide fragment, and a convergent native chemical ligation for final fragment assembly. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Antioxidant activity of black bean (Phaseolus vulgaris L.) protein hydrolysates

    Science.gov (United States)

    The objective of this work was to study the effect of enzymatic hydrolysis of black bean protein concentrate using different enzymes. Bean proteins were extracted and hydrolyzed over a period of 120 min using the enzymes pepsin or alcalase. The protein hydrolysates’ molecular weight was assayed by e...

  15. Antiviral and antitumor activities of the protein fractions from the ...

    African Journals Online (AJOL)

    In this study, we present the extraction and purification of protein fractions from the larvae of the housefly, Musca domestica. The bioactivities of the protein fractions were indicated by pseudorabies virus (PRV) and human lung cancer cell line A 549. The crude protein fractions had no toxicity to chick embryo fibroblast-like ...

  16. Expression of the GM2 activator protein in mouse testis.

    Science.gov (United States)

    Li, Yu-Teh; Li, Su-Chen; Chen, I-Li

    2017-12-01

    The GM2-activator protein (GM2-AP), revealed by Li et al. in 1973 in human liver, was initially identified as a protein cofactor that stimulated β-hexosaminidase A to hydrolyze N-acetylgalactosamine from GM2 ganglioside. This cofactor was found to be missing in human variant AB Tay-Sachs disease. Over the years, the GM2-AP has also been shown to be involved in kidney vesicular transport, lipid presentation by CD1 molecule to T-cells, and interaction of human sperm with zona pellucida. Since the expression of the GM2-AP via mRNA detection in mouse tissues was found to be the highest in testis, we became interested in the localization of the GM2-AP at cellular level in mouse testis during spermatogenesis. Using immunohistochemical analysis and electron microscopy, we found that the GM2-AP was predominantly localized in the basal cytoplasm and the attenuated processes of Sertoli cells. The stained structure appeared to be lysosomes. The most interesting finding was the association of the GM2-AP with the acrosomal apparatus in early spermatids. A modest to intense staining was observed in some acrosomal granules and acrosomal caps. The GM2-AP seemed to disappear from acrosomal caps in the later stage of spermatids, in which the nucleus became elongated and condensed. These results suggest that the GM2-AP may be involved in the normal functions of Sertoli cells and play important roles during the development of acrosomal caps in the early spermatids. Copyright © 2017 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  17. Heat Shock Protein 70 Modulates Influenza A Virus Polymerase Activity*

    Science.gov (United States)

    Manzoor, Rashid; Kuroda, Kazumichi; Yoshida, Reiko; Tsuda, Yoshimi; Fujikura, Daisuke; Miyamoto, Hiroko; Kajihara, Masahiro; Kida, Hiroshi; Takada, Ayato

    2014-01-01

    The role of heat shock protein 70 (Hsp70) in virus replication has been discussed for many viruses. The known suppressive role of Hsp70 in influenza virus replication is based on studies conducted in cells with various Hsp70 expression levels. In this study, we determined the role of Hsp70 in influenza virus replication in HeLa and HEK293T cells, which express Hsp70 constitutively. Co-immunoprecipitation and immunofluorescence studies revealed that Hsp70 interacted with PB2 or PB1 monomers and PB2/PB1 heterodimer but not with the PB1/PA heterodimer or PB2/PB1/PA heterotrimer and translocated into the nucleus with PB2 monomers or PB2/PB1 heterodimers. Knocking down Hsp70 resulted in reduced virus transcription and replication activities. Reporter gene assay, immunofluorescence assay, and Western blot analysis of nuclear and cytoplasmic fractions from infected cells demonstrated that the increase in viral polymerase activity during the heat shock phase was accompanied with an increase in Hsp70 and viral polymerases levels in the nuclei, where influenza virus replication takes place, whereas a reduction in viral polymerase activity was accompanied with an increase in cytoplasmic relocation of Hsp70 along with viral polymerases. Moreover, significantly higher levels of viral genomic RNA (vRNA) were observed during the heat shock phase than during the recovery phase. Overall, for the first time, these findings suggest that Hsp70 may act as a chaperone for influenza virus polymerase, and the modulatory effect of Hsp70 appears to be a sequel of shuttling of Hsp70 between nuclear and cytoplasmic compartments. PMID:24474693

  18. Differences in patient outcomes and chronic care management of oral anticoagulant therapy: an explorative study

    NARCIS (Netherlands)

    Drewes, H.W.; Lambooij, M.S.; Baan, C.A.; Meijboom, B.R.; Graafmans, W.C.; Westert, G.P.

    2011-01-01

    BACKGROUND: The oral anticoagulant therapy - provided to prevent thrombosis - is known to be associated with substantial avoidable hospitalization. Improving the quality of the oral anticoagulant therapy could avoid drug related hospitalizations. Therefore, this study compared the patient outcomes

  19. Differences in patient outcomes and chronic care management of oral anticoagulant therapy : An explorative study

    NARCIS (Netherlands)

    Drewes, H.W.; Lambooij, M.; Baan, C.A.; Meijboom, B.R.; Graafmans, W.C.; Westert, G.P.

    2011-01-01

    Background The oral anticoagulant therapy - provided to prevent thrombosis - is known to be associated with substantial avoidable hospitalization. Improving the quality of the oral anticoagulant therapy could avoid drug related hospitalizations. Therefore, this study compared the patient outcomes

  20. A comparative assessment of efficacy of three anticoagulant rodenticides.

    Science.gov (United States)

    Renapurkar, D M

    1982-01-01

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

  1. Inhibition of warfarin anticoagulation associated with chelation therapy.

    Science.gov (United States)

    Grebe, Heidi Braun; Gregory, Philip J

    2002-08-01

    Chelation therapy originally was administered exclusively to patients with heavy metal poisoning. Now some physicians are administering this therapy for numerous conditions, most commonly coronary heart disease. A 64-year-old man experienced impaired warfarin anticoagulation after undergoing chelation therapy His international normalized ratio (INR) fell from 2.6 the day before to 1.6 the day after therapy was administered. Whether chelation therapy decreases the effectiveness of warfarin anticoagulation is uncertain. However, because of this potential interaction, clinicians should consider increased INR monitoring in patients undergoing chelation therapy.

  2. 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 anticoagulants...... (NOACs) have been extensively studied in patients with deep vein thrombosis (DVT), pulmonary embolism (PE) and non-valvular atrial fibrillation (NVAF). The aim of our work to review the available evidence for NOACs in the treatment of CVT. Based on our literature search there is insufficient evidence...... to support the use of NOACs in CVT, although case series with rivaroxaban and dabigatran have showed promising results....

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

    Science.gov (United States)

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

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

  4. 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

    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. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Regulatory, legislative, and policy updates with anticoagulant use.

    Science.gov (United States)

    Fanikos, John; Buckley, Leo F; Aldemerdash, Ahmed; Terry, Kimberly J; Piazza, Gregory; Connors, Jean M; Goldhaber, Samuel Z

    2015-04-01

    Thromboembolism afflicts millions of patients annually in the United States and is associated with a significant cost burden. Recent advances in oral anticoagulation have provided clinicians with more options for management of these diseases. Accordingly, regulatory, legislative, and policy-making organizations have intervened with the aim of improving patient outcomes, ensuring patient safety, and reducing costs. There have been a number of recent developments in surveillance, litigation, and regulatory oversight that clinicians should recognize. In this review article we summarize key updates related to the management of anticoagulant therapy as it relates to thrombosis prevention and treatment.

  6. Anticoagulant therapy duration. In favour of short-term courses.

    Science.gov (United States)

    Nieto Rodríguez, J A; Ramírez Luna, J C

    In recent years, we have observed a tendency to extend anticoagulant therapy for patients with venous thromboembolism disease (VTE). This practice exposes patients to a greater risk of severe and fatal haemorrhage, which, in certain conditions, outweighs the benefits related to the reduction in disease recurrence. This review examines the evidence in favour of reducing anticoagulant therapy as much as possible, especially for patients with VTE "caused" by temporary risk factors, with isolated deep vein thrombosis and with unprovoked VTE and a high risk of haemorrhage. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  7. Use of Thromboelastography (TEG) for Detection of New Oral Anticoagulants.

    Science.gov (United States)

    Dias, João D; Norem, Katherine; Doorneweerd, Derek D; Thurer, Robert L; Popovsky, Mark A; Omert, Laurel A

    2015-05-01

    The clinical introduction of new oral anticoagulants (NOACs) has stimulated the development of tests to quantify the effects of these drugs and manage complications associated with their use. Until recently, the only treatment choices for the prevention of venous thromboembolism in orthopedic surgical patients, as well as for stroke and systemic embolism in patients with atrial fibrillation, were vitamin K antagonists, antiplatelet drugs, and unfractionated and low-molecular-weight heparins. With the approval of NOACs, treatment options and consequent diagnostic challenges have expanded. To study the utility of thromboelastography (TEG) in monitoring and differentiating between 2 currently approved classes of NOACs, direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban and apixaban). Blood samples from healthy volunteers were spiked with each NOAC in both the presence and absence of ecarin, and the effects on TEG were evaluated. Both the kaolin test reaction time (R time) and the time to maximum rate of thrombus generation were prolonged versus control samples and demonstrated a dose response for apixaban (R time within the normal range) and dabigatran. The RapidTEG activated clotting time test allowed the creation of a dose-response curve for all 3 NOACs. In the presence of anti-Xa inhibitors, the ecarin test promoted significant shortening of kaolin R times to the hypercoagulable range, while in the presence of the direct thrombin inhibitor only small and dose-proportional R time shortening was observed. The RapidTEG activated clotting time test and the kaolin test appear to be capable of detecting and monitoring NOACs. The ecarin test may be used to differentiate between Xa inhibitors and direct thrombin inhibitors. Therefore, TEG may be a valuable tool to investigate hemostasis and the effectiveness of reversal strategies for patients receiving NOACs.

