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Zhang Y, Jiang F, Chen Y, Ju LA. Platelet Mechanobiology Inspired Microdevices: From Hematological Function Tests to Disease and Drug Screening. Front Pharmacol 2022; 12:779753. [PMID: 35126120 PMCID: PMC8811026 DOI: 10.3389/fphar.2021.779753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 12/28/2021] [Indexed: 12/30/2022] Open
Abstract
Platelet function tests are essential to profile platelet dysfunction and dysregulation in hemostasis and thrombosis. Clinically they provide critical guidance to the patient management and therapeutic evaluation. Recently, the biomechanical effects induced by hemodynamic and contractile forces on platelet functions attracted increasing attention. Unfortunately, the existing platelet function tests on the market do not sufficiently incorporate the topical platelet mechanobiology at play. Besides, they are often expensive and bulky systems that require large sample volumes and long processing time. To this end, numerous novel microfluidic technologies emerge to mimic vascular anatomies, incorporate hemodynamic parameters and recapitulate platelet mechanobiology. These miniaturized and cost-efficient microfluidic devices shed light on high-throughput, rapid and scalable platelet function testing, hematological disorder profiling and antiplatelet drug screening. Moreover, the existing antiplatelet drugs often have suboptimal efficacy while incurring several adverse bleeding side effects on certain individuals. Encouraged by a few microfluidic systems that are successfully commercialized and applied to clinical practices, the microfluidics that incorporate platelet mechanobiology hold great potential as handy, efficient, and inexpensive point-of-care tools for patient monitoring and therapeutic evaluation. Hereby, we first summarize the conventional and commercially available platelet function tests. Then we highlight the recent advances of platelet mechanobiology inspired microfluidic technologies. Last but not least, we discuss their future potential of microfluidics as point-of-care tools for platelet function test and antiplatelet drug screening.
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Affiliation(s)
- Yingqi Zhang
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
- Heart Research Institute, Newtown, NSW, Australia
| | - Fengtao Jiang
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
| | - Yunfeng Chen
- The Department of Biochemistry and Molecular Biology, The University of Texas Medical Branch, Galveston, TX, United States
- The Department of Pathology, The University of Texas Medical Branch, Galveston, TX, United States
| | - Lining Arnold Ju
- School of Biomedical Engineering, Faculty of Engineering, The University of Sydney, Sydney, NSW, Australia
- Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
- Heart Research Institute, Newtown, NSW, Australia
- *Correspondence: Lining Arnold Ju,
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Santana-Mateos M, Medina-Gil JM, Saavedra-Santana P, Martínez-Quintana E, Rodríguez-González F, Tugores A. Clinical and pharmacological parameters determine relapse during clopidogrel treatment of acute coronary syndrome. J Clin Pharmacol 2021; 62:783-791. [PMID: 34958683 DOI: 10.1002/jcph.2016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/14/2021] [Indexed: 11/06/2022]
Abstract
The therapeutic efficacy of clopidogrel as an anti-platelet drug varies among individuals, being the mainstream hypothesis that its bioavailability depends on the individual genetic background and/or interactions with other drugs. A total of 477 patients receiving double anti-aggregation therapy with aspirin and clopidogrel, after suffering a first event, were followed for 1 year to record relapse, as a surrogate end point to measure their therapeutic response, as defined by presenting with an acute coronary event (unstable angina, STEMI, or NSTEMI), stent thrombosis/restenosis or cardiac mortality. Anthropometric, clinical and pharmacological variables along with CYP2C19 genotypes were analyzed for their association with the disease relapse phenotype. Only 75 patients (15%) suffered a relapse, which occurred during the first six months of therapy, with a peak at 4.5 months. An initial univariate analysis identified that patients in the relapse group were significantly older (67.4 ± 11.0 vs 61.6 ± 12.3 years old) and presented with diffuse coronary disease, insulin-dependent type 2 diabetes mellitus dyslipidemia, and arterial hypertension. A poor clinical response to the platelet anti-aggregation regime also occurred more frequently among patients taking, along with aspirin and clopidogrel, acenocoumarol and Calcium Channel Blockers, while no association was found according to CYP2C19 genotypes. A retrospective multivariate analysis indicated that patients belonging to the non-responder phenotype to treatment with aspirin and clopidogrel were older, presented with diffuse coronary disease, a group largely overlapping with type 2 insulin-dependent diabetes mellitus, and were taking dihidropyrimidinic calcium channel blockers. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | - José M Medina-Gil
- Cardiology Department, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | | | - Efrén Martínez-Quintana
- Cardiology Department, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
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Affiliation(s)
- Jerrold H Levy
- From the Departments of Anesthesiology, Critical Care, and Surgery, Duke University School of Medicine, Durham, NC (J.H.L.); and the Hematology Division, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School - both in Boston (J.M.C.)
