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Sample records for hematocrit inhibits clotting

  1. The influence of inflammation and hematocrit on clot strength in canine thromboelastographic hypercoagulability.

    Science.gov (United States)

    Marschner, Clara B; Wiinberg, Bo; Tarnow, Inge; Markussen, Bo; Kühnel, Line; Bochsen, Louise; Kristensen, Annemarie T

    2018-01-01

    To investigate parameters causing canine thromboelastographic hypercoagulability and to investigate whether thromboelastography (TEG) with Cytochalasin D (Cyt D) added is related to parameters of platelet activity. Prospective observational study on hemostatic and inflammatory parameters. Data were collected between November 2012 and July 2013. University teaching hospital. Twenty-eight dogs suffering from diseases predisposing to thrombosis and 19 clinically healthy dogs. Diseased dogs were enrolled if they fulfilled inclusion criteria regarding age, size, informed client consent, and obtained a diagnosis of a disease that has been associated with thrombosis or hypercoagulability. None. Parameters of coagulation and anticoagulation, fibrinolysis, and antifibrinolysis, platelet activity, inflammation, platelet count, and hematocrit were measured using CBC, TEG, platelet aggregation on multiplate, platelet activity on flow cytometry, and hemostatic and inflammatory markers on plasma and serum analyses. ANOVA and multilinear regression analyses indicated that especially hematocrit and the inflammatory parameters C-reactive protein and interleukin-8 showed best association with overall clot strength in diseased dogs with hypercoagulable TEG tracings. Ratios presumed to reflect platelet contribution to the TEG tracing obtained in TEG analyses with Cyt D were related especially with hematocrit and P-selectin expression of platelets measured after γ-Thrombin activation on flow cytometry. Overall clot strength in TEG analyses of the hypercoagulable dogs included in the present study appears to be primarily associated with inflammation as well as hematocrit. Furthermore, the ratio between standard TEG analyses and TEG analyses with Cyt D may reflect some degree of platelet activity. © Veterinary Emergency and Critical Care Society 2017.

  2. Probing the coagulation pathway with aptamers identifies combinations that synergistically inhibit blood clot formation.

    Science.gov (United States)

    Bompiani, Kristin M; Lohrmann, Jens L; Pitoc, George A; Frederiksen, James W; Mackensen, George B; Sullenger, Bruce A

    2014-08-14

    Coordinated enzymatic reactions regulate blood clot generation. To explore the contributions of various coagulation enzymes in this process, we utilized a panel of aptamers against factors VIIa, IXa, Xa, and prothrombin. Each aptamer dose-dependently inhibited clot formation, yet none was able to completely impede this process in highly procoagulant settings. However, several combinations of two aptamers synergistically impaired clot formation. One extremely potent aptamer combination was able to maintain human blood fluidity even during extracorporeal circulation, a highly procoagulant setting encountered during cardiopulmonary bypass surgery. Moreover, this aptamer cocktail could be rapidly reversed with antidotes to restore normal hemostasis, indicating that even highly potent aptamer combinations can be rapidly controlled. These studies highlight the potential utility of using sets of aptamers to probe the functions of proteins in molecular pathways for research and therapeutic ends. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. 14-Day thawed plasma retains clot enhancing properties and inhibits tPA-induced fibrinolysis.

    Science.gov (United States)

    Huebner, Benjamin R; Moore, Ernest E; Moore, Hunter B; Shepherd-Singh, Raymond; Sauaia, Angela; Stettler, Gregory R; Nunns, Geoffrey R; Silliman, Christopher C

    2017-11-01

    Plasma-first resuscitation attenuates trauma-induced coagulopathy (TIC); however, the logistics of plasma-first resuscitation require thawed plasma (TP) be readily available due to the obligatory thawing time of fresh frozen plasma (FFP). The current standard is storage of TP for up to 5 days at 4°C, based on factor levels at outdate, for use in patients at risk for TIC, but there remains a 2.2% outdated wastage rate. However, the multitude of plasma proteins in attenuating TIC remains unknown. We hypothesize that TP retains the ability to enhance clotting and reduce tPA-induced fibrinolysis at 14-day storage. FFP was thawed and stored at 4°C at the following intervals: 14, 10, 7, 5, 3, and 1-day prior to the experiment. Healthy volunteers underwent blood draws followed by 50% dilution with TP stored at previously mentioned intervals as well as FFP, normal saline (NS), albumin, and whole blood (WB) control. Samples underwent tPA-modified (75 ng/mL) thrombelastography (TEG) with analysis of R-time, angle, maximum amplitude (MA), and LY30. TEG properties did not change significantly over the thawed storage. 14-day TP retained the ability to inhibit tPA-induced hyperfibrinolysis (median LY30% 9.6%) similar to FFP (5.6%), WB (14.6%), and superior to albumin (59.3%) and NS (58.1%). 14-day TP also retained faster clot formation (median angle, 66.2°) and superior clot strength (MA, 61.5 mm) to albumin (34.8°, 21.6 mm) and NS (41.6°, 32.2 mm). TP plasma stored for 14 days retains clot-enhancing ability and resistance to clot degradation similar to FFP. A clinical trial is needed to validate these in vitro results. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Blood Clots

    Science.gov (United States)

    ... much or prevent blood clots from dissolving properly. Risk factors for excessive blood clotting include Certain genetic disorders Atherosclerosis Diabetes Atrial fibrillation Overweight, obesity, and metabolic syndrome Some medicines Smoking Staying in ...

  5. Tissue factor-expressing monocytes inhibit fibrinolysis through a TAFI-mediated mechanism, and make clots resistant to heparins

    Science.gov (United States)

    Semeraro, Fabrizio; Ammollo, Concetta T.; Semeraro, Nicola; Colucci, Mario

    2009-01-01

    Background Thrombin is the main activator of the fibrinolysis inhibitor TAFI (thrombin activatable fibrinolysis inhibitor) and heightened clotting activation is believed to impair fibrinolysis through the increase of thrombin activatable fibrinolysis inhibitor activation. However, the enhancement of thrombin generation by soluble tissue factor was reported to have no effect on plasma fibrinolysis and it is not known whether the same is true for cell-associated tissue factor. The aim of this study was to evaluate the effect of tissue factor-expressing monocytes on plasma fibrinolysis in vitro. Design and Methods Tissue factor expression by human blood mononuclear cells (MNC) and monocytes was induced by LPS stimulation. Fibrinolysis was spectrophotometrically evaluated by measuring the lysis time of plasma clots containing LPS-stimulated or control cells and a low concentration of exogenous tissue plasminogen activator. Results LPS-stimulated MNC (LPS-MNC) prolonged fibrinolysis time as compared to unstimulated MNC (C-MNC) in contact-inhibited but not in normal citrated plasma. A significantly prolonged lysis time was observed using as few as 30 activated cells/μL. Fibrinolysis was also impaired when clots were generated on adherent LPS-stimulated monocytes. The antifibrinolytic effect of LPS-MNC or LPS-monocytes was abolished by an anti-tissue factor antibody, by an antibody preventing thrombin-mediated thrombin activatable fibrinolysis inhibitor activation, and by a TAFIa inhibitor (PTCI). Assays of thrombin and TAFIa in contact-inhibited plasma confirmed the greater generation of these enzymes in the presence of LPS-MNC. Finally, the profibrinolytic effect of unfractionated heparin and enoxaparin was markedly lower (~50%) in the presence of LPS-MNC than in the presence of a thromboplastin preparation displaying an identical tissue factor activity. Conclusions Our data indicate that LPS-stimulated monocytes inhibit fibrinolysis through a tissue factor

  6. Coagulation-dependent inhibition of fibrinolysis: role of carboxypeptidase-U and the premature lysis of clots from hemophilic plasma.

    Science.gov (United States)

    Broze, G J; Higuchi, D A

    1996-11-15

    Coagulation is initiated by the binding of factor VIIa to tissue factor, with resultant limited factor IX and X activation and thrombin production. Owing to the feedback inhibition of the factor VIIa/tissue factor complex by tissue factor pathway inhibitor (TFPI), additional factor X activation and thrombin generation must proceed through a pathway involving factors VIII, IX, and XI. Experiments designed to elucidate the requirement for amplified factor Xa and thrombin generation in normal hemostasis show that the resistance of plasma clots to tissue plasminogen activator (tPA)- and urokinase-induced fibrinolysis is related to the extent of thrombin generation. Inhibition of fibrinolysis is mediated in part by plasma carboxypeptidase-U ([CPU] carboxypeptidase-R, procarboxypeptidase-B, thrombin-activatable fibrinolysis inhibitor), a proenzyme that is proteolytically activated by thrombin in a process enhanced dramatically by the cofactor thrombomodulin. A clot induced in factor IX-deficient plasma with limited amounts of tissue factor in the presence of urokinase (100 U/mL) lyses prematurely, and this defect is corrected by supplementation of the deficient plasma with factor IX (5 micrograms/mL) or thrombomodulin (20 ng/mL). These additions enhance the rate and extent of CPU activation: in the case of factor IX, presumably by permitting amplified generation of factor Xa and thrombin, and in the case of thrombomodulin, presumably by increasing the degree of CPU activation produced by the low levels of thrombin generated in the absence of factor IX. Pretreatment of the factor IX-deficient plasma with specific anti-CPU antibodies prevents the increased resistance to fibrinolysis produced by addition of factor IX and thrombomodulin. Likewise, when coagulation is induced by thrombin (2 U/mL) in the presence of tPA (60 U/mL), clots formed from plasmas deficient in factors VIII, IX, X, or XI lyse prematurely unless the missing factor is replaced or thrombomodulin (20 ng

  7. Blood Clots

    Science.gov (United States)

    Symptoms Blood clots By Mayo Clinic Staff Blood clots are gel-like clumps of blood. They are beneficial when they form in response to an injury or a cut, plugging the injured blood vessel, which stops bleeding. Some blood clots form inside your veins without a good reason and don't ...

  8. How Blood Clots

    Science.gov (United States)

    ... Clotting Process How Blood Clots Bruising and Bleeding Hemostasis is the body's way of stopping injured blood vessels from bleeding. Hemostasis includes clotting of the blood. Too much clotting ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  10. Blood Clotting and Pregnancy

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    Full Text Available ... For Patients Blood Disorders Blood Clots Blood Clotting & Pregnancy If you are pregnant, or you have just ... The risk of developing a blood clot during pregnancy is increased by the following: Previous blood clots ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... Toolkit Home For Patients Blood Disorders Blood Clots Blood Clotting & Pregnancy If you are pregnant, or you ... g., cancer, infection) back to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Clots and Travel Blood Clotting and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  13. Blood Clotting and Pregnancy

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  14. Blood Clotting and Pregnancy

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  15. Blood Clotting and Pregnancy

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  16. Blood Clotting and Pregnancy

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    Full Text Available ... pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ... blood clots or blood clotting disorders in your family. Remain active, with your doctor's approval. Be aware ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... increased by the following: Previous blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e. ... Be aware of risk factors. Know your family history. Make sure your doctor knows about any history ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... for Educators Resources for Patients View all Guidelines & Quality Care Resources to help practitioners improve patient care ... with Your Doctor Patient Group Links Advocacy Toolkit Home For Patients Blood Disorders Blood Clots Blood Clotting & ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... are pregnant, or you have just had a baby, you are at greater risk of developing a ... Blood clots are also potentially dangerous to your baby. Blood clots can form inside the placenta, cutting ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... with Your Doctor Patient Group Links Advocacy Toolkit Home For Patients Blood Disorders Blood Clots Blood Clotting & ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  1. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants ... that may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official ...

  2. Blood Clotting and Pregnancy

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    Full Text Available ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during pregnancy is ... prevent blood clots during pregnancy: Be aware of risk factors. Know your family history. Make sure your ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) ...

  5. Ischemic Strokes (Clots)

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    ... Month Infographic Stroke Hero F.A.S.T. Quiz Ischemic Strokes (Clots) Updated:Apr 26,2017 Ischemic stroke ... stroke. Let's Talk Numbers Updated Guidelines for Acute Ischemic Strokes Infographic : Attacking Brain Clots to Save Lives ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... increased by the following: Previous blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  8. Blood Clotting and Pregnancy

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    Full Text Available ... Other medical illness (e.g., cancer, infection) back to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants are safe to use during pregnancy. back to top Are Blood ...

  9. Simukunin from the salivary glands of the black fly Simulium vittatum inhibits enzymes that regulate clotting and inflammatory responses.

    Directory of Open Access Journals (Sweden)

    Hitoshi Tsujimoto

    Full Text Available BACKGROUND: Black flies (Diptera: Simuliidae feed on blood, and are important vectors of Onchocerca volvulus, the etiolytic agent of River Blindness. Blood feeding depends on pharmacological properties of saliva, including anticoagulation, but the molecules responsible for this activity have not been well characterized. METHODOLOGY/PRINCIPAL FINDINGS: Two Kunitz family proteins, SV-66 and SV-170, were identified in the sialome of the black fly Simulium vittatum. As Kunitz proteins are inhibitors of serine proteases, we hypothesized that SV-66 and/or -170 were involved in the anticoagulant activity of black fly saliva. Our results indicated that recombinant (r SV-66 but not rSV-170 inhibited plasma coagulation. Mutational analysis suggested that SV-66 is a canonical BPTI-like inhibitor. Functional assays indicated that rSV66 reduced the activity of ten serine proteases, including several involved in mammalian coagulation. rSV-66 most strongly inhibited the activity of Factor Xa, elastase, and cathepsin G, exhibited lesser inhibitory activity against Factor IXa, Factor XIa, and plasmin, and exhibited no activity against Factor XIIa and thrombin. Surface plasmon resonance studies indicated that rSV-66 bound with highest affinity to elastase (K(D = 0.4 nM and to the active site of FXa (K(D = 3.07 nM. We propose the name "Simukunin" for this novel protein. CONCLUSIONS: We conclude that Simukunin preferentially inhibits Factor Xa. The inhibition of elastase and cathepsin G further suggests this protein may modulate inflammation, which could potentially affect pathogen transmission.

  10. Blood Clotting and Pregnancy

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    Full Text Available ... Be aware of risk factors. Know your family history. Make sure your doctor knows about any history of blood clots or blood clotting disorders in ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... developing a blood clot. Blood clots in pregnant women tend to form in the deep veins of the legs or in the pelvic area. This condition is known as deep vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening event that occurs when a DVT breaks ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... increased by the following: Previous blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top ...

  13. Blood Clotting and Pregnancy

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    Full Text Available ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during ... Advances The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards Membership ...

  14. Blood Clotting and Pregnancy

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    Full Text Available ... Action Alerts Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy Statements Congressional Fellowship Testimony and Correspondence ... View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous to your baby. ... immobility (e.g., bedrest, long distance travel) ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... a blood clot . Visit your doctor immediately if you think you have one. If you are pregnant and ... American Society of Hematology Support Opportunities | Privacy Policy | Terms of Service | Contact Us

  17. Blood Clotting and Pregnancy

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    Full Text Available ... Clotting & Pregnancy If you are pregnant, or you have just had a baby, you are at greater ... Visit your doctor immediately if you think you have one. If you are pregnant and have concerns ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... known as venous thromboembolism, are highly preventable (see prevention tips below). The U.S. Surgeon General has issued ... blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during ... Patients ASH Academy ASH On Demand ASH Image Bank Advocacy Action Alerts Policy News Advocacy Leadership Institute ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are ...

  1. Blood Clotting and Pregnancy

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    Full Text Available ... clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  2. Blood Clotting and Pregnancy

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    Full Text Available ... an immediate impact on your practice Summit on Emerging Immunotherapies Registration Schedule & Program Meeting on Lymphoma Biology ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during ...

  3. Dynamics of pathologic clot formation: a mathematical model.

    Science.gov (United States)

    Shavlyugin, Evgeny A; Hanin, Leonid G; Khanin, Mikhail A

    2014-01-07

    Recent studies have provided evidence of a significant role of the Hageman factor in pathologic clot formation. Since auto-activation of the Hageman factor triggers the intrinsic coagulation pathway, we study the dynamics of pathologic clot formation considering the intrinsic pathway as the predominant mechanism of this process. Our methodological approach to studying the dynamics of clot formation is based on mathematical modelling. Activation of the blood coagulation cascade, particularly its intrinsic pathway, is known to involve platelets. Therefore, equations accounting for the effects of activated platelets on the intrinsic pathway activation are included in our model. This brings about a considerable increase in the values of kinetic constants involved in the model of the principal biochemical processes resulting in clot formation. The purpose of this study is to elucidate the mechanism of pathologic clot formation. Since the time window of thrombolysis is 3-6h, we hypothesize that in many cases the rate of pathologic clot formation is much lower than that of haemostatic clot. This assumption is used to simplify the mathematical model and to estimate kinetic constants of biochemical reactions that initiate pathologic clot formation. The insights we gained from our mathematical model may lead to new approaches to the prophylaxis of pathologic clot formation. We believe that one of the most efficient ways to prevent pathologic clot formation is simultaneous inhibition of activated factors ХII and ХI. © 2013 Elsevier Ltd. All rights reserved.

  4. Freeze-dried plasma enhances clot formation and inhibits fibrinolysis in the presence of tissue plasminogen activator similar to pooled liquid plasma.

    Science.gov (United States)

    Huebner, Benjamin R; Moore, Ernest E; Moore, Hunter B; Sauaia, Angela; Stettler, Gregory; Dzieciatkowska, Monika; Hansen, Kirk; Banerjee, Anirban; Silliman, Christopher C

    2017-08-01

    Systemic hyperfibrinolysis is an integral part of trauma-induced coagulopathy associated with uncontrolled bleeding. Recent data suggest that plasma-first resuscitation attenuates hyperfibrinolysis; however, the availability, transport, storage, and administration of plasma in austere environments remain challenging and have limited its use. Freeze-dried plasma (FDP) is a potential alternative due to ease of storage, longer shelf life, and efficient reconstitution. FDP potentially enhances clot formation and resists breakdown better than normal saline (NS) and albumin and similar to liquid plasma. Healthy volunteers underwent citrated blood draw followed by 50% dilution with NS, albumin, pooled plasma (PP), or pooled freeze-dried plasma (pFDP). Citrated native and tissue plasminogen activator (t-PA)-challenge (75 ng/mL) thrombelastography were done. Proteins in PP, pFDP, and albumin were analyzed by mass spectroscopy. pFDP and PP had superior clot-formation rates (angle) and clot strength (maximum amplitude) compared with NS and albumin in t-PA-challenge thrombelastographies (angle: pFDP, 67.9 degrees; PP, 67.8 degrees; NS, 40.6 degrees; albumin, 35.8 degrees; maximum amplitude: pFDP, 62.4 mm; PP, 63.5 mm; NS, 44.8 mm; albumin, 41.1 mm). NS and albumin dilution increased susceptibility to t-PA-induced hyperfibrinolysis compared with pFDP and PP (NS, 62.4%; albumin, 62.6%; PP, 8.5%; pFDP, 6.7%). pFDP was similar to PP in the attenuation of t-PA-induced fibrinolysis. Most proteins (97%) were conserved during the freeze-dry process, with higher levels in 12% of pFDP proteins compared with PP. pFDP enhances clot formation and attenuates hyperfibrinolysis better than NS and albumin and is a potential alternative to plasma resuscitation in the treatment of hemorrhagic shock. © 2017 AABB.

  5. Hematocrit Test: MedlinePlus Lab Test Information

    Science.gov (United States)

    ... page: https://medlineplus.gov/labtests/hematocrittest.html Hematocrit Test To use the sharing features on this page, please enable JavaScript. What is a Hematocrit Test? A hematocrit test is a type of blood ...

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

    Directory of Open Access Journals (Sweden)

    Lesley J. Smith

    2008-01-01

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

  7. The influence of inflammation and hematocrit on clot strength in canine thromboelastographic hypercoagulability

    DEFF Research Database (Denmark)

    Marschner, Clara B.; Wiinberg, Bo; Tarnow, Inge

    2018-01-01

    Objective: To investigate parameters causing canine thromboelastographic hypercoagulability and to investigate whether thromboelastography (TEG) with Cytochalasin D (Cyt D) added is related to parameters of platelet activity. Design: Prospective observational study on hemostatic and inflammatory ...

  8. Exercise-induced changes in hematocrit and hematocrit/viscosity ratio in male rugby players.

    Science.gov (United States)

    Varlet-Marie, Emmanuelle; Brun, Jean-Frédéric; Raynaud de Mauverger, Eric; Fédou, Christine

    2016-01-01

    We investigated whether the concept of hematocrit/viscosity (h/η) ratio explains the "paradox of hematocrit in athletes", by calculating a "theoretical optimal hematocrit" (i.e., associated with the higher h/η value predicted with Quemada's equation from plasma viscosity, and erythrocyte rigidity index) before and after exercise. 14 rugby players (19-31 yr; weight 65.8-109.2 kg; height 1.7-1.96 m; BMI 21.7-33.1 kg/m2) underwent a standardized submaximal exercise session on cycloergometer corresponding to 225 kjoules over 30 min. The rheologic response to exercise was measured with the MT90 viscometer and the Myrenne aggregometer. After exercise there was an increase in whole blood viscosity (p values of h/η and hematocrit by models may help to interpret the actual values of these parameters. However, these models need to be more extendedly tested and improved.

  9. Reliability of hematocrit during rest and stress in healthy adults.

    NARCIS (Netherlands)

    Ring, C.; Patterson, S.M.; Bacon, S.L.; Veldhuijzen van Zanten, J.J.; Willemsen, G.; Carroll, D.

    2008-01-01

    Hematocrit has been implicated in the triggering of cardiovascular events and the development of cardiovascular disease. Studies have demonstrated the reliability of hematocrit at rest, however, data are lacking about hematocrit during repeated acute stress exposures. The current study assessed the

  10. Distinct increase in hematocrit associated with paroxysm of atrial fibrillation.

    Science.gov (United States)

    Okuno, S; Ashida, T; Ebihara, A; Sugiyama, T; Fujii, J

    2000-09-01

    In a previous study we found that hemoconcentration, which was identified by an increase in hematocrit, occured during a paroxysm of atrial fibrillation. In the present study we investigated the changes in hematocrit from sinus rhythm to paroxysm in 10 patients who had multiple paroxysms of atrial fibrillation in order to assess the ranges of the changes in hematocrit among the paroxysms. In these patients hematocrit was measured simultaneously with electrocardiographic recording during 3 or more paroxysms and sinus rhythm just before each paroxysm. The changes in hematocrit varied among the paroxysms. The maximum increase in hematocrit in each patient ranged from 3.5 to 8.0 points with an average of 5.1 points. Such a distinct increase in hematocrit which abruptly develops with a paroxysm of atrial fibrillation may be a potential risk for thrombus formation.

  11. Preavoidance hypercapnia and decreased hematocrit in micropigs.

    Science.gov (United States)

    Anderson, D E; Fedorova, O V; French, A W

    1996-01-01

    Previous studies found that regular confinement of dogs in an experimental environment preceding onset of an avoidance task was associated with increases in blood pressure and decreases in heart rate and respiration rate that were not prevented by adrenergic antagonists. The present study investigated a) whether divergent changes in blood pressure and heart rate also occur in micropigs preceding onset of an avoidance task, and b) the nature of changes in blood gases, plasma pH, plasma bicarbonate, hematocrit, and plasma electrolytes observed under these conditions. Blood pressure increased and heart rate decreased during 2-h preavoidance periods, whereas both blood pressure and heart rate were elevated during 20-min avoidance periods. During preavoidance periods, pO2, plasma pH, and plasma potassium pCO2 were decreased below home kennel levels during early preavoidance, whereas pCO2 and plasma bicarbonate were persistently increased and hematocrit was persistently decreased for the duration of the preavoidance periods. Each of these changes was reversed during the avoidance sessions. These findings suggest that behaviorally induced hypercapnia might participate in blood pressure regulation via increased renal sodium/hydrogen exchange and renal sodium retention.

  12. Peroxynitrite may affect fibrinolysis via the reduction of platelet-related fibrinolysis resistance and alteration of clot structure.

    Science.gov (United States)

    Misztal, Tomasz; Rusak, Tomasz; Brańska-Januszewska, Justyna; Ostrowska, Halina; Tomasiak, Marian

    2015-12-01

    We tested the hypothesis that in vitro peroxynitrite (ONOO(-), a product of activated inflammatory cells) may affect fibrinolysis in human blood through the reduction of platelet-related fibrinolysis resistance. It was found that ONOO(-) (25-300 µM) accelerated lysis of platelet-fibrin clots (in PRP) dose-dependently, whereas fibrinolysis of platelet-free clots was slightly inhibited by ≥ 1000 µM stressor. Concentrations of ONOO(-) affecting the lysis of platelet-rich clots, inhibited clot retraction (CR) in a dose-dependent manner. Thromboelastometry (ROTEM) measurements performed in PRP showed that treatment with ONOO(-) (threshold conc. 100 µM) prolongs clotting time, and reduces alpha angle, and clot formation velocity parameters indicating for reduced thrombin formation rate. In PRP, ONOO(-) (threshold conc. 100 µM) reduced the collagen-evoked exposure of phosphatidylserine (PS) on platelets' plasma membrane, the shedding of platelet-derived microparticles (PMP), and inhibited platelet-dependent thrombin generation (measured in artificial system), dose-dependently. As judged by confocal microscopy, similar ONOO(-) concentrations altered the architecture of clots formed in collagen-treated PRP. Clots formed in the presence of ONOO(-) were less dense and were composed of thicker fibers, which make them more susceptible to lysis. In platelet-depleted plasma, ONOO(-) (up to milimolar concentration) did not alter clot structure. Blockage of PS exposed on platelets resulted in an alteration of clot architecture toward more prone to lysis. ONOO(-), at lysis-affecting concentrations, inhibited the collagen-evoked secretion of fibrinolytic inhibitors from platelets. We conclude that physiologically relevant ONOO(-) concentrations may accelerate the lysis of platelet-fibrin clots predominantly via downregulation of platelet-related mechanisms including: platelet secretion, clot retraction, platelet procoagulant response, and the alteration in clot architecture

  13. The Hematocrit Affects the Volume of Plasma Treated With Coupled Plasma Filtration and Adsorption With Predilution.

    Science.gov (United States)

    Finazzi, Stefano; Garbero, Elena; Trussardi, Giampietro; Bertolini, Guido

    2017-05-01

    Coupled plasma filtration and adsorption (CPFA) is an extracorporeal blood purification technique proposed for the treatment of septic-shock. By removing pro- and anti-inflammatory mediators from plasma, CPFA is supposed to have a therapeutic effect on the abnormal inflammatory response seen in this condition. Recently, blood predilution with citrate solution has been adopted to prevent clotting in the CPFA circuit-one of the main problems of the technique. Taking into account the patient's hematocrit, we worked out a formula for the volume of plasma effectively treated by CPFA after predilution. Neglecting this effect, as is commonly done, introduces significant distortions in the estimation of the volume, possibly causing under-treatment. The distortion is stronger when the hematocrit and the predilution fraction are large and weaker when both values shrink. By correctly indicating the daily dose of plasma adsorption received by patients, this formula is essential for assessing the therapeutic efficacy of CPFA and, subsequently, establishing its optimal doses. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  14. Obstructive anuria due to blood clot.

    Science.gov (United States)

    Gupta, Anjali; Nanda, Smiti; Singhal, Savita Rani; Gupta, Anshu

    2008-10-01

    An unusual case of anuria due to the obstruction caused by blood clot following repair of ruptured uterus is presented. Although the blood clot usually dissolves, the awareness of this complication is important to avoid the unnecessary procedures.

  15. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Clots After Orthopaedic Surgery One of the major risks facing patients who undergo surgery is a complication ... on the legs and hip are especially at risk. A pulmonary embolism is a blood clot that ...

  16. Understand Your Risk for Excessive Blood Clotting

    Science.gov (United States)

    ... Vascular Health Peripheral Artery Disease Venous Thromboembolism Aortic Aneurysm More Understand Your Risk for Excessive Blood Clotting Updated:Nov 2,2015 Many factors can lead to excessive blood clotting, leading to limited or blocked blood flow. Blood clots can travel to the arteries or ...

  17. [Hematocrit measurement: comparison of conductimetry to microcentrifugation].

    Science.gov (United States)

    Daurès, M-F; Combescure, C; Demattei, C; Cristol, J P

    2009-01-01

    In general, blood gas analysers can also determine the value of haematocrite by measuring the blood's conductivity. The question to ask is whether this value is reliable. In this study, hematocrit obtained via conductivity from 6 different pieces of equipment were compared with those measured using the gold standard method, which is microcentrifugation. By interpreting the results of 320 arterial blood samples taken in the intensive care unit DAR "B" we can see that the reliability between two measurements on the same piece of equipment is very good, in general > 0.95 whatever the equipment. The reliability between the means of the two measurements and the gold standard is slightly lower but remains very satisfactory, most often between 0.8 and 0.9. The Gem Premier 3000 (IL) analyser and the Roche OMNI S gave the best reliability compared with centrifugation. The Spearman coefficients between the mean values of the analysers and those of centrifugation were high, with the exception of the Rapidpoint 405. They are all statistically different from zero (p<0.0001).

  18. Fluid Mechanics of Blood Clot Formation.

    Science.gov (United States)

    Fogelson, Aaron L; Neeves, Keith B

    2015-01-01

    Intravascular blood clots form in an environment in which hydrodynamic forces dominate and in which fluid-mediated transport is the primary means of moving material. The clotting system has evolved to exploit fluid dynamic mechanisms and to overcome fluid dynamic challenges to ensure that clots that preserve vascular integrity can form over the wide range of flow conditions found in the circulation. Fluid-mediated interactions between the many large deformable red blood cells and the few small rigid platelets lead to high platelet concentrations near vessel walls where platelets contribute to clotting. Receptor-ligand pairs with diverse kinetic and mechanical characteristics work synergistically to arrest rapidly flowing cells on an injured vessel. Variations in hydrodynamic stresses switch on and off the function of key clotting polymers. Protein transport to, from, and within a developing clot determines whether and how fast it grows. We review ongoing experimental and modeling research to understand these and related phenomena.

  19. Two different hematocrit detection methods: Different methods, different results?

    Directory of Open Access Journals (Sweden)

    Schuepbach Reto A

    2010-03-01

    Full Text Available Abstract Background Less is known about the influence of hematocrit detection methodology on transfusion triggers. Therefore, the aim of the present study was to compare two different hematocrit-assessing methods. In a total of 50 critically ill patients hematocrit was analyzed using (1 blood gas analyzer (ABLflex 800 and (2 the central laboratory method (ADVIA® 2120 and compared. Findings Bland-Altman analysis for repeated measurements showed a good correlation with a bias of +1.39% and 2 SD of ± 3.12%. The 24%-hematocrit-group showed a correlation of r2 = 0.87. With a kappa of 0.56, 22.7% of the cases would have been transfused differently. In the-28%-hematocrit group with a similar correlation (r2 = 0.8 and a kappa of 0.58, 21% of the cases would have been transfused differently. Conclusions Despite a good agreement between the two methods used to determine hematocrit in clinical routine, the calculated difference of 1.4% might substantially influence transfusion triggers depending on the employed method.

  20. Modified clotting properties of fibrinogen in the presence of acetylsalicylic acid in a purified system.

    Science.gov (United States)

    He, S; Blombäck, M; Yoo, G; Sinha, R; Henschen-Edman, A H

    2001-01-01

    To assess how treatment with acetylsalicylic acid (ASA) alters the fibrin network structure, clotting was initiated in purified fibrinogen incubated with ASA by adding thrombin. Clotting time and maximum absorbance of the fibrin aggregation curve were used to demonstrate the potential of fibrin generation. The results showed that the clotting properties of fibrinogen decreased and that the affinity of plasminogen to fibrin or thrombin inhibition by antithrombin increased if plasminogen or antithrombin, respectively, were present in the reaction system. The effect of ASA varied in a dose dependent manner. It was concluded that ASA may directly or indirectly confer positive or negative effects on the stability of the fibrin clot and that the balance between these effects may be regulated by the ASA dose.

  1. Improvement of electrical blood hematocrit measurements under various plasma conditions using a novel hematocrit estimation parameter.

    Science.gov (United States)

    Kim, Myounggon; Kim, Ayoung; Kim, Sohee; Yang, Sung

    2012-05-15

    This paper presents an electrical method for measurement of Hematocrit (HCT) using a novel HCT estimation parameter. Particularly in the case of electrical HCT measurements, the measurement error generally increases with changes in the electrical conditions of the plasma such as conductivity and osmolality. This is because the electrical properties of blood are a function not only of HCT, but also of the electrical conditions in the plasma. In an attempt to reduce the measurement errors, we herein propose a novel HCT estimation parameter reflecting the characteristics of both the changes in volume of red blood cells (RBCs) and electrical conditions of plasma, simultaneously. In order to characterize the proposed methods under various electrical conditions of plasma, we prepared twelve blood samples such as four kinds of plasma conditions (hypotonic, isotonic, two kinds of hypertonic conditions) at three different HCT levels. Using linear regression analysis, we confirmed that the proposed parameter was highly correlated with reference HCT (HCT(ref.)) values measured by microcentrifugation. Thus, the HCT measurement error was less than 4%, despite considerable variations in the conductivity and osmolality of the plasma at conditions of the HCT(ref.) of 20%. Multiple linear regression analysis showed that the proposed HCT estimation parameter also yielded a lower measurement error (1%) than the other parameter previously used for the same purpose. Thus, these preliminary results suggest that proposed method could be used for accurate, fast, easy, and reproducible HCT measurements in medical procedures. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Effects of hematocrit and red blood cell-independent viscosity on canine thromboelastographic tracings.

    Science.gov (United States)

    Brooks, Aimee C; Guillaumin, Julien; Cooper, Edward S; Couto, C Guillermo

    2014-03-01

    It is well established that hematocrit (Hct) influences whole blood thromboelastography (TEG) tracings. Previous studies showed hypercoagulable TEG tracings in anemic patients despite clinical expectations that anemia often prolongs bleeding. TEG is a viscoelastic assessment of clot kinetics, and Hct is the main determinant of whole blood viscosity. TEG changes in anemia may be an in vitro artifact due to Hct effect on blood viscosity rather than true in vivo changes in hemostasis. The effect of changes in whole blood viscosity on TEG independent of Hct is not well understood. Twenty-one blood samples from seven dogs were manipulated to produce one of three Hct conditions (45, 20, and 10%). Each was tested in two situations: viscosity adjusted to normal by adding alginate (ALG) or dilution with equal volume of saline (SAL). Both samples were analyzed with TEG simultaneously. Twenty percent Hct plus ALG and 10% Hct plus ALG were significantly more viscous than their SAL counterparts (p=0.0156). Ten percent Hct plus SAL, 20% Hct plus SAL, and 45% Hct plus SAL all had different viscosities (p=0.006). Twenty percent Hct plus SAL and 10% Hct plus SAL had significantly shorter K and higher angle, MA, and G compared to their ALG counterparts as well as 45% Hct plus SAL (pviscosity showed hypocoagulable tracings, whereas SAL samples with low Hct, low viscosity showed hypercoagulable tracings. TEG variables are influenced by whole blood viscosity altered with ALG, independently of Hct. © 2013 American Association of Blood Banks.

  3. Blood clot detection using magnetic nanoparticles

    Science.gov (United States)

    Khurshid, Hafsa; Friedman, Bruce; Berwin, Brent; Shi, Yipeng; Ness, Dylan B.; Weaver, John B.

    2017-05-01

    Deep vein thrombosis, the development of blood clots in the peripheral veins, is a very serious, life threatening condition that is prevalent in the elderly. To deliver proper treatment that enhances the survival rate, it is very important to detect thrombi early and at the point of care. We explored the ability of magnetic particle spectroscopy (MSB) to detect thrombus via specific binding of aptamer functionalized magnetic nanoparticles with the blood clot. MSB uses the harmonics produced by nanoparticles in an alternating magnetic field to measure the rotational freedom and, therefore, the bound state of the nanoparticles. The nanoparticles' relaxation time for Brownian rotation increases when bound [A.M. Rauwerdink and J. B. Weaver, Appl. Phys. Lett. 96, 1 (2010)]. The relaxation time can therefore be used to characterize the nanoparticle binding to thrombin in the blood clot. For longer relaxation times, the approach to saturation is more gradual reducing the higher harmonics and the harmonic ratio. The harmonic ratios of nanoparticles conjugated with anti-thrombin aptamers (ATP) decrease significantly over time with blood clot present in the sample medium, compared with nanoparticles without ATP. Moreover, the blood clot removed from the sample medium produced a significant MSB signal, indicating the nanoparticles are immobilized on the clot. Our results show that MSB could be a very useful non-invasive, quick tool to detect blood clots at the point of care so proper treatment can be used to reduce the risks inherent in deep vein thrombosis.

  4. Myth or reality : Hematocrit and hemoglobin differ in trauma

    NARCIS (Netherlands)

    Nijboer, Johanna M. M.; van der Horst, Iwan C. C.; Hendriks, Herman G. D.; ten Duis, Hendrik-Jan; Nijsten, Maarten W. N.

    Background: Estimating blood loss in trauma patients usually involves the determination of hematocrit (Ht) or hemoglobin (Hb). However, in trauma patients, a poorly substantiated habit exists to determine both Ht and Hb in assessing acute blood loss. This suggests that Ht and Hb provide different

  5. Hematocrit, anemia, and arm preference for blood sample collection ...

    African Journals Online (AJOL)

    Background: Anemia in pregnancy is a common cause of maternal morbidity and mortality in developing countries. Regular review of hematocrit (HCT) and anemia patterns in pregnancy is necessary in our environment. Aim: The aim was to determine the average HCT, prevalence, and pattern of anemia, as well the arm ...

  6. Blood Clotting Inspired Polymer Physics

    Science.gov (United States)

    Sing, Charles Edward

    The blood clotting process is one of the human body's masterpieces in targeted molecular manipulation, as it requires the activation of the clotting cascade at a specific place and a specific time. Recent research in the biological sciences have discovered that one of the protein molecules involved in the initial stages of the clotting response, von Willebrand Factor (vWF), exhibits counterintuitive and technologically useful properties that are driven in part by the physical environment in the bloodstream at the site of a wound. In this thesis, we take inspiration from initial observations of the vWF in experiments, and aim to describe the behaviors observed in this process within the context of polymer physics. By understanding these physical principles, we hope to harness nature's ability to both direct molecules in both spatial and conformational coordinates. This thesis is presented in three complementary sections. After an initial introduction describing the systems of interest, we first describe the behavior of collapsed Lennard-Jones polymers in the presence of an infinite medium. It has been shown that simple bead-spring homopolymer models describe vWF quite well in vitro. We build upon this previous work to first describe the behavior of a collapsed homopolymer in an elongational fluid flow. Through a nucleation-protrusion mechanism, scaling relationships can be developed to provide a clear picture of a first-order globule-stretch transition and its ramifications in dilute-solution rheology. The implications of this behavior and its relation to the current literature provides qualitative explanations for the physiological process of vasoconstriction. In an effort to generalize these observations, we present an entire theory on the behavior of polymer globules under influence of any local fluid flow. Finally, we investigate the internal dynamics of these globules by probing their pulling response in an analogous fashion to force spectroscopy. We elucidate

  7. A serpin released by an entomopathogen impairs clot formation in insect defense system.

    Science.gov (United States)

    Toubarro, Duarte; Avila, Mónica M; Hao, Youjin; Balasubramanian, Natesan; Jing, Yingjun; Montiel, Rafael; Faria, Tiago Q; Brito, Rui M; Simões, Nelson

    2013-01-01

    Steinernema carpocapsae is an entomopathogenic nematode widely used for the control of insect pests due to its virulence, which is mainly attributed to the ability the parasitic stage has to overcome insect defences. To identify the mechanisms underlying such a characteristic, we studied a novel serpin-like inhibitor (sc-srp-6) that was detected in a transcriptome analysis. Recombinant Sc-SRP-6 produced in Escherichia coli had a native fold of serpins belonging to the α-1-peptidase family and exhibited inhibitory activity against trypsin and α-chymotrypsin with Ki of 0.42 × 10(-7) M and 1.22 × 10(-7) M, respectively. Functional analysis revealed that Sc-SRP-6 inhibits insect digestive enzymes, thus preventing the hydrolysis of ingested particles. Moreover, Sc-SRP-6 impaired the formation of hard clots at the injury site, a major insect defence mechanism against invasive pathogens. Sc-SRP-6 does not prevent the formation of clot fibres and the activation of prophenoloxidases but impairs the incorporation of the melanin into the clot. Binding assays showed a complex formation between Sc-SRP-6 and three proteins in the hemolymph of lepidopteran required for clotting, apolipophorin, hexamerin and trypsin-like, although the catalytic inhibition occurred exclusively in trypsin-like. This data allowed the conclusion that Sc-SRP-6 promotes nematode virulence by inhibiting insect gut juices and by impairing immune clot reaction.

  8. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Multimedia Resources For Physicians Parts of the Body Shoulder & Elbow Hand & Wrist Hip & Thigh Knee & Lower Leg ... recovery from surgery. Warning Signs of Blood Clots Pain in your calf and leg, unrelated to your ...

  9. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Orthopaedic Surgeons Preventing Blood Clots After Orthopaedic Surgery One of the major risks facing patients who undergo ... consult his or her orthopaedic surgeon, or locate one in your area through the AAOS "Find an ...

  10. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... the development of blood clots after your surgery. This may include periodic elevation of your legs, lower ... support stockings, and medication to thin your blood. This video provides additional information about DVT and its ...

  11. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... of a blood clot within a deep vein. It commonly occurs in the thigh or calf. Deep ... breaks free and travels through the veins. If it reaches the lungs, it can block the flow ...

  12. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... recovery from surgery. Warning Signs of Blood Clots Pain in your calf and leg, unrelated to your ... of Pulmonary Embolism Sudden shortness of breath Chest pain, particularly with breathing Notify your doctor immediately if ...

  13. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... first several weeks of recovery from surgery. Warning Signs of Blood Clots Pain in your calf and ... of your thigh, calf, ankle, or foot Warning Signs of Pulmonary Embolism Sudden shortness of breath Chest ...

  14. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... major risks facing patients who undergo surgery is a complication called deep vein thrombosis. Deep vein thrombosis (DVT) is the formation of a blood clot within a deep vein. It commonly ...

  15. Preventing Blood Clots After Orthopaedic Surgery

    Medline Plus

    Full Text Available ... Bones & Injuries Diseases & Conditions Arthritis Tumors Sports Injuries & Prevention Children Bone Health Health & Safety Treatment Treatments & Surgeries ... Your doctor will outline a program to help prevent the development of blood clots after your surgery. ...

  16. Mechanical stability and fibrinolytic resistance of clots containing fibrin, DNA, and histones.

    Science.gov (United States)

    Longstaff, Colin; Varjú, Imre; Sótonyi, Péter; Szabó, László; Krumrey, Michael; Hoell, Armin; Bóta, Attila; Varga, Zoltán; Komorowicz, Erzsébet; Kolev, Krasimir

    2013-03-08

    Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nM dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator.

  17. Mechanical Stability and Fibrinolytic Resistance of Clots Containing Fibrin, DNA, and Histones*

    Science.gov (United States)

    Longstaff, Colin; Varjú, Imre; Sótonyi, Péter; Szabó, László; Krumrey, Michael; Hoell, Armin; Bóta, Attila; Varga, Zoltán; Komorowicz, Erzsébet; Kolev, Krasimir

    2013-01-01

    Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nm dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator. PMID:23293023

  18. The Phosphatase Inhibitor Calyculin-A Impairs Clot Retraction, Platelet Activation, and Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Renáta Hudák

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of the serine/threonine protein phosphatase inhibitor, calyculin-A (CLA, on clot formation and on the procoagulant activity of human platelets. Platelet-rich plasma (PRP samples were preincubated with buffer or CLA and subsequently platelets were activated by the protease-activated receptor 1 (PAR-1 activator, thrombin receptor activating peptide (TRAP. Clot retraction was detected by observing clot morphology up to 1 hour, phosphatidylserine- (PS- expression was studied by flow cytometry, and thrombin generation was measured by a fluorimetric assay. For the intracellular Ca2+ assay, platelets were loaded with calcium-indicator dyes and the measurements were carried out using a ratiometric method with real-time confocal microscopy. CLA preincubation inhibited clot retraction, PS-expression, and thrombin formation. TRAP activation elicited Ca2+ response and PS-expression in a subset of platelets. The activated PRP displayed significantly faster and enhanced thrombin generation compared to nonactivated samples. CLA pretreatment abrogated PS-exposure and clot retraction also in TRAP-activated samples. As a consequence of the inhibitory effect on calcium elevation and PS-expression, CLA significantly downregulated thrombin generation in PRP. Our results show that CLA pretreatment may be a useful tool to investigate platelet activation mechanisms that contribute to clot formation and thrombin generation.

  19. Systemic central venous oxygen saturation is associated with clot strength during traumatic hemorrhagic shock: A preclinical observational model

    Directory of Open Access Journals (Sweden)

    Brophy Donald F

    2010-12-01

    Full Text Available Abstract Background Clot strength by Thrombelastography (TEG is associated with mortality during trauma and has been linked to severity of tissue hypoperfusion. However, the optimal method for monitoring this important relationship remains undefined. We hypothesize that oxygen transport measurements will be associated with clot strength during traumatic shock, and test this hypothesis using a swine model of controlled traumatic shock. Methods N = 33 swine were subjected to femur fracture and hemorrhagic shock by controlled arterial bleeding to a predetermined level of oxygen debt measured by continuous indirect calorimetry. Hemodynamics, oxygen consumption, systemic central venous oxygenation (ScvO2, base excess, lactate, and clot maximal amplitude by TEG (TEG-MA as clot strength were measured at baseline and again when oxygen debt = 80 ml/kg during shock. Oxygen transport and metabolic markers of tissue perfusion were then evaluated for significant associations with TEG-MA. Forward stepwise selection was then used to create regression models identifying the strongest associations between oxygen transport and TEG-MA independent of other known determinants of clot strength. Results Multiple markers of tissue perfusion, oxygen transport, and TEG-MA were all significantly altered during shock compared to baseline measurements (p 2 demonstrated a strong bivariate association with TEG-MA measured during shock (R = 0.7, p 2 measured during shock was also selected by forward stepwise selection as an important covariate in linear regression models of TEG-MA after adjusting for the covariates fibrinogen, pH, platelet count, and hematocrit (Whole model R2 = 0.99, p ≤ 0.032. Conclusions Among multiple measurements of oxygen transport, only ScvO2 was found to retain a significant association with TEG-MA during shock after adjusting for multiple covariates. ScvO2 should be further studied for its utility as a clinical marker of both tissue hypoxia and clot

  20. Clot dissolution is better with ultrasound assisted thrombolysis for fresh clots with higher cholesterol content

    Science.gov (United States)

    Zhou, Yufeng; Sharma, Vijay Kumar; Murugappan, Kanna Suresh; Ahmad, Aftab

    2012-11-01

    Tissue plasminogen activator (tPA) remains the only drug for recanalization in acute ischemic stroke, and the dose is determined by the patient's body-weight. Properties of the blood clot as well as ultrasound exposure might affect the thrombolysis outcome. In this study, clot was prepared by mixing horse blood with CaCl2 solution and cholesterin up to 1.0 mg/ml. To simulate the aging effect serum was replaced by fresh blood periodically. 225 IU/ml of tPA was used to initiate lysis. Clot was exposed to continuous 2 MHz transcranial Doppler ultrasound at acoustic intensity of 340 mW/cm2. The weight of the blood clot increased with its age (from 37.28±2.87 mg at 2 hrs to 51.56±5.34 mg at 10 hrs, p < 0.05). Although no difference between clot-cholesterol levels and thrombolysis with ultrasound or tPA alone was found, combination of these modalities induced significant lysis in the clots with cholesterol levels of more than 0.5 mg/ml (clot-weight reduced by 41.68±2.3%) as compared to clots with normal cholesterol (30.60±4.10%; p < 0.05). Altogether, sonothrombolysis seems to work better in fresh thrombi with high-cholesterol levels.

  1. Hematocrit estimation using online sequential extreme learning machine.

    Science.gov (United States)

    Huynh, Hieu Trung; Won, Yonggwan; Kim, Jinsul

    2015-01-01

    Hematocrit is a blood test that is defined as the volume percentage of red blood cells in the whole blood. It is one of the important indicators for clinical decision making and the most effective factor in glucose measurement using handheld devices. In this paper, a method for hematocrit estimation that is based upon the transduced current curve and the neural network is presented. The salient points of this method are that (1) the neural network is trained by the online sequential extreme learning machine (OS-ELM) in which the devices can be still trained with new samples during the using process and (2) the extended features are used to reduce the number of current points which can save the battery power of devices and speed up the measurement process.

  2. 21 CFR 864.8165 - Calibrator for hemoglobin or hematocrit measurement.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calibrator for hemoglobin or hematocrit....8165 Calibrator for hemoglobin or hematocrit measurement. (a) Identification. A calibrator for hemoglobin or hematocrit measurement is a device that approximates whole blood, red blood cells, or a...

  3. Human pancreatic tumors grown in mice release tissue factor-positive microvesicles that increase venous clot size.

    Science.gov (United States)

    Hisada, Y; Ay, C; Auriemma, A C; Cooley, B C; Mackman, N

    2017-11-01

    Essentials Tumor-bearing mice have larger venous clots than controls. Human tissue factor is present in clots in tumor-bearing mice. Inhibition of human tissue factor reduces clot size in tumor-bearing mice. This new mouse model may be useful to study mechanisms of cancer-associated thrombosis. Background Pancreatic cancer patients have a high rate of venous thromboembolism. Human pancreatic tumors and cell lines express high levels of tissue factor (TF), and release TF-positive microvesicles (TF+ MVs). In pancreatic cancer patients, tumor-derived TF+ MVs are present in the blood, and increased levels are associated with venous thromboembolism and decreased survival. Previous studies have shown that mice with orthotopic human or murine pancreatic tumors have circulating tumor-derived TF+ MVs, an activated clotting system, and increased incidence and mean clot weight in an inferior vena cava stenosis model. These results suggest that TF+ MVs contribute to thrombosis. However, the specific role of tumor-derived TF+ MVs in venous thrombosis in mice has not been determined. Objectives To test the hypothesis that tumor-derived TF+ MVs enhance thrombosis in mice. Methods We determined the contribution of TF+ MVs derived from human pancreatic tumors grown orthotopically in nude mice to venous clot formation by using an anti-human TF mAb. We used an inferior vena cava stasis model of venous thrombosis. Results Tumor-bearing mice had significantly larger clots than control mice. Clots from tumor-bearing mice contained human TF, suggesting the incorporation of tumor-derived MVs. Importantly, administration of an anti-human TF mAb reduced clot size in tumor-bearing mice but did not affect clot size in control mice. Conclusions Our results indicate that TF+ MVs released from orthotopic pancreatic tumors increase venous thrombosis in mice. This new model may be useful for evaluating the roles of different factors in cancer-associated thrombosis. © 2017 International Society on

  4. In vivo quantification of clot formation in extracorporeal circuits.

    Science.gov (United States)

    Gerrah, Rabin; David, Omid

    2013-01-01

    Clot formation is a common complication in extracorporeal circuits. In this paper we describe a novel method for clot formation analysis using image processing. We assembled a closed extracorporeal circuit and circulated blood at varying speeds. Blood filters were placed in downstream of the flow, and clotting agents were added to the circuit. Digital images of the filter were subsequently taken, and image analysis was applied to calculate the density of the clot. Our results show a significant correlation between the cumulative size of the clots, the density measure of the clot based on image analysis, and flow duration in the system.

  5. Fibrinolytic proteins in human bile accelerate lysis of plasma clots and induce breakdown of fibrin sealants.

    Science.gov (United States)

    Boonstra, Elizabeth A; Adelmeijer, Jelle; Verkade, Henkjan J; de Boer, Marieke T; Porte, Robert J; Lisman, Ton

    2012-08-01

    We investigated the effect of human bile on the stability of plasma clots and of fibrin sealants. Fibrin sealants are extensively used in liver surgery, for example, during liver resections. Although these sealants have been developed to induce hemostasis, in practice these products are actually mainly used to seal dissected bile ducts to prevent postsurgical bile leakage. We performed in vitro assays in which clotting and lysis of human plasma clots or fibrin sealants was studied in presence or absence of human bile. Addition of bile to human plasma resulted in a dose-dependent increase in clotting time, and a dose-dependent decrease in clot lysis time. Bile also accelerated lysis of in vitro clotted fibrin sealants. Immunodepletion of tissue-type plasminogen activator (tPA) resulted in partial depletion of the lysis promoting activity of bile. Immunodepletion of both tPA and lysine-binding proteins from bile fully abolished the lytic activity, suggesting that tPA and plasminogen present in human bile are responsible for the lysis-promoting effect. Surprisingly, addition of high dose plasminogen activator inhibitor type 1 (PAI-1) to bile did not attenuate the lytic activity toward fibrin sealants, which suggested that tPA in a biliary environment may be unsusceptible to PAI-1 inhibition. Indeed, bile acids were shown to prevent tPA from interacting with PAI-1, although preformed complexes were not destabilized upon addition of bile acids. These combined results suggest that the presence of tPA and other fibrinolytic proteins in human bile results in lysis of plasma clots or fibrin sealants, which potentially could affect the efficacy of the latter products.

  6. Mechanical suction for clot evacuation: experience with "suction bridge" for safe and effective clot removal.

    Science.gov (United States)

    Goel, Apul; Dalela, Diwakar

    2015-05-01

    To present the experience with the use of a "suction bridge" for removal of bladder clots. In all patients presenting with bladder clots, mechanical suction was done using a "suction bridge". This bridge has a luer lock that is fixed to the cystoscope sheath, and the other end is connected to suction tube. The suction pressure was started at 250 mmHg and was increased up to 400 mmHg if needed. Twenty patients with a mean age of 59.4 years were included. The etiologies of bladder clots included bladder tumor in nine, benign prostate hyperplasia (BPH) in two, BPH with bladder stone in one, hematochyluria in three, and post-transurethral prostate resection in 10. Eighteen patients presented in clot retention. The estimated clot size ranged from 50 mL to more than 1 L. The mean duration for clot removal was 15 min (range 5-60). The procedure was successful in all patients. There was no bladder injury. The limitations include the small number of recruits, the non-randomized nature of study, and no control group for comparison. Mechanical suction is another safe, fast, and effective option of clot removal from the urinary bladder. The suction bridge is useful while using this method.

  7. Abnormal blood clot formation induced by temperature responsive polymers by altered fibrin polymerization and platelet binding.

    Science.gov (United States)

    Lai, Benjamin F L; Zou, Yuquan; Yang, Xiaoqiang; Yu, Xifei; Kizhakkedathu, Jayachandran N

    2014-03-01

    Thermoresponsive polymers (TRPs) have been extensively investigated as smart devices, drug delivery systems and protein conjugates due to their unique phase transition properties. Here, we report the unusual influence of TRPs in blood clotting and the mechanism by which TRPs change the three dimensional organization of blood clot structure. Ten different TRPs with lower critical solution temperatures ranged from 26 to 80 °C are studied. TRPs altered the fibrin polymerization by increasing the rate of protofibril aggregation, decreased the fibrin fiber diameter and changed the platelet integration within the clot. The mechanical properties of the clot decreased considerably in presence of TRPs due to the poor platelet binding. The poor integration of platelets within the clot is not due to the inhibition of platelet activation by TRPs but may due to the unusual organization of fibrin structure. The plasma phase of the blood coagulation is not affected in presence of TRPs. We anticipate that our results will have significant implications on the use of TRPs in applications where blood contact is essential. These observations may also open up new avenues, for example, in the design of new generation antithrombotics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Clot-embedded natural surfactant: kinetics of fibrinolysis and surface activity.

    Science.gov (United States)

    Günther, A; Kalinowski, M; Elssner, A; Seeger, W

    1994-11-01

    Polymerization of fibrin in the presence of pulmonary surfactant was recently noted to induce incorporation of phospholipids into the insoluble clot material, thereby effecting severe loss of surface activity (W. Seeger, A. Elssner, A. Günther, H.-J. Krämer, and H. O. Kalinowski. Am. J. Respir. Cell Mol. Biol. 9: 213-220, 1993). In the present study, we investigated the influence of such incorporation of calf lung surfactant extract (CLSE) on the enzymatic cleavage of the fibrin network with the use of plasmin, trypsin, or elastase. Employing a fibrin-plate assay, the proteolytic release of radioactivity originating from 125I-labeled fibrinogen was assessed, and the pattern of split products was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. Surface activity of CLSE was measured in the pulsating bubble surfactometer. When incorporated into the fibrin clot, CLSE inhibited the cleavage of fibrin by all proteases in a dose-dependent manner without affecting the profile of scission products. Inhibition of plasmin-induced clot lysis was also noted on incorporation of CLSE into clotted plasma and on incorporation of dipalmitoylphosphatidylcholine into fibrin polymers. In contrast, corresponding concentrations of CLSE added to the incubation medium after preformation of the fibrin matrix did not substantially influence the kinetics of fibrinolysis. CLSE incorporation into the nascent fibrin clot resulted in complete loss of surface activity, but adsorption and surface tension-lowering properties were largely restored by subsequent plasmic clot lysis. Arising fibrin split products were shown to display similar inhibitory strength on CLSE surface activity compared with fibrinogen split products.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Blood Clots and Travel: What You Need to Know

    Science.gov (United States)

    ... Facebook Tweet Share Compartir More than 300 million people travel on long-distance flights (generally more than four ... have any other risks for blood clots. Most people who develop travel-associated blood clots have one or more other ...

  10. In Vivo Quantification of Clot Formation in Extracorporeal Circuits

    OpenAIRE

    David, Omid; Gerrah, Rabin

    2012-01-01

    Clot formation is a common complication in extracorporeal circuits. In this paper we describe a novel method for clot formation analysis using image processing. We assembled a closed extracorporeal circuit and circulated blood at varying speeds. Blood filters were placed in downstream of the flow, and clotting agents were added to the circuit. Digital images of the filter were subsequently taken, and image analysis was applied to calculate the density of the clot. Our results show a significa...

