Science.gov

Sample records for blood coagulation factors

  1. Colorimetric assay of blood coagulation factor XIII in plasma.

    PubMed

    Lee, K N; Birckbichler, P J; Patterson, M K

    1988-05-01

    In this new colorimetric assay for Factor XIII in plasma, 5-(biotinamido)pentylamine is used as the amine substrate. Factor XIII, a zymogen, is transformed by thrombin and Ca2+ to active Factor XIIIa, and the incorporation of 5-(biotinamido)pentylamine into N,N-dimethylcasein is used to measure catalytically active Factor XIIIa. The biotinylated enzymatic product is immobilized onto 96-well microtiter plates, complexed with streptavidin-beta-galactosidase, and the absorbance at 405 nm is monitored for production of p-nitrophenol from p-nitrophenyl-beta-D-galactopyranoside. Concentrations of N,N-dimethylcasein, 5-(biotinamido)pentylamine, Ca2+, and thrombin were chosen to allow near-maximum velocity of amine incorporation. A linear relationship was obtained between assay product and plasma volume, from 0.5 to 50 microL of plasma. Results correlated well (r greater than 0.924) with those from the most frequently utilized radiometric filter-paper assay for Factor XIII. The method appears to be ideal for routine diagnostic estimation of Factor XIII in plasma because of its simplicity, its lack of use of radioisotopes, and its potential for assay of large numbers of samples by use of microtiter plates and automated plate readers. PMID:2897256

  2. Lonomia obliqua caterpillar spicules trigger human blood coagulation via activation of factor X and prothrombin.

    PubMed

    Donato, J L; Moreno, R A; Hyslop, S; Duarte, A; Antunes, E; Le Bonniec, B F; Rendu, F; de Nucci, G

    1998-03-01

    In southern Brazil, envenomation by larvae of the moth Lonomia obliqua (Walker) may result in blood clotting factor depletion, leading to disseminated intravascular coagulation with subsequent haemorrhage and acute renal failure which may prove fatal. We have examined the effect of a crude extract of spicules from these caterpillars on in vitro hemostasis. The extract alone did not aggregate platelets and had no detectable effect on purified fibrinogen, suggesting that extract induces clot formation by triggering activation of the clotting cascade. In agreement with the presence of thrombin-mediated activity, hirudin prevented clot formation. The extract was found to activate both prothrombin and factor X, suggesting that the depletion of blood clotting factors results from the steady activation of factor X and prothrombin. Heating and diisopropylfluorophosphate abolished the procoagulant activity of the extract, indicating that the active component involved is a protein that may belong to the serine protease family of enzymes. The ability of hirudin to inhibit this coagulant activity suggests that this inhibitor could be beneficial in the treatment of patients envenomed by L. obliqua caterpillars. PMID:9531036

  3. Dimeric Organization of Blood Coagulation Factor VIII bound to Lipid Nanotubes

    PubMed Central

    Dalm, Daniela; Galaz-Montoya, Jesus G.; Miller, Jaimy L.; Grushin, Kirill; Villalobos, Alex; Koyfman, Alexey Y.; Schmid, Michael F.; Stoilova-McPhie, Svetla

    2015-01-01

    Membrane-bound Factor VIII (FVIII) has a critical function in blood coagulation as the pro-cofactor to the serine-protease Factor IXa (FIXa) in the FVIIIa-FIXa complex assembled on the activated platelet membrane. Defects or deficiency of FVIII cause Hemophilia A, a mild to severe bleeding disorder. Despite existing crystal structures for FVIII, its membrane-bound organization has not been resolved. Here we present the dimeric FVIII membrane-bound structure when bound to lipid nanotubes, as determined by cryo-electron microscopy. By combining the structural information obtained from helical reconstruction and single particle subtomogram averaging at intermediate resolution (15-20 Å), we show unambiguously that FVIII forms dimers on lipid nanotubes. We also demonstrate that the organization of the FVIII membrane-bound domains is consistently different from the crystal structure in solution. The presented results are a critical step towards understanding the mechanism of the FVIIIa-FIXa complex assembly on the activated platelet surface in the propagation phase of blood coagulation. PMID:26082135

  4. Primary structure of blood coagulation factor XIIIa (fibrinoligase, transglutaminase) from human placenta.

    PubMed Central

    Takahashi, N; Takahashi, Y; Putnam, F W

    1986-01-01

    We have determined the primary structure of human placental factor XIIIa, an enzyme [fibrinoligase, transglutaminase, fibrin-stabilizing factor, EC 2.3.2.13 (protein-glutamine:amine gamma-glutamyltransferase)] that forms intermolecular isopeptide bonds between fibrin molecules as the last step in blood coagulation. Placental factor XIIIa is an unglycosylated polypeptide chain of 730 amino acid residues (Mr = 83,005) that appears to be identical to the a subunit of the plasma zymogen factor XIII. Ca2+-dependent activation of factor XIIIa by thrombin removes a blocked amino-terminal peptide and unmasks a reactive thiol group at Cys-314. A second specific cleavage after Lys-513 by thrombin inactivates factor XIIIa and produces an amino-terminal 56-kDa fragment and a 24-kDa fragment. The amino acid sequence of factor XIIIa is unique and does not exhibit internal homology, but its active center is similar to that of the thiol proteases. The probable Ca2+-binding site of factor XIIIa has been identified by homology to the high-affinity sites in calmodulins. Knowledge of the primary structure of factor XIIIa will aid elucidation of the mechanism of its enzymatic action and that of the many tissue transglutaminases of which it is the prototype. This will also facilitate production of factor XIIIa by recombinant DNA technology for use in treatment of congenital factor XIII deficiencies and in the postoperative healing of wounds. Images PMID:2877456

  5. Interaction of blood coagulation factor Va with phospholipid vesicles examined by using lipophilic photoreagents

    SciTech Connect

    Krieg, U.C.; Isaacs, B.S.; Yemul, S.S.; Esmon, C.T.; Bayley, H.; Johnson, A.E.

    1987-01-13

    Two different lipophilic photoreagents, (/sup 3/H)adamantane diazirine and 3-(trifluoromethyl)-3-(m-(/sup 125/I)iodophenyl)diazirine (TID), have been utilized to examine the interactions of blood coagulation factor Va with calcium, prothrombin, factor Xa, and, in particular, phospholipid vesicles. With each of these structurally dissimilar reagents, the extent of photolabeling of factor Va was greater when the protein was bound to a membrane surface than when it was free in solution. Specifically, the covalent photoreaction with Vl, the smaller subunit of factor Va, was 2-fold higher in the presence of phosphatidylcholine/phosphatidylserine (PC/PS, 3:1) vesicles, to which factor Va binds, than in the presence of 100% PC vesicles, to which the protein does not bind. However, the magnitude of the PC/PS-dependent photolabeling was much less than has been observed previously with integral membrane proteins. It therefore appears that the binding of factor Va to the membrane surface exposes Vl to the lipid core of the bilayer, but that only a small portion of the Vl polypeptide is exposed to, or embedded in, the bilayer core. Addition of either prothrombin or active-site-blocked factor Xa to PC/PS-bound factor Va had little effect on the photolabeling of Vl with TID, but reduced substantially the covalent labeling of Vh, the larger subunit of factor Va. This indicates that prothrombin and factor Xa each cover nonpolar surfaces on Vh when the macromolecules associate on the PC/PS surface. It therefore seems likely that the formation of the prothrombinase complex involves a direct interaction between Vh and factor Xa and between Vh and prothrombin.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Physiological levels of blood coagulation factors IX and X control coagulation kinetics in an in vitro model of circulating tissue factor

    NASA Astrophysics Data System (ADS)

    Tormoen, Garth W.; Khader, Ayesha; Gruber, András; McCarty, Owen J. T.

    2013-06-01

    Thrombosis significantly contributes to cancer morbidity and mortality. The mechanism behind thrombosis in cancer may be circulating tissue factor (TF), as levels of circulating TF are associated with thrombosis. However, circulating TF antigen level alone has failed to predict thrombosis in patients with cancer. We hypothesize that coagulation factor levels regulate the kinetics of circulating TF-induced thrombosis. Coagulation kinetics were measured as a function of individual coagulation factor levels and TF particle concentration. Clotting times increased when pooled plasma was mixed at or above a ratio of 4:6 with PBS. Clotting times increased when pooled plasma was mixed at or above a ratio of 8:2 with factor VII-depleted plasma, 7:3 with factor IX- or factor X-depleted plasmas, or 2:8 with factor II-, V- or VIII-depleted plasmas. Addition of coagulation factors VII, X, IX, V and II to depleted plasmas shortened clotting and enzyme initiation times, and increased enzyme generation rates in a concentration-dependent manner. Only additions of factors IX and X from low-normal to high-normal levels shortened clotting times and increased enzyme generation rates. Our results demonstrate that coagulation kinetics for TF particles are controlled by factor IX and X levels within the normal physiological range. We hypothesize that individual patient factor IX and X levels may be prognostic for susceptibility to circulating TF-induced thrombosis.

  7. Novel aspects of blood coagulation factor XIII. I. Structure, distribution, activation, and function

    SciTech Connect

    Muszbek, L.; Adany, R.; Mikkola, H.

    1996-10-01

    Blood coagulation factor XIII (FXIII) is a protransglutaminase that becomes activated by the concerted action of thrombin and Ca{sup 2+} in the final stage of the clotting cascade. In addition to plasma, FXIII also occurs in platelets, monocytes, and monocyte-derived macrophages. While the plasma factor is a heterotetramer consisting of paired A and B subunits (A{sub 2}B{sub 2}), its cellular counterpart lacks the B subunits and is a homodimer of potentially active A subunits (A{sub 2}). The gene coding for the A and B subunits has been localized to chromosomes 6p24-25 and 1q31-32.1, respectively. The genomic as well as the primary protein structure of both subunits has been established. Plasma FXIII circulates in association with its substrate precursor, fibrinogen. Fibrin(ogen) has an important regulatory role in the activation of plasma FXIII, for instance the proteolytic removal of activation peptide by thrombin, the dissociation of subunits A and B, and the exposure of the originally buried active site on the free A subunits. The end result of this process is the formation of an active transglutaminase, which crosslinks peptide chains through {epsilon}({gamma}-glutamyl)lysyl isopeptide bonds. The protein substrates of activated FXIII include components of the clotting-fibrinolytic system, adhesive and contractile proteins. The main physiological function of plasma FXIII is to cross-link fibrin and protect it from the fibrinolytic enzyme plasmin. The latter effect is achieved mainly by covalently linking {alpha}{sub 2} antiplasmin, the most potent physiological inhibitor of plasmin, to fibrin. Plasma FXIII seems to be involved in wound healing and tissue repair, and it is essential to maintaining pregnancy. Cellular FXIII, if exposed to the surface of the cells, might support or perhaps take over the hemostatic functions of plasma FXIII; however, its intracellular role has remained mostly unexplored. 328 refs., 4 figs.

  8. Minimum wound size for clotting: flowing blood coagulates on a single collagen fiber presenting tissue factor and von Willebrand factor.

    PubMed

    Zhu, Shu; Tomaiuolo, Maurizio; Diamond, Scott L

    2016-08-01

    It is unknown if a lower size limit exists for human blood coagulation under flow over physiological vessel wall triggers as small as a single collagen fiber. Prior determinations of the smallest sized surface stimuli necessary for clotting of human blood, defined as the patch size threshold, have not deployed whole blood, hemodynamic flow, and platelet adhesive stimuli. For whole blood perfused in microfluidic devices, we report that steady venous flow (wall shear rate, 100 s(-1)) was sufficient to drive platelet deposition on 20 micron long zones of collagen fibers or on a single fiber. With tissue factor (TF)-coated collagen, flowing blood generated robust platelet deposits, platelet-localized thrombin, and fibrin on a single collagen fiber, thus demonstrating the absence of a physiological patch size threshold under venous flow. In contrast, at arterial wall shear rate (1000 s(-1)) with TF present, essentially no platelet or fibrin deposition occurred on 20 micron collagen zones or on a single collagen fiber, demonstrating a patch threshold, which was overcome by pre-coating the collagen with von Willebrand factor (vWF). For venous flows, human blood can clot on one of the smallest biological units of a single collagen fiber presenting TF. For arterial flows, vWF together with TF allows human blood to generate thrombin and fibrin on a patch stimulus as limited as a single collagen fiber. vWF-dependent platelet adhesion represents a particle-based sensing mechanism of micron-scale stimuli that then allows amplification of the molecular components of TF-driven thrombin and fibrin production under arterial flow. PMID:27339024

  9. In Silico Design of Novel Anticoagulant Peptides targeting Blood Coagulation Factor VIIa

    PubMed Central

    Al-Amri, Manal S Q; Alrasadi, Khalid; Bayoumi, Riad; Banerjee, Yajnavalka

    2011-01-01

    Objectives: The coagulation cascade initiated during vascular injury prevents bleeding. Unwanted clot formation is however detrimental and requires the use of anticoagulants for prophylaxis and treatment. Anticoagulants targeting a specific step or an enzyme in the clotting process are most preferred as they minimise disadvantageous side-effects. A principal step in the discovery of novel anticoagulants encompasses the in silico design of potential leads. This study depicts the in silico design of peptide anticoagulants targeting coagulation factor VIIa. Methods: Applying the proline bracket rule and using various bioinformatics tools: the basic alignment search tool (BLAST) of National Center for Biotechnology Information; the T-coffee module provided by European Molecular Biology Laboratory-European Bioinformatics Institute, and several modules available on the ExPASy server, we designed five bivalent chimeric anticoagulants targeting factor VIIa, using factor VIIa inhibitors – hemextin A from Hemachatus haemachatus (African Ringhals cobra) venom and factor VIIa exosite-inhibitor peptide as templates. Six peptides were derived from hemextin A, which were concomitantly fused with factor VIIa exosite-inhibitor peptide intermediated by a polyalanine spacer, and analysed for structural stability using the SWISS-MODEL software developed at the Swiss Institute of Bioinformatics and WebLab ViewerPro (Version 4.2). Results: Twelve chimeric peptides were obtained; only five exhibited stable structures in silico. Conclusion: The five peptides obtained are probable anticoagulant leads that should be further evaluated using suitable in vitro and in vivo assays. Further, this study shows how simple web-based modules can be used for the rational design of probable leads targeting specific physiological molecular targets. PMID:21509213

  10. Hemophilia as a defect of the tissue factor pathway of blood coagulation: Effect of factors VIII and IX on factor X activation in a continuous-flow reactor

    SciTech Connect

    Repke, D.; Gemmell, C.H.; Guha, A.; Turitto, V.T.; Nemerson, Y. ); Broze, G.J. Jr. )

    1990-10-01

    The effect of factors VIII and IX on the ability of the tissue factor-factor VIIa complex to activate factor X was studied in a continuous-flow tubular enzyme reactor. Tissue factor immobilized in a phospholipid bilayer on the inner surface of the tube was exposed to a perfusate containing factors VIIa, VIII, IX, and X flowing at a wall shear rate of 57, 300, or 1130 sec{sup {minus}1}. The addition of factors VIII and IX at their respective plasma concentrations resulted in a further 2{endash}-to 3{endash}fold increase. The direct activation of factor X by tissue factor-factor VIIa could be virtually eliminated by the lipoprotein-associated coagulation inhibitor. These results suggest that the tissue factor pathway, mediated through factors VIII and IX, produces significant levels of factor Xa even in the presence of an inhibitor of the tissue factor-factor VIIa complex; moreover, the activation is dependent on local shear conditions. These findings are consistent both with a model of blood coagulation in which initiation of the system results from tissue factor and with the bleeding observed in hemophilia.

  11. Enhanced specificity of immunoblotting using radiolabeled antigen overlay: studies of blood coagulation factor XII and prekallikrein in plasma

    SciTech Connect

    Laemmle, B.; Berrettini, M.; Griffin, J.H.

    1986-01-01

    Immunoblotting of blood coagulation Factor XII and plasma prekallikrein in whole plasma was performed using radiolabeled antigen for detection. After sodium dodecyl sulfate-polyacrylamide gel electrophoresis of plasma and transfer to nitrocellulose sheets, the blots were first reacted with polyclonal goat anti-Factor XII or anti-prekallikrein antisera and then with /sup 125/I-Factor XII or /sup 125/I-prekallikrein, respectively. A major advantage of using radiolabeled antigen rather than radiolabeled secondary antibody was enhanced specificity of immunodetection of these antigens in plasma. This procedure was sensitive to approx.0.3 ng of either Factor XII or prekallikrein antigen and was useful for detection of Factor XII cleavage fragments in contact activated plasma. Radiolabeled antigen overlay may improve the specificity of immunoblotting of trace antigens in any complex mixtures.

  12. Positive Selection during the Evolution of the Blood Coagulation Factors in the Context of Their Disease-Causing Mutations

    PubMed Central

    Rallapalli, Pavithra M.; Orengo, Christine A.; Studer, Romain A.; Perkins, Stephen J.

    2014-01-01

    Blood coagulation occurs through a cascade of enzymes and cofactors that produces a fibrin clot, while otherwise maintaining hemostasis. The 11 human coagulation factors (FG, FII–FXIII) have been identified across all vertebrates, suggesting that they emerged with the first vertebrates around 500 Ma. Human FVIII, FIX, and FXI are associated with thousands of disease-causing mutations. Here, we evaluated the strength of selective pressures on the 14 genes coding for the 11 factors during vertebrate evolution, and compared these with human mutations in FVIII, FIX, and FXI. Positive selection was identified for fibrinogen (FG), FIII, FVIII, FIX, and FX in the mammalian Primates and Laurasiatheria and the Sauropsida (reptiles and birds). This showed that the coagulation system in vertebrates was under strong selective pressures, perhaps to adapt against blood-invading pathogens. The comparison of these results with disease-causing mutations reported in FVIII, FIX, and FXI showed that the number of disease-causing mutations, and the probability of positive selection were inversely related to each other. It was concluded that when a site was under positive selection, it was less likely to be associated with disease-causing mutations. In contrast, sites under negative selection were more likely to be associated with disease-causing mutations and be destabilizing. A residue-by-residue comparison of the FVIII, FIX, and FXI sequence alignments confirmed this. This improved understanding of evolutionary changes in FVIII, FIX, and FXI provided greater insight into disease-causing mutations, and better assessments of the codon sites that may be mutated in applications of gene therapy. PMID:25158795

  13. A comparative study of tissue factor and kaolin on blood coagulation assays using rotational thromboelastometry and thromboelastography.

    PubMed

    Peng, Henry T; Grodecki, Richard; Rizoli, Sandro; Shek, Pang N

    2016-01-01

    Rotational thromboelastometry (ROTEM) and thromboelastography (TEG) have been increasingly used to diagnose acute coagulopathy and guide blood transfusion. The tests are routinely performed using different triggering activators such as tissue factor and kaolin, which activate different pathways yielding different results. To optimize the global blood coagulation assays using ROTEM and TEG, we conducted a comparative study on the activation methods employing tissue factor and kaolin at different concentrations as well as standard reagents as recommended by the manufacturer of each device. Key parameter values were obtained at various assay conditions to evaluate and compare coagulation and fibrinolysis profiles of citrated whole blood collected from healthy volunteers. It was found that tissue factor reduced ROTEM clotting time and TEG R, and increased ROTEM clot formation time and TEG K in a concentration-dependent manner. In addition, tissue factor affected ROTEM alpha angle, and maximum clot firmness, especially in the absence of kaolin activation, whereas both ROTEM and TEG clot lysis (LI30, CL30, and LY30) remained unaffected. Moreover, kaolin reduced ROTEM clotting time and TEG R and K, but to a lesser extent than tissue factor, in-tem and ex-tem. Correlations in all corresponding parameters between ROTEM and TEG were observed, when the same activators were used in the assays compared with lesser correlations between standard kaolin TEG and ROTEM (INTEM/EXTEM). The two types of viscoelastic point-of-care devices provide different results, depending on the triggering reagent used to perform the assay. Optimal assay condition was obtained to reduce assay time and improve assay accuracy. PMID:26340454

  14. [Cellular model of blood coagulation process].

    PubMed

    Bijak, Michał; Rzeźnicka, Paulina; Saluk, Joanna; Nowak, Paweł

    2015-07-01

    Blood coagulation is a process which main objective is the prevention of blood loss when the integrity of the blood vessel is damaged. Over the years, have been presented a number of concepts characterizing the mechanism of thrombus formation. Since the 60s of last century was current cascade model of the coagulation wherein forming of the fibrin clot is determined by two pathways called extrinsic and intrinsic pathways. In the nineties of the last century Monroe and Hoffman presented his concept of blood coagulation process which complement the currently valid model of cells participation especially of blood platelets which aim is to provide a negatively charged phospholipid surface and thereby allow the coagulation enzymatic complexes formation. Developed conception they called cellular model of coagulation. The aim of this work was to present in details of this blood coagulation, including descriptions of its various phases. PMID:26277170

  15. [Progress in research of the blood coagulation system].

    PubMed

    Urano, H; Karasaki, Y; Shirahata, A

    1999-09-01

    Blood coagulation is an amplification system consisting of reactions between enzymes and zymogens. It has been illustrated as a cascade model. However, the exact mechanism by which haemostasis is achieved under physiological conditions remains to be clarified. The solving of structure-function relation of each coagulation factor, analysis of the enzymological characteristics of each reaction, analysis of the regulation mechanism of the reactions and identification of novel factors involved in coagulation reactions contribute to the understanding of this complex system. Based on these findings, some new conceptions of blood coagulation are proposed. In the model introduced in this review, the extrinsic pathway and the intrinsic pathway of the 'classical' cascade model of the blood coagulation system could not be separated, and the suppression of fibrinolysis by TAFI (thrombin activatable fibrinolysis inhibitor) during coagulation reactions is thought to be a critical process for effective haemostasis. PMID:10589463

  16. The pro-coagulant fibrinogenolytic serine protease isoenzymes purified from Daboia russelii russelii venom coagulate the blood through factor V activation: role of glycosylation on enzymatic activity.

    PubMed

    Mukherjee, Ashis K

    2014-01-01

    Proteases from Russell's viper venom (RVV) induce a variety of toxic effects in victim. Therefore, four new RVV protease isoenzymes of molecular mass 32901.044 Da, 333631.179 Da, 333571.472 Da, and 34594.776 Da, were characterized in this study. The first 10 N-terminal residues of these serine protease isoenzymes showed significant sequence homology with N-terminal sequences of snake venom thrombin-like and factor V-activating serine proteases, which was reconfirmed by peptide mass fingerprinting analysis. These proteases were found to be different from previously reported factor V activators isolated from snake venoms. These proteases showed significantly different fibrinogenolytic, BAEE-esterase and plasma clotting activities but no fibrinolytic, TAME-esterase or amidolytic activity against the chromogenic substrate for trypsin, thrombin, plasmin and factor Xa. Their Km and Vmax values towards fibrinogen were determined in the range of 6.6 to 10.5 µM and 111.0 to 125.5 units/mg protein, respectively. On the basis of fibrinogen degradation pattern, they may be classified as A/B serine proteases isolated from snake venom. These proteases contain ∼ 42% to 44% of N-linked carbohydrates by mass whereas partially deglycosylated enzymes showed significantly less catalytic activity as compared to native enzymes. In vitro these protease isoenzymes induce blood coagulation through factor V activation, whereas in vivo they provoke dose-dependent defibrinogenation and anticoagulant activity in the mouse model. At a dose of 5 mg/kg, none of these protease isoenzymes were found to be lethal in mice or house geckos, suggesting therapeutic application of these anticoagulant peptides for the prevention of thrombosis. PMID:24520323

  17. Adhesion of Blood Clots Can Be Enhanced When Copolymerized with a Macromer That Is Crosslinked by Coagulation Factor XIIIa.

    PubMed

    Chan, Karen Y T; Zhao, Chunyi; Siren, Erika M J; Chan, Jeanne C Y; Boschman, Jeffrey; Kastrup, Christian J

    2016-06-13

    The adhesion of blood clots to blood vessels, such as through the adhesion of fibrin, is essential in hemostasis. While numerous strategies for initiating clot formation and preventing clot lysis are being developed to create improved hemostatic agents, strategies for enhancing clot adhesion have not been widely explored. Here, we show that adhesion of blood clots can be increased by adding a previously characterized synthetic polymer that is crosslinked by coagulation factor XIIIa during clotting. Addition of the polymer to normal plasma increased the adhesive strength of clots by 2-fold. It also recovered the adhesive strength of nonadhesive fibrinogen-deficient whole blood clots from <0.06 kPa to 1.9 ± 0.14 kPa, which is similar to the adhesive strength of a fibrinogen-rich clot (1.8 ± 0.64 kPa). The polymer also enabled plasma clots to remain adhered under fibrinolytic conditions. By demonstrating that the adhesive strength of clots can be increased with a synthetic material, this provides a potential strategy for creating advanced hemostatic materials, such as treatments for fibrinogen deficiency in trauma-induced coagulopathy. PMID:27140446

  18. Blood coagulation factor XII drives adaptive immunity during neuroinflammation via CD87-mediated modulation of dendritic cells.

    PubMed

    Göbel, Kerstin; Pankratz, Susann; Asaridou, Chloi-Magdalini; Herrmann, Alexander M; Bittner, Stefan; Merker, Monika; Ruck, Tobias; Glumm, Sarah; Langhauser, Friederike; Kraft, Peter; Krug, Thorsten F; Breuer, Johanna; Herold, Martin; Gross, Catharina C; Beckmann, Denise; Korb-Pap, Adelheid; Schuhmann, Michael K; Kuerten, Stefanie; Mitroulis, Ioannis; Ruppert, Clemens; Nolte, Marc W; Panousis, Con; Klotz, Luisa; Kehrel, Beate; Korn, Thomas; Langer, Harald F; Pap, Thomas; Nieswandt, Bernhard; Wiendl, Heinz; Chavakis, Triantafyllos; Kleinschnitz, Christoph; Meuth, Sven G

    2016-01-01

    Aberrant immune responses represent the underlying cause of central nervous system (CNS) autoimmunity, including multiple sclerosis (MS). Recent evidence implicated the crosstalk between coagulation and immunity in CNS autoimmunity. Here we identify coagulation factor XII (FXII), the initiator of the intrinsic coagulation cascade and the kallikrein-kinin system, as a specific immune cell modulator. High levels of FXII activity are present in the plasma of MS patients during relapse. Deficiency or pharmacologic blockade of FXII renders mice less susceptible to experimental autoimmune encephalomyelitis (a model of MS) and is accompanied by reduced numbers of interleukin-17A-producing T cells. Immune activation by FXII is mediated by dendritic cells in a CD87-dependent manner and involves alterations in intracellular cyclic AMP formation. Our study demonstrates that a member of the plasmatic coagulation cascade is a key mediator of autoimmunity. FXII inhibition may provide a strategy to combat MS and other immune-related disorders. PMID:27188843

  19. Blood coagulation factor XII drives adaptive immunity during neuroinflammation via CD87-mediated modulation of dendritic cells

    PubMed Central

    Göbel, Kerstin; Pankratz, Susann; Asaridou, Chloi-Magdalini; Herrmann, Alexander M.; Bittner, Stefan; Merker, Monika; Ruck, Tobias; Glumm, Sarah; Langhauser, Friederike; Kraft, Peter; Krug, Thorsten F.; Breuer, Johanna; Herold, Martin; Gross, Catharina C.; Beckmann, Denise; Korb-Pap, Adelheid; Schuhmann, Michael K.; Kuerten, Stefanie; Mitroulis, Ioannis; Ruppert, Clemens; Nolte, Marc W.; Panousis, Con; Klotz, Luisa; Kehrel, Beate; Korn, Thomas; Langer, Harald F.; Pap, Thomas; Nieswandt, Bernhard; Wiendl, Heinz; Chavakis, Triantafyllos; Kleinschnitz, Christoph; Meuth, Sven G.

    2016-01-01

    Aberrant immune responses represent the underlying cause of central nervous system (CNS) autoimmunity, including multiple sclerosis (MS). Recent evidence implicated the crosstalk between coagulation and immunity in CNS autoimmunity. Here we identify coagulation factor XII (FXII), the initiator of the intrinsic coagulation cascade and the kallikrein–kinin system, as a specific immune cell modulator. High levels of FXII activity are present in the plasma of MS patients during relapse. Deficiency or pharmacologic blockade of FXII renders mice less susceptible to experimental autoimmune encephalomyelitis (a model of MS) and is accompanied by reduced numbers of interleukin-17A-producing T cells. Immune activation by FXII is mediated by dendritic cells in a CD87-dependent manner and involves alterations in intracellular cyclic AMP formation. Our study demonstrates that a member of the plasmatic coagulation cascade is a key mediator of autoimmunity. FXII inhibition may provide a strategy to combat MS and other immune-related disorders. PMID:27188843

  20. Contact Activation of Blood Plasma Coagulation

    PubMed Central

    Vogler, Erwin A.; Siedlecki, Christopher A.

    2009-01-01

    This opinion identifies inconsistencies in the generally-accepted surface biophysics involved in contact activation of blood-plasma coagulation, reviews recent experimental work aimed at resolving inconsistencies, and concludes that this standard paradigm requires substantial revision to accommodate new experimental observations. Foremost among these new findings is that surface-catalyzed conversion of the blood zymogen factor XII (FXII, Hageman factor) to the enzyme FXIIa ( FXII→surfaceFXIIa, a.k.a. autoactivation) is not specific for anionic surfaces, as proposed by the standard paradigm. Furthermore, it is found that surface activation is moderated by the protein composition of the fluid phase in which FXII autoactivation occurs by what appears to be a protein adsorption-competition effect. Both of these findings argue against the standard view that contact activation of plasma coagulation is potentiated by assembly of activation-complex proteins (FXII, FXI, prekallikrein, and high-molecular-weight kininogen) directly onto activating surfaces (procoagulants) through specific protein/surface interactions. These new findings supplement the observation that adsorption behavior of FXII and FXIIa is not remarkably different from a wide variety of other blood proteins surveyed. Similarity in adsorption properties further undermines the idea that FXII and/or FXIIa are distinguished from other blood proteins by unusual adsorption properties resulting in chemically-specific interactions with activating anionic surfaces. PMID:19168215

  1. Extensive small-angle X-ray scattering studies of blood coagulation factor VIIa reveal interdomain flexibility.

    PubMed

    Mosbaek, Charlotte Rode; Nolan, David; Persson, Egon; Svergun, Dmitri I; Bukrinsky, Jens Thostrup; Vestergaard, Bente

    2010-11-16

    Blood coagulation factor VIIa (FVIIa) is used in the treatment of replacement therapy resistant hemophilia patients, and FVIIa is normally activated upon complex formation with tissue factor (TF), potentially in context with structural rearrangements. The solution behavior of uncomplexed FVIIa is important for understanding the mechanism of activation and for the stability and activity of the pharmaceutical product. However, crystal structures of FVIIa in complex with TF and of truncated free FVIIa reveal different overall conformations while previous small-angle scattering studies suggest FVIIa always to be fully extended in solution. Here, small-angle X-ray scattering analysis of multiple forms of FVIIa and TF under several experimental conditions elaborate extensively on the understanding of the solution behavior of FVIIa. We reveal significant FVIIa domain flexibility in solution, whereas TF has a well-defined conformation. Unspecific formation of dimers of FVIIa is also observed and varies with experimental conditions. In particular, active site-inhibited FVIIa displays a distinct solution behavior different from that of uninhibited FVIIa, which may reflect structural rearrangements causing resistance to activation, thereby emphasizing the connection between the distribution of different conformations of FVII and the mechanism of activation. PMID:20873866

  2. Coagulation Factor Concentrates Fail to Restore Alterations in Fibrin Formation Caused by Rivaroxaban or Dabigatran in Studies With Flowing Blood From Treated Healthy Volunteers.

    PubMed

    Arellano-Rodrigo, Eduardo; Lopez-Vilchez, Irene; Galan, Ana M; Molina, Patricia; Reverter, Joan Carles; Carné, Xavier; Villalta, Jaume; Tassies, Dolors; Lozano, Miguel; Díaz-Ricart, Maribel; Escolar, Gines

    2015-10-01

    We evaluated the hemostatic alterations in blood from healthy individuals treated for 5 days with direct oral anticoagulants (DOACs) rivaroxaban (20 mg/d) or dabigatran (150 mg/12 h) in a single-blind clinical trial with crossover assignment (NCT01478282). We assessed the potential of prothrombin complex concentrates, activated prothrombin complex concentrates, or recombinant activated factor VII, when added ex vivo, to reverse the alterations caused by these DOACs. Blood was drawn at maximum plasma concentration after the last dose of each DOAC, and modifications in coagulation biomarkers were evaluated using a series of tests performed under steady conditions including routine coagulation, thrombin generation, and thromboelastometry assays. Additional studies in standardized flow devices were applied to evaluate alterations on platelet deposition and fibrin formation on damaged vascular surfaces exposed to flowing blood. Both DOACs caused important modifications of all coagulation biomarkers and significantly reduced fibrin formation in flow studies. Alterations in biomarkers observed in steady laboratory tests were normalized and occasionally overcompensated by procoagulant strategies. In contrast, reductions in fibrin formation observed in studies with flowing blood were improved, although never completely restored to baseline levels. Effects of dabigatran in flow studies appeared more resistant to reversal strategies than those of rivaroxaban. Inconsistencies between results of coagulation studies in steady or flowing assays not only raise concerns about the adequacy of the earlier tests to predict the restoration of the coagulopathy induced by DOACs but also suggest limitations of nonspecific procoagulant strategies to control severe coagulopathy in patients inadvertently overexposed these agents. PMID:26364029

  3. Systemic blood coagulation activation in acute coronary syndromes

    PubMed Central

    Undas, Anetta; Szułdrzyński, Konstanty; Brummel-Ziedins, Kathleen E.; Tracz, Wiesława; Zmudka, Krzysztof

    2009-01-01

    We evaluated systemic alterations to the blood coagulation system that occur during a coronary thrombotic event. Peripheral blood coagulation in patients with acute coronary thrombosis was compared with that in people with stable coronary artery disease (CAD). Blood coagulation and platelet activation at the microvascular injury site were assessed using immunochemistry in 28 non-anticoagulated patients with acute myocardial infarction (AMI) versus 28 stable CAD patients matched for age, sex, risk factors, and medications. AMI was associated with increased maximum rates of thrombin-antithrombin complex generation (by 93.8%; P < .001), thrombin B-chain formation (by 57.1%; P < .001), prothrombin consumption (by 27.9%; P = .012), fibrinogen consumption (by 27.0%; P = .02), factor (f) Va light chain generation (by 44.2%; P = .003), and accelerated fVa inactivation (by 76.1%; P < .001), and with enhanced release of platelet-derived soluble CD40 ligand (by 44.4%; P < .001). FVa heavy chain availability was similar in both groups because of enhanced formation and activated protein C (APC)–mediated destruction. The velocity of coagulant reactions in AMI patients showed positive correlations with interleukin-6. Heparin treatment led to dampening of coagulant reactions with profiles similar to those for stable CAD. AMI-induced systemic activation of blood coagulation markedly modifies the pattern of coagulant reactions at the site of injury in peripheral vessels compared with that in stable CAD patients. PMID:18931343

  4. [Resistance to activated protein C by mutation of the factor V gene. Most frequent blood coagulation defect in venous thromboses].

    PubMed

    Peus, D; Scharf, R E; Witt, I; Ruzicka, T

    1997-02-01

    Deep venous thromboses, in particular when recurrent, can be associated with chronic venous leg ulcers. Such complications are often seen in dermatology departments and frequently represent a therapeutic problem. Resistance to activated protein C (APCR) has recently been identified as the most frequent coagulation defect associated with an increased risk of venous thrombosis. In most cases, APCR is caused by a point mutation in the factor V gene which results in an impaired inactivation of activated factor V (Va). As a consequence of this, an important anti-coagulant mechanism in the physiological balance of the hemostatic system is abolished. This autosomal dominantly inherited genetic defects affects about 5% of the general population. In this article we draw attention to the existence of this recently identified, genetically determined risk factor for venous thrombosis, describe recent diagnostic developments and discuss therapeutic options. PMID:9173065

  5. Extrinsic blood coagulation pathway and risk factors for thrombotic events in patients with essential thrombocythemia.

    PubMed

    Stankowska, Katarzyna; Gadomska, Grażyna; Boinska, Joanna; Michalska, Małgorzata; Bartoszewska-Kubiak, Alicja; Rość, Danuta

    2016-05-31

    INTRODUCTION    The clinical course of essential thrombocythemia (ET) is varied, and some patients do not exhibit any clinical signs of the disease at the time of diagnosis. The most frequent complications that occur during the course of ET are hemostasis abnormalities manifesting as hemorrhagic or thrombotic events. The mechanism of thrombotic events in patients with ET is complex and not fully understood. OBJECTIVES    The aim of the study was to evaluate the concentration and activity of tissue factor (TF) and tissue factor pathway inhibitor (TFPI), depending on the most important risk factors of thrombotic complications (age >60 years, history of thrombotic episodes, presence or absence of the JAK2 V617F mutation, and increased leukocyte count). PATIENTS AND METHODS    The study group included 113 patients with diagnosed ET, and the control group, 30 healthy volunteers matched for age and sex. The concentration and activity of TF and TFPI were measured using enzyme-linked immunosorbent assays. RESULTS    Patients with ET had a significantly higher activity and concentration of TF and increased activity of TFPI, as compared with controls. The analysis of the studied parameters in relation to risk factors revealed that patients with ET with a history of thrombotic events had a significantly higher concentration of TF, and patients with the JAK2 V617F mutation had a lower TFPI activity, as compared with patients without the mutation. CONCLUSIONS    Our study showed that in patients with ET who have a history of thrombosis or the JAK2 V617F mutation, the enhanced risk of thrombosis may result from an increased TF concentration or decreased TFPI activity. PMID:27243342

  6. Impaired Activity of Blood Coagulant Factor XIII in Patients with Necrotizing Enterocolitis

    PubMed Central

    Tao, Guo-Zhong; Liu, Bo; Zhang, Rong; Liu, Gigi; Abdullah, Fizan; Harris, Mary Cay; Brandt, Mary L.; Ehrenkranz, Richard A.; Bowers, Corinna; Martin, Camilia R.; Moss, R. Lawrence; Sylvester, Karl G.

    2015-01-01

    Necrotizing enterocolitis (NEC) is the most common gastrointestinal (GI) medical/surgical emergency of the newborn and a leading cause of preterm neonate morbidity and mortality. NEC is a challenge to diagnose since it often shares similar clinical features with neonatal sepsis. In the present study, plasma protein profiling was compared among NEC, sepsis and control cohorts using gel electrophoresis, immunoblot and mass spectrometry. We observed significant impairment in the formation of fibrinogen-γ dimers (FGG-dimer) in the plasma of newborns with NEC that could efficiently differentiate NEC and sepsis with a high level of sensitivity and specificity. Interestingly, the impaired FGG-dimer formation could be restored in NEC plasma by the addition of exogenous active factor XIII (FXIII). Enzymatic activity of FXIII was determined to be significantly lower in NEC subject plasma for crosslinking FGG when compared to sepsis. These findings demonstrate a potential novel biomarker and related biologic mechanism for diagnosing NEC, as well as suggest a possible therapeutic strategy. PMID:26277871

  7. Magnetic particle imaging of blood coagulation

    SciTech Connect

    Murase, Kenya Song, Ruixiao; Hiratsuka, Samu

    2014-06-23

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  8. Magnetic particle imaging of blood coagulation

    NASA Astrophysics Data System (ADS)

    Murase, Kenya; Song, Ruixiao; Hiratsuka, Samu

    2014-06-01

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl2 to whole sheep blood mixed with magnetic nanoparticles (MNPs). The "MPI value" was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  9. New method for detection of blood coagulation using fiber-optic sensor

    NASA Astrophysics Data System (ADS)

    Fediay, Sergey G.; Kuznetzov, Alexsey V.

    1991-07-01

    The detection of blood coagulation is very important in therapeutics and surgery. It is necessary to determine the overall time taken for blood clotting, production rate of thrombin, presence or absence of blood coagulation factors, etc. In this paper a new method for detection of blood coagulation is presented. This method is based on the fiber-optic sensor and allows for the study of different ways of blood clotting (such as blood coagulation and platelets aggregation) separately, thus enhancing the precision of determination. The method for determining the blood coagulation presented possesses high precision in monitoring the process of coagulation. An elaborate mathematical model of the process of blood coagulation has been developed to help the computer handle obtained data.

  10. Contact activation of blood-plasma coagulation

    NASA Astrophysics Data System (ADS)

    Golas, Avantika

    Surface engineering of biomaterials with improved hemocompatibility is an imperative, given the widespread global need for cardiovascular devices. Research summarized in this dissertation focuses on contact activation of FXII in buffer and blood plasma frequently referred to as autoactivation. The extant theory of contact activation imparts FXII autoactivation ability to negatively charged, hydrophilic surfaces. According to this theory, contact activation of plasma involves assembly of proteins comprising an "activation complex" on activating surfaces mediated by specific chemical interactions between complex proteins and the surface. This work has made key discoveries that significantly improve our core understanding of contact activation and unravel the existing paradigm of plasma coagulation. It is shown herein that contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension t°a=g° Iv costheta in dyne/cm, where g°Iv is water interfacial tension in dyne/cm and theta is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties --36 < t°a < 72 dyne/cm (O° ≤ theta < 120°), falling sharply through a broad minimum within the 20 < t°a < 40 dyne/cm (55° < theta < 75°). Furthermore, contact activation of FXII in buffer solution produces an ensemble of protein fragments exhibiting either procoagulant properties in plasma (proteolysis of blood factor XI or prekallikrein), amidolytic properties (cleavage of s-2302 chromogen), or the ability to suppress autoactivation through currently unknown biochemistry. The relative proportions of these fragments depend on activator surface chemistry/energy. We have also discovered that contact activation is moderated by adsorption of plasma proteins unrelated to coagulation through an

  11. Blood coagulation reactions on nanoscale membrane surfaces

    NASA Astrophysics Data System (ADS)

    Pureza, Vincent S.

