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Sample records for intravenous direct thrombin

  1. Translational Success Stories Development of Direct Thrombin Inhibitors

    NARCIS (Netherlands)

    Coppens, Michiel; Eikelboom, John W.; Gustafsson, David; Weitz, Jeffrey I.; Hirsh, Jack

    2012-01-01

    Anticoagulants are the cornerstone of therapy for conditions associated with arterial and venous thrombosis. Direct thrombin inhibitors (DTIs) are anticoagulants that bind to thrombin and block its enzymatic activity. The bivalent parenteral DTIs hirudin and bivalirudin were based on the observation

  2. Identification of berberine as a direct thrombin inhibitor from traditional Chinese medicine through structural, functional and binding studies

    Science.gov (United States)

    Wang, Xing; Zhang, Yuxin; Yang, Ying; Wu, Xia; Fan, Hantian; Qiao, Yanjiang

    2017-03-01

    Thrombin acts as a key enzyme in the blood coagulation cascade and represents a potential drug target for the treatment of several cardiovascular diseases. The aim of this study was to identify small-molecule direct thrombin inhibitors from herbs used in traditional Chinese medicine (TCM). A pharmacophore model and molecular docking were utilized to virtually screen a library of chemicals contained in compositions of traditional Chinese herbs, and these analyses were followed by in vitro bioassay validation and binding studies. Berberine (BBR) was first confirmed as a thrombin inhibitor using an enzymatic assay. The BBR IC50 value for thrombin inhibition was 2.92 μM. Direct binding studies using surface plasmon resonance demonstrated that BBR directly interacted with thrombin with a KD value of 16.39 μM. Competitive binding assay indicated that BBR could bind to the same argartroban/thrombin interaction site. A platelet aggregation assay demonstrated that BBR had the ability to inhibit thrombin-induced platelet aggregation in washed platelets samples. This study proved that BBR is a direct thrombin inhibitor that has activity in inhibiting thrombin-induced platelet aggregation. BBR may be a potential candidate for the development of safe and effective thrombin-inhibiting drugs.

  3. Measuring Direct Thrombin Inhibitors With Routine and Dedicated Coagulation Assays Which Assay Is Helpful?

    NARCIS (Netherlands)

    Curvers, Joyce; van de Kerkhof, Daan; Stroobants, An K.; van den Dool, Erik-Jan; Scharnhorst, Volkher

    2012-01-01

    The use of direct thrombin inhibitors (DTIs) for prophylactic or therapeutic anticoagulation is increasing because of the predictable bioavailability and short half-life of these DTIs. However, in certain situations, indication of the concentration is warranted. We investigated the effects of 3 DTIs

  4. Spontaneous pseudoaneurysm of the uterine artery during pregnancy treated by direct thrombin injection: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jung Hee; Kim, See Hyung; Kim, Young Hwan [Dept. Radiology, Keimyung University School of Medicine, Dongsan Medical Center, Daegu (Korea, Republic of)

    2016-04-15

    Pseudoaneurysm of uterine artery during pregnancy is a very rare disease. It is mostly associated with uterine artery injury, usually occurring after proceeding conditions such as history of gynecologic operation and infection. However, the best treatment modality has not been established yet. Herein, we reported a case of spontaneous formation of uterine artery pseudoaneurysm during pregnancy treated by direct thrombin injection without any complication or recurrence.

  5. The king is dead (warfarin): direct thrombin and factor Xa inhibitors: the next Diadochian War?

    Science.gov (United States)

    Diener, Hans-Christoph; Eikelboom, John; Granger, Christopher B; Hacke, Werner

    2012-02-01

    Atrial fibrillation is an important risk factor for stroke. New drugs for oral anticoagulation that do not exhibit the limitations of vitamin K antagonists like warfarin are under investigation. These include direct factor Xa inhibitors and direct thrombin-inhibitors. Recent studies provide promising results for apixaban, dabigatran, and rivaroxaban, including higher efficacy and significantly lower incidences of intracranial bleeds compared with warfarin. The new oral anticoagulants substances show similar results in secondary as in primary stroke prevention in patients with AF and will on the long run replace warfarin.

  6. Diagnostic Accuracy of a Novel Chromogenic Direct Thrombin Inhibitor Assay: Clinical Experiences for Dabigatran Monitoring.

