1
|
Cudjoe EK, Hassan ZH, Kang L, Reynolds PS, Fisher BJ, McCarter J, Sweeney C, Martin EJ, Middleton P, Ellenberg M, Fowler AA, Spiess BD, Brophy DF, Hawkridge AM, Natarajan R. Temporal map of the pig polytrauma plasma proteome with fluid resuscitation and intravenous vitamin C treatment. J Thromb Haemost 2019; 17:1827-1837. [PMID: 31322812 DOI: 10.1111/jth.14580] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/16/2019] [Indexed: 01/12/2023]
Abstract
BACKGROUND Fluid resuscitation plays a prominent role in stabilizing trauma patients with hemorrhagic shock yet there remains uncertainty with regard to optimal administration time, volume, and fluid composition (e.g., whole blood, component, colloids) leading to complications such as trauma-induced coagulopathies (TIC), acidosis, and poor oxygen transport. Synthetic fluids in combination with antioxidants (e.g., vitamin C) may resolve some of these problems. OBJECTIVES We applied quantitative mass spectrometry-based proteomics [liquid chromatography-mass spectrometry (LC-MS/MS)] to map the effects of fluid resuscitation and intravenous vitamin C (VitC) in a pig model of polytrauma (hemorrhagic shock, tissue injury, liver reperfusion, hypothermia, and comminuted bone fracture). The goal was to determine the effects of VitC on plasma protein expression, with respect to changes associated with coagulation and trauma-induced coagulopathy (TIC). METHODS Longitudinal blood samples were drawn from nine male Sinclair pigs at baseline, 2 h post trauma, and 0.25, 2, and 4 h post fluid resuscitation with 500 mL hydroxyethyl starch. Pigs were treated intravenously (N = 3/treatment group) with saline, 50 mg VitC/kg (Lo-VitC), or 200 mg VitC/kg (Hi-VitC) during fluid resuscitation. RESULTS A total of 436 plasma proteins were quantified of which 136 changed following trauma and resuscitation; 34 were associated with coagulation, complement cascade, and glycolysis. Unexpectedly, Lo-VitC and Hi-VitC treatments stabilized ADAMTS13 levels by ~4-fold (P = .056) relative to saline and enhanced ADAMTS13/von Willebrand factor (VWF) cleavage efficiency based on LC-MS/MS evidence for the semitryptic VWF cleavage product (VWF1275-1286 ). CONCLUSIONS This study provides the first comprehensive map of trauma-induced changes to the plasma proteome, especially with respect to proteins driving the development of TIC.
Collapse
Affiliation(s)
- Emmanuel K Cudjoe
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
| | - Zaneera H Hassan
- Department of Pharmaceutics, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
| | - Le Kang
- Department of Biostatistics, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Penny S Reynolds
- Department of Anesthesiology, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Bernard J Fisher
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Jacquelyn McCarter
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Christopher Sweeney
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Erika J Martin
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
| | - Paul Middleton
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Matthew Ellenberg
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Alpha A Fowler
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Bruce D Spiess
- Department of Anesthesiology, Virginia Commonwealth University Medical Center, Richmond, Virginia
| | - Donald F Brophy
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
| | - Adam M Hawkridge
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
- Department of Pharmaceutics, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
- Institute for Structural Biology, Drug Discovery, and Development, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia
| | - Ramesh Natarajan
- Department of Internal Medicine, Virginia Commonwealth University Medical Center, Richmond, Virginia
| |
Collapse
|
2
|
Reynolds PS, Fisher BJ, McCarter J, Sweeney C, Martin EJ, Middleton P, Ellenberg M, Fowler E, Brophy DF, Fowler AA, Spiess BD, Natarajan R. Interventional vitamin C: A strategy for attenuation of coagulopathy and inflammation in a swine multiple injuries model. J Trauma Acute Care Surg 2018; 85:S57-S67. [PMID: 29538225 DOI: 10.1097/ta.0000000000001844] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Coagulopathy and inflammation induced by hemorrhagic shock and traumatic injury are associated with increased mortality and morbidity. Vitamin C (VitC) is an antioxidant with potential protective effects on the proinflammatory and procoagulant pathways. We hypothesized that high-dose VitC administered as a supplement to fluid resuscitation would attenuate inflammation, coagulation dysfunction, and end-organ tissue damage in a swine model of multiple injuries and hemorrhage. METHODS Male Sinclair swine (n = 24; mean body weight, 27 kg) were anesthetized, intubated, mechanically ventilated, and instrumented for physiologic monitoring. Following stabilization, swine were subjected to shock/traumatic injury (hypothermia, liver ischemia and reperfusion, comminuted femur fracture, hemorrhagic hypotension), resuscitated with 500 mL of hydroxyethyl starch, and randomized to receive either intravenous normal saline (NS), low-dose VitC (50 mg/kg; LO), or high-dose VitC (200 mg/kg; HI). Hemodynamics, blood chemistry, hematology, and coagulation function (ROTEM) were monitored to 4 hours postresuscitation. Histological and molecular analyses were obtained for liver, kidney, and lung. RESULTS Compared with VitC animals, NS swine showed significant histological end-organ damage, elevated acute lung injury scores, and increased mRNA expression of tissue proinflammatory mediators (IL-1β, IL-8, TNFα), plasminogen activation inhibitor-1 and tissue factor. There were no statistically significant differences between treatment groups on mean arterial pressure or univariate measures of coagulation function; however, NS showed impaired multivariate clotting function at 4 hours. CONCLUSION Although correction of coagulation dysfunction was modest, intravenous high-dose VitC may mitigate the proinflammatory/procoagulant response that contributes to multiple organ failure following acute severe multiple injuries. LEVEL OF EVIDENCE Prospective randomized controlled blinded trial study, Preclinical (animal-based).