  8. Rheb Inhibits Protein Synthesis by Activating the PERK-eIF2α Signaling Cascade

    Directory of Open Access Journals (Sweden)

    Richa Tyagi

    2015-02-01

    Full Text Available Rheb, a ubiquitous small GTPase, is well known to bind and activate mTOR, which augments protein synthesis. Inhibition of protein synthesis is also physiologically regulated. Thus, with cell stress, the unfolded protein response system leads to phosphorylation of the initiation factor eIF2α and arrest of protein synthesis. We now demonstrate a major role for Rheb in inhibiting protein synthesis by enhancing the phosphorylation of eIF2α by protein kinase-like ER kinase (PERK. Interplay between the stimulatory and inhibitory roles of Rheb may enable cells to modulate protein synthesis in response to varying environmental stresses.

  9. Background on international activities on protein quality assessment of foods.

    Science.gov (United States)

    Gilani, G Sarwar

    2012-08-01

    The subject of protein quality assessment of foods and diets was addressed at the Codex Committee on Vegetable Proteins (1982-1989), FAO/WHO (1989, 2001) and WHO/FAO (2002) expert reviews. These international developments are summarized in this manuscript. In 1989, a Joint FAO/WHO Expert Consultation on Protein Quality Evaluation reviewed knowledge of protein quality assessment of foods, and specifically evaluated amino acid score corrected for protein digestibility, the method recommended by the Codex Committee on Vegetable Proteins. The report of the Consultation published in 1991 concluded that the Protein Digestibility-corrected Amino Acid Score (PDCAAS) method was the most suitable approach for routine evaluation of protein quality for humans. The Consultation recognized that the amino acid scoring pattern proposed by FAO/WHO/UNU (1985) for preschool children was at that time the most suitable pattern for calculating PDCAAS for all ages except infants in which case the amino acid composition of human milk was recommended to be the basis of the scoring pattern. The rat balance method was considered as the most suitable practical method for predicting protein digestibility by humans. Since its adoption by FAO/WHO (1991), the PDCAAS method has been criticised for a number of reasons. The FAO/WHO (2001) Working Group on analytical issues related to protein quality assessed the validity of criticisms of the PDCAAS method. While recognizing a distinct regulatory use of protein quality data, the Working Group recommended that the PDCAAS method may be inappropriate for the routine prediction of protein quality of novel and sole source foods which contain high levels of anti nutritional factors; and that for regulatory purposes, the method should be revised to permit values of >100 for high quality proteins. In evaluating the recommendations of the Working Group, the WHO/FAO (2002) Expert Consultation on Protein and Amino Acid Requirements endorsed the PDCAAS method

  10. Protein Conformational Gating of Enzymatic Activity in Xanthine Oxidoreductase

    Energy Technology Data Exchange (ETDEWEB)

    Ishikita, Hiroshi; Eger, Bryan T.; Okamoto, Ken; Nishino, Takeshi; Pai, Emil F. (Toronto); (Kyoto)

    2012-05-24

    In mammals, xanthine oxidoreductase can exist as xanthine dehydrogenase (XDH) and xanthine oxidase (XO). The two enzymes possess common redox active cofactors, which form an electron transfer (ET) pathway terminated by a flavin cofactor. In spite of identical protein primary structures, the redox potential difference between XDH and XO for the flavin semiquinone/hydroquinone pair (E{sub sq/hq}) is {approx}170 mV, a striking difference. The former greatly prefers NAD{sup +} as ultimate substrate for ET from the iron-sulfur cluster FeS-II via flavin while the latter only accepts dioxygen. In XDH (without NAD{sup +}), however, the redox potential of the electron donor FeS-II is 180 mV higher than that for the acceptor flavin, yielding an energetically uphill ET. On the basis of new 1.65, 2.3, 1.9, and 2.2 {angstrom} resolution crystal structures for XDH, XO, the NAD{sup +}- and NADH-complexed XDH, E{sub sq/hq} were calculated to better understand how the enzyme activates an ET from FeS-II to flavin. The majority of the E{sub sq/hq} difference between XDH and XO originates from a conformational change in the loop at positions 423-433 near the flavin binding site, causing the differences in stability of the semiquinone state. There was no large conformational change observed in response to NAD{sup +} binding at XDH. Instead, the positive charge of the NAD{sup +} ring, deprotonation of Asp429, and capping of the bulk surface of the flavin by the NAD{sup +} molecule all contribute to altering E{sub sq/hq} upon NAD{sup +} binding to XDH.

  11. Protective features of resveratrol on human spermatozoa cryopreservation may be mediated through 5' AMP-activated protein kinase activation.

    Science.gov (United States)

    Shabani Nashtaei, M; Amidi, F; Sedighi Gilani, M A; Aleyasin, A; Bakhshalizadeh, Sh; Naji, M; Nekoonam, S

    2017-03-01

    Biochemical and physical modifications during the freeze-thaw process adversely influence the restoration of energy-dependent sperm functions required for fertilization. Resveratrol, a phytoalexin, has been introduced to activate 5' AMP-activated protein kinase which is a cell energy sensor and a cell metabolism regulator. The cryoprotection of resveratrol on sperm cryoinjury via activation of AMP-activated protein kinase also remains to be elucidated. Our aim, thus, was to investigate: (i) the presence and intracellular localization of AMP-activated protein kinase protein; (ii) whether resveratrol may exert a protective effect on certain functional properties of fresh and post-thaw human spermatozoa through modulation of AMP-activated protein kinase. Spermatozoa from normozoospermic men were incubated with or without different concentrations of Compound C as an AMP-activated protein kinase inhibitor or resveratrol as an AMP-activated protein kinase activator for different lengths of time and were then cryopreserved. AMP-activated protein kinase is expressed essentially in the entire flagellum and the post-equatorial region. Viability of fresh spermatozoa was not significantly affected by the presence of Compound C or resveratrol. However, although Compound C caused a potent inhibition of spermatozoa motility parameters, resveratrol did not induce negative effect, except a significant reduction in motility at 25 μm for 1 h. Furthermore, resveratrol significantly increased AMP-activated protein kinase phosphorylation and mitochondrial membrane potential and decreased reactive oxygen species and apoptosis-like changes in frozen-thawed spermatozoa. Nevertheless, it was not able to compensate decreased sperm viability and motility parameters following cryopreservation. In contrast, Compound C showed opposite effects to resveratrol on AMP-activated protein kinase phosphorylation, reactive oxygen species, apoptosis-like changes, mitochondrial membrane potential, and

  12. Mitogen-activated protein kinases interacting kinases are autoinhibited by a reprogrammed activation segment.

    Science.gov (United States)

    Jauch, Ralf; Cho, Min-Kyu; Jäkel, Stefan; Netter, Catharina; Schreiter, Kay; Aicher, Babette; Zweckstetter, Markus; Jäckle, Herbert; Wahl, Markus C

    2006-09-06

    Autoinhibition is a recurring mode of protein kinase regulation and can be based on diverse molecular mechanisms. Here, we show by crystal structure analysis, nuclear magnetic resonance (NMR)-based nucleotide affinity studies and rational mutagenesis that nonphosphorylated mitogen-activated protein (MAP) kinases interacting kinase (Mnk) 1 is autoinhibited by conversion of the activation segment into an autoinhibitory module. In a Mnk1 crystal structure, the activation segment is repositioned via a Mnk-specific sequence insertion at the N-terminal lobe with the following consequences: (i) the peptide substrate binding site is deconstructed, (ii) the interlobal cleft is narrowed, (iii) an essential Lys-Glu pair is disrupted and (iv) the magnesium-binding loop is locked into an ATP-competitive conformation. Consistently, deletion of the Mnk-specific insertion or removal of a conserved phenylalanine side chain, which induces a blockade of the ATP pocket, increase the ATP affinity of Mnk1. Structural rearrangements required for the activation of Mnks are apparent from the cocrystal structure of a Mnk2 D228G -staurosporine complex and can be modeled on the basis of crystal packing interactions. Our data suggest a novel regulatory mechanism specific for the Mnk subfamily.

  13. Function of the activated protein C (APC) autolysis loop in activated FVIII inactivation.

    Science.gov (United States)

    Cramer, Thomas J; Gale, Andrew J

    2011-06-01

    Activated protein C (APC) binds to its substrates activated factor V (FVa) and activated factor VIII (FVIIIa) with a basic exosite that consists of loops 37, 60, 70 and the autolysis loop. These loops have a high density of basic residues, resulting in a positive charge on the surface of APC. Many of these residues are important in the interaction of APC with FVa and FVIIIa. The current study focused on the function of the autolysis loop in the interaction with FVIIIa. This loop was previously shown to interact with FVa, and it inhibits APC inactivation by plasma serpins. Charged residues of the autolysis loop were individually mutated to alanine and the activity of these mutants was assessed in functional FVIIIa inactivation assays. The autolysis loop was functionally important for FVIIIa inactivation. Mutation of R306, K311 and R314 each resulted in significantly reduced FVIIIa inactivation. The inactivating cleavages of FVIIIa at R336 and R562 were affected equally by the mutations. Protein S and FV stimulated cleavage at R562 more than cleavage at R336, independent of mutations in the autolysis loop. Together, these results confirmed that the autolysis loop plays a significant role as part of the basic exosite on APC in the interaction with FVIIIa. © 2011 Blackwell Publishing Ltd.