    Blood coagulation requires the assembly of several membrane-bound protein complexes composed of regulatory and catalytic subunits. The biomembranes involved in these reactions not only provide a platform for these procoagulant proteins, but can also affect their function. Increased exposure of acidic phospholipids on the outer leaflet of the plasma membrane can dramatically modulate the catalytic efficiencies of such membrane-bound enzymes. Under physiologic conditions, however, these phospholipids spontaneously cluster into a patchwork of membrane microdomains upon which membrane binding proteins may preferentially assemble. As a result, the membrane composition surrounding these proteins is largely unknown. Through the development and use of a nanometer-scale bilayer system that provides rigorous control of the phospholipid membrane environment, I investigated the role of phosphatidylserine, an acidic phospholipid, in the direct vicinity (within nanometers) of two critical membrane-bound procoagulant protein complexes and their respective natural substrates. Here, I present how the assembly and function of the tissue factor˙factor VIIa and factor Va˙factor Xa complexes, the first and final cofactor˙enzyme complexes of the blood clotting cascade, respectively, are mediated by changes in their immediate phospholipid environments.

  12. Coagulation Factor XIIIa Substrates in Human Plasma

    PubMed Central

    Nikolajsen, Camilla Lund; Dyrlund, Thomas F.; Poulsen, Ebbe Toftgaard; Enghild, Jan J.; Scavenius, Carsten

    2014-01-01

    Coagulation factor XIII (FXIII) is a transglutaminase with a well defined role in the final stages of blood coagulation. Active FXIII (FXIIIa) catalyzes the formation of ϵ-(γ-glutamyl)lysine isopeptide bonds between specific Gln and Lys residues. The primary physiological outcome of this catalytic activity is stabilization of the fibrin clot during coagulation. The stabilization is achieved through the introduction of cross-links between fibrin monomers and through cross-linking of proteins with anti-fibrinolytic activity to fibrin. FXIIIa additionally cross-links several proteins with other functionalities to the clot. Cross-linking of proteins to the clot is generally believed to modify clot characteristics such as proteolytic susceptibility and hereby affect the outcome of tissue damage. In the present study, we use a proteomic approach in combination with transglutaminase-specific labeling to identify FXIIIa plasma protein substrates and their reactive residues. The results revealed a total of 147 FXIIIa substrates, of which 132 have not previously been described. We confirm that 48 of the FXIIIa substrates were indeed incorporated into the insoluble fibrin clot during the coagulation of plasma. The identified substrates are involved in, among other activities, complement activation, coagulation, inflammatory and immune responses, and extracellular matrix organization. PMID:24443567

  13. Tissue Factor in Coagulation: Which? Where? When?

    PubMed Central

    Butenas, Saulius; Orfeo, Thomas; Mann, Kenneth G.

    2009-01-01

    Tissue factor (TF) is an integral membrane protein, normally separated from the blood by the vascular endothelium, which plays a key role in the initiation of blood coagulation. With a perforating vascular injury, TF becomes exposed to blood and binds plasma factor VIIa. The resulting complex initiates a series of enzymatic reactions leading to clot formation and vascular sealing. In some pathologic states, circulating blood cells express TF as a result of exposure to an inflammatory stimulus leading to intravascular clotting, vessel occlusion and thrombotic pathology. Numerous controversies have arisen related to the influence of structural features of TF, its presentation and its function. There are contradictory reports about the synthesis and presentation of TF on blood cells and the presence (or absence) of functionally active TF circulating in normal blood either on microparticles or as a soluble protein. In this review we discuss TF structure-function relationships and the role of TF during various phases of the blood coagulation process. We also highlight controversies concerning the expression/presence of TF on various cells and in blood in normal and pathologic states. PMID:19592470

  14. Effect of nano-scale curvature on the intrinsic blood coagulation system

    NASA Astrophysics Data System (ADS)

    Kushida, Takashi; Saha, Krishnendu; Subramani, Chandramouleeswaran; Nandwana, Vikas; Rotello, Vincent M.

    2014-11-01

    The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation `silent' surface, while nanoparticles with lower surface curvature show denaturation and concomitant coagulation.The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation `silent' surface, while nanoparticles with lower surface curvature show denaturation and concomitant coagulation. Electronic supplementary information (ESI) available: Physical properties and scanning electron micrographs (SEM) of silica NPs, intrinsic coagulation activity after 3 h. See DOI: 10.1039/c4nr04128c

  15. Principles of dielectric blood coagulometry as a comprehensive coagulation test.

    PubMed

    Hayashi, Yoshihito; Brun, Marc-Aurèle; Machida, Kenzo; Nagasawa, Masayuki

    2015-10-01

    Dielectric blood coagulometry (DBCM) is intended to support hemostasis management by providing comprehensive information on blood coagulation from automated, time-dependent measurements of whole blood dielectric spectra. We discuss the relationship between the series of blood coagulation reactions, especially the aggregation and deformation of erythrocytes, and the dielectric response with the help of clot structure electron microscope observations. Dielectric response to the spontaneous coagulation after recalcification presented three distinct phases that correspond to (P1) rouleau formation before the onset of clotting, (P2) erythrocyte aggregation and reconstitution of aggregates accompanying early fibrin formation, and (P3) erythrocyte shape transformation and/or structure changes within aggregates after the stable fibrin network is formed and platelet contraction occurs. Disappearance of the second phase was observed upon addition of tissue factor and ellagic acid for activation of extrinsic and intrinsic pathways, respectively, which is attributable to accelerated thrombin generation. A series of control experiments revealed that the amplitude and/or quickness of dielectric response reflect platelet function, fibrin polymerization, fibrinolysis activity, and heparin activity. Therefore, DBCM sensitively measures blood coagulation via erythrocytes aggregation and shape changes and their impact on the dielectric permittivity, making possible the development of the battery of assays needed for comprehensive coagulation testing. PMID:26368847

  16. Influence of blood coagulability after spinal surgeries

    PubMed Central

    Matsumoto, Marcelo Hide; Rodrigues, Luiz Claudio Lacerda; Batalini, Luiz Gustavo da silva; Fonteles, Thales Arcanjo; Bortoletto, Adalberto

    2014-01-01

    Objective: To verify whether spinal surgery causes relevant changes in the blood clotting process and define which factors have the greatest influence on changes found. Method: This is a not randomized, cross-sectional study, Forty seven patients were evaluated between August 2011 and February 2013, whose clinical, surgical, laboratory and image daata were collected. The data obtained were crossed with the epidemiological data of each patient in a moment prior to and another after surgery searching which variables have been directly influenced. Result: Our analysis showed that the most important changes occurred in patients with BMI classified, according to the World Health Organization (WHO) as out of healthy range. Other smaller correlations were also found. Another important consideration was the tendency to observe hypercoagulability in smoker patients, a fact that is not influenced by spinal procedures. Conclusion: We concluded that spinal surgeries cause few relevant changes in the blood clotting process and that among the factors studied, BMI (when out of the healthy range, according to the WHO classification) showed closer relationship with changes in laboratory coagulation tests. Level of Evidence III, Cross-Sectional Study. PMID:25328429

  17. Discovery of a Highly Potent, Selective, and Orally Bioavailable Macrocyclic Inhibitor of Blood Coagulation Factor VIIa-Tissue Factor Complex.

    PubMed

    Zhang, Xiaojun; Glunz, Peter W; Johnson, James A; Jiang, Wen; Jacutin-Porte, Swanee; Ladziata, Vladimir; Zou, Yan; Phillips, Monique S; Wurtz, Nicholas R; Parkhurst, Brandon; Rendina, Alan R; Harper, Timothy M; Cheney, Daniel L; Luettgen, Joseph M; Wong, Pancras C; Seiffert, Dietmar; Wexler, Ruth R; Priestley, E Scott

    2016-08-11

    Inhibitors of the tissue factor (TF)/factor VIIa complex (TF-FVIIa) are promising novel anticoagulants which show excellent efficacy and minimal bleeding in preclinical models. Starting with an aminoisoquinoline P1-based macrocyclic inhibitor, optimization of the P' groups led to a series of highly potent and selective TF-FVIIa inhibitors which displayed poor permeability. Fluorination of the aminoisoquinoline reduced the basicity of the P1 group and significantly improved permeability. The resulting lead compound was highly potent, selective, and achieved good pharmacokinetics in dogs with oral dosing. Moreover, it demonstrated robust antithrombotic activity in a rabbit model of arterial thrombosis. PMID:27455395

  18. Ca2+ Switches the Effect of PS-containing Membranes on Factor Xa from Activating to Inhibiting: Implications for Initiation of Blood Coagulation

    PubMed Central

    Koklic, Tilen; Majumder, Rinku; Lentz, Barry R.

    2014-01-01

    Calcium (Ca2+) plays a pivotal role in cellular and organismal physiology. The Ca2+ ion has an intermediate protein-binding affinity, thus it can serve as an on/off switch in regulation of different biochemical processes. The serum level of ionized Ca2+ is regulated with normal ionized Ca2+ being in the range from 1.10 to 1.29 mM. Hypocalcaemia (free Ca2+ < 1.1mM) in critically ill patients is commonly accompanied by hemostatic abnormalities, ranging from isolated thrombocytopenia to complex defects such as disseminated intravascular coagulation, commonly thought to be due to insufficient functioning of anticoagulation pathways. A small amount of Factor Xa (fXa) produced by Factor VIIa and exposed tissue factor is key to initiating blood coagulation by producing enough thrombin to induce later stages of coagulation. FXa must bind to phosphatidylserine (PS)-containing membranes to produce thrombin at a physiologically significant rate. In this work, we show that overall fXa activity on PS-containing membranes is sharply regulated by a “Ca2+ switch” centered at 1.16 mM, below which fXa is active and above which fXa forms inactive dimers on PS-exposing membranes. Our data lead to a mathematical model that predicts the variation of fXa activity as a function of both calcium and membrane concentrations. Because the critical Ca2+ concentration is at the lower end of the normal plasma ionized Ca2+ concentration range, we propose a new regulatory mechanism by which local Ca2+ concentration switches fXa from an intrinsically active form to a form requiring its cofactor (fVa) to achieve significant activity. PMID:24920080

  19. Thymoquinone Modulates Blood Coagulation in Vitro via Its Effects on Inflammatory and Coagulation Pathways

    PubMed Central

    Muralidharan-Chari, Vandhana; Kim, Jaehan; Abuawad, Ahlam; Naeem, Mubeena; Cui, Huadong; Mousa, Shaker A.

    2016-01-01

    Thymoquinone (THQ) is a major component of black seeds. Given that both THQ and black seeds exhibit anti-cancer and anti-inflammatory activities, we hypothesized that THQ will affect cancer-associated thrombosis (CAT), which is primarily triggered by tissue factor (TF) and inflammation. The effect of both black seed-extracted and purchased (“pure”) THQ on normal blood coagulation was tested with in vitro thromboelastography (TEG) and activated partial thromboplastin time (aPTT) coagulation assays. The effect of pure THQ on CAT was tested with aPTT assay using pancreatic cancer cell lines that are either positive or negative for TF, and with TEG assay using lipopolysaccharide as an inflammatory trigger. Additionally, the direct effect of THQ on the inactivation of factors IIa and Xa was assessed. Since TNF-α facilitates crosstalk between inflammation and thrombosis by triggering the NF-κB pathway, we tested THQ’s ability to interfere with this communication with a luciferase assay. Both extracted and pure THQ had minimal effects on normal blood coagulation. Pure THQ reversed CAT initiated by both TF and inflammation to basal levels (p < 0.001). Mechanistically, while THQ had minimal to no effect on factor IIa and Xa inactivation, it strongly reduced the effects of TNF-α on NF-κB elements (p < 0.001). THQ has a minimal effect on basal coagulation and can reverse CAT in vitro, possibly by interfering with the crosstalk between inflammation and coagulation. This study suggests the utility of THQ as a preventative anticoagulant and/or as a supplement to existing chemotherapies and anticoagulant therapies. PMID:27043539

  20. Blood coagulation and platelet adhesion on polyaniline films.

    PubMed

    Humpolíček, Petr; Kuceková, Zdenka; Kašpárková, Věra; Pelková, Jana; Modic, Martina; Junkar, Ita; Trchová, Miroslava; Bober, Patrycja; Stejskal, Jaroslav; Lehocký, Marián

    2015-09-01

    Polyaniline is a promising conducting polymer with still increasing application potential in biomedicine. Its surface modification can be an efficient way how to introduce desired functional groups and to control its properties while keeping the bulk characteristics of the material unchanged. The purpose of the study was to synthetize thin films of pristine conducting polyaniline hydrochloride, non-conducting polyaniline base and polyaniline modified with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) and investigate chosen parameters of their hemocompatibility. The modification was performed either by introduction of PAMPSA during the synthesis or by reprotonation of polyaniline base. The polyaniline hydrochloride and polyaniline base had no impact on blood coagulation and platelet adhesion. By contrast, the polyaniline reprotonated with PAMPSA completely hindered coagulation thanks to its interaction with coagulation factors Xa, Va and IIa. The significantly lower platelets adhesion was also found on this surface. Moreover, this film maintains its conductivity at pH of 6, which is an improvement in comparison with standard polyaniline hydrochloride losing most of its conductivity at pH of 4. Polyaniline film with PAMPSA introduced during synthesis had an impact on platelet adhesion but not on coagulation. The combined conductivity, anticoagulation activity, low platelet adhesion and improved conductivity at pH closer to physiological, open up new possibilities for application of polyaniline reprotonated by PAMPSA in blood-contacting devices, such as catheters or blood vessel grafts. PMID:26119372

  1. Proteins, Platelets, and Blood Coagulation at Biomaterial Interfaces

    PubMed Central

    Xu, Li-Chong; Bauer, James; Siedlecki, Christopher A.

    2015-01-01

    Blood coagulation and platelet adhesion remain major impediments to the use of biomaterials in implantable medical devices. There is still significant controversy and question in the field regarding the role that surfaces play in this process. This manuscript addresses this topic area and reports on state of the art in the field. Particular emphasis is placed on the subject of surface engineering and surface measurements that allow for control and observation of surface-mediated biological responses in blood and test solutions. Appropriate use of surface texturing and chemical patterning methodologies allow for reduction of both blood coagulation and platelet adhesion, and new methods of surface interrogation at high resolution allow for measurement of the relevant biological factors. PMID:25448722

  2. Silica Nanoparticles Effects on Blood Coagulation Proteins and Platelets

    PubMed Central

    Gryshchuk, Volodymyr; Galagan, Natalya

    2016-01-01

    Interaction of nanoparticles with the blood coagulation is important prior to their using as the drug carriers or therapeutic agents. The aim of present work was studying of the primary effects of silica nanoparticles (SiNPs) on haemostasis in vitro. We studied the effect of SiNPs on blood coagulation directly estimating the activation of prothrombin and factor X and to verify any possible effect of SiNPs on human platelets. It was shown that SiNPs shortened coagulation time in APTT and PT tests and increased the activation of factor X induced by RVV possibly due to the sorption of intrinsic pathway factors on their surface. SiNPs inhibited the aggregation of platelet rich plasma induced by ADP but in the same time partially activated platelets as it was shown using flow cytometry. The possibility of SiNPs usage in nanomedicine is strongly dependant on their final concentration in bloodstream and the size of the particles that are used. However SiNPs are extremely promising as the haemostatic agents for preventing the blood loss after damage. PMID:26881078

  3. Monitoring the blood coagulation process under various flow conditions with optical coherence tomography.

    PubMed

    Xu, Xiangqun; Geng, Jinhai; Teng, Xiangshuai

    2014-04-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique was able to characterize the whole blood coagulation process. The 1/e light penetration depth (d(1/e)) derived from the profiles of reflectance versus depth was developed for detecting the whole blood coagulation process in static state. To consider the effect of blood flow, in the present study, d(1/e) versus time from the coagulating porcine blood circulated in a mock flow loop with various steady laminar flows at mean flow speed in the range from 5 to 25  mm/s. The variation of d(1/e) was used to represent the change of blood properties during coagulation in different hematocrits (HCT) ranging from 25% to 55%, velocities from 5 to 25  mm/s, and tubing sizes from 0.9 to 2 mm. The results showed that there were positive correlations between coagulation time (t(c)) and HCT, velocity, and tubing size, respectively. In addition, the coagulation rate (S(r)) was decreased with the increase of HCT, velocity, and tubing size. This study testified that HCT, flow velocity, and tubing size were substantial factors affecting the backscattering properties during flowing blood coagulation. Furthermore, OCT has the potential to represent the process of flowing blood coagulation with proper parameters. PMID:24781589

  4. Human plasma kallikrein releases neutrophil elastase during blood coagulation.

    PubMed Central

    Wachtfogel, Y T; Kucich, U; James, H L; Scott, C F; Schapira, M; Zimmerman, M; Cohen, A B; Colman, R W

    1983-01-01

    Elastase is released from human neutrophils during the early events of blood coagulation. Human plasma kallikrein has been shown to stimulate neutrophil chemotaxis, aggregation, and oxygen consumption. Therefore, the ability of kallikrein to release neutrophil elastase was investigated. Neutrophils were isolated by dextran sedimentation, and elastase release was measured by both an enzyme-linked immunosorbent assay, and an enzymatic assay using t-butoxy-carbonyl-Ala-Ala-Pro-Val-amino methyl coumarin as the substrate. Kallikrein, 0.1-1.0 U/ml, (0.045-0.45 microM), was incubated with neutrophils that were preincubated with cytochalasin B (5 micrograms/ml). The release of elastase was found to be proportional to the kallikrein concentration. Kallikrein released a maximum of 34% of the total elastase content, as measured by solubilizing the neutrophils in the nonionic detergent Triton X-100. A series of experiments was carried out to determine if kallikrein was a major enzyme involved in neutrophil elastase release during blood coagulation. When 10 million neutrophils were incubated in 1 ml of normal plasma in the presence of 30 mM CaCl2 for 90 min, 2.75 micrograms of elastase was released. In contrast, neutrophils incubated in prekallikrein-deficient or Factor XII-deficient plasma released less than half of the elastase, as compared with normal plasma. The addition of purified prekallikrein to prekallikrein-deficient plasma restored neutrophil elastase release to normal levels. Moreover, release of elastase was enhanced in plasma deficient in C1-inhibitor, the major plasma inhibitor of kallikrein. This release was not dependent upon further steps in the coagulation pathway, or on C5a, since levels of elastase, released in Factor XI- or C5-deficient plasma, were similar to that in normal plasma, and an antibody to C5 failed to inhibit elastase release. These data suggest that kallikrein may be a major enzyme responsible for the release of elastase during blood

  5. Changes in the human blood coagulating system during prolonged hypokinesia

    NASA Technical Reports Server (NTRS)

    Filatova, L. M.; Anashkin, O. D.

    1978-01-01

    Changes in the coagulating system of the blood were studied in six subjects during prolonged hypokinesia. Thrombogenic properties of the blood rose in all cases on the 8th day. These changes are explained by stress reaction due to unusual conditions for a healthy person. Changes in the blood coagulating system in the group subjected to physical exercise and without it ran a practically parallel course. Apparently physical exercise is insufficient to prevent such changes that appear in the coagulating system of the blood during prolonged hypokinesia.

  6. Ranking reactive glutamines in the fibrinogen αC region that are targeted by blood coagulant factor XIII.

    PubMed

    Mouapi, Kelly Njine; Bell, Jacob D; Smith, Kerrie A; Ariëns, Robert A S; Philippou, Helen; Maurer, Muriel C

    2016-05-01

    Factor XIIIa (FXIIIa) introduces covalent γ-glutamyl-ε-lysyl crosslinks into the blood clot network. These crosslinks involve both the γ and α chains of fibrin. The C-terminal portion of the fibrin α chain extends into the αC region (210-610). Crosslinks within this region help generate a stiffer clot, which is more resistant to fibrinolysis. Fibrinogen αC (233-425) contains a binding site for FXIIIa and three glutamines Q237, Q328, and Q366 that each participate in physiological crosslinking reactions. Although these glutamines were previously identified, their reactivities toward FXIIIa have not been ranked. Matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry and nuclear magnetic resonance (NMR) methods were thus used to directly characterize these three glutamines and probe for sources of FXIIIa substrate specificity. Glycine ethyl ester (GEE) and ammonium chloride served as replacements for lysine. Mass spectrometry and 2D heteronuclear single quantum coherence NMR revealed that Q237 is rapidly crosslinked first by FXIIIa followed by Q366 and Q328. Both (15)NH4Cl and (15)N-GEE could be crosslinked to the three glutamines in αC (233-425) with a similar order of reactivity as observed with the MALDI-TOF mass spectrometry assay. NMR studies using the single αC mutants Q237N, Q328N, and Q366N demonstrated that no glutamine is dependent on another to react first in the series. Moreover, the remaining two glutamines of each mutant were both still reactive. Further characterization of Q237, Q328, and Q366 is important because they are located in a fibrinogen region susceptible to physiological truncations and mutation. The current results suggest that these glutamines play distinct roles in fibrin crosslinking and clot architecture. PMID:26951791

  7. Oxidation inhibits iron-induced blood coagulation.

    PubMed

    Pretorius, Etheresia; Bester, Janette; Vermeulen, Natasha; Lipinski, Boguslaw

    2013-01-01

    Blood coagulation under physiological conditions is activated by thrombin, which converts soluble plasma fibrinogen (FBG) into an insoluble clot. The structure of the enzymatically-generated clot is very characteristic being composed of thick fibrin fibers susceptible to the fibrinolytic degradation. However, in chronic degenerative diseases, such as atherosclerosis, diabetes mellitus, cancer, and neurological disorders, fibrin clots are very different forming dense matted deposits (DMD) that are not effectively removed and thus create a condition known as thrombosis. We have recently shown that trivalent iron (ferric ions) generates hydroxyl radicals, which subsequently convert FBG into abnormal fibrin clots in the form of DMDs. A characteristic feature of DMDs is their remarkable and permanent resistance to the enzymatic degradation. Therefore, in order to prevent thrombotic incidences in the degenerative diseases it is essential to inhibit the iron-induced generation of hydroxyl radicals. This can be achieved by the pretreatment with a direct free radical scavenger (e.g. salicylate), and as shown in this paper by the treatment with oxidizing agents such as hydrogen peroxide, methylene blue, and sodium selenite. Although the actual mechanism of this phenomenon is not yet known, it is possible that hydroxyl radicals are neutralized by their conversion to the molecular oxygen and water, thus inhibiting the formation of dense matted fibrin deposits in human blood. PMID:23170793

  8. Metals in airpollution particles decrease whole blood coagulation time

    EPA Science Inventory

    The mechanism underlying the pro-coagulative effect of air pollution particle exposure is not known. We tested the postulate that 1) the soluble fraction ofan air pollution particle can affect whole blood coagulation time and 2) metals included in the soluble fraction are respons...

  9. In vitro/in vivo effect of Citrus limon (L. Burm. f.) juice on blood parameters, coagulation and anticoagulation factors in rabbits.

    PubMed

    Riaz, Azra; Khan, Rafeeq Alam; Mirza, Talat; Mustansir, Tazeen; Ahmed, Mansoor

    2014-07-01

    The genus Citrus of the family Rutaceae includes many species e.g. Citrus indica, Citrus aurantifolia and Citrus limon, among which Citrus limon L. Burm. f. has been reported to have highest antimicrobial activity. It is used as antidote against certain venom, due to its platelet inhibitory effect and also reported to have hypocholesterolemic effect. However its anticoagulant and thrombolytic effect were not been investigated, hence a prospective in-vitro/in-vivo study was designed to determine the effect of Citrus limon on blood parameters, coagulation and anticoagulation factors. In-vitro tests revealed highly significant increase in thrombin time and activated partial thromboplastin time by Citrus limon, whereas fibrinogen concentration was significantly reduced in comparison to control, however prothrombin time was not affected significantly. In-vivo testing of Citrus limon was done at three different doses i.e. 0.2ml/kg, 0.4ml/kg and 0.6ml/kg in healthy rabbits. Significant changes were observed in hematological parameters such as erythrocytes, hemoglobin and mean corpuscular hemoglobin concentration. Bleeding time and thrombin time was significantly prolonged and there was increase in protein C and thrombin antithrombin complex levels. These results may be due to inactivation of thrombin because it significantly decreases fibrinogen concentration and inhibit platelet aggregation. Citrus limon showed maximal anticoagulant effect at 0.4ml/kg, which suggest that Citrus limon possesses an anti-thrombin component and could prevent thrombosis playing a cardio protective role. PMID:25015459

  10. Coagulation factor XII protease domain crystal structure

    PubMed Central

    Pathak, M; Wilmann, P; Awford, J; Li, C; Hamad, BK; Fischer, PM; Dreveny, I; Dekker, LV; Emsley, J

    2015-01-01

    Background Coagulation factor XII is a serine protease that is important for kinin generation and blood coagulation, cleaving the substrates plasma kallikrein and FXI. Objective To investigate FXII zymogen activation and substrate recognition by determining the crystal structure of the FXII protease domain. Methods and results A series of recombinant FXII protease constructs were characterized by measurement of cleavage of chromogenic peptide and plasma kallikrein protein substrates. This revealed that the FXII protease construct spanning the light chain has unexpectedly weak proteolytic activity compared to β-FXIIa, which has an additional nine amino acid remnant of the heavy chain present. Consistent with these data, the crystal structure of the light chain protease reveals a zymogen conformation for active site residues Gly193 and Ser195, where the oxyanion hole is absent. The Asp194 side chain salt bridge to Arg73 constitutes an atypical conformation of the 70-loop. In one crystal form, the S1 pocket loops are partially flexible, which is typical of a zymogen. In a second crystal form of the deglycosylated light chain, the S1 pocket loops are ordered, and a short α-helix in the 180-loop of the structure results in an enlarged and distorted S1 pocket with a buried conformation of Asp189, which is critical for P1 Arg substrate recognition. The FXII structures define patches of negative charge surrounding the active site cleft that may be critical for interactions with inhibitors and substrates. Conclusions These data provide the first structural basis for understanding FXII substrate recognition and zymogen activation. PMID:25604127

  11. Characterization of Blood Properties from Coagulating Blood of Different Hematocrits Using Ultrasonic Backscatter and Attenuation

    NASA Astrophysics Data System (ADS)

    Huang, Chih-Chung; Wang, Shyh-Hau

    2006-09-01

    The influence of hematocrit on the change of blood properties during coagulating was extensively investigated using ultrasonic integrated backscatter and attenuation. Measurements were performed with porcine blood at hematocrits ranging from 25 to 55% using a 10 MHz transducer. Results showed that both integrated backscatter and attenuation are able to sensitively differentiate various stages of blood properties during coagulating. The slopes of integrated backscatter (Sr, dB/S) and attenuation (αr, dB\\cdotcm-1\\cdotMHz-1\\cdotmS-1) are increased relative to hematocrit. The best fits for Sr and αr as a function of hematocrit (H) equal to Sr=0.0357+1.62e-0.108H and αr=0.0281+0.003H, respectively. Variations of clotting time (Ts) and reaction time (Tα), estimated respectively from ultrasonic integrated backscatter and attenuation, associated with clot formation are also increased with hematocrit. This study demonstrates that blood hematocrit is a substantial factor affecting viscosity and backscattering properties of blood during coagulation capable of being discerned by ultrasonic backscattering and attenuation.

  12. Fibrinolysis and the control of blood coagulation

    PubMed Central

    Chapin, John C.; Hajjar, Katherine A.

    2014-01-01

    Fibrin plays an essential role in hemostasis as both the primary product of the coagulation cascade and the ultimate substrate for fibrinolysis. Fibrinolysis efficiency is greatly influenced by clot structure, fibrinogen isoforms and polymorphisms, the rate of thrombin generation, the reactivity of thrombus-associated cells such as platelets, and the overall biochemical environment. Regulation of the fibrinolytic system, like that of the coagulation cascade, is accomplished by a wide array of cofactors, receptors, and inhibitors. Fibrinolytic activity can be generated either on the surface of a fibrin-containing thrombus, or on cells that express profibrinolytic receptors. In a widening spectrum of clinical disorders, acquired and congenital defects in fibrinolysis contribute to disease morbidity, and new assays of global fibrinolysis now have potential predictive value in multiple clinical settings. Here, we summarize the basic elements of the fibrinolytic system, points of interaction with the coagulation pathway, and some recent clinical advances. PMID:25294122

  13. Coagulant Activity of Leukocytes. TISSUE FACTOR ACTIVITY

    PubMed Central

    Niemetz, J.

    1972-01-01

    Peritoneal leukocytes harvested from rabbits which have received two spaced doses of endotoxin have significantly greater (10-fold) coagulant activity than leukocytes from control rabbits. The coagulant activity accelerates the clotting of normal plasma and activates factor X in the presence of factor VII and calcium and is therefore regarded as tissue factor. A total of 40-80 mg tissue factor activity was obtained from the peritoneal cavity of single endotoxin-treated rabbits. In leukocyte subcellular fractions, separated by centrifugation, the specific tissue factor activity sedimented mainly at 14,500 g and above. The procoagulant activity was destroyed after heating for 10 min at 65°C but was preserved at lower temperatures. Polymyxin B, when given with the first dose of endotoxin, reduced both the number of peritoneal leukocytes and their tissue factor activity by two-thirds. When given immediately before the second dose of endotoxin, polymyxin B had no inhibitory effect. PMID:4333021

  14. Mathematical Modeling of Intravascular Blood Coagulation under Wall Shear Stress

    PubMed Central

    Rukhlenko, Oleksii S.; Dudchenko, Olga A.; Zlobina, Ksenia E.; Guria, Georgy Th.

    2015-01-01

    Increased shear stress such as observed at local stenosis may cause drastic changes in the permeability of the vessel wall to procoagulants and thus initiate intravascular blood coagulation. In this paper we suggest a mathematical model to investigate how shear stress-induced permeability influences the thrombogenic potential of atherosclerotic plaques. Numerical analysis of the model reveals the existence of two hydrodynamic thresholds for activation of blood coagulation in the system and unveils typical scenarios of thrombus formation. The dependence of blood coagulation development on the intensity of blood flow, as well as on geometrical parameters of atherosclerotic plaque is described. Relevant parametric diagrams are drawn. The results suggest a previously unrecognized role of relatively small plaques (resulting in less than 50% of the lumen area reduction) in atherothrombosis and have important implications for the existing stenting guidelines. PMID:26222505

  15. Histidine-rich glycoprotein inhibits contact activation of blood coagulation.

    PubMed

    Vestergaard, A B; Andersen, H F; Magnusson, S; Halkier, T

    1990-12-01

    Histidine-rich glycoprotein has been purified from bovine plasma employing two different purification procedures. The first procedure was one-step ion-exchange chromatography using phosphocellulose, while the second procedure involved fractionation using polyethyleneglycol 6000 followed by column chromatography employing CM-Sepharose and heparin-Sepharose. The effect of purified bovine histidine-rich glycoprotein on the contact activation of blood coagulation was studied in human plasma by using as activating surface either an ellagic acid-phospholipid suspension (Cephotest) or sulfatide. Contact activation was monitored by the generation of amidolytic activity towards a synthetic chromogenic substrate (S-2302) for factor XIIa and plasma kallikrein. Bovine histidine-rich glycoprotein inhibits the contact activation induced by both of these activating surfaces. PMID:2084959

  16. Sequential coagulation factor VIIa domain binding to tissue factor

    SciTech Connect

    Oesterlund, Maria; Persson, Egon; Freskgard, Per-Ola . E-mail: msv@ifm.liu.se

    2005-12-02

    Vessel wall tissue factor (TF) is exposed to blood upon vascular damage which enables association with factor VIIa (FVIIa). This leads to initiation of the blood coagulation cascade through localization and allosteric induction of FVIIa procoagulant activity. To examine the docking pathway of the FVIIa-TF complex, various residues in the extracellular part of TF (sTF) that are known to interact with FVIIa were replaced with cysteines labelled with a fluorescent probe. By using stopped-flow fluorescence kinetic measurements in combination with surface plasmon resonance analysis, we studied the association of the resulting sTF variants with FVIIa. We found the docking trajectory to be a sequence of events in which the protease domain of FVIIa initiates contact with sTF. Thereafter, the two proteins are tethered via the first epidermal growth factor-like and finally the {gamma}-carboxyglutamic acid (Gla) domain. The two labelled sTF residues interacting with the protease domain of FVIIa bind or become eventually ordered at different rates, revealing kinetic details pertinent to the allosteric activation of FVIIa by sTF. Moreover, when the Gla domain of FVIIa is removed the difference in the rate of association for the remaining domains is much more pronounced.

  17. Blood coagulation using High Intensity Focused Ultrasound (HIFU)

    NASA Astrophysics Data System (ADS)

    Nguyen, Phuc V.; Oh, Junghwan; Kang, Hyun Wook

    2014-03-01

    High Intensity Focused Ultrasound (HIFU) technology provides a feasible method of achieving thermal coagulation during surgical procedures. One of the potential clinical benefits of HIFU can induce immediate hemostasis without suturing. The objective of this study was to investigate the efficiency of a HIFU system for blood coagulation on severe vascular injury. ngHIFU treatment was implemented immediately after bleeding in artery. The ultrasound probe was made of piezoelectric material, generating a central frequency of 2.0 MHz as well as an ellipsoidal focal spot of 2 mm in lateral dimension and 10 mm in axial dimension. Acoustic coagulation was employed on a perfused chicken artery model in vitro. A surgical incision (1 to 2 mm long) was made with a scapel on the arterial wall, and heparinized autologous blood was made to leak out from the incision with a syringe pump. A total of 5 femoral artery incisions was treated with the HIFU beam. The intensity of 4500 W/cm2 at the focus was applied for all treatments. Complete hemostasis was achieved in all treatments, along with the treatment times of 25 to 50 seconds. The estimated intraoperative blood loss was from 2 to 5 mL. The proposed HIFU system may provide an effective method for immediate blood coagulation for arteries and veins in clinical applications.

  18. Evaluation of whole blood coagulation process by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Lin, Jia

    2010-11-01

    This study was to investigate the feasibility of using optical coherence tomography (OCT) to evaluate whole blood coagulation process. Attenuation coefficients and 1/e light penetration depth (D1/e) against time of human whole blood during in vitro clot formation under static were measured from the OCT profiles of reflectance vs depth. The results obtained clearly showed that the optical parameters are able to identify three stages during the in vitro blood clotting process. It is concluded that D1/e measured by OCT is a potential parameter to quantify and follow the liquid-gel transition of blood during clotting.

  19. Multifrequency acoustics as a probe of mesoscopic blood coagulation dynamics

    NASA Astrophysics Data System (ADS)

    Ganesan, Adarsh; Rajendran, Gokulnath; Ercole, Ari; Seshia, Ashwin

    2016-08-01

    Coagulation is a complex enzymatic polymerisation cascade. Disordered coagulation is common in medicine and may be life-threatening yet clinical assays are typically bulky and/or provide an incomplete picture of clot mechanical evolution. We present the adaptation of an in-plane acoustic wave device: quartz crystal microbalance with dissipation at multiple harmonics to determine the time-evolution of mesoscale mechanical properties of clot formation in vitro. This approach is sensitive to changes in surface and bulk clot structure in various models of induced coagulopathy. Furthermore, we are able to show that clot formation at surfaces has different kinetics and mechanical strength to that in the bulk, which may have implications for the design of bioprosthetic materials. The "Multifrequency acoustics" approach thus enables unique capability to portray biological processes concerning blood coagulation.

  20. The influence of riboflavin photochemistry on plasma coagulation factors

    PubMed Central

    Larrea, Luis; Calabuig, María; Roldán, Vanesa; Rivera, José; Tsai, Han-Mou; Vicente, Vicente; Roig, Roberto

    2011-01-01

    Studies with riboflavin in the 1960s showed that it could be effective at inactivating pathogens when exposed to light. The principal mode of action is through electron transfer reactions, most importantly in nucleic acids. This suggested that it could act as a photosensitizer useful in the inactivation of pathogens found in blood products. Objective To study the influence of photo-inactivation with riboflavin on the coagulation factors of plasma. Methods The photo-inactivation procedure of riboflavin plus light was applied. Fifty isogroup pools of two plasmas were made from 100 U of plasma that were derived from whole blood products that had previously been held overnight. Pools were split into two bags. One of them was photo-inactivated, and post inactivation samples were obtained. The second bag was not photo-inactivated and samples were taken. Total protein, fibrinogen, FII, FV, FVII, FVIII, FIX, FX, FXI, FXIII, antithrombin III, PC, PS, α-2 antiplasmin and vWF:Ag, the multimeric structure of vWF and ADAMTS-13 were analyzed. Results In plasma, the proteins most sensitive to photo-inactivation were fibrinogen, FXI, FVIII, FV, and FIX (33%, 32%, 30%, 18% and 18% loss, respectively). Coagulation inhibitors, PS, antithrombin III and PC showed little decrease (all 2%). Retention of vWF and ADAMTS-13 were 99% and 88%, respectively. Conclusions As with other pathogen reduction procedures for plasma products, treatment with riboflavin and UV light resulted in reduction in the activity levels of several pro-coagulant factors. Coagulation inhibitors are well preserved. PMID:19782644

  1. Blood viscosity during coagulation at different shear rates

    PubMed Central

    Ranucci, Marco; Laddomada, Tommaso; Ranucci, Matteo; Baryshnikova, Ekaterina

    2014-01-01

    Abstract During the coagulation process, blood changes from a liquid to a solid gel phase. These changes are reflected by changes in blood viscosity; however, blood viscosity at different shear rates (SR) has not been previously explored during the coagulation process. In this study, we investigated the viscosity changes of whole blood in 10 subjects with a normal coagulation profile, using a cone‐on‐plate viscosimeter. For each subject, three consecutive measurements were performed, at a SR of 20, 40, 80 sec−1. On the basis of the time‐dependent changes in blood viscosity, we identified the gel point (GP), the time‐to‐gel point (TGP), the maximum clot viscosity (MCV), and the clot lysis half‐time (CLH). The TGP significantly (P = 0.0023) shortened for increasing SR, and was significantly associated with the activated partial thromboplastin time at a SR of 20 sec−1 (P = 0.038) and 80 sec−1 (P = 0.019). The MCV was significantly lower at a SR of 80 sec−1 versus 40 sec−1 (P = 0.027) and the CLH significantly (P = 0.048) increased for increasing SR. These results demonstrate that measurement of blood viscosity during the coagulation process offers a number of potentially useful parameters. In particular, the association between the TGP and the activated partial thromboplastin time is an expression of the clotting time (intrinsic and common pathway), and its shortening for increasing SR may be interpreted the well‐known activating effects of SR on platelet activation and thrombin generation. Further studies focused on the TGP under conditions of hypo‐ or hypercoagulability are required to confirm its role in the clinical practice. PMID:24994896

  2. Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial

    PubMed Central

    Nemeth, Banne; Scheres, Luuk J J; Lijfering, Willem M

    2015-01-01

    Objective To assess whether, as has been hypothesised since medieval times, acute fear can curdle blood. Design Crossover trial. Setting Main meeting room of Leiden University’s Department of Clinical Epidemiology, the Netherlands, converted to a makeshift cinema. Participants 24 healthy volunteers aged ≤30 years recruited among students, alumni, and employees of the Leiden University Medical Center: 14 were assigned to watch a frightening (horror) movie followed by a non-threatening (educational) movie and 10 to watch the movies in reverse order. The movies were viewed more than a week apart at the same time of day and both lasted approximately 90 minutes. Main outcome measures The primary outcome measures were markers, or “fear factors” of coagulation activity: blood coagulant factor VIII, D-dimer, thrombin-antithrombin complexes, and prothrombin fragments 1+2. The secondary outcome was participant reported fear experienced during each movie using a visual analogue fear scale. Results All participants completed the study. The horror movie was perceived to be more frightening than the educational movie on a visual analogue fear scale (mean difference 5.4, 95% confidence interval 4.7 to 6.1). The difference in factor VIII levels before and after watching the movies was higher for the horror movie than for the educational movie (mean difference of differences 11.1 IU/dL (111 IU/L), 95% confidence interval 1.2 to 21.0 IU/dL). The effect of either movie on levels of thrombin-antithrombin complexes, D-dimer, and prothrombin fragments 1+2 did not differ. Conclusion Frightening (in this case, horror) movies are associated with an increase of blood coagulant factor VIII without actual thrombin formation in young and healthy adults. Trial registration ClinicalTrials.gov NCT02601053. PMID:26673787

  3. Numerical simulations of a reduced model for blood coagulation

    NASA Astrophysics Data System (ADS)

    Pavlova, Jevgenija; Fasano, Antonio; Sequeira, Adélia

    2016-04-01

    In this work, the three-dimensional numerical resolution of a complex mathematical model for the blood coagulation process is presented. The model was illustrated in Fasano et al. (Clin Hemorheol Microcirc 51:1-14, 2012), Pavlova et al. (Theor Biol 380:367-379, 2015). It incorporates the action of the biochemical and cellular components of blood as well as the effects of the flow. The model is characterized by a reduction in the biochemical network and considers the impact of the blood slip at the vessel wall. Numerical results showing the capacity of the model to predict different perturbations in the hemostatic system are discussed.

  4. Coagulation profile, gene expression and bioinformatics characterization of coagulation factor X of striped murrel Channa striatus.