Collapse
Affiliation(s)
- Penny S Reynolds
- From the Department of Anesthesiology (P.S.R., B.D.S.), Department of Internal Medicine (B.J.F., J.M., C.S., P.M., M.E., E.F., A.A.F., R.N.), Department of Pharmacotherapy and Outcomes Science (E.J.M., D.F.B.), Virginia Commonwealth University, Richmond, Virginia; Department of Anesthesiology (P.S.R., B.D.S.), University of Florida, Gainesville, Florida; and Naval Medical Center Portsmouth (R.N.), Portsmouth, Virginia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
3
|
Impaired contraction of blood clots as a novel prothrombotic mechanism in systemic lupus erythematosus. Clin Sci (Lond) 2018; 132:243-254. [PMID: 29295895 DOI: 10.1042/cs20171510] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 12/13/2017] [Accepted: 01/01/2018] [Indexed: 11/17/2022]
Abstract
The aim of this work was to examine a possible role of clot contraction/retraction in thrombotic complications of systemic lupus erythematosus (SLE). Using a novel automated method, we investigated kinetics of clot contraction in the blood of 51 SLE patients and 60 healthy donors. The functionality of platelets in the SLE patients was assessed using flow cytometry by expression of P-selectin and fibrinogen-binding capacity. The rate and degree of clot contraction were significantly reduced in SLE patients compared with healthy subjects, especially in the patients with higher blood levels of anti-dsDNA antibodies. The reduced platelet contractility correlated with partial refractoriness of platelets isolated from the blood of SLE patients to stimulation induced by the thrombin receptor activating peptide. To test if the anti-dsDNA autoantibodies cause continuous platelet activation, followed by exhaustion and dysfunction of the cells, we added purified exogenous anti-dsDNA autoantibodies from SLE patients to normal blood before clotting. In support of this hypothesis, the antibodies first enhanced clot contraction and then suppressed it in a time-dependent manner. Importantly, a direct correlation of clot contraction parameters with the disease severity suggests that the reduced compactness of intravascular clots and thrombi could be a pathogenic factor in SLE that may exaggerate the impaired blood flow at the site of thrombosis. In conclusion, autoantibodies in SLE can affect platelet contractility, resulting in reduced ability of clots and thrombi to shrink in volume, which increases vessel obstruction and may aggravate the course and outcomes of thrombotic complications in SLE.
Collapse
|
4
|
Activated Monocytes Enhance Platelet-Driven Contraction of Blood Clots via Tissue Factor Expression. Sci Rep 2017; 7:5149. [PMID: 28698680 PMCID: PMC5506001 DOI: 10.1038/s41598-017-05601-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 05/31/2017] [Indexed: 01/13/2023] Open
Abstract
Platelet-driven reduction in blood clot volume (clot contraction or retraction) has been implicated to play a role in hemostasis and thrombosis. Although these processes are often linked with inflammation, the role of inflammatory cells in contraction of blood clots and thrombi has not been investigated. The aim of this work was to study the influence of activated monocytes on clot contraction. The effects of monocytes were evaluated using a quantitative optical tracking methodology to follow volume changes in a blood clot formed in vitro. When a physiologically relevant number of isolated human monocytes pre-activated with phorbol-12-myristate-13-acetate (PMA) were added back into whole blood, the extent and rate of clot contraction were increased compared to addition of non-activated cells. Inhibition of tissue factor expression or its inactivation on the surface of PMA-treated monocytes reduced the extent and rate of clot contraction back to control levels with non-activated monocytes. On the contrary, addition of tissue factor enhanced clot contraction, mimicking the effects of tissue factor expressed on the activated monocytes. These data suggest that the inflammatory cells through their expression of tissue factor can directly affect hemostasis and thrombosis by modulating the size and density of intra- and extravascular clots and thrombi.
Collapse
|
5
|
Tutwiler V, Wang H, Litvinov RI, Weisel JW, Shenoy VB. Interplay of Platelet Contractility and Elasticity of Fibrin/Erythrocytes in Blood Clot Retraction. Biophys J 2017; 112:714-723. [PMID: 28256231 DOI: 10.1016/j.bpj.2017.01.005] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/17/2016] [Accepted: 01/06/2017] [Indexed: 12/15/2022] Open
Abstract
Blood clot contraction (retraction) is driven by platelet-generated forces propagated by the fibrin network and results in clot shrinkage and deformation of erythrocytes. To elucidate the mechanical nature of this process, we developed a model that combines an active contractile motor element with passive viscoelastic elements. Despite its importance for thrombosis and wound healing, clot contraction is poorly understood. This model predicts how clot contraction occurs due to active contractile platelets interacting with a viscoelastic material, rather than to the poroelastic nature of fibrin, and explains the observed dynamics of clot size, ultrastructure, and measured forces. Mechanically passive erythrocytes and fibrin are present in series and parallel to active contractile cells. This mechanical interplay induces compressive and tensile resistance, resulting in increased contractile force and a reduced extent of contraction in the presence of erythrocytes. This experimentally validated model provides the fundamental mechanical basis for understanding contraction of blood clots.
Collapse
Affiliation(s)
- Valerie Tutwiler
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; School of Biomedical Engineering, Sciences and Health Systems, Drexel University, Philadelphia, Pennsylvania
| | - Hailong Wang
- Department of Modern Mechanics, CAS Key Laboratory of Mechanical Behavior and Design of Materials, University of Science and Technology of China, Hefei, Anhui, China; Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rustem I Litvinov
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John W Weisel
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Vivek B Shenoy
- Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania.
| |
Collapse
|
6
|
Hudson NE. Biophysical Mechanisms Mediating Fibrin Fiber Lysis. BIOMED RESEARCH INTERNATIONAL 2017; 2017:2748340. [PMID: 28630861 PMCID: PMC5467299 DOI: 10.1155/2017/2748340] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 04/30/2017] [Indexed: 01/19/2023]
Abstract
The formation and dissolution of blood clots is both a biochemical and a biomechanical process. While much of the chemistry has been worked out for both processes, the influence of biophysical properties is less well understood. This review considers the impact of several structural and mechanical parameters on lytic rates of fibrin fibers. The influences of fiber and network architecture, fiber strain, FXIIIa cross-linking, and particle transport phenomena will be assessed. The importance of the mechanical aspects of fibrinolysis is emphasized, and future research avenues are discussed.