  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. An activated medium with high durability and low nonspecific adsorption: application to protein A chromatography.

    Science.gov (United States)

    Maeno, Katsuyuki; Hirayama, Aya; Sakuma, Kenichi; Miyazawa, Kazuyuki

    2011-02-01

    Activated media allow the user to easily synthesize a variety of affinity media. We have developed a novel activated medium based on porous silica modified with phosphorylcholine (PC) and N-hydroxysuccinimide (NHS) groups for the purpose of high-throughput purification and reducing nonspecific protein adsorption. The PC groups function as suppressors of nonspecific protein adsorption, whereas the NHS groups are able to covalently bind to the primary amino groups of ligands. Because protein A affinity medium is the most frequently used affinity medium, we prepared protein A media in which a recombinant protein A was bound to the NHS groups of the activated media and evaluated its utility. After optimizing various factors in the synthetic process, the resultant protein A medium showed improved durability at a high flow rate over 300 purification cycles and reduced nonspecific protein adsorption compared with commercially available protein A media. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Unc-51 controls active zone density and protein composition by downregulating ERK signaling

    OpenAIRE

    Wairkar, Yogesh P.; Toda, Hirofumi; Mochizuki, Hiroaki; Furukubo-Tokunaga, Katsuo; Tomoda, Toshifumi; DiAntonio, Aaron

    2009-01-01

    Efficient synaptic transmission requires the apposition of neurotransmitter release sites opposite clusters of postsynaptic neurotransmitter receptors. Transmitter is released at active zones, which are composed of a large complex of proteins necessary for synaptic development and function. Many active zone proteins have been identified, but little is known of the mechanisms that ensure that each active zone receives the proper complement of proteins. Here we use a genetic analysis in Drosoph...

  17. Acid-denatured Green Fluorescent Protein (GFP) as model substrate to study the chaperone activity of protein disulfide isomerase.

    Science.gov (United States)

    Mares, Rosa E; Meléndez-López, Samuel G; Ramos, Marco A

    2011-01-01

    Green fluorescent protein (GFP) has been widely used in several molecular and cellular biology applications, since it is remarkably stable in vitro and in vivo. Interestingly, native GFP is resistant to the most common chemical denaturants; however, a low fluorescence signal has been observed after acid-induced denaturation. Furthermore, this acid-denatured GFP has been used as substrate in studies of the folding activity of some bacterial chaperones and other chaperone-like molecules. Protein disulfide isomerase enzymes, a family of eukaryotic oxidoreductases that catalyze the oxidation and isomerization of disulfide bonds in nascent polypeptides, play a key role in protein folding and it could display chaperone activity. However, contrasting results have been reported using different proteins as model substrates. Here, we report the further application of GFP as a model substrate to study the chaperone activity of protein disulfide isomerase (PDI) enzymes. Since refolding of acid-denatured GFP can be easily and directly monitored, a simple micro-assay was used to study the effect of the molecular participants in protein refolding assisted by PDI. Additionally, the effect of a well-known inhibitor of PDI chaperone activity was also analyzed. Because of the diversity their functional activities, PDI enzymes are potentially interesting drug targets. Since PDI may be implicated in the protection of cells against ER stress, including cancer cells, inhibitors of PDI might be able to enhance the efficacy of cancer chemotherapy; furthermore, it has been demonstrated that blocking the reductive cleavage of disulfide bonds of proteins associated with the cell surface markedly reduces the infectivity of the human immunodeficiency virus. Although several high-throughput screening (HTS) assays to test PDI reductase activity have been described, we report here a novel and simple micro-assay to test the chaperone activity of PDI enzymes, which is amenable for HTS of PDI

  18. Purification of recombinant tissue plasminogen activator (rtPA) protein from transplastomic tobacco plants.

    Science.gov (United States)

    Abdoli Nasab, Maryam; Jalali Javaran, Mokhtar; Cusido, Rosa M; Palazon, Javier

    2016-11-01

    Plants are low cost platforms for the production of recombinant proteins, but their complexity renders the purification of plant recombinant proteins more difficult than proteins expressed in yeast or bacteria. Plastid transformation enables high-level expression of foreign genes and the accumulation of recombinant proteins in plastid organelles. Histidine (His) tags are widely used for affinity purification of recombinant proteins in a nickel column. The human tissue-type plasminogen activator (tPA) is one of the most important pharmaceutical recombinant proteins involved in the breakdown of blood clots in different parts of the body. The truncated form of the tissue plasminogen activator (K2S) has a longer plasma half-life, better diffusion into the clot, and higher fibrinolytic activity. In a construct designed to insert the K2S gene in the tobacco chloroplast, the sequence of six histidines and a factor Xa protease site was fused to the C-terminus of the K2S protein. The presence and amount of tPA recombinant protein in transplastomic tobacco plants was estimated by ELISA analysis using a specific antibody. The protein was purified from total soluble protein, insoluble protein aggregates and the protein was extracted from the isolated chloroplast using nickel resin and a chromatography column. After digestion of the purified protein with factor Xa, the presence of the purified tPA protein was confirmed by western blot analysis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Beyond AICA riboside: in search of new specific AMP-activated protein kinase activators.

    Science.gov (United States)

    Guigas, Bruno; Sakamoto, Kei; Taleux, Nellie; Reyna, Sara M; Musi, Nicolas; Viollet, Benoit; Hue, Louis

    2009-01-01

    5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICA riboside) has been extensively used in vitro and in vivo to activate the AMP-activated protein kinase (AMPK), a metabolic sensor involved in both cellular and whole body energy homeostasis. However, it has been recently highlighted that AICA riboside also exerts AMPK-independent effects, mainly on AMP-regulated enzymes and mitochondrial oxidative phosphorylation (OXPHOS), leading to the conclusion that new compounds with reduced off target effects are needed to specifically activate AMPK. Here, we review recent findings on newly discovered AMPK activators, notably on A-769662, a nonnucleoside compound from the thienopyridone family. We also report that A-769662 is able to activate AMPK and stimulate glucose uptake in both L6 cells and primary myotubes derived from human satellite cells. In addition, A-769662 increases AMPK activity and phosphorylation of its main downstream targets in primary cultured rat hepatocytes but, by contrast with AICA riboside, does neither affect mitochondrial OXPHOS nor change cellular AMP:ATP ratio. We conclude that A-769662 could be one of the new promising chemical agents to activate AMPK with limited AMPK-independent side effects.

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

    Directory of Open Access Journals (Sweden)

    Alexandre Holthausen Campos

    2011-09-01

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

  1. Construction and genetic selection of small transmembrane proteins that activate the human erythropoietin receptor.

    Science.gov (United States)

    Cammett, Tobin J; Jun, Susan J; Cohen, Emily B; Barrera, Francisco N; Engelman, Donald M; Dimaio, Daniel

    2010-02-23

    This work describes a genetic approach to isolate small, artificial transmembrane (TM) proteins with biological activity. The bovine papillomavirus E5 protein is a dimeric, 44-amino acid TM protein that transforms cells by specifically binding and activating the platelet-derived growth factor beta receptor (PDGFbetaR). We used the E5 protein as a scaffold to construct a retrovirus library expressing approximately 500,000 unique 44-amino acid proteins with randomized TM domains. We screened this library to select small, dimeric TM proteins that were structurally unrelated to erythropoietin (EPO), but specifically activated the human EPO receptor (hEPOR). These proteins did not activate the murine EPOR or the PDGFbetaR. Genetic studies with one of these activators suggested that it interacted with the TM domain of the hEPOR. Furthermore, this TM activator supported erythroid differentiation of primary human hematopoietic progenitor cells in vitro in the absence of EPO. Thus, we have changed the specificity of a protein so that it no longer recognizes its natural target but, instead, modulates an entirely different protein. This represents a novel strategy to isolate small artificial proteins that affect diverse membrane proteins. We suggest the word "traptamer" for these transmembrane aptamers.

  2. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    International Nuclear Information System (INIS)

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-01-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs

  3. Anticoagulant rodenticide toxicity in six dogs presenting for ocular disease.

    Science.gov (United States)

    Griggs, Angela N; Allbaugh, Rachel A; Tofflemire, Kyle L; Ben-Shlomo, Gil; Whitley, David; Paulsen, Michael E

    2016-01-01

    To describe cases of suspected anticoagulant rodenticide toxicity manifesting with predominantly ocular signs. Six canine cases that presented to veterinary referral hospitals for ocular abnormalities and were diagnosed with suspected or confirmed anticoagulant rodenticide ingestion were reviewed for commonalities in presentation and outcome. Five dogs had unilateral ocular signs and one dog had bilateral manifestations. Signs included subconjunctival hemorrhage, exophthalmos, and commonly orbital pain without other significant physical examination findings. Prothrombin time was measured in 5 of 6 dogs and was prolonged in all. Partial thromboplastin time was measured in 4 of 6 dogs and was prolonged in all. Complete blood cell count and serum chemistry profiles demonstrated mild, if any, abnormalities. Five dogs had known anticoagulant rodenticide exposure, and rodenticide ingestion was suspected in 1 additional case based on clinical signs, clinical pathologic abnormalities, and response to treatment. Five of 6 cases were hospitalized overnight for plasma transfusions along with oral or injectable vitamin K1 , and all dogs were treated with oral vitamin K1 for 30 days. All dogs experienced complete resolution of clinical signs within 6 weeks of initiating treatment. Anticoagulant rodenticide toxicity can present with predominantly ocular manifestations. Rodenticide ingestion should be considered in dogs with unilateral or bilateral subconjunctival hemorrhage, exophthalmos, and orbital pain. © 2015 American College of Veterinary Ophthalmologists.