    Science.gov (United States)

    Poli, Sven; Härtig, Florian; Spencer, Charlotte; Ebner, Matthias; Birschmann, Ingvild; Kuhn, Joachim; Faix, Susanne; Ziemann, Ulf; Häring, Hans-Ulrich; Lehmann, Rainer; Peter, Andreas; Hörber, Sebastian

    2017-12-01

    Background Direct oral anticoagulants (DOACs) are increasingly replacing vitamin K antagonists (VKA) for clinical indications requiring long-term oral anticoagulation. In contrast to VKA, treatment with DOAC including dabigatran—the only direct thrombin inhibitor amongst them—does not require therapeutic drug monitoring. However, in case of treatment complications (e.g., major haemorrhage) and conditions requiring urgent surgery or thrombolytic therapy, information about actual DOAC plasma levels is needed to guide treatment decisions. Due to short reagent stability, limited accuracy at low dabigatran levels and high heparin sensitivity, the applicability of the widely used Hemoclot thrombin inhibitor (HTI) coagulation assay is limited in the emergency setting. Methods Dabigatran concentrations of 288 citrated plasma samples taken from 48 dabigatran-treated patients with drug concentrations of up to 300 ng/mL were measured with the chromogenic anti-IIa Biophen direct thrombin inhibitor (BDTI) assay and results compared with HTI using ultra performance liquid chromatography—tandem mass spectrometry as the reference method for measuring dabigatran plasma concentrations. Results BDTI results showed a very strong correlation with dabigatran concentrations (r = 0.965, p < 0.0001) as well as a low intra- and inter-assay variation of <5%. Compared with HTI, BDTI provides an improved on-board reagent stability of 72 hours, rapid turnaround times comparable to routine coagulation assays, high accuracy at low drug levels and reduced heparin sensitivity. Conclusion The BDTI is an ideal coagulation assay for the around-the-clock determination of dabigatran plasma levels in clinical routine including emergency situations.

  7. Rapid Detection of Thrombin and Other Protease Activity Directly in Whole Blood

    Science.gov (United States)

    Yu, Johnson Chung Sing

    Thrombin is a serine protease that plays a key role in the clotting cascade to promote hemostasis following injury to the endothelium. From a clinical diagnostic perspective, in-vivo thrombin activity is linked to various blood clotting disorders, as well as cardiovascular disease (DVT, arteriosclerosis, etc). Thus, the ability to rapidly measure protease activity directly in whole blood will provide important new diagnostics, and clinical researchers with a powerful tool to further elucidate the relationship between circulating protease levels and disease. The ultimate goal is to design novel point of care (POC) diagnostic devices that are capable of monitoring protease activities directly in whole blood and biological sample. A charge-changing substrate specific to the thrombin enzyme was engineered and its functionality was confirmed by a series of experiments. This led to the preliminary design, construction, and testing of two device platforms deemed fully functional for the electrophoretic separation and focusing of charged peptide fragments. The concept of using the existing charge-changing substrate platform for bacterial protease detection was also investigated. Certain strains of E coli are associated with severe symptoms such as abdominal cramps, bloody diarrhea, and vomiting. The OmpT protease is expressed on the outer membrane of E coli and plays a role in the cleavage of antimicrobial peptides, the degradation of recombinant heterologous proteins, and the activation of plasminogen in the host. Thus, a synthetic peptide substrate specific to the OmpT protease was designed and modeled for the purpose of detecting E coli in biological sample.

  8. First Steps in the Direction of Synthetic, Allosteric, Direct Inhibitors of Thrombin and Factor Xa

    OpenAIRE

    Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R.

    2009-01-01

    Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and iii) the mechanism of...

  9. First steps in the direction of synthetic, allosteric, direct inhibitors of thrombin and factor Xa.

    Science.gov (United States)

    Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R

    2009-08-01

    Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that (i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; (ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and (iii) the mechanism of inhibition is allosteric. The molecules represent the first allosteric small molecule inhibitors of the two enzymes.

  10. First Steps in the Direction of Synthetic, Allosteric, Direct Inhibitors of Thrombin and Factor Xa

    Science.gov (United States)

    Verghese, Jenson; Liang, Aiye; Sidhu, Preet Pal Singh; Hindle, Michael; Zhou, Qibing; Desai, Umesh R.

    2009-01-01

    Designing non-saccharide functional mimics of heparin is a major challenge. In this work, a library of small, aromatic molecules based on the sulfated DHP scaffold was synthesized and screened against thrombin and factor Xa. The results reveal that i) selected monomeric benzofuran derivatives inhibit the two enzymes, albeit weakly; ii) the two enzymes recognize different structural features in the benzofurans studied suggesting significant selectivity of recognition; and iii) the mechanism of inhibition is allosteric. The molecules represent the first allosteric small molecule inhibitors of the two enzymes. PMID:19540113

  11. An electrochemical aptasensor for thrombin detection based on direct electrochemistry of glucose oxidase using a functionalized graphene hybrid for amplification.