Collapse
Affiliation(s)
- Nathan E. Hudson
- Department of Physics, East Carolina University, N304 Howell Science Complex, Greenville, NC 27858, USA
| |
Collapse
|
7
|
Mehta AY, Mohammed BM, Martin EJ, Brophy DF, Gailani D, Desai UR. Allosterism-based simultaneous, dual anticoagulant and antiplatelet action: allosteric inhibitor targeting the glycoprotein Ibα-binding and heparin-binding site of thrombin. J Thromb Haemost 2016; 14:828-38. [PMID: 26748875 PMCID: PMC4828251 DOI: 10.1111/jth.13254] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/24/2015] [Indexed: 12/01/2022]
Abstract
BACKGROUND Allosteric inhibition is a promising approach for developing a new group of anticoagulants with potentially reduced bleeding consequences. Recently, we designed sulfated β-O4 lignin (SbO4L) as an allosteric inhibitor that targets exosite 2 of thrombin to reduce fibrinogen cleavage through allostery and compete with glycoprotein Ibα to reduce platelet activation. OBJECTIVE To assess: (i) the antithrombotic potential of a novel approach of simultaneous exosite 2-dependent allosteric inhibition of thrombin and competitive inhibition of platelet activation; and (ii) the promise of SbO4L as the first-in-class antithrombotic agent. METHODS A combination of whole blood thromboelastography, hemostasis analysis, mouse arterial thrombosis models and mouse tail bleeding studies were used to assess antithrombotic potential. RESULTS AND CONCLUSIONS SbO4L extended the clot initiation time, and reduced maximal clot strength, platelet contractile force, and the clot elastic modulus, suggesting dual anticoagulant and antiplatelet effects. These effects were comparable to those observed with enoxaparin. A dose of 1 mg of SbO4L per mouse prevented occlusion in 100% of arteries, and lower doses resulted in a proportionally reduced response. Likewise, the time to occlusion increased by ~ 70% with a 0.5-mg dose in the mouse Rose Bengal thrombosis model. Finally, tail bleeding studies demonstrated that SbO4L does not increase bleeding propensity. In comparison, a 0.3-mg dose of enoxaparin increased the bleeding time and blood volume loss. Overall, this study highlights the promise of the allosteric inhibition approach, and presents SbO4L as a novel anticoagulant with potentially reduced bleeding side effects.
Collapse
Affiliation(s)
- Akul Y. Mehta
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Bassem M. Mohammed
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA 23298, USA
- Department of Clinical Pharmacy, Faculty of Pharmacy, Cairo University, Cairo 11562, Egypt
| | - Erika J. Martin
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Donald F. Brophy
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - David Gailani
- Department of Pathology, Immunology and Microbiology, Vanderbilt University Medical Center, Nashville, TN 37203
| | - Umesh R. Desai
- Department of Medicinal Chemistry and Institute for Structural Biology, Drug Discovery and Development, Virginia Commonwealth University, Richmond, VA 23219, USA
| |
Collapse
|
8
|
Kinetics and mechanics of clot contraction are governed by the molecular and cellular composition of the blood. Blood 2015; 127:149-59. [PMID: 26603837 DOI: 10.1182/blood-2015-05-647560] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 11/17/2015] [Indexed: 12/17/2022] Open
Abstract
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.
Collapse
|
9
|
Shiu HT, Goss B, Lutton C, Crawford R, Xiao Y. Formation of blood clot on biomaterial implants influences bone healing. TISSUE ENGINEERING PART B-REVIEWS 2014; 20:697-712. [PMID: 24906469 DOI: 10.1089/ten.teb.2013.0709] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The first step in bone healing is forming a blood clot at injured bones. During bone implantation, biomaterials unavoidably come into direct contact with blood, leading to a blood clot formation on its surface prior to bone regeneration. Despite both situations being similar in forming a blood clot at the defect site, most research in bone tissue engineering virtually ignores the important role of a blood clot in supporting healing. Dental implantology has long demonstrated that the fibrin structure and cellular content of a peri-implant clot can greatly affect osteoconduction and de novo bone formation on implant surfaces. This article reviews the formation of a blood clot during bone healing in relation to the use of platelet-rich plasma (PRP) gels. It is implicated that PRP gels are dramatically altered from a normal clot in healing, resulting in conflicting effect on bone regeneration. These results indicate that the effect of clots on bone regeneration depends on how the clots are formed. Factors that influence blood clot structure and properties in relation to bone healing are also highlighted. Such knowledge is essential for developing strategies to optimally control blood clot formation, which ultimately alter the healing microenvironment of bone. Of particular interest are modification of surface chemistry of biomaterials, which displays functional groups at varied composition for the purpose of tailoring blood coagulation activation, resultant clot fibrin architecture, rigidity, susceptibility to lysis, and growth factor release. This opens new scope of in situ blood clot modification as a promising approach in accelerating and controlling bone regeneration.
