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Functional clotting assay

Mito Kobayashi, Tomoyuki Kawase, Kazuhiro Okuda, Larry F Wolff, Hiromasa Yoshie
BACKGROUND: Platelet-rich fibrin (PRF), a platelet-rich plasma (PRP) derivative mainly composed of fibrin networks, has been increasingly demonstrated to be effective in wound healing in clinical and pre-clinical animal studies. However, there has still been a concern that major growth factors may significantly be loss from PRF during its preparation through the slow clotting process. To address this concern, we compared the angiogenic potential of PRF and PRP by standardization of procedures based on volume ratios...
December 2015: Int J Implant Dent
Ji Young Kim, Yu Rim Shin, Hae Keum Kil, Mi Ran Park, Jong Wha Lee
BACKGROUND Rotational thromboelastometry (ROTEM®) is a point-of-care test for coagulation, enabling physicians to make a swift decision. The aim of this investigation was to establish reference intervals of thromboelastometric evaluation for coagulation in pediatric patients with congenital heart diseases (CHD). MATERIAL AND METHODS As baseline data, 3 assays of ROTEM® (INTEM, EXTEM, and FIBTEM) were measured after anesthesia induction. ROTEM® parameters were clotting time (CT), amplitude at 10 min (A10), clot formation time (CFT), a angle, maximal clot firmness (MCF), clot lysis index at 60 min (LI60), and maximal clot elasticity (MCE)...
October 6, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Xin-Gang Li, Ning Ma, Bo Wang, Xiao-Qing Li, Sheng-Hui Mei, Kun Zhao, Yong-Jun Wang, Wei Li, Zhi-Gang Zhao, Shu-Sen Sun, Zhong-Rong Miao
The primary mechanism of clopidogrel resistance is still unclear. We aimed to investigate whether the methylation status of the P2Y12 promoter has effects on platelet function and clinical ischemic events. Patients with ischemic cerebrovascular disease were enrolled into our study. Venous blood samples were drawn for thrombelastograpy (TEG) and active metabolite assay. Patients were divided into a case- or control-group based on the occurrence of ischemic events during a one year follow-up. Two TEG parameters between the case and control groups were statistically significant [ADP inhibition rate (ADP%): P = 0...
September 30, 2016: Scientific Reports
Meiling Luo, Donghong Deng, Liqun Xiang, Peng Cheng, Lin Liao, Xuelian Deng, Jie Yan, Faquan Lin
Congenital dysfibrinogenemia (CD) is a qualitative fibrinogen disorder caused by an abnormal fibrinogen molecule structure, leading to dysfunctional blood coagulation. This study describes 3 cases of dysfibrinogenemia identified in the unrelated Chinese pedigrees.Routine coagulation screening tests were performed on the probands and their families. The antigens and functionality of fibrinogen was measured using an immunoturbidimetry assay and the Clauss method, respectively. To identify the genetic mutation responsible for these dysfibrinogens, genomic DNA extracted from the blood was analyzed using PCR amplification and direct sequencing...
September 2016: Medicine (Baltimore)
Mariann Tang, Per Wierup, Catherine J Rea, Jrgen Ingerslev, Vibeke E Hjortdal, Benny Srensen
Cardiac surgery induces a multifactorial coagulopathy. Regular use of tranexamic acid (TXA) is becoming standard of care. Clinical challenges include selecting optimal dosing regimen and balancing the benefit versus risk of additional dosing with antifibrinolytics. The objective was to evaluate the effect of TXA by assessing kinetic properties of plasma clot formation, clot stability, and clot fibrinolysis. The study was a prospective case follow-up of 28 patients undergoing cardiac surgery (mean age 63.9 years, 29% women)...
September 2, 2016: Blood Coagulation & Fibrinolysis: An International Journal in Haemostasis and Thrombosis
Xiaohua Zhou, Maarten L V Hendrickx, Gholamreza Hassanzadeh-Ghassabeh, Serge Muyldermans, Paul J Declerck
Plasminogen activator inhibitor 1 (PAI-1) is the principal physiological inhibitor of tissue-type plasminogen activator (t-PA) and has been identified as a risk factor in cardiovascular diseases. In order to generate nanobodies against PAI-1 to interfere with its functional properties, we constructed three nanobody libraries upon immunisation of three alpacas with three different PAI-1 variants. Three panels of nanobodies were selected against these PAI-1 variants. Evaluation of the amino acid sequence identity of the complementarity determining region-3 (CDR3) reveals 34 clusters in total...
September 8, 2016: Thrombosis and Haemostasis
Yuki Takagi, Moe Murata, Toshihiro Kozuka, Yukiko Nakata, Ryo Hasebe, Shogo Tamura, Akira Takagi, Tadashi Matsushita, Hidehiko Saito, Tetsuhito Kojima
Antithrombin (AT) and thrombomodulin (TM) play important roles in the process of natural anticoagulation in vivo. Recently, we reported that the prothrombin Yukuhashi mutation (p.Arg596Leu) was associated with AT and TM resistance-related thrombophilia. To assess the AT and TM resistances associated with other missense mutations by single base substitution in the Arg596 codon, we generated recombinant variants (596Gln, 596Trp, 596Gly, and 596Pro) and investigated the effects on AT and TM anticoagulant functions...