    Science.gov (United States)

    Bai, Lijuan; Yan, Bin; Chai, Yaqin; Yuan, Ruo; Yuan, Yali; Xie, Shunbi; Jiang, Liping; He, Ying

    2013-11-07

    In this work, we reported a new label-free electrochemical aptasensor for highly sensitive detection of thrombin using direct electron transfer of glucose oxidase (GOD) as a redox probe and a gold nanoparticle-polyaniline-graphene (Au-PANI-Gra) hybrid for amplification. The Au-PANI-Gra hybrid with large surface area provided a biocompatible sensing platform for the immobilization of GOD. GOD was encapsulated into the three-dimensional netlike (3-mercaptopropyl)trimethoxysilane (MPTS) to form the MPTS-GOD biocomposite, which not only retained the native functions and properties, but also exhibited tunable porosity, high thermal stability, and chemical inertness. With abundant thiol tail groups on MPTS, MPTS-GOD was able to chemisorb onto the surface of the Au-PANI-Gra modified electrode through the strong affinity of the Au-S bond. The electrochemical signal originated from GOD, avoiding the addition or labeling of other redox mediators. After immobilizing the thiolated thrombin binding aptamer through gold nanoparticles (AuNPs), GOD as a blocking reagent was employed to block the remaining active sites of the AuNPs and avoid the nonspecific adsorption. The proposed method avoided the labeling process of redox probes and increased the amount of electroactive GOD. The concentration of thrombin was monitored based on the decrease of current response through cyclic voltammetry (CV) in 0.1 M PBS (pH 7.4). With the excellent direct electron transfer of double layer GOD membranes, the resulting aptasensor exhibited high sensitivity for detection of thrombin with a wide linear range from 1.0 × 10(-12) to 3.0 × 10(-8) M. The proposed aptasensor also showed good stability, satisfactory reproducibility and high specificity, which provided a promising strategy for electrochemical aptamer-based detection of other biomolecules.

  12. Personal experiences in direct ultrasound-guided injection of thrombin into the lumen of pseudoaneurysm as a method of treatment in case of iatrogenic femoral artery damage

    International Nuclear Information System (INIS)

    Slonina, J.; Zaleska-Dorobisz, U.; Malczewska, J.; Kozminska, U.; Sasiadek, M.; Obremska, M.; Agrawal, A.

    2010-01-01

    Background: Pseudoaneurysms constitute a quite common complication of procedures requiring puncture of the common femoral artery. The risk factors of the condition include: obesity, arterial hypertension, sex (more prevalent in males) as well as antithrombotic therapy. Material/Methods: The US-guided injection of thrombin into the pseudoaneurysm lumen was performed in patients referred from the Department of Invasive Cardiology who had undergone coronarography or coronary angioplasty. Pseudoaneurysms constituted the complication of common femoral artery canulation. After setting the diagnosis of pseudoaneurysm by means of Doppler ultrasound, patients with large pseudoaneurysms of volume exceeding 10 mm were qualified for thrombin injection. Generally, 33 patients underwent the treatment. In 3 cases - due to the presence of multiocular pseudoaneurysm - thrombin was administered twice. Results: Taking into account the safety of the procedure, ultimately 33 patients were qualified for thrombin administration, in whom aneurism of diameter exceeding 10 mm was diagnosed. In 3 patients with aneurysm of less than 10 mm, only a compression band was used prophylactically. In one case, because of a considerable oedema surrounding the tissue, as well as deep location of the aneurysm in the groin, thrombin treatment was not given due to technical reasons. In 30 cases, single administration of thrombin was effective and resulted in a complete thrombosis of the pseudoaneurism lumen within a couple of seconds following thrombin injection. In 3 patients with multicellular aneurysm, thrombin was given twice, resulting in a total obliteration of the pseudoaneurysm in two cases only. No complications were observed after the performed procedures. No recanalisation of pseudoaneurysms was demonstrated in follow-up examinations. Conclusions: 1. Direct thrombin injection into the pseudoaneurysm lumen can constitute an alternative method of treatment for open surgical techniques. 2. The

  13. Personal experiences in direct ultrasound-guided injection of thrombin into the lumen of pseudoaneurysm as a method of treatment in case of iatrogenic femoral artery damage

    International Nuclear Information System (INIS)

    Słonina, Joanna; Obremska, Marta; Zaleska-Dorobisz, Urszula; Agrawal, Anil; Malczewska, Joanna; Koźmińska, Urszula; Sąsiadek, Marek