Collapse
Affiliation(s)
- Hoi Ting Shiu
- 1 Science and Engineering Faculty, Institute of Health and Biomedical Innovation, Queensland University of Technology , Brisbane, Australia
| | | | | | | | | |
Collapse
|
10
|
Rusak T, Piszcz J, Misztal T, Brańska-Januszewska J, Tomasiak M. Platelet-related fibrinolysis resistance in patients suffering from PV. Impact of clot retraction and isovolemic erythrocytapheresis. Thromb Res 2014; 134:192-8. [DOI: 10.1016/j.thromres.2014.04.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 04/04/2014] [Accepted: 04/23/2014] [Indexed: 11/27/2022]
|
11
|
Shiu HT, Goss B, Lutton C, Crawford R, Xiao Y. Controlling whole blood activation and resultant clot properties by carboxyl and alkyl functional groups on material surfaces: a possible therapeutic approach for enhancing bone healing. J Mater Chem B 2014; 2:3009-3021. [DOI: 10.1039/c4tb00009a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Most research virtually ignores the important role of a blood clot in supporting bone healing.
Collapse
Affiliation(s)
- Hoi Ting Shiu
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Ben Goss
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Cameron Lutton
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Ross Crawford
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| | - Yin Xiao
- Bone and Tissue Engineering
- Institute of Health and Biomedical Innovation
- Queensland University of Technology
- Brisbane, Australia
| |
Collapse
|
12
|
McLean KC, Bernstein IM, Brummel-Ziedins KE. Tissue factor-dependent thrombin generation across pregnancy. Am J Obstet Gynecol 2012; 207:135.e1-6. [PMID: 22840726 DOI: 10.1016/j.ajog.2012.05.027] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/16/2012] [Accepted: 05/30/2012] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Normal pregnancy results in a prothrombotic state. Studies that have investigated the capacity of pregnant women to generate thrombin are limited. Our aim was to evaluate thrombin generation longitudinally from the preconception period, through pregnancy, and after pregnancy. STUDY DESIGN We evaluated young, healthy nulligravid women (n = 20) at 4 time points and compared the data with 10 control women at 2 time points. Coagulation was initiated with tissue factor in contact pathway inhibited plasma, and thrombin generation was determined in the presence of a fluorogenic substrate. RESULTS The maximum level and rate of thrombin generation increased during pregnancy; the highest level and rate occurred in late pregnancy compared with prepregnancy (P < .001). Subsequently, thrombin generation decreased in the postpregnancy samples that included maximum level, rate, and area under the curve (P < .001). CONCLUSION Our data provide evidence for an increase in tissue factor-dependent thrombin generation with pregnancy progression, followed by a return to prepregnancy thrombin levels.
Collapse
Affiliation(s)
- Kelley C McLean
- Department of Obstetrics, Gynecology, and Reproductive Sciences, Fletcher Allen Health Care/University of Vermont, Burlington, USA
| | | | | |
Collapse
|
13
|
Feghhi S, Sniadecki NJ. Mechanobiology of platelets: techniques to study the role of fluid flow and platelet retraction forces at the micro- and nano-scale. Int J Mol Sci 2011; 12:9009-30. [PMID: 22272117 PMCID: PMC3257114 DOI: 10.3390/ijms12129009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 11/24/2011] [Accepted: 11/28/2011] [Indexed: 12/29/2022] Open
Abstract
Coagulation involves a complex set of events that are important in maintaining hemostasis. Biochemical interactions are classically known to regulate the hemostatic process, but recent evidence has revealed that mechanical interactions between platelets and their surroundings can also play a substantial role. Investigations into platelet mechanobiology have been challenging however, due to the small dimensions of platelets and their glycoprotein receptors. Platelet researchers have recently turned to microfabricated devices to control these physical, nanometer-scale interactions with a higher degree of precision. These approaches have enabled exciting, new insights into the molecular and biomechanical factors that affect platelets in clot formation. In this review, we highlight the new tools used to understand platelet mechanobiology and the roles of adhesion, shear flow, and retraction forces in clot formation.
Collapse
Affiliation(s)
- Shirin Feghhi
- Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA; E-Mail:
| | - Nathan J. Sniadecki
- Department of Mechanical Engineering, University of Washington, Stevens Way, Box 352600, Seattle, WA 98195, USA; E-Mail:
- Department of Bioengineering, University of Washington, 3720 15th Ave NE, Seattle, WA 98105, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-206-685-6591; Fax: +1-206-685-8047
| |
Collapse
|
14
|
Mooney R, Tawil B, Mahoney M. Specific Fibrinogen and Thrombin Concentrations Promote Neuronal Rather Than Glial Growth When Primary Neural Cells Are Seeded Within Plasma-Derived Fibrin Gels. Tissue Eng Part A 2010; 16:1607-19. [DOI: 10.1089/ten.tea.2009.0372] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Rachael Mooney
- Department of Biochemistry, University of Colorado, Boulder, Colorado
| | - Bill Tawil
- Bioengineering Department, University of California at Los Angeles, Los Angeles, California
| | - Melissa Mahoney
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, Colorado
| |
Collapse
|
15
|
White NJ, Martin EJ, Brophy DF, Ward KR. Coagulopathy and traumatic shock: characterizing hemostatic function during the critical period prior to fluid resuscitation. Resuscitation 2009; 81:111-6. [PMID: 19854556 DOI: 10.1016/j.resuscitation.2009.09.017] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 09/19/2009] [Indexed: 11/26/2022]
Abstract
AIMS Identifying early changes in hemostatic clot function as a result of tissue injury and hypoperfusion may provide important information regarding the mechanisms of traumatic coagulopathy. A combat-relevant swine model was used to investigate the development of coagulopathy during trauma by monitoring hemostatic function during increasing severity of shock. METHODS Swine were injured (soft tissue+femur fracture) and hemorrhaged while continuously monitoring Oxygen Debt (OD) by indirect calorimetry at the airway. Hemostatic function was assessed by Thrombelastography (TEG), Prothrombin Time (PT), Partial Thromboplastin Time (PTT), and fibrinogen concentration and compared before hemorrhage (D0) and during shock when OD=40 and 80 ml/kg. An instrumented sham group was used for comparison. RESULTS N=23 swine (N=18 hemorrhage, N=5 sham) weighing 45+/-6 kg were studied after removing an average of 34+/-14% of blood volume during hemorrhage. Hgb, Hct, platelet counts, PT and PTT did not change with increasing OD (p<0.05). Fibrinogen was reduced significantly by OD=40 ml/kg (mean diff.=-59.9 mg/dl, 95% CI diff. [-95.1, -24.6]). TEG parameters representing clot initiation (R) and polymerization (K and Alpha Angle) did not change with increasing OD during shock (p>0.053). Clot strength (MA) was reduced in the hemorrhage group by OD=80 ml/kg (mean diff.=-4.1mm, 95% CI diff. [-7.4, -0.8]). CONCLUSION In this swine model of traumatic shock, fibrinogen was significantly reduced and an isolated reduction in clot strength (MA) was found with increasing OD. Fibrinogen consumption and altered platelet function may account for the earliest changes in hemostatic function during traumatic shock.