  4. Prevalence of Lupus Anticoagulant in Women with Spontaneous ...

    African Journals Online (AJOL)

    2017-10-26

    Oct 26, 2017 ... Presence of lupus anticoagulant (LA), one of the antiphospholipid antibodies, has been associated with SA in many ... (a hexagonal-phase phospholipid) test and calculated Rosner index for prolonged. KCT were used for the ... marker for APL syndrome, the demonstration that β2-GPI can bind to anionic ...

  5. Citrate Anticoagulation for CRRT in Children: Comparison with Heparin

    Directory of Open Access Journals (Sweden)

    Sara Nicole Fernández

    2014-01-01

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

  6. 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.

  7. 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

  8. Prevalence of Lupus Anticoagulant in Women with Spontaneous ...

    African Journals Online (AJOL)

    Introduction: Spontaneous abortion (SA) is a common complication of pregnancy. Presence of lupus anticoagulant (LA), one of the antiphospholipid antibodies, has been associated with SA in many studies, especially in Caucasians. This study was carried out to determine the prevalence of LA in women with SA in ABUTH, ...

  9. Challenges in management of Warfarin anti-coagulation in ...

    African Journals Online (AJOL)

    Challenges in management of Warfarin anti-coagulation in advanced HIV/AIDS patients with venous thrombotic events - A case series from a research clinic in rural Kericho, Kenya. ... VTE was diagnosed 52 (1-469) days after ART initiation, and 81.8% of cases were outpatients at presentation. All patients received at least ...

  10. pattern of anticoagulation control after heart valve surgery at the ...

    African Journals Online (AJOL)

    hi-tech

    2000-07-07

    Jul 7, 2000 ... Regular attendance by the patients, supplemented by a system of quality control anticaogulation are the prerequisites of such a service. In some centres where such quality control systems are in place, levels of adequate. INR control maintained up to 80% of the patients attending the anticoagulation clinic ...

  11. Perioperative anticoagulation for children with prosthetic mechanical valves

    OpenAIRE

    Grech, Victor E.; Rees, Philip G.

    2000-01-01

    The insertion of a mechanical heart valve predisposes to thrombosis and embolism, and for this reason, individuals with mechanical valves who undergo dental/surgical procedures must take special precautions. In this article, we illustrate a protocol for anticoagulation during such procedures in individuals with mechanical valves.

  12. New developments in parenteral anticoagulation for arterial and venous thromboembolism

    NARCIS (Netherlands)

    van Es, Nick; Bleker, Suzanne M.; Büller, Harry R.; Coppens, Michiel

    2013-01-01

    The efficacy and safety of heparin and low-molecular-weight heparins (LMWHs) are well documented in venous and arterial thromboembolism. Several drawbacks of heparins have inspired the development of newer parenteral anticoagulants for specific indications, including heparin-induced thrombocytopenia

  13. Standardisation of the Laboratory Control of Anticoagulant Therapy

    African Journals Online (AJOL)

    1974-09-11

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

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

    NARCIS (Netherlands)

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

    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

  15. Comparative response of platelet fV and plasma fV to activated protein C and relevance to a model of acute traumatic coagulopathy.

    Directory of Open Access Journals (Sweden)

    James E Campbell

    Full Text Available BACKGROUND: Acute traumatic coagulopathy (ATC has been linked to an increase in activated protein C (aPC from 40 pM in healthy individuals to 175 pM. aPC exerts its activity primarily through cleavage of active coagulation factor Va (fVa. Platelets reportedly possess fVa which is more resistant to aPC cleavage than plasma fVa; this work examines the hypothesis that normal platelets are sufficient to maintain coagulation in the presence of elevated aPC. METHODS: Coagulation responses of normal plasma, fV deficient plasma (fVdp, and isolated normal platelets in fVdp were conducted: prothrombin (PT tests, turbidimetry, and thromboelastography (TEG, including the dose response of aPC on the samples. RESULTS: PT and turbidimetric assays demonstrate that normal plasma is resistant to aPC at doses much higher than those found in ATC. Additionally, an average physiological number of washed normal platelets (200,000 platelets/mm3 was sufficient to eliminate the anti-coagulant effects of aPC up to 10 nM, nearly two orders of magnitude above the ATC concentration and even the steady-state pharmacological concentration of human recombinant aPC, as measured by TEG. aPC also demonstrated no significant effect on clot lysis in normal plasma samples with or without platelets. CONCLUSIONS: Although platelet fVa shows slightly superior resistance to aPC's effects compared to plasma fVa in static models, neither fVa is sufficiently cleaved in simulations of ATC or pharmacologically-delivered aPC to diminish coagulation parameters. aPC is likely a correlative indicator of ATC or may play a cooperative role with other activity altering products generated in ATC.

  16. Cheese from ultrafiltered milk : whey proteins and chymosin activity

    NARCIS (Netherlands)

    Buijsse, C.A.P.

    1999-01-01

    The manufacture of (semi-)hard cheese from ultrafiltered milk (UF-cheese) enables the partial incorporation of whey proteins in the cheese, thereby increasing its yield. The transfer of whey proteins in curd from (UF-)milk was studied in relation to the degree of ultrafiltration of the milk

  17. A monomeric G protein-coupled receptor isolated in a high-density lipoprotein particle efficiently activates its G protein

    DEFF Research Database (Denmark)

    Whorton, Matthew R; Bokoch, Michael P; Rasmussen, Søren Gøgsig Faarup

    2007-01-01

    G protein-coupled receptors (GPCRs) respond to a diverse array of ligands, mediating cellular responses to hormones and neurotransmitters, as well as the senses of smell and taste. The structures of the GPCR rhodopsin and several G proteins have been determined by x-ray crystallography, yet...... the organization of the signaling complex between GPCRs and G proteins is poorly understood. The observations that some GPCRs are obligate heterodimers, and that many GPCRs form both homo- and heterodimers, has led to speculation that GPCR dimers may be required for efficient activation of G proteins. However......, technical limitations have precluded a definitive analysis of G protein coupling to monomeric GPCRs in a biochemically defined and membrane-bound system. Here we demonstrate that a prototypical GPCR, the beta2-adrenergic receptor (beta2AR), can be incorporated into a reconstituted high-density lipoprotein...

  18. Regulation of protease-activated receptor 1 signaling by the adaptor protein complex 2 and R4 subfamily of regulator of G protein signaling proteins.

    Science.gov (United States)

    Chen, Buxin; Siderovski, David P; Neubig, Richard R; Lawson, Mark A; Trejo, Joann

    2014-01-17

    The G protein-coupled protease-activated receptor 1 (PAR1) is irreversibly proteolytically activated by thrombin. Hence, the precise regulation of PAR1 signaling is important for proper cellular responses. In addition to desensitization, internalization and lysosomal sorting of activated PAR1 are critical for the termination of signaling. Unlike most G protein-coupled receptors, PAR1 internalization is mediated by the clathrin adaptor protein complex 2 (AP-2) and epsin-1, rather than β-arrestins. However, the function of AP-2 and epsin-1 in the regulation of PAR1 signaling is not known. Here, we report that AP-2, and not epsin-1, regulates activated PAR1-stimulated phosphoinositide hydrolysis via two different mechanisms that involve, in part, a subset of R4 subfamily of "regulator of G protein signaling" (RGS) proteins. A significantly greater increase in activated PAR1 signaling was observed in cells depleted of AP-2 using siRNA or in cells expressing a PAR1 (420)AKKAA(424) mutant with defective AP-2 binding. This effect was attributed to AP-2 modulation of PAR1 surface expression and efficiency of G protein coupling. We further found that ectopic expression of R4 subfamily members RGS2, RGS3, RGS4, and RGS5 reduced activated PAR1 wild-type signaling, whereas signaling by the PAR1 AKKAA mutant was minimally affected. Intriguingly, siRNA-mediated depletion analysis revealed a function for RGS5 in the regulation of signaling by the PAR1 wild type but not the AKKAA mutant. Moreover, activation of the PAR1 wild type, and not the AKKAA mutant, induced Gαq association with RGS3 via an AP-2-dependent mechanism. Thus, AP-2 regulates activated PAR1 signaling by altering receptor surface expression and through recruitment of RGS proteins.

  19. Effects of gamma irradiation on chickpea seeds vis-a-vis total seed storage proteins, antioxidant activity and protein profiling.

    Science.gov (United States)

    Bhagyawant, S S; Gupta, N; Shrivastava, N

    2015-10-23

    The present work describes radiation—induced effects on seed composition vis—à—vis total seed proteins, antioxidant levels and protein profiling employing two dimensional gel electrophoresis (2D—GE) in kabuli and desi chickpea varities. Seeds were exposed to the radiation doses of 1,2,3,4 and 5 kGy. The total protein concentrations decreased and antioxidant levels were increased with increasing dose compared to control seed samples. Radiation induced effects were dose dependent to these seed parameters while it showed tolerance to 1 kGy dose. Increase in the dose was complimented with increase in antioxidant levels, like 5 kGy enhanced % scavenging activities in all the seed extracts. Precisely, the investigations reflected that the dose range from 2 to 5 kGy was effective for total seed storage proteins, as depicted quantitatively and qualitative 2D—GE means enhance antioxidant activities in vitro.

  20. Ohmyungsamycins promote antimicrobial responses through autophagy activation via AMP-activated protein kinase pathway.