    2010-01-01

    Pseudoaneurysms constitute a quite common complication of procedures requiring puncture of the common femoral artery. The risk factors of the condition include: obesity, arterial hypertension, sex (more prevalent in males) as well as antithrombotic therapy. The US-guided injection of thrombin into the pseudoaneurysm lumen was performed in patients referred from the Department of Invasive Cardiology who had undergone coronarography or coronary angioplasty. Pseudoaneurysms constituted the complication of common femoral artery canulation. After setting the diagnosis of pseudoaneurysm by means of Doppler ultrasound, patients with large pseudoaneurysms of volume exceeding 10 mm were qualified for thrombin injection. Generally, 33 patients underwent the treatment. In 3 cases – due to the presence of multiocular pseudoaneurysm – thrombin was administered twice. Taking into account the safety of the procedure, ultimately 33 patients were qualified for thrombin administration, in whom aneurism of diameter exceeding 10 mm was diagnosed. In 3 patients with aneurysm of less than 10mm, only a compression band was used prophylactically. In one case, because of a considerable oedema surrounding the tissue, as well as deep location of the aneurysm in the groin, thrombin treatment was not given due to technical reasons. In 30 cases, single administration of thrombin was effective and resulted in a complete thrombosis of the pseudoaneurism lumen within a couple of seconds following thrombin injection. In 3 patients with multicellular aneurysm, thrombin was given twice, resulting in a total obliteration of the pseudoaneurysm in two cases only. No complications were observed after the performed procedures. No recanalisation of pseudoaneurysms was demonstrated in follow-up examinations. 1. Direct thrombin injection into the pseudoaneurysm lumen can constitute an alternative method of treatment for open surgical techniques. 2. The procedure is highly effective, cheap and minimally

  14. Successful endovascular treatment of a hemodialysis graft pseudoaneurysm by covered stent and direct percutaneous thrombin injection.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2011-07-25

    Vascular access for hemodialysis remains a challenge for nephrologists, vascular surgeons, and interventional radiologists alike. Arteriovenous fistula and synthetic grafts remain the access of choice for long-term hemodialysis; however, they are subject to complications from infection and repeated needle cannulation. Pseudoaneurysms are an increasingly recognized adverse event. At present, there are many minimally invasive methods to repair these wall defects. We present a graft pseudoaneurysm, which required a combination of endovascular stent graft placement and percutaneous thrombin injection for successful occlusion.

  15. Recent developments in topical thrombins.

    Science.gov (United States)

    Kessler, Craig M; Ortel, Thomas L

    2009-07-01

    Managing blood loss is part of the surgeon's responsibility during surgical procedures, and a variety of therapeutic strategies are available to help accomplish this. Topical haemostatic agents are among the agents used to control surgical bleeding and locally arrest blood flow. Bovine thrombin is a commonly used topical haemostatic agent; however, its use has been associated with potential risks, including well-documented cases of antibody-mediated coagulopathy. This coagulopathy develops as a consequence of antibody formation directed against bovine thrombin, other bovine coagulation proteins, and their human orthologs. The fact that a coagulopathy can result in association with the use of bovine plasma-derived thrombin preparations prompted the FDA to require pharmaceutical companies to place a black-box warning in their prescribing information for products containing bovine plasma-derived thrombin. Recently, human plasma-derived thrombin and recombinant human thrombin have been approved by the FDA with the expectation that they will be less immunogenic than the bovine-derived product. In clinical studies, purified human plasma-derived thrombin and recombinant thrombin have demonstrated equivalent efficacy and safety, with improved immunogenicity profiles compared with bovine-derived thrombin agents. Well-designed and adequately powered clinical trials should be conducted to indicate whether human thrombin products would improve the risk-benefit and cost-benefit profiles for surgeries complicated by excessive bleeding.

  16. 2-(2-Br-phenyl)-8-methoxy-benzoxazinone (HPW-RX2), a direct thrombin inhibitor with a suppressive effect on thromboxane formation in platelets.

    Science.gov (United States)