  11. Identification of fibrin clot-bound plasma proteins

    NARCIS (Netherlands)

    S. Talens (Simone); F.W.G. Leebeek (Frank); J.A.A. Demmers (Jeroen); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractSeveral proteins are known to bind to a fibrin network and to change clot properties or function. In this study we aimed to get an overview of fibrin clot-bound plasma proteins. A plasma clot was formed by adding thrombin, CaCl2 and aprotinin to citrated platelet-poor plasma and unbound

  12. 21 CFR 173.150 - Milk-clotting enzymes, microbial.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Milk-clotting enzymes, microbial. 173.150 Section... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.150 Milk-clotting enzymes, microbial. Milk-clotting enzyme produced by pure-culture fermentation process may be safely used in the production...

  13. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

    Directory of Open Access Journals (Sweden)

    Robinson RA

    2013-05-01

    Full Text Available Ronald A Robinson, Luke H Herbertson, Srilekha Sarkar Das, Richard A Malinauskas, William F Pritchard, Laurence W GrossmanOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USAAbstract: The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm, length-to-diameter ratios (1:1, 3:1, 10:1, and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the

  14. Utilization of salt whey from Egyptian Ras (cephalotyre) cheese in microbial milk clotting enzymes production.

    Science.gov (United States)

    El-Tanboly, El-Sayed; El-Hofi, Mahmoud; Youssef, Youssef Bahr; El-Desoki, Wahed; Ismail, Azza

    2013-01-01

    Microbial milk-clotting enzymes are valued as calf rennet substitutes in the cheese industry. The worldwide increase of cheese production coupled with a reduced supply of calf rennet has prompted a search for calf rennet substitutes, including microbial and plant rennets. However, most plant rennets have proved unsuitable because they impart a bitter taste to the cheese. Microbial rennet appears to be more promising because its production is cheaper, biochemical diversity is greater, and genetic modification is easier. Most cheese manufacturing facilities in Egypt perform land spreading of salt whey. However, this practice increases the chloride levels of soil, and elevates the risk of crop damage. One possible application for salt whey is to use it as a whole medium for growth and production of milk clotting enzyme from fungi. Mucor pusillus QM 436 was identified to produce the highest milk-clotting activity during screening of 19 fungal strains. Salted whey results from Ras (Cephalotyre) cheese manufacture as a whole medium for growth of Mucor pusillus QM 436 and production of the enzyme. The milk-clotting enzyme from Mucor pusillus QM 436 was purified to 7.14-fold with 54.4% recovery by precipitation in ammonium sulfate, ethanol and fractionated by gel filtration on Sephadex G-100. The enzyme was active in the pH range 5.5-7.5 and was inactivated completely by heating 5 min at 70°C and 30 min at 65°C. The highest level of enzyme activity was obtained at 60°C, pH 5.5. A positive and proportional relationship occurred in the presence of CaCl2 in milk, with inhibition which occurred in the presence of NaCl. The high level of milk-clotting activity coupled with a low level of thermal stability suggested that the milk-clotting enzyme from Mucor pusillus QM 436 should be considered as a potential substitute for calf rennet.

  15. "Liver clot" - a rare periodontal postsurgical complication.

    Science.gov (United States)

    Pandya, Dhara; Manohar, Balaji; Mathur, L K; Shankarapillai, Rajesh

    2012-01-01

    Bleeding is a common sequela of oral and periodontal surgery. Generally, bleeding is self-limiting. Following traumatic injury or surgical procedures, hemorrhage can range from a minor leakage or oozing at the site, to extensive bleeding leading to complete exsanguinations. Significant postsurgical hemorrhage following periodontal surgery is uncommon due to the primary closure of the soft tissues. This case report describes the unique formation of a "liver clot" or "currant jelly clot" following periodontal flap surgery. The likelihood of this may be attributed to many factors, like infection, intrinsic trauma, presence of foreign bodies like splinter of bone, a fleck of enamel, or a piece of dental restorative dressing material that may cause repeated, delayed organization of blood coagulum.

  16. Massive clot formation after tooth extraction

    Directory of Open Access Journals (Sweden)

    Santosh Hunasgi

    2015-01-01

    Full Text Available Oral surgical procedures mainly tooth extraction can be related with an extended hemorrhage owed to the nature of the process resulting in an "open wound." The attempt of this paper is to present a case of massive postoperative clot formation after tooth extraction and highlight on the oral complications of surgical procedures. A 32-year-old male patient reported to the Dental Clinic for evaluation and extraction of grossly decayed 46. Clinical evaluation of 46 revealed root stumps. Extraction of the root stumps was performed, and it was uneventful. Hemostasis was achieved and postsurgical instructions were specified to the patient. The patient reported to the clinic, the very subsequent morning with a criticism of bleeding at the extraction site. On clinical examination, bleeding was noted from the socket in relation to 46. To control bleeding, oral hemostatic drugs Revici - E (Ethamsylate 500 mg was prescribed and bleeding was stopped in 2 h. However, a massive clot was formed at the extraction site. Further, this clot resolved on its own in 1-week time. Despite the fact that dental extraction is considered to be a minor surgical procedure, some cases may present with life-threatening complications including hemorrhage. Vigilant and significant history taking, physical and dental examinations prior to dental procedures are a must to avoid intraoperative and postoperative complications.

  17. Formation of blood clot on biomaterial implants influences bone healing.

    Science.gov (United States)

    Shiu, Hoi Ting; Goss, Ben; Lutton, Cameron; Crawford, Ross; Xiao, Yin

    2014-12-01

    The first step in bone healing is forming a blood clot at injured bones. During bone implantation, biomaterials unavoidably come into direct contact with blood, leading to a blood clot formation on its surface prior to bone regeneration. Despite both situations being similar in forming a blood clot at the defect site, most research in bone tissue engineering virtually ignores the important role of a blood clot in supporting healing. Dental implantology has long demonstrated that the fibrin structure and cellular content of a peri-implant clot can greatly affect osteoconduction and de novo bone formation on implant surfaces. This article reviews the formation of a blood clot during bone healing in relation to the use of platelet-rich plasma (PRP) gels. It is implicated that PRP gels are dramatically altered from a normal clot in healing, resulting in conflicting effect on bone regeneration. These results indicate that the effect of clots on bone regeneration depends on how the clots are formed. Factors that influence blood clot structure and properties in relation to bone healing are also highlighted. Such knowledge is essential for developing strategies to optimally control blood clot formation, which ultimately alter the healing microenvironment of bone. Of particular interest are modification of surface chemistry of biomaterials, which displays functional groups at varied composition for the purpose of tailoring blood coagulation activation, resultant clot fibrin architecture, rigidity, susceptibility to lysis, and growth factor release. This opens new scope of in situ blood clot modification as a promising approach in accelerating and controlling bone regeneration.

  18. Sea urchin coelomocyte arylsulfatase: a modulator of the echinoderm clotting pathway.

    Science.gov (United States)

    D'Andrea-Winslow, Lisanne; Radke, David W; Utecht, Tim; Kaneko, Takuya; Akasaka, Koji

    2012-03-01

    Sea urchin petalloid coelomocytes effectuate the clotting pathway by undergoing a rapid and dynamic cellular transformation that leads to cellular adhesion and wounds closure. We have identified high levels of activity of arylsulfatase (Ars) associated with coelomocytes of the sea urchin Lytechinus variegatus (Lamarck, 1816). Ars activity was extracted from clotted coelomocytes with EDTA and showed high levels of activity up to a 1:100 dilution. Clot formation from isolated coelomic fluid was significantly inhibited by the ARS inhibitor, p-nitrophenyl phosphate. Ars activity was collected by 80% ethanol precipitation, a diagnostic test previously used in Ars isolation. Cellular extraction studies in the presence and absence of the non-ionic detergent Triton X-100 indicated that some Ars activity was present intracellularly, possibly in intracellular membrane-bound compartments, however the majority of Ars activity was extracted from the extracellular coelomocyte membrane. Polyclonal anti-sea urchin embryo Ars antibodies recognized a single protein band with an approximate molecular weight of 75 kDa on western blots. Immunofluorescence using the anti-sea urchin Ars antibody revealed an intracellular and extracellular staining of Ars in both petalloid and filopodial coelomocytes. Taken together, these data indicate that coelomocyte Ars might be involved in cell-to-cell crosslinking of surface sulfated polysaccharides vital for clot formation. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

  19. Identification of quantitative trait loci for fibrin clot phenotypes: the EuroCLOT study

    DEFF Research Database (Denmark)

    Williams, Frances M K; Carter, Angela M; Kato, Bernet

    2009-01-01

    OBJECTIVE: Fibrin makes up the structural basis of an occlusive arterial thrombus, and variability in fibrin phenotype relates to cardiovascular risk. The aims of the current study from the EU consortium EuroCLOT were to (1) determine the heritability of fibrin phenotypes and (2) identify QTLs as...

  20. Trapped plasma vs. osmolality in canine microcapillary hematocrits

    Energy Technology Data Exchange (ETDEWEB)

    Morris, T.W.; Reece, K.

    The trapped plasma in the packed red cell portion of the microcapillary hematocrit of hypertonic canine blood was measured with I-125 labelled albumin. Blood osmolalities were raised by the addition of sodium chloride and meglumine/sodium diatrizoate. The trapped plasma was 1.12 +/- 0.15%, 1.75 +/- 0.27% and 1.77 +/- 0.22% at 300, 580, and 723 mOsm/kg, respectively, for sodium chloride solutions. At 924 mOsm/kg some of the blood plus sodium chloride samples hemolyzed. In the group without hemolysis the trapped plasma was 5.84 +/- 1.35% while in the group with hemolysis it measured 12.43 +/- 1.90%. The trapped plasma with diatrizoate solutions was 1.41 +/- 0.11, 2.15 +/- 0.18 and 5.32 +/- 0.56 at 458, 531 and 602 mOsm/kg, respectively. Above an osmolality of 458 mOsm/kg the trapped plasma was significantly greater for the diatrizoate solutions than for the sodium chloride solutions. At osmolalities below 458 mOsm/kg only a small correction is needed for trapped plasma with either sodium chloride or meglumine/sodium diatrizoate solutions.

  1. Cell-Free DNA Modulates Clot Structure and Impairs Fibrinolysis in Sepsis.

    Science.gov (United States)

    Gould, Travis J; Vu, Trang T; Stafford, Alan R; Dwivedi, Dhruva J; Kim, Paul Y; Fox-Robichaud, Alison E; Weitz, Jeffrey I; Liaw, Patricia C

    2015-12-01

    Sepsis is characterized by systemic activation of inflammation and coagulation in response to infection. In sepsis, activated neutrophils extrude neutrophil extracellular traps composed of cell-free DNA (CFDNA) that not only trap pathogens but also provide a stimulus for clot formation. Although the effect of CFDNA on coagulation has been extensively studied, much less is known about the impact of CFDNA on fibrinolysis. To address this, we (1) investigated the relationship between CFDNA levels and fibrinolytic activity in sepsis and (2) determined the mechanisms by which CFDNA modulates fibrinolysis. Plasma was collected from healthy and septic individuals, and CFDNA was quantified. Clot lysis assays were performed in plasma and purified systems, and lysis times were determined by monitoring absorbance. Clot morphology was assessed using scanning electron microscopy. Clots formed in plasma from septic patients containing >5 µg/mL CFDNA were dense in structure and resistant to fibrinolysis, a phenomenon overcome by deoxyribonuclease addition. These effects were recapitulated in control plasma supplemented with CFDNA. In a purified system, CFDNA delayed fibrinolysis but did not alter tissue-type plasminogen activator-induced plasmin generation. Using surface plasmon resonance, CFDNA bound plasmin with a Kd value of 4.2±0.3 µmol/L, and increasing concentrations of CFDNA impaired plasmin-mediated degradation of fibrin clots via the formation of a nonproductive ternary complex between plasmin, CFDNA, and fibrin. Our studies suggest that the increased levels of CFDNA in sepsis impair fibrinolysis by inhibiting plasmin-mediated fibrin degradation, thereby identifying CFDNA as a potential therapeutic target for sepsis treatment. © 2015 American Heart Association, Inc.

  2. The impact of the endothelial protein C receptor on thrombin generation and clot lysis.

    Science.gov (United States)

    Pepler, Laura; Wu, Chengliang; Dwivedi, Dhruva J; Wu, Cynthia; Kim, Paul Y; Liaw, Patricia C

    2017-04-01

    When thrombin is bound to thrombomodulin (TM), it becomes a potent activator of protein C (PC) and thrombin-activable fibrinolysis inhibitor (TAFI). Activation of PC is enhanced when PC is bound to the endothelial protein C receptor (EPCR). Activated protein C (APC) inhibits thrombin generation while activated TAFI (TAFIa) attenuates fibrinolysis. To determine the impact of diminished EPCR function on thrombin generation and fibrinolysis we generated cells that expressed TM and a variant of EPCR (R96C) that does not bind PC. To determine the impact of EPCR on the generation of APC and TAFIa and how this affects thrombin generation and fibrinolysis we performed thrombin generation and clot lysis assays in the presence of cells expressing wild-type TM and EPCR (WT cells) or wild-type TM and the R96C variant of EPCR (R96C cells). In the presence of R96C cells, thrombin generation in normal plasma is increased, as a result of impaired PC activation when compared to WT cells. In addition, clot lysis is delayed in normal plasma in the presence of R96C cells, despite no increase in TAFI activation. In PC deficient plasma, clot lysis is delayed in the presence of WT and R96C cells as a result of increased TAFI activation. We demonstrate that impaired EPCR function can be detected by thrombin generation and clot lysis assays on cells expressing TM and EPCR. We also demonstrated that deficiency in EPCR has procoagulant effects that lead to a delay in clot lysis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. From Development to Implementation: Adjusting the Hematocrit of Deglycerolized Red Cell Concentrates to Meet Regulatory Standards.

    Science.gov (United States)

    Turner, Tracey; Hansen, Adele; Kurach, Jayme; Acker, Jason P

    2017-01-01

    Before transfusion, thawed frozen red cell concentrates (RCCs) must be deglycerolized. In order to ensure that these products meet regulatory standards for hematocrit, an approach to manipulate hematocrit post deglycerolization was developed and implemented. Glycerolized and frozen RCCs were thawed and deglycerolized using the COBE 2991 cell processor, and the final product's hematocrit was adjusted by addition of various volumes of 0.9% saline / 0.2% dextrose. The in vitro quality of RCCs (hematocrit, hemolysis, hemoglobin content, volume, recovery, ATP, supernatant potassium, and others) were compared to Canadian Standards Association (CSA) and other standards for deglycerolized RCCs. Addition of saline/dextrose re-suspension solution in a range of 65-90 g post deglycerolization led to acceptable hematocrits. In the pilot study, this approach resulted in RCCs meeting all CSA standards for deglycerolized RCCs, with stimulation of RBC metabolism demonstrated by increased ATP concentration. In the validation phase, results were similar, although the CSA hemolysis standard was not met. Pre- and post-implementation data confirmed that manipulated RCCs met CSA hematocrit standards. This process was implemented at Canadian Blood Services to provide deglycerolized RCCs that meet the CSA hematocrit standard. However, pre- and post-implementation data reveal that this deglycerolization process is not sufficient to have RCCs consistently meet hemolysis standards.

  4. Purification and characterization of a fibrinolytic enzyme and identification of fibrinogen clotting enzyme in a marine green alga, Codium divaricatum.

    Science.gov (United States)

    Matsubara, K; Hori, K; Matsuura, Y; Miyazawa, K

    2000-01-01

    A fibrinolytic enzyme was isolated from a marine green alga, Codium divaricatum, and designated C. divaricatum protease (CDP). This protease effectively hydrolyzed fibrinogen A alpha chain, while it had very low hydrolyzing efficiency for B beta and gamma chains. This property was similar to that of alpha-fibrinogenase isolated from snake venom. Protease activity peaked at pH 9, and was completely inhibited by diisopropyl fluorophosphate (DFP) and phenylmethylsulfonyl fluoride (PMSF), identifying it as a serine protease. Its molecular form was single polypeptide structure and molecular weight was estimated as 31,000 by SDS-PAGE. Fibrinogen clotting enzyme was also identified in a fraction by ion-exchange chromatography. Analysis of clots formed by the enzyme and by thrombin by SDS-PAGE showed that the fibrinogen clotting enzyme would act like thrombin and have high substrate specificity.

  5. Milk clotting and proteolytic activity of enzyme preparation from ...

    African Journals Online (AJOL)

    Some microorganisms have the ability to produce enzymes that could clot milk and used as a substitute for calf rennet. Strains of lactic acid bacteria (LAB) could produce proteolytic enzymes that may have the potential to be used as a source of milk clotting enzyme (MCE). In the present study, LAB isolated from shrimp paste ...

  6. Milk-clotting potential of fruit extracts from Solanum esculentum ...

    African Journals Online (AJOL)

    The release of substances associated with milk-clotting was highly dependent upon quantity of berries, extraction duration and sodium chloride concentration. The highest milk-clotting activity ... S. macrocarpon and S. melongena. Extracts from S. esculentum and S. macrocarpon exhibited a proteolytic activity on the casein.

  7. Blood Thinners: Can I Still Get Blood Clots?

    Science.gov (United States)

    ... get blood clots? If you're taking a blood thinner, is it still possible to get a blood clot? Answers from Rekha Mankad, M.D. Yes. Medications that are commonly called blood thinners — such as aspirin, warfarin (Coumadin, Jantoven), dabigatran ( ...

  8. Evaluation of the effects of levobupivacaine on clotting and fibrinolysis using thromboelastography.

    LENUS (Irish Health Repository)

    Leonard, S A

    2012-02-03

    Amide local anaesthetics inhibit platelet function. We hypothesized that residual anaesthetic in the epidural space could decrease efficacy of an epidural blood patch in preventing postdural puncture headache. Levobupivacaine has recently been approved for epidural anaesthesia. Its effects on coagulation have not previously been studied. The aim of this study was to determine the effects of levobupivacaine on clotting using thromboelastography. Ten ASA Class I volunteers were studied. Venous blood samples were analysed using a Haemoscope 2000D TEG analyser. Whole blood, a 50% saline control and two levobupivacaine solutions (2.5 mg mL(-1) and 2.5 microg mL(-1) in blood) were compared. The former reproduces that produced in the epidural space by blood (20 mL for an epidural blood patch) and levobupivacaine 0.5% (20 mL). The latter approximates plasma concentrations following epidural injection of levobupivacaine 0.5% (20 mL). P < 0.05 was considered significant. Maximum amplitude (MA), a measure of clot strength, is decreased by levobupivacaine 2.5 mg mL(-1). Levobupivacaine 2.5 mg mL(-1) decreases clot strength and may reduce efficacy of a prophylactic epidural blood patch.

  9. Hematocrit as a simple method to predict and manage ovarian hyperstimulation syndrome in assisted reproduction

    Directory of Open Access Journals (Sweden)

    Taswin Kaur

    2015-01-01

    Full Text Available Aim: The aim was to analyze the hematocrit levels in cases of ovarian hyperstimulation syndrome (OHSS, syndrome occurring during in-vitro fertilization (IVF, and study its role as a prognostic indicator. Subjects and Methods: Two years data of 66 women at high risk for developing OHSS was analyzed. Twenty-seven women who developed OHSS were further analyzed based on their hematocrit levels on the day of oocyte pick-up (OPU and the day of embryo transfer (ET to see if there was a prognostic trend. Results: Of the total 225 IVF cases, 66 were deemed high risk for developing OHSS. Twenty-seven of these developed OHSS (40.9%. Of these 27, 21 (77.8% had a hematocrit >35% on the day of OPU. The mean hematocrit in women developing OHSS on the day of OPU was 37.39% (standard deviation [SD] 2.66 as against 35.97% (2.80 in those not developing OHSS. This difference was statistically significant (P = 0.043. On the day of ET, 23/27 (85.8% who developed OHSS had a hematocrit of >35%. The mean hematocrit was 39.29% (SD 3.85 in those who developed OHSS as against 34.7% (2.88 in those who did not. This difference (4.85 was statistically significant (P 35%. Those who required cancellation of ET had a hematocrit of >35% on the day of ET or showed a significant increase of 3% from OPU to ET.

  10. Drug-drug interaction of the anti-TFPI aptamer BAX499 and factor VIII: studies of spatial dynamics of fibrin clot formation in hemophilia A.

    Science.gov (United States)

    Parunov, Leonid A; Soshitova, Natalia P; Fadeeva, Olga A; Balandina, Anna N; Kopylov, Konstantin G; Kumskova, Maria A; Gilbert, James C; Schaub, Robert G; McGinness, Kathleen E; Ataullakhanov, Fazoil I; Panteleev, Mikhail A

    2014-01-01

    In recent years, a number of tissue factor pathway inhibitor (TFPI) antagonists have been developed to serve as bypassing agents to improve hemostasis in hemophilia A. Since TFPI antagonists and FVIII concentrates are procoagulants, their combined effect on spatial clot formation could be potentially pro-thrombotic. To investigate the cooperative effect of TFPI inhibition and supplementation of FVIII in hemophilia A in a spatial, reaction-diffusion experiment in vitro. Plasma was collected at different time points from hemophilia A patients undergoing prophylaxis and was supplemented in vitro with TFPI inhibitor BAX499 (formerly ARC19499) at concentrations from 0 up to 600nM. Clotting propagation in recalcified plasma activated by a surface with immobilized tissue factor (TF) was monitored by videomicroscopy. Increasing concentration of BAX499 improved coagulation for all hemophilia A plasma samples activated with TF at 1.6pmole/m(2) by shortening lag time and increasing initial clot growth velocity and clot size. In contrast, plasma concentration of FVIII had little effect on lag time, but increased spatial clot growth velocity. There was a decrease in the BAX499 efficiency as FVIII concentration increased (lag time shortened by 50% if FVIII:C30%). The results indicate that BAX499 has an effect on clotting in hemophilia A plasma at low FVIII concentrations, however has little effect at high FVIII concentrations. © 2013.

  11. Milk-clotting potential of fruit extracts from Solanum esculentum ...

    African Journals Online (AJOL)

    USER

    2010-03-22

    Mar 22, 2010 ... The loss of milk-clotting activity was dramatic after wet-heating of extracts from S. esculentum and S. macrocarpon at 80°C for 10 min and after dry-heating of fruits at 100°C for 24 h. Heat treatment did not significantly affect the clotting activity of extract from S. melongena. Fruit extracts from S. esculentum.

  12. Phospholipid composition controls thromboplastin sensitivity to individual clotting factors.

    Science.gov (United States)

    Smith, S A; Comp, P C; Morrissey, J H

    2006-04-01

    Tissue factor is the active ingredient in thromboplastin reagents used to perform prothrombin time (PT) clotting tests to monitor oral anticoagulant therapy and to screen for clotting factor deficiencies. Thromboplastins are complex mixtures prepared from extracts of brain or placenta, although newer thromboplastins contain recombinant tissue factor incorporated into phospholipid vesicles. Thromboplastins can vary widely in their sensitivity to reductions in the levels of vitamin K-dependent clotting factors. A system to compensate for this, the International Sensitivity Index (ISI) and International Normalized Ratio (INR), has revolutionized the monitoring of oral anticoagulant therapy. The INR system is also sometimes used to monitor coagulopathies in patients with sepsis or liver failure, applications for which it was not originally designed and for which it has not been rigorously validated. To better understand thromboplastin performance, we systematically investigated which properties of recombinant thromboplastins influence their sensitivities to changes in the levels of specific clotting factors. We now report that relative sensitivities to changes in the plasma levels of factors V, VII, X (FV, FVII, FX) and prothrombin are differentially influenced by a recombinant thromboplastin's content of phospholipid and sodium chloride. Furthermore, thromboplastins of similar ISI values may exhibit quite different sensitivities to each of these clotting factors. Differing sensitivities of thromboplastin reagents to individual clotting factor levels have implications for monitoring of oral anticoagulant therapy and interpreting results of the PT assay.

  13. Late umbilical cord clamping, neonatal hematocrit and Apgar scores: a randomized controlled trial.

    Science.gov (United States)

    Salari, Z; Rezapour, M; Khalili, N

    2014-01-01

    Based on current evidence, there is a little agreement on the best timing for after birth umbilical cord clamping. This study was designed to compare the impact of using two different times for cord clamping on hematocrit concentration and Apgar scores of the neonate. Fifty-six healthy full-term vaginally born neonates were allocated to early (10 seconds after delivery) and late (3 minutes after delivery) umbilical cord clamping groups in this randomized clinical trial. We recorded the length of the 3rd stage of labor and Apgar score at 5 minutes. Infant's hematocrit was measured at 2 and 18 hours of age. Neonatal hematocrit differed between the two groups. Late cord clamping group had greater hematocrit at 2 hours (45.5 ± 4 vs. 49.5 ± 4.4, P = 0.0003) and 18 hours (47.7 ± 5.5 vs. 52.9 ± 4.3, P = 0.0002). Apgar scores at 5 minutes (9.3 ± 0.6 vs. 9.4 ± 0.6, p = 0.5) and duration of delivery 3rd stage (10.2 ± 3.7 min vs. 8.9 ± 5 min, P = 0.2) did not differ between early and late cord clamping groups respectively. Late cord clamping leads to a significant increase in the hematocrit of the neonate but it does not have effects on Apgar score and duration of the 3rd stage of labor.

  14. Correlation of hematocrit and Apgar scores in newborns of women with hypertensive disorders in pregnancy.

    Science.gov (United States)

    Okoye, Helen Chioma; Nwogoh, Benedict; Odetunde, Odutola Israel

    2017-01-01

    To compare the incidence of polycythemia in newborns of women with hypertensive disorders in pregnancy (HDP) with those of normotensive mothers, to determine the incidence of perinatal stress using Apgar scores and to correlate hematocrit with Apgar scores in these newborn. This was a hospital-based comparative study conducted in the University of Port Harcourt Teaching Hospital, Nigeria. Apgar scores of 200 newborns- 100 from mothers with HDP (case group) and 100 from normotensive mothers (control group)- were taken at 1st and 5th minute of birth and cord blood samples collected to determine hematocrit. The subjects were categorized into polycythemic and non polycythemic using a hematocrit ≥65%. Eight percent of newborns of women with HDP had polycythemia while none of the controls did. Apgar scores in the case group with and without polycythemia at one-minute were 4.1±1.8 and 6.6±2.1, respectively and at 5 minutes were 6.9±1.7 and 8.5±1.4 respectively. Hematocrit correlated positively with Apgar scores (both at one and five minutes) in cases without polycythemia (r = 0.221, p = 0.034 and r = 0.255, p = 0.014). Hematocrit of polycythemic newborns did not correlate with Apgar scores (r = -0.287, p = 0.491 and r = -0.436, p = 0.281). The incidence of polycythemia is significantly higher in newborns of women with HDP and these polycythemic neonates had a significantly higher incidence of birth asphyxia. Therefore, birth outcome as determined by Apgar score is influenced by hematocrit.

  15. Extracellular volume quantification by cardiac magnetic resonance imaging without hematocrit sampling : Ready for prime time?

    Science.gov (United States)

    Kammerlander, Andreas A; Duca, Franz; Binder, Christina; Aschauer, Stefan; Zotter-Tufaro, Caroline; Koschutnik, Matthias; Marzluf, Beatrice A; Bonderman, Diana; Mascherbauer, Julia

    2017-10-04

    Myocardial tissue characterization by cardiovascular magnetic resonance (CMR) T1 mapping currently receives increasing interest as a diagnostic tool in various disease settings. The T1-mapping technique allows non-invasive estimation of myocardial extracellular volume (ECV) using T1-times before and after gadolinium administration; however, for calculation of the myocardial ECV the hematocrit is needed, which limits its utility in routine application. Recently, the alternative use of the blood pool T1-time instead of the hematocrit has been described. The results of CMR T1 mapping data of 513 consecutive patients were analyzed for this study. Blood for hematocrit measurement was drawn when placing the i. v. line for contrast agent administration. Data from the first 200 consecutive patients (derivation cohort) were used to establish a regression formula allowing synthetic hematocrit calculation, which was then validated in the following 313 patients (validation cohort). Synthetic ECV was calculated using synthetic hematocrit, and was compared with conventionally derived ECV. Among the entire cohort of 513 patients (mean age 57.4 ± 17.5 years old, 49.1% female) conventionally measured hematocrit was 39.9 ± 4.7% and native blood pool T1-time was 1570.6 ± 117.8 ms. Hematocrit and relaxivity of blood (R1 = 1/blood pool T1 time) were significantly correlated (r = 0.533, r(2) = 0.284, p ECV showed significant correlation in the validation (r = 0.533, r(2) = 0.284, p ECV was found in the validation cohort (mean difference: 0.007%, limits of agreement: -4.32 and 4.33%, respectively). Synthetic ECV using native blood pool T1-times to calculate the hematocrit, is feasible and leads to almost identical results in comparison with the conventional method. It may allow fully automatic ECV-mapping and thus enable broader use of ECV by CMR T1 mapping in clinical practice.

  16. Disproportional changes in hematocrit, plasma volume, and proteins during exercise and bed rest.

    Science.gov (United States)

    Van Beaumont, W.; Greenleaf, J. E.; Juhos, L.

    1972-01-01

    The interrelationships between the changes in plasma volume, hematocrit, and plasma proteins during muscular exercise and bed rest were investigated. Proportionally, the changes in hematocrit are always smaller than the changes in plasma volume. For this reason changes in the concentration of blood constituents can only be quantitated on the basis of plasma volume changes. During short periods of intensive exercise, there was a small loss of plasma proteins. With prolonged submaximal exercise there was a net gain in plasma protein, which contributes to stabilization of the vascular volume. Prolonged bed rest induced hypoproteinemia; this loss of plasma protein probably plays an important role in recumbency hypovolemia.

  17. Disseminating clot burden post- craniotomy: The difficult balancing act of clot versus haemorrhage post-neurosurgery

    Directory of Open Access Journals (Sweden)

    Emma Bowcock

    2016-01-01

    Full Text Available Venous thromboembolism (VTE is the most common complication following craniotomy for neoplastic disease. Its occurrence is associated with a significant morbidity and mortality, and balancing the risks for the subsequent development of VTE versus intracranial haemorrhage (ICH can lead to difficult management decisions for treating clinicians. We present a case of VTE following craniotomy for meningioma complicated by ICH in the presence of a disseminating clot burden that included pulmonary, intra-cardiac and paradoxical arterial embolic sequelae. Management strategies incorporated pharmacological, radiological and surgical methods. We discuss the evidence for VTE prevention and treatment, as well as the role of inferior vena cava filters and thrombectomy. We finally highlight the use of desmopressin as a potential risk factor for VTE, and encourage the need for an individualised approach to peri-operative risk stratification in the neurosurgical intensive care population.

  18. VIDEOTHORACOSCOPY FOR CLOTTED HEMOTHORAX IN PATIENTS WITH PENETRATING CHEST TRAUMA

    Directory of Open Access Journals (Sweden)

    O. V. Voskresensky

    2015-01-01

    Full Text Available BACKGROUND. Clotted hemothorax is the most common complication of the chest injury requiring surgical treatment in most patients.MATERIAL AND METHODS. Videothoracoscopy was performed in 51 patients with complications of penetrating chest trauma in 2011–2012. Clotted hemothorax occured in 27 cases (52.9%.RESULTS. It was found that the main cause of this complication was inadequate pleural drainage effect. Clotted hemothorax developed after drainage of the pleural cavity and primary surgical debridement in 12 patients (44.4%, in 8 patients (29.6% after atypical thoracotomy and in 7 patients (25.9% after typical thoracotomy. The average interval between operations was 8.1±5.0 days.CONCLUSION. The best results of treatment for clotted hemothorax were achieved under the early detection of clotted hemothorax in case of thoracoscopic evacuation in the range from 3 to 7 days (4.7±2.1. Videothoracoscopy performed more than 7 days after detection may increase the volume of surgery, cause significant complications, and considerably prolong treatment. 

  19. The formation of blood sediment at low hematocrit: a kinetic study by a laser scattering technique

    Science.gov (United States)

    Grzegorzewski, Bronislaw; Gornicki, A.; Czarnecki, S.; Gutsze, A.

    2004-06-01

    In this paper the formation of erythrocyte aggregates and their sedimentation was studied by optical method. The movement and aggregation of erythrocytes produce a variation in scattered-light intensity. The well-mixed blood sample at hematocrit of 5% was vertically scanned by laser light. The scattered light intensity was continuously recorded and analyzed. The initially observed increase in the transmitted-light intensity reflected the reorganization of the structure formed by erythrocytes, and was followed by the decrease of light intensity due to an increase of blood sample optical density. In blood samples of 5% hematocrit the new, specific sedimentation curve was obtained. From this curve three different phases of sedimentation process can be distinguished. In the first phase no deposit is observed. This phase corresponds to falling of single cells as well as formation and sedimentation of small aggregates takes place. The second phase, when rapid growth of deposit is observed, corresponds to formation and sedimentation of rouleaux and large aggregates. Finally in the third phase the boundary between deposit and settling cells is slowly going down due to packing of erythrocyte aggregates. These results show that in blood samples of low hematocrit both the kinetics of erythrocyte aggregation and sedimentation process are different from those of the blood with normal and high hematocrit.

  20. Erythrocyte flow and dynamic hematocrit in the renal papilla of the rat.

    Science.gov (United States)

    Zimmerhackl, B; Dussel, R; Steinhausen, M

    1985-12-01

    The microcirculation of the renal papilla was investigated in 32 vasa recta of Wistar rats. Using fluorescence microscopy in combination with a high-sensitivity television system we measured the velocity and flux of fluorescent-tagged erythrocytes in descending (DVR) and ascending vasa recta (AVR). After staining the plasma with fluorescent high molecular weight dextran we determined the diameters of DVR and AVR. Red cell flux (Qrbc) was determined from the ratio of the frequency of fluorescent-tagged red cells detected per unit time (fFITC) to the number of fluorescent-tagged red cells per nanoliter packed red cells (NFITC). From red cell velocity (Vrbc) and vessel diameter (D) we calculated the volume flow (Vapp). The dynamic hematocrit was directly derived as the ratio of Qrbc to Vapp. During antidiuresis Vrbc was 1.35 +/- 0.15 mm X s-1 (mean +/- SE) in DVR and 0.47 +/- 0.07 mm X s-1 in AVR. Qrbc in the same vessels averaged 3.26 +/- 0.9 and 1.72 +/- 0.35 nl X min-1, respectively. The diameter in DVR was 14.3 +/- 0.9 and in AVR 17.9 +/- 0.9 micron. From these values we calculated a dynamic hematocrit of 26 +/- 4 in DVR and 25 +/- 4% in AVR. The systemic hematocrit was 44 +/- 1%. The dynamic hematocrit in vasa recta represented 59 +/- 9 and 57 +/- 8% of the value in the systemic circulation, respectively.

  1. Operative risk and preoperative hematocrit in bypass graft surgery: Role of gender and blood transfusion.

    Science.gov (United States)

    Ad, Niv; Holmes, Sari D; Massimiano, Paul S; Spiegelstein, Dan; Shuman, Deborah J; Pritchard, Graciela; Halpin, Linda

    2015-01-01

    The association between lower preoperative hematocrit (Hct) and risk for morbidity/mortality after cardiac surgery is well established. We examined whether the impact of low preoperative Hct on outcome is modified by blood transfusion and operative risk in women and men undergoing nonemergent CABG surgery. Patients having nonemergent, first-time, isolated CABG were included (N=2757). Logistic regressions assessed effect of hematocrit on major perioperative morbidity/mortality separately by males (n=2232) and females (n=525). Mean age was 63.2±10.1years, preoperative hematocrit was 38.9±4.8%, and STS risk score was 1.3±1.8%. Blood transfusion was more likely in female patients (26% vs. 12%, Ptransfusion in males and females, whereas older age (OR=1.03, P=0.017) also predicted transfusion in females. Major morbidity was also more likely in female patients (12% vs. 7%, Pblood transfusion was the only predictive factor for major morbidity in females (OR=4.56, Pblood transfusion (OR=9.22, Pblood transfusion and major morbidities after nonemergent CABG. Traditional factors that have been found to predict outcomes, such as hematocrit and STS risk, were related only to major morbidity in male patients. However, blood transfusion negatively impacted major outcome after nonemergent CABG surgery across all STS risk levels in both genders. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Comparative evaluation of Bacillus licheniformis 5A5 and Aloe variegata milk-clotting enzymes

    Directory of Open Access Journals (Sweden)

    S. A. Ahmed

    2012-03-01

    Full Text Available The properties of a milk clotting enzyme (MCE produced by bacteria (Bacillus licheniformis 5A5 were investigated and compared to those of rennet extracted from a plant (Aloe variegata. Production of MCE by B. licheniformis 5A5 was better in static than in shaken cultures. Maximum activity (98.3 and 160.3 U/ml of clotting was obtained at 75ºC and 80ºC with bacterial and plant rennet, respectively. In the absence of substrate, the clotting activity of Aloe MCE was found to be less sensitive to heat inactivation up to 80ºC for 75 min, retaining 63.8% of its activity, while bacterial MCE was completely inhibited. CaCl2 stimulated milk clotting activity (MCA up to 2% and 1.5% for bacterial and plant enzymes. NaCl inhibited MCA for both enzymes, even at low concentration (1%. Plant MCE was more sensitive to NaCl at 3% concentration it retained 30.2% of its activity, whereas bacterial MCE retained 64.1%. Increasing skim milk concentration caused a significant increase in MCA up to 6% for both enzymes. Mn2+ stimulated the activity of bacterial and plant enzymes to 158.6 and 177.9%, respectively. EDTA and PMSF increased the activity of plant MCE by 34.4 and 41.1%, respectively, which is higher than those for the bacterial MCE (19.1 and 20.9%. Some natural materials activated MCE, the highest activation of bacterial MCE (128.1% was obtained in the presence of Fenugreek (with acid extraction. However Lupine Giza 1 (with neutral extraction gave the highest activation of plant MCE (137.9%. All extracts from Neem plant increased MCA at range from 105.6% to 136.4%. Plant MCE exhibited much better stability when stored at room temperature (25-30ºC for 30 days, retaining 51.2% of its activity. Bacterial MCE was highly stabile when stored under freezing (-18ºC, retaining 100% of its activity after 30 days. Moreover, bacterial MCE was highly tolerant to repeated freezing and thawing without loss of activity for 8 months.

  3. Evaluation of Hematocrit Influence on Self-Monitoring of Blood Glucose Based on ISO 15197:2013: Comparison of a Novel System With Five Systems With Different Hematocrit Ranges.

    Science.gov (United States)

    Hattemer, Andrew; Wardat, Sami

    2018-01-01

    ISO 15197:2013 recommends testing procedures and acceptance criteria for the evaluation of influence quantities such as hematocrit on measurement results with systems for self-monitoring of blood glucose (SMBG). In this study, hematocrit influence was evaluated for a novel SMBG system (system A) and five other systems with different hematocrit ranges based on ISO 15197:2013. Test procedures were performed with one test strip lot for each system. Each system was tested within the hematocrit range indicated in the manufacturer's labeling (system A: 10-65%, B: 15-65%, C: 20-60%, D: 35-60%, E: 30-60%, F: 30-55%). According to ISO 15197:2013, clause 6.4.2, venous blood samples were used for the evaluation of hematocrit influence. The evaluation was performed for three glucose concentration categories (30-50 mg/dL, 96-144 mg/dL, and 280-420 mg/dL). For each glucose concentration category, at least five different hematocrit levels were investigated. The novel system A and systems B, E, and F complied with the tested lot with the defined criteria and showed ≤10 mg/dL and ≤10% difference between the test sample and the respective control sample with a hematocrit value of 42% ± 2% for BG concentrations 10% difference at glucose concentrations ≥100 mg/dL. Remarkable hematocrit influence within the labeled hematocrit range was obtained in two systems with the tested reagent system lot. Adequate SMBG systems should be carefully chosen by patients and their health care professionals, particularly for patients with increased and decreased hematocrit values.

  4. Milk Clotting Activity of Protease, Extracted from Rhizome of Taffin ...

    African Journals Online (AJOL)

    MBI

    2017-03-07

    Mar 7, 2017 ... Keywords: Ginger Protease, Milk Clotting Activity, Calf rennet, Characterization, Extraction. INTRODUCTION. Ginger rhizome (Zingiber officinale roscoe), the main source of ginger proteases is grown in many parts of Africa, tropical Asia, southeast Asia,. India and the West Indies (Hou-Pin et al., 2009).

  5. Effect of acute hyperglycemia on clotting time and relative plasma ...

    African Journals Online (AJOL)

    Menstruating females seem to bleed more when they ingest sugar or sugar containing substances. This study was carried out to determine the effect of acute hyperglycemia on clotting time and relative plasma viscosity during menstruation. Forty menstruating females from the St. Philomena School of Midwifery, Benin, ...

  6. Compound sodium lactate (Hartmann's) solution. Caution: risk of clotting.

    Science.gov (United States)

    Edwards, M P; Clark, D J; Mark, J S; Wyld, P J

    1986-10-01

    We have observed blood clotting in blood administration sets where Hartmann's solution (Travenol) has preceded blood transfusion. This is due to calcium ions (Ca++) contained in the Hartmann's solution and is more likely to occur at 37 degrees C. We suggest that this potential hazard be more widely realised and that the practice cease.

  7. Identification and characterization of milk-clotting proteases ...

    African Journals Online (AJOL)

    Two strains of fungi were isolated and identified as Aspergillus tamarii and Penicillium pinophilum which showed good enzymatic activity on casein, 1933.33U and 1822, 21U, respectively. The search for milk clotting enzymes by fermentation at acid pH on culture medium containing whey and, after purification by molecular ...

  8. Photoacoustic monitoring of clot formation during surgery and tumor surgery

    Science.gov (United States)

    Juratli, Mazen A.; Galanzha, Ekaterina I.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Suen, James Y.; Zharov, Vladimir P.

    2013-03-01

    When a blood vessel is injured, the normal physiological response of the body is to form a clot (thrombus) to prevent blood loss. Alternatively, even without injury to the blood vessel, the pathological condition called thromboembolism may lead to the formation of circulating blood clots (CBCs), also called emboli, which can clog blood vessels throughout the body. Veins of the extremities (venous thromboembolism), lungs (pulmonary embolism ), brain (embolic stroke), heart (myocardial infarction), kidneys, and gastrointestinal tract are often affected. Emboli are also common complications of infection, inflammation, cancer, surgery, radiation and coronary artery bypass grafts. Despite the clear medical significance of CBCs, however, little progress has been made in the development of methods for real-time detection and identification of CBCs. To overcome these limitations, we developed a new modification of in vivo photoacoustic (PA) flow cytometry (PAFC) for real-time detection of white, red, and mixed clots through a transient decrease, increase or fluctuation of PA signal amplitude, respectively. In this work, using PAFC and mouse models, we present for the first time direct evidence that some medical procedures, such as conventional or cancer surgery may initiate the formation of CBCs. In conclusion, the PA diagnostic platform can be used in real-time to define risk factors for cardiovascular diseases, assist in the prognosis and potential prevention of stroke by using a well-timed therapy or as a clot count as a marker of therapy efficacy.

  9. Comparative Studies Of The Proteolytic And The Milk Clotting ...

    African Journals Online (AJOL)

    The use of enzymes as catalysts for industrial processes is becoming increasingly widespread, particularly in the food industry. The proteolytic and milk clotting activities of the crude latex of Calotropis procera, Carica papaya, and Musa paradisiaca were examined. The proteolytic activities of the crude latex were determined ...

  10. The in-vitro effect of fibrinogen, factor XIII and thrombin-activatable fibrinolysis inhibitor on clot formation and susceptibility to tissue plasminogen activator-induced fibrinolysis in hemodilution model.

    Science.gov (United States)

    Shenkman, Boris; Livnat, Tami; Lubetsky, Aharon; Tamarin, Ilia; Budnik, Ivan; Einav, Yulia; Martinowitz, Uriel

    2012-07-01

    Patients suffering major traumatic or surgical bleeding are often exposed to hemodilution resulting in dilutional coagulopathy. The aim of this study was to evaluate in vitro the effects of fibrinogen, factor XIII and thrombin-activatable fibrinolysis inhibitor (TAFI) on clot formation and resistance to fibrinolysis in hemodilution conditions. Citrated whole blood from 36 healthy volunteers was diluted to 30 and 60% with lactated Ringer's solution. Blood samples were subsequently supplemented with fibrinogen, FXIII, TAFI or their combinations. Rotation thromboelastometry (ROTEM) in whole blood and thrombin generation in plasma were performed in the presence of CaCl₂ and tissue factor/EXTEM reagent, and fibrinolysis was induced by tissue plasminogen activator (tPA). Hemodilution was expressed by decrease of peak height in thrombin generation and α-angle and maximum clot firmness (MCF) in ROTEM. Fibrinogen, FXIII or TAFI did not correct the decrease in thrombin generation peak height. In ROTEM, spiking of diluted blood with fibrinogen stimulated clot propagation. In tPA-treated blood fibrinogen, FXIII and TAFI increased clot firmness and inhibited fibrinolysis. Stronger protection against fibrinolysis was achieved combining FXIII with TAFI. Hemodilution was associated with inhibition of thrombin generation; however, this effect was not sensitive to blood spiking with fibrinogen, FXIII and TAFI. In ROTEM, these hemostasis agents improved clot strength and decreased clot susceptibility to tPA in nondiluted and to more extent in diluted blood. The maximal protection against fibrinolysis was caused by TAFI. Combining FXIII with TAFI exerted synergistic inhibitory effect on fibrinolysis.

  11. Jacaratia corumbensis O. Kuntze a new vegetable source for milk-clotting enzymes

    Directory of Open Access Journals (Sweden)

    Ana Rodrigues Duarte

    2009-02-01

    Full Text Available The partial characterization and purification of milk clotting enzyme obtained from the (root latex of Jacaratia corumbensis O. kuntze was studied, by fractional precipitation with ammonium sulphate and ion exchange chromatography. The ammonium sulphate precipitate showed five fractions (AS1- 0-20%; AS2 - 20-40%; AS3 - 40-60%; AS4 - 60-80%; AS5 - 80-100% and among the fractions obtained, the 40-60% fraction (AS3 showed the highest milk clotting activity with a purification factor of 1.2 fold in relation to the crude extract. This fraction when applied on Mono Q column yielded two protein peaks (p1 and p2, but p1 pool showed the best milk-clotting activity. The optimal pH for the crude and partially purified extract was 6.5 and 7.0, respectively. The maximum milk-clotting activity was at 55ºC for the both crude and partially purified extracts. The enzyme was inhibited by iodoacetic acid which suggested that this enzyme was a cysteine protease, with molecular weight of 33 kDa.A enzima coagulante de leite obtida de látex de raiz de Jacaratia corumbensis O. kuntze foi caracterizada parcialmente e purificada, por precipitação fracionária com sulfato de amônio e cromatografia de troca de íon. Foram utilizadas cinco frações de sulfato de amônio (AS1 - 0-20%; AS2 - 20-40%; AS3 - 40-60%; AS4 - 60-80%; AS5 - 80-100%, a fração 40-60% (AS3 mostrou alta atividade coagulante com um fator de purificação de 1,2 vezes em relação ao extrato bruto. Esta fração foi aplicada em coluna Mono Q obtendo dois picos de proteína (p1 e p2, o p1 mostrou melhor atividade coagulante. O pH ótimo para o extrato bruto e parcialmente purificado foi 6,5 e 7,0, respectivamente. A atividade coagulante foi atingida a 55ºC para ambos os extratos, bruto e parcialmente purificado. A enzima foi inibida por ácido iodoacético que sugere que esta enzima é uma cisteína protease, com peso molecular de 33 kDa.

  12. Purification and characterization of a milk-clotting aspartic proteinase from globe artichoke (Cynara scolymus L.).

    Science.gov (United States)

    Llorente, Berta E; Brutti, Cristina B; Caffini, Néstor O

    2004-12-29

    The study of proteinase expression in crude extracts from different organs of the globe artichoke (Cynara scolymus L.) disclosed that enzymes with proteolytic and milk-clotting activity are mainly located in mature flowers. Maximum proteolytic activity was recorded at pH 5.0, and inhibition studies showed that only pepstatin, specific for aspartic proteinases, presented a significant inhibitory effect. Such properties, in addition to easy enzyme inactivation by moderate heating, make this crude protease extract potentially useful for cheese production. Adsorption with activated carbon, together with anion exchange and affinity chromatography, led to the isolation of a heterodimeric milk-clotting proteinase consisting of 30- and 15-kDa subunits. MALDI-TOF MS of the 15-kDa chain determined a 15.358-Da mass, and the terminal amino sequence presented 96% homology with the smaller cardosin A subunit. The amino terminal sequence of the 30-kDa chain proved to be identical to the larger cardosin A subunit. Electrophoresis evidenced proteinase self-processing that was confirmed by immunoblots presenting 62-, 30-, and 15-kDa bands.

  13. Development of an in vitro model to study clot lysis activity of thrombolytic drugs

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    Taori Girdhar M

    2006-09-01

    Full Text Available Abstract Background Thrombolytic drugs are widely used for the management of cerebral venous sinus thrombosis patients. Several in vitro models have been developed to study clot lytic activity of thrombolytic drugs, but all of these have certain limitations. There is need of an appropriate model to check the clot lytic efficacy of thrombolytic drugs. In the present study, an attempt has been made to design and develop a new model system to study clot lysis in a simplified and easy way using a thrombolytic drug, streptokinase. Methods Whole blood from healthy individuals (n = 20 was allowed to form clots in a pre-weighed sterile microcentrifuge tubes; serum was removed and clot was weighed. After lysis by streptokinase fluid was removed and remnants of clot were again weighed along with the tube. Percentage of Clot lysis was calculated on the basis of the weight difference of microcentrifuge tubes obtained before and after clot lysis. Results There was a significant percentage of clot lysis observed when streptokinase was used. On the other hand with water (negative control, minimal (2.5% clot lysis was observed. There was a significant difference between clot lysis done by streptokinase and water. Conclusion Our study could be a rapid and effective methodology to study clot-lytic effect of newly developed drugs as well as known drugs.

  14. Capture of lipopolysaccharide (endotoxin by the blood clot: a comparative study.

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    Margaret T Armstrong

    Full Text Available In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse operate to capture lipopolysaccharide (LPS, endotoxin. The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

  15. Capture of lipopolysaccharide (endotoxin) by the blood clot: a comparative study.

    Science.gov (United States)

    Armstrong, Margaret T; Rickles, Frederick R; Armstrong, Peter B

    2013-01-01

    In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot) and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse) operate to capture lipopolysaccharide (LPS, endotoxin). The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL) test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

  16. 21 CFR 864.7140 - Activated whole blood clotting time tests.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Activated whole blood clotting time tests. 864....7140 Activated whole blood clotting time tests. (a) Identification. An activated whole blood clotting time tests is a device, used to monitor heparin therapy for the treatment of venous thrombosis or...

  17. Evaluation of newly developed veterinary portable blood glucose meter with hematocrit correction in dogs and cats.

    Science.gov (United States)

    Mori, Akihiro; Oda, Hitomi; Onozawa, Eri; Shono, Saori; Sako, Toshinori

    2017-10-07

    This study evaluated the accuracy of a newly developed veterinary portable blood glucose meter (PBGM) with hematocrit correction in dogs and cats. Sixty-one dogs and 31 cats were used for the current study. Blood samples were obtained from each dog and cat one to six times. Acceptable results were obtained in error grid analysis between PBGM and reference method values (glucose oxidation methods) in both dogs and cats. Bland-Altman plot analysis revealed a mean difference between the PBGM value and reference method value of -1.975 mg/dl (bias) in dogs and 1.339 mg/dl (bias) in cats. Hematocrit values did not affect the results of the veterinary PBGM. Therefore, this veterinary PBGM is clinically useful in dogs and cats.

  18. Comparative changes in plasma protein concentration, hematocrit and plasma volume during exercise, bedrest and + Gz acceleration.

    Science.gov (United States)

    Van Beaumont, W.; Greenleaf, J. E.

    1972-01-01

    Discussion of experiments which indicate that under conditions of a constant red cell volume the proportional changes in hematocrit and plasma volume during exercise are never equal. On the basis of direct measurements and calculated changes of plasma volume it is concluded that during maximal exercise there is a small loss of protein from the plasma. It is clear that changes in content of blood constituents can only be evaluated correctly after determination of changes in plasma volume.

  19. Seasonal hematocrit variation and health risks in the adult population of Kinshasa, Democratic Republic of Congo

    OpenAIRE

    C Makena Hightower; Hightower, Joyce D; Beatriz Y Salazar Vázquez; et al.

    2009-01-01

    C Makena Hightower1, Joyce D Hightower2, Beatriz Y Salazar Vázquez1,3, Marcos Intaglietta11Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA; 2Group de Reflection, Actions et Etude de Culture, Kinshasa, Democratic Republic of Congo; 3Facultad de Medicina, Universidad Juárez del Estado de Durango, Durango, Durango, MéxicoAbstract: Hematocrit (Hct) as an indicator of blood viscosity and mean arterial blood pressure (MA...

  20. Optical measurement of isolated canine lung filtration coefficients at normal hematocrits.

    Science.gov (United States)

    Klaesner, J W; Pou, N A; Parker, R E; Finney, C; Roselli, R J

    1997-12-01

    In this study, lung filtration coefficient (Kfc) values were measured in eight isolated canine lung preparations at normal hematocrit values using three methods: gravimetric, blood-corrected gravimetric, and optical. The lungs were kept in zone 3 conditions and subjected to an average venous pressure increase of 10.24 +/- 0.27 (SE) cmH2O. The resulting Kfc (ml . min-1 . cmH2O-1 . 100 g dry lung wt-1) measured with the gravimetric technique was 0.420 +/- 0.017, which was statistically different from the Kfc measured by the blood-corrected gravimetric method (0.273 +/- 0.018) or the product of the reflection coefficient (sigmaf) and Kfc measured optically (0. 272 +/- 0.018). The optical method involved the use of a Cellco filter cartridge to separate red blood cells from plasma, which allowed measurement of the concentration of the tracer in plasma at normal hematocrits (34 +/- 1.5). The permeability-surface area product was measured using radioactive multiple indicator-dilution methods before, during, and after venous pressure elevations. Results showed that the surface area of the lung did not change significantly during the measurement of Kfc. These studies suggest that sigmafKfc can be measured optically at normal hematocrits, that this measurement is not influenced by blood volume changes that occur during the measurement, and that the optical sigmafKfc agrees with the Kfc obtained via the blood-corrected gravimetric method.

  1. Haemostatic and immune role of cellular clotting in the sipunculan Themiste petricola.

    Science.gov (United States)

    Cavaliere, Victoria; Papademetrio, Daniela L; Alvarez, Elida M C; Blanco, Guillermo A

    2010-03-01

    Sipunculans, a small phylum of coelomated marine worms closely related to polychaete annelids, lack a true circulatory system. We have previously shown that the sipunculan Themiste petricola can form a cellular clot, without congealing, of cell-free coelomic fluid. The clot is formed by the aggregation of large granular leukocytes (LGLs) and may serve not only haemostatic but immune functions, since dissimilar particles may become entrapped within it. We have now evaluated the capacity of a massive clot, induced in vitro by sea water contact, to stop coelomic fluid flow. We have further studied smaller clots induced on glass-slides either with or without the presence of bacteria placed for entrapment within the clot. The fate of clotting LGLs is cell death while forming a cohesive mass, although cytoplasmic and nuclear remnants are shed from the clot. These remnants and any bacteria that avoid clot entrapment or are detached from the clot are engulfed by non-clotting cells that include small granular leukocytes (SGLs) and large hyaline amebocytes (LHAs). Both cell types can be found other than in the clot but SGLs also occur around the clot edges heavily loaded with engulfed material. The cytoskeletal arrangement of SGLs evaluated with phalloidin-rhodamine correspond to motile cells and contrast with that of clotting LGLs that form a massive network of F-actin. Thus, the complementary roles between clotting LGLs and non-clotting SGLs and LHAs act a central immune strategy of Themiste petricola to deal with body wall injury and pathogen intrusion into the coelomic cavity.

  2. Comparison between the clot-protecting activity of a mutant plasminogen activator inhibitor-1 with a very long half-life and 6-aminocaproic acid.

    Science.gov (United States)

    Kindell, Daniel Glenn; Keck, Rick Wayne; Jankun, Jerzy

    2015-06-01

    Plasminogen activator inhibitor (PAI)-1 is a serpin glycoprotein that can stabilize blood clots by inhibiting fibrinolysis. However, wild-type PAI-1 has the disadvantage of a short half-life of ∼2 h. A very long half-life (VLHL) PAI-1 mutant was developed previously with an active-form half-life of >700 h, making it a possible candidate for use in hemorrhagic therapy. Current treatments for mitigating hemorrhage, other than inducers of blood clotting, are limited to lysine analog antifibrinolytics, including 6-aminocaproic acid and tranexamic acid. VLHL PAI-1 has been previously demonstrated to limit bleeding; however, the efficacy of this protein compared with lysine analog antifibrinolytics has not been investigated. The aim of the current study was to compare the clot stabilizing properties of the novel antifibrinolytic VLHL PAI-1 with those of 6-aminocaproic acid in reference plasma. Using thromboelastographic analysis, VLHL PAI-1 exhibited an IC 50 (half maximal inhibitory concentration) of 8.8×10 -8 mol/l, while 6-aminocaproic acid showed an IC 50 of 1.6×10 -4 mol/l. However, at doses of >9.0×10 -7 mol/l, VLHL PAI-1 exhibited a delay in the onset of clot formation, which may be attributed to thrombin inhibition by excess PAI-1. The inhibition of tissue plasminogen activator by VLHL PAI-1 demonstrated improved efficacy over 6-aminocaproic acid in mitigating hemorrhage. In addition, patients with a PAI-1 deficiency, which causes blood clots to lyse rapidly resulting in profuse bleeding, may benefit from the application of VLHL PAI-1 as an antihemorrhagic therapy.

