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Sample records for blood clotting

  1. Blood Clots

    Science.gov (United States)

    ... a doctor immediately. There have been many research advances that have improved the prevention and treatment of blood clots. Some current treatments include: Anticoagulants - medicine that prevents clots from forming Thrombolytics - medicine that ...

  2. 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 ...

  3. 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 ...

  4. 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 ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... America Asia-Pacific Latin America Meeting on Hematologic Malignancies Gain knowledge, through “How I Treat” presentations, that ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated ... Clots Blood Clotting and Pregnancy Clots and Travel DVT Myths vs. Facts Blood ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Clots Blood Clotting and Pregnancy Clots and Travel DVT Myths vs. Facts Blood Disorder Fact Sheets ... that occurs when a DVT breaks off and travels to the blood vessels of the lungs. DVT ...

  8. Blood Clotting and Pregnancy

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    Full Text Available ... Hematology 2017 A collection of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A ... Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ...

  9. 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) ... doctor's approval. Be aware of the signs and symptoms of a blood clot . Visit your doctor immediately ...

  10. Postpartum Blood Clots

    Science.gov (United States)

    ... Kidney Infections Breast Infection Postpartum Blood Clots Postpartum Thyroid Disorders Postpartum Depression The risk of developing blood clots ( ... Kidney Infections Breast Infection Postpartum Blood Clots Postpartum Thyroid Disorders Postpartum Depression NOTE: This is the Consumer Version. ...

  11. Blood Clotting and Pregnancy

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

  12. Blood Clotting and Pregnancy

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    Full Text Available ... 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 Clots ...

  13. 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 ...

  14. 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 ... blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots are treated with an ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  16. 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 ...

  17. 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 ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... In This Section Agenda for Hematology Research Precision Medicine Initiative Research Registry Research Recommendations Research Programs and ... blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... these blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially ... immobility (e.g., bedrest, long distance travel) ...

  20. 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 ... you are interested in learning more about blood diseases and disorders, here are a few other resources ...

  1. 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 ...

  2. 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 ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... 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 ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births ... treating blood conditions. back to top Antiphospholipid Antibody Syndrome: A Patient's Journey back to top Where Can ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... Apps Share Your Idea Donate My Account Search Show Main Menu + About Awards Membership ASH Foundation Global ... are pregnant and have concerns about blood clots, talk with your doctor about your risks and prevention. ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... Your Idea Donate My Account Search Show Main Menu + About Awards Membership ASH Foundation Global Initiatives Newsroom ... genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased ...

  7. 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 ...

  8. National Blood Clot Alliance

    Science.gov (United States)

    ... Pregnancy & Childbirth Treatment of Menopause Symptoms Women’s Health Menopause and Hormone Replacement Therapy FAQs Blood Clots and Women’s Health ... Family Planning, Pregnancy & Childbirth, and the onset of Menopause Symptoms that might be treated ... therapy. Learn More The public health impact of ...

  9. 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 ...

  10. 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 ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... Schedule & Program Registration Receipts Abstracts View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances ... reflect the most recent scientific research View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... all Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus ... Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal ...

  13. Blood Clotting and Pregnancy

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    Full Text Available ... scientific research View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood ... that provide information. back to top ASH Foundation Support the mission of ASH and help move hematology ...

  14. Blood Clotting and Pregnancy

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    Full Text Available ... Research Programs and Awards View all Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed ... Receipts Abstracts View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... Blood articles updated to reflect the most recent scientific research View all publications For Patients Blood Basics ... help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... that may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... to Action on DVT and PE to raise public awareness of these blood conditions and increase research ... may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official journal ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, patients interested in ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... in the field Hematology 2017 A collection of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated to reflect the most recent scientific research ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... a subscriber login, patients interested in viewing an access-controlled article in Blood may obtain a copy by e-mailing a request to the Blood ... ASH Foundation Support the mission ...

  1. Blood Clotting and Pregnancy

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    Full Text Available ... In This Section Agenda for Hematology Research Precision Medicine Initiative Research Registry Research Recommendations Research Programs and Awards View all Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus ...

  2. Blood Clotting and Pregnancy

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    Full Text Available ... articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated ... Doctor Patient Group Links Advocacy Toolkit Home For Patients ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and ... a subscriber login, patients interested in viewing an access-controlled article in Blood may obtain a copy ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... ASH Apps Share Your Idea Donate My Account Search Show Main Menu + About Awards Membership ASH Foundation ... help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... 4, 2018 2017 Resources CME & Certificates Schedule & Program Registration Receipts Abstracts View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a unique focus ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... Emerging Immunotherapies Registration Schedule & Program Meeting on Lymphoma Biology Registration Schedule & Program Abstracts 60th ASH Annual Meeting & ... Malignancies Consultative Hematology Course ASH Meeting on Lymphoma Biology ASH Workshop on Genome Editing Publications Blood Blood ...

  8. Blood Clotting and Pregnancy

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    Full Text Available ... Section Action Alerts Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy Statements Congressional Fellowship Testimony and ... Malignancies Consultative Hematology Course ASH Meeting on Lymphoma Biology ASH Workshop on Genome Editing Publications Blood Blood ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... copy by e-mailing a request to the Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that provide information. back to top ASH ... Blood Blood Advances The Hematologist ASH Clinical News ASH ...

  10. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... that may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, patients interested in ...

  11. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... online only, open access journal with a unique focus on scholarly and educational content The Hematologist ... Group Links Advocacy Toolkit Home For Patients Blood Disorders ...

  12. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... login, patients interested in viewing an access-controlled article in Blood may obtain a copy by e-mailing a request to the Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that provide information. back to top ASH Foundation Support the mission ...

  13. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... educational meetings and webinars ASH Image Bank Educational Web-based library of hematologic imagery In This Section: ... Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that ...

  14. Blood Clotting and Pregnancy

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    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly and educational content Annual Meeting Abstracts Call for Abstracts Abstract Review Categories Abstracts Archive View all Education ASH Academy ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... for Hematology Research Research Registry Research Recommendations Research Programs and Awards View all Blood Current Issue First ... for continuing medical education (CME) and recertification Educational Programs Programs to enhance knowledge, research, and expertise Advocacy ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... content Annual Meeting Abstracts Call for Abstracts Abstract Review Categories Abstracts Archive View all Education ASH Academy ... First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a unique focus ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... mission of ASH and help move hematology forward. Learn more Find a Hematologist Search a database of ...

  18. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... and webinars ASH Image Bank Educational Web-based library of hematologic imagery In This Section: Resources for ... to Action on DVT and PE to raise public awareness of these blood conditions and increase research ...

  19. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy ... Surgeon General has issued a Call to Action on DVT and PE to raise public awareness of these blood conditions and increase research ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... Membership ASH Foundation Global Initiatives Newsroom facebook twitter youtube linkedin Copyright © 2018 by American Society of Hematology ...

  1. Blood Clotting and Pregnancy

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    Full Text Available ... bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back ... a request to the Blood Publishing Office . Patient Groups A list of Web links to patient groups ...

  2. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly and educational ... Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and educational ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... condition is known as deep vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening event that ... and travels to the blood vessels of the lungs. DVT and PE, collectively known as venous thromboembolism, ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... of Web links to patient groups and other organizations that provide information. back to top ASH Foundation ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... blood conditions. back to top Antiphospholipid Antibody Syndrome: A Patient's Journey back to top Where Can I ... and help move hematology forward. Learn more Find a Hematologist Search a database of practicing hematologists in ...

  6. 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 ... you are interested in learning more about blood diseases and disorders, here are a few other resources ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  8. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Assessment Program A comprehensive resource to help stay current with the latest advances in the field Hematology 2017 A collection of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay ... Blood Advances The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards ...

  10. Blood Clotting and Pregnancy

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    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly and educational content Annual Meeting Abstracts Call for Abstracts Abstract Review Categories Abstracts Archive View all Education ASH Academy The eLearning platform for hematologists ASH ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay current ... Blood Advances The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards Membership ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and educational content The Hematologist Features Diffusion President's Column ASH Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay ...

  13. 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.

  14. 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

  15. 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 ( ...

  16. A rat model of reproducible cerebral infarction using thrombotic blood clot emboli

    DEFF Research Database (Denmark)

    Overgaard, K.; Sereghy, T.; Boysen, G.

    1992-01-01

    Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat......Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat...

  17. 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

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

    Science.gov (United States)

    Robinson, Ronald A; Herbertson, Luke H; Sarkar Das, Srilekha; Malinauskas, Richard A; Pritchard, William F; Grossman, Laurence W

    2013-01-01

    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 filter in the IVC model flow loop, they were more likely to pass between the peripheral filter struts, while the softer, physiological clots tended to fold and were captured by the filter. These experiments demonstrated that if synthetic clots are used as a surrogate for animal or human blood

  19. Elasticity and fracture strain of whole blood clots

    Czech Academy of Sciences Publication Activity Database

    Říha, Pavel; Wang, X.; Liao, R.; Stoltz, J. F.

    1999-01-01

    Roč. 21, č. 1 (1999), s. 45-49 ISSN 1386-0291 Institutional research plan: CEZ:AV0Z2060917 Keywords : viscoelasticity * fracture strain * blood clots Subject RIV: BK - Fluid Dynamics Impact factor: 0.395, year: 1999

  20. 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...

  1. Blood clotting and platelets: a delicate balance

    International Nuclear Information System (INIS)

    Heyns, A. du P.; Loetter, M.G.; Badenhorst, P.N.

    1988-01-01

    The Medical Research Council Blood Platelet Research Unit has studied many of the facets of platelets. The research highlights of the Unit include the following: the identification of ADPase, an enzyme found in the blood vessel wall, which breaks down adenosine diphospate (ADP) to adenosine, and which inhibits platelet aggregation; the determination of the relationship between the biochemical activity of the vessel wall with the development of atherosclerosis; the development of a method to label platelets with the compound In-111-oxine; the use of labelled platelets to study platelets in the spleen: an investigation of the life-span of platelets, which revealed how aged platelets are removed from circulation, and recently a study of methods to demonstrate in vivo activation of platelets. 1 fig

  2. Seamless particle-based modeling of blood clotting

    Science.gov (United States)

    Yazdani, Alireza; Karniadakis, George

    2016-11-01

    We propose a new multiscale framework that seamlessly integrate four key components of blood clotting namely, blood rheology, cell mechanics, coagulation kinetics and transport of species and platelet adhesive dynamics. We use transport dissipative particle dynamics (tDPD) which is an extended form of original DPD as the base solver to model both blood flow and the reactive transport of chemical species in the coagulation cascade. Further, we use a coarse-grained representation of blood cell's membrane that accounts for its mechanics; both red blood cells and platelets are resolved at sub-cellular resolution, and stochastic bond formation/dissociation are included to account for platelet adhesive dynamics at the site of injury. Our results show good qualitative agreement with in vivo experiments. The numerical framework allows us to perform systematic analysis on different mechanisms of blood clotting. In addition, this new multiscale particle-based methodology can open new directions in addressing different biological processes from sub-cellular to macroscopic scales. NIH Grant No. U01HL116323.

  3. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

    Science.gov (United States)

    Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

    2014-01-01

    Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with “undecorated” chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (P<0.05) (n=4) shorter than that of a clot induced by a phosphate-buffered solution (PBS) (clot/PBS) (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively). The ΔF2 values in the spectra of frequency shifts associated with the propagation of fibrin networks in the clot/ANPs and clot/FNPs were significantly lower than those of clot/PBS. Interestingly, texture profile analysis of the compressional properties showed significantly lower hardness and compressibility in clot/NPs and clot/ANPs (P<0.05 or better) (n=4) compared with clot/PBS and

  4. Procoagulant control strategies for the human blood clotting process.

    Science.gov (United States)

    Laurino, Marco; Menara, Tommaso; Stella, Alessandro; Betta, Monica; Landi, Alberto

    2015-08-01

    This paper describes the comparison between two drug control strategies to hemophilia A. To emulate blood clotting and the pathological condition of hemophilia, a mathematical model composed by 14 ordinary differential equations is considered. We adopt a variable structure non-linear PID approach and a Model Predictive Control in order to control the dosage of procoagulant factor used in the treatment of hemophiliac patient. The two control actions are sampled for a practical application. Finally, we discuss and compare the results of the two control approaches, introducing a suited control index (eINR).

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

    Directory of Open Access Journals (Sweden)

    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.

  6. 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...

  7. Blood Clots That Kill: Preventing DVT | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... clot. This also is true of treatment with hormone therapy or birth control pills. Sometimes, blood clots can form from no known cause. Risk Many factors increase your risk for deep vein thrombosis (DVT). They include: A history of DVT. Disorders or factors that make your ...

  8. 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.

  9. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

    Directory of Open Access Journals (Sweden)

    Chung TW

    2014-03-01

    Full Text Available Tze-Wen Chung,1,3 Pei-Yi Lin,2 Shoei-Shen Wang,2 Yen-Fung Chen31Department of Biomedical Engineering, National Yang-Ming University, 2Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Republic of China; 3Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, Taiwan, Republic of ChinaAbstract: Chitosan nanoparticles (NPs decorated with adenosine diphosphate (ADP (ANPs or fibrinogen (FNPs were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP or FNP (clot/FNP were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4, respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP, clot/ANP, and clot/FNP (at 0.05 wt% were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM, were significantly (P<0.05 (n=4 shorter than that of a clot induced by a phosphate-buffered solution (PBS (clot/PBS (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively. The ∆F2

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

    Indian Academy of Sciences (India)

    Ai-Ping Zhou

    2017-11-14

    Nov 14, 2017 ... 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. Keywords. Blood plasma; Zakharov equations; viscosity; modulation instability. PACS Nos 52.27.–h; 52.35.

  11. An alternate method for DNA and RNA extraction from clotted blood.

    Science.gov (United States)

    Zakaria, Z; Umi, S H; Mokhtar, S S; Mokhtar, U; Zaiharina, M Z; Aziz, A T A; Hoh, B P

    2013-02-04

    We developed an alternative method to extract DNA and RNA from clotted blood for genomic and molecular investigations. A combination of the TRIzol method and the QIAamp spin column were used to extract RNA from frozen clotted blood. Clotted blood was sonicated and then the QIAamp DNA Blood Mini Kit was used for DNA extraction. Extracted DNA and RNA were adequate for gene expression analysis and copy number variation (CNV) genotyping, respectively. The purity of the extracted RNA and DNA was in the range of 1.8-2.0, determined by absorbance ratios of A(260):A(280). Good DNA and RNA integrity were confirmed using gel electrophoresis and automated electrophoresis. The extracted DNA was suitable for qPCR and microarrays for CNV genotyping, while the extracted RNA was adequate for gene analysis using RT-qPCR.

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

    Indian Academy of Sciences (India)

    ... 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.

  13. 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.

  14. Pre-analytical variation in glucose concentration due to atmospheric temperature and clot in blood specimens

    International Nuclear Information System (INIS)

    Butt, T.; Masud, K.; Khan, J.A.; Bhatti, M.S.

    2016-01-01

    Objective: To determine the effect of temperature and contact of clot with serum on laboratory results of glucose concentration in blood. Study Design: Quasi-experimental study. Place and Duration of Study: December 2014 to August 2015 at the laboratory of Shoaib Hospital, Fateh Jang, Attock Pakistan. Material and Methods: Samples were collected for estimation of blood glucose (Random) concentration from patients reporting to the hospital. Blood specimens (n=94) of such volunteers were analyzed for glucose level. Each sample was put up in five tubes. When the blood clotted the serum from tube-1 was analyzed for glucose level within 30 minutes. In tube-2 and tube-3 serum was kept for 24 hours at room temperature and refrigerator temperature respectively before glucose estimation. In tube-4 and tube-5 serum was not separated from clot and kept at room temperature and refrigerator temperature respectively before glucose estimation. The value of tube 1 was taken as reference value for comparison with other parts of the specimen. The equipment used for blood glucose level estimation was semi auto chemistry analyzer (Rayto, China). The kit used for analysis was Glucose - Liquizyme (Germany). Results: The difference between the mean reference value (tube-1) and refrigerated serum without clot (tube-3) was 4.63 mg/100 ml while that of unrefrigerated portion (tube-2) had a difference of 10.68 mg/100 ml. The mean of unrefrigerated (tube-4) and refrigerated (tube-5) portions of serum kept with the clot had difference of 42.05 mg/100 ml and 25.84 mg/100 ml respectively. The fall in the blood glucose level in all (n=94) the samples in the tube number 3 (serum separated and kept at refrigerated temperature) was 4.63 mg/100 ml +- 3.68 (Mean +- SD) and it ranged from 0 to 20 mg/100 ml whereas fall was maximum in the tube number 4 (serum with clotted blood and kept at room temperature) was 42.04 mg/100 ml +- 10.61 (Mean +- SD) and it ranged from 13 to 82 mg/100 ml. The sample in

  15. High-Quality and -Quantity DNA Extraction from Frozen Archival Blood Clots for Genotyping of Single-Nucleotide Polymorphisms

    DEFF Research Database (Denmark)

    Bank, Steffen; Nexø, Bjørn Andersen; Andersen, Vibeke

    2013-01-01

    Background: The recovery of biological samples for genetic epidemiological studies can be cumbersome. Blood clots are routinely collected for serological examinations. However, the extraction of DNA from blood clots can be difficult and often results in low yields. Aim: The aim was to compare the...

  16. 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.

  17. 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.

  18. RESULTS OF QUALITY COMPREHENSIVE EVALUATION OF DENTAL CARE FOR CHILDREN WITH BLOOD CLOTTING (PATHOLOGY

    Directory of Open Access Journals (Sweden)

    M. A. Gavrilenko

    2014-04-01

    Full Text Available Background. Treatment methods for diseases of teeth hard tissues and periodontium for children with blood clotting pathology are described in modern literature. But in practice we are faced with the problem of providing dental treatment for these children. Work of pediatric dentist is prevented by the risk of bleeding, fear of dental procedures, child’s psychoemotional tension and refusal of treatment because of bleeding. Taking into account the specificity of blood clotting pathology, surgical methods of dental treatment prevail for these children, which is evidenced by the early loss of deciduous and permanent teeth, occlusal surface disturbances, dentoalveolar anomalies, inflammatory diseases of periodontal tissues. Aim. To evaluate the level of dental care for children with the diseases of blood clotting. Materials and methods. 120 children between 2 and 18 years old with blood clotting disorders (hemophilia A, B, thrombocytopenia, thrombocytopathy were examined. Children were divided into groups: I group – 2-5 years old (40 children, II group – 6-10 years old (40 children, III group – 11-18 years old (40 children, according to the periods of tooth development, with an equal number of children in groups according to diagnoses. Clinical examination was carried out according to the standard scheme, including the analysis of complaints, anamnesis of treatment at the dentist, objective data with the use of statistical method of masticatory efficiency (according to N.I. Agapov, the level of dental care (according to P.A. Leus. Results. During clinical dental examination of children with blood clotting pathology it was found that destruction of crowns of maxillary front teeth, the first deciduous molars and the second deciduous molars, as well as their loss, prevails in the temporary occlusion. During the examination of 2-5 years old children with blood clotting pathology, loss of less than 25% of masticatory efficiency was revealed for 25

  19. 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.

  20. Phase transitions during compression and decompression of clots from platelet-poor plasma, platelet-rich plasma and whole blood.

    Science.gov (United States)

    Liang, Xiaojun; Chernysh, Irina; Purohit, Prashant K; Weisel, John W

    2017-09-15

    Blood clots are required to stem bleeding and are subject to a variety of stresses, but they can also block blood vessels and cause heart attacks and ischemic strokes. We measured the compressive response of human platelet-poor plasma (PPP) clots, platelet-rich plasma (PRP) clots and whole blood clots and correlated these measurements with confocal and scanning electron microscopy to track changes in clot structure. Stress-strain curves revealed four characteristic regions, for compression-decompression: (1) linear elastic region; (2) upper plateau or softening region; (3) non-linear elastic region or re-stretching of the network; (4) lower plateau in which dissociation of some newly made connections occurs. Our experiments revealed that compression proceeds by the passage of a phase boundary through the clot separating rarefied and densified phases. This observation motivates a model of fibrin mechanics based on the continuum theory of phase transitions, which accounts for the pre-stress caused by platelets, the adhesion of fibrin fibers in the densified phase, the compression of red blood cells (RBCs), and the pumping of liquids through the clot during compression/decompression. Our experiments and theory provide insights into the mechanical behavior of blood clots that could have implications clinically and in the design of fibrin-based biomaterials. The objective of this paper is to measure and mathematically model the compression behavior of various human blood clots. We show by a combination of confocal and scanning electron microscopy that compression proceeds by the passage of a front through the sample that separates a densified region of the clot from a rarefied region, and that the compression/decompression response is reversible with hysteresis. These observations form the basis of a model for the compression response of clots based on the continuum theory of phase transitions. Our studies may reveal how clot rheology under large compression in vivo due

  1. 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.

  2. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus

    DEFF Research Database (Denmark)

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    /Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially......It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V...

  3. A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy.

    Science.gov (United States)

    Krebs, C R; Li, Ling; Wolberg, Alisa S; Oldenburg, Amy L

    2015-07-01

    Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring.

  4. Changes to the structure of blood clots formed in the presence of fine particulate matter

    International Nuclear Information System (INIS)

    Metassan, Sofian; Routledge, Michael N; Ariens, Robert A S; Scott, D Julian

    2009-01-01

    Both long-term and short-term exposure (one to two hours) to particulate matter are associated with morbidity and mortality caused by cardiovascular diseases. The underlying mechanisms leading to cardiovascular events are unclear, however, changes to blood coagulability upon exposure to ultrafine particulate matter (UFPM, the smallest of which can enter the circulation) is a plausible mechanism. Objectives: This study aims to investigate the direct effects of particulate matter on fibrin polymerization, lateral aggregation and the formation of fibrin network structure. Methods: Standard Urban Particulate Matter (PM) was suspended in Tris buffer centrifuged and filtered with <200nm filter to obtain ultrafine PM or their water-soluble components. Purified normal fibrinogen was made to clot by adding thrombin and calcium chloride in the presence of varying concentrations of PM. Permeation properties (Darcy constant [Ks]) and turbidity of clots were measured to investigate the effects on flow-rate, pore size, and fibrin polymerization. In addition, confocal microscopy was performed to study detailed clot structure. Results: Total PM increased the Ks of clots in a dose dependant manner (Ks = 4.4, 6.9 and 13.2 x 10-9 cm2 for 0, 50 and 100 |ag/ml total PM concentrations, respectively). Filtered PM also produced a significant increase in Ks at PM concentration of 17 |ag/ml. Final turbidity measurements at 20min were obtained for varying concentrations of PM. Maximum optical density (OD) for 1 mg/ml fibrinogen at 0, 50, 100 and 200 |ag/ml total PM concentrations were 0.39, 0.42, 0.45 and 0.46, respectively. The maximum OD for 0, 17, 34 and 68 |ag/ml filtered PM concentrations were 0.39, 0.42 0.47 and 0.51, respectively, suggesting an increase in fibre diameter with increasing particulate concentration. The lag phase was significantly shorter and the rate of polymerisation was significantly faster in the presence of 68 |ag/ml filtered PM. Confocal microscopy results showed

  5. Effect of anticoagulant administration on blood clotting and some hormones related to rat-fertility

    International Nuclear Information System (INIS)

    Abdel-Khalek, L.G.

    2009-01-01

    This study was performed using 30 mature male albino rats divided into 3 equal groups; control and two treated groups to assess the effect of anticoagulant (warfarin) administration on the level of some hormones related to fertility. The two treated groups were injected intraperitoneally every other day with 1 ml (0.03 mg)and 2 ml (0.06 mg)warfarin/ 100 g body weight respectively where, two specimens were taken from each group after two and four weeks. Clotting time (CT), prothrombin time (PT), partial prothrombin time (PTT) platelets count, fasting blood sugar (F.B.S), calcium levels in addition to triiodothyronine (T 3 ), thyroxin (T 4 ), insulin, corticosterone, and testosterone hormones were determined. The results showed that the intraperitoneal injection of warfarin caused significant increase in clotting time, prothrombin time , partial prothrombin time, platelets count and glucose level, while serum calcium level showed significant decrease. Intraperitoneal injection of warfarin caused significant decrease of insulin and significant increase of corticosterone, T 3 showed significant decrease in high dose group while T 4 showed significant decrease in small dose group. The high dose was associated with the highest level of testosterone hormone. these results denoted that warfarin anticoagulant had no negative effect on gonadal sex hormone and hence on male fertility

  6. 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.

  7. Intracameral air injection during Ahmed glaucoma valve implantation in neovascular glaucoma for the prevention of tube obstruction with blood clot: Case Report.

    Science.gov (United States)

    Hwang, Sung Ha; Yoo, Chungkwon; Kim, Yong Yeon; Lee, Dae Young; Nam, Dong Heun; Lee, Jong Yeon

    2017-12-01

    Glaucoma drainage implant surgery is a treatment option for the management of neovascular glaucoma. However, tube obstruction by blood clot after Ahmed glaucoma valve (AGV) implantation is an unpredictable clinically challenging situation. We report 4 cases using intracameral air injection for the prevention of the tube obstruction of AGV by blood clot. The first case was a 57-year-old female suffering from ocular pain because of a tube obstruction with blood clot after AGV implantation in neovascular glaucoma. Surgical blood clot removal was performed. However, intractable bleeding was noted during the removal of the blood clot, and so intracameral air injection was performed to prevent a recurrent tube obstruction. After the procedure, although blood clots formed around the tube, the tube opening where air could touch remained patent. In 3 cases of neovascular glaucoma with preoperative severe intraocular hemorrhages, intracameral air injection and AGV implantation were performed simultaneously. In all 3 cases, tube openings were patent. It appears that air impeded the blood clots formation in front of the tube opening. Intracameral air injection could be a feasible option to prevent tube obstruction of AGV implant with a blood clot in neovascular glaucoma with high risk of tube obstruction. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  8. Iodine based radiopacity of experimental blood clots for testing of mechanical thrombectomy devices

    International Nuclear Information System (INIS)

    Luo, Zhong Hua; Chung, Alex; Choi, Gibok; Lin, Yih Huie; Pang, Huajin; Uchida, Barry T.; Pavcnik, Dusan; Jeromel, Miran; Keller, Frederick S.; Rösch, Josef

    2013-01-01

    Barium sulfate powder used for radiopacity of experimental blood clots (EBCs) for testing mechanical thrombectomy devices (MTD) has negative effects on EBCs mechanical properties. In vitro and in vivo exploration was performed to determine if the iodine based contrast medium will have less negative effects on the EBCs than barium. Fresh blood from 2 swine was used to create fibrinogen enhanced and thrombin initiated EBC in tubes. Iodine radiopacity was achieved by mixing the blood with 65% Iohexol or by soaking the EBCs for 2 or 24 hours in Iohexol. The EBCs opacified with barium served as controls. In vitro study: The EBCs were subjected to four tests, manual elongation, catheter injection, radiopacity and contrast wash out tests. In vivo study: The common carotid arteries of 2 swine were embolized by either barium EBC or EBC soaked for 24 hours in Iohexol. The duration of radiopacity of the different EBCs was compared. The EBCs opacified with Iohexol initially had higher radiopacity than the barium opacified EBCs. However, their opacity rapidly decreased with saline soaking and, particularly, after they were embolized in live animals. The mechanical properties of Iohexol opacified EBCs were inferior to barium opacified EBCs. The Iohexol mixed EBCs were less firm and elastic and half of them fragmented during catheter injection. The Iohexol soaked EBCs exhibited decreased tensile strength and elasticity compared to the barium EBCs. Compared to barium, iodine based contrast medium does not offer any advantage for opacifying EBCs

  9. 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.

  10. 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.

  11. Prostatic Fossa Gauze-Packing in the Prevention of Blood Clot ...

    African Journals Online (AJOL)

    BACKGROUND: Clot obstruction often complicates transvesical prostatectomy. Any measure that prevents this will be a great relief to both surgeon and patient. OBJECTIVE: To demonstrate that packing the prostatic fossa with roller gauze bandage after transvesical prostatectomy can prevent post-operative clot blockage of ...

  12. A targeted ferritin-microplasmin based thrombolytic nanocage selectively dissolves blood clots.

    Science.gov (United States)

    Seo, Junyoung; Al-Hilal, Taslim A; Jee, Jun-Goo; Kim, Yong-Lim; Kim, Ha-Jeong; Lee, Byung-Heon; Kim, Soyoun; Kim, In-San

    2018-04-01

    The use of thrombolytic therapies is limited by an increased risk of systemic hemorrhage due to lysis of hemostatic clots. We sought to develop a plasmin-based thrombolytic nanocage that efficiently dissolves the clot without causing systemic fibrinolysis or disrupting hemostatic clots. Here, we generated a double chambered short-length ferritin (sFt) construct that has an N-terminal region fused to multivalent clot targeting peptides (CLT: CNAGESSKNC) and a C-terminal end fused to a microplasmin (μPn); CLT recognizes fibrin-fibronectin complexes in clots, μPn efficiently dissolves clots, and the assembly of double chambered sFt (CLT-sFt-μPn) into nanocage structure protects the activated-μPn from its circulating inhibitors. Importantly, activated CLT-sFt-μPn thrombolytic nanocage showed a prolonged circulatory life over activated-μPn and efficiently lysed the preexisting clots in both arterial and venous thromboses models. Thus, CLT-sFt-μPn thrombolytic nanocage platform represents the prototype of a targeted clot-busting agent with high efficacy and safety over existing thrombolytic therapies. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. 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).

  14. 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...... laboratory-based analysis, however, requires validation of the activators employed and the effect of storage of the WB sample in citrate before analysis. STUDY DESIGN AND METHODS: The effect of kaolin, tissue factor (TF) 1:17,000, or TF 1:42,500 on TEG clotting time (R), Angle (velocity of clot formation......), and maximum clot strength (amplitude [MA]) were evaluated, together with day-to-day variation, the coefficient of variance (CV%), and the effect of citrate storage time. RESULTS: Clot formation variables were equally affected by TF 1:17,000 and kaolin activation, whereas R was significantly longer when TF 1...

  15. 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.

  16. Response of the blood clotting system of the American horseshoe crab, Limulus polyphemus, to a novel form of lipopolysaccharide from a green alga.

    Science.gov (United States)

    Conrad, Mara L; Pardy, R L; Wainwright, Norman; Child, Alice; Armstrong, Peter B

    2006-08-01

    Lipopolysaccharide (LPS, endotoxin) is a component of Gram-negative bacteria and is the principal indicator to the innate immune systems of higher animals of a Gram-negative bacterial invasion. LPS activates the blood clotting system of the American horseshoe crab, Limulus polyphemus. By stimulating blood cell degranulation, LPS triggers the release of the proteins of the clotting system from the cells, and by activating a protease cascade that converts coagulogen, a soluble zymogen, to coagulin, the structural protein of the clot, LPS triggers the production of the fibrillar coagulin blood clot. Although originally thought to be restricted to the Gram-negative bacteria and the cyanobacteria, LPS, or a very similar molecule, has recently been described from a eukaryotic green alga, Chlorella. Here we show that, like LPS from Gram-negative bacteria, the algal molecule stimulates exocytosis of the Limulus blood cell and the clotting of coagulin. The coagulin clot efficiently entraps the cells of Chlorella in a network of fibrils. Invasion and erosion of the carapace by green algae is an important cause of mortality of Limulus, and it is suggested that the cellular response to aLPS may contribute to defense against this pathogen.

  17. 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.

  18. 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.

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

    Indian Academy of Sciences (India)

    Ai-Ping Zhou

    2017-11-14

    Nov 14, 2017 ... than 200 negative charges. Therefore, the blood plasma can be considered as a viscous, electrically conducting fluid containing protons and negative ions, and the rhe- ological properties of blood have been widely studied in the past few years [1–3]. So far, many studied blood coagulation using theoret-.

  20. Dimensional evaluation of blood clot gap distances within the intrabony defects following grafting and EDTA root surface treatment - experimental study in dogs.

    Science.gov (United States)

    Gamal, Ahmed Y; Abdel-Ghaffar, Khaled A; Zouair, Mohamed G; Salama, Mohamed H; Destawy, Mahmoud T El

    2018-03-14

    Since it is important to establish and maintain a firm blood clot to the surrounding tissues within the intrabony lesion; we have to investigate the potentials of different materials in resisting clot retraction that disrupt clot adhesion to the root surface. This study was designed to measure the gap distance created by clot retraction within the defect following intrabony defects grafting with and without root surface EDTA etching. Eight mongrel dogs with surgically created acute-chronic bilateral mandibular interproximal intrabony defects in the premolar-molar areas were enrolled in this study (total 8 defects per dog). Intrabony defects were divided into four groups, the first group (OFD): control open flap debridement, the second group, (EDTA treated defects) in which debridement of the defects was followed by two minute root surface etching with a neutral 24% EDTA gel followed by two minute copious saline irrigation, the third group (only grafted defects): defects received closely packed β-TCP of a particle size ranged from 150 to 500 mm, and the fourth group, (Graft + EDTA treated defects): defects were etched for 2 minutes with a neutral 24% EDTA gel and saline irrigation followed by intrabony defect fill of β-TCP. Twenty four hours post treatment, animal euthanasia was carried out for histomorphometric analysis of the tooth and root side gap distances. EDTA treated group and EDTA + graft group showed statistically significant lower degree of clot shrinkage compared to both the control and only grafted group. Clot shrinkage in EDTA treated group showed no significant difference from that of the EDTA + graft group (p = 0.197). OFD and only grafted groups were found to show statistically higher clot retraction percnetage compared to both EDTA and EDTA+graft groups. following intrabony defect debridement, blood clot undergoes clot retraction creating a micro gap with the root surface. EDTA root surface etching before graft application into the defect area

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

    Indian Academy of Sciences (India)

    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 ...

  2. Vibrations and spatial patterns in biomimetic surfaces: using the shark-skin effect to control blood clotting.

    Science.gov (United States)

    Ramachandran, Rahul; Maani, Nazanin; Rayz, Vitaliy L; Nosonovsky, Michael

    2016-08-06

    We study the effect of small-amplitude fast vibrations and small-amplitude spatial patterns on various systems involving wetting and liquid flow, such as superhydrophobic surfaces, membranes and flow pipes. First, we introduce a mathematical method of averaging the effect of small spatial and temporal patterns and substituting them with an effective force. Such an effective force can change the equilibrium state of a system as well as a phase state, leading to surface texture-induced and vibration-induced phase control. Vibration and patterns can effectively jam holes in vessels with liquid, separate multi-phase flow, change membrane properties, result in propulsion and locomotion and lead to many other multi-scale, nonlinear effects including the shark-skin effect. We discuss the application of such effects to blood flow for novel biomedical 'haemophobic' applications which can prevent blood clotting and thrombosis by controlling the surface pattern at a wall of a vessel (e.g. a catheter or stent).This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  3. Anticoagulant Carryover May Influence Clot Formation in Direct Tube Coagulase Tests from Blood Cultures

    OpenAIRE

    Varettas, Kerry; Mukerjee, Chinmoy; Taylor, Peter C.

    2005-01-01

    The tube coagulase test (TCT) performed directly from positive blood culture bottles has been used to reduce the turnaround time for identifying Staphylococcus aureus. Most reports have shown the test to be specific but often lacking sufficient sensitivity to be useful. In a prospective study of blood culture bottles (BCB) signaling positive, with a Gram-stained smear showing gram-positive cocci resembling staphylococci, the sensitivity of the direct TCT was improved by diluting the BCB broth...

  4. 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

  5. Anticoagulant carryover may influence clot formation in direct tube coagulase tests from blood cultures.

    Science.gov (United States)

    Varettas, Kerry; Mukerjee, Chinmoy; Taylor, Peter C

    2005-09-01

    The tube coagulase test (TCT) performed directly from positive blood culture bottles has been used to reduce the turnaround time for identifying Staphylococcus aureus. Most reports have shown the test to be specific but often lacking sufficient sensitivity to be useful. In a prospective study of blood culture bottles (BCB) signaling positive, with a Gram-stained smear showing gram-positive cocci resembling staphylococci, the sensitivity of the direct TCT was improved by diluting the BCB broth 1:10 in saline before inoculating 0.1 ml into 1.0 ml of 10% pooled human plasma. It was hypothesized that the improved sensitivity might be explained by reduced carryover of the anticoagulant sodium polyanetholesulfonate (SPS) used in blood culture media. By titrating the inoculum size and the concentration of SPS in an in vitro checkerboard assay, it was shown that concentrations of SPS >0.0008% prevented plasma coagulation. The 1:10 dilution of blood culture broth reduced the amount of residual SPS carried over to the TCT to a level (0.0005%) that did not impair plasma coagulation. The direct TCT inoculated with a 1:10 saline dilution of blood culture broth achieved 100% specificity and sensitivity within 4 h of inoculation without reducing the quality or quantity of coagulum.