| | - Jean M Connors
- From the Departments of Anesthesiology, Critical Care, and Surgery, Duke University School of Medicine, Durham, NC (J.H.L.); and the Hematology Division, Department of Medicine, Brigham and Women's Hospital, and Harvard Medical School - both in Boston (J.M.C.)
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Abstract
Studies using whole blood platelet aggregometry as a laboratory research tool, provided important insights into the mechanism and modulators of platelet aggregation. Subsequently, a number of point-of-care (POC) platelet function tests (PFTs) were developed for clinical use, based on the concept that an individual’s thrombotic profile could be assessed in vitro by assessing the response to stimulation of platelet aggregation by specific, usually solo agonists such as adenosine diphosphate (ADP), collagen and thrombin. However, adjusting antiplatelet medication in order to improve the results of such POC PFTs has not translated into a meaningful reduction in cardiovascular events, which may be attributable to important differences between the POC PFT techniques and in vivo conditions, including patient-to-patient variability. Important limitations of most tests include the use of citrate-anticoagulated blood. Citrate directly and irreversibly diminishes platelet function and even after recalcification, it may result in altered platelet aggregation in response to ADP, epinephrine or collagen, and interfere with thrombin generation from activated platelets. Furthermore, most tests do not employ flowing blood and therefore do not assess the effect of high shear forces on platelets that initiate, propagate and stabilize arterial thrombi. Finally, the effect of endogenous thrombolysis, due to fibrinolysis and dislodgement, which ultimately determines the outcome of a thrombotic stimulus, is mostly not assessed. In order to accurately reflect an individual’s predisposition to arterial thrombosis, future tests of thrombotic status which overcome these limitations should be used, to improve cardiovascular risk prediction and to guide pharmacotherapy.
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Affiliation(s)
- Diana A Gorog
- National Heart and Lung Institute, Imperial College, Dovehouse Street, London, SW3 6LY, UK.
- University of Hertfordshire, Hertfordshire, UK.
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Griffin MT, Kim D, Ku DN. Shear-induced platelet aggregation: 3D-grayscale microfluidics for repeatable and localized occlusive thrombosis. BIOMICROFLUIDICS 2019; 13:054106. [PMID: 31592301 PMCID: PMC6773594 DOI: 10.1063/1.5113508] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 09/13/2019] [Indexed: 05/20/2023]
Abstract
Atherothrombosis leads to complications of myocardial infarction and stroke as a result of shear-induced platelet aggregation (SIPA). Clinicians and researchers may benefit from diagnostic and benchtop microfluidic assays that assess the thrombotic activity of an individual. Currently, there are several different proposed point-of-care diagnostics and microfluidic thrombosis assays with different design parameters and end points. The microfluidic geometry, surface coatings, and anticoagulation may strongly influence the precision of these assays. Variability in selected end points also persists, leading to ambiguous results. This study aims to assess the effects of three physiologically relevant extrinsic design factors on the variability of a single end point to provide a quantified rationale for design parameter and end-point standardization. Using a design of experiments approach, we show that the methods of channel fabrication and collagen surface coating significantly impact the variability of occlusion time from porcine whole blood, while anticoagulant selection between heparin and citrate did not significantly impact the variability. No factor was determined to significantly impact the mean occlusion time within the assay. Occlusive thrombus was found to consistently form in the first third (333 μm) of the high shear zone and not in the shear gradient regions. The selection of these factors in the design of point-of-care diagnostics and experimental SIPA assays may lead to increased precision and specificity in high shear thrombosis studies.