  3. Does prior administration of enoxaparin influence the effects of levobupivacaine on blood clotting? Assessment using the Thrombelastograph.

    LENUS (Irish Health Repository)

    Leonard, S A

    2012-02-03

    The low molecular weight heparin, enoxaparin (by inhibition of factors Xa and IIa) and amide local anaesthetics (by altering platelet function) exert anti-clotting effects. Although these agents are often used in combination during the perioperative period, their potential interactive effect on clotting has not been defined. Blood from 10 ASA I-II patients who received enoxaparin 0.5 mg kg(-1) s.c. was studied using a Thrombelastograph (TEG) either alone or in combination with levobupivacaine (2.5 mg ml(-1) or 2.5 microg ml(-1)) or saline (50% dilution). In blood from patients who had received enoxaparin 0.5 mg kg(-1) s.c. 12 h previously, levobupivacaine 2.5 mg ml(-1) (but not 2.5 microg ml(-1)) produced significant changes in TEG clotting parameters (mean (SD) 15.7 (4.8) mm, 29.6 (25.6) mm, 34.4 (14.6) mm, 34.3 (12.2) degrees compared with control values of 6.1 (1.3) mm, 2.5 (0.5) mm, 63.5 (6.4) mm and 74.1 (2.9) degrees for r, K, MA, and alpha angle respectively).

  4. Developing Mesoscale Model of Fibrin-Platelet Network Representing Blood Clotting =

    Science.gov (United States)

    Sun, Yueyi; Nikolov, Svetoslav; Bowie, Sam; Alexeev, Alexander; Lam, Wilbur; Myers, David

    Blood clotting disorders which prevent the body's natural ability to achieve hemostasis can lead to a variety of life threatening conditions such as, excessive bleeding, stroke, or heart attack. Treatment of these disorders is highly dependent on understanding the underlying physics behind the clotting process. Since clotting is a highly complex multi scale mechanism developing a fully atomistic model is currently not possible. We develop a mesoscale model based on dissipative particle dynamics (DPD) to gain fundamental understanding of the underlying principles controlling the clotting process. In our study, we examine experimental data on clot contraction using stacks of confocal microscopy images to estimate the crosslink density in the fibrin networks and platelet location. Using this data we reconstruct the platelet rich fibrin network and study how platelet-fibrin interactions affect clotting. Furthermore, we probe how different system parameters affect clot contraction. ANSF CAREER Award DMR-1255288.

  5. "Liver clot"-A rare periodontal postsurgical complication

    Directory of Open Access Journals (Sweden)

    Dhara Pandya

    2012-01-01

    Full Text Available Bleeding is a common sequela of oral and periodontal surgery. Generally, bleeding is self-limiting. Following traumatic injury or surgical procedures, hemorrhage can range from a minor leakage or oozing at the site, to extensive bleeding leading to complete exsanguinations. Significant postsurgical hemorrhage following periodontal surgery is uncommon due to the primary closure of the soft tissues. This case report describes the unique formation of a "liver clot" or "currant jelly clot" following periodontal flap surgery. The likelihood of this may be attributed to many factors, like infection, intrinsic trauma, presence of foreign bodies like splinter of bone, a fleck of enamel, or a piece of dental restorative dressing material that may cause repeated, delayed organization of blood coagulum.

  6. Aggregation of red blood cells: From rouleaux to clot formation

    Science.gov (United States)

    Wagner, Christian; Steffen, Patrick; Svetina, Saša

    2013-06-01

    Red blood cells are known to form aggregates in the form of rouleaux. This aggregation process is believed to be reversible, but there is still no full understanding on the adhesion mechanism. There are at least two competing models, based either on bridging or on depletion. We review recent experimental results on the single cell level and theoretical analyses of the depletion model and of the influence of the cell shape on the adhesion strength. Another important aggregation mechanism is caused by activation of platelets. This leads to clot formation which is life-saving in the case of wound healing, but also a major cause of death in the case of a thrombus induced stroke. We review historical and recent results on the participation of red blood cells in clot formation.

  7. Bidirectional functions of thrombin on fibrinolysis: Evidence of thrombin-dependent enhancement of fibrinolysis provided by spontaneous plasma clot lysis.

    Science.gov (United States)

    Tomczyk, Martyna; Suzuki, Yuko; Sano, Hideto; Brzoska, Tomasz; Tanaka, Hiroki; Urano, Tetsumei

    2016-07-01

    Besides procoagulant activity, thrombin exhibits anticoagulant and profibrinolytic activities. We demonstrated that the euglobulin clot lysis time (ECLT) was shortened by endogenously generated thrombin as a result of the inactivation of plasminogen activator inhibitor type 1 (PAI-1). In contrast, thrombin suppressed fibrinolytic activity through the activation of thrombin activatable fibrinolysis inhibitor (TAFI). Here, using three different clot lysis assays of the ECLT, the tissue plasminogen activator supplemented plasma clot lysis time (tPA-PCLT) and the spontaneous plasma clot lysis time (s-PCLT), we analyzed how the coagulation process modifies fibrinolysis. The ECLT was shortened by exogenously supplemented thrombin in a dose-dependent manner in the absence of calcium ion (Ca(++)), whereas this shortening was not observed in the presence of Ca(++) where endogenous prothrombin was effectively activated to thrombin. This shortening was also not observed for the tPA-PCLT, in which tPA is supplemented in excess and PAI-1 activity is mostly lost. On the contrary, thrombin dose-dependently prolonged the tPA-PCLT, which was mostly abolished by inhibitors of carboxypeptidase and activated FXIII, suggesting that the prolongation is TAFI- and Factor XIII-dependent. The s-PCLT was shortened when thrombin generation was boosted by supplementing tissue factor and phosphatidylserine together with Ca(++), which was more apparent in the presence of inhibitors of activated FXIII and activated TAFI. Thus, thrombin appeared to express its enhancing effect on fibrinolysis even in plasma, in addition to its inhibiting effect. These bidirectional functions of thrombin on fibrinolysis seem to take place on demand under different environments to maintain adequate vascular blood flow. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Purification and characterization of a milk-clotting protease from ...

    African Journals Online (AJOL)

    Crude enzymatic extract obtained from five fermentations (300 g of wheat bran) was characterized by a clotting activity of 0.34 ± 0.08 UP/ml with a strength ratio of 1/1: 200. The comparative study of the summaries from 2 purification protocols showed that it is possible to recover 6% of the initial proteins with a 44.54% activity ...

  9. A miniaturized hemoretractometer for blood clot retraction testing

    OpenAIRE

    Li, Zida; Li, Xiang; McCracken, Brendan; Shao, Yue; Ward, Kevin; Fu, Jianping

    2016-01-01

    Blood coagulation is a critical hemostatic process that must be properly regulated to maintain a delicate balance between bleeding and clotting. Disorders of blood coagulation can expose patients to the risk of either bleeding disorders or thrombotic diseases. Coagulation diagnostics using whole blood is very promising for assessing the complexity of the coagulation system and for global measurements of hemostasis. Despite the clinic values that existing whole blood coagulation tests have dem...

  10. Thromboelastography on plasma reveals delayed clot formation and accelerated clot lyses in HIV-1 infected persons compared with healthy controls

    DEFF Research Database (Denmark)

    Rönsholt, Frederikke Falkencrone; Gerstoft, Jan; Ullum, Henrik

    2015-01-01

    PA), and measured levels of C-reactive protein, thrombomodulin, syndecan-1, sVE-cadherin, soluble CD40 ligand (sCD40L), adrenaline and noradrenaline. RESULTS: Compared to CON, HIV+ had delayed clot formation (reaction (R)-time 14.2 min. vs. 11.2 min., p = 0.0004) and reduced clot formation rapidity (angle 22.6° vs......BACKGROUND: Thromboembolic events among HIV infected persons are a recognized clinical problem but the underlying mechanisms are poorly understood. To assess whether coagulation and fibrinolysis differ between long-term treated HIV infected individuals (HIV+) and healthy controls (CON), we...... investigated functional plasma coagulation by thrombelastography (TEG) and plasma markers of endothelial and platelet activation. METHODS: In 67 successfully long-term treated HIV+ and 15 CON we analyzed stored plasma samples by TEG, with or without addition of tissue-type plasminogen activator (t...

  11. Co-ordinated spatial propagation of blood plasma clotting and fibrinolytic fronts

    Science.gov (United States)

    Zhalyalov, Ansar S.; Panteleev, Mikhail A.; Gracheva, Marina A.; Ataullakhanov, Fazoil I.

    2017-01-01

    Fibrinolysis is a cascade of proteolytic reactions occurring in blood and soft tissues, which functions to disintegrate fibrin clots when they are no more needed. In order to elucidate its regulation in space and time, fibrinolysis was investigated using an in vitro reaction-diffusion experimental model of blood clot formation and dissolution. Clotting was activated by a surface with immobilized tissue factor in a thin layer of recalcified blood plasma supplemented with tissue plasminogen activator (TPA), urokinase plasminogen activator or streptokinase. Formation and dissolution of fibrin clot was monitored by videomicroscopy. Computer systems biology model of clot formation and lysis was developed for data analysis and experimental planning. Fibrin clot front propagated in space from tissue factor, followed by a front of clot dissolution propagating from the same source. Velocity of lysis front propagation linearly depended on the velocity clotting front propagation (correlation r2 = 0.91). Computer model revealed that fibrin formation was indeed the rate-limiting step in the fibrinolysis front propagation. The phenomenon of two fronts which switched the state of blood plasma from liquid to solid and then back to liquid did not depend on the fibrinolysis activator. Interestingly, TPA at high concentrations began to increase lysis onset time and to decrease lysis propagation velocity, presumably due to plasminogen depletion. Spatially non-uniform lysis occurred simultaneously with clot formation and detached the clot from the procoagulant surface. These patterns of spatial fibrinolysis provide insights into its regulation and might explain clinical phenomena associated with thrombolytic therapy. PMID:28686711

  12. PARTIAL PURIFICATION OF MILK-CLOTTING ENZYME FROM THE SEEDS OF MORINGA OLEIFERA

    Directory of Open Access Journals (Sweden)

    Amna E. Tajalsir

    2014-08-01

    Full Text Available The aim of the present study was to search for milk clotting substitute from different parts (flowers, seeds, stem, leaves, ripe and unripe fruits of Moringa oleifera. The samples were blended and extracted using different types of extracting solutions. The most reliable, quick and efficient enzyme extracting solution was found to be 5% NaCl in 100 mM sodium acetate buffer, pH 5.0, which was used throughout the study. The milk clotting activity was only observed in the seeds extract while the other parts were either deficient or has very low milk clotting activity. Thus, the moringa seeds were used as source of milk clotting enzyme. The extracted proteins were fractionated with ammonium sulfate at concentration of 20, 30, 40, 50 and 60 %. Highest milk clotting activity was observed in the 20 % fraction. This fraction was assumed to contain the clotting enzymes and characterized for its heating stability (30 – 90°C and optimum temperature (30 – 90°C. The results demonstrated that moringa seeds milk clotting enzyme is stable up to 50°C with an optimum milk clotting activity of 70°C. The high ratio of milk-clotting to proteolytic activity of the partially purified enzyme indicates the potential of this enzyme as suitable rennet substitute in dairy industry. However, further study is needed to completely purify and characterize this promising milk clotting enzyme from moringa seeds.

  13. Non-invasive prediction of hematocrit levels by portable visible and near-infrared spectrophotometer.

    Science.gov (United States)

    Sakudo, Akikazu; Kato, Yukiko Hakariya; Kuratsune, Hirohiko; Ikuta, Kazuyoshi

    2009-10-01

    After blood donation, in some individuals having polycythemia, dehydration causes anemia. Although the hematocrit (Ht) level is closely related to anemia, the current method of measuring Ht is performed after blood drawing. Furthermore, the monitoring of Ht levels contributes to a healthy life. Therefore, a non-invasive test for Ht is warranted for the safe donation of blood and good quality of life. A non-invasive procedure for the prediction of hematocrit levels was developed on the basis of a chemometric analysis of visible and near-infrared (Vis-NIR) spectra of the thumbs using portable spectrophotometer. Transmittance spectra in the 600- to 1100-nm region from thumbs of Japanese volunteers were subjected to a partial least squares regression (PLSR) analysis and leave-out cross-validation to develop chemometric models for predicting Ht levels. Ht levels of masked samples predicted by this model from Vis-NIR spectra provided a coefficient of determination in prediction of 0.6349 with a standard error of prediction of 3.704% and a detection limit in prediction of 17.14%, indicating that the model is applicable for normal and abnormal value in Ht level. These results suggest portable Vis-NIR spectrophotometer to have potential for the non-invasive measurement of Ht levels with a combination of PLSR analysis.

  14. Maternal hematocrite level and risk of low birth weight and preterm delivery

    Directory of Open Access Journals (Sweden)

    A. Garshasbi

    2006-07-01

    Full Text Available Background: The aim of the study was to investigate associations between maternal characteristics, with emphasis on hematological status, and risk of low birth weight and preterm delivery among pregnant women Methods: In a cohort study, 1,500 pregnant women attending Hazrat Zaynab Hospital for prenatal care and delivery in the period 2000-2001, without any risk factors for preterm delivery and low birth weight were included. Maternal characteristics including hematocrit values were recorded at the first antenatal visit. Main outcome measures included birth weight and gestation at delivery. Linear and logistic regression models were used to analyze data. Results: Severe anemia (hematocrit 40% did not increase the risk of low birth weight and preterm delivery. Teenagers, women with short height or low body mass index had significantly higher risk of delivering low birth weight infants. Conclusion.: Severe maternal anemia, particularly in the first trimester, was significantly associated with adverse pregnancy outcome. Low maternal age, height or body mass index also increased the risk of low birth weight. Improved nutritional status of young women could contribute to improved health among their infant.

  15. Fibrin Clots Are Equilibrium Polymers That Can Be Remodeled Without Proteolytic Digestion

    Science.gov (United States)

    Chernysh, Irina N.; Nagaswami, Chandrasekaran; Purohit, Prashant K.; Weisel, John W.

    2012-11-01

    Fibrin polymerization is a necessary part of hemostasis but clots can obstruct blood vessels and cause heart attacks and strokes. The polymerization reactions are specific and controlled, involving strong knob-into-hole interactions to convert soluble fibrinogen into insoluble fibrin. It has long been assumed that clots and thrombi are stable structures until proteolytic digestion. On the contrary, using the technique of fluorescence recovery after photobleaching, we demonstrate here that there is turnover of fibrin in an uncrosslinked clot. A peptide representing the knobs involved in fibrin polymerization can compete for the holes and dissolve a preformed fibrin clot, or increase the fraction of soluble oligomers, with striking rearrangements in clot structure. These results imply that in vivo clots or thrombi are more dynamic structures than previously believed that may be remodeled as a result of local environmental conditions, may account for some embolization, and suggest a target for therapeutic intervention.

  16. Three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes.

    Science.gov (United States)

    Gagaoua, Mohammed; Hoggas, Naouel; Hafid, Kahina

    2015-02-01

    The present work describes for the first time an elegant non-chromatographic method, the three phase partitioning for the purification and recovery of zingibain, a milk-clotting enzyme, from Zingiber officinale rhizomes. Factors affecting partitioning efficiency such as (NH4)2SO4 saturation, crude extract to t-butanol ratio and pH on zingibain partitioning were investigated. Optimal purification parameters were 50% (NH4)2SO4 saturation with 1.0:1.0 ratio of crude extract:t-butanol at pH 7.0, which gave 14.91 purification fold with 215% recovery of zingibain. The enzyme was found to be exclusively partitioned in the aqueous phase. The enzyme showed a prominent single band on SDS-PAGE. It is a monomeric protein of 33.8 kDa and its isoelectric point is 4.38. The enzyme exhibited maximal proteolytic activity at a temperature of 60 °C and pH 7.0. It was found to be stable at 40-65 °C during 2 h. The enzyme was found to be highly stable against numerous metal ions and its activity was enhanced by Ca(2+), K(+) and Na(+). It was completely inhibited by heavy metal ions such as Cu(2+) and Hg(2+) and partially by Cd(+). Zingibain milk-clotting activity (MCA) was found to be highly stable when stored under freezing (-20 °C) for 30 days compared at 4 °C. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Invasive landscape : el Clot del Moro (Berguedà)

    OpenAIRE

    Valcárcel Cavallé, Jorge

    2012-01-01

    El proyecto propone la reutilización de la colonia industrial del “Clot del Moro” y su reconversión en centro de alojamiento temporal. El elemento singular,la antigua fábrica Asland se transforma con el objetivo de adaptarse a unos nuevos requerimientos y diferentes tipos de usuarios : se potencia el programa actual (Museo del Cemento) y se incorporan las zonas en ruinas al sistema de espacios públicos del sector aprovechando el estado de invasividad actual. Por último se incorpora un nuevo...

  18. Travail et pouvoir d’agir d’Yves Clot

    Directory of Open Access Journals (Sweden)

    Jacques Leplat

    2008-11-01

    Full Text Available Yves Clot est titulaire de la Chaire de psychologie du travail du Conservatoire National des Arts et Métiers (CNAM au sein duquel il dirige l’équipe de clinique de l’activité. Cet ouvrage est le second qu’il publie dans cette collection, le premier « La fonction psychologique du travail » est paru en 1999. Entre les deux s’inscrivent un grand nombre de publications, dont beaucoup avec d’autres chercheurs, comme on pourra le constater en consultant la bibliographie de ce livre. Ce denier réun...

  19. The spatial dynamics of fibrin clot dissolution catalyzed by erythrocyte-bound vs. free fibrinolytics.

    Science.gov (United States)

    Gersh, K C; Zaitsev, S; Muzykantov, V; Cines, D B; Weisel, J W

    2010-05-01

    Coupling fibrinolytic plasminogen activators to red blood cells (RBCs) has been proposed as an effective, yet safe method of thromboprophylaxis, because of increased circulation lifetime and reduced propensity to induce hemorrhage by selectivity for nascent thrombi rather than pre-formed hemostatic clots. We used confocal microscopy of fluorescently labeled fibrin and erythrocytes in plasma-derived clots to study the spatial dynamics of lysis catalyzed by RBC-coupled vs. free plasminogen activators (RBC-PA vs. PA). Clot lysis catalyzed by free PA progressed gradually and uniformly. In contrast, distinct holes formed surrounding RBC-PA while the rest of the clot remained intact until these holes enlarged sufficiently to merge, causing sudden clot dissolution. Compared with naïve RBCs within clots lysed by free PA, RBC-PA moved faster inside the fibrin network prior to clot dissolution, providing a potential mechanism for spatial propagation of RBC-PA induced lysis. We also showed the focal nature of fibrinolysis by RBC-PA as dense loading of PA onto RBCs initiates more efficient lysis than equal amounts of PA spread sparsely over more RBCs. In an in vitro model of clots exposed to buffer flow, incorporated RBC-PA increased permeability and formed channels eventually triggering clot dissolution, whereas clots containing free PA remained intact. Clot lysis by RBC-PA begins focally, has a longer lag phase when measured by residual mass than homogeneous lysis by PA, is propagated by RBC-PA motility and provides more effective clot reperfusion than free PA, making RBC-PA attractive for short-term thromboprophylaxis.

  20. EFFECT OF CONSUMING PAPAYA (CARICA PAPAYA LINN. ON THE LEVEL OF HEMOGLOBIN AND HEMATOCRIT IN PREGNANT WOMEN WITH ANEMIA

    Directory of Open Access Journals (Sweden)

    Choralina Eliagita

    2017-04-01

    Full Text Available Background: The prevalence of anemia among pregnant women was still high in Indonesia, especially in Bengkulu. Consuming papaya is considered as one of the solutions to increase hemoglobin and hematocrit level. Objective: This study aims to examine the effect of consuming papaya on the level of hemoglobin and hematocrit in pregnant women. Methods: This study employed a true experiment with randomized pretest and posttest design with control group. There were 42 respondents recruited in this study using simple random sampling. Randomization was performed to divide the samples into two groups, namely 21 respondents in the treatment group and 21 respondents in the control group. A total of 110 grams of papaya was given to the intervention group every day for 14 days. Data were analyzed using dependent t-test and independent t-test. Result: There was a significant effect of consuming papaya on the hemoglobin and hematocrit level with p-value 0.000 (< .05. The mean difference between two groups showed that hemoglobin level (control group 10.010 gr/dL; intervention group 10.838 gr/dL and hematocrit level (control group 27.43 %; intervention group 30.10 %. Conclusion: Consuming papaya has a significant effect on changes in hemoglobin and hematocrit levels. It is suggested that consuming papaya should be one of alternative treatment for midwives to prevent anemia in pregnant women.

  1. Effect of Delayed Cord Clamping Above Versus Below the Perineum on Neonatal Hematocrit: A Randomized Controlled Trial.

    Science.gov (United States)

    Mansaray, Aminata; Yetman, Robert; Berens, Pamela

    2015-12-01

    The purpose of this study was to determine if there is a difference in neonatal hematocrit at 24 hours of life in full-term newborns for which delayed cord clamping is performed above versus below the perineum. One hundred one patients with singleton pregnancies >37 weeks of gestation presenting for delivery were randomized to delayed cord clamping above or below the perineum. At 24 hours of life, neonatal hematocrit was determined, and the difference was compared using statistical analysis. Secondary outcomes measured were need for phototherapy, transfusion, and neonatal intensive care unit (NICU) admission. Of 101 patients recruited for the study, 53 were randomized to the above group, and 48 were randomized to the below group. Twenty-seven patients in the above group and 26 patients in the below group completed the study. The above group had an average neonatal hematocrit of 52.7% (± 2.58%). The below group had an average neonatal hematocrit of 55.8% (± 2.42%). There was no statistical difference between groups (p = 0.10). Similarly, differences in secondary outcomes did not reach statistical significance. Three infants in the above group and one infant in the below group required phototherapy. None of the infants required blood transfusion. Three infants in the above group and one infant in the below group required NICU admission. When comparing delayed cord clamping above versus below the perineum, there is no difference in the neonatal hematocrit at 24 hours of life.

  2. Quantitative photoacoustic characterization of blood clot in blood: A mechanobiological assessment through spectral information

    Science.gov (United States)

    Biswas, Deblina; Vasudevan, Srivathsan; Chen, George C. K.; Sharma, Norman

    2017-02-01

    Formation of blood clots, called thrombus, can happen due to hyper-coagulation of blood. Thrombi, while moving through blood vessels can impede blood flow, an important criterion for many critical diseases like deep vein thrombosis and heart attacks. Understanding mechanical properties of clot formation is vital for assessment of severity of thrombosis and proper treatment. However, biomechanics of thrombus is less known to clinicians and not very well investigated. Photoacoustic (PA) spectral response, a non-invasive technique, is proposed to investigate the mechanism of formation of blood clots through elasticity and also differentiate clots from blood. Distinct shift (increase in frequency) of the PA response dominant frequency during clot formation is reported. In addition, quantitative differentiation of blood clots from blood has been achieved through parameters like dominant frequency and spectral energy of PA spectral response. Nearly twofold increases in dominant frequency in blood clots compared to blood were found in the PA spectral response. Significant changes in energy also help in quantitatively differentiating clots from blood, in the blood. Our results reveal that increase in density during clot formation is reflected in the PA spectral response, a significant step towards understanding the mechanobiology of thrombus formation. Hence, the proposed tool, in addition to detecting thrombus formation, could reveal mechanical properties of the sample through quantitative photoacoustic spectral parameters.

  3. Erythrocyte migration and gap formation in rabbit blood clots in vitro.

    Science.gov (United States)

    Ueki, T; Yazama, F; Horiuchi, T; Yamada, M

    2008-04-01

    Thrombolytic agents must be carried by the blood circulation to thrombi to exert their functions. Structural gaps exist between blood vessels and thrombi or in the area surrounding thrombi. Therefore, information about fundamental gap formation at thrombotic areas is critically important for thrombolytic therapy. We previously reported that t-PA accelerates the activities of bovine erythrocytes and hemoglobin (Hb) towards bovine plasminogen activation. Here, we examined gap generation by observing morphological changes during thrombolytic processes in rabbit blood clots deformation of erythrocytes from blood clots and Hb transfer from erythrocytes to serum in vitro. Rabbit venous blood samples (1 ml) were stored under sterile conditions in glass tubes at 37 degrees C for 2, 24, 48 h, 1, and 2 weeks. We examined clot diameter, erythrocyte diameter and number as well as Hb volume in the serum, as well as histological changes in the clots. The diameter of blood clots did not change until 2 weeks after sampling. Erythrocyte diameter decreased within 48 h and at 2 weeks after sampling at the clot surface (p erythrocytes in the serum started to increase starting from 24 h after sampling (p erythrocyte envelope became disrupted and cytoplasm started to flow through pores into the serum at 24 h. The results indicated that blood clots are reduced due to clot retraction, erythrocyte dissociation and cytoplasm leakage without a distinct fibrinolytic reaction. These results indicated that gaps start to form between 2 and 24 h after blood clotting.

  4. A lab-on-a-chip for rapid blood separation and quantification of hematocrit and serum analytes.

    Science.gov (United States)

    Browne, Andrew W; Ramasamy, Lakshminarayanan; Cripe, Timothy P; Ahn, Chong H

    2011-07-21

    In this work, a new lab-on-a-chip for rapid analysis of low volume blood samples was designed, fabricated and demonstrated for integration of serum separation, hematocrit evaluation, and protein quantitation. Blood separation was achieved using microchannel flow-based separation. A novel method for evaluating hematocrit from microfluidic flow-separated blood samples was developed using gray scale analysis of a point-and-shoot digital photograph of separated blood in a micochannel. Protein quantitation was subsequently performed in a high surface area-to-volume ratio microfluidic chemiluminescent immunoassay using cell depleted serum produced by microfluidic flow-based separation of whole blood samples. All three steps were achieved in a single microchannel with separation of blood samples and hematocrit evaluation in less than 1 min, and protein quantitation in 5 min.

  5. Influence of Ringer’s lactated solution in continuous infusion and general anesthesia on hematocrit in dogs

    Directory of Open Access Journals (Sweden)

    Rogério Luizari Guedes

    2015-08-01

    Full Text Available The measurement of serum parameters during general anesthesia procedures are subject to variations due to differences in protocol, splenic storage, and by the instituted fluid therapy. The aim of this study was to assess the hematocrit changes promoted by controlled fluid therapy and general anesthesia. Six mongrel female dogs underwent an anesthetic protocol with acepromazine (0.03 mg kg-1 and tramadol (5 mg kg-1 for premedication, induction with propofol (3 mg kg-1, and maintained with isoflurane and mechanical ventilation for 120 minutes. After induction, they were infused with 10 ml kg hr-1 of Ringer’s lactate solution. Hematocrit measurements were performed from the start until 72 hours from anesthesia and evaluated statistically to check if there were significant changes over time. The fluid therapy, the acepromazine and propofol in the anesthetic protocol promotes a significant reduction of hematocrit up to four hours after general anesthesia.

  6. Effect of aminocaproic acid on clot strength and clot lysis of canine blood determined by use of an in vitro model of hyperfibrinolysis.

    Science.gov (United States)

    Brown, Jamie C; Brainard, Benjamin M; Fletcher, Daniel J; Nie, Ben; Arnold, Robert D; Schmiedt, Chad W

    2016-11-01

    OBJECTIVE To determine pharmacodynamic and pharmacokinetic profiles of aminocaproic acid (ACA) by use of a thromboelastography (TEG)-based in vitro model of hyperfibrinolysis and high-performance liquid chromatography-mass spectrometry. ANIMALS 5 healthy adult dogs. PROCEDURES A single dose of injectable ACA (20, 50, or 100 mg/kg) or an ACA tablet (approximately 100 mg/kg) was administered orally. Blood samples were collected at 0, 15, 30, 45, 60, 90, 120, and 240 minutes after ACA administration for pharmacokinetic analysis. Samples were obtained at 0, 60, and 240 minutes for pharmacodynamic analysis by use of a TEG model of hyperfibrinolysis. RESULTS No adverse effects were detected. In the hyperfibrinolysis model, after all doses, a significantly higher TEG maximum amplitude (clot strength), compared with baseline, was detected at 60 and 240 minutes. Additionally, the percentage of fibrinolysis was reduced from the baseline value at 60 and 240 minutes, with the greatest reduction at 60 minutes. At 240 minutes, there was significantly less fibrinolysis for the 100 mg/kg dose than the 20 mg/kg dose. Maximum plasma ACA concentration was dose dependent. There was no significant difference in pharmacokinetic parameters between 100 mg/kg formulations. CONCLUSIONS AND CLINICAL RELEVANCE In an in vitro model of hyperfibrinolysis, ACA inhibited fibrinolysis at all doses tested. At 240 minutes after administration, the 100 mg/kg dose inhibited fibrinolysis more effectively than did the 20 mg/kg dose. Thus, ACA may be useful for in vivo prevention of fibrinolysis in dogs. IMPACT FOR HUMAN MEDICINE These data may improve research models of hyperfibrinolytic diseases.

  7. Clot dynamics and mortality: The MA-R ratio.

    Science.gov (United States)

    Savage, Stephanie A; Zarzaur, Ben L; Pohlman, Timothy H; Brewer, Brian L; Magnotti, Louis J; Croce, Martin A; Lim, Garrett H; Martin, Ali C

    2017-10-01

    The coagulopathy of trauma, illustrated by a short R-time, is common and well understood. The physiology behind this may be early thrombin burst with rapid clot formation. Rapid consumption of fibrinogen, however, may result in weak clot and substrate depletion, resulting in low MA. While these characteristics are interesting, utilizing thromboelastography (TEG) to identify those at risk of subsequent bleeding diathesis, especially in those who do not demonstrate early signs of physiologic derangement, is challenging. We have developed a novel ratio utilizing TEG values to describe patients at specific risk of traumatic coagulopathy. The purpose of this study was to create a single TEG value, which would reflect both the hypercoagulability and hypocoagulability of TIC. We hypothesized that this ratio, at admission, would be indicative of TIC and predictive of both blood product transfusion volumes and subsequent mortality. Patients admitted via the highest activation criteria at one of two Level I trauma centers were included if they received at least 1 unit of packed red blood cells in the first 24 hours of admission. The admission TEG was collected, and a ratio was calculated by dividing the MA by the R-time (MA-R). MA-R quartiles were developed, and multivariable logistic regression was utilized to determine odds of mortality. Three hundred thirty patients with admission TEG were included. In all patients, median age was 35 years (interquartile range, 25-54 years), Injury Severity Score (ISS) was 20 (interquartile range, 13-29), 76% were male, and 43% had penetrating trauma. The MA-R groups were based on quartiles. Multivariable analysis, controlling for mechanism of injury, ISS, and admission pH, showed that increasing ratios were associated with decreased odds of death. The lowest MA-R ratios were also significantly associated with higher ISS, higher rates of blunt injury, and higher plasma utilization without a significant difference in packed red blood cell

  8. Individual clotting factor contributions to mortality following trauma.

    Science.gov (United States)

    Kunitake, Ryan C; Howard, Benjamin M; Kornblith, Lucy Z; Christie, Sabrinah A; Conroy, Amanda S; Cohen, Mitchell J; Callcut, Rachael A

    2017-02-01

    Acute traumatic coagulopathy affects 20% to 30% of trauma patients, but the extensive collinearity of the coagulation cascade complicates attempts to clarify global clotting factor dysfunction. This study aimed to characterize phenotypes of clotting factor dysfunction and their contributions to mortality after major trauma. This prospective cohort study examines all adult trauma patients of the highest activation level presenting to San Francisco General Hospital between February 2005 and February 2015. Factors II, V, VII, VIII, IX, and X and protein C activity on admission and mortality status at 28 days were assessed. Predictors of 28-day mortality in univariate analysis were included in multiple logistic regression controlling for traumatic brain injury (TBI), acidosis, age, and mechanism of injury. Principal component analysis was utilized to identify phenotypic coagulation. Complete coagulation factor data were available for 876 (61%) of 1,429 patients. In multiple logistic regression, factors V (odds ratio [OR], 0.86; 95% confidence interval [CI], 0.76-0.97), VIII (OR, 0.97; 95% CI, 0.95-0.99), and X (OR, 0.79; 95% CI, 0.68-0.92) and protein C (OR, 1.17; 95% CI, 1.05-1.30) significantly predicted 28-day mortality after controlling for age, base deficit, mechanism of injury, and TBI. Principal component analysis identified two significant principal components (Phenotypes 1 and 2) that accounted for 66.3% of the total variance. Phenotype 1 (factors II, VII, IX, and X and protein C abnormalities) explained 49.3% and was associated with increased injury, coagulopathy, TBI, and mortality. Phenotype 2 (factors V and VIII abnormalities) explained 17.0% and was associated with increased coagulopathy, blunt injury, and mortality. Only Phenotype 2 remained significantly associated with 28-day mortality in multiple logistic regression. Principal component analysis identified two distinct phenotypes within the entirety of global clotting factor abnormalities, and these

  9. Thermal Blood Clot Formation and use in Microfluidic Device Valving Applications

    Science.gov (United States)

    Tai, Yu-Chong (Inventor); Shi, Wendian (Inventor); Guo, Luke (Inventor)

    2014-01-01

    The present invention provides a method of forming a blood-clot microvalve by heating blood in a capillary tube of a microfluidic device. Also described are methods of modulating liquid flow in a capillary tube by forming and removing a blood-clot microvalve.

  10. Clot Formation in the Sipunculid Worm Themiste petricola: A Haemostatic and Immune Cellular Response

    Directory of Open Access Journals (Sweden)

    Tomás Lombardo

    2012-01-01

    Full Text Available Clot formation in the sipunculid Themiste petricola, a coelomate nonsegmented marine worm without a circulatory system, is a cellular response that creates a haemostatic mass upon activation with sea water. The mass with sealing properties is brought about by homotypic aggregation of granular leukocytes present in the coelomic fluid that undergo a rapid process of fusion and cell death forming a homogenous clot or mass. The clot structure appears to be stabilized by abundant F-actin that creates a fibrous scaffold retaining cell-derived components. Since preservation of fluid within the coelom is vital for the worm, clotting contributes to rapidly seal the body wall and entrap pathogens upon injury, creating a matrix where wound healing can take place in a second stage. During formation of the clot, microbes or small particles are entrapped. Phagocytosis of self and non-self particles shed from the clot occurs at the clot neighbourhood, demonstrating that clotting is the initial phase of a well-orchestrated dual haemostatic and immune cellular response.

  11. Effects of aspirin on clot structure and fibrinolysis using a novel in vitro cellular system.

    Science.gov (United States)

    Ajjan, R A; Standeven, K F; Khanbhai, M; Phoenix, F; Gersh, K C; Weisel, J W; Kearney, M T; Ariëns, R A S; Grant, P J

    2009-05-01

    The purpose of this study was to investigate the direct effects of aspirin on fibrin structure/function. Chinese Hamster Ovary cell lines stably transfected with fibrinogen were grown in the absence (0) and presence of increasing concentrations of aspirin. Fibrinogen was purified from the media using affinity chromatography, and clots were made from recombinant protein. Mean final turbidity [OD(+/-SEM)] was 0.083(+/-0.03), 0.093(+/-0.002), 0.101(+/-0.005), and 0.125(+/-0.003) in clots made from 0, 1, 10, and 100 mg/L aspirin-treated fibrinogen, respectively (Paspirin respectively (Pstructure and increased fiber thickness of clots made from aspirin-treated fibrinogen, whereas rheometer studies showed a significant 30% reduction in clot rigidity. Fibrinolysis was quicker in clots made from aspirin-treated fibrinogen. Ex vivo studies in 3 normal volunteers given 150 mg aspirin daily for 1 week demonstrated similar changes in clot structure/function. Aspirin directly altered clot structure resulting in the formation of clots with thicker fibers and bigger pores, which are easier to lyse. This study clearly demonstrates an alternative mode of action for aspirin, which should be considered in studies evaluating the biochemical efficacy of this agent.

  12. 42 CFR 410.63 - Hepatitis B vaccine and blood clotting factors: Conditions.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Hepatitis B vaccine and blood clotting factors... Other Health Services § 410.63 Hepatitis B vaccine and blood clotting factors: Conditions... under § 410.10, subject to the specified conditions: (a) Hepatitis B vaccine: Conditions. Effective...

  13. A viscoelastic fluid model for describing the mechanics of a Coarse ligated plasma clot

    Energy Technology Data Exchange (ETDEWEB)

    Anand, M.; Rajagopal, K.R. [Texas A and M University, Department of Mechanical Engineering, College Station, TX (United States); Rajagopal, K. [Duke University Medical Center, Department of Surgery, Durham, NC (United States)

    2006-09-15

    Thrombi are formed at the end of a series of complex biochemical processes. There are various types of thrombi, and their rheological properties change depending on the conditions during clot formation. In this paper, a model for a particular type of clot, formed from human plasma, is proposed within a thermodynamic framework that recognizes that viscoelastic fluids possess multiple natural configurations. (orig.)

  14. Intracameral tissue plasminogen activator: management of a fibrin clot occluding a Molteno tube.

    Science.gov (United States)

    Pastor, S A; Schumann, S P; Starita, R J; Fellman, R L

    1993-12-01

    We report the use of intracameral tissue plasminogen activator to dissolve a fibrin clot occluding a Molteno tube in the immediate postoperative period. This technique is an effective alternative to awaiting clot lysis or reoperation with minimal risk. The only complication was a small, layering hyphema.

  15. Biological variation in tPA-induced plasma clot lysis time

    NARCIS (Netherlands)

    S. Talens (Simone); J.J.M.C. Malfliet (Joyce); G. Rudež (Goran); H.M.H. Spronk (Henri); N.A.H. Janssen (Nicole); P. Meijer (Piet); C. Kluft (Cornelius); M.P.M. de Maat (Moniek); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractHypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis.

  16. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture Regulations of the Department of Agriculture (Continued... clotting enzymes and flavor enzymes. Enzyme preparations used in the manufacture of cheese shall be safe...

  17. Integration of acoustic radiation force and optical imaging for blood plasma clot stiffness measurement.

    Directory of Open Access Journals (Sweden)

    Caroline W Wang

    Full Text Available Despite the life-preserving function blood clotting serves in the body, inadequate or excessive blood clot stiffness has been associated with life-threatening diseases such as stroke, hemorrhage, and heart attack. The relationship between blood clot stiffness and vascular diseases underscores the importance of quantifying the magnitude and kinetics of blood's transformation from a fluid to a viscoelastic solid. To measure blood plasma clot stiffness, we have developed a method that uses ultrasound acoustic radiation force (ARF to induce micron-scaled displacements (1-500 μm on microbeads suspended in blood plasma. The displacements were detected by optical microscopy and took place within a micro-liter sized clot region formed within a larger volume (2 mL sample to minimize container surface effects. Modulation of the ultrasound generated acoustic radiation force allowed stiffness measurements to be made in blood plasma from before its gel point to the stage where it was a fully developed viscoelastic solid. A 0.5 wt % agarose hydrogel was 9.8-fold stiffer than the plasma (platelet-rich clot at 1 h post-kaolin stimulus. The acoustic radiation force microbead method was sensitive to the presence of platelets and strength of coagulation stimulus. Platelet depletion reduced clot stiffness 6.9 fold relative to platelet rich plasma. The sensitivity of acoustic radiation force based stiffness assessment may allow for studying platelet regulation of both incipient and mature clot mechanical properties.

  18. Reduced clot debris size using standing waves formed via high intensity focused ultrasound

    Science.gov (United States)

    Guo, Shifang; Du, Xuan; Wang, Xin; Lu, Shukuan; Shi, Aiwei; Xu, Shanshan; Bouakaz, Ayache; Wan, Mingxi

    2017-09-01

    The feasibility of utilizing high intensity focused ultrasound (HIFU) to induce thrombolysis has been demonstrated previously. However, clinical concerns still remain related to the clot debris produced via fragmentation of the original clot potentially being too large and hence occluding downstream vessels, causing hazardous emboli. This study investigates the use of standing wave fields formed via HIFU to disintegrate the thrombus while achieving a reduced clot debris size in vitro. The results showed that the average diameter of the clot debris calculated by volume percentage was smaller in the standing wave mode than in the travelling wave mode at identical ultrasound thrombolysis settings. Furthermore, the inertial cavitation dose was shown to be lower in the standing wave mode, while the estimated cavitation bubble size distribution was similar in both modes. These results show that a reduction of the clot debris size with standing waves may be attributed to the particle trapping of the acoustic potential well which contributed to particle fragmentation.

  19. Confocal microscopy movies of fibrin clots during ultrasound-accelerated thrombolysis

    Science.gov (United States)

    Everbach, E. Carr; Chernysh, Irina N.; Weisel, John W.

    2005-04-01

    Blood clots made of human purified fibrin (white clots) were insonified with 1 MHz pulsed ultrasound during observation by fluorescence confocal microscopy. A deconvolution microscope allowed extremely thin sheets (0.2 μm) of fibrin to be viewed at a resolution of 0.2 μm per pixel, and the clot microstructure visualized. Acoustic pressure amplitudes from 0.1 to 0.8 MPa (peak-to-peak) were inferred using the image blur of 0.6-μm-diameter polystyrene spheres coated with FITC fluorecent label present in the clots. Acoustic pulse widths of 1 ms and pulse repetition frequencies of 125 Hz reduced clot heating to less than 3°C during each 30-minute exposure. Still 100 μm by 100 μm images were recorded every 10 seconds during pauses in insonificaiton, to produce time-lapse movies that are compared with movies made during sham ultrasound exposures.

  20. Clotting Factor Deficiency in Early Trauma-Associated Coagulopathy

    Science.gov (United States)

    Rizoli, Sandro B.; Scarpelini, Sandro; Callum, Jeannie; Nascimento, Bartolomeu; Mann, Kenneth G.; Pinto, Ruxandra; Jansen, Jan; Tien, Homer

    2011-01-01

    Background Coagulopathic bleeding is a leading cause of in-hospital death after injury. A recently proposed transfusion strategy calls for early and aggressive frozen plasma transfusion to bleeding trauma patients, thus addressing trauma-associated coagulopathy (TAC) by transfusing clotting factors (CF). This strategy may dramatically improve survival of bleeding trauma patients. However, other studies suggest that early TAC occurs by protein C activation and is independent of CF deficiency. The present study investigated whether CF deficiency is associated with early trauma-associated coagulopathy. Methods Prospective observational cohort study of severely traumatized patients (ISS ≥16) admitted shortly after injury, receiving minimal fluids and no prehospital blood. Blood was assayed for CF levels, thromboelastography and routine coagulation tests. Critical CF deficiency was defined as ≤30% activity of any CF. Results Of 110 patients, 22 (20%) had critical CF deficiency: critically low factor V level was evident in all these patients. INR, aPTT and TEG were abnormal in 32%, 36% and 35% respectively of patients with any critically low CF. Patients with critical CF deficiency suffered more severe injuries, were more acidotic, received more blood transfusions and showed a trend towards higher mortality (32% vs. 18% p=.23). Computational modelling showed coagulopathic patients had pronounced delays and quantitative deficits in generating thrombin. Conclusions 20% of all severely injured patients had critical clotting factor deficiency on admission, particularly of factor V. The observed factor V deficit aligns with current understanding of the mechanisms underlying early TAC. Critical deficiency of factor V impairs thrombin generation and profoundly affects hemostasis. PMID:22071999

  1. The influence of type 2 diabetes on fibrin clot properties in patients with coronary artery disease.

    Science.gov (United States)

    Neergaard-Petersen, S; Hvas, A-M; Kristensen, S D; Grove, E L; Larsen, S B; Phoenix, F; Kurdee, Z; Grant, P J; Ajjan, R A

    2014-12-01

    Type 2 diabetes mellitus (T2DM) increases the risk of coronary thrombosis and both conditions are associated with altered fibrin clot properties. However, the influence of T2DM on fibrin clot properties in patients with coronary artery disease (CAD) remains unclear. We aimed to investigate the influence of T2DM on fibrin clot properties in patients with CAD. Fibrin clot structure and fibrinolysis were investigated in 581 CAD patients (148 with T2DM) using turbidimetric assays, confocal and scanning electron microscopy. Clots made from plasma and plasma-purified fibrinogen were studied, and plasma levels of inflammatory markers were analysed. T2DM patients had increased clot maximum absorbance compared with non-diabetic patients (0.36 ± 0.1 vs 0.33 ± 0.1 au; p=0.01), displayed longer lysis time (804 [618;1002] vs 750 [624;906] seconds; p=0.03) and showed more compact fibrin structure assessed by confocal and electron microscopy. Fibrinogen levels were elevated in T2DM (p< 0.001), but clots made from purified fibrinogen showed no differences in fibrin properties in the two populations. Adjusting for fibrinogen levels, T2DM was associated with C-reactive protein and complement C3 plasma levels, with the former correlating with clot maximum absorbance (r=0.24, p< 0.0001) and the latter with lysis time (r=0.30, p< 0.0001). Independent of fibrinogen levels, females had more compact clots with prolonged lysis time compared with males (all p-values< 0.001). In conclusion, T2DM is associated with prothrombotic changes in fibrin clot properties in patients with CAD. This is related to quantitative rather than qualitative changes in fibrinogen with a possible role for inflammatory proteins.

  2. A Semi-Physiological Population Model to Quantify the Effect of Hematocrit on Everolimus Pharmacokinetics and Pharmacodynamics in Cancer Patients

    NARCIS (Netherlands)

    Erp, N.P. van; Herpen, C.M. van; Wit, D. de; Willemsen, A.; Burger, D.M.; Huitema, A.D.; Kapiteijn, E.; Heine, R. ter

    2016-01-01

    INTRODUCTION AND OBJECTIVE: Everolimus (a drug from the class of mammalian target of rapamycin [mTOR] inhibitors) is associated with frequent toxicity-related dose reductions. Everolimus accumulates in erythrocytes, but the extent to which hematocrit affects everolimus plasma pharmacokinetics and

  3. Modeling severely discordant hematocrits and normal amniotic fluids after incomplete laser therapy in twin-to-twin transfusion syndrome

    NARCIS (Netherlands)

    van den Wijngaard, Jeroen P. H. M.; Lewi, Liesbeth; Lopriore, Enrico; Robyr, Romaine; Middeldorp, Johanna M.; Vandenbussche, Frank P. H. A.; Devlieger, Roland; Deprest, Jan; Ville, Yves; van Gemert, Martin J. C.

    2007-01-01

    Our objective was to explain the clinical presentations of sustained arteriovenous anastomotic transfusion of blood after incomplete laser therapy in twin-to-twin transfusion syndrome (TTTS). We extended our mathematical model of TTTS by adding the dynamics of hematocrit, and simulated incomplete

  4. Reliability of point-of-care hematocrit, blood gas, electrolyte, lactate and glucose measurement during cardiopulmonary bypass.

    NARCIS (Netherlands)

    Steinfelder-Visscher, J.; Weerwind, P.W.; Teerenstra, S.; Brouwer, M.H.J.

    2006-01-01

    BACKGROUND: Recently, the GEM Premier blood gas analyser was upgraded to the GEM Premier 3000. In addition to pH, pCO2, pO2, Na+, K+, Ca2+, and hematocrit measurement, glucose and lactate can be measured on the GEM Premier 3000. In this prospective clinical study, the analytical performance of the

  5. Evaluation of point-of-care analyzers' ability to reduce bias in conductivity-based hematocrit measurement during cardiopulmonary bypass

    NARCIS (Netherlands)

    Teerenstra, S.; Steinfelder-Visscher, J.; Gunnewiek, J.K.; Weerwind, P.W.

    2014-01-01

    Most point-of-care testing analyzers use the conductivity method to measure hematocrit (hct). During open-heart surgery, blood-conductivity is influenced by shifts in electrolyte and colloid concentrations caused by infusion media used, and this may lead to considerable bias in the hct measurement.

  6. Complexes of anti-prothrombin antibodies and prothrombin cause lupus anticoagulant activity by competing with the binding of clotting factors for catalytic phospholipid surfaces.

    Science.gov (United States)

    Simmelink, M J; Horbach, D A; Derksen, R H; Meijers, J C; Bevers, E M; Willems, G M; De Groot, P G

    2001-06-01

    We investigated the mechanism by which anti-prothrombin antibodies cause lupus anticoagulant (LAC) activity. Addition of affinity-purified anti-prothrombin antibodies from LAC-positive plasma samples (alpha-FII-LAC+) to normal plasma induced LAC activity. Upon increasing the phospholipid concentration, LAC activity was neutralized. Addition of purified alpha-FII-LAC+ to normal plasma strongly inhibited factor Xa formation. No inhibition was measured when alpha-FII-LAC+ were added to prothrombin-deficient plasma or when purified anti-prothrombin antibodies from LAC-negative plasma samples (alpha-FII-LAC-) were added. When a combination of prothrombin and alpha-FII-LAC+ was added to the purified clotting complex, a strong inhibition of factor Xa and IIa formation was seen. The alpha-FII-LAC+ alone or a combination of prothrombin and alpha-FII-LAC- did not show inhibition. Ellipsometry studies showed that, in the presence of alpha-FII-LAC+, the affinity of prothrombin for a phospholipid surface increased dramatically, whereas a much lower increase was observed with alpha-FII-LAC-. Our results show that complexes of prothrombin and anti-prothrombin antibodies with LAC activity inhibit both prothrombinase and tenase. The antibodies increase the affinity of prothrombin for the phospholipid surface, thereby competing with clotting factors for the available catalytic phospholipid surface, a mechanism similar to that of anti-beta2-glycoprotein I antibodies.

  7. Studies on cytotoxic and clot lysis activity of probiotically fermented cocktail juice prepared using Camellia sinensis and Punica grantum

    Science.gov (United States)

    Biswas, Ananya; Deori, Meenakshi; Nivetha, A.; Mohansrinivasan, V.

    2017-11-01

    In the current research the effect of probiotic microorganisms viz; Lactococcus lactis and Lactobacillus plantarum on fermentation of Camellia sinensis and Punica grantum was studied. In vitro test were done to analyze the anticancer, antioxidant and atherosclerosis (clot lysis) properties of fermented juice. The juice was fermented for 48 and 96h, during which concentration of phenolic content, total acid content and free radical scavenging activity of the sample was analyzed by DPPH assay (α, α-diphenyl-β-picrylhydrazyl). Dropping of pH was observed after 48 h of fermentation. The clot lysis activity was found to be 80 % in 100μl concentration of fermented cocktail juice. The 96 h fermented sample has shown around 70% inhibition against colon cancer cell lines. Analytical study of HPLC proves the organic acid production such as ascorbic acid in superior amount for 96h of fermented sample, Based on the retention time, the corresponding peaks were detected at 4.919 and 4.831 min.

  8. A comparison of the mechanical, kinetic, and biochemical properties of fibrin clots formed with two different fibrin sealants.

    Science.gov (United States)

    Hickerson, William L; Nur, Israel; Meidler, Roberto

    2011-01-01

    The objective of the present study was to compare the mechanical, kinetic, and biochemical properties of fibrin clots produced using EVICEL Fibrin Sealant (Human) and TISSEEL Fibrin Sealant. The stiffness/elasticity and strength of fibrin clots formed with EVICEL and TISSEEL were assessed using applied mechanical force and thromboelastography (TEG). The factor XIII content of the fibrin clots was also evaluated. Mean Young modulus and tensile strength of the fibrin clots produced by EVICEL were significantly higher than those of clots produced by TISSEEL (P < 0.05 for both). The mean time to initial clot formation and mean time to the predefined level of clot formation were numerically shorter for EVICEL compared with TISSEEL. Furthermore, mean maximal amplitude of the clots formed with EVICEL was significantly greater than that for the clots formed with TISSEEL. Mean concentration of factor XIII for the EVICEL fibrinogen samples tested was 9 IU/ml compared with undetectable concentrations of factor XIII for the TISSEEL fibrinogen samples. Fibrin clots formed with EVICEL have a much higher resistance to stretching and tensile strength and are more capable of maintaining their structure against applied force than those formed with TISSEEL. EVICEL also allows more rapid development of fibrin clots than TISSEEL. This superior clot strength and resilience obtained with EVICEL relative to TISSEEL may be due in large part to the presence of factor XIII.

  9. Hematocrit and Hemoglobin Levels of Nonhuman Apes at Moderate Altitudes: A Comparison with Humans.

    Science.gov (United States)

    Mortola, Jacopo P; Wilfong, DeeAnn

    2016-12-01

    Mortola, Jacopo P. and DeeAnn Wilfong. Hematocrit and hemoglobin levels of nonhuman apes at moderate altitudes: a comparison with humans. High Alt Med Biol. 17:323-335, 2016.-We asked to what extent the hematologic response (increase in hematocrit [Hct] and in blood hemoglobin concentration [Hb]) of humans to altitude hypoxia was shared by our closest relatives, the nonhuman apes. Data were collected from 29 specimens of 7 species of apes at 2073 m altitude (barometric pressure Pb = 598 mm Hg); additional data originated from apes located at a lower altitude (1493 m, Pb = 639 mm Hg). The human altitude profiles of Hct and Hb between sea level and 3000 m were constructed from a compilation of literature sources that (all combined) comprised data sets of 10,000-12,000 subjects for each gender. These human data were binned for 0-250 m altitude (sea level) and for each 500 m of progressively higher altitudes. Values of Hb and Hct of both men and women were significantly higher than at sea level at the 1500 bin (1250-1750 m); hence, the altitude threshold for the human hematological responses must be between 1000 and 1500 m. In the nonhuman apes, no increase in Hct or Hb was apparent at 1500 m; at 2000 m, the increase was significant only for the Hb of females. At either altitude in the group of nonhuman apes, the increase in Hct was much less than in humans, and that of Hb was significantly less at 1500 m. We conclude that lack of, or minimal, hematopoietic response to moderate altitude can occur in mammalian species that are not genetically adapted to high altitudes. Polycythemia is not a common response to altitude hypoxia and, at least at moderate altitudes, the degree of the human response may represent the exception among apes rather than the rule.

  10. Determination of hematocrit interference in blood samples derived from patients with different blood glucose concentrations.

    Science.gov (United States)

    Pfützner, Andreas; Schipper, Christina; Ramljak, Sanja; Flacke, Frank; Sieber, Jochen; Forst, Thomas; Musholt, Petra B

    2013-01-01

    We performed a blood glucose meter hematocrit (HCT) interference test with lower sample manipulation requirements by using blood samples from patients with different blood glucose (BG) levels. Blood from five patients with different BG levels (2.8, 5.6, 8.3, 13.9, 19.4 mmol/liter) was manipulated to contain five different HCT concentrations (35/40/45/50/55%). Each sample was measured three times in parallel with 14 BG testing devices (reference method: YSI 2300 STAT Plus™ Glucose Analyzer). The largest mean deviations in both directions from the reference method (normalized to 100% at 45% HCT) were added as a measure for hematocrit interference factor (HIF). A HIF >10% was considered to represent clinically relevant HCT interference. Few devices showed no clinically relevant HCT interference at high/low BG levels: BGStar® (7.2%, 7.3%), iBGStar® (9.0%, 8.6%), Contour® (10.0%, 4.6%), OneTouch® Verio™ 2 (10.0%, 5.2%), and GlucoMen® LX (7.2%, 5.1%). Other devices showed interference at one or both glucose ranges: ACCU-CHEK® Aviva (12.6%, 10.7%), Aviva Nano (7.2%, 10.5%), Breeze2 (3.6%, 30.2%), GlucoCard G+ (12.6%, 7.0%), OneTouch® Ultra®2 (12.6%, 25.6%), FreeStyle Freedom Lite® (9.0%, 11.0%), Precision Xceed (16.2%, 15.3%), and MediTouch® (19.8%, 28.0%). The deviations in all devices were less pronounced in the HCT range of 35-50%. The results of this trial with less sample manipulation (HCT only) confirmed previous examinations with HCT and glucose manipulation. The same devices showed HCT stability as previously observed. Artificial sample manipulation may be less crucial than expected when evaluating HCT interference. © 2012 Diabetes Technology Society.

  11. Potential of quixaba (Sideroxylon obtusifolium latex as a milk-clotting agent

    Directory of Open Access Journals (Sweden)

    Anna Carolina da Silva

    2013-09-01

    Full Text Available There are several obstacles to the use of chymosin in cheese production. Consequently, plant proteases have been studied as possible rennet substitutes, but most of these enzymes are unsuitable for the manufacture of cheese. The aim of this study was to evaluate the potential of latex from Sideroxylon obtusifolium as a source of milk-clotting proteases and to partially characterize the enzyme. The enzyme extract showed high protease and coagulant activities, with an optimal pH of 8.0 and temperature of 55 °C. The enzyme was stable in wide ranges of temperature and pH. Its activity was not affected by any metal ions tested; but was inhibited by phenylmethanesulfonyl fluoride and pepstatin. For the coagulant activity, the optimal concentration of CaCl2 was 10 µmol L- 1. Polyacrylamide gel electrophoresis showed four bands, with molecular weights between 17 and 64 kDa. These results indicate that the enzyme can be applied to the cheese industry.

  12. The role of activated coagulation factor XII in overall clot stability and fibrinolysis.

    Science.gov (United States)

    Konings, Joke; Hoving, Lisa R; Ariëns, Robert S; Hethershaw, Emma L; Ninivaggi, Marisa; Hardy, Lewis J; de Laat, Bas; Ten Cate, Hugo; Philippou, Helen; Govers-Riemslag, José W P

    2015-08-01

    Activated coagulation factor XII (α-FXIIa) is able to bind to fibrin(ogen) and increases the density and stiffness of the fibrin clot. Conversely, proteins of the contact system and the fibrinolytic system show a high degree of homology and α-FXIIa can convert plasminogen into plasmin resulting in fibrin degradation. Therefore, we studied the contribution of α-FXIIa to overall clot stability and plasmin driven fibrinolysis in the absence and presence of tissue plasminogen activator (tPA). We observed that α-FXIIa directly converted plasminogen into plasmin and reduced clot lysis time at all tPA concentrations tested (15-1500 pM). Simultaneous assessment of plasmin generation (chromogenic substrate S-2251) and fibrin formation and degradation (absorbance at 405nm), showed an earlier onset of fibrinolysis and plasmin formation in the presence of α-FXIIa. Fibrinolysis of clots formed under flow conditions, revealed that incorporation of α-FXIIa accelerated clot breakdown (fluorescence release of labeled fibrin) by additional plasmin generation on top of formation by tPA. Scanning electron microscopy (SEM) revealed that the surface area pore size increased in the presence compared with the absence of α-FXIIa when fibrinolysis was initiated by the conversion of plasminogen with tPA during clot formation. α-FXIIa enhances fibrinolysis in the presence of plasminogen, irrespective of whether tPA was present during clot formation or was added afterwards to initiate fibrinolysis. We postulate that FXIIa first strengthens the clot structure during clot formation and thereafter contributes towards fibrinolysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Fibrin clot formation and fibrinolysis in patients with a history of coronary stent thrombosis.