    Science.gov (United States)

    Kim, Tae Sung; Shin, Yern-Hyerk; Lee, Hye-Mi; Kim, Jin Kyung; Choe, Jin Ho; Jang, Ji-Chan; Um, Soohyun; Jin, Hyo Sun; Komatsu, Masaaki; Cha, Guang-Ho; Chae, Han-Jung; Oh, Dong-Chan; Jo, Eun-Kyeong

    2017-06-13

    The induction of host cell autophagy by various autophagy inducers contributes to the antimicrobial host defense against Mycobacterium tuberculosis (Mtb), a major pathogenic strain that causes human tuberculosis. In this study, we present a role for the newly identified cyclic peptides ohmyungsamycins (OMS) A and B in the antimicrobial responses against Mtb infections by activating autophagy in murine bone marrow-derived macrophages (BMDMs). OMS robustly activated autophagy, which was essentially required for the colocalization of LC3 autophagosomes with bacterial phagosomes and antimicrobial responses against Mtb in BMDMs. Using a Drosophila melanogaster-Mycobacterium marinum infection model, we showed that OMS-A-induced autophagy contributed to the increased survival of infected flies and the limitation of bacterial load. We further showed that OMS triggered AMP-activated protein kinase (AMPK) activation, which was required for OMS-mediated phagosome maturation and antimicrobial responses against Mtb. Moreover, treating BMDMs with OMS led to dose-dependent inhibition of macrophage inflammatory responses, which was also dependent on AMPK activation. Collectively, these data show that OMS is a promising candidate for new anti-mycobacterial therapeutics by activating antibacterial autophagy via AMPK-dependent signaling and suppressing excessive inflammation during Mtb infections.

  1. Regulation of AMP-activated protein kinase by natural and synthetic activators

    Directory of Open Access Journals (Sweden)

    David Grahame Hardie

    2016-01-01

    Full Text Available The AMP-activated protein kinase (AMPK is a sensor of cellular energy status that is almost universally expressed in eukaryotic cells. While it appears to have evolved in single-celled eukaryotes to regulate energy balance in a cell-autonomous manner, during the evolution of multicellular animals its role has become adapted so that it also regulates energy balance at the whole body level, by responding to hormones that act primarily on the hypothalamus. AMPK monitors energy balance at the cellular level by sensing the ratios of AMP/ATP and ADP/ATP, and recent structural analyses of the AMPK heterotrimer that have provided insight into the complex mechanisms for these effects will be discussed. Given the central importance of energy balance in diseases that are major causes of morbidity or death in humans, such as type 2 diabetes, cancer and inflammatory disorders, there has been a major drive to develop pharmacological activators of AMPK. Many such activators have been described, and the various mechanisms by which these activate AMPK will be discussed. A particularly large class of AMPK activators are natural products of plants derived from traditional herbal medicines. While the mechanism by which most of these activate AMPK has not yet been addressed, I will argue that many of them may be defensive compounds produced by plants to deter infection by pathogens or grazing by insects or herbivores, and that many of them will turn out to be inhibitors of mitochondrial function.

  2. Primary care monitoring of patients under oral anticoagulation.

    Science.gov (United States)

    Agnelo, Pedro; Alexandra, Denise; Matias, Sara

    2014-01-01

    With the advent of new oral anticoagulants that do not require regular laboratory control but are significantly more expensive, there has been renewed interest in the quality of the classic agents and the monitoring of patients taking them. We set out to analyze time in therapeutic range of patients under oral anticoagulation monitored in our health unit, to determine whether primary care monitoring is comparable to that in anticoagulation clinics. At the same time, we aimed to ascertain whether there was any association between the dosing method (unit protocol vs. computer-assisted) and the time in therapeutic range achieved.Methods We analyzed all INR values determined in our health unit during the first six months of 2012, using Excel 2007 and SPSS version 17.0, and applying the Student's t test for a level of significance of 0.05. All INR assessments during the first six months of 2012 were recorded, a total of 320 tests; mean patient age was 69.9±11.25 years, 63% male. Dose adjustments were made according to the unit protocol in 77% of cases. Atrial fibrillation was the most prevalent indication. Most values (65.3%) were within the target therapeutic range; 24.1% were subtherapeutic and 10.6% supratherapeutic. Computer-assisted dosing achieved better control than the protocol (72.5% vs. 62.9%), without statistical significance. Primary care monitoring of oral anticoagulation appears to be comparable to that in anticoagulation clinics, while affording better access and cost reductions. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  3. Adverse effects of anticoagulation treatment: clinically significant upper gastrointestinal hemorrhage

    Directory of Open Access Journals (Sweden)

    Pavel Skok

    2006-12-01

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

  4. Reduced activity of AMP-activated protein kinase protects against genetic models of motor neuron disease.

    Science.gov (United States)

    Lim, M A; Selak, M A; Xiang, Z; Krainc, D; Neve, R L; Kraemer, B C; Watts, J L; Kalb, R G

    2012-01-18

    A growing body of research indicates that amyotrophic lateral sclerosis (ALS) patients and mouse models of ALS exhibit metabolic dysfunction. A subpopulation of ALS patients possesses higher levels of resting energy expenditure and lower fat-free mass compared to healthy controls. Similarly, two mutant copper zinc superoxide dismutase 1 (mSOD1) mouse models of familial ALS possess a hypermetabolic phenotype. The pathophysiological relevance of the bioenergetic defects observed in ALS remains largely elusive. AMP-activated protein kinase (AMPK) is a key sensor of cellular energy status and thus might be activated in various models of ALS. Here, we report that AMPK activity is increased in spinal cord cultures expressing mSOD1, as well as in spinal cord lysates from mSOD1 mice. Reducing AMPK activity either pharmacologically or genetically prevents mSOD1-induced motor neuron death in vitro. To investigate the role of AMPK in vivo, we used Caenorhabditis elegans models of motor neuron disease. C. elegans engineered to express human mSOD1 (G85R) in neurons develops locomotor dysfunction and severe fecundity defects when compared to transgenic worms expressing human wild-type SOD1. Genetic reduction of aak-2, the ortholog of the AMPK α2 catalytic subunit in nematodes, improved locomotor behavior and fecundity in G85R animals. Similar observations were made with nematodes engineered to express mutant tat-activating regulatory (TAR) DNA-binding protein of 43 kDa molecular weight. Altogether, these data suggest that bioenergetic abnormalities are likely to be pathophysiologically relevant to motor neuron disease.

  5. Demodex-associated bacterial proteins induce neutrophil activation.

    LENUS (Irish Health Repository)

    2012-02-01

    Background: Patients with rosacea demonstrate a higher density of Demodex mites in their skin than controls. A bacterium isolated from a Demodex mite from a patient with papulopustular rosacea (PPR) was previously shown to provoke an immune response in patients with PPR or ocular rosacea thus suggesting a possible role for bacterial proteins in the etiology of this condition. Objectives: To examine the response of neutrophils to proteins derived from a bacterium isolated from a Demodex mite. Methods: Bacterial cells were lysed and proteins were partially purified by AKTA-FPLC. Isolated neutrophils were exposed to bacterial proteins and monitored for alterations in migration, degranulation and cytokine production. Results: Neutrophils exposed to proteins from Bacillus cells demonstrated increased levels of migration and elevated release of MMP-9, an enzyme known to degrade collagen and cathelicidin, an antimicrobial peptide. In addition neutrophils exposed to the bacterial proteins demonstrated elevated rates of Il-8 and TNF-alpha production. Conclusions: Proteins produced by a bacterium isolated from a Demodex mite have the ability to increase the migration, degranulation and cytokine production abilities of neutrophils. These results suggest that bacteria may play a role in the inflammatory erythema associated with rosacea.

  6. Double-stranded RNA-induced activation of activating protein-1 promoter is differentially regulated by the non-structural protein 1 of avian influenza A viruses.

    Science.gov (United States)

    Munir, Muhammad; Zohari, Siamak; Belák, Sándor; Berg, Mikael

    2012-02-01

    Non-structural protein 1 (NS1) of influenza A viruses is a multifunctional protein that antagonizes the host immune response by interfering with several host signaling pathways. Based on putative amino acid sequences, NS1 proteins are categorized into two gene pools, allele A and allele B. Here we identified that allele A NS1 proteins of H6N8 and H4N6 are able to inhibit double-stranded RNA (dsRNA)-induced activating protein-1 (AP-1) promoter in cultured cell lines (human A549 and mink lung cells). Allele B NS1 proteins from corresponding subtypes of influenza A viruses are weak in this inhibition, despite significant levels of expression of each NS1 protein in human A549 cells. Furthermore, the capability to inhibit AP-1 promoter was mapped in the effector domain, since RNA binding domain alone lost its ability to inhibit this promoter activation. Chimeric forms of NS1 protein, composed of either RNA binding domain of allele A or B and effector domain of allele A or B, showed comparable inhibition to that of their wild-type NS1 proteins, or to the effector domain of corresponding NS1 proteins. Both alleles A and B NS1 proteins of H6N8 and H4N6 were expressed to significant levels, and were localized predominantly in the nucleus of human A549 cells. These results underscore the importance of the effector domain in inhibiting AP-1 promoter activation, and the biological function of the effector domain in stabilizing the RNA binding domain. Further, we revealed the versatile nature of NS1 in inhibiting the AP-1 transcription factor, in a manner dependent on allele type. Comprehensive studies, focusing on the molecular mechanisms behind this differential inhibition, may facilitate exploration of the zoonotic and pathogenic potential of influenza A viruses.