September 8, 2016: Thrombosis and Haemostasis
Nicole Green, Nadia Odell, Molly Zych, Cheryl Clark, Zong-Heng Wang, Bridget Biersmith, Clara Bajzek, Kevin R Cook, Mitchell S Dushay, Erika Geisbrecht
The organization and stability of higher order structures that form in the extracellular matrix (ECM) to mediate the attachment of muscles are poorly understood. We have made the surprising discovery that a subset of clotting factor proteins are also essential for muscle attachment in the model organism Drosophila melanogaster One such coagulation protein, Fondue (Fon), was identified as a novel muscle mutant in a pupal lethal genetic screen. Fon accumulates at muscle attachment sites and removal of this protein results in decreased locomotor behavior and detached larval muscles...
August 31, 2016: Genetics
Bhiken I Naik, Marcel E Durieux, Anne Knisely, Juhee Sharma, Vivien C Bui-Huynh, Bhavana Yalamuru, Abdullah S Terkawi, Edward C Nemergut
BACKGROUND: Sonic estimation of elasticity via resonance (SEER) sonorheometry is a novel technology that uses acoustic deformation of the developing clot to measure its viscoelastic properties and extract functional measures of coagulation. Multilevel spine surgery is associated with significant perioperative blood loss, and coagulopathy occurs frequently. The aim of this study was to correlate SEER sonorheometry results with those of equivalent rotation thromboelastometry (ROTEM) and laboratory parameters obtained during deformity correction spine surgery...
August 31, 2016: Anesthesia and Analgesia
Jingyi Zhou, Qiulan Ding, Wenman Wu, Qi Ouyang, Yinyin Xie, Xi Wu, Yeling Lu, Jing Dai, Qian Liang, Hongli Wang, Xuefeng Wang, Yiqun Hu
AIMS: A novel heterozygous variant, FGA c.169_180+2 del (designated fibrinogen Shanghai), was identified in a patient with dysfibrinogenemia with antiphospholipid antibody syndrome (APS) and recurrent venous thrombosis, and in his asymptomatic father. We aimed to reveal the functional implication of structural change caused by this variant. METHODS: Transcription analysis was performed with FGA minigene transfection assay to evaluate the impact of nucleosides deletion on mRNA editing...
August 23, 2016: Journal of Clinical Pathology
Michael Fabbro, Jacob T Gutsche, Todd A Miano, John G Augoustides, Prakash A Patel
BACKGROUND: The inflated costs and documented deleterious effects of excess perioperative transfusion have led to the investigation of targeted coagulation factor replacement strategies. One particular coagulation factor of interest is factor I (fibrinogen). Hypofibrinogenemia is typically tested for using time-consuming standard laboratory assays. The thrombelastography (TEG)-based functional fibrinogen level (FLEV) provides an assessment of whole blood clot under platelet inhibition to report calculated fibrinogen levels in significantly less time...
September 2016: Anesthesia and Analgesia
Ahmad F Arbaeen, Katherine Serrano, Elena Levin, Dana V Devine
BACKGROUND: There is poor correlation between in vivo platelet concentrate (PC) transfusion outcome and in vitro tests, which typically do not test the functional effectiveness of platelets (PLTs), but rather measure PLT characteristics. We hypothesize that the application of thromboelastography (TEG) or rotational thromboelastometry (ROTEM) to evaluate the procoagulant activity of stored PLTs can predict PLT quality and, ultimately, distinguish among hyper- and nonresponsive PCs. Additionally, we hypothesize that due to their procoagulant properties, PLT microvesicles (PMVs) contribute to the clot signature in these methods...
August 16, 2016: Transfusion
Daryl Crimmins, Peter Flanagan, Richard Charlewood, Katya Ruggiero
BACKGROUND: Cryopreserved platelet (PLT) components stored at -80°C in 5% to 6% dimethyl sulfoxide (DMSO) demonstrate enhanced hemostatic activity. Alterations in PLT surface glycoprotein expression and release of procoagulant microparticles during the freeze/thaw cycle result in PLT activation. Nothing is known of the effect of gamma irradiation on the in vitro quality of reconstituted cryopreserved PLTs. STUDY DESIGN AND METHODS: Gamma-irradiated (25-50 Gy) buffy coat-derived PLT components were either stored at room temperature for 7 days (the current expiry in New Zealand) or cryopreserved at -80°C using 5% to 6% DMSO...