Collapse
Affiliation(s)
- Nathan J White
- Department of Emergency Medicine, Virginia Commonwealth University, AD Williams Clinic 2nd Floor, Room 242, 1201 East Marshall Street, Richmond, VA 23298, USA.
| | | | | | | |
Collapse
|
16
|
Impact of fibrinogen concentration in severely ill patients on mechanical properties of whole blood clots. Blood Coagul Fibrinolysis 2008; 19:765-70. [DOI: 10.1097/mbc.0b013e32830f1b68] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
17
|
Neeves KB, Diamond SL. A membrane-based microfluidic device for controlling the flux of platelet agonists into flowing blood. LAB ON A CHIP 2008; 8:701-9. [PMID: 18432339 PMCID: PMC2612095 DOI: 10.1039/b717824g] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The flux of platelet agonists into flowing blood is a critical event in thrombosis and hemostasis. However, few in vitro methods exist for examining and controlling the role of platelet agonists on clot formation and stability under hemodynamic conditions. In this paper, we describe a membrane-based method for introducing a solute into flowing blood at a defined flux. The device consisted of a track-etched polycarbonate membrane reversibly sealed between two microfluidic channels; one channel contained blood flowing at a physiologically relevant shear rate, and the other channel contained the agonist(s). An analytical model described the solute flux as a function of the membrane permeability and transmembrane pressure. The model was validated using luciferase as a model solute for transmembrane pressures of 50-400 Pa. As a proof-of-concept, the weak platelet agonist ADP was introduced into whole blood flowing at 250 s(-1) at three fluxes (1.5, 2.4, and 4.4 x 10(-18) mol microm(-2) s(-1)). Platelet aggregation was monitored by fluorescence microscopy during the experiment and the morphology of aggregates was determined by post hoc confocal and electron microscopy. At the lowest flux (1.5 x 10(-18) mol microm(-2) s(-1)), we observed little to no aggregation. At the higher fluxes, we observed monolayer (2.4 x 10(-18) mol microm(-2) s(-1)) and multilayer (4.4 x 10(-18) mol microm(-2) s(-1)) aggregates of platelets and found that the platelet density within an aggregate increased with increasing ADP flux. We expect this device to be a useful tool in unraveling the role of platelet agonists on clot formation and stability.
Collapse
Affiliation(s)
- Keith B. Neeves
- 1050 Vagelos Laboratories, Department of Chemical and Biomolecular Engineering and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Scott L. Diamond
- 1050 Vagelos Laboratories, Department of Chemical and Biomolecular Engineering and Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, 19104, USA
| |
Collapse
|
18
|
Brummel-Ziedins K, Undas A, Orfeo T, Gissel M, Butenas S, Zmudka K, Mann KG. Thrombin generation in acute coronary syndrome and stable coronary artery disease: dependence on plasma factor composition. J Thromb Haemost 2008; 6:104-10. [PMID: 17944993 DOI: 10.1111/j.1538-7836.2007.02799.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Acute coronary syndrome (ACS) is associated with thrombin formation, triggered by ruptured or eroded coronary atheroma. We investigated whether thrombin generation based on circulating coagulation protein levels, could distinguish between acute and stable coronary artery disease (CAD). METHODS AND RESULTS Plasma coagulation factor (F) compositions from 28 patients with ACS were obtained after onset of chest pain. Similar data were obtained from 25 age- and sex-matched patients with stable CAD. All individuals took aspirin. Patients on anticoagulant therapy were excluded. The groups were similar in demographic characteristics, comorbidities and concomitant treatment. Using each individual's coagulation protein composition, tissue factor (TF) initiated thrombin generation was assessed both computationally and empirically. TF pathway inhibitor (TFPI), antithrombin (AT), factor II (FII) and FVIII differed significantly (P < 0.01) between the groups, with levels of FII, FVIII and TFPI higher and AT lower in ACS patients. When thrombin generation profiles from individuals in each group were compared, simulated maximum thrombin levels (P < 0.01) and rates (P < 0.01) were 50% higher with ACS while the initiation phases of thrombin generation were shorter. Empirical reconstructions of the populations reproduced the thrombin generation profiles generated by the computational model. The differences between the thrombin generation profiles for each population were primarily dependent upon the collective contribution of AT, FII and FVIII. CONCLUSION Simulations of thrombin formation based on plasma composition can discriminate between acute and stable CAD.