    Wu, Chin-Chung; Wang, Tsai-Wei; Wang, Wei-Ya; Hsieh, Pei-Wen; Wu, Yang-Chang

    2005-12-19

    2-(2-Br-phenyl)-8-methoxy-benzoxazinone (HPW-RX2), a newly synthetic benzoxazinone derivative, has previously been shown to inhibit rabbit platelet aggregation caused by thrombin and arachidonic acid. In the present study, the mechanism for the antiplatelet effect of HPW-RX2 was further investigated. In human platelets, HPW-RX2 concentration-dependently inhibited platelet aggregation, ATP release, P-selectin expression, and intracellular calcium mobilization caused by thrombin. In contrast, HPW-RX2 had no significant effect on either SFLLRN- or GYPGKF-induced platelet aggregation, indicating that HPW-RX2 did not interfere with platelet thrombin receptors. Moreover, HPW-RX2 inhibited the amidolytic activity of thrombin and prolonged the fibrinogen clotting time. These results suggest that the inhibitory effect of HPW-RX2 on thrombin-induced platelet aggregation is via direct inhibition of thrombin proteolytic activity. Besides the inhibition on thrombin, HPW-RX2 also prevented platelet aggregation, ATP release, and increase in [Ca2+]i caused by arachidonic acid and low concentration collagen. In a parallel manner, both arachidonic acid-induced thromboxane B2 and prostaglandin D2 formations were decreased in platelets treated with HPW-RX2. This indicates that HPW-RX2 is able to inhibit the arachidonic acid cascade at the cyclooxygenase level. This is the first report of a benzoxazinone derivative possessing both thrombin and cyclooxygenase inhibitory properties. The dual effect of HPW-RX2 might provide extra therapeutic benefits for treatment of arterial thrombosis.

  17. Thrombin Time

    Science.gov (United States)

    ... functional fibrinogen assay is now routinely available in clinical laboratories and has largely replaced the need for thrombin ... including fibrinogen activity assay (now routinely available in clinical laboratories), fibrinogen antigen assay, and liver function tests . Is ...

  18. The immobilization of a direct thrombin inhibitor to a polyurethane as a nonthrombogenic surface coating for extracorporeal circulation

    Science.gov (United States)

    Yu, Jane; Brisbois, Elizabeth; Handa, Hitesh; Annich, Gail; Meyerhoff, Mark; Bartlett, Robert; Major, Terry

    2016-01-01

    A biomaterial with both antithrombin and antiplatelet properties is the ideal surface for use in extracorporeal circulation (ECC) as it targets both fibrin generation and platelet adhesion. A hemocompatible surface coating avoids the need for systemic anticoagulation by providing a local anticoagulant effect at the polymer-blood interface. Previous work has demonstrated the potential use of argatroban, a direct thrombin inhibitor, as a nonthrombogenic material for extracorporeal devices. The work reported here focuses on the characterization of argatroban linked to a polyurethane-silicone polymer, CarboSil®. Chemical immobilization, the amount of argatroban, incubation times, and saturation point were evaluated to achieve maximal antithrombin activity at the polymer surface. Cross-linked polymer coatings reacted with 10 and 30 µmole of argatroban were prepared and tested. These coatings resulted in argatroban activity levels of 0.131 µM and 0.446 µM, respectively. After refining the cross-linking process, argatroban activity increased by approximately 3.6 fold. Maintenance of activity and leaching from the polymer surface were also evaluated. Using the refined process for linking argatroban to polymer, the resulting polymer was applied as a surface coating to the inner lumen of poly(vinyl chloride) ECC circuit tubing and its antithrombin effect evaluated using a 4 h rabbit ECC model. Following 4 h of blood exposure, the argatroban circuit demonstrated significantly less thrombus formation compared to the control CarboSil® coating with a 4.1 cm2 thrombus average area for the control coating compared to 1.2 cm2 for the argatroban coating (n=4). There was no significant change in thrombin time from baseline in plasma from animals in which the argatroban coated circuit was used, with a thrombin time of 16.2 s at t=0 and 14.5 s after 4 h. These results demonstrate the potential efficacy of immobilized argatroban as a hemocompatible biomaterial for extracorporeal

  19. CVS-1123, a direct thrombin inhibitor, prevents occlusive arterial and venous thrombosis in a canine model of vascular injury.

    Science.gov (United States)

    Rebello, S S; Miller, B V; Basler, G C; Lucchesi, B R

    1997-02-01

    CVS-1123, low-molecular-weight, direct thrombin inhibitor was studied in an anesthetized canine model of arterial and venous thrombosis to determine whether thrombin inhibition could reduce the incidence of occlusive thrombosis in response to vessel-wall injury. The left carotid artery (LCA) and right jugular vein (RJV) were instrumented with a flow probe, intraluminal electrode, and critical stenosis. Either saline (n = 9), or CVS-1123 (n = 12) was administered in a loading dose of 2 mg/kg i.v., followed by an infusion (2.46 mg/kg/h for 180 min). Vessel-wall injury was initiated by applying a 300-microA anodal current to the intimal surface of the LCA and RJV. Platelet aggregation in response to gamma-thrombin remained inhibited by CVS-1123 for 8 h. The activated partial thromboplastin time (aPTT) was increased and remained elevated for the duration of the protocol. The prothrombin time (PT) showed an initial increase and then a rapid decrease after the infusion was discontinued. There was a twofold increase in the bleeding time (BT) at 2 h. The time to occlusion of the LCA was prolonged (380 +/- 22 min in the CVS-1123 group vs. 152 +/- 18 min in the saline group) with seven of 12 patent arteries at 8 h. Similarly, the time to occlusion for RJV was prolonged (415 +/- 16 min in the CVS-1123 group vs. 99 +/- 8 min in the saline group) with eight of 12 veins remaining patent at 8 h. CVS-1123 administration was associated with a decrease in the thrombus weights in both the LCA and RJV as compared with the saline-treated animals. In summary, CVS-1123 modifies the thrombogenic response to deep vessel-wall injury in both the arterial and venous circulations. The results suggest that CVS-1123 is an effective antithrombin and may offer a therapeutic alternative to current antithrombins in the management of arterial and venous thrombosis.

