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V G Nielsen, R W Matika
Hypofibrinogenemia is an important clinical consequence following envenomation by Lachesis muta muta, usually attenuated or prevented by administration of antivenom. The venom of L. m. muta contains both a metalloproteinase fibrinogenase and a serine protease thrombin-like enzyme, and exposure of fibrinogen to iron (Fe) and carbon monoxide (CO) has been demonstrated to decrease its catalysis by such enzymes. Using thrombelastographic analytical techniques, it was determined that this venom displayed weak procoagulant effects combined with fibrinogenolytic effects, and pretreatment of plasma with Fe and CO markedly attenuated venom-mediated effects...
August 3, 2016: Human & Experimental Toxicology
Jacob Steinmetz, Anne Marie Sørensen, Hanne Hee Henriksen, Theis Lange, Claus Falck Larsen, Pär I Johansson, Jakob Stensballe
BACKGROUND: Haemorrhage remains a leading cause of morbidity and mortality in trauma patients. Fibrinogen is an essential endogenous component of haemostasis and the plasma level is associated with bleeding, transfusion and outcome. Fibrinogen concentrate is widely used to correct acquired hypofibrinogenaemia, recommended by several international guidelines for the treatment of trauma patients, but evidence is lacking regarding the treatment safety and efficacy. We aim to assess the efficacy and safety of an immediate pre-emptive first-line treatment with fibrinogen concentrate in patients with trauma haemorrhage in need of haemostatic resuscitation...
2016: Trials
Vance G Nielsen, Leslie V Boyer, Daniel T Redford, Paul Ford
Annually, thousands suffer venomous snake-bite from Crotalus simus and Bothrops asper vipers in central and South America. The goals of the present study were to generally characterize the thrombin-like effects of venom from these snakes in human plasma with viscoelastic methods. Human plasma was exposed to the venom of three different C. simus subspecies and venoms obtained from B. asper vipers located in three different locations in Mexico. To characterize the factor X-activating and thrombin-like activity of these venoms, plasma (normal or factor XIII deficient) was pretreated with a variety of additives (e...
June 16, 2016: Blood Coagulation & Fibrinolysis: An International Journal in Haemostasis and Thrombosis
C F Zhou, Y H Ren, Y Q Song, J Yi, B S Han, Q Xue, Z H Fu, D Y Li
OBJECTIVE: To observe the relationship between ATP-binding cassette subfamily B member 1 (ABCB1) and cytochrome P450 (CYP)2C19 polymorphisms and the effect of clopidogrel post percutaneous coronary intervention in patients with coronary artery disease. METHODS: A total of 300 consecutive patients with acute coronary syndrome undergoing selected percutaneous coronary intervention in General Hospital of the People's Liberation Army from October 2010 to August 2012 and treated with clopidogrel were enrolled and retrospectively analyzed...
April 24, 2016: Zhonghua Xin Xue Guan Bing za Zhi
Xin Wang, Yan Luo, Paul P Masci, Ross Crawford, Yin Xiao
OBJECTIVES: Hematoma quality (especially the fibrin matrix) plays an important role in the bone healing process. Here, we investigated the effect of interleukin-1 beta (IL-1β) on fibrin clot formation from platelet-poor plasma (PPP). METHODS: Five-milliliter of rat whole-blood samples were collected from the hepatic portal vein. All blood samples were firstly standardized via a thrombelastograph (TEG), blood cell count, and the measurement of fibrinogen concentration...
2016: PloS One
Vance G Nielsen
Fibrinogen depletion via catalysis by snake venom enzymes as a therapeutic strategy to prevent or treat thrombotic disorders was utilized for over four decades, with ancrod being the quintessential agent. However, ancrod eventually was found to not be of clinical utility in large scale stroke trial, resulting in the eventual discontinuation of the administration of the drug for any indication. It was hypothesized that ancrod, possessing thrombin-like activity, may have unappreciated robust coagulation kinetics...
August 2016: Journal of Thrombosis and Thrombolysis
Vance G Nielsen
Viscoelastic methods have been developed to assess the contribution of plasma proteins and platelets to coagulation in vitro to guide clinical transfusion therapy. One of the cardinal precepts of determining clot strength is making sure that the viscoelastic technique includes complete exposure of the plastic pin in the testing chamber with the fluid analyzed so as to assure maximal interaction of the cup wall with the pin surface. However, the various contributions of the pin surface area to final clot strength have not been investigated...
