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Nørregaard LB, Wickham KA, Jeppesen JS, Rytter N, Christoffersen LC, Gliemann L, Lawrence M, Evans PA, Kruuse C, Hellsten Y. Exercise transiently increases the density of incipient blood clots in antiplatelet-treated lacunar stroke patients. Thromb J 2024; 22:35. [PMID: 38581046 PMCID: PMC10996168 DOI: 10.1186/s12959-024-00604-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 03/25/2024] [Indexed: 04/07/2024] Open
Abstract
INTRODUCTION Older individuals and, in particular, individuals at risk of recurrent stroke, may be susceptible to thrombosis when participating in exercise, however, this aspect has not been well investigated. METHODS Clot microstructure and conventional markers of thrombotic risk were determined in twenty lacunar stroke patients and fifteen healthy age-matched controls before, immediately after and 1 h after a bout of moderate intensity cycling exercise. Data were analyzed using a linear mixed model approach. RESULTS At rest, clot microstructure (1.69 ± 0.07 vs. 1.64 ± 0.05, corresponding to a difference of ~ 50% in normalized clot mass; p = 0.009) and thrombocyte count (73%; p < 0.0001) were higher, and activated partial thromboplastin time was lower (18%; p = 0.0001) in stroke patients compared to age-matched controls. Acute exercise increased thrombogenic markers similarly in the two groups: incipient clot microstructure (1.69 ± 0.07 vs. 1.74 ± 0.05; p = 0.0004 and 1.64 ± 0.05 vs. 1.71 ± 0.04; p < 0.0001, for stroke and controls respectively), plasma fibrinogen (12%; p < 0.0001 and 18%; p < 0.0001, for stroke and controls respectively) and the combined coagulation factors II, VII and X (p = 0.0001 and p < 0.0001, for stroke and controls respectively). CONCLUSION The results show that exercise transiently increases the risk of blood clot formation in both stroke patients and controls, however, due to the higher baseline thrombogenicity in stroke patients, the post exercise risk of forming blood clots may be higher in this group. TRIAL REGISTRATION Registered at ClinicalTrials.gov (NCT03635177).
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Affiliation(s)
- L B Nørregaard
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - K A Wickham
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
- Environmental Ergonomics Lab, Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
| | - J S Jeppesen
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - N Rytter
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - L C Christoffersen
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - L Gliemann
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - M Lawrence
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
| | - P A Evans
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School, Swansea, UK
| | - C Kruuse
- Neurovascular Research Unit, Department of Neurology, Herlev Gentofte Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Y Hellsten
- The Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
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2
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Pillai S, Evans V, Davies G, Lawrence MJ, Whitley J, Battle CE, Williams PR, Morris K, Evans PA. A comparative study into the effects of venous and arterial blood on clot microstructure in critically unwell patients. Assessment of the diagnostic potential of a biomarker of haemostasis. J Intensive Care Soc 2023; 24:224-226. [PMID: 37260426 PMCID: PMC10227903 DOI: 10.1177/17511437211060154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023] Open
Abstract
Blood for coagulation analysis can be sampled from the arterial or venous system in intensive care units (ICU). The determination of clot microstructure and strength by fractal analysis (df) gives valuable information in a range of vascular haemostatic disease and sepsis. We aimed to determine if df could be measured equally and comparatively in arterial or venous blood, and 45 critically ill patients in an ICU were recruited. df was found to be readily measured in arterial blood with results comparable to those in venous blood and that add value of df as a potential marker of haemostasis in these patients.
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Affiliation(s)
- Suresh Pillai
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
- Ed. Major Critical Care Unit, Morriston Hospital, Swansea, UK
- Medical School, Swansea University, Swansea, UK
| | - Vanessa Evans
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
- Medical School, Swansea University, Swansea, UK
| | - Gareth Davies
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
| | - Matthew J Lawrence
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
- Medical School, Swansea University, Swansea, UK
| | - Janet Whitley
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
- Medical School, Swansea University, Swansea, UK
| | - Ceri E Battle
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
- Ed. Major Critical Care Unit, Morriston Hospital, Swansea, UK
| | | | - Keith Morris
- School of Applied Science, Cardiff Metropolitan University, Cardiff, UK
| | - Phillip A Evans
- Welsh Centre for Emergency Medicine
Research, Emergency Department, Swansea Bay University Health Board, Swansea, UK
- Medical School, Swansea University, Swansea, UK
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3
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Fall L, Stacey BS, Calverley T, Owens T, Thyer K, Griffiths R, Phillips R, Bailey DM. Acute high-intensity interval exercise is less pro-oxidative/thrombotic compared to isovolumic moderate-intensity steady-state exercise. J Physiol Biochem 2023; 79:35-46. [PMID: 36038705 DOI: 10.1007/s13105-022-00918-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 08/17/2022] [Indexed: 02/08/2023]
Abstract
While high-intensity interval training (HIIT) has emerged as a more time-efficient alternative to moderate-intensity steady-state exercise (MISS), the impact on systemic free radical formation and link to activated coagulation remains unknown. We recruited sixteen healthy males aged 21 ± 3 y who performed incremental cycle ergometry to determine peak oxygen uptake ([Formula: see text] PEAK). Participants were randomly assigned single blind to two separate groups (MISS: n = 8; HIIT: n = 8) matched for [Formula: see text] PEAK. HIIT participants completed five exercise cycles, each consisting of 3 min at 80%[Formula: see text] PEAK alternating with 3 min at 40% [Formula: see text] PEAK, whereas MISS participants performed an isovolumic bout of 30 min at 60% [Formula: see text] PEAK. Cephalic venous blood was assayed for ascorbate free radical (A•-, electron paramagnetic resonance spectroscopy) and clot fractal dimension (df, rheometry) at rest every hour over a 6-h period to determine critical difference (CD) and before/after submaximal/peak exercise. Submaximal MISS increased A• - and df to a greater extent compared to HIIT (P = 0.039 to 0.057) although elevations generally fell within CD boundaries (54.2% and 5.5% respectively). No further elevations were observed during peak exercise (P = 0.508 to 0.827) and no relationships were observed between A•- and df (r = 0.435 to - 0.121, P = 0.092 to 0.655). Collectively, these findings suggest that HIIT is less pro-oxidative/thrombotic compared to more traditional MISS, advocating its prescription in patients given the potential for superior vascular adaptive benefit.
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Affiliation(s)
- Lewis Fall
- Neurovascular Research Laboratory, University of South Wales, Pontypridd, UK.,Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, UK
| | - Benjamin S Stacey
- Neurovascular Research Laboratory, University of South Wales, Pontypridd, UK.,Faculty of Life Sciences and Education, University of South Wales, CF37 4AT, Pontypridd, UK
| | - Thomas Calverley
- Neurovascular Research Laboratory, University of South Wales, Pontypridd, UK.,Faculty of Life Sciences and Education, University of South Wales, CF37 4AT, Pontypridd, UK
| | - Thomas Owens
- Neurovascular Research Laboratory, University of South Wales, Pontypridd, UK.,Faculty of Life Sciences and Education, University of South Wales, CF37 4AT, Pontypridd, UK
| | - Kaitlin Thyer
- Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, UK
| | - Rhodri Griffiths
- Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, UK
| | - Rhodri Phillips
- Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd, UK
| | - Damian M Bailey
- Neurovascular Research Laboratory, University of South Wales, Pontypridd, UK. .,Faculty of Life Sciences and Education, University of South Wales, CF37 4AT, Pontypridd, UK.
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4
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Watson O, Zaldua JC, Pillai S, Whitley J, Howard M, Lawrence M, Hawkins K, Morris K, Evans PA. The efficacy of low molecular weight heparin is reduced in COVID-19. Clin Hemorheol Microcirc 2023; 84:333-344. [PMID: 36442189 DOI: 10.3233/ch-221635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND A significant degree of mortality and morbidity in COVID-19 is through thromboembolic complications, only partially mitigated by anticoagulant therapy. Reliable markers of infection severity are not fully established. OBJECTIVES This study investigated whether visco-elastic biomarkers predict disease severity on presentation to the Emergency Department (ED) and how they measure response to anticoagulationMETHODS:Patients testing positive for COVID-19 at a large University Teaching Hospital ED were recruited at presentation. Multiple blood samples were taken throughout hospital admission to monitor disease progression with end outcome recorded. Visco-elastic markers, fractal dimension (df) and Time to Gel Point (TGP) which measure the properties of the incipient clot were compared in patients with and without anticoagulation by Low Molecular Weight Heparin (LMWH). RESULTS TGP and df did not predict severity of infection with COVID-19. Although LMWH prolonged TGP, there was no change in df indicating LMWH did not change clot microstructure. CONCLUSIONS Therapeutic efficacy of LMWH appears blunted in COVID-19 infection. This may be due to the inflammatory state creating a resistance to LMWH activity, which may explain why LMWH appears less effective in COVID-19 compared to other disease states. COVID-19 was not predicted by visco-elastic testing at the time of ED presentation.
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Affiliation(s)
- Oliver Watson
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
| | - Jun-Cezar Zaldua
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
| | - Suresh Pillai
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
| | - Janet Whitley
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
| | - Matthew Howard
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
| | - Matthew Lawrence
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
| | - Karl Hawkins
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
| | - Keith Morris
- Cardiff Metropolitan University, Llandaff Campus Western Avenue, Cardiff, UK
| | - Phillip Adrian Evans
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK
- Swansea University Medical School Swansea University, Singleton Park, Swansea, UK
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5
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Anzini P, Redoglio D, Rocco M, Masciocchi N, Ferri F. Light Scattering and Turbidimetry Techniques for the Characterization of Nanoparticles and Nanostructured Networks. NANOMATERIALS 2022; 12:nano12132214. [PMID: 35808049 PMCID: PMC9268389 DOI: 10.3390/nano12132214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/15/2022] [Accepted: 06/21/2022] [Indexed: 12/10/2022]
Abstract
Light scattering and turbidimetry techniques are classical tools for characterizing the dynamics and structure of single nanoparticles or nanostructured networks. They work by analyzing, as a function of time (Dynamic Light Scattering, DLS) or angles (Static Light Scattering, SLS), the light scattered by a sample, or measuring, as a function of the wavelength, the intensity scattered over the entire solid angle when the sample is illuminated with white light (Multi Wavelength Turbidimetry, MWT). Light scattering methods probe different length scales, in the ranges of ~5−500 nm (DLS), or ~0.1−5 μm (Wide Angle SLS), or ~1−100 μm (Low Angle SLS), and some of them can be operated in a time-resolved mode, with the possibility of characterizing not only stationary, but also aggregating, polymerizing, or self-assembling samples. Thus, the combined use of these techniques represents a powerful approach for studying systems characterized by very different length scales. In this work, we will review some typical applications of these methods, ranging from the field of colloidal fractal aggregation to the polymerization of biologic networks made of randomly entangled nanosized fibers. We will also discuss the opportunity of combining together different scattering techniques, emphasizing the advantages of a global analysis with respect to single-methods data processing.