  7. The yeast Pan2 protein is required for poly(A)-binding protein-stimulated poly(A)-nuclease activity.

    Science.gov (United States)

    Boeck, R; Tarun, S; Rieger, M; Deardorff, J A; Müller-Auer, S; Sachs, A B

    1996-01-05

    The removal of the mRNA poly(A) tail in the yeast Saccharomyces cerevisiae is stimulated by the poly(A)-binding protein (Pab1p). A large scale purification of the Pab1p-stimulated poly(A) ribonuclease (PAN) identifies a 76-kDa and two 135-Da polypeptides as candidate enzyme subunits. Antibodies against the Pan1p protein, which is the minor 135-kDa protein in the preparation, can immunodeplete Pan1p but not PAN activity. The protein sequence of the major 135-kDa protein, Pan2p, reveals a novel protein that was also found in the previously reported PAN purification (Sachs, A. B., and Deardorff, J. A. (1992) Cell 70, 961-973). Deletion of the non-essential PAN2 gene results in an increase of the average length of mRNA poly(A) tails in vivo, and a loss of Pab1p-stimulated PAN activity in crude extracts. These data confirm that Pan2p and not Pan1p is required for PAN activity, and they suggest that ribonucleases other than the Pab1p-stimulated PAN are capable of shortening poly(A) tails in vivo.

  8. Isolation and characterization of anticoagulant compound from ...

    African Journals Online (AJOL)

    Glycosaminoglycans (GAGs) are linear polysaccharides found in the extracellular matrix and biological fluids of animals where they interact with hundreds of proteins and perform a variety of critical roles. There are five classes of animal GAGs: heparan sulfate (HS), chondroitin sulfate (CS), dermatan sulfate (DS), keratan ...

  9. Fibroblast activation protein alpha expression identifies activated fibroblasts after myocardial infarction.

    Science.gov (United States)

    Tillmanns, Jochen; Hoffmann, Daniel; Habbaba, Yasmin; Schmitto, Jan D; Sedding, Daniel; Fraccarollo, Daniela; Galuppo, Paolo; Bauersachs, Johann

    2015-10-01

    Fibroblast activation protein α (FAP) is a membrane-bound serine protease expressed by activated fibroblasts during wound healing in the skin. Expression of FAP after myocardial infarction (MI) and potential effects on cardiac wound healing are largely unknown. MI was induced in rats and FAP expression was analyzed at 3, 7 and 28 days post-MI by microarray, Western blot and immunohistochemistry. In human hearts after MI, a FAP(+) fibroblast population was identified, and characterized by immunohistochemistry for prolyl-4-hydroxylase β, α-smooth muscle actin, Thy-1 and vimentin. Signaling pathways leading to FAP expression were studied in human cardiac fibroblasts by Western blot and ELISA using TGFβ1, TGF-beta type I-receptor (TGFbR1)-inhibitor SB431542 or the MAPK-inhibitor U0126 as well as siRNA targeting SMAD2 and SMAD3. Finally, fibroblasts were assayed for FAP-dependent migration (modified Boyden-chamber), proliferation (BrdU-assay) and gelatinolytic activity by gelatin zymography. In rats, FAP expression was increased after MI especially in the peri-infarct area peaking at 7 days post-MI. Co-localization analysis identified the majority of FAP(+) cells as activated proto-myofibroblasts and myofibroblasts. Concordantly, FAP(+) fibroblasts were abundant in ischemic tissue of human hearts after MI, but not in healthy control hearts. In vitro, FAP was induced by TGFβ1 via the canonical SMAD2/SMAD3 pathway. Depletion of FAP in fibroblasts reduced migratory capacity, while proliferation was not affected. Gelatin zymography revealed gelatinase activity by fibroblast-derived FAP. In this study, we show for the first time the expression of FAP in activated fibroblasts after MI and its activation by TGFβ1. Effects of FAP on fibroblast migration and gelatinolytic activity indicate a potential role in cardiac wound healing and remodeling. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. The Increasing Impact of Activity-Based Protein Profiling in Plant Science.

    Science.gov (United States)

    Morimoto, Kyoko; van der Hoorn, Renier A L

    2016-03-01

    The active proteome dictates plant physiology. Yet, active proteins are difficult to predict based on transcript or protein levels, because protein activities are regulated post-translationally in their microenvironments. Over the past 10 years, activity-based protein profiling (ABPP) is increasingly used in plant science. ABPP monitors the activities of hundreds of plant proteins using tagged chemical probes that react with the active site of proteins in a mechanism-dependent manner. Since labeling is covalent and irreversible, labeled proteins can be detected and identified on protein gels and by mass spectrometry using tagged fluorophores and/or biotin. Here, we discuss general concepts, approaches and practical considerations of ABPP, before we summarize the discoveries made using 40 validated probes representing 14 chemotypes that can monitor the active state of >4,500 plant proteins. These discoveries and new opportunities indicate that this emerging functional proteomic technology is a powerful discovery tool that will have an increasing impact on plant science. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  11. Strategies for production of active eukaryotic proteins in bacterial expression system

    OpenAIRE

    Orawan Khow; Sunutcha Suntrarachun

    2012-01-01

    Bacteria have long been the favorite expression system for recombinant protein production. However, the flaw of the system is that insoluble and inactive proteins are co-produced due to codon bias, protein folding, phosphorylation, glycosylation, mRNA stability and promoter strength. Factors are cited and the methods to convert to soluble and active proteins are described, for example a tight control of Escherichia coli milieu, refolding from inclusion body and through fusion technology.

  12. Vitamin K dependent protein activity and incident ischemic cardiovascular disease: The multi ethnic study of atherosclerosis

    Science.gov (United States)

    OBJECTIVE: Vitamin K-dependent proteins (VKDPs), which require post-translational modification to achieve biological activity, seem to contribute to thrombus formation, vascular calcification, and vessel stiffness. Whether VKDP activity is prospectively associated with incident cardiovascular diseas...

  13. Mitogen activated protein kinase signaling in the kidney: Target for intervention?

    NARCIS (Netherlands)

    de Borst, M.H.; Wassef, L.; Kelly, D.J.; van Goor, H.; Navis, Ger Jan

    2006-01-01

    Mitogen activated protein kinases (MAPKs) are intracellular signal transduction molecules, which connect cell-surface receptor signals to intracellular processes. MAPKs regulate a range of cellular activities including cell proliferation, gene expression, apoptosis, cell differentiation and cytokine

  14. Effects of protein kinase C activators and staurosporine on protein kinase activity, cell survival, and proliferation in Tetrahymena thermophila

    DEFF Research Database (Denmark)

    Straarup, EM; Schousboe, P; Hansen, HQ

    1997-01-01

    with either PMA or OAG, or at 2,500 cells ml-1. At 500 cells ml-1 PMA induced the in vivo phosphorylation of at least six proteins. The myelin basic protein fragment 4-14 was phosphorylated in vitro in crude extracts of a culture of 250,000 cells ml-1. Both the in vivo and the in vitro phosphorylation were...

  15. 5'-Monophosphate-activated protein kinase (AMPK improves autophagic activity in diabetes and diabetic complications

    Directory of Open Access Journals (Sweden)

    Fan Yao

    2016-01-01

    Full Text Available Diabetes mellitus (DM, an endocrine disorder, will be one of the leading causes of death world-wide in about two decades. Cellular injuries and disorders of energy metabolism are two key factors in the pathogenesis of diabetes, which also become the important causes for the process of diabetic complications. AMPK is a key enzyme in maintaining metabolic homeostasis and has been implicated in the activation of autophagy in distinct tissues. An increasing number of researchers have confirmed that autophagy is a potential factor to affect or induce diabetes and its complications nowadays, which could remove cytotoxic proteins and dysfunctional organelles. This review will summarize the regulation of autophagy and AMPK in diabetes and its complications, and explore how AMPK stimulates autophagy in different diabetic syndromes. A deeper understanding of the regulation and activity of AMPK in autophagy would enhance its development as a promising therapeutic target for diabetes treatment.

  16. A novel antifungal protein with lysozyme-like activity from seeds of Clitoria ternatea.

    Science.gov (United States)

    K, Ajesh; K, Sreejith

    2014-06-01

    An antifungal protein with a molecular mass of 14.3 kDa was isolated from the seeds of butterfly pea (Clitoria ternatea) and designated as Ct protein. The antifungal protein was purified using different methods including ammonium sulphate precipitation, ion exchange chromatography on DEAE-cellulose and gel filtration on Sephadex G-50 column. Ct protein formed a single colourless rod-shaped crystal by hanging drop method after 7 days of sample loading. The protein showed lytic activity against Micrococcus luteus and broad-spectrum, fungicidal activity, particularly against the most clinically relevant yeasts, such as Cryptococcus neoformans, Cryptococcus albidus, Cryptococcus laurentii, Candida albicans and Candida parapsilosis. It also exerted an inhibitory activity on mycelial growth in several mould species including Curvularia sp., Alternaria sp., Cladosporium sp., Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Rhizopus sp., and Sclerotium sp. The present study adds to the literature on novel seed proteins with antifungal activity.

  17. Demodex-associated bacterial proteins induce neutrophil activation

    OpenAIRE

    O'Reilly, N.; Bergin, D.; Reeves, E.P.; McElvaney, N.G.; Kavanagh, K.

    2012-01-01

    Background: Patients with rosacea demonstrate a higher density of Demodex mites in their skin than do controls. A bacterium isolated from a Demodex mite from a patient with papulopustular rosacea (PPR) was previously shown to provoke an immune response in patients with PPR or ocular rosacea, thus suggesting a possible role for bacterial proteins in the aetiology of this condition. Objectives To examine the response of neutrophils to proteins derived from a bacterium isolated...

  18. Extraction and characterization of proteins from banana (Musa Sapientum L) flower and evaluation of antimicrobial activities.