Collapse
|
19
|
Dempfle CE, Bindeballe N, Münchbach M, Blume C, Borggrefe M, Mosesson MW. Changes in fibrinogen and fibrin induced by a peptide analog of fibrinogen gamma365-380. J Thromb Haemost 2007; 5:1707-14. [PMID: 17663740 DOI: 10.1111/j.1538-7836.2007.02633.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The effects of synthetic peptides with sequences derived from the gamma-chain of fibrinogen on the functional properties of fibrinogen and fibrin were investigated. METHODS Methods included thrombelastography, clot turbidity measurement, clot elasticity measurement, platelet aggregation, and scanning transmission electron microscopy (STEM). RESULTS Peptide gamma369-380 (NH(2)-WATWKTRWYSMK-COOH) showed the greatest impact on fibrin structure, compared with the 76 other overlapping dodecapeptides. Addition of this peptide, or peptide gamma365-380 (NH(2)-NGIIWATKTREWYSMK-COOH) to a mixture of fibrinogen and thrombin resulted a shorter clotting time, higher clot turbidity, lower clot elastic modulus, a higher degree of D-trimer and D-tetramer formation, and impaired plasmin proteolysis of the clot. In STEM, fibrin formed in the presence of peptide gamma369-380 consisted of a more extensive array of linear fibrils typically consisting of 20 or more molecules. Fibrils were better organized than those from non-peptide containing mixtures. CONCLUSIONS Replacement of the tryptophan residue gamma376 massively reduced the effect of the peptide on fibrin structure. Binding of the peptide to fibrinogen induces conformational changes, which result in accelerated clotting and increased lateral association of fibrin protofibrils. The results imply a relevant functional role of sites interacting with peptide gamma369-380 region in the fibrinogen molecule.
Collapse
Affiliation(s)
- C-E Dempfle
- I. Department of Medicine, University Hospital of Mannheim, Mannheim, Germany.
| | | | | | | | | | | |
Collapse
|
20
|
|
21
|
Brummel-Ziedins K, Whelihan MF, Ziedins EG, Mann KG. The Resuscitative Fluid You Choose May Potentiate Bleeding. ACTA ACUST UNITED AC 2006; 61:1350-8. [PMID: 17159676 DOI: 10.1097/01.ta.0000235525.64176.01] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Trauma is the leading cause of death in the younger population in the United States, frequently from the development of hemorrhagic shock. Controversy exists over the type of volume resuscitation for restoring hemodynamic stability that should be used in hemorrhagic shock. Little is known about how various resuscitative paradigms affect the coagulation cascade, which is essential to controlling hemorrhagic shock. METHODS We studied the effect of various resuscitative formulas on blood coagulation using a new model of whole blood in a controlled setting with corn trypsin inhibitor and a 5-pM stimulus of tissue factor. We investigated thrombin generation, fibrin formation, and platelet activation with four diluents: 0.9% NaCl (NS), lactated Ringer's solution (LR), 6% hydroxyethyl starch (HES), and 3% NaCl (HS), each from 0% to 75% blood dilution. Thrombin generation was measured periodically during a time course of 20 minutes in its complex with antithrombin III. Platelet activation and fibrinopeptide A (FPA) release were monitored in serum at a 20-minute time point. Fibrin clots were collected and weighed. RESULTS The coagulation markers (thrombin generation, platelet activation, and FPA release) were significantly different by dilution (p < 0.001 in all) and diluent by dilution (p < 0.001 in all). Thrombin generation, platelet activation, and FPA release decreased the least with the diluents NS and LR. LR caused the least amount of variation in thrombin generation over the dilution course. HS produced the most dramatic change in all of the markers; no coagulation was seen between 30% to 75% dilution (p < 0.05). HES produced greater decreases in thrombin generation and FPA release than NS and LR. Fibrin clot mass decreased with a 10% to 20% dilution for NS and LR, whereas stable fibrin mass did not decrease with the diluents HES and HS at 10% to 20% dilutions. At >30% dilutions, HS produced no stable clots and HES dramatically decreased clot formation by 61% and maintained this level. CONCLUSIONS LR and NS had the least effect on thrombin generation, clot formation, and platelet activation at various concentrations compared with HES and HS. This observational data suggests that volume expanders such as HES and HS may be detrimental in treatment of hemorrhagic shock.
Collapse
Affiliation(s)
- Kathleen Brummel-Ziedins
- Department of Biochemistry, School of Medicine, University of Vermont, Burlington, Vermont 05405, USA.
| | | | | | | |
Collapse
|
22
|
Gennisson JL, Lerouge S, Cloutier G. Assessment by transient elastography of the viscoelastic properties of blood during clotting. ULTRASOUND IN MEDICINE & BIOLOGY 2006; 32:1529-37. [PMID: 17045874 DOI: 10.1016/j.ultrasmedbio.2006.06.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2005] [Revised: 06/01/2006] [Accepted: 06/08/2006] [Indexed: 05/12/2023]
Abstract
Blood clotting is a natural process that can be both beneficial and life-threatening for the human body. It allows the maintenance of hemostasis after vascular injury, but it can also cause deep vein thrombosis and heart stroke. This study aimed better to understand the clotting process from a biomechanical point of view by using an acoustic method. The long-term objective is the staging of the age of clots in deep veins for therapy planning. The transient elastography method using a shear elasticity probe served to evaluate the shear wave velocity (V(S)) and shear wave attenuation (alpha(S)) of porcine whole blood during in vitro clot formation. By solving an inverse problem, it was then possible to provide images of the elasticity (mu(B)) and of the viscosity (eta(B)) from clotting blood. The time-varying elasticity and viscosity were very similar to what has been observed for the sol-gel transition of polymers. The mechanical properties of blood clot, which were modified by varying the hematocrit and by adding heparin or fibrinogen, were clearly assessed by the transient elastography technique. It is concluded that the shear elasticity probe is an appropriate tool to quantify and follow the sol-gel transition of blood during clotting.