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Affiliation(s)
- Pietro Anzini
- Dipartimento di Scienza e Alta Tecnologia and To.Sca.Lab, Università degli Studi dell’Insubria, Via Valleggio 11, 22100 Como, Italy; (P.A.); (D.R.); (N.M.)
| | - Daniele Redoglio
- Dipartimento di Scienza e Alta Tecnologia and To.Sca.Lab, Università degli Studi dell’Insubria, Via Valleggio 11, 22100 Como, Italy; (P.A.); (D.R.); (N.M.)
| | - Mattia Rocco
- Proteomica e Spettrometria di Massa, IRCCS Ospedale Policlinico San Martino, Largo R. Benzi 10, 16132 Genova, Italy;
| | - Norberto Masciocchi
- Dipartimento di Scienza e Alta Tecnologia and To.Sca.Lab, Università degli Studi dell’Insubria, Via Valleggio 11, 22100 Como, Italy; (P.A.); (D.R.); (N.M.)
| | - Fabio Ferri
- Dipartimento di Scienza e Alta Tecnologia and To.Sca.Lab, Università degli Studi dell’Insubria, Via Valleggio 11, 22100 Como, Italy; (P.A.); (D.R.); (N.M.)
- Correspondence:
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6
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Lawrence MJ, Evans V, Whitley J, Pillai S, Williams PR, Coulson J, Krishnan M, Slade P, Power K, Morris RHK, Evans PA. The effects of apixaban on clot characteristics in atrial fibrillation: A novel pharmacodynamic biomarker. Pharmacol Res Perspect 2022; 10:e00937. [PMID: 35338612 PMCID: PMC8956932 DOI: 10.1002/prp2.937] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 12/18/2021] [Indexed: 01/09/2023] Open
Abstract
Atrial fibrillation (AF) is a major risk factor for stroke. We aim to characterize AF patients and the effects of apixaban therapy in terms of clot microstructure using gel point analysis, a novel biomarker. Seventy-eight patients were included in the study, 50 Stroke with AF (AF-S), and 28 AF without stroke (AF). Pre- and post-anticoagulation samples were collected: gel point (GP) analysis was performed to obtain (i) TGP (the time taken to reach the GP or the clot formation time) and (ii) df , the fractal dimension of the clot, a quantification of clot fibrin microstructure at the GP. At baseline, the AF-S group had a df = 1.70 (±0.05) and TGP = 306 (±73 s). The AF group had a df = 1.70 ± 0.05 and TGP = 346 ± 78 s, showing a significantly shortened TGP in the stroke group (p = .008). For both groups, apixaban significantly prolonged TGP, p = .005, but resulted in no change in df. Apixaban prolonged clotting time while having no significant impact on the blood's ability to form stable clots (no change in df ). This indicates that apixaban provides protection from the formation of thrombi by reducing clotting kinetics.
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Affiliation(s)
- Matthew J Lawrence
- Welsh Centre for Emergency Medicine Research, Swansea Bay University Health Board, Swansea, UK.,Medical School, Swansea University, Swansea, UK
| | - Vanessa Evans
- Welsh Centre for Emergency Medicine Research, Swansea Bay University Health Board, Swansea, UK.,Medical School, Swansea University, Swansea, UK
| | - Janet Whitley
- Welsh Centre for Emergency Medicine Research, Swansea Bay University Health Board, Swansea, UK.,Medical School, Swansea University, Swansea, UK
| | - Suresh Pillai
- Welsh Centre for Emergency Medicine Research, Swansea Bay University Health Board, Swansea, UK.,Medical School, Swansea University, Swansea, UK
| | | | | | - Manju Krishnan
- Stroke Unit, Swansea Bay University Health Board, Swansea, UK
| | - Peter Slade
- Stroke Unit, Swansea Bay University Health Board, Swansea, UK
| | - Kieron Power
- Pharmacy Department, Swansea Bay University Health Board, Swansea, UK
| | - Roger H K Morris
- School of Applied Science, Cardiff Metropolitan University, Cardiff, UK
| | - Phillip A Evans
- Welsh Centre for Emergency Medicine Research, Swansea Bay University Health Board, Swansea, UK.,Medical School, Swansea University, Swansea, UK
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7
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The procoagulant effects of extracellular vesicles derived from hypoxic endothelial cells can be selectively inhibited by inorganic nitrite. Nitric Oxide 2022; 122-123:6-18. [DOI: 10.1016/j.niox.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/11/2022] [Accepted: 02/14/2022] [Indexed: 11/20/2022]
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8
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Abstract
Mechanical properties have been extensively studied in pure elastic or viscous materials; however, most biomaterials possess both physical properties in a viscoelastic component. How the biomechanics of a fibrin clot is related to its composition and the microenvironment where it is formed is not yet fully understood. This review gives an outline of the building mechanisms for blood clot mechanical properties and how they relate to clot function. The formation of a blood clot in health conditions or the formation of a dangerous thrombus go beyond the mere polymerization of fibrinogen into a fibrin network. The complex composition and localization of in vivo fibrin clots demonstrate the interplay between fibrin and/or fibrinogen and blood cells. Studying these protein–cell interactions and clot mechanical properties may represent new methods for the evaluation of cardiovascular diseases (the leading cause of death worldwide), creating new possibilities for clinical diagnosis, prognosis, and therapy. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Marco M. Domingues
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Filomena A. Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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9
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Yeh HH, Yu K, Vappala S, Kalathottukaren MT, Abbina S, Luo HD, Grecov D, Kizhakkedathu JN. Rheological and clot microstructure evaluation of heparin neutralization by UHRA and protamine. J Mech Behav Biomed Mater 2021; 124:104851. [PMID: 34600430 DOI: 10.1016/j.jmbbm.2021.104851] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 06/16/2021] [Accepted: 09/19/2021] [Indexed: 11/27/2022]
Abstract
The current study reports the use of small amplitude oscillatory rheometry to investigate the dynamics of blood clot formation upon heparin neutralization under three different oscillatory frequencies, two of which were mimicking physiological heart rates. We utilized two different heparin antidotes, namely protamine and newly developed universal heparin reversal agent (UHRA-7), at different concentrations to determine the quality of blood clot formed upon heparin neutralization by analyzing several key rheological parameters. Scanning electron microscopy (SEM) was used to determine the morphology and microstructure of the blood clot after heparin neutralization to support the rheological observations. The current study revealed that the structure of blood clots formed had significant differences when an oscillatory frequency that mimicked the physiological heart rate was used in comparison to a lower frequency commonly used in current clinical measurements. The limited working dose range for protamine and its intrinsic anticoagulation behaviour was observed. The neutralization profile of UHRA-7 showed a large window of activity. The global assessment of rheological parameters and microstructure of the clot together revealed additional details describing anticoagulant reversal and blood coagulation dynamics by relating the blood clot's fiber thickness and the oscillatory measurements, including storage modulus and blood clot's contractile force. Additionally, a mechanical characterization was conducted to provide a further assessment of blood coagulation using the rheological data.
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Affiliation(s)
- Han Hung Yeh
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
| | - Kai Yu
- Centre for Blood Research and Life Science Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Sreeparna Vappala
- Centre for Blood Research and Life Science Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Manu Thomas Kalathottukaren
- Centre for Blood Research and Life Science Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Srinivas Abbina
- Centre for Blood Research and Life Science Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Haiming D Luo
- Centre for Blood Research and Life Science Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada
| | - Dana Grecov
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Mechanical Engineering, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada.
| | - Jayachandran N Kizhakkedathu
- School of Biomedical Engineering, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Centre for Blood Research and Life Science Institute, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Pathology & Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada; Department of Chemistry, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
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10
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Pillai S, Davies G, Lawrence M, Whitley J, Stephens J, Williams PR, Morris K, Evans PA. The effect of diabetic ketoacidosis (DKA) and its treatment on clot microstructure: Are they thrombogenic? Clin Hemorheol Microcirc 2021; 77:183-194. [PMID: 32925001 DOI: 10.3233/ch-200957] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Diabetic ketoacidosis (DKA) is a medical emergency with a high mortality rate and is associated with severe metabolic acidosis and dehydration. DKA patients have an increased risk of arterial and venous thromboembolism, however little is known about this metabolic derangement in the first 24 hours of admission and to assess its effect on coagulation. We therefore utilised a novel functional marker of clot microstructure (fractal dimension - df) to assess these changes within the first 24 hours. METHODS Prospective single centre observational study to demonstrate whether the tendency of blood clot formation differs in DKA patients. RESULTS 15 DKA patients and 15 healthy matched controls were recruited. Mean df in the healthy control group was 1.74±0.03. An elevated df of 1.78±0.07 was observed in patients with DKA on admission. The mean pH on admission was 7.14±0.13 and the lactate was 3.6±2.0. df changed significantly in response to standard treatment and was significantly reduced to 1.68±0.09 (2-6& h) and to 1.66±0.08 at 24& h (p < 0.01 One-way ANOVA). df also correlated significantly with lactate and pH (Pearson correlation coefficient 0.479 and -0.675 respectively, p < 0.05). CONCLUSIONS DKA patients at presentation have a densely organising less permeable thrombogenic clot microstructure as evidenced by high df. These structural changes are due to a combination of dehydration and a profound metabolic acidosis, which was reversed with treatment. These changes were not mirrored in standard clinical markers of thromboge-nicity.