    PubMed

    Arasu, Abirami; Kumaresan, Venkatesh; Sathyamoorthi, Akila; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Arockiaraj, Jesu

    2016-08-01

    A transcriptome wide analysis of the constructed cDNA library of snakehead murrel Channa striatus revealed a full length cDNA sequence of coagulation factor X. Sequence analysis of C. striatus coagulation factor X (CsFX) showed that the cDNA contained 1232 base pairs (bp) comprising 1209 bp open reading frame (ORF). The ORF region encodes 424 amino acids with a molecular mass of 59 kDa. The polypeptide contains γ-carboxyglutamic acid (GLA) rich domain and two epidermal growth factor (EGF) like domains including EGF-CA domain and serine proteases trypsin signature profile. CsFX exhibited the maximum similarity with fish species such as Stegastes partitus (78%), Poecilia formosa (76%) and Cynoglossus semilaevis (74%). Phylogenetically, CsFX is clustered together with the fish group belonging to Actinopterygii. Secondary structure of factor X includes alpha helix 28.54%, extended strand 20.75%, beta turn 7.78% and random coil 42.92%. A predicted 3D model of CsFX revealed a short α-helix and a Ca(2+) (Gla domain) binding site in the coil. Four disulfide bridges were found in serine protease trypsin profile. Obviously, the highest gene expression (P < 0.05) was noticed in blood. Further, the changes in expression of CsFX was observed after inducing with bacterial (Aeromonas hydrophila) and fungal (Aphanomyces invadans) infections and other synthetic immune stimulants. Variation in blood clotting time (CT), prothrombin time (PT) and activated prothromboplastin time (APTT) was analyzed and compared between healthy and bacterial infected fishes. During infection, PT and APTT showed a declined clotting time due to the raised level of thrombocytes. PMID:27235370

  5. Using a Systems Pharmacology Model of the Blood Coagulation Network to Predict the Effects of Various Therapies on Biomarkers

    PubMed Central

    Nayak, S; Lee, D; Patel-Hett, S; Pittman, DD; Martin, SW; Heatherington, AC; Vicini, P; Hua, F

    2015-01-01

    A number of therapeutics have been developed or are under development aiming to modulate the coagulation network to treat various diseases. We used a systems model to better understand the effect of modulating various components on blood coagulation. A computational model of the coagulation network was built to match in-house in vitro thrombin generation and activated Partial Thromboplastin Time (aPTT) data with various concentrations of recombinant factor VIIa (FVIIa) or factor Xa added to normal human plasma or factor VIII-deficient plasma. Sensitivity analysis applied to the model revealed that lag time, peak thrombin concentration, area under the curve (AUC) of the thrombin generation profile, and aPTT show different sensitivity to changes in coagulation factors’ concentrations and type of plasma used (normal or factor VIII-deficient). We also used the model to explore how variability in concentrations of the proteins in coagulation network can impact the response to FVIIa treatment. PMID:26312163

  6. Substitution of blood coagulation factor X-binding to Ad5 by position-specific PEGylation: Preventing vector clearance and preserving infectivity.

    PubMed

    Krutzke, L; Prill, J M; Engler, T; Schmidt, C Q; Xu, Z; Byrnes, A P; Simmet, T; Kreppel, F

    2016-08-10

    The biodistribution of adenovirus type 5 (Ad5) vector particles is heavily influenced by interaction of the particles with plasma proteins, including coagulation factor X (FX), which binds specifically to the major Ad5 capsid protein hexon. FX mediates hepatocyte transduction by intravenously-injected Ad5 vectors and shields vector particles from neutralization by natural antibodies and complement. In mice, mutant Ad5 vectors that are ablated for FX-binding become detargeted from hepatocytes, which is desirable for certain applications, but unfortunately such FX-nonbinding vectors also become sensitive to neutralization by mouse plasma proteins. To improve the properties of Ad5 vectors for systemic delivery, we developed a strategy to replace the natural FX shield by a site-specific chemical polyethylene glycol shield. Coupling of polyethylene glycol to a specific site in hexon hypervariable region 1 yielded vector particles that were protected from neutralization by natural antibodies and complement although they were unable to bind FX. These vector particles evaded macrophages in vitro and showed significantly improved pharmacokinetics and hepatocyte transduction in vivo. Thus, site-specific shielding of Ad5 vectors with polyethylene glycol rendered vectors FX-independent and greatly improved their properties for systemic gene therapy. PMID:27302248

  7. [Vasoactive prostanoids and inhibitors of blood coagulation in pregnancy-induced hypertension].

    PubMed

    Peterseim, H; Kemkes-Matthes, B

    1994-01-01

    The aim of the present study was to investigate the occurrence of changes in the plasma levels of vasoactive prostanoids and inhibitors of blood coagulation in normal pregnancy and in cases of pregnancy induced hypertension. Levels of the coagulation inhibitors antithrombin III, protein C, Protein S as well as the prostaglandin metabolites thromboxane B2 and 6-oxo-prostaglandin F1 alpha were measured between 13 and 37 weeks gestation in 36 primigravidae. In 8 of the examined patients persistently raised blood pressure values of 140/90 and above were measured after 20 weeks of gestation. Our results indicated that an imbalance of vasoactive prostanoids may precede the appearance of clinical symptoms of PIH. The determination of coagulation factors before blood pressure is elevated has no predictive value regarding the later development of PIH. The reduced levels of protein C associated with our PIH group are considered to be the result of an activated coagulation followed by consumption of clotting factors. Reduced measured levels of protein S in normotensive as well as hypertensive pregnancies offer an explanation for the increased risk of thromboembolic disease. This increased susceptibility to thromboembolic disorders is further enhanced by the altered balance between the platelet aggregator and vasoconstrictor thromboxane A2 and its antagonist prostacyclin. PMID:8048287

  8. Coagulation Factor X Activates Innate Immunity to Human Species C Adenovirus

    PubMed Central

    Doronin, Konstantin; Flatt, Justin W.; Di Paolo, Nelson C.; Khare, Reeti; Kalyuzhniy, Oleksandr; Acchione, Mauro; Sumida, John P.; Ohto, Umeharu; Shimizu, Toshiyuki; Akashi-Takamura, Sachiko; Miyake, Kensuke; MacDonald, James W.; Bammler, Theo K.; Beyer, Richard P.; Farin, Frederico M.; Stewart, Phoebe L.; Shayakhmetov, Dmitry M.

    2016-01-01

    Although coagulation factors play a role in host defense for “living fossils” such as horseshoe crabs, the role of the coagulation system in immunity in higher organisms remains unclear. We modeled the interface of human species C adenovirus (HAdv) interaction with coagulation factor X (FX) and introduced a mutation that abrogated formation of the HAdv-FX complex. In vivo genome-wide transcriptional profiling revealed that FX-binding–ablated virus failed to activate a distinct network of nuclear factor κB–dependent early-response genes that are activated by HAdv-FX complex downstream of TLR4/MyD88/TRIF/TRAF6 signaling. Our study implicates host factor “decoration” of the virus as a mechanism to trigger an innate immune sensor that responds to a misplacement of coagulation FX from the blood into intracellular macrophage compartments upon virus entry into the cell. PMID:23019612

  9. Coagulation factor X activates innate immunity to human species C adenovirus.

    PubMed

    Doronin, Konstantin; Flatt, Justin W; Di Paolo, Nelson C; Khare, Reeti; Kalyuzhniy, Oleksandr; Acchione, Mauro; Sumida, John P; Ohto, Umeharu; Shimizu, Toshiyuki; Akashi-Takamura, Sachiko; Miyake, Kensuke; MacDonald, James W; Bammler, Theo K; Beyer, Richard P; Farin, Frederico M; Stewart, Phoebe L; Shayakhmetov, Dmitry M

    2012-11-01

    Although coagulation factors play a role in host defense for "living fossils" such as horseshoe crabs, the role of the coagulation system in immunity in higher organisms remains unclear. We modeled the interface of human species C adenovirus (HAdv) interaction with coagulation factor X (FX) and introduced a mutation that abrogated formation of the HAdv-FX complex. In vivo genome-wide transcriptional profiling revealed that FX-binding-ablated virus failed to activate a distinct network of nuclear factor κB-dependent early-response genes that are activated by HAdv-FX complex downstream of TLR4/MyD88/TRIF/TRAF6 signaling. Our study implicates host factor "decoration" of the virus as a mechanism to trigger an innate immune sensor that responds to a misplacement of coagulation FX from the blood into intracellular macrophage compartments upon virus entry into the cell. PMID:23019612

  10. Combined Deficiency of Coagulation Factors V and VIII: An Update

    PubMed Central

    Zheng, Chunlei; Zhang, Bin

    2015-01-01

    Combined deficiency of factor V (FV) and FVIII (F5F8D) is an autosomal recessive bleeding disorder characterized by simultaneous decreases of both coagulation factors. This review summarizes recent reports on the clinical presentations, treatments, and molecular mechanism of F5F8D. Genetic studies identified LMAN1 and MCFD2 as causative genes for this disorder, revealing a previously unknown intracellular transport pathway shared by the two important blood coagulation factors. LMAN1 and MCFD2 form a Ca2+-dependent cargo receptor complex that functions in the transport of FV/FVIII from the endoplasmic reticulum (ER) to the Golgi. Disrupting the LMAN1-MCFD2 receptor, complex formation is the primary molecular defect of missense mutations leading to F5F8D. The EF-hand domains of MCFD2 are necessary and sufficient for the interactions with both LMAN1 and FV/FVIII. Similarly, the carbohydrate recognition domain of LMAN1 contains distinct and separable binding sites for both MCFD2 and FV/FVIII. Therefore, FV and FVIII likely carry duel sorting signals that are separately recognized by LMAN1 and MCFD2 and necessary for the efficient ER-to-Golgi transport. FV and FVIII likely bind LMAN1 through the high-mannose N-linked glycans under the higher Ca2+ conditions in the ER and dissociate in the lower Ca2+ environment of the ER–Golgi intermediate compartment. PMID:23852824

  11. Combined deficiency of coagulation factors V and VIII: an update.

    PubMed

    Zheng, Chunlei; Zhang, Bin

    2013-09-01

    Combined deficiency of factor V (FV) and FVIII (F5F8D) is an autosomal recessive bleeding disorder characterized by simultaneous decreases of both coagulation factors. This review summarizes recent reports on the clinical presentations, treatments, and molecular mechanism of F5F8D. Genetic studies identified LMAN1 and MCFD2 as causative genes for this disorder, revealing a previously unknown intracellular transport pathway shared by the two important blood coagulation factors. LMAN1 and MCFD2 form a Ca2+-dependent cargo receptor complex that functions in the transport of FV/FVIII from the endoplasmic reticulum (ER) to the Golgi. Disrupting the LMAN1-MCFD2 receptor, complex formation is the primary molecular defect of missense mutations leading to F5F8D. The EF-hand domains of MCFD2 are necessary and sufficient for the interactions with both LMAN1 and FV/FVIII. Similarly, the carbohydrate recognition domain of LMAN1 contains distinct and separable binding sites for both MCFD2 and FV/FVIII. Therefore, FV and FVIII likely carry duel sorting signals that are separately recognized by LMAN1 and MCFD2 and necessary for the efficient ER-to-Golgi transport. FV and FVIII likely bind LMAN1 through the high-mannose N-linked glycans under the higher Ca2+ conditions in the ER and dissociate in the lower Ca2+ environment of the ER-Golgi intermediate compartment. PMID:23852824

  12. [Status of the blood coagulation system in traumatic disease].

    PubMed

    Nemchenko, N S; Nasonkin, O S; Deriabin, I I; Zhambalzhav, L

    1988-10-01

    Under examination there were 198 patients with severe mechanical traumas at their admission to the clinic and on the 1st, 3d, 7th, 14th and 21st days by 25 hemocoagulation parameters determined by common present-day methods. The direction and degree of hemocoagulation alterations were found to be related with the severity of trauma, blood loss volume and severity of shock. It was shown that disseminated intravascular coagulation (DIC) of the II and III degree was developing in critical associated traumas, massive blood loss and severe shock in acute period of the disease. The acute form of DIC with reactive fibrinolysis was established in the lethal outcome during the shock period, latent (slow) DIC with local fibrinolysis took place in lethal outcomes in later periods. PMID:3242235

  13. The susceptibility of plasma coagulation factor XI to nitration and peroxynitrite action.

    PubMed

    Ponczek, Michał Błażej

    2016-10-01

    Coagulation factor XI is present in blood plasma as the zymogen, like other serine proteases of hemostatic system, but as the only coagulation factor forms 140-160kDa homodimers. Its activation is induced by thrombin, and a positive feedback increases the generation of the extra thrombin. Experimental and clinical observations confirm protective roles of factor XI deficiencies in certain types of thromboembolic disorders. Thromboembolism still causes serious problems for modern civilization. Diseases associated with the blood coagulation system are often associated with inflammation and oxidative stress. Peroxynitrite is produced from nitric oxide and superoxide in inflammatory diseases. The aim of the current study is to evaluate effects of nitrative stress triggered by peroxynitrite on coagulation factor XI in human plasma employing biochemical and bioinformatic methods. The amidolytic assay shows increase in factor XI activity triggered by peroxynitrite. Peroxynitrite interferes factor XI by nitration and fragmentation, which is demonstrated by immunoprecipitation followed by western blotting. Nitrated factor XI is even present in control blood plasma. The results suggest possible modifications of factor XI on the molecular level. Computer simulations show tyrosine residues as targets of peroxynitrite action. The modifications induced by peroxynitrite in factor XI might be important in thrombotic disorders. PMID:27268383

  14. Self-production of tissue factor-coagulation factor VII complex by ovarian cancer cells

    PubMed Central

    Yokota, N; Koizume, S; Miyagi, E; Hirahara, F; Nakamura, Y; Kikuchi, K; Ruf, W; Sakuma, Y; Tsuchiya, E; Miyagi, Y

    2009-01-01

    Background: Thromboembolic events are a major complication in ovarian cancer patients. Tissue factor (TF) is frequently overexpressed in ovarian cancer tissue and correlates with intravascular thrombosis. TF binds to coagulation factor VII (fVII), changing it to its active form, fVIIa. This leads to activation of the extrinsic coagulation cascade. fVII is produced by the liver and believed to be supplied from blood plasma at the site of coagulation. However, we recently showed that ovarian cancer cells express fVII transcripts under normoxia and that this transcription is inducible under hypoxia. These findings led us to hypothesise that ovarian cancer cells are intrinsically associated with TF-fVIIa coagulation activity, which could result in thrombosis. Methods: In this study, we examined whether ectopically expressed fVII could cause thrombosis by means of immunohistochemistry, RT–PCR, western blotting and flow cytometry. Results: Ectopic fVII expression occurs frequently in ovarian cancers, particularly in clear cell carcinoma. We further showed that ovarian cancer cells express TF-fVIIa on the cell surface under normoxia and that this procoagulant activity is enhanced by hypoxic stimuli. Moreover, we showed that ovarian cancer cells secrete microparticles (MPs) with TF-fVIIa activity. Production of this procoagulant secretion is enhanced under hypoxia. Conclusion: These results raise the possibility that cancer cell-derived TF-fVIIa could cause thrombotic events in ovarian cancer patients. PMID:19904262

  15. Nonsense-mediated mRNA decay among coagulation factor genes

    PubMed Central

    Shahbazi, Shirin

    2016-01-01

    Objective(s): Haemostasis prevents blood loss following vascular injury. It depends on the unique concert of events involving platelets and specific blood proteins, known as coagulation factors. The clotting system requires precise regulation and coordinated reactions to maintain the integrity of the vasculature. Clotting insufficiency mostly occurs due to genetically inherited coagulation factor deficiencies such as hemophilia. Materials and Methods: A relevant literature search of PubMed was performed using the keywords coagulation factors, Nonsense-mediated mRNA decay and premature translation termination codons. Search limitations included English language and human-based studies. Results: Mutations that cause premature translation termination codons probably account for one-third of genetically inherited diseases. Transcripts bearing aberrant termination codons are selectively identified and eliminated by an evolutionarily conserved posttranscriptional pathway known as nonsense-mediated mRNA decay (NMD). There are many pieces of evidence of decay among coagulation factor genes. However, the hemophilia gene (F8) does not seem to be subjected to NMD. Since the F8 gene is located on the X-chromosome, a connection between X-linked traits and mRNA decay could be assumed. Conclusion: Considering that not all genes go through decay, this review focuses on the basics of the mechanism in coagulation genes. It is interesting to determine whether this translation-coupled surveillance system represents a general rule for the genes encoding components of the same physiological cascade. PMID:27279976

  16. Surface-mediated molecular events in material-induced blood-plasma coagulation

    NASA Astrophysics Data System (ADS)

    Chatterjee, Kaushik

    Coagulation and thrombosis persist as major impediments associated with the use of blood-contacting medical devices. We are investigating the molecular mechanism underlying material-induced blood-plasma coagulation focusing on the role of the surface as a step towards prospective development of improved hemocompatible biomaterials. A classic observation in hematology is that blood/blood-plasma in contact with clean glass surface clots faster than when in contact with many plastic surfaces. The traditional biochemical theory explaining the underlying molecular mechanism suggests that hydrophilic surfaces, like that of glass, are specific activators of the coagulation cascade because of the negatively-charged groups on the surface. Hydrophobic surfaces are poor procoagulants or essentially "benign" because they lack anionic groups. Further, these negatively-charged surfaces are believed to not only activate blood factor XII (FXII), the key protein in contact activation, but also play a cofactor role in the amplification and propagation reactions that ultimately lead to clot formation. In sharp contrast to the traditional theory, our investigations indicate a need for a paradigm shift in the proposed sequence of contact activation events to incorporate the role of protein adsorption at the material surfaces. These studies have lead to the central hypothesis for this work proposing that protein adsorption to hydrophobic surfaces attenuates the contact activation reactions so that poorly-adsorbent hydrophilic surfaces appear to be stronger procoagulants relative to hydrophobic surfaces. Our preliminary studies measuring the plasma coagulation response of activated FXII (FXIIa) on different model surfaces suggested that the material did not play a cofactor role in the processing of this enzyme dose through the coagulation pathway. Therefore, we focused our efforts on studying the mechanism of initial production of enzyme at the procoagulant surface. Calculations for the

  17. Blood coagulation profiling in patients using optical thromboelastography (OTEG) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Tripathi, Markandey M.; Tshikudi, Diane M.; Hajjarian, Zeinab; Van Cott, Elizabeth M.; Nadkarni, Seemantini K.

    2016-02-01

    Impaired blood coagulation is often associated with increased postoperative mortality and morbidity in cardiovascular patients. The capability for blood coagulation profiling rapidly at the bedside will enable the timely detection of coagulation defects and open the opportunity for tailoring therapy to correct specific coagulation deficits Optical Thromboelastography (OTEG), is an optical approach to quantify blood coagulation status within minutes using a few drops of whole blood. The goal of the current study is to evaluate the diagnostic accuracy of OTEG for rapid coagulation profiling in patients. In OTEG, temporal laser speckle intensity fluctuations from a drop of clotting blood are measured using a CMOS camera. To quantify coagulation status, the speckle intensity autocorrelation function is measured, the mean square displacement of scattering particles is extracted, and viscoelastic modulus (G), during coagulation is measured via the generalized Stokes-Einstein relation. By quantifying time-resolved changes in G, the coagulation parameters, reaction time (R), clot progression time (K), clot progression rate (Angle), and maximum clot strength (MA) are derived. In this study, the above coagulation parameters were measured using OTEG in 269 patients and compared with standard mechanical Thromboelastography (TEG). Our results showed a strong correlation between OTEG and TEG measurements for all parameters: R-time (R=0.80, p<0.001), clotting time (R=0.78, p<0.001), Angle (R=0.58, p<0.001), and MA (R=0.60, p<0.001). These results demonstrate the unique capability of OTEG for rapid quantification of blood coagulation status to potentially improve clinical capability for identifying impaired coagulation in cardiovascular patients at the point of care.

  18. [Seasonal changes in the blood coagulating and anticoagulating system indices in men at the preclinical stage of ischemic heart disease].

    PubMed

    Andreenko, G V; Panchenko, V M; Liutova, L V; Lisina, A N; Karabasova, M A

    1980-03-01

    Examination of 52 males (aged 23 to 40 years) in the preclinical stage of ischemic heart disease revealed seasonal differences in the values of the blood coagulation and anticoagulation systems: in the spring, there was an increase in blood coagulation activity displayed by growth of the concentration of fibrinogen and soluble fibrin and a reduction in the amount of the plasminogen activator. The authors suggest conducting preventive treatment of patients in the spring, the most unfavourable season in respect of the effect of the pathogenetic factors. PMID:6103080

  19. Blood coagulation and fibrinolysis in aortic valve stenosis: links with inflammation and calcification.

    PubMed

    Natorska, J; Undas, A

    2015-08-01

    Aortic valve stenosis (AS) increasingly afflicts our aging population. However, the pathobiology of the disease is still poorly understood and there is no effective pharmacotherapy for treating those at risk for clinical progression. The progression of AS involves complex inflammatory and fibroproliferative processes that resemble to some extent atherosclerosis. Accumulating evidence indicates that several coagulation proteins and its inhibitors, including tissue factor, tissue factor pathway inhibitor, prothrombin, factor XIII, von Willebrand factor, display increased expression within aortic stenotic valves, predominantly on macrophages and myofibroblasts around calcified areas. Systemic impaired fibrinolysis, along with increased plasma and valvular expression of plasminogen activator inhibitor-1, has also been observed in patients with AS in association with the severity of the disease. There is an extensive cross-talk between inflammation and coagulation in stenotic valve tissue which contributes to the calcification and mineralisation of the aortic valve leaflets. This review summarises the available data on blood coagulation and fibrinolysis in AS with the emphasis on their interactions with inflammation and calcification. PMID:25809537

  20. Red blood cell coagulation induced by low-temperature plasma treatment.

    PubMed

    Miyamoto, Kenji; Ikehara, Sanae; Takei, Hikaru; Akimoto, Yoshihiro; Sakakita, Hajime; Ishikawa, Kenji; Ueda, Masashi; Ikeda, Jun-Ichiro; Yamagishi, Masahiro; Kim, Jaeho; Yamaguchi, Takashi; Nakanishi, Hayao; Shimizu, Tetsuji; Shimizu, Nobuyuki; Hori, Masaru; Ikehara, Yuzuru

    2016-09-01

    Low-temperature plasma (LTP) treatment promotes blood clot formation by stimulation of the both platelet aggregation and coagulation factors. However, the appearance of a membrane-like structure in clots after the treatment is controversial. Based on our previous report that demonstrated characteristics of the form of coagulation of serum proteins induced by LTP treatment, we sought to determine whether treatment with two plasma instruments, namely BPC-HP1 and PN-110/120TPG, formed clots only from red blood cells (RBCs). LTP treatment with each device formed clots from whole blood, whereas LTP treatment with BPC-HP1 formed clots in phosphate-buffered saline (PBS) containing 2 × 10(9)/mL RBCs. Light microscopic analysis results showed that hemolysis formed clots consisting of materials with membrane-like structures from both whole blood and PBS-suspended RBCs. Moreover, electron microscopic analysis results showed a monotonous material with high electron density in the formed clots, presenting a membrane-like structure. Hemolysis disappeared with the decrease in the current through the targets contacting with the plasma flare and clot formation ceased. Taken together, our results and those of earlier studies present two types of blood clot formation, namely presence or absence of hemolysis capability depending on the current through the targets. PMID:27033148

  1. Mesoscopic Modeling of Blood Clotting: Coagulation Cascade and Platelets Adhesion

    NASA Astrophysics Data System (ADS)

    Yazdani, Alireza; Li, Zhen; Karniadakis, George

    2015-11-01

    The process of clot formation and growth at a site on a blood vessel wall involve a number of multi-scale simultaneous processes including: multiple chemical reactions in the coagulation cascade, species transport and flow. To model these processes we have incorporated advection-diffusion-reaction (ADR) of multiple species into an extended version of Dissipative Particle Dynamics (DPD) method which is considered as a coarse-grained Molecular Dynamics method. At the continuum level this is equivalent to the Navier-Stokes equation plus one advection-diffusion equation for each specie. The chemistry of clot formation is now understood to be determined by mechanisms involving reactions among many species in dilute solution, where reaction rate constants and species diffusion coefficients in plasma are known. The role of blood particulates, i.e. red cells and platelets, in the clotting process is studied by including them separately and together in the simulations. An agonist-induced platelet activation mechanism is presented, while platelets adhesive dynamics based on a stochastic bond formation/dissociation process is included in the model.

  2. Effect of onion and garlic on blood coagulation and fibrinolysis in vitro.

    PubMed

    Nagda, K K; Ganeriwal, S K; Nagda, K C; Diwan, A M

    1983-01-01

    The effects of aqueous extracts of onion and garlic as well as of garlic oil were studied on the process of blood coagulation and fibrinolysis in vitro. Only onion was found to exhibit anti-coagulant and fibrinolytic activity while garlic extract as well as garlic oil were inactive. PMID:6885127

  3. Analysis of the coagulation of human blood cells on diamond surfaces by atomic force microscopy

    NASA Astrophysics Data System (ADS)

    Baranauskas, V.; Fontana, M.; Guo, Zhao Jing; Ceragioli, H. J.; Peterlevitz, A. C.

    2004-11-01

    Atomic force microscopy (AFM) was used to study the morphology and coagulation of human blood cells in contact with solid surfaces. Blood was extracted from the veins of healthy adult donors and the samples were used immediately after extraction, deposited either on borosilicate glass or diamond substrates. Some blood samples were anti-coagulated by adding heparin for single cell AFM imaging. No chemicals were used for attaching or immobilizing the cells. The diamond substrates were produced by chemical vapour deposition (CVD diamond) using a hot-filament CVD system fed with ethanol highly diluted in hydrogen. AFM imaging of isolated cells (anti-coagulated by heparin) was only possible on the glass substrates due to the lack of adherence of the cells to the diamond surface. The coagulation results suggest that blood clotting on diamond produces a less rough surface than blood clotting on glass.

  4. Role of hydrophobic mutations on the binding affinity and stability of blood coagulation factor VIIIa: a computational molecular dynamics and free-energy analysis.

    PubMed

    Venkateswarlu, Divi

    2014-07-18

    Factor VIIIa is a non-covalently bound hetero-trimer among A1, A2 and A3-C1-C2 domains and an essential co-factor for factor IXa enzyme during proteolytic activation of factor X zymogen. The relatively weak interactions between A2 and the interface A1/A3 domains dampen the functional stability of FVIIIa in plasma and results in rapid degradation. We studied the mutational effect of three charged residues (Asp519, Glu665 and Asp666) to several hydrophobic residues by molecular dynamics simulations. Analysis of the binding free energy by MM-PBSA and MM-GBSA methods shows that the mutation of Asp519 and Glu665 residues to either Val or Ala enhance the A2 domain binding affinity in agreement with the experimental site-specific mutagenesis data. Mutation of Asp666 to Val, Tyr, Met and Phe showed largest improvement in the A2-domain binding among the eight hydrophobic mutants studied. Our studies suggest that the enrichment of hydrophobic interactions in the buried surface regions of A2 domain plays crucial role in improving the overall stability of FVIIIa. PMID:24952158

  5. Matriptase activation connects tissue factor-dependent coagulation initiation to epithelial proteolysis and signaling.

    PubMed

    Le Gall, Sylvain M; Szabo, Roman; Lee, Melody; Kirchhofer, Daniel; Craik, Charles S; Bugge, Thomas H; Camerer, Eric

    2016-06-23

    The coagulation cascade is designed to sense tissue injury by physical separation of the membrane-anchored cofactor tissue factor (TF) from inactive precursors of coagulation proteases circulating in plasma. Once TF on epithelial and other extravascular cells is exposed to plasma, sequential activation of coagulation proteases coordinates hemostasis and contributes to host defense and tissue repair. Membrane-anchored serine proteases (MASPs) play critical roles in the development and homeostasis of epithelial barrier tissues; how MASPs are activated in mature epithelia is unknown. We here report that proteases of the extrinsic pathway of blood coagulation transactivate the MASP matriptase, thus connecting coagulation initiation to epithelial proteolysis and signaling. Exposure of TF-expressing cells to factors (F) VIIa and Xa triggered the conversion of latent pro-matriptase to an active protease, which in turn cleaved the pericellular substrates protease-activated receptor-2 (PAR2) and pro-urokinase. An activation pathway-selective PAR2 mutant resistant to direct cleavage by TF:FVIIa and FXa was activated by these proteases when cells co-expressed pro-matriptase, and matriptase transactivation was necessary for efficient cleavage and activation of wild-type PAR2 by physiological concentrations of TF:FVIIa and FXa. The coagulation initiation complex induced rapid and prolonged enhancement of the barrier function of epithelial monolayers that was dependent on matriptase transactivation and PAR2 signaling. These observations suggest that the coagulation cascade engages matriptase to help coordinate epithelial defense and repair programs after injury or infection, and that matriptase may contribute to TF-driven pathogenesis in cancer and inflammation. PMID:27114461

  6. Influence of a constant and variable magnetic field on the coagulation of human blood in vitro and in vivo

    NASA Technical Reports Server (NTRS)

    Degen, I. L.; Plaksenko, V. Y.

    1974-01-01

    The influence of constant and varying magnetic fields on the coagulation of the blood was studied in experiments performed in vitro and vivo. In the in vitro tests it was found that a constant magnetic field with a strength of 100 or 200 oersteds influences the coagulation of the blood, retarding it in some cases and speeding up the coagulation time in others. In the in vivo studies, both retarding and accelerating effects were likewise observed with respect to the coagulation of the blood, but the nature of the change was a function of the background. A normalizing effect of the magnetic field on the coagulation of the blood was observed.

  7. CARDIOVASCULAR AND BLOOD COAGULATION EFFECTS OF PULMONARY ZINC EXPOSURE

    EPA Science Inventory

    Cardiovascular damage induced by pulmonary exposure to environmental chemicals can result from direct action or, secondarily, from pulmonary injury. We have developed a rat model of pulmonary exposure to zinc to demonstrate cardiac, coagulative, and fibrinolytic alterations. Mal...

  8. Seawater Immersion Aggravates Burn Injury Causing Severe Blood Coagulation Dysfunction

    PubMed Central

    Yan, Hong; Mao, Qingxiang; Ma, Yongda; Wang, Li; Chen, Xian; Hu, Yi; Ge, Hengjiang

    2016-01-01

    This study aimed to investigate the endothelial function in a canine model of burn injury combined with seawater immersion. The model of burn injury was established. The dogs were randomly divided into four groups including dogs with burn injury (B group), or burn injury combined with seawater immersion (BI group), or only immersion in seawater (I group), or control animals with no injury or immersion (C group). The circulating endothelial cell (CEC) count and coagulation-fibrinolysis parameters were measured. The CEC count in B group increased at 4 h, 7 h, and 10 h after injury and then reduced, whereas it continuously increased to a greater extent in BI group (P < 0.05). The von Willebrand factor (vWF) activity, plasminogen activator inhibitor (PAI-1), and the ratio of thromboxane B2 (TXB2) to 6-keto-prostaglandin F1α (6-K-PGF1α) in BI group had a marked increase after injury, and the tissue-type plasminogen activator (tPA) in the BI group decreased. Microscope observations revealed thrombus formation in lungs of the animals in BI group, but not in C, I, or B groups. Burn injury causes endothelial dysfunction, and seawater immersion lastingly aggravates this injury, leading to a higher risk of developing thrombosis. PMID:26885523

  9. EPCR-dependent PAR2 activation by the blood coagulation initiation complex regulates LPS-triggered interferon responses in mice

    PubMed Central

    Liang, Hai Po H.; Kerschen, Edward J.; Hernandez, Irene; Basu, Sreemanti; Zogg, Mark; Botros, Fady; Jia, Shuang; Hessner, Martin J.; Griffin, John H.; Ruf, Wolfram

    2015-01-01

    Infection and inflammation are invariably associated with activation of the blood coagulation mechanism, secondary to the inflammation-induced expression of the coagulation initiator tissue factor (TF) on innate immune cells. By investigating the role of cell-surface receptors for coagulation factors in mouse endotoxemia, we found that the protein C receptor (ProcR; EPCR) was required for the normal in vivo and in vitro induction of lipopolysaccharide (LPS)-regulated gene expression. In cultured bone marrow–derived myeloid cells and in monocytic RAW264.7 cells, the LPS-induced expression of functionally active TF, assembly of the ternary TF-VIIa-Xa initiation complex of blood coagulation, and the EPCR-dependent activation of protease-activated receptor 2 (PAR2) by the ternary TF-VIIa-Xa complex were required for the normal LPS induction of messenger RNAs encoding the TLR3/4 signaling adaptor protein Pellino-1 and the transcription factor interferon regulatory factor 8. In response to in vivo challenge with LPS, mice lacking EPCR or PAR2 failed to fully initiate an interferon-regulated gene expression program that included the Irf8 target genes Lif, Iigp1, Gbp2, Gbp3, and Gbp6. The inflammation-induced expression of TF and crosstalk with EPCR, PAR2, and TLR4 therefore appear necessary for the normal evolution of interferon-regulated host responses. PMID:25733582

  10. Optical coherence tomography-guided laser microsurgery for blood coagulation with continuous-wave laser diode

    PubMed Central

    Chang, Feng-Yu; Tsai, Meng-Tsan; Wang, Zu-Yi; Chi, Chun-Kai; Lee, Cheng-Kuang; Yang, Chih-Hsun; Chan, Ming-Che; Lee, Ya-Ju

    2015-01-01

    Blood coagulation is the clotting and subsequent dissolution of the clot following repair to the damaged tissue. However, inducing blood coagulation is difficult for some patients with homeostasis dysfunction or during surgery. In this study, we proposed a method to develop an integrated system that combines optical coherence tomography (OCT) and laser microsurgery for blood coagulation. Also, an algorithm for positioning of the treatment location from OCT images was developed. With OCT scanning, 2D/3D OCT images and angiography of tissue can be obtained simultaneously, enabling to noninvasively reconstruct the morphological and microvascular structures for real-time monitoring of changes in biological tissues during laser microsurgery. Instead of high-cost pulsed lasers, continuous-wave laser diodes (CW-LDs) with the central wavelengths of 450 nm and 532 nm are used for blood coagulation, corresponding to higher absorption coefficients of oxyhemoglobin and deoxyhemoglobin. Experimental results showed that the location of laser exposure can be accurately controlled with the proposed approach of imaging-based feedback positioning. Moreover, blood coagulation can be efficiently induced by CW-LDs and the coagulation process can be monitored in real-time with OCT. This technology enables to potentially provide accurate positioning for laser microsurgery and control the laser exposure to avoid extra damage by real-time OCT imaging. PMID:26568136

  11. Optical coherence tomography-guided laser microsurgery for blood coagulation with continuous-wave laser diode

    NASA Astrophysics Data System (ADS)

    Chang, Feng-Yu; Tsai, Meng-Tsan; Wang, Zu-Yi; Chi, Chun-Kai; Lee, Cheng-Kuang; Yang, Chih-Hsun; Chan, Ming-Che; Lee, Ya-Ju

    2015-11-01

    Blood coagulation is the clotting and subsequent dissolution of the clot following repair to the damaged tissue. However, inducing blood coagulation is difficult for some patients with homeostasis dysfunction or during surgery. In this study, we proposed a method to develop an integrated system that combines optical coherence tomography (OCT) and laser microsurgery for blood coagulation. Also, an algorithm for positioning of the treatment location from OCT images was developed. With OCT scanning, 2D/3D OCT images and angiography of tissue can be obtained simultaneously, enabling to noninvasively reconstruct the morphological and microvascular structures for real-time monitoring of changes in biological tissues during laser microsurgery. Instead of high-cost pulsed lasers, continuous-wave laser diodes (CW-LDs) with the central wavelengths of 450 nm and 532 nm are used for blood coagulation, corresponding to higher absorption coefficients of oxyhemoglobin and deoxyhemoglobin. Experimental results showed that the location of laser exposure can be accurately controlled with the proposed approach of imaging-based feedback positioning. Moreover, blood coagulation can be efficiently induced by CW-LDs and the coagulation process can be monitored in real-time with OCT. This technology enables to potentially provide accurate positioning for laser microsurgery and control the laser exposure to avoid extra damage by real-time OCT imaging.

  12. Effect of fibrinogen on blood coagulation detected by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-05-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d1/e) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0-8 g L-1) and 2) native plasma with commercial Fbg added (0-8 g L-1). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels.

  13. [Characteristics of the indicators of the blood coagulation and fibrinolysis systems in the pre-clinical stage of ischemic heart disease].

    PubMed

    Andreenko, G V; Panchenko, V M; Lisina, A N; Liutova, L V

    1978-10-01

    Signs of dysfunction of the coagulation system and fibrinolysis were determined in 45 healthy young individuals who had such risk factors in relation to ischemic heart disease as arterial hypertension, hypercholesterolemia, smoking, aggravated heredity, permanent emotional overstress, etc. These signs were manifested by a tendency to augmentation of blood coagulation and compensatory activation of fibrinolysis. Ischemic-type changes were detected on the ECG after a physical load. It is assumed that dysfunction of the coagulation system and fibrinolysis is an additional risk factor in relation to ischemic heart disease, while derangement of compensatory fibrinolysis tension with the subsequent tension of its components may lead to the development of coronary thrombosis. PMID:713256

  14. Factor II deficiency

    MedlinePlus

    ... blood. It leads to problems with blood clotting (coagulation). Factor II is also known as prothrombin. ... blood clots form. This process is called the coagulation cascade. It involves special proteins called coagulation, or ...

  15. Untangling the complexity of blood coagulation network: use of computational modelling in pharmacology and diagnostics.

    PubMed

    Shibeko, Alexey M; Panteleev, Mikhail A

    2016-05-01

    Blood coagulation is a complex biochemical network that plays critical roles in haemostasis (a physiological process that stops bleeding on injury) and thrombosis (pathological vessel occlusion). Both up- and down-regulation of coagulation remain a major challenge for modern medicine, with the ultimate goal to correct haemostasis without causing thrombosis and vice versa. Mathematical/computational modelling is potentially an important tool for understanding blood coagulation disorders and their treatment. It can save a huge amount of time and resources, and provide a valuable alternative or supplement when clinical studies are limited, or not ethical, or technically impossible. This article reviews contemporary state of the art in the modelling of blood coagulation for practical purposes: to reveal the molecular basis of a disease, to understand mechanisms of drug action, to predict pharmacodynamics and drug-drug interactions, to suggest potential drug targets or to improve quality of diagnostics. Different model types and designs used for this are discussed. Functional mechanisms of procoagulant bypassing agents and investigations of coagulation inhibitors were the two particularly popular applications of computational modelling that gave non-trivial results. Yet, like any other tool, modelling has its limitations, mainly determined by insufficient knowledge of the system, uncertainty and unreliability of complex models. We show how to some extent this can be overcome and discuss what can be expected from the mathematical modelling of coagulation in not-so-far future. PMID:26116831

  16. EFFECTS OF LOW LEVEL CARBON MONOXIDE EXPOSURE. BLOOD LIPIDS AND COAGULATION PARAMETERS

    EPA Science Inventory

    The study examined the effects of carbon monoxide (CO) in 50 and 100 ppm doses on response to treadmill exercise, blood coagulation and blood lipids in normal men. Twenty-three men were exposed to CO or to air in a double-blind protocol. After exposure, each underwent a graded ex...

  17. Sphingosine-1-Phosphate and Its Receptors: A Mutual Link between Blood Coagulation and Inflammation

    PubMed Central

    Mahajan-Thakur, Shailaja; Böhm, Andreas; Jedlitschky, Gabriele; Schrör, Karsten; Rauch, Bernhard H.

    2015-01-01

    Sphingosine-1-phosphate (S1P) is a versatile lipid signaling molecule and key regulator in vascular inflammation. S1P is secreted by platelets, monocytes, and vascular endothelial and smooth muscle cells. It binds specifically to a family of G-protein-coupled receptors, S1P receptors 1 to 5, resulting in downstream signaling and numerous cellular effects. S1P modulates cell proliferation and migration, and mediates proinflammatory responses and apoptosis. In the vascular barrier, S1P regulates permeability and endothelial reactions and recruitment of monocytes and may modulate atherosclerosis. Only recently has S1P emerged as a critical mediator which directly links the coagulation factor system to vascular inflammation. The multifunctional proteases thrombin and FXa regulate local S1P availability and interact with S1P signaling at multiple levels in various vascular cell types. Differential expression patterns and intracellular signaling pathways of each receptor enable S1P to exert its widespread functions. Although a vast amount of information is available about the functions of S1P and its receptors in the regulation of physiological and pathophysiological conditions, S1P-mediated mechanisms in the vasculature remain to be elucidated. This review summarizes recent findings regarding the role of S1P and its receptors in vascular wall and blood cells, which link the coagulation system to inflammatory responses in the vasculature. PMID:26604433

  18. Coagulation of blood plasma of guinea pig by the bone matrix.

    PubMed

    Huggins, C B; Reddi, A H

    1973-03-01

    Optimal amounts of demineralized bone matrix possess the ability to coagulate platelet-free heparinized, citrated, and oxalated blood plasmas of guinea pigs. Clotting constituents become denatured in contact with the insoluble coagulant proteins. Quantities in excess of optimal modify plasma so that it does not gel when thrombin is added. The newly described coagulant effects are not restricted to the bone matrix, but are present also in the demineralized matrices of tooth and ivory, and in denatured tendon as well. They are regulated properties that were not demonstrated in mineralized bone or native tendon. The coagulant attributes of bone matrix are consistent with those of electropositive polymers of a specific sort. PMID:4515003

  19. Sequence-specific sup 1 H NMR assignments, secondary structure, and location of the calcium binding site in the first epidermal growth factor like domain of blood coagulation factor IX

    SciTech Connect

    Huang, L.H.; Cheng, H.; Sweeney, W.V. ); Pardi, A. ); Tam, J.P. )

    1991-07-30

    Factor IX is a blood clotting protein that contains three regions, including a {gamma}-carboxyglutamic acid (Gla) domain, two tandemly connected epidermal growth factor like (EGF-like) domains, and a serine protease region. The protein exhibits a high-affinity calcium binding site in the first EGF0like domain, in addition to calcium binding in the Gla domain. The first EGF-like domain, factor IX (45-87), has been synthesized. Sequence-specific resonance assignment of the peptide has been made by using 2D NMR techniques, and its secondary structure has been determined. The protein is found to have two antiparallel {beta}-sheets, and preliminary distance geometry calculations indicate that the protein has two domains, separated by Trp{sup 28}, with the overall structure being similar to that of EGF. An NMR investigation of the calcium-bound first EGF-like domain indicates the presence and location of a calcium binding site involving residues on both strands of one of the {beta}-sheets as well as the N-terminal region of the peptide. These results suggest that calcium binding in the first EGF-like domain could induce long-range (possibly interdomain) conformational changes in factor IX, rather than causing structural alterations in the EGF-like domain itself.

  20. Dynamic and quantitative assessment of blood coagulation using optical coherence elastography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Zhu, Jiang; Chen, Zhongping

    2016-04-01

    Reliable clot diagnostic systems are needed for directing treatment in a broad spectrum of cardiovascular diseases and coagulopathy. Here, we report on non-contact measurement of elastic modulus for dynamic and quantitative assessment of whole blood coagulation using acoustic radiation force orthogonal excitation optical coherence elastography (ARFOE-OCE). In this system, acoustic radiation force (ARF) is produced by a remote ultrasonic transducer, and a shear wave induced by ARF excitation is detected by the optical coherence tomography (OCT) system. During porcine whole blood coagulation, changes in the elastic property of the clots increase the shear modulus of the sample, altering the propagating velocity of the shear wave. Consequently, dynamic blood coagulation status can be measured quantitatively by relating the velocity of the shear wave with clinically relevant coagulation metrics, including reaction time, clot formation kinetics and maximum shear modulus. The results show that the ARFOE-OCE is sensitive to the clot formation kinetics and can differentiate the elastic properties of the recalcified porcine whole blood, blood added with kaolin as an activator, and blood spiked with fibrinogen.