Collapse
Affiliation(s)
- Jean-Luc Gennisson
- Laboratory of Biorheology and Medical Ultrasonics, University of Montreal Hospital Research Center, Montreal, Quebec, Canada
| | | | | |
Collapse
|
23
|
BRUMMEL-ZIEDINS K, VOSSEN CY, ROSENDAAL FR, UMEZAKI K, MANN KG. The plasma hemostatic proteome: thrombin generation in healthy individuals. J Thromb Haemost 2005; 3:1472-81. [PMID: 15978105 PMCID: PMC1414093 DOI: 10.1111/j.1538-7836.2005.01249.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND OBJECTIVES The range of plasma concentrations of hemostatic analytes in the population is wide. In this study these components of blood coagulation phenotype are integrated in an attempt to predict clinical risk. METHODS We modeled tissue factor (TF)-induced thrombin generation in the control population (N = 473) from the Leiden Thrombophilia Study utilizing a numerical simulation model. Hypothetical thrombin generation curves were established by modeling pro- and anticoagulant factor levels for each individual. These curves were evaluated using parameters which describe the initiation, propagation and termination phases of thrombin generation, i.e. time to 10 nm thrombin (approximate clot time), total thrombin and the maximum rates and levels of thrombin generated. RESULTS AND CONCLUSIONS The time to 10 nm thrombin varied over a 3-fold range (2.9-9.5 min), maximum levels varied over a approximately 4-fold range (200-800 nm), maximum rates varied approximately 4.8-fold (90-435 nm min(-1)) and total thrombin varied approximately 4.5-fold (39-177 microm s(-1)) within this control population. Thrombin generation curves, defined by the clotting factor concentrations, were distinguished by sex, age, alcohol consumption, body mass index (BMI) and oral contraceptive (OC) use (OC > sex > BMI > age). Our results show that the capacity for thrombin generation in response to a TF challenge may represent a method to identify an individual's propensity for developing thrombosis.
Collapse
Affiliation(s)
- K. BRUMMEL-ZIEDINS
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, VT, USA; and
| | - C. Y. VOSSEN
- Department of Clinical Epidemiology and Hemostasis and Thrombosis Research Center, Leiden University Medical Center, Leiden, the Netherlands
| | - F. R. ROSENDAAL
- Department of Clinical Epidemiology and Hemostasis and Thrombosis Research Center, Leiden University Medical Center, Leiden, the Netherlands
| | - K. UMEZAKI
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, VT, USA; and
| | - K. G. MANN
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, VT, USA; and
| |
Collapse
|
24
|
Brophy DF, Martin EJ, Best AM, Gehr TWB, Carr ME. Antifactor Xa activity correlates to thrombin generation time, platelet contractile force and clot elastic modulus following ex vivo enoxaparin exposure in patients with and without renal dysfunction. J Thromb Haemost 2004; 2:1299-304. [PMID: 15304034 DOI: 10.1111/j.1538-7836.2004.00789.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Antifactor Xa activity is the gold standard monitoring parameter for low molecular weight heparin (LMWH) derivatives. It is frequently measured in high-risk populations, such as patients with renal dysfunction. Despite antifactor Xa monitoring, however, bleeding in renal dysfunction patients receiving LMWH remains a problem. This study determined the relationship between antifactor Xa activity and three novel coagulation monitoring parameters: thrombin generation time (TGT), platelet contractile force (PCF) and clot elastic modulus (CEM). This study also assessed the effect of renal dysfunction on these relationships. This was an ex vivo pharmacodynamic study of the relationship between antifactor Xa activity and TGT, PCF and CEM in subjects both with and without renal dysfunction. Thirty subjects completed this study (10 controls, 10 chronic kidney disease subjects, and 10 end-stage renal disease subjects receiving hemodialysis). Blood samples obtained from participants were spiked with increasing enoxaparin concentrations (0.25, 0.5, 1.0 and 3.0 IU mL(-1)). Samples were analyzed for TGT, PCF and CEM. The relationship between antifactor Xa activity and TGT, PCF and CEM was determined by Pearson's correlation. The effect of renal dysfunction on the relationship between antifactor Xa activity and TGT, PCF and CEM was determined by analysis of covariance. There is strong correlation between antifactor Xa activity and TGT, CEM and PCF. The presence of renal dysfunction significantly prolongs the TGT, and decreases the CEM relative to controls. These results suggest that patients with renal dysfunction have a greater pharmacodynamic response to LMWH, independent of the pharmacokinetics of LMWH.
Collapse
Affiliation(s)
- D F Brophy
- Department of Pharmacy, Virginia Commonwealth University, Medical College of Virginia Campus, Richmond, Virginia, USA.
| | | | | | | | | |
Collapse
|
25
|
Sundell IB, Rånby M, Zuzel M, Robinson KA, Theakston RDG. In vitro procoagulant and anticoagulant properties of Naja naja naja venom. Toxicon 2003; 42:239-47. [PMID: 14559074 DOI: 10.1016/s0041-0101(03)00137-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bites by the Indian cobra (Naja naja naja) are common in India and Sri Lanka because of its close association with humans. Cobra venoms are complex and contain several toxic components, including neurotoxins that cause post-synaptic neuromuscular blockade with respiratory paralysis and even death. Bites may also cause extensive local necrosis by mechanisms not fully elucidated. Although no significant coagulopathy has been reported, N.n. naja venom can form blood clots in vitro by activating prothrombin as demonstrated by thrombin-specific chromogenic substrate. Scanning electron microscopy demonstrates that the clots formed by venom lack the thin fibrin strands of normal blood clots formed by thromboplastin or glass contact. Rheometry shows that clots formed by venom have abnormally low elasticity over an extended period and then, as the platelets contract, a retarded and more feeble increase in elasticity. Purified N.n. naja venom PLA2 inhibits platelet aggregation in PRP and explains the decreased clot retraction and retarded and compromised elasticity build up. The present study shows that the PLA2 and the prothrombin activator from N.n. naja venom have effects on haemostasis and blood clotting, although such effects are not observed systemically in envenomed humans.