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Affiliation(s)
- Suresh Pillai
- Welsh Centre for Emergency Medicine Research, Emergency Department, Morriston Hospital, Swansea, UK.,Morriston Hospital, Swansea, UK.,Swansea University, Swansea, UK
| | - Gareth Davies
- Welsh Centre for Emergency Medicine Research, Emergency Department, Morriston Hospital, Swansea, UK
| | - Matthew Lawrence
- Welsh Centre for Emergency Medicine Research, Emergency Department, Morriston Hospital, Swansea, UK.,Swansea University, Swansea, UK
| | - Janet Whitley
- Welsh Centre for Emergency Medicine Research, Emergency Department, Morriston Hospital, Swansea, UK.,Swansea University, Swansea, UK
| | - Jeffrey Stephens
- Morriston Hospital, Swansea, UK.,Swansea University, Swansea, UK
| | | | | | - Phillip Adrian Evans
- Welsh Centre for Emergency Medicine Research, Emergency Department, Morriston Hospital, Swansea, UK.,Morriston Hospital, Swansea, UK.,Swansea University, Swansea, UK
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11
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Evans VJ, Lawrence M, Whitley J, Johns C, Pillai S, Hawkins K, Power K, Morris K, Williams R, Evans PA. The treatment effect of rivaroxaban on clot characteristics in patients who present acutely with first time deep vein thrombosis. Clin Hemorheol Microcirc 2021; 80:139-151. [PMID: 33682699 DOI: 10.3233/ch-201030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND The acute vascular disease deep vein thrombosis (DVT) requires oral anticoagulants to prevent progression. Monitoring therapeutic efficacy of direct oral anticoagulants (DOAC), including rivaroxaban, is problematic as no reliable test is available. Advances in rheometry have led to the development of a functional coagulation biomarker using Gel Point (GP) analysis which assesses clot structure formation. The biomarker measures incipient clot formation time (TGP) and quantifies fibrin clot structure in terms of fractal dimension (df). OBJECTIVE This study aimed to investigate clot structure formation in first time DVT and the effect of rivaroxaban treatment. METHODS This prospective observational cohort study measured the GP and standard laboratory markers at three sample points: pre-treatment and at 20 and 60 days following 15 mg BD and 20 mg OD rivaroxaban respectively. RESULTS Forty DVT patients (mean age 64 years [SD±14.8]; 23 males, 17 female) were recruited. The results show that DVT vs non-DVT patients did not have a significantly different GP profile (df: 1.72±0.06 vs 1.70±0.06 and TGP: 267±68 sec vs 262±73 sec) with both within the defined healthy index. In addition, rivaroxaban therapy increased TGP to 392 s (±135 s) after 20 days, and subsequently increased to 395 s (±194 s) at 60 days but did not significantly increase df (from 1.69±0.05 to 1.71±0.06). CONCLUSIONS The results indicate in this cohort of DVT patients there was no underlying hypercoagulable effect as determined by gel point analysis. Furthermore, the anticoagulant effect of rivaroxaban prolonged clotting, suggesting a protective effect against clot formation, without significantly reducing clot microstructural properties.
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Affiliation(s)
- V J Evans
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK.,Swansea University, Swansea, UK
| | - M Lawrence
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK.,Swansea University, Swansea, UK
| | - J Whitley
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK.,Swansea University, Swansea, UK
| | - C Johns
- Swansea Bay University Health Board, Swansea, UK
| | - S Pillai
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK.,Swansea University, Swansea, UK
| | | | - K Power
- Swansea Bay University Health Board, Swansea, UK
| | - K Morris
- Cardiff Metropolitan University, Cardiff, UK
| | | | - P A Evans
- Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea Bay University Health Board, Swansea, UK.,Swansea University, Swansea, UK
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12
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Olsen LN, Fischer M, Evans PA, Gliemann L, Hellsten Y. Does Exercise Influence the Susceptibility to Arterial Thrombosis? An Integrative Perspective. Front Physiol 2021; 12:636027. [PMID: 33708141 PMCID: PMC7940832 DOI: 10.3389/fphys.2021.636027] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/01/2021] [Indexed: 12/14/2022] Open
Abstract
Arterial thrombosis is the primary cause of death worldwide, with the most important risk factors being smoking, unhealthy diet, and physical inactivity. However, although there are clear indications in the literature of beneficial effects of physical activity in lowering the risk of cardiovascular events, exercise can be considered a double-edged sword in that physical exertion can induce an immediate pro-thrombotic environment. Epidemiological studies show an increased risk of cardiovascular events after acute exercise, a risk, which appear to be particularly apparent in individuals with lifestyle-related disease. Factors that cause the increased susceptibility to arterial thrombosis with exercise are both chemical and mechanical in nature and include circulating catecholamines and vascular shear stress. Exercise intensity plays a marked role on such parameters, and evidence in the literature accordingly points at a greater susceptibility to thrombus formation at high compared to light and moderate intensity exercise. Of importance is, however, that the susceptibility to arterial thrombosis appears to be lower in exercise-conditioned individuals compared to sedentary individuals. There is currently limited data on the role of acute and chronic exercise on the susceptibility to arterial thrombosis, and many studies include incomplete assessments of thrombogenic clotting profile. Thus, further studies on the role of exercise, involving valid biomarkers, are clearly warranted.
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Affiliation(s)
- Line Nørregaard Olsen
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Mads Fischer
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Phillip Adrian Evans
- Haemostasis Biomedical Research Unit, Welsh Centre for Emergency Medicine Research, Morriston Hospital, SBU Health Board, Swansea, United Kingdom.,College of Medicine, Swansea University, Swansea, United Kingdom
| | - Lasse Gliemann
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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13
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Machlus S, Zhang S, Mao X. Correlated rigidity percolation in fractal lattices. Phys Rev E 2021; 103:012104. [PMID: 33601532 DOI: 10.1103/physreve.103.012104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/17/2020] [Indexed: 11/07/2022]
Abstract
Rigidity percolation (RP) is the emergence of mechanical stability in networks. Motivated by the experimentally observed fractal nature of materials like colloidal gels and disordered fiber networks, we study RP in a fractal network where intrinsic correlations in particle positions is controlled by the fractal iteration. Specifically, we calculate the critical packing fractions of site-diluted lattices of Sierpiński gaskets (SG's) with varying degrees of fractal iteration. Our results suggest that although the correlation length exponent and fractal dimension of the RP of these lattices are identical to that of the regular triangular lattice, the critical volume fraction is dramatically lower due to the fractal nature of the network. Furthermore, we develop a simplified model for an SG lattice based on the fragility analysis of a single SG. This simplified model provides an upper bound for the critical packing fractions of the full fractal lattice, and this upper bound is strictly obeyed by the disorder averaged RP threshold of the fractal lattices. Our results characterize rigidity in ultralow-density fractal networks.
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Affiliation(s)
- Shae Machlus
- Department of Physics, University of Chicago, Chicago, Illinois 60637, USA
| | - Shang Zhang
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Xiaoming Mao
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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14
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Thomas BR, Hambly RJ, Weisel JW, Rauova L, Badiei N, Brown MR, Thornton CA, Williams PR, Hawkins K. Abnormal clot microstructure formed in blood containing HIT-like antibodies. Thromb Res 2020; 193:25-30. [PMID: 32505081 DOI: 10.1016/j.thromres.2020.05.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 04/26/2020] [Accepted: 05/18/2020] [Indexed: 01/03/2023]
Abstract
INTRODUCTION Thrombosis is a severe and frequent complication of heparin-induced thrombocytopenia (HIT). However, there is currently no knowledge of the effects of HIT-like antibodies on the resulting microstructure of the formed clot, despite such information being linked to thrombotic events. We evaluate the effect of the addition of pathogenic HIT-like antibodies to blood on the resulting microstructure of the formed clot. MATERIALS AND METHODS Pathogenic HIT-like antibodies (KKO) and control antibodies (RTO) were added to samples of whole blood containing Unfractionated Heparin and Platelet Factor 4. The formed clot microstructure was investigated by rheological measurements (fractal dimension; df) and scanning electron microscopy (SEM), and platelet activation was measured by flow cytometry. RESULTS AND CONCLUSIONS Our results revealed striking effects of KKO on clot microstructure. A significant difference in df was found between samples containing KKO (df = 1.80) versus RTO (df = 1.74; p < 0.0001). This increase in df was often associated with an increase in activated platelets. SEM images of the clots formed with KKO showed a network consisting of a highly branched and compact arrangement of thin fibrin fibres, typically found in thrombotic disease. This is the first study to identify significant changes in clot microstructure formed in blood containing HIT-like antibodies. These observed alterations in clot microstructure can be potentially exploited as a much-needed biomarker for the detection, management and monitoring of HIT-associated thrombosis.
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Affiliation(s)
- Bethan R Thomas
- Swansea University Medical School, Swansea University, Swansea, UK
| | - Rebecca J Hambly
- Swansea University Medical School, Swansea University, Swansea, UK
| | - John W Weisel
- University of Pennsylvania School of Medicine, PA, USA
| | - Lubica Rauova
- University of Pennsylvania School of Medicine, PA, USA; Children's Hospital of Philadelphia, PA, USA
| | | | - M Rowan Brown
- College of Engineering, Swansea University, Swansea, UK
| | | | | | - Karl Hawkins
- Swansea University Medical School, Swansea University, Swansea, UK.
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15
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Marsden NJ, Lawrence M, Davies N, Davies G, Morris K, Williams PR, Whitaker IS, Evans PA. The effect of the acute inflammatory response of burns and its treatment on clot characteristics and quality: A prospective case controlled study. Burns 2019; 46:1051-1059. [PMID: 31866177 DOI: 10.1016/j.burns.2019.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/07/2019] [Accepted: 11/13/2019] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Burns are known to have an effect on coagulation in the early period after burn. Current coagulation tests have been criticised in acute burns due to their inherent limitations. This study aims to investigate the potential for a new quantitative functional biomarker of clot quality, fractal dimension, to identify changes in clot microstructure as a result of the burn inflammatory response and its treatment. METHODS A total of fifty-eight burn patients were included in this prospective case-controlled study. The control group (29 patients mean TBSA 1%), and case group (29 patients mean TBSA 30%) were compared at baseline and the case group investigated further over four time points (baseline, 12h, 24h and 5-7 days). Fractal analysis was performed, as well as current markers of coagulation, inflammatory markers and point-of-care tests, Thromboelastography and Multiplate analysis. RESULTS Fractal dimension did not differ between groups at admission (1.73±0.06 and 1.72±0.1), and fell within the healthy index normal range (1.74±0.7), suggesting a normal clot microstructure in the early period after burn. Fractal dimension significantly reduced from baseline over the first 24h following injury (1.59±0.03 p<0.005), indicating a significant reduction in mechanical clot strength and functionality consistent with a hypocoagulable state, not identified with other markers. CONCLUSIONS This is the first study to quantify the changes in clot microstructure following burn injury. This study confirms clot microstructure is significantly altered during the first 24h after burn, with the production of a weaker, more porous fibrin clot, consistent with a hypocoagulable state.