  20. Meta-analysis of randomized controlled trials on risk of myocardial infarction from the use of oral direct thrombin inhibitors

    DEFF Research Database (Denmark)

    Artang, Ramin; Rome, Eric; Nielsen, Jørn Dalsgaard

    2013-01-01

    . To address these questions, we systematically searched MEDLINE and performed a meta-analysis on randomized trials that compared oral DTIs with warfarin for any indication with end point of MIs after randomization. We furthermore performed a secondary meta-analysis on atrial fibrillation stroke prevention...... trials with alternative anticoagulants compared with warfarin with end point of MIs after randomization. A total of 11 trials (39,357 patients) that compared warfarin to DTIs (dabigatran, ximelagatran, and AZD0837) were identified. In these trials, patients treated with oral DTIs were more likely......Dabigatran has been associated with greater risk of myocardial infarction (MI) than warfarin. It is unknown whether the increased risk is unique to dabigatran, an adverse effect shared by other oral direct thrombin inhibitors (DTIs), or the result of a protective effect of warfarin against MI...

  1. [Human thrombin: drug stability and stabilization].

    Science.gov (United States)

    Kolodzeĭskaia, M V; Sokolovskiĭ, V A; Volkov, G L

    2006-01-01

    Stabilization of enzymes is a key factor when using biocatalysis in practice. Each enzyme stability depends both on the structure of its molecule and on the effect of various environmental factors, thus, one of the methods of the enzyme stability preservation is the formation of optimal macromedium. Thus, water structure and enzyme hydration change in the presence of solvable additives that affects its stability and catalytic properties. The paper deals with a new method of stabilization of human thrombin developed by the authors. It is proposed to use some known organic-ligands which have ion group and different nonpolar hydrophobic groups instead of traditional additives (salts, aminoacids, polyols, polyethylene glycols etc.). Thrombin stabilization proceeds in the conditions something changed compared with traditional ones. Processes of thrombin stabilization by the above compound have been investigated, enzyme stability at different temperatures and long-term storage of diluted solutions of the preparation in different conditions have been studied. It has been established that rosselin and orange II are the most efficient ligands. Optimal finite concentrations of stabilizing agents make approximately 0.0012-0.0014 M which are rather low in the system thrombin-ligand. It has been found that diluted solutions of thrombin are more stable, than concentrated ones. In the latter case the process of autolysis is included that affects negatively the catalytic effect of the enzyme, as far as there occurs the change of thrombin molecule structure, especially of thrombin beta-chain sections, evoking conformational changes of some sites of its active centre. The experiments directed to increasing thrombin intensity in the presence of organic ligands rosselin and orange II are discussed in details. Special attention is given to autolytic method of thrombin inactivation. It is admitted on the basis of already obtained data that thrombin binding with organic ligands proceeds

  2. Red wine polyphenolic compounds strongly inhibit pro-matrix metalloproteinase-2 expression and its activation in response to thrombin via direct inhibition of membrane type 1-matrix metalloproteinase in vascular smooth muscle cells.

    Science.gov (United States)