  6. an unusual cause of clotted blood in epidural catheter : case studies

    African Journals Online (AJOL)

    pharyngeal temperature probe, intra-arterial blood pressure monitoring and a central venous pressure catheter. Three hours after the commencement of surgery we failed to inject a second bolus via the epidural catheter, as marked resistance to the injection was encountered. The initial patent catheter was now.

  7. 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.

  8. Blood Clotting and Pregnancy

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  1. Blood Clotting and Pregnancy

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  7. How Blood Clots

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  2. Postpartum Blood Clots

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  5. The Effect of Radioactive Lantern Mantle Powder and Bentonite-Zeoloite Minerals on the Volume of Blood Loss, Bleeding and Clotting Time

    Directory of Open Access Journals (Sweden)

    M Atefi

    2009-04-01

    Full Text Available ABSTRACT Introduction & Objective: Over the past decade the US army has widely studied new technologies for stopping sever hemorrhages and has introduced an effective Zeolite based hemostatic agent. On the other hand, Mortazavi and his colleagues previously reported the bio-stimulatory effects of the topical application of radioactive lantern mantle powder on wound healing. Their subsequent studies showed significant changes in some histological parameters concerning healing. In this light, here the bio-stimulatory effect of burned radioactive lantern mantles powder as well as two minerals bentonite and zeolite are presented. Materials & Methods: This experimental study was conducted in the center for radiological studies, Shiraz University of Medical Sciences in 2008. Fifty male Wistar rats were divided randomly into 5 groups of 10 animals each. Following anesthesia, animals’ tails were cut at a thickness of 5 mm by using a surgical scissor. No intervention was made on the animals of the 1st group. The 2nd to 4th group received topical non-radioactive lantern mantle powder, radioactive lantern mantle powder, Bentonite mineral or a mixture of Bentonite-Zeoliteat minerals respectively. After treatment with above mentioned agents, the volume of blood loss was measured using a scaled test-tube. The bleeding time and clotting time were also measured using a chronometer. SPSS software was used for statistical analysis. ANOVA was used for comparing the means of each parameter in the 5 groups. Results: The the volume of blood loss, bleeding and clotting times in control animals were 4.39±1.92 cc, 112.10±39.60 sec and 94.9±54.26 sec, respectively. In the 5th group in which the animals were treated with a mixture of Bentonite-Zeoliteat minerals, the volume of blood loss, bleeding and clotting times were 1.31±0.60 cc, 34.50±4.65 sec and 24.2±4.61 sec, respectively. Conclusion: This is the 1st investigation that studied the alterations of bleeding

  6. Endogenous fibrinolysis facilitates clot retraction in vivo.

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    Samson, Andre L; Alwis, Imala; Maclean, Jessica A A; Priyananda, Pramith; Hawkett, Brian; Schoenwaelder, Simone M; Jackson, Shaun P

    2017-12-07

    Clot retraction refers to the process whereby activated platelets transduce contractile forces onto the fibrin network of a thrombus, which over time increases clot density and decreases clot size. This process is considered important for promoting clot stability and maintaining blood vessel patency. Insights into the mechanisms regulating clot retraction at sites of vascular injury have been hampered by a paucity of in vivo experimental models. By pairing localized vascular injury with thrombin microinjection in the mesenteric circulation of mice, we have demonstrated that the fibrin network of thrombi progressively compacts over a 2-hour period. This was a genuine retraction process, as treating thrombi with blebbistatin to inhibit myosin IIa-mediated platelet contractility prevented shrinkage of the fibrin network. Real-time confocal analysis of fibrinolysis after recombinant tissue-type plasminogen activator (tPA) administration revealed that incomplete proteolysis of fibrin polymers markedly facilitated clot retraction. Similarly, inhibiting endogenous fibrinolysis with tranexamic acid reduced retraction of fibrin polymers in vivo. In vitro clot retraction experiments indicated that subthreshold doses of tPA facilitated clot retraction through a plasmin-dependent mechanism. These effects correlated with changes in the elastic modulus of fibrin clots. These findings define the endogenous fibrinolytic system as an important regulator of clot retraction, and show that promoting clot retraction is a novel and complementary means by which fibrinolytic enzymes can reduce thrombus size. © 2017 by The American Society of Hematology.

  7. Emergency endoscopic variceal ligation in cirrhotic patients with blood clots in the stomach but no active bleeding or stigmata increases the risk of rebleeding

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    Su Jin Kim

    2016-12-01

    Full Text Available Background/Aims This study aimed to evaluate the efficacy and safety of emergency variceal ligation for the prevention of rebleeding in cirrhotic patients who are found on initial endoscopy to have blood clots in the stomach but no actively bleeding esophageal and gastric varices or stigmata. Methods This study included 28 cirrhotic patients who underwent emergency prophylactic EVL and 41 who underwent an elective intervention between January 2009 and June 2014. Clinical outcomes were analyzed, including the rebleeding, 6-week mortality, and rebleeding-free survival rates. Results The rebleeding rate was higher in the emergency than in the elective group (28.6% vs. 7.3%, P=0.041. Multivariate analysis showed that emergency prophylactic EVL (odds ratio [OR] = 7.4, 95% confidence interval [CI]=1.634.8, P=0.012 and Child-Pugh score C (OR=10.6, 95% CI=1.4-80.8, P=0.022 were associated with rebleeding. In the emergency group, the gastric varices were associated with rebleeding (OR=12.0, 95% CI=1.7-83.5, P=0.012. Conclusions Emergency EVL may be associated with variceal rebleeding when blood clots are present in the stomach without active esophageal and gastric variceal bleeding or stigmata. Elective intervention should be considered as a safer strategy for preventing variceal rebleeding in this situation.

  8. Pulsed cavitational therapy using high-frequency ultrasound for the treatment of deep vein thrombosis in an in vitro model of human blood clot

    Science.gov (United States)

    Goudot, G.; Mirault, T.; Arnal, B.; Boisson-Vidal, C.; Le Bonniec, B.; Gaussem, P.; Galloula, A.; Tanter, M.; Messas, E.; Pernot, M.

    2017-12-01

    Post-thrombotic syndrome, a frequent complication of deep venous thrombosis, can be reduced with early vein recanalization. Pulsed cavitational therapy (PCT) using ultrasound is a recent non-invasive approach. We propose to test the efficacy and safety of high-frequency focused PCT for drug-free thrombolysis (thrombotripsy) in a realistic in vitro model of venous thrombosis. To reproduce venous thrombosis conditions, human whole blood was allowed to clot by stasis in silicone tubes (6 mm internal diameter) at a 30 cm H2O pressure, maintained during the whole experiment. We engineered an ultrasound device composed of dual 2.25 MHz transducers centered around a 6 MHz imaging probe. A therapeutic focus was generated at a 3.2 cm depth from the probe. Thrombotripsy was performed by longitudinally scanning the thrombus at three different speeds: 1 mm s-1 (n  =  6) 2 mm s-1 (n  =  6) 3 mm s-1 (n  =  12). Restored outflow was measured every three passages. Filters were placed to evaluate the debris size. Twenty-four occlusive thrombi, of 2.5 cm mean length and 4.4 kPa mean stiffness, were studied. Flow restoration was systematically obtained by nine subsequent passages (4.5 min maximum). By varying the device’s speed, we found an optimal speed of 1 mm s-1 to be efficient for effective recanalization with 90 s (three passages). Within 90 s, flow restoration was of 80, 62 and 74% at respectively 1, 2 and 3 mm s-1. For all groups, cavitation cloud drilled a 1.7 mm mean diameter channel throughout the clot. Debris analysis showed 92% of debris    200 µm.

  9. Transient Expression of Lumbrokinase (PI239 in Tobacco (Nicotiana tabacum Using a Geminivirus-Based Single Replicon System Dissolves Fibrin and Blood Clots

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    Alexia Dickey

    2017-01-01

    Full Text Available Lumbrokinases, a group of fibrinolytic enzymes extracted from earthworm, have been widely used to prevent and treat various cardiovascular diseases. They specifically target fibrin to effectively degrade thrombi without major side effects. Plant expression systems are becoming potential alternative expression platforms for producing pharmaceutical proteins. In this work, a lumbrokinase (PI239 was produced from a plant system. Both wild-type (WT and plant codon-optimized (OP PI239 gene sequences were synthesized and cloned into a geminivirus-based single-vector DNA replicon system. Both vectors were independently expressed in tobacco (Nicotiana tabacum leaves transiently by agroinfiltration. Overexpressed PI239 resulted in sudden tissue necrosis 3 days after infiltration. Remaining proteins were purified through His-tag affinity chromatography and analyzed with SDS-PAGE and Western blot methods. Purified PI239 successfully degraded artificial fibrin with relative activity of 13,400 U/mg when compared with commercial lumbrokinase product. In vitro tests demonstrated that plant-derived PI239 dissolved human blood clots and that the plant expression system is capable of producing functional PI239.

  10. Preventing and Treating Blood Clots

    Science.gov (United States)

    ... Pacific Islander descent. A condition that is inherited, meaning it is passed down from parent to child ... Enoxaparin (Lovenox) Fondaparinux (Arixtra) Tinzaparin (Innohep) Warfarin (multiple brand names). Some of these drugs are taken orally ...

  11. 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.

  12. Recombinant clotting factors.

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    Pipe, Steven W

    2008-05-01

    The recombinant era for haemophilia began in the early 1980s with the cloning and subsequent expression of functional proteins for both factors VIII and IX. Efficient production of recombinant clotting factors in mammalian cell culture systems required overcoming significant challenges due to the complex post-translational modifications that were integral to their pro-coagulant function. The quick development and commercialization of recombinant clotting factors was, in part, facilitated by the catastrophic impact of viral contamination of plasma-derived clotting factor concentrates at the time. Since their transition into the clinic, the recombinant versions of both factor VIII and IX have proven to be remarkable facsimiles of their plasma-derived counterparts. The broad adoption of recombinant therapy throughout the developed world has significantly increased the supply of clotting factor concentrates and helped advance aggressive therapeutic interventions such as prophylaxis. The development of recombinant VIIa was a further advance bringing a recombinant option to haemophilia patients with inhibitors. Recombinant DNA technology remains the platform to address ongoing challenges in haemophilia care such as reducing the costs of therapy, increasing the availability to the developing world, and improving the functional properties of these proteins. In turn, the ongoing development of new recombinant clotting factor concentrates is providing alternatives for patients with other inherited bleeding disorders.

  13. The clotting action of Russell viper venom. 1954.

    Science.gov (United States)

    2016-03-03

    Samuel I. Rapaport made seminal contributions to our basic understanding of blood coagulation. This paper beautifully illustrates his scientific approach through characterization of the clotting activity of venom from Daboia russelii, distinguishing it from the brain “thromboplastic” activity used in the prothrombin time. Using plasma from patients with deficiencies of proconvertin (factor VII), proaccelerin (factor V), antihemophilic globulin (factor VIII), or Christmas factor (factor IX), Rapaport and colleagues demonstrated that the venom's clotting activity does not require factor VII, but does require factor V and lipid. Thus, by combining the venom clotting test with the quick clotting time (prothrombin time), it was possible to diagnose factor VII deficiency. The venom is now known to act by directly activating factor X, and a form of the clotting test is used in the diagnosis of lupus anticoagulants.

  14. [Clotting disorders and preeclampsia].

    Science.gov (United States)

    Ducloy-Bouthors, A-S

    2010-05-01

    Clotting disorders are associated with the severe, early and complicated forms of PE. Compensated hypercoagulability states associated with a thrombocytopenia (PLTdepression of the fibrinolysis appears to contribute towards the hypercoagulable state. The etiological importance of the erythrocyte and leucocyte activation with regards to the abnormal clotting activation is highlighted in the setting of maternal systematic inflammatory disease. The state of compensated coagulopathy found in the PE patient can suffer a pro-coagulatory imbalance because of a quantitative, or a qualitative failure (i.e. thrombophilia) of the physiological coagulation inhibitors, or a combination of both. This disseminated intravascular coagulation, qualified as chronic, is associated with clinically evident signs of foeto-placental unit impairment (i.e. IUGR, foetal death) with or without systemic repercussions in the mother (i.e. renal failure, HELLP syndrome, eclampsia). This set of haemostatic disturbances found in the PE patient is a dynamic phenomenon, which can evolve by the hour therefore requires frequent laboratory investigations. Delivery remains the only curative treatment for these haemostatic disturbances. A better understanding of the aetiology of DIC in PE, an early detection method and a specific identification of the at-risk patients could allow prophylactic and curative treatment. Copyright 2010. Published by Elsevier SAS.

  15. Clot friction variation with fibrin content; implications for resistance to thrombectomy.

    Science.gov (United States)

    Gunning, Gillian M; McArdle, Kevin; Mirza, Mahmood; Duffy, Sharon; Gilvarry, Michael; Brouwer, Patrick A

    2018-01-01

    Despite significant advancements in the procedural efficacy of mechanical thrombectomy in patients with ischemic stroke in recent years, there still remains a portion of the population that does not achieve good recanalization. The reasons for this may be varied. We hypothesized that static friction between the clot and the vessel, or catheter wall might contribute to the difficulty in removing the clot. To determine if there is a relationship between clot composition and the resistance to sliding (friction) which might contribute to resistance to clot removal. As clot composition can vary significantly, we investigated five different types of clot in order to measure their respective frictional properties. To do this, a custom-made testing apparatus was created, consisting of various replaceable low-friction surfaces on which the clots could be placed. The surface was then gradually tilted until the clots began to slide; the angle at which this occurred is related to the coefficient of friction of the clots. The experiment was repeated on a bovine aortic surface in order to confirm the results. We found that fibrin-rich clots (friction than clots with a red blood cell content >20%. This result was confirmed by repeating the experiment on a bovine aortic surface as a representation of the interaction between clots and the arterial wall. The friction properties of clots were found to be related to the content ratio of fibrin to red blood cells. Future imaging techniques that could show fibrin and red blood cell content might help us to predict the 'stickiness' of a clot. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  16. 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.

  17. Makers of clotting medicine not entitled to liability shield.

    Science.gov (United States)

    1996-02-23

    The Indiana Court of Appeals, Second District, reversed a ruling that protected the manufacturer of a hemophilia blood clotting medicine from legal liability. A boy with hemophilia, known in court records as J.K.B. Jr., contracted HIV from the blood clotting medicine, Factor VIII. His parents sued four pharmaceutical companies, Armour Pharmaceutical Company, Cutter Laboratories, Baxter Healthcare Corporation, and Alpha Therapeutics Corporation, alleging that their products caused J.K.B. Jr.'s death. The companies convinced a Superior Court judge that they were protected under the Indiana Blood Shield Statute. The appeals court ruled that pharmaceutical companies are not included in the Blood Shield Statute. The statute was originally established to protect state-approved blood banks, hospitals, and blood storage facilities because they provide a vital public service.

  18. 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.

  19. High blood pressure - infants

    Science.gov (United States)

    Hypertension - infants ... and blood vessels The health of the kidneys High blood pressure in infants may be due to kidney or ... blood vessel of the kidney) In newborn babies, high blood pressure is often caused by a blood clot in ...

  20. Understand Your Risk for Excessive Blood Clotting

    Science.gov (United States)

    ... travel to the arteries or veins in the brain, heart, kidneys, lungs and limbs, which in turn can cause heart attack, stroke, damage to the body’s organs or even death. Acquired Risk Factors Smoking Overweight and obesity Pregnancy Prolonged ...

  1. Factor XIII stiffens fibrin clots by causing fiber compaction.

    Science.gov (United States)

    Kurniawan, N A; Grimbergen, J; Koopman, J; Koenderink, G H

    2014-10-01

    Factor XIII-induced cross-linking has long been associated with the ability of fibrin blood clots to resist mechanical deformation, but how FXIII can directly modulate clot stiffness is unknown. We hypothesized that FXIII affects the self-assembly of fibrin fibers by altering the lateral association between protofibrils. To test this hypothesis, we studied the cross-linking kinetics and the structural evolution of the fibers and clots during the formation of plasma-derived and recombinant fibrins by using light scattering, and the response of the clots to mechanical stresses by using rheology. We show that the lateral aggregation of fibrin protofibrils initially results in the formation of floppy fibril bundles, which then compact to form tight and more rigid fibers. The first stage is reflected in a fast (10 min) increase in clot stiffness, whereas the compaction phase is characterized by a slow (hours) development of clot stiffness. Inhibition of FXIII completely abrogates the slow compaction. FXIII strongly increases the linear elastic modulus of the clots, but does not affect the non-linear response at large deformations. We propose a multiscale structural model whereby FXIII-mediated cross-linking tightens the coupling between the protofibrils within a fibrin fiber, thus making the fiber stiffer and less porous. At small strains, fiber stiffening enhances clot stiffness, because the clot response is governed by the entropic elasticity of the fibers, but once the clot is sufficiently stressed, the modulus is independent of protofibril coupling, because clot stiffness is governed by individual protofibril stretching. © 2014 International Society on Thrombosis and Haemostasis.

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

    OpenAIRE

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

    2012-01-01

    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 the...

  3. Antithrombin III blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003661.htm Antithrombin III blood test To use the sharing features on this page, ... a protein that helps control blood clotting. A blood test can determine the amount of AT III present ...

  4. Intrinsic clotting factors in dependency of age, sex, body mass index, and oral contraceptives: definition and risk of elevated clotting factor levels.

    Science.gov (United States)

    Luxembourg, Beate; Schmitt, Joern; Humpich, Marek; Glowatzki, Matthias; Seifried, Erhard; Lindhoff-Last, Edelgard

    2009-10-01

    Elevated clotting factors have been demonstrated to be a risk factor for venous thromboembolism (VTE). The aim of our study was to investigate the impact of age, sex, body mass index, and oral contraceptives on the clotting factor activities of factors VIII, IX, XI, and XII and their impact on the cutoff definition and risk of VTE associated with elevated clotting factors. Factor VIII, IX, XI, and XII activities were measured in 499 blood donors and 286 patients with VTE. Age and body mass index predicted significantly and independently the clotting factor activities of factors VIII, IX, and XI, whereas use of oral contraceptives predicted factor IX, XI, and XII levels. Percentiles of clotting factor activities, which are often used for the cutoff definition of elevated clotting factors, varied due to the effect of age, body mass index, and oral contraceptives. The adjusted odds ratios for VTE were 10.3 [95% confidence interval (CI) 5.1-20.7], 6.1 (95% CI 3.1-12.0), and 3.3 (95% CI 1.9-5.8) for elevated factors VIII, IX, and XI, respectively. Furthermore, our study demonstrates for the first time that elevated factor XII is associated with an increased risk of VTE (adjusted odds ratio 2.9, 95% CI 1.6-5.3).

  5. 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).

  6. Experimental and imaging techniques for examining fibrin clot structures in normal and diseased states.

    Science.gov (United States)

    Fan, Natalie K; Keegan, Philip M; Platt, Manu O; Averett, Rodney D

    2015-04-01

    Fibrin is an extracellular matrix protein that is responsible for maintaining the structural integrity of blood clots. Much research has been done on fibrin in the past years to include the investigation of synthesis, structure-function, and lysis of clots. However, there is still much unknown about the morphological and structural features of clots that ensue from patients with disease. In this research study, experimental techniques are presented that allow for the examination of morphological differences of abnormal clot structures due to diseased states such as diabetes and sickle cell anemia. Our study focuses on the preparation and evaluation of fibrin clots in order to assess morphological differences using various experimental assays and confocal microscopy. In addition, a method is also described that allows for continuous, real-time calculation of lysis rates in fibrin clots. The techniques described herein are important for researchers and clinicians seeking to elucidate comorbid thrombotic pathologies such as myocardial infarctions, ischemic heart disease, and strokes in patients with diabetes or sickle cell disease.

  7. Artificial Stroke Clots: How Wide is the Gap to the Real World?

    Science.gov (United States)

    Berndt, Maria; Prothmann, Sascha; Maegerlein, Christian; Oberdieck, Paul; Zimmer, Claus; Hegge, Barbara; Pelisek, Jaroslav; Schirmer, Lucas; Poppert, Holger; Boeckh-Behrens, Tobias

    2018-02-01

    Especially since the establishment of mechanical thrombectomy as part of standard stroke therapy, artificial thrombi have become important in the training of interventionalists as well as for the development and testing of devices. So far, these in vitro clots have lacked direct comparisons with ex vivo thrombi. We therefore compared the histologic appearance of dynamically produced clots with that of stroke thrombi acquired during mechanical recanalization. Thrombi of 145 consecutive patients with stroke with large-vessel occlusions were histologically compared with 10 artificial clots, dynamically created from human blood and pig's blood using a Chandler loop system. Quantified FP/RBC ratios (fibrin/platelets divided by red blood cell fraction) and white blood cell (WBC) fractions were identified and compared between artificial (human and pig) and ex vivo thrombi obtained from patients with various stroke causes. There were no significant differences in the analysis of FP/RBC ratios between artificial thrombi and ex vivo thrombi (P = 0.42) or in the more precise analyses considering etiologic subgroups. Distinct differences were observed for the WBC fraction, with lower values in artificial thrombi (median, 1.34%) than in ex vivo thrombi (median, 5%) (P < 0.001). The main clot components, FP and RBC, are presumably the most influential factors for clot stability and mechanical resistance. Similarities between artificially generated and ex vivo stroke clots (and when considering different stroke subgroups) support the usefulness of these artificial thrombi in the pre-evaluation of thrombus extraction devices and as appropriate training material. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. 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 ...

  9. Effects of exercise intensity on clot microstructure and mechanical properties in healthy individuals.

    Science.gov (United States)

    Davies, N A; Llwyd, O; Brugniaux, J V; Davies, G R; Marley, C J; Hodson, D; Lawrence, M J; D'Silva, L A; Morris, R H K; Hawkins, K; Williams, P R; Bailey, D M; Evans, P A

    2016-07-01

    Exercise is well established to lead to exercise-induced hypercoagulability, as demonstrated by kinetic coagulation markers. It remains unclear as to whether exercise-induces changes lead in clot development and increased polymerisation. Fractal dimension (df) has been shown to act as a marker of clot microstructure and mechanical properties, and may provide a more meaningful method of determining the relationship between exercise-induced hypercoagulability and potential clot development. df was measured in 24 healthy individuals prior to, after 5min of submaximal exercise, following maximal exercise, 45min of passive recovery and following 60min of recovery. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly increased df was observed following exercise, returning to resting values following 60min of recovery. The relationship between df and mature clot microstructure was confirmed by SEM: higher df was associated with dense clots formed of smaller fibrin fibres immediately following exercise compared to at rest. Conventional markers of coagulation confirmed findings of previous studies. This study demonstrates that df is a sensitive technique which quantifies the structure and properties of blood clots following exercise. In healthy individuals, the haemostatic balance between coagulation and fibrinolysis is maintained in equilibrium following exercise. In individuals with underlying vascular damage who participate in exercise, this equilibrium may be displaced and lead to enhanced clot formation and a prothrombotic state. df may therefore have the potential to not only quantify hypercoagulability, but may also be useful in screening these individuals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Influence of clot retraction on the short-T2 appearance of an acute hematoma

    International Nuclear Information System (INIS)

    Clark, R.A.; Watanabe, A.T.; Bradley, W.G. Jr.; Roberts, J.D.

    1988-01-01

    The short-T2 appearance of acute hematomas has been previously explained solely by water diffusing in and out of deoxyhemoglobin-containing red cells. According to this theory, the maximum effect occurs at a 50% hematocrit and should be absent at 100% hematocrit. This theory fails to take clot retraction per se into account. The authors have confirmed that the shortest T2 of heparinized blood (deoxyhemoglobin form by Raman spectroscopy) occurs at 50% hematocrit. Retraction of nonparamagnetic plasma and oxyhemogloblin clots over 24 hours shortens T2 by 10%-40% at 90 MHz, depending on the platelet concentration. The additional T2 shortening observed after formation of deoxyhemoglobin is thus primarily due to clot retraction

  11. 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.

  12. 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...

  13. 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

    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. Blood was drawn from 15 subjects after IRB approval. Clots were made in 20 microL 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 (+US) or without (-US) ultrasound for 30 minutes at 37 degrees 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. 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 combined

  14. 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

  15. 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.

  16. {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.)

  17. Determining Human Clot Lysis Time (in vitro with Plasminogen/Plasmin from Four Species (Human, Bovine, Goat, and Swine

    Directory of Open Access Journals (Sweden)

    Omaira Cañas Bermúdez

    2015-05-01

    Full Text Available Cardiovascular disease is the leading cause of death worldwide, including failures in the plasminogen/plasmin system which is an important factor in poor lysis of blood clots. This article studies the fibrinolytic system in four species of mammals, and it identifies human plasminogen with highest thrombolysis efficiency. It examines plasminogen from four species (human, bovine, goat, and swine and identifies the most efficient one in human clot lysis in vitro. All plasminogens were identically purified by affinity chromatography. Human fibrinogen was purified by fractionation with ethanol. The purification of both plasminogen and fibrinogen was characterized by one-dimensional SDS-PAGE (10%. Human clot formation in vitro and its dissolution by plasminogen/plasmin consisted of determining lysis time from clot formation to its dilution. Purification of proteins showed greater than 95% purity, human plasminogen showed greater ability to lyse clot than animal plasminogen. The article concludes that human plasminogen/plasmin has the greatest catalysis and efficiency, as it dissolves human clot up to three times faster than that of irrational species.

  18. Quantification of bone marrow plasma cell infiltration in multiple myeloma: usefulness of bone marrow aspirate clot with CD138 immunohistochemistry.

    Science.gov (United States)

    Matsue, Kosei; Matsue, Yuya; Kumata, Kaoru; Usui, Yoshiaki; Suehara, Yasuhito; Fukumoto, Kota; Fujisawa, Manabu; Narita, Kentaro; Takeuchi, Masami

    2017-09-01

    Accurate quantification of plasma cells (PCs) in bone marrow (BM) is critical for diagnosis and assessment of treatment response in patients with multiple myeloma (MM). We compared the % of BM PC quantified by 250 cell differential count on May-Giemsa-stained BM smears, by counting 500 - 2500 cells in 2 - 5 representative microscopy fields in CD138-immunostained BM clot and biopsy sections, and CD38/CD45/CD138 gated BM PCs on flow cytometry (FCM) in 150 sets of BM samples from 120 patients. Percentages of PC were significantly correlated between BM biopsy and clot, and between smear and FCM (r = 0.96, 0.93, respectively). However, quantification by smear and FCM significantly underestimated the PC compared to biopsy or clot, and the degree of underestimation increased with blood dilution. FCM consistently showed lower % of PC compared to aspirate smears. Fifty-nine of 103 patients with M-protein level smoldering MM when reassessed using CD138-stained biopsy/clot sections. Among the 72 patients with sMM diagnosed by BM biopsy and/clot, three patients (4.2%) had extensive BM infiltration of PC (≥ 60%) and required treatment. Our data clearly showed the necessity of CD138 immunostaining of BM biopsy/clot specimens for correct diagnosis of MM and related disorders. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Fibrin clot adhesion to root surface treated with tetracycline hydrochloride and ethylenediaminetetraacetic acid: A scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Chandran Preeja

    2013-01-01

    Full Text Available Background: Connective tissue attachment following periodontal regenerative surgery is directly related to the attachment of fibrin clot on to the root surface during early wound healing events.The adhesion of fibrin clot to the root surface affected by periodontal disease depends on the biologic acceptance of the root surface which can be accomplished by various root conditioning procedures during periodontal therapy. The present in vitro study has been designed to evaluate and compare the degree of fibrin clot adhesion to root surfaces treated with root conditioning agents tetracycline hydrochloride and ethylenediaminetetraacetic acid (EDTA. Materials and Methods: A total of 30 dentin blocks are divided into three groups and treated with tetracycline hydrochloride, EDTA and phosphate buffered saline and a drop of blood is added to each dentin block. The dentin blocks are then prepared for scanning electron microscopic analysis and examined for the degree of fibrin network frmation and entrapped erythrocytes. Results: The degree of fibrin clot adhesion was highest with tetracycline hydrochloride group, then with control group and least with EDTA treated group. Conclusion: According to the results of the present study, root conditioning with tetracycline hydrochloride produces a biologically acceptable root surface with enhanced fibrin clot adhesion, which is a critical step in early wound healing process. EDTA gel appears less effective in producing a root surface necessary for the adhesion of fibrin clot. The control without any root conditioning procedure showed poor fibrin clot adhesion when compared to tetracycline treated group, but when compared to EDTA treated group the fibrin clot adhesion was slightly better.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Cloning and expression of hybrid streptokinase towards clot-specific activity.

    Science.gov (United States)

    Buniya, Harith K; Murugan, Vadivel; Thangadurai, Chinnathambi

    2014-03-01

    Streptokinase (SK) is a thrombolytic agent that is widely used to treat myocardial infarction and pulmonary embolism. The lack of fibrin specificity of SK for the clot lysis is one of the limitations of SK. In this study, we have incorporated the finger and Kringle 2 domains from the human tissue type plasminogen activator gene (t-PA) at the 5' end of the SK gene. These domains are responsible for specific binding to fibrin. We have used the pRSETB vector in an attempt to express the hybrid streptokinase possessing specificity for fibrin. On this regard, three hybrid streptokinase were constructed and expressed in Escherichia coli BL21 (DE3): the finger domain with SK (FSK), the Kringle 2 domain with SK (KSK) and the finger domain+Kringle 2 with SK (FKSK). The activities of the hybrid SKs were assessed by caseinolytic assay and clot lysis assay. All hybrid SKs were found to activate plasminogen in the caseinolytic plate assay. In the clot lysis assay, KSK and FSK were able to dissolute human blood and artificial clots in a fibrin-dependent manner unlike the SK and FKSK proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. 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...

  3. Utility of single-energy and dual-energy computed tomography in clot characterization: An in-vitro study.

    Science.gov (United States)

    Brinjikji, Waleed; Michalak, Gregory; Kadirvel, Ramanathan; Dai, Daying; Gilvarry, Michael; Duffy, Sharon; Kallmes, David F; McCollough, Cynthia; Leng, Shuai

    2017-06-01

    Background and purpose Because computed tomography (CT) is the most commonly used imaging modality for the evaluation of acute ischemic stroke patients, developing CT-based techniques for improving clot characterization could prove useful. The purpose of this in-vitro study was to determine which single-energy or dual-energy CT techniques provided optimum discrimination between red blood cell (RBC) and fibrin-rich clots. Materials and methods Seven clot types with varying fibrin and RBC densities were made (90% RBC, 99% RBC, 63% RBC, 36% RBC, 18% RBC and 0% RBC with high and low fibrin density) and their composition was verified histologically. Ten of each clot type were created and scanned with a second generation dual source scanner using three single (80 kV, 100 kV, 120 kV) and two dual-energy protocols (80/Sn 140 kV and 100/Sn 140 kV). A region of interest (ROI) was placed over each clot and mean attenuation was measured. Receiver operating characteristic curves were calculated at each energy level to determine the accuracy at differentiating RBC-rich clots from fibrin-rich clots. Results Clot attenuation increased with RBC content at all energy levels. Single-energy at 80 kV and 120 kV and dual-energy 80/Sn 140 kV protocols allowed for distinguishing between all clot types, with the exception of 36% RBC and 18% RBC. On receiver operating characteristic curve analysis, the 80/Sn 140 kV dual-energy protocol had the highest area under the curve for distinguishing between fibrin-rich and RBC-rich clots (area under the curve 0.99). Conclusions Dual-energy CT with 80/Sn 140 kV had the highest accuracy for differentiating RBC-rich and fibrin-rich in-vitro thrombi. Further studies are needed to study the utility of non-contrast dual-energy CT in thrombus characterization in acute ischemic stroke.

  4. 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.

  5. Protein C blood test

    Science.gov (United States)

    ... in the body that prevents blood clotting. A blood test can be done to see how much of ... Certain medicines can change blood test results. Tell your health care provider about all the medicines you take. Your provider will tell you if you need ...

  6. Protein S blood test

    Science.gov (United States)

    ... in your body that prevents blood clotting. A blood test can be done to see how much of ... Certain medicines can change blood test results: Tell your health care provider about all the medicines you take. Your provider will tell you if you need ...

  7. 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 ...

  8. New polymorphic variants of human blood clotting factor IX

    Energy Technology Data Exchange (ETDEWEB)

    Surin, V.L.; Luk`yanenko, A.V.; Tagiev, A.F.; Smirnova, O.V. [Hematological Research Center, Moscow (Russian Federation); Plutalov, O.V.; Berlin, Yu.A. [Shemyakin Institute of Bioorganic Chemistry, Moscow (Russian Federation)

    1995-04-01

    The polymorphism of Alu-repeats, which are located in the introns of the human factor IX gene (copies 1-3), was studied. To identify polymorphic variants, direct sequencing of PCR products that contained appropriate repeats was used. In each case, 20 unrelated X chromosomes were studied. A polymorphic Dra I site was found near the 3{prime}-end of Alu copy 3 within the region of the polyA tract. A PCR-based testing system with internal control of restriction hydrolysis was suggested. Testing 81 unrelated X chromosomes revealed that the frequency of the polymorphic Dra I site is 0.23. Taq I polymorphism, which was revealed in Alu copy 4 of factor IX gene in our previous work, was found to be closely linked to Dra I polymorphism. Studies in linkage between different types of polymorphisms of the factor IX gene revealed the presence of a rare polymorphism in intron a that was located within the same minisatellite region as the known polymorphic insertion 50 bp/Dde I. However, the size of the insertion in our case was 26 bp. Only one polymorphic variant was found among over 150 unrelated X chromosomes derived from humans from Moscow and its vicinity. 10 refs., 4 figs., 1 tab.

  9. 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...

  10. Society for Pediatric Radiology John Caffey Award. MR appearance of blood and blood products: an in vitro study.

    Science.gov (United States)

    Cohen, M D; McGuire, W; Cory, D A; Smith, J A

    1986-06-01

    There are conflicting reports on the appearance of blood and blood clot as seen in the human body by MRI. This study was designed to show the in vitro MR signal intensity of human blood products in the fresh state and to evaluate the serial MRI changes that occur over time (2 weeks). T1 relaxation times were also measured. Anticoagulated whole blood, plasma, serum, white blood cell concentrates, platelet concentrates, lysed red cells, red cell concentrates, and blood clot were studied. The results show that plasma and serum have similar T1 values, as do lysed and intact erythrocytes. T1 of serum and plasma rose initially and then fell with the aging of the samples. T1 of red blood cells, clot, and packed red blood cells decreased for the first 48 hr and then remained constant for 7 days before increasing to the initial values by 2 weeks. Platelets and white blood cells had little influence on the MR image. However, temperature had a significant effect on T1 and signal intensity. In vivo clots are complex mixtures of whole clot, lysing clot, serum, and plasma influenced in various ways by the adjacent normal or diseased tissues. The chemical and physical properties of the mixture change constantly. Because of the clot's complex nature, determining the age of a hematoma from the appearance of clots on the MR image may not be possible.

  11. 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.

  12. Fibrin degradation products blood test

    Science.gov (United States)

    ... behind when clots dissolve in the blood. A blood test can be done to measure these products. ... Certain medicines can change blood test results. Tell your health care provider about all the medicines you take. Your provider will tell you if you need ...

  13. Comparison of standard fibrinogen measurement methods with fibrin clot firmness assessed by thromboelastometry in patients with cirrhosis.