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Affiliation(s)
| | - Dongjune Kim
- G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30318, USA
| | - David N. Ku
- Author to whom correspondence should be addressed:
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Lee H, Na W, Lee BK, Lim CS, Shin S. Recent advances in microfluidic platelet function assays: Moving microfluidics into clinical applications. Clin Hemorheol Microcirc 2019; 71:249-266. [PMID: 30584134 DOI: 10.3233/ch-189416] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The analysis of platelet aggregation and thrombosis kinetics has significantly advanced with progress in microfluidic technology. However, the results of platelet aggregation tests do not fully reflect the observed clinical outcomes. To address the present unmet clinical needs, the basic but essential biology of platelets should be reconsidered in relation to the characteristics of microfluidic systems employed for platelet tests. To this end, the present article provides an overview of commercially available point of care devices and focuses on recent microfluidic studies, describing their measurement principles. We critically discuss the characteristics of the microfluidics systems used to evaluate the complex processes underlying platelet aggregation, and that are specifically designed to mimic the pathophysiological environment of blood vessels, including hemodynamic factors as well as blood vessel injury. To this end, we summarize unsolved issues related to the application of platelet function tests based on microfluidics. Overall, we confirm that platelet function tests based on microfluidics provide a versatile platform that encompasses a variety of basic research, as well as clinical diagnostic applications.
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Affiliation(s)
- Hoyoon Lee
- Department of Mechanical Engineering, Korea University, Seoul, Korea
| | - Wonwhi Na
- Engineering Research Center for Biofluid Biopsy, Korea University, Seoul, Korea
| | - Byoung-Kwon Lee
- Department of Internal Medicine, Gangnam Severance Hospital, Yonsei University Medical College, Seoul, Korea
| | - Chae-Seung Lim
- Department of Laboratory Medicine, Guro Hospital, Korea University, Seoul, Korea
| | - Sehyun Shin
- Department of Mechanical Engineering, Korea University, Seoul, Korea.,Engineering Research Center for Biofluid Biopsy, Korea University, Seoul, Korea
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Pfrepper C, Deters S, Metze M, Siegemund R, Gockel I, Petros S. Metamizole inhibits arachidonic acid-induced platelet aggregation after surgery and impairs the effect of aspirin in hospitalized patients. Eur J Clin Pharmacol 2019; 75:777-784. [PMID: 30778625 DOI: 10.1007/s00228-019-02646-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 02/04/2019] [Indexed: 12/29/2022]
Abstract
PURPOSE The inhibitory effect of metamizole on platelet aggregation is known for several years, but most studies were conducted in healthy volunteers with contradictory results. Recent studies have shown an inhibitory effect of metamizole on acetylsalicylic acid (ASA)-induced platelet aggregation. We aimed to investigate the effect of metamizole on platelet aggregation after an elective surgery and the effect of metamizole on ASA-induced platelet aggregation in hospitalized patients. METHODS We performed platelet aggregation analysis after induction with ADP, arachidonic acid (AA), epinephrine, and collagen in 37 patients prior to an elective visceral or thoracic surgery and on postoperative day (POD) 1 and POD 3 1-2 h and 5-6 h after metamizole. In another cohort of 10 hospitalized patients receiving the combination of metamizole and ASA for more than 7 days, AA-induced platelet aggregation was analyzed in the morning prior to the intake of both drugs. RESULTS Metamizole induced a strong inhibitory effect on AA-induced platelet aggregation at all time points being detectable up to 41 h in some patients. Besides a less pronounced effect on collagen-induced platelet aggregation on POD 3 1-2 h after metamizole, all other inductors showed no effect. In 4 out of 10 hospitalized patients, no ASA-induced inhibition of platelet aggregation was detectable without correlation to sequence of administration. CONCLUSIONS The reason why some patients have a long-lasting inhibitory effect of metamizole on COX-induced platelet aggregation that might interfere with ASA should be investigated in a larger cohort of patients.