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Affiliation(s)
- N J Marsden
- Haemostasis Biomedical Research Unit, Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea, UK; Welsh Centre for Burns and Plastic Surgery, Morriston Hospital, Swansea, UK
| | - M Lawrence
- Haemostasis Biomedical Research Unit, Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea, UK; Swansea University Medical School, Swansea, UK
| | - N Davies
- Haemostasis Biomedical Research Unit, Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea, UK; Swansea University Medical School, Swansea, UK
| | - G Davies
- Haemostasis Biomedical Research Unit, Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea, UK
| | - K Morris
- Cardiff School of Health Sciences, Cardiff Metropolitan University, Cardiff, UK
| | - P R Williams
- School of Engineering, Swansea University, Swansea, UK
| | - I S Whitaker
- Welsh Centre for Burns and Plastic Surgery, Morriston Hospital, Swansea, UK
| | - P A Evans
- Haemostasis Biomedical Research Unit, Welsh Centre for Emergency Medicine Research, Morriston Hospital, Swansea, UK; Swansea University Medical School, Swansea, UK.
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16
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Sabra A, Lawrence MJ, Curtis D, Hawkins K, Williams PR, Evans PA. In vitro clot model to evaluate fibrin-thrombin effects on fractal dimension of incipient blood clot. Clin Hemorheol Microcirc 2019; -1:147-153. [PMID: 31381508 DOI: 10.3233/ch-190615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION This aim of this study is to investigate the individual effects of varying concentrations of thrombin and fibrinogen on clot microstructure (characterised through the fractal dimension of the incipient clot network, df) and clot formation time (TGP) using a fibrin-thrombin clot model. df and TGP markers are measured using a haemorheological method that has already been investigated for whole blood. METHODS This is an in vitro study using three thrombin concentrations (0.1, 0.05 and 0.02 NIH/ml) and two fibrinogen concentrations (8 mg/ml and 12 mg/ml) to investigate a fibrin-thrombin clot model. The haemorheological changes were measured at the gel point using df and TGP. RESULTS Fractal dimension (df) increased with increasing concentrations of thrombin both at 8 mg/ml (1.60±0.024, 1.67±0.022, 1.74±0.079) and 12 mg/ml fibrinogen concentrations (1.63±0.02, 1.87±0.019, 1.95±0.014). On the other hand, TGP decreased for both 8 mg/ml (1089±265, 637±80, 223±22 seconds) and 12 mg/ml fibrinogen concentrations (2008±247, 776±20, 410±20 seconds). In contrast to previous studies investigating whole blood, TGP increased with higher fibrinogen levels. CONCLUSIONS The findings from this fibrin-thrombin clot model confirmed that df and TGP can detect changes in the incipient clot following manipulation of fibrinogen and thrombin concentration. df increases (indicating stronger clot) with higher concentrations of thrombin and fibrinogen. On the other hand, TGP decreased as expected with higher thrombin level but not with higher fibrinogen concentrations.
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Affiliation(s)
- Ahmed Sabra
- Welsh Centre for Emergency Medicine Research, Swansea University, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UK.,Morriston Cardiac Centre, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UK
| | - Matthew J Lawrence
- Welsh Centre for Emergency Medicine Research, Swansea University, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UK
| | - Dan Curtis
- College of Engineering, Swansea University, Swansea, UK
| | - Karl Hawkins
- College of Medicine, Swansea University, Swansea, UK
| | | | - Phillip A Evans
- Welsh Centre for Emergency Medicine Research, Swansea University, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UK.,Emergency Department, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UK
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17
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Fibrinography: A Multiwavelength Light-Scattering Assay of Fibrin Structure. Hemasphere 2019; 3:e166. [PMID: 31723805 PMCID: PMC6745935 DOI: 10.1097/hs9.0000000000000166] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 11/20/2018] [Indexed: 02/06/2023] Open
Abstract
We have previously developed a fibrin structural assay dedicated to purified fibrinogen-thrombin system. Here, we extend the pertinence of this test, called Fibrinography, to tissue factor-triggered plasma coagulation. We show that Fibrinography determines quantitatively the structure of fibrin fibers in plasma with an excellent reproducibility. We compare this assay with the commonly used single wavelength turbidity method, showing that the latter is not a proper structural assay, but determines essentially the fibrinogen content in plasma. In addition, we also show, in model plasmas, that Fibrinography is able to discriminate normal and hypocoagulant plasmas, and even between hypercoagulant plasmas. Therefore, Fibrinography, by measuring the final step of the coagulation cascade, may be used to evaluate patients’ plasma in hypo- or hypercoagulant diseases.
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18
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Dibiasi C, Plewka J, Ploszczanski L, Glanz V, Lichtenegger H, Windberger U. Viscoelasticity and structure of blood clots generated in-vitro by rheometry: A comparison between human, horse, rat, and camel. Clin Hemorheol Microcirc 2018; 69:515-531. [PMID: 29710696 DOI: 10.3233/ch-189203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Although the coagulation system is evolutionary well preserved, profound species differences exist in viscoelastic as well as in common laboratory tests of coagulation. OBJECTIVE Evaluating differences in clot formation and material characterisation of clots of four mammalian species on macro-, micro- and nanoscales by the means of rheometry, scanning electron microscopy (SEM) and small angle x-ray scattering (SAXS). METHODS Blood samples were collected from healthy human volunteers, laboratory rats (HL/LE inbred strain), warmblood horses and dromedary camels. Clot formation was observed by oscillating shear rheometry until plateau formation of the shear storage modulus G', at which point selected clots were prepared for scanning electron microscopy. SEM images were analysed for fibre diameter and fractal dimension. Additionally, scattering profiles for plasma and whole blood samples were obtained with SAXS. RESULTS Viscoelasticity of clots showed great interspecies variation: clots of rats and horses exhibited shorter clotting times and higher G' plateau values, when compared to human clots. Camel clots showed unique clotting characteristics with no G' plateau formation in the timeframe observed. Less differentiating features were found with SEM and SAXS, although the rat fibre network appears to be more convoluted and dense, which resulted in a higher fractal dimension. CONCLUSION Clotting kinetic differs between the species, which is not only of clinical interest, but could also be an important finding for animal models of blood coagulation.
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Affiliation(s)
- Christoph Dibiasi
- Department of Biomedical Research, Decentralized Biomedical Facilities, Medical University of Vienna, Austria
| | - Jacek Plewka
- Department of Material Sciences and Process Engineering, Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Leon Ploszczanski
- Department of Material Sciences and Process Engineering, Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Veronika Glanz
- Department of Biomedical Research, Decentralized Biomedical Facilities, Medical University of Vienna, Austria
| | - Helga Lichtenegger
- Department of Material Sciences and Process Engineering, Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Ursula Windberger
- Department of Biomedical Research, Decentralized Biomedical Facilities, Medical University of Vienna, Austria
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19
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Hood JE, Yesudasan S, Averett RD. Glucose Concentration Affects Fibrin Clot Structure and Morphology as Evidenced by Fluorescence Imaging and Molecular Simulations. Clin Appl Thromb Hemost 2018; 24:104S-116S. [PMID: 30114949 PMCID: PMC6714860 DOI: 10.1177/1076029618792304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Although in vivo studies have been conducted in the past to determine hyperglycemic effects and influence on clotting risk in patients with diabetes, the true extent of hyperglycemia on unstable and spontaneous clot formation remains highly debated. Factors such as increased glycation, elevated fibrinogen concentration, elevated prothrombin levels, and decreased plasminogen are known to influence fibrin conversion, clot morphology, and thrombus formation in these individuals. In this regard, the isolated effects of hyperglycemia on irregular fibrin clot formation were investigated in a controlled fibrinogen system. In this study, fibrin clot characteristic differences at 3 glucose concentrations were analyzed to determine the effects of glucose concentration on fibrinogen glycation and fibrin clot morphology using confocal microscopy, glycation quantification, molecular simulations, and image processing methods. Algorithms coupled with statistical analysis support in vivo findings that hyperglycemia increases fibrinogen glycation, with ensuing altered fibrin clot structure characteristics. Our experimental and molecular simulation results consistently show an increased glucose adsorption by fibrinogen with increased glucose concentration. Significant differences in clot structure characteristics were observed, and the results of this work can be used to further develop diagnostic tools for evaluating clotting risk in individuals with hypercoagulable and hyperglycemic conditions.
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Affiliation(s)
- Jacob E Hood
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Sumith Yesudasan
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
| | - Rodney D Averett
- School of Chemical, Materials, and Biomedical Engineering, College of Engineering, University of Georgia, Athens, GA, USA
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20
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Lawrence MJ, Davies G, Nyberg M, Whitley J, Evans V, Williams R, Hellsten Y, Evans PA. The effect of tyramine infusion and exercise on blood flow, coagulation and clot microstructure in healthy individuals. Thromb Res 2018; 170:32-37. [PMID: 30098458 DOI: 10.1016/j.thromres.2018.07.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 06/19/2018] [Accepted: 07/24/2018] [Indexed: 11/15/2022]
Abstract
BACKGROUND The long term benefits of exercise on the cardiovascular status of a patient have been proven, however, their benefit/risk relationship with exercise intensity is unclear. Furthermore, many thromboembolic diseases such as myocardial infarction and ischaemic stroke are associated with profound catecholamine release. In this study we explore the relationship between catecholamine release and hemodynamic changes and their effect on coagulation. MATERIALS AND METHODS Twelve healthy recreationally active males were recruited. Local anesthesia was given and catheters were placed under aseptic conditions, in the femoral artery and vein of the experimental leg. The first experiment involved tyramine infusion into the femoral artery at a dose of 1.0 μmol·min-1·L leg volume-1. The second experiment involved single leg knee-extensor exercise performed at 30 W for 15 min. Venous blood was collected at each time point to assess clot microstructure using the df biomarker. RESULTS AND CONCLUSIONS Tyramine infusion causes a local noradrenaline release in the leg. The increase in noradrenaline was associated with a significant increase in clot microstructure formation (df increased from 1.692 ± 0.029 to 1.722 ± 0.047, p = 0.016). Additionally moderate intensity single leg knee extensor exercise, which minimally alters sympathetic activity, also induced an increases in df (from 1.688 ± 0.025 to 1.723 ± 0.023, p = 0.001). This suggests that exercise can alter clot microstructure formation both via an increase in catecholeamine levels and by factors related to muscle activity per se, such as increased blood flow and consequent shear. These findings have implications for recommendations of exercise in patients at risk of cardiovascular events.