    Science.gov (United States)

    Vucelic, Dragica; Jesic, Rada; Jovicic, Snezana; Zivotic, Maja; Grubor, Nikica; Trajkovic, Goran; Canic, Ivana; Elezovic, Ivo; Antovic, Aleksandra

    2015-06-01

    The Clauss fibrinogen method and thrombin clotting time (TCT) are still routinely used in patients with cirrhosis to define fibrinogen concentration and clotting potential. The thromboelastometric functional fibrinogen FIBTEM assay evaluates the strength of fibrin-based clots in whole blood, providing information on both quantitative deficit and fibrin polymerization disorders. To compare these three methods of assessing fibrinogen in patients with cirrhosis of different aetiologies, characterized by impairment in fibrinogen concentration as well as functional aberrance. Sixty patients with alcoholic and 24 patients with cholestatic cirrhosis were included (Child-Pugh score (CPs)A, n=24; B, n=32; C, n=28). All parameters were compared with those from a control group. Maximum clot firmness (MCF) in the FIBTEM test was assessed in regard to its relevance in detection of qualitative fibrinogen disorders in comparison with results obtained by standard measurement methods, i.e. the Clauss fibrinogen method and TCT. With increased cirrhosis severity, fibrinogen and FIBTEM-MCF levels significantly declined (p=0.002), while TCT was significantly prolonged (p=0.002). In all CPs groups, fibrinogen strongly correlated with FIBTEM-MCF (r=0.77, r=0.72, r=0.74; pmeasurement in cirrhotic patients, especially in evaluating fibrin polymerization disorders in these patients. Further studies are needed to evaluate the usefulness of this assay in predicting bleeding complications in cirrhotic patients as well as monitoring replacement treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Determination of enoxaparin with rotational thrombelastometry using the prothrombinase-induced clotting time reagent.

    Science.gov (United States)

    Schaden, Eva; Schober, Andreas; Hacker, Stefan; Spiss, Christian; Chiari, Astrid; Kozek-Langenecker, Sibylle

    2010-04-01

    Drug monitoring of low molecular weight heparin is generally not recommended, but could be reasonable in critically ill patients, whose risk for bleeding or thrombosis shows a high interpatient variability. Anti-Xa assays are not available around the clock even in central hospitals, whereas rotational thrombelastometry (ROTEM) becomes increasingly used at the bedside. Prothrombinase-induced clotting time (PiCT) reagent allows determination of factor Xa-inhibition in plasma. The aim of our study was to evaluate enoxaparin determination in whole blood with the ROTEM using specific test modifications, including PiCT. After ethics committee's approval, citrated whole blood obtained from overall 16 healthy volunteers was incubated with enoxaparin at 16 different anti-Xa concentrations. Main endpoint was the clotting time (CT) in ROTEM representing initial activation of clot formation. CT was determined in the new PiCT-ROTEM test, in a low-tissue factor-activated modification (LowTF-ROTEM) as well as in the commercially available heparin-sensitive ROTEM assays (HEPTEM and INTEM). In the absence of enoxaparin, CT values were 168.6 +/- 6.1 s (PiCT-ROTEM), 247.3 +/- 18.6 s (LowTF-ROTEM), and -6.2 +/- 7.9 s (INTEM-HEPTEM). A linear dependency (P < 0.01) between anti-Xa concentration and CT was found for PiCT-ROTEM, LowTF-ROTEM, and for INTEM-HEPTEM with correlation coefficients of 0.93 for PiCT-ROTEM, 0.94 for LowTF-ROTEM, and 0.81 for INTEM-HEPTEM. This in-vitro experiment demonstrates a strong correlation between enoxaparin anti-Xa concentrations and specific ROTEM tests. These promising assays should be further evaluated for monitoring anticoagulation in high-risk patients in clinical studies.

  15. Interventional neuroradiology cases with intraprocedural clots: initial experience.

    Science.gov (United States)

    Gloss, David S; Alkire, Brian W

    2014-06-01

    Intraprocedural clot formation is rare but potentially serious complication of interventional neuroradiology procedures. We investigate if intraoperative monitoring (IOM) has utility to detect such clots. Intraprocedural clot formation is a rare but potentially serious complication of interventional neuroradiology procedures. Intraoperative monitoring detected nearly half of the included cases first. All of the included patients without improvement of the IOM changes were discharged home at best severely disabled. The study included patients with thromboembolic events during interventional neuroradiology cases at Barrow Neurologic Institute from 2006 to 2010, with prespecified outcomes. Electroneurodiagnostic recordings were reviewed. Twelve patients were included in this study. All showed changes in their IOM. Five showed a change in IOM recording before a change was seen on the angiogram. Two returned to baseline, four improved but not to baseline, and six did not improve at all. All six patients without IOM improvement were discharged at best severely disabled. Ten of the 12 patients with clots had a subarachnoid hemorrhage before treatment. Intraoperative monitoring recording may be a valuable tool in monitoring patients during endovascular treatment to identify intraprocedural thromboembolic events. Intraoperative monitoring may correlate with poor outcomes when the changed responses do not improve. These data might be important when determining how aggressive to be in treating intraprocedural clots. Electroneurodiagnostic seems to be particularly warranted in patients with subarachnoid hemorrhage before treatment. A larger study is needed to validate these findings.

  16. Clotting activation after transjugular intrahepatic portosystemic stent shunt.

    Science.gov (United States)

    Basili, S; Merli, M; Ferro, D; Lionetti, R; Rossi, E; Riggio, O; Valeriano, V; Capocaccia, L; Violi, F

    1999-05-01

    Aim of the study was to investigate the behaviour of clotting system in peripheral circulation of cirrhotic patients undergoing transjugular intrahepatic portosystemic stent shunt (TIPS). Clotting variables and endotoxemia were measured 48 h and 30 days after TIPS in patients randomised to receive heparin or not. Forty-eight hours after TIPS, a significant increase of prothrombin fragment F1+2 was observed; such increase was less evident in patients given heparin. Similar findings were observed for endotoxemia, which, however, was not affected by heparin treatment. Thirty days after TIPS procedure prothrombin fragment F1+2 and endotoxemia returned to baseline values independently of the treatment given. This study shows that TIPS is associated with an increase of clotting activation which might contribute to acute thrombosis observed after this procedure.

  17. Effect of Clotting Duration and Temperature on BDNF Measurement in Human Serum

    Science.gov (United States)

    Amadio, Patrizia; Sandrini, Leonardo; Tremoli, Elena

    2017-01-01

    Brain-derived neurothrophic factor (BDNF) is a neurotrophin expressed in different tissues and cells, including neurons, endothelial cells, leukocytes, megakaryocytes and platelets. Modifications of BDNF in plasma and/or in serum are associated with neurodegenerative and psychiatric disorders, cardiovascular diseases, metabolic syndrome and with mortality risk. Indeed, changes in blood levels of BDNF may reflect those of its tissue of origin and/or promote pathological dysfunctions. The measurement of BDNF amount in plasma or in serum has been characterized with particular attention in the impact of different anti-coagulants, clotting duration, temperature (≤21 °C) and delay in blood sample centrifugation as well as in stability of storage. However, the influences of normothermic conditions (37 °C) and of clotting duration on BDNF levels in human serum have not been investigated yet. Here, we showed that time and temperature during serum preparation could be taken into consideration to assess the association and/or impact of BDNF levels in the occurrence of pathological conditions. PMID:28914800

  18. 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-β 1 ) 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-β 1 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.

  19. 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.

  20. Blood

    Science.gov (United States)

    ... production of red blood cells, including: Iron deficiency anemia. Iron deficiency anemia is the most common type of anemia and ... inflammatory bowel disease are especially likely to have iron deficiency anemia. Anemia due to chronic disease. People with chronic ...

  1. [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.

  2. Thrombin and fibrinogen γ' impact clot structure by marked effects on intrafibrillar structure and protofibril packing.

    Science.gov (United States)

    Domingues, Marco M; Macrae, Fraser L; Duval, Cédric; McPherson, Helen R; Bridge, Katherine I; Ajjan, Ramzi A; Ridger, Victoria C; Connell, Simon D; Philippou, Helen; Ariëns, Robert A S

    2016-01-28

    Previous studies have shown effects of thrombin and fibrinogen γ' on clot structure. However, structural information was obtained using electron microscopy, which requires sample dehydration. Our aim was to investigate the role of thrombin and fibrinogen γ' in modulating fibrin structure under fully hydrated conditions. Fibrin fibers were studied using turbidimetry, atomic force microscopy, electron microscopy, and magnetic tweezers in purified and plasma solutions. Increased thrombin induced a pronounced decrease in average protofibril content per fiber, with a relatively minor decrease in fiber size, leading to the formation of less compact fiber structures. Atomic force microscopy under fully hydrated conditions confirmed that fiber diameter was only marginally decreased. Decreased protofibril content of the fibers produced by high thrombin resulted in weakened clot architecture as analyzed by magnetic tweezers in purified systems and by thromboelastometry in plasma and whole blood. Fibers produced with fibrinogen γ' showed reduced protofibril packing over a range of thrombin concentrations. High-magnification electron microscopy demonstrated reduced protofibril packing in γ' fibers and unraveling of fibers into separate protofibrils. Decreased protofibril packing was confirmed in plasma for high thrombin concentrations and fibrinogen-deficient plasma reconstituted with γ' fibrinogen. These findings demonstrate that, in fully hydrated conditions, thrombin and fibrinogen γ' have dramatic effects on protofibril content and that protein density within fibers correlates with strength of the fibrin network. We conclude that regulation of protofibril content of fibers is an important mechanism by which thrombin and fibrinogen γ' modulate fibrin clot structure and strength. © 2016 by The American Society of Hematology.

  3. Effect of acute exacerbations on circulating endothelial, clotting and fibrinolytic markers in COPD patients.

    Science.gov (United States)

    Polosa, Riccardo; Malerba, Mario; Cacciola, Rossella R; Morjaria, Jaymin B; Maugeri, Cinzia; Prosperini, Gaetano; Gullo, Raimondo; Spicuzza, Lucia; Radaeli, Alessandro; Di Maria, Giuseppe U

    2013-10-01

    Patients with chronic obstructive pulmonary disease (COPD) are prone to clinical exacerbations that are associated with increased airway inflammation, a potent pro-thrombotic stimulus. Limited information is available on the mechanisms underlying the putative alterations of the endothelial-coagulative system during acute exacerbations. The aim was to investigate whether the activation of the endothelial-coagulative system occurs in association with the acute inflammatory response of COPD exacerbation. We monitored the blood levels of surrogate markers of inflammation: interleukin-6 (IL-6); endothelium damage: von Willebrand's factor (vWF); clotting activation: D-dimer (D-D), and prothrombin fragment 1+2 (F1+2); fibrinolytic response: plasminogen activator inhibitor 1 (PAI-1), in COPD subjects, during hospital admission and after clinical resolution. In 30 COPD subjects, IL-6, vWF, D-D and F1+2 levels were elevated during exacerbation and decreased significantly at clinical stability (IL-6, p = 0.005; vWF, p < 0.001; D-D, p < 0.001; F1+2, p < 0.001). PAI-1 levels did not change at exacerbation compared to clinically stable situations. Positive correlations were observed between several of the markers measured. Elevation of IL-6, vWF, D-D and F1+2 levels during COPD exacerbations implies a strict association between acute inflammation, endothelial activation and clotting initiation. This was not associated with a change in PAI-1, implying an increase in the fibrinolytic response to inflammation. The pro-thrombotic nature of COPD exacerbations sustained by enhanced clotting activation appears to be mitigated by excessive fibrinolysis.

  4. 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.

  5. 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 173.150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... classified as follows: Class, Ascomycetes; order, Sphaeriales; family, Diaporthacesae; genus, Endothia...

  6. 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, ...

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

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... Desmazeaud M, Spinnler E (1997). Laits et produits laitiers. In «. Enzymes en agroalimentaires ». Ed. V. Larreta- Garde. Tech. et. Doc. Lavoisier. Esawy Mona A, Combet-blanc Yannick (2006). Immobilization of. Bacillus licheniformis 5A1 milk-clotting enzyme and characterization of its enzyme properties.

  8. 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 ...

  9. 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 ...

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

    African Journals Online (AJOL)

    SAM

    2014-03-12

    Mar 12, 2014 ... Biochem. Soc. Trans. 10:285. Hashem AM (2000). Purification and properities of a milk-clotting enzyme produced by Penicillium oxalicum. J. Bioresour. Technol. 75:219-222. Laemmli UK (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 227: 680-685.

  11. Altered plasma fibrin clot properties in essential thrombocythemia.

    Science.gov (United States)

    Małecki, Rafał; Gacka, Małgorzata; Kuliszkiewicz-Janus, Małgorzata; Jakobsche-Policht, Urszula; Kwiatkowski, Jacek; Adamiec, Rajmund; Undas, Anetta

    2016-01-01

    Patients with increased thromboembolic risk tend to form denser fibrin clots which are relatively resistant to lysis. We sought to investigate whether essential thrombocythemia (ET) is associated with altered fibrin clot properties in plasma. Ex vivo plasma fibrin clot permeability coefficient (Ks), turbidimetry and clot lysis time (CLT) were measured in 43 consecutive patients with ET (platelet count from 245 to 991 × 10(3)/µL) and 50 control subjects matched for age, sex and comorbidities. Fibrinolysis proteins and inhibitors together with platelet activation markers were determined. Reduced Ks (-38%, p < 0.0001) and prolonged CLT (+34%, p < 0.0001) were observed in ET. The differences remained significant after adjustment for fibrinogen and platelet count. ET was associated with a slightly shorter lag phase (-5%, p = 0.01) and higher maximum absorbency of the turbidimetric curve (+6%, p < 0.001). The ET patients had higher plasma P-selectin by 193% (p < 0.00001) and platelet factor 4 (PF4) by 173% (p < 0.00001), with higher P-selectin observed in 19 (44%) patients with JAK-2 gene V617F mutation. Higher t-PA (+20%, p < 0.001), 23% higher plasminogen activator inhibitor-1, PAI-1 (+23%, p < 0.01) and unaltered thrombin-activatable fibrinolysis inhibitor, plasminogen and α2-antiplasmin activity were found in the ET group. Ks inversely correlated with fibrinogen, PF4 and C-reactive protein. CLT positively correlated only with PAI-1. Patients with ET display prothrombotic plasma fibrin clot phenotype including impaired fibrinolysis, which represents a new prothrombotic mechanism in this disease.

  12. Evaluation of Fibrin Clot Attachment on Titanium Laser-Conditioned Surface Using Scanning Electron Microscopy.

    Science.gov (United States)

    Sinjari, Bruna; Traini, Tonino; Caputi, Sergio; Mortellaro, Carmen; Scarano, Antonio

    2018-03-22

    The study aimed to evaluate the effects of different titanium surface treatments on blood clot extension (bce). A total of 54 titanium disks with machined surface (M), laser-conditioned surface (L), and grit-blasted surface (S) were used in the present study. The surface characteristics such as contact angles and the microroughness were determined on each group (n = 4). To evaluate the bce, 0.1 mL of human blood was dropped onto the surface of each specimen and left for 7 minutes at room temperature. After fixation, dehydration, and gold sputtering treatments, the specimens were observed under scanning electron microscope. The bce values were expressed as percentage of specimen surface covered by blood clot. The surface roughness (Ra ± standard deviation [SD]) was 0.75 ± 0.02 μm for M, 0.25 ± 0.02 μm for L, and 1.30 ± 0.03 μm for S. The contact angles measured in static conditions (WCA ± SD) were 71 ± 5.4° for M, 107 ± 6.6° for L, and 91 ± 7.2° for S. Regarding the bce (bce ± SD) of M samples (65.5 ± 4.3%) was statistically lower compared with both L (83.4 ± 5.1%) and S samples (72.4 ± 4.7%) (P < 0.05). Meanwhile, the L group showed the higher bce value. The present results suggest that the laser-conditioned surface may increase the wettability and bce.

  13. The formation and breakdown of structured clots from whole milk during gastric digestion.

    Science.gov (United States)

    Ye, Aiqian; Cui, Jian; Dalgleish, Douglas; Singh, Harjinder

    2016-10-12

    The behaviour of milk fat globules in the coagula of unheated and heated (90 °C for 20 min) whole milk during gastric digestion was investigated using a human gastric simulator. Structured protein clots were formed by a coagulation process that was driven by the action of the milk-clotting enzyme, pepsin, on the protein fraction of the whole milk. The fat globules in the milk appeared to be embedded in the clots as they formed. After clot formation, the different structures of the clots formed with unheated and heated whole milk led to different rates of protein hydrolysis by pepsin and resulted in the release of fat globules from the clots into the digesta; the release of fat globules was faster in the clots from the heated whole milk. Comparison of the rates of fat globule release from the clots and the rates of the reduction in fat-free matter in the clots showed that the release of fat globules from the clots from both unheated and heated milk was linearly dependent on the breakdown of the protein in the clots. Coalescence of fat globules appeared to occur in the gastric digesta and also within the protein.

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

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    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. 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

    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......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...... HIV infected persons displays a hypocoagulable profile with reduced fibrinolytic resistance as compared to healthy controls....

  16. Effect of solvent/detergent-treated pooled plasma on fibrinolysis in reconstituted whole blood.

    Science.gov (United States)

    Saadah, Nicholas H; van der Meer, Pieter F; Brinkman, Herm Jan M; de Korte, Dirk; Bontekoe, Ido J; Korsten, Herbert H; Middelburg, Rutger A; van der Bom, Johanna G; Schipperus, Martin R

    2017-10-01

    Hyperfibrinolysis has been observed in patients heavily transfused with solvent/detergent-treated pooled plasma (S/D plasma). We compared coagulation and fibrinolytic variables in blood containing S/D plasma with blood containing fresh-frozen plasma (FFP), with and without α2-antiplasmin or tranexamic acid (TXA) supplementation. Whole blood samples were reconstituted from red blood cells, platelet (PLT) concentrates, and varying mixtures of FFP and S/D plasma. Hematocrit and PLT count of reconstituted whole blood samples were varied. For a subset of runs, α2-antiplasmin or TXA was added to S/D plasma whole blood samples. Thromboelastography (TEG) analysis was performed to assess 50% clot lysis time (CLT 50% ), maximum amplitude (MA), and initial clotting time (R-time). The change in CLT 50% of whole blood as the plasma compartment transitions from FFP to S/D plasma was -52% (95% confidence interval [CI], -60% to -45%; p plasma in whole blood. α2-Antiplasmin and TXA restored clot lysis time in S/D plasma whole blood. Whole blood with S/D plasma has shorter clot lysis times in vitro compared to whole blood with FFP. α2-Antiplasmin and TXA restore clot lysis time of S/D plasma whole blood to that of FFP whole blood. Clinicians should be aware of the decreased clot lysis time associated with S/D plasma transfusion. © 2017 AABB.

  17. Prospective randomized study evaluating the effects of PerClot® (Polysaccharide Hemostatic System) application in patients with high bleeding risk undergoing cardiac rhythm device implantation.

    Science.gov (United States)

    Tscholl, Verena; Spann, Felicitas; Moses, Jane; Nagel, Patrick; Bellmann, Barbara; Biewener, Sebastian; Amtenbrink, Marie; Stroux, Andrea; Rillig, Andreas; Landmesser, Ulf; Roser, Mattias

    2017-12-01

    Thus far, the topic hemostatic agent PerClot® is used for surgical procedures. Data about the use of PerClot® for cardiac-rhythm-devices (CRD) implantation are missing. The aim of this study was to evaluate the safety and efficacy of PerClot® in patients with high bleeding risk. In this prospective randomized study we planned to include 150 patients admitted for CRD-Implantation receiving anticoagulation and/or dual-antiplatelet-therapy. Participants were randomized to receive PerClot® versus standard-of-care. The primary endpoint was the incidence of pocket hematoma. Safety endpoint was pocket infection. After a planned safety-interim-analysis the study was terminated early because of safety concerns. 51 patients were included. The two groups were comparable with regard to age (73±11years vs. 74±10years; p=0.71), CHA 2 DS 2 VASc (3.6±1.5 vs. 4.0±1.5; p=0.27) and HASBLED-Score (2.4±1.1 vs. 2.5±1.0; p=0.98), CRD or procedure type, anticoagulant or anti-platelet therapy. The use of PerClot® resulted in a higher incidence of postoperative fever (7 (28%) vs. 0 (0%); p=0.004), higher C-Reactive Protein (66.1±50.5mg/l vs. 25.9±22.5mg/l; p=0.002); and higher postoperative white blood cell count (13.5±4.3/nl vs. 8.8±2.6/nl; p<0.001). Hematoma formation did not differ significantly (p=0.14). Reoperation was not necessary in any patient. This first randomized controlled study for the topical use of the hemostatic agent PerClot® in CRD implantation was terminated early by the safety monitoring board because of an augmented rate of fever and inflammatory markers in the PerClot® group. The addition of PerClot® does not suggest a benefit with regard to the frequency of pocket hematoma. Copyright © 2017 Elsevier B.V. All rights reserved.

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

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    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.

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

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    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...

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

    Science.gov (United States)

    Talens, Simone; Malfliet, Joyce J M C; Rudež, Goran; Spronk, Henri M H; Janssen, Nicole A H; Meijer, Piet; Kluft, Cornelis; de Maat, Moniek P M; Rijken, Dingeman C

    2012-10-01

    Hypofibrinolysis 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. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

  1. Cloning and expression of clt genes encoding milk-clotting proteases from Myxococcus xanthus 422.

    Science.gov (United States)

    Poza, M; Prieto-Alcedo, M; Sieiro, C; Villa, T G

    2004-10-01

    The screening of a gene library of the milk-clotting strain Myxococcus xanthus 422 constructed in Escherichia coli allowed the description of eight positive clones containing 26 open reading frames. Only three of them (cltA, cltB, and cltC) encoded proteins that exhibited intracellular milk-clotting ability in E. coli, Saccharomyces cerevisiae, and Pichia pastoris expression systems.

  2. Combination of recombinant factor VIIa and fibrinogen corrects clot formation in primary immune thrombocytopenia at very low platelet counts

    DEFF Research Database (Denmark)

    Larsen, Ole H; Stentoft, Jesper; Radia, Deepti

    2013-01-01

    Haemostatic treatment modalities alternative to platelet transfusion are desirable to control serious acute bleeds in primary immune thrombocytopenia (ITP). This study challenged the hypothesis that recombinant activated factor VII (rFVIIa) combined with fibrinogen concentrate may correct whole...... blood (WB) clot formation in ITP. Blood from ITP patients (n = 12) was drawn into tubes containing 3·2% citrate and corn trypsin inhibitor 18·3 μg/ml. WB [mean platelet count 22 × 10(9) /l (range 0-42)] was spiked in vitro with buffer, donor platelets (+40 × 10(9) /l), rFVIIa (1 or 4 μg/ml), fibrinogen...... low platelet counts. These data suggest that rFVIIa combined with fibrinogen corrects the coagulopathy of ITP even at very low platelet counts, and may represent an alternative to platelet transfusion....

  3. Fibrinolytic action on fresh human clots of whole body extracts and two semipurified fractions from Lonomia achelous caterpillar

    Directory of Open Access Journals (Sweden)

    E. Coll-Sangrona

    1998-06-01

    Full Text Available The severe bleeding diathesis produced by intoxication with the venom of Lonomia achelous caterpillars is characterized by prolonged bleeding from superficial skin wounds as well as massive hemorrhage into body cavities. The aim of the present study was to evaluate the effect of the crude venom and its fibrinolytic fractions on in vitro lysis of whole blood clots. Venom fractions with fibrinolytic activity were obtained by gel filtration chromatography on Sephadex G75 using imidazole buffer, pH 7.4, at a flow rate of 24 ml/h. Four peaks with fibrinolytic activity were obtained by this method. The highest activity was found in the first two peaks (both peaks were used for the experiments. The results show that the caterpillar venom degraded the preformed clots at a slower rate than plasmin. In addition, plasma protease inhibitors of the fibrinolytic system (a2-antiplasmin, a2-macroglobulin, PAI, etc. only weakly inhibited the lytic effect of the caterpillar venom. These characteristics, as well as the pattern of fibrinogen degradation products, the delay period on fibrin plate lysis and amidolytic activity on chromogenic substrate, reported previously, indicate that the caterpillar enzymes are different from plasmin and trypsin.

  4. Effect of Lipid Surface Composition on the Formation and Structure of Fibrin Clots.

    Science.gov (United States)

    Bakirova, D R; Faizullin, D A; Valiullina, Yu A; Salnikov, V V; Zuev, Yu F

    2017-10-01

    We studied the influence of lipid surface composition on the kinetics of fibrin clot formation and its structure. It was shown that lipid surface affects all phases of fibrin polymerization and chances clot morphology. The magnitude and character of the effect depend on the charge and phase state of lipids that determine the interaction of fibrinogen with the lipid surface and its conformational changes, which modulated the process of fibrinogen conversion into fibrin and, as a result, the formation and morphology of the fibrin clot.

  5. [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.

  6. Development and comparison of a minimally-invasive model of autologous clot pulmonary embolism in Sprague-Dawley and Copenhagen rats

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    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.

  7. 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.

  8. Time-dependent low-field MRI characteristics of canine blood: an in vitro study.

    Science.gov (United States)

    Jeong, Jimo; Park, Sangjun; Jeong, Eunseok; Kim, Namsoo; Kim, Minsu; Jung, Yechan; Cho, Youngkwon; Lee, Kichang

    2016-03-01

    This study was conducted to assess time-sensitive magnetic resonance (MR) changes in canine blood using low-field MR. Arterial and venous blood samples were collected from eight healthy beagle dogs. Samples were placed in 5-mL tubes and imaged within 3 hours of collection at 1 day intervals from day 1 to day 30. The following sequences were used: T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2-star gradient-echo (T2(*)-GRE). Visual comparison of the images revealed that four relatively homogenous blood clots and twelve heterogeneous blood clots developed. The margination of the clot and plasma changed significantly on day 2 and day 13. On day 2, heterogeneous blood clots were differentiated into 2 to 3 signal layers in the T2W, T1W, and especially the STIR images. Hypointense signal layers were also detected in the blood clots in STIR images, which have T2 hypo, FLAIR hypo, and T1 hyper intense signals. In all images, these signal layers remained relatively unchanged until day 13. Overall, the results suggest that hematomas are complex on low-field MRI. Accordingly, it may not be feasible to accurately characterize hemorrhages and predict clot age based on low-field MRI.

  9. Dynamics of motion of a clot through an arterial bifurcation: a finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Abolfazli, Ehsan; Fatouraee, Nasser [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Vahidi, Bahman, E-mail: e.abolfazli@aut.ac.ir, E-mail: nasser@aut.ac.ir, E-mail: bahman_vahidi@ut.ac.ir [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran (Iran, Islamic Republic of)

    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.

  10. 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.

  11. Plasma fibrin clot properties in postmenopausal women: effects of hormone therapy.

    Science.gov (United States)

    Piróg, Magdalena M; Milewicz, Tomasz; Jach, Robert; Undas, Anetta

    2016-05-01

    Postmenopausal women are at risk of thromboembolic events. It is unclear whether menopause alters fibrin clot properties. The aim of our study was to assess the effects of menopause and hormone therapy on clot characteristics. Ex vivo plasma clot permeability, turbidity, and susceptibility to lysis were determined in 70 premenopausal and 70 postmenopausal women (a case-control study). From the postmenopausal group, 30 women were randomly assigned (1:1) to a 24-week oral or transdermal treatment with 17β-estradiol, combined with norethisterone acetate (2 mg + 1 mg/d or 0.05 mg + 5 mg/d, respectively). Compared with premenopausal women (aged 29.2 ± 2.60 y), postmenopausal women (aged 49.7 ± 3.4 y; P = 0.009) were characterized by higher fibrinogen levels (by 36.8%), lower C-reactive protein levels (by 36.9%), and lower clot permeability (by 10.5%); also after adjustment for fibrinogen (all P hormone therapy, 24-week oral therapy was associated with higher absorbency of plasma clots by 16% (P Menopause age is associated with the formation of denser fibrin clots. Estrogen plus progestogen therapy has a minor effect on plasma fibrin properties, but leads to the formation of thicker and more branched fibrin fibers, particularly during oral administration.

  12. 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

  13. 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.

  14. 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.

  15. Complementary effect of fibrinogen and rFVIIa on clotting ex vivo in Bernard-Soulier syndrome and combined use during three deliveries

    DEFF Research Database (Denmark)

    Palsson, Ragnar; Vidarsson, Brynjar; Gudmundsdottir, Brynja R

    2014-01-01

    Women with Bernard-Soulier syndrome (BSS) are considered to be at high risk of serious bleeding during childbirth. Due to the frequently occurring platelet transfusion refractoriness, alternative prophylactic therapy is required. Using rotational thromboelastometry, we evaluated the whole blood...... coagulation profile of a pregnant woman with BSS before and after spiking ex vivo with different concentrations of recombinant activated factor VII (rFVIIa) and fibrinogen. As experiments suggested improved clotting with clinically applicable concentrations of both agents in a complementary manner...... effects were observed during these three deliveries. Our observations suggest that rFVIIa combined with fibrinogen may provide a beneficial clinical hemostatic effect partly by separate but complementary mechanisms....

  16. Effects of thrombosed vena cava filters on blood flow: flow visualization and numerical modeling.

    Science.gov (United States)

    Stewart, Sandy F C; Robinson, Ronald A; Nelson, Robert A; Malinauskas, Richard A

    2008-11-01

    Inferior vena cava (IVC) filters are used to prevent pulmonary embolism (PE) in patients with deep vein thrombosis for whom anticoagulation is contraindicated. IVC filters have been shown to be effective in trapping embolized clots and preventing PE; however, among the commercially available designs, the optimal balance of clot capture efficiency, clot dissolution, and prevention of to vena cava occlusion is unknown. Clot capture efficiency has been quantified in numerous in vitro studies, in which model clots are released into a mock circulation system, with the relative capture efficiency of various IVC filters analyzed statistically. In general, two-stage filters have been found to be more efficient than one-stage filters. However, other factors may play a role in the ultimate dissolution of clots and in the overall effect of the resulting blood flow on caval vasculature. Clot dissolution has been shown to increase with increasing wall shear stress, while low and oscillating wall shear stresses are known to have a deleterious effect on vessel walls, causing intimal hyperplasia. This paper describes the effect of IVC filters on blood flow, velocity patterns, and wall shear stress by flow visualization and computational fluid dynamics.

  17. 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.

  18. Discrepant coagulation profile in HIV infection: elevated D-dimer but impaired platelet aggregation and clot initiation.

    Science.gov (United States)

    Haugaard, Anna K; Lund, Tamara T; Birch, Carsten; Rönsholt, Frederikke; Trøseid, Marius; Ullum, Henrik; Gerstoft, Jan; Johansson, Per I; Nielsen, Susanne D; Ostrowski, Sisse R

    2013-11-13

    In HIV infection, cardiovascular disease (CVD) has emerged as a clinical problem, and elevated D-dimer has been reported. The pathophysiologic mechanisms underlying this remain unclear. We aimed to investigate whether untreated HIV-infected individuals display evidence of functional coagulopathy and whether this was associated with microbial translocation. The study population consisted of 50 HIV-infected untreated individuals and 50 HIV-infected individuals on combination antiretroviral therapy (cART). Groups were matched for age, sex and current CD4cell count. Coagulation analyses included D-dimer and the functional haemostatic whole blood tests, thromboelastography (TEG) and platelet aggregation (Multiplate, impedance aggregometry). Microbial translocation was assessed by plasma levels of lipopolysaccharide (LPS). A larger proportion of untreated individuals compared with treated individuals had D-dimer above normal reference range (27.7 vs. 2.2%, P = 0.001). In both treated and untreated individuals, delayed clot initiation with TEG R-time above upper reference range (18 and 28%, respectively, both P < 0.001) and TEG angle below lower reference range [14% (P = 0.004) and 24% (P < 0.001), respectively] was found. In untreated individuals, 64.6% had aggregation response below threshold in at least two of four tests compared with 36.7% in treated individuals (P = 0.010). Untreated individuals with increased D-dimer levels were relatively hypercoagulable by thromboelastography. Furthermore, in untreated patients, a negative association between microbial translocation and platelet aggregation was found. Elevated D-dimer in untreated HIV-infected individuals was confirmed. However, in both untreated and treated individuals, reduced platelet aggregation and clot initiation was found. The impact of reduced platelet function in HIV infection and a potential role of microbial translocation warrant further investigation.

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

    Science.gov (United States)

    ... Recommend on Facebook Tweet Share Compartir Deep Vein Thrombosis and Pulmonary Embolism (DVT/PE) are often underdiagnosed and serious, but preventable medical conditions. Deep vein thrombosis (DVT) is a medical condition that occurs when ...

  20. A feasible strategy for preventing blood clots in critically ill patients with acute kidney injury (FBI)

    DEFF Research Database (Denmark)

    Robinson, Sian; Zincuk, Aleksander; Larsen, Ulla Lei

    2014-01-01

    , and will continue for two years. The primary outcome is the occurrence of venous thromboembolism. Secondary outcomes include anti-factor Xa activity, bleeding, heparin-induced thrombocytopenia, filter lifespan, length of stay, ventilator free days, and mortality. We will also monitor neutrophil gelatinase...

  1. CHROMATOGRAPHY OF BLOOD-CLOTTING FACTORS AND SERUM PROTEINS ON COLUMNS OF DIATOMACEOUS EARTH

    Science.gov (United States)

    Milstone, J. H.

    1955-01-01

    1. In batch adsorptions with prothrombin solutions, hyflo was the weakest adsorbent, standard super-cel intermediate, and filter-cel strongest. Of these three grades of diatomaceous earth, hyflo has the smallest surface area per gram and filter-cel the largest. In parallel breakthrough experiments, a column of standard super-cel had a capacity almost six times that of a hyflo column. 2. After partial removal of impurities by diatomaceous earth, prothrombin preparations contained less thrombokinase, were more stable, and displayed less tendency to form thrombin "spontaneously." Thrombokinase (or its precursor) was removed from a preparation of prothrombin by passage through a filter cake of standard super-cel. The specific activity of the prothrombin was increased; and 62 per cent of the activity was recovered. 3. Prothrombin was adsorbed from an ammonium sulfate solution at pH 5.26 by columns of hyflo or standard super-cel. When eluted by phosphate solutions, the protein moved down the columns more readily at higher pH and higher concentration of phosphate salts, within the pH range 5.0 to 6.6, and within the phosphate range 0.1 to 1.0 M. 4. Thrombin was adsorbed on a column of standard super-cel at pH 5.11. As successive eluents passed through the column, the thrombin emerged between two bands of impurities. The specific activity of the thrombin was raised; and 83 per cent of the activity was recovered. 5. With a column of standard super-cel, and with a series of eluents within the pH range 5.1 to 6.3, total serum proteins were separated into four major bands. About 94 per cent of the protein was recovered. PMID:13242761

  2. Apixaban or Dalteparin in Reducing Blood Clots in Patients With Cancer Related Venous Thromboembolism

    Science.gov (United States)

    2017-12-28

    Cerebral Vein Thrombosis; Deep Vein Thrombosis; Gonadal Thrombosis; Hepatic Thrombosis; Malignant Neoplasm; Mesenteric Thrombosis; Metastatic Malignant Neoplasm; Portal Vein Thrombosis; Pulmonary Embolism; Renal Vein Thrombosis; Splenic Thrombosis; Venous Thromboembolism

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

    International Nuclear Information System (INIS)

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

    2009-01-01

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

  4. ADENOIDECTOMY/TONSILLECTOMY – Is the Clotting Profile ...

    African Journals Online (AJOL)

    Dr. Paul Adekunle Onakoya

    findings that could suggest bleeding disorders, values of prothrombin/activated partial thromboplastin time and ... history, complete blood count, platelet level and .... References. 1. Hartnick CJ, Ruben RJ. Preoperative coagulation studies prior to tonsillectomy. Arch Otolaryngol. Head Neck Surg 2000; 126: 684 – 688. 2.

  5. Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

    Directory of Open Access Journals (Sweden)

    Xu Zhiliang

    2010-01-01

    Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

  6. Early activation of inflammation and clotting in the preterm lamb with neonatal RDS : Comparison of conventional ventilation and high frequency oscillatory ventilation

    NARCIS (Netherlands)

    Jaarsma, AS; Geven, WB; Van Oeveren, W; Oetomo, SB

    2001-01-01

    In neonatal respiratory distress syndrome activation of inflammation and clotting is demonstrated. High frequency oscillatory ventilation (HFOV) is considered to be less damaging to the human preterm lung, resulting in less activation of inflammation and clotting compared with conventional

  7. 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 (K s ) 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 (K s -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 K s and CLT before rivaroxaban intake. At 2-6 h after rivaroxaban intake, clot properties improved in both G20210A carriers and non-carriers (K s +38 %, and +37 %, CLT -25 % and -25 %, CLT-TAFI -20 % and -24 %, respectively, all pCLT +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.