    Science.gov (United States)

    Sitthiya, Kewalee; Devkota, Lavaraj; Sadiq, Muhammad Bilal; Anal, Anil Kumar

    2018-02-01

    Ultrasonic assisted alkaline extraction of protein from banana flower was optimized using response surface methodology. The extracted proteins were characterized by Fourier transform infrared spectroscopy and molecular weight distribution was determined by gel electrophoresis. The maximum protein yield of 252.25 mg/g was obtained under optimized extraction conditions: temperature 50 °C, 30 min extraction time and 1 M NaOH concentration. The alkaline extraction produced a significantly high protein yield compared to enzymatic extraction of banana flower. Chemical finger printing of proteins showed the presence of tyrosine, tryptophan and amide bonds in extracted protein. Alkaline and pepsin assisted extracted banana flower proteins showed characteristic bands at 40 and 10 kDA, respectively. The extracted proteins showed antibacterial effects against both gram positive and gram negative bacteria. The high protein content and antimicrobial activity indicate the potential applications of banana flower in the food and feed industry.

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

    Science.gov (United States)

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

    2017-05-01

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

  20. 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

  1. Thymic Stromal Lymphopoietin Promotes Fibrosis and Activates Mitogen-Activated Protein Kinases in MRC-5 Cells.

    Science.gov (United States)

    Li, Li; Tang, Su; Tang, Xiaodong

    2016-07-06

    BACKGROUND Acute lung injury (ALI) is a life-threatening hypoxemic respiratory disorder with high incidence and mortality. ALI usually manifests as widespread inflammation and lung fibrosis with the accumulation of pro-inflammatory and pro-fibrotic factors and collagen. Thymic stromal lymphopoietin (TSLP) has a significant role in regulation of inflammation but little is known about its roles in lung fibrosis or ALI. This study aimed to define the role and possible regulatory mechanism of TSLP in lung fibrosis. MATERIAL AND METHODS We cultured human lung fibroblast MRC-5 cells and overexpressed or inhibited TSLP by the vector or small interfering RNA transfection. Then, the pro-fibrotic factors skeletal muscle actin alpha (α-SMA) and collagen I, and the 4 mitogen-activated protein kinases (MAPKs) - MAPK7, p38, extracellular signal-regulated kinase 1 (ERK1), and c-Jun N-terminal kinase 1 (JNK1) - were detected by Western blot. RESULTS Results showed that TSLP promoted the production of α-SMA and collagen I (PMRC-5 cell fibrosis. It also activated the expression of MAPK7, p-p38, p-ERK1, and p-JNK1, but the total MAPK7, p-38, ERK1, and JNK1 protein levels were mostly unchanged, indicating the activated MAPK pathways that might contribute to the promotion of cell fibrosis. CONCLUSIONS This study shows the pro-fibrotic role of TSLP in MRC-5 cells, suggesting TSLP is a potential therapeutic target for treating lung fibrosis in ALI. It possibly functions via activating MAPKs. These findings add to our understanding of the mechanism of fibrosis.

  2. Factors affecting antioxidant activity of soybean meal and caseine protein hydrolysates

    International Nuclear Information System (INIS)

    Korczak, J.

    1998-01-01

    Antioxidative activity of protein hydrolysates was dependent on the raw material, condition of hydrolysis and lipid substrate used in model systems. Soybean meal hydrolysate was more active in lard and in linoleic acid emulsion than caseine hydrolysate, whereas caseine was more active in vegetable oils. Antioxidant activity of evaluated protein hydrolysates in all lipid systems, with or without oxidation catalysts, suggests them as natural food additives for lipid stabilization, thus for improvement of its nutritional value and sensory properties

  3. Probing intracellular motor protein activity using an inducible cargo trafficking assay

    NARCIS (Netherlands)

    L.C. Kapitein (Lukas); M.A. Schlager (Max); W.A. van der Zwan (Wouter); P. Wulf (Phebe); N. Keijzer (Nanda); C.C. Hoogenraad (Casper)

    2010-01-01

    textabstractAlthough purified cytoskeletal motor proteins have been studied extensively with the use of in vitro approaches, a generic approach to selectively probe actin and microtubule-based motor protein activity inside living cells is lacking. To examine specific motor activity inside living

  4. Anticoagulation and endothelial cell behaviors of heparin-loaded graphene oxide coating on titanium surface

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Chang-Jiang, E-mail: panchangjiang@hyit.edu.cn [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an 223003 (China); Pang, Li-Qun [Department of General Surgery, Huai' an First People' s Hospital, Nanjing Medical University, Huai' an 223300 (China); Gao, Fei [Zhejiang Zylox Medical Devices Co., Ltd., Hangzhou 310000 (China); Wang, Ya-Nan; Liu, Tao; Ye, Wei; Hou, Yan-Hua [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huai' an 223003 (China)

    2016-06-01

    Owing to its unique physical and chemical properties, graphene oxide (GO) has attracted tremendous interest in many fields including biomaterials and biomedicine. The purpose of the present study is to investigate the endothelial cell behaviors and anticoagulation of heparin-loaded GO coating on the titanium surface. To this end, the titanium surface was firstly covered by the polydopamine coating followed by the deposition of the GO coating. Heparin was finally loaded on the GO coating to improve the blood compatibility. The results of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) indicated that the heparin-loaded GO coating was successfully created on the titanium surface. The scanning electron microscopy (SEM) images indicated that a relative uniform GO coating consisting of multilayer GO sheets was formed on the substrate. The hydrophilicity of the titanium surface was enhanced after the deposition of GO and further improved significantly by the loading heparin. The GO coating can enhance the endothelial cell adhesion and proliferation as compared with polydopamine coating and the blank titanium. Loading heparin on the GO coating can significantly reduce the platelet adhesion and prolong the activated partial thromboplastin time (APTT) while not influence the endothelial cell adhesion and proliferation. Therefore, the heparin-loaded GO coating can simultaneously enhance the cytocompatibility to endothelial cells and blood compatibility of biomaterials. Because the polydopamine coating can be easily prepared on most of biomaterials including polymer, ceramics and metal, thus the approach of the present study may open up a new window of promising an effective and efficient way to promote endothelialization and improve the blood compatibility of blood-contact biomedical devices such as intravascular stents. - Highlights: • Heparin-loaded graphene oxide coating was

  5. Soluble Milk Protein Supplementation with Moderate Physical Activity Improves Locomotion Function in Aging Rats.

    Directory of Open Access Journals (Sweden)

    Aude Lafoux

    Full Text Available Aging is associated with a loss of muscle mass and functional capacity. Present study was designed to compare the impact of specific dairy proteins on muscular function with or without a low-intensity physical activity program on a treadmill in an aged rat model. We investigated the effects of nutritional supplementation, five days a week over a 2-month period with a slow digestible protein, casein or fast digestible proteins, whey or soluble milk protein, on strength and locomotor parameters in sedentary or active aged Wistar RjHan rats (17-19 months of age. An extensive gait analysis was performed before and after protein supplementation. After two months of protein administration and activity program, muscle force was evaluated using a grip test, spontaneous activity using an open-field and muscular mass by specific muscle sampling. When aged rats were supplemented with proteins without exercise, only minor effects of different diets on muscle mass and locomotion were observed: higher muscle mass in the casein group and improvement of stride frequencies with soluble milk protein. By contrast, supplementation with soluble milk protein just after physical activity was more effective at improving overall skeletal muscle function in old rats compared to casein. For active old rats supplemented with soluble milk protein, an increase in locomotor activity in the open field and an enhancement of static and dynamic gait parameters compared to active groups supplemented with casein or whey were observed without any differences in muscle mass and forelimb strength. These results suggest that consumption of soluble milk protein as a bolus immediately after a low intensity physical activity may be a suitable nutritional intervention to prevent decline in locomotion in aged rats and strengthen the interest to analyze the longitudinal aspect of locomotion in aged rodents.

  6. Soluble Milk Protein Supplementation with Moderate Physical Activity Improves Locomotion Function in Aging Rats.

    Science.gov (United States)

    Lafoux, Aude; Baudry, Charlotte; Bonhomme, Cécile; Le Ruyet, Pascale; Huchet, Corinne

    2016-01-01

    Aging is associated with a loss of muscle mass and functional capacity. Present study was designed to compare the impact of specific dairy proteins on muscular function with or without a low-intensity physical activity program on a treadmill in an aged rat model. We investigated the effects of nutritional supplementation, five days a week over a 2-month period with a slow digestible protein, casein or fast digestible proteins, whey or soluble milk protein, on strength and locomotor parameters in sedentary or active aged Wistar RjHan rats (17-19 months of age). An extensive gait analysis was performed before and after protein supplementation. After two months of protein administration and activity program, muscle force was evaluated using a grip test, spontaneous activity using an open-field and muscular mass by specific muscle sampling. When aged rats were supplemented with proteins without exercise, only minor effects of different diets on muscle mass and locomotion were observed: higher muscle mass in the casein group and improvement of stride frequencies with soluble milk protein. By contrast, supplementation with soluble milk protein just after physical activity was more effective at improving overall skeletal muscle function in old rats compared to casein. For active old rats supplemented with soluble milk protein, an increase in locomotor activity in the open field and an enhancement of static and dynamic gait parameters compared to active groups supplemented with casein or whey were observed without any differences in muscle mass and forelimb strength. These results suggest that consumption of soluble milk protein as a bolus immediately after a low intensity physical activity may be a suitable nutritional intervention to prevent decline in locomotion in aged rats and strengthen the interest to analyze the longitudinal aspect of locomotion in aged rodents.