    Science.gov (United States)

    Godschalk, Thea C; Konings, Joke; Govers-Riemslag, José W; Ten Berg, Jurriën M; Hackeng, Christian M; Ten Cate, Hugo

    2016-07-01

    Coronary stent thrombosis is a devastating complication of percutaneous coronary intervention (PCI). Multiple factors underlie the pathophysiological mechanisms of stent thrombosis. Previous studies demonstrated that patients with stent thrombosis, compared to control PCI patients, formed denser fibrin clots in vitro which were more resistant to fibrinolysis, suggesting that altered fibrin clot properties may contribute to the pathophysiology of stent thrombosis. We assessed the plasma fibrin clot formation and fibrinolysis of patients with and without stent thrombosis. Cases (patients with stent thrombosis) and matched controls (patients without stent thrombosis) were included for a matched case-control study. Matching was performed on indication and time of the index PCI (initial stent implantation) from the cases. Fibrin clot formation and fibrinolysis were assessed in vitro by turbidimetric assays, with human thrombin to initiate fibrin polymerization and tissue type plasminogen activator to initiate fibrinolysis. Lag time, maximal absorbance and clot lysis time were determined by these assays. In total, 27 cases and 27 controls were included. No significant differences were observed between cases and controls in lag time (173 vs. 162s, p=0.18), maximal absorbance (0.78 vs. 0.83, p=0.36), and clot lysis time (69 vs. 71min, p=0.78). Fibrin clot formation and fibrinolysis were not associated with stent thrombosis. Plasma fibrin clot formation and fibrinolysis were not significantly different between patients with stent thrombosis and matched control patients, suggesting that fibrin clot formation and fibrinolysis play no significant role in the pathophysiology of stent thrombosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. The effect of chronic kidney disease on fibrin clot properties in patients with acute coronary syndrome.

    Science.gov (United States)

    Undas, Anetta; Nycz, Krzysztof; Pastuszczak, Maciej; Stompor, Tomasz; Zmudka, Krzysztof

    2010-09-01

    Chronic kidney disease (CKD), defined as a decreased estimated glomerular filtration rate (eGFR < 60 ml/min), is an independent risk factor for cardiovascular events. Both acute coronary syndrome (ACS) and end-stage renal disease have been shown to be associated with formation of compact fibrin clots relatively resistant to lysis. The aim of the current study was to evaluate the effect of CKD on fibrin clot properties in patients with ACS. In 30 ACS patients, aged 48-72 years, with CKD and 30 ACS patients with eGFR more than 60 ml/min, we investigated plasma fibrin clot properties using permeation and turbidity assays, including three different clot lysis assays. The ACS patients with eGFR less than 60 ml/min and those with normal filtration rate did not differ with regard to demographics, risk factors, medications and routine laboratory tests, including fibrinogen. The former group had higher plasminogen activator inhibitor-1 (P = 0.002) and tissue-type plasminogen activator (tPA) (P = 0.008). Compared with ACS patients with eGFR more than 60 ml/min, the ACS patients with CKD formed less porous fibrin clots (P = 0.004) and susceptible to fibrinolysis (P < 0.001), had thicker overall fibrin fibers (P = 0.007), earlier onset of fibrin clot formation (P = 0.004) and increased clot mass (P < 0.001). By multiple regression analysis, clot permeability was independently predicted by eGFR (P = 0.0005) and fibrinogen (P = 0.001), whereas the only predictors of lysis time were eGFR (P = 0.006) and tPA (P = 0.002). This study indicates that ACS patients with CKD display unfavorable fibrin clot properties including impaired fibrinolysis, which might contribute to worse outcome in this population.

  15. Relative blood flow changes measured using calibrated frequency-weighted Doppler power at different hematocrit levels.

    Science.gov (United States)

    Wallace, Sean; Logallo, Nicola; Faiz, Kashif W; Lund, Christian; Brucher, Rainer; Russell, David

    2014-04-01

    In theory, the power of a trans-cranial Doppler signal may be used to measure changes in blood flow and vessel diameter in addition to velocity. In this study, a flow index (FI) of relative changes in blood flow was derived from frequency-weighted Doppler power signals. The FI, plotted against velocity, was calibrated to the zero intercept with absent flow to reduce the effects of non-uniform vessel insonation. An area index was also calculated. FIs were compared with actual flow in four silicone tubes of different diameter at increasing flow rates and increasing hematocrit (Hct) in a closed-loop phantom model. FI values were strongly correlated with actual flow, at constant Hct, but varied substantially with changes in Hct. Percentage changes in area indexes, relative to the 4-mm tube, were strongly correlated with tube cross-sectional area. The implications of these results for in vivo use are discussed. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  16. Review of numerical methods for simulation of mechanical heart valves and the potential for blood clotting.

    Science.gov (United States)

    Zakaria, Mohamad Shukri; Ismail, Farzad; Tamagawa, Masaaki; Aziz, Ahmad Fazli Abdul; Wiriadidjaja, Surjatin; Basri, Adi Azrif; Ahmad, Kamarul Arifin

    2017-09-01

    Even though the mechanical heart valve (MHV) has been used routinely in clinical practice for over 60 years, the occurrence of serious complications such as blood clotting remains to be elucidated. This paper reviews the progress that has been made over the years in terms of numerical simulation method and the contribution of abnormal flow toward blood clotting from MHVs in the aortic position. It is believed that this review would likely be of interest to some readers in various disciplines, such as engineers, scientists, mathematicians and surgeons, to understand the phenomenon of blood clotting in MHVs through computational fluid dynamics.

  17. Viscoelastic methods of blood clotting assessment – a multidisciplinary review

    Directory of Open Access Journals (Sweden)

    Jan eBenes

    2015-09-01

    Full Text Available Viscoelastic methods made available the bed-side assessment of blood clotting. Unlike standard laboratory tests, the results are based on the whole blood coagulation, are available in real time and in much faster turnaround time. In combination with our new knowledge about pathophysiology of the trauma induced coagulopathy the goal oriented treatment protocols have been recently proposed for the initial management of bleeding in trauma victims. Besides, the utility of viscoelastic monitoring devices has been proved even outside this setting in cardiosurgical patients or those undergoing liver transplantation. Many other situations were described in literature showing potential use of bed-side analysis of coagulation for the management of bleeding or critically ill patients. In the near future, we may expect further improvement of current bed-side diagnostic tools enabling not only the assessment of secondary hemostasis but also platelet aggregation. More sensitive assays for new anticoagulants are underway. Aim of this review is to offer the reader a multidisciplinary overview on the topic of viscoelastic methods and their potential use in anesthesiology and critical care.

  18. Longitudinal changes in hematocrit in hypertensive chronic kidney disease: results from the African-American Study of Kidney Disease and Hypertension (AASK).

    Science.gov (United States)

    Chen, Teresa K; Estrella, Michelle M; Astor, Brad C; Greene, Tom; Wang, Xuelei; Grams, Morgan E; Appel, Lawrence J

    2015-08-01

    Anemia is common in chronic kidney disease (CKD) and associated with poor outcomes. In cross-sectional studies, lower estimated glomerular filtration rate (eGFR) has been associated with increased risk for anemia. The aim of this study was to determine how hematocrit changes as eGFR declines and what factors impact this longitudinal association. We followed 1094 African-Americans with hypertensive nephropathy who participated in the African-American Study of Kidney Disease and Hypertension. Mixed effects models were used to determine longitudinal change in hematocrit as a function of eGFR. Interaction terms were used to assess for differential effects of age, gender, baseline eGFR, baseline proteinuria, malnutrition and inflammation on eGFR-associated declines in hematocrit. In sensitivity analyses, models were run using iGFR (by renal clearance of I(125) iothalamate) in place of eGFR. At baseline, mean hematocrit was 39% and 441 (40%) individuals had anemia. The longitudinal relationship between eGFR and hematocrit differed by baseline eGFR and was steeper when baseline eGFR was proteinuria (protein-to-creatinine ratio >0.22) were associated with greater hematocrit declines per unit decrease in longitudinal eGFR compared with female sex, older age and low baseline proteinuria, respectively (P-interaction proteinuria are particularly at risk for eGFR-related declines in hematocrit. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  19. Deep Vein Thrombosis (DVT) / Pulmonary Embolism (PE) - Blood Clot Forming in a Vein

    Science.gov (United States)

    ... Facebook Tweet Share Compartir Deep Vein Thrombosis and Pulmonary Embolism (DVT/PE) are often underdiagnosed and serious, but ... bloodstream to the lungs, causing a blockage called pulmonary embolism (PE). If the clot is small, and with ...

  20. The HUGE formula (hematocrit, urea, gender) for screening for chronic kidney disease in elderly patients: a study of diagnostic accuracy.

    Science.gov (United States)

    Musso, Carlos G; de Los Rios, Eduardo; Vilas, Manuel; Terrasa, Sergio; Bratti, Griselda; Varela, Federico; Diez, Guillermo Rosa; Jauregui, Jose; Luna, Daniel

    2017-04-01

    Chronically reduced glomerular filtration rate (GFR) in old people does not always mean that they suffer from chronic kidney disease (CKD) since their GFR can just be reduced by aging. The HUGE equation has been recently described and validated in Spain for screening CKD without taking into account the patient's GFR value. This equation is based on patient's hematocrit, plasma urea levels and gender. The present study documented that the HUGE equation had and acceptable performance for screening CKD in elderly Argentine patients.

  1. Correlation between clot density and recanalization success or stroke etiology in acute ischemic stroke patients.

    Science.gov (United States)

    Jagani, Manoj; Kallmes, David F; Brinjikji, Waleed

    2017-06-01

    Background Predicting recanalization success for patients undergoing endovascular treatment for acute ischemic stroke is of significant interest. Studies have previously correlated the success of recanalization with the density of the clot. We evaluated clot density and its relationship to revascularization success and stroke etiology. Methods We conducted a retrospective review of 118 patients undergoing intra-arterial therapy for acute ischemic stroke. Mean and maximum thrombus density was measured by drawing a circular region of interest on an axial slice of a non-contrast computed tomography scan. T-tests were used to compare clot density to recanalization success or to stroke etiology, namely large artery atherosclerosis and cardioembolism. Recanalization success was compared in four device groups: aspiration, stent retriever, aspiration and stent retriever, and all other. Results There was no significant difference in the mean clot density in patients with successful ( n = 80) versus unsuccessful recanalization ( n = 38, 50.1 ± 7.4 Hounsfield unit (HU) vs. 53 ± 12.7 HU; P = 0.17). Comparing the large artery thromboembolism ( n = 35) to the cardioembolic etiology group ( n = 56), there was no significant difference in mean clot density (51.5 ± 7.7 HU vs. 49.7 ± 8.5 HU; P = 0.31). A subgroup analysis of middle cerebral artery occlusions ( n = 65) showed similar, non-statistically significant differences between groups. There was no difference in the rate of recanalization success in patients with a mean clot density greater than 50 HU or less than 50 HU in each of the four device groups. Conclusions There was no relationship between clot density and revascularization success or stroke etiology in our study. More research is needed to determine if clot density can predict recanalization rates or indicate etiology.

  2. Hematocrit and plasma osmolality values of young-of-year shortnose sturgeon following acute exposures to combinations of salinity and temperature

    Science.gov (United States)

    Ziegeweid, J.R.; Black, M.C.

    2010-01-01

    Little is known about the physiological capabilities of young-of-year (YOY) shortnose sturgeon. In this study, plasma osmolality and hematocrit values were measured for YOY shortnose sturgeon following 48-h exposures to 12 different combinations of salinity and temperature. Hematocrit levels varied significantly with temperature and age, and plasma osmolalities varied significantly with salinity and age. Plasma osmolality and hematocrit values were similar to previously published values for other sturgeons of similar age and size in similar treatment conditions. ?? 2010 Springer Science+Business Media B.V.

  3. Improvement of the accuracy in the optical hematocrit measurement by optimizing mean optical path length.

    Science.gov (United States)

    Oshima, Shiori; Sankai, Yoshiyuki

    2009-09-01

    Optical techniques have been developed to acquire blood information (e.g., hematocrit [Hct], saturation of oxygen, thrombus) noninvasively and continuously in an artificial heart. For the practical use of an optical Hct measurement, Twersky's theory has been shown to be useful and have a good agreement in forward-scattered measurements. However, it was not applied to backward-scattered measurements, which can provide the measurement with a less demanding spatial requirement. Additionally, optimal measurement for accuracy is not well examined. Therefore, we developed an accurate Hct measurement in an artificial heart using current optical devices. To this end, we focused on optimizing an emitter-detector distance to provide a maximum optical path length. We attached optical emitter and detector fibers on Tygon tubing at various distances to measure forward- and backward-scattered light. Fresh bovine blood (Hct: 30-50%) was circulated in the tubing by a nonpulsatile artificial heart. We calculated the optical path length at various emitter-detector distances by fitting the measured optical outputs and the reference Hcts to Twersky's theory. Then, we performed Hct measurements. As a result, Twersky's theory is applicable not only to forward- but also to backward-scattered measurements in the physiogical Hct range. In both forward- and backward-scattered measurements, calculated optical path lengths become maximum at the same emitter-detector distance. The accuracy of Hct measurement is improved two to three times with the emitter-detector distance compared with other distances. The mean error is less than 1 Hct%. This result shows that an accurate Hct measurement is realized by selecting the optimal emitter-detector distance, which provides maximum optical path length defined by Twersky's theory. Our study provides a framework for the practical and less restrictive application of the optical Hct measurement to patients with an artificial heart.

  4. Seasonal hematocrit variation and health risks in the adult population of Kinshasa, Democratic Republic of Congo

    Directory of Open Access Journals (Sweden)

    C Makena Hightower

    2009-11-01

    Full Text Available C Makena Hightower1, Joyce D Hightower2, Beatriz Y Salazar Vázquez1,3, Marcos Intaglietta11Department of Bioengineering, University of California, San Diego, La Jolla, CA, USA; 2Group de Reflection, Actions et Etude de Culture, Kinshasa, Democratic Republic of Congo; 3Facultad de Medicina, Universidad Juárez del Estado de Durango, Durango, Durango, MéxicoAbstract: Hematocrit (Hct as an indicator of blood viscosity and mean arterial blood pressure (MAP were assessed according to the season in adult participants of health screenings conducted throughout Kinshasa, Democratic Republic of Congo. Data was collected at the end of summer (April and the end of winter (August and identified by gender. Male Hcts in August were significantly higher (P < 0.0001 than in April (48.3% ± 4.2% and 45.7% ± 2.3%, respectively while male MAP (85.0 ± 8.4 mm Hg was identical to that recorded in April (85.4 ± 7.7 mm Hg. August female Hcts (41.4% ± 3.1% were statistically higher than those recorded in April (39.6% ± 1.9%, P = 0.001, MAP being 82.3 ± 7.3 vs 87.9 ± 6.6 mm Hg, respectively (P = 0.0001. Systolic and diastolic blood pressures, heart rate, body mass indices, ages, and personal and familial medical histories of the August and April groups were not significantly different. This study offers further support for the assertion that the relationship between blood viscosity and pressure of a healthy population shows that increased Hct, and therefore increased blood viscosity is associated with lowered MAP, and presumably peripheral vascular resistance.Keywords: blood pressure, African adults, blood viscosity, cardiovascular, shear stress

  5. Hematocrit of mammals (Artiodactyla, Carnivora, Primates) at 1500m and 2100m altitudes.

    Science.gov (United States)

    Mortola, Jacopo P; Wilfong, DeeAnn

    2017-12-01

    The rise in hematocrit (Hct) is one of the hallmarks of human acclimatization to high altitude and, in chronic conditions, reflects the hypoxia-induced polycythemia. However, it is not a uniform response among domestic species and it is not found in Andean camelids, species long adapted to high altitudes. Hence, we asked to what extent the polycythemia of humans is common among mammals. Hct data were collected from captive mammals of three orders (Primates, Artiodactyla, Carnivora), 70 specimens of 33 species at ∼1500m altitude (barometric pressure Pb=635mmHg) and 296 specimens of 64 species at ∼2100m (Pb=596mmHg), long-term residents at those altitudes. Sea level values and data in men and women at the corresponding altitudes were from a compilation of literature sources. At either altitude Hct was significantly higher than at sea level both in men and women; the increase (ΔHct) for genders combined averaged 3.4% (±0.7 SEM) at 1500m and 5.4% (±0.3) at 2100m. Differently, among the three mammalian orders studied a significant increase in Hct occurred only in females of Carnivora (at 1500m) and in males of Primates (at 2100m). The average ΔHct of all species combined was 0.8% (±0.7) at 1500m and 1.5% (±0.4) at 2100m, both significantly less than in humans (Pmammals examined. We conclude that, at least for the altitudes studied, a minimal polycythemia is a general feature of both high-altitude adapted and non-adapted species, and the magnitude of the human response is exceptional among mammals. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. The Effect of Growing Rod Treatment on Hemoglobin and Hematocrit Levels in Early-onset Scoliosis.

    Science.gov (United States)

    Barrett, Kody K; Lee, Christopher; Myung, Karen; Johnston, Charles; Shah, Suken A; Akbarnia, Behrooz A; Skaggs, David L

    2016-09-01

    This study examines preoperative hemoglobin (Hgb) and hematocrit (Hct) levels in a group of early-onset scoliosis (EOS) patients and the effect of distraction-based growing rods (GRs) on these levels. Children with EOS are at risk for respiratory insufficiency and chronic hypoxemia. Increased Hgb and Hct levels have been identified as surrogate markers for chronic hypoxemia. A study of patients who underwent VEPTR surgery showed a significant decrease in Hgb levels following surgery. Data were retrospectively collected on 66 EOS patients without confounding respiratory issues or oxygen dependence who were treated with GRs at 5 institutions. Average age at initial surgery was 5.5 years. Patients were followed for a minimum of 2 years (average 3.7 y). Preoperative and postoperative Hgb and Hct levels were converted to Z-scores based on age-adjusted mean blood indices and were compared using a paired t test. The prevalence of elevated Hgb and Hct levels (Z-score >2) preoperatively was 15% (10/66) and 19% (12/64), respectively. The average Hgb Z-score decreased from 0.20 to -0.31 (P=0.005) 6 to 24 months following surgery and the Hct Z-score decreased from 0.31 to -0.28 (P=0.002) 6 to 24 months following surgery. Following distraction-based GR treatment of children with EOS there was a significant decrease in both their Hgb and Hct. This is a physiological marker of decreased hypoxemia and improved pulmonary function. Level III-therapeutic study.

  7. Localization of Short-Chain Polyphosphate Enhances its Ability to Clot Flowing Blood Plasma

    Science.gov (United States)

    Yeon, Ju Hun; Mazinani, Nima; Schlappi, Travis S.; Chan, Karen Y. T.; Baylis, James R.; Smith, Stephanie A.; Donovan, Alexander J.; Kudela, Damien; Stucky, Galen D.; Liu, Ying; Morrissey, James H.; Kastrup, Christian J.

    2017-02-01

    Short-chain polyphosphate (polyP) is released from platelets upon platelet activation, but it is not clear if it contributes to thrombosis. PolyP has increased propensity to clot blood with increased polymer length and when localized onto particles, but it is unknown whether spatial localization of short-chain polyP can accelerate clotting of flowing blood. Here, numerical simulations predicted the effect of localization of polyP on clotting under flow, and this was tested in vitro using microfluidics. Synthetic polyP was more effective at triggering clotting of flowing blood plasma when localized on a surface than when solubilized in solution or when localized as nanoparticles, accelerating clotting at 10-200 fold lower concentrations, particularly at low to sub-physiological shear rates typical of where thrombosis occurs in large veins or valves. Thus, sub-micromolar concentrations of short-chain polyP can accelerate clotting of flowing blood plasma under flow at low to sub-physiological shear rates. However, a physiological mechanism for the localization of polyP to platelet or vascular surfaces remains unknown.

  8. The application of large amplitude oscillatory stress in a study of fully formed fibrin clots

    Science.gov (United States)

    Lamer, T. F.; Thomas, B. R.; Curtis, D. J.; Badiei, N.; Williams, P. R.; Hawkins, K.

    2017-12-01

    The suitability of controlled stress large amplitude oscillatory shear (LAOStress) for the characterisation of the nonlinear viscoelastic properties of fully formed fibrin clots is investigated. Capturing the rich nonlinear viscoelastic behaviour of the fibrin network is important for understanding the structural behaviour of clots formed in blood vessels which are exposed to a wide range of shear stresses. We report, for the first time, that artefacts due to ringing exist in both the sample stress and strain waveforms of a LAOStress measurement which will lead to errors in the calculation of nonlinear viscoelastic properties. The process of smoothing the waveforms eliminates these artefacts whilst retaining essential rheological information. Furthermore, we demonstrate the potential of LAOStress for characterising the nonlinear viscoelastic properties of fibrin clots in response to incremental increases of applied stress up to the point of fracture. Alternating LAOStress and small amplitude oscillatory shear measurements provide detailed information of reversible and irreversible structural changes of the fibrin clot as a consequence of elevated levels of stress. We relate these findings to previous studies involving large scale deformations of fibrin clots. The LAOStress technique may provide useful information to help understand why some blood clots formed in vessels are stable (such as in deep vein thrombosis) and others break off (leading to a life threatening pulmonary embolism).

  9. Mathematical Modeling of Blood Clot Fragmentation During Flow-Mediated Thrombolysis

    Science.gov (United States)

    Bajd, Franci; Serša, Igor

    2013-01-01

    A microscale mathematical model of blood clot dissolution based on coarse-grained molecular dynamics is presented. In the model, a blood clot is assumed to be an assembly of blood cells interconnected with elastic fibrin bonds, which are cleaved either biochemically (bond degradation) or mechanically (bond overstretching) during flow-mediated thrombolysis. The effect of a thrombolytic agent on biochemical bond degradation was modeled phenomenologically by assuming that the decay rate of an individual bond is a function of the remaining noncleaved bonds in the vicinity of that bond (spatial corrosion) and the relative stretching of the bond (deformational corrosion). The results of simulations indicate that the blood clot dissolution process progresses by a blood-flow-promoted removal of clot fragments, the sizes of which are flow-dependent. These findings are in good agreement with the results of our recent optical-microscopy experimental studies on a model of blood clot dissolution, as well as with clinical observations. The findings of this study may contribute to a better understanding of the clot fragmentation process and may therefore also help in designing new, safer thrombolytic approaches. PMID:23473501

  10. Effect of exercise training on clot strength in patients with peripheral artery disease and intermittent claudication: An ancillary study.

    Science.gov (United States)

    Mauer, Karin; Exaire, J Emilio; Stoner, Julie A; Saucedo, Jorge F; Montgomery, Polly S; Gardner, Andrew W

    2015-01-01

    Patients with peripheral artery disease have walking impairment, greater thrombotic risk, and are often treated with exercise training. We sought to determine the effect of a 3-month-long exercise program on clot strength among patients with peripheral artery disease and intermittent claudication. Twenty-three symptomatic peripheral artery disease patients were randomly assigned to a walking exercise program or to an attention control group who performed light resistance exercise. We investigated the effect of exercise training on clot strength and time to clot formation was assessed by thromboelastography. After 3 months of exercise, clot strength (maximal amplitude) and time to clot formation (R) did not change significantly from baseline, even after improvements in claudication onset time (p < 0.01) and peak walking time (p < 0.05). Furthermore, changes in clot formation parameters were not significantly different between groups. Among the 10 individuals demonstrating a reduction in clot strength (reduced maximal amplitude), one was a smoker (10%) compared to 9 of 13 non-responders (69%) whose maximal amplitude was unchanged or increased (p = 0.0097). In this ancillary study, a 12-week walking program improved ambulatory function in peripheral artery disease patients with claudication, but does not modify clot strength or time to clot formation. Larger studies are needed to confirm these hypothesis generating findings and to determine whether a different amount or type of exercise may induce a change in clotting in this patient population.

  11. Effect of exercise training on clot strength in patients with peripheral artery disease and intermittent claudication: An ancillary study

    Directory of Open Access Journals (Sweden)

    Karin Mauer

    2015-03-01

    Full Text Available Objectives: Patients with peripheral artery disease have walking impairment, greater thrombotic risk, and are often treated with exercise training. We sought to determine the effect of a 3-month-long exercise program on clot strength among patients with peripheral artery disease and intermittent claudication. Methods: Twenty-three symptomatic peripheral artery disease patients were randomly assigned to a walking exercise program or to an attention control group who performed light resistance exercise. We investigated the effect of exercise training on clot strength and time to clot formation was assessed by thromboelastography. Results: After 3 months of exercise, clot strength (maximal amplitude and time to clot formation (R did not change significantly from baseline, even after improvements in claudication onset time (p < 0.01 and peak walking time (p < 0.05. Furthermore, changes in clot formation parameters were not significantly different between groups. Among the 10 individuals demonstrating a reduction in clot strength (reduced maximal amplitude, one was a smoker (10% compared to 9 of 13 non-responders (69% whose maximal amplitude was unchanged or increased (p = 0.0097. Conclusion: In this ancillary study, a 12-week walking program improved ambulatory function in peripheral artery disease patients with claudication, but does not modify clot strength or time to clot formation. Larger studies are needed to confirm these hypothesis generating findings and to determine whether a different amount or type of exercise may induce a change in clotting in this patient population.

  12. Point-of-Care Hemoglobin/Hematocrit Testing: Comparison of Methodology and Technology.

    Science.gov (United States)

    Maslow, Andrew; Bert, Arthur; Singh, Arun; Sweeney, Joseph

    2016-04-01

    Point-of-care (POC) testing allows rapid assessment of hemoglobin (Hgb) and hematocrit (Hct) values. This study compared 3 POC testing devices--the Radical-7 pulse oximeter (Radical-7, Neuchȃtel, Switzerland), the i-STAT (Abbott Point of Care, Princeton, NJ), and the GEM 4000 (Instrumentation Laboratory, Bedford, MA)--to the hospital reference device, the UniCel DxH 800 (Beckman Coulter, Brea, CA) in cardiac surgery patients. Prospective study. Tertiary care cardiovascular center. Twenty-four consecutive elective adult cardiac surgery patients. Hgb and Hct values were measured using 3 POC devices (the Radical-7, i-STAT, and GEM 4000) and a reference laboratory device (UniCel DxH 800). Data were collected simultaneously before surgery, after heparin administration, after heparin reversal with protamine, and after sternal closure. Data were analyzed using bias analyses. POC testing data were compared with that of the reference laboratory device. Hgb levels ranged from 6.8 to 15.1 g/dL, and Hct levels ranged from 20.1% to 43.8%. The overall mean bias was lowest with the i-STAT (Hct, 0.22%; Hgb 0.05 g/dL) compared with the GEM 4000 (Hct, 2.15%; Hgb, 0.63 g/dL) and the Radical-7 (Hgb 1.16 g/dL). The range of data for the i-STAT and Radical-7 was larger than that with the GEM 4000, and the pattern or slopes changed significantly with the i-STAT and Radical-7, whereas that of the GEM 4000 remained relatively stable. The GEM 4000 demonstrated a consistent overestimation of laboratory data, which tended to improve after bypass and at lower Hct/Hgb levels. The i-STAT bias changed from overestimation to underestimation, the latter in the post-cardiopulmonary bypass period and at lower Hct/Hgb levels. By contrast, the Radical-7 biases increased during the surgical procedure and in the lower ranges of Hgb. Important clinical differences and limitations were found among the 3 POC testing devices that should caution clinicians from relying on these data as sole determinants of

  13. Addition of a sequence from α2-antiplasmin transforms human serum albumin into a blood clot component that speeds clot lysis

    Directory of Open Access Journals (Sweden)

    Gataiance Sharon

    2009-03-01

    Full Text Available Abstract Background The plasma protein α2-antiplasmin (α2AP is cross-linked to fibrin in blood clots by the transglutaminase factor XIIIa, and in that location retards clot lysis. Competition for this effect could be clinically useful in patients with thrombosis. We hypothesized that fusion of N-terminal portions of α2-antiplasmin to human serum albumin (HSA and production of the chimeric proteins in Pichia pastoris yeast would produce a stable and effective competitor protein. Results Fusion protein α2AP(13-42-HSA was efficiently secreted from transformed yeast and purified preparations contained within a mixed population the full-length intact form, while fusions with longer α2AP moieties were inefficiently secreted and/or degraded. The α2AP(13-42-HSA protein, but not recombinant HSA, was cross-linked to both chemical lysine donors and fibrin or fibrinogen by factor XIIIa, although with less rapid kinetics than native α2AP. Excess α2AP(13-42-HSA competed with α2AP for cross-linking to chemical lysine donors more effectively than a synthetic α2AP(13-42 peptide, and reduced the α2AP-dependent resistance to fibrinolysis of plasma clots equally effectively as the peptide. Native α2AP was found in in vivo clots in rabbits to a greater extent than α2AP(13-42, however. Conclusion In this first report of transfer of transglutamination substrate status from one plasma protein to another, fusion protein α2AP(13-42-HSA was shown to satisfy initial requirements for a long-lasting, well-tolerated competitive inhibitor of α2-antiplasmin predicted to act in a clot-localized manner.

  14. Investigating Interactions between Ultrasound Stimulated Microbubbles and the Fibrin Network of Blood Clots

    Science.gov (United States)

    Acconcia, Christopher N.

    The occlusion of blood vessels by thrombus is a major cause of mortality and morbidity in cardiovascular diseases such as deep vein thrombosis, myocardial infarction and ischemic stroke. In these contexts, prompt restoration of blood flow is of the utmost importance and is poorly addressed by current methods in many cases. For example, the treatment standard for ischemic stroke is administration of the thrombolytic agent tissue plasminogen activator, which is only minimally effective and has associated safety issues. There is, therefore, a need for the development of alternative recanalization strategies and amongst these, bubble mediated sonothrombolysis (thrombolysis by ultrasound) has emerged as a promising approach. Though it is well established that ultrasound stimulated microbubbles can potentiate the lysis of blood clots, the mechanisms are not well understood and this lack of understanding is a hindrance to the development of improved ultrasound exposure strategies. This thesis has revealed insights into the mechanisms of bubble mediated sonothrombolysis which can be used to guide the development of improved exposure strategies and contrast agents (i.e. bubble sizes) for sonothrombolysis treatments. The experimental approach involved fast frame optical imaging of ultrasound stimulated microbubbles interacting with clots, and two-photon fluorescence imaging of clots following ultrasound exposure. It was demonstrated that bubbles can penetrate fibrin clots, disrupt the fibrin network, generate patent tunnels, enhance the transport of fluid into the clot and induce clot boundary displacements. Furthermore, the occurrence and extent of these therapeutically relevant effects were shown to be highly dependent on pulse length and bubble size: longer pulses and larger bubbles were associated with greater disruption of fibrin networks and greater fluid transport distances. Finally, it was shown that bubbles can induce the ejection of erythrocytes from blood clots

  15. Prothrombotic Fibrin Clot Phenotype Is Associated With Recurrent Pulmonary Embolism After Discontinuation of Anticoagulant Therapy.

    Science.gov (United States)

    Zabczyk, Michal; Plens, Krzysztof; Wojtowicz, Wioletta; Undas, Anetta

    2017-02-01

    Pulmonary embolism (PE) is a life-threatening manifestation of venous thromboembolism with a high recurrence rate after anticoagulation cessation. Recently, we have reported that prothrombotic clot phenotype in venous thromboembolism patients is associated with an increased risk of recurrent deep-vein thrombosis. We tested whether abnormal clot properties are predictive of recurrent PE. We investigated 156 consecutive white patients aged 18 to 65 years after the first-ever provoked or unprovoked PE (n=89), with or without deep-vein thrombosis. Plasma fibrin clot permeability (Ks), turbidity measurements, calibrated automated thrombography, and efficiency of fibrinolysis using clot lysis time, maximum D-dimer levels, and rate of increase in D-dimer levels were evaluated at ≥3 months of anticoagulant therapy, at least 4 weeks since the anticoagulation withdrawal. The primary end point was recurrent PE during a median follow-up of 50 months. Recurrent PE was diagnosed in 23 (14.7%; 5%/yr) patients. Recurrent PE was associated with formation of denser fibrin networks reflected by lower Ks (P=0.007) and impaired fibrinolysis, as evidenced by prolonged clot lysis time (P=0.012) and reduced maximum rate of increase in D-dimer levels in the lysis assay (P=0.004). Patients with recurrent PE had higher plasma D-dimer (P<0.001) and thrombin peak (P=0.007) compared with the remainder, whereas turbidity measurements and maximum D-dimer levels did not differ in the recurrence. Multivariate model showed that independent predictors of recurrent PE were female sex, unprovoked venous thromboembolism, higher plasma D-dimer, reduced Ks, and reduced maximum rate of increase in D-dimer levels in the lysis assay (all P<0.05). Altered fibrin clot properties including formation of more compact clots displaying impaired susceptibility to lysis may predispose to recurrent PE. © 2016 American Heart Association, Inc.

  16. Quantification of intraventricular blood clot in MR-guided focused ultrasound surgery

    Science.gov (United States)

    Hess, Maggie; Looi, Thomas; Lasso, Andras; Fichtinger, Gabor; Drake, James

    2015-03-01

    Intraventricular hemorrhage (IVH) affects nearly 15% of preterm infants. It can lead to ventricular dilation and cognitive impairment. To ablate IVH clots, MR-guided focused ultrasound surgery (MRgFUS) is investigated. This procedure requires accurate, fast and consistent quantification of ventricle and clot volumes. We developed a semi-autonomous segmentation (SAS) algorithm for measuring changes in the ventricle and clot volumes. Images are normalized, and then ventricle and clot masks are registered to the images. Voxels of the registered masks and voxels obtained by thresholding the normalized images are used as seed points for competitive region growing, which provides the final segmentation. The user selects the areas of interest for correspondence after thresholding and these selections are the final seeds for region growing. SAS was evaluated on an IVH porcine model. SAS was compared to ground truth manual segmentation (MS) for accuracy, efficiency, and consistency. Accuracy was determined by comparing clot and ventricle volumes produced by SAS and MS, and comparing contours by calculating 95% Hausdorff distances between the two labels. In Two-One-Sided Test, SAS and MS were found to be significantly equivalent (p < 0.01). SAS on average was found to be 15 times faster than MS (p < 0.01). Consistency was determined by repeated segmentation of the same image by both SAS and manual methods, SAS being significantly more consistent than MS (p < 0.05). SAS is a viable method to quantify the IVH clot and the lateral brain ventricles and it is serving in a large-scale porcine study of MRgFUS treatment of IVH clot lysis.

  17. Recurrent clot anuria following laparoscopic pyeloplasty in a solitary functioning kidney: managing with double guide wire technique

    OpenAIRE

    Kumar, Santosh; Singh, Shivanshu; Parmar, Kalpesh Mahesh; Garg, Nitin

    2014-01-01

    Clot anuria in a solitary functioning kidney is an emergency situation. Haematuria with clot anuria in an early postoperative period represents a challenge, as treatment options are limited. Manipulation of the anastomotic site may lead to anastomotic disruption and urinoma while use of thrombolytic therapy poses the danger of increasing haematuria. We report a case of anuria due to clot retention in the upper tract following laparoscopic dismembered pyeloplasty in a solitary functioning kidn...

  18. Effect of Low Frequency Ultrasound on Combined rt-PA and Eptifibatide Thrombolysis in Human Clots

    Science.gov (United States)

    Meunier, Jason M.; Holland, Christy K.; Pancioli, Arthur M.; Lindsell, Christopher J.; Shaw, George J.

    2009-01-01

    Introduction Fibrinolytics such as recombinant tissue plasminogen activator (rt-PA) are used to treat thrombotic disease such as acute myocardial infarction (AMI) and ischemic stroke. Interest in increasing efficacy and reducing side effects has led to the study of adjuncts such as GP IIb-IIIa inhibitors and ultrasound (US) enhanced thrombolysis. Currently, GP IIb-IIIa inhibitor and fibrinolytic treatment are often used in AMI, and are under investigation for stroke treatment. However, little is known of the efficacy of combined GP IIb-IIIa inhibitor, fibrinolytic and ultrasound treatment. We measure the lytic efficacy of rt-PA, eptifibatide (Epf) and 120 kHz ultrasound treatment in an in-vitro human clot model. Materials and Methods Blood was drawn from 15 subjects after IRB approval. Clots were made in 20 μL pipettes, and placed in a water tank for microscopic visualization during lytic treatment. Clots were exposed to control, rt-PA (rt-PA), eptifibatide (Epf), or rt-PA+eptifibatide (rt-PA+Epf), with or without ultrasound for 30 minutes at 37°C in human plasma. Clot lysis was measured over time, using a microscopic imaging technique. The fractional clot loss (FCL) and initial lytic rate (LR) were used to quantify lytic efficacy. Results and Conclusions LR values for (−US) treated clots were 0.8±0.1(control), 1.8±0.3 (Epf), 1.5±0.2 (rt-PA), and 1.3±0.4 (rt-PA+Epf) (% clot width/minute) respectively. In comparison, the (+US) group exhibited LR values of 1.6±0.2 (control), 4.3±0.4 (Epf), 6.3±0.4 (rt-PA), and 4.6±0.6 (rt-PA+Epf). For (−US) treated clots, FCL was 6.0±0.8 (control), 9.2±2.5 (Epf), 15.6±1.7 (rt-PA), and 28.0±2.2% (rt-PA+Epf) respectively. FCL for (+US) clots was 13.5±2.4 (control), 20.7±6.4 (Epf), 44.4±3.6 (rt-PA) and 30.3±3.6% (rt-PA+Epf) respectively. Although the addition of eptifibatide enhances the in-vitro lytic efficacy of rt-PA in the absence of ultrasound, the efficacy of ultrasound and rt-PA is greater than that of

  19. Solulin increases clot stability in whole blood from humans and dogs with hemophilia

    Science.gov (United States)

    Petersen, Karl-Uwe; Rea, Catherine J.; Harpell, Lori; Powell, Sandra; Lillicrap, David; Nesheim, Michael E.; Sørensen, Benny

    2012-01-01

    Solulin is a soluble form of thrombomodulin that is resistant to proteolysis and oxidation. It has been shown to increase the clot lysis time in factor VIII (fVIII)–deficient plasma by an activated thrombin-activatable fibrinolysis inhibitor (TAFIa)–dependent mechanism. In the present study, blood was drawn from humans and dogs with hemophilia, and thromboelastography was used to measure tissue factor–initiated fibrin formation and tissue-plasminogen activator–induced fibrinolysis. The kinetics of TAFI and protein C activation by the thrombin-Solulin complex were determined to describe the relative extent of anticoagulation and antifibrinolysis. In severe hemophilia A, clot stability increased by > 4-fold in the presence of Solulin while minimally affecting clot lysis time. Patients receiving fVIII/fIX prophylaxis showed a similar trend of increased clot stability in the presence of Solulin. The catalytic efficiencies of TAFI and protein C activation by the thrombin-Solulin complex were determined to be 1.53 and 0.02/μM/s, respectively, explaining its preference for antifibrinolysis over anticoagulation at low concentrations. Finally, hemophilic dogs given Solulin had improved clot strength in thromboelastography assays. In conclusion, the antifibrinolytic properties of Solulin are exhibited in hemophilic human (in vitro) and dog (in vivo/ex vivo) blood at low concentrations. Our findings suggest the therapeutic utility of Solulin at a range of very low doses. PMID:22234684

  20. Effect of thiol derivatives on mixed mucus and blood clots in vitro.

    Science.gov (United States)

    Risack, L E; Vandevelde, M E; Gobert, J G

    1978-01-01

    The disintegrating effect of three reducing thiol derivatives: [sodium mercaptoethane sulphonate (Mesna), N-acetyl-L-cysteine (NAC) and dithio-1,4-threitol (DTT)] was investigated in vitro upon blood clots formed in the absence or in the presence of tracheobronchial secretions and compared with the effect of iso-osmotic saline solution. The amounts of haemoglobin released from the clots after 30 min incubation and the initial rates of haemoglobin release were compared for the different products at different concentrations. All three reducing agents showed some ability to disintegrate mixed clots to an extent depending on their concentration. After 30 min incubation, statistical analysis showed a highly significant difference in favour of Mesna at the three concentrations used, i.e. 0.1, 1.0 and 10 mmol/1. The initial rate of haemoglobin release in presence of Mesna was at all concentrations significantly higher than that of NAC or DTT. The effects on normal blood clots were much less pronounced. The effectiveness of Mesna in splitting up mixed blood and mucus clots in the management of patients who had inhaled blood is discussed.

  1. Fibrinogen and platelet contributions to clot formation: implications for trauma resuscitation and thromboprophylaxis.

    Science.gov (United States)

    Kornblith, Lucy Z; Kutcher, Matthew E; Redick, Brittney J; Calfee, Carolyn S; Vilardi, Ryan F; Cohen, Mitchell Jay

    2014-02-01

    Thromboelastography (TEG) is used to diagnose perturbations in clot formation and lysis that are characteristic of acute traumatic coagulopathy. With novel functional fibrinogen (FF) TEG, fibrin- and platelet-based contributions to clot formation can be elucidated to tailor resuscitation and thromboprophylaxis. We sought to describe the longitudinal contributions of fibrinogen and platelets to clot strength after injury, hypothesizing that low levels of FF and a low contribution of fibrinogen to clot strength on admission would be associated with coagulopathy, increased transfusion requirements, and worse outcomes. A total of 603 longitudinal plasma samples were prospectively collected from 251 critically injured patients at a single Level 1 trauma center from 0 hour to 120 hours. TEG maximal amplitude (MA), FF MA, FF levels, von Clauss fibrinogen, and standard coagulation measures were performed in parallel. Percentage contributions of FF (%MA(FF)) and platelets (%MA(platelets)) were calculated as each MA divided by overall kaolin TEG MA. Coagulopathic patients (international normalized ratio ≥ 1.3) had significantly lower admission %MA(FF) than noncoagulopathic patients (24.7% vs. 31.2%, p Coagulopathy and plasma transfusion were associated with a lower %MA(FF). Despite this importance of fibrinogen, platelets had a greater contribution to clot strength at all time points after injury. This suggests that attention to these relative contributions should guide resuscitation and thromboprophylaxis and that antiplatelet therapy may be of underrecognized importance to thromboprophylaxis after trauma. Prognostic study, level III.

  2. Hematocrit and blood osmolality in developing chicken embryos (Gallus gallus): in vivo and in vitro regulation.

    Science.gov (United States)

    Andrewartha, Sarah J; Tazawa, Hiroshi; Burggren, Warren W

    2011-12-15

    Hematocrit (Hct) regulation is a complex process involving potentially many factors. How such regulation develops in vertebrate embryos is still poorly understood. Thus, we investigated the role of blood pH in the regulation of Hct across developmental time in chicken embryos. We hypothesized that blood pH alterations in vitro (i.e., in a test tube) would affect Hct far more than in vivo because of in vivo compensatory regulatory processes for Hct. Large changes in Hct (through mean corpuscular volume (MCV)) and blood osmolality (Osm) occur when the blood was exposed to varying ambient temperatures (T(a)'s) and P(CO2) in vitro alongside an experimentally induced blood pH change from ~7.3 to 8.2. However, homeostatic regulatory mechanisms apparently limited these alterations in vivo. Changes in blood pH in vitro were accompanied by hydration or dehydration of red blood cells depending on embryonic age, resulting in changes in Hct that also were specific to developmental stage, due likely to initial blood gas and [HCO(3)(-)](v) values. Significant linear relationships between Hct and pH (Hct/ΔpH=-21.4%/(pH unit)), Hct and [HCO(3)(-)] (ΔHct/Δ[HCO(3)(-)]=1.6%/(mEq L(-1))) and the mean buffer value (Δ[HCO(3)(-)]/ΔpH=-13.4 (mEq L(-1))/(pH unit)) demonstrate that both pH and [HCO(3)(-)] likely play a role in the regulation of Hct through MCV at least in vitro. Low T(a) (24°C) resulted in relatively large changes in pH with small changes in Hct and Osm in vitro with increased T(a) (42°C) conversely resulting in larger changes in both Hct and Osm. In vivo exposure to altered T(a) caused age-dependent changes in Hct, demonstrating a trend towards increased Hct at higher T(a). Further, exposing embryos to a gas mixture where P(CO2) = 5.1 kPa for >4 h period at T(a) of 37 or 42°C also did not elicit a change in Hct or Osm. Presumably, homeostatic mechanisms ensured that in vivo Hct was stable during a 4-6 h temperature and/or hypercapnic stress. Thus, although blood p

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

    Directory of Open Access Journals (Sweden)

    Hossein Zolfagharian

    2015-12-01

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

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

    Science.gov (United States)

    Zolfagharian, Hossein; Mohajeri, Mohammad; Babaie, Mahdi

    2015-12-01

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

  5. Margination of Fluorescent Polylactic Acid–Polyaspartamide based Nanoparticles in Microcapillaries In Vitro: the Effect of Hematocrit and Pressure

    Directory of Open Access Journals (Sweden)

    Emanuela Fabiola Craparo

    2017-10-01

    Full Text Available The last decade has seen the emergence of vascular-targeted drug delivery systems as a promising approach for the treatment of many diseases, such as cardiovascular diseases and cancer. In this field, one of the major challenges is carrier margination propensity (i.e., particle migration from blood flow to vessel walls; indeed, binding of these particles to targeted cells and tissues is only possible if there is direct carrier–wall interaction. Here, a microfluidic system mimicking the hydrodynamic conditions of human microcirculation in vitro is used to investigate the effect of red blood cells (RBCs on a carrier margination in relation to RBC concentration (hematocrit and pressure drop. As model drug carriers, fluorescent polymeric nanoparticles (FNPs were chosen, which were obtained by using as starting material a pegylated polylactic acid–polyaspartamide copolymer. The latter was synthesized by derivatization of α,β-poly(N-2-hydroxyethyl-d,l-aspartamide (PHEA with Rhodamine (RhB, polylactic acid (PLA and then poly(ethyleneglycol (PEG chains. It was found that the carrier concentration near the wall increases with increasing pressure drop, independently of RBC concentration, and that the tendency for FNP margination decreases with increasing hematocrit. This work highlights the importance of taking into account RBC–drug carrier interactions and physiological conditions in microcirculation when planning a drug delivery strategy based on systemically administered carriers.

  6. The Prediction of Preeclampsia and Its Association With Hemoglobin and Hematocrit in the First Trimester of Pregnancy

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    Pakniat

    2016-07-01

    Full Text Available Background Hypertensive disorders in pregnancy are one of the most serious complications and their early diagnosis is one of the most important goals of prenatal care. Objectives The objective of this study was to determine the association of first trimester Hemoglobin (Hb and Hematocrit (Hct with preeclampsia. Patients and Methods This descriptive-analytic, prospective study was performed on 1376, less than 12 weeks of gestation, singleton pregnancies, visited for their prenatal care in health and medical clinics of the Qazvin province during years 2013 and 2014. At first, demographic data were recorded in a questionnaire and then all pregnant cases were referred to one of the three reference laboratories for their first trimester routine tests. After hemoglobin and hematocrit date collection, women were categorized in three groups: Hb 38% (4.41 - 12.044: CI 95%. According to Youden’s Index, optimum cut-off for 1st trimester Hb was 12.65 and for Hct, this was 38.05%. Conclusions The association of the 1st trimester high Hb and Hct with preeclampsia was revealed in this study, therefore it could be used as a prediction factor for early preeclampsia diagnosis.

  7. Real-time electrical impedimetric monitoring of blood coagulation process under temperature and hematocrit variations conducted in a microfluidic chip.

    Directory of Open Access Journals (Sweden)

    Kin Fong Lei

    Full Text Available Blood coagulation is an extremely complicated and dynamic physiological process. Monitoring of blood coagulation is essential to predict the risk of hemorrhage and thrombosis during cardiac surgical procedures. In this study, a high throughput microfluidic chip has been developed for the investigation of the blood coagulation process under temperature and hematocrit variations. Electrical impedance of the whole blood was continuously recorded by on-chip electrodes in contact with the blood sample during coagulation. Analysis of the impedance change of the blood was conducted to investigate the characteristics of blood coagulation process and the starting time of blood coagulation was defined. The study of blood coagulation time under temperature and hematocrit variations was shown a good agreement with results in the previous clinical reports. The electrical impedance measurement for the definition of blood coagulation process provides a fast and easy measurement technique. The microfluidic chip was shown to be a sensitive and promising device for monitoring blood coagulation process even in a variety of conditions. It is found valuable for the development of point-of-care coagulation testing devices that utilizes whole blood sample in microliter quantity.

  8. Clot resolution after 3 weeks of anticoagulant treatment for pulmonary embolism : comparison of computed tomography and perfusion scintigraphy

    NARCIS (Netherlands)

    van Es, J.; Douma, R. A.; Kamphuisen, P. W.; Gerdes, V. E. A.; Verhamme, P.; Wells, P. S.; Bounameaux, H.; Lensing, A. W. A.; Bueller, H. R.

    Introduction Little is known about the natural history of clot resolution in the initial weeks of anticoagulant therapy in patients with acute pulmonary embolism (PE). Clot resolution of acute PE was assessed with either computed tomography pulmonary angiography scan (CT-scan) or perfusion

  9. HEMOGLOBIN AND HEMATOCRIT DURING AN 8 DAY MOUNTAINBIKE RACE: A FIELD STUDY

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    Katharina C. Wirnitzer

    2007-06-01

    Full Text Available Considering the fact that mountainbike (MTB marathon and ultraendurance events also as MTB stage races have become very popular during the last decade knowledge is sparse about the effects on hematological system due to prolonged strenuous exercise. Endurance trained athletes generally show an increased blood volume mainly due to plasma volume (PV expansion, which already exerts after a few days of prolonged exercise, accompanied by lower hemoglobin (Hb and hematocrit (Hct levels. On a short term basis dehydration caused by prolonged exertive exercise leads to enhanced concentrations of Hb and Hct due to decreased PV. In contrast to acute exercise it has been well documented as a long term adaptation that regular endurance training over long term periods or repeated bouts of strenuous exercise, e. g. repetitive cycling races or cycling stage races over several consecutive days, lead to a fall in both Hb and Hct levels due to a progressive enlargement in particular in PV. Changes in hematological parameters are known to considerably influence physical performance, especially in aerobic endurance sports such as mountainbiking. An increase in PV normally results in enhanced aerobic performance due to reduced blood viscosity, thereby optimized microcirculation and improved oxygen delivery capacity to the working muscle (Schumacher et. al., 2000. Hematological parameters Hb and Hct are highly sensible to acute effects. The effects of prolonged exercise on hematological status are mainly dependent on total load (mode and duration of exercise, as well as thermal stress (temperature and humidity and fluid intake (FI (Convertino, 1991; Fellmann et. al., 1999; Neumayr et. al., 2002; Sawka et. al., 2000; Schumacher et. al., 2000. The Transalp Challenge (TAC is one of the hardest MTB marathon races in the world (besides Cape Epic/SA and Transrockies/USA, covering eight consecutive stages. The key data of TAC 2004 are: 22. 500 m (altitude difference, 662 km

  10. Purification and characterization of a novel C-type hemolytic lectin for clot lysis from the fresh water clam Villorita cyprinoides: a possible natural thrombolytic agent against myocardial infarction.

    Science.gov (United States)

    Sudhakar, G R Learnal; Vincent, S G Prakash

    2014-02-01

    Villorita cyprinoides (black clam) is a fresh water clam that belongs as a bivalve to the group of mollusc. The saline extracts from the muscle reveal high titers of agglutination potency on trypsin-treated rabbit erythrocytes. With the help of affinity chromatography a hemolytic protein with lectin activity which could all be inhibited by D-galactose were isolated. The lectins were separated on DEAE-cellulose and the main component was purified after an additional step of gel filtration on sephadex G-75. The main component is a non-glycosylated protein with a molecular weight of 96,560 Da determined by MALDI-ToF, consisting of a single protein chain and characterized by the lack of polymers and intermediate disulfide bonds. The pure main lectin with clot lytic feature shows two bands at molecular weights 36,360 and 26, 520 Da. Optimal inhibition of the pure lectin is achieved by D-galactose containing oligo- and polysaccharides. The lectin activity decreased above 40 °C and was lost at 62 °C, the stability over the pH range between 7.0 and 8.0 and requires divalent cations for their activity. The novel C-type hemolytic lectin for clot lysis from the clam Villorita cyprinoides was identified and evaluated, the purified hemolytic lectin (0.35 mg/ml and 0.175 mg/ml) enhanced clot lysis activity when compared to the different concentration (5 mg/ml and 1 mg/ml) of commercial streptokinase. In the present study identified hemolytic lectin was a rapid and effective clot lytic molecule and could be developed as new drug molecule in future. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Plasma fibrin clot properties in the G20210A prothrombin mutation carriers following venous thromboembolism: the effect of rivaroxaban.

    Science.gov (United States)

    Janion-Sadowska, Agnieszka; Natorska, Joanna; Siudut, Jakub; Ząbczyk, Michal; Stanisz, Andrzej; Undas, Anetta

    2017-08-30

    We sought to investigate whether the G20210A prothrombin mutation modifies plasma fibrin clot properties in patients after venous thromboembolism (VTE) and how rivaroxaban treatment affects these alterations. We studied 34 prothrombin mutation heterozygous carriers and sex- and age-matched 34 non-carriers, all at least three months since the first VTE episode, before and during treatment with rivaroxaban. Clot permeability (Ks) and clot lysis time (CLT) with or without elimination of thrombin activatable fibrinolysis inhibitor (TAFI) were assessed at baseline, 2-6 hours (h) after and 20-25 h after intake of rivaroxaban (20 mg/day). At baseline, the prothrombin mutation group formed denser clots (Ks -12 %, p=0.0006) and had impaired fibrinolysis (CLT +14 %, p=0.004, and CLT-TAFI +13 %, p=0.03) compared with the no mutation group and were similar to those observed in 15 healthy unrelated prothrombin mutation carriers. The G20210A prothrombin mutation was the independent predictor for Ks and CLT before rivaroxaban intake. At 2-6 h after rivaroxaban intake, clot properties improved in both G20210A carriers and non-carriers (Ks +38 %, and +37 %, CLT -25 % and -25 %, CLT-TAFI -20 % and -24 %, respectively, all p<0.001), but those parameters were worse in the prothrombin mutation group (Ks -12.8 %, CLT +17 %, CLT-TAFI +13 %, all p<0.001). Rivaroxaban concentration correlated with fibrin clot properties. After 20-25 h since rivaroxaban intake most clot properties returned to baseline. Rivaroxaban-related differences in clot structure were confirmed by scanning electron microscopy images. In conclusion, rivaroxaban treatment, though improves fibrin clot properties, cannot abolish more prothrombotic fibrin clot phenotype observed in prothrombin mutation carriers following VTE.

  12. MATHEMATICAL MODELING OF SELF-EXCITED VIBRATION OF PIPES CONTAINING MOBILE BOILING FLUID CLOTS

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    Yevgeniy Tolbatov

    2015-06-01

    Full Text Available Numerical modeling dynamic behavior of a pipe containing inner nonhomogeneous flows of a boiling fluid has been carried out. The system vibrations at different values of the parameters of the flow nonhomogeneity and its velocity are observed. The possibility of forming stable and unstable flows depending on the character ofnonhomogeneity and the velocity of fluid clots has been found.

  13. Purification and identification of a clotting protein from the hemolymph of Chinese shrimp ( Fenneropenaeus chinensis)

    Science.gov (United States)

    Wang, Baojie; Peng, Hongni; Liu, Mei; Jiang, Keyong; Zhang, Guofan; Wang, Lei

    2013-09-01

    The clotting protein (CP) plays important and diverse roles in crustaceans, such as coagulation and lipid transportation. A clotting protein was purified from the hemolymph of Chinese shrimp Fenneropenaeus chinensis (named as Fc-CP) with Q sepharose HP anion-exchange chromatography and phenyl sepharose HP hydrophobic interaction chromatography. Fc-CP was able to form stable clots in vitro in the presence of hemocyte lysate and Ca2+, suggesting that the clotting reaction is catalyzed by a Ca2+-dependent transglutaminase in shrimp hemocytes. The molecular mass of Fc-CP was 380 kDa under non-reducing conditions and 190 kDa under reducing conditions as was determined with SDS-PAGE. CP exists as disulfide-linked homodimers and oligomers. The N-terminal amino acid sequence of Fc-CP was identical to that of shrimps including Penaeus monodon, Farfantepenaeus paulensis and Litopenaeus vannamei; and similar to that of other decapods. The purified Fc-CP was digested with trypsin and verified on an ABI 4700 matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) mass spectrometry. Our results will aid to better understanding the coagulation mechanism of shrimp hemolymph.

  14. Clotting of cow (Bos taurus) and goat milk ( Capra hircus ) using ...

    African Journals Online (AJOL)

    The ease to locally produce kid rennet contrary to that of calve has led us to compare the proteolytic and clotting activities of these two rennets depending on their action on goat (Capra hircus) milk and cow (Bos taurus) milk. The proteolysis was measured by determining the increase of non-protein nitrogen according to the ...