  8. 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

    2016-01-01

    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. PMID:26912749

  9. 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.

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

    OpenAIRE

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

    2016-01-01

    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.

  11. 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...) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS...

  12. 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 ...

  13. 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 ...

  14. Transgenic mice can express mutant human coagulation factor IX with higher level of clotting activity.

    Science.gov (United States)

    Yan, Jing-Bin; Wang, Shu; Huang, Wen-Ying; Xiao, Yan-Ping; Ren, Zhao-Rui; Huang, Shu-Zheng; Zeng, Yi-Tao

    2006-10-01

    To improve the available values of transgenic animals, we produced a mutant human coagulation factor IX minigene (including cDNA and intron I) with arginine at 338 changed to alanine (R338A-hFIX) by using a direct mutation technique. The R338A-hFIX minigene was then cloned into a plasmid carrying the goat beta-casein promoter to get a mammary gland-specific expression vector. The clotting activity in the supernatant of the transfected HC-11 cells increased to approximately three times more than that of wild-type hFIX. Nine transgenic mice (three females and six males) were produced, and the copy number of the foreign gene was very different, ranging from 1 to 43 in different lines. ELISA, Western blot, and clotting assay experiments showed that the transgenic mice could express R338A-hFIX, showing higher average levels of clotting activity than wild-type hFIX in the milk (103.76% vs. 49.95%). The highest concentration and clotting activity of hFIX reached 26 mug/mL and 1287% in one founder (F(0)-7), which was over 10 times higher than that in human plasma. Furthermore, RT-PCR, APTT assay, and histological analysis indicated that hFIX was expressed specifically in the mammary gland without affecting the intrinsic coagulation pathway and physiologic performance of the local tissue.

  15. Ultrasonographic imaging of abomasal milk clotting and abomasal diameter in healthy and diarrheic calves.

    Science.gov (United States)

    Kirchner, Daniela; Schwedhelm, Lea; Wenge, Julia; Steinhöfel, Ilka; Heinrich, Christian; Coenen, Manfred; Bachmann, Lisa

    2015-11-01

    In case of diarrhea calves are treated with oral rehydration solutions (ORS), which are known to increase abomasal pH and inhibit milk clotting in vitro. Nevertheless, recent studies have shown that ORS with HCO3(-) ≤ 62 mmol/L do not interfere with abomasal milk clotting in healthy calves. However, in diarrheic calves, feeding ORS and milk simultaneously may disturb abomasal curd formation and exacerbate diarrhea due to faster abomasal passage of ingesta. Therefore, the aim of the present study was to ultrasonographically examine abomasal milk clotting and diameter after feeding milk and milk replacer (MR) with and without ORS to healthy and diarrheic calves. Abomasal curd formation and diameter in healthy and diarrheic calves were ultrasonographically imaged before and after feeding milk, MR and ORS prepared in milk or MR. Feeding mixtures of milk or MR with ORS did not cause any remarkable differences in the ultrasonographic images of abomasal content. Moreover, abomasal milk clotting was not disturbed due to diarrhea. Statistically significant differences of abomasal diameter after feeding between healthy and diarrheic calves indicated that abomasal emptying is delayed in diarrheic calves. Hence, further studies are needed to determine reasons for decelerated abomasal passage in calves suffering from diarrhea. © 2015 Japanese Society of Animal Science.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-06

    Oct 6, 2008 ... and Finance, 2001). Much effort has been put into animal rearing and local milk production. This has led to improvements in the production of local milk products ..... beta-casein. J. Agric. Food Chem. 47: 3632-3639. Berridge NJ (1952). An improved method of observing the clotting of milk containing rennin.

  18. A Less Invasive Approach for Ruptured Aneurysm with Intracranial Hematoma: Coil Embolization Followed by Clot Evacuation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Je Hoon; Koh, Jun Seok; Kim, Eui Jong [Kyung-Hee University, College of Medicine, Seoul (Korea, Republic of)

    2007-02-15

    The presence of an intracerebral hematoma from a ruptured aneurysm is a negative predictive factor and it is associated with high morbidity and mortality rates even though clot evacuation followed by the neck clipping is performed. Endovascular coil embolization is a useful alternative procedure to reduce the surgical morbidity and mortality rates. We report here on our experiences with the alternative option of endovascular coil placement followed by craniotomy for clot evacuation. Among 312 patients who were admitted with intracerebral subarachnoid hemorrhage during the recent three years, 119 cases were treated via the endovascular approach. Nine cases were suspected to show aneurysmal intracerebral hemorrhage (ICH) on CT scan and they underwent emergency cerebral angiograms. We performed immediate coil embolization at the same session of angiographic examination, and this was followed by clot evacuation. Seven cases showed to have ruptured middle cerebral artery (MCA) aneurysms and two cases had internal carotid artery aneurysms. The clinical status on admission was Hunt-Hess grade (HHG) IV in seven patients and HHG III in two. Surgical evacuation of the clot was done immediately after the endovascular coil placement. The treatment results were a Glasgow Outcome Scale score of good recovery and moderate disability in six patients (66.7%). No mortality was recorded and no procedural morbidity was incurred by both the endovascular and direct craniotomy procedures. The results indicate that the coil embolization followed by clot evacuation for the patients with aneurysmal ICH may be a less invasive and quite a valuable alternative treatment for this patient group, and this warrants further investigation.

  19. [Severe blood coagulation disorder as the first sign of a peritoneal hemangio-endothelioma: a new therapeutic approach (author's transl)].

    Science.gov (United States)

    Debray, P; Girot, R; Josso, F; Mselati, J C; Hubert, P; Lavaud, J; Cloup, M

    1980-10-01

    The authors describe a 3 1/2 month old infant with hemangio-endothelioma and a severe blood coagulation disorder. The tumor was inoperable and the severe blood coagulation disorder posed considerable therapeutic problem. After treatment with massive amounts of blood clotting factors, an antifibrinolytic drug and radiotherapy, the child's condition improved.

  20. Extraction of mRNA from coagulated horse blood and analysis of inflammation-related cytokine responses to coagulation

    DEFF Research Database (Denmark)

    Bovbjerg, Kirsten Katrine Lindegaard; Heegaard, Peter M. H.; Skovgaard, Kerstin

    2010-01-01

    available. Here, a protocol for RNA extraction from highly clotted blood was optimized and the regulation of a number of cytokine genes compared to stabilized blood was studied. Whole blood samples from 10 clinically healthy horses were incubated for 24 hours at 37°C and RNA was extracted from...

  1. Platelet-rich fibrin prepared from stored whole-blood samples.

    Science.gov (United States)

    Isobe, Kazushige; Suzuki, Masashi; Watanabe, Taisuke; Kitamura, Yutaka; Suzuki, Taiji; Kawabata, Hideo; Nakamura, Masayuki; Okudera, Toshimitsu; Okudera, Hajime; Uematsu, Kohya; Nakata, Koh; Tanaka, Takaaki; Kawase, Tomoyuki

    2017-12-01

    In regenerative therapy, self-clotted platelet concentrates, such as platelet-rich fibrin (PRF), are generally prepared on-site and are immediately used for treatment. If blood samples or prepared clots can be preserved for several days, their clinical applicability will expand. Here, we prepared PRF from stored whole-blood samples and examined their characteristics. Blood samples were collected from non-smoking, healthy male donors (aged 27-67 years, N = 6), and PRF clots were prepared immediately or after storage for 1-2 days. Fibrin fiber was examined by scanning electron microscopy. Bioactivity was evaluated by means of a bioassay system involving human periosteal cells, whereas PDGF-BB concentrations were determined by an enzyme-linked immunosorbent assay. Addition of optimal amounts of a 10% CaCl 2 solution restored the coagulative ability of whole-blood samples that contained an anticoagulant (acid citrate dextrose) and were stored for up to 2 days at ambient temperature. In PRF clots prepared from the stored whole-blood samples, the thickness and cross-links of fibrin fibers were almost identical to those of freshly prepared PRF clots. PDGF-BB concentrations in the PRF extract were significantly lower in stored whole-blood samples than in fresh samples; however, both extracts had similar stimulatory effects on periosteal-cell proliferation. Quality of PRF clots prepared from stored whole-blood samples is not reduced significantly and can be ensured for use in regenerative therapy. Therefore, the proposed method enables a more flexible treatment schedule and choice of a more suitable platelet concentrate immediately before treatment, not after blood collection.

  2. Chondrogenic Differentiation of Marrow Clots After Microfracture with BMSC-Derived ECM Scaffold In Vitro

    Science.gov (United States)

    Wei, Bo; Jin, Chengzhe; Xu, Yan; Du, Xiaotao; Yan, Chao; Tang, Cheng; Ansari, Mujtaba

    2014-01-01

    Repairing articular cartilage by combining microfracture and various scaffolds has been extensively performed in in vivo animal models. We previously described a novel extracellular matrix (ECM) scaffold for cartilage tissue engineering. The aim of this study was to investigate the effect of a bone marrow-derived mesenchymal stem cells-derived ECM (BMSC-dECM) scaffold on the chondrogenic differentiation of marrow clots following microfracture in vitro. In this study, we manufactured the BMSC-dECM scaffold using a freeze-drying method. To obtain the marrow clots, a full-thickness cartilage defect was established and microholes were created in the trochlear groove of New Zealand white rabbits. The samples were divided and cultured in vitro for 1, 2, 4, and 8 weeks. The samples included a culture of the marrow clot alone (Group 1), a culture of the marrow clot with transforming growth factor-beta 3 (TGF-β3) (Group 2), a culture of the composite of the BMSC-dECM scaffold and the marrow clot alone (Group 3), and a culture of the composite with TGF-β3 (Group 4). A smooth and glossy surface was observed in Group 2 and Group 4 over time, but the surface for Group 4 was larger from week 1 onward. Compressive strength gradually increased in Groups 2 and 4, and greater increases were observed in Group 4 during the 8-week culture period. Enhanced cartilage-like matrix deposition of glycosaminoglycan (GAG) and type II collagen were confirmed by Safranin O and immunohistochemistry staining, respectively, in Groups 2 and 4. The GAG and collagen contents also gradually increased over time in Groups 2 and 4; the increase was greater in Group 4. In addition, real-time-polymerase chain reaction demonstrated that the expression of chondrogenic genes, such as COL2, ACAN, and SOX9, was gradually upregulated in Groups 2 and 4. However, greater increases in the expression of these cartilage-like genes were observed in Group 4 from week 4 onward. Our results suggest that the BMSC

  3. The effect of copper and zinc at neutral and acidic pH on the blood ...

    African Journals Online (AJOL)

    The effect of copper and zinc on fish blood coagulation under alkaline and acidic conditions and the possible occurrence of disseminated intravascular clotting under these conditions have been poorly studied to date. It was found that the blood coagulation system of adult O. mossambicus exposed to copper and zinc at ...

  4. Training-induced changes in clotting parameters of athletic horses.

    Science.gov (United States)

    Piccione, Giuseppe; Bazzano, Marilena; Giannetto, Claudia; Marafioti, Simona; Fazio, Francesco

    2014-01-01

    The purpose of this study was to investigate the effects of training on prothrombin time, activated partial thromboplastin time, and fibrinogen (Fb) concentrations in horses to assess potential adaptive response to training. Fifteen clinically healthy horses were enrolled in the present study and equally divided into three groups. Group A completed an intense training program, group B participated in a light training program, and group C included sedentary horses. After 5 weeks, group B was subjected to the same training program completed by group A and renamed group B1. Blood samples were collected by jugular venipuncture from each animal at rest and analyzed within 2 h after sampling. A two-way ANOVA for repeated measures showed a significant effect of training (p < 0.05) on Fb concentrations in group B1 alone during the first week after changing the training program. Our findings demonstrated that Fb is a parameter susceptible to training. Fb plasma levels increase with a more intense training program. However, Fb plasma levels decreased after the first week and returned to basel levels, suggesting that the horses had adapted to the new training program.

  5. In Vitro Assessment of Nanoparticle Effects on Blood Coagulation.

    Science.gov (United States)

    Potter, Timothy M; Rodriguez, Jamie C; Neun, Barry W; Ilinskaya, Anna N; Cedrone, Edward; Dobrovolskaia, Marina A

    2018-01-01

    Blood clotting is a complex process which involves both cellular and biochemical components. The key cellular players in the blood clotting process are thrombocytes or platelets. Other cells, including leukocytes and endothelial cells, contribute to clotting by expressing the so-called pro-coagulant activity (PCA) complex on their surface. The biochemical component of blood clotting is represented by the plasma coagulation cascade, which includes plasma proteins also known as coagulation factors. The coordinated interaction between platelets, leukocytes, endothelial cells, and plasma coagulation factors is necessary for maintaining hemostasis and for preventing excessive bleeding. Undesirable activation of all or some of these components may lead to pathological blood coagulation and life-threatening conditions such as consumptive coagulopathy or disseminated intravascular coagulation (DIC). In contrast, unintended inhibition of the coagulation pathways may lead to hemorrhage. Thrombogenicity is the property of a test material to induce blood coagulation by affecting one or more elements of the clotting process. Anticoagulant activity refers to the property of a test material to inhibit coagulation. The tendency to cause platelet aggregation, perturb plasma coagulation, and induce leukocyte PCA can serve as an in vitro measure of a nanomaterial's likelihood to be pro- or anticoagulant in vivo. This chapter describes three procedures for in vitro analyses of platelet aggregation, plasma coagulation time, and activation of leukocyte PCA. Platelet aggregation and plasma coagulation procedures have been described earlier. The revision here includes updated details about nanoparticle sample preparation, selection of nanoparticle concentration for the in vitro study, and updated details about assay controls. The chapter is expanded to describe a method for the leukocyte PCA analysis and case studies demonstrating the performance of these in vitro assays.

  6. 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

    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. Conclusion: 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...

  7. Milk-clotting activity of berries extracts from nine Solanum plants

    African Journals Online (AJOL)

    USER

    2010-06-21

    Jun 21, 2010 ... Decree N° 62 /22/ CCR (1961). Réglementant l'élevage et la circulation du bétail dans l'Etat fédéré du Cameroun Oriental. Article 3. Duarte AR, Duarte DMR, Moreira KA, Cavalcanti MTH, Lima-Filho JL,. Porto ALF (2009). Jacaratia corumbensis O. kuntze a new vegetable source for milk-clotting enzymes.

  8. Assessing blood coagulation status with laser speckle rheology

    Science.gov (United States)

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

    2014-01-01

    We have developed and investigated a novel optical approach, Laser Speckle Rheology (LSR), to evaluate a patient’s coagulation status by measuring the viscoelastic properties of blood during coagulation. In LSR, a blood sample is illuminated with laser light and temporal speckle intensity fluctuations are measured using a high-speed CMOS camera. During blood coagulation, changes in the viscoelastic properties of the clot restrict Brownian displacements of light scattering centers within the sample, altering the rate of speckle intensity fluctuations. As a result, blood coagulation status can be measured by relating the time scale of speckle intensity fluctuations with clinically relevant coagulation metrics including clotting time and fibrinogen content. Our results report a close correlation between coagulation metrics measured using LSR and conventional coagulation results of activated partial thromboplastin time, prothrombin time and functional fibrinogen levels, creating the unique opportunity to evaluate a patient’s coagulation status in real-time at the point of care. PMID:24688816

  9. Clinical-scale investigation of stable isotopes in human blood: delta13C and delta15N from 406 patients at the Johns Hopkins Medical Institutions.

    Science.gov (United States)

    Kraft, Rebecca A; Jahren, A Hope; Saudek, Christopher D

    2008-11-01

    Objective chemical biomarkers are needed in clinical studies of diet-related diseases to supplement subjective self-reporting methods. We report on several critical experiments for the development of clinically legitimate dietary stable isotope biomarkers within human blood. Our examination of human blood revealed the following: (1) Within blood clot and serum from anonymous individuals (201 males, 205 females) we observed: mean serum delta13C = -19.1 +/- 0.8 per thousand (standard deviation, SD); clot, -19.3 +/- 0.8 per thousand (SD); range = -15.8 per thousand to -23.4 per thousand. Highly statistically significant differences are observed between clot and serum, males and females for both clot and serum. For 15N (n = 206), mean serum = +8.8 +/- 0.5 per thousand (SD); clot +7.4 +/- 0.4 per thousand (SD); range = +6.3 per thousand to +10.5 per thousand. Blood serum is enriched in 15N relative to blood clot by +1.4 per thousand on average, which may reflect differing protein amino acid content. Serum nitrogen is statistically significantly different for males and females, however, clot shows no statistical difference. (2) Relative to clot, capillary blood is marginally different for 13C, but not 15N. Clot 13C is not significantly different from serum; however, it is depleted in 15N by 1.5 per thousand relative to serum. (3) We assessed the effect of blood additives (sodium fluoride and polymerized acrylamide resin) and laboratory process (autoclaving, freeze drying) commonly used to preserve or prepare venous blood. On average, no alteration in delta13C or delta15N is detected compared with unadulterated blood from the same individual. (4) Storage of blood with and without the additives described above for a period of up to 115 days exhibits statistically significant differences for 13C and 15N for sodium fluoride. However, storage for unadulterated blood and blood preserved with polymerized acrylamide resin does not change the delta13C or delta15N isotopic

  10. Effect of rivaroxaban on blood coagulation using the viscoelastic coagulation test ROTEM™.

    Science.gov (United States)

    Casutt, M; Konrad, C; Schuepfer, G

    2012-11-01

    This study investigated the influence of the oral direct inhibitor of factor Xa rivaroxaban on blood coagulation measured by rotation thrombelastometry ROTEM™. Blood was obtained from 11 healthy male volunteers before and 2.5 h after oral administration of 10 mg rivaroxaban. In addition to standard coagulation tests clot formation was measured by ROTEM™ analyzing extrinsic (Extem) and intrinsic thrombelastometry (Intem). Significant differences to the baseline values were found in the Extem clotting time (Extem-CT, 58 ± 9 s and 87 ± 17 s, p coagulation by rivaroxaban.

  11. Intracorneal blood removal six weeks after canaloplasty

    Directory of Open Access Journals (Sweden)

    Alberto Rossetti

    2013-01-01

    Full Text Available In a 71-year-old patient with bilateral open-angle glaucoma, intracorneal blood was found after a canaloplasty procedure in the right eye. Six weeks after surgery on ultrasound biomicroscopy examination, liquified blood and blood clots could be observed nasally in the deep corneal stroma close to the Descemet′s membrane. The intracorneal blood was washed out with balanced saline solution following deep corneal incision and lamellar dissection. Descemet′s membrane was reattached with air injection into the anterior chamber. Two months later, visual acuity improved to 20/50, intraocular pressure was 16 mm Hg without medication and confocal microscopy showed deep stromal folds and limited endothelial cell loss. Viscoelastic entering the cornea at Schwalbe′s line and reflux of blood from the collector channels to Schlemm′s canal can account for corneal hematoma. Even six weeks after canaloplasty, successful blood removal could be fulfilled without rupturing the Descemet′s membrane.

  12. 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.

  13. Prediction of recurrent venous thromboembolism by clot lysis time: a prospective cohort study.

    Science.gov (United States)

    Traby, Ludwig; Kollars, Marietta; Eischer, Lisbeth; Eichinger, Sabine; Kyrle, Paul A

    2012-01-01

    Venous thromboembolism (VTE) is a chronic disease, which tends to recur. Whether an abnormal fibrinolytic system is associated with an increased risk of VTE is unclear. We assessed the relationship between fibrinolytic capacity (reflected by clot lysis time [CLT]) and risk of recurrent VTE. We followed 704 patients (378 women; mean age 48 yrs) with a first unprovoked VTE for an average of 46 months after anticoagulation withdrawal. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, cancer, homozygosity for factor V Leiden or prothrombin mutation, or requirement for indefinite anticoagulation were excluded. Study endpoint was symptomatic recurrent VTE. For measurement of CLT, a tissue factor-induced clot was lysed by adding tissue-type plasminogen activator. Time between clot formation and lysis was determined by measuring the turbidity. 135 (19%) patients had recurrent VTE. For each increase in CLT of 10 minutes, the crude relative risk (RR) of recurrence was 1.13 (95% CI 1.02-1.25; p = 0.02) and was 1.08 (95% CI 0.98-1.20; p = 0.13) after adjustment for age and sex. For women only, the adjusted RR was 1.14 (95% CI, 0.91-1.42, p = 0.22) for each increase in CLT of 10 minutes. CLT values in the 4(th) quartile of the female patient population, as compared to values in the 1(st) quartile, conferred a risk of recurrence of 3.28 (95% CI, 1.07-10.05; p = 0.04). No association between CLT and recurrence risk was found in men. Hypofibrinolysis as assessed by CLT confers a moderate increase in the risk of recurrent VTE. A weak association between CLT and risk of recurrence was found in women only.

  14. Prediction of recurrent venous thromboembolism by clot lysis time: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Ludwig Traby

    Full Text Available Venous thromboembolism (VTE is a chronic disease, which tends to recur. Whether an abnormal fibrinolytic system is associated with an increased risk of VTE is unclear. We assessed the relationship between fibrinolytic capacity (reflected by clot lysis time [CLT] and risk of recurrent VTE. We followed 704 patients (378 women; mean age 48 yrs with a first unprovoked VTE for an average of 46 months after anticoagulation withdrawal. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, cancer, homozygosity for factor V Leiden or prothrombin mutation, or requirement for indefinite anticoagulation were excluded. Study endpoint was symptomatic recurrent VTE. For measurement of CLT, a tissue factor-induced clot was lysed by adding tissue-type plasminogen activator. Time between clot formation and lysis was determined by measuring the turbidity. 135 (19% patients had recurrent VTE. For each increase in CLT of 10 minutes, the crude relative risk (RR of recurrence was 1.13 (95% CI 1.02-1.25; p = 0.02 and was 1.08 (95% CI 0.98-1.20; p = 0.13 after adjustment for age and sex. For women only, the adjusted RR was 1.14 (95% CI, 0.91-1.42, p = 0.22 for each increase in CLT of 10 minutes. CLT values in the 4(th quartile of the female patient population, as compared to values in the 1(st quartile, conferred a risk of recurrence of 3.28 (95% CI, 1.07-10.05; p = 0.04. No association between CLT and recurrence risk was found in men. Hypofibrinolysis as assessed by CLT confers a moderate increase in the risk of recurrent VTE. A weak association between CLT and risk of recurrence was found in women only.

  15. 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.

  16. Elevated NT-proBNP is associated with unfavorably altered plasma fibrin clot properties in atrial fibrillation.

    Science.gov (United States)

    Matusik, Paweł T; Matusik, Patrycja S; Kornacewicz-Jach, Zdzisława; Małecka, Barbara; Ząbek, Andrzej; Undas, Anetta

    2017-09-15

    Dense fibrin clot formation and hypofibrinolysis have been reported in atrial fibrillation (AF). It is unclear which factors affect fibrin clot properties in AF. We investigated plasma fibrin clot permeability (K s ), clot lysis time (CLT), endogenous thrombin potential (ETP) as well as other coagulation and fibrinolysis parameters along with N-terminal pro-B-type natriuretic peptide (NT-proBNP) in 160 AF patients (median age, 70.5years). Previous stroke (n=15; 9.4%) was associated with decreased K s (P=0.04) and longer CLT (P=0.005), together with higher antiplasmin (P=0.03) and lower tissue-type plasminogen activator (P=0.01). Lower K s (P=0.04) and tendency towards longer CLT (P=0.10) were observed in patients with a left atrium diameter>40mm. Patients with a CHA 2 DS 2 -VASc score of 3 or more (82.5%) were characterized by higher thrombin-activatable fibrinolysis inhibitor antigen (P=0.009). K s was inversely correlated with log NT-proBNP (r=-0.34, PCLT was positively correlated with log NT-proBNP (R=0.61, PCLT (the top quartile,≥109min). In AF patients prothrombotic fibrin clot properties assessed ex vivo are determined by PAI-1 and NT-proBNP and this phenotype is associated with prior ischemic stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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.

  18. Protein adsorption and clotting time of pHEMA hydrogels modified with C18 ligands to adsorb albumin selectively and reversibly.

    Science.gov (United States)

    Gonçalves, Inês C; Martins, M Cristina L; Barbosa, Mário A; Ratner, Buddy D

    2009-10-01

    This work intended to create a nanostructured biomaterial that would bind albumin in a selective and reversible way in order to inhibit the adsorption of other blood proteins and therefore minimize activation of coagulation. Different levels of C18 ligand have been immobilized on poly(2-hydroxyethyl methacrylate) (pHEMA). We hypothesize that samples with intermediate amounts of C18 ligand would allow albumin to recognize them and bind through its hydrophobic pockets specific for long chain fatty acids. Surface characterization has confirmed increasing amounts of C18 ligand on pHEMA as the percentage of C18 in solution increases, with maximum coverage achieved in 10% C18 samples. Adsorption from pure albumin solution revealed a small decrease in albumin adsorption from pHEMA to 1% C18 and 2.5% C18 samples, but on surfaces with 5% or higher C18 the amount of adsorbed albumin increased as the percentage of C18 increased. Competitive adsorption studies in the presence of both albumin and fibrinogen, and in the presence of all plasma proteins showed that 1% C18 and 2.5% C18 were the only surfaces selective for albumin, and that the presence of all plasma proteins may even potentiate albumin adsorption. Reversibility studies demonstrated that both 2.5% C18 and 5% C18 samples exchange (125)I-albumin selectively in the presence of both unlabeled albumin and plasma, but 2.5% C18 samples presented higher exchangeability rates (58%). Clotting times using recalcified plasma revealed that samples with none or small amounts of C18 (pHEMA to 5% C18) did not shorten the clotting time compared to the negative control (polystyrene), indicating low activation of the intrinsic coagulation cascade.

  19. RESEARCH ON THE QUALITY INDICATORS OF CURD PRODUCTS BASED ON PROTEIN-HERBAL CLOTS

    Directory of Open Access Journals (Sweden)

    Olena GREK

    2017-12-01

    Full Text Available The article presents the research of qualitative indicators of curd products with different nutritional ingredients based on protein-herbal clots. The effect of the number of Rumex juice and the duration of thermoacid processing on the process of precipitation of milk proteins was determined. It was established that the introduction of vegetative coagulant in the amount (9 ± 0.5% at a temperature (93 ... 95 °C and endurance (3 ... 5 min - provides the optimal yield of protein-herbal clot taking into account restrictions according to organoleptic parameters. The effect of white sugar and apple pectin in fiber on the organoleptic, physico-chemical and rheological indicators curd products was investigated. The dietary fibers increase moisture-proof ability and effective viscosity of samples, and white sugar reduces these indexes due to dehydrating properties. The optimal option is to add to the protein-herbal bunch at the same time two components when mixing - white sugar and apple pectin in fiber in quantities of 15% and 2% respectively. Taking into account the influence of individual non-dairy ingredients - Rumex juice of white sugar and apple pectin in fiber on curd products, the performance of the finished product can purposefully be affected.

  20. Venom Concentrations and Clotting Factor Levels in a Prospective Cohort of Russell's Viper Bites with Coagulopathy.

    Directory of Open Access Journals (Sweden)

    Geoffrey K Isbister

    Full Text Available Russell's viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell's viper envenoming.In a prospective cohort of 146 patients with Russell's viper envenoming, we measured venom concentrations, international normalised ratio [INR], prothrombin time (PT, activated partial thromboplastin time (aPTT, coagulation factors I, II, V, VII, VIII, IX and X, and von Willebrand factor antigen. The median age was 39 y (16-82 y and 111 were male. The median peak INR was 6.8 (interquartile range [IQR]: 3.7 to >13, associated with low fibrinogen [median,3 at 6 h post-antivenom but had reduced to <2, by 24 h. The aPTT had also returned to close to normal (<50 sec at 24 h. Factor VII, VIII and IX levels were unusually high pre-antivenom, median peak concentrations of 393%, 307% and 468% respectively. Pre-antivenom venom concentrations and the INR (r = 0.20, p = 0.02 and aPTT (r = 0.19, p = 0.03 were correlated (non-parametric Spearman analysis.Russell's viper coagulopathy results in prolonged aPTT, INR, low fibrinogen, factors V, VIII and X which recover over 48 h. Severity of clotting abnormalities was associated with venom concentrations.

  1. 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.

  2. Platelet microparticle-inspired clot-responsive nanomedicine for targeted fibrinolysis.

    Science.gov (United States)

    Pawlowski, Christa L; Li, Wei; Sun, Michael; Ravichandran, Kavya; Hickman, DaShawn; Kos, Clarissa; Kaur, Gurbani; Sen Gupta, Anirban

    2017-06-01

    Intravascular administration of plasminogen activators is a clinically important thrombolytic strategy to treat occlusive vascular conditions. A major issue with this strategy is the systemic off-target drug action, which affects hemostatic capabilities and causes substantial hemorrhagic risks. This issue can be potentially resolved by designing technologies that allow thrombus-targeted delivery and site-specific action of thrombolytic drugs. To this end, leveraging a liposomal platform, we have developed platelet microparticle (PMP)-inspired nanovesicles (PMINs), that can protect encapsulated thrombolytic drugs in circulation to prevent off-target uptake and action, anchor actively onto thrombus via PMP-relevant molecular mechanisms and allow drug release via thrombus-relevant enzymatic trigger. Specifically, the PMINs can anchor onto thrombus via heteromultivalent ligand-mediated binding to active platelet integrin GPIIb-IIIa and P-selectin, and release the thrombolytic payload due to vesicle destabilization triggered by clot-relevant enzyme phospholipase-A 2 . Here we report on the evaluation of clot-targeting efficacy, lipase-triggered drug release and resultant thrombolytic capability of the PMINs in vitro, and subsequently demonstrate that intravenous delivery of thrombolytic-loaded PMINs can render targeted fibrinolysis without affecting systemic hemostasis, in vivo, in a carotid artery thrombosis model in mice. Our studies establish significant promise of the PMIN technology for safe and site-targeted nanomedicine therapies in the vascular compartment. Copyright © 2017. Published by Elsevier Ltd.

  3. Ion suppression from blood collection devices

    DEFF Research Database (Denmark)

    Hasselstrøm, Jørgen Bo; Sejr Gothelf, Aase

    Terumo, S-monovette from Sarstedt, Vacuette from Greiner Bio-One and three BD Vacutainer serum tubes from BD. These seven different blood collection devices were used to withdraw blood from five healthy drug free donors (n=35) in random order. The samples were centrifuged and serum from each sample......The aim of the study was to examine the variation in ion suppression in ultra high pressure liquid chromatography tandem mass spectrometry (UHPLC-MS-MS) methods when using different blood collection devices. Three different methods measuring 18 antidepressants and antipsychotics in total were...... studied. The blood collection devices were all designed to activate clot formation. They were made of glass with or without silicone coating or plastic containing silicate particles, thrombin or polystyrene particles coated with kaolin. The blood collection devises Venoject and Venosafe were supplied from...

  4. Highly stable plasminogen activator inhibitor type one (VLHL PAI-1) protects fibrin clots from tissue plasminogen activator-mediated fibrinolysis.

    Science.gov (United States)

    Jankun, Jerzy; Aleem, Ansari M; Selman, Steven H; Skrzypczak-Jankun, Ewa; Lysiak-Szydlowska, Wieslawa; Grafos, Nicholas; Fryer, Hugh J L; Greenfield, Robert S

    2007-11-01

    Plasminogen activator inhibitor-1 (PAI-1) is the major specific inhibitor of tissue-type plasminogen activator (tPA) which mediates fibrin clot lysis through activation of plasminogen. Wild-type-PAI-1 (wPAI-1) is rapidly converted to the latent form (half-life of approximately 2 h) and loses its ability to inhibit tPA. We developed a very long half-life PAI-1 (VLHL PAI-1), a recombinant protein with a half-life >700 h compared with wPAI-1. In this study, VLHL PAI-1 was assessed for its ability to inhibit clot lysis in vitro. Clot formation was initiated in normal plasma supplemented with tPA by the addition of either tissue factor or human recombinant FVIIa. Clot lysis time, monitored turbidimetrically in a microtiter plate reader, was determined at various concentrations of wPAI-1 and VLHL PAI-1. Both wPAI-1 and VLHL PAI-1 caused a significant increase in clot lysis time, although the latter was somewhat less effective at lower concentrations. The VLHL PAI-1, but not wPAI-1, maintained its anti-fibrinolytic activity after preincubation overnight at 37 degrees. These studies demonstrate that VLHL PAI-1 is an effective inhibitor of fibrin clot degradation. Due to the high stability of VLHL PAI-1 compared with wPAI-1, this novel inhibitor of tPA-mediated fibrinolysis may have therapeutic applications for treating surgical and trauma patients when used directly or in conjunction with the procoagulant recombinant FVIIa.

  5. The effect of sepsis and septic shock on the viscoelastic properties of clot quality and mass using rotational thromboelastometry: A prospective observational study.

    Science.gov (United States)

    Davies, Gareth R; Lawrence, Matthew; Pillai, Suresh; Mills, Gavin M; Aubrey, Robert; Thomas, Dafydd; Williams, Rhodri; Morris, Keith; Evans, Phillip Adrian

    2018-04-01

    The study purpose was to define changes in coagulation across the sepsis spectrum using rotational thromboelastometry (ROTEM). Sepsis patients were recruited on admission to the Emergency Department and Intensive Care Units of a large teaching hospital in Wales. ROTEM markers of clot development and fibrinolysis were determined, as well as standard coagulation markers. A healthy control group matched for age and gender was also recruited (n=44). 100 patients were recruited (50 sepsis, 20 severe sepsis and 30 septic shock). Maximum clot firmness was significantly higher in the sepsis (p<0.001) and severe sepsis (p=0.012) groups than the healthy control (71.6±4.5 and 70.4±4.1 vs 64.4 respectively). In septic shock there was prolonged clot development; however, maximum clot firmness remained normal. Fibrinolytic function was significantly impaired in septic shock, which was also significantly associated with 28-day mortality (p<0.001). ROTEM indicated significantly enhanced clot structural development in sepsis and severe sepsis, which could be indicative of a hypercoagulable phase. In septic shock, despite there being a prolongation of clotting pathways and impaired fibrinolysis, clot mass was comparably normal, suggestive of the development of a clot with healthy characteristics. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Blood Types

    Science.gov (United States)

    ... Drive Home Types of Blood Donations Blood Types Blood Types Not all blood is alike. There are eight ... African descent. Learn More About Blood and Diversity Blood Types and Transfusion There are very specific ways in ...

  7. The F7 gene and clotting factor VII levels: dissection of a human quantitative trait locus.

    Science.gov (United States)

    Soria, Jose Manuel; Almasy, Laura; Souto, Juan Carlos; Sabater-Lleal, Maria; Fontcuberta, Jordi; Blangero, John

    2005-10-01

    Localization of human quantitative trait loci (QTLs) is now routine. However, identifying their functional DNA variants is still a formidable challenge. We present a complete dissection of a human QTL using novel statistical techniques to infer the most likely functional polymorphisms of a QTL that influence plasma levels of clotting factor VII (FVII), a risk factor for cardiovascular disease. Resequencing of 15 kb in and around the F7 gene identified 49 polymorphisms, which were then genotyped in 398 people. Using a Bayesian quantitative trait nucleotide (BQTN) method, we identified four to seven functional variants that completely account for this QTL. These variants include both rare coding variants and more common, potentially regulatory polymorphisms in intronic and promoter regions.

  8. 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.

  9. 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.; Laros, B.A.P.; Roest, M.; Meijers, J.C.; Kamphuisen, P.W.; Schutgens, R.E.

    2013-01-01

    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

  10. 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.

    2013-01-01

    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

  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. 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.

  13. 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

  14. Rearrangements of the fibrin network and spatial distribution of fibrinolytic components during plasma clot lysis: Study with confocal microscopy

    NARCIS (Netherlands)

    Sakharov, D.V.; Nagelkerkel, J.F.; Rijken, D.C.