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Affiliation(s)
- C Pfrepper
- Division of Hemostaseology, University Hospital Leipzig, Liebigstr, 20, 04103, Leipzig, Germany.
| | - S Deters
- Division of Hemostaseology, University Hospital Leipzig, Liebigstr, 20, 04103, Leipzig, Germany
| | - M Metze
- Department of Cardiology, University Hospital Leipzig, Leipzig, Germany
| | - R Siegemund
- Division of Hemostaseology, University Hospital Leipzig, Liebigstr, 20, 04103, Leipzig, Germany
| | - I Gockel
- Department of Visceral, Transplantation, Thoracic and Vascular Surgery, University Hospital Leipzig, Leipzig, Germany
| | - S Petros
- Division of Hemostaseology, University Hospital Leipzig, Liebigstr, 20, 04103, Leipzig, Germany
- University Hospital Leipzig, Medical ICU, Leipzig, Germany
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Rodríguez-González F, Martínez-Quintana E, Saavedra P, Medina-Gil JM, Riaño M, Garay-Sánchez P, Tugores A. CYP2C19 or CYP3A5 Genotyping Does Not Predict Clinical Response to Clopidogrel. J Clin Pharmacol 2018; 58:1274-1283. [PMID: 29723426 DOI: 10.1002/jcph.1144] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/26/2018] [Indexed: 01/01/2023]
Abstract
Along with aspirin, clopidogrel has been a widely used antiplatelet therapeutic regimen. Although generally well tolerated, its efficacy varies among individuals, with the main hypothesis that its bioavailability relies on its bioconversion to the active compound, which, in turn, depends on the genetic background and/or interactions with other drugs. To determine which factors influenced response in our patients, 368 patients receiving combined antiaggregation therapy with aspirin and clopidogrel were followed for 1 year to record 30 novel cardiovascular acute events. This clinical relapse was considered a surrogate end point to measure therapeutic response under the influence of the CYP2C19*2, *3, and *17 and CYP3A5*3 alleles, as well as the effects of concomitant medication and the presence of known cardiovascular risk factors and comorbidity. We show that either single CYP2C19 or CYP3A5 genotyping or combined were not useful to predict clinical efficacy in this cohort. Rather than genetic testing, we have found that clinical observations such as suffering type 2 diabetes mellitus requiring insulin, having several vessels affected, and concurrent medication with calcium channel blockers, regardless of CYP3A5 genotype or drug class were, in that order, the strongest independent predictors of disease relapse.
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Affiliation(s)
- Fayna Rodríguez-González
- Ophtalmology Department. Hospital Universitario Gran Canaria Doctor Negrín, Las Palmas de Gran Canaria, Spain
| | - Efren Martínez-Quintana
- Cardiology Department, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | - Pedro Saavedra
- Department of Mathematics, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - José M Medina-Gil
- Cardiology Department, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | - Marta Riaño
- Department of Biochemistry and Clinical Analyses, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | - Paloma Garay-Sánchez
- Research Unit, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
| | - Antonio Tugores
- Research Unit, Complejo Hospitalario Universitario Insular Materno-Infantil, Las Palmas de Gran Canaria, Spain
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Prevention of thrombotic disorders by antithrombotic diet and exercise: evidence by using global thrombosis tests. Future Sci OA 2018; 4:FSO285. [PMID: 29682320 PMCID: PMC5905641 DOI: 10.4155/fsoa-2017-0104] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 01/02/2018] [Indexed: 12/28/2022] Open
Abstract
Prevention of thrombotic disorders has priority over treatment. There are only two pathologically relevant tests which are suitable for measuring the overall thrombotic status both in experimental conditions and in humans. The Global Thrombosis Test (GTT) and the Global Parallel-Plate Thrombosis Test can detect the pathologically relevant global thrombotic status. These tests have been successfully used for monitoring the effect of antithrombotic drugs and for developing novel antithrombotic agents. By using GTT, varieties of fruits, vegetables, and regular physical exercise have been tested for the effect on global thrombotic status. This review discusses the published evidence for the benefit of diet of selected fruit and vegetable varieties and doing regular physical exercise on improving thrombotic status. Future clinical trials monitored by GTT or Global Parallel-Plate Thrombosis Test could decide on the effectiveness of an experimentally proven antithrombotic diet with regular physical exercise in the prevention of thrombotic diseases.