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Affiliation(s)
- Matthew J Lawrence
- Haemostasis Biomedical Research Unit, Welsh Centre in Emergency Medicine Research, Morriston Hospital, ABMU Health Board, Swansea, UK; College of Medicine, Swansea University, Swansea, UK
| | - Gareth Davies
- Haemostasis Biomedical Research Unit, Welsh Centre in Emergency Medicine Research, Morriston Hospital, ABMU Health Board, Swansea, UK; College of Medicine, Swansea University, Swansea, UK
| | - Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Janet Whitley
- Haemostasis Biomedical Research Unit, Welsh Centre in Emergency Medicine Research, Morriston Hospital, ABMU Health Board, Swansea, UK; College of Medicine, Swansea University, Swansea, UK
| | - Vanessa Evans
- Haemostasis Biomedical Research Unit, Welsh Centre in Emergency Medicine Research, Morriston Hospital, ABMU Health Board, Swansea, UK; College of Medicine, Swansea University, Swansea, UK
| | - Rhodri Williams
- Haemostasis Biomedical Research Unit, Welsh Centre in Emergency Medicine Research, Morriston Hospital, ABMU Health Board, Swansea, UK; College of Engineering, Swansea University, Swansea, UK
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Denmark
| | - Phillip A Evans
- Haemostasis Biomedical Research Unit, Welsh Centre in Emergency Medicine Research, Morriston Hospital, ABMU Health Board, Swansea, UK; College of Medicine, Swansea University, Swansea, UK.
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21
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Lawrence MJ, Marsden N, Kaczynski J, Davies G, Davies N, Hawkins K, Perumal S, Brown MR, Morris K, Davidson SJ, Williams PR, Evans PA. An Investigation Into the Effects of In Vitro Dilution With Different Colloid Resuscitation Fluids on Clot Microstructure Formation. Anesth Analg 2017; 123:1081-1088. [PMID: 27636739 DOI: 10.1213/ane.0000000000001536] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Balancing the beneficial effects of resuscitation fluids against their detrimental effect on hemostasis is an important clinical issue. We aim to compare the in vitro effects of 3 different colloid resuscitation fluids (4.5% albumin, hydroxyethyl starch [Voluven 6%], and gelatin [Geloplasma]) on clot microstructure formation using a novel viscoelastic technique, the gel point. This novel hemorheologic technique measures the biophysical properties of the clot and provides an assessment of clot microstructure from its viscoelastic properties. Importantly, in contrast to many assays in routine clinical use, the measurement is performed using unadulterated whole blood in a near-patient setting and provides rapid assessment of coagulation. We hypothesized that different colloids will have a lesser or greater detrimental effect on clot microstructure formation when compared against each other. METHODS Healthy volunteers were recruited into the study (n = 104), and a 20-mL sample of whole blood was obtained. Each volunteer was assigned to 1 of the 3 fluids, and the sample was diluted to 1 of 5 different dilutions (baseline, 10%, 20%, 40%, and 60%). The blood was tested using the gel point technique, which measures clot mechanical strength and quantifies clot microstructure (df) at the incipient stages of fibrin formation. RESULTS df and clot mechanical strength decrease with progressive dilution for all 3 fluids. A significant reduction in df from baseline was recorded at dilutions of 20% for albumin (P < .0001), 40% for starch (P < .0001), and 60% for gelatin (P < .0001). We also observed significant differences, in terms of df, when comparing the different types of colloid (P < .0001). We found that albumin dilution produced the largest changes in clot microstructure, providing the lowest values of df (= 1.41 ± 0.061 at 60% dilution) compared with starch (1.52 ± 0.081) and gelatin (1.58 ± 0.063). CONCLUSIONS We show that dilution with all 3 fluids has a significant effect on coagulation at even relatively low dilution volumes (20% and 40%). Furthermore, we quantify, using a novel viscoelastic technique, how the physiochemical properties of the 3 colloids exert individual changes on clot microstructure.
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Affiliation(s)
- Matthew James Lawrence
- From the *NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, United Kingdom; †NISCHR Biomedical Research Unit, Medical School, Swansea University, Swansea, United Kingdom; ‡The Welsh Centre for Burns and Plastic Surgery, Abertawe Bro Morgannwg University Health Board, Morriston Hospital, Swansea, United Kingdom; §Department of Surgery, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea University, Swansea, United Kingdom; ∥Emergency Department, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, United Kingdom; ¶Centre of Complex Fluids, College of Engineering, Swansea University, Swansea, United Kingdom; #School of Applied Science, University of Wales Institute Cardiff, Cardiff, United Kingdom; and **Department of Haematology, Royal Brompton Hospital, Royal Brompton and Harefield NHS Foundation Trust, London, United Kingdom
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22
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Sabra A, Lawrence MJ, Aubrey R, Obaid D, Chase A, Smith D, Thomas P, Storton S, Davies GR, Hawkins K, Williams PR, Morris K, Evans PA. Characterisation of clot microstructure properties in stable coronary artery disease. Open Heart 2017; 4:e000562. [PMID: 28761676 PMCID: PMC5515126 DOI: 10.1136/openhrt-2016-000562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 02/20/2017] [Accepted: 04/04/2017] [Indexed: 01/18/2023] Open
Abstract
Background Coronary artery disease (CAD) is associated with an increased prothrombotic tendency and is also linked to unfavourably altered clot microstructure. We have previously described a biomarker of clot microstructure (df) that is unfavourably altered in acute myocardial infarction. The df biomarker assesses whether the blood will form denser or looser microstructures when it clots. In this study we assessed in patients with stable chest pain whether df can differentiate between obstructed and unobstructed CAD. Methods A blood sample prior to angiography was obtained from 251 consecutive patients undergoing diagnostic coronary angiography. Patients were categorised based on angiographic findings as presence or absence of obstructive CAD (stenosis ≥50%). The blood sample was assessed using the df biomarker, standard laboratory markers and platelet aggregometry (Multiplate). Results A significant difference (p=0.028) in df was observed between obstructive CAD (1.748±0.057, n=83) and unobstructive CAD (1.732±0.052, n=168), where patients with significant CAD produce denser, more tightly packed clots. df was also raised in men with obstructive CAD compared with women (1.745±0.055 vs 1.723±0.052, p=0.007). Additionally df significantly correlated with the platelets response to arachidonic acid as measured by the ASPItest area under the curve readings from platelet aggregometry (correlation coefficient=0.166, p=0.008), a low value of the ASPItest indicating effective aspirin use was associated with looser, less dense clots. Conclusions For the first time, we characterise clot microstructure, as measured by df, in patients with stable CAD. df can potentially be used to risk-stratify patients with stable CAD and assess the efficacy of therapeutic interventions by measuring changes in clot microstructure.
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Affiliation(s)
- Ahmed Sabra
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, UK.,NISCHR Haemostasis Biomedical Research Unit, College of Medicine, Swansea University, Swansea, UK.,Department of Cardiology, Princess of Wales Hospital, ABMU Health Board, Bridgend, UK
| | - Matthew James Lawrence
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, UK.,NISCHR Haemostasis Biomedical Research Unit, College of Medicine, Swansea University, Swansea, UK
| | - Robert Aubrey
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, UK
| | - Daniel Obaid
- Cardiac Centre, Morriston Hospital, ABMU Health Board, Swansea, UK
| | - Alexander Chase
- Cardiac Centre, Morriston Hospital, ABMU Health Board, Swansea, UK
| | - Dave Smith
- Cardiac Centre, Morriston Hospital, ABMU Health Board, Swansea, UK
| | - Phillip Thomas
- Cardiac Centre, Morriston Hospital, ABMU Health Board, Swansea, UK
| | - Sharon Storton
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, UK.,NISCHR Haemostasis Biomedical Research Unit, College of Medicine, Swansea University, Swansea, UK
| | - Gareth R Davies
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, UK.,NISCHR Haemostasis Biomedical Research Unit, College of Medicine, Swansea University, Swansea, UK
| | - Karl Hawkins
- NISCHR Haemostasis Biomedical Research Unit, College of Medicine, Swansea University, Swansea, UK
| | | | - Keith Morris
- School of Applied Science, Cardiff Metropolitan University, Cardiff, UK
| | - Phillip Adrian Evans
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, UK.,NISCHR Haemostasis Biomedical Research Unit, College of Medicine, Swansea University, Swansea, UK.,Department of Emergency Medicine, Morriston Hospital, ABMU Health Board, Swansea, UK
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23
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Abstract
Fibrinogen and fibrin are essential for hemostasis and are major factors in thrombosis, wound healing, and several other biological functions and pathological conditions. The X-ray crystallographic structure of major parts of fibrin(ogen), together with computational reconstructions of missing portions and numerous biochemical and biophysical studies, have provided a wealth of data to interpret molecular mechanisms of fibrin formation, its organization, and properties. On cleavage of fibrinopeptides by thrombin, fibrinogen is converted to fibrin monomers, which interact via knobs exposed by fibrinopeptide removal in the central region, with holes always exposed at the ends of the molecules. The resulting half-staggered, double-stranded oligomers lengthen into protofibrils, which aggregate laterally to make fibers, which then branch to yield a three-dimensional network. Much is now known about the structural origins of clot mechanical properties, including changes in fiber orientation, stretching and buckling, and forced unfolding of molecular domains. Studies of congenital fibrinogen variants and post-translational modifications have increased our understanding of the structure and functions of fibrin(ogen). The fibrinolytic system, with the zymogen plasminogen binding to fibrin together with tissue-type plasminogen activator to promote activation to the active proteolytic enzyme, plasmin, results in digestion of fibrin at specific lysine residues. In spite of a great increase in our knowledge of all these interconnected processes, much about the molecular mechanisms of the biological functions of fibrin(ogen) remains unknown, including some basic aspects of clotting, fibrinolysis, and molecular origins of fibrin mechanical properties. Even less is known concerning more complex (patho)physiological implications of fibrinogen and fibrin.