    1996-01-01

    Binding of components of the fibrinolytic system to fibrin is important for the regulation of fibrinolysis. In this study, decomposition of the fibrin network and binding of plasminogen and plasminogen activators (PAs) to fibrin during lysis of a plasma clot were investigated with confocal

  15. 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.

  16. The venous thromboembolic risk and the clot wave analysis: a useful relationship?

    Science.gov (United States)

    Ruberto, Maria Filomena; Marongiu, Francesco; Mandas, Antonella; Mameli, Antonella; Porru, Mariagrazia; Cianchetti, Elisabetta; Barcellona, Doris

    2018-02-23

    Hospitalized patients with acute medical conditions have higher venous thromboembolism (VTE) risk. A patient with a final Padua Prediction Score (PPS) of ≥4 is considered to be at high risk for VTE. The aim of this study was to investigate on a possible relationship between PPS, the dynamics of the clot formation, i.e. the clot waveform analysis (CWA) of aPTT, fibrinogen and D-Dimer in a large group of medical patients. CWA in terms of velocity (first derivative), acceleration (second derivative), density (Delta) of aPTT, fibrinogen, D-Dimer and PPS for VTE were determined in 801 medical patients divided in three groups (without antithrombotic prophylaxis and high PPS, without antithrombotic prophylaxis and low PPS, with antithrombotic prophylaxis and high PPS) and a group of healthy subjects. CWA, fibrinogen and D-Dimer values were higher in the medical patients with high PPS with or without antithrombotic prophylaxis when compared with patients without antithrombotic prophylaxis with low PPS and healthy subjects. The second derivative, fibrinogen and D-Dimer were significantly associated with a high PPS score (≥4): odds ratio (OR) = 1.53, 95% confidence interval (CI) = 1.03-2.28; OR = 1.91, 95% CI = 1.3-2.79; OR = 3.16, 95% CI = 2.29-4.36, respectively. Interactions between first derivative and D-Dimer (OR = 2.14, 95% CI = 1.23-3.72) and first derivative and fibrinogen (OR = 1.75, 95% CI = 1.02-2.98) were found. CWA could give useful information to recognize a hypercoagulable state in patients admitted to a medical ward with high and low PPS. First and second derivative aPTT, D-Dimer and fibrinogen levels could be added to PPS to better assess the global thromboembolic risk of these patients.

  17. Determination of bacterial endotoxin (pyrogen) in radiopharmaceuticals by the gel clot method. Validation

    International Nuclear Information System (INIS)

    Fukumori, Neuza Taeko Okasaki

    2008-01-01

    Before the Limulus amebocyte lysate (LAL) test, the only available means of pirogenicity testing for parenteral drugs and medical devices was the United States Pharmacopoeia (USP) rabbit pyrogen test. Especially for radiopharmaceuticals, the LAL assay is the elective way to determine bacterial endotoxin. The aim of this work was to validate the gel clot method for some radiopharmaceuticals without measurable interference. The FDA's LALTest guideline defines interference as a condition that causes a significant difference between the endpoints of a positive water control and positive product control series using a standard endotoxin. Experiments were performed in accordance to the USP bacterial endotoxins test in the 131 I- m-iodobenzylguanidine; the radioisotopes Gallium-67 and Thallium-201; the lyophilized reagents DTPA, Phytate, GHA, HSA and Colloidal Tin. The Maximum Valid Dilution (MVD) was calculated for each product based upon the clinical dose of the material and a twofold serial dilution below the MVD was performed in duplicate to detect interferences. The labeled sensitivity of the used LAL reagent was 0.125 EU mL -1 (Endotoxin Units per milliliter). For validation, a dilution series was performed, a twofold dilution of control standard endotoxin (CSE) from 0.5 to 0.03 EU mL -1 , to confirm the labeled sensitivity of the LAL reagent being tested in sterile and non pyrogenic water, in quadruplicate. The same dilution series was performed with the CSE and the product in the 1:100 dilution factor, in three consecutive batches of each radiopharmaceutical. The products 131 I-m-iodobenzylguanidine, Gallium-67, Thallium-201, DTPA, HSA and Colloidal Tin were found compatible with the LAL test at a 1:100 dilution factor. Phytate and GHA showed some interference in the gel clot test. Other techniques to determine endotoxins as the chromogenic (color development) and the turbidimetric test (turbidity development), were also assessed to get valuable quantitative and

  18. A link between blood coagulation and prophenol oxidase activation in arthropod host defense.

    Science.gov (United States)

    Nagai, T; Kawabata, S

    2000-09-22

    Phenol oxidase, a copper-containing enzyme, is widely distributed not only in animals but also in plants and fungi, which is responsible for initiating the biosynthesis of melanin. Activation of prophenol oxidase in arthropods is important in host defense. However, the prophenol oxidase-activating system remains poorly understood at the molecular level. Here we show that the coagulation cascade of the horseshoe crab Tachypleus tridentatus is linked to prophenol oxidase activation, with the oxygen carrier hemocyanin functioning as a substitute for prophenol oxidase. Tachypleus clotting enzyme functionally transforms hemocyanin to phenol oxidase, and the conversion reaches a plateau at 1:1 stoichiometry without proteolytic cleavage. The active site-masked clotting enzyme also has the same effect, suggesting that complex formation of the clotting enzyme with hemocyanin is critical for the conversion. The two systems of blood coagulation and prophenol oxidase activation may have evolved from a common ancestral protease cascade.

  19. Incorporation of vitronectin into fibrin clots. Evidence for a binding interaction between vitronectin and gamma A/gamma' fibrinogen.

    Science.gov (United States)

    Podor, Thomas J; Campbell, Stephanie; Chindemi, Paul; Foulon, Denise M; Farrell, David H; Walton, Philip D; Weitz, Jeffrey I; Peterson, Cynthia B

    2002-03-01

    Vitronectin is an abundant plasma protein that regulates coagulation, fibrinolysis, complement activation, and cell adhesion. Recently, we demonstrated that plasma vitronectin inhibits fibrinolysis by mediating the interaction of type 1 plasminogen activator inhibitor with fibrin (Podor, T. J., Peterson, C. B., Lawrence, D. A., Stefansson, S., Shaughnessy, S. G., Foulon, D. M., Butcher, M., and Weitz, J. I. (2000) J. Biol. Chem. 275, 19788-19794). The current studies were undertaken to further examine the interactions between vitronectin and fibrin(ogen). Comparison of vitronectin levels in plasma with those in serum indicates that approximately 20% of plasma vitronectin is incorporated into the clot. When the time course of biotinylated-vitronectin incorporation into clots formed from (125)I-fibrinogen is monitored, vitronectin incorporation into the clot parallels that of fibrinogen in the absence or presence of activated factor XIII. Vitronectin binds specifically to fibrin matrices with an estimated K(d) of approximately 0.6 microm. Additional vitronectin subunits are assembled on fibrin-bound vitronectin multimers through self-association. Confocal microscopy of fibrin clots reveals the globular vitronectin aggregates anchored at intervals along the fibrin fibrils. This periodicity raised the possibility that vitronectin interacts with the gamma A/gamma' variant of fibrin(ogen) that represents about 10% of total fibrinogen. In support of this concept, the vitronectin which contaminates fibrinogen preparations co-purifies with the gamma A/gamma' fibrinogen fraction, and clots formed from gamma A/gamma' fibrinogen preferentially bind vitronectin. These studies reveal that vitronectin associates with fibrin during coagulation, and may thereby modulate hemostasis and inflammation.

  20. Polymorphism of the blood clot lysis enzyme tissue-type plasminogen activator is associated with myocardial infarction

    NARCIS (Netherlands)

    Bom, J.G. van der; Knijff, P. de; Bots, M.L.; Haverkate, F.; Hofman, A.; Kluft, C.; Grobbee, D.E.

    1996-01-01

    Objective: Impaired fibrinolysis has been suggested to be associated with increased risk of myocardial infarction. An insertion/deletion (I/D) polymorphism of the tissue-type plasminogen activator (t-PA) gene has been described which may be associated with impaired fibrinolysis. We studied the

  1. Technegas: A medical application of 99mTc for the study of buckyballs, blood clots, lung disease and AIDS

    International Nuclear Information System (INIS)

    Willett, G.D.; Dance, I.G.; Fisher, K.J.; Burch, W.M.; Dasaklis, C.; Mackey, D.W.J.

    1994-01-01

    Radionuclide studies of lung disease have been greatly enhanced by the introduction of an Australian invention; the Technegas generator. The properties of the open-quotes dry radio-aerosolsclose quotes produced by this device ensure lung images superior to those from true radio-gases such as 133 Xe with the additional advantage of employing 99m Tc, the most widespread radionuclide agent. A Technegas lung scan can enable identification of pulmonary mebolism (an immediately life threatening condition) emphysema and chronic obstructive lung disease. A simple modification to the generator gas mixture produces Pertechnegas an agent useful in studies of the integrity of the alveolar epithelial membrane in immunosuppressed patients such as transplants and AIDS. Although these agents are now common in Australia and Europe, little has been proven of their chemical composites. Technegas is formed by the initial evaporation of ( 99m Tc) sodium pertechnetate with the subsequent sublimation of carbon from a disposable graphite crucible at ∼2500 degrees C in an atmosphere of 100% argon. 99m Tc atoms are lifted off with the crystalline layers of graphite during the vaporization. Technegas then possibly consists of 99m Tc based metallo-fullerenes and fullerenes. Technegas has an effective half life in the lung very similar to the physical half life of Technetium (6 hours) regardless of clinical condition; a result which suggests that Technegas contains endohedral fullerenes. Pertechnegas is created in an atmosphere of 97% Ar 3% O 2 and has an effective half life in the lung of less than 15 minutes

  2. Lytic efficacy of apoli protein E2 (ApoE2) and recombinant tissue plasminogen activator (rt-PA) treatment with 120 kHz ultrasound in an in-vitro human clot model

    Science.gov (United States)

    Meunier, Jason M.; Cheng, Jason Y.; Clark, Joseph F.; Shaw, George J.

    2005-04-01

    Currently, the only FDA approved therapy for acute ischemic stroke is recombinant tissue plasminogen activator (rt-PA). However rt-PA has substantial side effects such as hemorrhage. This has led to interest in other potential therapies. For example, ultrasound (US) increases the lytic efficacy of rt-PA. Also, apolipoprotein E2 (ApoE2) increases rt-PA activity. This suggests combining US, ApoE2 and rt-PA to improve thrombolysis, but the efficacy is not known. Here, the lytic efficacy of apoE2, rt-PA and 120 kHz US is measured in a human clot model. Whole blood was obtained from volunteers, after local institutional approval. Clots were formed in 1.7 mm micropipettes, and placed in a water tank that allowed microscopic video imaging during US and thrombolytic exposure. Clots were treated with rt-PA ([rt-PA]=3.15 μg/ml), rt-PA and apoE2 ([apoE2]=9.8 μg/ml), or rt-PA, apoE2 and 120 kHz US (0.35 MPa, PRF=1667 Hz, 80% duty cycle) for 15 min at 37°C in human plasma. Clot lysis was visually recorded and the lysis depth (LD) determined from these data using an image analysis algorithm. LD was linear with time for all treatments (R2>=0.81), allowing the determination of a lytic rate (LR). LR was found to be 0.35+/-0.03, 1.55+/-0.11, and 0.75+/-0.04 μm/min for the rt-PA, rt-PA and apoE2, and US treated groups respectively. The thrombolytic efficacy of rt-PA is enhanced by ApoE2. The interaction of 120 kHz with apoE2 and rt-PA showed a reduced lytic efficacy compared with rt-PA and apoE2 treatment alone. It is possible that US interferes with the ApoE2-mediated activation of rt-PA.

  3. Blood Tests

    Science.gov (United States)

    ... your blood, as discussed in the following paragraphs. Red Blood Cells Red blood cells carry oxygen from ... leaks out, and its levels in your blood rise. For example, blood levels of troponin rise when ...

  4. Cow dung is a novel feedstock for fibrinolytic enzyme production from newly isolated Bacillus sp. IND7 and its application in in vitro clot lysis

    Directory of Open Access Journals (Sweden)

    Ponnuswamy eVijayaraghavan

    2016-03-01

    Full Text Available Bacterial fibrinolytic enzymes find great applications to treat and prevent cardiovascular diseases. The novel fibrinolytic enzymes from food grade organisms are useful for thrombolytic therapy. This study reports fibrinolytic enzyme production by Bacillus sp. IND7 in solid-state fermentation (SSF. In this study, cow dung was used as the cheap substrate for the production of fibrinolytic enzyme. Enzyme production was primarily improved by optimizing the nutrient and physical factors by one-variable-at-a-time approach. A statistical method (two-level full factorial design was applied to investigate the significant variables. Of the different variables, pH, starch, and beef extract significantly influenced on the production of fibrinolytic enzyme (p < 0.05. The optimum levels of these significant factors were further investigated using response surface methodology. The optimum conditions for enhanced fibrinolytic enzyme production were 1.23% (w/w starch and 0.3 % (w/w beef extract with initial medium pH 9.0. Under the optimized conditions, cow dung substrate yielded 8,345 U/g substrate, and an overall 2.5-fold improvement in fibrinolytic enzyme production was achieved due to its optimization. This is the first report of fibrinolytic enzyme production using cow dung substrate from Bacillus sp. in SSF. The crude enzyme displayed potent activity on zymography and digested goat blood clot completely in in vitro condition.

  5. 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.

  6. Ionizing radiation induces upregulation of cellular procoagulability and tissue factor expression in human peripheral blood mononuclear cells.

    Science.gov (United States)

    Goldin-Lang, Petra; Niebergall, Florian; Antoniak, Silvio; Szotowski, Bjoern; Rosenthal, Peter; Pels, Klaus; Schultheiss, Heinz-Peter; Rauch, Ursula

    2007-01-01

    The therapeutic application of ionizing radiation is associated with thrombotic events, but the exact underlying molecular mechanisms are still unclear. Tissue factor (TF), the primary initiator of blood coagulation, is essentially involved in the pathophysiology of thrombosis. Circulating monocytes have been identified to upregulate TF under inflammatory conditions and, thereby, enhance blood thrombogenicity. The study examines the effect of irradiation on the cellular procoagulability and TF protein expression of human peripheral blood mononuclear cells (PBMNCs) in a time period of 7 days. Human PBMNCs were irradiated with 20 Gy. Procoagulability of PBMNCs, released microparticles and microparticle-free cell supernatant was analyzed by a chromogenic assay and TF protein expression quantified by TF ELISA. To determine whether irradiated PBMNCs and shed microparticles initiate plasma clotting, a one stage clotting assay was performed. We found a significant increase of PBMNC-associated procoagulant activity over a time period of 7 days post irradiation. Moreover, 3 days post irradiation PBMNCs initiated the plasma clotting faster than non-irradiated cells. An enhanced cellular TF protein concentration was persistently observed throughout the investigated time up to 7 days post irradiation. Microparticle-associated TF activity significantly increased 3 days post irradiation compared with the non-irradiated controls. PBMNC-derived microparticles post irradiation also initiated the plasma clotting faster than microparticles derived from controls. The results show irradiation to induce TF expression and to increase procoagulability of PBMNCs and cell-derived microparticles. This could be a possible mechanism by which ionizing radiation enhances blood thrombogenicity.

  7. Haemopoietic progenitor cells in human peripheral blood

    International Nuclear Information System (INIS)

    Zwaan, F.E.

    1980-01-01

    The purpose of the investigation reported is to purify haemopoietic progenitor cells from human peripheral blood using density gradient centrifugation in order to isolate a progenitor cell fraction without immunocompetent cells. The purification technique of peripheral blood flow colony forming unit culture (CFU-c) by means of density gradient centrifugation and a combined depletion of various rosettes is described. The results of several 'in vitro' characteristics of purified CFU-c suspensions and of the plasma clot diffusion chamber culture technique are presented. Irradiation studies revealed that for both human bone marrow and peripheral blood the CFU-c were less radioresistant than clusters. Elimination of monocytes (and granulocytes) from the test suspensions induced an alteration in radiosensitivity pararmeters. The results obtained with the different techniques are described by analysing peripheral progenitor cell activity in myeloproliferative disorders. (Auth.)

  8. [Estrogens, progestins and blood lipids].

    Science.gov (United States)

    Tikkanen, M J

    1984-01-01

    Progestins and estrogens can affect blood lipids and, as a result, contribute to cardiovascular disease. Since the very first studies, scientists have treated progestins and estrogens separately instead of studying their combined effect. Studies have shown that oral contraceptives (OCs) increase the risk of heart attack and brain hemorrhage. Heart attacks are 3-4 times more likely to occur in women aged 25-49 who are using OCs than those who are not. The risk diminishes after use is discontinued, but women aged 40-49 with a long history of OC use remain twice as prone to heart attacks even after giving up these contraceptives. OCs can cause problems with clotting, resulting in coronary and other arterial complications, increasing atherogenic risk. The effect of steroids on clotting and blood pressure must be studied before it can be determined how cardiovascular disease can be prevented. The author advocates the use of natural and synthetic estrogens in small quantities. He recommends the following in particular: progestins of the pregnal series, desogestrel, and a combination of 19-nortestosterone and estrogen. Synthetic estrogens (mestronol, ethinylestradio) increase high density lipoprotein (HDL) cholesterol levels, and androgens reduce them. Except for desogestrel, currently available progestins are related to androgens. It was discovered in 1977 that progestins in the pregnal series can cause tumors in the breast glands of beagles. Synthetic estrogens increase triglyceride levels by accelerating very low density lipoprotein (VLDL) synthesis. Currently available OCs which contain fewer estrogens, do not affect triglyceride levels to any significant degree. Conjugated estrogens are widely used in Anglo-Saxon countries and can cause hypertriglyceridemia. All other estrogens used to treat symptoms of menopause increase HDL cholesterol and reduce atherogenic LDL cholesterol.

  9. Blood viscosity during coagulation at different shear rates

    Science.gov (United States)

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

    2014-01-01

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

  10. [Embolic complications by ink clots removed from syringes during cerebral angiography].

    Science.gov (United States)

    Kohyama, Shinya; Ishihara, Shoichiro; Yamane, Fumitaka; Ishihara, Hideaki; Kanazawa, Ryuzaburo; Suzuki, Masanori; Neki, Hiroaki; Ohkawara, Mai

    2009-01-01

    We noted, during cerebral angiography, that the contrast medium was contaminated with numerous small black ink clots from gradation marks on syringes. In this report, we show that ink can be removed from syringes in solid form, and that they may result in embolic complications during cerebral angiography. To demonstrate that the ink from gradation marks on syringes can come off in a solid form and attach itself to the gloves during cerebral angiography, syringes were gripped many times (just as in an angiographic procedure) after immersion in contrast medium or 0.9% saline for 10 minutes. To see if difference of contrast medium and syringes could affect the removing of ink, five types of nonangiographic syringes and one type of angiographic syringe were rubbed with gauze after certain time periods after immersing them in four kinds of contrast medium or 0.9% saline. Ink attached itself to the gloves in a solid form by repeated gripping due to adherence of contrast medium. Ink was removed from all nonangiographic syringes by rubbing after immersion in any type of contrast medium for two hours. Gradation marks on angiographic syringes were stable with all types of contrast medium. Thus, ink for gradation marks on nonangiographic syringes, which is easily removed in a solid form due to contrast medium, can be the source of embolic complication during cerebral angiography.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2018-01-31

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

  13. Transgenic rabbits as a model organism for production of human clotting factor VIII

    International Nuclear Information System (INIS)

    Vasicek, D.; Chrenek, P.; Makarevich, A.; Bauer, M.; Jurcik, R.; Suvegova, K.; Rafay, J.; Bulla, J.; Hetenyi, L.; Erickson, J.; Paleyanda, R.K.

    2005-01-01

    Human clotting factor VIII (hFVIII) is a very complex and large protein whose expression is difficult, as hFVIII requires extensive post-translational modification to be biologically active. This paper reports the generation of transgenic rabbits as a model species for testing the expression of hFVIII in the mammary gland. For micro-injection, a fusion gene construct was used, consisting of 2.5 kb murine whey acidic protein (mWAP) promoter, 7.2 kb cDNA of hFVIII, and 4.6 kb of 3' flanking sequences of the mWAP gene. from 130 micro-injected zygotes transferred into recipients, 30 offspring were delivered. The pups were screened for the transgene by PCR, using DNA isolated from the ear, and results were confirmed by Southern blot analysis. The transgene was identified in one female founder animal, and it was transmitted to the offspring in a Mendelian fashion, thus demonstrating stable integration of the gene construct into the germline of the transgenic rabbits. (author)

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Low-grade endotoxemia and clotting activation in the early phase of pneumonia.

    Science.gov (United States)

    Cangemi, Roberto; Della Valle, Patrizia; Calvieri, Camilla; Taliani, Gloria; Ferroni, Patrizia; Falcone, Marco; Carnevale, Roberto; Bartimoccia, Simona; D'Angelo, Armando; Violi, Francesco

    2016-11-01

    Community-acquired pneumonia (CAP) is associated with an increased risk of arterial and venous thrombosis but the underlying pathophysiological mechanisms are still unclear. We investigated if, in patients with CAP, a pro-thrombotic state does exist and its relationship with serum levels of endotoxins. A total of 104 consecutive patients with CAP were prospectively recruited and followed up until discharge. At admission and at discharge, serum endotoxins, systemic markers of clotting activation and zonulin, a marker of gut permeability, were analysed. Hospitalized patients matched for gender, age and comorbidities but without infections were used as control. At admission, CAP patients showed higher plasma levels of F 1 +2 , a marker of thrombin generation (P = 0.023), and lower levels of protein C (PC; P zonulin were higher in CAP patients than controls (P zonulin was detected (R = 0.575; P < 0.001) CONCLUSION: This study provides the first evidence that CAP patients disclose an ongoing pro-thrombotic state and suggests a role for endotoxemia in determining enhanced thrombin generation. © 2016 Asian Pacific Society of Respirology.

  17. Point-of-care testing of activated clotting time in the ICU: is it relevant?

    Science.gov (United States)

    Brown, Ellenora; Clarke, Jody; Edward, Karen-leigh; Giandinoto, Jo-Ann

    Over the past 50 years there have been significant advances in both the clinical techniques and equipment used in the intensive care environment. One traditionally used point-of-care test is activated clotting time (ACT), a coagulation test primarily used during cardiopulmonary bypass surgery to monitor the anticoagulation effects of heparin. The ACT test has since emerged into the intensive care environment to guide clinical assessment and management of haemostasis in postoperative cardiac patients. The aim of this integrative systematic review was to critique the available research evaluating the effectiveness of ACT point-of-care testing in the intensive care unit for adult patients following cardiopulmonary bypass and cardiac surgery and any impacts this may have on nursing care. A systematic search of Medline, CINAHL and PubMed was undertaken. The search identified five research papers reporting on the use of ACT point-of-care testing in the intensive care unit for adult cardiac surgical patients. Meta-analysis was not performed due to the lack of homogeneity between the papers included. There was a lack of clear evidence for the use of the ACT point-of-care test after cardiac surgery in the intensive care environment. This review has highlighted that conventional laboratory tests are generally more accurate and reliable than this point-of-care test in guiding nursing care management.

  18. Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

    Science.gov (United States)

    de Lange, Zelda; Pieters, Marlien; Jerling, Johann C; Kruger, Annamarie; Rijken, Dingeman C

    2012-01-01

    Studies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years) were cross-sectionally analysed.Increased PAI-1(act), BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

  19. 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.

  20. 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.

  1. 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

    sepsis admitted to the intensive care unit (ICU). Clinical scores/variables, infection, TEG, biochemistry, therapy, and overall mortality were recorded. RESULTS: Fifty patients (60% men, median age 62 years, 28-day mortality 24%) were included. At admission, 22%, 48%, and 30% had a hypocoagulable......, 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...

  2. Blood coagulation and fibrinolysis of the whole-body irradiated rabbits

    International Nuclear Information System (INIS)

    Hishikawa-Itoh, Youko; Ayakawa, Yoshio; Miyata, Nobuki

    1984-01-01

    To study the effects of irradiation on blood coagulation and fibrinolysis, rabbits were irradiated with 60 Co γ-rays (whole-body: 0, 100, 400, 800, 1200 rads). Clotting time, activity of plasmin and plasminogen, and fibrinogen contents of irradiated rabbit plasma were measured at 4 days before, immediately after, and at 1, 3, 7, 10, and 14 days after irradiation. Both clotting times obtained by addition of (kaolin+phospholipid) which expressed effects on the total intrinsic coagulation system, and by addition of (Ca 2+ ) which expressed effects on the total extrinsic coagulation system, were prolonged with small dose irradiation (100 rads) immediately and 3 days after irradiation. However, with high dose irradiation (400-1200 rads), these clotting times were prolonged 1 day after irradiation. The times of manifestation of irradiation effects on clotting time were different in small and high dose irradiation. Plasmin activity was decreased immediately, 1 day after and recovered 3 days after irradiation. Plasminogen activity was markedly increased in 800 and 1200 rads irradiated groups from 3 days after irradiation. Conversion of plasminogen into plasmin was impaired by irradiation. Fibrinogen contents increased rapidly in all irradiated rabbits except for 100 rads from 1 day after irradiation. These results revealed decreased coagulation and fibrinolysis activities in rabbit blood, irradiation injury of both coagulation and fibrinolysis activation systems, and accumulation of the precursors of fibrin and plasmin (i.e., fibrinogen and plasminogen). (author)

  3. Activation of blood coagulation in cancer: implications for tumour progression

    Science.gov (United States)

    Lima, Luize G.; Monteiro, Robson Q.

    2013-01-01

    Several studies have suggested a role for blood coagulation proteins in tumour progression. Herein, we discuss (1) the activation of the blood clotting cascade in the tumour microenvironment and its impact on primary tumour growth; (2) the intravascular activation of blood coagulation and its impact on tumour metastasis and cancer-associated thrombosis; and (3) antitumour therapies that target blood-coagulation-associated proteins. Expression levels of the clotting initiator protein TF (tissue factor) have been correlated with tumour cell aggressiveness. Simultaneous TF expression and PS (phosphatidylserine) exposure by tumour cells promote the extravascular activation of blood coagulation. The generation of blood coagulation enzymes in the tumour microenvironment may trigger the activation of PARs (protease-activated receptors). In particular, PAR1 and PAR2 have been associated with many aspects of tumour biology. The procoagulant activity of circulating tumour cells favours metastasis, whereas the release of TF-bearing MVs (microvesicles) into the circulation has been correlated with cancer-associated thrombosis. Given the role of coagulation proteins in tumour progression, it has been proposed that they could be targets for the development of new antitumour therapies. PMID:23889169

  4. 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.

  5. 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.

  6. Blood culture

    Science.gov (United States)

    Culture - blood ... A blood sample is needed . The site where blood will be drawn is first cleaned with an antiseptic such ... organism from the skin getting into (contaminating) the blood sample and causing a false-positive result (see ...

  7. Unfavorably Altered Fibrin Clot Properties in Patients with Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome): Association with Thrombin Generation and Eosinophilia

    Science.gov (United States)

    Mastalerz, Lucyna; Celińska-Lӧwenhoff, Magdalena; Krawiec, Piotr; Batko, Bogdan; Tłustochowicz, Witold; Undas, Anetta

    2015-01-01

    Objectives Given reports on the increased prevalence of thromboembolic incidents in patients with eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauss syndrome), we investigated whether fibrin clot properties are unfavorably altered in EGPA. Methods Ex vivo plasma fibrin clot characteristics, including clot permeability, turbidimetry and efficiency of fibrinolysis using two assays, were investigated in 34 consecutive patients with remission in EGPA according to the Birmingham Vasculitis Activity Score version 3 (23 female, 11 male), aged 48 (range, 21–80) years. The control group comprised 34 age- and sex- matched volunteers. Results Compared with controls, patients with EGPA were characterized by denser fiber clots (estimated pore size, Ks, 7.30±0.93 vs 10.14±1.07 10−9 cm2), faster fibrin polymerization (lag phase in a turbidimetric curve, 41.8±3.6 vs 47.4±2.9 s), thicker fibrin fibers (maximum absorbance, ΔAbs, 0.87±0.09 vs 0.72±0.07), higher maximum levels of D-dimer released from clots (DDmax 4.10±0.46 vs 3.54±0.35 mg/L), and prolonged clot lysis time (t50%; 9.50±1.45 vs 7.56±0.87 min); all p<0.0001. Scanning electron microscopy images confirmed denser plasma fibrin networks composed of thinner fibers formed in EGPA. Antineutrophil cytoplasmic antibody status and C-reactive protein did not affect clot variables. Multivariate analysis adjusted for fibrinogen showed that Ks was predicted by eosinophil count, peak thrombin generation, factor VIII, and soluble CD40 ligand, whereas eosinophil count, peak thrombin generation and antiplasmin predicted t50%. Conclusion This study is the first to show that EGPA is associated with prothrombotic plasma fibrin clot phenotype, which may contribute to thromboembolic manifestations reported in this disease. PMID:26540111

  8. Unfavorably Altered Fibrin Clot Properties in Patients with Eosinophilic Granulomatosis with Polyangiitis (Churg-Strauss Syndrome: Association with Thrombin Generation and Eosinophilia.

    Directory of Open Access Journals (Sweden)

    Lucyna Mastalerz

    Full Text Available Given reports on the increased prevalence of thromboembolic incidents in patients with eosinophilic granulomatosis with polyangiitis (EGPA; Churg-Strauss syndrome, we investigated whether fibrin clot properties are unfavorably altered in EGPA.Ex vivo plasma fibrin clot characteristics, including clot permeability, turbidimetry and efficiency of fibrinolysis using two assays, were investigated in 34 consecutive patients with remission in EGPA according to the Birmingham Vasculitis Activity Score version 3 (23 female, 11 male, aged 48 (range, 21-80 years. The control group comprised 34 age- and sex- matched volunteers.Compared with controls, patients with EGPA were characterized by denser fiber clots (estimated pore size, Ks, 7.30±0.93 vs 10.14±1.07 10-9 cm2, faster fibrin polymerization (lag phase in a turbidimetric curve, 41.8±3.6 vs 47.4±2.9 s, thicker fibrin fibers (maximum absorbance, ΔAbs, 0.87±0.09 vs 0.72±0.07, higher maximum levels of D-dimer released from clots (DDmax 4.10±0.46 vs 3.54±0.35 mg/L, and prolonged clot lysis time (t50%; 9.50±1.45 vs 7.56±0.87 min; all p<0.0001. Scanning electron microscopy images confirmed denser plasma fibrin networks composed of thinner fibers formed in EGPA. Antineutrophil cytoplasmic antibody status and C-reactive protein did not affect clot variables. Multivariate analysis adjusted for fibrinogen showed that Ks was predicted by eosinophil count, peak thrombin generation, factor VIII, and soluble CD40 ligand, whereas eosinophil count, peak thrombin generation and antiplasmin predicted t50%.This study is the first to show that EGPA is associated with prothrombotic plasma fibrin clot phenotype, which may contribute to thromboembolic manifestations reported in this disease.

  9. Acoustic radiation force induced resonance elastography of coagulating blood: theoretical viscoelasticity modeling and ex vivo experimentation

    Science.gov (United States)

    Bhatt, Manish; Montagnon, Emmanuel; Destrempes, François; Chayer, Boris; Kazemirad, Siavash; Cloutier, Guy

    2018-03-01

    Deep vein thrombosis is a common vascular disease that can lead to pulmonary embolism and death. The early diagnosis and clot age staging are important parameters for reliable therapy planning. This article presents an acoustic radiation force induced resonance elastography method for the viscoelastic characterization of clotting blood. The physical concept of this method relies on the mechanical resonance of the blood clot occurring at specific frequencies. Resonances are induced by focusing ultrasound beams inside the sample under investigation. Coupled to an analytical model of wave scattering, the ability of the proposed method to characterize the viscoelasticity of a mimicked venous thrombosis in the acute phase is demonstrated. Experiments with a gelatin-agar inclusion sample of known viscoelasticity are performed for validation and establishment of the proof of concept. In addition, an inversion method is applied in vitro for the kinetic monitoring of the blood coagulation process of six human blood samples obtained from two volunteers. The computed elasticity and viscosity values of blood samples at the end of the 90 min kinetics were estimated at 411  ±  71 Pa and 0.25  ±  0.03 Pa · s for volunteer #1, and 387  ±  35 Pa and 0.23  ±  0.02 Pa · s for volunteer #2, respectively. The proposed method allowed reproducible time-varying thrombus viscoelastic measurements from samples having physiological dimensions.

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

    Science.gov (United States)

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

    2015-10-06

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

  12. Blood typing

    Science.gov (United States)

    Blood typing is a method to tell what type of blood you have. Blood typing is done so you can safely donate your blood or receive a blood transfusion. It is also done to see if you have a substance called Rh factor on the surface of your red ...

  13. Blood Types

    Science.gov (United States)

    ... KidsHealth / For Teens / Blood Types What's in this article? Four Blood Groups... Plus Rh Factor... ...Make Eight Blood Types Why Blood Type Matters Print en español Tipos de sangre About 5 million Americans need blood transfusions every ...

  14. Impact of an innovative blood factor stewardship program on drug expense and patient care.

    Science.gov (United States)

    Amerine, Lindsey B; Chen, Sheh-Li; Daniels, Rowell; Key, Nigel; Eckel, Stephen F; Savage, Scott W

    2015-09-15

    An innovative pharmacist-led program to improve prescribing, dosing, and monitoring of clotting factor therapy within a large health system is described. In an initiative to optimize patient outcomes and control costs associated with the use of clotting factor concentrates, the pharmacy department at University of North Carolina Medical Center (UNCMC) led the development of a "factor stewardship program" in collaboration with UNCMC hematologists. Key steps in program development and implementation included (1) selection of one formulary product within each clotting factor class, (2) establishment of guidelines on blood factor prescribing, order review, compounding, and administration, and (3) initial and ongoing education of pharmacy, nursing, and medical staff. As part of the program, a designated pharmacist rounds with hematologists daily, recommending treatment plan modifications and dosage adjustments as appropriate. Now in its fifth year, the stewardship program has enabled consistent pharmacist oversight of all aspects of clotting factor use and enhanced transitions-of-care coordination. Through optimization of product selection, dosing regimens, and infusion frequencies, the number of blood factor doses in fiscal year 2013 was reduced by 45% from the prior year despite a 22% increase in the volume of treated patients; in patients with hemophilia A, re-admissions due to bleeding episodes have declined. During the four-year period ending in July 2014, estimated cost savings attributable to the stewardship program exceeded $4 million annually. Implementation of the UNCMC stewardship program has led to improved outcomes in patients receiving clotting factor concentrates, with significant institutional cost savings. Copyright © 2015 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  15. Types of Blood Donations

    Science.gov (United States)

    ... ill patients. Blood Donation 101 Blood Donation FAQs Types of Blood Donations The Foundation for America's Blood Centers Donate Blood Blood Donation 101 Blood Donation FAQs Types of Blood Donations About Blood What is Blood? ...

  16. Hydroxyethyl Starch Reduces Coagulation Competence and Increases Blood Loss During Major Surgery

    DEFF Research Database (Denmark)

    Rasmussen, Kirsten C; Johansson, Pär I; Højskov, Michael

    2014-01-01

    OBJECTIVE: This study evaluated whether administration of hydroxyethyl starch (HES) 130/0.4 affects coagulation competence and influences the perioperative blood loss. BACKGROUND: Artificial colloids substitute blood volume during surgery; with the administration of HES 130/0.4 (Voluven, Fresenius...... patients were randomized to receive lactated Ringer's solution and 17 to receive HES 130/0.4. RESULTS: Among the patients receiving HES 130/0.4, thrombelastography indicated reduced clot strength (P blood loss was 2.2 (range 0.5 to 5.0) versus 1.4 (range...

  17. 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.