January 2016: Anesthesia and Analgesia
Vance G Nielsen, Leslie V Boyer, Ryan W Matika, Quinlan Amos, Daniel T Redford
In addition to degrading fibrinogen as a source of consumptive coagulopathy, rattlesnake venom has also been demonstrated to enhance fibrinolysis and degrade alpha-2-antiplasmin. The goals of this investigation was to characterize the kinetic fibrinolytic profile of Crotalus atrox venom in the absence and presence of tissue-type plasminogen activator (tPA), and to also ascertain if iron and carbon monoxide (CO, a positive modulator of alpha-2-antiplasmin) could attenuate venom-enhanced fibrinolysis. Utilizing thrombelastographic methods, the coagulation and fibrinolytic kinetic profiles of human plasma exposed to C...
July 2016: Blood Coagulation & Fibrinolysis: An International Journal in Haemostasis and Thrombosis
Vance G Nielsen, Jon Henderson
Thrombelastographic methods have been recently introduced to detect iron mediated hypercoagulability in settings such as sickle cell disease, hemodialysis, mechanical circulatory support, and neuroinflammation. However, these inflammatory situations may have heme oxygenase-derived, coexistent carbon monoxide present, which also enhances coagulation as assessed by the same thrombelastographic variables that are affected by iron. This brief report presents a novel, Sonoclot-based method to detect iron enhanced coagulation that is independent of carbon monoxide influence...
July 2016: Journal of Thrombosis and Thrombolysis
Ming'en Lyu, Yang Li, Feng Xue, Xiaofan Liu, Wenjie Liu, Tiantian Sun, Cuicui Lyu, Rongfeng Fu, Lei Zhang, Renchi Yang
OBJECTIVE: To explore the clinical value of immature platelet fraction (IPF), absolute immature platelet fraction (A- IPF) and thrombelastograph (TEG) on assessment of bleeding risk of immune thrombocytopenia (ITP). METHODS: two hundred and seventy- one patients with ITP were assessed based on ITP-BAT bleeding grading system. IPF, A-IPF were determined in 271 patients ,TEG in 125 patients. The correlations between bleeding grades and IPF, A-IPF, variables of TEG in subgroups were analyzed by statistical method...
September 2015: Zhonghua Xue Ye Xue za Zhi, Zhonghua Xueyexue Zazhi
Vance G Nielsen
In addition to degrading fibrinogen as a source of consumptive coagulopathy, purified fractions of southern copperhead (Agkistrodon contortrix contortrix; A. c. contortrix) venom has been demonstrated to enhance fibrinolysis. The goal of this investigation was to characterize the kinetic fibrinolytic profile of A. c. contortrix venom in the absence and presence of tissue-type plasminogen activator (tPA) to determine if intact venom had tPA independent fibrinolytic properties. Utilizing thrombelastographic methods, the coagulation and fibrinolytic kinetic profiles of human plasma exposed to A...
July 2016: Journal of Thrombosis and Thrombolysis
Vance Girard Nielsen, Wendi Kulin, John Samuel LaWall, Felesia Nancy MacFarland, Andrew Chen, Heidi Adelleen Hadley, Adam James DaDeppo, Evangelina Barbara Steinbrenner, Ryan William Matika
Chronic migraine (CM) is a disabling painful condition that is associated with dementia and thrombotic disease. It has been proposed that carbon monoxide (CO) and iron may play a role in CM, and CO and iron are products of the heme oxygenase system which is widespread within the brain. Further, CO and iron enhance plasmatic coagulation in part via a fibrinogen-dependent mechanism. Thus, our goal was to determine whether patients with CM had experienced carboxyhemefibrinogen formation, iron bound fibrinogen formation and plasmatic hypercoagulability...
2015: CNS & Neurological Disorders Drug Targets
Jing-gang Xia, Yang Qu, Shao-dong Hu, Ji Xu, Chun-lin Yin, Dong Xu
OBJECTIVE: To evaluate the safety and efficacy of antiplatelet therapy of ticagrelor on patients suffering from acute ST segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. METHODS: In the study, 96 patients suffering from acute ST segment elevation myocardial infarction onset within 12 h undergoing primary percutaneous coronary intervention from May to October in 2013 were randomly divided into ticagrelor group (n=48) and clopidogrel group (n=48) by using the method of random number table...