  15. Staphylococcus chromogenes, a Coagulase-Negative Staphylococcus Species That Can Clot Plasma.

    Science.gov (United States)

    Dos Santos, Danielle Cabral; Lange, Carla Christine; Avellar-Costa, Pedro; Dos Santos, Katia Regina Netto; Brito, Maria Aparecida Vasconcelos Paiva; Giambiagi-deMarval, Marcia

    2016-05-01

    Staphylococcus chromogenes is one of the main coagulase-negative staphylococci isolated from mastitis of dairy cows. We describe S. chromogenes isolates that can clot plasma. Since the main pathogen causing mastitis is coagulase-positive Staphylococcus aureus, the coagulase-positive phenotype of S. chromogenes described here can easily lead to misidentification. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. Pharmacokinetic-guided dosing of clotting factor concentrates in bleeding disorders : towards individualization of treatment

    NARCIS (Netherlands)

    H.C.A.M. Hazendonk (Carolien)

    2017-01-01

    markdownabstractAll studies described in this thesis are part of the “OPTI-CLOT” research program on patient tailOred PharmacokineTIc (PK)-guided dosing of CLOTting factor concentrate in bleeding disorders. These are (inter)national multicenter studies which aim to implement PK-guided dosing of

  17. Clotting of cow (Bos taurus) and goat milk (Capra hircus) using calve ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-06

    Oct 6, 2008 ... phosphate buffer with a flow rate of 9.5 mL/h. Collection of fractions was made using Microcol TDC 80 (Gilson). Fractions of 5 mL were collected. The optical density was obtained by passing different fractions through a spectrophotometer at 280 nm using a 1.0 cm length curvet. Measuring of milk clotting ...

  18. Elution of ciprofloxacin from acrylic bone cement and fibrin clot: an in vitro study.

    Science.gov (United States)

    Tsourvakas, Stefanos; Alexandropoulos, Christos; Karatzios, Christos; Egnatiadis, Nikolaos; Kampagiannis, Nikolaos

    2009-08-01

    The purpose of this study was to investigate the release of ciprofloxacin from acrylic bone cement and fibrin clot. Under sterile conditions, bone cement and fibrin clot were individually mixed with ciprofloxacin. Ten specimens of each complex were placed in 1 ml of nutrient broth and incubated at 37 degrees C. The nutrient broth was changed daily, and the removed samples were stored at -70 degrees C until the antibiotic concentration in each sample was determined by a microbiological method. The maximum level in bone cement specimens was obtained at the second day (80.80 microg/ml) and its diffusion was rapid at first, decreasing gradually over a period of 365 days. Fibrin clot biodegradable specimens released high concentrations of ciprofloxacin (1.52-49.91 microg/ml) in vitro for the period of time needed to treat bone infections (i.e. 65 days). We conclude that the high release of ciprofloxacin in vitro from acrylic bone cement and fibrin clot is very promising since the obtained levels are much higher than the required minimal inhibitory concentration (MIC) against the implicated pathogens in soft tissue and bone infections. The in vivo relevance of the obtained results requires carefully performed studies in animal models.

  19. The effects of Aloe vera [gel] on clotting time, prothrombin time and ...

    African Journals Online (AJOL)

    Background: Published reports on the effects of Aloe vera gel on blood coagulation in experimental animals are relatively scanty. Aim: To determine the effect of Aloe vera gel on clotting time, prothrombin time and plasma fibrinogen concentration in albino Wistar rats. Methods: A total of 28 adult albino Wistar rats divided ...

  20. Production of milk-clotting enzyme by Bacillus subtilis B1 from wheat ...

    African Journals Online (AJOL)

    Three strains, Bacillus subtilis B1, B. subtilis B18 and Bacillus thuringiensis B12, were screened from wheat bran to produce milk-clotting enzyme. Among them, B. subtilis B1 exhibited considerable milkclotting activity with low proteolytic activity. After response surface methodology optimization, milkclotting activity was ...

  1. Using hydrogen peroxide as a bladder irrigation solution for clot evacuation

    Directory of Open Access Journals (Sweden)

    Mahdi Bagheri

    2017-03-01

    Full Text Available Gross hematuria or macroscopic hematuria is a high risk urologic condition that might occur in different settings. In the case of continued gross hematuria, blood clot size may grow and lead to complete obstruction of urinary outflow. Placement of three-way catheter, continuous bladder irrigation with normal saline, and cystoscopy are conventional treatments. Here we introduce a case with urinary obstruction who did not respond to conventional therapies. A subject of Hodgkin lymphoma with urinary obstruction caused by heavy gross hematuria was presented to emergency department. Three-way catheter was inserted to facilitate urination. However, there was no urinary drainage and bladder was distended. Consequently, 100 ml solution of hydrogen peroxide 0.15% was prepared and administered into the bladder to irrigate and evacuate the clots. A single intravesical infusion of hydrogen peroxide rapidly resolved urinary obstruction and improved patient distress. After administration of hydrogen peroxide solution, blood clots and bloody urine were evacuated successfully. These findings suggest that an intravesical injection of hydrogen peroxide can induce dissolution of blood clots and may be a simple and efficient therapy for urinary obstruction due to gross hematuria.

  2. Fibrin clot structure and platelet aggregation in patients with aspirin treatment failure.

    Science.gov (United States)

    Neergaard-Petersen, Søs; Ajjan, Ramzi; Hvas, Anne-Mette; Hess, Katharina; Larsen, Sanne Bøjet; Kristensen, Steen Dalby; Grove, Erik Lerkevang

    2013-01-01

    Aspirin is a cornerstone in prevention of cardiovascular events and modulates both platelet aggregation and fibrin clot formation. Some patients experience cardiovascular events whilst on aspirin, often termed aspirin treatment failure (ATF). This study evaluated both platelet aggregation and fibrin clot structure in patients with ATF. We included 177 stable coronary artery disease patients on aspirin monotherapy. Among these, 116 (66%) had ATF defined as myocardial infarction (MI) whilst on aspirin. Platelet aggregation was assessed by Multiplate® aggregometry and VerifyNow®, whereas turbidimetric assays and scanning electron microscopy were employed to study fibrin clot characteristics. Enhanced platelet aggregation was observed in patients with ATF compared with non-MI patients following stimulation with arachidonic acid 1.0 mM (median 161 (IQR 95; 222) vs. 97 (60; 1776) AU*min, p = 0.005) and collagen 1.0 µg/mL (293 (198; 427) vs. 220 (165; 370) AU*min, p = 0.03). Similarly, clot maximum absorbance, a measure of fibrin network density, was increased in patients with ATF (0.48 (0.41; 0.52) vs. 0.42 (0.38; 0.50), p = 0.02), and this was associated with thinner fibres (mean ± SD: 119.7±27.5 vs. 127.8±31.1 nm, p = 0.003) and prolonged lysis time (552 (498; 756) vs. 519 (468; 633) seconds; p = 0.02). Patients with ATF also had increased levels of C-reactive protein (CRP) (1.34 (0.48; 2.94) and 0.88 (0.32; 1.77) mg/L, p = 0.01) compared with the non-MI group. Clot maximum absorbance correlated with platelet aggregation (r = 0.31-0.35, p-valuesaspirin treatment failure showed increased platelet aggregation and altered clot structure with impaired fibrinolysis compared with stable CAD patients without previous MI. These findings suggest that an increased risk of aspirin treatment failure may be identified by measuring both platelet function and fibrin clot structure.

  3. Fibrin clot structure and platelet aggregation in patients with aspirin treatment failure.

    Directory of Open Access Journals (Sweden)

    Søs Neergaard-Petersen

    Full Text Available Aspirin is a cornerstone in prevention of cardiovascular events and modulates both platelet aggregation and fibrin clot formation. Some patients experience cardiovascular events whilst on aspirin, often termed aspirin treatment failure (ATF. This study evaluated both platelet aggregation and fibrin clot structure in patients with ATF.We included 177 stable coronary artery disease patients on aspirin monotherapy. Among these, 116 (66% had ATF defined as myocardial infarction (MI whilst on aspirin. Platelet aggregation was assessed by Multiplate® aggregometry and VerifyNow®, whereas turbidimetric assays and scanning electron microscopy were employed to study fibrin clot characteristics.Enhanced platelet aggregation was observed in patients with ATF compared with non-MI patients following stimulation with arachidonic acid 1.0 mM (median 161 (IQR 95; 222 vs. 97 (60; 1776 AU*min, p = 0.005 and collagen 1.0 µg/mL (293 (198; 427 vs. 220 (165; 370 AU*min, p = 0.03. Similarly, clot maximum absorbance, a measure of fibrin network density, was increased in patients with ATF (0.48 (0.41; 0.52 vs. 0.42 (0.38; 0.50, p = 0.02, and this was associated with thinner fibres (mean ± SD: 119.7±27.5 vs. 127.8±31.1 nm, p = 0.003 and prolonged lysis time (552 (498; 756 vs. 519 (468; 633 seconds; p = 0.02. Patients with ATF also had increased levels of C-reactive protein (CRP (1.34 (0.48; 2.94 and 0.88 (0.32; 1.77 mg/L, p = 0.01 compared with the non-MI group. Clot maximum absorbance correlated with platelet aggregation (r = 0.31-0.35, p-values<0.001 and CRP levels (r = 0.60, p<0.001.Patients with aspirin treatment failure showed increased platelet aggregation and altered clot structure with impaired fibrinolysis compared with stable CAD patients without previous MI. These findings suggest that an increased risk of aspirin treatment failure may be identified by measuring both platelet function and fibrin clot structure.

  4. The use of regression analysis in determining reference intervals for low hematocrit and thrombocyte count in multiple electrode aggregometry and platelet function analyzer 100 testing of platelet function.

    Science.gov (United States)

    Kuiper, Gerhardus J A J M; Houben, Rik; Wetzels, Rick J H; Verhezen, Paul W M; Oerle, Rene van; Ten Cate, Hugo; Henskens, Yvonne M C; Lancé, Marcus D

    2017-11-01

    Low platelet counts and hematocrit levels hinder whole blood point-of-care testing of platelet function. Thus far, no reference ranges for MEA (multiple electrode aggregometry) and PFA-100 (platelet function analyzer 100) devices exist for low ranges. Through dilution methods of volunteer whole blood, platelet function at low ranges of platelet count and hematocrit levels was assessed on MEA for four agonists and for PFA-100 in two cartridges. Using (multiple) regression analysis, 95% reference intervals were computed for these low ranges. Low platelet counts affected MEA in a positive correlation (all agonists showed r(2) ≥ 0.75) and PFA-100 in an inverse correlation (closure times were prolonged with lower platelet counts). Lowered hematocrit did not affect MEA testing, except for arachidonic acid activation (ASPI), which showed a weak positive correlation (r(2) = 0.14). Closure time on PFA-100 testing was inversely correlated with hematocrit for both cartridges. Regression analysis revealed different 95% reference intervals in comparison with originally established intervals for both MEA and PFA-100 in low platelet or hematocrit conditions. Multiple regression analysis of ASPI and both tests on the PFA-100 for combined low platelet and hematocrit conditions revealed that only PFA-100 testing should be adjusted for both thrombocytopenia and anemia. 95% reference intervals were calculated using multiple regression analysis. However, coefficients of determination of PFA-100 were poor, and some variance remained unexplained. Thus, in this pilot study using (multiple) regression analysis, we could establish reference intervals of platelet function in anemia and thrombocytopenia conditions on PFA-100 and in thrombocytopenia conditions on MEA.

  5. Correlation of hematocrit, platelet concentration, and plasma coagulation factors with results of thromboelastometry in canine whole blood samples.

    Science.gov (United States)

    Smith, Stephanie A; McMichael, Maureen A; Gilor, Shir; Galligan, Alyssa J; Hoh, Crystal M

    2012-06-01

    To evaluate the components of canine whole blood samples that contribute to results of thromboelastometry (TEM). 127 healthy dogs. For each dog, a blood sample was collected from a jugular vein into tubes containing no anticoagulant, EDTA, or citrate anticoagulant. Citrated whole blood samples underwent TEM with tissue factor and TEM with ellagic acid. Indicators of RBC mass and platelet concentration were evaluated, and plasma coagulation tests were performed; data obtained were compared with results of TEM. For technical reasons, samples were not available from all dogs for all tests. Coagulation time was correlated with concentrations of primarily extrinsic pathway coagulation factors for TEM with tissue factor and with most factors via TEM with ellagic acid. Clot formation time, α angle, and maximum clot firmness were highly correlated with fibrinogen and platelet concentrations and some individual factor concentrations. Sample Hct was strongly correlated with most measured variables; low Hct was associated with relative hypercoagulability, and high Hct was associated with relative hypocoagulability. For TEM of canine blood samples, coagulation time was primarily a function of coagulation factor concentrations, whereas other variables were dependent on platelet and fibrinogen concentrations. Sample Hct strongly influenced the results of TEM, likely because RBCs act as a diluent for plasma coagulation factors. Thromboelastometry appeared to be affected by abnormalities of coagulation factors, platelet concentrations, and RBC mass. In samples from anemic patients, results of TEM indicative of hypercoagulability may be artifactual because of low RBC mass.

  6. Fibrinogen and clot-related phenotypes determined by fibrinogen polymorphisms: Independent and IL-6-interactive associations.

    Directory of Open Access Journals (Sweden)

    H Toinét Cronjé

    Full Text Available Interleukin-6 (IL-6 induces the expression of fibrinogen, and polymorphic variation within the fibrinogen genes is believed to alter the magnitude of this expression. The identification of the functional relevance of individual fibrinogen single nucleotide polymorphisms (SNPs has been hindered by the high linkage disequilibrium (LD reported in the European fibrinogen gene locus. This study investigated two novel and 12 known fibrinogen SNPs of potential functional relevance, in 2010 Tswana individuals known to have low LD. We aimed to identify functional polymorphisms that contribute to clot-related phenotypes and total and γ' fibrinogen concentrations independently and through their interaction with IL-6, by taking advantage of the high fibrinogen and IL-6 concentrations and the low LD reported in black South Africans. Fibrinogen was significantly associated with IL-6, thereby mediating associations of IL-6 with clot formation and structure, although attenuating the association of IL-6 with clot lysis time. None of the common European fibrinogen haplotypes was present in this study population. Putative functional fibrinogen SNPs FGB-rs7439150, rs1800789 (-1420G/A and rs1800787 (-148C/T were significantly associated with fibrinogen concentration and altered clot properties, with several associations significantly influenced by IL-6 concentrations. The impact of harbouring several minor fibrinogen SNP alleles on the association of IL-6 and fibrinogen concentration was cumulative, with possession of each additional minor allele showing a stronger relationship of IL-6 with fibrinogen. This was also reflected in differences in clot properties, suggesting potential clinical relevance. Therefore, when investigating the effect of fibrinogen genetics on fibrinogen concentrations and CVD outcome, the possible interactions with modulating factors and the fact that SNP effects seem to be additive should be taken into account.

  7. An exploration of the reflow technique for the fabrication of an in vitro microvascular system to study occlusive clots.

    Science.gov (United States)

    Li, Yang; Pan, Chuer; Li, Yunfeng; Kumacheva, Eugenia; Ramachandran, Arun

    2017-09-08

    Embolic ischemia and pulmonary embolism are health emergencies that arise when a particle such as a blood clot occludes a smaller blood vessel in the brain or the lungs, and restricts flow of blood downstream of the vessel. In this work, the reflow technique (Wang et al. Biomed. Microdevices 2007, 9, 657) was adapted to produce a microchannel network that mimics the occlusion process. The technique was first revisited and a simple geometrical model was developed to quantitatively explain the shapes of the resulting microchannels for different reflow parameters. A critical modification was introduced to the reflow protocol to fabricate nearly circular microchannels of different diameters from the same master, which is not possible with the traditional reflow technique. To simulate the phenomenon of occlusion by clots, a microchannel network with three generations of branches with different diameters and branching angles was fabricated, into which fibrin clots were introduced. At low constant pressure drop (ΔP), a clot blocked a branch entrance only partially, while at higher ΔP, the branch was completely blocked. Instances of simultaneous blocking of multiple channels by clots, and the consequent changes in the flow rates in the unblocked branches of the network, were also monitored. This work provides the framework for a systematic study of the distribution of clots in a network, and the rate of dissolution of embolic clots upon the introduction of a thrombolytic drug into the network.

  8. Kinetics and mechanics of clot contraction are governed by the molecular and cellular composition of the blood.

    Science.gov (United States)

    Tutwiler, Valerie; Litvinov, Rustem I; Lozhkin, Andrey P; Peshkova, Alina D; Lebedeva, Tatiana; Ataullakhanov, Fazoil I; Spiller, Kara L; Cines, Douglas B; Weisel, John W

    2016-01-07

    Platelet-driven blood clot contraction (retraction) is thought to promote wound closure and secure hemostasis while preventing vascular occlusion. Notwithstanding its importance, clot contraction remains a poorly understood process, partially because of the lack of methodology to quantify its dynamics and requirements. We used a novel automated optical analyzer to continuously track in vitro changes in the size of contracting clots in whole blood and in variously reconstituted samples. Kinetics of contraction was complemented with dynamic rheometry to characterize the viscoelasticity of contracting clots. This combined approach enabled investigation of the coordinated mechanistic impact of platelets, including nonmuscle myosin II, red blood cells (RBCs), fibrin(ogen), factor XIIIa (FXIIIa), and thrombin on the kinetics and mechanics of the contraction process. Clot contraction is composed of 3 sequential phases, each characterized by a distinct rate constant. Thrombin, Ca(2+), the integrin αIIbβ3, myosin IIa, FXIIIa cross-linking, and platelet count all promote 1 or more phases of the clot contraction process. In contrast, RBCs impair contraction and reduce elasticity, while increasing the overall contractile stress generated by the platelet-fibrin meshwork. A better understanding of the mechanisms by which blood cells, fibrin(ogen), and platelet-fibrin interactions modulate clot contraction may generate novel approaches to reveal and to manage thrombosis and hemostatic disorders. © 2016 by The American Society of Hematology.

  9. The spider hemolymph clot proteome reveals high concentrations of hemocyanin and von Willebrand factor-like proteins.

    Science.gov (United States)

    Sanggaard, Kristian W; Dyrlund, Thomas F; Bechsgaard, Jesper S; Scavenius, Carsten; Wang, Tobias; Bilde, Trine; Enghild, Jan J

    2016-02-01

    Arthropods include chelicerates, crustaceans, and insects that all have open circulation systems and thus require different properties of their coagulation system than vertebrates. Although the clotting reaction in the chelicerate horseshoe crab (Family: Limulidae) has been described in details, the overall protein composition of the resulting clot has not been analyzed for any of the chelicerates. The largest class among the chelicerates is the arachnids, which includes spiders, ticks, mites, and scorpions. Here, we use a mass spectrometry-based approach to characterize the spider hemolymph clot proteome from the Brazilian whiteknee tarantula, Acanthoscurria geniculata. We focused on the insoluble part of the clot and demonstrated high concentrations of proteins homologous to the hemostasis-related and multimerization-prone von Willebrand factor. These proteins, which include hemolectins and vitellogenin homologous, were previously identified as essential components of the hemolymph clot in crustaceans and insects. Their presence in the spider hemolymph clot suggests that the origin of these proteins' function in coagulation predates the split between chelicerates and mandibulata. The clot proteome reveals that the major proteinaceous component is the oxygen-transporting and phenoloxidase-displaying abundant hemolymph protein hemocyanin, suggesting that this protein also plays a role in clot biology. Furthermore, quantification of the peptidome after coagulation revealed the simultaneous activation of both the innate immune system and the coagulation system. In general, many of the identified clot-proteins are related to the innate immune system, and our results support the previously suggested crosstalk between immunity and coagulation in arthropods. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Recurrent clot anuria following laparoscopic pyeloplasty in a solitary functioning kidney: managing with double guide wire technique.

    Science.gov (United States)

    Kumar, Santosh; Singh, Shivanshu; Parmar, Kalpesh Mahesh; Garg, Nitin

    2014-12-24

    Clot anuria in a solitary functioning kidney is an emergency situation. Haematuria with clot anuria in an early postoperative period represents a challenge, as treatment options are limited. Manipulation of the anastomotic site may lead to anastomotic disruption and urinoma while use of thrombolytic therapy poses the danger of increasing haematuria. We report a case of anuria due to clot retention in the upper tract following laparoscopic dismembered pyeloplasty in a solitary functioning kidney, managed successfully with double guide wire technique. 2014 BMJ Publishing Group Ltd.

  11. In vitro sensitivity of different activated partial thromboplastin time reagents to mild clotting factor deficiencies.

    Science.gov (United States)

    Toulon, P; Eloit, Y; Smahi, M; Sigaud, C; Jambou, D; Fischer, F; Appert-Flory, A

    2016-08-01

    Activated partial thromboplastin time (aPTT) is a routine clotting assay that is widely used to globally screen for coagulation abnormalities. It is commonly admitted that a prolonged test result, may trigger the need for specific assays to be performed, particularly factor measurement. However, the sensitivity of aPTT reagents to deficiencies of clotting factors varies. We evaluated, according to the recommendation of the CLSI H47-A2 guideline, the responsiveness to single factor levels of five aPTT reagents by using factor-deficient plasmas spiked with a calibration plasma to produce individual factor activities ranging from sensitivity of the tested aPTT reagents to single factor deficiency is highly variable. Moreover, for one given aPTT reagent, its sensitivity was very different depending on the deficient factor. This must be considered when analyzing clinical materials. © 2016 John Wiley & Sons Ltd.

  12. Hematocrit analysis through the use of an inexpensive centrifugal polyester-toner device with finger-to-chip blood loading capability

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Brandon L.; Gilbert, Rachel J. [Department of Chemistry, McCormick Road, University of Virginia, Charlottesville, VA 22904 (United States); Mejia, Maximo [Department of Mechanical Engineering, Engineer' s Way, University of Virginia, Charlottesville, VA 22904 (United States); Shukla, Nishant [Department of Computer Science, Engineer' s Way, University of Virginia, Charlottesville, VA 22904 (United States); Haverstick, Doris M. [Department of Pathology, University of Virginia Health Science Center, Charlottesville, VA 22908 (United States); Garner, Gavin T. [Department of Mechanical Engineering, Engineer' s Way, University of Virginia, Charlottesville, VA 22904 (United States); Landers, James P., E-mail: landers@virginia.edu [Department of Chemistry, McCormick Road, University of Virginia, Charlottesville, VA 22904 (United States); Department of Mechanical Engineering, Engineer' s Way, University of Virginia, Charlottesville, VA 22904 (United States); Department of Pathology, University of Virginia Health Science Center, Charlottesville, VA 22908 (United States)

    2016-06-14

    Hematocrit (HCT) measurements are important clinical diagnostic variables that help physicians diagnose and treat various medical conditions, ailments, and diseases. In this work, we present the HCT Disc, a centrifugal microdevice fabricated by a Print, Cut and Laminate (PCL) method to generate a 12-sample HCT device from materials costing <0.5 USD (polyester and toner or PeT). Following introduction from a drop of blood (finger stick), whole blood metering and cell sedimentation are controlled by centrifugal force, only requiring a CD player motor as external hardware and, ultimately, a cell phone for detection. The sedimented volume from patient blood in the HCT Disc was analyzed using a conventional scanner/custom algorithm for analysis of the image to determine a hematocrit value, and these were compared to values generated in a clinical laboratory, which correlated well. To enhance portability and assure simplicity of the HCT measurement, values from image analysis by a cell phone using a custom application was compared to the scanner. Fifteen samples were analyzed with cell phone image analysis system and were found to be within 4% of the HCT values determined in the clinical lab. We demonstrate the feasibility of the PeT device for HCT measurement, and highlight its uniquely low cost (<0.5 USD), speed (sample-to-answer <8 min), multiplexability (12 samples), low volume whole blood requirement (<3 μL), rotation speeds (<4000 rpm) needed for effective measurement as well as the direct finger-to-chip sample loading capability. - Highlights: • A 12-sample hematocrit device was developed from polyester-toner materials. • The device can analyze a patient's hematocrit within 8 min from 3 μL of blood. • Cell phone image analysis is used to correctly determine clinical hematocrits.

  13. Myosin: a noncovalent stabilizer of fibrin in the process of clot dissolution.

    Science.gov (United States)

    Kolev, Krasimir; Tenekedjiev, Kiril; Ajtai, Katalin; Kovalszky, Ilona; Gombas, Judit; Váradi, Balázs; Machovich, Raymund

    2003-06-01

    Myosin modulates the fibrinolytic process as a cofactor of the tissue plasminogen activator and as a substrate of plasmin. We report now that myosin is present in arterial thrombi and it forms reversible noncovalent complexes with fibrinogen and fibrin with equilibrium dissociation constants in the micromolar range (1.70 and 0.94 microM, respectively). Competition studies using a peptide inhibitor of fibrin polymerization (glycl-prolyl-arginyl-proline [GPRP]) indicate that myosin interacts with domains common in fibrinogen and fibrin and this interaction is independent of the GPRP-binding polymerization site in the fibrinogen molecule. An association rate constant of 1.81 x 10(2) M(-1) x s(-1) and a dissociation rate constant of 3.07 x 10(-4) s(-1) are determined for the fibrinogen-myosin interaction. Surface plasmon resonance studies indicate that fibrin serves as a matrix core for myosin aggregation. The fibrin clots equilibrated with myosin are stabilized against dissolution initiated by plasminogen and tissue-type plasminogen activator (tPA) or urokinase (at fibrin monomer-myosin molar ratio as high as 30) and by plasmin under static and flow conditions (at fibrin monomer-myosin molar ratio lower than 15). Myosin exerts similar effects on the tPA-induced dissolution of blood plasma clots. Covalent modification involving factor XIIIa does not contribute to this stabilizing effect; myosin is not covalently attached to the clot by the time of complete cross-linking of fibrin. Thus, our in vitro data suggest that myosin detected in arterial thrombi binds to the polymerized fibrin, in the bound form its tPA-cofactor properties are masked, and the myosin fibrin clot is relatively resistant to plasmin.

  14. Flow-dependent channel formation in clots by an erythrocyte-bound fibrinolytic agent

    OpenAIRE

    Gersh, Kathryn C.; Zaitsev, Sergei; Cines, Douglas B.; Muzykantov, Vladimir; John W. Weisel

    2011-01-01

    Studies in animal models have shown that plasminogen activators bound to erythrocytes (RBC-PA) have an extended lifetime in the circulation and are safer than free PAs. RBC-PAs incorporate into nascent thrombi, which are focally lysed from within, an attractive thromboprophylactic option. In static systems, RBC-PAs cleave surrounding fibrin fibers, forming pores larger than the cells themselves, and move around the pore edges, enlarging them until eventual clot dissolution. We hypothesized th...

  15. Using hydrogen peroxide as a bladder irrigation solution for clot evacuation

    OpenAIRE

    Mahdi Bagheri; Mamak Tahmasebi; Sheyda Najafi; Zahra Jahangard Rafsanjani

    2017-01-01

    Gross hematuria or macroscopic hematuria is a high risk urologic condition that might occur in different settings. In the case of continued gross hematuria, blood clot size may grow and lead to complete obstruction of urinary outflow. Placement of three-way catheter, continuous bladder irrigation with normal saline, and cystoscopy are conventional treatments. Here we introduce a case with urinary obstruction who did not respond to conventional therapies. A subject of Hodgkin lymphoma with uri...

  16. Kinetic analysis of the clotting system in the presence of heparin and depolymerized heparin.

    Science.gov (United States)

    Heuck, C C; Baumann, P

    1991-01-01

    The kinetics of the activation of the plasmatic clotting system in the presence of heparin and depolymerized heparin (Kabi 2165), respectively, was compared with the kinetics of activation in plasma with isolated factor deficiency. Measurements were made with a chromogenic substrate method using Tos-Gly-Pro-Arg-p-nitroanilide acetate. The extinction curves were analyzed to determine the characteristics of a curve that was fitted to the experimental data to sufficiently describe the slope of the curves by constants. In the activated extrinsic clotting system, the action of heparin and depolymerized heparin results in a distribution pattern for the two relevant constants. K(1), defining the time of the point of inflection of the curve, and K(2), relating to the slope of the curve at the point of inflection, which is identical with the pattern observed in plasma with factor II deficiency. This distribution pattern can be explained by an inhibitory reaction on factor IIa, which is accelerated by the anticoagulant. In contrast, the pattern of K(2)/K(1) for the activated intrinsic system is identical with the pattern for plasma with factor X deficiency. Qualitative differences in the action of heparin and depolymerized heparin are not evident. The investigation confirms that the molecular action of heparin and depolymerized heparin as accelerators of the plasmatic clotting system is qualitatively the same. However, their action in the extrinsic and intrinsic system has different effects. Furthermore, the study reveals that constant K(2) is a more sensitive indicator to measure low heparin and depolymerized heparin activities than K(1) or its equivalent, the clotting time.

  17. Shock releases bile acid inducing platelet inhibition and fibrinolysis.

    Science.gov (United States)

    Wiener, Gregory; Moore, Hunter B; Moore, Ernest E; Gonzalez, Eduardo; Diamond, Scott; Zhu, Shu; D'Alessandro, Angelo; Banerjee, Anirban

    2015-05-15

    Metabolites are underappreciated for their effect on coagulation. Taurocholic acid (TUCA), a bile acid, has been shown to regulate cellular activity and promote fibrin sealant degradation. We hypothesize that TUCA impairs whole blood clot formation and promotes fibrinolysis. TUCA was exogenously added to whole blood obtained from volunteers. A titration from 250 μM-750 μM was used due to biologic relevance. Whole blood mixtures were assayed using thrombelastography for clot strength (maximum amplitude [MA]) and fibrinolysis (LY30) quantification. Tranexamic acid was used to block plasmin-mediated fibrinolysis. Platelet microfluidics were performed. A proteomic analysis was completed on citrated plasma obtained from a shock and resuscitation rat model. Fibrinolysis increased when 750-μM TUCA was added to whole blood (median LY30 0.08-5.7, P = 0.010) and clot strength decreased (median MA of 53.3-43.8, P = 0.010). The addition of tranexamic acid, to a 750-μM TUCA titration, partially reversed the induced fibrinolysis (LY30: without 7.7 versus with 2.7) and the decrease in clot strength (MA: without 48.2 versus with 53.2), but did not reverse the effects to whole blood levels. Platelet function reduced by 50% in the presence of 100-μM TUCA. Rats had a median 52-fold increase in TUCA, after a shock state that stayed elevated after resuscitation. TUCA reduces clot strength and promotes fibrinolysis. The clot strength reduction is attributable to platelet inhibition. This metabolic effect on coagulation warrants further investigation, as localized areas of the body, with high levels of bile acid, may be at risk for postoperative bleeding. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Tranexamic acid combined with recombinant factor VIII increases clot resistance to accelerated fibrinolysis in severe hemophilia A

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Sørensen, Hanne Thykjær; Norengaard, Lisbeth

    2007-01-01

    BACKGROUND: Most patients with severe hemophilia A suffer from a profoundly compromised hemostatic response. In addition to both the delayed and slow development of a clot, previous studies have documented that severe hemophilia A is also associated with reduced clot stability. OBJECTIVES: We...... examined whether the clot stability in hemophiliacs could be improved by treatment with tranexamic acid (TXA) in combination with recombinant factor VIII (rFVIII). PATIENTS/METHODS: Baseline blood samples were obtained from eight males with severe hemophilia A. Thereafter, a bolus injection of r...... the elasticity curve increased 5-fold after rFVIII and 24-fold after addition of TXA. CONCLUSIONS: The study demonstrates that simultaneous treatment with TXA and rFVIII significantly improves the clot stability in patients with hemophilia A. Udgivelsesdato: December...

  19. Real-time monitoring of human blood clotting using a lateral excited film bulk acoustic resonator

    Science.gov (United States)

    Chen, Da; Wang, Jingjng; Wang, Peng; Guo, Qiuquan; Zhang, Zhen; Ma, Jilong

    2017-04-01

    Frequent assay of hemostatic status is an essential issue for the millions of patients using anticoagulant drugs. In this paper, we presented a micro-fabricated film bulk acoustic sensor for the real-time monitoring of blood clotting and the measurement of hemostatic parameters. The device was made of an Au/ZnO/Si3N4 film stack and excited by a lateral electric field. It operated under a shear mode resonance with the frequency of 1.42 GHz and had a quality factor of 342 in human blood. During the clotting process of blood, the resonant frequency decreased along with the change of blood viscosity and showed an apparent step-ladder curve, revealing the sequential clotting stages. An important hemostatic parameter, prothrombin time, was quantitatively determined from the frequency response for different dilutions of the blood samples. The effect of a typical anticoagulant drug (heparin) on the prothrombin time was exemplarily shown. The proposed sensor displayed a good consistency and clinical comparability with the standard coagulometric methods. Thanks to the availability of direct digital signals, excellent potentials of miniaturization and integration, the proposed sensor has promising application for point-of-care coagulation technologies.

  20. Engineered isopeptide bond stabilized fibrin inspired nanoscale peptide based sealants for efficient blood clotting.

    Science.gov (United States)

    Ghosh, Snehasish; Mukherjee, Sanchita; Dutta, Chiranjit; Chakraborty, Kasturee; Gayen, Paramita; Jan, Somnath; Bhattacharyya, Dhananjay; Roy, Rituparna Sinha

    2017-07-26

    Designing biologically inspired nanoscale molecular assembly with desired functionality is a challenging endeavour. Here we report the designing of fibrin-inspired nanostructured peptide based sealants which facilitate remarkably fast entrapping of blood corpuscles (~28 seconds) in contrast to fibrin (~56 seconds). Our engineered sealants are stabilized by lysine-aspartate ionic interactions and also by N(ε)(γ-glutamyl) lysine isopeptide bond mediated covalent interaction. Each sealant is formed by two peptides having complementary charges to promote lysine-aspartate ionic interactions and designed isopeptide bond mediated interactions. Computational analysis reveals the isopeptide bond mediated energetically favourable peptide assemblies in sealants 1-3. Our designed sealants 2 and 3 mimic fibrin-mediated clot formation mechanism in presence of transglutaminase enzyme and blood corpuscles. These fibrin-inspired peptides assemble to form sealants having superior hemostatic activities than fibrin. Designed sealants feature mechanical properties, biocompatibility, biodegradability and high adhesive strength. Such nature-inspired robust sealants might be potentially translated into clinics for facilitating efficient blood clotting to handle traumatic coagulopathy and impaired blood clotting.

  1. [Water-tight closure of spinal dura with a new clot suture technique (author's transl)].

    Science.gov (United States)

    Matras, H; Jesch, W; Kletter, G; Dinges, H P

    1978-06-09

    A new clot-suturing Technique (using high-concentration fibrinogen solutions) for water-tight closure of the dura is reported. Six dogs underwent laminectomy of the thoracic spine with medial longitudinal incision in the chordal dura. After the dural split had been sealed with natural tissue adhesive and closure of the wound in layers, the animals were sacrificed at intervals of 1 to 21 days postoperatively and the chordal segments involved were removed and histologically examined. Early fibrinolysis of the clot was prevented by adding a natural proteinase inhibitor and factor XIII concentrate to the clotting substances. Histological analysis showed that healing was almost complete after 2 weeks, with delicate connective tissue overgrowing the dural split. After complete reabsorption of fibrin, the originally abundant absorbent granulation tissue had largely disappeared. Among the satisfactory results of fibrin suturing are optimum healing tendency in the fibrin-sutured region, absence of tissue irritation and neurotoxicity, which are known attributes of the synthetic alkl-cyano-acrylate tissue adhesives.

  2. Effect of Progesterone and Synthetic Progestins on Whole Blood Clot Formation and Erythrocyte Structure.

    Science.gov (United States)

    Swanepoel, Albe C; Emmerson, Odette; Pretorius, Etheresia

    2017-06-01

    Combined oral contraceptive (COC) use is a risk factor for venous thrombosis (VT) and related to the specific type of progestin used. VT is accompanied by inflammation and pathophysiological clot formation, that includes aberrant erythrocytes and fibrin(ogen) interactions. In this paper, we aim to determine the influence of progesterone and different synthetic progestins found in COCs on the viscoelasticity of whole blood clots, as well as erythrocyte morphology and membrane ultrastructure, in an in vitro laboratory study. Thromboelastography (TEG), light microscopy, and scanning electron microscopy were our chosen methods. Our results point out that progestins influence the rate of whole blood clot formation. Alterations to erythrocyte morphology and membrane ultrastructure suggest the presence of eryptosis. We also note increased rouleaux formation, erythrocyte aggregation, and spontaneous fibrin formation in whole blood which may explain the increased risk of VT associated with COC use. Although not all COC users will experience a thrombotic event, individuals with a thrombotic predisposition, due to inflammatory or hematological illness, should be closely monitored to prevent pathological thrombosis.

  3. BβArg448Lys polymorphism is associated with altered fibrin clot structure and fibrinolysis in type 2 diabetes.

    Science.gov (United States)

    Greenhalgh, Katie A; Strachan, Mark W; Alzahrani, Saad; Baxter, Paul D; Standeven, Kristina F; Storey, Robert F; Ariens, Robert A S; Grant, Peter J; Price, Jackie F; Ajjan, Ramzi A

    2017-01-26

    Both type 2 diabetes (T2DM) and Bβ448Lys variant of fibrinogen are associated with dense fibrin clots, impaired fibrinolysis and increased cardiovascular risk. It was our objective to investigate whether BβArg448Lys adds to vascular risk by modulating fibrin network structure and/or fibrinolysis in diabetes. The primary aim was to study effects of BβArg448Lys on fibrin network characteristics in T2DM. Secondary aims investigated interactions between gender and BβArg448Lys substitution in relation to fibrin clot properties and vascular disease. Genotyping for BβArg448Lys and dynamic clot studies were carried out on 822 T2DM patients enrolled in the Edinburgh Type 2 Diabetes Study. Turbidimetric assays of individual plasma samples analysed fibrin clot characteristics with additional experiments conducted on clots made from purified fibrinogen, further examined by confocal and electron microscopy. Plasma clot lysis time in Bβ448Lys was longer than Bβ448Arg variant (mean ± SD; 763 ± 322 and 719 ± 351 seconds [s], respectively; pmanagement strategies.

  4. Prothrombin and fibrinogen carbonylation: How that can affect the blood clotting.

    Science.gov (United States)

    Harutyunyan, Hayk A

    2017-07-01

    The aim of the work was the development of a simple method for measuring the plasma prothrombin carbonylation and the study the impact of prothrombin and fibrinogen oxidation on the rate of plasma clotting. A new method was based on the ability of prothrombin to be adsorbed by the barium sulfate. It consists of four steps: prothrombin mixing with the water suspension of BaSO4; reaction of 2,4-dinitrophenylhydrazine with the BaSO4-bound prothrombin; desorption of prothrombin-2,4-dinitrophenylhydrazone complex from BaSO4 in an alkaline medium; neutralization and reading of the optical absorbance of the complex (λ = 370 nm). The prothrombin/fibrinogen carbonylation and plasma clotting rate in vitro in the presence of reactive oxygen species (ROS)-generating agents (0.05-0.8 mM Fe2+/H2O2) were monitored. The plasma volume required for measurement of carbonylated prothrombin was 0.4 ml. High level of linearity and reproducibility was observed (r = 0.9995, P = 0.0005 - for the protein; r = 0.9971, P = 0.0029 - for carbonyls). In the intact rats, the concentration of blood plasma prothrombin was 0.355 ± 0.009 mg/ml, and that of carbonyls was 4.94 ± 0.09 nmol/mg. Prothrombin and plasma clotting rate was not affected by low concentrations of ROS (0.05-0.2 mM Fe2+/H2O2). The fibrinogen was susceptible to ROS-related effect over all the used range of concentration (0.05-0.8 mM Fe2+/H2O2). Carbonylation of fibrinogen did not affect the plasma clotting activity at low ROS concentration (0.05-0.2 mM Fe2+/H2O2), however it retarded the clotting at higher ROS (0.2-0.8 mM Fe2+/H2O2).

  5. Exothermic reaction in zeolite hemostatic dressings: QuikClot ACS and ACS+.

    Science.gov (United States)

    Arnaud, Françoise; Tomori, Toshiki; Carr, Walter; McKeague, Anne; Teranishi, Kohsuke; Prusaczyk, Keith; McCarron, Richard

    2008-10-01

    Zeolites have hemostatic properties used to stop bleeding in severe hemorrhage. Manufactured QuikClot is an approved zeolite-based hemostatic agent for battlefield use. The exothermic reaction associated with QuikClot as loose granules or as granules packaged in a mesh bag has potential burn effects; this led to the development of a formulation of "cooler" non-exothermic QuikClot. The goal of this study was to compare the elevation of temperature of these formulations upon contact with blood. Following full transection of the femoral vasculature, anesthetized Yorkshire pigs (n = 15) (28.8 +/- 1.5 kg) were hemorrhaged for 2 min and treated with 100 g of bagged QuikClot (Advanced Clotting Sponge (ACS) (n = 4)) or a modified non-exothermic formulation (ACS+ (n = 11)). Vital signs and temperature at the dressing/tissue interface were continuously recorded for 3 h. Additional procedures were used to examine effects of different ratios of blood to zeolite on temperature elevation. Total post-treatment blood loss was comparable for ACS+_E and ACS_E groups (overall average: 18.6 +/- 10.5% EBV). Temperature recorded at the dressing/tissue interface was significantly lower with ACS+ vs. ACS (40.3 +/- 1.8 vs. 61.4 +/- 10.7 degrees C, respectively, p < 0.01) and was 3.2 +/- 2.6 degrees C higher than rectal temperature (38.0 +/- 0.7 degrees C, p < 0.01). Survival at endpoint (7/11 vs. 4/4) and average survival time (134 +/- 64 vs. 180 min) were greater for both ACS+ and ACS in comparison to Standard Dressing. The wound temperature with ACS was reduced with greater blood to product ratios and this pattern was paralleled with in vitro measurements. The lower heat release with ACS+ compared to ACS was confirmed in an animal model and ACS+ had similar efficacy in arresting bleeding when compared to Standard Dressing.

  6. Response of a New Low-Coherence Fabry-Perot Sensor to Hematocrit Levels in Human Blood

    Directory of Open Access Journals (Sweden)

    Małgorzata Jędrzejewska-Szczerska

    2014-04-01

    Full Text Available In this paper, a low-coherence Fabry-Perot sensor with a spectrally measured signal processing response to the refractive index of liquids is presented. Optical fiber sensors are potentially capable of continuous measuring hematocrit levels in blood. Low-coherence Fabry-Perot interferometric sensors offer a robust solution, where information about the measurand is encoded in the full spectrum of light reflected from the sensing interferometer. The first step in the research on such sensor is the assessment of its performance under favorable conditions, i.e., using blood samples from healthy volunteers tested in vitro. Such an experiment was conducted using a sensor comprising a superluminescent diode source, an optical spectrum analyzer working as the detection setup and a sensing Fabry-Perot interferometer providing high interference contrast. The response of this sensor was recorded for several samples and compared with the reference laboratory method. The coefficient of determination (R2 for a linear relationship between the results given by both methods was 0.978 and the difference between these results was less than 1%. The presented results suggest that further research into the performance of the sensor is merited.

  7. Acute regulation of hematocrit and acid-base balance in chicken embryos in response to severe intrinsic hypercapnic hypoxia.

    Science.gov (United States)

    Andrewartha, Sarah J; Tazawa, Hiroshi; Burggren, Warren W

    2014-05-01

    The regulation of blood acid-base balance and hematology in day 15 chicken embryos in response to partial water submersion (with egg's air cell in air) and complete submersion producing severe intrinsic hypercapnic hypoxia and recovery in air was studied. The acid-base disturbance during submersion was characterized by initial rapid respiratory changes and then superseded by metabolic processes, resulting in a large progressive hysteresis. Throughout submersion and recovery, blood lactate concentration changed swiftly along with the changes in bicarbonate concentration ([HCO3(-)]), indicating that anaerobic glycolysis determined overall acid-base disturbances. Both partial and complete submersion produced large, rapid increases in hematocrit through proportional increases in mean corpuscular volume and red blood cell concentration. Death ensued once the internal pool of O2 was exhausted and/or the acid-base disturbance became too severe for survival (i.e., [HCO3(-)]a<∼10mmolL(-1)). However, embryos recovered from acid-base and hematological disturbances within 120min recovery in air after short bouts of complete (20min) or partial (60min) submersion, suggesting that shorter severe intrinsic hypercapnic hypoxia does not compromise viability of embryos. Copyright © 2014. Published by Elsevier B.V.

  8. Cellular-level near-wall unsteadiness of high-hematocrit erythrocyte flow using confocal μPIV

    Science.gov (United States)

    Patrick, Michael J.; Chen, Chia-Yuan; Frakes, David H.; Dur, Onur; Pekkan, Kerem

    2011-04-01

    In hemodynamics, the inherent intermittency of two-phase cellular-level flow has received little attention. Unsteadiness is reported and quantified for the first time in the literature using a combination of fluorescent dye labeling, time-resolved scanning confocal microscopy, and micro-particle image velocimetry (μPIV). The near-wall red blood cell (RBC) motion of physiologic high-hematocrit blood in a rectangular microchannel was investigated under pressure-driven flow. Intermittent flow was associated with (1) the stretching of RBCs as they passed through RBC clusters with twisting motions; (2) external flow through local obstacles; and (3) transitionary rouleaux formations. Velocity profiles are presented for these cases. Unsteady flow clustered in local regions. Extra-cellular fluid flow generated by individual RBCs was examined using submicron fluorescent microspheres. The capabilities of confocal μPIV post-processing were verified using synthetic raw PIV data for validation. Cellular interactions and oscillating velocity profiles are presented, and 3D data are made available for computational model validation.

  9. Relative permittivity measurement during the thrombus formation process using the dielectric relaxation method for various hematocrit values.

    Science.gov (United States)

    Asakura, Yuta; Sapkota, Achyut; Maruyama, Osamu; Kosaka, Ryo; Yamane, Takashi; Takei, Masahiro

    2015-12-01

    The relative permittivity ε' and the dielectric loss ε″ for various hematocrit values H for static bovine blood condition have been measured using the dielectric relaxation method to detect thrombosis in real time. The suitable measurement frequency f m ranged within 60 kHz to 1 MHz, and the relaxation frequency of red blood cells (RBCs) f rc was observed to be 2 MHz. In the f m, the temporal change of normalized ε' exhibited a minimum (called as bottom point). The bottom point was observed to be exponentially shortened as H increased. This characteristic of the ε'* minimum is discussed from three viewpoints: during fibrin formation, direct thrombus formation, and rouleaux formation processes. ε'* during the fibrin formation process decreased over time, irrespective of f. However, ε'* in f m during the direct thrombus formation process and during the aggregation formation process increased immediately and rapidly over time. Therefore, the ε'* bottom point in f m might be the indication of micrometer-scale thrombus formation by RBC aggregation due to fibrin formation.

  10. Cellular-level near-wall unsteadiness of high-hematocrit erythrocyte flow using confocal {mu}PIV

    Energy Technology Data Exchange (ETDEWEB)

    Patrick, Michael J. [Carnegie Mellon University, Molecular Biosensor and Imaging Center (MBIC), Pittsburgh, PA (United States); Chen, Chia-Yuan; Dur, Onur; Pekkan, Kerem [Carnegie Mellon University, Department of Biomedical and Mechanical Engineering, Pittsburgh, PA (United States); Frakes, David H. [Arizona State University, School of Biological and Health Systems Engineering and School of Electrical, Computer, and Energy Engineering, Tempe, AZ (United States)

    2011-04-15

    In hemodynamics, the inherent intermittency of two-phase cellular-level flow has received little attention. Unsteadiness is reported and quantified for the first time in the literature using a combination of fluorescent dye labeling, time-resolved scanning confocal microscopy, and micro-particle image velocimetry ({mu}PIV). The near-wall red blood cell (RBC) motion of physiologic high-hematocrit blood in a rectangular microchannel was investigated under pressure-driven flow. Intermittent flow was associated with (1) the stretching of RBCs as they passed through RBC clusters with twisting motions; (2) external flow through local obstacles; and (3) transitionary rouleaux formations. Velocity profiles are presented for these cases. Unsteady flow clustered in local regions. Extra-cellular fluid flow generated by individual RBCs was examined using submicron fluorescent microspheres. The capabilities of confocal {mu}PIV post-processing were verified using synthetic raw PIV data for validation. Cellular interactions and oscillating velocity profiles are presented, and 3D data are made available for computational model validation. (orig.)

  11. Clot formation in canine whole blood as measured by rotational thromboelastometry is influenced by sample handling and coagulation activator.

    Science.gov (United States)

    Smith, Stephanie A; McMichael, Maureen; Galligan, Alyssa; Gilor, Shir; Hoh, Crystal M

    2010-10-01

    The objective of the present study was to systematically evaluate the impact of methodology on thromboelastometry with canine whole blood. Thromboelastometry was performed on citrated blood using a variety of combinations of clotting activators [ex-tem (tissue factor or TF), in-tem (ellagic acid), diluted TF from Innovin, or Ca (recalcification only)] and storage times. Thromboelastometry was also performed using diluted TF from Innovin on blood collected into a contact inhibitor. Ex-vivo contact activation was compared between canine and human blood. Clotting activator had a marked impact on coagulation time, a minor impact on alpha angle, and no impact on clot formation time or maximum clot firmness. When ex-tem or in-tem was the clotting activator, sample storage up to 30 min did not affect results. With diluted TF from Innovin or Ca, sample storage was associated with the development of increased coagulability (as indicated by shorter coagulation time and clot formation time and higher alpha angle) due to ex-vivo contact activation. Canine blood underwent markedly more ex-vivo contact activation than did human blood. Canine blood undergoes significant ex-vivo contact activation during and after collection, which influences thromboelastometry results when a weak clotting activator (such as low TF or recalcification) is used. Thromboelastometry with a strong activator (such as ex-tem or in-tem) is less influenced by ex-vivo changes, and, therefore, likely to be more reflective of in-vivo hemostatic capabilities and to provide consistently interpretable and comparable results.

  12. Thrombin generation and fibrin clot formation under hypothermic conditions: an in vitro evaluation of tissue factor initiated whole blood coagulation.

    Science.gov (United States)

    Whelihan, Matthew F; Kiankhooy, Armin; Brummel-Ziedins, Kathleen E

    2014-02-01

    Despite trauma-induced hypothermic coagulopathy being familiar in the clinical setting, empirical experimentation concerning this phenomenon is lacking. In this study, we investigated the effects of hypothermia on thrombin generation, clot formation, and global hemostatic functions in an in vitro environment using a whole blood model and thromboelastography, which can recapitulate hypothermia. Blood was collected from healthy individuals through venipuncture and treated with corn trypsin inhibitor, to block the contact pathway. Coagulation was initiated with 5pM tissue factor at temperatures 37°C, 32°C, and 27°C. Reactions were quenched over time, with soluble and insoluble components analyzed for thrombin generation, fibrinogen consumption, factor (f)XIII activation, and fibrin deposition. Global coagulation potential was evaluated through thromboelastography. Data showed that thrombin generation in samples at 37°C and 32°C had comparable rates, whereas 27°C had a much lower rate (39.2 ± 1.1 and 43 ± 2.4 nM/min vs 28.6 ± 4.4 nM/min, respectively). Fibrinogen consumption and fXIII activation were highest at 37°C, followed by 32°C and 27°C. Fibrin formation as seen through clot weights also followed this trend. Thromboelastography data showed that clot formation was fastest in samples at 37°C and lowest at 27°C. Maximum clot strength was similar for each temperature. Also, percent lysis of clots was highest at 37°C followed by 32°C and then 27°C. Induced hypothermic conditions directly affect the rate of thrombin generation and clot formation, whereas global clot stability remains intact. © 2013.

  13. Comparative in vitro study of five mechanical embolectomy systems: effectiveness of clot removal and risk of distal embolization

    Energy Technology Data Exchange (ETDEWEB)

    Liebig, Thomas [Technische Universitaet Muenchen, Abteilung fuer Neuroradiologie, Klinikum rechts der Isar, Munich (Germany); Reinartz, Joerg; Miloslavski, Elina [Robert Janker Klinik, Abteilung Radiologie und Neuroradiologie, Bonn (Germany); Hannes, Ralf [Phenox GmbH, Bochum (Germany); Henkes, Hans [Katharinenhospital Stuttgart, Institut fuer diagnostische und interventionelle Neuroradiologie, Stuttgart (Germany)

    2008-01-15

    We report an in vitro study comparing the effectiveness of clot removal and clot fragmentation of five embolectomy systems. A flow model was embolized with fresh and old thrombi, occluding an inner diameter of 2-5 mm simulating internal carotid artery (ICA), basilar artery (BA) and middle cerebral artery (MCA) branch occlusion. Embolectomy was performed using five retrieval systems: CATCH (Balt), Merci retriever (Concentric), InTime and Attracter (Boston Scientific), and the Phenox Clot Retriever (Phenox). Clot removal and evidence and type of thrombus fragmentation and distal embolization were recorded. There were no observable differences attributable to thrombus age. The Merci, CATCH and Phenox Clot Retriever were equally able to mobilize and remove thrombi with the exception of one particularly firm clot. There were marked differences in terms of thrombus fragmentation and distal embolization. All devices produced micro- and macrofragments during penetration and retrieval. The Phenox Clot Retriever was able to filter fragments. The InTime and Attracter devices failed to retrieve thrombi in this model and achieved partial removal at best with a tendency towards thrombus displacement and fragmentation. Within limits, the experimental setup was appropriate for generating occlusions of diameter 2-5 mm of various lengths, simulating ICA, BA and MCA thromboembolism. In this model, thrombus mobilization appeared to be less dependent upon the individual design of the retrieval system than on thrombus fragmentation. The ability to prevent distal embolization is, however, strongly dependent on the ability of a thrombectomy device to capture fragments that are generated during removal of the device. (orig.)

  14. Blood Clots

    Science.gov (United States)

    ... a vein may detach from its point of origin and travel through the heart to the lungs ... Image Bank Advocacy Action Alerts Policy News Advocacy Leadership Institute Policy Statements Testimony & Correspondence Meetings ASH Annual ...

  15. Expression, activation and processing of a novel plant milk-clotting aspartic protease in Pichia pastoris.

    Science.gov (United States)

    Feijoo-Siota, Lucía; Rama, José Luis R; Sánchez-Pérez, Angeles; Villa, Tomás G

    2018-02-20

    Galium verum, also known as Lady's Bedstraw or Cheese Rennet, is an herbaceous perennial plant traditionally used in cheese-making. We used RACE PCR to isolate novel enzymes from Galium verum with the ability to clot milk. This approach generated two cDNA sequences (named preprogaline A and B) encoding proteins displaying the typical plant aspartic protease primary structure. Preprogaline B was expressed in the yeast Pichia pastoris, after deleting and replacing its original signal peptide with the yeast α-factor signal peptide from Saccharomyces cerevisiae. The secreted recombinant protein was obtained by growing P. pastoris in YPD medium and had the ability to clot milk. The mature form of progaline B is a heterodimeric glycosylated enzyme, with a molecular weight of approximately 48 kDa, that contains a heavy (30.7 kDa) and a light (13.5 kDa) polypeptide chains linked by disulfide bonds. Western blot analysis revealed that progaline B is activated by the acidification of the yeast culture medium and that enzymatic activation requires two steps. First the precursor protein is cleaved into two polypeptide chains by partial removal of the plant-specific insert (PSI) present in plant aspartic proteases; this is later followed by propeptide removal. By altering the pH of the P. pastoris culture medium, we were able to obtain either active or inactive forms of the enzyme. Recombinant progaline B displayed a κ-casein hydrolysis pattern analogous to those produced by the animal and microbial coagulants currently used in the dairy industry, but it exhibited a different digestion profile on α- and β-caseins. The plant protease progaline B displays milk-clotting activities suitable for the production of novel dairy products. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Computational Study of Thrombus Formation and Clotting Factor Effects under Venous Flow Conditions

    Science.gov (United States)

    Govindarajan, Vijay; Rakesh, Vineet; Reifman, Jaques; Mitrophanov, Alexander Y.

    2016-01-01

    A comprehensive understanding of thrombus formation as a physicochemical process that has evolved to protect the integrity of the human vasculature is critical to our ability to predict and control pathological states caused by a malfunctioning blood coagulation system. Despite numerous investigations, the spatial and temporal details of thrombus growth as a multicomponent process are not fully understood. Here, we used computational modeling to investigate the temporal changes in the spatial distributions of the key enzymatic (i.e., thrombin) and structural (i.e., platelets and fibrin) components within a growing thrombus. Moreover, we investigated the interplay between clot structure and its mechanical properties, such as hydraulic resistance to flow. Our model relied on the coupling of computational fluid dynamics and biochemical kinetics, and was validated using flow-chamber data from a previous experimental study. The model allowed us to identify the distinct patterns characterizing the spatial distributions of thrombin, platelets, and fibrin accumulating within a thrombus. Our modeling results suggested that under the simulated conditions, thrombin kinetics was determined predominantly by prothrombinase. Furthermore, our simulations showed that thrombus resistance imparted by fibrin was ∼30-fold higher than that imparted by platelets. Yet, thrombus-mediated bloodflow occlusion was driven primarily by the platelet deposition process, because the height of the platelet accumulation domain was approximately twice that of the fibrin accumulation domain. Fibrinogen supplementation in normal blood resulted in a nonlinear increase in thrombus resistance, and for a supplemented fibrinogen level of 48%, the thrombus resistance increased by ∼2.7-fold. Finally, our model predicted that restoring the normal levels of clotting factors II, IX, and X while simultaneously restoring fibrinogen (to 88% of its normal level) in diluted blood can restore fibrin generation to

  17. Interactions of acid-base balance and hematocrit regulation during environmental respiratory gas challenges in developing chicken embryos (Gallus gallus).