  18. Activity of clotting factors in fresh-frozen plasma during storage at 4 degrees C over 6 days.

    Science.gov (United States)

    von Heymann, Christian; Keller, Mareike Kristina; Spies, Claudia; Schuster, Michael; Meinck, Kristian; Sander, Michael; Wernecke, Klaus-Dieter; Kiesewetter, Holger; Pruss, Axel

    2009-05-01

    Fresh-frozen plasma (FFP) requires thawing, which delays availability. We investigated clotting factor activity and bacterial contamination of FFP when stored at 4 degrees C +/- 2 degrees C for 6 days. Plasma of 20 healthy plasma donors was sampled, frozen, and analyzed at baseline and repeatedly over a period of 6 days after thawing. The activity of fibrinogen, Factor (F)II, FV, FVII, FVIII, F IX, FX, XI, FXII, FXIII, antithrombin III (ATIII), von Willebrand factor antigen (VWF-Ag), protein C (PC), and free protein S (FPS) were determined and analyzed over time. Immediately after thawing there was a significant decrease of fibrinogen (-9%), FII (-7%), FV (-14%), FVII (-12%), FX (-11%), FXIII (-20%), PC (-7%), and ATIII (-4%), whereas FVIII (+8%), F IX (+1%), FXI (+11%), FXII (-1%), FPS (-1%), and VWF-Ag (-6%) remained stable without significant change. Over 6 days after thawing fibrinogen, ATIII (+2%) and VWF-Ag (+2%) remained stable whereas FXII (+2%), FXIII (+6%), and PC (+3%) changed significantly over time and increased at the end. FII (-8%), FV (-16%), FVII (-31%), FVIII (-47%), F IX (-12%), FX (-10%), FXI (-25%), and FPS (+/-0%) changed also significantly over time and decreased at the end. All clotting factors and inhibitors remained within the reference range requested by quality assurance regulations. No FFP bag showed bacterial contamination. This provides evidence for maintaining quality of thawed FFP and may improve rapid availability in emergency situations and reduce cost for health care givers.

  19. In vitro Ca(2+)-dependent maturation of milk-clotting recombinant Epr: minor extracellular protease: from Bacillus licheniformis.

    Science.gov (United States)

    Ageitos, José Manuel; Vallejo, Juan Andrés; Serrat, Manuel; Sánchez-Pérez, Angeles; Villa, Tomás G

    2013-06-01

    The minor extracellular protease (Epr) is secreted into the culture medium during Bacillus licheniformis, strain USC13, stationary phase of growth. Whereas, B. subtilis Epr has been reported to be involved in swarming; the B. licheniformis protease is also involved in milk-clotting as shown by the curd forming ability of culture broths expressing this protein. The objectives of this study are the characterization of recombinant B. licheniformis Epr (minor extracellular protease) and the determination of its calcium-dependent activation process. In this work, we have cloned and expressed B. licheniformis Epr in Escherichia coli. We were also able to construct a tridimensional model for Epr based on its homology to Thermococcus kodakarensis pro-tk-subtilisin 2e1p, fervidolysin from Fervidobacterium pennivorans 1rv6, and B. lentus 1GCI subtilisin. Recombinant Epr was accumulated into inclusion bodies; after protein renaturation, Epr undergoes an in vitro calcium-dependent activation, similar to that described for tk protease. The recombinant Epr is capable of producing milk curds with the same clotting activity previously described for the native B. licheniformis Epr enzyme although further rheological and industrial studies should be carried out to confirm its real applicability. This work represents for the first time that Epr may be successfully expressed in a non-bacilli microorganism.

  20. Clot lysis time in platelet-rich plasma: method assessment, comparison with assays in platelet-free and platelet-poor plasmas, and response to tranexamic acid.

    Science.gov (United States)

    Panes, Olga; Padilla, Oslando; Matus, Valeria; Sáez, Claudia G; Berkovits, Alejandro; Pereira, Jaime; Mezzano, Diego

    2012-01-01

    Fibrinolysis dysfunctions cause bleeding or predisposition to thrombosis. Platelets contain several factors of the fibrinolytic system, which could up or down regulate this process. However, the temporal relationship and relative contributions of plasma and platelet components in clot lysis are mostly unknown. We developed a clot lysis time (CLT) assay in platelet-rich plasma (PRP-CLT, with and without stimulation) and compared it to a similar one in platelet-free plasma (PFP) and to another previously reported test in platelet-poor plasma (PPP). We also studied the differential effects of a single dose of tranexamic acid (TXA) on these tests in healthy subjects. PFP- and PPP-CLT were significantly shorter than PRP-CLT, and the three assays were highly correlated (p plasma PAI-1, von Willebrand factor, fibrinogen, LDL-cholesterol, and triglycerides (p platelet aggregation/secretion, platelet counts, and pro-coagulant tests to explore factor X activation by platelets, PRP clotting time, and thrombin generation in PRP. Among all the studied variables, PFP-CLT was independently associated with plasma PAI-1, LDL-cholesterol, and triglycerides and, additionally, stimulated PRP-CLT was also independently associated with plasma fibrinogen. A single 1 g dose of TXA strikingly prolonged all three CLTs, but in contrast to the results without the drug, the lysis times were substantially shorter in non-stimulated or stimulated PRP than in PFP and PPP. This standardized PRP-CLT may become a useful tool to study the role of platelets in clot resistance and lysis. Our results suggest that initially, the platelets enmeshed in the clot slow down the fibrinolysis process. However, the increased clot resistance to lysis induced by TXA is overcome earlier in platelet-rich clots than in PFP or PPP clots. This is likely explained by the display of platelet pro-fibrinolytic effects. Focused research is needed to disclose the mechanisms for the relationship between CLT and plasma

  1. 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

  2. Discrepant fibrinolytic response in plasma and whole blood during experimental endotoxemia in healthy volunteers.

    Directory of Open Access Journals (Sweden)

    Sisse R Ostrowski

    Full Text Available Sepsis induces early activation of coagulation and fibrinolysis followed by late fibrinolytic shutdown and progressive endothelial damage. The aim of the present study was to investigate and compare the functional hemostatic response in whole blood and plasma during experimental human endotoxemia by the platelet function analyzer, Multiplate and by standard and modified thrombelastography (TEG.Prospective physiologic study of nine healthy male volunteers undergoing endotoxemia by means of a 4-hour infusion of E. coli lipopolysaccharide (LPS, 0.5 ng/kg/hour, with blood sampled at baseline and at 4 h and 6 h. Physiological and standard biochemical data and coagulation tests, TEG (whole blood: TEG, heparinase-TEG, Functional Fibrinogen; plasma: TEG±tissue-type plasminogen activator (tPA and Multiplate (TRAPtest, ADPtest, ASPItest, COLtest were recorded. Mixed models with Tukey post hoc tests and correlations were applied.Endotoxemia induced acute SIRS with increased HR, temperature, WBC, CRP and procalcitonin and decreased blood pressure. It also induced a hemostatic response with platelet consumption and reduced APTT while INR increased (all p<0.05. Platelet aggregation decreased (all tests, p<0.05, whereas TEG whole blood clot firmness increased (G, p = 0.05. Furthermore, during endotoxemia (4 h, whole blood fibrinolysis increased (clot lysis time (CLT, p<0.001 and Functional Fibrinogen clot strength decreased (p = 0.049. After endotoxemia (6 h, whole blood fibrinolysis was reduced (CLT, p<0.05. In contrast to findings in whole blood, the plasma fibrin clot became progressively more resistant towards tPA-induced fibrinolysis at both 4 h and 6 h (p<0.001.Endotoxemia induced a hemostatic response with reduced primary but enhanced secondary hemostasis, enhanced early fibrinolysis and fibrinogen consumption followed by downregulation of fibrinolysis, with a discrepant fibrinolytic response in plasma and whole blood. The finding that blood cells are

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

    Science.gov (United States)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-05-21

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

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

    International Nuclear Information System (INIS)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-01-01

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

  5. Blood transfusions

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000431.htm Blood transfusions To use the sharing features on this page, ... There are many reasons you may need a blood transfusion: After knee or hip replacement surgery, or other ...

  6. Blood Donation

    Science.gov (United States)

    ... A, B, AB or O — and your Rh factor. The Rh factor refers to the presence or absence of a ... information is important because your blood type and Rh factor must be compatible with the blood type and ...

  7. What's Blood?

    Science.gov (United States)

    ... toes. Let's find out more about each ingredient. Red Blood Cells Red blood cells (also called erythrocytes, ... after you are better, B cells can become memory cells that remember how to make the special ...

  8. Donating Blood

    Science.gov (United States)

    ... KidsHealth / For Teens / Donating Blood What's in this article? Who Can Donate Blood? Before Donating Are There Any Risks? Print en español Donar sangre According to the American Red Cross, there's a ...

  9. Vomiting Blood

    Science.gov (United States)

    ... if vomiting blood causes dizziness after standing, rapid, shallow breathing or other signs of shock. Call 911 ... severe blood loss or shock, such as: Rapid, shallow breathing Dizziness or lightheadedness after standing up Blurred ...

  10. A sensitive substrate for the clotting enzyme in horseshoe crab hemocytes.

    Science.gov (United States)

    Nakamura, S; Morita, T; Iwanaga, S; Niwa, M; Takahashi, K

    1977-05-01

    An endotoxin-activated hemocyte lysate from horseshoe crab (Tachypleus and Limulus) was found to hydrolyze specifically BZ-Ile-Glu-Gly-Arg-p-nitroanilide, which was recently introduced as the substrate for assay of the blood coagulation factor, Factor Xa. Further, this amidase activity increased by increasing the concentration of bacterial endotoxin (Salmonella minnesota R595) added to the lysate. Thus, the measurement of the amidase activity in the hemocyte lysate can be very useful to detect and determine the endotoxin.

  11. In Vitro Evaluation of a Rheolytic Thrombectomy System for Clot Removal from Five Different Temporary Vena Cava Filters

    International Nuclear Information System (INIS)

    Buecker, Arno; Neuerburg, Joerg; Schmitz-Rode, Thomas; Vorwerk, Dierk; Guenther, Rolf W.

    1997-01-01

    Purpose: To evaluate the feasibility of thrombus removal from temporary vena cava filters using a rheolytic thrombectomy device and to assess the embolization rate of this procedure. Methods: Five temporary vena cava filters together with porcine thrombi were placed in a vena cava flow model (semitranslucent silicone tube of 23 mm diameter, pulsatile flow at a mean flow rate of 4 L/min). A rheolytic thrombectomy system (Hydrolyser) was used with a 9 Fr guiding catheter to remove the clots. The effluent was passed through filters of different size and the amount of embolized particles as well as the remaining thrombus were measured. Results: Thrombus removal rates ranged from 85% to 100%. Embolization rates between 47% and 60% were calculated for the different filters. Conclusion: The Hydrolyser is able to remove sufficiently high amounts of thrombus from temporary vena cava filters. However, the amount of embolized particles makes it impossible to utilize this method without special precautions against embolization

  12. Thrombin generation assay as a possible tool for assessment of reduced activity of clotting factors induced by antiphospholipid antibodies and in-vitro evaluation of treatment options.

    Science.gov (United States)

    Livnat, Tami; Zivelin, Ariella; Tamarin, Ilia; Guetta, Victor; Salomon, Ophira

    2009-12-01

    Bleeding is a rare manifestation of antiphospholipid syndrome, unless associated with reduced clotting factors or severe thrombocytopenia. Accurate assessment of the autoantibodies in plasma is very important since the autoantibodies can lead to bleeding or thrombosis. The objective of the present study was to define the inhibitors causing reduced clotting activity in a patient with antiphospholipids antibodies and to assess the potential of thrombin generation assay to assist in establishment of optimal treatment in case of major bleeding. Levels of clotting factors as well as inhibitors to factors II, V, VII, VIII, IX, X and XI were defined. For detection of inhibitors to prothrombin crossed immunoelectrophoresis was used. IgG was purified by commercial protein A column. Thrombin generation was measured using a fluorometric assay in platelet-poor and platelet-rich plasma. Inhibitors toward the activity of factors V, VII, VIII, IX, X and XI were defined and also an inhibitor to prothrombin antigen. No thrombin generation was induced in the patient's plasma by recalcification even in the presence of recombinant factor VIIa or factor VIII inhibitor bypassing activity. In contrast, addition of platelets from either donor or patient or synthetic phospholipids normalized the thrombin generation. The thrombin generation model showed that the addition of platelets and no recombinant factor VIIa or factor VIII inhibitor bypassing activity would correct thrombin generation in vitro. On this basis, platelet concentrates were administered to a patient with bleeding caused by lupus anticoagulant and low clotting factors activity.

  13. 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

  14. Design and rationale of the Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy (MR RESCUE) Trial.

    Science.gov (United States)

    Kidwell, Chelsea S; Jahan, Reza; Alger, Jeffry R; Schaewe, Timothy J; Guzy, Judy; Starkman, Sidney; Elashoff, Robert; Gornbein, Jeffrey; Nenov, Val; Saver, Jeffrey L

    2014-01-01

    Multimodal imaging has the potential to identify acute ischaemic stroke patients most likely to benefit from late recanalization therapies. The general aim of the Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy Trial is to investigate whether multimodal imaging can identify patients who will benefit substantially from mechanical embolectomy for the treatment of acute ischaemic stroke up to eight-hours from symptom onset. Mechanical Retrieval and Recanalization of Stroke Clots Using Embolectomy is a randomized, controlled, blinded-outcome clinical trial. Acute ischaemic stroke patients with large vessel intracranial internal carotid artery or middle cerebral artery M1 or M2 occlusion enrolled within eight-hours of symptom onset are eligible. The study sample size is 120 patients. Patients are randomized to endovascular embolectomy employing the Merci Retriever (Concentric Medical, Mountain View, CA) or the Penumbra System (Penumbra, Alameda, CA) vs. standard medical care, with randomization stratified by penumbral pattern. The primary aim of the trial is to test the hypothesis that the presence of substantial ischaemic penumbral tissue visualized on multimodal imaging (magnetic resonance imaging or computed tomography) predicts patients most likely to respond to mechanical embolectomy for treatment of acute ischaemic stroke due to a large vessel, intracranial occlusion up to eight-hours from symptom onset. This hypothesis will be tested by analysing whether pretreatment imaging pattern has a significant interaction with treatment as a determinant of functional outcome based on the distribution of scores on the modified Rankin Scale measure of global disability assessed 90 days post-stroke. Nested hypotheses test for (1) treatment efficacy in patients with a penumbral pattern pretreatment, and (2) absence of treatment benefit (equivalency) in patients without a penumbral pattern pretreatment. An additional aim will only be tested if the

  15. Geometrical Aspects During Formation of Compact Aggregates of Red Blood Cells

    Directory of Open Access Journals (Sweden)

    Cardoso A.V.

    2002-01-01

    Full Text Available In the past forty years considerable progress has been achieved on the knowledge of human blood as a non-Newtonian shear-thinning suspension, whose initial state, that is at rest (stasis or at very low shear rates, has a gel-like internal structure which is destroyed as shear stress increases. The main goal of this communication is to describe the role of geometrical aspects during RBC (red blood cell aggregate formation, growth and compaction on naturally aggregate (porcine blood and non-aggregate (bovine blood samples. We consider how these aspects coupled with tension equilibrium are decisive to transform red cell linear roleaux to three-dimensional aggregates or clusters. Geometrical aspects are also crucial on the compaction of red blood cell aggregates. These densely packed aggregates could precipitate out of blood- either as dangerous deposits on arterial walls, or as clots which travel in suspension until they block some crucial capillary.

  16. Intraoperative Changes in Blood Coagulation and Thrombelastographic Monitoring in Liver Transplantation

    Science.gov (United States)

    Kang, Yoo Goo; Martin, Douglas J.; Marquez, Jose; Lewis, Jessica H.; Bontempo, Franklin A.; Shaw, Byers W.; Starzl, Thomas E.; Winter, Peter M.

    2010-01-01

    The blood coagulation system of 66 consecutive patients undergoing consecutive liver transplantations was monitored by thrombelastograph and analytic coagulation profile. A poor preoperative coagulation state, decrease in levels of coagulation factors, progressive fibrinolysis, and whole blood clot lysis were observed during the preanhepatic and anhepatic stages of surgery. A further general decrease in coagulation factors and platelets, activation of fibrinolysis, and abrupt decrease in levels of factors V and VIII occurred before and with reperfusion of the homograft. Recovery of blood coagulability began 30–60 min after reperfusion of the graft liver, and coagulability had returned toward baseline values 2 hr after reperfusion. A positive correlation was shown between the variables of thrombelastography and those of the coagulation profile. Thrombelastography was shown to be a reliable and rapid monitoring system. Its use was associated with a 33% reduction of blood and fluid infusion volume, whereas blood coagulability was maintained without an increase in the number of blood product donors. PMID:3896028

  17. Cord Blood

    Directory of Open Access Journals (Sweden)

    Saeed Abroun

    2014-05-01

    Full Text Available   Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord blood is a sample of blood taken from a newborn baby's umbilical cord. It is a rich source of stem cells, umbilical cord blood and tissue are collected from material that normally has no use following a child’s birth. Umbilical cord blood and tissue cells are rich sources of stem cells, which have been used in the treatment of over 80 diseases including leukemia, lymphoma and anemia as bone marrow stem cell potency.  The most common disease category has been leukemia. The next largest group is inherited diseases. Patients with lymphoma, myelodysplasia and severe aplastic anemia have also been successfully transplanted with cord blood. Cord blood is obtained by syringing out the placenta through the umbilical cord at the time of childbirth, after the cord has been detached from the newborn. Collecting stem cells from umbilical blood and tissue is ethical, pain-free, safe and simple. When they are needed to treat your child later in life, there will be no rejection or incompatibility issues, as the procedure will be using their own cells. In contrast, stem cells from donors do have these potential problems. By consider about cord blood potency, cord blood banks (familial or public were established. In IRAN, four cord blood banks has activity, Shariati BMT center cord blood bank, Royan familial cord blood banks, Royan public cord blood banks and Iranian Blood Transfusion Organ cord blood banks. Despite 50,000 sample which storage in these banks, but the

  18. Evaluation of the Efficacy and Safety of Rivaroxaban Using a Computer Model for Blood Coagulation

    Science.gov (United States)

    Burghaus, Rolf; Coboeken, Katrin; Gaub, Thomas; Kuepfer, Lars; Sensse, Anke; Siegmund, Hans-Ulrich; Weiss, Wolfgang; Mueck, Wolfgang; Lippert, Joerg

    2011-01-01

    Rivaroxaban is an oral, direct Factor Xa inhibitor approved in the European Union and several other countries for the prevention of venous thromboembolism in adult patients undergoing elective hip or knee replacement surgery and is in advanced clinical development for the treatment of thromboembolic disorders. Its mechanism of action is antithrombin independent and differs from that of other anticoagulants, such as warfarin (a vitamin K antagonist), enoxaparin (an indirect thrombin/Factor Xa inhibitor) and dabigatran (a direct thrombin inhibitor). A blood coagulation computer model has been developed, based on several published models and preclinical and clinical data. Unlike previous models, the current model takes into account both the intrinsic and extrinsic pathways of the coagulation cascade, and possesses some unique features, including a blood flow component and a portfolio of drug action mechanisms. This study aimed to use the model to compare the mechanism of action of rivaroxaban with that of warfarin, and to evaluate the efficacy and safety of different rivaroxaban doses with other anticoagulants included in the model. Rather than reproducing known standard clinical measurements, such as the prothrombin time and activated partial thromboplastin time clotting tests, the anticoagulant benchmarking was based on a simulation of physiologically plausible clotting scenarios. Compared with warfarin, rivaroxaban showed a favourable sensitivity for tissue factor concentration inducing clotting, and a steep concentration–effect relationship, rapidly flattening towards higher inhibitor concentrations, both suggesting a broad therapeutic window. The predicted dosing window is highly accordant with the final dose recommendation based upon extensive clinical studies. PMID:21526168

  19. Viscoelastic blood coagulation measurement with Sonoclot predicts postoperative bleeding in cardiac surgery after heparin reversal.

    Science.gov (United States)

    Bischof, Dominique B; Ganter, Michael T; Shore-Lesserson, Linda; Hartnack, Sonja; Klaghofer, Richard; Graves, Kirk; Genoni, Michele; Hofer, Christoph K

    2015-01-01

    The aim of the study was to determine if Sonoclot with its sensitive glass bead-activated, viscoelastic test can predict postoperative bleeding in patients undergoing cardiac surgery at predefined time points. A prospective, observational clinical study. A teaching hospital, single center. Consecutive patients undergoing cardiac surgery (N = 300). Besides routine laboratory coagulation studies and heparin management with standard (kaolin) activated clotting time, additional native blood samples were analyzed on a Sonoclot using glass bead-activated tests. Glass bead-activated clotting time, clot rate, and platelet function were recorded immediately before anesthesia induction and at the end of surgery after heparin reversal but before chest closure. Primary outcome was postoperative blood loss (chest tube drainage at 4, 8, and 12 hours postoperatively). Secondary outcome parameters were transfusion requirements, need for surgical re-exploration, time of mechanical ventilation, length of intensive care unit and hospital stay, and hospital morbidity and mortality. Patients were categorized into "bleeders" and "nonbleeders." Patient characteristics, operations, preoperative standard laboratory parameters, and procedural times were comparable between bleeders and nonbleeders except for sex and age. Bleeders had higher rates of transfusions, surgical re-explorations, and complications. Only glass bead measurements by Sonoclot after heparin reversal before chest closure but not preoperatively were predictive for increased postoperative bleeding. Sonoclot with its glass bead-activated tests may predict the risk for postoperative bleeding in patients undergoing cardiac surgery at the end of surgery after heparin reversal but before chest closure. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. The influence of platelets, plasma and red blood cells on functional haemostatic assays

    DEFF Research Database (Denmark)

    Bochsen, Louise; Johansson, Pär I.; Kristensen, Annemarie Thuri

    2011-01-01

    and combined, influenced the two methodologically different assays, thrombelastography (TEG) and impedance aggregometry (Multiplate). Platelet-rich plasma (200 × 10/l) or pure plasma (0 platelets), with and without added red blood cells (RBCs), hematocrit 0, 0.15 or 0.29, were produced in vitro from platelet...... concentrates, fresh frozen plasma and stored RBC. Pure platelets were investigated by removing plasma components from platelet concentrates by diafiltration against the platelet storage solution Intersol. Plasma was readded by diafiltration against plasma in Intersol. Haemostatic function was evaluated by TEG...... and Multiplate. In the TEG, increasing amounts of RBC reduced clot strength and clot kinetics (α-angle), most markedly in plasma/RBC without platelets. In contrast, RBC in a platelet concentrate matrix enhanced Multiplate aggregation in response to weak agonists (ADP and arachidonic acid). Furthermore, removing...

  1. Dual-body magnetic helical robot for drilling and cargo delivery in human blood vessels

    Science.gov (United States)

    Lee, Wonseo; Jeon, Seungmun; Nam, Jaekwang; Jang, Gunhee

    2015-05-01

    We propose a novel dual-body magnetic helical robot (DMHR) manipulated by a magnetic navigation system. The proposed DMHR can generate helical motions to navigate in human blood vessels and to drill blood clots by an external rotating magnetic field. It can also generate release motions which are relative rotational motions between dual-bodies to release the carrying cargos to a target region by controlling the magnitude of an external magnetic field. Constraint equations were derived to selectively manipulate helical and release motions by controlling external magnetic fields. The DMHR was prototyped and various experiments were conducted to demonstrate its motions and verify its manipulation methods.

  2. Effect of hyperbilirubunemia on coagulation system of blood in patients with obstructive jaundice

    Directory of Open Access Journals (Sweden)

    Sarkisian Z.O.

    2012-06-01

    Full Text Available Objective of the study: determination of the degree of influence of bilirubin in the blood during obstructive jaundice, on blood clotting. Methods. A retrospective study of case histories of patients with obstructive jaundice who have been treated at the Regional Hospital of Saratov in the period from 2000 to 2010. Results. The results confirm the assumption that the causes of bleeding in obstructive jaundice is hepatic failure. Conclusion. Absence of bile in the small intestine in obstructive jaundice is not the cause of bleeding. Bile acids are not involved in metabolizing fat-soluble vitamin K1

  3. Medical image of the week: pneumatosis intestinalis secondary to massive acute blood loss

    Directory of Open Access Journals (Sweden)

    Assar S

    2013-10-01

    Full Text Available The patient was a 32 year-old male with a past medical history significant for end stage liver disease secondary to severe alcoholism who was found with an altered mental status. In the emergency department, the patient divulged he had been throwing up blood clots in the preceding days. Shortly into his presentation he began throwing up voluminous bright red blood. Initial hemoglobin concentration was 2.8 mg/dL. CT scan of the abdomen revealed pneumatosis within the ascending colon, small bowel, and mesenteric veins. Despite massive transfusion efforts and two episodes of successful cardiac resuscitation the patient expired.

  4. Canadian inquiry assesses blame for tainted blood supply.

    Science.gov (United States)

    1997-12-26

    A commission of inquiry, headed by Justice Horace Krever of the Ontario Court of Appeal, found that hundreds of hemophiliacs and blood transfusion recipients could have avoided HIV if the government regulators and medical suppliers had taken precautions in the early 1980s to protect Canada's blood supply. The report documents an inventory of errors and misjudgments that resulted in the infection of more than 1,200 people with HIV and roughly 60,000 with hepatitis C. The report noted that one U.S. blood fractionator, Armour Pharmaceutical, violated Canadian law by not informing government regulators in 1985 that its products might be tainted with HIV. Other findings conclude that the Red Cross, the agency with principal responsibility for protecting Canada's blood supply, put forth a halfhearted and ineffective response, and little effort was made to promote the use of safer blood clotting agents for hemophiliacs. Canada only began testing its blood supply for HIV eight months after the U.S. initiated ELISA testing. The commission recommends compensating all past and future recipients of contaminated blood and blood products.

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

    Science.gov (United States)

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

    2013-08-01

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

  6. Immunoelectrophoresis - blood

    Science.gov (United States)

    IEP - serum; Immunoglobulin electrophoresis - blood; Gamma globulin electrophoresis; Serum immunoglobulin electrophoresis; Amyloidosis - electrophoresis serum; Multiple myeloma - serum electrophoresis; Waldenström - serum electrophoresis

  7. Blood collection from the American horseshoe crab, Limulus polyphemus.

    Science.gov (United States)

    Armstrong, Peter; Conrad, Mara

    2008-10-13

    The horseshoe crab has the best-characterized immune system of any long-lived invertebrate. The study of immunity in horseshoe crabs has been facilitated by the ease in collecting large volumes of blood and from the simplicity of the blood. Horseshoe crabs show only a single cell type in the general circulation, the granular amebocyte. The plasma has the salt content of sea water and only three abundant proteins, hemocyanin, the respiratory protein, the C-reactive proteins, which function in the cytolytic destruction of foreign cells, including bacterial cells, and alpha2-macroglobulin, which inhibits the proteases of invading pathogens. Blood is collected by direct cardiac puncture under conditions that minimize contamination by lipopolysaccharide (a.k.a., endotoxin, LPS), a product of the Gram-negative bacteria. A large animal can yield 200 - 400 mL of blood. For the study of the plasma, blood cells are immediately removed from the plasma by centrifugation and the plasma can then be fractionated into its constituent proteins. The blood cells are conveniently studied microscopically by collecting small volumes of blood into LPS-free isotonic saline (0.5 M NaCl) under conditions that permit direct microscopic examination by placing one of more LPS-free coverglasses on the culture dish surface, then mounting those coverglasses in simple observation chambers following cell attachment. A second preparation for direct observation is to collect 3 - 5 mL of blood in a LPS-free embryo dish and then explanting fragments of aggregated amebocytes to a chamber that sandwiches the tissue between a slide and a coverglass. In this preparation, the motile amebocytes migrate onto the coverglass surface, where they can readily be observed. The blood clotting system involves aggregation of amebocytes and the formation of an extracellular clot of a protein, coagulin, which is released from the secretory granules of the blood cells. Biochemical analysis of washed blood cells requires

  8. Blood coagulation screening using a paper-based microfluidic lateral flow device.

    Science.gov (United States)

    Li, H; Han, D; Pauletti, G M; Steckl, A J

    2014-10-21

    A simple approach to the evaluation of blood coagulation using a microfluidic paper-based lateral flow assay (LFA) device for point-of-care (POC) and self-monitoring screening is reported. The device utilizes whole blood, without the need for prior separation of plasma from red blood cells (RBC). Experiments were performed using animal (rabbit) blood treated with trisodium citrate to prevent coagulation. CaCl2 solutions of varying concentrations are added to citrated blood, producing Ca(2+) ions to re-establish the coagulation cascade and mimic different blood coagulation abilities in vitro. Blood samples are dispensed into a paper-based LFA device consisting of sample pad, analytical membrane and wicking pad. The porous nature of the cellulose membrane separates the aqueous plasma component from the large blood cells. Since the viscosity of blood changes with its coagulation ability, the distance RBCs travel in the membrane in a given time can be related to the blood clotting time. The distance of the RBC front is found to decrease linearly with increasing CaCl2 concentration, with a travel rate decreasing from 3.25 mm min(-1) for no added CaCl2 to 2.2 mm min(-1) for 500 mM solution. Compared to conventional plasma clotting analyzers, the LFA device is much simpler and it provides a significantly larger linear range of measurement. Using the red colour of RBCs as a visible marker, this approach can be utilized to produce a simple and clear indicator of whether the blood condition is within the appropriate range for the patient's condition.

  9. BLOOD DONATION

    CERN Document Server

    SC Unit

    2008-01-01

    A blood donation, organized by EFS (Etablissement Français du Sang) of Annemasse will take place On Wednesday 12 November 2008, from 8:30 to 16:00, at CERN Restaurant 2 If possible, please, bring your blood group Card.

  10. Blood irradiation

    International Nuclear Information System (INIS)

    Chandy, Mammen

    1998-01-01

    Viable lymphocytes are present in blood and cellular blood components used for transfusion. If the patient who receives a blood transfusion is immunocompetent these lymphocytes are destroyed immediately. However if the patient is immunodefficient or immunosuppressed the transfused lymphocytes survive, recognize the recipient as foreign and react producing a devastating and most often fatal syndrome of transfusion graft versus host disease [T-GVHD]. Even immunocompetent individuals can develop T-GVHD if the donor is a first degree relative since like the Trojan horse the transfused lymphocytes escape detection by the recipient's immune system, multiply and attack recipient tissues. T-GVHD can be prevented by irradiating the blood and different centers use doses ranging from 1.5 to 4.5 Gy. All transfusions where the donor is a first degree relative and transfusions to neonates, immunosuppressed patients and bone marrow transplant recipients need to be irradiated. Commercial irradiators specifically designed for irradiation of blood and cellular blood components are available: however they are expensive. India needs to have blood irradiation facilities available in all large tertiary institutions where immunosuppressed patients are treated. The Atomic Energy Commission of India needs to develop a blood irradiator which meets international standards for use in tertiary medical institutions in the country. (author)

  11. Blood Transfusion

    Science.gov (United States)

    ... amount of blood given. Although rare, a hemolytic transfusion reaction can occur when transfused red cells are damaged ... center staff needs to be aware of this reaction and take precautions if you undergo subsequent transfusions. Viral infection transmission . Since blood is a biological ...

  12. Blood Sugar

    Science.gov (United States)

    ... of your body's cells to use for energy. Diabetes is a disease in which your blood sugar levels are too high. Over time, having too ... serious problems. Even if you don't have diabetes, sometimes you may have problems with blood sugar that is too low or too high. Keeping ...

  13. Blood donation

    CERN Multimedia

    GS Department

    2009-01-01

    A blood donation is organised by the Cantonal Hospital of Geneva On Thursday 19 March 2009 from 9 a.m. to 5 p.m. CERN RESTAURANT 2 Number of donations during the last blood donations :135 donors in July 2008 122 donors in November 2008 Let’s do better in 2009 !!! Give 30 minutes of your time to save lives...

  14. Tainted blood

    DEFF Research Database (Denmark)

    Deleuran, Ida; Sheikh, Zainab Afshan; Hoeyer, Klaus

    2015-01-01

    study of the historical rise and current workings of safety practices in the Danish blood system. Here, we identify a strong focus on contamination in order to avoid 'tainted blood', at the expense of working with risks that could be avoided through enhanced blood monitoring practices. Of further...... significance to this focus are the social dynamics found at the heart of safety practices aimed at avoiding contamination. We argue that such dynamics need more attention, in order to achieve good health outcomes in transfusion medicine. Thus, we conclude that, to ensure continuously safe blood systems, we...... need to move beyond the bifurcation of the social and medical aspects of blood supply as two separate issues and approach social dynamics as key medical safety questions....

  15. Pediatric blood sample collection from a pre-existing peripheral intravenous (PIV) catheter.

    Science.gov (United States)

    Braniff, Heather; DeCarlo, Ann; Haskamp, Amy Corey; Broome, Marion E

    2014-01-01

    Aiming to minimize pain in a hospitalized child, the purpose of this observational study was to describe characteristics of blood samples collected from pre-existing peripheral intravenous (PIV) catheters in pediatric patients. One hundred and fifty blood samples were reviewed for number of unusable samples requiring a specimen to be re-drawn. Success of the blood draw and prevalence of the loss of the PIV following blood collection was also measured. Findings included one clotted specimen, success rate of 91.3%, and 1.3% of PIVs becoming non-functional after collection. Obtaining blood specimens from a pre-existing PIV should be considered in a pediatric patient. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Transcriptional changes in blood after aerobic interval training in patients with the metabolic syndrome.

    Science.gov (United States)

    Bye, Anja; Tjønna, Arnt E; Stølen, Tomas O; Røsbjørgen, Ragnhild E N; Wisløff, Ulrik

    2009-02-01

    Regular physical activity has beneficial effects on the metabolic syndrome. Eleven metabolic syndrome patients performing 16 weeks of aerobic interval training, significantly reduced their risk of cardiovascular disease, in terms of improved VO2max, endothelial function, blood pressure, insulin signaling, and plasma lipid composition. The knowledge on underlying mechanism of exercise-induced improvements is sparse, and a broad spectrum of methods is needed to gain more insight. The aim was, for the first time, to determine whether transcriptional changes occur in blood cells of metabolic syndrome patients after participating in an exercise program. Blood was collected in PAXgene and EDTA tubes before and after 16 weeks of exercise. RNA was extracted and run on microarrays. Eleven biological processes and molecular functions were upregulated after exercise, whereas seven were downregulated. Blood clotting, cell adhesion, and steroid metabolism were among the downregulated processes, whereas steroid hormone-mediated signaling was upregulated. Downregulated protein levels of arginase 1 and von Willebrand factor confirmed microarray results. Increased transcription of genes involved in steroid hormone-mediated signaling, decreased levels of arginase 1, and reduced transcription of genes involved in cell adhesion, and blood clotting are likely to be involved in exercise-induced improvements of endothelial function, and improved cardiovascular risk profile of metabolic syndrome patients. These findings have provided new insights on exercise-induced improvement of cardiovascular health.

  17. Chapter 3. Biological properties of ethynyl-piperidol polymers. 3.1. Activating effect of quaternized linear and graft-polymers of ethynyl-piperidol on blood coagulation system

    International Nuclear Information System (INIS)

    Khalikov, D.Kh.

    2012-01-01

    This article is devoted to activating effect of quaternized linear and graft-polymers of ethynyl-piperidol on blood coagulation system. The indexes of blood clotting at intraperitoneal injection of polymers were considered. The anti heparin activity of methiodide of poly-isopropenyl trimethyl ethynyl piperidol was considered as well. The influence of molecular weight on styptic activity and toxicity of methiodide of poly-isopropenyl trimethyl ethynyl piperidol was studied. The styptic activity of grafted polymers of ethynyl piperidol was defined.

  18. Blood flow in stented coronary artery: numerical fluid dynamics analysis.

    Science.gov (United States)

    Bénard, N; Perrault, R; Coisne, D

    2004-01-01

    Recent generalization of stent implantation in interventional cardiology require full understanding of blood flow cartography. Interdepency between fluid stresses and in vivo cells covering lumen artery are regularly accused to be one of the instigator of neointimal proliferation (thickening of the inner layer of blood vessels) and mid-term restenosis. This study purpose to numericaly investigate the three dimensional flow in vicinity of an endoprothesis. We used a finite element method to simulate a steady flow of non-Newtonian fluid in a coronary artery using a rigid wall approximation. Results on the velocities, wall shear stress and wall shear stress gradients are presented. Theses simulations allow identification of stagnation site and low wall shear stress area that may be prone to clot formation and neointimal hyperplasia. Intra stent flow knowledge can potentially contribute to optimization of prothesis design and decreasing second intervention rate.