Collapse
Affiliation(s)
- I B Sundell
- Department of Haematology, University of Liverpool, Liverpool L69 3GA, UK.
| | | | | | | | | |
Collapse
|
26
|
|
27
|
Carr ME, Martin EJ, Kuhn JG, Spiess BD. Onset of force development as a marker of thrombin generation in whole blood: the thrombin generation time (TGT). J Thromb Haemost 2003; 1:1977-83. [PMID: 12941040 DOI: 10.1046/j.1538-7836.2003.00337.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Prothrombin activation requires the direct interplay of activated platelets and plasma clotting factors. Once formed, thrombin causes profound, irreversible activation of platelets and reinforces the platelet plug via fibrin formation. Delayed or deficient thrombin production increases bleeding risk. Commonly employed coagulation assays, the prothrombin and partial thromboplastin times, use clot formation as a surrogate marker of thrombin generation. These assays routinely utilize platelet-poor plasma and completely miss the effects of platelets. Other markers of thrombin generation, prothrombin fragment 1 + 2 (F1 + 2) and thrombin-antithrombin complex, are typically measured after the fact. We report a simple assay, which employs the onset of platelet contractile force (PCF) as a surrogate marker of thrombin generation. PCF generation occurs concomitant with the burst of F1 + 2 release. The time between assay start and PCF onset is termed the thrombin generation time (TGT). TGT is prolonged in clotting factor deficiencies and in the presence of direct and indirect thrombin inhibitors. TGT shortens to normal with clotting factor replacement and shortens with administration of recombinant factor VIIa. TGT is short in thrombophilic states such as coronary artery disease, diabetes and thromboangiitis obliterans and prolongs toward normal with oral and intravenous anticoagulants.
Collapse
Affiliation(s)
- M E Carr
- Coagulation Special Studies Laboratory, Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond, VA 23298-0230, USA.
| | | | | | | |
Collapse
|
28
|
Carr ME, Kuhn JG, Martin EJ, Tidwell AR, Hagan MK. Pseudoprolongation of the prothrombin time during treatment with recombinant factor VIIa for bleeding in a patient with a spontaneous factor VIII inhibitor. Int J Hematol 2003; 77:308-9. [PMID: 12731678 DOI: 10.1007/bf02983792] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
29
|
Carr ME, Carr SL, Roa V, McCardell KA, Greilich PE. Aprotinin counteracts heparin-induced inhibition of platelet contractile force. Thromb Res 2002; 108:161-8. [PMID: 12590953 DOI: 10.1016/s0049-3848(02)00403-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Aprotinin interferes with heparin binding to platelets and decreases blood loss during cardiopulmonary bypass (CPB). Heparin abolishes platelet force during CPB, and the extent of platelet force recovery after protamine administration appears to correlate with blood loss. This study assessed the effect of aprotinin on heparin suppression of platelet force. METHODS Platelet force was measured using the Hemodyne Hemostasis Analyzer. Clots were formed from platelet-rich plasma (PRP) by the addition of batroxobin and 10 mM CaCl(2). Clotting conditions included pH 7.4, ionic strength 0.15 M, fibrinogen level 1 mg/ml and 75,000 platelets/microl. RESULTS After 1200 s of clotting, force was reduced from 7110+/-1190 to 450+/-450 dyn by 0.2 U/ml of heparin. Platelet force in aprotinin [20 microg/ml (140 KIU/ml)] containing PRP was not suppressed by heparin addition (7480+/-2410 dyn). Aprotinin [40 microg/ml (280 KIU/ml)] addition to previously heparinized plasma counteracted heparin force suppression. Aprotinin (40 microg/ml) increased platelet force from 5630 to 11,138+/-562 in PRP devoid of heparin. Aprotinin did not affect thrombin activity, fibrin structure, platelet aggregation or secretion. CONCLUSIONS Aprotinin counteracts heparin suppression of platelet force and enhances platelet force in the absence of heparin. Aprotinin-heparin-platelet interactions may help explain aprotinin's ability to reduce blood loss during CPB.
Collapse
Affiliation(s)
- Marcus E Carr
- Department of Internal Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond, 23298, USA.
| | | | | | | | | |
Collapse
|
30
|
Carr ME, Krishnaswami A, Martin EJ. Platelet contractile force (PCF) and clot elastic modulus (CEM) are elevated in diabetic patients with chest pain. Diabet Med 2002; 19:862-6. [PMID: 12358876 DOI: 10.1046/j.1464-5491.2002.00834.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Platelet function and clot structure may be altered in diabetes. We have noted increased platelet contractile force (PCF) and clot elastic modulus (CEM) in patients presenting to the emergency department with chest pain. Twenty-six of the chest pain patients were diabetic. Here, we compare the PCF, CEM and platelet aggregation in diabetic chest pain patients, non-diabetic patients with chest pain and asymptomatic controls. PATIENTS AND METHODS PCF, CEM and collagen whole blood aggregations were measured in 100 chest pain patients and 25 asymptomatic controls. RESULTS Platelet concentrations for diabetic patients, non-diabetic patients and controls were identical. PCF was significantly (P < 0.05) elevated in diabetic chest pain patients (9.42 +/- 0.59 kdynes) vs. controls (7.40 +/- 0.32 kdynes). CEM in diabetic patients (29.96 +/- 2.19 kdynes/cm2) was significantly elevated relative to that in non-diabetic chest pain patients (25.22 +/- 0.84 kdynes/cm2) and normal controls (23.18 +/- 0.74 kdynes/cm2). Collagen-induced whole blood aggregation was decreased (P < 0.05) in diabetic chest pain patients vs. controls. PCF values (10.23 +/- 0.76 kdynes) in diabetic patients with haemoglobin A1c > 7% were higher than in any other group. CONCLUSION PCF and CEM are elevated in diabetic chest pain patients. The significance of these laboratory findings awaits additional clinical studies.
Collapse
Affiliation(s)
- M E Carr
- Departments of Internal Medicine and Pathology, McGuire VA Medical Center and Virgina Commonwealth University, Richmond, VA 23298-0230, USA.
| | | | | |
Collapse
|