  1. Dynamic and quantitative assessment of blood coagulation using optical coherence elastography.

    PubMed

    Xu, Xiangqun; Zhu, Jiang; Chen, Zhongping

    2016-01-01

    Reliable clot diagnostic systems are needed for directing treatment in a broad spectrum of cardiovascular diseases and coagulopathy. Here, we report on non-contact measurement of elastic modulus for dynamic and quantitative assessment of whole blood coagulation using acoustic radiation force orthogonal excitation optical coherence elastography (ARFOE-OCE). In this system, acoustic radiation force (ARF) is produced by a remote ultrasonic transducer, and a shear wave induced by ARF excitation is detected by the optical coherence tomography (OCT) system. During porcine whole blood coagulation, changes in the elastic property of the clots increase the shear modulus of the sample, altering the propagating velocity of the shear wave. Consequently, dynamic blood coagulation status can be measured quantitatively by relating the velocity of the shear wave with clinically relevant coagulation metrics, including reaction time, clot formation kinetics and maximum shear modulus. The results show that the ARFOE-OCE is sensitive to the clot formation kinetics and can differentiate the elastic properties of the recalcified porcine whole blood, blood added with kaolin as an activator, and blood spiked with fibrinogen. PMID:27090437

  2. Dynamic and quantitative assessment of blood coagulation using optical coherence elastography

    PubMed Central

    Xu, Xiangqun; Zhu, Jiang; Chen, Zhongping

    2016-01-01

    Reliable clot diagnostic systems are needed for directing treatment in a broad spectrum of cardiovascular diseases and coagulopathy. Here, we report on non-contact measurement of elastic modulus for dynamic and quantitative assessment of whole blood coagulation using acoustic radiation force orthogonal excitation optical coherence elastography (ARFOE-OCE). In this system, acoustic radiation force (ARF) is produced by a remote ultrasonic transducer, and a shear wave induced by ARF excitation is detected by the optical coherence tomography (OCT) system. During porcine whole blood coagulation, changes in the elastic property of the clots increase the shear modulus of the sample, altering the propagating velocity of the shear wave. Consequently, dynamic blood coagulation status can be measured quantitatively by relating the velocity of the shear wave with clinically relevant coagulation metrics, including reaction time, clot formation kinetics and maximum shear modulus. The results show that the ARFOE-OCE is sensitive to the clot formation kinetics and can differentiate the elastic properties of the recalcified porcine whole blood, blood added with kaolin as an activator, and blood spiked with fibrinogen. PMID:27090437

  3. Coagulating activity of the blood, vascular wall, and myocardium under hypodynamia conditions

    NASA Technical Reports Server (NTRS)

    Petrovskiy, B. V. (Editor); Chazov, E. I. (Editor); Andreyev, S. V. (Editor)

    1980-01-01

    In order to study the effects of hypodynamia on the coagulating properties of the blood, vascular wall, and myocardium, chinchilla rabbits were kept for varying periods in special cages which restricted their movements. At the end of the experiment, blood samples were taken and the animals were sacrificed. Preparations were made from the myocardium venae cavae, and layers of the aorta. Two resultant interrelated and mutually conditioned syndromes were discovered: thrombohemorrhagic in the blood and hemorrago-thrombotic in the tissues.

  4. Targeting the coagulation factor fibrinogen for arthritis therapy.

    PubMed

    Raghu, Harini; Flick, Matthew J

    2011-09-01

    Fibrinogen is a provisional matrix protein of the coagulation system that following proteolytic cleavage by the protease thrombin polymerizes to form fibrin, the structural basis of the blood clot. Fibrin polymer formation at sites of vessel injury is critical to normal hemostasis. However, fibrin deposition within damaged tissues is also a common pathological feature of inflammatory diseases, including rheumatoid arthritis. Fibrin deposition has been readily detected along articular surfaces, within inflamed hyperplastic synovial tissue, and as a component of insoluble "rice bodies" within the synovial fluid of arthritic joints. Recent data has suggested that fibrin deposition within inflamed tissues is not simply a reflection of a disease process but rather actively contributes to disease pathogenesis. One mechanism that has been demonstrated to directly link fibrin(ogen) to the regulation of inflammation is the ability of fibrin(ogen) to serve as a ligand for cell-surface receptors, particularly integrins. Indeed, engagement of fibrin(ogen) by the leukocyte integrin receptor αMβ2 appears to be a common and fundamental event driving local inflammation. Recent studies have demonstrated that eliminating fibrin(ogen)-αMβ2 interactions can significantly limit the progression of multiple inflammatory diseases, including arthritis, without compromising the ability of fibrinogen to function in coagulation. These exciting findings have opened the door to new opportunities for targeting fibrinogen as an inflammatory mediator while leaving intact its hemostatic properties. PMID:21401516

  5. Coagulation factor Xa drives tumor cells into apoptosis through BH3-only protein Bim up-regulation

    SciTech Connect

    Borensztajn, Keren S. . E-mail: K.S.Borensztajn@amc.uva.nl; Bijlsma, Maarten F.; Groot, Angelique P.; Brueggemann, Lois W.; Versteeg, Henri H.; Reitsma, Pieter H.; Peppelenbosch, Maikel P.; Spek, C. Arnold

    2007-07-15

    Coagulation Factor (F)Xa is a serine protease that plays a crucial role during blood coagulation by converting prothrombin into active thrombin. Recently, however, it emerged that besides this role in coagulation, FXa induces intracellular signaling leading to different cellular effects. Here, we show that coagulation factor (F)Xa drives tumor cells of epithelial origin, but not endothelial cells or monocytes, into apoptosis, whereas it even enhances fibroblast survival. FXa signals through the protease activated receptor (PAR)-1 to activate extracellular-signal regulated kinase (ERK) 1/2 and p38. This activation is associated with phosphorylation of the transcription factor CREB, and in tumor cells with up-regulation of the BH3-only pro-apoptotic protein Bim, leading to caspase-3 cleavage, the main hallmark of apoptosis. Transfection of tumor cells with dominant negative forms of CREB or siRNA for either PAR-1, Bim, ERK1 and/or p38 inhibited the pro-apoptotic effect of FXa. In fibroblasts, FXa-induced PAR-1 activation leads to down-regulation of Bim and pre-treatment with PAR-1 or Bim siRNA abolishes proliferation. We thus provide evidence that beyond its role in blood coagulation, FXa plays a key role in cellular processes in which Bim is the central player in determining cell survival.

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  7. Monoclonal antibodies to coagulation factor IX define a high-frequency polymorphism by immunoassays.

    PubMed Central

    Smith, K J

    1985-01-01

    Monoclonal antibodies have been used to demonstrate a polymorphism of human plasma coagulation factor IX antigen in double antibody solid-phase immunoradiometric assays. This polymorphism is detected in an assay where a monoclonal antibody (A-1) adsorbed to microtiter wells is used to bind factor IX from diluted plasma samples. Plasma samples with the factor IX polymorphism have less than 0.2 U/ml of apparent antigen when tested with the A-1 antibody, while assays with other monoclonal antibodies and assays with goat antisera to factor IX show normal amounts of factor IX antigen. Factor IX coagulant activity was normal in samples from donors with the polymorphism. The thin-layer polyacrylamide gel isoelectric focusing pattern of factor IX purified from a donor with the factor IX polymorphism (IXp) was identical to that obtained with factor IX prepared from a donor who did not have the polymorphism (IXn). Purified radiolabeled factor IX prepared from a donor with the polymorphism showed a Ka for the A-1 antibody that was threefold less than that measured for IXn. The gene frequency of IXp in male blood donors is 0.25. This polymorphism may be useful as a marker for the X chromosome in genetic studies on plasma samples. Further studies are necessary to determine the explanation for decreased reaction of IXp with the A-1 monoclonal antibody. Images Fig. 1 PMID:9556657

  8. Effects of Hyperbaric and Decompression Stress on Blood Coagulation and Fibrinolysis: Comparison of Thromboelastography and Thromboelastometry.

    PubMed

    Peng, Henry T; Cameron, Bruce A; Rhind, Shawn G

    2016-05-01

    Hyperbaric and decompression stress from diving impairs blood coagulation and fibrinolysis. We hypothesized that thromboelastography (TEG) and rotational thromboelastometry (ROTEM) were suitable to characterize the effects of stress on global hemostatic profiles. We thus conducted a comparative study of the hyperbaric effects on human coagulation using TEG and ROTEM. Maximum clot strength (maximum amplitude [MA]) and clot lysis (lysis index at time 30 minutes [LI30]) were reduced as indicated by TEG MA and EXTEM LI30, respectively. The relative changes in coagulation and fibrinolysis by the hyperbaric effects of diving were indicated by reduced TEG reaction time R at 5 hours, MA at 24 hours postdive, and reduced EXTEM coagulation time at 15 minutes postdive as well as decreased fibrinolysis (EXTEM LI30) at all postdiving time points investigated. Comparison of the parameter values and the diving-induced changes in each parameter between TEG and ROTEM showed both differences and correlations. The discrepancies between the 2 systems may be due to the different assay reagents used. Future studies will seek to further elucidate the changes in blood coagulation and fibrinolysis following varying levels of hyperbaric and decompression stress. PMID:25616490

  9. Influence of a constant magnetic field on thrombocytes. [delay of blood coagulation time

    NASA Technical Reports Server (NTRS)

    Meyerova, Y. A.

    1974-01-01

    In an experiment on white mice it was found that a constant electromagnetic field with strength of 250-275 oersteds is biologically active at an exposure of 55 minutes. Qualitative and morphological changes in thrombocytes 1-3 days following exposure reduced their numbers, prolonged blood coagulation time and increased the number of leucocytes.

  10. EFFECT OF CONCENTRATED AMBIENT PARTICULATE MATTER ON BLOOD COAGULATION PARAMETERS IN RATS

    EPA Science Inventory

    Dr. Nadziejko and her colleagues at the New York University School of Medicine plan to evaluate the effects of exposing healthy rats to concentrated ambient particles (CAPs) and changes in blood coagulation parameters. The investigators expect to measure platelet number, bl...

  11. In vitro thrombogenesis resulting from decreased shear rate and blood coagulability.

    PubMed

    Maruyama, Osamu; Kosaka, Ryo; Nishida, Masahiro; Yamane, Takashi; Tatsumi, Eisuke; Taenaka, Yoshiyuki

    2016-06-15

    In vitro antithrombogenic testing with mock circulation is a useful type of pre-evaluation in ex vivo testing of mechanical assist devices. For effective in vitro testing, we have been developing a clear quantitative thrombogenesis model based on shear stress and blood coagulability. Bovine blood was used as the test medium. The activating clotting time (ACT) was adjusted with trisodium citrate and calcium chloride from 200 to 1,000 seconds. The blood was then applied to a rheometer and subjected to shear at 50 to 2,880 s-1. Blood coagulation time and degree of thrombogenesis were measured by the torque sensor of the rheometer. Prothrombin time (PT) and activated partial thromboplastin time (APTT) of the test blood were also measured after the application of shear. Blood coagulation time increased, and the degree of thrombogenesis decreased, with increases in shear rate to between 50 and 2,880 s-1. for test bloods with ACTs of 200 to 250 seconds. An ACT of 200 to 250 seconds is thus appropriate for in vitro antithrombogenic testing under a shear rate of 2,880 s-1. APTT was prolonged, whereas PT did not change, with increasing shear rate: that is, increasing the shear rate reduced thrombogenesis related to the intrinsic clotting pathway. An ACT of 200 to 250 seconds was suitable for in vitro antithrombogenic testing, and increasing the shear stress generated in the mechanical assist device reduced thrombogenesis via the intrinsic clotting pathway. PMID:27199137

  12. Sulfation of tyrosine residues in coagulation factor V

    SciTech Connect

    Hortin, G.L. )

    1990-09-01

    Sulfation of human coagulation factor V was investigated by biosynthetically labeling the products of HepG2 cells with ({sup 35}S)sulfate. There was abundant incorporation of the sulfate label into a product identified as factor V by immunoprecipitation, lability to proteases, affinity for the lectin jacalin, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two or more sites in factor V incorporated sulfate as indicated by labeling of different peptide chains of factor Va. The 150-Kd activation fragment of factor Va incorporated the greatest amounts of sulfate. This fragment of factor Va was bound selectively by jacalin-agarose, reflecting its content of O-linked oligosaccharides. Analysis of an alkaline hydrolysate of sulfate-labeled factor Va by anion-exchange chromatography showed that the sulfate occurred partly in tyrosine sulfate residues and partly in alkaline-labile linkages. Sulfate groups are potentially important structural and functional elements in factor V, and labeling with (35S)sulfate provides a useful approach for examining the biosynthesis and processing of this protein. The hypothesis is advanced that sites of sulfation in factor V and several other plasma proteins contribute to the affinity and specificity of thrombin for these molecules, just as it does for the interaction of thrombin with the potent inhibitor hirudin from leeches.

  13. Characteristics of rat platelets and relative contributions of platelets and blood coagulation to haemostasis.

    PubMed

    Takahashi, O

    2000-01-01

    In order to understand some of the haemostatic mechanisms in rats for the interpretation of toxicological data, basic haemostatic parameters with a special emphasis on platelet functions were first measured in vitro. The results of reactions of rat platelets to many aggregating agents suggest that only ADP may be a consistently significant aggregator. The search for physiologic aggregators revealed ADP to be available from erythrocytes. Adhesion reaction also required ADP. Collagen was not considered to be essential for either reaction. Aggregation and adhesion were probably both reversible in flowing blood, while irreversible thrombi were formed in blood at rest ex vivo. Blood coagulation parameters determined revealed that the intrinsic pathway may be more important than the extrinsic one. The rate of intrinsic coagulation reaction was rapid, and plasma coagulation appeared to be of primary importance while the influence of platelet aggregation was minor. A simple model of rat haemostatic mechanism is proposed based on these results. Additionally, to define the relative contribution of platelets versus other cellular and plasma coagulation in vivo, rats were administered antiplatelet drugs (ticlopidine, suprofen and clopidogrel) and an anticoagulant (warfarin) intraperitoneally. Bleeding times (BTs) were significantly increased in all treated groups. ADP-induced platelet aggregations were significantly depressed by the administration of the three antiplatelet drugs, while kaolon-activated partial thromboplastin time and prothrombin time were greatly increased in the warfarin-treated rats. The increase in BT may be due to the inhibition of platelet activity or blood coagulation defect in rats given antiplatelet drugs or warfarin, respectively. These results suggest that platelets play a key role in haemostasis in the rat. Two possible explanations of the disparity between in vitro and in vivo results may be that functional tests used here are not adequate to cover

  14. [Status of blood coagulation and various background endocrine indices in patients with basal meningiomas during pre- and postoperative periods].

    PubMed

    Burgman, G P; Snigireva, R Ia; Vial'tseva, I N; Shvorneva, V Z; Snigirev, V S

    1980-01-01

    The condition of blood coagulation activity and the indices of the endocrine background were studied in patients with tumors of prevalently basal localization which caused a direct effect on the central regulating centers. Thirty patients with basal and medially located meningiomas were examined in the pre- and postoperative periods. Before the operation most patients had clinical signs of endocrine-metabolic disorders, often in the presence of an increased content of ACTH and cortisol in the blood. Blood coagulation was disturbed in the majority of patients, mainly due to increased activity of the blood coagulation system. In the postoperative period, blood coagulation activity in 24 of 30 patients was increased or showed a tendency to increase in the presence of elevated blood ACTH content while processes of fibrinolysis were inhibited, which substantiates the necessity for anticoagulant therapy when large doses of glucocorticoids are used. PMID:6254292

  15. Contact activation of blood coagulation on a defined kaolin/collagen surface in a microfluidic assay

    PubMed Central

    Zhu, Shu; Diamond, Scott L.

    2014-01-01

    Generation of active Factor XII (FXIIa) triggers blood clotting on artificial surfaces and may also enhance intravascular thrombosis. We developed a patterned kaolin (0 to 0.3 pg/μm2)/type 1 collagen fibril surface for controlled microfluidic clotting assays. Perfusion of whole blood (treated only with a low level of 4 μg/mL of the XIIa inhibitor, corn trypsin inhibitor) drove platelet deposition followed by fibrin formation. At venous wall shear rate (100 s−1), kaolin accelerated onset of fibrin formation by ~100 sec when compared to collagen alone (250 sec vs. 350 sec), with little effect on platelet deposition. Even with kaolin present, arterial wall shear rate (1000 s−1) delayed and suppressed fibrin formation compared to venous wall shear rate. A comparison of surfaces for extrinsic activation (tissue factor TF/collagen) versus contact activation (kaolin/collagen) that each generated equal platelet deposition at 100 s−1 revealed: (1) TF surfaces promoted much faster fibrin onset (at 100 sec) and more endpoint fibrin at 600 sec at either 100 s−1 or 1000 s−1, and (2) kaolin and TF surfaces had a similar sensitivity for reduced fibrin deposition at 1000 s−1 (compared to fibrin formed at 100 s−1) despite differing coagulation triggers. Anti-platelet drugs inhibiting P2Y1, P2Y12, cyclooxygenase-1 or activating IP-receptor or guanylate cyclase reduced platelet and fibrin deposition on kaolin/collagen. Since FXIIa or FXIa inhibition may offer safe antithrombotic therapy, especially for biomaterial thrombosis, these defined collagen/kaolin surfaces may prove useful in drug screening tests or in clinical diagnostic assays of blood under flow conditions. PMID:25303860

  16. Inhibitors of propagation of coagulation (factors VIII, IX and XI): a review of current therapeutic practice

    PubMed Central

    Franchini, Massimo; Mannucci, Pier Mannuccio

    2011-01-01

    The management of patients with congenital haemophilia who develop alloantibodies against factors of the propagation phase of blood coagulation, commonly known as inhibitors, is the most important challenge facing haemophilia caregivers at present, as this complication not only compromises the efficacy of replacement therapy but also consumes an enormous amount of economic resources. Development of inhibitors further complicates the clinical course of severe haemophilia, with a prevalence of up to 30% in patients with haemophilia A (factor VIII deficiency) and up to 5% in those with haemophilia B (factor IX deficiency) and haemophilia C (factor XI deficiency). While the short-term goal of treatment of patients who develop alloantibodies is the control of bleeding, the eradication of the inhibitor is the main long-term goal. The management of severe bleeding episodes and the eradication of the autoantibody are also the mainstays of treatment of patients with acquired haemophilia, a rare but life-threatening haemorrhagic condition characterized by the development of inhibitory autoantibodies against coagulation factor VIII. The most recent options available for treating patients with congenital haemophilia complicated by inhibitors and acquired haemophilia because of autoantibodies against factor VIII are summarized in this review article. PMID:21204915

  17. Mannose-binding lectin and its associated proteases (MASPs) mediate coagulation and its deficiency is a risk factor in developing complications from infection, including disseminated intravascular coagulation

    PubMed Central

    Takahashi, Kazue; Chang, Wei-Chuan; Takahashi, Minoru; Pavlov, Vasile; Ishida, Yumi; La Bonte, Laura; Shi, Lei; Fujita, Teizo; Stahl, Gregory L.; Van Cott, Elizabeth M.

    2010-01-01

    The first line of host defense is the innate immune system that includes coagulation factors and pattern recognition molecules, one of which is mannose-binding lectin (MBL). Previous studies have demonstrated that MBL deficiency increases susceptibility to infection. Several mechanisms are associated with increased susceptibility to infection, including reduced opsonophagocytic killing and reduced lectin complement pathway activation. In this study, we demonstrate that MBL and MBL-associated serine protease (MASP)-1/3 together mediate coagulation factor-like activities, including thrombin-like activity. MBL and/or MASP-1/3 deficient hosts demonstrate in vivo evidence that MBL and MASP-1/3 are involved with hemostasis following injury. Staphylococcus aureus infected MBL null mice developed disseminated intravascular coagulation (DIC), which was associated with elevated blood IL-6 levels (but not TNF-α and multi-organ inflammatory responses). Infected MBL null mice also develop liver injury. These findings suggest that MBL deficiency may manifest into DIC and organ failure during infectious diseases. PMID:20399528

  18. Platelet and coagulation factors in proliferative diabetic retinopathy.

    PubMed Central

    Borsey, D Q; Prowse, C V; Gray, R S; Dawes, J; James, K; Elton, R A; Clarke, B F

    1984-01-01

    Plasma beta-thromboglobulin, platelet factor 4, fibrinogen, fibrinopeptide A, antithrombin III, factor VIII related antigen, alpha 2-macroglobulin, platelet count, and total glycosylated haemoglobin were measured in three well matched groups of subjects: non-diabetic controls, diabetics without retinopathy, and diabetics with proliferative retinopathy. beta-thromboglobulin and platelet factor 4 concentrations were significantly higher in the diabetics with retinopathy than in the controls and platelet factor 4 was also increased in the diabetics without retinopathy compared with controls. Fibrinogen concentration was raised in diabetics without retinopathy compared with controls, diabetics with retinopathy compared with controls, and diabetics with retinopathy compared with those without. Fibrinopeptide A concentration did not differ significantly between groups. Antithrombin III levels were increased in diabetics with retinopathy compared with controls, and in diabetics with retinopathy compared with those without. Factor VIII related antigen values were higher in both the diabetic groups when compared with the controls. Fibrinopeptide A concentration correlated with both beta-thromboglobulin and platelet factor 4 in each of the three groups. Haemostatic abnormalities in diabetes have been shown, although a hypercoagulable state has not been confirmed. These changes in platelet and coagulation function may be secondary to the development of microvascular disease and their role in the pathogenesis of retinopathy remains uncertain. PMID:6202721

  19. The Massive Bleeding after the Operation of Hip Joint Surgery with the Acquired Haemorrhagic Coagulation Factor XIII(13) Deficiency: Two Case Reports.

    PubMed

    Kanda, Akio; Kaneko, Kazuo; Obayashi, Osamu; Mogami, Atsuhiko

    2013-01-01

    Two women, aged 81 and 61, became haemorrhagic after surgery. Their previous surgeries were uneventful with no unexpected bleeding observed. Blood tests prior to the current surgeries indicated normal values including those related to coagulation. There were no problems with the current surgeries prior to leaving the operating room. At 3 hours after the surgery, the 81-year-old patient had an outflow of the drain at 1290 grams and her blood pressure decreased. She had disseminated intravascular coagulation (DIC). The 61-year-old woman had repeated haemorrhages after her current surgery for a long time. Their abnormal haemorrhages were caused by a deficiency of coagulation factor XIII(13). The mechanism of haemorrhagic coagulation factor XIII(13) deficiency is not understood, and it is a rare disorder. The only diagnostic method to detect this disorder is to measure factor XIII(13) activity in the blood. In this paper, we used Arabic and Roman numerals at the same time to avoid confusion of coagulation factor XIII(13) with coagulation factor VIII(8) that causes hemophilia A. PMID:23533879

  20. Intron-exon organization of the human gene coding for the lipoprotein-associated coagulation inhibitor: The factor Xa dependent inhibitor of the extrinsic pathway of coagulation

    SciTech Connect

    van der Logt, C.P.E.; Reitsma, P.H.; Bertina, R.M. )

    1991-02-12

    Blood coagulation can be initiated when factor VII(a) binds to its cofactor tissue factor. This factor VIIa/tissue factor complex proteolytically activates factors IX and X, which eventually leads to the formation of a fibrin clot. Plasma contains a lipoprotein-associated coagulation inhibitor (LACI) which inhibits factor Xa directly and, in a Xa-dependent manner, also inhibits the factor VIIa/tissue factor complex. Here the authors report the cloning of the human LACI gene and the elucidation of its intron-exon organization. The LACI gene, which spans about 70 kb, consists of nine exons separated by eight introns. As has been found for other Kunitz-type protease inhibitors, the domain structure of human LACI is reflected in the intron-exon organization of the gene. The 5{prime} terminus of the LACI mRNA has been determined by primer extension and S1 nuclease mapping. The putative promoter was examined and found to contain two consensus sequences for AP-1 binding and one for NF-1 binding, but no TATA consensus promoter element.

  1. Prophylactic use of tranexamic acid combined with thrombelastogram guided coagulation management may reduce blood loss and allogeneic transfusion in pediatric hemispherectomy: case series.

    PubMed

    Xiao, Wei; Fu, Wenya; Wang, Tianlong; Zhao, Lei

    2016-09-01

    Hemispherectomy is an established surgical procedure to treat medically refractory epilepsy caused by diffuse hemispheric diseases. The most common complication of hemispherectomy is intraoperative bleeding. Perioperative allogeneic blood transfusion increases mortality and morbidity in pediatric patients. Etiologies of massive blood loss during hemispherectomy include intraoperative diffuse vascular damage, antileptic drugs induced coagulation dysfunction, hyperfibrinolysis and dilutional coagulopathy. Great efforts should be made to minimize the need of blood transfusion. We present a series of three cases undergoing pediatric hemispherectomy, where a new algorithm was employed to manage coagulation. This new algorithm was mainly based on timely thrombelastogram analyses guided clotting factors supplement and continuous administration of tranexamic acid. In our cases, the amount of blood loss and subsequent allogeneic blood transfusion seemed to be less than literature reported. PMID:27555151

  2. Air quality improvement during 2010 Asian games on blood coagulability in COPD patients.

    PubMed

    Zhang, Zili; Wang, Jian; Guo, Meihua; Xiong, Mingmei; Zhou, Qipeng; Li, Defu; Shu, Jiaze; Lu, Wenju; Sun, Dejun

    2016-04-01

    Exposure to elevated levels of ambient air pollutants can lead to adverse cardiovascular effects. Perturbation of the coagulation balance is one of the potential mechanisms. However, evidence regarding the impact of improvement in air pollution on blood coagulability in COPD patients has never been reported. Coagulation processes are known to be of relevance for cardiovascular pathology; therefore, this study aimed to investigate the association of short-term air pollution exposure with blood marker (D-dimer) of coagulation. A 3-year (through the Asian game) cohort study based on the GIRD COPD Biobank Project was conducted in 36 COPD patients to estimate whether changes in measurements of D-dimer were associated with changes in pollutant concentration, comparing for 51 intervention days (November 1-December 21) in 2010 with the same calendar date of baseline years (2009 and 2011). Daily mean concentrations of air pollutants and meteorological variables were measured during the time. Daily PM10 decreased from 65.86 μg/m(3) during the baseline period to 62.63 μg/m(3) during the Asian Games period; daily NO2 decreased from 51.33 to 42.63 μg/m(3). SO2 and other weather variables did not differ substantially. We did not observe statistically significant improvements in D-dimer levels by 9.86 % from a pre-Asian game mean of 917 ng/ml to a during-Asian game mean of 1007 ng/ml, platelet number by 11.66 %, PH by -0.15 %, PCO2 by -6.54 %, and PO2 by -1.16 %. In the post-Asian game period, when pollutant concentrations increased, most outcomes approximated pre-Asian game levels, and similar effects were also demonstrated in D-dimer, platelet number, and arterial blood gas. For D-dimer and platelet number, we observed statistically significant increases associated with increases in NO2 at lag 1-3 and SO2 at lag 2-4. For PH, PCO2, and PO2, any significant effect was not demonstrated. This study gives no support to the hypothesis that reduction in air pollution

  3. Lowering blood glucose during hip surgery does not influence coagulation activation

    PubMed Central

    Sechterberger, Marjolein K.; Hermanides, Jeroen; Poolman, Rudolf W.; Kal, Jasper E.; Meijers, Joost C.M.; Hoekstra, Joost B.L.; Hans DeVries, J.

    2015-01-01

    Background Hyperglycaemia during and after hip surgery is associated with coagulation activation and an increased risk of venous thromboembolism. Whether lowering of glucose levels during hip surgery diminishes coagulation activation is unknown. We investigated the efficacy of the human GLP-1 analogue liraglutide to lower glucose during and after hip surgery and studied its influence on coagulation activation. Methods A total of 37 obese subjects who underwent hip surgery were randomized to subcutaneous liraglutide or placebo for 4 consecutive days, starting one day prior to surgery. Glucose levels and coagulation indices at three fixed time-points (pre-operative, 2 h post-operative and 3 days post-operative) were measured. Results Liraglutide reduced glucose at day three post-surgery (median glucose (IQR) liraglutide 5.5 (5.2–5.7) vs. placebo 5.8 (5.5–6.2); difference 0.3 mmol/L, P = 0.04). Changes in 6 out of 8 coagulation indices studied did not differ between the two groups. Only D-dimer levels were significantly lower in the liraglutide group at day three post-surgery and FVIII levels were significantly higher in the liraglutide group 2 h post-surgery. Conclusion Although the human GLP-1 analogue liraglutide moderately reduced post-operative blood glucose levels in non-diabetic and prediabetic obese patients undergoing elective hip surgery, no changes were observed with respect to coagulation activation. PMID:26675337

  4. Point of Care and Factor Concentrate-Based Coagulation Algorithms

    PubMed Central

    Theusinger, Oliver M.; Stein, Philipp; Levy, Jerrold H.

    2015-01-01

    In the last years it has become evident that the use of blood products should be reduced whenever possible. There is increasing evidence regarding serious adverse events, including higher mortality and morbidity, related to transfusions. The use of point of care (POC) devices integrated in algorithms is one of the important mechanisms to limit blood product exposure. Any type of algorithm, especially the POC-based ones, allows goal-directed transfusions of blood products and even better targeted factor concentrate substitutions. Different types of algorithms in different surgical settings (cardiac surgery, trauma, liver surgery etc.) have been established with growing interest in their use as they offer objective therapy for management and reduction of blood product use. The use of POC devices with evidence-based algorithms is important in the bleeding patient independent of its origin (traumatic vs. surgical). The use of factor concentrates compared to the classical blood products can be cost-saving, beneficial for the patient, and in agreement with the WHO-requested standard of care. The empiric and uncontrolled use of blood products such as fresh frozen plasma, red blood cells, and platelets without POC monitoring should no longer be followed with regard to actual evidence in literature. Furthermore, the use of factor concentrates may provide better outcomes and potential for cost saving. PMID:26019707

  5. Synthetic oligopeptide substrates: their diagnostic application in blood coagulation, fibrinolysis, and other pathologic states

    SciTech Connect

    Huseby, R.M.; Smith, R.E.

    1980-01-01

    This review article with 522 references, focuses on the use of synthetic oligopepide substrates to measure the activity of proteoytic enzymes in human physiology and pathology. A classification of proteinases based on their mechanism of action is presented. The application of these synthetic oligopeptide substrates to understand the disorders of the blood coagulation and fibrinolytic system is reviewed. Intracellular functioning proteinases were also assessed in relation to certain pathologies where their abnormal activity is recognized.

  6. Optical coherence tomography to investigate optical properties of blood during coagulation

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Lin, Jia; Fu, Feifei

    2011-09-01

    This study investigates the optical properties of human blood during the coagulation process under statics using optical coherence tomography (OCT). OCT signal slope (OCTSS) and 1/e light penetration depth (d1/e) were obtained from the profiles of reflectance versus depth. Results showed that both OCTSS and d1/e were able to sensitively differentiate various stages of blood properties during coagulating. After 1 h clotting, OCTSS decreased by 47.0%, 15.0%, 13.7%, and 8.5% and d1/e increased by 34.7%, 29.4%, 24.3%, and 22.9% for the blood samples at HCT of 25%, 35%, 45%, and 55%, respectively. The slope of d1/e versus time (Sr, ×10-4 mm/s), associated with clot formation rate decreased from 6.0+/-0.3, 3.7+/-0.5 to 2.3+/-0.4 with the increasing of HCT from 35%, 45%, to 55%. The clotting time (tc) from the d1/e evolution curves was estimated to be 1969+/-92 s, 375+/-12 s, 455+/-11 s, and 865+/-47 s for the blood of 25%, 35%, 45%, and 55%. This study demonstrates that the parameters (tc and Sr) from the variations in d1/e had better sensitivity and smaller standard deviation. Furthermore, blood hematocrit affecting backscattering properties of blood during coagulation was capable of being discerned by OCT parameters. It is concluded that OCT is a potential technique to quantify and follow the liquid-gel transition of blood during clotting.

  7. Effects of Hemoglobin-Based Oxygen Carriers on Blood Coagulation

    PubMed Central

    Roghani, Kimia; Holtby, Randall J.; Jahr, Jonathan S.

    2014-01-01

    For many decades, Hemoglobin-based oxygen carriers (HBOCs) have been central in the development of resuscitation agents that might provide oxygen delivery in addition to simple volume expansion. Since 80% of the world population lives in areas where fresh blood products are not available, the application of these new solutions may prove to be highly beneficial (Kim and Greenburg 2006). Many improvements have been made to earlier generation HBOCs, but various concerns still remain, including coagulopathy, nitric oxide scavenging, platelet interference and decreased calcium concentration secondary to volume expansion (Jahr et al. 2013). This review will summarize the current challenges faced in developing HBOCs that may be used clinically, in order to guide future research efforts in the field. PMID:25514567

  8. Interest of ICG blood clearance monitoring for reproducible 810-nm diode laser coagulation of blood vessels

    NASA Astrophysics Data System (ADS)

    Desmettre, Thomas; Soulie-Begu, Sylvie; Devoisselle, Jean-Marie; Mordon, Serge R.

    1999-02-01

    Purpose: To evaluate a method of control of diode laser fluence leading to a reproducible ICG-enhanced selective photocoagulation of blood vessels. This method would use the chromophore clearance, i.e. ICG blood concentration decay to adapt the laser fluence. Materials and Methods: A skin flap window was used on hamsters. After a 15 mg/kg ICG solution injection, photocoagulation of vessels were performed. Results: Selective photocoagulation of blood vessels was obtained only during the first 10 minutes. The fluence required to obtain a selective photocoagulation of vessels (F) was modelized using a one compartment phamacokinetic equation: F equals Of(1-e-t/(tau )). The best fit was obtained for a time constant (tau) equals 4.8 min and Of equals 300 J/cm2 (correlation coefficient r2 equals 0.996). During the first 10 minutes, the fluence required for selective photocoagulation of vessels was increased by a factor 4.5. Conclusion: Fluence required for a selective photocoagulation of vessels was correlated to ICG blood concentration decay. The time constant was equivalent to ICG half-life time in human blood. These results demonstrate that diode laser ICG-enhanced photocoagulation can be controlled by monitoring the ICG blood clearance.

  9. Contributions of contact activation pathways of coagulation factor XII in plasma.

    PubMed

    Chatterjee, Kaushik; Guo, Zhe; Vogler, Erwin A; Siedlecki, Christopher A

    2009-07-01

    Activation of human blood plasma coagulation by contact with hydrophilic or hydrophobic surfaces (procoagulants) is dominated by kallikrein (Kal)-mediated activation of the blood zymogen FXII (Hageman Factor). Mathematical modeling of prekallikrein (PK)-deficient platelet-poor plasma (d(PK)PPP) and PK-reconstituted d(PK)PPP (Rd(PK)PPP) coagulation shows that autoactivation of FXII (FXII-->[surface]FXII) produces no more than about 25% of the total FXIIa produced by the intrinsic pathway. Autoactivation and reciprocal-activation increase in the same proportion with procoagulant surface energy (water-wettability), whereas total amount of FXIIa produced per-unit-area procoagulant remains roughly constant for any particular procoagulant. These results suggest that procoagulant surfaces initiate the intrinsic cascade by producing a bolus of FXIIa in proportion to surface energy or surface area but play no additional role in subsequent molecular events in the cascade. Results further suggest that reciprocal-activation occurs in proportion to the amount of FXIIa produced by the initiating autoactivation step. PMID:18481791

  10. Moojenactivase, a novel pro-coagulant PIIId metalloprotease isolated from Bothrops moojeni snake venom, activates coagulation factors II and X and induces tissue factor up-regulation in leukocytes.

    PubMed

    Sartim, Marco A; Costa, Tassia R; Laure, Helen J; Espíndola, Milena S; Frantz, Fabiani G; Sorgi, Carlos A; Cintra, Adélia C O; Arantes, Eliane C; Faccioli, Lucia H; Rosa, José C; Sampaio, Suely V

    2016-05-01

    Coagulopathies following snakebite are triggered by pro-coagulant venom toxins, in which metalloproteases play a major role in envenomation-induced coagulation disorders by acting on coagulation cascade, platelet function and fibrinolysis. Considering this relevance, here we describe the isolation and biochemical characterization of moojenactivase (MooA), a metalloprotease from Bothrops moojeni snake venom, and investigate its involvement in hemostasis in vitro. MooA is a glycoprotein of 85,746.22 Da, member of the PIIId group of snake venom metalloproteases, composed of three linked disulfide-bonded chains: an N-glycosylated heavy chain, and two light chains. The venom protease induced human plasma clotting in vitro by activating on both blood coagulation factors II (prothrombin) and X, which in turn generated α-thrombin and factor Xa, respectively. Additionally, MooA induced expression of tissue factor (TF) on the membrane surface of peripheral blood mononuclear cells (PBMC), which led these cells to adopt pro-coagulant characteristics. MooA was also shown to be involved with production of the inflammatory mediators TNF-α, IL-8 and MCP-1, suggesting an association between MooA pro-inflammatory stimulation of PBMC and TF up-regulation. We also observed aggregation of washed platelets when in presence of MooA; however, the protease had no effect on fibrinolysis. Our findings show that MooA is a novel hemostatically active metalloprotease, which may lead to the development of coagulopathies during B. moojeni envenomation. Moreover, the metalloprotease may contribute to the development of new diagnostic tools and pharmacological approaches applied to hemostatic disorders. PMID:26026608

  11. Releasing the brakes in coagulation Factor IXa by co-operative maturation of the substrate-binding site.

    PubMed

    Kristensen, Line Hyltoft; Olsen, Ole H; Blouse, Grant E; Brandstetter, Hans

    2016-08-01

    Coagulation Factor IX is positioned at the merging point of the intrinsic and extrinsic blood coagulation cascades. Factor IXa (activated Factor IX) serves as the trigger for amplification of coagulation through formation of the so-called Xase complex, which is a ternary complex of Factor IXa, its substrate Factor X and the cofactor Factor VIIIa on the surface of activated platelets. Within the Xase complex the substrate turnover by Factor IXa is enhanced 200000-fold; however, the mechanistic and structural basis for this dramatic enhancement remains only partly understood. A multifaceted approach using enzymatic, biophysical and crystallographic methods to evaluate a key set of activity-enhanced Factor IXa variants has demonstrated a delicately balanced bidirectional network. Essential molecular interactions across multiple regions of the Factor IXa molecule co-operate in the maturation of the active site. This maturation is specifically facilitated by long-range communication through the Ile(212)-Ile(213) motif unique to Factor IXa and a flexibility of the 170-loop that is further dependent on the conformation in the Cys(168)-Cys(182) disulfide bond. Ultimately, the network consists of compensatory brakes (Val(16) and Ile(213)) and accelerators (Tyr(99) and Phe(174)) that together allow for a subtle fine-tuning of enzymatic activity. PMID:27208168

  12. The first EGF domain of coagulation factor IX attenuates cell adhesion and induces apoptosis.

    PubMed

    Ishikawa, Tomomi; Kitano, Hisataka; Mamiya, Atsushi; Kokubun, Shinichiro; Hidai, Chiaki

    2016-07-01

    Coagulation factor IX (FIX) is an essential plasma protein for blood coagulation. The first epidermal growth factor (EGF) motif of FIX (EGF-F9) has been reported to attenuate cell adhesion to the extracellular matrix (ECM). The purpose of the present study was to determine the effects of this motif on cell adhesion and apoptosis. Treatment with a recombinant EGF-F9 attenuated cell adhesion to the ECM within 10 min. De-adhesion assays with native FIX recombinant FIX deletion mutant proteins suggested that the de-adhesion activity of EGF-F9 requires the same process of FIX activation as that which occurs for coagulation activity. The recombinant EGF-F9 increased lactate dehydrogenase (LDH) activity release into the medium and increased the number of cells stained with annexin V and activated caspase-3, by 8.8- and 2.7-fold respectively, indicating that EGF-F9 induced apoptosis. Activated caspase-3 increased very rapidly after only 5 min of administration of recombinant EGF-F9. Treatment with EGF-F9 increased the level of phosphorylated p38 mitogen-activated protein kinase (MAPK), but not that of phosphorylated MAPK 44/42 or c-Jun N-terminal kinase (JNK). Inhibitors of caspase-3 suppressed the release of LDH. Caspase-3 inhibitors also suppressed the attenuation of cell adhesion and phosphorylation of p38 MAPK by EGF-F9. Our data indicated that EGF-F9 activated signals for apoptosis and induced de-adhesion in a caspase-3 dependent manner. PMID:27129300

  13. Microparticles as Biomarkers of Blood Coagulation in Cancer.

    PubMed

    Nomura, Shosaku; Niki, Maiko; Nisizawa, Tohru; Tamaki, Takeshi; Shimizu, Michiomi

    2015-01-01

    Cancer is associated with hypercoagulopathy and increased risk of thrombosis. This negatively influences patient morbidity and mortality. Cancer is also frequently complicated by the development of venous thromboembolism (VTE). Tumor-derived tissue factor (TF)-bearing microparticles (MPs) are associated with VTE events in malignancy. MPs are small membrane vesicles released from many different cell types by exocytic budding of the plasma membrane in response to cellular activation or apoptosis. MPs may also be involved in clinical diseases through expression of procoagulative phospholipids. The detection of TF-expressing MPs in cancer patients may be clinically useful. In lung and breast cancer patients, MPs induce metastasis and angiogenesis and may be indicators of vascular complications. Additionally, MPs in patients with various types of cancer possess adhesion proteins and bind target cells to promoting cancer progression or metastasis. Overexpression of TF by cancer cells is closely associated with tumor progression, and shedding of TF-expressing MPs by cancer cells correlates with the genetic status of cancer. Consequently, TF-expressing MPs represent important markers to consider in the prevention of and therapy for VTE complications in cancer patients. PMID:26462252

  14. Utilization Patterns of Coagulation Factor Consumption for Patients with Hemophilia.

    PubMed

    Lee, Soo Ok; Yu, Su-Yeon

    2016-01-01

    Hemophilia is a serious rare disease that requires continuous management and treatment for which the medicine is costly at the annual average of 100 million KRW for an individual. The aim of this study was to investigate trends in the utilization of coagulation factor (CF) used for hemophilia treatment using the National Health Insurance database from 2010 to 2013 in Korea and compare the utilization of CF with other countries. The consumption of CF per capita (IU) in Korea was not more than other countries with similar income to Korea. However, CF usage per patient IU was higher because the prevalence rate of hemophilia in Korea was lower than in other countries while the number of serious patients was much more. Therefore, it is difficult to say that the consumption of hemophilia medicine in Korea is higher than that in other countries. The consumption and cost of hemophilia medicine in Korea is likely to increase due to the increased utilization of expensive bypassing agents and the widespread use of prophylaxis for severe hemophilia. Even during the research period, it increased slightly and other countries show a similar trend. Thus, hemophilia patient management should accompany active monitoring on the health and cost outcomes of pharmaceutical treatment in the future. This study is expected to contribute to further insight into drug policies for other countries that face similar challenges with high price pharmaceuticals. PMID:26770035

  15. Targeted inactivation of the mouse locus encoding coagulation factor XIII-A: hemostatic abnormalities in mutant mice and characterization of the coagulation deficit.