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10
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Abstract
Platelets contribute to thrombus formation in a variety of ways. Platelet adhesion, activation, and thrombus growth depend greatly on the type of hemodynamic environment surrounding an inciting event. Microfluidic systems may be used to explore these relationships. In this review, we describe some important considerations required in the design of a microfluidic system and identify some limitations that may require use of a macroscale system.
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Affiliation(s)
- Susan M Hastings
- a GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences , Georgia Institute of Technology , Atlanta , GA , USA
| | - Michael T Griffin
- a GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences , Georgia Institute of Technology , Atlanta , GA , USA
| | - David N Ku
- a GWW School of Mechanical Engineering, Institute for Bioengineering and Biosciences , Georgia Institute of Technology , Atlanta , GA , USA
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11
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Ikarugi H, Yamamoto J. The exercise paradox may be solved by measuring the overall thrombotic state using native blood. Drug Discov Ther 2017; 11:15-19. [PMID: 28202881 DOI: 10.5582/ddt.2016.01077] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
While exercise is widely believed to prevent atherothrombotic diseases, it occasionally causes sudden death. This exercise paradox may be due to the inadequate testing of the thrombotic and thrombolytic status. A recently developed shear-induced thrombosis/endogenous fibrinolysis test performed with non-anticoagulated blood samples allows the assessment of the thrombotic state of an individual both at rest and after exercise. This sensitive and physiologically relevant test may help to solve the aforementioned exercise paradox.
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12
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Lee H, Kim G, Lim C, Lee B, Shin S. A simple method for activating the platelets used in microfluidic platelet aggregation tests: Stirring-induced platelet activation. BIOMICROFLUIDICS 2016; 10:064118. [PMID: 28058084 PMCID: PMC5176351 DOI: 10.1063/1.4972077] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/29/2016] [Indexed: 06/06/2023]
Abstract
High-shear stimulation is well known as one of the key factors affecting platelet activation and aggregation, which can lead to the formation of a thrombus. In one of our previous studies, we introduced migration distance-based platelet function analysis in a microfluidic system. In this study, we set out to examine the effects of stirring on shear-induced platelet activation and aggregation in a chamber system by using a rotating stirrer. We found that the rotating stirrer caused not only rotational shear flow but also a strong radial secondary flow. The latter flow led to efficient mixing in the chamber. Moreover, the rotational flow led to the generation of shear stress, the magnitude of which can be controlled to activate the platelets. Activated platelets tend to aggregate themselves. The maximum platelet aggregation was observed at a critical shear rate of 3100 s-1, regardless of the stirrer shape. Furthermore, the time taken to attain maximum aggregation was significantly shortened when using a wide stirrer (30 s) instead of a narrow one (180 s). When using a flat stirrer, the non-uniform shear field in the chamber system was resolved with the radial secondary flow-induced mixing; thus, most of the platelets were homogenously activated. The stirring-induced platelet activation mechanism was experimentally confirmed in a microfluidic system for a platelet aggregation test while monitoring the migration distance until the microfluidic channel is occluded. Our findings indicate that the present system, consisting of a rotating stirrer and a confined chamber, provides effective shear stimulation for activating platelets and inducing platelet aggregates.
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Affiliation(s)
- Hoyoon Lee
- School of Mechanical Engineering, Korea University , Seoul 136-701, South Korea
| | - Gyehyu Kim
- School of Mechanical Engineering, Korea University , Seoul 136-701, South Korea
| | - Chaeseung Lim
- Department of Laboratory Medicine, College of Medicine, Korea University Guro Hospital , Seoul 152-703, South Korea
| | - ByoungKwon Lee
- Department of Internal Medicine, College of Medicine, Yonsei University Gangnam Severance Hospital , Seoul 135-720, South Korea
| | - Sehyun Shin
- School of Mechanical Engineering, Korea University , Seoul 136-701, South Korea
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The effect of physiological levels of South African puff adder (Bitis arietans) snake venom on blood cells: an in vitro model. Sci Rep 2016; 6:35988. [PMID: 27775063 PMCID: PMC5075924 DOI: 10.1038/srep35988] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 10/10/2016] [Indexed: 12/13/2022] Open
Abstract
A significant burden of illness is caused globally by snakebites particularly by the puff adder, Bitis arietans. Presently there is no reliable and rapid method to confirm envenomation on blood chemistry; although coagulation parameters like prothrombin time, partial thromboplastin time, international normalized ratio and also serum electrolytes are tested. Here, we found that direct in vitro exposure of physiological relevant whole venom levels to human healthy blood (N = 32), caused significant physiological changes to platelet activity using a hematology analyzer, and measuring occlusion time, as well as lyses time, with the global thrombosis test (GTT). Disintegrated platelets were confirmed by scanning electron microscopy (SEM). We also confirmed the pathologic effects on erythrocytes (RBCs) (visible as eryptotic RBCs), by looking at both light microscopy and SEM. Thromboelastography showed that no clot formation in whole blood could be induced after addition of whole venom. We propose further clinical studies to investigate the use of light microscopy smears and hematology analyzer results immediately after envenomation, as a possible first-stage of clinical confirmation of envenomation.