  19. 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

  20. Genome scan of clot lysis time and its association with thrombosis in a protein C deficient kindred

    Science.gov (United States)

    Meltzer, M.E.; Hasstedt, S.J.; Vossen, C.Y.; Callas, P.W.; de Groot, Ph.G.; Rosendaal, F.R.; Lisman, T.; Bovill, E.G.

    2011-01-01

    Summary Background Previously we found increased clot lysis time (CLT), as measured with a plasma-based assay, to increase the risk of venous thrombosis in two population-based case-control studies. Genes influencing CLT are yet unknown. Objectives and Patients/Methods We tested CLT as risk factor for venous thrombosis in Kindred Vermont II (n=346), a pedigree suffering from a high thrombosis risk, partially attributable to a type I protein C deficiency. Furthermore we tested for quantitative trait loci (QTL) for CLT using variance component linkage analysis. Results Protein C deficient family members had shorter CLT than non-deficient members (median CLT 67 versus 75 minutes). One standard deviation increase in CLT increased risk of venous thrombosis 2.4-fold in non-deficient family members. Protein C deficiency without elevated CLT increased risk 6.9-fold. Combining both risk factors yielded a 27.8-fold increased risk. Heritability of CLT was 42-52%. We found suggestive evidence of linkage on chromosome 11 (62 cM), partly explained by the prothrombin 20210A mutation, and on chromosome 13 (52 cM). Thrombin Activatable Fibrinolysis Inhibitor genotypes did not explain the variation in CLT. Conclusion Hypofibrinolysis appears to increase thrombosis risk in this family especially in combination with protein C deficiency. Protein C deficiency is associated with short CLT. CLT is partly genetically regulated. Suggestive QTL were found on chromosome 11 and 13. PMID:21575129

  1. Purification and Physico-Chemical Properties of Milk Clotting Enzyme Produced by Mucor Lamprosporus Comparable with Calf Rennet

    International Nuclear Information System (INIS)

    Moussa, L.A.; El-Fouly, M.Z.; El-Kabbany, H.; Kamel, Z.M.; Moubasher, M.H.

    1999-01-01

    Fractional precipitation of the crude enzyme produced by Mucor Lamprosporus fungus using 70% ammonium sulfate gave the highest MCA at 40 degree. Further purification of the partially purified enzyme was achieved by using Sephadex G-100 and rechromatographed on DEAE Sephadex A-50 and gave 22.5 fold then the crude enzyme with 301% enzyme recovery. Addition of NaCl to the skim milk caused pronounced decline in MCA of the enzyme while addition of 160 ppm of NaCl increased the MCA from 26.6 su/ml to 200 su/ml. The optimum temperature of the skin milk which induced the maximum activity of the purified enzyme in skim milk was found to be 40 degree while preheating the enzyme at 50 degree for 10 min caused a complete inhibition. Mild acidic condition did not affect the activity of the purified enzyme which remained almost stable till pH 6.0 while at pH 7.0 or more, the enzyme completely lost its clotting activity. The present data also showed that Mucor Lamprosporus rennin like enzyme exhibited higher activity than calf rennet

  2. Thrombin activatable fibrinolysis inhibitor and clot lysis time in pregnant patients with antiphospholipid syndrome: relationship with pregnancy outcome and thrombosis.

    Science.gov (United States)

    Martinez-Zamora, Maria Angeles; Tassies, Dolors; Carmona, Francisco; Espinosa, Gerard; Cervera, Ricard; Reverter, Juan Carlos; Balasch, Juan

    2009-12-01

    Antiphospholipid syndrome (APS) pregnancies are associated with thrombotic obstetric complications, despite treatment. This study evaluated Thrombin Activatable Fibrinolysis Inhibitor (TAFI) levels, TAFI gene polymorphisms and Clot Lysis Time (CLT) in pregnant patients with APS in relation to pregnancy outcome and thrombosis. Group 1 consisted of 67 pregnant patients with APS. Group 2 included 66 pregnant patients with uneventful term pregnancies and delivery. Patients were sampled during each trimester and at baseline. TAFI antigen and CLT and two polymorphisms of the TAFI gene, Ala147Thr and +1542C/G, were determined. Significantly prolonged CLT was found at baseline in Group 1. Allele distribution of the TAFI gene polymorphisms was similar in both groups. Basal TAFI and CLT in patients with APS having an adverse or a good obstetrical outcome were similar. Comparison of TAFI and CLT baseline levels in patients with APS with or without previous thrombosis showed no statistical differences. Patients with APS have impairment in fibrinolysis evidenced by prolonged CLT at baseline. TAFI and CLT do not seem to be useful as markers of obstetric outcome or risk of thrombosis in patients with APS.

  3. Indium-111 platelet scintigraphy and two-dimensional echocardiography for detection of left ventricular thrombus: influence of clot size and age

    International Nuclear Information System (INIS)

    Seabold, J.E.; Schroeder, E.C.; Conrad, G.R.

    1987-01-01

    Two-dimensional echocardiography and indium-111 platelet scintigraphy were performed on 50 dogs to determine the influence of clot age and size on the detection of experimentally induced left ventricular mural thrombus. Thrombus was induced by apical infarction and injection of a sclerosing agent and thrombin. The animals were classified into four groups according to the time of indium-111 platelet injection after thrombus induction: Group I (17 dogs, 1/2 hour after induction; 3 dogs, before induction), Group II (12 dogs, 24 hours after induction) and Group III (12 dogs, 1 week after induction). In Group IV (six control dogs) apical infarction was produced, but thrombin was not injected; indium-111 platelets were injected 1/2 to 1 hour after infarction. The dogs were studied by indium-111 platelet scintigraphy and by two-dimensional echocardiography 1/2 to 5 hours (Group I) and 1 to 5 and up to 72 hours (Groups II to IV) after platelet administration and before death was induced. Two-dimensional echocardiography showed the best overall sensitivity for detection of acute thrombus (97%; 29 of 30). The sensitivity of indium-111 platelet scintigraphy was 86% (18 of 21) for clots greater than or equal to 0.08 ml in size, and 67% (20 of 30) for detection of all clots. Thrombus did not form in 14 dogs of Groups I to III and in 6 of 6 control dogs. The specificity of scintigraphy was 100% (20 of 20) compared with 80% (16 of 20) for echocardiography. Echocardiography was more sensitive than scintigraphy for detecting very small clots in this experimental model

  4. 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

  5. Blood smear

    Science.gov (United States)

    ... protein in red blood cells that carries oxygen (hemoglobinopathies) Iron deficiency Liver disease Spleen removal Presence of ... in which there is excessive breakdown of hemoglobin ( thalassemia ) The presence of cells called burr cells may ...

  6. Moving blood.

    Science.gov (United States)

    Pelis, K

    1997-01-01

    Our internationally acclaimed journalist Sanguinia has returned safely from her historic assignment. Travelling from Homeric Greece to British Romanticism, she was witness to blood drinking, letting, bathing, and transfusion. In this report, she explores connections between the symbolic and the sadistic; the mythic and the medical--all in an effort to appreciate the layered meanings our culture has given to the movement of blood between our bodies.

  7. 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.

  8. 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.

  9. Blood Facts and Statistics

    Science.gov (United States)

    ... Home > Learn About Blood > Blood Facts and Statistics Blood Facts and Statistics Facts about blood needs Facts ... about American Red Cross Blood Services Facts about blood needs Every two seconds someone in the U.S. ...

  10. Biology of Blood

    Science.gov (United States)

    ... switch to the Professional version Home Blood Disorders Biology of Blood Overview of Blood Resources In This ... Version. DOCTORS: Click here for the Professional Version Biology of Blood Overview of Blood Components of Blood ...

  11. Three-dimensional black-blood contrast-enhanced MRI improves detection of intraluminal thrombi in patients with acute ischaemic stroke.

    Science.gov (United States)

    Jang, Won; Kwak, Hyo Sung; Chung, Gyung Ho; Hwang, Seung Bae

    2018-03-19

    This study evaluated the utility of three-dimensional (3D), black-blood (BB), contrast-enhanced, magnetic resonance imaging (MRI) for the detection of intraluminal thrombi in acute stroke patients. Forty-seven patients with acute stroke involving the anterior circulation underwent MRI examination within 6 h of clinical onset. Cerebral angiography was used as the reference standard. In a blinded manner, two neuroradiologists interpreted the following three data sets: (1) diffusion-weighted imaging (DWI) + 3D BB contrast-enhanced MRI; (2) DWI + susceptibility weighted imaging (SWI); (3) DWI + 3D BB contrast-enhanced MRI + SWI. Of these patients, 47 had clots in the middle cerebral artery and four had clots in the anterior cerebral artery. For both observers, the area under the curve (Az) for data sets 1 and 3, which included 3D BB contrast-enhanced MRI, was significantly greater than it was for data set 2, which did not include 3D BB contrast-enhanced MR imaging (observer 1, 0.988 vs 0.904, p = 0.001; observer 2, 0.988 vs 0.894, p = 0.000). Three-dimensional BB contrast-enhanced MRI improves detection of intraluminal thrombi compared to conventional MRI methods in patients with acute ischaemic stroke. • BB contrast-enhanced MRI helps clinicians to assess the intraluminal clot • BB contrast-enhanced MRI improves detection of intraluminal thrombi • BB contrast-enhanced MRI for clot detection has a higher sensitivity.

  12. 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.

  13. Plasma fractionation for blood products: isolation and purification of coagulating factors, albumin and immunoglobulin

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib; Shaharuddin Mohd; Wan Hamirul Bahrin Wan Kamal

    2005-01-01

    Approximately 12 million liters of human plasma are fractionated world-wide annually. However, with the market for clotting factors and other haemoderivatives steadily increasing from year to year, the amount processed will also increase correspondingly to keep up with the demand. In Malaysia, part of the need for the blood products are obtained commercially but a major portion of the requirement involves sending the plasma collected by the National Blood Centre to Australia for processing. Following purification and isolation of the blood products, they are sent back to Malaysia for local consumption. As yet there are no plasma fractionation plants in the South East Asia region, it would be advantageous to establish a local fractionation plant as it would be able to cater for local demands of the haemoderivatives and thus reduces the cost of importing these products. Besides, this facility will be able to provide contract fractionation services to the surrounding region. Early work in MINT has started in trying to purify plasma obtained from rats. Purification of the plasma was performed by using Sephadex G-25 column. Short term objective of this project is to develop the technique of extraction, fractionation and purification of blood products such as albumin, globulin and clotting factors (Factor VIII and Factor IX). The long term emphasis will be to scale up the production facility to a pilot plant stage and eventually to a national fractionation and purification plant. (Author)

  14. Purification and characterization of Cc-Lec, C-type lactose-binding lectin: A platelet aggregation and blood-clotting inhibitor from Cerastes cerastes venom.

    Science.gov (United States)

    Samah, Saoud; Fatah, Chérifi; Jean-Marc, Berjeaud; Safia, Kellou-Taîri; Fatima, Laraba-Djebari

    2017-09-01

    In this study, we reported for the first time the biochemical and structural characterization of Cc-Lec, a C-type lectin purified from Cerastes cerastes venom by affinity chromatography. This lectin was homogeneous by SDS-PAGE, and was shown to be a 34 271.59Da polypeptide by Electrospray mass spectrometry MS-ES-TOF. Its identified sequence of 160 amino acids corresponding to one subunit, revealed a high identity with other related proteins. Cc-Lec modeled 3D structure appeared as homodimer cross-linked by one disulfide bridge. Cc-Lec exhibited a calcium dependent hemagglutinating activity against human group O erythrocytes. Cc-Lec inhibited platelet aggregation induced by ADP, arachidonic acid or fibrinogen suggesting its interaction with their specific receptors namely P2Y1 and/or P2Y12, GPIIb/IIIa and TPα respectively. Cc-Lec was not lethal for mice until 10mg/kg administered by i.p. route. The lectin displayed a lasting anticoagulation on mice plasma even two days post-injection. This anticoagulation seems to be related to its interaction with coagulation factors Xa and IXa. Therefore, Cc-Lec prevented FXa amidolytic activity with Km=4.3310 -4 μg/mL and ki=14.4μg/mL. It seems to interact with these targets through CRD domain which could make it a good target as a pharmacological promising molecule in thrombosis diagnosis and therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Svendsen, M.S.; Salado, J.

    2008-01-01

    , in part, depend on its reflection of the dynamics of thrombin generation. MATERIAL AND METHODS: The kinetics of thrombin generation of platelets stored for 2 and 7 days, respectively, was assessed by calibrated automated thrombogram (CAT) and the lag time (min), time to peak (ttPeak; min), peak (nm...

  16. Comparison of Topical Hemostatic Agents in a Swine Model of Extremity Arterial Hemorrhage: BloodSTOP iX Battle Matrix vs. QuikClot Combat Gauze

    Science.gov (United States)

    2016-04-12

    either group. After removal of the laparotomy gauze and products, re-bleeding occurred in 9.1% (0.23%–41.3%, 1/11) of BM animals and 100% (47.8%–100%, 5...After removal of the laparotomy gauze and products, re-bleeding occurred in 9.1% (0.23%–41.3%, 1/11) of BM animals and 100% (47.8%–100%, 5/5) of CG...before surgery . Animals were pre-medicated with buprenorphine (0.025 mg/kg intramuscularly (IM)) for analgesia and glycopyrrolate (0.01 mg/kg, IM) to

  17. Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Svendsen, M.S.; Salado, J.

    2008-01-01

    BACKGROUND AND OBJECTIVES: Transfusion based on the Thrombelastograph (TEG) results reduces transfusion requirements in cardiac surgery and in liver transplantation. Taking the pivotal role of thrombin generation in the coagulation process into consideration, the clinical utility of the TEG may...

  18. Endothelial Dysfunction and Blood Viscosity Inpatients with Unstable Angina in Different Periods of a Solar Activity

    Science.gov (United States)

    Parshina, S. S.; Tokaeva, L. K.; Dolgova, E. M.; Afanas'yeva, T. N.; Strelnikova, O. A.

    The origin of hemorheologic and endothelial defects in patients with unstable angina (comparing with healthy persons) is determined by a solar activity period: the blood viscosity increases in a period of high solar activity in the vessels of small, medium and macro diameters, a local decompensate dysfunction of small vessels endothelium had been fixed (microcirculation area). In the period of a low solar activity there is an increase of a blood viscosity in vessels of all diameters, generalized subcompensated endothelial dysfunction is developed (on the background of the III phase blood clotting activating). In the period of a high solar activity a higher blood viscosity had been fixed, comparing with the period of a low solar activity.

  19. Do trichothecenes reduce viability of circulating blood cells and modify haemostasis parameters?

    Science.gov (United States)

    Froquet, R; Arnold, F; Batina, P; Parent-Massin, D

    2003-01-01

    This manuscript describes the results of experiments conducted using human blood cells to determine the ability of T-2 toxin and DON to cause changes in clotting time, platelet aggregation, red blood cell haemolysis, RBC glucose content, lactate release, glutathione depletion, as well as white blood cell viability. In vitro results showed that haemostasis parameters and erythrocytes were not affected at concentrations able to induce inhibition of haematopoietic progenitor proliferation. In the presence of 10(-8) M and 10(-6) M T-2, the leucocyte number decreased at 24 h by 30% and 50% respectively. A 50% decrease in leucocyte number was observed for 10(-5) M DON. Results were compared with haematopoietic progenitor sensitivities. Due to the differences in sensitivities between mature blood cells and haematopoietic progenitors, haematological problems associated with trichothecene intoxication could be attributed to haematopoiesis inhibition.

  20. Blood transfusion; additional historical aspects. Part 1. The birth of transfusion immunology.

    Science.gov (United States)

    Boulton, F E

    2013-12-01

    The decades around the turn of the 19th into the 20th centuries covered a seminal period in the history of transfusion medicine as there was an increasing appreciation of a potential role in the management of surgical and obstetric bleeding, and also in severe non-surgical anaemias. The main obstacles to transfusing human blood were first the occasional devastating adverse reactions due, we now know, to ABO blood group incompatibility; and second the awkward propensity of shed blood to clot. This article describes in more detail how the pioneers in human transfusion immunology in the late 19th century and early 20th century learnt to recognise and avoid ABO incompatibility, and includes some hitherto obscure and rarely cited material. A companion article (Boulton, 2013, Submitted for publication) describes early attempts to find suitable anticoagulants. © 2013 The Author. Transfusion Medicine © 2013 British Blood Transfusion Society.

  1. Relative Abundance of Proteins in Blood Plasma Samples from Patients with Chronic Cerebral Ischemia.

    Science.gov (United States)

    Kaysheva, Anna L; Kopylov, Artur T; Ponomarenko, Elena A; Kiseleva, Olga I; Teryaeva, Nadezhda B; Potapov, Alexander A; Izotov, Alexander А; Morozov, Sergei G; Kudryavtseva, Valeria Yu; Archakov, Alexander I

    2018-03-01

    A comparative protein profile analysis of 17 blood plasma samples from patients with ischemia and 20 samples from healthy volunteers was carried out using ultra-high resolution mass spectrometry. The analysis of measurements was performed using the proteomics search engine OMSSA. Normalized spectrum abundance factor (NSAF) in the biological samples was assessed using SearchGUI. The findings of mass spectrometry analysis of the protein composition of blood plasma samples demonstrate that the depleted samples are quite similar in protein composition and relative abundance of proteins. By comparing them with the control samples, we have found a small group of 44 proteins characteristic of the blood plasma samples from patients with chronic cerebral ischemia. These proteins contribute to the processes of homeostasis maintenance, including innate immune response unfolding, the response of a body to stress, and contribution to the blood clotting cascade.

  2. Genome scan of clot lysis time and its association with thrombosis in a protein C-deficient kindred.

    Science.gov (United States)

    Meltzer, M E; Hasstedt, S J; Vossen, C Y; Callas, P W; DE Groot, Ph G; Rosendaal, F R; Lisman, T; Bovill, E G

    2011-07-01

     Previously, we found increased clot-lysis time (CLT), as measured with a plasma-based assay, to increase the risk of venous thrombosis in two population-based case-control studies. The genes influencing CLT are as yet unknown.  We tested CLT as risk factor for venous thrombosis in Kindred Vermont II (n = 346), a pedigree suffering from a high thrombosis risk, partially attributable to a type I protein C deficiency. Furthermore, we tested for quantitative trait loci (QTLs) for CLT, using variance component linkage analysis.  Protein C-deficient family members had shorter CLTs than non-deficient members (median CLT 67 min vs. 75 min). One standard deviation increase in CLT increased the risk of venous thrombosis 2.4-fold in non-deficient family members. Protein C deficiency without elevated CLT increased the risk 6.9-fold. Combining both risk factors yielded a 27.8-fold increased risk. The heritability of CLT was 42-52%. We found suggestive evidence of linkage on chromosome 11 (62 cM), partly explained by the prothrombin 20210A mutation, and on chromosome 13 (52 cM). Thrombin-activatable fibrinolysis inhibitor genotypes did not explain the variation in CLT. Hypofibrinolysis appears to increase thrombosis risk in this family, especially in combination with protein C deficiency. Protein C deficiency is associated with short CLT. CLT is partly genetically regulated. Suggestive QTLs were found on chromosomes 11 and 13. © 2011 International Society on Thrombosis and Haemostasis.

  3. Chondrogenic Regeneration Using Bone Marrow Clots and a Porous Polycaprolactone-Hydroxyapatite Scaffold by Three-Dimensional Printing

    Science.gov (United States)

    Yao, Qingqiang; Wei, Bo; Liu, Nancy; Li, Chenshuang; Guo, Yang; Shamie, Arya Nick; Chen, James; Tang, Cheng; Jin, Chengzhe; Xu, Yan

    2015-01-01

    Scaffolds play an important role in directing three-dimensional (3D) cartilage regeneration. Our recent study reported the potential advantages of bone marrow clots (MC) in promoting extracellular matrix (ECM) scaffold chondrogenic regeneration. The aim of this study is to build a new scaffold for MC, with improved characteristics in mechanics, shaping, and biodegradability, compared to our previous study. To address this issue, this study prepared a 3D porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffold combined with MC (Group A), while the control group (Group B) utilized a bone marrow stem cell seeded PCL-HA scaffold. The results of in vitro cultures and in vivo implantation demonstrated that although an initial obstruction of nutrient exchange caused by large amounts of fibrin and erythrocytes led to a decrease in the ratio of live cells in Group A, these scaffolds also showed significant improvements in cell adhesion, proliferation, and chondrogenic differentiation with porous recanalization in the later culture, compared to Group B. After 4 weeks of in vivo implantation, Group A scaffolds have a superior performance in DNA content, Sox9 and RunX2 expression, cartilage lacuna-like cell and ECM accumulation, when compared to Group B. Furthermore, Group A scaffold size and mechanics were stable during in vitro and in vivo experiments, unlike the scaffolds in our previous study. Our results suggest that the combination with MC proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The MC-PCL-HA scaffold is a candidate for future cartilage regeneration studies. PMID:25530453

  4. 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

  5. Cord Blood

    OpenAIRE

    Saeed Abroun

    2014-01-01

      Stem cells are naïve or master cells. This means they can transform into special 200 cell types as needed by body, and each of these cells has just one function. Stem cells are found in many parts of the human body, although some sources have richer concentrations than others. Some excellent sources of stem cells, such as bone marrow, peripheral blood, cord blood, other tissue stem cells and human embryos, which last one are controversial and their use can be illegal in some countries. Cord...

  6. Changes in the nervous system state and peripheral blood parameters under benzene intoxication during an experiment

    Directory of Open Access Journals (Sweden)

    R.A. Orujov

    2017-12-01

    Full Text Available Benzene is a widely spread chemical health risk factor. Our research goal was to examine the nervous system state and the blood system state under benzene intoxication during an experiment. An acute experiment was performed on 45 white mice with 5-fold poisoning with benzene; a chronic one was performed on 72 rabbits being under inhalation exposure to benzene during 4 months, its concentrations increasing and fluctuating. We determined the following blood parameters: number of reticulocytes, eosinophils, basocytes, and erythrocytes; erythrocytes sedimentation rate; blood clotting period; blood clot retraction; plasma re-calcification period; plasma tolerance to heparin; prothrombin time; prothrombin index; fibrinogen concentration; blood fibrinolytic activity; acetylcholine and choline esterase contents. We also determined adrenalin, noradrenalin, dopamine, and dihydroxyphenylalanine contents in urine. Acute experiments results revealed that one-time exposure to benzene exerted a narcotic effect on the central nervous system which had an excitation phase and inhibition phase. Under a repeat exposure to benzene animals' drug intoxication was shorter. And here neutrophils / leucocytes gradient first increased to 139.5 % from its standards value and then when down under consequent intoxications. We detected relevant changes in morphological picture of animals' peripheral blood and their central and vegetative nervous system under chronic exposure to intermittent and increasing benzene concentrations. So, our research revealed that effects exerted by benzene in small concentrations led to apparent shifts in white blood and catecholamines (adrenalin, noradrenalin, dopamine, and dihydroxyphenylalanine. We also detected certain signs that cate-cholamines endogenous reserves (dihydroxyphenylalanine were depleted and, and also signs of eosinophils-basocytes disso-ciation; such prognostic signs were considered to be unfavorable as it was exactly at that

  7. [Abnormality of blood coagulation indexes in patients with de novo acute leukemia and its clinical significance].

    Science.gov (United States)

    Xiao, Fang-Fang; Hu, Kai-Xun; Guo, Mei; Qiao, Jian-Hui; Sun, Qi-Yun; Ai, Hui-Sheng; Yu, Chang-Lin

    2013-04-01

    To explore hemorrhage risk and the clinical significance of abnormal change of prothrombin time (PT), activated partial thromboplastin time (APTT), plasma fibrinogen (FIB), plasma thrombin time (TT) and d-dimer (D-D) in de novo acute leukemia (except for APL), the different bleeding manifestations of 114 cases of de novo acute leukemia with different coagulation indexes were analyzed retrospectively. The correlation between these blood coagulation indexes and the possible correlative clinical characteristics were analysed, including age, sex, type of acute leukemia, initial white blood cell(WBC) and platelet(Plt) count, the proportion of blast cells in bone marrow and cytogenetic abnormality of patients at diagnosis. The results indicated that the incidence of abnormal blood coagulation was as high as 78.1% for de novo AL patients. These patients with 5 normal blood coagulation indexes may have mild bleeding manifestation, but the more abnormal indexes, the more severe bleeding. Both PT and D-D were sensitive indexes for diagnosis of level II bleeding. Incidence of abnormal blood coagulation significantly correlates with the proportion of blast cells in bone marrow (χ(2) = 4.184, OR = 1.021, P coagulation. It is concluded that the coagulation and fibrinolysis are abnormal in most patients with de novo acute leukemia. More abnormal indexes indicate more severe bleeding, and both PT and D-D are sensitive indexes for diagnosis of level II bleeding. Higher proportion of blast cells in bone marrow predicts higher incidence of abnormal blood clotting. Acute leukemia with elderly age, high white blood cell count and adverse cytogenetics do not predict severer abnormal blood clotting. Detection of PT, APTT, TT, FIB, and D-D may help to judge whether the patients are in a state of hypercoagulability or disseminated intravenous coagulation, which will provide experiment evidences for early intervention and medication.

  8. Effect of spirapril and hydrochlorothiazide on platelet function and euglobulin clot lysis time in patients with mild hypertension

    DEFF Research Database (Denmark)

    Fonitz, Gitte (Gleerup); Petersen, J R; Mehlsen, J

    1996-01-01

    Thirteen patients with mild hypertension (untreated diastolic blood pressure of 95 to 114 mmHg) received, in random order, three successive treatments of four weeks with placebo, spirapril (6 mg daily), or hydrochlorothiazide (HCT2) (24 mg daily). At the end of each treatment, blood samples...

  9. Blood Typing

    Science.gov (United States)

    ... blood cells, resulting in a condition known as hemolytic disease of the fetus and newborn (HDFN) . To prevent development of Rh antibodies, an ... consequences, one of the most common causes of hemolytic disease of the fetus and newborn (HDFN) is actually an incompatibility between the mother's ...

  10. Impact of sickle cell trait on the thrombotic risk associated with non-O blood groups in northern Nigeria.

    Science.gov (United States)

    Ahmed, Sagir G; Kagu, Modu B; Ibrahim, Umma A; Bukar, Audu A

    2015-10-01

    The non-O blood group is an established risk factor for deep vein thrombosis (DVT), while controversy surrounds the role of sickle cell trait (SCT) as a risk factor for DVT. We hypothesised that if SCT is a risk factor for DVT, individuals with non-O blood groups and SCT (Hb AS) would have a higher risk of DVT than their counterparts with non-O blood groups and normal haemoglobin phenotype (Hb AA). We retrospectively analysed the prevalence of SCT and non-O blood groups among 148 DVT patients with control subjects in order to determine the role of SCT as a risk factor for DVT and its impact on the risk of DVT among patients with non-O blood groups. In comparison with control subjects, DVT patients had significantly higher prevalences of SCT (35.1% vs 27.7%, p=0.04) and non-O blood groups (68.9% vs 45.9%, p=0.02). The odds ratios for DVT due to SCT, non-O blood groups with normal Hb phenotype (Hb AA) and non-O blood groups with SCT (Hb AS) were 1.3, 2.4 and 3.5, respectively. These results suggest that SCT by itself is a weak risk factor for DVT but it has the potential of escalating the DVT risk among patients with non-O blood groups. The combined effects of elevated clotting factors (non-O group effect) and increased clotting factor activation (SCT effect) were responsible for the escalated DVT risk among patients with co-inheritance of non-O blood groups and SCT. Co-inheritance of SCT and non-O blood group is, therefore, an important mixed risk factor for DVT. This should be taken into account when assessing DVT risk profiles of patients in Africa and other parts of the world where the SCT is prevalent.

  11. Stability of HE4 and CA125 in blood samples from patients diagnosed with ovarian cancer

    DEFF Research Database (Denmark)

    Sandhu, Noreen; Karlsen, Mona A; Høgdall, Claus

    2014-01-01

    OBJECTIVE: To investigate the influence of handling and storage on HE4 and CA125 serum and EDTA plasma levels to clarify any important consequences for a clinical setting. METHODS: Blood samples from 13 ovarian cancer (OC) patients were collected and allowed to clot or sediment for up to 72 hours.......024). No significant difference between CA125 serum and plasma levels were found (p = 0.46). Serum and EDTA plasma samples were stable during the eight cycles of freezing and thawing (CA125: all p > 0.2; HE4: all p > 0.5). CONCLUSION: No systematic difference could be demonstrated for HE4. CA125 is not dependent...

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

    Science.gov (United States)

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

    2005-03-15

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

  13. Cord-Blood Banking

    Science.gov (United States)

    ... types of mature blood cells found in blood — red blood cells, white blood cells, and platelets. Cord-blood stem cells also may have the potential to give rise to other cell types in the body. Some ...

  14. Blood sugar test

    Science.gov (United States)

    ... level; Fasting blood sugar; Glucose test; Diabetic screening - blood sugar test; Diabetes - blood sugar test ... than likely, the doctor will order a fasting blood sugar test. The blood glucose test is also used to ...

  15. Types of Blood Transfusions

    Science.gov (United States)

    ... Research Home / Blood Transfusion Blood Transfusion What Is A blood transfusion is a safe, ... store your blood for your use. Alternatives to Blood Transfusions Researchers are trying to find ways to make ...

  16. Blood Urea Nitrogen Test

    Science.gov (United States)

    ... Culture Blood Gases Blood Ketones Blood Smear Blood Typing Blood Urea Nitrogen (BUN) BNP and NT-proBNP ... Luteinizing Hormone (LH) Lyme Disease Tests Magnesium Maternal Serum Screening, Second Trimester Measles and Mumps Tests Mercury ...

  17. Air bubbles and hemolysis of blood samples during transport by pneumatic tube systems.

    Science.gov (United States)

    Mullins, Garrett R; Bruns, David E

    2017-10-01

    Transport of blood samples through pneumatic tube systems (PTSs) generates air bubbles in transported blood samples and, with increasing duration of transport, the appearance of hemolysis. We investigated the role of air-bubble formation in PTS-induced hemolysis. Air was introduced into blood samples for 0, 1, 3 or 5min to form air bubbles. Hemolysis in the blood was assessed by (H)-index, lactate dehydrogenase (LD) and potassium in plasma. In an effort to prevent PTS-induced hemolysis, blood sample tubes were completely filled, to prevent air bubble formation, and compared with partially filled samples after PTS transport. We also compared hemolysis in anticoagulated vs clotted blood subjected to PTS transport. As with transport through PTSs, the duration of air bubble formation in blood by a gentle stream of air predicted the extent of hemolysis as measured by H-index (pblood sample prevented bubble formation and fully protected the blood from PTS-induced hemolysis (pblood developed less foaming during PTS transport and was partially protected from hemolysis vs anticoagulated blood as indicated by lower LD (psample transport. Prevention of air bubble formation in blood samples during PTS transport protects samples from hemolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Blood gases

    Science.gov (United States)

    ... 5.1 to 5.6 kPa) Arterial blood pH: 7.38 to 7.42 Oxygen saturation (SaO2): 94% to 100% Bicarbonate - (HCO3): 22 to 28 mEq/L Note: mEq/L = milliequivalents per liter; mmHg = millimeters of mercury At altitudes of 3,000 feet (900 meters) and higher, the oxygen value is lower. Normal ...

  19. Hot-clot artifacts in the lung parenchyma on F-18-fluorodeoxyglucose position emission tomography/CT due to faulty injection techniques: Two case report

    Energy Technology Data Exchange (ETDEWEB)

    Ozdemir, Elif; Yildirim, Nilufer; Keskin, Mutlay; Kandemir, Zuhai; Turkolmez, Seyda [Dept. of Nuclear Medicine, Ataturk Training and Research Hospital, Ankara (Turkmenistan)

    2014-08-15

    F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.

  20. Hot-clot artifacts in the lung parenchyma on F-18-fluorodeoxyglucose position emission tomography/CT due to faulty injection techniques: Two case report

    International Nuclear Information System (INIS)

    Ozdemir, Elif; Yildirim, Nilufer; Keskin, Mutlay; Kandemir, Zuhai; Turkolmez, Seyda

    2014-01-01

    F-18-fluorodeoxyglucose (FDG) positron emission tomography/CT is an important whole-body imaging tool in the oncology and widely utilized to stage and restage various malignancies. The findings of significant focal accumulation of FDG in the lung parenchyma in the absence of corresponding CT abnormalities are related to the lung microembolism and known as hot-clot artifacts. Herein we present two cases with focal FDG uptake in the lung parenchyma with no structural lesions on the CT scan and discuss the possible mechanisms.

  1. Effect of spirapril and hydrochlorothiazide on platelet function and euglobulin clot lysis time in patients with mild hypertension

    DEFF Research Database (Denmark)

    Fonitz, Gitte (Gleerup); Petersen, J R; Mehlsen, J

    1996-01-01

    Thirteen patients with mild hypertension (untreated diastolic blood pressure of 95 to 114 mmHg) received, in random order, three successive treatments of four weeks with placebo, spirapril (6 mg daily), or hydrochlorothiazide (HCT2) (24 mg daily). At the end of each treatment, blood samples for a...... not produce any unwanted side effect on platelet function or fibrinolysis. HCT2 seems to decrease platelet activity at rest, whereas spirapril seems to some extent to decrease platelet activity at exercise....

  2. Evaluation of resuscitation fluids on endothelial glycocalyx, venular blood flow, and coagulation function after hemorrhagic shock in rats.

    Science.gov (United States)

    Torres, Luciana N; Sondeen, Jill L; Ji, Lisa; Dubick, Michael A; Torres Filho, Ivo

    2013-11-01

    Endothelial glycocalyx (EG) plays an essential role in endothelium integrity and may be compromised by hemorrhagic shock. The effects of currently available resuscitation fluids such as Hextend (HEX) or lactated Ringer's solution (LR) on vascular function and coagulation are not well understood. The aim of the present study was to compare the effects of fresh frozen plasma (FFP) with HEX or LR in their ability to repair EG structure, promote volume expansion, increase blood flow, and prevent coagulopathy. A total of 121 microvessels from cremaster muscle were studied in 32 anesthetized instrumented rats. After baseline systemic and microvascular measurements, 40% hemorrhage followed by resuscitation was performed, and measurements were repeated. Coagulation was evaluated using ROTEM to assay clot formation time, clotting time, firmness, strength, and lysis. Velocity and "platelet component" of strength were calculated. Fluorescein isothiocyanate or Texas Red bound to Dextrans was injected to estimate EG thickness in vivo. Respiratory rate, blood pH, base excess, and lactate returned to near-baseline levels in all treatments. Hemodilution caused by LR and HEX decreased firmness, prolonged clotting time, and lowered platelet counts. EG thickness in HEX- and LR-treated rats was 50% lower, and plasma syndecan 1 was 50% higher than sham and FFP groups. Blood flow and shear rate were restored in the HEX group. Resuscitation with FFP improved coagulation and blood flow. Our findings support the concept of cardiovascular and microvascular stabilization by infused FFP, in which the increase in microvascular perfusion associated with restored EG is essential for an optimal resuscitation strategy.

  3. Blood exposure.

    Science.gov (United States)

    1999-11-26

    [Name removed], an HIV-positive Illinois man, was sentenced to 5 years in prison for splattering 2 police officers with his blood and threatening to give them AIDS. The police were called to [name removed]'s apartment after receiving a report about an attempted suicide. [Name removed] pleaded guilty to attempted transmission of HIV in a plea bargain agreement, and the prosecutor dropped the more serious charge of attempted battery of a police officer. The officers show no sign of infection to date.