    PubMed

    Lauer, Peter; Metzner, Hubert J; Zettlmeissl, Gerd; Li, Meng; Smith, Austin G; Lathe, Richard; Dickneite, Gerhard

    2002-12-01

    Blood coagulation factor XIII (FXIII) promotes cross-linking of fibrin during blood coagulation; impaired clot stabilization in human genetic deficiency is associated with marked pathologies of major clinical impact, including bleeding symptoms and deficient wound healing. To investigate the role of FXIII we employed homologous recombination to generate a targeted deletion of the inferred exon 7 of the FXIII-A gene. FXIII transglutaminase activity in plasma was reduced to about 50% in mice heterozygous for the mutant allele, and was abolished in homozygous null mice. Plasma fibrin gamma-dimerization was also indetectable in the homozygous deficient animals, confirming the absence of activatable FXIII. Homozygous mutant mice were fertile, although reproduction was impaired. Bleeding episodes, hematothorax, hematoperitoneum and subcutaneous hemorrhage in mutant mice were associated with reduced survival. Arrest of tail-tip bleeding in FXIII-A deficient mice was markedly and significantly delayed; replacement of mutant mice with human plasma FXIII (Fibrogammin P) restored bleeding time to within the normal range. Thrombelastography (TEG) experiments demonstrated impaired clot stabilization in FXIII-A mutant mice, replacement with human FXIII led to dose-dependent TEG normalization. The mutant mice thus reiterate some key features of the human genetic disorder: they will be valuable in assessing the role of FXIII in other associated pathologies and the development of new therapies. PMID:12529747

  16. Changes in Dietary Fat Content Rapidly Alters the Mouse Plasma Coagulation Profile without Affecting Relative Transcript Levels of Coagulation Factors

    PubMed Central

    van Diepen, Janna A.; Verhoef, Daniël; Voshol, Peter J.; Reitsma, Pieter H.; van Vlijmen, Bart J. M.

    2015-01-01

    Background Obesity is associated with a hypercoagulable state and increased risk for thrombotic cardiovascular events. Objective Establish the onset and reversibility of the hypercoagulable state during the development and regression of nutritionally-induced obesity in mice, and its relation to transcriptional changes and clearance rates of coagulation factors as well as its relation to changes in metabolic and inflammatory parameters. Methods Male C57BL/6J mice were fed a low fat (10% kcal as fat; LFD) or high fat diet (45% kcal as fat; HFD) for 2, 4, 8 or 16 weeks. To study the effects of weight loss, mice were fed the HFD for 16 weeks and switched to the LFD for 1, 2 or 4 weeks. For each time point analyses of plasma and hepatic mRNA levels of coagulation factors were performed after overnight fasting, as well as measurements of circulating metabolic and inflammatory parameters. Furthermore, in vivo clearance rates of human factor (F) VII, FVIII and FIX proteins were determined after 2 weeks of HFD-feeding. Results HFD feeding gradually increased the body and liver weight, which was accompanied by a significant increase in plasma glucose levels from 8 weeks onwards, while insulin levels were affected after 16 weeks. Besides a transient rise in cytokine levels at 2 weeks after starting the HFD, no significant effect on inflammation markers was present. Increased plasma levels of fibrinogen, FII, FVII, FVIII, FIX, FXI and FXII were observed in mice on a HFD for 2 weeks, which in general persisted throughout the 16 weeks of HFD-feeding. Interestingly, with the exception of FXI the effects on plasma coagulation levels were not paralleled by changes in relative transcript levels in the liver, nor by decreased clearance rates. Switching from HFD to LFD reversed the HFD-induced procoagulant shift in plasma, again not coinciding with transcriptional modulation. Conclusions Changes in dietary fat content rapidly alter the mouse plasma coagulation profile, thereby

  17. Blood Coagulation Induced by Iranian Saw-Scaled Viper (Echis Carinatus) Venom: Identification, Purification and Characterization of a Prothrombin Activator

    PubMed Central

    Babaie, Mahdi; Salmanizadeh, Hossein; Zolfagharian, Hossein

    2013-01-01

    Objective(s): Echis carinatus is one of the venomous snakes in Iran. The venom of Iranian Echis carinatus is a rich source of protein with various factors affecting the plasma protein and blood coagulation factor. Some of these proteins exhibit types of enzymatic activities. However, other items are proteins with no enzymatic activity. Materials and Methods: In order to study the mechanism and effect of the venom on human plasma proteins, the present study has evaluated the effect of crude venom and all fractions. A procoagulant factor (prothrombin activator) was isolated from the venom of the Iranian snake Echis carinatus with a combination of gel filtration (Sephadex G-75), ion-exchange chromatography (DEAE- Sepharose) and reverse phase HPLC. Furthermore, proteolytic activity of the crude venom and all fractions on blood coagulation factors such as prothrombin time (PT) was studied. Results: In the present study, the PT test was reduced from 13.4 s to 8.6 s when human plasma was treated with crude venom (concentraion of venom was 1 mg/ml). The purified procoagulant factor revealed a single protein band in SDS polyacrylamide electrophoresis under reducing conditions and its molecular weight was estimated at about 65 kDa. A single-band protein showed fragment patterns similar to those generated by the group A prothrombin activators, which convert prothrombin into meizothrombin independent of the prothrombinase complex. Conclusion: This study showed that the fraction which separated from Iranian snake Echis carinatus venom can be a prothrombin activators. It can be concluded that this fraction is a procoagulant factor. PMID:24494066

  18. Treatment of Epilepsy with Bipolar Electro-coagulation: An Analysis of Cortical Blood Flow and Histological Change in Temporal Lobe

    PubMed Central

    Cui, Zhi-Qiang; Luan, Guo-Ming; Zhou, Jian; Zhai, Feng; Guan, Yu-Guang; Bao, Min

    2015-01-01

    Background: Bipolar electro-coagulation has a reported efficacy in treating epilepsy involving functional cortex by pure electro-coagulation or combination with resection. However, the mechanisms of bipolar electro-coagulation are not completely known. We studied the acute cortical blood flow and histological changes after bipolar electro-coagulation in 24 patients with intractable temporal lobe epilepsy. Methods: Twenty-four patients were consecutively enrolled, and divided into three groups according to the date of admission. The regional cortical blood flow (rCBF), electrocorticography, the depth of cortex damage, and acute histological changes (H and E staining, neuronal staining and neurofilament (NF) staining) were analyzed before and after the operation. The t-test analysis was used to compare the rCBF before and after the operation. Results: The rCBF after coagulation was significantly reduced (P < 0.05). The spikes were significantly reduced after electro-coagulation. For the temporal cortex, the depth of cortical damage with output power of 2–9 W after electro-coagulation was 0.34 ± 0.03, 0.48 ± 0.06, 0.69 ± 0.06, 0.84 ± 0.09, 0.98 ± 0.08, 1.10 ± 0.11, 1.11 ± 0.09, and 1.22 ± 0.11 mm, respectively. Coagulation with output power of 4–5 W completely damaged the neurons and NF protein in the molecular layer, external granular layer, and external pyramidal layer. Conclusions: The electro-coagulation not only destroyed the neurons and NF protein, but also reduced the rCBF. We concluded that the injuries caused by electro-coagulation would prevent horizontal synchronization and spread of epileptic discharges, and partially destroy the epileptic focus. PMID:25591564

  19. [State of the blood coagulation in glial tumors of the brain].

    PubMed

    Burgman, G P; Kachkov, I A; Vial'tseva, I N; Shcherbakova, G G

    1979-01-01

    The data presented may be of definite value in the prevention of hemorrhage and thrombosis in patients with malignant glial tumors. A malignant glioma may lead to increased activity of the blood coagulation system (BCS). Preoperative staining of the tumor was not attended by marked changes in the BCS and blood viscocity, though a tendency towards an increase in BCS activity according to some of the indices may sometimes be noted. Chemotherapy with nitrosourea and methotrexate was attended by thrombocytopenia but there was practically no changes in the other BCS indices. The postoperative period is usually marked by increased BCS activity according to most of the indices. Increased blood viscocity is often encountered in patients with glial cerebral tumors in the preoperative and postoperative periods, which is evidently due to the intensive dehydration therapy to which they are subjected in marked increase of intracranial pressure. PMID:223352

  20. Acquired coagulant factor VIII deficiency induced by Bacillus anthracis lethal toxin in mice.

    PubMed

    Sun, Der-Shan; Lee, Po-Chien; Kau, Jyh-Hwa; Shih, Yung-Luen; Huang, Hsin-Hsien; Li, Chen-Ru; Lee, Chin-Cheng; Wu, Yu-Ping; Chen, Kuo-Ching; Chang, Hsin-Hou

    2015-01-01

    Mice treated with anthrax lethal toxin (LT) exhibit hemorrhage caused by unknown mechanisms. Moreover, LT treatment in mice induced liver damage. In this study, we hypothesized that a suppressed coagulation function may be associated with liver damage, because the liver is the major producing source of coagulation factors. The hepatic expression of coagulant factors and the survival rates were analyzed after cultured cells or mice were exposed to LT. In agreement with our hypothesis, LT induces cytotoxicity against hepatic cells in vitro. In addition, suppressed expression of coagulation factor VIII (FVIII) in the liver is associated with a prolonged plasma clotting time in LT-treated mice, suggesting a suppressive role of LT in coagulation. Accordingly, we further hypothesized that a loss-of-function approach involving treatments of an anticoagulant should exacerbate LT-induced abnormalities, whereas a gain-of-function approach involving injections of recombinant FVIII to complement the coagulation deficiency should ameliorate the pathogenesis. As expected, a sublethal dose of LT caused mortality in the mice that were non-lethally pretreated with an anticoagulant (warfarin). By contrast, treatments of recombinant FVIII reduced the mortality from a lethal dose of LT in mice. Our results indicated that LT-induced deficiency of FVIII is involved in LT-mediated pathogenesis. Using recombinant FVIII to correct the coagulant defect may enable developing a new strategy to treat anthrax. PMID:25906166

  1. Acquired coagulant factor VIII deficiency induced by Bacillus anthracis lethal toxin in mice

    PubMed Central

    Sun, Der-Shan; Lee, Po-Chien; Kau, Jyh-Hwa; Shih, Yung-Luen; Huang, Hsin-Hsien; Li, Chen-Ru; Lee, Chin-Cheng; Wu, Yu-Ping; Chen, Kuo-Ching; Chang, Hsin-Hou

    2015-01-01

    Mice treated with anthrax lethal toxin (LT) exhibit hemorrhage caused by unknown mechanisms. Moreover, LT treatment in mice induced liver damage. In this study, we hypothesized that a suppressed coagulation function may be associated with liver damage, because the liver is the major producing source of coagulation factors. The hepatic expression of coagulant factors and the survival rates were analyzed after cultured cells or mice were exposed to LT. In agreement with our hypothesis, LT induces cytotoxicity against hepatic cells in vitro. In addition, suppressed expression of coagulation factor VIII (FVIII) in the liver is associated with a prolonged plasma clotting time in LT-treated mice, suggesting a suppressive role of LT in coagulation. Accordingly, we further hypothesized that a loss-of-function approach involving treatments of an anticoagulant should exacerbate LT-induced abnormalities, whereas a gain-of-function approach involving injections of recombinant FVIII to complement the coagulation deficiency should ameliorate the pathogenesis. As expected, a sublethal dose of LT caused mortality in the mice that were non-lethally pretreated with an anticoagulant (warfarin). By contrast, treatments of recombinant FVIII reduced the mortality from a lethal dose of LT in mice. Our results indicated that LT-induced deficiency of FVIII is involved in LT-mediated pathogenesis. Using recombinant FVIII to correct the coagulant defect may enable developing a new strategy to treat anthrax. PMID:25906166

  2. Abnormal factor VIII coagulant antigen in patients with renal dysfunction and in those with disseminated intravascular coagulation.

    PubMed Central

    Weinstein, M J; Chute, L E; Schmitt, G W; Hamburger, R H; Bauer, K A; Troll, J H; Janson, P; Deykin, D

    1985-01-01

    Factor VIII antigen (VIII:CAg) exhibits molecular weight heterogeneity in normal plasma. We have compared the relative quantities of VIII:CAg forms present in normal individuals (n = 22) with VIII:CAg forms in renal dysfunction patients (n = 19) and in patients with disseminated intravascular coagulation (DIC; n = 7). In normal plasma, the predominant VIII: CAg form, detectable by sodium dodecyl sulfate polyacrylamide gel electrophoresis, was of molecular weight 2.4 X 10(5), with minor forms ranging from 8 X 10(4) to 2.6 X 10(5) D. A high proportion of VIII:CAg in renal dysfunction patients, in contrast, was of 1 X 10(5) mol wt. The patients' high 1 X 10(5) mol wt VIII: CAg level correlated with increased concentrations of serum creatinine, F1+2 (a polypeptide released upon prothrombin activation), and with von Willebrand factor. Despite the high proportion of the 1 X 10(5) mol wt VIII:CAg form, which suggests VIII:CAg proteolysis, the ratio of Factor VIII coagulant activity to total VIII:CAg concentration was normal in renal dysfunction patients. These results could be simulated in vitro by thrombin treatment of normal plasma, which yielded similar VIII:CAg gel patterns and Factor VIII coagulant activity to antigen ratios. DIC patients with high F1+2 levels but no evidence of renal dysfunction had an VIII:CAg gel pattern distinct from renal dysfunction patients. DIC patients had elevated concentrations of both the 1 X 10(5) and 8 X 10(4) mol wt VIII:CAg forms. We conclude that an increase in a particular VIII:CAg form correlates with the severity of renal dysfunction. The antigen abnormality may be the result of VIII:CAg proteolysis by a thrombinlike enzyme and/or prolonged retention of proteolyzed VIII:CAg fragments. Images PMID:3932466

  3. The impact of schistosomes and schistosomiasis on murine blood coagulation and fibrinolysis as determined by thromboelastography (TEG).

    PubMed

    Da'dara, Akram A; de Laforcade, Armelle M; Skelly, Patrick J

    2016-05-01

    Schistosomes are parasitic platyhelminths that currently infect over 200 million people and cause the chronic debilitating disease schistosomiasis. While these large intravascular parasites can disturb blood flow, surprisingly they do not appear to provoke thrombus formation around them in vivo. In order to determine if the worms can alter their local environment to impede coagulation, we incubated adult worms (50 pairs) in murine blood (500 µl) for 1 h at 37 °C and, using thromboelastography (TEG), we compared the coagulation profile of the blood with control blood that never contained worms. Substantial differences were apparent between the two profiles. Blood that had been exposed to schistosomes clotted more slowly and yielded relatively poor, though stable, thrombi; all TEG measures of blood coagulation (R, K, α-angle, MA, G and TMA) differed significantly between conditions. No fibrinolysis (as determined by LY30 and LY60 values) was detected in either case. The observed TEG profile suggests that the worms are acting as local anti-coagulants. Blood recovered from schistosome-infected mice, however, does not behave in this way. At an early time point post infection (4-weeks), the TEG profile of infected murine blood is essentially the same as that of control blood. However at a later time point (7-weeks) infected murine blood clots significantly faster than control blood but these clots also break down faster. The R, K, α-angle, and TMA measures of coagulation are all significantly different between the control versus infected mice as are the LY30 and LY60 values. This profile is indicative of a hypercoagulable state with fibrinolysis and is akin to that seen in human patients with advanced schistosomiasis. PMID:26573180

  4. Transfusion and coagulation management in liver transplantation.

    PubMed

    Clevenger, Ben; Mallett, Susan V

    2014-05-28

    There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation. The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently. Allogenic blood products have been shown to increase morbidity and mortality. Primary haemostasis, coagulation and fibrinolysis are altered by liver disease. This, combined with intraoperative disturbances of coagulation, increases the risk of bleeding. Meanwhile, the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis. The application of the principles of patient blood management to transplantation can reduce the risk of transfusion. This includes: preoperative recognition and treatment of anaemia, reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers. The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management. Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis, and rarely, the use of recombinant factor VIIa. Factor concentrates are increasingly used; fibrinogen concentrates to improve clot strength and stability, and prothrombin complex concentrates to improve thrombin generation. Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure. The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion. Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation. PMID:24876736

  5. Coagulation defects associated with massive blood transfusion: A large multicenter study

    PubMed Central

    YANG, JIANG-CUN; SUN, YANG; XU, CUI-XIANG; DANG, QIAN-LI; LI, LING; XU, YONG-GANG; SONG, YAO-JUN; YAN, HONG

    2015-01-01

    The variations in the coagulation indices of patients receiving massive blood transfusion were investigated across 20 large-scale general hospitals in China. The data of 1,601 surgical inpatients receiving massive transfusion were retrospectively collected and the trends in the platelet counts and coagulation indices prior to and at 16 different time points during packed red blood cell (pRBC; after 2–40 units of pRBC) transfusion were evaluated by linear regression analysis. Temporal variations in the means of prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (APTT) and fibrinogen (FIB) concentration were also assessed and the theoretical estimates and actual measurements of the platelet count were compared. The results demonstrated that the platelet count decreased linearly with an increase in the number of pRBC units transfused (Y=150.460−3.041X; R2 linear=0.775). Following transfusion of 18 units of pRBC (0.3 units of pRBC transfused per kilogram of body weight), the average platelet count decreased to 71×109/l (<75×109/l). Furthermore, variations in the means of PT, INR, APTT and FIB did not demonstrate any pronounced trends and actual platelet counts were markedly higher than the theoretical estimates. In conclusion, no variations in the means of traditional coagulation indices were identified, however, the platelet count demonstrated a significant linear decrease with an increase in the number of pRBC units transfused. Furthermore, actual platelet counts were higher than theoretical estimates, indicating the requirement for close monitoring of actual platelet counts during massive pRBC transfusion. PMID:26095897

  6. Reduced Blood Coagulation on Roll-to-Roll, Shrink-Induced Superhydrophobic Plastics.

    PubMed

    Nokes, Jolie M; Liedert, Ralph; Kim, Monica Y; Siddiqui, Ali; Chu, Michael; Lee, Eugene K; Khine, Michelle

    2016-03-01

    The unique antiwetting properties of superhydrophobic (SH) surfaces prevent the adhesion of water and bodily fluids, including blood, urine, and saliva. While typical manufacturable approaches to create SH surfaces rely on chemical and structural modifications, such approaches are expensive, require postprocessing, and are often not biocompatible. By contrast, it is demonstrated that purely structural SH features are easily formed using high throughput roll-to-roll (R2R) manufacturing by shrinking a prestressed thermoplastic with a thin, stiff layer of silver and calcium. These features are subsequently embossed into any commercially available and Food and Drug Administration (FDA)-approved plastic. The R2R SH surfaces have contact angles >150° and contact angle hysteresis <10°. Importantly, the surfaces minimize blood adhesion, leading to reduced blood coagulation without the need for anticoagulants. SH surfaces have >4200× reduction of blood residue area compared to the nonstructured controls of the same material. In addition, blood clotting is reduced >5× using whole blood directly from the patient. Furthermore, these surfaces can be easily configured into 3D shapes, as demonstrated with SH tubes. With the simple scale-up production and the eliminated need for anticoagulants to prevent clotting, the proposed conformable SH surfaces can be impactful for a wide range of medical tools, including catheters and microfluidic channels. PMID:26784916

  7. Disequilibrium of Blood Coagulation and Fibrinolytic System in Patients With Coronary Artery Ectasia

    PubMed Central

    Wu, Wei; Liu, Ruifeng; Chen, Lianfeng; Chen, Houzao; Zhang, Shuyang

    2016-01-01

    Abstract Thrombus formation and myocardial infarction are not uncommon in patients with coronary artery ectasia (CAE). In light of this, the present study aims to systemically evaluate the blood coagulation and fibrinolytic systems in CAE patients. In this study, we enrolled 30 patients with CAE, 30 patients with coronary atherosclerosis disease (CAD), and 29 subjects with normal coronary arteries (control). The coagulation system was evaluated using a routine coagulation function test performed in the hospital laboratory before coronary angiography, and measurements included prothrombin time, international normalized ratio, activated partial thromboplastin time, fibrinogen time, and thrombin time. The evaluation of the fibrinolytic system included measurements of D-dimer, euglobulin lysis time, plasminogen activator inhibitor 1, plasminogen, plasminogen activity assay, α1-antitrypsin (α1-AT), α2 plasmin inhibitor (α2-PI), and α2-macroglobulin (α2-MG). Alpha1-AT, α2-PI, and α2-MG also inhibit activities of 3 neutrophil serine proteases, namely human neutrophil elastase (HNE), cathepsin G (CG), and proteinase 3 (PR3); therefore, the plasma levels of these 3 proteinases were also evaluated. In CAE patients, the circulating coagulation system was normal. For the fibrinolytic system, a decrease of plasminogen activity was observed (P = 0.029) when compared with CAD patients, and the concentrations of α1-AT (both P < 0.001), α2-PI (P = 0.002 and P = 0.025), and α2-MG (P = 0.034 and P < 0.001) were significantly elevated when compared with CAD patients and normal controls. Moreover, the plasma levels of HNE (both P < 0.001) and CG (P = 0.027 and 0.016) in CAE patients were also significantly higher than those of the CAD and control groups. There was no difference in plasma PR3 concentration among these 3 groups. Disequilibrium of the coagulation/fibrinolytic system may contribute to thrombus formation and clinical coronary

  8. Duvernoy's gland secretion of Philodryas patagoniensis from the northeast of Argentina: its effects on blood coagulation.

    PubMed

    Peichoto, M E; Leiva, L C; Guaimás Moya, L E; Rey, L; Acosta, O

    2005-03-15

    Duvernoy's gland secretion of Philodryas patagoniensis exhibits high hemorrhagic activity, containing enzymes that are able to degrade the vascular wall. In this work we aim to determine if the secretion can also affect the hemostatic system by causing changes in blood coagulation. Procoagulant and coagulant activities were evaluated on plasma and fibrinogen, respectively. The delay in the thrombin clotting time of fibrinogen previously incubated with the secretion was also determined. Specific hydrolysis of fibrinogen and fibrin incubated with the secretion at different time intervals was shown by electrophoresis on polyacrylamide gel. To determine the structural characteristics of the enzymes degrading fibrinogen and fibrin, secretion were incubated in the presence of 45 mM Na(2)EDTA, 40 mM Benzamidine, and/or 2 mM PMSF before the incubation with fibrinogen or fibrin, respectively. The effect in vivo was investigated in adult male rats injected with different dose of secretion, aliquots of blood were withdrawn at different time intervals, and the fibrinogen concentration was determined. Duvernoy's gland secretion of P. patagoniensis did not clot plasma or fibrinogen. It exhibited a potent fibrinogenolytic activity degrading the Aalpha-chain faster than the Bbeta-chain, whereas gamma-chain was resistant. This latter corresponded with a strong delay in the thrombin clotting time of fibrinogen (4 mg/ml) pre-incubated with the secretion, being 9.53 microg the amount of protein from Duvernoy's gland secretion that increased the thrombin clotting time from 20 to 60 s. In vivo, the loss of rat plasma fibrinogen was proportional to the amount of secretion injected. The secretion also hydrolyzed fibrin degrading the alpha-monomer. Inhibition studies with Na(2)EDTA, Benzamidine, and/or PMSF showed that metalloproteinases and serinoproteinases are the main enzymes responsible for the hydrolyzing activity on fibrinogen and fibrin. All these results demonstrate that Duvernoy

  9. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    SciTech Connect

    Ogami, M; Kulkarni, R; Wang, H; Reif, R; Wang, R K

    2014-08-31

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing. (laser biophotonics)

  10. Laser speckle contrast imaging of skin blood perfusion responses induced by laser coagulation

    NASA Astrophysics Data System (ADS)

    Ogami, M.; Kulkarni, R.; Wang, H.; Reif, R.; Wang, R. K.

    2014-08-01

    We report application of laser speckle contrast imaging (LSCI), i.e., a fast imaging technique utilising backscattered light to distinguish such moving objects as red blood cells from such stationary objects as surrounding tissue, to localise skin injury. This imaging technique provides detailed information about the acute perfusion response after a blood vessel is occluded. In this study, a mouse ear model is used and pulsed laser coagulation serves as the method of occlusion. We have found that the downstream blood vessels lacked blood flow due to occlusion at the target site immediately after injury. Relative flow changes in nearby collaterals and anastomotic vessels have been approximated based on differences in intensity in the nearby collaterals and anastomoses. We have also estimated the density of the affected downstream vessels. Laser speckle contrast imaging is shown to be used for highresolution and fast-speed imaging for the skin microvasculature. It also allows direct visualisation of the blood perfusion response to injury, which may provide novel insights to the field of cutaneous wound healing.

  11. Acute effects of calcium supplements on blood pressure and blood coagulation: secondary analysis of a randomised controlled trial in post-menopausal women.

    PubMed

    Bristow, Sarah M; Gamble, Greg D; Stewart, Angela; Horne, Anne M; Reid, Ian R

    2015-12-14

    Recent evidence suggests that Ca supplements increase the risk of cardiovascular events, but the mechanism(s) by which this occurs is uncertain. In a study primarily assessing the effects of various Ca supplements on blood Ca levels, we also investigated the effects of Ca supplements on blood pressure and their acute effects on blood coagulation. We randomised 100 post-menopausal women to 1 g/d of Ca or a placebo containing no Ca. Blood pressure was measured at baseline and every 2 h up to 8 h after their first dose and after 3 months of supplementation. Blood coagulation was measured by thromboelastography (TEG) in a subgroup of participants (n 40) up to 8 h only. Blood pressure declined over 8 h in both the groups, consistent with its normal diurnal rhythm. The reduction in systolic blood pressure was smaller in the Ca group compared with the control group by >5 mmHg between 2 and 6 h (P≤0·02), and the reduction in diastolic blood pressure was smaller at 2 h (between-groups difference 4·5 mmHg, P=0·004). Blood coagulability, assessed by TEG, increased from baseline over 8 h in the calcium citrate and control groups. At 4 h, the increase in the coagulation index was greater in the calcium citrate group compared with the control group (P=0·03), which appeared to be due to a greater reduction in the time to clot initiation. These data suggest that Ca supplements may acutely influence blood pressure and blood coagulation. Further investigation of this possibility is required. PMID:26420590

  12. Blood coagulation protein fibrinogen promotes autoimmunity and demyelination via chemokine release and antigen presentation

    PubMed Central

    Ryu, Jae Kyu; Petersen, Mark A.; Murray, Sara G.; Baeten, Kim M.; Meyer-Franke, Anke; Chan, Justin P.; Vagena, Eirini; Bedard, Catherine; Machado, Michael R.; Coronado, Pamela E. Rios; Prod'homme, Thomas; Charo, Israel F.; Lassmann, Hans; Degen, Jay L.; Zamvil, Scott S.; Akassoglou, Katerina

    2015-01-01

    Autoimmunity and macrophage recruitment into the central nervous system (CNS) are critical determinants of neuroinflammatory diseases. However, the mechanisms that drive immunological responses targeted to the CNS remain largely unknown. Here we show that fibrinogen, a central blood coagulation protein deposited in the CNS after blood–brain barrier disruption, induces encephalitogenic adaptive immune responses and peripheral macrophage recruitment into the CNS leading to demyelination. Fibrinogen stimulates a unique transcriptional signature in CD11b+ antigen-presenting cells inducing the recruitment and local CNS activation of myelin antigen-specific Th1 cells. Fibrinogen depletion reduces Th1 cells in the multiple sclerosis model, experimental autoimmune encephalomyelitis. Major histocompatibility complex (MHC) II-dependent antigen presentation, CXCL10- and CCL2-mediated recruitment of T cells and macrophages, respectively, are required for fibrinogen-induced encephalomyelitis. Inhibition of the fibrinogen receptor CD11b/CD18 protects from all immune and neuropathologic effects. Our results show that the final product of the coagulation cascade is a key determinant of CNS autoimmunity. PMID:26353940

  13. Mitogenic effects of coagulation factor XII and factor XIIa on HepG2 cells

    SciTech Connect

    Schmeidler-Sapiro, K.T.; Gordon, E.M. ); Ratnoff, O.D. )

    1991-05-15

    The structure of coagulation factor XII (Hageman factor), inferred from its DNA sequence, includes two epidermal growth factor (EGF)-homologous domains in its amino-terminal region. This suggests that factor XII may exhibit EGF-like activities. Reciprocal antigenic cross-reactivity between factor XII and EGF was shown by exposing purified human factor XII or mouse EGF to anti-mouse EGF or anti-human factor XII. Western blot analysis showed that anti-mouse EGF recognized intact factor XII at 80 kDa. Together, these results suggest that the EGF-homologous domains are accessible for anti-EGF binding in native factor XII. To determine whether factor XII has mitogenic activity, HepG2 or L cells (10{sup 4} cells per well) were grown in serum-free medium in the presence or absence of factor XII or kaolin-activated factor XII (factor XIIa). Both factors XII and XIIa (6.0 {mu}g/ml) enhanced cell proliferation. Various doses of factor XII enhanced cell proliferation, ({sup 3}H)thymidine incorporation, and ({sup 3}H)leucine incorporation in HepG2 cells cultured under the same conditions. These data indicate that factor XII, like EGF, is a mitogen for HepG2 cells and suggest a possible autocrine role in the liver.

  14. Tissue factor is induced by interleukin-33 in human endothelial cells: a new link between coagulation and inflammation

    PubMed Central

    Stojkovic, Stefan; Kaun, Christoph; Basilio, Jose; Rauscher, Sabine; Hell, Lena; Krychtiuk, Konstantin A.; Bonstingl, Cornelia; de Martin, Rainer; Gröger, Marion; Ay, Cihan; Holnthoner, Wolfgang; Eppel, Wolfgang; Neumayer, Christoph; Huk, Ihor; Huber, Kurt; Demyanets, Svitlana; Wojta, Johann

    2016-01-01

    Tissue factor (TF) is the primary trigger of coagulation. Elevated levels of TF are found in atherosclerotic plaques, and TF leads to thrombus formation when released upon plaque rupture. Interleukin (IL)-33 was previously shown to induce angiogenesis and inflammatory activation of endothelial cells (ECs). Here, we investigated the impact of IL-33 on TF in human ECs, as a possible new link between inflammation and coagulation. IL-33 induced TF mRNA and protein in human umbilical vein ECs and coronary artery ECs. IL-33-induced TF expression was ST2- and NF-κB-dependent, but IL-1-independent. IL-33 also increased cell surface TF activity in ECs and TF activity in ECs-derived microparticles. IL-33-treated ECs reduced coagulation time of whole blood and plasma but not of factor VII-deficient plasma. In human carotid atherosclerotic plaques (n = 57), TF mRNA positively correlated with IL-33 mRNA expression (r = 0.691, p < 0.001). In this tissue, IL-33 and TF protein was detected in ECs and smooth muscle cells by immunofluorescence. Furthermore, IL-33 and TF protein co-localized at the site of clot formation within microvessels in plaques of patients with symptomatic carotid stenosis. Through induction of TF in ECs, IL-33 could enhance their thrombotic capacity and thereby might impact on thrombus formation in the setting of atherosclerosis. PMID:27142573

  15. Tissue factor is induced by interleukin-33 in human endothelial cells: a new link between coagulation and inflammation.

    PubMed

    Stojkovic, Stefan; Kaun, Christoph; Basilio, Jose; Rauscher, Sabine; Hell, Lena; Krychtiuk, Konstantin A; Bonstingl, Cornelia; de Martin, Rainer; Gröger, Marion; Ay, Cihan; Holnthoner, Wolfgang; Eppel, Wolfgang; Neumayer, Christoph; Huk, Ihor; Huber, Kurt; Demyanets, Svitlana; Wojta, Johann

    2016-01-01

    Tissue factor (TF) is the primary trigger of coagulation. Elevated levels of TF are found in atherosclerotic plaques, and TF leads to thrombus formation when released upon plaque rupture. Interleukin (IL)-33 was previously shown to induce angiogenesis and inflammatory activation of endothelial cells (ECs). Here, we investigated the impact of IL-33 on TF in human ECs, as a possible new link between inflammation and coagulation. IL-33 induced TF mRNA and protein in human umbilical vein ECs and coronary artery ECs. IL-33-induced TF expression was ST2- and NF-κB-dependent, but IL-1-independent. IL-33 also increased cell surface TF activity in ECs and TF activity in ECs-derived microparticles. IL-33-treated ECs reduced coagulation time of whole blood and plasma but not of factor VII-deficient plasma. In human carotid atherosclerotic plaques (n = 57), TF mRNA positively correlated with IL-33 mRNA expression (r = 0.691, p < 0.001). In this tissue, IL-33 and TF protein was detected in ECs and smooth muscle cells by immunofluorescence. Furthermore, IL-33 and TF protein co-localized at the site of clot formation within microvessels in plaques of patients with symptomatic carotid stenosis. Through induction of TF in ECs, IL-33 could enhance their thrombotic capacity and thereby might impact on thrombus formation in the setting of atherosclerosis. PMID:27142573

  16. Removal of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from water by coagulation: mechanisms and influencing factors.

    PubMed

    Bao, Yueping; Niu, Junfeng; Xu, Zesheng; Gao, Ding; Shi, Jianghong; Sun, Xiaomin; Huang, Qingguo

    2014-11-15

    In this study, alum (Al2(SO4)3⋅18H2O), ferric chloride (FeCl3⋅6H2O) and polyaluminium chloride (PACl) were used to remove perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) from water. The influencing factors, including pH and natural organic matter (NOM), were investigated. A positive correlation was found between the size of the flocs and the removal efficiency of PFOX (X=S and A). The removal ratios of PFOS and PFOA were 32% and ∼12%, respectively, when 50 mg/L of FeCl3⋅6H2O was added as the coagulant at the initial pH. Coagulation achieved high removal ratios for PFOX under acidic conditions (∼47.6% and 94.7% for PFOA and PFOS at pH 4, respectively). In addition, increasing NOM concentrations decreased the removal rates of PFOX because of the existence of competitive adsorption between NOM molecules and PFOX on the surface of the coagulants and flocs. The combination of adsorption by powdered activated carbon (PAC) and coagulation increased the removal ratios up to >90% for PFOX at the initial concentration of 1mg/L, implying that the adsorption enhanced coagulation. Meantime, the experiments with natural water showed that coagulation is a feasible method to remove PFOS and PFOA from surface water. PMID:25168583

  17. Short-term Effects of Air Temperature on Blood Markers of Coagulation and Inflammation in Potentially Susceptible Individuals

    EPA Science Inventory

    Objectives: Changes in air temperature are associated with an increase in cardiovascular events, but the role of pro-coagulant and pro-inflammatory blood markers is still poorly understood. We investigated the association between air temperature and fibrinogen, plasminogen act...

  18. Differential Kinetics of Coagulation Factors and Natural Anticoagulants in Patients with Liver Cirrhosis: Potential Clinical Implications

    PubMed Central

    Tischendorf, Michael; Miesbach, Wolfgang; Chattah, Umer; Chattah, Zenab; Maier, Sebastian; Welsch, Christoph; Zeuzem, Stefan; Lange, Christian M.

    2016-01-01

    Background Advanced liver diseases are associated with profound alterations of the coagulation system increasing the risk not only of bleeding, but also of thromboembolic complications. A recent milestone study has shown that prophylactic anticoagulation in liver cirrhosis patients results in a reduced frequency of hepatic decompensation. Yet, INR measurement, one of the most widely applied tests to assess liver function, only inaccurately predicts the risk of hepatic decompensation related to alterations of the coagulation system. To assess the relationship between selected coagulation factors / natural anticoagulants with INR, MELD score, and hepatic decompensation, we performed the present pilot study. A total number of 92 patients with various stages of liver cirrhosis were included and prospectively followed for at least 6 months. We found that important natural anticoagulants, namely antithrombin and protein C, as well as factor XI (which may also serve as an anticoagulant) decreased earlier and by a larger magnitude than one would expect from classical coagulation test results. The correlation between these factors and INR was only moderate. Importantly, reduced plasma activities of natural anticoagulants but not INR or MELD score were independent predictors of hepatic encephalopathy (P = 0.013 and 0.003 for antithrombin and protein C, respectively). Conclusion In patients with liver cirrhosis plasma activities of several natural anticoagulants are earlier and stronger affected than routine coagulation tests. Reduced activities of natural anticoagulants may be predictive for the development of hepatic encephalopathy. PMID:27171213

  19. Impact of experimental haemodilution on platelet function, thrombin generation and clot firmness: effects of different coagulation factor concentrates

    PubMed Central

    Caballo, Carolina; Escolar, Gines; Diaz-Ricart, Maribel; Lopez-Vílchez, Irene; Lozano, Miguel; Cid, Joan; Pino, Marcos; Beltrán, Joan; Basora, Misericordia; Pereira, Arturo; Galan, Ana M.

    2013-01-01

    Background Haemodilution during resuscitation after massive haemorrhage may worsen the coagulopathy and perpetuate bleeding. Materials and methods Blood samples from healthy donors were diluted (30 and-60%) using crystalloids (saline, Ringer’s lactate, PlasmalyteTM) or colloids (6% hydroxyethylstarch [HES130/0.4], 5% human albumin, and gelatin). The effects of haemodilution on platelet adhesion (Impact R), thrombin generation (TG), and thromboelastometry (TEM) parameters were analysed as were the effects of fibrinogen, prothrombin complex concentrates (PCC), activated recombinant factor VII (FVIIa), and cryoprecipates on haemodilution. Results Platelet interactions was already significantly reduced at 30% haemodilution. Platelet reactivity was not improved by addition of any of the concentrates tested. A decrease in TG and marked alterations of TEM parameters were noted at 60% haemodilution. HES130/0.4 was the expander with the most deleterious action. TG was significantly enhanced by PCC whereas rFVIIa only caused a mild acceleration of TG initiation. Fibrinogen restored the alterations of TEM parameters caused by haemodilution including those caused by HES 130/0.4. Cryoprecipitates significantly improved the alterations caused by haemodilution on TG and TEM parameters; the effects on TG disappeared after ultracentrifugation of the cryoprecipitates. Discussion The haemostatic alterations caused by haemodilution are multifactorial and affect both blood cells and coagulation. In our in vitro approach, HES 130/0.4 had the most deleterious effect on haemostasis parameters. Coagulation factor concentrates did not improve platelet interactions in the Impact R, but did have favourable effects on coagulation parameters measured by TG and TEM. Fibrinogen notably improved TEM parameters without increasing thrombin generation, suggesting that this concentrate may help to preserve blood clotting abilities during haemodilution without enhancing the prothrombotic risk. PMID

  20. Preparation, blood coagulation and cell compatibility evaluation of chitosan-graft-polylactide copolymers.

    PubMed

    Wang, Qi; Liu, Pei; Liu, Peifeng; Gong, Tao; Li, Suming; Duan, Yourong; Zhang, Zhirong

    2014-02-01

    Biodegradable chitosan-graft-polylactide (PLA-CS) copolymers were prepared by the grafting of a poly(L-lactide) (PLLA) or poly(D-lactide) (PDLA) precursor to the backbone of chitosan using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC ⋅ HCl) and N-hydroxysuccinimide (NHS) as a coupling agent. The blood and cell compatibility of the graft copolymers were investigated in comparison to PLLA and PDLA homopolymers. The coagulation properties of PLA-CS were evaluated by hemolysis, plasma recalcification, dynamic blood clotting and protein absorption assays. PLA-CS copolymers present similar hemolysis ratio and plasma recalcification time as PLA, but slower dynamic blood clotting and lower protein absorption. The cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), agar diffusion and lactate dehydrogenase (LDH) experiments. All the samples presented no effect on the viability to cells. Inflammatory cytokine analysis using sandwich ELISAs revealed that PLA-CS would not stimulate inflammatory activity. PMID:24448591

  1. Expression of Functional Human Coagulation Factor XIII A-domain in Plant Cell Suspensions and Whole Plants

    SciTech Connect

    Gao, Johnway; Hooker, Brian S.; Anderson, Daniel B.

    2004-09-01

    Coagulation factor XIII, a zymogen present in blood as a tetramer (A2B2) of A- and B-domains, is one of the components of many ''wound sealants'' which are proposed for use or currently in use as effective hemostatic agents, sealants and tissue adhesives in surgery. After activation by ?-thrombin cleavage, coagulation factor XIII A-domain, a transglutaminase, is formed and catalyzes the covalent crosslinking of the ?- and ?-chains of linear fibrin to form homopolymers, which can quickly stop bleeding. We have successfully expressed the A-domain of factor XIII in both plant cell cultures and whole plants. Transgenic plant cell culture allows a rapid method for testing production feasibility while expression in whole plants demonstrates an economic production system for recombinant human plasma-based proteins. The expressed factor XIII A-domain had a similar size as that of human plasma-derived factor XIII. Crude plant extract containing recombinant factor XIII A-domain showed transglutaminase activity with monodansylcadaverine and casein as substrates and crosslinking activity in the presence of linear fibrin. The expression of factor XIII A-domain was not affected by plant leaf position.

  2. Monitoring time course of human whole blood coagulation using a microfluidic dielectric sensor with a 3D capacitive structure.