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14
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Bester J, Soma P, Kell DB, Pretorius E. Viscoelastic and ultrastructural characteristics of whole blood and plasma in Alzheimer-type dementia, and the possible role of bacterial lipopolysaccharides (LPS). Oncotarget 2016; 6:35284-303. [PMID: 26462180 PMCID: PMC4742105 DOI: 10.18632/oncotarget.6074] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 12/22/2022] Open
Abstract
Alzheimer-type dementia (AD) is a neurodegenerative disorder and the most common form of dementia. Patients typically present with neuro- and systemic inflammation and iron dysregulation, associated with oxidative damage that reflects in hypercoagulability. Hypercoagulability is closely associated with increased fibrin(ogen) and in AD patients fibrin(ogen) has been implicated in the development of neuroinflammation and memory deficits. There is still no clear reason precisely why (a) this hypercoagulable state, (b) iron dysregulation and (c) increased fibrin(ogen) could together lead to the loss of neuronal structure and cognitive function. Here we suggest an alternative hypothesis based on previous ultrastructural evidence of the presence of a (dormant) blood microbiome in AD. Furthermore, we argue that bacterial cell wall components, such as the endotoxin lipopolysaccharide (LPS) of Gram-negative strains, might be the cause of the continuing and low-grade inflammation, characteristic of AD. Here, we follow an integrated approach, by studying the viscoelastic and ultrastructural properties of AD plasma and whole blood by using scanning electron microscopy, Thromboelastography (TEG®) and the Global Thrombosis Test (GTT®). Ultrastructural analysis confirmed the presence and close proximity of microbes to erythrocytes. TEG® analysis showed a hypercoagulable state in AD. TEG® results where LPS was added to naive blood showed the same trends as were found with the AD patients, while the GTT® results (where only platelet activity is measured), were not affected by the added LPS, suggesting that LPS does not directly impact platelet function. Our findings reinforce the importance of further investigating the role of LPS in AD.
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Affiliation(s)
- Janette Bester
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Prashilla Soma
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
| | - Douglas B Kell
- School of Chemistry and The Manchester Institute of Biotechnology, The University of Manchester, Manchester, UK
| | - Etheresia Pretorius
- Department of Physiology, Faculty of Health Sciences, University of Pretoria, Arcadia, South Africa
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15
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Ford NF. The Metabolism of Clopidogrel: CYP2C19 Is a Minor Pathway. J Clin Pharmacol 2016; 56:1474-1483. [DOI: 10.1002/jcph.769] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/06/2016] [Accepted: 05/06/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Neville F. Ford
- Woodfield Clinical Consulting LLC; Green Valley AZ USA
- Rutgers-RWJ Medical School; New Brunswick NJ USA
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16
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Farag M, Niespialowska-Steuden M, Okafor O, Artman B, Srinivasan M, Khan A, Sullivan K, Wellsted D, Gorog DA. Relative effects of different non-vitamin K antagonist oral anticoagulants on global thrombotic status in atrial fibrillation. Platelets 2016; 27:687-693. [DOI: 10.3109/09537104.2016.1158402] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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17
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Yamamoto J, Ijiri Y, Tamura Y, Iwasaki M, Murakami M, Okada Y. Reevaluation of antithrombotic fruits and vegetables: great variation between varieties. Drug Discov Ther 2016; 10:129-40. [DOI: 10.5582/ddt.2016.01043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Yoshinobu Ijiri
- Faculty of Health and Nutrition, Osaka Shoin Women’s University