June 18, 2015: Beijing da Xue Xue Bao. Yi Xue Ban, Journal of Peking University. Health Sciences
Bo Wang, Xiao-Qing Li, Ning Ma, Dapeng Mo, Feng Gao, Xuan Sun, Xiaotong Xu, Lian Liu, Ligang Song, Xin-Gang Li, Zhigang Zhao, Xingquan Zhao, Zhong-Rong Miao
BACKGROUND AND PURPOSE: Thrombelastography (TEG) is widely used for the measurement of platelet function. However, few studies have investigated the TEG parameters in patients receiving extracranial or intracranial artery stenting for ischemic cerebrovascular disease. This study sought to describe the association of TEG parameters before the procedure with post-procedural ischemic events after extracranial or intracranial artery stenting. METHODS: Patients in whom stenting was performed for extracranial or intracranial artery stenosis (70-99%) were recruited into the study...
June 3, 2015: Journal of Neurointerventional Surgery
P Ranjit, Y Lau, G Y H Lip, A D Blann
INTRODUCTION: Research and routine laboratory assessment of clot integrity can be time consuming, expensive, and cannot be batched as it is generally performed in real time. To address these issues, we developed and validated a micro-titre based assay to quantify thrombogenesis and fibrinolysis, the purpose being to assess patients at risk of cardiovascular events by virtue of hypercoagulability. In further validation, thrombogenesis results were compared to similar indices from the thrombelastograph (TEG)...
August 2015: Vascular Pharmacology
Xiao-Fang Tang, Ya-Ling Han, Jia-Hui Zhang, Jing Wang, Yin Zhang, Bo Xu, Zhan Gao, Shu-Bin Qiao, Jue Chen, Yuan Wu, Ji-Lin Chen, Run-Lin Gao, Yue-Jin Yang, Jin-Qing Yuan
BACKGROUND: Several platelet function tests are currently used to measure responsiveness to antiplatelet therapy. This study was to compare two tests, light transmittance aggregometry (LTA) and modified thrombelastography (mTEG), for predicting clinical outcomes in Chinese patients after percutaneous coronary intervention (PCI). METHODS: Prospective, observational, single-center study of 789 Chinese patients undergoing PCI was enrolled. This study was investigated the correlations between the two tests and performed receiver operating characteristic curve (ROC) analysis for major adverse cardiovascular events (MACEs) at 1-year follow-up...
March 20, 2015: Chinese Medical Journal
Vance G Nielsen, Michael A Sobieski, Mark S Slaughter
Left ventricular assist device (LVAD) therapy is associated with thrombophilia despite anticoagulation. Of interest, LVAD patients have increased carboxyhemoglobin, a measure of upregulated heme oxygenase (Hmox) activity that releases carbon monoxide (CO) and iron. Given that CO and iron enhance plasmatic coagulation, we determined if LVAD patients had hypercoagulability and decreased fibrinolytic vulnerability with measurable CO and iron-mediated effects. Blood samples were obtained a month or more after implantation of the LVAD...
July 2015: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
Michael P Chapman, Ernest E Moore, Dominykas Burneikis, Hunter B Moore, Eduardo Gonzalez, Kelsey C Anderson, Christopher R Ramos, Anirban Banerjee
BACKGROUND: Thrombelastography (TEG) is a viscoelastic hemostatic assay. We have observed that end-stage renal disease (ESRD) and trauma-induced coagulopathy (TIC) produce distinctive TEG tracings. We hypothesized that rigorously definable TEG patterns could discriminate between healthy controls and patients with ESRD and TIC. METHODS: TEG was performed on blood from ESRD patients (n = 54) and blood from trauma patients requiring a massive blood transfusion (n = 16)...
March 2015: Journal of Surgical Research
S V Barinov, V T Dolgikh, I V Mediannikova
BACKGROUND: The aim of the study was the reduction of adverse pregnancy outcomes in women with gestational and genetically determined changes in the hemostatic system. PATIENTS AND METHODS: The study group comprised 98 patients with obstetric complications on the background of changes in the parameters of coagulation screening. In 63 pregnant women, hemostatic disorders were not corrected, in 35 patients medical tactic defined clinical situation and the results of laboratory and instrumental studies of the hemostatic system...
2014: Vestnik Rossiĭskoĭ Akademii Meditsinskikh Nauk
Ryan W Matika, Vance G Nielsen, Evangelina B Steinbrenner, Amy N Sussman, Machaiah Madhrira
Chronic hemodialysis is associated with significant thrombophilia. Of interest, hemodialysis patients have increased carboxyhemoglobin (COHb) and exhaled carbon monoxide (CO), signs of upregulated heme oxygenase (Hmox) activity. Given that CO enhances plasmatic coagulation, we determined whether patients requiring chronic hemodialysis had an increase in endogenous CO, plasmatic hypercoagulability and decreased fibrinolytic vulnerability. Carbon monoxide was determined by noninvasive pulse oximetry measurement of COHb...
November 2014: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
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