    Science.gov (United States)

    Burggren, Warren W; Andrewartha, Sarah J; Tazawa, Hiroshi

    2012-08-15

    How the determinants of hematocrit (Hct) - alterations in mean corpuscular volume (MCV) and/or red blood cell concentration ([RBC]) - are influenced by acid-base balance adjustments across development in the chicken embryo is poorly understood. We hypothesized, based on oxygen transport needs of the embryos, that Hct will increase during 1 day of hypercapnic hypoxia (5%CO(2), 15%O(2)) or hypoxia alone (0%CO(2), 15%O(2)), but decrease in response to hyperoxia (0%CO(2), 40%O(2)). Further, age-related differences in acid-base disturbances and Hct regulation may arise, because the O(2) transport and hematological regulatory systems are still developing in embryonic chickens. Our studies showed that during 1 day of hypoxia (with or without hypercapnia) Hct increased through both increased MCV and [RBC] in day 15 (d15) embryo, but only through increased MCV in d17 embryo and therefore enhancement of O(2) transport was age-dependent. Hypercapnia alone caused a ≈ 14% decrease in Hct through decreased [RBC] and therefore did not compensate for decreased blood oxygen affinity resulting from the Bohr shift. The 11% (d15) and 14% (d17) decrease in Hct during hyperoxia in advanced embryos was because of an 8% and 9% decrease, respectively, in [RBC], coupled with an associated 3% and 5% decrease in MCV. Younger, d13 embryos were able to metabolically compensate for respiratory acidosis induced by hypercapnic hypoxia, and so were more tolerant of disturbances in acid-base status induced via alterations in environmental respiratory gas composition than their more advanced counterparts. This counter-intuitive increased tolerance likely results from the relatively low [Formula: see text] and immature physiological functions of younger embryos. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Evaluation of point-of-care analyzers' ability to reduce bias in conductivity-based hematocrit measurement during cardiopulmonary bypass.

    Science.gov (United States)

    Teerenstra, Steven; Steinfelder-Visscher, Jacoline; Gunnewiek, Jacqueline Klein; Weerwind, Patrick W

    2014-04-01

    Most point-of-care testing analyzers use the conductivity method to measure hematocrit (hct). During open-heart surgery, blood-conductivity is influenced by shifts in electrolyte and colloid concentrations caused by infusion media used, and this may lead to considerable bias in the hct measurement. We evaluated to what extent different analyzers correcting for 0, 1, 2, or 3 factors, respectively, compensated for this electrolyte/colloid interference: (1) the conductivity method with no correction (IRMA), (2) with a [Na(+)]-correction (GEM Premier 3000), (3) with a [Na(+)]/[K(+)]-correction (i-STAT), and (4) with a [Na(+)]/[K(+)]-correction in combination with an algorithm that estimates the protein dilution [i-STAT in cardiopulmonary bypass (CPB)-mode]. Bias in hct was measured during three consecutive stages of a CPB procedure: (I) before CPB, (II) start of CPB and (III) after cardioplegia. In order of high to low electrolyte/colloid interference: the analyzer with no correction, [Na(+)]-correction, [Na(+)/]/[K(+)]-correction, and [Na(+)/]/[K(+)]/estimated protein-correction showed a change of bias from stage I to stage III of -3.9 ± 0.5, -3.4 ± 0.4, -2.1 ± 0.5, -0.3 ± 0.5%. We conclude that correcting for more parameters (Na(+), K(+), estimated protein) gives less bias, but residual bias remains even after [Na(+)/]/[K(+)]/estimated protein-correction. This suggests that a satisfactory algorithm should also correct for other colloidal factors than protein.

  19. Anesthesia with Isoflurane and Sevoflurane in the Crested Serpent Eagle (Spilornis cheela hoya): Minimum Anesthetic Concentration, Physiological Effects, Hematocrit, Plasma Chemistry and Behavioral Effects

    Science.gov (United States)

    CHAN, Fang-Tse; CHANG, Geng-Ruei; WANG, Hsien-Chi; HSU, Tien-Huan

    2013-01-01

    ABSTRACT The initial goal of this study was to determine the minimum anesthetic concentration (MAC) for isoflurane (ISO) and sevoflurane (SEVO) for the crested serpent eagle. Next, we compared the anesthetic effects of each on the physiological effects, hematocrit, plasma chemistry values and behavior in spontaneously breathing captive adult crested serpent eagles. Sixteen eagles were randomly allocated to two groups for anesthesia with ISO (n=8) or SEVO (n=8). First, we measured the MAC values of ISO and SEVO, and four weeks later, we investigated the effect of each on the physiological effects, hematocrit (HCT) and plasma chemistry values. The MAC values of ISO and SEVO for crested serpent eagles were 1.46 ± 0.30 and 2.03 ± 0.32%, respectively. The results revealed no significant differences between the two anesthetics in induction time, while time of extubation to recovery was significantly shorter with SEVO. A time-related increase in end-tidal CO2 and decreases in body temperature and respiratory rates were observed during anesthesia with each anesthetic. There were no significant differences between the effect of the two anesthetics on heart rate, hematocrit, plasma chemistry values or respiration, although each caused minor respiration depression. We concluded that SEVO is a more effective inhalant agent than ISO for use in eagles, showing the most rapidest induction and recovery from anesthesia. PMID:23955396

  20. Zakharov equations for viscous flow and their use in the blood clot formation

    Science.gov (United States)

    Zhou, Ai-Ping; Li, Xiao-Qing

    2017-12-01

    For theoretical study, blood can be regarded as a viscous electrically conducting fluid of negative ions and protons. Zakharov equations including viscosity are relevant for describing the behaviour of blood plasma. The dispersion formula is derived from the perturbation method and is solved numerically. It turns out that the imaginary part of one root of the perturbation frequency is greater than zero, and modulation instability occurs. This would lead to the formation of blood clot. The viscous force can suppress the occurrence of instability and prevent thrombosis. One can find that the chaotic state of blood signals human health.

  1. Platelet-related fibrinolysis resistance in patients suffering from PV. Impact of clot retraction and isovolemic erythrocytapheresis.

    Science.gov (United States)

    Rusak, Tomasz; Piszcz, Jarosław; Misztal, Tomasz; Brańska-Januszewska, Justyna; Tomasiak, Marian

    2014-07-01

    Using patients with polycythemia vera (PV) as an experimental model, we evaluated the impact of clot retraction (CR) and architecture of the clot on fibrinolysis. We studied the kinetics of clot retraction and the fibrinolysis rate in whole blood from 48 PV patients and 48 healthy controls. Measurements were performed before and after isovolemic eryhrocytapheresis (ECP). CR was measured by optical method. Clot lysis time (CLT) and maximum clot firmness (MCF) were measured by thromboelastometry in recalcified blood supplemented with t-PA and tissue factor. Compared with healthy controls, CR rate in PV patients was higher (0.0219 vs. 0.0138; p0.3). Compared with healthy controls, CLT in PV patients was significantly prolonged (158 min vs. 71 min). Fibrinolysis rate inversely correlated with CR rate (r=-0.566; pfibrinolysis speeds were not normalized following the ECP procedure. Tirofiban (a blocker of platelet GPIIb/IIIa receptors), unlike aspirin, normalized abnormal CR and fibrinolysis in blood from PV patients. Collectively, our data indicate that in PV patients, abnormal CR may result in formation of thrombi that are more resistant to fibrinolysis. ECP and aspirin failed to normalize platelet-related fibrinolysis resistance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Prothrombotic Fibrin Clot Phenotype in Patients with Deep Vein Thrombosis and Pulmonary Embolism: A New Risk Factor for Recurrence

    Directory of Open Access Journals (Sweden)

    Anetta Undas

    2017-01-01

    Full Text Available Prothrombotic fibrin clot phenotype, involving faster formation of dense meshwork composed of thinner and highly branched fibers that are relatively resistant to plasmin-induced lysis, has been reported in patients with not only myocardial infarction or stroke, but also venous thromboembolism (VTE, encompassing deep vein thrombosis (DVT, and/or pulmonary embolism (PE. Prothrombotic fibrin clot phenotype, in particular prolonged clot lysis time, is considered a novel risk factor for VTE as well as venous thrombosis at unusual location, for example, cerebral sinus venous thrombosis, retinal vein obstruction, and Budd-Chiari syndrome. Growing evidence from observational studies indicates that abnormal fibrin clot properties can predict recurrent DVT and PE and they are involved in serious complications of VTE, for example, thromboembolic pulmonary hypertension and postthrombotic syndrome. The purpose of this article is to review our current understanding of the role of fibrin clot structure and function in venous thrombosis with emphasis on clinical issues ranging from prognosis to therapy.

  3. Multidisciplinary approach to the Clot Brun large slope instability (Susa Valley, Italian NW-Alps)

    Science.gov (United States)

    Giardino, M.; Fontan, D.; Ambrogio, S.; Dematteis, A.; Nervo, B.; Walkate, J.; Fratianni, S.

    2003-04-01

    The Clot Brun slope is affected by a large deep-seated gravitational deformation and by other correlated and non-correlated minor gravitational instabilities (rock falls and debris flows). The activation of the slope instabilities may involve several lifelines along the Susa Valley (motorway, railway, hydro-electrical tunnel, ...) as well as some small villages with sites of historical and architectural interest. In order to develope effective protection measures of the affected structures, a multidisciplinary study of the Clot Brun large slope has been carried out including geomorphology, structural geology, hydrogeology and pedology through the application of up-to-date scientific methodologies (geomorphological mapping of the surface deformation markers, structural geology analisys carried out with climbing technics, pedological profile studies along the main active sectors of the slope, 3D computer modelling of the deformed rock masses and general slope characteristics). The data have been collected in modular form and organized in a geo-database. Output geothematic maps have been produced both at 1:10000 and 1:5000 scales. GIS methodologies have been applied for the analisys and interpretation of long-term slope dynamics and to evaluate possible impulsive instability, failure and related hazards.

  4. Global clotting assays - monitoring the effect of by-passing agents in haemophilia patients with inhibitors

    Directory of Open Access Journals (Sweden)

    Șerban Margit

    2017-04-01

    Full Text Available The development of FVIII/FIX inhibitor alloantibodies represents a severe complication requiring specific laboratory evaluation for establishing a life-saving therapy regimen. Our preliminary study aimed at elaborating a laboratory strategy for monitoring the effectiveness of Activated Prothrombin Complex Concentrate (APCC and recombinant activated factor VII (rFVIIa in haemophiliacs with inhibitors, by checking the reliability and clinical value of three complementary assays: clotting-time based coagulometry, thrombelastography (TEG and thrombin generation assay (TGA. The investigations were performed on 7 patients with severe haemophilia A with high titer inhibitors treated for 12 episodes of severe bleedings, 5 of them for surgical interventions. After the administration of bypassing agents (BPAs the clotting-time based assay brought changes only on prothrombin (p<0.01, potentially signaling a thrombotic risk, without any impact on the global hemostasis. TEG displayed prompt significant improvement only after rFVIIa (90μg/kg. TGA revealed significantly improved values for peak and velocity index, time to peak and start tail after both BPAs. Despite some disparities between biological hemostatic phenotype and clinical response to therapy, we concluded that TEG and TGA are the only current exploratory assays, expressing the quality of haemostatic control, representing a real support for a personalized, adapted therapy in hemophilia with inhibitors.

  5. Efficacy and survival associated with cystoscopy and clot evacuation for radiation or cyclophosphamide induced hemorrhagic cystitis.

    Science.gov (United States)

    Kaplan, Joshua R; Wolf, J Stuart

    2009-02-01

    We assessed the outcome of patients with hemorrhagic cystitis severe enough to require cystoscopy and clot evacuation. We retrospectively evaluated the records of 33 patients with cyclophosphamide or radiation induced hemorrhagic cystitis treated with cystoscopy. Mean followup of living patients was 76 months. Of 33 patients 20 (61%) had resolution of hematuria after single cystoscopy unrelated to hemorrhagic cystitis etiology. Only 4 of 11 patients (36%) had resolution after 2 or more cystoscopies, and all were in the radiation induced hemorrhagic cystitis group (4 of 6, 67%) with none in the cyclophosphamide induced hemorrhagic cystitis group (0 of 5, p = 0.02). Hematuria was refractory to cystoscopy in 9 patients and ileal conduits were created in 4. Kaplan-Meier overall survival at 1, 2 and 5 years was 58%, 51% and 43%, respectively, with survival tending to be worse in patients who received cyclophosphamide for bone marrow transplantation induction. Of the 18 deaths 3 were due to complications of hemorrhagic cystitis, 13 were due to the disease underlying the hemorrhagic cystitis and 2 were unrelated. The response of hemorrhagic cystitis to single cystoscopy and clot evacuation is reasonable but response to subsequent cystoscopy (unless the hemorrhagic cystitis is radiation induced) is less likely, so alternate interventions should be considered if hematuria does not resolve after initial cystoscopy. Patients with hemorrhagic cystitis requiring cystoscopy have a poor prognosis even if hematuria resolves, although most deaths are related to the disease underlying the hemorrhagic cystitis rather than its direct result.

  6. Characterisation of general proteolytic, milk clotting and antifungal activity of Ficus carica latex during fruit ripening.

    Science.gov (United States)

    Raskovic, Brankica; Lazic, Jelena; Polovic, Natalija

    2016-01-30

    The physiological role of fig latex is to protect the plant from pathogens. Latex is a rich source of proteases, predominantly ficin. Fig latex also contains collagenolytic protease and chitinolytic enzymes. Our aim was to investigate changes in protein composition, enzyme and antifungal activities of fig latex during fruit ripening. Comparison of latex samples in different time periods showed a uniform increase of protein concentration in chronological order. The content of collagenolytic protease did not differ significantly in the latex samples, while the content of ficin decreased. Ficin-specific activity towards casein was the highest at the beginning of fruit development (about 80 U mg(-1)). Specific milk clotting activity increased as well as the abundance of casein band in the clots. Specific chitinolytic activity at the beginning of flowering was 6.5 times higher than the activity in the period when fruits are ripe. Antifungal activity is the most extensive in spring. Ficin forms with different casein specificities are present in different proportions during fruit ripening, which is of importance for applications in the dairy industry. The protection mechanism against insects and fungi, which relies on chitinolytic activity, is the most important in the early phases of flowering and is replaced with other strategies over time. © 2015 Society of Chemical Industry.

  7. The Influence of a Micropolar Fluid on Peristaltic Transport in an Annulus: Application of the Clot Model

    Directory of Open Access Journals (Sweden)

    Kh. S. Mekheimer

    2008-01-01

    Full Text Available A serious pathological condition is encountered when some blood constituents deposited on the blood vessels get detached from the wall, join the blood stream again and form a clot. Study of the peristaltic transport of a micropolar fluid in an annular region is investigated under low Reynolds number and long wavelength approximations. We model a small artery as a tube having a sinusoidal wave travelling down its wall and a clot model inside it. Closed form solutions are obtained for the velocity and the microrotation components, as well as the stream function, and they contain new additional parameters, namely, δ, the height of the clot, N, the coupling number and m, the micropolar parameter. The pressure rise and friction force on the inner and the outer tubes have been discussed for various values of the physical parameters of interest.

  8. Prothrombin time sensitivity and specificity to mild clotting factor deficiencies of the extrinsic pathway: evaluation of eight commercial thromboplastins.

    Science.gov (United States)

    Massignon, D; Moulsma, M; Bondon, P; Debize, G; Abidi, H; Buttin, T; Bon, C; Pillonchery, G; Coeur, P

    1996-04-01

    Prothrombin-time (PT) sensitivity and specificity to mild clotting factor II, V, VII and X deficiencies have rarely been studied. We therefore carried out a prospective study, in 350 patients, of eight commercial thromboplastins (CTs) in their ability to detect mild clotting factor deficiencies, notably in factor VII. In each patient the factor II, V, VII and X clotting activities and PT performed with each CT were determined. For each CT, PT sensitivity and specificity in detecting factor deficiencies below 0.5 U/ml or below 0.4 U/ml were determined at various PTs, and then Receiver Operator Characteristic curves constructed. At optimum PT threshold level (sensitivity = specificity), exactitude varied from 0.64 to 0.74 (p sensitivity and specificity on monitoring certain patients subjects to decrease in coagulation factor, and, in particular, of those under low dose oral anticoagulant, remains to be determined.

  9. High-density cholesterol and apolipoprotein AI as modifiers of plasma fibrin clot properties in apparently healthy individuals.

    Science.gov (United States)

    Ząbczyk, Michał; Hońdo, Łukasz; Krzek, Marzena; Undas, Anetta

    2013-01-01

    Low high-density lipoprotein cholesterol (HDL-C) increases cardiovascular risk, whereas its high levels protect against atherosclerosis via multiple beneficial effects. Dense and poorly lysable fibrin clot formation is observed in cardiovascular disease. We sought to investigate whether HDL-C and its major component apolipoprotein A (Apo A)-I affect fibrin clot properties. In 136 apparently healthy individuals (99 men, 37 women, aged 49-69 years) we determined plasma fibrin clot permeability (Ks coefficient) and lysis time (t50%) together with Apo A-I and lipoprotein (a) [Lp(a)] levels. The median HDL-C level was 1.33  mmol/l (range from 0.77 to 2.19  mmol/l). HDL-C was positively associated with Apo A-I (r = 0.62, P effects of therapy targeted at HDL-C.

  10. Do some of physiotherapy and rehabilitation programs improve the health state of patients suffering from cerebral clot?

    Directory of Open Access Journals (Sweden)

    Ayad OMAR

    2014-09-01

    Full Text Available Cerebral stroke represents one of the most important diseases resulting from blood clot in the middle cerebral artery, this is due to atherosclerotic clot and the brain has area of deprived blood , therefore blood becomes unable to pass the clot, in this case leads to total or partial paralysis. Rehabilitation programs are one of the most effective therapies for cerebral stroke. These pr ograms include rehabilitation exercises, therapeutic massage and kinet otherapy. The present study deals with the application of organized rehabilitation program and identify it's effect on the movement system and joints. This study examined the effect of rehabilitation program to improve the efficiency of the Locomotor system of patient who complain of cerebral stroke.

  11. Influence of Interleukin-1 Beta on Platelet-Poor Plasma Clot Formation: A Potential Impact on Early Bone Healing.

    Directory of Open Access Journals (Sweden)

    Xin Wang

    Full Text Available Hematoma quality (especially the fibrin matrix plays an important role in the bone healing process. Here, we investigated the effect of interleukin-1 beta (IL-1β on fibrin clot formation from platelet-poor plasma (PPP.Five-milliliter of rat whole-blood samples were collected from the hepatic portal vein. All blood samples were firstly standardized via a thrombelastograph (TEG, blood cell count, and the measurement of fibrinogen concentration. PPP was prepared by collecting the top two-fifths of the plasma after centrifugation under 400 × g for 10 min at 20°C. The effects of IL-1β cytokines on artificial fibrin clot formation from PPP solutions were determined by scanning electronic microscopy (SEM, confocal microscopy (CM, turbidity, and clot lysis assays.The lag time for protofibril formation was markedly shortened in the IL-1β treatment groups (243.8 ± 76.85 in the 50 pg/mL of IL-1β and 97.5 ± 19.36 in the 500 pg/mL of IL-1β compared to the control group without IL-1β (543.8 ± 205.8. Maximal turbidity was observed in the control group. IL-1β (500 pg/mL treatment significantly decreased fiber diameters resulting in smaller pore sizes and increased density of the fibrin clot structure formed from PPP (P < 0.05. The clot lysis assay revealed that 500 pg/mL IL-1β induced a lower susceptibility to dissolution due to the formation of thinner and denser fibers.IL-1β can significantly influence PPP fibrin clot structure, which may affect the early bone healing process.

  12. Acute regulation of hematocrit and blood acid-base balance during severe hypoxic challenges in late chicken embryos (Gallus gallus).

    Science.gov (United States)

    Tazawa, Hiroshi; Andrewartha, Sarah J; Burggren, Warren W

    2012-10-15

    Acid-base and hematocrit (Hct) responses of vertebrate embryos to severe hypoxia are as yet unknown, but may reveal the maturation process of physiological regulatory mechanisms. The present study elucidated how acute, severe hypoxia (10% O2, with and without 5% CO2) affects Hct and blood acid-base balance in late prenatal (days 11-19) chicken embryos. The time-course of the resulting Hct changes and blood acid-base disturbances was examined in detail in day 15 (d15) embryos to further understand the magnitude and time-components of these physiological changes. We hypothesized that Hct of developing embryos increases during severe hypoxia (10% O2) and hypercapnic hypoxia (5% CO2, 10% O2), due to increased mean corpuscular volume (MCV) and red blood cell concentration ([RBC]). We additionally hypothesized that 10% O2 would induce anaerobic glycolysis and the attendant increase in lactate concentration ([La-]) would create a severe metabolic acidosis. Hct increased in all embryos (d11-d19) during severe hypoxia (2h) but, with the exception of d19 embryos, the increase was due to increased MCV and was therefore unlikely related to O2 transport. The time-course of the d15 embryonic Hct response to hypoxic or hypercapnic hypoxic exposure was very rapid with MCV increasing within 30min. Severe metabolic acidosis occurred in all developing embryos (d11-d19) during 2h hypoxic exposure. Additionally, respiratory acidosis was induced in d15 embryos during hypercapnic hypoxia, with acid-base status recovering within 120 min in air. Throughout hypoxic exposure and recovery, changes in [HCO3-] were matched by those in [La-], indicating that anaerobic glycolysis is a key factor determining the metabolic alterations and overall acid-base status. Further, the blood gas and Hct values recovered in air and unchanged embryo mass suggest that the hypoxia-induced disturbances were only transient and may not affect long-term survival. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Differential clot stabilising effects of rFVIIa and rFXIII-A2 in whole blood from thrombocytopenic patients and healthy volunteers

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Jacobsen, Niels; Viuff, D.

    2008-01-01

    in platelets. The combined effects of rFVIIa andrFXIII-A2 were evaluated in clot lysis assays using factor XIII-deficient plasma and by whole blood thrombelastography (TEG) analysis from normal donors and thrombocytopenic stem cell transplantation patients. Clotting time was shortened by rFVIIa (0.6-10 microg...

  14. Protraction of whole blood and plasma clot lysis in patients with high levels of an inhibitor of tissue-type plasminogen activator.

    Science.gov (United States)

    Brommer, E J; Boks, A L; Koopman, J; Haverkate, F

    1985-08-01

    The influence of the newly discovered, fast-acting inhibitor of tissue-type plasminogen activator (t-PA) on the lysis time of plasma clots was studied by visual observation of lysis of clotted citrated plasma after addition of purified t-PA. To a series of plasma samples with various concentrations of naturally occurring PA-inhibitor purified t-PA was added to a final concentration, which in pooled normal plasma is sufficient to induce clot lysis within a few hours. In those plasma samples with a high free inhibitor level, determined by measuring the recovery of the activity of added purified t-PA, clot lysis was retarded. Whole blood clots were made by clotting freshly collected non-anticoagulated blood with thrombin after admixture of a trace amount of radiolabeled fibrinogen and a fixed amount of t-PA. Lysis rate, read from the appearance of radioactivity in the serum after centrifugation, was significantly lower in clots obtained from subjects with a high free inhibitor level than in those with a low inhibitor level. It is concluded that the PA-inhibitor protracts clot lysis and may be relevant for physiological fibrinolysis.

  15. Leakage of protein into lungs of preterm ventilated rabbits is correlated with activation of clotting, complement, and polymorphonuclear leukocytes in plasma

    NARCIS (Netherlands)

    Brus, F; vanOeveren, W; Heikamp, A; Okken, A; Oetomo, SB

    We investigated whether leakage of protein in lungs of pre term ventilated rabbits of 28- and 29-d gestational age is correlated with activation of clotting, complement, and polymorphonuclear leukocytes (PMN) in plasma. We found signs of systemic activation of clotting, complement, and PMN in

  16. Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces

    Science.gov (United States)

    Wheatley Myerson, Jacob; He, Li; Allen, John Stacy; Williams, Todd; Lanza, Gregory; Tollefsen, Douglas; Caruthers, Shelton; Wickline, Samuel

    2014-09-01

    Restoring an antithrombotic surface to suppress ongoing thrombosis is an appealing strategy for treatment of acute cardiovascular disorders such as erosion of atherosclerotic plaque. An antithrombotic surface would present an alternative to systemic anticoagulation with attendant risks of bleeding. We have designed thrombin-targeted nanoparticles (NPs) that bind to sites of active clotting to extinguish local thrombin activity and inhibit platelet deposition while exhibiting only transient systemic anticoagulant effects. Perfluorocarbon nanoparticles (PFC NP) were functionalized with thrombin inhibitors (either D-phenylalanyl-L-prolyl-L-arginyl-chloromethyl ketone or bivalirudin) by covalent attachment of more than 15 000 inhibitors to each PFC NP. Fibrinopeptide A (FPA) ELISA demonstrated that thrombin-inhibiting NPs prevented cleavage of fibrinogen by both free and clot-bound thrombin. Magnetic resonance imaging (MRI) confirmed that a layer of thrombin-inhibiting NPs prevented growth of clots in vitro. Thrombin-inhibiting NPs were administered in vivo to C57BL6 mice subjected to laser injury of the carotid artery. NPs significantly delayed thrombotic occlusion of the artery, whereas an equivalent bolus of free inhibitor was ineffective. For thrombin-inhibiting NPs, only a short-lived (˜10 min) systemic effect on bleeding time was observed, despite prolonged clot inhibition. Imaging and quantification of in vivo antithrombotic NP layers was demonstrated by MRI of the PFC NP. 19F MRI confirmed colocalization of particles with arterial thrombi, and quantitative 19F spectroscopy demonstrated specific binding and retention of thrombin-inhibiting NPs in injured arteries. The ability to rapidly form and image a new antithrombotic surface in acute vascular syndromes while minimizing risks of bleeding would permit a safer method of passivating active lesions than current systemic anticoagulant regimes.

  17. Yves Clot, Le Travail à cœur. Pour en finir avec les risques psychosociaux

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Durand

    2013-03-01

    Full Text Available Cet ouvrage synthétise les travaux précédents de l’auteur pour en faire un livre plus facile d’accès à un moment où les pathologies professionnelles et les suicides sont relayés par les médias, alors que se développe les officines chargées d’alerter les directions d’entreprise sur les risques ou de les traiter a posteriori. En même temps, Yves Clot marque ses divergences avec d’autres approches du travail ou du mal être au travail (Christophe Dejours, Philippe Zarifian.... Présenter le livre...

  18. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Science.gov (United States)

    Minet, Valentine; Alpan, Lutfiye; Mullier, François; Toussaint, Olivier; Lucas, Stéphane; Dogné, Jean-Michel; Laloy, Julie

    2015-07-01

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  19. Investigation of platelet responses and clotting characteristics of in situ albumin binding surfaces.

    Science.gov (United States)

    Guha Thakurta, Sanjukta; Miller, Robert; Subramanian, Anuradha

    2012-01-01

    The response of biomaterial surfaces when exposed to blood is in part dependent upon the nature and composition of the adsorbed layer of proteins. Surfaces passivated with albumin have been shown to reduce platelet adhesion and activation. In an attempt to develop surfaces that can selectively and specifically bind albumin, silicon-based surfaces were functionalized with linear peptides and chemical ligands that displayed an affinity for albumin. Peptide functionalized surfaces were observed to preferentially bind albumin when compared to human immunoglobulin and human fibrinogen, which possess low densities of surface adsorbed platelets. The platelet morphology was noted to be discoid on the peptide modified surface. Both the unmodified control and SCL functionalized surfaces had high densities of surface adhered platelets with spread out morphology. The peptide and SCL functionalized surfaces were noted to have no impact on PTT and PT clotting times, indicating that the extrinsic and intrinsic pathways were unperturbed by the surfaces generated.

  20. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Valentine, E-mail: valentine.minet@unamur.be; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: julie.laloy@unamur.be [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)

    2015-07-15

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  1. A Clot Model Examination: with Impulsion of Nanoparticles under Influence of Variable Viscosity and Slip Effects

    Science.gov (United States)

    Ijaz, S.; Shahzadi, Iqra; Nadeem, S.; Saleem, Anber

    2017-11-01

    In this speculative analysis, our main focused is to address the neurotic condition that occurs due to accumulation of blood components on the wall of the artery that results in blood coagulation. Specifically, to perceive this phenomena clot model is considered. To discuss this analysis mathematical model is formed in the presence of the effective thermal conductivity and variable viscosity of base fluid. Appropriate slip conditions are employed to obtain the close form solutions of temperature and velocity profile. The graphical illustrations have been presented for the assessment of pressure rise, pressure gradient and velocity profile. The effects of several parameters on the flow quantities for theoretical observation are investigated. At the end, the results confirmed that the impulsion of copper and silver nanoparticles as drug agent enlarges the amplitude of the velocity and hence nanoparticles play an important role in engineering and biomedical applications such as drug delivery system.

  2. PEMANFAATAN MILK CLOTTING ENZYME DARI Lactobacillus casei D11 UNTUK PEMBUATAN KEJU MOZZARELLA [Utilization of Milk Clotting Enzyme from Lactobacillus casei D11 for Mozzarella Cheese Making

    Directory of Open Access Journals (Sweden)

    Rohmatussolihat -

    2015-07-01

    Full Text Available Milk Clotting Enzyme (MCE is an active agent for cheese making which may be produced by Lactic acid bacteria (LAB. MCE activity differs according to the LAB strains used. Lactobacillus casei D11 could produced MCE when it is grown in MRS broth medium. In this study, MCE of L. casei D11 with the addition of rennet is used and optimized for the production of mozzarella cheese using Response Surface Method (RSM with Central Composite Design (CCD. The organoleptic properties were determined by hedonics test involving 30 respondents and analyzed statistically which was followed by a Duncan's test. Furthermore, a proximate analysis of mozzarella cheese was conducted. Our results show that the MCE activity produced by L. casei D11 was 8.471 Soxhlet Unit with protease activity of 3.28 U/mL. The ANOVA results showed that the concentration of MCE significantly influence the production of curd. Theoptimum concentration of MCE and rennet for the production of curd suited for the production of mozzarella cheese were 20 and 0.002%, respectively, with a maximum predicted curd yield of 14.996% (g/100 mL milk which is increased by 13.9% as compared to the curd yield before optimization. The statistical analysis on taste, color, flavor, and cheese texture by respondents shows that mozzarella cheese made by a combination of 15% of MCE and 0.00079 and 0.0015% of rennet, were organoleptically superior to the commercial mozzarella used in this experiment. The proximate analysis shows that mozzarella produced has a moisture content of 33.34%(w/w, 3.48% ash, 30.44% fat, 25.12% protein, 7.53% carbohydrate and energy of 404 kkal/100g.

  3. MASP-1 Induced Clotting--The First Model of Prothrombin Activation by MASP-1.

    Directory of Open Access Journals (Sweden)

    Lorenz Jenny

    Full Text Available Mannan-binding lectin-associated serine protease-1 (MASP-1, a protein of the complement lectin pathway, resembles thrombin in terms of structural features and substrate specificity. Due to its interplay with several coagulation factors, it has the ability to induce fibrin clot formation independent of the usual coagulation activation pathways. We have recently shown that MASP-1 activates prothrombin and identified arginine (R 155, R271, and R393 as potential cleavage sites. FXa cleaves R320 instead of R393, and thrombin cleaves R155 and R284 in prothrombin. Here we have used three arginine-to-glutamine mutants of prothrombin, R271Q, R320Q, R393Q and the serine-to-alanine active site mutant S525A to investigate in detail the mechanism of MASP-1 mediated prothrombin activation. Prothrombin wildtype and mutants were digested with MASP-1 and the cleavage products were analysed by SDS-PAGE and N-terminal sequencing. A functional clotting assay was performed by thrombelastography. We have found that MASP-1 activates prothrombin via two simultaneous pathways, either cleaving at R271 or R393 first. Both pathways result in the formation of several active alternative thrombin species. Functional studies confirmed that both R393 and R320 are required for prothrombin activation by MASP-1, whereas R155 is not considered to be an important cleavage site in this process. In conclusion, we have described for the first time a detailed model of prothrombin activation by MASP-1.

  4. Pulmonary embolism in congenital bleeding disorders: intriguing discrepancies among different clotting factors deficiencies.

    Science.gov (United States)

    Girolami, Antonio; Cosi, Elisabetta; Tasinato, Valentina; Peroni, Edoardo; Girolami, Bruno; Lombardi, Anna Maria

    2016-07-01

    Pulmonary embolism is a complication of deep vein thrombosis. It occurs in the population with a normal clotting mechanism, but it may also occur in patients with congenital bleeding conditions. Here, we report on all cases of pulmonary embolism in congenital hemorrhagic disorders. All reported cases of pulmonary embolism in congenital coagulation disorders have been gathered by a time-unlimited PubMed search. Cross-checking of the references listed at the end of the single papers was carried out to avoid omissions. Seventy-two patients had an objectively demonstrated pulmonary embolism. The event occurred in patients with fibrinogen, factor V, factor VIII (FVII), FVIII, FIX, and FXI deficiency, and in those with von Willebrand's disease. No embolism was reported in FII, factor X, and FXIII deficiency. Thirty were women and 28 were men, whereas in the remaining 14 cases, sex was not reported. Age varied from 6 to 81 years (mean age 34.3 years). The management varied from only supportive to the administration of unfractionated heparin, low-molecular-weight heparin, and anti-vitamin K medications, accompanied by adequate replacement therapy. Evolution was fair or good in the majority of cases, but there were 10 fatalities. Risk factors were present in 61 patients. The most frequent of these were replacement therapy (35 cases), surgery (34), and old age (13). Some patients had more than one risk factor. Eleven patients had no risk factors. There are discrepancies in the prevalence of pulmonary embolism among different clotting disorders. The conditions most frequently affected are FVII deficiency and fibrinogen defects. The significance of the findings is discussed.

  5. Weighing biointeractions between fibrin(ogen) and clot-binding peptides using microcantilever sensors.

    Science.gov (United States)

    Puiggalí-Jou, Anna; Del Valle, Luis J; Alemán, Carlos; Pérez-Madrigal, Maria M

    2017-02-01

    Peptides homing tumor vasculature are considered promising molecular imaging agents for cancer detection at an early stage. In addition to their high binding affinity, improved tissue penetrating ability, and low immunogenicity, they can deliver targeted anticancer drugs, thus expanding therapeutic treatments. Among those, CREKA, a linear peptide that specifically binds to clotted-plasma proteins in tumor vessels, has been recently employed to design bioactive systems able to target different cancer types. Within this context, this paper explores the biorecognition event between CR(NMe)EKA, an engineered CREKA-analog bearing a noncoded amino acid (N-methyl-Glu) that is responsible for its enhanced activity, and clotted-plasma proteins (fibrin and fibrinogen) by nanomechanical detection. Specifically, the tumor-homing peptide was covalently attached via epoxysilane chemistry onto silicon microcantilever chips that acted as sensors during dynamic mode experiments. Before that, each step of the functionalization process was followed by contact angle measurements, interferometry, X-ray photoelectron spectroscopy, and atomic force microscopy, thus revealing the applied protocol as a suitable strategy. The fibrin(ogen)-binding induced by CR(NMe)EKA was detected by the resonance frequency shift of the cantilevers, and a detection limit of 100 ng/mL was achieved for both proteins. Even though further development is required, this work reflects the promising application of emerging technologies capable of assisting in the comprehension of biological interactions and their implications in the biotechnological field. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  6. Three-dimensional architecture and cell composition of a Choukroun's platelet-rich fibrin clot and membrane.

    Science.gov (United States)

    Dohan Ehrenfest, David M; Del Corso, Marco; Diss, Antoine; Mouhyi, Jaafar; Charrier, Jean-Baptiste

    2010-04-01

    Platelet-rich fibrin (PRF; Choukroun's technique) is a second-generation platelet concentrate for surgical use. This easy protocol allows the production of leukocyte and platelet-rich fibrin clots and membranes starting from 10-ml blood samples. The purposes of this study were to determine the cell composition and three-dimensional organization of this autologous biomaterial and to evaluate the influence of different collection tubes (dry glass or glass-coated plastic tubes) and compression procedures (forcible or soft) on the final PRF-membrane architecture. After centrifugation, blood analyses were performed on the residual waste plasmatic layers after collecting PRF clots. The PRF clots and membranes were processed for examination by light microscopy and scanning electron microscopy. Approximately 97% of the platelets and >50% of the leukocytes were concentrated in the PRF clot and showed a specific three-dimensional distribution, depending on the centrifugation forces. Platelets and fibrin formed large clusters of coagulation in the first millimeters of the membrane beyond the red blood cell base. The fibrin network was very mature and dense. Moreover, there was no significant difference in the PRF architecture between groups using the different tested collection tubes and compression techniques, even if these two parameters could have influenced the growth factor content and biologic matrix properties. The PRF protocol concentrated most platelets and leukocytes from a blood harvest into a single autologous fibrin biomaterial. This protocol offers reproducible results as long as the main production principles are respected.

  7. In vitro effect of hemodilution on activated clotting time and high-dose thrombin time during cardiopulmonary bypass

    NARCIS (Netherlands)

    Huyzen, RJ; vanOeveren, W; Wei, FY; Stellingwerf, P; Boonstra, PW; Gu, YJ

    Background. Extreme dilution of clotting factors, as may occur during pediatric or neonatal cardiopulmonary bypass, often leads to inadequate monitoring of anticoagulation with activated dotting time (ACT). In this study we postulate that the high-dose thrombin time (HiTT) is less influenced by

  8. Increased Oxidation as an Additional Mechanism Underlying Reduced Clot Permeability and Impaired Fibrinolysis in Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Anna Lados-Krupa

    2015-01-01

    Full Text Available Aims. We sought to investigate whether enhanced oxidation contributes to unfavorable fibrin clot properties in patients with diabetes. Methods. We assessed plasma fibrin clot permeation (Ks, a measure of the pore size in fibrin networks and clot lysis time induced by recombinant tissue plasminogen activator (CLT in 163 consecutive type 2 diabetic patients (92 men and 71 women aged 65 ± 8.8 years with a mean glycated hemoglobin (HbA1c of 6.8%. We also measured oxidative stress markers, including nitrotyrosine, the soluble form of receptor for advanced glycation end products (sRAGE, 8-iso-prostaglandin F2α (8-iso-PGF2α, oxidized low-density lipoprotein (oxLDL, and advanced glycation end products (AGE. Results. There were inverse correlations between Ks and nitrotyrosine, sRAGE, 8-iso-PGF2α, and oxLDL. CLT showed a positive correlation with oxLDL and nitrotyrosine but not with other oxidation markers. All these associations remained significant for Ks after adjustment for fibrinogen, disease duration, and HbA1c (all P<0.05, while oxLDL was the only independent predictor of CLT. Conclusions. Our study shows that enhanced oxidative stress adversely affects plasma fibrin clot properties in type 2 diabetic patients, regardless of disease duration and glycemia control.

  9. Factors Affecting the Growth and Production of Milk-Clotting Enzyme by Amylomyces rouxii in Rice Liquid Medium

    Directory of Open Access Journals (Sweden)

    Pei-Jing Yu

    2005-01-01

    Full Text Available Amylomyces rouxii is one of the main fungi usually coexisting with yeasts in Chinese yeast ball, the starter of chiu-niang, a traditional Chinese fermented product from rice. In the present study, growth and production of milk-clotting enzyme (MCE in gelatinous rice liquid culture of A. rouxii as influenced by waxy (gelatinous rice content in the medium (5–20 %, temperature (25–40 °C, cultivation time (1–6 days, shaking speeds (0–150 rpm and metal ions (Na+, K+, Zn2+, Mg2+, Mn2+, Cu2+, Ca2+, Fe3+ and Al3+ were investigated. Results revealed that rice content in the medium, shaking speed, temperature and cultivation time all affected the mycelial propagation and the production of milk-clotting enzyme by A. rouxii in the rice liquid culture. The maximum milk-clotting enzyme activity of ca. 1.22 unit/mL of medium was observed in the 3-day static culture of test organism grown at 30 °C in the medium containing 20 % of gelatinous rice, while mycelial propagation increased with the increase of cultivation time and shaking speed. Furthermore, a significant increase (p<0.05 in the milk-clotting enzyme activity of ca. 1.90 unit/mL of medium, which was about 1.55-fold of the control, was observed when Al3+ was added to the rice liquid medium.

  10. Plasma carboxypeptidase U (CPU, CPB2, TAFIa) generation during in vitro clot lysis and its interplay between coagulation and fibrinolysis.

    Science.gov (United States)

    Leenaerts, Dorien; Aernouts, Jef; Van Der Veken, Pieter; Sim, Yani; Lambeir, Anne-Marie; Hendriks, Dirk

    2017-07-26

    Carboxypeptidase U (CPU, CPB2, TAFIa) is a basic carboxypeptidase that is able to attenuate fibrinolysis. The inactive precursor procarboxypeptidase U is converted to its active form by thrombin, the thrombin-thrombomodulin complex or plasmin. The aim of this study was to investigate and characterise the time course of CPU generation in healthy individuals. In plasma of 29 healthy volunteers, CPU generation was monitored during in vitro clot lysis. CPU activity was measured by means of an enzymatic assay that uses the specific substrate Bz-o-cyano-Phe-Arg. An algorithm was written to plot the CPU generation curve and calculate the parameters that define it. In all individuals, CPU generation was biphasic. Marked inter-individual differences were present and a reference range was determined. The endogenous CPU generation potential is the composite effect of multiple factors. With respect to the first CPU activity peak characteristics, we found correlations with baseline proCPU concentration, proCPU Thr325Ile polymorphism, time to clot initiation and the clot lysis time. The second CPU peak related with baseline proCPU levels and with the maximum turbidity of the clot lysis profile. In conclusion, our method offers a technique to determine the endogenous CPU generation potential of an individual. The parameters obtained by the method quantitatively describe the different mechanisms that influence CPU generation during the complex interplay between coagulation and fibrinolysis, which are in line with the threshold hypothesis.

  11. Obesity in haemophilia patients : effect on bleeding frequency, clotting factor concentrate usage, and haemostatic and fibrinolytic parameters

    NARCIS (Netherlands)

    Tuinenburg, A.; Biere-Rafi, S.; Peters, M.; Verhamme, P.; Peerlinck, K.; Kruip, M.J.H.A.; Laros-Van Gorkom, B.A.P.; Roest, M.; Meijers, J.C.M.; Kamphuisen, P.W.; Schutgens, R.E.G.

    The prevalence of obesity in patients with haemophilia (PWH) is increasing. We investigated the effect of obesity on bleeding frequency and clotting factor concentrate (CFC) usage in PWH and assessed whether prothrombotic changes observed in obesity differ between controls and PWH. Number of bleeds

  12. Clot Burden Score on Baseline Computerized Tomographic Angiography and Intra-Arterial Treatment Effect in Acute Ischemic Stroke

    NARCIS (Netherlands)

    Treurniet, K.M.; Yoo, A.J.; Berkhemer, O.A.; Lingsma, H.F.; Boers, A.M.; Fransen, P.S.; Beumer, D.; Berg, L.A. van den; Sprengers, M.E.; Jenniskens, S.F.M.; Lycklama, A.N.G.J.; Walderveen, M.A. van; Bot, J.C.; Beenen, L.F.; Berg, R. van den; Zwam, W.H. van; Lugt, A. van der; Oostenbrugge, R.J. van; Dippel, D.W.; Roos, Y.B.; Marquering, H.A.; Majoie, C.B.; Dijk, E.J. van; Vries, J. de

    2016-01-01

    BACKGROUND AND PURPOSE: A high clot burden score (CBS) is associated with favorable outcome after intravenous treatment for acute ischemic stroke. The added benefit of intra-arterial treatment might be less in these patients. The aim of this exploratory post hoc analysis was to assess the relation

  13. Cloning, expression and characterization of a gene from earthworm Eisenia fetida encoding a blood-clot dissolving protein.

    Directory of Open Access Journals (Sweden)

    GangQiang Li

    Full Text Available A lumbrokinase gene encoding a blood-clot dissolving protein was cloned from earthworm (Eisenia fetida by RT-PCR amplification. The gene designated as CST1 (GenBank No. AY840996 was sequence analyzed. The cDNA consists of 888 bp with an open reading frame of 729 bp, which encodes 242 amino acid residues. Multiple sequence alignments revealed that CST1 shares similarities and conserved amino acids with other reported lumbrokinases. The amino acid sequence of CST1 exhibits structural features similar to those found in other serine proteases, including human tissue-type (tPA, urokinase (uPA, and vampire bat (DSPAα1 plasminogen activators. CST1 has a conserved catalytic triad, found in the active sites of protease enzymes, which are important residues involved in polypeptide catalysis. CST1 was expressed as inclusion bodies in Escherichia coli BL21(DE3. The molecular mass of recombinant CST1 (rCST was 25 kDa as estimated by SDS-PAGE, and further confirmed by Western Blot analysis. His-tagged rCST1 was purified and renatured using nickel-chelating resin with a recovery rate of 50% and a purity of 95%. The purified, renatured rCST1 showed fibrinolytic activity evaluated by both a fibrin plate and a blood clot lysis assay. rCST1 degraded fibrin on the fibrin plate. A significant percentage (65.7% of blood clot lysis was observed when blood clot was treated with 80 mg/mL of rCST1 in vitro. The antithrombotic activity of rCST1 was 912 units/mg calculated by comparison with the activity of a lumbrokinase standard. These findings indicate that rCST1 has potential as a potent blood-clot treatment. Therefore, the expression and purification of a single lumbrokinase represents an important improvement in the use of lumbrokinases.

  14. Cloning, Expression and Characterization of a Gene from Earthworm Eisenia fetida Encoding a Blood-Clot Dissolving Protein

    Science.gov (United States)

    Li, DaHui; Wang, Nan; Liu, DeHu

    2012-01-01

    A lumbrokinase gene encoding a blood-clot dissolving protein was cloned from earthworm (Eisenia fetida) by RT-PCR amplification. The gene designated as CST1 (GenBank No. AY840996) was sequence analyzed. The cDNA consists of 888 bp with an open reading frame of 729 bp, which encodes 242 amino acid residues. Multiple sequence alignments revealed that CST1 shares similarities and conserved amino acids with other reported lumbrokinases. The amino acid sequence of CST1 exhibits structural features similar to those found in other serine proteases, including human tissue-type (tPA), urokinase (uPA), and vampire bat (DSPAα1) plasminogen activators. CST1 has a conserved catalytic triad, found in the active sites of protease enzymes, which are important residues involved in polypeptide catalysis. CST1 was expressed as inclusion bodies in Escherichia coli BL21(DE3). The molecular mass of recombinant CST1 (rCST) was 25 kDa as estimated by SDS–PAGE, and further confirmed by Western Blot analysis. His-tagged rCST1 was purified and renatured using nickel-chelating resin with a recovery rate of 50% and a purity of 95%. The purified, renatured rCST1 showed fibrinolytic activity evaluated by both a fibrin plate and a blood clot lysis assay. rCST1 degraded fibrin on the fibrin plate. A significant percentage (65.7%) of blood clot lysis was observed when blood clot was treated with 80 mg/mL of rCST1 in vitro. The antithrombotic activity of rCST1 was 912 units/mg calculated by comparison with the activity of a lumbrokinase standard. These findings indicate that rCST1 has potential as a potent blood-clot treatment. Therefore, the expression and purification of a single lumbrokinase represents an important improvement in the use of lumbrokinases. PMID:23300872

  15. Changes in clot lysis levels of reteplase and streptokinase following continuous wave ultrasound exposure, at ultrasound intensities following attenuation from the skull bone

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    Roijer Anders

    2008-08-01

    Full Text Available Abstract Background Ultrasound (US has been used to enhance thrombolytic therapy in the treatment of stroke. Considerable attenuation of US intensity is however noted if US is applied over the temporal bone. The aim of this study was therefore to explore possible changes in the effect of thrombolytic drugs during low-intensity, high-frequency continuous-wave ultrasound (CW-US exposure. Methods Clots were made from fresh venous blood drawn from healthy volunteers. Each clot was made from 1.4 ml blood and left to coagulate for 1 hour in a plastic test-tube. The thrombolytic drugs used were, 3600 IU streptokinase (SK or 0.25 U reteplase (r-PA, which were mixed in 160 ml 0.9% NaCl solution. Continuous-wave US exposure was applied at a frequency of 1 MHz and intensities ranging from 0.0125 to 1.2 W/cm2. For each thrombolytic drug (n = 2, SK and r-PA and each intensity (n = 9 interventional clots (US-exposed, n = 6 were submerged in thrombolytic solution and exposed to CW-US while control clots (also submerged in thrombolytic solution, n = 6 were left unexposed to US. To evaluate the effect on clot lysis, the haemoglobin (Hb released from each clot was measured every 20 min for 1 hour (20, 40 and 60 min. The Hb content (mg released was estimated by spectrophotometry at 540 nm. The difference in effect on clot lysis was expressed as the difference in the amount of Hb released between pairs of US-exposed clots and control clots. Statistical analysis was performed using Wilcoxon's signed rank test. Results Continuous-wave ultrasound significantly decreased the effects of SK at intensities of 0.9 and 1.2 W/cm2 at all times (P 2 and at 1.2 W/cm2, following 40 min exposure at 0.3, 0.6, 0.9 and at 1.2 W/cm2, and following 60 min of exposure at 0.05 0.3, 0.6, 0.9 and at 1.2 W/cm2 (all P Conclusion Increasing intensities of CW-US exposure resulted in increased clot lysis of r-PA-treated blood clots, but decreased clot lysis of SK-treated clots.

  16. Continuous noninvasive in vivo monitoring of intravascular plasma volume and hematocrit changes during hemodialysis in humans: direct comparison with the CRIT-LINE

    Science.gov (United States)

    Deng, Bin; Kastner, Evan; Narsipur, Sriram S.; Goodisman, Jerry; Chaiken, J.

    2014-02-01

    We report a new device and algorithm that allows simultaneous monitoring of the hematocrit and plasma volume fraction of blood within the intravascular space of an optically probed volume of skin. Skin is probed with a near infrared (NIR) laser and simultaneously collecting the Rayleigh and Mie scattered light as one raw signal and the undifferentiated Raman and fluorescence emission as the second raw signal. These signals are combined using six parameters that can be obtained by either direct calculation or empirical calibration to permit monitoring of the blood in human skin (e.g. fingertips). We tested a device based on the algorithm that might be useful in allowing the early detection of blood loss for people who have no external injury but may be hemorrhaging internally. IRB allowed experiments monitoring blood in human fingertip skin in vivo during routine hemodialysis demonstrated good agreement between the experimental device and the CRIT-LINE®, an FDA approved device that is built into the dialysis machine and applies the Twersky algorithm to blood in the dialysis machine (i.e. in vitro). Based on observation of 9 different test subjects, as dialysis removes fluid from the intravascular space causing an increase in hematocrit and a decrease in plasma volume, the CRIT-LINE response is closely emulated (typical per session linear correlation r2=0.78, N=87, pfactors will also be discussed.

  17. {sup 99m}Tc-NC100668, a new tracer for imaging venous thromboemboli: pre-clinical biodistribution and incorporation into plasma clots in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, David [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden); Lewis, Joanne; Battle, Mark; Lear, Rochelle; Farrar, Gill; Barnett, D.J.; Godden, Vanessa; Oliveira, Alexandra; Coombes, Catherine [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Ahlstroem, Haakan [Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden)

    2006-11-15

    {sup 99m}Tc-NC100668 is a new radiotracer being developed to aid the diagnosis of thromboembolism. The structure of NC100668 is similar to a region of human {alpha}{sub 2}-antiplasmin, which is a substrate for factor XIIIa (FXIIIa). The purpose of this study was to confirm the uptake of {sup 99m}Tc-NC100668 into forming plasma clot and to establish the biodistribution of {sup 99m}Tc-NC100668 in Wistar rats. The in vitro plasma clot uptake of {sup 99m}Tc-NC100668 and other compounds with known affinities to FXIIIa was measured using a plasma clot assay. The biodistribution and blood clot uptake of radioactivity of {sup 99m}Tc-NC100668 in normal Wistar rats and those bearing experimentally induced deep vein thrombi were investigated. The in vitro uptake of {sup 99m}Tc-NC100668 was greater than that for [{sup 14}C]dansyl cadaverine, a known substrate of FXIIIa in the plasma clot assay. The biodistribution of {sup 99m}Tc-NC100668 in male and female Wistar rats up to 24 h p.i. showed that radioactivity was rapidly excreted, predominantly into the urine, with very little background tissue retention. In vivo the uptake and retention of {sup 99m}Tc-NC100668 into the blood clot was greater than could be accounted for by non-specific accumulation of the radiotracer within the blood clot. {sup 99m}Tc-NC100668 was retained by plasma clots in vitro and blood clots in vivo. No significant tissue retention which could interfere with the ability to image thrombi in vivo was observed. This evidence suggests that {sup 99m}Tc-NC100668 might be useful in the detection of thromboembolism. (orig.)

  18. Fibrin Clot Permeability as a Predictor of Stroke and Bleeding in Anticoagulated Patients With Atrial Fibrillation.

    Science.gov (United States)

    Drabik, Leszek; Wołkow, Paweł; Undas, Anetta

    2017-10-01

    Formation of denser fiber networks has been reported in atrial fibrillation and ischemic stroke. In this longitudinal cohort study, we evaluated whether fibrin clot density may predict thromboembolic and bleeding risk in patients with atrial fibrillation on vitamin K antagonists. In 236 patients with atrial fibrillation receiving vitamin K antagonists treatment, we measured ex vivo plasma clot permeability (K s ), a measure of the pore size in fibrin networks. During a median follow-up of 4.3 (interquartile range, 3.7-4.8) years, annual rates of ischemic stroke or transient ischemic attack and major bleeds were 2.96% and 3.45%, respectively. In multivariate Cox regression analysis, patients with lower K s (stroke or transient ischemic attack (hazard ratio [HR], 6.55; 95% confidence interval [CI], 2.17-19.82) and major bleeds (HR, 10.65; 95% CI, 3.52-32.22). Patients with elevated K s (≥6.8 cm 2 ×10 -9 ) had an increased rate of minor bleeding compared with the remainder (11.63% per year versus 3.55% per year; P stroke or transient ischemic attack were low K s (<6.8 cm 2 ×10 - 9 ; HR, 7.24; 95% CI, 2.53-20.76), age (HR, 1.05; 95% CI, 1.01-1.10), and treatment with angiotensin-converting enzyme inhibitors (HR, 2.27; 95% CI, 1.08-4.77). Major bleeds were predicted by low K s (<6.8 cm 2 ×10 -9 ; HR, 8.48; 95% CI, 2.99-24.1) and HAS-BLED score ≥3 (HR, 2.22; 95% CI, 1.12-4.38). This study is the first to show that unfavorable fibrin properties reflected by formation of denser fibrin networks determine, in part, the efficacy and safety of anticoagulation with vitamin K antagonists in patients with atrial fibrillation. © 2017 American Heart Association, Inc.

  19. Plasma fibrin clot phenotype independently affects intracoronary thrombus ultrastructure in patients with acute myocardial infarction.

    Science.gov (United States)

    Zalewski, Jaroslaw; Bogaert, Jan; Sadowski, Marcin; Woznicka, Olga; Doulaptsis, Konstantinos; Ntoumpanaki, Maria; Ząbczyk, Michal; Nessler, Jadwiga; Undas, Anetta

    2015-06-01

    Determinants of intracoronary thrombus (ICT) composition in patients with ST-elevation myocardial infarction (STEMI) are largely unknown. We sought to investigate whether plasma fibrin phenotype and platelet reactivity affect ICT ultrastructure. We assessed the content of fibrin, platelets and erythrocytes including polyhedrocytes by scanning electron microscopy on the surface and inside ICT aspirated from 80 STEMI patients within 12 hours since chest pain onset. Plasma fibrin clot permeability (Ks), which indicates the average pore size, lysis time (t50 %), platelet reactivity index (PRI) and ADP-induced platelet aggregation (ADP5, 20µM) were evaluated on admission. All patients received aspirin and 45 (56.3 %) 600 mg of clopidogrel, 80 (60-120) min prior to aspiration. Higher content of fibrin (61.6 vs 34.3 %, P< 0.0001) and platelets (8.2 vs 4.8 %, P=0.018) and lower erythrocyte content (15.8 vs 42.9 %, P< 0.0001) were found on ICT surface compared with its inner part. After adjustment for fibrinogen, in both ICT parts fibrin content was correlated with Ks (r≤-0.55, P< 0.0001) and t50 % (r≥ 0.29, P≤ 0.02) but not with PRI and ADP5,20µM. Polyhedrocytes were observed in 16 (20 %) patients and their large amount expressed as ≥ 50 % fields of view covered by polyhedrocytes was associated with the lower PRI values (40 vs 69 %, P=0.015), but not Ks or t50 %. By multivariate regression, Ks (β=-0.62, P< 0.0001), clopidogrel pretreatment (β=-0.36, P< 0.001), ischemia time (β=0.19, P=0.044) and family history (β=0.18, P=0.049) independently predicted fibrin content in the whole ICT (R²=0.65, P< 0.0001). Formation of denser plasma fibrin clots is independently associated with high fibrin content within the ICT in STEMI.

  20. Effect of ingestion of raw garlic on serum cholesterol level, clotting time and fibrinolytic activity in normal subjects.

    Directory of Open Access Journals (Sweden)

    Gadkari J

    1991-07-01

    Full Text Available The effect of raw garlic on serum cholesterol, fibrinolytic activity and clotting time was studied in 50 medical students of the age group of 17 to 22 years before and after feeding raw garlic. All pre-experimental values ranged within normal limits. The volunteers were then divided into experimental and control groups. The subjects of the experimental group were given 10 gm of raw garlic daily after breakfast for two months. Fasting blood samples of all the subjects were investigated after two months. In the control group, there was no significant change in any of the above parameters. In the experimental group, there was a significant decrease in serum cholesterol and an increase in clotting time and fibrinolytic activity. Hence, garlic may be an useful agent in prevention of thromboembolic phenomenon.