  7. A Nucleotide Phosphatase Activity in the Nucleotide Binding Domain of an Orphan Resistance Protein from Rice*

    Science.gov (United States)

    Fenyk, Stepan; de San Eustaquio Campillo, Alba; Pohl, Ehmke; Hussey, Patrick J.; Cann, Martin J.

    2012-01-01

    Plant resistance proteins (R-proteins) are key components of the plant immune system activated in response to a plethora of different pathogens. R-proteins are P-loop NTPase superfamily members, and current models describe their main function as ATPases in defense signaling pathways. Here we show that a subset of R-proteins have evolved a new function to combat pathogen infection. This subset of R-proteins possesses a nucleotide phosphatase activity in the nucleotide-binding domain. Related R-proteins that fall in the same phylogenetic clade all show the same nucleotide phosphatase activity indicating a conserved function within at least a subset of R-proteins. R-protein nucleotide phosphatases catalyze the production of nucleoside from nucleotide with the nucleotide monophosphate as the preferred substrate. Mutation of conserved catalytic residues substantially reduced activity consistent with the biochemistry of P-loop NTPases. Kinetic analysis, analytical gel filtration, and chemical cross-linking demonstrated that the nucleotide-binding domain was active as a multimer. Nuclear magnetic resonance and nucleotide analogues identified the terminal phosphate bond as the target of a reaction that utilized a metal-mediated nucleophilic attack by water on the phosphoester. In conclusion, we have identified a group of R-proteins with a unique function. This biochemical activity appears to have co-evolved with plants in signaling pathways designed to resist pathogen attack. PMID:22157756

  8. A nucleotide phosphatase activity in the nucleotide binding domain of an orphan resistance protein from rice.

    Science.gov (United States)

    Fenyk, Stepan; Campillo, Alba de San Eustaquio; Pohl, Ehmke; Hussey, Patrick J; Cann, Martin J

    2012-02-03

    Plant resistance proteins (R-proteins) are key components of the plant immune system activated in response to a plethora of different pathogens. R-proteins are P-loop NTPase superfamily members, and current models describe their main function as ATPases in defense signaling pathways. Here we show that a subset of R-proteins have evolved a new function to combat pathogen infection. This subset of R-proteins possesses a nucleotide phosphatase activity in the nucleotide-binding domain. Related R-proteins that fall in the same phylogenetic clade all show the same nucleotide phosphatase activity indicating a conserved function within at least a subset of R-proteins. R-protein nucleotide phosphatases catalyze the production of nucleoside from nucleotide with the nucleotide monophosphate as the preferred substrate. Mutation of conserved catalytic residues substantially reduced activity consistent with the biochemistry of P-loop NTPases. Kinetic analysis, analytical gel filtration, and chemical cross-linking demonstrated that the nucleotide-binding domain was active as a multimer. Nuclear magnetic resonance and nucleotide analogues identified the terminal phosphate bond as the target of a reaction that utilized a metal-mediated nucleophilic attack by water on the phosphoester. In conclusion, we have identified a group of R-proteins with a unique function. This biochemical activity appears to have co-evolved with plants in signaling pathways designed to resist pathogen attack.

  9. Heat Shock Proteins and Mitogen-activated Protein Kinases in Steatotic Livers Undergoing Ischemia-Reperfusion: Some Answers

    Science.gov (United States)

    Massip-Salcedo, Marta; Casillas-Ramirez, Araní; Franco-Gou, Rosah; Bartrons, Ramón; Ben Mosbah, Ismail; Serafin, Anna; Roselló-Catafau, Joan; Peralta, Carmen

    2006-01-01

    Ischemic preconditioning protects steatotic livers against ischemia-reperfusion (I/R) injury, but just how this is achieved is poorly understood. Here, I/R or preconditioning plus I/R was induced in steatotic and nonsteatotic livers followed by investigating the effect of pharmacological treatments that modulate heat shock proteins (HSPs) and mitogen-activated protein kinases (MAPKs). MAPKs, HSPs, protein kinase C, and transaminase levels were measured after reperfusion. We report that preconditioning increased HSP72 and heme-oxygenase-1 (HO-1) at 6 and 24 hours of reperfusion, respectively. Unlike nonsteatotic livers, steatotic livers benefited from HSP72 activators (geranylgeranylacetone) throughout reperfusion. This protection seemed attributable to HO-1 induction. In steatotic livers, preconditioning and geranylgeranylacetone treatment (which are responsible for HO-1 induction) increased protein kinase C activity. HO-1 activators (cobalt(III) protoporphyrin IX) protected both liver types. Preconditioning reduced p38 MAPK and c-Jun N-terminal kinase (JNK), resulting in HSP72 induction though HO-1 remained unmodified. Like HSP72, both p38 and JNK appeared not to be crucial in preconditioning, and inhibitors of p38 (SB203580) and JNK (SP600125) were less effective against hepatic injury than HO-1 activators. These results provide new data regarding the mechanisms of preconditioning and may pave the way to the development of new pharmacological strategies in liver surgery. PMID:16651615

  10. Antiplatelet and anticoagulation for patients with prosthetic heart valves.

    Science.gov (United States)

    Massel, David R; Little, Stephen H

    2013-07-09

    Patients with prosthetic heart valves are at increased risk for valve thrombosis and arterial thromboembolism. Oral anticoagulation alone, or the addition of antiplatelet drugs, has been used to minimise this risk. An important issue is the effectiveness and safety of the latter strategy. This is an update of our previous review; the goal was to create a valid synthesis of all available, methodologically sound data to further assess the safety and efficacy of combined oral anticoagulant and antiplatelet therapy versus oral anticoagulant monotherapy in patients with prosthetic heart valves. We updated the previous searches from 2003 and 2010 on 16 January 2013 and searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (2012, Issue 12), MEDLINE (OVID, 1946 to January Week 1 2013), and EMBASE (OVID, 1980 to 2013 Week 02). We have also looked at reference lists of individual reports, review articles, meta-analyses, and consensus statements. We included reports published in any language or in abstract form. All reports of randomised controlled trials comparing standard-dose oral anticoagulation to standard-dose oral anticoagulation and antiplatelet therapy in patients with one or more prosthetic heart valves. Two review authors independently performed the search strategy, assessed trials for inclusion and study quality, and extracted data. We collected adverse effects information from the trials. One new study has been identified and included in this update. In total, 13 studies involving 4122 participants were included in this review update. Years of publication ranged from 1971 to 2011. Compared with anticoagulation alone, the addition of an antiplatelet agent reduced the risk of thromboembolic events (odds ratio (OR) 0.43, 95% confidence interval (CI) 0.32 to 0.59; P heart valves. The risk of major bleeding is increased with antiplatelet therapy. These results apply to patients with mechanical prosthetic valves or those with

  11. The NAP motif of activity-dependent neuroprotective protein (ADNP) regulates dendritic spines through microtubule end binding proteins.

    Science.gov (United States)

    Oz, S; Kapitansky, O; Ivashco-Pachima, Y; Malishkevich, A; Giladi, E; Skalka, N; Rosin-Arbesfeld, R; Mittelman, L; Segev, O; Hirsch, J A; Gozes, I

    2014-10-01

    The NAP motif of activity-dependent neuroprotective protein (ADNP) enhanced memory scores in patients suffering from mild cognitive impairment and protected activities of daily living in schizophrenia patients, while fortifying microtubule (MT)-dependent axonal transport, in mice and flies. The question is how does NAP fortify MTs? Our sequence analysis identified the MT end-binding protein (EB1)-interacting motif SxIP (SIP, Ser-Ile-Pro) in ADNP/NAP and showed specific SxIP binding sites in all members of the EB protein family (EB1-3). Others found that EB1 enhancement of neurite outgrowth is attenuated by EB2, while EB3 interacts with postsynaptic density protein 95 (PSD-95) to modulate dendritic plasticity. Here, NAP increased PSD-95 expression in dendritic spines, which was inhibited by EB3 silencing. EB1 or EB3, but not EB2 silencing inhibited NAP-mediated cell protection, which reflected NAP binding specificity. NAPVSKIPQ (SxIP=SKIP), but not NAPVAAAAQ mimicked NAP activity. ADNP, essential for neuronal differentiation and brain formation in mouse, a member of the SWI/SNF chromatin remodeling complex and a major protein mutated in autism and deregulated in schizophrenia in men, showed similar EB interactions, which were enhanced by NAP treatment. The newly identified shared MT target of NAP/ADNP is directly implicated in synaptic plasticity, explaining the breadth and efficiency of neuroprotective/neurotrophic capacities.

  12. The Cytotoxicity of Elderberry Ribosome-Inactivating Proteins Is Not Solely Determined by Their Protein Translation Inhibition Activity.

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    Chenjing Shang

    Full Text Available Although the protein translation inhibition activity of ribosome inactivating proteins (RIPs is well documented, little is known about the contribution of the lectin chain to the biological activity of these proteins. In this study, we compared the in vitro and intracellular activity of several S. nigra (elderberry RIPs and non-RIP lectins. Our data demonstrate that RIPs from elderberry are much more toxic to HeLa cells than to primary fibroblasts. Differences in the cytotoxicity between the elderberry proteins correlated with differences in glycan specificity of their lectin domain, cellular uptake efficiency and intracellular destination. Despite the fact that the bulk of the RIPs accumulated in the lysosomes and partly in the Golgi apparatus, we could demonstrate effective inhibition of protein synthesis in cellula. As we also observed cytotoxicity for non-RIP lectins, it is clear that the lectin chain triggers additional pathways heralding cell death. Our data suggest that one of these pathways involves the induction of autophagy.

  13. Activation of AMP-activated protein kinase attenuates hepatocellular carcinoma cell adhesion stimulated by adipokine resistin

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