    PubMed

    Maji, Debnath; Suster, Michael A; Stavrou, Evi; Gurkan, Umut A; Mohseni, Pedram

    2015-08-01

    This paper reports on the design, fabrication, and testing of a microfluidic sensor for dielectric spectroscopy (DS) of human whole blood during coagulation. The sensor employs a three-dimensional (3D), parallel-plate, capacitive sensing structure with a floating electrode integrated into a microfluidic channel. Using an impedance analyzer and after a 5-point calibration, the sensor is shown to measure the real part of complex relative dielectric permittivity of human whole blood in a frequency range of 10kHz to 100MHz. The temporal variation of dielectric permittivity at 1MHz for human whole blood from three different healthy donors shows a peak in permittivity at ~ 4 to 5 minutes, which also corresponds to the onset of CaCl2-initiated coagulation of the blood sample verified visually. PMID:26737635

  3. Post-traumatic immunosuppression is reversed by anti-coagulated salvaged blood transfusion: deductions from studying immune status after knee arthroplasty

    PubMed Central

    Islam, N; Whitehouse, M; Mehendale, S; Hall, M; Tierney, J; O'Connell, E; Blom, A; Bannister,, G; Hinde, J; Ceredig, R; Bradley, B A

    2014-01-01

    Major trauma increases vulnerability to systemic infections due to poorly defined immunosuppressive mechanisms. It confers no evolutionary advantage. Our objective was to develop better biomarkers of post-traumatic immunosuppression (PTI) and to extend our observation that PTI was reversed by anti-coagulated salvaged blood transfusion, in the knowledge that others have shown that non-anti-coagulated (fibrinolysed) salvaged blood was immunosuppressive. A prospective non-randomized cohort study of patients undergoing primary total knee arthroplasty included 25 who received salvaged blood transfusions collected post-operatively into acid–citrate–dextrose anti-coagulant (ASBT cohort), and 18 non-transfused patients (NSBT cohort). Biomarkers of sterile trauma included haematological values, damage-associated molecular patterns (DAMPs), cytokines and chemokines. Salvaged blood was analysed within 1 and 6 h after commencing collection. Biomarkers were expressed as fold-changes over preoperative values. Certain biomarkers of sterile trauma were common to all 43 patients, including supranormal levels of: interleukin (IL)-6, IL-1-receptor-antagonist, IL-8, heat shock protein-70 and calgranulin-S100-A8/9. Other proinflammatory biomarkers which were subnormal in NSBT became supranormal in ASBT patients, including IL-1β, IL-2, IL-17A, interferon (IFN)-γ, tumour necrosis factor (TNF)-α and annexin-A2. Furthermore, ASBT exhibited subnormal levels of anti-inflammatory biomarkers: IL-4, IL-5, IL-10 and IL-13. Salvaged blood analyses revealed sustained high levels of IL-9, IL-10 and certain DAMPs, including calgranulin-S100-A8/9, alpha-defensin and heat shock proteins 27, 60 and 70. Active synthesis during salvaged blood collection yielded increasingly elevated levels of annexin-A2, IL-1β, Il-1-receptor-antagonist, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-17A, IFN-γ, TNF-α, transforming growth factor (TGF)-β1, monocyte chemotactic protein-1 and macrophage inflammatory

  4. The Effects of Exogenous Administration of Human Coagulation Factors Following Pig-to-Baboon Liver Xenotransplantation.

    PubMed

    Navarro-Alvarez, N; Shah, J A; Zhu, A; Ligocka, J; Yeh, H; Elias, N; Rosales, I; Colvin, R; Cosimi, A B; Markmann, J F; Hertl, M; Sachs, D H; Vagefi, P A

    2016-06-01

    We sought to determine the effects of exogenous administration of human coagulation factors following pig-to-baboon liver xenotransplantation (LXT) using GalT-KO swine donors. After LXT, baboons received no coagulation factors (historical control, n = 1), bolus administration of a human prothrombin concentrate complex (hPCC; 2.5 mL/kg, n = 2), continuous infusion of hPCC (1.0 mL/h, n = 1) or continuous infusion of human recombinant factor VIIa (1 µg/kg per hour, n = 3). The historical control recipient demonstrated persistent thrombocytopenia despite platelet administration after transplant, along with widespread thrombotic microangiopathy (TMA). In contrast, platelet levels were maintained in bolus hPCC recipients; however, these animals quickly developed large-vessel thrombosis and TMA, leading to graft failure with shortened survival. Recipients of continuous coagulation factor administration experienced either stabilization or an increase in their circulating platelets with escalating doses. Furthermore, transfusion requirements were decreased, and hepatic TMA was noticeably absent in recipients of continuous coagulation factor infusions compared with the historical control and bolus hPCC recipients. This effect was most profound with a continuous, escalating dose of factor VIIa. Further studies are warranted because this regimen may allow for prolonged survival following LXT. PMID:26613235

  5. Coagulation factors and recurrence of ischemic and bleeding adverse events in patients with acute coronary syndromes.

    PubMed

    Campo, Gianluca; Pavasini, Rita; Pollina, Alberto; Tebaldi, Matteo; Ferrari, Roberto

    2013-08-01

    In the last years, management and prognosis of patients with acute coronary syndromes (ACS) are significantly improved. Nowadays antithrombotic (antiplatelet plus anticoagulant drugs) therapy represents the main treatment of ACS patients. Anticoagulant drugs are particularly helpful in the acute phase of ACS, whereas in the chronic phase are maintained only in selected cases. Many studies demonstrate that exists a significant variability in the coagulation factor levels between patients affected by ACS. This variation on coagulation factors levels is due to environmental (smoking, inflammation, sex, oral contraceptive, triglycerides, diabetes mellitus) and genetic determinants. Particularly several gene polymorphisms have been selected and clearly associated with significant variations in the coagulation factors values. The heightened levels of tissue factor, factor VII and fibrinogen are related with a "hypercoagulable status" and with a higher occurrence of ischemic complications after ACS and/or PCI. On the contrary, less data are available regarding the relationship between coagulation factors levels (or their gene polymorphisms) and bleeding complications. Recently, new anticoagulant drugs have been developed. They show less side effects and a better tolerability and, probably, their selected use in patients with a "hypercoagulable status" may improve the clinical outcome after ACS. In this review we analyze the current available data and we discuss how this finding may be useful for planning future studies to optimize the treatment of ACS patients. PMID:23827698

  6. Factors influencing occurrence of postpartum haemorrhage in pregnant women with hepatitis E infection and deranged coagulation profile

    PubMed Central

    Puri, Manju; Patra, Sharda; Singh, Preeti; Malhotra, Nidhi; Trivedi, Shubha Sagar; Sharma, Sunita; Kumar, Ashish; Sarin, Shiv Kumar

    2011-01-01

    Coagulopathy is an important complication associated with hepatitis E virus (HEV) infection in pregnant women. Postpartum haemorrhage (PPH) remains a serious risk while managing the labour of these women. The aim of this paper is to study the factors influencing the occurrence of PPH in pregnant women with hepatitis E infection with coagulopathy. The labours of 38 pregnant women with hepatitis E and deranged coagulation profile were followed. Factors that may predict postpartum bleeding complications in women with HEV infection and deranged coagulation profile were statistically analysed. Of 38 pregnant women with acute viral hepatitis due to HEV, 13 (34%) suffered a PPH while 25 (66%) did not. On univariate analysis low alanine aminotransferase (P = 0.016), high international normalized ratio (P = 0.003), high levels of d-dimer (P = 0.008), presence of hepatic encephalopathy (P = 0.028), intrauterine fetal death (P = 0.001) and gastrointestinal bleeding (P = 0.004) were found to predict PPH. However, on multivariate analysis the only independent variable that predicted PPH was the presence gastrointestinal (GI) bleeding (odds ratio [OR] 11.363; 95% CI: 1.003, 125; P = 0.050). Women with GI bleeding have 11 times higher risk of PPH than those without a GI bleed; however, the confidence interval is very wide. Administration of fresh frozen plasma in the peripartum period reduces the risk of PPH. In conclusion, early recognition of factors which predict the risk of PPH and timely intervention with judicious use of blood and blood components in the peripartum period can improve the outcome of pregnant women with HEV infection with deranged coagulation.

  7. The Coagulative Profile of Cyanotic Children Undergoing Cardiac Surgery: The Role of Whole Blood Preoperative Thromboelastometry on Postoperative Transfusion Requirement.

    PubMed

    Vida, Vladimiro L; Spiezia, Luca; Bortolussi, Giacomo; Marchetti, Marta E; Campello, Elena; Pittarello, Demetrio; Gregori, Dario; Stellin, Giovanni; Simioni, Paolo

    2016-07-01

    The objective of this study is to evaluate the preoperative coagulation pattern and its association to postoperative blood products transfusion in children with congenital heart disease (CHD), focusing on cyanotic patients (oxygen saturation, SATO 2  < 85%). From January to August 2014, preoperative standard coagulation tests and rotational thromboelastometry assays were performed on 81 pediatric patients (<16 years old) who underwent surgery for CHD with the aid of cardiopulmonary bypass. Sixty patients (74%) were acyanotic and 21 (26%) cyanotic. Mean age at time of surgery was 7.9 months (interquartile range 2.9-43.6 months). Cyanotic patients had a significantly higher hematocrit (P < 0.001), a reduced prothrombin activity (PT) (P = 0.01) level, and a lower platelet count (P = 0.02) than acyanotic patients. An inverse linear association was found between patient's SATO2 and clot formation time (CFT) (INTEM, P = 0.001, and EXTEM, P < 0.0001). A direct linear association was found between patient's SATO2 and maximum clot firmness (MCF) (INTEM, P = 0.04, and EXTEM, P = 0.05). Preoperative cyanosis was also associated with a lower median MCF in FIBTEM (P = 0.02). Cyanotic patients required more frequent postoperative transfusions of fibrinogen (7/21 patients, 33% vs. 4/60 patients, 6.7%, P = 0.01) and fresh frozen plasma (14/21, 67% vs. 25/60, 42%, P = 0.08). Patients with a lower presurgery PT and platelet count subsequently required more fibrinogen transfusion P = 0.02 and P = 0.003, respectively); the same goes for patients with a longer CFT (INTEM, P = 0.01 and EXTEM, P = 0.03) and a reduced MCF (INTEM, P = 0.02 and FIBTEM, P = 0.01) as well. Cyanotic patients showed significant preoperative coagulation anomalies and required a higher postoperative fibrinogen supplementation. The preoperative MCF FIBTEM has become an important factor in our postoperative thromboelastometry-guided transfusion

  8. The relevance of coagulation factor X protection of adenoviruses in human sera

    PubMed Central

    Duffy, M R; Doszpoly, A; Turner, G; Nicklin, S A; Baker, A H

    2016-01-01

    Intravenous delivery of adenoviruses is the optimal route for many gene therapy applications. Once in the blood, coagulation factor X (FX) binds to the adenovirus capsid and protects the virion from natural antibody and classical complement-mediated neutralisation in mice. However, to date, no studies have examined the relevance of this FX/viral immune protective mechanism in human samples. In this study, we assessed the effects of blocking FX on adenovirus type 5 (Ad5) activity in the presence of human serum. FX prevented human IgM binding directly to the virus. In individual human sera samples (n=25), approximately half of those screened inhibited adenovirus transduction only when the Ad5–FX interaction was blocked, demonstrating that FX protected the virus from neutralising components in a large proportion of human sera. In contrast, the remainder of sera tested had no inhibitory effects on Ad5 transduction and FX armament was not required for effective gene transfer. In human sera in which FX had a protective role, Ad5 induced lower levels of complement activation in the presence of FX. We therefore demonstrate for the first time the importance of Ad–FX protection in human samples and highlight subject variability and species-specific differences as key considerations for adenoviral gene therapy. PMID:27014840

  9. Cryo-electron microscopy of coagulation Factor VIII bound to lipid nanotubes

    SciTech Connect

    Parmenter, Christopher D.J.; Cane, Matthew C.; Zhang Rui; Stoilova-McPhie, Svetla

    2008-02-08

    Factor VIII (FVIII) is a key protein in blood coagulation, deficiency or malfunction of which causes Haemophilia A. The sole cure for this condition is intravenous administration of FVIII, whose membrane-bound structure we have studied by Cryo-electron microscopy and image analysis. Self-assembled lipid nanotubes were optimised to bind FVIII at close to native conditions. The tubes diameter was constant at 30 nm and the lipid bilayer resolved. The FVIII molecules were well defined, forming an 8.5 nm thick outer layer, and appeared to reach the hydrophobic core of the bilayer. The two known FVIII atomic models were superimposed with the averaged 2D protein densities. The insertion of the FVIII within the membrane was evaluated, reaffirming that the membrane-binding C2 or C1-C2 domain(s) fully penetrate the outer leaflet of the lipid layer. The presented results lay the basis for new models of the FVIII overall orientation and membrane-binding mechanism.

  10. EspP, an Extracellular Serine Protease from Enterohemorrhagic E. coli, Reduces Coagulation Factor Activities, Reduces Clot Strength, and Promotes Clot Lysis

    PubMed Central

    Rand, Margaret L.; Mian, Hira S.; Brnjac, Elena; Sandercock, Linda E.; Akula, Indira; Julien, Jean-Philippe; Pai, Emil F.; Chesney, Alden E.

    2016-01-01

    Background EspP (E. coli secreted serine protease, large plasmid encoded) is an extracellular serine protease produced by enterohemorrhagic E. coli (EHEC) O157:H7, a causative agent of diarrhea-associated Hemolytic Uremic Syndrome (D+HUS). The mechanism by which EHEC induces D+HUS has not been fully elucidated. Objectives We investigated the effects of EspP on clot formation and lysis in human blood. Methods Human whole blood and plasma were incubated with EspPWT at various concentrations and sampled at various time points. Thrombin time (TT), prothrombin time (PT), and activated partial thromboplastin time (aPTT), coagulation factor activities, and thrombelastgraphy (TEG) were measured. Results and Conclusions Human whole blood or plasma incubated with EspPWT was found to have prolonged PT, aPTT, and TT. Furthermore, human whole blood or plasma incubated with EspPWT had reduced activities of coagulation factors V, VII, VIII, and XII, as well as prothrombin. EspP did not alter the activities of coagulation factors IX, X, or XI. When analyzed by whole blood TEG, EspP decreased the maximum amplitude of the clot, and increased the clot lysis. Our results indicate that EspP alters hemostasis in vitro by decreasing the activities of coagulation factors V, VII, VIII, and XII, and of prothrombin, by reducing the clot strength and accelerating fibrinolysis, and provide further evidence of a functional role for this protease in the virulence of EHEC and the development of D+HUS. PMID:26934472

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

    PubMed Central

    Zolfagharian, Hossein; Mohajeri, Mohammad; Babaie, Mahdi

    2015-01-01

    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. PMID:26998384

  12. Effects of the new glycopeptide antibiotic teicoplanin on platelet function and blood coagulation.

    PubMed Central

    Agnelli, G; Longetti, M; Guerciolini, R; Menichetti, F; Grasselli, S; Boldrini, F; Bucaneve, G; Nenci, G G; Del Favero, A

    1987-01-01

    Teicoplanin, a new glycopeptide antibiotic, is structurally related to ristocetin, an antibiotic known to induce human platelet agglutination and, thus, thrombocytopenia and thromboembolic side effects. The aim of this study was to evaluate the effects of teicoplanin on platelet function in vitro and ex vivo and on blood coagulation ex vivo. In the in vitro studies, spontaneous platelet aggregation; platelet aggregation induced by ADP, collagen, and ristocetin; and the release of beta-thromboglobulin from platelets were assessed. Platelets from healthy subjects were incubated with teicoplanin at final concentrations of 100, 1,500, 5,000, and 10,000 micrograms/ml. The maximal achievable concentration with therapeutic doses is 100 micrograms/ml. When compared with saline, teicoplanin at concentrations of 100 and 1,500 micrograms/ml had no effect on platelet function, but at concentrations of 5,000 and 10,000 micrograms/ml, it induced greater spontaneous platelet aggregation (P less than 0.01) and inhibited platelet aggregation induced by ADP, collagen, and ristocetin (P less than 0.01). Teicoplanin at concentrations of 100, 1,500, and 5,000 micrograms/ml did not induce the release of beta-thromboglobulin, in contrast to teicoplanin at a concentration of 10,000 micrograms/ml and ristocetin at a concentration of 1.5 mg/ml (P less than 0.01). In the ex vivo studies, platelet count, bleeding time, plasma beta-thromboglobulin, platelet aggregation induced by ADP, ristocetin, and epinephrine, activated partial thromboplastin time, prothrombin time, thrombin clotting time, and serum fibrinogen degradation products were evaluated at days 0, 3, and 6 and at 72 h after the end of therapy. All subjects completed the study without evidence of side effects. When compared with the pretreatment values, none of the values from these assays showed a significant change at any time during and after treatment. We concluded that platelet function and blood coagulation are not affected by

  13. Novel pathway of iron‑induced blood coagulation: implications for diabetes mellitus and its complications.

    PubMed

    Lipinski, Boguslaw; Pretorius, Etheresia

    2012-01-01

    Fibrinogen (FBG) is a high-molecular-weight protein and precursor to the enzymatically formed fibrin. It has been recently discovered that FBG can be converted into an insoluble, fibrin-like polymer by a nonenzymatic action of hydroxyl radicals (HRs). These free radicals are generated due to the reaction between hydroxyl groups of water and trivalent ferric ions without the participation of any redox agent. The interaction between HRs and FBG occurs in a purified system, as well as in human plasma and in whole blood. Scanning electron microscopy (SEM) of thrombin-induced fibers and those generated with ferric chloride has shown substantial differences in their morphology and susceptibility to enzymatic degradation. Fibrin strands caused by thrombin are thick and easily digested with chymotrypsin. By contrast, the dense matted deposits formed from FBG in the presence of ferric ions are remarkably resistant to proteolytic and chemical degradations due to the presence of intermolecular hydrophobic bonds. Thus, we postulate that this iron-catalyzed reaction represents a novel blood coagulation pathway operating in degenerative diseases. By means of SEM, we showed the presence of dense fibrin-like deposits in the blood of diabetic patients. Therefore, the prothrombotic state and cardiovascular complications observed in diabetes can be explained in terms of the persistent in vivo action of free iron. This phenomenon may explain hemorheologic disturbances in patients with metabolic syndrome and other diseases caused by iron overload. Of note, HRs can be effectively scavenged by phenolic substances; therefore, certain natural polyphenolic substances, which also scavenge HRs, may be considered to have a potential antidiabetic effect. Moreover, natural or synthetic iron-binding substances may also be considered as a new class of antidiabetic drugs. PMID:22460041

  14. The effect of a new impregnated gauze containing bentonite and halloysite minerals on blood coagulation and wound healing.

    PubMed

    Alavi, Mehrosadat; Totonchi, Alireza; Okhovat, Mohammad Ali; Motazedian, Motahareh; Rezaei, Peyman; Atefi, Mohammad

    2014-12-01

    In recent years, a wide variety of research has been carried out in the field of novel technologies to stop severe bleeding. In several studies, coagulation properties of minerals such as zeolite, bentonite and halloysite have been proven. In this study, the effect of a new impregnated sterile gauze containing bentonite and halloysite minerals was studied on blood coagulation and wound healing rate in male Wistar rats. Initially, impregnated sterile gauze was prepared from the mixture of bentonite and halloysite minerals and petroleum jelly (Vaseline). Then, the effect of gauze was studied on the blood coagulation time and wound healing process in 40 Wistar rats. SPSS software was used for data analysis and P values less than 0.05 were considered significant. The coagulation time of 81.10 ± 2.532 s in the control group and 33.00 ± 1.214 s in the study group (bentonite-halloysite treated) were reported (P < 0.0005). Time for complete wound healing in the group, which is treated with impregnated sterile pads, was calculated approximately from 10 to 12 days. However, in the control group, there was no complete wound healing (P < 0.0005). According to the results of the present study, topical application of the bentonite-halloysite impregnated sterile gauze significantly decreases the clotting time and increase the wound healing rate. PMID:25004023

  15. In vitro and in vivo evaluation of blood coagulation activation of polyvinyl alcohol hydrogel plus dextran-based vascular grafts.

    PubMed

    Alexandre, Nuno; Costa, Elísio; Coimbra, Susana; Silva, Alice; Lopes, Ascensão; Rodrigues, Miguel; Santos, Marta; Maurício, Ana Colette; Santos, José Domingos; Luís, Ana Lúcia

    2015-04-01

    Polyvinyl alcohol hydrogel (PVA) is a water-soluble synthetic polymer that is commonly used in biomedical applications including vascular grafting. It was argued that the copolymerization of PVA with dextran (Dx) can result in improvement of blood-biomaterial interactions. The focus of this experimental study was to assess that interaction through an in vivo and in vitro evaluation of the coagulation system activation. The thrombogenicity of the copolymer was determined by quantification of platelet adhesion through the lactate dehydrogenase assay, determination of whole blood clotting time, and by quantification of platelet activation by flow cytometry. The thrombin-antithrombin complex blood levels were also determined. The obtained results for the in vitro assays suggested a non-thrombogenic profile for PVA/Dx. Additionally in vivo coagulation and hematological parameters were determined in an animal model after PVA/Dx vascular graft implantation. For coagulation homeostasis assessment, the intrinsic and extrinsic pathway's activation was determined by measuring prothrombin time (PT) and activated partial thromboplastin time (aPTT). Other markers of coagulation and inflammation activation including d-dimers, interleukin-6, and C-reactive protein were also assessed. The PVA/Dx copolymer tended to inhibit platelet adhesion/activation process and the contact activation process for coagulation. These results were also confirmed with the in vivo experiments where the measurements for APTT, interleukin-6, and C-reactive protein parameters were normal considering the species normal range of values. The response to those events is an indicator of the in vitro and in vivo hemocompatibility of PVA/Dx and it allows us to select this biomaterial for further preclinical trials in vascular reconstruction. PMID:25044790

  16. Coagulation factors X, Xa, and protein S as potent mitogens of cultured aortic smooth muscle cells.

    PubMed Central

    Gasic, G P; Arenas, C P; Gasic, T B; Gasic, G J

    1992-01-01

    Smooth muscle cells (SMCs) in the rat carotid artery leave the quiescent state and proliferate after balloon catheter injury. The precise signals responsible for this SMC mitogenesis need to be elucidated. Although platelet-derived growth factor (PDGF), a potent SMC mitogen, is released from activated platelets, damaged endothelium, and macrophages, it cannot be solely responsible for this proliferation. In search of other SMC growth factors, we have examined several proteins of the coagulation cascade. At nanomolar concentrations, factors X, Xa, and protein S promote cultured rat aortic SMC mitosis. In contrast, factor IX is only weakly mitogenic, whereas factor VII and protein C fail to stimulate SMC division. Protein S, the most mitogenic of these coagulation cascade factors, stimulates DNA synthesis in cultured SMCs with a time course similar to that of PDGF-AA and without the delay observed for transforming growth factor beta. Antistasin and tick anticoagulant peptide, two specific factor Xa inhibitors, inhibit SMC mitogenesis due to Xa and protein S. Coagulation factors that possess mitogenic activity may contribute to intimal SMC proliferation after vascular injury as a result of angioplasty or vascular compromise during atherogenesis. Images PMID:1532256

  17. Evidence for a prevalent dimorphism in the activation peptide of human coagulation factor IX.

    PubMed Central

    McGraw, R A; Davis, L M; Noyes, C M; Lundblad, R L; Roberts, H R; Graham, J B; Stafford, D W

    1985-01-01

    We have independently isolated and characterized cDNA and genomic clones for the human coagulation factor IX. Sequence analysis in both cases indicates that threonine is encoded by the triplet ACT as the third residue of the activation peptide. This is in agreement with some earlier reports but in disagreement with others that show the alanine triplet GCT at this position. The discrepancy can thus be accounted for by natural variation of a single nucleotide in the normal population. Amino acid sequence analyses of activated factor IX from plasma samples of four individuals yielded two cases of alanine and two cases of threonine at the third position of the activation peptide. In factor IX from pooled plasma and in factor IX from a heterozygous individual, however, both alanine and threonine were found. Taken together, the findings show that a prevalent nondeleterious dimorphism exists in the activation peptide of human coagulation factor IX. PMID:3857619

  18. Massive Exploration of Perturbed Conditions of the Blood Coagulation Cascade through GPU Parallelization

    PubMed Central

    Cazzaniga, Paolo; Nobile, Marco S.; Besozzi, Daniela; Bellini, Matteo; Mauri, Giancarlo

    2014-01-01

    The introduction of general-purpose Graphics Processing Units (GPUs) is boosting scientific applications in Bioinformatics, Systems Biology, and Computational Biology. In these fields, the use of high-performance computing solutions is motivated by the need of performing large numbers of in silico analysis to study the behavior of biological systems in different conditions, which necessitate a computing power that usually overtakes the capability of standard desktop computers. In this work we present coagSODA, a CUDA-powered computational tool that was purposely developed for the analysis of a large mechanistic model of the blood coagulation cascade (BCC), defined according to both mass-action kinetics and Hill functions. coagSODA allows the execution of parallel simulations of the dynamics of the BCC by automatically deriving the system of ordinary differential equations and then exploiting the numerical integration algorithm LSODA. We present the biological results achieved with a massive exploration of perturbed conditions of the BCC, carried out with one-dimensional and bi-dimensional parameter sweep analysis, and show that GPU-accelerated parallel simulations of this model can increase the computational performances up to a 181× speedup compared to the corresponding sequential simulations. PMID:25025072

  19. Dynamics of spatially nonuniform patterning in the model of blood coagulation

    NASA Astrophysics Data System (ADS)

    Zarnitsina, V. I.; Ataullakhanov, F. I.; Lobanov, A. I.; Morozova, O. L.

    2001-03-01

    We propose a reaction-diffusion model that describes in detail the cascade of molecular events during blood coagulation. In a reduced form, this model contains three equations in three variables, two of which are self-accelerated. One of these variables, an activator, behaves in a threshold manner. An inhibitor is also produced autocatalytically, but there is no inhibitor threshold, because it is generated only in the presence of the activator. All model variables are set to have equal diffusion coefficients. The model has a stable stationary trivial state, which is spatially uniform and an excitation threshold. A pulse of excitation runs from the point where the excitation threshold has been exceeded. The regime of its propagation depends on the model parameters. In a one-dimensional problem, the pulse either stops running at a certain distance from the excitation point, or it reaches the boundaries as an autowave. However, there is a parameter range where the pulse does not disappear after stopping and exists stationarily. The resulting steady-state profiles of the model variables are symmetrical relative to the center of the structure formed.

  20. The Mechanisms of Coagulation.

    ERIC Educational Resources Information Center

    Kurtz, Richard; Jesty, Jolyon

    1994-01-01

    Several topics such as heart disease, strokes, biochemical reactions, blood components, and genetics can be related to blood clotting. Introduces a simple, safe and inexpensive hands-on demonstration using bovine (cattle) blood plasma of normal and abnormal coagulation. (ZWH)

  1. Effects of Blood Coagulate Removal Method on Aedes albopictus (Diptera: Culicidae) Life Table Characteristics and Vector Competence for Dengue Virus.

    PubMed

    van Dodewaard, Caitlin A M; Richards, Stephanie L; Harris, Jonathan W

    2016-01-01

    Commercially available blood can be used as an alternative to live animals to maintain mosquito colonies and deliver infectious bloodmeals during research studies. We analyzed the extent to which two methods for blood coagulate removal (defibrination or addition of sodium citrate) affected life table characteristics (i.e., fecundity, fertility, hatch rate, and adult survival) and vector competence (infection, dissemination, and transmission) of Aedes albopictus (Skuse) for dengue virus (DENV). Two types of bovine blood were tested at two extrinsic incubation temperatures (27 or 30°C) for DENV-infected and uninfected mosquitoes. Fully engorged mosquitoes were transferred to individual cages containing an oviposition cup and a substrate. Eggs (fecundity) and hatched larvae (fertility) were counted. At 14 and 21 d post feeding on a DENV-infected bloodmeal, 15 mosquitoes were sampled from each group, and vector competence was analyzed (bodies [infection], legs [dissemination], and saliva [transmission]). Differences in life table characteristics and vector competence were analyzed for mosquitoes fed blood processed using different methods for removal of coagulates. The method for removal of coagulates significantly impacted fecundity, fertility, and hatch time in the uninfected group, but not DENV-infected group. Infected mosquitoes showed significantly higher fecundity and faster hatch time than uninfected mosquitoes. We show no significant differences in infection or dissemination rates between groups; however, horizontal transmission rate was significantly higher in mosquitoes fed DENV-infected citrated compared with defibrinated blood. We expect the findings of this study to inform research using artificial blood delivery methods to assess vector competence. PMID:26474883

  2. Coagulation factor XII (Hageman factor) Washington D.C.: inactive factor XIIa results from Cys-571----Ser substitution.

    PubMed Central

    Miyata, T; Kawabata, S; Iwanaga, S; Takahashi, I; Alving, B; Saito, H

    1989-01-01

    Structural studies on a congenital abnormal coagulation factor XII (Hageman factor), factor XII Washington D.C., have been performed to identify the defect responsible for its lack of procoagulant activity. Amino acid sequence analysis of a tryptic peptide isolated from the abnormal factor XII indicated that Cys-571 (equivalent to Cys-220 in the chymotrypsin numbering system) had been replaced by serine. No other substitutions in the active-site triad--namely, His-393, Asp-442, and Ser-544--were found. We propose that the Cys-571----Ser replacement found in this factor XII variant destroys the formation of the disulfide linkage between Cys-540 and Cys-571, giving rise to an altered conformation of the active-site serine residue or the secondary substrate-binding site and, thus, leads to the loss of enzyme activity. PMID:2510163

  3. Blood Coagulation Parameters and Platelet Indices: Changes in Normal and Preeclamptic Pregnancies and Predictive Values for Preeclampsia

    PubMed Central

    Li, Hongmei; Zou, Jiaqun; Yang, Zhiling; Han, Jian; Huang, Wei; Yu, Lili; Zheng, Yingru; Li, Li

    2014-01-01

    Background Preeclampsia (PE) is an obstetric disorder with high morbidity and mortality rates but without clear pathogeny. The dysfunction of the blood coagulation-fibrinolysis system is a salient characteristic of PE that varies in severity, and necessitates different treatments. Therefore, it is necessary to find suitable predictors for the onset and severity of PE. Objectives We aimed to evaluate blood coagulation parameters and platelet indices as potential predictors for the onset and severity of PE. Methods Blood samples from 3 groups of subjects, normal pregnant women (n = 79), mild preeclampsia (mPE) (n = 53) and severe preeclampsia (sPE) (n = 42), were collected during early and late pregnancy. The levels of coagulative parameters and platelet indices were measured and compared among the groups. The receiver-operating characteristic (ROC) curves of these indices were generated, and the area under the curve (AUC) was calculated. The predictive values of the selected potential parameters were examined in binary regression analysis. Results During late pregnancy in the normal pregnancy group, the activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT) and platelet count decreased, while the fibrinogen level and mean platelet volume (MPV) increased compared to early pregnancy (p<0.05). However, the PE patients presented with increased APTT, TT, MPV and D-dimer (DD) during the third trimester. In the analysis of subjects with and without PE, TT showed the largest AUC (0.743) and high predictive value. In PE patients with different severities, MPV showed the largest AUC (0.671) and ideal predictive efficiency. Conclusion Normal pregnancy causes a maternal physiological hypercoagulable state in late pregnancy. PE may trigger complex disorders in the endogenous coagulative pathways and consume platelets and FIB, subsequently activating thrombopoiesis and fibrinolysis. Thrombin time and MPV may serve as early monitoring

  4. Risk Factors for High Blood Pressure

    MedlinePlus

    ... the NHLBI on Twitter. Risk Factors for High Blood Pressure Anyone can develop high blood pressure; however, age, ... can increase your risk for developing high blood pressure. Age Blood pressure tends to rise with age. About 65 ...

  5. Acquired coagulation factor XIII deficiency: a case report.

    PubMed

    Jia, Yongqing; Hu, Huixian; Wei, Bin

    2016-06-01

    The main objective of the study is to summarize the clinical characteristics of acquired factor XIII (FXIII) deficiency caused by a spontaneous FXIII inhibitor. Here we report a new case of acquired FXIII deficiency caused by FXIII inhibitor and review the medical literature regarding the characteristics and treatment of this disorder. FXIII deficiency caused by FXIII inhibitors is rare and of uncertain pathogenesis. Experience with therapeutic measures is limited to data from case reports. Immunosuppressive drugs may reduce autoantibodies or inhibit the cell clone generating the antibodies and may have been of benefit in our patient. The impact of such therapy on patient prognosis is incompletely known. PMID:26588447

  6. [Gene mutation analysis of coagulation factor VIII from a female patient with hemophilia A].

    PubMed

    Zhou, Jing; Yan, Nai-hong; Jia, Yong-qian; Lu, Yi-lu; Yu, Jiang; Cao, Gui-qun; Chen, Qing-ying; Wang, Ling; Zhang, Fa-qiang; Xia, Oing-jie

    2006-05-01

    Hemophilia A affects male, whereas females are carriers and generally spared from this disease. However, we here reported a 65-year-old female with Hemophilia A while screening the gene mutation of coagulation factor VIII. The female went to hospital because of tripping to lead her right chest to be injured with subcutaneous hematoma. She had historically a hemorrhagic diathesis. The physical examination discovered her hip limited to bend and move, but no discrepancy length between her two legs. The initial laboratory tests showed that the activated partial thromboplastin time (APTT) was 61. 3 seconds (20-40 seconds), and the APTT corrected by mixing with normal plasma was 41.3 s, but the levels of PT, FIB and TT were normal. The plain radiographs revealed the hip joints to suffer from the acetabular dysplasia and osteoarthritis. The level of FVIII:C was 2%, F IX:C 200%, vWF:Ag 120%, vWF:Rcof 100%, vWF:CBA 128%, and the F VIII binding assay to vWF was normal. The primers for exon 14 of F VIII gene were designed according to the NM - 000132 gene sequence. DNA was abstracted from the patient blood. PCR were carried out and the DNA sequence was followed. A new mutation of 4111A-->C was discovered, which caused the amino acid sequence changed (T 1314 P). The mutation of T 1314 P may be the cause of this female patient to get the hemophilia A. This mutation was a novel one which has never been reported before. PMID:16761442

  7. Platelet surface-associated activation and secretion-mediated inhibition of coagulation factor XII.

    PubMed

    Zakharova, Natalia V; Artemenko, Elena O; Podoplelova, Nadezhda A; Sveshnikova, Anastasia N; Demina, Irina A; Ataullakhanov, Fazly I; Panteleev, Mikhail A

    2015-01-01

    Coagulation factor XII (fXII) is important for arterial thrombosis, but its physiological activation mechanisms are unclear. In this study, we elucidated the role of platelets and platelet-derived material in fXII activation. FXII activation was only observed upon potent platelet stimulation (with thrombin, collagen-related peptide, or calcium ionophore, but not ADP) accompanied by phosphatidylserine exposure and was localised to the platelet surface. Platelets from three patients with grey platelet syndrome did not activate fXII, which suggests that platelet-associated fXII-activating material might be released from α-granules. FXII was preferentially bound by phosphotidylserine-positive platelets and annexin V abrogated platelet-dependent fXII activation; however, artificial phosphotidylserine/phosphatidylcholine microvesicles did not support fXII activation under the conditions herein. Confocal microscopy using DAPI as a poly-phosphate marker did not reveal poly-phosphates associated with an activated platelet surface. Experimental data for fXII activation indicates an auto-inhibition mechanism (ki/ka = 180 molecules/platelet). Unlike surface-associated fXII activation, platelet secretion inhibited activated fXII (fXIIa), particularly due to a released C1-inhibitor. Platelet surface-associated fXIIa formation triggered contact pathway-dependent clotting in recalcified plasma. Computer modelling suggests that fXIIa inactivation was greatly decreased in thrombi under high blood flow due to inhibitor washout. Combined, the surface-associated fXII activation and its inhibition in solution herein may be regarded as a flow-sensitive regulator that can shift the balance between surface-associated clotting and plasma-dependent inhibition, which may explain the role of fXII at high shear and why fXII is important for thrombosis but negligible in haemostasis. PMID:25688860

  8. Platelet Surface-Associated Activation and Secretion-Mediated Inhibition of Coagulation Factor XII

    PubMed Central

    Zakharova, Natalia V.; Artemenko, Elena O.; Podoplelova, Nadezhda A.; Sveshnikova, Anastasia N.; Demina, Irina A.; Ataullakhanov, Fazly I.; Panteleev, Mikhail A.

    2015-01-01

    Coagulation factor XII (fXII) is important for arterial thrombosis, but its physiological activation mechanisms are unclear. In this study, we elucidated the role of platelets and platelet-derived material in fXII activation. FXII activation was only observed upon potent platelet stimulation (with thrombin, collagen-related peptide, or calcium ionophore, but not ADP) accompanied by phosphatidylserine exposure and was localised to the platelet surface. Platelets from three patients with grey platelet syndrome did not activate fXII, which suggests that platelet-associated fXII-activating material might be released from α-granules. FXII was preferentially bound by phosphotidylserine-positive platelets and annexin V abrogated platelet-dependent fXII activation; however, artificial phosphotidylserine/phosphatidylcholine microvesicles did not support fXII activation under the conditions herein. Confocal microscopy using DAPI as a poly-phosphate marker did not reveal poly-phosphates associated with an activated platelet surface. Experimental data for fXII activation indicates an auto-inhibition mechanism (ki/ka = 180 molecules/platelet). Unlike surface-associated fXII activation, platelet secretion inhibited activated fXII (fXIIa), particularly due to a released C1-inhibitor. Platelet surface-associated fXIIa formation triggered contact pathway-dependent clotting in recalcified plasma. Computer modelling suggests that fXIIa inactivation was greatly decreased in thrombi under high blood flow due to inhibitor washout. Combined, the surface-associated fXII activation and its inhibition in solution herein may be regarded as a flow-sensitive regulator that can shift the balance between surface-associated clotting and plasma-dependent inhibition, which may explain the role of fXII at high shear and why fXII is important for thrombosis but negligible in haemostasis. PMID:25688860

  9. Correction of the coagulation defect in hemophilia using a factor Xa variant with novel engineered protease function

    PubMed Central

    Ivanciu, Lacramioara; Toso, Raffaella; Margaritis, Paris; Pavani, Giulia; Kim, Haein; Schlachterman, Alexander; Liu, Jian-Hua; Clerin, Valerie; Pittman, Debra D.; Rose-Miranda, Rosalind; Shields, Kathleen M.; Erbe, David V.; Tobin, James F.; Arruda, Valder R.; Camire, Rodney M.

    2011-01-01

    Effective therapies are needed to control excessive bleeding in a range of clinical conditions. We describe a surprisingly useful approach to improve hemostasis in vivo using a variant of coagulation factor Xa (FXaI16L). This conformationally pliant derivative is partially inactive due to a defect in transitioning from zymogen to protease 1,2. Using mouse models of hemophilia, we show that FXaI16L has a prolonged half-life, relative to wild-type FXa and does not cause excessive activation of coagulation. Once clotting mechanisms are activated to produce its cofactor FVa, FXaI16L is driven to the protease state and restores hemostasis in hemophilic animals upon vascular injury. Moreover, using human or murine analogs, we show that FXaI16L is more efficacious than FVIIa which is used to treat bleeding in hemophilia inhibitor patients3. Because of its underlying mechanism of action, FXaI16L may provide an effective strategy to enhance blood clot formation and act as a rapid pan-hemostatic agent for the treatment of bleeding conditions. PMID:22020385

  10. The Coagulation Factor XIIa Inhibitor rHA-Infestin-4 Improves Outcome after Cerebral Ischemia/Reperfusion Injury in Rats

    PubMed Central

    Krupka, Jennifer; May, Frauke; Weimer, Thomas; Pragst, Ingo; Kleinschnitz, Christoph; Stoll, Guido; Panousis, Con; Dickneite, Gerhard; Nolte, Marc W.

    2016-01-01

    Background and Purpose Ischemic stroke provokes severe brain damage and remains a predominant disease in industrialized countries. The coagulation factor XII (FXII)-driven contact activation system plays a central, but not yet fully defined pathogenic role in stroke development. Here, we investigated the efficacy of the FXIIa inhibitor rHA-Infestin-4 in a rat model of ischemic stroke using both a prophylactic and a therapeutic approach. Methods For prophylactic treatment, animals were treated intravenously with 100 mg/kg rHA-Infestin-4 or an equal volume of saline 15 min prior to transient middle cerebral artery occlusion (tMCAO) of 90 min. For therapeutic treatment, 100 mg/kg rHA-Infestin-4, or an equal volume of saline, was administered directly after the start of reperfusion. At 24 h after tMCAO, rats were tested for neurological deficits and blood was drawn for coagulation assays. Finally, brains were removed and analyzed for infarct area and edema formation. Results Within prophylactic rHA-Infestin-4 treatment, infarct areas and brain edema formation were reduced accompanied by better neurological scores and survival compared to controls. Following therapeutic treatment, neurological outcome and survival were still improved although overall effects were less pronounced compared to prophylaxis. Conclusions With regard to the central role of the FXII-driven contact activation system in ischemic stroke, inhibition of FXIIa may represent a new and promising treatment approach to prevent cerebral ischemia/reperfusion injury. PMID:26815580

  11. Imbalance of Pro- vs. Anti-Coagulation Factors in Chinese Patients with Budd-Chiari Syndrome and Non-Cirrhotic Portal Vein Thrombosis

    PubMed Central

    He, Chuangye; Yin, Zhanxin; Wu, Feifei; Fan, Daiming; Han, Guohong

    2015-01-01

    Background and Aim The coagulation abnormalities in non-cirrhotic Budd-Chiari syndrome (NC-BCS) and non-cirrhotic portal vein thrombosis (NC-PVT) are unclear. We conducted this case-control study to investigate the coagulation profile of NC-BCS and NC-PVT in Chinese patients. Methods We measured the levels of factors II, V, VII, VIII, IX, X, XI, XII, protein C (PC), protein S (PS) and antithrombin (AT) in blood samples from 37 NC-BCS patients, 74 NC-PVT patients, and 100 healthy controls. The levels and ratios of pro- and anti-coagulation factors were compared between patients with NC-BCS and healthy controls, between different types of NC-BCS and between NC-PVT and healthy controls. Results In patients with NC-BCS, factor VIII (P<0.001) was significantly elevated; factor V (P<0.001), VII (P<0.001), IX (P = 0.003), X (P<0.001), XI (P<0.001), XII (P<0.001), PC (P<0.001) and AT (P<0.001) were significantly decreased; and no difference was observed for factor II (P = 0.088) and PS (P = 0.199) compared with healthy controls. Factor VIII-to-PC (P = 0.008), factor VIII-to-PS (P = 0.037) and factor VIII-to-AT (P = 0.001) were significantly increased; other ratios were significantly reduced or did not show any difference. No differences were observed between different types of NC-BCS for individual pro- and anti-coagulation factors or the ratios between them. Among patients with NC-PVT, factor VIII (P<0.001) was significantly elevated and other factors were significantly decreased. Factor II-to-PC (P<0.001), factor VIII-to-PC (P<0.001), factor IX-to-PC (P<0.001), factor VIII-to-PS (P<0.001), factor II-to-AT (P<0.001), factor VIII-to-AT (P<0.001) and factor IX-to-AT (P<0.001) were significantly increased; all other ratios for NC-PVT were significantly reduced or did not show any significant difference. Conclusions NC-BCS and NC-PVT are associated with elevated levels of factor VIII and the decreased levels of PC and AT were probably the most significant features of

  12. Contribution of a portable air plasma torch to rapid blood coagulation as a method of preventing bleeding

    NASA Astrophysics Data System (ADS)

    Kuo, S. P.; Tarasenko, O.; Chang, J.; Popovic, S.; Chen, C. Y.; Fan, H. W.; Scott, A.; Lahiani, M.; Alusta, P.; Drake, J. D.; Nikolic, M.