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Affiliation(s)
- John W Weisel
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
| | - Rustem I Litvinov
- Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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24
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Badiei N, Sowedan AM, Curtis DJ, Brown MR, Lawrence MJ, Campbell AI, Sabra A, Evans PA, Weisel JW, Chernysh IN, Nagaswami C, Williams PR, Hawkins K. Effects of unidirectional flow shear stresses on the formation, fractal microstructure and rigidity of incipient whole blood clots and fibrin gels. Clin Hemorheol Microcirc 2016; 60:451-64. [PMID: 25624413 PMCID: PMC4923731 DOI: 10.3233/ch-151924] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Incipient clot formation in whole blood and fibrin gels was studied by the rheometric techniques of controlled stress parallel superposition (CSPS) and small amplitude oscillatory shear (SAOS). The effects of unidirectional shear stress on incipient clot microstructure, formation kinetics and elasticity are reported in terms of the fractal dimension (df) of the fibrin network, the gel network formation time (TGP) and the shear elastic modulus, respectively. The results of this first haemorheological application of CSPS reveal the marked sensitivity of incipient clot microstructure to physiologically relevant levels of shear stress, these being an order of magnitude lower than have previously been studied by SAOS. CSPS tests revealed that exposure of forming clots to increasing levels of shear stress produces a corresponding elevation in df, consistent with the formation of tighter, more compact clot microstructures under unidirectional flow. A corresponding increase in shear elasticity was recorded. The scaling relationship established between shear elasticity and df for fibrin clots and whole blood confirms the fibrin network as the dominant microstructural component of the incipient clot in terms of its response to imposed stress. Supplementary studies of fibrin clot formation by rheometry and microscopy revealed the substantial additional network mass required to increase df and provide evidence to support the hypothesis that microstructural changes in blood clotted under unidirectional shear may be attributed to flow enhanced thrombin generation and activation. CSPS also identified a threshold value of unidirectional shear stress above which no incipient clot formation could be detected. CSPS was shown to be a valuable haemorheological tool for the study of the effects of physiological and pathological levels of shear on clot properties.
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Affiliation(s)
- N Badiei
- College of Engineering, Swansea University, Swansea, UK
| | - A M Sowedan
- College of Engineering, Swansea University, Swansea, UK.,College of Medicine, Swansea University, Swansea, UK
| | - D J Curtis
- College of Engineering, Swansea University, Swansea, UK
| | - M R Brown
- College of Engineering, Swansea University, Swansea, UK
| | - M J Lawrence
- College of Medicine, Swansea University, Swansea, UK.,NISCHR Clinical Haemostasis and Biomarker Research Unit, ABMU NHS Trust Hospital, Morriston, Swansea, UK
| | - A I Campbell
- College of Engineering, Swansea University, Swansea, UK
| | - A Sabra
- College of Medicine, Swansea University, Swansea, UK.,NISCHR Clinical Haemostasis and Biomarker Research Unit, ABMU NHS Trust Hospital, Morriston, Swansea, UK
| | - P A Evans
- College of Medicine, Swansea University, Swansea, UK.,NISCHR Clinical Haemostasis and Biomarker Research Unit, ABMU NHS Trust Hospital, Morriston, Swansea, UK
| | - J W Weisel
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - I N Chernysh
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - C Nagaswami
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - P R Williams
- College of Engineering, Swansea University, Swansea, UK
| | - K Hawkins
- College of Medicine, Swansea University, Swansea, UK.,NISCHR Clinical Haemostasis and Biomarker Research Unit, ABMU NHS Trust Hospital, Morriston, Swansea, UK
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25
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Fibrin Fiber Stiffness Is Strongly Affected by Fiber Diameter, but Not by Fibrinogen Glycation. Biophys J 2016; 110:1400-10. [PMID: 27028649 PMCID: PMC4816776 DOI: 10.1016/j.bpj.2016.02.021] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 01/24/2016] [Accepted: 02/02/2016] [Indexed: 11/24/2022] Open
Abstract
The major structural component of a blood clot is a mesh of fibrin fibers. Our goal was to determine whether fibrinogen glycation and fibrin fiber diameter have an effect on the mechanical properties of single fibrin fibers. We used a combined atomic force microscopy/fluorescence microscopy technique to determine the mechanical properties of individual fibrin fibers formed from blood plasma. Blood samples were taken from uncontrolled diabetic patients as well as age-, gender-, and body-mass-index-matched healthy individuals. The patients then underwent treatment to control blood glucose levels before end blood samples were taken. The fibrinogen glycation of the diabetic patients was reduced from 8.8 to 5.0 mol glucose/mol fibrinogen, and the healthy individuals had a mean fibrinogen glycation of 4.0 mol glucose/mol fibrinogen. We found that fibrinogen glycation had no significant systematic effect on single-fiber modulus, extensibility, or stress relaxation times. However, we did find that the fiber modulus, Y, strongly decreases with increasing fiber diameter, D, as Y∝D−1.6. Thin fibers can be 100 times stiffer than thick fibers. This is unusual because the modulus is a material constant and should not depend on the sample dimensions (diameter) for homogeneous materials. Our finding, therefore, implies that fibrin fibers do not have a homogeneous cross section of uniformly connected protofibrils, as is commonly thought. Instead, the density of protofibril connections, ρPb, strongly decreases with increasing diameter, as ρPb∝D−1.6. Thin fibers are denser and/or have more strongly connected protofibrils than thick fibers. This implies that it is easier to dissolve clots that consist of fewer thick fibers than those that consist of many thin fibers, which is consistent with experimental and clinical observations.
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26
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Is GERD a Factor in Osteonecrosis of the Jaw? Evidence of Pathology Linked to G6PD Deficiency and Sulfomucins. DISEASE MARKERS 2016; 2016:8376979. [PMID: 27773962 PMCID: PMC5059643 DOI: 10.1155/2016/8376979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 05/18/2016] [Accepted: 07/20/2016] [Indexed: 11/30/2022]
Abstract
Osteonecrosis of the jaw (ONJ), a rare side effect of bisphosphonate therapy, is a debilitating disorder with a poorly understood etiology. FDA's Adverse Event Reporting System (FAERS) provides the opportunity to investigate this disease. Our goals were to analyze FAERS data to discover possible relationships between ONJ and specific conditions and drugs and then to consult the scientific literature to deduce biological explanations. Our methodology revealed a very strong association between gastroesophageal reflux and bisphosphonate-induced ONJ, suggesting acidosis as a key factor. Overgrowth of acidophilic species, particularly Streptococcus mutans, in the oral microbiome in the context of insufficient acid buffering due to impaired salivary glands maintains the low pH that sustains damage to the mucosa. Significant associations between ONJ and adrenal insufficiency, vitamin C deficiency, and Sjögren's syndrome were found. Glucose 6 phosphate dehydrogenase (G6PD) deficiency can explain much of the pathology. An inability to maintain vitamin C and other antioxidants in the reduced form leads to vascular oxidative damage and impaired adrenal function. Thus, pathogen-induced acidosis, hypoxia, and insufficient antioxidant defenses together induce ONJ. G6PD deficiency and adrenal insufficiency are underlying factors. Impaired supply of adrenal-derived sulfated sterols such as DHEA sulfate may drive the disease process.
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27
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The effect of sepsis and its inflammatory response on mechanical clot characteristics: a prospective observational study. Intensive Care Med 2016; 42:1990-1998. [DOI: 10.1007/s00134-016-4496-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/08/2016] [Indexed: 11/27/2022]
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28
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Davies N, Llwyd O, Brugniaux J, Davies G, Marley C, Hodson D, Lawrence M, D'Silva L, Morris R, Hawkins K, Williams P, Bailey D, Evans P. Effects of exercise intensity on clot microstructure and mechanical properties in healthy individuals. Thromb Res 2016; 143:130-6. [DOI: 10.1016/j.thromres.2016.05.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 05/11/2016] [Accepted: 05/18/2016] [Indexed: 11/30/2022]
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29
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D'Silva L, Wilczynska M, Lewis K, Lawrence M, Hawkins K, Williams R, Stanford S, Davidson S, Morris K, Evans A. Altered clot microstructure detected in obstructive sleep apnoea hypopnoea syndrome. ACTA ACUST UNITED AC 2016; 9:14-9. [PMID: 27226818 PMCID: PMC4867923 DOI: 10.1016/j.slsci.2016.02.175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Revised: 01/19/2016] [Accepted: 02/11/2016] [Indexed: 11/26/2022]
Abstract
Abnormal clot microstructure plays a pivotal role in the pathophysiology of thromboembolic diseases. Assessing the viscoelastic properties of clot microstructure using novel parameters, Time to Gel Point (TGP), Fractal Dimension (df) and clot elasticity (G׳GP) could explain the increased cardiovascular and thromboembolic events in patients with Obstructive Sleep Apnoea Hypopnea Syndrome (OSAHS). We wanted to compare TGP, df, and G׳GP and their diurnal variation in OSAHS and symptomatic comparators. thirty six patients attending a sleep disturbed breathing clinic with symptoms of OSAHS were recruited. TGP, df and G׳GP were measured alongside standard coagulation screening, thrombin generation assays, and platelet aggregometry at 16:00 h and immediately after an in-patient sleep study at 07:30 h. OSAHS group had significantly lower afternoon df than comparators (1.705±0.033 vs. 1.731±0.031, p<0.05). df showed diurnal variation and only in the OSAHS group, being significantly lower in the afternoon than morning (p<0.05). Diurnal changes in df correlated with 4% DR, even after controlling for BMI (r=0.37, p=0.02). The lower df in the afternoon in OSAHS suggests a partial compensatory change that may make up for other pro-clotting abnormalities/hypertension during the night. The change to the thrombotic tendency in the afternoon is biggest in severe OSAHS. df Shows promise as a new microstructural indicator for abnormal haemostasis in OSAHS.