    Oak, Min-Ho; El Bedoui, Jasser; Anglard, Patrick; Schini-Kerth, Valérie B

    2004-09-28

    Regular consumption of moderate amounts of red wine is associated with a reduced risk of coronary disease. Matrix metalloproteinases (MMPs) that participate in extracellular matrix degradation have been involved in atherosclerotic plaque growth and instability. The present study examined whether red wine polyphenolic compounds (RWPCs) inhibit activation of MMP-2, a major gelatinase, in vascular smooth muscle cells (VSMCs). Expression of pro-MMP-2 was assessed by Western and Northern blot analyses; MMP-2 activity was assessed by zymography and cell invasion by a modified Boyden's chamber assay. High levels of pro-MMP-2 and low levels of MMP-2 activity were found in conditioned medium from unstimulated VSMCs. Thrombin induced cell-associated pro-MMP-2 protein expression and MMP-2 activity in conditioned medium of VSMCs. The stimulatory effect of thrombin on MMP-2 activation was prevented by RWPCs in a concentration-dependent and reversible manner. Thrombin markedly increased cell-associated membrane type 1 (MT1)-MMP activity, the physiological activator of pro-MMP-2, and this response was not affected by RWPCs. However, addition of RWPCs directly to MT1-MMP abolished its metalloproteinase activity in a reversible manner. Finally, matrix invasion of VSMCs was stimulated by thrombin, and this response was prevented by RWPCs as efficiently as a broad-spectrum MMP inhibitor. The present findings demonstrate that RWPCs effectively inhibit thrombin-induced matrix invasion of VSMCs, most likely by preventing the expression and activation of MMP-2 via direct inhibition of MT1-MMP activity. The inhibitory effect of RWPCs on the activation of pro-MMP-2 and matrix degradation might contribute to their beneficial effects on the cardiovascular system.

  3. New oral antithrombotics: focus on dabigatran, an oral, reversible direct thrombin inhibitor for the prevention and treatment of venous and arterial thromboembolic disorders

    Directory of Open Access Journals (Sweden)

    Dahl OE

    2012-01-01

    Full Text Available Ola E Dahl1,21Department of Orthopaedics, Innlandet Hospital Trust, Elverum Central Hospital, Elverum, Norway; 2Thrombosis Research Institute, London, UKAbstract: Venous thromboembolism, presenting as deep vein thrombosis or pulmonary embolism, is a major challenge for health care systems. It is the third most common vascular disease after coronary heart disease and stroke, and many hospitalized patients have at least one risk factor. In particular, patients undergoing hip or knee replacement are at risk, with an incidence of asymptomatic deep vein thrombosis of 40%–60% without thromboprophylaxis. Venous thromboembolism is associated with significant mortality and morbidity, with patients being at risk of recurrence, post-thrombotic syndrome, and chronic thromboembolic pulmonary hypertension. Arterial thromboembolism is even more frequent, and atrial fibrillation, the most common embolic source (cardiac arrhythmia, is associated with a five-fold increase in the risk of stroke. Strokes due to atrial fibrillation tend to be more severe and disabling and are more often fatal than strokes due to other causes. Currently, recommended management of both venous and arterial thromboembolism involves the use of anticoagulants such as coumarin and heparin derivatives. These agents are effective, although have characteristics that prevent them from providing optimal anticoagulation and convenience. Hence, new improved oral anticoagulants are being investigated. Dabigatran is a reversible, direct thrombin inhibitor, which is administered as dabigatran etexilate, the oral prodrug. Because it is the first new oral anticoagulant that has been licensed in many countries worldwide for thromboprophylaxis following orthopedic surgery and for stroke prevention in patients with atrial fibrillation, this compound will be the main focus of this review. Dabigatran has been investigated for the treatment of established venous thromboembolism and prevention of

  4. Crystal structure of two new bifunctional nonsubstrate type thrombin inhibitors complexed with human alpha-thrombin.

    Science.gov (United States)

    Féthière, J; Tsuda, Y; Coulombe, R; Konishi, Y; Cygler, M

    1996-06-01

    The crystal structures of two new thrombin inhibitors, P498 and P500, complexed with human alpha-thrombin have been determined at 2.0 A resolution and refined to crystallographic R-factors of 0.170 and 0.169, respectively. These compounds, with picomolar binding constants, belong to a family of potent bifunctional inhibitors that bind thrombin at two remote sites: the active site and the fibrinogen recognition exosite (FRE). The inhibitors incorporate a nonsubstrate type active site binding fragment: Dansyl-Arg-(D)Pipecolic acid (Dns-Arg-(D)Pip), reminiscent of the active-site directed inhibitors MD-805 and MQPA, rendering them resistant to thrombin-induced hydrolysis. The FRE binding fragment of these inhibitors corresponds to the hirudin55-65 sequence. They differ in the chemical nature of the nonpeptidyl linker bridging these two functional activities. In both cases, the active site binding fragment is well defined in the electron density. The DnsH1, ArgH2, and (D)PipH3 groups occupy the S3, S1, and S2 subsites of thrombin, respectively, in a way similar to that observed in the thrombin-MQPA complexes. Binding in the active site of thrombin is characterized by numerous van der Waals contacts and ring-ring system interactions. Unlike in the substrate-like inhibitors, ArgH2 enters the S1 specificity pocket from the P2 position and adopts a bent conformation to make an hydrogen bond to the carboxylate of Asp189. In this noncanonical position, its carbonyl points away from the oxyanion hole, which is now occupied by well-ordered solvent molecules. The linkers fit in the groove extending from the active site to the FRE. The C-terminal fragments of both inhibitors bind in the same way as analogous FRE binding elements in previously described complexes.