    2009-11-01

    The effectiveness and mechanism of a low temperature air plasma torch in clotting blood are explored. Both blood droplets and smeared blood samples were used in the tests. The treated droplet samples reveal how blood clotting depends on the distance at which the torch operated, and for how long the droplets have been exposed to the torch. Microscopy and cell count of smeared blood samples shed light on dependencies of erythrocyte and platelet counts on torch distance and exposure time. With an increase of torch distance, the platelet count of treated blood samples increases but is less than that of the control. The flux of reactive atomic oxygen (RAO) and the degree of blood clotting decreased. With an increase of exposure time, platelet count of treated samples decreased, while the degree of clot increased. The correlation among these dependencies and published data support a blood clotting mechanism that RAO as well as other likely reactive oxygen species generated by the plasma torch activate erythrocyte-platelets interactions and induces blood coagulation.

  13. Surface-Energy Dependent Contact Activation of Blood Factor XII

    PubMed Central

    Golas, Avantika; Parhi, Purnendu; Dimachkie, Ziad O.; Siedlecki, Christopher A.; Vogler, Erwin A.

    2009-01-01

    Contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension τao=γlvocosθ in dyne/cm, where γlvo is water interfacial tension in dyne/cm and θ is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties −36<τao<72 dyne/cm (0° ≤ θ < 120°), falling sharply through a broad minimum within the 20<τao<40 dyne/cm (55° < θ < 75°) range over which activation yield (putatively FXIIa) rises just above detection limits. Activation is very rapid upon contact with all activators tested and did not significantly vary over 30 minutes of continuous FXII-procoagulant contact. Results suggest that materials falling within the 20<τao<40 dyne/cm surface-energy range should exhibit minimal activation of blood-plasma coagulation through the intrinsic pathway. Surface chemistries falling within this range are, however, a perplexingly difficult target for surface engineering because of the critical balance that must be struck between hydrophobicity and hydrophilicity. Results are interpreted within the context of blood plasma coagulation and the role of water and proteins at procoagulant surfaces. PMID:19892397

  14. Increased activity of coagulation factor XII (Hageman factor) causes hereditary angioedema type III.

    PubMed

    Cichon, Sven; Martin, Ludovic; Hennies, Hans Christian; Müller, Felicitas; Van Driessche, Karen; Karpushova, Anna; Stevens, Wim; Colombo, Roberto; Renné, Thomas; Drouet, Christian; Bork, Konrad; Nöthen, Markus M

    2006-12-01

    Hereditary angioedema (HAE) is characterized clinically by recurrent acute skin swelling, abdominal pain, and potentially life-threatening laryngeal edema. Three forms of HAE have been described. The classic forms, HAE types I and II, occur as a consequence of mutations in the C1-inhibitor gene. In contrast to HAE types I and II, HAE type III has been observed exclusively in women, where it appears to be correlated with conditions of high estrogen levels--for example, pregnancy or the use of oral contraceptives. A recent report proposed two missense mutations (c.1032C-->A and c.1032C-->G) in F12, the gene encoding human coagulation factor XII (FXII, or Hageman factor) as a possible cause of HAE type III. Here, we report the occurrence of the c.1032C-->A (p.Thr328Lys) mutation in an HAE type III-affected family of French origin. Investigation of the F12 gene in a large German family did not reveal a coding mutation. Haplotype analysis with use of microsatellite markers is compatible with locus heterogeneity in HAE type III. To shed more light on the pathogenic relevance of the HAE type III-associated p.Thr328Lys mutation, we compared FXII activity and plasma levels in patients carrying the mutation with that of healthy control individuals. Our data strongly suggest that p.Thr328Lys is a gain-of-function mutation that markedly increases FXII amidolytic activity but that does not alter FXII plasma levels. We conclude that enhanced FXII enzymatic plasma activity in female mutation carriers leads to enhanced kinin production, which results in angioedema. Transcription of F12 is positively regulated by estrogens, which may explain why only women are affected with HAE type III. The results of our study represent an important step toward an understanding of the molecular processes involved in HAE type III and provide diagnostic and possibly new therapeutic opportunities. PMID:17186468

  15. Intraoperative blood loss in orthotopic liver transplantation: The predictive factors

    PubMed Central

    Pandey, Chandra Kant; Singh, Anshuman; Kajal, Kamal; Dhankhar, Mandeep; Tandon, Manish; Pandey, Vijay Kant; Karna, Sunaina Tejpal

    2015-01-01

    Liver transplantation has been associated with massive blood loss and considerable transfusion requirements. Bleeding in orthotopic liver transplantation is multifactorial. Technical difficulties inherent to this complex surgical procedure and pre operative derangements of the primary and secondary coagulation system are thought to be the principal causes of perioperative hemorrhage. Intraoperative practices such as massive fluid resuscitation and resulting hypothermia and hypocalcemia secondary to citrate toxicity further aggravate the preexisting coagulopathy and worsen the perioperative bleeding. Excessive blood loss and transfusion during orthotopic liver transplant are correlated with diminished graft survival and increased septic episodes and prolonged ICU stay. With improvements in surgical skills, anesthetic technique, graft preservation, use of intraoperative cell savers and overall perioperative management, orthotopic liver transplant is now associated with decreased intra operative blood losses. The purpose of this review is to discuss the risk factors predictive of increased intra operative bleeding in patients undergoing orthotopic liver transplant. PMID:26131330

  16. Interactions of PLGA nanoparticles with blood components: protein adsorption, coagulation, activation of the complement system and hemolysis studies

    NASA Astrophysics Data System (ADS)

    Fornaguera, Cristina; Calderó, Gabriela; Mitjans, Montserrat; Vinardell, Maria Pilar; Solans, Conxita; Vauthier, Christine

    2015-03-01

    The intravenous administration of poly(lactic-co-glycolic) acid (PLGA) nanoparticles has been widely reported as a promising alternative for delivery of drugs to specific cells. However, studies on their interaction with diverse blood components using different techniques are still lacking. Therefore, in the present work, the interaction of PLGA nanoparticles with blood components was described using different complementary techniques. The influence of different encapsulated compounds/functionalizing agents on these interactions was also reported. It is worth noting that all these techniques can be simply performed, without the need for highly sophisticated apparatus or skills. Moreover, their transference to industries and application of quality control could be easily performed. Serum albumin was adsorbed onto all types of tested nanoparticles. The saturation concentration was dependent on the nanoparticle size. In contrast, fibrinogen aggregation was dependent on nanoparticle surface charge. The complement activation was also influenced by the nanoparticle functionalization; the presence of a functionalizing agent increased complement activation, while the addition of an encapsulated compound only caused a slight increase. None of the nanoparticles influenced the coagulation cascade at low concentrations. However, at high concentrations, cationized nanoparticles did activate the coagulation cascade. Interactions of nanoparticles with erythrocytes did not reveal any hemolysis. Interactions of PLGA nanoparticles with blood proteins depended both on the nanoparticle properties and the protein studied. Independent of their loading/surface functionalization, PLGA nanoparticles did not influence the coagulation cascade and did not induce hemolysis of erythrocytes; they could be defined as safe concerning induction of embolization and cell lysis.The intravenous administration of poly(lactic-co-glycolic) acid (PLGA) nanoparticles has been widely reported as a promising

  17. Inhibition by CāINH of Hageman Factor Fragment Activation of Coagulation, Fibrinolysis, and Kinin Generation

    PubMed Central

    Schreiber, Alan D.; Kaplan, Allen P.; Austen, K. Frank

    1973-01-01

    Highly purified inhibitor of the first component of complement (CāINH) was shown to inhibit the capacity of active Hageman factor fragments to initiate kinin generation, fibrinolysis, and coagulation. The inhibition of prealbumin Hageman factor fragments observed was dependent upon the time of interaction of the fragments with CāINH and not to an effect upon kallikrein or plasmin generated. The inhibition of the coagulant activity of the intermediate sized Hageman factor fragment by CāINH was not due to an effect on PTA or other clotting factors. The inhibition by CāINH of both the prealbumin and intermediate sized Hageman factor fragments occurred in a dose response fashion. The CāINH did not appear to be consumed when the activity of the Hageman factor fragments was blocked, although the fragments themselves could no longer be recovered functionally or as a protein on alkaline disc gel electrophoretic analysis. These results suggest that the CāINH may have an enzymatic effect on the fragments or that an additional site on CāINH is involved in Cā inactivation. Images PMID:4703226

  18. Evaluation of Consequences of Dust Positioned in Southwest of Iran on Coagulant Factors

    PubMed Central

    Saeb, Keivan; Sarizade, Gholamreza; Khodadi, Mohammad; Biazar, Esmaeil

    2013-01-01

    Background: Various regions in Iran, especially the Khuzestan Province, have been covered by dust and dirt during the past two years due to environmental changes in the Middle East. We sought to evaluate the effect of these pollutants on the coagulant factors of people residing in Abadan and Khoramshahr, two major cities of Khuzestan Province. Methods: One hundred twenty-nine healthy individuals were enrolled into this study, and their prothrombin time as well as fibrinogen, platelet, and Factor VIII levels were measured before and after climate changes. Results: After climate changes, the mean prothrombin time decreased, while the fibrinogen, platelet, and Factor VIII levels rose. Conclusion: The results of this study suggest that the pollutants deployed in the Middle East can affect prothrombin time as well as fibrinogen, platelet, and Factor VII levels considerably and increase coagulant state. The pollutants can, consequently, increase the risk of cardiovascular diseases. It seems that cooperation at government levels between Iran and its neighboring countries is required to reverse desertification and avoid inaccurate usage of subterranean water resources so as to lessen air pollution. PMID:23825886

  19. Inflammation and the coagulation system in tuberculosis: Tissue Factor leads the dance.

    PubMed

    Caccamo, Nadia; Dieli, Francesco

    2016-02-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, drives the formation of granulomas, structures in which both immune cells and the bacterial pathogen cohabit. The most abundant cells in granulomas are macrophages, which contribute as both cells with bactericidal activity and as targets for M. tuberculosis infection and proliferation during the entire course of infection. The mechanisms and factors involved in the regulation and control of macrophage microenvironment-specific polarization and plasticity are not well understood, as some granulomas are able to control bacteria growth and others fail to do so, permitting bacterial spread. In this issue of the European Journal of Immunology, Venkatasubramanian et al. [Eur. J. Immunol. 2016. 46: 464-479] show that mice lacking the tissue factor gene in myeloid cells have augmented M. tuberculosis growth and increased inflammation in the lungs. This suggests that tissue factor, an initiator of coagulation, is important for the generation of fibrin, which supports granuloma formation. This article demonstrates for the first time the involvement of tissue factor in inducing effective immunity against M. tuberculosis, and sheds new lights on the complex interplay between host inflammatory response, the coagulation system, and the control of M. tuberculosis infection. PMID:26763085

  20. Monitoring the effects of fibrinogen concentration on blood coagulation using quartz crystal microbalance (QCM) and its comparison with thromboelastography

    NASA Astrophysics Data System (ADS)

    Lakshmanan, Ramji S.; Efremov, Vitaly; Cullen, Sinéad; Byrne, Barry; Killard, Anthony J.

    2013-05-01

    Fibrinogen has been identified as a major risk factor in cardiovascular disorders. Fibrinogen (340 kDa) is a soluble dimeric glycoprotein found in plasma and is a major component of the coagulation cascade. It has been identified as a major risk factor in cardiovascular disorders. The time taken for its conversion to fibrin is usually used as an "endpoint" in most clot-based assays, without any information on dynamic changes in physical properties or kinetics of a forming clot. A global coagulation profile as measured by Thromboelastography® (TEG®) provides information on both the time and kinetics of changes in physical property of the forming clot. In this work, Quartz crystal microbalance (QCM), which is a piezoelectric resonator has been used to study coagulation of plasma and compared with TEG. The changes in resonant frequency (Δf) and half width at half maximum (HWHM or ΔΓ) were used to evaluate effect of fibrinogen concentration. It has been shown that TEG is less sensitive to low concentrations of fibrinogen and dilution while QCM is able to monitor clot formation in both the circumstances.

  1. von Willebrand Factor Test

    MedlinePlus

    ... Platelet Count , Platelet Function Tests , Complete Blood Count , Coagulation Factor VIII , PT , PTT At a Glance Test ... a protein , one of several components of the coagulation system that work together to stop bleeding and ...

  2. Absence of in vitro Procoagulant Activity in Immunoglobulin Preparations due to Activated Coagulation Factors

    PubMed Central

    Oviedo, Adriana E.; Bernardi, María E.; Guglielmone, Hugo A.; Vitali, María S.

    2015-01-01

    Summary Background Immunoglobulin (IG) products, including intravenous (IVIG) or subcutaneous (SCIG) immunoglobulins are considered safe and effective for medical therapy; however, a sudden and unexpected increase in thromboembolic events (TE) after administration of certain batches of IVIG products has been attributed to the presence of activated coagulation factors, mainly factor XIa. Our aims were to examine the presence of enduring procoagulant activity during the manufacturing process of IGs, with special focus on monitoring factor XIa, and to evaluate the presence of in vitro procoagulant activity attributed to coagulation factors in different lots of IVIG and SCIG. Methods Samples of different steps of IG purification, 19 lots of IVIG and 9 of SCIG were analyzed and compared with 1 commercial preparation of IVIG and 2 of SCIG, respectively. Factors II, VII, IX, XI and XIa and non-activated partial thromboplastin time (NAPTT) were assayed. Results The levels of factors II, VII, IX, X and XI were non-quantifiable once fraction II had been re-dissolved and in all analyzed lots of IVIG and SCIG. The level of factor XIa at that point was under the detection limits of the assay, and NAPTT yielded values greater than the control during the purification process. In SCIG, we detected higher concentrations of factor XIa in the commercial products, which reached values up to 5 times higher than the average amounts found in the 9 batches produced by UNC-Hemoderivados. Factor XIa in commercial IVIG reached levels slightly higher than those of the 19 batches produced by UNC-Hemoderivados. Conclusion IVIG and SCIG manufactured by UNC-Hemoderivados showed a lack of thrombogenic potential, as demonstrated not only by the laboratory data obtained in this study but also by the absence of any reports of TE registered by the post marketing pharmacovigilance department. PMID:26733772

  3. Inactivation of human immunodeficiency virus by gamma radiation and its effect on plasma and coagulation factors

    SciTech Connect

    Hiemstra, H.; Tersmette, M.; Vos, A.H.; Over, J.; van Berkel, M.P.; de Bree, H. )

    1991-01-01

    The inactivation of HIV by gamma-radiation was studied in frozen and liquid plasma; a reduction of the virus titer of 5 to 6 logs was achieved at doses of 5 to 10 Mrad at -80 degrees C and 2.5 Mrad at 15 degrees C. The effect of irradiation on the biologic activity of a number of coagulation factors in plasma and in lyophilized concentrates of factor VIII (FVIII) and prothrombin complex was examined. A recovery of 85 percent of the biologic activity of therapeutic components present in frozen plasma and in lyophilized coagulation factor concentrates was reached at radiation doses as low as 1.5 and 0.5 Mrad, respectively. As derived from the first-order radiation inactivation curves, the radiosensitive target size of HIV was estimated to be 1 to 3 MDa; the target size of FVIII was estimated to be 130 to 160 kDa. Gamma radiation must be disregarded as a method for the sterilization of plasma and plasma-derived products, because of the low reduction of virus infectivity at radiation doses that still give acceptable recovery of biologic activity of plasma components.

  4. Effects of compounds from Passiflora edulis Sims f. flavicarpa juice on blood coagulation and on proteolytic enzymes.

    PubMed

    Sato, Ana Claudia; Andrade, Sonia A; Brito, Marlon V; Miranda, Antonio; Sampaio, Misako Uemura; de Abreu Maffei, Francisco Humberto; Oliva, Maria Luiza Vilela

    2012-05-01

    Passion fruit (Passiflora edulis Sims f. flavicarpa) is popularly known for its sedative and calming properties and is consumed as a fresh fruit or as a juice. The clinical observation of blood incoagulability associated with excessive consumption of passion fruit juice, in a patient treated with warfarin, prompted the current study to investigate in vitro the presence of blood clotting inhibitors in Passiflora edulis Sims f. flavicarpa extract. After purification process, two compounds of distinct molecular weight and inhibitory action were better characterized. One is a trypsin inhibitor similar to inhibitors from Bowman-Birk family, named PeTI-I12, and other is a compound active in coagulation that prolongs aPTT and PT, but does not change TT. The aim of this study is to provide evidence that passion fruit extract's components play a role on hemostasis and therefore may be relevant in the handling of patients treated with anticoagulants or suffering hemorrhagic diseases. PMID:22486645

  5. Behavior of optical properties of coagulated blood sample at 633 nm wavelength

    NASA Astrophysics Data System (ADS)

    Morales Cruzado, Beatriz; Vázquez y Montiel, Sergio; Delgado Atencio, José Alberto

    2011-03-01

    Determination of tissue optical parameters is fundamental for application of light in either diagnostics or therapeutical procedures. However, in samples of biological tissue in vitro, the optical properties are modified by cellular death or cellular agglomeration that can not be avoided. This phenomena change the propagation of light within the biological sample. Optical properties of human blood tissue were investigated in vitro at 633 nm using an optical setup that includes a double integrating sphere system. We measure the diffuse transmittance and diffuse reflectance of the blood sample and compare these physical properties with those obtained by Monte Carlo Multi-Layered (MCML). The extraction of the optical parameters: absorption coefficient μa, scattering coefficient μs and anisotropic factor g from the measurements were carried out using a Genetic Algorithm, in which the search procedure is based in the evolution of a population due to selection of the best individual, evaluated by a function that compares the diffuse transmittance and diffuse reflectance of those individuals with the experimental ones. The algorithm converges rapidly to the best individual, extracting the optical parameters of the sample. We compare our results with those obtained by using other retrieve procedures. We found that the scattering coefficient and the anisotropic factor change dramatically due to the formation of clusters.

  6. Factor B Is the Second Lipopolysaccharide-binding Protease Zymogen in the Horseshoe Crab Coagulation Cascade*

    PubMed Central

    Kobayashi, Yuki; Takahashi, Toshiaki; Shibata, Toshio; Ikeda, Shunsuke; Koshiba, Takumi; Mizumura, Hikaru; Oda, Toshio; Kawabata, Shun-ichiro

    2015-01-01

    Factor B is a serine-protease zymogen in the horseshoe crab coagulation cascade, and it is the primary substrate for activated factor C, the LPS-responsive initiator of the cascade. Factor C is autocatalytically activated to α-factor C on LPS and is artificially converted to β-factor C, another activated form, by chymotrypsin. It is not known, however, whether LPS is required for the activation of factor B. Here we found that wild-type factor B expressed in HEK293S cells is activated by α-factor C, but not by β-factor C, in an LPS-dependent manner and that β-factor C loses the LPS binding activity of factor C through additional cleavage by chymotrypsin within the N-terminal LPS-binding region. Surface plasmon resonance and quartz crystal microbalance analyses revealed that wild-type factor B binds to LPS with high affinity comparable with that of factor C, demonstrating that factor B is the second LPS-binding zymogen in the cascade. An LPS-binding site of wild-type factor B was found in the N-terminal clip domain, and the activation rate of a clip domain deletion mutant was considerably slower than that of wild-type factor B. Moreover, in the presence of LPS, Triton X-100 inhibited the activation of wild-type factor B by α-factor C. We conclude that the clip domain of factor B has an important role in localizing factor B to the surface of Gram-negative bacteria or LPS released from bacteria to initiate effective proteolytic activation by α-factor C. PMID:26109069

  7. Factor B Is the Second Lipopolysaccharide-binding Protease Zymogen in the Horseshoe Crab Coagulation Cascade.

    PubMed

    Kobayashi, Yuki; Takahashi, Toshiaki; Shibata, Toshio; Ikeda, Shunsuke; Koshiba, Takumi; Mizumura, Hikaru; Oda, Toshio; Kawabata, Shun-ichiro

    2015-07-31

    Factor B is a serine-protease zymogen in the horseshoe crab coagulation cascade, and it is the primary substrate for activated factor C, the LPS-responsive initiator of the cascade. Factor C is autocatalytically activated to α-factor C on LPS and is artificially converted to β-factor C, another activated form, by chymotrypsin. It is not known, however, whether LPS is required for the activation of factor B. Here we found that wild-type factor B expressed in HEK293S cells is activated by α-factor C, but not by β-factor C, in an LPS-dependent manner and that β-factor C loses the LPS binding activity of factor C through additional cleavage by chymotrypsin within the N-terminal LPS-binding region. Surface plasmon resonance and quartz crystal microbalance analyses revealed that wild-type factor B binds to LPS with high affinity comparable with that of factor C, demonstrating that factor B is the second LPS-binding zymogen in the cascade. An LPS-binding site of wild-type factor B was found in the N-terminal clip domain, and the activation rate of a clip domain deletion mutant was considerably slower than that of wild-type factor B. Moreover, in the presence of LPS, Triton X-100 inhibited the activation of wild-type factor B by α-factor C. We conclude that the clip domain of factor B has an important role in localizing factor B to the surface of Gram-negative bacteria or LPS released from bacteria to initiate effective proteolytic activation by α-factor C. PMID:26109069

  8. Cloning, characterization and expression analysis of coagulation factor II gene in grass carp (Ctenopharyngodon idella).

    PubMed

    Xu, B H; Chen, K J; Yao, Y B; Liu, Q L; Xiao, T Y; Su, J M; Peng, H Z

    2015-01-01

    Here, we characterized the structure and function of the coagulation factor II (FII) gene in grass carp and determined its role in coagulation mechanisms. The FII gene EST was obtained using a constructed splenic transcriptome database; the full-length FII gene sequence was obtained by 3' and 5' RACE. The open reading frame (ORF) of FII was cloned and the full-length gene was found to be 1718 bp, with an ORF of 1572 bp; the gene contained a 25 bp 5'-untranslated region (UTR) and 108 bp 3'-UTR. The ORF encoded 524 amino acids, including 74 alkaline amino acids (arginine and lysine) and 69 acidic amino acids (aspartic acid and glutamic acid). The theoretical pI was 6.22. The calculated instability index (II) was 39.81, indicating that FII was a stable protein; the half-life period was predicted to be approximately 30 h. Amino acid sequence comparisons indicated that grass carp FII showed most similarity (71%) to FII of Takifugu rubripes, followed by Oplegnathus fasciatus (48% similarity) and Larimichthys crocea (47% similarity). A real-time reverse transcription PCR analysis showed that under normal circumstances, FII was most highly expressed in the liver, followed by the gill, spleen, thymus, and head-kidney (P < 0.001). After injection of the grass carp reovirus 873 (GCRV873), the pattern of FII expression was significantly altered (P < 0.001); gene expression was high after injection, suggesting a response involving the initiation of the coagulation system and defense of the body in combination with the platelet and complement system. PMID:26535692

  9. Coagulation abnormalities in sepsis.

    PubMed

    Tsao, Cheng-Ming; Ho, Shung-Tai; Wu, Chin-Chen

    2015-03-01

    Although the pathophysiology of sepsis has been elucidated with the passage of time, sepsis may be regarded as an uncontrolled inflammatory and procoagulant response to infection. The hemostatic changes in sepsis range from subclinical activation of blood coagulation to acute disseminated intravascular coagulation (DIC). DIC is characterized by widespread microvascular thrombosis, which contributes to multiple organ dysfunction/failure, and subsequent consumption of platelets and coagulation factors, eventually causing bleeding manifestations. The diagnosis of DIC can be made using routinely available laboratory tests, scoring algorithms, and thromboelastography. In this cascade of events, the inhibition of coagulation activation and platelet function is conjectured as a useful tool for attenuating inflammatory response and improving outcomes in sepsis. A number of clinical trials of anticoagulants were performed, but none of them have been recognized as a standard therapy because recombinant activated protein C was withdrawn from the market owing to its insufficient efficacy in a randomized controlled trial. However, these subgroup analyses of activated protein C, antithrombin, and thrombomodulin trials show that overt coagulation activation is strongly associated with the best therapeutic effect of the inhibitor. In addition, antiplatelet drugs, including acetylsalicylic acid, P2Y12 inhibitors, and glycoprotein IIb/IIIa antagonists, may reduce organ failure and mortality in the experimental model of sepsis without a concomitant increased bleeding risk, which should be supported by solid clinical data. For a state-of-the-art treatment of sepsis, the efficacy of anticoagulant and antiplatelet agents needs to be proved in further large-scale prospective, interventional, randomized validation trials. PMID:25544351

  10. Factor V deficiency

    MedlinePlus

    ... as many as 20 different proteins in blood plasma. These proteins are called blood coagulation factors. Factor ... You will be given fresh blood plasma or fresh frozen plasma infusions ... These treatments will correct the deficiency temporarily.

  11. The activated coagulation time of whole blood as a routine pre-operative sceening test.

    PubMed

    Hattersley, P G

    1971-05-01

    Patients with disorders of hemostasis who undergo surgical procedures are in danger of hemorrhage. While the careful medical history remains the most sensitive test of a bleeding tendency, some such patients can give no suggestive history. In three patients with coagulopathy-one with mild classical hemophilia, one with Christmas disease, and one with warfarin toxicity-the abnormality was missed by routine preoperative history but promptly detected by the routine preoperative use of the activated coagulation time (act). Either this test or the activated partial thromboplastin time should be included in the routine preoperative work-up, along with appropriate additional tests of the hemostatic mechanism. PMID:5087876

  12. The Activated Coagulation Time of Whole Blood as a Routine Pre-Operative Screening Test

    PubMed Central

    Hattersley, Paul G.

    1971-01-01

    Patients with disorders of hemostasis who undergo surgical procedures are in danger of hemorrhage. While the careful medical history remains the most sensitive test of a bleeding tendency, some such patients can give no suggestive history. In three patients with coagulopathy—one with mild classical hemophilia, one with Christmas disease, and one with warfarin toxicity—the abnormality was missed by routine preoperative history but promptly detected by the routine preoperative use of the activated coagulation time (act). Either this test or the activated partial thromboplastin time should be included in the routine preoperative work-up, along with appropriate additional tests of the hemostatic mechanism. PMID:5087876

  13. Blood Hypomethylation of Inflammatory Genes Mediates the Effects of Metal-rich Airborne Pollutants on Blood Coagulation

    PubMed Central

    Tarantini, Letizia; Bonzini, Matteo; Tripodi, Armando; Angelici, Laura; Nordio, Francesco; Cantone, Laura; Apostoli, Pietro; Bertazzi, Pier Alberto; Baccarelli, Andrea A.

    2014-01-01

    Objectives Recent investigations have associated airborne Particulate Matter (PM) with increased coagulation and thrombosis, but underlying biological mechanisms are still incompletely characterized. DNA methylation is an environmentally-sensitive mechanism of gene regulation that could potentially contribute to PM-induced hypercoagulability. We aimed to test whether altered methylation mediates environmental effects on coagulation. Methods We investigated 63 steel workers exposed to a wide range of PM levels, as a work-related condition with well-characterized prothrombotic exposure. We measured personal PM10 (PM≤10 μm in aerodynamic diameter), PM1 (≤1 μm), and air metal components. We determined leukocyte DNA methylation of NOS3 (nitric-oxide-synthase-3) and EDN1 (endothelin-1) through bisulfite-pyrosequencing and we measured Endogenous Thrombin Potential (ETP), as a global coagulation-activation test after standardized triggers. Results ETP increased in association with PM10 (β=20.0, 95%CI: 3.0, 37.0), PM1 (β=80.8 95%CI: 14.9, 146.7), and zinc (β=51.3, 95%CI: 0.01, 111.1) exposures. NOS3 methylation was negatively associated with PM10 (β=−0.2, 95%CI: −0.4, −0.03), PM1 (β=−0.8, 95%CI: −1.4, −0.1), zinc (β=−0.9, 95%CI: −1.4, −0.3) and iron (β=−0.7, 95%CI: −1.4, −0.01) exposures. Zinc exposure was negatively associated with EDN1 (β=−0.3, 95%CI: −0.8, −0.1) methylation. Lower NOS3 (β=−42.3; p<0.001) and EDN1 (β=−14.5; p=0.05) were associated with higher ETP. Statistical mediation analysis formally confirmed NOS3 and EDN1 hypomethylation as intermediate mechanisms for PM-related coagulation effects. Conclusions Our study showed for the first time, that gene hypomethylation contributes to environmentally-induced hypercoagulability. PMID:23476046

  14. Network-Based Biomarkers for Cold Coagulation Blood Stasis Syndrome and the Therapeutic Effects of Shaofu Zhuyu Decoction in Rats

    PubMed Central

    Su, Shulan; Duan, Jinao; Cui, Wenxia; Shang, Erxing; Liu, Pei; Bai, Gang; Guo, Sheng; Qian, Dawei; Tang, Yuping

    2013-01-01

    In this study, the reverse docking methodology was applied to predict the action targets and pathways of Shaofu Zhuyu decoction (SFZYD) bioactive ingredients. Furthermore, Traditional Chinese Medicine (TCM) cold coagulation blood stasis (CCBS) syndrome was induced in female Sprague-Dawley rats with an ice-water bath and epinephrine, and SFZYD was used to treat CCBS syndrome. A metabolomic approach was used to evaluate changes in the metabolic profiles and to analyze the pharmacological mechanism of SFZYD actions. Twenty-three potential protein targets and 15 pathways were discovered, respectively; among these, pathways are associated with inflammation and immunological stress, hormone metabolism, coagulation function, and glycometabolism. There were also changes in the levels of endogenous metabolites of LysoPCs and glucuronides. Twenty endogenous metabolites were identified. Furthermore, the relative quantities of 6 endogenous metabolites in the plasma and 5 in the urine were significantly affected by SFZYD (P < 0.05). The pharmacological mechanism of SFZYD was partially associated with glycerophospholipid metabolism and pentose and glucuronate interconversions. In conclusion, our findings demonstrated that TCM CCBS pattern induced by ice water and epinephrine was complex and related to multiple metabolic pathways. SFZYD did regulate the TCM CCBS by multitargets, and biomarkers and SFZYD should be used for the clinical treatment of CCBS syndrome. PMID:24288569

  15. Agent based modeling of blood coagulation system: implementation using a GPU based high speed framework.

    PubMed

    Chen, Wenan; Ward, Kevin; Li, Qi; Kecman, Vojislav; Najarian, Kayvan; Menke, Nathan

    2011-01-01

    The coagulation and fibrinolytic systems are complex, inter-connected biological systems with major physiological roles. The complex, nonlinear multi-point relationships between the molecular and cellular constituents of two systems render a comprehensive and simultaneous study of the system at the microscopic and macroscopic level a significant challenge. We have created an Agent Based Modeling and Simulation (ABMS) approach for simulating these complex interactions. As the scale of agents increase, the time complexity and cost of the resulting simulations presents a significant challenge. As such, in this paper, we also present a high-speed framework for the coagulation simulation utilizing the computing power of graphics processing units (GPU). For comparison, we also implemented the simulations in NetLogo, Repast, and a direct C version. As our experiments demonstrate, the computational speed of the GPU implementation of the million-level scale of agents is over 10 times faster versus the C version, over 100 times faster versus the Repast version and over 300 times faster versus the NetLogo simulation. PMID:22254271

  16. Combining bioinformatics, chemoinformatics and experimental approaches to design chemical probes: Applications in the field of blood coagulation.

    PubMed

    Villoutreix, B O

    2016-07-01

    Bioinformatics and chemoinformatics approaches contribute to the discovery of novel targets, chemical probes, hits, leads and medicinal drugs. A vast repertoire of computational methods has indeed been reported over the years and in this review, I will briefly introduce some concepts and approaches, namely the analysis of potential therapeutic target binding pockets, the preparation of compound collections and virtual screening. An example of application is provided for two proteins acting in the blood coagulation system. Overall, in silico methods have been shown to improve R and D productivity in both, academic settings and in the private sector, if they are integrated in a rational manner with experimental approaches. However, integration of tools and pluridisciplinarity are seldom achieved. Efforts should be done in this direction as pluridisciplinarity and a true acknowledgment of all the contributing actors along the value chain could enhance innovation and reduce skyrocketing costs. PMID:27133312

  17. A comprehensive model for the humoral coagulation network in humans.

    PubMed

    Wajima, T; Isbister, G K; Duffull, S B

    2009-09-01

    Coagulation is an important process in hemostasis and comprises a complicated interaction of multiple enzymes and proteins. We have developed a mechanistic quantitative model of the coagulation network. The model accurately describes the time courses of coagulation factors following in vivo activation as well as in vitro blood coagulation tests of prothrombin time (PT, often reported as international normalized ratio (INR)) and activated partial thromboplastin time (aPTT). The model predicts the concentration-time and time-effect profiles of warfarin, heparins, and vitamin K in humans. The model can be applied to predict the time courses of coagulation kinetics in clinical situations (e.g., hemophilia) and for biomarker identification during drug development. The model developed in this study is the first quantitative description of the comprehensive coagulation network. PMID:19516255

  18. Haem-assisted dityrosine-cross-linking of fibrinogen under non-thermal plasma exposure: one important mechanism of facilitated blood coagulation

    PubMed Central

    Ke, Zhigang; Huang, Qing

    2016-01-01

    Although blood coagulation facilitated by non-thermal plasma has been reported several years ago, the insight to the involved mechanisms is still rather limited. In this work, we report our discovery of a new mechanism for the haem-promoted blood-coagulation caused by non-thermal plasma treatment. The reason for the haem role is due to that its oxidized form, namely, hematin, can promote the dityrosine cross-linking of fibrinogen, the most important coagulation protein, to form a membrane-like layer on the surface of the treated blood with plasma exposure. Both haem and non-thermal-plasma generated hydrogen peroxide are requisite for the cross-linking process. We confirmed that fibrinogen can coordinate with the haem iron to form a protein-haem complex which shows pseudo-peroxidase activity, and in the presence of hydrogen peroxide, the complex can induce the dityrosine formation between fibrinogen molecules, leading to the fibrin network necessary for the blood coagulation. Understanding of such an underlying mechanism can be useful to guide more efficient application of non-thermal plasma in the management of hemostasis, thrombosis and etc. PMID:27229173

  19. Haem-assisted dityrosine-cross-linking of fibrinogen under non-thermal plasma exposure: one important mechanism of facilitated blood coagulation.

    PubMed

    Ke, Zhigang; Huang, Qing

    2016-01-01

    Although blood coagulation facilitated by non-thermal plasma has been reported several years ago, the insight to the involved mechanisms is still rather limited. In this work, we report our discovery of a new mechanism for the haem-promoted blood-coagulation caused by non-thermal plasma treatment. The reason for the haem role is due to that its oxidized form, namely, hematin, can promote the dityrosine cross-linking of fibrinogen, the most important coagulation protein, to form a membrane-like layer on the surface of the treated blood with plasma exposure. Both haem and non-thermal-plasma generated hydrogen peroxide are requisite for the cross-linking process. We confirmed that fibrinogen can coordinate with the haem iron to form a protein-haem complex which shows pseudo-peroxidase activity, and in the presence of hydrogen peroxide, the complex can induce the dityrosine formation between fibrinogen molecules, leading to the fibrin network necessary for the blood coagulation. Understanding of such an underlying mechanism can be useful to guide more efficient application of non-thermal plasma in the management of hemostasis, thrombosis and etc. PMID:27229173

  20. Coagulation factor concentrate-based therapy for remote damage control resuscitation (RDCR): a reasonable alternative?

    PubMed

    Maegele, Marc

    2016-04-01

    The concept of remote damage control resuscitation (RDCR) is still in its infancy and there is significant work to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical and if shock and coagulopathy can be rapidly minimized before hospital admission this will very likely reduce morbidity and mortality. The optimum transfusion strategy for these patients is still highly debated and the potential implications of the recently published pragmatic, randomize, optimal platelet, and plasma ratios trial (PROPPR) for RDCR have been reviewed. Identifying the appropriate transfusion strategy is mandatory before adopting prehospital hemostatic resuscitation strategies. An alternative approach is based on the early administration of coagulation factor concentrates combined with the antifibrinolytic tranexamic acid (TXA). The three major components to this approach in the context of RDCR target the following steps to achieve hemostasis: 1) stop (hyper)fibrinolysis; 2) support clot formation; and 3) increase thrombin generation. Strong evidence exists for the use of TXA. The data from the prospective fibrinogen in trauma induced coagulopathy (FIinTIC) study will inform on the prehospital use of fibrinogen in bleeding trauma patients. Deficits in thrombin generation may be addressed by the administration of prothrombin complex concentrates. Handheld point-of-care devices may be able to support and guide the prehospital and remote use of intravenous hemostatic agents including coagulation factor concentrates along with clinical presentation, assessment, and the extent of bleeding. Combinations may even be more effective for bleeding control. More studies are urgently needed. PMID:27100752

  1. Virus elimination during the recycling of chromatographic columns used during the manufacture of coagulation factors.

    PubMed

    Roberts, Peter L

    2014-07-01

    Various chromatographic procedures are used during the purification and manufacture of plasma products such as coagulation factors. These steps contribute to the overall safety of such products by removing potential virus contamination. Virus removal by two affinity chromatography procedures, i.e. monoclonal antibody chromatography and metal chelate chromatography (immobilised metal ion affinity chromatography), used during the manufacture of the high purity factor VIII (Replenate®) and factor IX (Replenine®-VF), respectively, has been investigated. In addition, as these columns are recycled after use, the effectiveness of the sanitisation procedures for preventing possible cross-contamination, has also been investigated. Both chromatographic steps proved effective for eliminating a range of model enveloped and non-enveloped viruses by 4 to >6 and 5 to >8 log for the monoclonal and metal chelate columns, respectively. The effectiveness of the relatively mild column sanitisation conditions used, i.e. ethanol for factor IX and acetic acid for factor VIII, was confirmed using non-spiked column runs. The chemicals used contributed to virus elimination by inactivation and/or by physical removal of the virus. In summary, these studies demonstrate that potential virus contamination between chromatographic runs can be prevented when an effective column recycling and sanitisation procedure is included. PMID:24981392

  2. Genetic variants of coagulation factor XIII, postmenopausal estrogen therapy, and risk of nonfatal myocardial infarction.

    PubMed

    Reiner, Alexander P; Heckbert, Susan R; Vos, Hans L; Ariëns, Robert A S; Lemaitre, Rozenn N; Smith, Nicholas L; Lumley, Thomas; Rea, Thomas D; Hindorff, Lucia A; Schellenbaum, Gina D; Rosendaal, Frits R; Siscovick, David S; Psaty, Bruce M

    2003-07-01

    We hypothesized that possession of either of 2 functional coagulation factor XIII polymorphisms, one within subunit A (Val34Leu) and one within subunit B (His95Arg), might modulate the prothrombotic effects of estrogen and help to explain the variation in incidence of arterial thrombotic events among postmenopausal women using hormone replacement therapy. In a population-based case-control study of 955 postmenopausal women, we assessed the associations of factor XIII genotypes and their interactions with estrogen therapy on risk of nonfatal myocardial infarction (MI). The presence of the factor XIIIA Leu34 allele was associated with a reduced risk of MI (odds ratio [OR] = 0.70, 95% confidence interval [95% CI] = 0.51-0.95). The presence of the factor XIIIB Arg95 allele had little association with MI risk. Neither factor XIII polymorphism alone significantly modified the association between the risk of MI and current estrogen use. In exploratory analyses, however, there was a significant factor XIII subunit gene-gene interaction. Compared to women homozygous for both common factor XIII alleles, the Arg95 variant was associated with a reduced risk of MI in the presence of the Leu34 variant (OR = 0.36, 95% CI = 0.17-0.75) but not in the absence of the Leu34 variant (OR = 1.11, 95% CI = 0.69-1.79). Moreover, among women who had at least 2 copies of the variant factor XIII alleles and were current estrogen users, the risk of MI was reduced by 70% relative to estrogen nonusers with fewer than 2 factor XIII variant alleles (P value for interaction =.03). If confirmed, these findings may permit a better assessment of the cardiovascular risks and benefits associated with postmenopausal estrogen therapy. PMID:12456499

  3. Repeated action of a constant magnetic field on the blood coagulation system in artificially produced anemia

    NASA Technical Reports Server (NTRS)

    Zabrodina, L. V.

    1974-01-01

    Changes are discussed in the coagulatory system of the blood in rabbits under the influence of a constant magnetic field of an intensity of 2500 oersteds against the background of artificially induced anemia. Reversibility of the changes produced and the presence of the adaptational effect are noted. Taking all this into consideration, the changes involving the coagulatory system of the blood which arise under the influence of a constant magnetic field may be considered to have a nerve-reflex nature.