  1. Random Forests Are Able to Identify Differences in Clotting Dynamics from Kinetic Models of Thrombin Generation.

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    Jayavel Arumugam

    Full Text Available Current methods for distinguishing acute coronary syndromes such as heart attack from stable coronary artery disease, based on the kinetics of thrombin formation, have been limited to evaluating sensitivity of well-established chemical species (e.g., thrombin using simple quantifiers of their concentration profiles (e.g., maximum level of thrombin concentration, area under the thrombin concentration versus time curve. In order to get an improved classifier, we use a 34-protein factor clotting cascade model and convert the simulation data into a high-dimensional representation (about 19000 features using a piecewise cubic polynomial fit. Then, we systematically find plausible assays to effectively gauge changes in acute coronary syndrome/coronary artery disease populations by introducing a statistical learning technique called Random Forests. We find that differences associated with acute coronary syndromes emerge in combinations of a handful of features. For instance, concentrations of 3 chemical species, namely, active alpha-thrombin, tissue factor-factor VIIa-factor Xa ternary complex, and intrinsic tenase complex with factor X, at specific time windows, could be used to classify acute coronary syndromes to an accuracy of about 87.2%. Such a combination could be used to efficiently assay the coagulation system.

  2. Minimally Invasive Subcortical Parafascicular Transsulcal Access for Clot Evacuation (Mi SPACE for Intracerebral Hemorrhage

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    Benjamin Ritsma

    2014-01-01

    Full Text Available Background. Spontaneous intracerebral hemorrhage (ICH is common and causes significant mortality and morbidity. To date, optimal medical and surgical intervention remains uncertain. A lack of definitive benefit for operative management may be attributable to adverse surgical effect, collateral tissue injury. This is particularly relevant for ICH in dominant, eloquent cortex. Minimally invasive surgery (MIS offers the potential advantage of reduced collateral damage. MIS utilizing a parafascicular approach has demonstrated such benefit for intracranial tumor resection. Methods. We present a case of dominant hemisphere spontaneous ICH evacuated via the minimally invasive subcortical parafascicular transsulcal access clot evacuation (Mi SPACE model. We use this report to introduce Mi SPACE and to examine the application of this novel MIS paradigm. Case Presentation. The featured patient presented with a left temporal ICH and severe global aphasia. The hematoma was evacuated via the Mi SPACE approach. Postoperative reassessments showed significant improvement. At two months, bedside language testing was normal. MRI tractography confirmed limited collateral injury. Conclusions. This case illustrates successful application of the Mi SPACE model to ICH in dominant, eloquent cortex and subcortical regions. MRI tractography illustrates collateral tissue preservation. Safety and feasibility studies are required to further assess this promising new therapeutic paradigm.

  3. Highly Effective DNA Extraction Method from Fresh, Frozen, Dried and Clotted Blood Samples

    Directory of Open Access Journals (Sweden)

    Jaleh Barar

    2011-09-01

    Full Text Available Introduction: Today, with the tremendous potential of genomics and other recent advances in science, the role of science to improve reliable DNA extraction methods is more relevant than ever before. The ideal process for genomic DNA extraction demands high quantities of pure, integral and intact genomic DNA (gDNA from the sample with minimal co-extraction of inhibitors of downstream processes. Here, we report the development of a very rapid, less-hazardous, and high throughput protocol for extracting of high quality DNA from blood samples. Methods: Dried, clotted and ethylene diamine tetra-acetic acid (EDTA treated fresh and frozen blood samples were extracted using this method in which the quality and integrity of the extracted DNA were corroborated by agarose gel electrophoresis, PCR reaction and DNA digestion using restricted enzyme. The UV spectrophotometric and gel electrophoresis analysis resulted in high A260/A280 ratio (>1.8 with high intactness of DNA. Results: PCR and DNA digestion experiments indicated that the final solutions of extracted DNA contained no inhibitory substances, which confirms that the isolated DNA is of good quality. Conclusion: The high quality and quantity of current method, no enzymatic processing and accordingly its low cost, make it appropriate for DNA extraction not only from human but also from animal blood samples in any molecular biology labs.

  4. High Milk-Clotting Activity Expressed by the Newly Isolated Paenibacillus spp. Strain BD3526

    Directory of Open Access Journals (Sweden)

    Feng Hang

    2016-01-01

    Full Text Available Paenibacillus spp. BD3526, a bacterium exhibiting a protein hydrolysis circle surrounded with an obvious precipitation zone on skim milk agar, was isolated from raw yak (Bos grunniens milk collected in Tibet, China. Phylogenetic analysis based on 16S rRNA and whole genome sequence comparison indicated the isolate belong to the genus Paenibacillus. The strain BD3526 demonstrated strong ability to produce protease with milk clotting activity (MCA in wheat bran broth. The protease with MCA was predominantly accumulated during the late-exponential phase of growth. The proteolytic activity (PA of the BD3526 protease was 1.33-fold higher than that of the commercial R. miehei coagulant. A maximum MCA (6470 ± 281 SU mL−1 of the strain BD3526 was reached under optimal cultivation conditions. The protease with MCA was precipitated from the cultivated supernatant of wheat bran broth with ammonium sulfate and purified by anion-exchange chromatography. The molecular weight of the protease with MCA was determined as 35 kDa by sodium dodecyl sulfate-polyacrylamide gels electrophoresis (SDS-PAGE and gelatin zymography. The cleavage site of the BD3526 protease with MCA in κ-casein was located at the Met106–Ala107 bond, as determined by mass spectrometry analysis.

  5. A Simple, Inexpensive and Safe Method for DNA Extraction of Frigid and Clotted Blood Samples

    Directory of Open Access Journals (Sweden)

    Nasrin Mohammadi

    2015-07-01

    Full Text Available Background: Extraction of blood genomicDNAis one of the main approaches for clinical and molecular biology studies. Although several methods have been developed for extraction of blood genomic DNA, most of these methods consume long time and use expensive chemicals such as proteinase K and toxic organic solvent such as phenol and chloroform. The objective of this study was to developed easy and safe method forDNAextraction from clotted and frozen whole blood. This method has many advantages: time reducing, using inexpensive materials, without phenol and chloroform, achieving of high molecular weight and good quality genomicDNA.Materials and Methods: DNA extraction was performed by two methods (new and phenol-chloroform method. Then quantity and quality parameters were evaluated by 1% agarose gel electrophoresis, Nano drop analysis and efficiency of Polymerase Chain Reaction (PCR.Results: Extracted DNA from 500μL of blood samples were 457.7ng/μl and 212ng/μL and their purity (OD260/OD280 were 1.8 and 1.81 for new recommended and phenol–chloroform methods respectively. The PCR results indicated that D16S539 and CSF1PO loci were amplified.Conclusion: These results shown that this method is simple, fast, safe and most economical.

  6. [Guidelines for certification of Activated clotting time (ACT) according to the EN ISO 22870 standards].

    Science.gov (United States)

    Lasne, Dominique; Bauters, Anne; Le Querrec, Agnès; Bourdin, Carole; Voisin, Sophie

    2015-01-01

    Point of care testing (POCT) must comply with regulatory requirements according to standard EN ISO 22870, which identify biologists as responsible for POCT. Activated clotting time (ACT) is mandatory to monitor on whole blood, anticoagulation achieved by unfractionated heparin during cardiopulmonary bypass (CPB) or cardiac catheterization. This test has no equivalent in the laboratory. With the aim to help the multidisciplinary groups for POCT supervision when they have to analyse the wish of medical departments to use ACT and to help the biologists to be in accordance with the standard, we present the guidelines of the GEHT (Groupe d'étude d'hémostase et thrombose) subcommittee "CEC et Biologie délocalisée" for the certification of ACT. These guidelines are based on the SFBC guidelines for the certification of POCT and on the analysis of the literature to ascertain the justification of clinical need and assess the analytical performance of main analyzers used in France, as well as on a survey conducted with French and Belgian biologists.

  7. Streptococcus sanguis-induced platelet clotting in rabbits and hemodynamic and cardiopulmonary consequences.

    Science.gov (United States)

    Meyer, M W; Gong, K; Herzberg, M C

    1998-12-01

    By mimicking hemostatic structural domains of collagen, Streptococcus sanguis (aggregation-positive phenotype; Agg+) induces platelets to aggregate in vitro. To test the hypothesis that aggregation occurs in vivo, S. sanguis (Agg+ or Agg- suspension) was infused intravenously into rabbits. The extent of hemodynamic and cardiopulmonary changes and the fate of circulating platelets were Agg+ strain dose dependent. Within 45 to 50 s of the start of infusion, 40 x 10(8) CFU of the Agg+ strain caused increased blood pressure. Thirty seconds after infusion, other changes occurred. Intermittent electrocardiographic abnormalities (13 of 15 rabbits), ST-segment depression (10 of 15 rabbits), and preventricular contractions (7 of 15 rabbits) manifested at 3 to 7 min, with frequencies dose dependent. Respiratory rate and cardiac contractility increased during this phase. Blood catecholamine concentration, thrombocytopenia, accumulation of 111Indium-labeled platelets in the lungs, and ventricular axis deviation also showed dose dependency. Rabbits were unaffected by inoculation of an Agg- strain. Therefore, Agg+ S. sanguis induced platelet aggregation in vitro. Platelet clots caused hemodynamic changes, acute pulmonary hypertension, and cardiac abnormalities, including ischemia.

  8. Fibrin Association at Hybrid Biointerfaces Made of Clot-Binding Peptides and Polythiophene.

    Science.gov (United States)

    Puiggalí-Jou, A; Del Valle, Luis J; Armelin, Elaine; Alemán, Carlos

    2016-10-01

    The properties as biointerfaces of electroactive conducting polymer-peptide biocomposites formed by poly(3,4-ethylenedioxythiophene) (PEDOT) and CREKA or CR(NMe)EKA peptide sequences (where Glu has been replaced by N-methyl-Glu in the latter) have been compared. CREKA is a linear pentapeptide that recognizes clotted plasma proteins and selectively homes to tumors, while CR(NMe)EKA is an engineer to improve such properties by altering peptide-fibrin interactions. Differences between PEDOT-CREKA and PEDOT-CR(NMe)EKA reflect dissemblance in the organization of the peptides into the polymeric matrix. Both peptides affect fibrinogen thrombin-catalyzed polymerization causing the immediate formation of fibrin, whereas in the absence of thrombin this phenomenon is only observed for CR(NMe)EKA. Consistently, the fibrin-adsorption capacity is higher for PEDOT-CR(NMe)EKA than for PEDOT-CREKA, even though in both cases adsorbed fibrin exhibits round-like morphologies rather than the characteristic fibrous structure. PEDOT-peptide films coated with fibrin are selective in terms of cell adhesion, promoting the attachment of metastatic cells with respect to normal cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Googling Service Boundaries for Endovascular Clot Retrieval Hub Hospitals in a Metropolitan Setting: Proof-of-Concept Study.

    Science.gov (United States)

    Phan, Thanh G; Beare, Richard; Chen, Jian; Clissold, Benjamin; Ly, John; Singhal, Shaloo; Ma, Henry; Srikanth, Velandai

    2017-05-01

    There is great interest in how endovascular clot retrieval hubs provide services to a population. We applied a computational method to objectively generate service boundaries for such endovascular clot retrieval hubs, defined by traveling time to hub. Stroke incidence data merged with population census to estimate numbers of stroke in metropolitan Melbourne, Australia. Traveling time from randomly generated addresses to 4 endovascular clot retrieval-capable hubs (Royal Melbourne Hospital [RMH], Monash Medical Center [MMC], Alfred Hospital [ALF], and Austin Hospital [AUS]) estimated using Google Map application program interface. Boundary maps generated based on traveling time at various times of day for combinations of hubs. In a 2-hub model, catchment was best distributed when RMH was paired with MMC (model 1a, RMH 1765 km2 and MMC 1164 km2) or with AUS (model 1c, RMH 1244 km2 and AUS 1685 km2), with no statistical difference between models (P=0.20). Catchment was poorly distributed when RMH was paired with ALF (model 1b, RMH 2252 km2 and ALF 676 km2), significantly different from both models 1a and 1c (both P<0.05). Model 1a had the greatest proportion of patients arriving within ideal time of 30 minutes followed by model 1c (P<0.001). In a 3-hub model, the combination of RMH, MMC, and AUS was superior to that of RMH, MMC, and ALF in catchment distribution and travel time. The method was also successfully applied to the city of Adelaide demonstrating wider applicability. We provide proof of concept for a novel computational method to objectively designate service boundaries for endovascular clot retrieval hubs. © 2017 American Heart Association, Inc.

  10. Optimal monitoring of bypass therapy in hemophilia A patients with inhibitors by the use of clot waveform analysis.

    Science.gov (United States)

    Haku, J; Nogami, K; Matsumoto, T; Ogiwara, K; Shima, M

    2014-01-01

    Assays to determine the optimal hemostatic effects of bypass therapy in hemophilia A (HA) patients with inhibitors are difficult to compare. Clot waveform analysis (CWA), based on the continuous monitoring of routine coagulation parameters (prothrombin time/activated partial thromboplastin time), offers a useful method for assessing global clotting function. To investigate the technique of CWA for the hemostatic monitoring of bypass therapy in HA patients with inhibitors. Ellagic acid (Elg), tissue factor (TF) or both (Elg/TF) were used as trigger reagents in CWA. The standard parameters - clot time (CT), maximum coagulation velocity (|min1|), and acceleration (|min2|) - were recorded. Optimal monitoring was defined as: (i) a significant difference in these parameters between plasma from HA patients with inhibitors and normal plasmas; and (ii) a significant improvement in these indices in HA patients with inhibitors after bypass therapy. Experiments in vitro demonstrated that there were significant differences between plasma from HA patients with inhibitors and normal plasma with various triggers, in the order Elg > Elg/TF > TF. Addition of therapeutically achievable concentrations of bypassing agents, however, showed significant improvements in the different parameters only with Elg/TF, suggesting that this reagent provided the most appropriate assay. A total of 20 plasmas from HA patients with inhibitors in which bypassing agents were infused were evaluated ex vivo by Elg/TF CWA. The postinfusion parameters CT and |min2| reflected clinical effects, and were close to normal levels. Furthermore, Elg/TF CWA facilitated quantitative evaluation of perioperative hemostatic management of bypass therapy in HA patients with inhibitors. CWA is a promising method for the quantitative monitoring of bypass therapy during routine automated clotting assays with a modified trigger reagent comprising a well-balanced mixture of Elg and TF. © 2013 International Society on

  11. Consecutive thrombelastography clot strength profiles in patients with severe sepsis and their association with 28-day mortality

    DEFF Research Database (Denmark)

    Ostrowski, Sisse R; Windeløv, Nis A; Ibsen, Michael

    2013-01-01

    , normocoagulable, and hypercoagulable TEG clot strength (maximum amplitude [MA]), respectively. Hypocoagulable patients had higher Sequential Organ Failure Assessment and disseminated intravascular coagulation scores compared with hypercoagulable patients and higher 28-day mortality compared with normocoagulable......PURPOSE: The aim of this study was to assess associations between consecutive thrombelastography (TEG) profiles and standard coagulation tests and disease severity and mortality in patients with severe sepsis. MATERIALS AND METHODS: This was a prospective observational study of adults with severe...

  12. The function of the milk-clotting enzymes bovine and camel chymosin studied by a fluorescence resonance energy transfer assay.

    Science.gov (United States)

    Jensen, Jesper Langholm; Jacobsen, Jonas; Moss, Marcia L; Rasmussen, Fred; Qvist, Karsten Bruun; Larsen, Sine; van den Brink, Johannes M

    2015-05-01

    Enzymatic coagulation of bovine milk can be divided in 2 steps: an enzymatic step, in which the Phe105-Met106 bond of the milk protein bovine κ-casein is cleaved, and an aggregation step. The aspartic peptidases bovine and camel chymosin (EC 3.4.23.4) are typically used to catalyze the enzymatic step. The most commonly used method to study chymosin activity is the relative milk-clotting activity test that measures the end point of the enzymatic and aggregation step. This method showed that camel chymosin has a 2-fold higher milk-clotting activity toward bovine milk than bovine chymosin. To enable a study of the enzymatic step independent of the aggregation step, a fluorescence resonance energy transfer assay has been developed using a peptide substrate derived from the 98-108 sequence of bovine κ-casein. This assay and Michaelis-Menten kinetics were employed to determine the enzymatic activity of camel and bovine chymosin under milk clotting-like conditions (pH 6.65, ionic strength 80 mM). The results obtained show that the catalytic efficiency of camel chymosin is 3-fold higher than bovine chymosin. The substrate affinity and catalytic activity of bovine and camel chymosin increase at lower pH (6.00 and 5.50). The glycosylation of bovine and camel chymosin did not affect binding of the fluorescence resonance energy transfer substrate, but doubly glycosylated camel chymosin seems to have slightly higher catalytic efficiency. In the characterization of the enzymes, the developed assay is easier and faster to use than the traditionally used relative milk-clotting activity test method. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Dynamics of Thrombin Generation and Flux from Clots during Whole Human Blood Flow over Collagen/Tissue Factor Surfaces.

    Science.gov (United States)

    Zhu, Shu; Lu, Yichen; Sinno, Talid; Diamond, Scott L

    2016-10-28

    Coagulation kinetics are well established for purified blood proteases or human plasma clotting isotropically. However, less is known about thrombin generation kinetics and transport within blood clots formed under hemodynamic flow. Using microfluidic perfusion (wall shear rate, 200 s(-1)) of corn trypsin inhibitor-treated whole blood over a 250-μm long patch of type I fibrillar collagen/lipidated tissue factor (TF; ∼1 TF molecule/μm(2)), we measured thrombin released from clots using thrombin-antithrombin immunoassay. The majority (>85%) of generated thrombin was captured by intrathrombus fibrin as thrombin-antithrombin was largely undetectable in the effluent unless Gly-Pro-Arg-Pro (GPRP) was added to block fibrin polymerization. With GPRP present, the flux of thrombin increased to ∼0.5 × 10(-12) nmol/μm(2)-s over the first 500 s of perfusion and then further increased by ∼2-3-fold over the next 300 s. The increased thrombin flux after 500 s was blocked by anti-FXIa antibody (O1A6), consistent with thrombin-feedback activation of FXI. Over the first 500 s, ∼92,000 molecules of thrombin were generated per surface TF molecule for the 250-μm-long coating. A single layer of platelets (obtained with αIIbβ3 antagonism preventing continued platelet deposition) was largely sufficient for thrombin production. Also, the overall thrombin-generating potential of a 1000-μm-long coating became less efficient on a per μm(2) basis, likely due to distal boundary layer depletion of platelets. Overall, thrombin is robustly generated within clots by the extrinsic pathway followed by late-stage FXIa contributions, with fibrin localizing thrombin via its antithrombin-I activity as a potentially self-limiting hemostatic mechanism. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Risk management in acute pulmonary embolism: correlation between right heart dysfunction, pulmonary clots distribution, biomarkers and prognosis

    Directory of Open Access Journals (Sweden)

    Luca Masotti

    2013-05-01

    Full Text Available BACKGROUND Right heart dysfunction (RHD is related to adverse outcomes in acute pulmonary embolism (PE. AIM OF THE STUDY To evaluate the relation between RHD, pulmonary clots distribution and biomarkers and prognosis of patients with PE. METHODS We analysed echocardiographic data of 70 patients with diagnosis of PE confirmed by pulmonary computer tomography, hCT. We considered the enddiastolic right/left ventricles ratio > 1 as index of RHD; echocardiographic data were compared with clots distribution in pulmonary vascular tree such as hCT findings and biomarkers. For each patient we calculated the shock index (heart rate/systolic blood pressure ratio, shock defined as ratio ≥ 1. RESULTS Hospital mortality was 8.5%. Mean age of dead patients was significantly higher compared to alive (85.67 vs 71.57 years, p < 0.05. 41% of patients revealed unilateral PE, 59% had bilateral. In 10% of patients main pulmonary artery was interested by clot, 48% of patients had involved one of the main branches, 90% had involved at least one of the lobar branches, 59% one of segmental branches of pulmonary arteries. 52% of patients had RHD. Mortality in RHD patients was 14.8% vs 8% in no RHD, p < 0.05. Mean values of troponin I and D-dimer were significantly higher in RHD patients. Shock index was ≥ 1 in 37.5% of RHD and 20% in no RHD. RHD patients showed significantly higher involvement of main pulmonary artery and its branches and higher bilateral involvement. CONCLUSIONS RHD is related to proximal and bilateral pulmonary clots distribution and troponin I and D-dimer values and poorer prognosis.

  15. Zeolite-based hemostat QuikClot releases calcium into blood and promotes blood coagulation in vitro.

    Science.gov (United States)

    Li, Jing; Cao, Wei; Lv, Xiao-xing; Jiang, Li; Li, Yue-jun; Li, Wang-zhou; Chen, Shao-zong; Li, Xue-yong

    2013-03-01

    To examine the changes in electrolyte concentrations after addition of zeolite-based hemostat QuikClot in blood and the effects of zeolite on blood coagulation in vitro. Fresh blood was taken from healthy adult volunteers and sheep, and the electrolyte concentrations in blood were measured using a blood electrolyte analyzer. Zeolite Saline Solution (ZSS) was prepared by addition of 2 g zeolite to 0.9% NaCl solution (4, 8, or 16 mL). The electrolytes in ZSS were measured using inductively coupled plasma atomic emission spectroscopy. The prothrombin time (PT) and activated partial thromboplastin time (APTT) of blood were measured using the test tube method. The activated clotting time (ACT) and clotting rate (CR) of blood were measured with Sonoclot Coagulation and Platelet Function Analyzer. Addition of zeolite (50 and 100 mg) in 2 mL human blood significantly increased Ca(2+) concentration, while Na(+) and K(+) concentrations were significantly decreased. Addition of zeolite (50 and 100 mg) in 0.9% NaCl solution (2 mL) caused similar changes in Ca(2+) and Na(+) concentrations. Si(4+) (0.2434 g/L) and Al(3+) (0.2575 g/L) were detected in ZSS (2 g/8 mL). Addition of ZSS in sheep blood shortened APTT in a concentration dependent manner, without changing PT. ZSS or aqueous solution of CaCl2 that contained Ca(2+) concentration identical to that of ZSS significantly shortened ACT in human blood without significantly changing CR, and the effect of ZSS on ACT was not significantly different from that of CaCl2. Zeolite releases Ca(2+) into blood, thus accelerating the intrinsic pathway of blood coagulation and shortening the clot formation time.

  16. Transfusion packages for massively bleeding patients: the effect on clot formation and stability as evaluated by Thrombelastograph (TEG)

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Stensballe, J.

    2008-01-01

    We investigated the effect of administering a transfusion package encompassing 5 red blood cells (RBC), 5 fresh frozen plasma (FFP), and 2 platelet concentrates (PC) on clot formation and stability as evaluated by Thrombelastograph (TEG) in 10 patients presenting with massive bleeding. Blood...... was successful and 6 of these patients survived. The result indicates that an early balanced transfusion strategy maintains haemostatic competence in massively bleeding patients Udgivelsesdato: 2008/8...

  17. Reduced clot strength upon admission, evaluated by thrombelastography (TEG), in trauma patients is independently associated with increased 30-day mortality

    DEFF Research Database (Denmark)

    Nystrup, Kristin B; Windeløv, Nis A; Thomsen, Annemarie B

    2011-01-01

    Exsanguination due to uncontrolled bleeding is the leading cause of potentially preventable deaths among trauma patients. About one third of trauma patients present with coagulopathy on admission, which is associated with increased mortality and will aggravate bleeding in a traumatized patient. T....... Thrombelastographic (TEG) clot strength has previously been shown to predict outcome in critically ill patients. The aim of the present study was to investigate this relation in the trauma setting....

  18. The Sentinel Clot Sign: a Useful CT Finding for the Evaluation of Intraperitoneal Bladder Rupture Following Blunt Trauma

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sang Soo; Jeong, Yong Yeon; Chung, Tae Woong; Yoon, Woong; Kang, Heoung Keun; Kang, Taek Won; Shin, Hee Young [Chonnam National University Medical School, Gwangju (Korea, Republic of)

    2007-12-15

    To evaluate the frequency and relevance of the 'sentinel clot' sign on CT for patients with traumatic intraperitoneal bladder rupture in a retrospective study. During a recent 42-month period, 74 consecutive trauma patients (45 men, 29 women; age range, 12 84 years; mean age, 50.8 years) with gross hematuria were examined by the use of intravenous contrast enhanced CT of the abdomen and pelvis, followed by retrograde cystography. Contrast-enhanced CT scanning was performed by using a helical CT scanner. CT images were retrospectively reviewed in consensus by two radiologists. The CT findings including the sentinel clot sign, pelvic fracture, traumatic injury to other abdominal viscera, and the degree of intraperitoneal free fluid were assessed and statistically analyzed using the two-tailed x{sup 2} test. Twenty of the 74 patients had intraperitoneal bladder rupture. The sentinel clot sign was seen for 16 patients (80%) with intraperitoneal bladder rupture and for four patients (7%) without intraperitoneal bladder rupture (p < 0.001). Pelvic fracture was noted in five patients (25%) with intraperitoneal bladder rupture and in 39 patients (72%) without intraperitoneal bladder rupture (p < 0.001). Intraperitoneal free fluid was found in all patients (100%) with intraperitoneal bladder rupture, irrespective of an associated intraabdominal visceral injury, whereas 19 (35%) of the 54 patients without intraperitoneal bladder rupture had intraperitoneal free fluid (p < 0.001). Detection and localization of the sentinel clot sign abutting on the bladder dome may improve the accuracy of CT in the diagnosis of traumatic intraperitoneal bladder rupture, especially when the patients present with gross hematuria.

  19. Reduced clot strength upon admission, evaluated by thrombelastography (TEG, in trauma patients is independently associated with increased 30-day mortality

    Directory of Open Access Journals (Sweden)

    Thomsen Annemarie B

    2011-09-01

    Full Text Available Abstract Introduction Exsanguination due to uncontrolled bleeding is the leading cause of potentially preventable deaths among trauma patients. About one third of trauma patients present with coagulopathy on admission, which is associated with increased mortality and will aggravate bleeding in a traumatized patient. Thrombelastographic (TEG clot strength has previously been shown to predict outcome in critically ill patients. The aim of the present study was to investigate this relation in the trauma setting. Methods A retrospective study of trauma patients with an injury severity qualifying them for inclusion in the European Trauma Audit and Research Network (TARN and a TEG analysis performed upon arrival at the trauma centre. Results Eighty-nine patients were included. The mean Injury Severity Score (ISS was 21 with a 30-day mortality of 17%. Patients with a reduced clot strength (maximal amplitude Conclusion Low clot strength upon admission is independently associated with increased 30-day mortality in trauma patients and it could be speculated that targeted interventions based on the result of the TEG analysis may improve patient outcome. Prospective randomized trials investigating this potential are highly warranted.

  20. Fibrinolytic Activity and Dose-Dependent Effect of Incubating Human Blood Clots in Caffeic Acid Phenethyl Ester: In Vitro Assays

    Directory of Open Access Journals (Sweden)

    Abuzar Elnager

    2015-01-01

    Full Text Available Background. Caffeic acid phenethyl ester (CAPE has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM. After 3 hours, D-dimer (DD levels and WB clot weights were measured for each concentration. Thromboelastography (TEG parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM. The 50% effective dose (ED50 of CAPE (based on DD was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted.

  1. Staphylococcus aureus-induced clotting of plasma is an immune evasion mechanism for persistence within the fibrin network.

    Science.gov (United States)

    Loof, Torsten G; Goldmann, Oliver; Naudin, Clément; Mörgelin, Matthias; Neumann, Yvonne; Pils, Marina C; Foster, Simon J; Medina, Eva; Herwald, Heiko

    2015-03-01

    Recent work has shown that coagulation and innate immunity are tightly interwoven host responses that help eradicate an invading pathogen. Some bacterial species, including Staphylococcus aureus, secrete pro-coagulant factors that, in turn, can modulate these immune reactions. Such mechanisms may not only protect the micro-organism from a lethal attack, but also promote bacterial proliferation and the establishment of infection. Our data showed that coagulase-positive S. aureus bacteria promoted clotting of plasma which was not seen when a coagulase-deficient mutant strain was used. Furthermore, in vitro studies showed that this ability constituted a mechanism that supported the aggregation, survival and persistence of the micro-organism within the fibrin network. These findings were also confirmed when agglutination and persistence of coagulase-positive S. aureus bacteria at the local focus of infection were studied in a subcutaneous murine infection model. In contrast, the coagulase-deficient S. aureus strain which was not able to induce clotting failed to aggregate and to persist in vivo. In conclusion, our data suggested that coagulase-positive S. aureus have evolved mechanisms that prevent their elimination within a fibrin clot. © 2015 The Authors.

  2. Locally Sustainable School Lunch Intervention Improves Hemoglobin and Hematocrit Levels and Body Mass Index among Elementary Schoolchildren in Rural West Java, Indonesia.

    Science.gov (United States)

    Sekiyama, Makiko; Roosita, Katrin; Ohtsuka, Ryutaro

    2017-08-12

    School lunch is not provided in public elementary schools in Indonesia, and students frequently buy and eat snacks at school. We hypothesized that providing a traditional Sundanese meal as school lunch would be beneficial for children in rural West Java. To test this hypothesis, we evaluated the effect of a 1-month school lunch intervention aiming at sustainability and based on children's nutritional intake, hemoglobin and hematocrit levels, and body mass index (BMI). A lunch (including rice, vegetable dish, animal protein dish, plant protein dish, and fruit) containing one-third of the recommended daily allowance of energy was offered every school day for 1 month, targeting 68 fourth-grade elementary schoolchildren. At baseline, the prevalence of anemia was 33.3%. The prevalence of stunting and underweight were 32.4% and 2.9%, respectively, whereas that of overweight and obesity combined was 17.6%, indicating a double burden of malnutrition among the subjects. During the intervention, intakes of protein ( p < 0.05), calcium ( p < 0.05), and vitamin C ( p < 0.001) significantly increased, while that of fat significantly decreased ( p < 0.001). After the intervention, hemoglobin ( p < 0.05) and hematocrit ( p < 0.05) levels were significantly improved, thereby almost halving the rate of anemia. These changes were significantly larger in the baseline anemic group than the non-anemic group ( p < 0.01). BMI significantly increased in the baseline underweight/normal group ( p < 0.001) but not in the overweight/obese group. The school lunch intervention significantly improved nutritional intakes and health statuses, implying its potential for reducing anemia and resolving the double burden of malnutrition among rural Indonesian schoolchildren.

  3. Pilot production of recombinant human clotting factor IX from transgenic sow milk.

    Science.gov (United States)

    Sun, Yu-ling; Chang, Yuo-sheng; Lin, Yin-shen; Yen, Chon-ho

    2012-06-01

    Valuable pharmaceutical proteins produced from the mammary glands of transgenic livestock have potential use in the biomedical industry. In this study, recombinant human clotting factor IX (rhFIX) produced from transgenic sow milk for preclinical animal studies have been established. The transgenic sow milk was skimmed and treated with sodium phosphate buffer to remove abundant casein protein. Then, the γ-carboxylated rhFIX fraction was segregated through the Q Sepharose chromatography from uncarboxylated one. For safety issue, the process included virus inactivation by solvent/detergent (S/D) treatment. Subsequently, the S/D treated sample was loaded into the Heparin Sepharose column to recover the rhFIX fraction, which was then reapplied to the Heparin Sepharose column to enhance rhFIX purity and lower the ratio of activated form rhFIX (rhFIXa) easily. This was possible due to the higher affinity of the Heparin affinity sorbent for rhFIXa than for the rhFIX zymogen. Furthermore, an IgA removal column was used to eliminate porcine IgA in purified rhFIX. Finally, nanofiltration was performed for viral clearance. Consequently, a high-quality rhFIX product was produced (approximately 700 mg per batch). Other values for final rhFIX preparation were as follows: purity, >99%; average specific activity, 415.6±57.7 IU/mL and total milk impurity, production of bioactive rhFIX from transgenic sow milk. The overall manufacturing process presented here has the potential for industrial production of rhFIX for treatment of hemophilia B patients. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Dynamics of motion of a clot through an arterial bifurcation: a finite element analysis

    Science.gov (United States)

    Abolfazli, Ehsan; Fatouraee, Nasser; Vahidi, Bahman

    2014-10-01

    Although arterial embolism is important as a major cause of brain infarction, little information is available about the hemodynamic factors which govern the path emboli tend to follow. A method which predicts the trajectory of emboli in carotid arteries would be of a great value in understanding ischemic attack mechanisms and eventually devising hemodynamically optimal techniques for prevention of strokes. In this paper, computational models are presented to investigate the motion of a blood clot in a human carotid artery bifurcation. The governing equations for blood flow are the Navier-Stokes formulations. To achieve large structural movements, the arbitrary Lagrangian-Eulerian formulation (ALE) with an adaptive mesh method was employed for the fluid domain. The problem was solved by simultaneous solution of the fluid and the structure equations. In this paper, the phenomenon was simulated under laminar and Newtonian flow conditions. The measured stress-strain curve obtained from ultrasound elasticity imaging of the thrombus was set to a Sussman-Bathe material model representing embolus material properties. Shear stress magnitudes in the inner wall of the internal carotid artery (ICA) were measured. High magnitudes of wall shear stress (WSS) occurred in the areas in which the embolus and arterial are in contact with each other. Stress distribution in the embolus was also calculated and areas prone to rapture were identified. Effects of embolus size and embolus density on its motion velocity were investigated and it was observed that an increase in either embolus size or density led to a reduction in movement velocity of the embolus. Embolus trajectory and shear stress from a simulation of embolus movement in a three-dimensional model with patient-specific carotid artery bifurcation geometry are also presented.

  5. Differences in lupus anticoagulant final conclusion through clotting time or Rosner index for mixing test interpretation.

    Science.gov (United States)

    Depreter, Barbara; Devreese, Katrien M J

    2016-09-01

    Lupus anticoagulant (LAC) testing includes a screening, mixing and confirmation step. Although recently published guidelines on LAC testing are a useful step towards standardization, a lack of consensus remains whether to express mixing tests in clotting time (CT) or index of circulating anticoagulant (ICA). The influence of anticoagulant therapy, e.g. vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC) on both methods of interpretation remains to be investigated. The objective of this study was to contribute to a simplification and standardization of the LAC three-step interpretation on the level of the mixing test. Samples from 148 consecutive patients with LAC request and prolonged screening step, and 77 samples from patients non-suspicious for LAC treated with VKA (n=37) or DOAC (n=30) were retrospectively evaluated. An activated partial thromboplastin time (aPTT) and dilute Russell's viper venom time (dRVVT) were used for routine LAC testing. The supplemental anticoagulant samples were tested with dRVVT only. We focused on the interpretation differences for mixing tests expressed as CT or ICA and compared the final LAC conclusion within each distinct group of concordant and discordant mixing test results. Mixing test interpretation by CT resulted in 10 (dRVVT) and 16 (aPTT) more LAC positive patients compared to interpretation with ICA. Isolated prolonged dRVVT screen mix ICA results were exclusively observed in samples from VKA-treated patients without suspicion for LAC. We recommend using CT in respect to the 99th percentile cut-off for interpretation of mixing steps in order to reach the highest sensitivity and specificity in LAC detection.

  6. The effects of acclimatization on blood clotting parameters in exertional heat stress

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    Vesić Zoran

    2013-01-01

    Full Text Available Background/Aim. Exertional heat stress is a common problem in military services. Considering the coagulation abnormalities are of major importance in development of severe heat stroke, we wanted to examine changes in hemostatic parameters in soldiers during exertional heat stress test as well as the effects of a 10-day passive or active acclimatization in a climatic chamber. Methods. A total of 40 male soldiers with high aerobic capacity performed exertional heat stress test (EHST either in cool [20ºC, 16ºC wet bulb globe temperature (WBGT], or hot (40ºC, 29ºC, (WBGT environment, unacclimatized (U or after 10 days of passive (P or active (A acclimatization. Physiological strain was measured by tympanic temperatures (Tty and heart rates (HR. Platelet count (PC, antithrombin III (AT, and prothrombin time (PT were assessed in blood samples collected before and immediately after the EHST. Results. EHST in hot conditions induced physiological heat stress (increase in Tty and HR, with a significant increase in prothrombin time in the groups U and A. Platelet counts were significantly higher after the EHST compared to the basic levels in all the investigated groups, regardless environmental conditions and acclimatization state. Antithrombin levels were not affected by EHST whatsoever. Conclusion. In the trained soldiers, physiological heat stress caused mild changes in some serum parameters of blood clotting such as prothrombin time, while others such as antithrombin levels were not affected. Platelet counts were increased after EHST in all groups. A 10-day passive or active acclimatization in climatic chamber showed no effect on parameters investigated.

  7. Batroxobin Binds Fibrin with Higher Affinity and Promotes Clot Expansion to a Greater Extent than Thrombin*

    Science.gov (United States)

    Vu, Trang T.; Stafford, Alan R.; Leslie, Beverly A.; Kim, Paul Y.; Fredenburgh, James C.; Weitz, Jeffrey I.

    2013-01-01

    Batroxobin is a thrombin-like serine protease from the venom of Bothrops atrox moojeni that clots fibrinogen. In contrast to thrombin, which releases fibrinopeptide A and B from the NH2-terminal domains of the Aα- and Bβ-chains of fibrinogen, respectively, batroxobin only releases fibrinopeptide A. Because the mechanism responsible for these differences is unknown, we compared the interactions of batroxobin and thrombin with the predominant γA/γA isoform of fibrin(ogen) and the γA/γ′ variant with an extended γ-chain. Thrombin binds to the γ′-chain and forms a higher affinity interaction with γA/γ′-fibrin(ogen) than γA/γA-fibrin(ogen). In contrast, batroxobin binds both fibrin(ogen) isoforms with similar high affinity (Kd values of about 0.5 μm) even though it does not interact with the γ′-chain. The batroxobin-binding sites on fibrin(ogen) only partially overlap with those of thrombin because thrombin attenuates, but does not abrogate, the interaction of γA/γA-fibrinogen with batroxobin. Furthermore, although both thrombin and batroxobin bind to the central E-region of fibrinogen with a Kd value of 2–5 μm, the α(17–51) and Bβ(1–42) regions bind thrombin but not batroxobin. Once bound to fibrin, the capacity of batroxobin to promote fibrin accretion is 18-fold greater than that of thrombin, a finding that may explain the microvascular thrombosis that complicates envenomation by B. atrox moojeni. Therefore, batroxobin binds fibrin(ogen) in a manner distinct from thrombin, which may contribute to its higher affinity interaction, selective fibrinopeptide A release, and prothrombotic properties. PMID:23612970

  8. Comparison of Hemostasis Times With a Kaolin-Based Hemostatic Pad (QuikClot Radial) vs Mechanical Compression (TR Band) Following Transradial Access: A Pilot Prospective Study.

    Science.gov (United States)

    Roberts, Jonathan S; Niu, Jianli; Pastor-Cervantes, Juan A

    2017-10-01

    Hemostasis following transradial access (TRA) is usually achieved by mechanical compression. We investigated use of the QuikClot Radial hemostasis pad (Z-Medica) compared with the TR Band (Terumo Medical) to shorten hemostasis after TRA. Thirty patients undergoing TRA coronary angiography and/or percutaneous coronary intervention were randomized into three cohorts post TRA: 10 patients received mechanical compression with the TR Band, 10 patients received 30 min of compression with the QuikClot Radial pad, and 10 patients received 60 min of compression with the QuikClot Radial pad. Times to hemostasis and access-site complications were recorded. Radial artery patency was evaluated 1 hour after hemostasis by the reverse Barbeau's test. There were no differences in patient characteristics, mean dose of heparin (7117 ± 1054 IU), or mean activated clotting time value (210 ± 50 sec) at the end of procedure among the three groups. Successful hemostasis was achieved in 100% of patients with both the 30-min and 60-min compression groups using the QuikClot pad. Hemostasis failure occurred in 50% of patients when the TR Band was initially weaned at the protocol-driven time (40 min after sheath removal). Mean compression time for hemostasis with the TR Band was 149.4 min compared with 30.7 min and 60.9 min for the 30-min and 60-min QuikClot groups, respectively. No radial artery occlusion occurred in any subject at the end of the study. Use of the QuikClot Radial pad following TRA in this pilot trial significantly shortened hemostasis times when compared with the TR Band, with no increased complications noted.

  9. Point-of-Care Versus Central Laboratory Measurements of Hemoglobin, Hematocrit, Glucose, Bicarbonate and Electrolytes: A Prospective Observational Study in Critically Ill Patients.

    Science.gov (United States)

    Allardet-Servent, Jérôme; Lebsir, Melissa; Dubroca, Christian; Fabrigoule, Martine; Jordana, Sylvie; Signouret, Thomas; Castanier, Matthias; Thomas, Guillemette; Soundaravelou, Rettinavelou; Lepidi, Anne; Delapierre, Laurence; Penaranda, Guillaume; Halfon, Philippe; Seghboyan, Jean-Marie

    2017-01-01

    Rapid detection of abnormal biological values using point-of-care (POC) testing allows clinicians to promptly initiate therapy; however, there are concerns regarding the reliability of POC measurements. We investigated the agreement between the latest generation blood gas analyzer and central laboratory measurements of electrolytes, bicarbonate, hemoglobin, hematocrit, and glucose. 314 paired samples were collected prospectively from 51 critically ill patients. All samples were drawn simultaneously in the morning from an arterial line. BD Vacutainer tubes were analyzed in the central laboratory using Beckman Coulter analyzers (AU 5800 and DxH 800). BD Preset 3 ml heparinized-syringes were analyzed immediately in the ICU using the POC Siemens RAPIDPoint 500 blood gas system. We used CLIA proficiency testing criteria to define acceptable analytical performance and interchangeability. Biases, limits of agreement (±1.96 SD) and coefficients of correlation were respectively: 1.3 (-2.2 to 4.8 mmol/L, r = 0.936) for sodium; 0.2 (-0.2 to 0.6 mmol/L, r = 0.944) for potassium; -0.9 (-3.7 to 2 mmol/L, r = 0.967) for chloride; 0.8 (-1.9 to 3.4 mmol/L, r = 0.968) for bicarbonate; -11 (-30 to 9 mg/dL, r = 0.972) for glucose; -0.8 (-1.4 to -0.2 g/dL, r = 0.985) for hemoglobin; and -1.1 (-2.9 to 0.7%, r = 0.981) for hematocrit. All differences were below CLIA cut-off values, except for hemoglobin. Compared to central Laboratory analyzers, the POC Siemens RAPIDPoint 500 blood gas system satisfied the CLIA criteria of interchangeability for all tested parameters, except for hemoglobin. These results are warranted for our own procedures and devices. Bearing these restrictions, we recommend clinicians to initiate an appropriate therapy based on POC testing without awaiting a control measurement.

  10. Point-of-Care Versus Central Laboratory Measurements of Hemoglobin, Hematocrit, Glucose, Bicarbonate and Electrolytes: A Prospective Observational Study in Critically Ill Patients.

    Directory of Open Access Journals (Sweden)

    Jérôme Allardet-Servent

    Full Text Available Rapid detection of abnormal biological values using point-of-care (POC testing allows clinicians to promptly initiate therapy; however, there are concerns regarding the reliability of POC measurements. We investigated the agreement between the latest generation blood gas analyzer and central laboratory measurements of electrolytes, bicarbonate, hemoglobin, hematocrit, and glucose.314 paired samples were collected prospectively from 51 critically ill patients. All samples were drawn simultaneously in the morning from an arterial line. BD Vacutainer tubes were analyzed in the central laboratory using Beckman Coulter analyzers (AU 5800 and DxH 800. BD Preset 3 ml heparinized-syringes were analyzed immediately in the ICU using the POC Siemens RAPIDPoint 500 blood gas system. We used CLIA proficiency testing criteria to define acceptable analytical performance and interchangeability.Biases, limits of agreement (±1.96 SD and coefficients of correlation were respectively: 1.3 (-2.2 to 4.8 mmol/L, r = 0.936 for sodium; 0.2 (-0.2 to 0.6 mmol/L, r = 0.944 for potassium; -0.9 (-3.7 to 2 mmol/L, r = 0.967 for chloride; 0.8 (-1.9 to 3.4 mmol/L, r = 0.968 for bicarbonate; -11 (-30 to 9 mg/dL, r = 0.972 for glucose; -0.8 (-1.4 to -0.2 g/dL, r = 0.985 for hemoglobin; and -1.1 (-2.9 to 0.7%, r = 0.981 for hematocrit. All differences were below CLIA cut-off values, except for hemoglobin.Compared to central Laboratory analyzers, the POC Siemens RAPIDPoint 500 blood gas system satisfied the CLIA criteria of interchangeability for all tested parameters, except for hemoglobin. These results are warranted for our own procedures and devices. Bearing these restrictions, we recommend clinicians to initiate an appropriate therapy based on POC testing without awaiting a control measurement.

  11. Heat transfer analysis on peristaltically induced motion of particle-fluid suspension with variable viscosity: Clot blood model.

    Science.gov (United States)

    Bhatti, M M; Zeeshan, A; Ellahi, R

    2016-12-01

    In this article, heat transfer analysis on clot blood model of the particle-fluid suspension through a non-uniform annulus has been investigated. The blood propagating along the whole length of the annulus was induced by peristaltic motion. The effects of variable viscosity and slip condition are also taken into account. The governing flow problem is modeled using lubrication approach by taking the assumption of long wavelength and creeping flow regime. The resulting equation for fluid phase and particle phase is solved analytically and closed form solutions are obtained. The physical impact of all the emerging parameters is discussed mathematically and graphically. Particularly, we considered the effects of particle volume fraction, slip parameter, the maximum height of clot, viscosity parameter, average volume flow rate, Prandtl number, Eckert number and fluid parameter on temperature profile, pressure rise and friction forces for outer and inner tube. Numerical computations have been used to determine the behavior of pressure rise and friction along the whole length of the annulus. The present study is also presented for an endoscope as a special case of our study. It is observed that greater influence of clot tends to rise the pressure rise significantly. It is also found that temperature profile increases due to the enhancement in Prandtl number, Eckert number, and fluid parameter. The present study reveals that friction forces for outer tube have higher magnitude as compared to the friction forces for an inner tube. In fact, the results for present study can also be reduced to the Newtonian fluid by taking ζ → ∞. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  12. Design and Testing of a Minimally Invasive Blood Clot Removal Device ConstructedWith Elements of Superelastic Nitinol

    Science.gov (United States)

    Puffer, Andrew J.

    Many vascular system problems stem from insufficient blood return flow to the heart. One of the main causes is a blockage within veins or arteries known as a blood clot, or thrombus. This can occur after trauma, surgery, or other phenomenological reasons. Each year in the U.S. more than 175,000 bypass procedures and more than 160,000 amputations resulting from peripheral vessel disease are performed. Clinical data indicates that clot removal devices and procedures can reduce the need for an amputation by 80 percent. Percutaneous thrombectomy refers to the removal of thrombus using catheter based non-surgical methods. The ultimate goal of any modality to treat these conditions of the arterial or venous system is to restore patency, quickly, safely, and cost effectively. Catheter directed thrombectomy and thrombolysis is less traumatic and avoids the morbidity and mortality associated with conventional surgical technique. As a result, there has been a push recently for the use of percutaneous mechanical thrombectomy (PMT) devices. However, all devices have their own set of drawbacks: distal embolization, vessel wall trauma, hemolysis, to name a few. Ongoing efforts have been made to create a prototype thrombectomy device that uses elements of superelastic nitinol (a type of shape memory alloy), that seeks to address some of the drawbacks of current devices. The prototype was designed and tested in a simulated human circulatory system along side a commercially available device (The DiverCE Clot Extraction Catheter). The test evaluated how well the devices minimized distal embolization of a human blood clot created in vitro.. Results of the testing showed that the prototype device created significantly less embolization when compared to the DiverCE particles greater than 102mum (p = 0.0332). Means were statistically not different for particles between 25mum and 102mum (p = 0.2454), and particles between 5mum and 25mum (p = 0.6524). In addition the prototype was shown

  13. Partial deletion of the αC-domain in the Fibrinogen Perth variant is associated with thrombosis, increased clot strength and delayed fibrinolysis.

    Science.gov (United States)

    Westbury, Sarah K; Duval, Cédric; Philippou, Helen; Brown, Rebecca; Lee, Kurtis R; Murden, Sherina L; Phillips, Emma; Reilly-Stitt, Christopher; Whalley, Daniel; Ariëns, Robert A; Mumford, Andrew D

    2013-12-01

    Genetic fibrinogen (FGN) variants that are associated with bleeding or thrombosis may be informative about fibrin polymerisation, structure and fibrinolysis. We report a four generation family with thrombosis and heritable dysfibrinogenaemia segregating with a c.[1541delC];[=] variation in FGA (FGN-Perth). This deletion predicts a truncated FGN αC-domain with an unpaired terminal Cys at residue 517 of FGN-Aα. In keeping with this, SDS-PAGE of purified FGN-Perth identified a truncated FGN-Aα chain with increased co-purification of albumin, consistent with disulphide bonding to the terminal Cys of the variant FGN-Aα. Clot visco-elastic strength in whole blood containing FGN-Perth was greater than controls and tPA-mediated fibrinolysis was delayed. In FGN-Perth plasma and in purified FGN-Perth, there was markedly reduced final turbidity after thrombin-mediated clot generation. Consistent with this, FGN-Perth formed tighter, thinner fibrin fibres than controls indicating defective lateral aggregation of protofibrils. Clots generated with thrombin in FGN-Perth plasma were resistant to tPA-mediated fibrinolysis. FGN-Perth clot also displayed impaired tPA-mediated plasmin generation but incorporated α2-antiplasmin at a similar rate to control. Impaired fibrinolysis because of defective plasmin generation potentially explains the FGN-Perth clinical phenotype. These findings highlight the importance of the FGN αC-domain in the regulation of clot formation and fibrinolysis.

  14. The effect of Carica papaya leaves extract capsules on platelets count and hematocrit levels in acute febrile illness with thrombocytopenia patient

    Directory of Open Access Journals (Sweden)

    Abhishek Singhai

    2016-01-01

    Full Text Available Carica papaya leaves have been used in folk medicine for centuries. In addition to the nutritional value of its fruit, the leaves of C. papaya possess medicinal properties and are widely used in traditional medicines. This study was conducted to determine the effect of C. papaya leaves extract capsules (CPC in acute febrile illness with thrombocytopenia. An observational, prospective, uncontrolled, open label, single centre study in Indian patients. Total 80 patients were enrolled in the study. These subjects were randomized into two groups of 40, including the control and intervention groups (received two CPC three times daily. The result showed that CPC had significant increased the platelet count (p<0.05 and maintained stability of hematocrit in the normal level. Carica papaya leaf extract could be used as an additional or as a complementary drug in acute febrile illness patients with thrombocytopenia; it accelerates the increase in the platelet count and shorten the hospitalization thereby reducing the cost of hospitalization significantly.

  15. Absolute transmitted light plethysmography for assessment of dental pulp vitality through quantification of pulp chamber hematocrit by a three-layer model.

    Science.gov (United States)

    Kakino, Satoko; Takagi, Yuzo; Takatani, Setsuo

    2008-01-01

    After confirming that the gingival circulation had little effect on transmitted light plethysmography measurement in the upper central incisor in both in vivo experiments and numerical Monte Carlo simulation studies, a three-layer model comprising of a pulp chamber sandwiched between two dentin layers has been introduced to quantify the pulp chamber hematocrit (Hctp) from the measured optical density. Two-flux theory was utilized to derive a mathematical equation for transmitted intensity in terms of tooth dimensions, Hctp, and light-source wavelength. Each layer was assumed homogeneous so as to represent its optical properties by the bulk absorption and scattering constants. The mean error between the Hctp estimate based on the three-layer-model equation and the Hctp actual in the extracted model tooth was -0.00115 with standard deviation (SD) of 0.00733 at 522 nm wavelength, while for 810 nm +0.09157 and 0.02493. The Hctp estimate of the upper central incisor in 10 young volunteers at 522 nm using the three-layer model ranged from 0.002 to 0.061 with the mean of 0.032. The Hctp change reflects blood volume shift in the pulp microcirculation to possibly indicate dental pulp vitality.

  16. The relationship between serum total testosterone and free testosterone levels with serum hemoglobin and hematocrit levels: a study in 1221 men.

    Science.gov (United States)

    Shin, Yu Seob; You, Jae Hyung; Cha, Jai Seong; Park, Jong Kwan

    2016-12-01

    To investigate the relationship between serum total testosterone (TT) and free testosterone (FT) levels in men with anemia. We reviewed the records of 1221 subjects between March 2009 and December 2014. All the subjects' blood samples were drawn for TT and FT assays. Their serum hemoglobin (Hb) and serum hematocrit (Hct) levels were measured. The primary objective of our study was to investigate the association between TT and FT levels with Hb and Hct levels. The mean age was 59.82 ± 12.71 years. The mean TT and FT levels were 4.54 ± 2.02 ng/mL and 10.63 ± 3.69 pg/mL, respectively. The mean Hb and Hct levels were 14.72 ± 1.34 g/dL and 43.11 ± 3.75%, respectively. Subjects with low TT (Testosterone replacement therapy may be effective in men with hypogonadism to reduce the incidence of anemia.

  17. Effects of competitive red blood cell binding and reduced hematocrit on the blood and plasma levels of (/sup 14/C)Indapamide in the rat

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    Lettieri, J.T.; Portelli, S.T.

    1983-02-01

    The effects of chlorthalidone and acetazolamide on the red blood cell binding of indapamide were investigated. Both drugs caused a substantial decrease in the amount of indapamide bound to the erythrocytes in vitro. This effect was demonstrated by a change in the indapamide blood/plasma ratio from approximately 6 in control samples, to a value of 1 when either of the displacing agents was added. Coadministration of acetazolamide with /sup 14/C-labeled indapamide to rats, resulted in a 5-fold drop in the blood levels of total radioactivity, relative to rats dosed with (/sup 14/C)indapamide alone. Concomitantly, there was a 2-fold increase in the plasma levels of total radioactivity after acetazolamide coadministration. In rats whose hematocrits had been reduced by extensive bleeding, there were only minor alterations in the blood/plasma partitioning of (/sup 14/C)indapamide. Thus, chlorthalidone and acetazolamide were able to displace indapamide from erythrocytes in vitro and in vivo, possibly by competition at a carbonic anhydrase binding site. The pharmacokinetics of drugs which are extensively bound to erythrocytes may be significantly altered by the presence of other agents capable of competitive binding.

  18. Hematocrit and plasma albumin levels difference may be a potential biomarker to discriminate preeclampsia and eclampsia in patients with hypertensive disorders of pregnancy.

    Science.gov (United States)

    Dai, Dong-Mei; Cao, Jing; Yang, Hong-Mei; Sun, Hai-Mei; Su, Yu; Chen, Yuan-Yuan; Fang, Xiao; Xu, Wang-Bin

    2017-01-01

    We evaluated whether alterations of hemoglobin (HB), hematocrit (HCT), serum albumin level (ALB), and the difference of HCT and ALB can be used in the diagnosis of preeclampsia and eclampsia in patients with hypertensive disorders of pregnancy (HDP). A total of 509 individuals were recruited and divided into 4 groups: Group 1, 170 healthy non-pregnant women; Group 2, 125 normal pregnant women; Group 3, 105 pregnant women diagnosed with gestational and chronic hypertension; Group 4, 109 pregnant women diagnosed as having preeclampsia and eclampsia. Data of HB, HCT, ALB, globulin (GLB) were collected at the time of a prenatal examination during the third trimester. Alterations in the HCT and the ALB levels in these groups were significantly different. Group 4 had a higher mean HCT-ALB value (P57.0%, specificity>98.9%), respectively. The value of HCT-ALB>12.65 might be used as a potential biomarker for the auxiliary diagnosis of preeclampsia and eclampsia in HDP. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Antipsychotic Drugs Inhibit Platelet Aggregation via P2Y1 and P2Y12 Receptors

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    Chang-Chieh Wu

    2016-01-01

    Full Text Available Antipsychotic drugs (APDs used to treat clinical psychotic syndromes cause a variety of blood dyscrasias. APDs suppress the aggregation of platelets; however, the underlying mechanism remains unknown. We first analyzed platelet aggregation and clot formation in platelets treated with APDs, risperidone, clozapine, or haloperidol, using an aggregometer and rotational thromboelastometry (ROTEM. Our data indicated that platelet aggregation was inhibited, that clot formation time was increased, and that clot firmness was decreased in platelets pretreated with APDs. We also examined the role two major adenosine diphosphate (ADP receptors, P2Y1 and P2Y12, play in ADP-mediated platelet activation and APD-mediated suppression of platelet aggregation. Our results show that P2Y1 receptor stimulation with ADP-induced calcium influx was inhibited by APDs in human and rats’ platelets, as assessed by in vitro or ex vivo approach, respectively. In contrast, APDs, risperidone and clozapine, alleviated P2Y12-mediated cAMP suppression, and the release of thromboxane A2 and arachidonic acid by activated platelets decreased after APD treatment in human and rats’ platelets. Our data demonstrate that each APD tested significantly suppressed platelet aggregation via different mechanisms.

  20. New photoacoustic platform for early detection of circulating clots to prevent stroke and other fatal thromboembolic complications (Conference Presentation)

    Science.gov (United States)

    Carey, Kai A.

    2017-03-01

    Nearly 800,000 people in the U.S. experience an incident of stroke each year; 80% of these are first time occurrences and 87% are ischemic in nature. Someone dies of a stroke every few minutes in the U.S. but despite its prevalence there have been minimal advances in the early detection and screening of thromboembolic events, especially during patient post-operative periods or in genetically predisposed individuals. Environmental or genetic factors may disrupt the balance between coagulation and lysis of micro-thrombi in circulation and increase the risk of stroke. We introduced here a novel in vivo multicolor negative-contrast photoacoustic (PA) flow cytometry (PAFC ) platform with many innovations including customized high pulse repetition rate 1064 laser from IPG Photonics Corporation, powerful laser diode array, multichannel optical schematic, and time-resolved recording system. Using animal models, we verified the potential of this technology to detect small clots in relatively large vessels in vivo. If future clinical trials using a cost-effective, easy-to-use, safe, watch-like, wearable PA probe are successful, PAFC could provide breakthroughs in early monitoring of the growth in size and number of small clots that may predict and potentially prevent fatal thromboembolic complications. We also believe that this technology could be utilized to assess therapeutic benefits of anticoagulants and develop more efficient dosage in treatments by analyzing changes in the composition and frequency of micro-thrombi

  1. High-intensity focused ultrasound sonothrombolysis: the use of perfluorocarbon droplets to achieve clot lysis at reduced acoustic power.