August 16, 2016: Transfusion
Kieron South, Marta O Freitas, David A Lane
Recent work has revealed that ADAMTS13 circulates in a 'closed' conformation, only fully interacting with VWF following a conformational change. We hypothesised that this conformational quiescence also maintains the substrate specificity of ADAMTS13 and that the 'open' conformation of the protease might facilitate proteolytic promiscuity OBJECTIVES: To identify a novel substrate for a constitutively active gain of function (GoF) ADAMTS13 variant (R568K/F592Y/R660K/Y661F/Y665F) METHODS: Fibrinogen proteolysis was characterised using SDS PAGE and LC-MS/MS...
August 11, 2016: Journal of Thrombosis and Haemostasis: JTH
Hanne Berg Ravn, Jo Bnding Andreasen, Anne-Mette Hvas
Developmental haemostasis has been well documented over the last 3 decades and age-dependent reference ranges have been reported for a number of plasmatic coagulation parameters. With the increasing use of whole blood point-of-care tests like rotational thromboelastometry (ROTEM) and platelet function tests, an evaluation of age-dependent changes is warranted for these tests as well. We obtained blood samples from 149 children, aged 1 day to 5.9 years, and analysed conventional plasmatic coagulation tests, including activated partial prothrombin time, prothrombin time, and fibrinogen (functional)...
July 27, 2016: Blood Coagulation & Fibrinolysis: An International Journal in Haemostasis and Thrombosis
Anoop K Enjeti, Anita Ariyarajah, Angel D'Crus, Michael Seldon, Lisa F Lincz
INTRODUCTION: Circulating microvesicles (MV) can be analysed using a number of different techniques. The aim of this study was to evaluate the correlation between functional procoagulant based assays including thrombin generation, factor Xa activation test (XaCT), and phosphatidylserine factor Xa-activity by ELISA with optical MV enumeration by flow cytometry and nanoparticle tracking analysis. METHODS: Citrated blood samples were collected from 60 healthy volunteer blood donors after informed consent...
September 2016: Thrombosis Research
Brian C Cooley
Whereas the extrinsic pathway of coagulation seals off bleeding at the cut tissue edges, it is proposed that the intrinsic pathway exploits the dirt from the skin surface to generate an outer coagulum of the oozing blood. Activated Factor XII (FXIIa) in this outer cap generates Factor XIa, which triggers clotting, and kallikrein that feeds back to form more FXIIa to promote the process. This dirty-wound hypothesis of coagulation function by the intrinsic pathway is supported by the use of dirt-based compounds in activated partial thromboplastin time assays as well as the evolutionary record where marine life that do not have skin-adherent dirt lack Factor XII, including marine mammals that have returned to sea life...
September 2016: Thrombosis Research
E L G Pryzdial, S C Meixner, K Talbot, L J Eltringham-Smith, J R Baylis, F M H Lee, C J Kastrup, W P Sheffield
UNLABELLED: Essentials Factor Xa (FXa) acquires cleavage-mediated tissue plasminogen activator (tPA) cofactor activity. Recombinant (r) tPA is the predominant thrombolytic drug, but it may cause systemic side effects. Chemically modified, non-enzymatic FXa was produced (Xai-K), which rapidly lysed thrombi in mice. Unlike rtPA, Xai-K had no systemic fibrinolysis activation markers, indicating improved safety. SUMMARY: Background Enzymatic thrombolysis carries the risk of hemorrhage and re-occlusion must be evaded by co-administration with an anticoagulant...
September 2016: Journal of Thrombosis and Haemostasis: JTH
A Casini, P de Moerloose
Congenital fibrinogen disorders are rare diseases affecting either the quantity (afibrinogenaemia and hypofibrinogenaemia) or the quality (dysfibrinogenaemia) or both (hypodysfibrinogenaemia) of fibrinogen. In addition to bleeding, unexpected thrombosis, spontaneous spleen ruptures, painful bone cysts and intrahepatic inclusions can complicate the clinical course of patients with quantitative fibrinogen disorders. Clinical manifestations of dysfibrinogenaemia include absence of symptoms, major bleeding or thrombosis as well as systemic amyloidosis...
September 2016: Haemophilia: the Official Journal of the World Federation of Hemophilia
Tomoko Kawakami, Airi Fujikawa, Yohei Ishiyama, Michihiro Hosojima, Akihiko Saito, Masatoshi Kubota, Shinobu Fujimura, Motoni Kadowaki
Thrombosis is the leading cause of mortality globally. It is not only a complication but also a risk factor for progression of diabetes. However, alternative oral therapies and prophylaxis with less adverse effect for thrombosis have not been well studied. In this study, composite powder containing earthworm (CEP) was used and its fibrinolytic activity was measured. CEP was found to have a high urokinase-type plasminogen activator like activity in an in vitro assay. It also had significantly shortened euglobulin clot lysis time (ECLT) at 4 and 24 h after ingestion in Sprague Dawley rats...
October 2016: Bioscience, Biotechnology, and Biochemistry
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