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Affiliation(s)
- Lindsay D'Silva
- College of Medicine, Institute of Life Science, Swansea University, Swansea, United Kingdom; NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, Swansea SA6 6NL, United Kingdom
| | - Maria Wilczynska
- Respiratory Department, Prince Philip Hospital, Llanelli, Hywel Dda University Health Board, United Kingdom
| | - Keir Lewis
- College of Medicine, Institute of Life Science, Swansea University, Swansea, United Kingdom; Respiratory Department, Prince Philip Hospital, Llanelli, Hywel Dda University Health Board, United Kingdom
| | - Matthew Lawrence
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, Swansea SA6 6NL, United Kingdom
| | - Karl Hawkins
- College of Medicine, Institute of Life Science, Swansea University, Swansea, United Kingdom; NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, Swansea SA6 6NL, United Kingdom
| | - Rhodri Williams
- College of Engineering, Swansea University, Swansea, United Kingdom
| | - Sophia Stanford
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, Swansea SA6 6NL, United Kingdom
| | - Simon Davidson
- Department of Haematology, Royal Brompton Hospital, London, United Kingdom
| | - Keith Morris
- School of Applied Sciences, Cardiff Metropolitan University, Cardiff, United Kingdom
| | - Adrian Evans
- College of Medicine, Institute of Life Science, Swansea University, Swansea, United Kingdom; NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Swansea, Abertawe Bro Morgannwg University Health Board, Swansea SA6 6NL, United Kingdom
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30
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Lawrence MJ, Marsden N, Mothukuri R, Morris RHK, Davies G, Hawkins K, Curtis DJ, Brown MR, Williams PR, Evans PA. The Effects of Temperature on Clot Microstructure and Strength in Healthy Volunteers. Anesth Analg 2016; 122:21-6. [PMID: 26440418 DOI: 10.1213/ane.0000000000000992] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Anesthesia, critical illness, and trauma are known to alter thermoregulation, which can potentially affect coagulation and clinical outcome. This in vitro preclinical study explores the relationship between temperature change and hemostasis using a recently validated viscoelastic technique. We hypothesize that temperature change will cause significant alterations in the microstructural properties of clot. METHODS We used a novel viscoelastic technique to identify the gel point of the blood. The gel point identifies the transition of the blood from a viscoelastic liquid to a viscoelastic solid state. Furthermore, identification of the gel point provides 3 related biomarkers: the elastic modulus at the gel point, which is a measure of clot elasticity; the time to the gel point (TGP), which is a measure of the time required to form the clot; and the fractal dimension of the clot at the gel point, df, which quantifies the microstructure of the clot. The gel point measurements were performed in vitro on whole blood samples from 136 healthy volunteers over a temperature range of 27°C to 43°C. RESULTS There was a significant negative correlation between increases in temperature, from 27°C to 43°C, and TGP (r = -0.641, P < 0.0005). Conversely, significant positive correlations were observed for both the elastic modulus at the gel point (r = 0.513, P = 0.0008) and df (r = 0.777, P < 0.0005) across the range of 27°C to 43°C. When temperature was reduced below 37°C, significant reductions in df and TGP occurred at ≤32°C (Bonferroni-corrected P = 0.0093) and ≤29°C (Bonferroni-corrected P = 0.0317), respectively. No significant changes were observed when temperature was increased to >37°C. CONCLUSIONS This study demonstrates that the gel point technique can identify alterations in clot microstructure because of changes in temperature. This was demonstrated in slower-forming clots with less structural complexity as temperature is decreased. We also found that significant changes in clot microstructure occurred when the temperature was ≤32°C.
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Affiliation(s)
- Matthew James Lawrence
- From the *NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, Wales, United Kingdom; †College of Medicine, Swansea University, Swansea, Wales, United Kingdom; ‡The Welsh Centre for Burns and Plastic Surgery, Morriston Hospital, Swansea, Wales, United Kingdom; §Emergency Department, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, Wales, United Kingdom; ‖School of Health Science, Cardiff Metropolitan University, Cardiff, Wales, United Kingdom; and ¶College of Engineering, Swansea University, Swansea, Wales, United Kingdom
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31
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Longstaff C, Hogwood J, Gray E, Komorowicz E, Varjú I, Varga Z, Kolev K. Neutralisation of the anti-coagulant effects of heparin by histones in blood plasma and purified systems. Thromb Haemost 2015; 115:591-9. [PMID: 26632486 DOI: 10.1160/th15-03-0214] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 10/22/2015] [Indexed: 12/14/2022]
Abstract
Neutrophil extracellular traps (NETs) composed primarily of DNA and histones are a link between infection, inflammation and coagulation. NETs promote coagulation and approaches to destabilise NETs have been explored to reduce thrombosis and treat sepsis. Heparinoids bind histones and we report quantitative studies in plasma and purified systems to better understand physiological consequences. Unfractionated heparin (UFH) was investigated by activated partial thromboplastin time (APTT) and alongside low-molecular-weight heparins (LMWH) in purified systems with thrombin or factor Xa (FXa) and antithrombin (AT) to measure the sensitivity of UFH or LMWH to histones. A method was developed to assess the effectiveness of DNA and non-anticoagulant heparinoids as anti-histones. Histones effectively neutralised UFH, the IC50 value for neutralisation of 0.2 IU/ml UFH was 1.8 µg/ml histones in APTT and 4.6 µg/ml against 0.6 IU/ml UFH in a purified system. Histones also inhibited the activities of LMWHs with thrombin (IC50 6.1 and 11.0 µg/ml histones, for different LMWHs) or FXa (IC50 7.8 and 7.0 µg/ml histones). Direct interactions of UFH and LMWH with DNA and histones were explored by surface plasmon resonance, while rheology studies showed complex effects of histones, UFH and LMWH on clot resilience. A conclusion from these studies is that anticoagulation by UFH and LMWH will be compromised by high affinity binding to circulating histones even in the presence of DNA. A complete understanding of the effects of histones, DNA and heparins on the haemostatic system must include an appreciation of direct effects on fibrin and clot structure.
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Affiliation(s)
- Colin Longstaff
- Colin Longstaff, Biotherapeutics Group, National Institute for Biological Standards and Control, S Mimms, Herts, EN6 3QG, UK, Tel.: +44 1707 641253, Fax: +44 1707 641050, E-Mail:
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32
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Davies NA, Harrison NK, Morris RHK, Noble S, Lawrence MJ, D'Silva LA, Broome L, Brown MR, Hawkins KM, Williams PR, Davidson S, Evans PA. Fractal dimension (df) as a new structural biomarker of clot microstructure in different stages of lung cancer. Thromb Haemost 2015; 114:1251-9. [PMID: 26293709 DOI: 10.1160/th15-04-0357] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 06/28/2015] [Indexed: 12/21/2022]
Abstract
Venous thromboembolism (VTE) is common in cancer patients, and is the second commonest cause of death associated with the disease. Patients with chronic inflammation, such as cancer, have been shown to have pathological clot structures with modulated mechanical properties. Fractal dimension (df) is a new technique which has been shown to act as a marker of the microstructure and mechanical properties of blood clots, and can be performed more readily than current methods such as scanning electron microscopy (SEM). We measured df in 87 consecutive patients with newly diagnosed lung cancer prior to treatment and 47 matched-controls. Mean group values were compared for all patients with lung cancer vs controls and for limited disease vs extensive disease. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly higher values of df were observed in lung cancer patients compared with controls and patients with extensive disease had higher values than those with limited disease (p< 0.05), whilst conventional markers failed to distinguish between these groups. The relationship between df of the incipient clot and mature clot microstructure was confirmed by SEM and computational modelling: higher df was associated with highly dense clots formed of smaller fibrin fibres in lung cancer patients compared to controls. This study demonstrates that df is a sensitive technique which quantifies the structure and mechanical properties of blood clots in patients with lung cancer. Our data suggests that df has the potential to identify patients with an abnormal clot microstructure and greatest VTE risk.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Phillip Adrian Evans
- Prof. Phillip Adrian Evans, Director, NISCHR Haemostasis Biomedical Research Unit, Abertawe Bro Morgannwg University Health Board, NISCHR Haemostasis Biomedical Research Unit, Emergency Department, Morriston Hospital Abertawe Bro Morgannwg University Health Board, Swansea, UK, SA6 6NL, Tel.: +44 1792 703418, E-mail:
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33
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Ferri F, Calegari GR, Molteni M, Cardinali B, Magatti D, Rocco M. Size and Density of Fibers in Fibrin and Other Filamentous Networks from Turbidimetry: Beyond a Revisited Carr–Hermans Method, Accounting for Fractality and Porosity. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b00893] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fabio Ferri
- Dipartimento
di Scienza e Alta Tecnologia and To.Sca.Lab, Università dell’Insubria, Via Valleggio 11, I-22100 Como, Italy
| | - Gabriele Re Calegari
- Dipartimento
di Scienza e Alta Tecnologia and To.Sca.Lab, Università dell’Insubria, Via Valleggio 11, I-22100 Como, Italy
| | - Matteo Molteni
- Dipartimento
di Scienza e Alta Tecnologia and To.Sca.Lab, Università dell’Insubria, Via Valleggio 11, I-22100 Como, Italy
| | - Barbara Cardinali
- Biopolimeri
e Proteomica, IRCCS AOU San Martino-IST, Istituto Nazionale per la Ricerca sul Cancro, c/o CBA, Largo R. Benzi 10, I-16132 Genova, Italy
| | - Davide Magatti
- Dipartimento
di Scienza e Alta Tecnologia and To.Sca.Lab, Università dell’Insubria, Via Valleggio 11, I-22100 Como, Italy
| | - Mattia Rocco
- Biopolimeri
e Proteomica, IRCCS AOU San Martino-IST, Istituto Nazionale per la Ricerca sul Cancro, c/o CBA, Largo R. Benzi 10, I-16132 Genova, Italy
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34
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Lawrence MJ, Sabra A, Thomas P, Obaid DR, D'Silva LA, Morris RH, Hawkins K, Brown MR, Williams PR, Davidson SJ, Chase AJ, Smith D, Evans PA. Fractal dimension: A novel clot microstructure biomarker use in ST elevation myocardial infarction patients. Atherosclerosis 2015; 240:402-7. [DOI: 10.1016/j.atherosclerosis.2015.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 03/12/2015] [Accepted: 04/06/2015] [Indexed: 11/27/2022]
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35
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Stanford SN, Sabra A, D'Silva L, Lawrence M, Morris RHK, Storton S, Brown MR, Evans V, Hawkins K, Williams PR, Davidson SJ, Wani M, Potter JF, Evans PA. The changes in clot microstructure in patients with ischaemic stroke and the effects of therapeutic intervention: a prospective observational study. BMC Neurol 2015; 15:35. [PMID: 25885595 PMCID: PMC4367933 DOI: 10.1186/s12883-015-0289-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 02/25/2015] [Indexed: 11/18/2022] Open
Abstract
Background Stroke is the second largest cause of death worldwide. Hypercoagulability is a key feature in ischaemic stroke due to the development of an abnormally dense clot structure but techniques assessing the mechanics and quality of clot microstructure have limited clinical use. We have previously validated a new haemorheological technique using three parameters to reflect clot microstructure (Fractal Dimension (df)) ex-vivo, real-time clot formation time (TGP) and blood clot strength (elasticity at the gel point (G’GP)). We aimed to evaluate these novel clotting biomarkers in ischaemic stroke and changes of clot structure following therapeutic intervention. Methods In a prospective cohort study clot microstructure was compared in ischaemic stroke patients and a control group of healthy volunteers. Further assessment took place at 2–4 hours and at 24 hours after therapeutic intervention in the stroke group to assess the effects of thrombolysis and anti-platelet therapy. Results 75 patients (mean age 72.8 years [SD 13.1]; 47 male, 28 female) with ischaemic stroke were recruited. Of the 75 patients, 32 were thrombolysed with t-PA and 43 were loaded with 300 mg aspirin. The following parameters were significantly different between patients with stroke and the 74 healthy subjects: df (1.760 ± .053 versus 1.735 ± 0.048, p = 0.003), TGP (208 ± 67 versus 231 ± 75, p = 0.05), G’GP (0.056 ± 0.017 versus 0.045 ± 0.014, p < 0.0001) and fibrinogen (3.7 ± 0.8 versus 3.2 ± 0.5, p < 0.00001). There was a significant decrease in df (p = 0.02), G’GP (p = 0.01) and fibrinogen (p = 0.01) following the administration of aspirin and for df (p = 0.003) and fibrinogen (p < 0.001) following thrombolysis as compared to baseline values. Conclusion Patients with ischaemic stroke have denser and stronger clot structure as detected by df and G’GP. The effect of thrombolysis on clot microstructure (df) was more prominent than antiplatelet therapy. Further work is needed to assess the clinical and therapeutic implications of these novel biomarkers.