    Science.gov (United States)

    Pajek, Daniel; Burgess, Alison; Huang, Yuexi; Hynynen, Kullervo

    2014-09-01

    The purpose of this study was to evaluate use of intravascular perfluorocarbon droplets to reduce the sonication power required to achieve clot lysis with high-intensity focused ultrasound. High-intensity focused ultrasound with droplets was initially applied to blood clots in an in vitro flow apparatus, and inertial cavitation thresholds were determined. An embolic model for ischemic stroke was used to illustrate the feasibility of this technique in vivo. Recanalization with intravascular droplets was achieved in vivo at 24 ± 5% of the sonication power without droplets. Recanalization occurred in 71% of rabbits that received 1-ms pulsed sonications during continuous intravascular droplet infusion (p = 0.041 vs controls). Preliminary experiments indicated that damage was confined to the ultrasonic focus, suggesting that tolerable treatments would be possible with a more tightly focused hemispheric array that allows the whole focus to be placed inside of the main arteries in the human brain. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  2. [The influence of increased clotting reactions as shown by thrombosis formation in the immediate postoperative period on aortic valve prothesis (author's transl)].

    Science.gov (United States)

    Harke, H; Schwarze, E W; Stambolis, C; Bernhard, A

    1975-08-01

    Massive thrombosis formation on the valve periphery and on the top surface of the valve occurred in three patients (1,5%) in the immediate postoperative period with the Björk-Shiley valve in the aortic position. Between the third and sixth day these patients died of acute heart failure as a result of coronary artery displacement. Upon autopsy operative technical complications and postoperative infections were ruled out as the cause of death. What appears to be clinically important is an increase in clotting time in the immediate postoperative period which can be proven statistically. This increased clotting inclination was only found in these three patients and in one patient with frequent immediate postoperative peripheral embolic episodes. We therefore feel that early anticoagulation therapy is necessary. Heparin administration is preferred as it not only lowers the clotting ability of the blood but also the adhesive quality of the platelets.

  3. Long-term cytokine and growth factor release from equine platelet-rich fibrin clots obtained with two different centrifugation protocols.

    Science.gov (United States)

    Jiménez-Aristizabal, Román F; López, Catalina; Álvarez, María E; Giraldo, Carlos; Prades, Marta; Carmona, Jorge U

    2017-09-01

    To compare the temporal release (over three weeks) of tumor necrosis factor alpha (TNF-α), interleukin 4 (IL-4), IL-1 receptor antagonist (IL-1ra), platelet-derived growth factor BB (PDGF-BB) and transforming growth factor beta-1 (TGF-β1) from two platelet-rich fibrin (PRF) preparations from equine blood obtained at either 240g/8min or 416g/10min. Whole blood from 10 horses was used to obtain PRF clots by two different centrifugation protocols. After 1h of rest, PRF clots were deposited in wells with culture medium, which was changed at 6h, 24h and then every 48h to 21days. Cytokines and GFs were measured by ELISA at 1h (serum supernatants from PRF clots) and all time points of culture medium change. A negative control (plasma) and a positive control (blood lysate) were also included. There were no relevant differences between the two protocols for the temporal release of proteins. However, a significant (p=0.01) effect of time was noted. All cytokines were detected after 6h of PRF clot culture until day 21. GF were detected at 1h until day 21. The concentrations for these proteins diminished gradually over time. A highly significant (p=0.01) correlation was noticed between all the proteins evaluated. Leukocytes enmeshed in PRF clots were able to produce cytokines, TGF-β1 and PDGF-BB. These findings demonstrate a paramount role of leukocytes in wound healing induced or modified by PRF clots in mammals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Increased Clot Formation in the Absence of Increased Thrombin Generation in Patients with Peripheral Arterial Disease: A Case–Control Study

    Directory of Open Access Journals (Sweden)

    Marie-Claire F. Kleinegris

    2017-04-01

    Full Text Available BackgroundIn peripheral arterial disease (PAD, activation of the hemostatic system may contribute to atherosclerosis progression and atherothrombotic events.ObjectiveThis case–control study assesses the overall coagulation status in PAD patients by evaluating coagulation markers in combination with thrombin generation potential, whole blood (WB clot formation, and fibrinolysis.MethodsIn blood from 40 PAD patients (n = 20 with cardiovascular event within 1 year after initial diagnosis, n = 20 without and 40 apparently healthy controls, thrombin generation was determined in WB and platelet-poor plasma. Whole blood rotational thromboelastometry (ROTEM measurements were triggered with tissue factor with/without tissue plasminogen activator.ResultsWe observed increased levels of erythrocyte sedimentation rate, leukocytes, eosinophil granulocytes, vWF antigen, fibrinogen, and D-dimer in PAD patients (p < 0.05. Markers of thrombin generation potential showed no difference between patients and healthy controls. In PAD patients with event compared to patients without, WB-thrombin generation showed a lower thrombin potential when triggered with 0 and 2.5 pM tissue factor. The ROTEM clotting assay showed significantly faster clot formation and increased clot firmness in PAD patients compared to controls. No significant differences were found for parameters of clot degradation.ConclusionThere are no significant differences between the thrombin generation profiles of PAD patients and healthy controls. Between PAD patients with and without cardiovascular event, the WB thrombin generation appears to differ. Mechanistically, PAD patients show an increased ability to form a stable clot in WB in comparison to healthy controls. This is most likely due to the increased fibrinogen levels related to the inflammation in atherosclerosis, confirming the importance of the inflammation-coagulation axis.

  5. Incorporation of albumin fusion proteins into fibrin clots in vitro and in vivo: comparison of different fusion motifs recognized by factor XIIIa

    Directory of Open Access Journals (Sweden)

    Sheffield William P

    2011-12-01

    Full Text Available Abstract Background The transglutaminase activated factor XIII (FXIIIa acts to strengthen pathological fibrin clots and to slow their dissolution, in part by crosslinking active α2-antiplasmin (α2AP to fibrin. We previously reported that a yeast-derived recombinant fusion protein comprising α2AP residues 13-42 linked to human serum albumin (HSA weakened in vitro clots but failed to become specifically incorporated into in vivo clots. In this study, our aims were to improve both the stability and clot localization of the HSA fusion protein by replacing α2AP residues 13-42 with shorter sequences recognized more effectively by FXIIIa. Results Expression plasmids were prepared encoding recombinant HSA with the following N-terminal 23 residue extensions: H6NQEQVSPLTLLAG4Y (designated XL1; H6DQMMLPWAVTLG4Y (XL2; H6WQHKIDLPYNGAG4Y (XL3; and their 17 residue non-His-tagged equivalents (XL4, XL5, and XL6. The HSA moiety of XL4- to XL6-HSA proteins was C-terminally His-tagged. All chimerae were efficiently secreted from transformed Pichia pastoris yeast except XL3-HSA, and following nickel chelate affinity purification were found to be intact by amino acid sequencing, as was an N-terminally His-tagged version of α2AP(13-42-HSA. Of the proteins tested, XL5-HSA was cross-linked to biotin pentylamine (BPA most rapidly by FXIIIa, and was the most effective competitor of α2AP crosslinking not only to BPA but also to plasma fibrin clots. In the mouse ferric chloride vena cava thrombosis model, radiolabeled XL5-HSA was retained in the clot to a greater extent than recombinant HSA. In the rabbit jugular vein stasis thrombosis model, XL5-HSA was also retained in the clot, in a urea-insensitive manner indicative of crosslinking to fibrin, to a greater extent than recombinant HSA. Conclusions Fusion protein XL5-HSA (DQMMLPWAVTLG4Y-HSAH6 was found to be more active as a substrate for FXIIIa-mediated transamidation than seven other candidate fusion proteins in

  6. Corrosion inhibition..

    African Journals Online (AJOL)

    ABSTRACT. The corrosion inhibition of carbon steel in 3% de-aerated NaCl acidic solution with amine—fatty acid corrosion inhibitor, KI384, .... reduction reaction causing no decrease in the limiting current density of that process. On the .... value when compared to the base solution. This provides a support to the physical ...

  7. Properties of a milk clotting protease isolated from fruits of Bromelia balansae Mez.

    Science.gov (United States)

    Pardo, M F; López, L M; Caffini, N O; Natalucci, C L

    2001-05-01

    Unripe fruit extracts of Bromelia balansae Mez (Bromeliaceae), whose principal endopeptidase is balansain I (isolated for anion exchange chromatography: pI = 5.45, molecular weight = 23192), exhibit a pH profile with a maximum activity around pH 9.0 and are inhibited only by cysteine peptidases inhibitors. The alanine and glutamine derivatives of N-alpha-carbobenzoxy-L-amino acid p-nitrophenyl esters were strongly preferred by the enzyme. Enzymatic hydrolysis of milk and soy proteins yield characteristic patterns at pH 9.0. The N-terminal sequence showed a very high homology (85-90%) with other known Bromeliaceae endopeptidases.

  8. Data in support of three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes.

    Science.gov (United States)

    Gagaoua, Mohammed; Hafid, Kahina; Hoggas, Naouel

    2016-03-01

    This paper describes data related to a research article titled "Three Phase Partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes" (Gagaoua et al., 2015) [1]. Zingibain (EC 3.4.22.67), is a coagulant cysteine protease and a meat tenderizer agent that have been reported to produce satisfactory final products in dairy and meat technology, respectively. Zingibains were exclusively purified using chromatographic techniques with very low yield purification. This paper includes data of the effect of temperature, usual salts and organic solvents on the efficiency of the three phase partitioning (TPP) system. Also it includes data of the kinetic activity characterization of the purified zingibain using TPP purification approach.

  9. Data in support of three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes

    Directory of Open Access Journals (Sweden)

    Mohammed Gagaoua

    2016-03-01

    Full Text Available This paper describes data related to a research article titled “Three Phase Partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes” (Gagaoua et al., 2015 [1]. Zingibain (EC 3.4.22.67, is a coagulant cysteine protease and a meat tenderizer agent that have been reported to produce satisfactory final products in dairy and meat technology, respectively. Zingibains were exclusively purified using chromatographic techniques with very low yield purification. This paper includes data of the effect of temperature, usual salts and organic solvents on the efficiency of the three phase partitioning (TPP system. Also it includes data of the kinetic activity characterization of the purified zingibain using TPP purification approach.

  10. Data in support of three phase partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes

    Science.gov (United States)

    Gagaoua, Mohammed; Hafid, Kahina; Hoggas, Naouel

    2016-01-01

    This paper describes data related to a research article titled “Three Phase Partitioning of zingibain, a milk-clotting enzyme from Zingiber officinale Roscoe rhizomes” (Gagaoua et al., 2015) [1]. Zingibain (EC 3.4.22.67), is a coagulant cysteine protease and a meat tenderizer agent that have been reported to produce satisfactory final products in dairy and meat technology, respectively. Zingibains were exclusively purified using chromatographic techniques with very low yield purification. This paper includes data of the effect of temperature, usual salts and organic solvents on the efficiency of the three phase partitioning (TPP) system. Also it includes data of the kinetic activity characterization of the purified zingibain using TPP purification approach. PMID:26909379

  11. High-intensity focused ultrasound (HIFU for dissolution of clots in a rabbit model of embolic stroke.

    Directory of Open Access Journals (Sweden)

    Alison Burgess

    Full Text Available It is estimated that only 2-6% of patients receive thrombolytic therapy for acute ischemic stroke suggesting that alternative therapies are necessary. In this study, we investigate the potential for high intensity focused ultrasound (HIFU to initiate thrombolysis in an embolic model of stroke. Iron-loaded blood clots were injected into the middle cerebral artery (MCA of New Zealand White rabbits, through the internal carotid artery and blockages were confirmed by angiography. MRI was used to localize the iron-loaded clot and target the HIFU beam for treatment. HIFU pulses (1.5 MHz, 1 ms bursts, 1 Hz pulse repetition frequency, 20 s duration were applied to initiate thrombolysis. Repeat angiograms and histology were used to assess reperfusion and vessel damage. Using 275 W of acoustic power, there was no evidence of reperfusion in post-treatment angiograms of 3 rabbits tested. In a separate group of animals, 415 W of acoustic power was applied and reperfusion was observed in 2 of the 4 (50% animals treated. In the last group of animals, acoustic power was further increased to 550 W, which led to the reperfusion in 5 of 7 (∼70% animals tested. Histological analysis confirmed that the sonicated vessels remained intact after HIFU treatment. Hemorrhage was detected outside of the sonication site, likely due to the proximity of the target vessel with the base of the rabbit skull. These results demonstrate the feasibility of using HIFU, as a stand-alone method, to cause effective thrombolysis without immediate damage to the targeted vessels. HIFU, combined with imaging modalities used to identify and assess stroke patients, could dramatically reduce the time to achieve flow restoration in patients thereby significantly increasing the number of patients which benefit from thrombolysis treatments.

  12. Sonorheometry assessment of platelet function in cardiopulmonary bypass patients: Correlation of blood clot stiffness with platelet integrin αIIbβ3 activity, aspirin usage, and transfusion risk.

    Science.gov (United States)

    Viola, Francesco; Lin-Schmidt, Xiefan; Bhamidipati, Castigliano; Haverstick, Doris M; Walker, William F; Ailawadi, Gorav; Lawrence, Michael B

    2016-02-01

    Impaired platelet function may underlie bleeding associated with cardiopulmonary bypass (CPB) and at present is incompletely evaluated with existing diagnostic technologies. Sonorheometry (SR) is a recently developed ultrasound-based technology that quantifies hemostasis and platelet activity from a blood sample by measuring ex vivo clot stiffness (S). We hypothesized that impaired platelet-fibrin interactions as assessed by SR would correlate with transfusion during CPB and history of prior aspirin therapy. Thirty-nine patients undergoing elective cardiopulmonary bypass (CPB) were enrolled following informed consent (University of Virginia IRB#14050) in a prospective observational pilot study to assess pre-operative platelet function and transfusion frequency. To assess platelet activity, abciximab was added to blood prior to SR and native S versus abciximab treated S created a differential test for platelet activity. Patient blood samples were activated with kaolin and SR was then used to measure clot stiffness. Patients were transfused with blood products as directed by clinical practice, with the surgical team blinded to SR results. Blood clot stiffness with and without abciximab, was compared in a ratio test (S/Sabciximab) named the Platelet Function Index (PFI). PFI was hypothesized to be positively correlated with platelet contributions through integrin αIIbβ3 to clot stiffness. PFI for CPB subjects was lower for those receiving transfusions than those not receiving transfusions (paspirin therapy was lower than for those not on aspirin therapy (paspirin effects on risk of surgical bleeding. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Investigation of the effect of kaolin and tissue factor-activated citrated whole blood, on clot forming variables, as evaluated by thromboelastograph

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Andersen, S.

    2008-01-01

    BACKGROUND: The Thrombelastograph (TEG; Haemoscope Corp.) analyzes clot formation in whole blood (WB) and treatment based on this analysis has been shown to reduce transfusion requirements in liver and cardiac surgery when compared to conventional coagulation analysis. Implementing TEG as a routine...

  14. Statistical optimization of culture conditions for milk-clotting enzyme production by bacillus amyloliquefaciens using wheat bran-an agro-industry waste.

    Science.gov (United States)

    Zhang, Weibing; He, Xiaoling; Liu, Hongna; Guo, Huiyuan; Ren, Fazheng; Wen, Pengcheng

    2013-12-01

    In order to improve the production of the milk-clotting enzyme under submerged fermentation, two statistical methods were applied to optimize the culture conditions of Bacillus amyloliquefaciens D4 using wheat bran as nutrient source. First, initial pH, agitation speed, and fermentation time were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, optimal conditions were obtained using the Box-Behnken method, which were as follows: initial pH 7.57, agitation speed 241 rpm, fermentation time 53.3 h. Under these conditions, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 1996.9 SU/mL, which was 2.92-fold higher than that of the initial culture conditions, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize culture conditions. The research can provide a reference for full utilization of wheat bran and the production of milk-clotting enzyme by B. amyloliquefaciens D4 under submerged fermentation.

  15. IMPROVED HEALING OF SMALL-CALIBER POLYTETRAFLUOROETHYLENE PROSTHESES BY INDUCTION OF A CLOT LAYER - A REVIEW OF EXPERIMENTAL STUDIES IN RATS

    NARCIS (Netherlands)

    VANDERLEI, B; STRONCK, JW; WILDEVUUR, CRH

    1991-01-01

    This report reviews our experiments that have been undertaken to test the hypothesis whether the induction of a clot layer on the graft surface of small-caliber polytetrafluoroethylene ( PTFE) prostheses might improve their healing. 1 2 PTFE prostheses with a fibril length of 30-mu-m, PTFE

  16. The role of the lysyl binding site of tissue-type plasminogen activator in the interaction with a forming fibrin clot

    NARCIS (Netherlands)

    Bakker, A.H.F.; Weening-Verhoeff, E.J.D.; Verheijen, J.H.

    1995-01-01

    To describe the role of the lysyl binding site in the interaction of tissue-type plasminogen activator (t-PA, FGK1K2P) with a forming fibrin clot, we performed binding experiments with domain deletion mutants GK1K2P, K2P, and the corresponding point mutants lacking the lysyl binding site in the

  17. Synthetic hematocrit derived from the longitudinal relaxation of blood can lead to clinically significant errors in measurement of extracellular volume fraction in pediatric and young adult patients.

    Science.gov (United States)

    Raucci, Frank J; Parra, David A; Christensen, Jason T; Hernandez, Lazaro E; Markham, Larry W; Xu, Meng; Slaughter, James C; Soslow, Jonathan H

    2017-08-02

    Extracellular volume fraction (ECV) is altered in pathological cardiac remodeling and predicts death and arrhythmia. ECV can be quantified using cardiovascular magnetic resonance (CMR) T1 mapping but calculation requires a measured hematocrit (Hct). The longitudinal relaxation of blood has been used in adults to generate a synthetic Hct (estimate of true Hct) but has not been validated in pediatric populations. One hundred fourteen children and young adults underwent a total of 163 CMRs with T1 mapping. The majority of subjects had a measured Hct the same day (N = 146). Native and post-contrast T1 were determined in blood pool, septum, and free wall of mid-LV, avoiding areas of late gadolinium enhancement. Synthetic Hct and ECV were calculated and intraclass correlation coefficient (ICC) and linear regression were used to compare measured and synthetic values. The mean age was 16.4 ± 6.4 years and mean left ventricular ejection fraction was 59% ± 9%. The mean measured Hct was 41.8 ± 3.0% compared to the mean synthetic Hct of 43.2% ± 2.9% (p ECV was 30.5% ± 4.8% and mean synthetic mid-free wall ECV of local model was 29.7% ± 4.6% (p ECV ranged from -8.4% to 4.3% in the septum and -12.6% to 15.8% in the free wall. Using our laboratory's normal cut-off of 28.5%, 59 patients (37%) were miscategorized (53 false negatives, 6 false positives) with published model ECV. The local model had 37 miscategorizations (20 false negatives, 17 false positives), significantly fewer but still a substantial number (23%). Our data suggest that use of synthetic Hct for the calculation of ECV results in miscategorization of individual patients. This difference may be less significant once synthetic ECV is calculated and averaged over a large research cohort, making it potentially useful as a research tool. However, we recommend formal measurement of Hct in children and young adults for clinical CMRs.

  18. Pre-Operative Autologous Blood Donation Does Not Affect Pre-Incision Hematocrit in Adolescent Idiopathic Scoliosis Patients. A Retrospective Cohort of a Prospective Randomized Trial.

    Science.gov (United States)

    Boniello, Anthony J; Verma, Kushagra; Peters, Austin; Lonner, Baron S; Errico, Thomas

    2016-01-01

    Pre-donation of autologous blood prior to spine fusion for adolescent idiopathic scoliosis (AIS) has been used in deformity surgery. The effect of pre-donation on pre-operative hematocrit (Hct) remains debated. Multiple factors may influence pre-operative Hct including intravascular volume status, patient factors, and timing of pre-operative blood donation. The purpose of this study was to determine if pre-donation significantly lowers pre-incision Hct in AIS patients. A retrospective cohort study of a Level-1 prospective randomized trial was conducted. 125 patients from the homogeneous population were included. AIS patients undergoing a posterior only spinal fusion for AIS were separated into two groups based on their pre-operative blood donation history. Demographic variables, pre-incision Hct, and transfusion rates were compared between the two groups using the Student's T-test. Pre-donation and non pre-donation groups had 28 and 97 patients, respectively. Pre-donation group was 75% female (21F, 7M) and non pre-donation group was 78% female (76F, 21M). There was no difference between pre-donation and non pre-donation groups in mean age (15.6 ± 2.2 vs 14.8 ± 2.2, p = 0.081), BMI (23.1 ± 4.2 vs 21.7 ± 5.3, p = 0.219), and pre-incision Hct (32.8 ± 3.4 vs 33.8 ± 3.1, p = 0.628). The overall transfusion rates were equivalent (32.1± 48.0% vs 25.8 ± 44.0%, p = 0.509), however, the rate of allogenic transfusion for the pre-donation group was significantly lower (3.6 ± 18.9% vs 25.8 ± 44.0%, p = 0.011). This study supports the use of pre-donation for AIS, without a significant drop in pre-incision Hct. Patients that donate are also much less likely to be exposed to allogenic blood. There may be a surgeon bias to recommend pre-donation in patients with a larger BMI and older age. Future studies are needed from a larger population of patients including those with non-AIS pathology. Level III.

  19. Factors affecting the lung perfused blood volume in patients with intrapulmonary clots after anti-coagulation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Masuda, Yu [4th Grade of 6-year Medicine Doctor Program, Department of Medicine, Yamaguchi University Faculty of Medicine and Health Sciences 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi; Nakao, Sei [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-08-15

    Highlights: • Dual-energy CT can provide morphological and functional lung images in the same examination. • The subsequent dual-energy CT demonstrates the increased whole lung perfused blood volume (V{sub 120}) despite the residual intrapulmonary clots after treatment in one examination. • The increased whole lung perfusion (V{sub 120}) and a decreased low perfusion volume (V{sub 5}) result in the improvement in the low perfusion rate (%V{sub 5}) in the patients with acute pulmonary embolism after treatment. - Abstract: Objectives: Factors affecting the improvement in the lung perfused blood volume (LPBV) were evaluated based on the presence of intrapulmonary clots (IPCs) after anti-coagulation therapy using 64-slice dual-energy CT. Materials and methods: 96 patients exhibiting venous thromboembolism underwent initial and repeated LPBV examinations between December 2008 and July 2014. Fifteen patients were excluded due to pulmonary comorbidities, and a total of 81 patients were included in this study. Acute pulmonary embolism (PE) was diagnosed in 46 of the patients (56.7%). LPBV images were three-dimensionally reconstructed with two threshold ranges: 1–120 HU (V{sub 120}) and 1–5 HU (V{sub 5}), and the relative value of V{sub 5} per V{sub 120} expressed as %V{sub 5}. These values were subsequently compared with indicators of the severity of PE, such as the D-dimer level, heart rate and CT measurements. This study was approved by the local ethics committee. Results: In patients with IPCs, the D-dimer, V{sub 5} and %V{sub 5}values were significantly larger (p ≤ 0.01) in the initial LPBV, although these differences disappeared in subsequent LPBV after treatment. The right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio and %V{sub 5} values were also significantly reduced, whereas the V{sub 5} value did not significantly decrease (p = 0.07), but V{sub 120} value significantly increased (p < 0.001) after treatment. However, in

  20. Lyso-Sulfatide Binds Factor Xa and Inhibits Thrombin Generation by the Prothrombinase Complex.

    Directory of Open Access Journals (Sweden)

    Subramanian Yegneswaran

    Full Text Available Blood coagulation reactions are strongly influenced by phospholipids, but little is known about the influence of sphingolipids on coagulation mechanisms. Lysosulfatide (lyso-SF (sulfogalactosyl sphingosine prolonged factor Xa (fXa 1-stage plasma clotting assays, showing it had robust anticoagulant activity. In studies using purified clotting factors, lyso-SF inhibited >90% of prothrombin (II activation for reaction mixtures containing fXa/factor Va (fVa/II, and also inhibited II activation generation by fXa/ phospholipids and by Gla-domainless-fXa/fVa/phospholipids. When lyso-SF analogs were tested, results showed that N-acetyl-sulfatide was not anticoagulant, implying that the free amine group was essential for the anticoagulant effects of lyso-SF. Lyso-SF did not inhibit fXa enzymatic hydrolysis of small peptide substrates, showing it did not directly inhibit the fXa activity. In surface plasmon resonance studies, lyso-SF bound to immobilized inactivated fXa as well as inactivated Gla-domainless-fXa. Confirming this lyso-SF:fXa interaction, fluorescence studies showed that fluorescently-labeled-fXa in solution bound to lyso-SF. Thus, lyso-SF is an anticoagulant lipid that inhibits fXa when this enzyme is bound to either phospholipids or to fVa. Mechanisms for inhibition of procoagulant activity are likely to involve lyso-SF binding to fXa domain(s that are distinct from the fXa Gla domain. This suggests that certain sphingolipids, including lyso-SF and some of its analogs, may down-regulate fXa activity without inhibiting the enzyme's active site or binding to the fXa Gla domain.

  1. Development and implementation of tPA clot lysis activity assay using ACL TOP™ hemeostasis testing system in QC laboratories

    Directory of Open Access Journals (Sweden)

    Lichun Huang

    2017-12-01

    Full Text Available This report describes the design, development, validation and long-term performance of tPA clot lysis activity assay using Advanced Chemistry Line Total Operational Performance (ACL TOP™ Homeostasis Testing System. The results of the study demonstrated robust and stable performance of the analytical method. The accuracy of the assay, expressed by percent recovery is 98–99%. The intermediate precision and repeatability precision, expressed as Relative Standard Deviation (RSD, was 3% and less than 2% respectively. The validated range is from 70% to 130% of the target potency of 5.8 × 105 IU/mg. The linearity of this range, expressed in correlation coefficient, is 0.997. After the assay is transferred to a QC laboratory, the assay retained high accuracy and precision with a success rate of >99%. Keywords: Potency assay, Clot lysis, Comparability, Automation

  2. Role of Inclined Magnetic Field and Copper Nanoparticles on Peristaltic Flow of Nanofluid through Inclined Annulus: Application of the Clot Model

    Science.gov (United States)

    Shahzadi, Iqra; Nadeem, S.

    2017-06-01

    A genuine neurotic condition is experienced when some blood constituents accumulate on the wall of the artery get withdrew from the wall, again join the circulatory system and coagulation occur. Role of copper nanoparticles and inclined magnetic field on the peristaltic flow of a nanofluid in an annular region of inclined annulus is investigated. We represent the clot model by considering the small artery as an annulus whose outer tube has a wave of sinusoidal nature and inner tube has a clot on its walls. Lubrication approach is used to simplify the problem. Close form solutions are determined for temperature and velocity profile. Impact of related parameters on pressure rise, pressure gradient, velocity and streamlines are interpreted graphically. Comparison among the pure blood and copper blood is presented and analyzed. One main finding of the considered analysis is that the inclusion of copper nanoparticles enlarges the amplitude of the velocity. Therefore, the considered study plays a dominant role in biomedical applications.

  3. [The behavior of blood clotting and its inhibitors under long term treatment with 5,6-benzo-alpha-pyrone (coumarin). Double blind study].

    Science.gov (United States)

    Köstering, H; Bandura, B; Merten, H A; Wieding, J U

    1985-01-01

    The analyses on hemostaseological variables are recorded in connection with blood tests in the course of a double-blind study in 41 patients suffering from chronic venous insufficiency of higher degrees of severity. They were treated in addition to compression measures with two active ingredients, a coumarin (5,6-benzo-alpha-pyrone)/troxerutin combination (Venalot Depot) (n = 20) or benzarone (n = 21) receiving 3 X 2 dragees daily for 6 weeks. Good clinical efficacy and the improvement of symptoms were observed together with almost no side-effects. The coagulation analysis showed no influence of the active principles on the global coagulation or the clotting factors and the inhibitors and factors of the fibrinolysis. In particular there was no phenprocoumon-like effect on the blood clotting system.

  4. Enzymatic milk clotting activity in artichoke (Cynara scolymus) leaves and alpine thistle (Carduus defloratus) flowers. Immobilization of alpine thistle aspartic protease.

    Science.gov (United States)

    Esposito, Marilena; Di Pierro, Prospero; Dejonghe, Winnie; Mariniello, Loredana; Porta, Raffaele

    2016-08-01

    Two different milk clotting enzymes, belonging to the aspartic protease family, were extracted from both artichoke leaves and alpine thistle flowers, and the latter was covalently immobilized by using a polyacrylic support containing polar epoxy groups. Our findings showed that the alpine thistle aspartic protease was successfully immobilized at pH 7.0 on Immobeads IB-150P beads and that, under these experimental conditions, an immobilization yield of about 68% and a recovery of about 54% were obtained. Since the enzyme showed an optimal pH of 5.0, a value very similar to the one generally used for milk clotting during cheese making, and exhibited a satisfactory stability over time, the use of such immobilized vegetable rennet for the production of novel dairy products is suggested. Copyright © 2016. Published by Elsevier Ltd.

  5. Effects of melagatran on activated partial thromboplastin time and on ecarin clotting time in cord versus adult plasma.

    Science.gov (United States)

    Koestenberger, Martin; Gallistl, Siegfried; Bettina, Leschnik; Cimenti, Christina; Kutschera, Joerg; Cvirn, Gerhard

    2006-11-01

    Melagatran is the active form of the oral direct thrombin inhibitor ximelagatran. Melagatran does not require antithrombin as a cofactor. Its administration is therefore of special interest in neonatal patients, whose plasma is relatively deficient in antithrombin. We investigated the effects of increasing amounts of melagatran (0.05-1 micromol/l) on the activated partial thromboplastin time (APTT) and ecarin clotting time (ECT) in cord versus adult plasma. Both the APTT and ECT were dose-dependently prolonged in the presence of increasing amounts of melagatran. Furthermore, the ECT revealed a higher susceptibility of cord plasma to addition of melagatran than adult plasma. Whereas similar amounts of melagatran were required in cord and adult plasma samples to double the APTT (IC(50), 0.47 vs 0.46 micromol/l), significantly less melagatran was required in cord versus adult plasma to double the ECT (IC(50), 0.26 vs 0.56 micromol/l). Based on APTT measurements, similar plasma levels of melagatran might be required in neonates and in adults to treat thromboembolic complications. The APTT, however, is relatively insensitive to plasma melagatran concentrations. When the sensitive indicator ECT is used, results suggest that lower amounts of melagatran might be required in neonates than in adults. This has to be scrutinized in future clinical studies.

  6. Role of B Cells in Breaking and Maintaining Tolerance to Clotting Factor VIII in Congenital and Acquired Hemophilia A

    Directory of Open Access Journals (Sweden)

    Amanda M. Actor

    2014-04-01

    Full Text Available Immune responses directed against clotting factor FVIII (FVIII seriously complicate treatments for patients with hemophilia A. This response can manifest in congenital hemophilia A patients who generate inhibitor antibodies that bind and inactivate “transplanted” replacement FVIII, as well as in acquired hemophiliacs, whose immune systems have lost tolerance to self-FVIII. Regardless of the mechanism by which production of anti-FVIII inhibitor antibody is triggered, the maintenance of this deleterious response in both congenital and acquired hemophiliacs likely relies upon FVIII specific memory B cells. In this review, the similarities and differences in the kinetics, specificities, and subclasses of antibodies produced in response to allo- and auto-FVIII is outlined. A brief description of the immune cell interactions that contribute to maintenance of antibody response, focusing on development of memory B cells and/or long lived plasma cells is also presented. As current treatments for inhibitor antibodies are not successful in all patients, a better understanding of the functions and persistence of memory B cells specific for FVIII is required. Herein, both clinical and experimental data regarding the effects of immune tolerance induction on memory B cell subpopulations is discussed. Finally, the outcomes of B cell-specific depletion via rituximab in hemophilia and other autoimmune diseases are discussed to highlight insights into the subpopulations of memory B cells that contribute to the development and maintenance of successful tolerance to FVIII.

  7. Recombinant Factor VIIa (Eptacog Alfa): A Pharmacoeconomic Review of its Use in Haemophilia in Patients with Inhibitors to Clotting Factors VIII or IX

    OpenAIRE

    Katherine A. Lyseng-Williamson; Greg L. Plosker

    2007-01-01

    Recombinant factor VIIa (NovoSeven(R); also known as recombinant activated factor VII or eptacog alfa) is indicated as an intravenous haemostatic agent in haemophilia patients with inhibitors to clotting factors VIII or IX. In noncomparative trials in haemophilia patients with inhibitors, on-demand home treatment with recombinant factor VIIa was effective in controlling episodes of mild to moderate bleeding and well tolerated, with early treatment being associated with a greater rate of succe...

  8. A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study

    Directory of Open Access Journals (Sweden)

    Isha Narang

    2015-01-01

    Full Text Available Introduction: This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF, platelet-rich plasma (PRP, and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis. Methods: Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold. Results: The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher′s exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2 which showed statistically significant values in Group III as compared to other Groups. Conclusion: PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot.

  9. Development and comparison of a minimally-invasive model of autologous clot pulmonary embolism in Sprague-Dawley and Copenhagen rats

    Directory of Open Access Journals (Sweden)

    Sanapareddy Nina

    2010-02-01

    Full Text Available Abstract Background Experimental models of pulmonary embolism (PE that produce pulmonary hypertension (PH employ many different methods of inducing acute pulmonary occlusion. Many of these models induce PE with intravenous injection of exogenous impervious objects that may not completely reproduce the physiological properties of autologous thromboembolism. Current literature lacks a simple, well-described rat model of autlogous PE. Objective: Test if moderate-severity autologous PE in Sprague-Dawley (SD and Copenhagen (Cop rats can produce persistent PH. Methods blood was withdrawn from the jugular vein, treated with thrombin-Ca++ and re-injected following pretreatment with tranexamic acid. Hemodynamic values, clot weights and biochemical measurements were performed at 1 and 5 days. Results Infusion of clot significantly increased the right ventricular peak systolic pressure to 45-55 mm Hg, followed by normalization within 24 hours in SD rats, and within 5 days in COP rats. Clot lysis was 95% (24 hours and 97% (5 days in SD rats and was significantly lower in COP rats (70%, 24 hours; 87% 5 days. Plasma D-dimer was elevated in surgical sham animals and was further increased 8 hours after pulmonary embolism. Neither strain showed a significant increase in bronchoalveolar chemotactic activity, myeloperoxidase activity, leukocyte infiltration, or chemokine accumulation, indicating that there was no significant pulmonary inflammation. Conclusions Both SD and COP rats exhibited near complete fibrinolysis of autologous clot PE within 5 days. Neither strain developed persistent PH. Experimental models of PE designed to induce sustained PH and a robust inflammatory response appear to require significant, persistent pulmonary vascular occlusion.

  10. Poly(carboxybetaine methacrylamide)-modified nanoparticles: a model system for studying the effect of chain chemistry on film properties, adsorbed protein conformation, and clot formation kinetics.

    Science.gov (United States)

    Abraham, Sinoj; So, Alan; Unsworth, Larry D

    2011-10-10

    Nonfouling polymer architectures are considered important to the successful implementation of many biomaterials. It is thought that how these polymers induce conformational changes in proteins upon adsorption may dictate the fate of the device being utilized. Herein, oxidized silicon nanoparticles (SiNP) were modified with various forms of poly(carboxybetaine methacrylamide) (PCBMA) for the express purpose of understanding how polymer chemistry affects film hydration, adsorbed protein conformation, and clot formation kinetics. To this end, carboxybetaine monomers differing in intercharge separating spacer groups were synthesized, and nitroxide-mediated free radical polymerization (NMP) was conducted using alkoxyamine initiators with hydrophobic (TEMPO) and hydrophilic (β-phosphonate) terminal groups. The physical properties (surface composition, thickness, grafting density, etc.) of the resulting polymer-SiNP conjugates were quantified using several techniques, including Fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), and thermogravimetric analysis (TGA). The effect of spacer group on the surface charge density was determined using zeta potential measurements. Three proteins, viz., lysozyme, bovine α-lactalbumin, and human serum albumin, were used to evaluate the effect film properties (charge, hydration, end-group) have on adsorbed protein conformation, as determined by circular dichroism (CD), fluorescence spectroscopy, and fluorescence quenching techniques. Hemocompatibility of these surfaces was observed by measuring clot formation kinetics using the plasma recalcification time assay. It was found that chain chemistry, as opposed to end-group chemistry, was a major determiner for water structure, adsorbed protein conformation, and clotting kinetics. It is thought that the systematic evaluation of how both chain (internal) and end-group (external) polymer properties affect film hydration, protein conformation, and clot formation

  11. Can we safely decrease intensive care unit admissions for children with high grade isolated solid organ injuries? Using the shock index, pediatric age-adjusted and hematocrit to modify APSA admission guidelines.

    Science.gov (United States)

    Arbuthnot, Mary; Armstrong, Lindsey Bendure; Mooney, David P

    2017-06-01

    In 2000, the American Pediatric Surgical Association (APSA) disseminated consensus practice guidelines for the management of blunt liver and splenic injury which included intensive care unit (ICU) admission for children with grade IV injuries. We sought to determine if we could better predict which children with isolated solid organ injuries (SOI) underwent an ICU-level intervention, thus necessitating ICU admission. Children with isolated liver, spleen, or kidney injuries admitted to the ICU from November 2003 to August 2015 were identified in our trauma registry, and data were extracted from the medical record. ICU-level interventions were defined as transfusion, vasopressor use, intubation, and operative/procedural intervention. Shock index and pediatric age-adjusted (SIPA) was calculated for all patients. The sensitivity and negative predictive values (NPV) were determined. 133 children met inclusion criteria. 19 (14.3%) required ICU-level intervention, and 114 (85.1%) did not. 95% (n=18) of the intervention group had either an elevated SIPA or a hematocrit <30% on admission compared to 22% (n=25) of patients in the no intervention group. Sensitivity was 95%, and NPV was 99%. Limiting ICU admission in children with isolated SOI to those with an elevated SIPA or hematocrit <30% would reduce the ICU admission rate by two-thirds while maintaining patient safety. Diagnostic study. III. Published by Elsevier Inc.

  12. Biochemical and milk-clotting properties and mapping of catalytic subsites of an extracellular aspartic peptidase from basidiomycete fungus Phanerochaete chrysosporium.

    Science.gov (United States)

    da Silva, Ronivaldo Rodrigues; de Oliveira, Lilian Caroline Gonçalves; Juliano, Maria Aparecida; Juliano, Luiz; de Oliveira, Arthur H C; Rosa, Jose C; Cabral, Hamilton

    2017-06-15

    For a long time, proteolytic enzymes have been employed as key tools of industrial processes, especially in the dairy industry. In the present work, we used Phanerochaete chrysosporium for biochemical characterization and analysis of catalytic specificity of an aspartic peptidase. Our results revealed an aspartic peptidase with molecular mass ∼38kDa, maximal activity at pH 4.5 and 50°C, and stability above 80% in the pH range of 3-8 and temperature up to 55°C for 1h. In a milk-clotting assay, this peptidase showed maximal milk clotting activity at 60-65°C and maintenance of enzymatic activity above 80% in the presence of 20mM CaCl2. In a specificity assay, we observed stronger restriction of catalysis at the S1 subsite, with a preference for lysine, arginine, leucine, tyrosine, and phenylalanine residues. The restricted proteolysis and milk-clotting potential are attractive properties for the use in cheese production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. OPTIMIZATION OF MILK-CLOTTING PROTEASE PRODUCTION BY A LOCAL ISOLATE OF ASPERGILLUS NIGER FFB1 IN SOLID-STATE FERMENTATION

    Directory of Open Access Journals (Sweden)

    Souhila Bensmail

    2015-04-01

    Full Text Available The need to surmount the limitation of obtaining rennin, has been actively pushed researches to find new substitutes that present high milk-clotting activity which enables the production of high yields of cheese. In this study, the production of extracellular milk-clotting protease by locally isolated fungal specie, Aspergillus niger FFB1 under solid-state fermentation (SSF using cheep agro-industrial byproduct (wheat bran was optimized. The effects of several physicochemical and environmental factors were investigated to select the optimal conditions that ensure the best milk-clotting activity by application of "One-factor-at-a-time" method. A trial of cheese production using the crude extract was also carried out. The maximum enzyme activity (830 SU/g bran with a ratio MCA/PA of 4.25 was obtained under the optimum conditions of temperature (30°C, spores concentration (106 spores/mL, incubation time (72 hours, and moisture content of solid substrate (39.2% adjusted suitably with mineral solution (Czapek-Dox of pH 4.

  14. Characterization of the clotting activities of structurally different forms of activated factor IX. Enzymatic properties of normal human factor IXa alpha, factor IXa beta, and activated factor IX Chapel Hill.

    OpenAIRE

    Griffith, M J; Breitkreutz, L; Trapp, H; Briet, E; Noyes, C M; Lundblad, R L; Roberts, H. R.

    1985-01-01

    Two structurally different forms of activated human Factor IX (Factor IXa alpha and IXa beta) have been previously reported to have essentially identical clotting activity in vitro. Although it has been shown that activated Factor IX Chapel Hill, an abnormal Factor IX isolated from the plasma of a patient with mild hemophilia B, and normal Factor IXa alpha are structurally very similar, the clotting activity of activated Factor IX Chapel Hill is much lower (approximately fivefold) than that o...

  15. The Effect of a Simulated Commercial Flight Environment with Hypoxia and Low Humidity on Clotting, Platelet, and Endothelial Function in Participants with Type 2 Diabetes – A Cross-over Study

    Directory of Open Access Journals (Sweden)

    Judit Konya

    2018-02-01

    Full Text Available AimsTo determine if clotting, platelet, and endothelial function were affected by simulated short-haul commercial air flight conditions (SF in participants with type 2 diabetes (T2DM compared to controls.Methods10 participants with T2DM (7 females, 3 males and 10 controls (3 females, 7 males completed the study. Participants were randomized to either spend 2 h in an environmental chamber at sea level conditions (temperature: 23°C, oxygen concentration 21%, humidity 45%, or subject to a simulated 2-h simulated flight (SF: temperature: 23°C, oxygen concentration 15%, humidity 15%, and crossed over 7 days later. Main outcome measures: clot formation and clot lysis parameters, functional platelet activation markers, and endothelial function measured by reactive hyperemia index (RHI by EndoPAT and serum microparticles.ResultsComparing baseline with SF conditions, clot maximal absorption was increased in controls (0.375 ± 0.05 vs. 0.39 ± 0.05, p < 0.05 and participants with T2DM (0.378 ± 0.089 vs. 0.397 ± 0.089, p < 0.01, while increased basal platelet activation for both fibrinogen binding and P-selectin expression (p < 0.05 was seen in participants with T2DM. Parameters of clot formation and clot lysis, stimulated platelet function (stimulated platelet response to ADP and sensitivity to prostacyclin, and endothelial function were unchanged.ConclusionWhile SF resulted in the potential of denser clot formation with enhanced basal platelet activation in T2DM, the dynamic clotting, platelet, and endothelial markers were not affected, suggesting that short-haul commercial flying adds no additional hazard for venous thromboembolism for participants with T2DM compared to controls.

  16. Diastolic timed Vibro-Percussion at 50 Hz delivered across a chest wall sized meat barrier enhances clot dissolution and remotely administered Streptokinase effectiveness in an in-vitro model of acute coronary thrombosis

    Directory of Open Access Journals (Sweden)

    Hoffmann Andrew

    2012-11-01

    Full Text Available Abstract Background Low Frequency Vibro-Percussion (LFVP assists clearance of thrombi in catheter systems and when applied to the heart and timed to diastole is known to enhance coronary flow. However LFVP on a clotted coronary like vessel given engagement over a chest wall sized barrier (to resemble non-invasive heart attack therapy requires study. Methods One hour old clots (n=16 were dispensed within a flexible segment of Soft-Flo catheter (4 mm lumen, weighted, interfaced with Heparinized Saline (HS, secured atop a curved dampening base, and photographed. A ~4 cm meat slab was placed over the segment and randomized to receive intermittent LFVP (engaged, - disengaged at 1 second intervals, or no LFVP for 20 minutes. HS was pulsed (~120/80 mmHg, with the diastolic phase coordinated to match LFVP delivery. The segment was then re-photographed and aspirated of fluid to determine post clot weight. The trial was then repeated with 0.5 mls of Streptokinase (15,000 IU/100 microlitre delivered ~ 2 cm upstream from the clot. Results LFVP - HS only samples (vs. controls showed; a development of clot length fluid channels absent in the control group (p Conclusion Diastolic timed LFVP (50 Hz engaged across a chest wall sized barrier enhances clot disruptive effects to an underlying coronary like system.

  17. Diastolic timed Vibro-Percussion at 50 Hz delivered across a chest wall sized meat barrier enhances clot dissolution and remotely administered Streptokinase effectiveness in an in-vitro model of acute coronary thrombosis.

    Science.gov (United States)

    Hoffmann, Andrew; Gill, Harjit

    2012-11-12

    Low Frequency Vibro-Percussion (LFVP) assists clearance of thrombi in catheter systems and when applied to the heart and timed to diastole is known to enhance coronary flow. However LFVP on a clotted coronary like vessel given engagement over a chest wall sized barrier (to resemble non-invasive heart attack therapy) requires study. One hour old clots (n=16) were dispensed within a flexible segment of Soft-Flo catheter (4 mm lumen), weighted, interfaced with Heparinized Saline (HS), secured atop a curved dampening base, and photographed. A ~4 cm meat slab was placed over the segment and randomized to receive intermittent LFVP (engaged, - disengaged at 1 second intervals), or no LFVP for 20 minutes. HS was pulsed (~120/80 mmHg), with the diastolic phase coordinated to match LFVP delivery. The segment was then re-photographed and aspirated of fluid to determine post clot weight. The trial was then repeated with 0.5 mls of Streptokinase (15,000 IU/100 microlitre) delivered ~ 2 cm upstream from the clot. LFVP - HS only samples (vs. controls) showed; a) development of clot length fluid channels absent in the control group (p dissolution (23.0% vs. 1.8% respectively, p dissolution more than doubled (51.0% vs. 3.0%, p< 9.8 E- 6). Diastolic timed LFVP (50 Hz) engaged across a chest wall sized barrier enhances clot disruptive effects to an underlying coronary like system.

  18. Monitoring of unfractionated heparin with rotational thrombelastometry using the prothrombinase-induced clotting time reagent (PiCT®).

    Science.gov (United States)

    Schaden, E; Jilch, S; Hacker, S; Schober, A; Kozek-Langenecker, S

    2012-12-24

    To achieve sufficient and safe anticoagulation with unfractionated heparin (UFH) a close and reliable drug monitoring is necessary. In general, the activated partial thromboplastin time (APTT) is used for this purpose. In acute phase response, however, the APTT test procedure might be unreliable e.g. with false low results in the presence of elevated factor VIII. In this so called heparin resistance, measurement of anti-Xa activity is recommended over APTT to avoid potentially harmful dose escalation. A combination of anti-Xa measurement and global hemostatic testing with ROTEM® employing the anti-Xa sensitive PiCT® reagent showed high correlation with enoxaparin levels. This test modification could also be suitable for monitoring UFH. Aim of the study was to evaluate the correlation between PiCT®-ROTEM® and levels of UFH. In this in-vitro study blood samples from healthy volunteers were spiked with UFH and subjected to different ROTEM® tests. There was a linear correlation between UFH level and clotting time (CT) in the PiCT®-ROTEM® test with an excellent correlation coefficient of 0.92. Additional endpoints showed similar results (PiCT®-ROTEM® MaxVel r = -0.85 and PiCT®-ROTEM® t_MaxVel r = 0.88). As a point-of-care applicable tool ROTEM® is immediately at hand. If further clinical studies confirm sensitivity in heparin resistance, PiCT®-ROTEM® could permit rapid UFH dose adjustments especially required in critical illness with acute phase response. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. The Anti-Clot Treatment Scale (ACTS in clinical trials: cross-cultural validation in venous thromboembolism patients

    Directory of Open Access Journals (Sweden)

    Cano Stefan J

    2012-09-01

    Full Text Available Abstract Background The Anti-Clot Treatment Scale (ACTS is a 15-item patient-reported instrument of satisfaction with anticoagulant treatment. It includes a 12-item ACTS Burdens scale and a 3-item ACTS Benefits scale. Its role in clinical trials and other settings should be supported by evidence that it is both clinically meaningful and scientifically sound. The aim of the study was to evaluate the measurement performance of the ACTS (Dutch, Italian, French, German and English language versions in patients with venous thromboembolism based on traditional psychometric methods. Methods ACTS Burdens and Benefits scale data from a large clinical trial (EINSTEIN DVT involving 1336 people with venous thromboembolism were analysed at both the scale and item level. Five key psychometric properties were examined using traditional psychometric methods: acceptability, scaling assumptions, reliability (including internal consistency reliability, test-retest reproducibility; validity (including known groups and discriminant validity; and responsiveness. These methods of examination underpin the US Food and Drug Administration recommendations for patient-reported outcome instrument evaluation. Results Overall, the 12-item ACTS Burdens scale and 3-item ACTS Benefits scale met the psychometric criteria evaluated at both item and scale levels, with the exception of some relatively minor issues in the Dutch language version, which were just below reliability criteria (i.e. alpha = 0.72, test-retest intraclass correlation = 0.79. A consistent finding from item-level evaluations of aggregate endorsement frequencies and skewness suggested that response scales may be improved by reducing the number of response options from five to four. Conclusions Both the ACTS Burdens and ACTS Benefits scales consistently satisfied traditional reliability and validity criteria across multiple language datasets, supporting it as a clinically useful patient

  20. Activated clotting time level with weight based heparin dosing during percutaneous coronary intervention and its determinant factors.

    Science.gov (United States)

    Soleimannejad, Majid; Aslanabadi, Naser; Sohrabi, Bahram; Shamshirgaran, Morteza; Separham, Ahmad; Kazemi, Babak; Khayati Shal, Ebrahim; Madadi, Reza; Shirzadi, Hamidreza; Azizi, Hoda; Ghaffari, Samad

    2014-01-01

    Percutaneous coronary intervention (PCI) may be associated with Thrombotic complications. Unfractionated heparin (UFH) is a potent and preferable antithrombotic agent during this procedure. Activated clotting time (ACT) is a good assay for accurate titration of UFH during PCI. The aim of this study was to evaluate ACT levels 10 minutes after administration of 100U/kg IV heparin and determining its associated factors. This study was performed in Madani hospital, Tabriz, Iran between January 2013 to January 2014. One hundred and two patients candidates for elective PCI were enrolled in the study. Data including demographic and risk factors were collected. The range of ACT was between 165 to 750 seconds (mean 319.8 seconds), 52 (51%) patients had ACT levels lower than 300sec and 12 (11.8%) patients had ACT levels between 300 to 350 seconds which is known optimal range and 38 (37.2%) cases had ACT levels above this value. Major risk factors had no effect on ACT value, but there was a trend to higher levels with increasing age (P=0.06). There was no difference in the rate of major or minor bleeding with respect to ACT levels (P=0.52). There was a trend to higher rate of minimal bleeding in those with ACT >350 sec (P=0.06). Weight based UFH injection may result in suboptimal anticoagulation during the procedure. Routine ACT measurement may be necessary to ascertain adequate anticoagulation. Major risk factors had no effect on ACT level and it was not associated with the rate of bleeding.

  1. Septic transfusion case caused by a platelet pool with visible clotting due to contamination with Staphylococcus aureus.

    Science.gov (United States)

    Loza-Correa, Maria; Kou, Yuntong; Taha, Mariam; Kalab, Miloslav; Ronholm, Jennifer; Schlievert, Patrick M; Cahill, Michael P; Skeate, Robert; Cserti-Gazdewich, Christine; Ramirez-Arcos, Sandra

    2017-05-01

    Contamination of platelet concentrates (PCs) with Staphylococcus aureus is one of the most significant ongoing transfusion safety risks in developed countries. This report describes a transfusion reaction in an elderly patient diagnosed with acute myeloid leukemia, transfused with a 4-day-old buffy coat PC through a central venous catheter. The transfusion was interrupted when a large fibrous clot in the PC obstructed infusion pump flow. Shortly afterward, a red blood cell (RBC) unit transfusion started. After septic symptoms were developed, the RBC transfusion was also interrupted. While the RBC unit tested negative for bacterial contamination, the PC and the patient samples were found to be contaminated with a S. aureus strain that exhibited the same phenotypic and genome sequencing profiles. The isolated S. aureus forms biofilms and produces the superantigen enterotoxin-like U, which was detected in a sample of the transfused PCs. The patient received posttransfusion antibiotic treatment and had her original central line removed and replaced. As the implicated PC had been tested for bacterial contamination during routine screening yielding negative results, this is a false-negative transfusion sepsis case. Using a point-of-care test could have prevented the transfusion reaction. This report highlights the increasing incidence of S. aureus as a major PC contaminant with grave clinical implications. Importantly, S. aureus is able to interact with platelet components resulting in visible changes in PCs. Visual inspection of blood components before transfusion is an essential safety practice to interdict the transfusion of bacterially contaminated units. © 2017 AABB.

  2. Defining optimal activated clotting time for percutaneous coronary intervention: A systematic review and Bayesian meta-regression.

    Science.gov (United States)

    Mottillo, Salvatore; Filion, Kristian B; Joseph, Lawrence; Eisenberg, Mark J

    2017-02-15

    Guidelines recommend routine monitoring of unfractionated heparin (UFH) with activated clotting time (ACT) during percutaneous coronary intervention (PCI). However, the optimal ACT for patients undergoing PCI is unclear. We sought to determine the association of peak ACT during PCI with 30-day major adverse cardiac events (MACE; all-cause mortality, myocardial infarction, and revascularization) and bleeding events. We searched the Cochrane Central Register of Controlled Trials, EMBASE, and Medline for randomized controlled trials (RCTs) evaluating UFH through May 2015. Only patients randomized to UFH alone or to UFH with a glycoprotein IIb/IIIa inhibitor (GPI) were analyzed using Bayesian meta-regression. Among 13 included RCTs (n = 17455), eight (n = 5521) included study arms of UFH alone and 12 (n = 11934) included arms of UFH with a GPI. Peak ACT ranged from 201 to 460 sec for UFH alone and 248-317 sec for UFH with a GPI. With UFH alone, the probability of MACE was 7.0% (95% credible interval [CrI] 1.5, 31.5) for a peak ACT of 200 sec and 5.8% (95% CrI 2.6, 12.0) for 300 sec. Among UFH with a GPI, the probability of MACE was 2.8% (95% CrI 0.8, 6.8) for a peak ACT of 200 sec and 7.2% (95% CrI 5.4, 9.7) for 300 sec. Among individual RCTs, the probability of MACE and major bleeding events associated with low versus high values of peak ACT is inconsistent. Our meta-regression results are inconclusive, emphasizing the need for RCTs comparing low versus high doses of UFH. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Clot Burden Score on Baseline Computerized Tomographic Angiography and Intra-Arterial Treatment Effect in Acute Ischemic Stroke.

    Science.gov (United States)

    Treurniet, Kilian M; Yoo, Albert J; Berkhemer, Olvert A; Lingsma, Hester F; Boers, Anna M M; Fransen, Puck S S; Beumer, Debbie; van den Berg, Lucie A; Sprengers, Marieke E S; Jenniskens, Sjoerd F M; Lycklama À Nijeholt, Geert J; van Walderveen, Marianne A A; Bot, Joseph C J; Beenen, Ludo F M; van den Berg, René; van Zwam, Wim H; van der Lugt, Aad; van Oostenbrugge, Robert J; Dippel, Diederik W J; Roos, Yvo B W E M; Marquering, Henk A; Majoie, Charles B L M

    2016-12-01

    A high clot burden score (CBS) is associated with favorable outcome after intravenous treatment for acute ischemic stroke. The added benefit of intra-arterial treatment might be less in these patients. The aim of this exploratory post hoc analysis was to assess the relation of CBS with neurological improvement and endovascular treatment effect. For 499 of 500 patients in the MR CLEAN study (Multicenter Randomized Clinical Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands), the CBS was determined. Ordinal logistic regression models with and without main baseline prognostic variables were used to assess the association between CBS (continuous or dichotomized at CBS of 6) and a shift toward better outcome on the modified Rankin Scale. The model without main baseline prognostic variables only included treatment allocation and CBS. Models with and without a multiplicative interaction term of CBS and treatment were compared using the χ2 test to assess treatment effect modification by CBS. Higher CBS was associated with a shift toward better outcome on the modified Rankin Scale; adjusted common odds ratio per point CBS was 1.12 (95% confidence interval, 1.04-1.20]. Dichotomized CBS had an adjusted common odds ratio of 1.67 (95% confidence interval, 1.12-2.51). Both effect estimates were slightly attenuated by adding baseline prognostic variables. The addition of the interaction terms did not significantly improve the fit of the models. There was a small and insignificant increase of intra-arterial treatment efficacy in the high CBS group. A higher CBS is associated with improved outcome and may be used as a prognostic marker. We found no evidence that CBS modifies the effect of intra-arterial treatment. URL: http://www.trialregister.nl. Unique identifier: NTR1804. URL: http://www.controlled-trials.com. Unique identifier: ISRCTN10888758. © 2016 American Heart Association, Inc.

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  6. Yves Clot, Vygotski maintenant

    OpenAIRE

    Geffrotin, Loïc

    2012-01-01

    Lev Vygotski (1896-1934), psychologue pour enfant, pédagogue, et intellectuel russe, diagnostiquait en 1926 une crise dans la psychologie, du fait de l'extrême division de ses conceptions (idéaliste, matérialiste), de ses méthodes (expérimentale à tendance mécaniste réduisant le psychologique au biologique, introspective à tendance subjective...) et de ses objets d'études (le comportement, la conscience, l'inconscient...). Il proposait de solutionner cette crise en avançant une psychologie ma...

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