  4. Structural and functional influences of coagulation factor XIII subunit B heterozygous missense mutants

    PubMed Central

    Thomas, Anne; Biswas, Arijit; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2015-01-01

    The coagulation factor XIII(FXIII) is a plasma circulating heterotetrameric protransglutaminase that acts at the end of the coagulation cascade by covalently cross-linking preformed fibrin clots (to themselves and to fibrinolytic inhibitors) in order to stabilize them against fibrinolysis. It circulates in the plasma as a heterotetramer composed of two homomeric catalytic Factor XIIIA2 (FXIIIA2) and two homomeric protective/carrier Factor XIIIB2 subunit (FXIIIB2). Congenital deficiency of FXIII is of two types: severe homozygous/compound heterozygous FXIII deficiency which results in severe bleeding symptoms and mild heterozygous FXIII deficiency which is associated with mild bleeding (only upon trauma) or an asymptomatic phenotype. Defects in the F13B gene (Factor XIIIB subunit) occur more frequently in mild FXIII deficiency patients than in severe FXIII deficiency. We had recently reported secretion-related defects for seven previously reported F13B missense mutations. In the present study we further analyze the underlying molecular pathological mechanisms as well as the heterozygous expression phenotype for these mutations using a combination of in vitro heterologous expression (in HEK293T cells) and confocal microscopy. In combination with the in vitro work we have also performed an in silico solvated molecular dynamic simulation study on previously reported FXIIIB subunit sushi domain homology models in order to predict the putative structure-functional impact of these mutations. We were able to categorize the mutations into the following functional groups that: (1) affect antigenic stability as well as binding to FXIIIA subunit, that is, Cys5Arg, Cys316Phe, and Pro428Ser (2) affect binding to FXIIIA subunit with little or no influence on antigenic stability, that is, Ile81Asn and Val401Gln c) influence neither aspects and are most likely causality linked polymorphisms or functional polymorphisms, that is, Leu116Phe and Val217Ile. The Cys5Arg mutation was the

  5. Structural and functional influences of coagulation factor XIII subunit B heterozygous missense mutants.

    PubMed

    Thomas, Anne; Biswas, Arijit; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2015-07-01

    The coagulation factor XIII(FXIII) is a plasma circulating heterotetrameric protransglutaminase that acts at the end of the coagulation cascade by covalently cross-linking preformed fibrin clots (to themselves and to fibrinolytic inhibitors) in order to stabilize them against fibrinolysis. It circulates in the plasma as a heterotetramer composed of two homomeric catalytic Factor XIIIA2 (FXIIIA2) and two homomeric protective/carrier Factor XIIIB2 subunit (FXIIIB2). Congenital deficiency of FXIII is of two types: severe homozygous/compound heterozygous FXIII deficiency which results in severe bleeding symptoms and mild heterozygous FXIII deficiency which is associated with mild bleeding (only upon trauma) or an asymptomatic phenotype. Defects in the F13B gene (Factor XIIIB subunit) occur more frequently in mild FXIII deficiency patients than in severe FXIII deficiency. We had recently reported secretion-related defects for seven previously reported F13B missense mutations. In the present study we further analyze the underlying molecular pathological mechanisms as well as the heterozygous expression phenotype for these mutations using a combination of in vitro heterologous expression (in HEK293T cells) and confocal microscopy. In combination with the in vitro work we have also performed an in silico solvated molecular dynamic simulation study on previously reported FXIIIB subunit sushi domain homology models in order to predict the putative structure-functional impact of these mutations. We were able to categorize the mutations into the following functional groups that: (1) affect antigenic stability as well as binding to FXIIIA subunit, that is, Cys5Arg, Cys316Phe, and Pro428Ser (2) affect binding to FXIIIA subunit with little or no influence on antigenic stability, that is, Ile81Asn and Val401Gln c) influence neither aspects and are most likely causality linked polymorphisms or functional polymorphisms, that is, Leu116Phe and Val217Ile. The Cys5Arg mutation was the

  6. Blood Component Utilization for Disseminated Intravascular Coagulation (DIC) Cases with Respect to Underlying Condition.

    PubMed

    Gupte, Snehalata C; Jhaveri, Abhay G

    2016-06-01

    To understand transfusion requirement in DIC with respect to (wrt) underlying cause. Patients' details were analyzed using parameters like yearly requirement, hemoglobin (Hb) and blood components utilization wrt age, sex and cause of DIC. Total 1931 DIC cases from 167 hospitals received 21,153 blood units including whole blood, red cell concentrate fresh frozen plasma, random donor platelets, single donor platelets and cryoprecipitate from year 2001 to 2013. Significant risk of DIC was for females compared to males (p < 0.0001). Whole blood utilization was 25.5 % in 2001 which reduced to 1.2 % in 2013. Mean ± SD Hb concentration was 8.6 ± 3.0 in females and 9.8 ± 3.2 g/dL in males. The lowest mean Hb was 7 g/dL in female DIC cases having malignancy. Septicemia was the major cause of DIC followed by obstetric complications. The highest requirement was for trauma associated with septicemia, requiring 35 units/case. Combination of two or more underlying causes for DIC increased the blood component requirement. PMID:27065584

  7. A high affinity monoclonal antibody recognizing the light chain of human coagulating factor VII.

    PubMed

    Sarial, Sheila; Asadi, Farzad; Jeddi-Tehrani, Mahmood; Hadavi, Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Taghizadeh-Jahed, Masoud; Shokri, Fazel; Rabbani, Hodjattallah

    2012-12-01

    Factor VII (FVII) is a serine protease-coagulating element responsible for the initiation of an extrinsic pathway of clot formation. Here we generated and characterized a high affinity monoclonal antibody that specifically recognizes human FVII. Recombinant human FVII (rh-FVII) was used for the production of a monoclonal antibody using BALB/c mice. The specificity of the antibody was determined by Western blot using plasma samples from human, mouse, sheep, goat, bovine, rabbit, and rat. Furthermore, the antibody was used to detect transiently expressed rh-FVII in BHK21 cell line using Western blot and sandwich ELISA. A mouse IgG1 (kappa chain) monoclonal antibody clone 1F1-B11 was produced against rh-FVII. The affinity constant (K(aff)) of the antibody was calculated to be 6.4×10(10) M(-1). The antibody could specifically recognize an epitope on the light chain of hFVII, with no reactivity with factor VII from several other animals. In addition, transiently expressed rh-FVII in BHK21 cells was recognized by 1F1-B11. The high affinity as well as the specificity of 1F1-B11 for hFVII will facilitate the affinity purification of hFVII and also production of FVII deficient plasma and minimizes the risk of bovine FVII contamination when fetal bovine serum-supplemented media are used for production and subsequent purification of rh-FVII. PMID:23244324

  8. Polyphosphate, Platelets, and Coagulation

    PubMed Central

    Travers, Richard J.; Smith, Stephanie A.; Morrissey, James H.

    2015-01-01

    While we have understood the basic outline of the enzymes and reactions that make up the traditional blood coagulation cascade for many years, recently our appreciation of the complexity of these interactions has greatly increased. This has resulted in unofficial “revisions” of the coagulation cascade to include new amplification pathways and connections between the standard coagulation cascade enzymes, as well as the identification of extensive connections between the immune system and the coagulation cascade. The discovery that polyphosphate is stored in platelet dense granules and is secreted during platelet activation has resulted in a recent burst of interest in the role of this ancient molecule in human biology. Here we review the increasingly complex role of platelet polyphosphate in hemostasis, thrombosis, and inflammation that has been uncovered in recent years, as well as novel therapeutics centered on modulating polyphosphate’s roles in coagulation and inflammation. PMID:25976958

  9. Inhibition of coagulation activation and inflammation by a novel Factor Xa inhibitor synthesized from the earthworm Eisenia andrei.

    PubMed

    Joo, Seong Soo; Won, Tae Joon; Kim, Jong Sung; Yoo, Yeong Min; Tak, Eun Sik; Park, So-Young; Park, Hee Yong; Hwang, Kwang Woo; Park, Soon Cheol; Lee, Do Ik

    2009-02-01

    We have cloned an earthworm-derived Factor Xa (FXa) inhibitor, with an excellent inhibitory specificity from the midgut of the Eisenia andrei. We designate this inhibitor eisenstasin. An eisenstasin-derived small peptide (ESP) was synthesized and we examined whether ESP played an essential role in FXa inhibition. Compared to antistasin-derived small peptides (ASP) originating from leech, ESP primarily exhibited a high level of FXa inhibition in chromogenic peptide substrate assays and revealed an approximately 2-fold greater inhibition of FXa cleavage of a target protein than ASP. This suggests that ESP could be an effective anti-coagulant that targets FXa during the propagation step of coagulation. ESP also inhibited proteinase-activated receptor 2-mediated FXa activation, which may trigger endothelial inflammation. Endothelial nitric oxide (NO) was significantly reduced by ESP (p<0.0001), indicating that protease-activated receptor-2 (PAR-2) was effectively inactivated. We also found that ESP reduced the expressions of pro-inflammatory cytokines (IL-1alpha, IL-1beta, IL-8, IL-16, MCP-1, MIP-1alpha and MIP-1beta) by cultured cells treated with both ESP and FXa. Our results provide the first evidence that ESP might interrupt coagulation cascades by inhibiting FXa, and thereby may effectively control the bidirectional alternation between coagulation and inflammation. PMID:19182385

  10. Neutralisation of the anti-coagulant effects of heparin by histones in blood plasma and purified systems.

    PubMed

    Longstaff, Colin; Hogwood, John; Gray, Elaine; Komorowicz, Erzsebet; Varjú, Imre; Varga, Zoltán; Kolev, Krasimir

    2016-03-01

    Neutrophil extracellular traps (NETs) composed primarily of DNA and histones are a link between infection, inflammation and coagulation. NETs promote coagulation and approaches to destabilise NETs have been explored to reduce thrombosis and treat sepsis. Heparinoids bind histones and we report quantitative studies in plasma and purified systems to better understand physiological consequences. Unfractionated heparin (UFH) was investigated by activated partial thromboplastin time (APTT) and alongside low-molecular-weight heparins (LMWH) in purified systems with thrombin or factor Xa (FXa) and antithrombin (AT) to measure the sensitivity of UFH or LMWH to histones. A method was developed to assess the effectiveness of DNA and non-anticoagulant heparinoids as anti-histones. Histones effectively neutralised UFH, the IC50 value for neutralisation of 0.2 IU/ml UFH was 1.8 µg/ml histones in APTT and 4.6 µg/ml against 0.6 IU/ml UFH in a purified system. Histones also inhibited the activities of LMWHs with thrombin (IC50 6.1 and 11.0 µg/ml histones, for different LMWHs) or FXa (IC50 7.8 and 7.0 µg/ml histones). Direct interactions of UFH and LMWH with DNA and histones were explored by surface plasmon resonance, while rheology studies showed complex effects of histones, UFH and LMWH on clot resilience. A conclusion from these studies is that anticoagulation by UFH and LMWH will be compromised by high affinity binding to circulating histones even in the presence of DNA. A complete understanding of the effects of histones, DNA and heparins on the haemostatic system must include an appreciation of direct effects on fibrin and clot structure. PMID:26632486

  11. Defective glycosylation of coagulation factor XII underlies hereditary angioedema type III

    PubMed Central

    Björkqvist, Jenny; de Maat, Steven; Lewandrowski, Urs; Di Gennaro, Antonio; Oschatz, Chris; Schönig, Kai; Nöthen, Markus M.; Drouet, Christian; Braley, Hal; Nolte, Marc W.; Sickmann, Albert; Panousis, Con; Maas, Coen; Renné, Thomas

    2015-01-01

    Hereditary angioedema type III (HAEIII) is a rare inherited swelling disorder that is associated with point mutations in the gene encoding the plasma protease factor XII (FXII). Here, we demonstrate that HAEIII-associated mutant FXII, derived either from HAEIII patients or recombinantly produced, is defective in mucin-type Thr309-linked glycosylation. Loss of glycosylation led to increased contact-mediated autoactivation of zymogen FXII, resulting in excessive activation of the bradykinin-forming kallikrein-kinin pathway. In contrast, both FXII-driven coagulation and the ability of C1-esterase inhibitor to bind and inhibit activated FXII were not affected by the mutation. Intravital laser-scanning microscopy revealed that, compared with control animals, both F12–/– mice reconstituted with recombinant mutant forms of FXII and humanized HAEIII mouse models with inducible liver-specific expression of Thr309Lys-mutated FXII exhibited increased contact-driven microvascular leakage. An FXII-neutralizing antibody abolished bradykinin generation in HAEIII patient plasma and blunted edema in HAEIII mice. Together, the results of this study characterize the mechanism of HAEIII and establish FXII inhibition as a potential therapeutic strategy to interfere with excessive vascular leakage in HAEIII and potentially alleviate edema due to other causes. PMID:26193639

  12. Revisiting the mechanism of coagulation factor XIII activation and regulation from a structure/functional perspective.

    PubMed

    Gupta, Sneha; Biswas, Arijit; Akhter, Mohammad Suhail; Krettler, Christoph; Reinhart, Christoph; Dodt, Johannes; Reuter, Andreas; Philippou, Helen; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2016-01-01

    The activation and regulation of coagulation Factor XIII (FXIII) protein has been the subject of active research for the past three decades. Although discrete evidence exists on various aspects of FXIII activation and regulation a combinatorial structure/functional view in this regard is lacking. In this study, we present results of a structure/function study of the functional chain of events for FXIII. Our study shows how subtle chronological submolecular changes within calcium binding sites can bring about the detailed transformation of the zymogenic FXIII to its activated form especially in the context of FXIIIA and FXIIIB subunit interactions. We demonstrate what aspects of FXIII are important for the stabilization (first calcium binding site) of its zymogenic form and the possible modes of deactivation (thrombin mediated secondary cleavage) of the activated form. Our study for the first time provides a structural outlook of the FXIIIA2B2 heterotetramer assembly, its association and dissociation. The FXIIIB subunits regulatory role in the overall process has also been elaborated upon. In summary, this study provides detailed structural insight into the mechanisms of FXIII activation and regulation that can be used as a template for the development of future highly specific therapeutic inhibitors targeting FXIII in pathological conditions like thrombosis. PMID:27453290

  13. Revisiting the mechanism of coagulation factor XIII activation and regulation from a structure/functional perspective

    PubMed Central

    Gupta, Sneha; Biswas, Arijit; Akhter, Mohammad Suhail; Krettler, Christoph; Reinhart, Christoph; Dodt, Johannes; Reuter, Andreas; Philippou, Helen; Ivaskevicius, Vytautas; Oldenburg, Johannes

    2016-01-01

    The activation and regulation of coagulation Factor XIII (FXIII) protein has been the subject of active research for the past three decades. Although discrete evidence exists on various aspects of FXIII activation and regulation a combinatorial structure/functional view in this regard is lacking. In this study, we present results of a structure/function study of the functional chain of events for FXIII. Our study shows how subtle chronological submolecular changes within calcium binding sites can bring about the detailed transformation of the zymogenic FXIII to its activated form especially in the context of FXIIIA and FXIIIB subunit interactions. We demonstrate what aspects of FXIII are important for the stabilization (first calcium binding site) of its zymogenic form and the possible modes of deactivation (thrombin mediated secondary cleavage) of the activated form. Our study for the first time provides a structural outlook of the FXIIIA2B2 heterotetramer assembly, its association and dissociation. The FXIIIB subunits regulatory role in the overall process has also been elaborated upon. In summary, this study provides detailed structural insight into the mechanisms of FXIII activation and regulation that can be used as a template for the development of future highly specific therapeutic inhibitors targeting FXIII in pathological conditions like thrombosis. PMID:27453290

  14. A novel DFP tripeptide motif interacts with the coagulation factor XI apple 2 domain

    PubMed Central

    Wong, Szu S.; Østergaard, Søren; Hall, Gareth; Li, Chan; Williams, Philip M.; Stennicke, Henning

    2016-01-01

    Factor XI (FXI) is the zymogen of FXIa, which cleaves FIX in the intrinsic pathway of coagulation. FXI is known to exist as a dimer and interacts with multiple proteins via its 4 apple domains in the “saucer section” of the enzyme; however, to date, no complex crystal structure has been described. To investigate protein interactions of FXI, a large random peptide library consisting of 106 to 107 peptides was screened for FXI binding, which identified a series of FXI binding motifs containing the signature Asp-Phe-Pro (DFP) tripeptide. Motifs containing this core tripeptide were found in diverse proteins, including the known ligand high-molecular-weight kininogen (HK), as well as the extracellular matrix proteins laminin and collagen V. To define the binding site on FXI, we determined the crystal structure of FXI in complex with the HK-derived peptide NPISDFPDT. This revealed the location of the DFP peptide bound to the FXI apple 2 domain, and central to the interaction, the DFP phenylalanine side-chain inserts into a major hydrophobic pocket in the apple 2 domain and the isoleucine occupies a flanking minor pocket. Two further structures of FXI in complex with the laminin-derived peptide EFPDFP and a DFP peptide from the random screen demonstrated binding in the same pocket, although in a slightly different conformation, thus revealing some flexibility in the molecular interactions of the FXI apple 2 domain. PMID:27006387

  15. Defective glycosylation of coagulation factor XII underlies hereditary angioedema type III.

    PubMed

    Björkqvist, Jenny; de Maat, Steven; Lewandrowski, Urs; Di Gennaro, Antonio; Oschatz, Chris; Schönig, Kai; Nöthen, Markus M; Drouet, Christian; Braley, Hal; Nolte, Marc W; Sickmann, Albert; Panousis, Con; Maas, Coen; Renné, Thomas

    2015-08-01

    Hereditary angioedema type III (HAEIII) is a rare inherited swelling disorder that is associated with point mutations in the gene encoding the plasma protease factor XII (FXII). Here, we demonstrate that HAEIII-associated mutant FXII, derived either from HAEIII patients or recombinantly produced, is defective in mucin-type Thr309-linked glycosylation. Loss of glycosylation led to increased contact-mediated autoactivation of zymogen FXII, resulting in excessive activation of the bradykinin-forming kallikrein-kinin pathway. In contrast, both FXII-driven coagulation and the ability of C1-esterase inhibitor to bind and inhibit activated FXII were not affected by the mutation. Intravital laser-scanning microscopy revealed that, compared with control animals, both F12-/- mice reconstituted with recombinant mutant forms of FXII and humanized HAEIII mouse models with inducible liver-specific expression of Thr309Lys-mutated FXII exhibited increased contact-driven microvascular leakage. An FXII-neutralizing antibody abolished bradykinin generation in HAEIII patient plasma and blunted edema in HAEIII mice. Together, the results of this study characterize the mechanism of HAEIII and establish FXII inhibition as a potential therapeutic strategy to interfere with excessive vascular leakage in HAEIII and potentially alleviate edema due to other causes. PMID:26193639

  16. Antisense inhibition of coagulation factor XI prolongs APTT without increased bleeding risk in cynomolgus monkeys.

    PubMed

    Younis, Husam S; Crosby, Jeff; Huh, Jung-Im; Lee, Hong Soo; Rime, Soyub; Monia, Brett; Henry, Scott P

    2012-03-01

    A strategy to produce sufficient anticoagulant properties with reduced risk of bleeding may be possible through inhibition of factor XI (FXI), a component of the intrinsic coagulation cascade. The objective of this work was to determine the safety profile of ISIS 416858, a 2'-methoxyethoxy (2'-MOE) antisense oligonucleotide inhibitor of FXI, with focus on assessment of bleeding risk. Cynomolgus monkeys administered ISIS 416858 (4, 8, 12, and 40 mg/kg/wk, subcutaneous) for up to 13 weeks produced a dose-dependent reduction in FXI (mRNA in liver and plasma activity) and a concomitant increase in activated partial thromboplastin time (APTT). ISIS 416858 (20 or 40 mg/kg/wk) reduced plasma FXI activity by 80% at 4 weeks of treatment that resulted in a 33% increase in APTT by 13 weeks with no effects on PT, platelets, or increased bleeding following partial tail amputation or gum and skin laceration. The dose-dependent presence of basophilic granules in multiple tissues in ISIS 416858-treated animals was an expected histologic change for a 2'-MOE antisense oligonucleotide, and no toxicity was attributed to hepatic FXI reduction. Basophilic granules reflect cellular drug uptake and subsequent visualization on hematoxylin staining. These results suggest that ISIS 416858 has an acceptable preclinical safety profile and is a promising clinical candidate to treat thrombotic disease. PMID:22246038

  17. Yogurt: effect on leukocytes and blood coagulation in an acute liver injury model.

    PubMed

    Haro, Cecilia; Lazarte, Sandra; Zelaya, Hortensia; Alvarez, Susana; Agüero, Graciela

    2009-08-01

    This study determined whether cow or goat yogurt administration has a preventive effect on the hepatic damage undergone during an acute liver injury. Acute liver injury was induced by an intraperitoneal injection of d-galactosamine. Groups of mice were fed with cow or goat yogurt for 2 days or 7 days before the d-galactosamine injection. Blood and liver samples were obtained 12 hours after d-galactosamine inoculation. d-Galactosamine induced an increase in serum amino-transaminases, a reduction in the number of blood leukocytes, an enhancement in neutrophil myeloperoxidase activity, a recruitment of leukocytes toward the liver, an increase in cell death, and an alteration in prothrombin time, activated partial thromboplastin time, and fibrinogen levels. Treatment with cow or goat yogurt was effective at increasing leukocyte number and decrease myeloperoxidase activity. We also observed a decrease in leukocyte accumulation in the liver and a reduction in cell death. Activated partial thromboplastin time and fibrinogen were normalized, but prothrombin time only showed an improvement without reaching normal values. Cow or goat yogurts were effective at protecting against an experimental acute liver injury, especially when administered for 7 days. PMID:19735179

  18. Activation of Coagulation by Administration of Recombinant Factor VIIa Elicits Interleukin 6 (IL-6) and IL-8 Release in Healthy Human Subjects

    PubMed Central

    de Jonge, Evert; Friederich, Philip W.; Vlasuk, George P.; Rote, William E.; Vroom, Margaretha B.; Levi, Marcel; van der Poll, Tom

    2003-01-01

    The activation of coagulation has been shown to contribute to proinflammatory responses in animal and in vitro experiments. Here we report that the activation of coagulation in healthy human subjects by the administration of recombinant factor VIIa also elicits a small but significant increase in the concentrations of interleukin 6 (IL-6) and IL-8 in plasma. This increase was absent when the subjects were pretreated with recombinant nematode anticoagulant protein c2, the inhibitor of tissue factor-factor VIIa. PMID:12738659

  19. Improved muscle-derived expression of human coagulation factor IX from a skeletal actin/CMV hybrid enhancer/promoter.

    PubMed

    Hagstrom, J N; Couto, L B; Scallan, C; Burton, M; McCleland, M L; Fields, P A; Arruda, V R; Herzog, R W; High, K A

    2000-04-15

    Hemophilia B is caused by the absence of functional coagulation factor IX (F.IX) and represents an important model for treatment of genetic diseases by gene therapy. Recent studies have shown that intramuscular injection of an adeno-associated viral (AAV) vector into mice and hemophilia B dogs results in vector dose-dependent, long-term expression of biologically active F.IX at therapeutic levels. In this study, we demonstrate that levels of expression of approximately 300 ng/mL (6% of normal human F.IX levels) can be reached by intramuscular injection of mice using a 2- to 4-fold lower vector dose (1 x 10(11) vector genomes/mouse, injected into 4 intramuscular sites) than previously described. This was accomplished through the use of an improved expression cassette that uses the cytomegalovirus (CMV) immediate early enhancer/promoter in combination with a 1.2-kilobase portion of human skeletal actin promoter. These results correlated with enhanced levels of F.IX transcript and secreted F.IX protein in transduced murine C2C12 myotubes. Systemic F.IX expression from constructs containing the CMV enhancer/promoter alone was 120 to 200 ng/mL in mice injected with 1 x 10(11) vector genomes. Muscle-specific promoters performed poorly for F.IX transgene expression in vitro and in vivo. However, the incorporation of a sequence from the alpha-skeletal actin promoter containing at least 1 muscle-specific enhancer and 1 enhancer-like element further improved muscle-derived expression of F.IX from a CMV enhancer/promoter-driven expression cassette over previously published results. These findings will allow the design of a clinical protocol for therapeutic levels of F.IX expression with lower vector doses, thus enhancing efficacy and safety of the protocol. (Blood. 2000;95:2536-2542) PMID:10753832

  20. Effects of three novel metalloproteinases from the venom of the West African saw-scaled viper, Echis ocellatus on blood coagulation and platelets.

    PubMed

    Howes, J-M; Kamiguti, A S; Theakston, R D G; Wilkinson, M C; Laing, G D

    2005-06-20

    Two metalloproteinases, a 24-kDa P-I EoVMP1 and a 56-kDa P-III EoVMP2, have recently been isolated from the venom of the West African saw-scaled viper Echis ocellatus. We now reveal a new 65-kDa haemorrhagic group P-III metalloproteinase which we have designated EoVMP3. The aim of this study was to determine whether these three snake venom metalloproteinases (SVMPs) affect platelets and blood coagulation. EoVMP1 had no effect on the aggregation of washed human platelets, whereas EoVMP2 inhibited collagen-induced platelet aggregation. In contrast, EoVMP3 did not inhibit the aggregation of platelets by collagen but instead activated platelets in the absence of any additional co-factors. All three SVMPs were capable of activating prothrombin to varying degrees and can therefore be described as procoagulants. EoVMP1, EoVMP2 and EoVMP3 share sequence identity with other members of the reprolysin family, but differ greatly in their effects on some of the components that control haemostasis. PMID:15863354

  1. Effect of the root extract of Fagara zanthoxyloides on blood coagulation.

    PubMed

    Essien, E M; Okogun, J I

    1976-12-31

    The clot-promoting activity of the aqueous extract of Fagara-zanthoxyloides Lam plant is described for the first time. It significantly shortened the PTT (K) of normal and factor VIII deficient plasma while it manifested no such action on factor IX-deficient plasma. This activity could be demonstrated in the residue of the lyophilized aqueous extract after its successive extraction with ether, chloroform and methanol. It could not be attributed to the purified fractions: Zanthoxylol or its modified form 3, 4-dihydro-2,2-dimethyl-2H-1 benzopyran-6-butyric acid (DBA), hesperidin, Fagaramide or the ether soluble fraction of the aqueous extract. PMID:1037149

  2. The effect of exercise on coagulation and fibrinolysis factors in patients with peripheral arterial disease.

    PubMed

    Patelis, Nikolaos; Karaolanis, Georgios; Kouvelos, Georgios N; Hart, Collin; Metheiken, Sean

    2016-09-01

    Peripheral arterial disease is a widely prevalent atherosclerotic occlusive disorder. Symptoms commence with exercise-induced pain in the lower extremities, known as claudication. Despite the fact that exercise has been shown to improve fibrinolytic profile some patients, the effect of exercise on coagulation and fibrinolysis cascades in claudicants has not been comprehensively defined. Literature search in English language yielded 13 studies of exercise on claudicants, including 420 patients. Claudicants tend to have a higher coagulation activity at rest compared to healthy individuals, a trend that persists even after exercise. Post-exercise coagulation activity of claudicants is increased when compared to their respective baseline levels, but it is so in a non-consistent manner. From the available data, it has been suggested that claudicants have a functional and effective fibrinolytic mechanism in place, operating continuously at a relatively higher activity level compared to healthy individuals. Fibrinolysis seems to be activated by exercise; a positive outcome with a prolonged effect as shown by a few of the studies. A final conclusion whether coagulation or fibrinolysis activity is affected mostly by exercise type and intensity in claudicants could not be answered. All conclusions regarding the effect of exercise on the coagulation and fibrinolysis mechanisms should be taken under cautious consideration, due to the limited number of studies, the small number of patients and the different exercise strategies employed in each study. Further randomized studies with similar exercise protocols could provide safer conclusions in the future. PMID:27444152

  3. Effects of aliskiren, a renin inhibitor, on biomarkers of platelet activity, coagulation and fibrinolysis in subjects with multiple risk factors for vascular disease.

    PubMed

    Serebruany, V L; Malinin, A; Barsness, G; Vahabi, J; Atar, D

    2008-05-01

    Aliskiren, an octanamide, is nonpeptide, low molecular weight, orally active renin inhibitor effectively preventing angiotensin and aldosterone release. This drug has been recently approved for the treatment of hypertension. Considering potential links between hypertension, platelets, the coagulation cascade and fibrinolysis we sought to evaluate the effect of aliskiren on human biomarkers of hemostasis. In vitro effects of whole blood preincubation with escalating concentrations of aliskiren (500, 1,000 and 2,000 ng ml(-1)) were assessed in 20 aspirin-naive volunteers with multiple risk factors for vascular disease. A total of 33 biomarkers were measured, of which 18 are related to platelet function, 12 to coagulation and 3 to fibrinolysis. Pretreatment of blood samples with aliskiren 500 ng ml(-1) resulted in a significant increase of antithrombin-III (AT-III) activity (P=0.003). All other tested biomarkers were not significantly affected. Spiking whole blood with the higher aliskiren doses was associated with various trends in biomarker activity, where 1000 ng ml(-1) concentration mostly decreased (7/33), and 2,000 ng ml(-1) mostly increased (6/33) some biomarkers. In the therapeutic concentration of 500 ng ml(-1) aliskiren does not affect hemostatic biomarkers, except for a moderate but highly significant (P=0.003) increase of AT-III activity. Higher aliskiren doses were associated with more profound biomarker changes, but they are likely not to be clinically relevant since they show diverging (that is, both mild antiplatelet and platelet-activating) trends, and considering the 2- to 4-fold safety margin. It is suggested that antithrombotic properties of aliskiren be explored further in an ex vivo clinical setting. PMID:18273042

  4. Aestivation induces changes in transcription and translation of coagulation factor II and fibrinogen gamma chain in the liver of the African lungfish Protopterus annectens.

    PubMed

    Hiong, Kum C; Tan, Xiang R; Boo, Mel V; Wong, Wai P; Chew, Shit F; Ip, Yuen K

    2015-12-01

    This study aimed to sequence and characterize two pro-coagulant genes, coagulation factor II (f2) and fibrinogen gamma chain (fgg), from the liver of the African lungfish Protopterus annectens, and to determine their hepatic mRNA expression levels during three phases of aestivation. The protein abundance of F2 and Fgg in the liver and plasma was determined by immunoblotting. The results indicated that F2 and Fgg of P. annectens were phylogenetically closer to those of amphibians than those of teleosts. Three days of aestivation resulted in an up-regulation in the hepatic fgg mRNA expression level, while 6 days of aestivation led to a significant increase (3-fold) in the protein abundance of Fgg in the plasma. Hence, there could be an increase in the blood-clotting ability in P. annectens during the induction phase of aestivation. By contrast, the blood-clotting ability in P. annectens might be reduced in response to decreased blood flow and increased possibility of thrombosis during the maintenance phase of aestivation, as 6 months of aestivation led to significant decreases in mRNA expression levels of f2 and fgg in the liver. There could also be a decrease in the export of F2 and Fgg from the liver to the plasma so as to avert thrombosis. Three to 6 days after arousal from 6 months of aestivation, the protein abundance of F2 and Fgg recovered partially in the plasma of P. annectens; a complete recovery of the transcription and translation of f2/F2 in the liver might occur only after refeeding. PMID:26449974

  5. Effects on fibrinogen, fibrin, and blood coagulation of proteolytic extracts from fruits of Pseudananas macrodontes, Bromelia balansae, and B. hieronymi (Bromeliaceae) in comparison with bromelain.

    PubMed

    Errasti, María E; Prospitti, Anabela; Viana, Carolina A; Gonzalez, Mariana M; Ramos, Márcio V; Rotelli, Alejandra E; Caffini, Néstor O

    2016-06-01

    Extracts rich in cysteine proteases obtained from fruits of Pseudananas macrodontes (Pm), Bromelia balansae (Bb), and B. hieronymi (Bh) have previously shown an anti-inflammatory effect on animal models. Given the close relationship between hemostasis and inflammation, it is attractive to investigate therapeutic agents capable of modulating both systems. The aim of this work was to study the effect of Pm, Bb, and Bh on fibrin(ogen) and blood coagulation compared with stem bromelain (Bro). Action on fibrinogen was electrophoretically and spectrophotometrically evaluated, fibrinolytic activity was measured both electrophoretically and by the fibrin plate assay, and the effect on blood coagulation was studied by conventional coagulation tests (PT and APPT). All extracts showed the same proteolytic preference for fibrinogen subunits, that is Aα > Bβ, whereas γ was partially hydrolyzed by 100-fold concentration increase. Unlike Bro, cysteine proteases of Pm, Bb, and Bh increased absorbance at 540 nm of fibrinogen solution, suggesting thrombin-like activity, which was time-dependent and reached maximum values at lower concentration. All extracts showed the same proteolytic preference for fibrin subunits; however Pm, Bb, and Bh showed lower fibrinolytic activity than Bro at the assayed concentrations. Although Bb acted only as anticoagulant, Pm, Bh, and unexpectedly Bro showed dual action on blood coagulation: at low concentration showed procoagulant effect and at high concentration anticoagulant effect. Results reveal new plant species as potential sources of pharmacological agents for the treatment of a wide range of hemostatic disorders as well as to wound healing. PMID:26886361

  6. In silico designing of hyper-glycosylated analogs for the human coagulation factor IX.

    PubMed

    Ghasemi, Fahimeh; Zomorodipour, Alireza; Karkhane, Ali Asghar; Khorramizadeh, M Reza

    2016-07-01

    N-glycosylation is a process during which a glycan moiety attaches to the asparagine residue in the N-glycosylation consensus sequence (Asn-Xxx-Ser/Thr), where Xxx can be any amino acid except proline. Introduction of a new N-glycosylation site into a protein backbone leads to its hyper-glycosylation, and may improve the protein properties such as solubility, folding, stability, and secretion. Glyco-engineering is an approach to facilitate the hyper-glycosylation of recombinant proteins by application of the site-directed mutagenesis methods. In this regard, selection of a suitable location on the surface of a protein for introduction of a new N-glycosylation site is a main concern. In this work, a computational approach was conducted to select suitable location(s) for introducing new N-glycosylation sites into the human coagulation factor IX (hFIX). With this aim, the first 45 residues of mature hFIX were explored to find out suitable positions for introducing either Asn or Ser/Thr residues, to create new N-glycosylation site(s). Our exploration lead to detection of five potential positions, for hyper-glycosylation. For each suggested position, an analog was defined and subjected for N-glycosylation efficiency prediction. After generation of three-dimensional structures, by homology-based modeling, the five designed analogs were examined by molecular dynamic (MD) simulations, to predict their stability levels and probable structural distortions caused by amino acid substitutions, relative to the native counterpart. Three out of five suggested analogs, namely; E15T, K22N, and R37N, reached equilibration state with relatively constant Root Mean Square Deviation values. Additional analysis on the data obtained during MD simulations, lead us to conclude that, R37N is the only qualified analog with the most similar structure and dynamic behavior to that of the native counterpart, to be considered for further experimental investigations. PMID:27356208

  7. Proof-of-concept Studies for siRNA-mediated Gene Silencing for Coagulation Factors in Rat and Rabbit

    PubMed Central

    Chen, Zhu; Luo, Bin; Cai, Tian-Quan; Thankappan, Anil; Xu, Yiming; Wu, Weizhen; DiMuzio, Jillian; Lifsted, Traci; DiPietro, Marty; Disa, Jyoti; Ng, Bruce; Leander, Karen; Clark, Seth; Hoos, Lizbeth; Zhou, Yuchen; Jochnowitz, Nina; Jachec, Christine; Szczerba, Peter; Gindy, Marian E.; Strapps, Walter; Sepp-Lorenzino, Laura; Seiffert, Dietmar A.; Lubbers, Laura; Tadin-Strapps, Marija

    2015-01-01

    The present study aimed at establishing feasibility of delivering short interfering RNA (siRNA) to target the coagulation cascade in rat and rabbit, two commonly used species for studying thrombosis and hemostasis. siRNAs that produced over 90% mRNA knockdown of rat plasma prekallikrein and rabbit Factor X (FX) were identified from in vitro screens. An ionizable amino lipid based lipid nanoparticle (LNP) formulation for siRNA in vivo delivery was characterized as tolerable and exerting no appreciable effect on coagulability at day 7 postdosing in both species. Both prekallikrein siRNA-LNP and FX siRNA-LNP resulted in dose-dependent and selective knockdown of target gene mRNA in the liver with maximum reduction of over 90% on day 7 following a single dose of siRNA-LNP. Knockdown of plasma prekallikrein was associated with modest clot weight reduction in the rat arteriovenous shunt thrombosis model and no increase in the cuticle bleeding time. Knockdown of FX in the rabbit was accompanied with prolongation in ex vivo clotting times. Results fit the expectations with both targets and demonstrate for the first time, the feasibility of targeting coagulation factors in rat, and, more broadly, targeting a gene of interest in rabbit, via systemic delivery of ionizable LNP formulated siRNA. PMID:25625614

  8. Monocyte tissue factor-dependent activation of coagulation in hypercholesterolemic mice and monkeys is inhibited by simvastatin.

    PubMed

    Owens, A Phillip; Passam, Freda H; Antoniak, Silvio; Marshall, Stephanie M; McDaniel, Allison L; Rudel, Lawrence; Williams, Julie C; Hubbard, Brian K; Dutton, Julie-Ann; Wang, Jianguo; Tobias, Peter S; Curtiss, Linda K; Daugherty, Alan; Kirchhofer, Daniel; Luyendyk, James P; Moriarty, Patrick M; Nagarajan, Shanmugam; Furie, Barbara C; Furie, Bruce; Johns, Douglas G; Temel, Ryan E; Mackman, Nigel

    2012-02-01

    Hypercholesterolemia is a major risk factor for atherosclerosis. It also is associated with platelet hyperactivity, which increases morbidity and mortality from cardiovascular disease. However, the mechanisms by which hypercholesterolemia produces a procoagulant state remain undefined. Atherosclerosis is associated with accumulation of oxidized lipoproteins within atherosclerotic lesions. Small quantities of oxidized lipoproteins are also present in the circulation of patients with coronary artery disease. We therefore hypothesized that hypercholesterolemia leads to elevated levels of oxidized LDL (oxLDL) in plasma and that this induces expression of the procoagulant protein tissue factor (TF) in monocytes. In support of this hypothesis, we report here that oxLDL induced TF expression in human monocytic cells and monocytes. In addition, patients with familial hypercholesterolemia had elevated levels of plasma microparticle (MP) TF activity. Furthermore, a high-fat diet induced a time-dependent increase in plasma MP TF activity and activation of coagulation in both LDL receptor-deficient mice and African green monkeys. Genetic deficiency of TF in bone marrow cells reduced coagulation in hypercholesterolemic mice, consistent with a major role for monocyte-derived TF in the activation of coagulation. Similarly, a deficiency of either TLR4 or TLR6 reduced levels of MP TF activity. Simvastatin treatment of hypercholesterolemic mice and monkeys reduced oxLDL, monocyte TF expression, MP TF activity, activation of coagulation, and inflammation, without affecting total cholesterol levels. Our results suggest that the prothrombotic state associated with hypercholesterolemia is caused by oxLDL-mediated induction of TF expression in monocytes via engagement of a TLR4/TLR6 complex. PMID:22214850

  9. Markers of inflammation, activation of blood platelets and coagulation disorders in inflammatory bowel diseases.

    PubMed

    Matowicka-Karna, Joanna

    2016-01-01

    Inflammatory bowel disease (IBD) includes ulcerative colitis and Crohn's disease. It is a group of chronic disorders characterized by inflammation of the gastrointestinal track with unknown etiology. Currently applied biomarkers include CRP, ESR, pANCA, ASCA, and fecal calprotectin. The etiopathogenesis of IBD is multifactorial. In patients with IBD in inflamed alimentary tract mucosa the number of recruited monocytes and activated macrophages which are source of cytokines. In IBD, the exacerbation is accompanied by thrombocytosis. Platelets play a crucial role in the hemostasis and inflammatory response. Selectins, which regulates the hemostasis and inflammatory response, stimulates the secretion of many inflammatory mediators such as β-thromboglobuline, CD40L, fibrinogen, IL-1β, platelet factor-4. In the course of IBD the following changes are observed: an increase in the number of platelets (reactive thrombocytosis), PDW and PCT, reduction in MPV, increased production and excretion of granular content products (P-selectin, GP53, β-TG, PF-4, vWF, fibrinolytic inhibitors). PMID:27117106

  10. The Association of Coagulation Factor V (Leiden) and Factor II (Prothrombin) Mutations With Stroke

    PubMed Central

    Pirhoushiaran, Maryam; Ghasemi, Mohammad Reza; Hami, Javad; Zargari, Peyman; Sasan Nezhad, Payam; Azarpazhooh, Mahmood Reza; Sadr Nabavi, Ariane

    2014-01-01

    Background: Epidemiological studies indicate that over the past forty years, the stroke incidence rates has increased. Factors V and II mutations are established genetic-variant risk factors for venous thrombosis; however, their contribution to stroke is a controversial issue. Objectives: This study aimed to investigate the potential association of FV and FII mutations with stroke in an Iranian population. Patients and Methods: The study population consisted of 153 patients of different stroke subtypes (except cryptogenic strokes), admitted to Ghaem Hospital, Mashhad, Iran. The control group included 153 age- and sex-matched subjects without a history of cerebrovascular or neurologic diseases. Mutations of FV and FII were determined by using a TaqMan SNP Genotyping technique. The chi-square and Exact Fisher tests were used to analyze the baseline characteristics. Results were as follows: The calculated P-value for sex and diabetes mellitus were 0.907 and 1.000, respectively. The case and control groups were also matched in low density lipoprotein (P = 0.816), high density lipoprotein (P = 0.323), triglyceride (P = 0.846), and total cholesterol (P = 0.079). Results: Analysis of the FV showed that none of the study subjects were AA homozygous for this mutation and only 6 heterozygous subjects were detected in the case and control groups. Regarding FII variants, none of the study subjects were AG heterozygous and only 1 AA homozygous was detected in the control group. Conclusions: The prevalence of both FV and FII variants are population based. Iran is an ethnically diverse country. Therefore, for a comprehensive analysis of a potential association of FV and/or FII mutations with stroke among Iranian population, epidemiological studies could be conducted among different ethnic groups. PMID:25763204