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Affiliation(s)
- Sophia N Stanford
- School of Medicine, Swansea University, Swansea, UK. .,NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK.
| | - Ahmed Sabra
- School of Medicine, Swansea University, Swansea, UK. .,NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK. .,The Emergency Department, Morriston Hospital, ABMU Health Board, Swansea, UK.
| | - Lindsay D'Silva
- School of Medicine, Swansea University, Swansea, UK. .,NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK.
| | - Matthew Lawrence
- School of Medicine, Swansea University, Swansea, UK. .,NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK.
| | - Roger H K Morris
- School of Applied Sciences, Cardiff Metropolitan University, Cardiff, UK.
| | - Sharon Storton
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK.
| | | | - Vanessa Evans
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK.
| | - Karl Hawkins
- School of Medicine, Swansea University, Swansea, UK.
| | | | - Simon J Davidson
- Department of Haematology, Royal Brompton Hospital, Royal Brompton and Harefield NHS Foundation Trust, London, UK.
| | - Mushtaq Wani
- Department of Stroke Medicine, Morriston Hospital, Swansea, UK.
| | - John F Potter
- Norwich Medical School, University of East Anglia, Norwich, UK.
| | - Phillip A Evans
- School of Medicine, Swansea University, Swansea, UK. .,NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, ABMU Health Board, Swansea, SA6 6NL, UK. .,The Emergency Department, Morriston Hospital, ABMU Health Board, Swansea, UK.
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36
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Gannavarpu R, Bhaduri B, Tangella K, Popescu G. Spatiotemporal characterization of a fibrin clot using quantitative phase imaging. PLoS One 2014; 9:e111381. [PMID: 25386701 PMCID: PMC4227684 DOI: 10.1371/journal.pone.0111381] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 09/23/2014] [Indexed: 11/24/2022] Open
Abstract
Studying the dynamics of fibrin clot formation and its morphology is an important problem in biology and has significant impact for several scientific and clinical applications. We present a label-free technique based on quantitative phase imaging to address this problem. Using quantitative phase information, we characterized fibrin polymerization in real-time and present a mathematical model describing the transition from liquid to gel state. By exploiting the inherent optical sectioning capability of our instrument, we measured the three-dimensional structure of the fibrin clot. From this data, we evaluated the fractal nature of the fibrin network and extracted the fractal dimension. Our non-invasive and speckle-free approach analyzes the clotting process without the need for external contrast agents.
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Affiliation(s)
- Rajshekhar Gannavarpu
- Quantitative Light Imaging Laboratory, Department of Electrical and Computer Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Basanta Bhaduri
- Quantitative Light Imaging Laboratory, Department of Electrical and Computer Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Krishnarao Tangella
- Department of Pathology, Christie Clinic, and University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Gabriel Popescu
- Quantitative Light Imaging Laboratory, Department of Electrical and Computer Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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37
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Lawrence MJ, Sabra A, Mills G, Pillai SG, Abdullah W, Hawkins K, Morris RHK, Davidson SJ, D'Silva LA, Curtis DJ, Brown MR, Weisel JW, Williams PR, Evans PA. A new biomarker quantifies differences in clot microstructure in patients with venous thromboembolism. Br J Haematol 2014; 168:571-5. [PMID: 25302653 DOI: 10.1111/bjh.13173] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 09/12/2014] [Indexed: 11/30/2022]
Abstract
This study compared patients with venous thromboembolism (VTE) to non-VTE patients using a biomarker of clot microstructure (df ) and clot formation time (TGP ). df was the only marker that identified a significant difference (P < 0·001) between the VTE (n = 60) and non-VTE cohorts (n = 69). The 'abnormal' clot microstructures in the VTE patients suggests either inadequate response to anticoagulant therapy or the presence of a procoagulant state not detected by other markers of coagulation (i.e., International Normalized Ratio). Furthermore, elevated values of df in first time VTE patients who later develop a secondary event indicates that df may identify those at risk of recurrence.
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Affiliation(s)
- Matthew J Lawrence
- NISCHR Haemostasis Biomedical Research Unit, Morriston Hospital, Abertawe Bro Morgannwg University Health Board, Swansea, UK; College of Medicine, Swansea University, Swansea, UK
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38
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Weisel JW. Monitoring coagulopathies in fluid resuscitation for trauma or surgery. Thromb Res 2014; 134:535-6. [DOI: 10.1016/j.thromres.2014.07.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 07/07/2014] [Accepted: 07/10/2014] [Indexed: 10/25/2022]
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39
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Lawrence MJ, Kumar S, Hawkins K, Boden S, Rutt H, Mills G, Sabra A, Morris RH, Davidson SJ, Badiei N, Brown MR, Williams PR, Evans PA. A new structural biomarker that quantifies and predicts changes in clot strength and quality in a model of progressive haemodilution. Thromb Res 2014; 134:488-94. [DOI: 10.1016/j.thromres.2014.05.039] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 04/15/2014] [Accepted: 05/22/2014] [Indexed: 10/25/2022]
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40
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Ranucci M, Laddomada T, Ranucci M, Baryshnikova E. Blood viscosity during coagulation at different shear rates. Physiol Rep 2014; 2:2/7/e12065. [PMID: 24994896 PMCID: PMC4187573 DOI: 10.14814/phy2.12065] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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.
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Affiliation(s)
- Marco Ranucci
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
| | - Tommaso Laddomada
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
| | - Matteo Ranucci
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
| | - Ekaterina Baryshnikova
- Department of Cardiothoracic, Vascular Anesthesia and Intensive Care, IRCCS Policlinico San Donato, Milan, Italy
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41
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The pathophysiology, diagnosis and treatment of the acute coagulopathy of trauma and shock: a literature review. Eur J Trauma Emerg Surg 2013; 41:259-72. [DOI: 10.1007/s00068-013-0360-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2013] [Accepted: 12/01/2013] [Indexed: 10/25/2022]
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42
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Abstract
Research on all stages of fibrin polymerization, using a variety of approaches including naturally occurring and recombinant variants of fibrinogen, x-ray crystallography, electron and light microscopy, and other biophysical approaches, has revealed aspects of the molecular mechanisms involved. The ordered sequence of fibrinopeptide release is essential for the knob-hole interactions that initiate oligomer formation and the subsequent formation of 2-stranded protofibrils. Calcium ions bound both strongly and weakly to fibrin(ogen) have been localized, and some aspects of their roles are beginning to be discovered. Much less is known about the mechanisms of the lateral aggregation of protofibrils and the subsequent branching to yield a 3-dimensional network, although the αC region and B:b knob-hole binding seem to enhance lateral aggregation. Much information now exists about variations in clot structure and properties because of genetic and acquired molecular variants, environmental factors, effects of various intravascular and extravascular cells, hydrodynamic flow, and some functional consequences. The mechanical and chemical stability of clots and thrombi are affected by both the structure of the fibrin network and cross-linking by plasma transglutaminase. There are important clinical consequences to all of these new findings that are relevant for the pathogenesis of diseases, prophylaxis, diagnosis, and treatment.
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Messina PV, Hassan N, Soltero A, Ruso JM. Identifying emerging trends of protein hydrogels for biological scaffolding. RSC Adv 2013. [DOI: 10.1039/c3ra42204f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Lawrence M, Kaczynski J, Stanford S, Morris R, Evans P. Templating effect of clot structure can predict clot development and outcome in diluted blood: a comparison with thromboelastography. Crit Care 2012. [PMCID: PMC3363847 DOI: 10.1186/cc11036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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45
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Davies GR, Stanford SN, Lawrence MJ, Gill D, Williams PR, Morris K, Thomas D, Evans PA. Fractal analysis: a new biomarker for determining clot characteristics in critically ill patients. Crit Care 2012. [PMCID: PMC3363848 DOI: 10.1186/cc11037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Abstract
In this issue of Blood, Evans et al report that fractal analysis of the mechanical properties of whole-blood clots defines a unique property of the incipient clot that can be used as a functional biomarker of hemostasis.
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