  4. Study on blood compatibility of the radiation sterilized disposable burette transfusion apparatus

    International Nuclear Information System (INIS)

    Chen Guochong; Liu Wen; Liu Qingfang

    2011-01-01

    The blood compatibility of the radiation sterilized disposable burette transfusion apparatus was investigated to provide evidence for the safety of radiation sterilized medical devices. The initial bacteria burden of the disposable burette transfusion apparatus was examined according to the ISO11737 standard, and the whole blood clotting time, prothrombin time, partial thromboplastin time and hemolysis rate of the samples were determined. There was no significant difference between the radiation sterilized samples and negative controls on WBCT, PT and PTT (p>0.05). Haemolysis test showed that the haemolysis rate of the sample sterilized by irradiation was 1.38%, which was coincidence with the criteria of the medical devices. After sterilization by irradiation, disposable burette transfusion apparatus show good blood compatibility, which could be considered that radiation sterilization is a biologically safe method for the medical apparatus. (authors)

  5. Hydroxyethyl Starch Reduces Coagulation Competence and Increases Blood Loss During Major Surgery

    DEFF Research Database (Denmark)

    Rasmussen, Kirsten C; Johansson, Pär I; Højskov, Michael

    2014-01-01

    OBJECTIVE: This study evaluated whether administration of hydroxyethyl starch (HES) 130/0.4 affects coagulation competence and influences the perioperative blood loss. BACKGROUND: Artificial colloids substitute blood volume during surgery; with the administration of HES 130/0.4 (Voluven, Fresenius...... Kabi, Uppsala, Sweden) only a minor effect on coagulation competence is expected. METHODS: Eighty patients were scanned for enrollment in the study, and 40 patients fulfilled the inclusion criteria. Two patients withdrew their consent to participate in the study, and 5 patients were excluded. Thus, 16...... patients were randomized to receive lactated Ringer's solution and 17 to receive HES 130/0.4. RESULTS: Among the patients receiving HES 130/0.4, thrombelastography indicated reduced clot strength (P evaluation of the perioperative blood loss was 2.2 (range 0.5 to 5.0) versus 1.4 (range...

  6. Nanostructural haemocompatible coatings for the internal side of artificial blood vessels

    Science.gov (United States)

    Trembecka-Wojciga, K.; Major, R.; Lackner, J. M.; Butruk-Raszeja, B.; Sanak, M.; Major, B.

    2016-03-01

    The main goal of the work was to elaborate low thrombogenicity of surface inside tube-like elements for cardiovascular system support by combination of low-temperature glow discharge and hydrogel coatings to inhibit blood-clotting cascade activation. A large share of amorphous phase silicon was observed in the microstructure analysis. The crystalline elements were uniformly distributed in the amorphous structure. Combination of low thickness, the proper microstructure and density of the coatings provided a highly flexible nature of the whole system. The blood-material interaction was analyzed in vitro in dynamic conditions by using a designed and fabricated novel blood flow simulator. Coatings deposited by the glow discharge expressed good hemocopatibile properties. The use of hydrogel coatings did not reduce coagulation parameter. Hydrogel coatings did not improve the hemocompatibility of the surface modified with carbon based coatings. Modification of surface with hydrogel resulted in further increased risk of hemolysis.

  7. The use of high-hydrostatic pressure treatment to decellularize blood vessels.

    Science.gov (United States)

    Funamoto, Seiichi; Nam, Kwangwoo; Kimura, Tsuyoshi; Murakoshi, Ayako; Hashimoto, Yoshihide; Niwaya, Kazuo; Kitamura, Soichiro; Fujisato, Toshiya; Kishida, Akio

    2010-05-01

    A decellularization method using high-hydrostatic pressure (HHP) technology (>600MPa) is described. The HHP disrupts the cells inside the tissue. The cell debris can be eliminated with a simple washing process, producing clean, decellularized tissue. In this study, porcine aortic blood vessel was decellularized by HHP. The mechanical properties and in vivo performance of the decellularized tissue were evaluated. Mechanical properties of the decellularized tissue were not altered by the HHP treatment. Reduced inflammation of the decellularized tissue was confirmed by xenogenic transplant experimentation. An allogenic transplantation study showed that decellularized blood vessel endured the arterial blood pressure, and there was no clot formation on the luminal surface. In addition, cellular infiltration into the vessel wall was observed 4 weeks after implantation, suggesting that HHP treatments could be applied widely as a high-quality decellularization method. Copyright 2010 Elsevier Ltd. All rights reserved.

  8. CONTENTS OF CYTOKINES IN BLOOD OF THE PATIENTS WITH LOCAL FROSTBITES

    Directory of Open Access Journals (Sweden)

    K. G. Shapovalov

    2008-01-01

    Full Text Available Abstract. Cytokines provide important connecting links between immunity, blood clotting, and nonspecific resistance that become altered in local frostbites. The aim of study was to determine the contents of cytokines in blood of patients with local frostbites at various terms following the lesion. Fifty patients, 17 to 50 years old, with frostbites of extremities (grade II to IV were under observation. Arterial and venous blood, as well as venous blood from damaged and intact extremities were examined. Cytokine concentrations were determined using ELISA technique. It was shown that blood concentrations of TNFα, IL-1β, IL-4, IL-8 and IL-18 reached their maximum at early reactive period of the trauma (a 2.3- to 19-fold increase. IL-1β concentration exceeded appropriate control values during all the periods of local frostbites. IL 18 levels were increased at early reactive period of the trauma. IL-1β and IL-8 concentration at pre-reactive period proved to be higher in arterial blood of damaged extremities, than in effluent venous blood. Both during early and late reactive periods, the levels of pro-inflammatory cytokines in effluent blood from damaged extremities were 1.2- to 8-fold higher than in venous blood from intact extremities, whereas IL-4 levels were 2- to 5-fold lower.

  9. Zwitterionic sulfobetaine-grafted poly(vinylidene fluoride) membrane with highly effective blood compatibility via atmospheric plasma-induced surface copolymerization.

    Science.gov (United States)

    Chang, Yung; Chang, Wan-Ju; Shih, Yu-Ju; Wei, Ta-Chin; Hsiue, Ging-Ho

    2011-04-01

    Development of nonfouling membranes to prevent nonspecific protein adsorption and platelet adhesion is critical for many biomedical applications. It is always a challenge to control the surface graft copolymerization of a highly polar monomer from the highly hydrophobic surface of a fluoropolymer membrane. In this work, the blood compatibility of poly(vinylidene fluoride) (PVDF) membranes with surface-grafted electrically neutral zwitterionic poly(sulfobetaine methacrylate) (PSBMA), from atmospheric plasma-induced surface copolymerization, was studied. The effect of surface composition and graft morphology, electrical neutrality, hydrophilicity and hydration capability on blood compatibility of the membranes were determined. Blood compatibility of the zwitterionic PVDF membranes was systematically evaluated by plasma protein adsorption, platelet adhesion, plasma-clotting time, and blood cell hemolysis. It was found that the nonfouling nature and hydration capability of grafted PSBMA polymers can be effectively controlled by regulating the grafting coverage and charge balance of the PSBMA layer on the PVDF membrane surface. Even a slight charge bias in the grafted zwitterionic PSBMA layer can induce electrostatic interactions between proteins and the membrane surfaces, leading to surface protein adsorption, platelet activation, plasma clotting and blood cell hemolysis. Thus, the optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and the best antifouling, anticoagulant, and antihemolytic activities when comes into contact with human blood. © 2011 American Chemical Society

  10. Whole blood treated with riboflavin and ultraviolet light: quality assessment of all blood components produced by the buffy coat method.

    Science.gov (United States)

    Schubert, Peter; Culibrk, Brankica; Karwal, Simrath; Serrano, Katherine; Levin, Elena; Bu, Daniel; Bhakta, Varsha; Sheffield, William P; Goodrich, Raymond P; Devine, Dana V

    2015-04-01

    Pathogen inactivation (PI) technologies are currently licensed for use with platelet (PLT) and plasma components. Treatment of whole blood (WB) would be of benefit to the blood banking community by saving time and costs compared to individual component treatment. However, no paired, pool-and-split study directly assessing the impact of WB PI on the subsequently produced components has yet been reported. In a "pool-and-split" study, WB either was treated with riboflavin and ultraviolet (UV) light or was kept untreated as control. The buffy coat (BC) method produced plasma, PLT, and red blood cell (RBC) components. PLT units arising from the untreated WB study arm were treated with riboflavin and UV light on day of production and compared to PLT concentrates (PCs) produced from the treated WB units. A panel of common in vitro variables for the three types of components was used to monitor quality throughout their respective storage periods. PCs derived from the WB PI treatment were of significantly better quality than treated PLT components for most variables. RBCs produced from the WB treatment deteriorated earlier during storage than untreated units. Plasma components showed a 3% to 44% loss in activity for several clotting factors. Treatment of WB with riboflavin and UV before production of components by the BC method shows a negative impact on all three blood components. PLT units produced from PI-treated WB exhibited less damage compared to PLT component treatment. © 2014 AABB.

  11. Silver nanoparticles influence on the blood activation process and their release to blood plasma from synthetic polymer scaffold

    Science.gov (United States)

    Major, R.; Lackner, J. M.; Sanak, M.; Major, B.

    2016-03-01

    In the present work, blood and blood plasma interaction to silver stabilised polyelectrolytes was investigated in vitro. The designed materials are dedicated for regeneration of the cardiovascular system. Silver nanoparticles were introduced into the polyelectrolyte structure in order to reduce the risk of bacterial biofilm formation. The introduction of Ag nanoparticles occurred by deposition at high vacuum by magnetron sputtering. The analysis of blood-materials interactions were performed by using commercially available tester, Impact-R (Diamed). The assessment of silver ion nanoparticles release into the plasma consisted in determining the Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT). Unmodified surface of polyelectrolytes is a strong activator for blood elements. The introduction of silver nanoparticles resulted in a significant reduction in the probability of clotting. The extrinsic pathway of coagulation determined on the basis of the PT and the intrinsic and common pathways of coagulation measured by the APTT did not indicate the danger out of range. Microstructure was studied using TEM on thin foils prepared from the cross-section of samples subjected to biomedical treatments. The observations revealed hetero- interface between two different crystalline solids.

  12. Lead levels - blood

    Science.gov (United States)

    Blood lead levels ... A blood sample is needed. Most of the time blood is drawn from a vein located on the inside ... may be used to puncture the skin. The blood collects in a small glass tube called a ...

  13. Blood donation before surgery

    Science.gov (United States)

    ... very safe, some people choose to use a method called autologous blood donation. Autologous blood is blood donated by you, which you later receive if you need a transfusion during or after surgery. You can have blood ...

  14. Blood Donation Process

    Science.gov (United States)

    ... Drive Biomedical Services Hospital Partners Blood Products Blood Banking Resources Order Blood Products Invoice Central Case Reports ... Speed up your donation by completing a RapidPass® online or on the Blood Donor app on the ...

  15. Symptoms of Blood Disorders

    Science.gov (United States)

    ... In This Article Generic Name Select Brand Names aspirin No US brand name Symptoms and Diagnosis of Blood Disorders Overview of Blood Disorders Symptoms of Blood Disorders Medical History and Physical Examination for Blood Disorders Laboratory Tests ...

  16. High Blood Cholesterol

    Science.gov (United States)

    ... To Health Topics / High Blood Cholesterol High Blood Cholesterol Also known as Hypercholesterolemia High blood cholesterol is ... Lipid panel tests to check for healthy blood cholesterol levels Doctors use lipid panels to check whether ...

  17. Porphyrins - blood test

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/article/003372.htm Porphyrins blood test To use the sharing features on this page, ... blood or the urine . This article discusses the blood test. How the Test is Performed A blood sample ...

  18. Platelet antibodies blood test

    Science.gov (United States)

    This blood test shows if you have antibodies against platelets in your blood. Platelets are a part of the blood ... Chernecky CC, Berger BJ. Platelet antibody - blood. In: Chernecky ... caused by platelet destruction, hypersplenism, or hemodilution. ...

  19. Blood Pressure Test

    Science.gov (United States)

    ... pressure monitors may have some limitations. Tracking your blood pressure readings It can be helpful in diagnosing or ... more Stage 2 high blood pressure (hypertension) Elevated blood pressure and stages 1 and 2 high blood pressure ( ...

  20. Fusaric acid, a mycotoxin, and its influence on blood coagulation and platelet function.

    Science.gov (United States)

    Devaraja, Sannaningaiah; Girish, Kesturu S; Santhosh, Martin S; Hemshekhar, Mahadevappa; Nayaka, Siddaiah C; Kemparaju, Kempaiah

    2013-06-01

    The current study intended to explore the effect of fusaric acid on blood coagulation including plasma coagulation and platelet aggregation. Fusaric acid exhibited biphasic effects on citrated human plasma recalcification time. At concentrations below 50 ng, fusaric acid decreased the clotting time of plasma dose-dependently from 130 ± 3s control value to 32 ± 3s; however, above 50 ng, fusaric acid increased the clotting time from 32 ± 3s and reached a maximum of 152 s at 100 ng and remained unaltered thereafter for the increased dose of fusaric acid. Fusaric acid without damaging red blood cells and platelets, inhibited agonists such as collagen, ADP, thrombin, and epinephrine-induced aggregation of both platelet-rich plasma (PRP) and washed platelets preparations of human. Interestingly, fusaric acid showed biphasic effects only in thrombin-induced platelet aggregation of washed platelets, and at lower concentration (below 900 ng) it activated platelet aggregation; however, in increased concentration (above 900 ng) it inhibited the platelet aggregation of washed platelets. In addition, fusaric acid also inhibited the agonist ADP-induced platelet aggregation of washed platelet suspension but did not show biphasic effect. Further, fusaric acid did not induce the platelets to generate reactive oxygen species (ROS) that clearly suggests that the induction of platelet function could be the result of the fusaric acid-mediated receptor interaction but not through the morphological shape change.

  1. Microparticles from stored red blood cells enhance procoagulant and proinflammatory activity.

    Science.gov (United States)

    Fischer, Dania; Büssow, Julian; Meybohm, Patrick; Weber, Christian Friedrich; Zacharowski, Kai; Urbschat, Anja; Müller, Markus Matthias; Jennewein, Carla

    2017-11-01

    The pathomechanisms of morbidity due to blood transfusions are not yet entirely understood. Elevated levels of red blood cell-derived microparticles (RMPs) are found in coagulation-related pathologies and also in stored blood. Previous research has shown that RMPs mediate transfusion-related complications by the intrinsic pathway. We hypothesized that RMPs might play a role in post-transfusion thrombotic complications by enhancing procoagulant activity also through the extrinsic pathway of coagulation. In this laboratory study, blood from 18 healthy volunteers was stimulated with microparticles from expired stored red blood cells. Various clotting parameters were recorded. Flow cytometry, enzyme-linked immunosorbent assays, and real-time polymerase chain reaction were used to investigate possible mediating mechanisms. The addition of RMPs shortened the clotting time from 194 to 161 seconds (p monocytes and in plasma. TF messenger RNA expression increased in a time-dependent and concentration-dependent manner. There was a significant induction of interleukin-1β and interleukin-6. After stimulation with RMPs, there was a significant increase in the number of activated platelets, an increased percentage of PAC-1/CD62P (procaspase activating compound-1/platelet surface P-selectin) double-positive platelets, and an increased number of platelet-neutrophil duplets and platelet-monocyte duplets, indicating enhanced interaction of platelets with neutrophils and monocytes. Levels of CXCL-8 (C-X-C motif chemokine ligand 1) and interleukin-6 were significantly higher after treatment with RMPs. Our results suggest that RMPs trigger coagulation through TF signaling, induce the secretion of proinflammatory cytokines, and induce cell-cell interaction between platelets and neutrophils. Thus, under certain conditions, RMPs could play a role in post-transfusion complications through these mechanisms. © 2017 AABB.

  2. Bisphenol S impairs blood functions and induces cardiovascular risks in rats

    Directory of Open Access Journals (Sweden)

    Sanghamitra Pal

    Full Text Available Bisphenol S (BPS is an industrial chemical which is recently used to replace the potentially toxic Bisphenol A (BPA in making polycarbonate plastics, epoxy resins and thermal receipt papers. The probable toxic effects of BPS on the functions of haemopoietic and cardiovascular systems have not been reported till to date. We report here that BPS depresses haematological functions and induces cardiovascular risks in rat. Adult male albino rats of Sprague-Dawley strain were given BPS at a dose level of 30, 60 and 120 mg/kg BW/day respectively for 30 days. Red blood cell (RBC count, white blood cell (WBC count, Hb concentration, and clotting time have been shown to be significantly (*P < 0.05 reduced in a dose dependent manner in all exposed groups of rats comparing to the control. It has also been shown that BPS increases total serum glucose and protein concentration in the exposed groups of rats. We have observed that BPS increases serum total cholesterol, triglyceride, glycerol free triglyceride, low density lipoprotein (LDL and very low density lipoprotein (VLDL concentration, whereas high density lipoprotein (HDL concentration has been found to be reduced in the exposed groups. BPS significantly increases serum aspartate aminotransferase (AST, alanine aminotransferase (ALT and alkaline phosphatase (ALP activities dose dependently. Moreover, serum calcium, bilirubin and urea concentration have been observed to be increased in all exposed groups. In conclusion, BPS probably impairs the functions of blood and promotes cardiovascular risks in rats. Keywords: Bisphenol S, Red blood cell count, White blood cell count, Clotting time, LDL cholesterol, HDL cholesterol, Cardiovascular risks

  3. Management of major blood loss: an update

    DEFF Research Database (Denmark)

    Johansson, P I; Ostrowski, S R; Secher, N H

    2010-01-01

    Haemorrhage remains a major cause of potentially preventable deaths. Trauma and massive transfusion are associated with coagulopathy secondary to tissue injury, hypoperfusion, dilution and consumption of clotting factors and platelets. Concepts of damage control surgery have evolved, prioritizing...

  4. Synthesis and Evaluation of Poly(hexamethylene-urethane and PEG-Poly(hexamethylene-urethane and Their Cholesteryl Oleyl Carbonate Composites for Human Blood Biocompatibility

    Directory of Open Access Journals (Sweden)

    Jong Yuh Cherng

    2011-09-01

    Full Text Available Two new urethane-based acrylates (UAA and PEG-UAA were synthesized as polymer blocks. The chemical composition of the two monomers was confirmed by IR and NMR. After cross-linking these blockers by radical polymerization, “hexamethylene PU” [poly(hexamethylene-urethane] and “PEG-hexamethylene PU” [PEG-poly(hexa-methylene-urethane] were obtained. The platelet adhesion and platelet activation of these polymers were evaluated in the presence of Platelet Rich Plasma (PRP blood. The relative blood clotting indexes of the polymers were determined to measure their capability of reducing thrombogenicity. The hemolysis of red blood cells was also assessed to examine the haemocompatibility of the polymers. The hexamethylene PU and PEG-hexamethylene PU showed less platelet adhesion, platelet activation, blood clotting and hemolysis than a commercial PU (Tecoflex. The liquid crystal molecule, cholesteryl oleyl carbonate (COC, showed further improved biocompatibility to human blood, after COC was embedded in the PU polymers. PEG-hexamethylene PU + 10% COC demonstrated the best activity in reducing thrombogenicity and the best haemocompatibility. The inclusion of PEG segments into the PEG-UAA structure increased its hydrophilicity. The methylene bis(cyclohexyl segments in Tecoflex PU decreased haemocompatibility. These observations are in good agreement with performed contact angle measurements. The PEG-hexamethylene PU loaded with COC might be a promising material for applications in bioengineering.

  5. Choreito, a formula from Japanese traditional medicine (Kampo medicine), for massive hemorrhagic cystitis and clot retention in a pediatric patient with refractory acute lymphoblastic leukemia.

    Science.gov (United States)

    Kawashima, Nozomu; Deveaux, Teykia E; Yoshida, Nao; Matsumoto, Kimikazu; Kato, Koji

    2012-09-15

    Hemorrhagic cystitis is critical in patients with hemato-oncological disorders. Unlike adult patients, there are limited modalities and invasive procedures are often not well tolerated in children with poor general conditions. We report a pediatric patient with refractory acute lymphoblastic leukemia who developed life-threatening massive gross hematuria. Along with platelet infusion every other day due to suppressed hematopoiesis, his gross hematuria and clot retention in the bladder were successfully treated with choreito, a formula from Japanese traditional medicine (Kampo medicine). He survived free from hematuria for more than four months. Choreito was well tolerated, and no adverse effects were observed throughout the course. Copyright © 2012 Elsevier GmbH. All rights reserved.

  6. Parvovirus transmission by blood products - a cause for concern?

    Science.gov (United States)

    Norja, Päivi; Lassila, Riitta; Makris, Mike

    2012-11-01

    The introduction of dual viral inactivation of clotting factor concentrates has practically eliminated infections by viruses associated with significant pathogenicity over the last 20 years. Despite this, theoretical concerns about transmission of infection have remained, as it is known that currently available viral inactivation methods are unable to eliminate parvovirus B19 or prions from these products. Recently, concern has been raised following the identification of the new parvoviruses, human parvovirus 4 (PARV4) and new genotypes of parvovirus B19, in blood products. Parvoviruses do not cause chronic pathogenicity similar to human immunodeficiency virus or hepatitis C virus, but nevertheless may cause clinical manifestations, especially in immunosuppressed patients. Manufacturers should institute measures, such as minipool polymerase chain reaction testing, to ensure that their products contain no known viruses. So far, human bocavirus, another new genus of parvovirus, has not been detected in fractionated blood products, and unless their presence can be demonstrated, routine testing during manufacture is not essential. Continued surveillance of the patients and of the safety of blood products remains an important ongoing issue. © 2012 Blackwell Publishing Ltd.

  7. THYMUS PEPTIDES (THYMULIN, THYMOSIN ALPHA 1 AND THYMOSIN BETA 4 INHIBITING EFFECTS ON THE INTRINSIC BLOOD COAGULATION PATHWAY IN RATS

    Directory of Open Access Journals (Sweden)

    Negrin Negrev

    2017-08-01

    Full Text Available Thymus peptides (thymulin, thymosin alpha 1 and thymosin beta 4 inhibiting effects on the intrinsic blood coagulation pathway in rats Background and purpose: Hemostasis is a basic homeostatic mechanism protecting the body from thrombosis or haemorrhage. A number of pathological conditions, including multiple endocrine disorders modulate the balance between pro- and anticoagulation factors and establish conditions of hyper- or hypocoagulability. Endocrine effects of thymus gland on blood coagulation are not completely elucidated, and data existing on the theme are relatively scarce and partially controversial. The present study was designed to investigate thymus peptides (thymulin, thymosin alpha 1 and thymosin beta 4 effects on key intrinsic pathway plasma clotting factors XII, XI, IX, X and activated partial thromboplastin time (aPTT – a principal marker of blood coagulation via intrinsic pathway of hemocoagulation, in rats. Materials and methods: Plasma clotting factor activities and aPTT were studied on 52 male Wistar intact rats after 3 day s.c. application of the thymic peptides envisaged using routine kinetic coagulometry. Results of the study indicate a significant reduction of FXII activity by thymulin and thymosin alpha 1, and FXI and FIX activity by thymulin and thymosin beta 4. Conclusion: Upper results support the conclusion that thymus peptides thymulin, thymosin alpha 1 and thymosin beta 4 application in rats imposes a distinct tendency of hypocoagulability.

  8. Establishment of the 2nd Korean national biological reference standard for blood coagulation factor VIII:C concentrate.

    Science.gov (United States)

    Lee, Naery; Seo, Ji Suk; Kim, Jae Ok; Ban, Sang Ja

    2017-05-01

    Since the 1st Korean national biological reference standard for factor (F)VIII concentrate, established in 2001, has shown declining potency, we conducted this study to replace this standard with a 2nd Korean national biological reference standard for blood coagulation FVIII concentrate. The candidate materials for the 2nd standard were prepared in 8000 vials with 10 IU/ml of target potency, according to the approved manufacturing process of blood coagulation Factor VIII:C Monoclonal Antibody-purified, Freeze-dried Human Blood Coagulation Factor VIII:C. Potency was evaluated by one-stage clotting and chromogenic methods and the stability was confirmed to meet the specifications during a period of 73 months. Since the potencies obtained by the two methods differed significantly (P < 0.015), the values were determined separately according to the geometric means (8.9 and 7.4 IU/vial, respectively). The geometric coefficients of interlaboratory variability were 3.4% and 7.6% by the one-stage clotting and chromogenic assays, respectively. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  9. Laboratory heterogeneity of the lupus anticoagulant: a multicentre study using different clotting assays on a panel of 78 samples. Hemostasis Committee of the "Société Française de Biologie Clinique".

    Science.gov (United States)

    1992-05-15

    The laboratory heterogeneity of the lupus anticoagulant (LA) was investigated in a multicentre study using a panel of 78 plasma samples diagnosed as containing a LA. Consecutive samples were collected by 12 participants using various screening tests, and sent to 7 laboratories which performed one or more clotting assays among the following: activated partial thromboplastin time (APTT), dilute Russell viper venom time, kaolin clotting time (KCT), dilute tissue thromboplastin time (dTTI) and a platelet neutralization test. For APTT and dTTI, 10 versions of these tests including standard and mixing procedures were carried out. They varied by reagents, phospholipid concentration or methodology. Cut-off times were determined for each test by comparing the results of the panel to those of a control population. When the data of all clotting assays were pooled, 70 of the 78 selected plasmas were considered to contain LA, 15 of them having a low-titer inhibitor. Sensitivity, defined as the proportion of positive results among LA-containing plasmas, varied from 62 to 100% and was positively related to responsiveness (defined as the mean ratio of clotting time to cut-off time). Laboratory heterogeneity of LA-containing plasma was illustrated by a star symbol plot analysis. Different populations of samples, with LA preferentially recognized by one assay (or group of assays) irrespective of the overall sensitivity of this assay, were identified. Multiple component analysis demonstrated the heterogeneity of low-titer inhibitors, which complicates their recognition in routine laboratory investigation.

  10. Use of autologous human mesenchymal stromal cell/fibrin clot constructs in upper limb non-unions: long-term assessment.

    Directory of Open Access Journals (Sweden)

    Stefano Giannotti

    Full Text Available BACKGROUND: Tissue engineering appears to be an attractive alternative to the traditional approach in the treatment of fracture non-unions. Mesenchymal stromal cells (MSCs are considered an appealing cell source for clinical intervention. However, ex vivo cell expansion and differentiation towards the osteogenic lineage, together with the design of a suitable scaffold have yet to be optimized. Major concerns exist about the safety of MSC-based therapies, including possible abnormal overgrowth and potential cancer evolution. AIMS: We examined the long-term efficacy and safety of ex vivo expanded bone marrow MSCs, embedded in autologous fibrin clots, for the healing of atrophic pseudarthrosis of the upper limb. Our research work relied on three main issues: use of an entirely autologous context (cells, serum for ex vivo cell culture, scaffold components, reduced ex vivo cell expansion, and short-term MSC osteoinduction before implantation. METHODS AND FINDINGS: Bone marrow MSCs isolated from 8 patients were expanded ex vivo until passage 1 and short-term osteo-differentiated in autologous-based culture conditions. Tissue-engineered constructs designed to embed MSCs in autologous fibrin clots were locally implanted with bone grafts, calibrating their number on the extension of bone damage. Radiographic healing was evaluated with short- and long-term follow-ups (range averages: 6.7 and 76.0 months, respectively. All patients recovered limb function, with no evidence of tissue overgrowth or tumor formation. CONCLUSIONS: Our study indicates that highly autologous treatment can be effective and safe in the long-term healing of bone non-unions. This tissue engineering approach resulted in successful clinical and functional outcomes for all patients.

  11. Comparison of Clot-based, Chromogenic, and Fluorescence Assays for Measurement of Factor VIII Inhibitors in the U.S. Hemophilia Inhibitor Research Study

    Science.gov (United States)

    Miller, Connie H.; Rice, Anne S.; Boylan, Brian; Shapiro, Amy D.; Lentz, Steven R.; Wicklund, Brian M.; Kelly, Fiona M.; Soucie, J. Michael

    2015-01-01

    Summary Background Detection and validation of inhibitors (antibodies) to hemophilia treatment products are important for clinical care, evaluation of product safety, and assessment of population trends. Methods Centralized monitoring for factor VIII (FVIII) inhibitors was conducted for patients in the Hemophilia Inhibitor Research Study using a previously reported modified Nijmegen-Bethesda clotting assay (NBA), a chromogenic Bethesda assay (CBA), and a novel fluorescence immunoassay (FLI). Results NBA and CBA were performed on 1005 specimens and FLI on 272 specimens. CBA was negative on 880/883 specimens (99.7%) with Nijmegen-Bethesda units (NBU)NBA and negative CBA, 58.1% were FLI-negative, 12.9% had evidence of lupus anticoagulant, and 35.5% had non-time-dependent inhibition. CBA and FLI were positive on 72.4% and 100% of 1.0–1.9 NBU specimens and 43.1% and 50.0% of 0.5–0.9 NBU specimens. FLI detected antibodies in 98.0% of CBA-positive and 81.6% of NBA-positive specimens (P=0.004). Among 21 new inhibitors detected by NBA, 5 (23.8%) with 0.7–1.3 NBU did not react in CBA or FLI. Among previously positive patients with 0.5–1.9 NBU, 7/25 (28%) were not CBA or FLI positive. FLI was positive on 36/169 NBU-negative specimens (21.3%). Conclusions FVIII specificity could not be demonstrated by CBA or FLI for 26% of inhibitors of 0.5–1.9 NBU; such results must be interpreted with caution. Low titer inhibitors detected in clot-based assays should always be repeated, with consideration given to evaluating their reactivity with FVIII using more specific assays. PMID:23601690

  12. In black South Africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time.

    Science.gov (United States)

    de Lange, Zelda; Rijken, Dingeman C; Hoekstra, Tiny; Conradie, Karin R; Jerling, Johann C; Pieters, Marlien

    2013-01-01

    Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysis time (CLT). We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1act increased across genotypes in the urban subgroup (p = 0.009) but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1act or CLT but they did influence the association of other environmental factors with PAI-1act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1act, it contributed less than 1% to the PAI-1act variance. (Central) obesity was the biggest contributor to PAI-1act variance (12.5%). Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1act and CLT.

  13. In black South Africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time.

    Directory of Open Access Journals (Sweden)

    Zelda de Lange

    Full Text Available Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysis time (CLT. We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1act increased across genotypes in the urban subgroup (p = 0.009 but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1act or CLT but they did influence the association of other environmental factors with PAI-1act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1act, it contributed less than 1% to the PAI-1act variance. (Central obesity was the biggest contributor to PAI-1act variance (12.5%. Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1act and CLT.

  14. Blood compatibility assessment of graft copolymer (NR-g-DMAA) tubes

    International Nuclear Information System (INIS)

    Razzak, M.T.; Otsuhata, Kazushige; Tabata, Yoneho; Ohashi, Fumio; Takeuchi, Atsuki

    1992-01-01

    Graft copolymer (NR-g-DMAA) tubes have been prepared using simultaneous radiation induced grafting of N,N-dimethyl-acrylamide, (DMAA) onto natural rubber (NR) tubes. The blood compatibility of the NR-g-DMAA tubes was assessed with three methods, namely in vitro test, ex vivo once through test and ex vivo loops test. In the case of the in vitro test, a simple whole blood contacting procedure has been employed. The ex vivo once through test involves the exposing of NR-g-DMAA tubes with once through flow of fresh canine blood and then it was inspected for any evidence of clot. In the case of ex vivo loops test, the NR-g-DMAA tube was implanted at external jugular vein of a mongrel canine and the blood flow in the NR-g-DMAA tube was detected with an ultrasonic flow meter. It was found that the blood compatibility of NR-g-DMAA tubes is improved significantly with the increasing degree of grafting. All the NR-g-DMAA tubes having a degree of grafting of about 30 wt% or more exhibit good blood compatibility. It was found that the blood compatibility of the NR-g-DMAA tube is better than that of a medical grade silicon rubber (SiR) tube. (Author)

  15. Red Blood Cell Hematocrit Influences Platelet Adhesion Rate in a Microchannel

    Science.gov (United States)

    Spann, Andrew; Campbell, James; Fitzgibbon, Sean; Rodriguez, Armando; Shaqfeh, Eric

    2014-11-01

    The creation of a blood clot to stop bleeding involves platelets forming a plug at the site of injury. Red blood cells indirectly play a role in ensuring that the distribution of platelets across the height of the channel is not uniform - the contrast in deformability and size between platelets and red blood cells allows the platelets to preferentially marginate close to the walls. We perform 3D boundary integral simulations of a suspension of platelets and red blood cells in a periodic channel with a model that allows for platelet binding at the walls. The relative rate of platelet activity with varying hematocrit (volume fraction of red blood cells) is compared to experiments in which red blood cells and platelets flow through a channel coated with von Willebrand factor. In the simulations as well as the experiments, a decrease in hematocrit of red blood cells is found to reduce the rate at which platelets adhere to the channel wall in a manner that is both qualitatively and quantitatively similar. We conclude with a discussion of the tumbling and wobbling motions of platelets in 3D leading up to the time at which the platelets bind to the wall. Funded by Stanford Army High Performance Computing Research Center, experiments by US Army Institute of Surgical Research.

  16. Ex-vivo response to blood products and haemostatic agents after paediatric cardiac surgery

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Andreasen, Jo B; Christiansen, Kirsten

    2013-01-01

    . The aims of the present study were to investigate changes in coagulation profiles after paediatric cardiac surgery and the effect after ex-vivo addition of blood products and haemostatic agents. Coagulation profiles were evaluated by thromboelastometry (ROTEM) in 54 children before and immediately after...... cardiac surgery. The haemostatic potential of various factor concentrates (fibrinogen concentrate, recombinant factor VIIa and factor XIII), fresh frozen plasma (FFP), pooled platelets and tranexamic acid was investigated. After surgery, the coagulation profiles revealed significantly prolonged clotting......Bleeding complications after cardiac surgery are of particular importance in children because they are more prone to volume overload. To optimize haemostatic intervention, the coagulopathy has to be characterized, and knowledge about the effect of blood products and haemostatic agents is needed...

  17. Theories About Blood Coagulation in the Writings of Ancient Greek Medico-philosophers.

    Science.gov (United States)

    Tsoucalas, Gregory; Karamanou, Marianna; Papaioannou, Theodoros G; Sgantzos, Markos

    2017-01-01

    Anaxagoras and Empedocles both established during the Presocratic era a pioneering theory for the creation of everything in the universe. Macrocosmos' impact through the "Four Elements Theory" explained the conglomeration of the blood inside the vessels. Hippocrates, who instituted the "Four Humours theory", clearly understood blood's coagulation and introduced the term "thrombus". Plato, Aristotle and Galen, all engaged with the clotting phenomenon trying to interpret it. After eons of inquiry, it was the innovative thinking of the ancient Greek medico philosophers that set the scientific bases towards the understanding of a process that had been analyzing until our era. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Role of plasmin on the double antibody radioimmunoassay of carcinoembryonic antigen in human blood samples

    International Nuclear Information System (INIS)

    Das, S.; Das, B.R.

    1976-01-01

    Double antibody radioimmunoassay (RIA) of carcinoembryonic antigen (CEA) on a series of freshly drawn out concurrent plasma and serum samples of normal human blood donors showed that the serum CEA values were invariably higher than the corresponding plasma CEA values. Extraneous addition of fibrinogen brought down the serum--CEA level to a value comparable to or less than the corresponding plasma value. The effect of certain factors associated with blood clotting, particularly Ca ++ , fibrinogen, and the fibrinolytic enzyme plasmin, was investigated. Ca ++ was shown to play no role whereas the effect of fibrinogen was shown to be indirect in that it served as a specific substrate for plasmin, thereby preventing the plasmin degradation of the primary antibody used in the RIA. The finding stresses the role of enzymes like plasmin in double antibody RIA in general and may explain some of the anomalous results obtained when testing biologic material containing plasmin-like substances

  19. Red blood cell alloimmunization after blood transfusion

    OpenAIRE

    Schonewille, Henk

    2008-01-01

    Current pretransfusion policy requires the patients’ serum to be tested for the presence of irregular red blood cell antibodies. In case of an antibody, red blood cells lacking the corresponding antigen are transfused after an antiglobulin crossmatch. The aim of the studies in this thesis is primarily to investigate whether this policy should change to improve transfusion safety. This thesis explores the risk on red blood cell alloimmunization after blood transfusion in oncohematologic patien...

  20. Blood vessels, circulation and blood pressure.

    Science.gov (United States)

    Hendry, Charles; Farley, Alistair; McLafferty, Ella

    This article, which forms part of the life sciences series, describes the vessels of the body's blood and lymphatic circulatory systems. Blood pressure and its regulatory systems are examined. The causes and management of hypertension are also explored. It is important that nurses and other healthcare professionals understand the various mechanisms involved in the regulation of blood pressure to prevent high blood pressure or ameliorate its damaging consequences.