| | | | - Masahiro Iwasaki
- Division of Nutrition and Metabolism, Original Nutrition Co., Ltd
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18
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Rowcliffe M, Nezami B, Westphal ES, Rainka M, Janda M, Bates V, Gengo F. Topical diclofenac does not affect the antiplatelet properties of aspirin as compared to the intermediate effects of oral diclofenac: A prospective, randomized, complete crossover study. J Clin Pharmacol 2015; 56:422-8. [PMID: 26265197 DOI: 10.1002/jcph.615] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 08/06/2015] [Indexed: 11/07/2022]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) adversely interact with aspirin, diminishing its antiplatelet effect and potentially placing patients at an increased risk for recurrent thrombotic events. This crossover study aimed to determine whether the topical NSAID diclofenac epolamine 1.3% patch or oral diclofenac 50 mg interfered with the antiplatelet effects of aspirin 325 mg. Twelve healthy men and women aged 18-50 were included. Participants were randomized into 5 treatment arms: aspirin, diclofenac potassium 50 mg, diclofenac patch, diclofenac potassium plus ASA 325 mg, and diclofenac patch plus aspirin. Platelet responsiveness was determined using whole-blood impedance aggregation (WBA) to collagen 1 μg/mL and arachidonic acid (AA) 0.5 mM and was sampled every 2 hours. No significant difference in platelet function was observed following the diclofenac patch and aspirin vs aspirin alone. Oral diclofenac produced a mixed effect with significant reduction in platelet inhibition at hour 2 and hour 8 following aspirin administration. Topical diclofenac does not significantly interfere with the antiplatelet effects of aspirin and may be a safer alternative to the oral formulation.
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Affiliation(s)
- M Rowcliffe
- Dent Neurologic Institute, Amherst, NY, USA.,State University at Buffalo School of Pharmacy and Pharmaceutical Sciences, Buffalo, NY, USA
| | | | | | - M Rainka
- Dent Neurologic Institute, Amherst, NY, USA
| | - M Janda
- State University at Buffalo School of Pharmacy and Pharmaceutical Sciences, Buffalo, NY, USA
| | - V Bates
- Dent Neurologic Institute, Amherst, NY, USA
| | - F Gengo
- Dent Neurologic Institute, Amherst, NY, USA.,State University at Buffalo School of Pharmacy and Pharmaceutical Sciences, Buffalo, NY, USA
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Gengo F, Westphal ES, Rainka MM, Janda M, Robson MJ, Hourihane JM, Bates V. Platelet response to increased aspirin dose in patients with persistent platelet aggregation while treated with aspirin 81 mg. J Clin Pharmacol 2015; 56:414-21. [DOI: 10.1002/jcph.608] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/30/2015] [Indexed: 11/08/2022]
Affiliation(s)
- Fran Gengo
- Dent Neurologic InstituteBuffaloNYUSA
- State University at Buffalo School of Pharmacy and Pharmaceutical SciencesBuffaloNYUSA
| | | | | | - Maria Janda
- State University at Buffalo School of Pharmacy and Pharmaceutical SciencesBuffaloNYUSA
| | - Matthew J. Robson
- Dent Neurologic InstituteBuffaloNYUSA
- Vanderbilt University School of MedicineDepartment of PharmacologyNashvilleTNUSA
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20
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Yamamoto J, Tamura Y, Ijiri Y, Iwasaki M, Murakami M, Matsuo O. Evaluation of antithrombotic effect: Importance of testing components and methodologies. Drug Discov Ther 2015; 9:258-66. [DOI: 10.5582/ddt.2015.01043] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
| | - Yukinori Tamura
- Department of Physiology and Regenerative Medicine, Faculty of Medicine, Kinki University
| | - Yoshinobu Ijiri
- Department of Health and Nutrition, Faculty of Health and Nutrition, Osaka Shoin Women’s University
| | - Masahiro Iwasaki
- Division of Metabolism and Clinical Nutrition, Kansai Electric Power Hospital
| | - Masahiro Murakami
- Laboratory of Pharmaceutics, Faculty of Pharmacy, Osaka Ohtani University
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