  5. Synergy between thrombin and serotonin in inducing vascular smooth muscle cell proliferation.

    Science.gov (United States)

    Pakala, R; Benedict, C

    1999-12-01

    Previous studies have indicated that apart from playing an important role in hemostasis and thrombosis, thrombin may also contribute to the development of postangioplasty restenosis caused by the stimulation of vascular smooth muscle cell (VSMC) proliferation. Because thrombin generation in vivo is accompanied by platelet activation and release of smooth muscle cell (SMC) growth factors such as serotonin, we examined the possible interaction between these two compounds on VSMC proliferation. Thrombin (0.01 to 100 nmol/L), thrombin receptor-activating peptide (0.1 to 1000 micromol/L), and serotonin (5HT; 0.1 to 1000 micromol/L) increased tritiated thymidine incorporation into the DNA of canine aortic VSMCs in a dose-dependent manner. When thrombin and 5HT were added together at sub-threshold concentrations, they acted synergistically in inducing tritiated thymidine incorporation. These findings were paralleled by a 90%+/-5% increase in the cell number at 48 hours, as compared with a 37%+/-2% increase with 50 micromol/L serotonin and a 13%+/-3% increase with 0.1 nmol/L thrombin. We also demonstrated that a brief exposure to thrombin (1 hour) is sufficient to show its potentiating effect on serotonin. The mitogenic effect of serotonin and its synergistic interaction with thrombin on VSMC proliferation was abolished by serotonin type 2 receptor antagonist LY281067. Similarly, gamma-hirudin--a direct thrombin inhibitor--blocked the mitogenic effect of thrombin and its synergistic interaction with serotonin. When LY281067 and gamma-hirudin were used together, they abolished the mitogenic effects of both the agonists. Because clot-bound active thrombin can escape inactivation by anti-thrombin, this thrombin may potentiate the mitogenic effect of serotonin and keep the SMCs in a proliferative state for a long period of time. These findings support the use of 5HT2 receptor antagonists in combination with thrombin inhibitors in the prevention of SMC proliferation after

  6. Behaviour of homologous 125I fibrinogen after thrombin and ancrod infusion in rabbits

    International Nuclear Information System (INIS)

    Setter, R.

    1977-01-01

    The behaviour of radioactively labelled fibrinogen after infusion of thrombin or ancrod is investigated. Common factors and differences in the behaviour of fibrinogen after infusion of these two enzymes, which act proteolytically on the fibrinogen, are dealt with. Rabbits received an i.v. injection of homologous 125 I-fibrinogen 3 days before ancrod or thrombin infusion. On the day of the experiments, one group of animals received an ancrod infusion (1.5 U/kg body weight for 30 minutes), the other a thrombin infusion (600 U/kg body weight for 60 minutes). Intravenous ancrod and thrombin infusions lowered the fibrinogen level to 30% or 50% of the initial value due to intravascular coagulation. About 50% of the 125 I fibrinogen was transformed after ancrod exposure into a non-coagulating fraction of fibrinogen derivatives which produces no fibrinolytic decomposition products. (orig./AJ) [de

  7. Three different signal amplification strategies for the impedimetric sandwich detection of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Ocaña, Cristina; Valle, Manel del, E-mail: manel.delvalle@uab.cat

    2016-03-17

    In this work, we report a comparative study on three highly specific amplification strategies for the ultrasensitive detection of thrombin with the use of aptamer sandwich protocol. The protocol consisted on the use of a first thrombin aptamer immobilized on the electrode surface, the recognition of thrombin protein, and the reaction with a second biotinylated thrombin aptamer forming the sandwich. Through the exposed biotin end, three variants have been tested to amplify the electrochemical impedance signal. The strategies included (a) silver enhancement treatment, (b) gold enhancement treatment and (c) insoluble product produced by the combination of the enzyme horseradish peroxidase (HRP) and 3-amino-9-ethylcarbazole (AEC). The properties of the sensing surface were probed by electrochemical impedance measurements in the presence of the ferrocyanide/ferricyanide redox marker. Insoluble product strategy and silver enhancement treatment resulted in the lowest detection limit (0.3 pM), while gold enhancement method resulted in the highest reproducibility, 8.8% RSD at the pM thrombin concentration levels. Results of silver and gold enhancement treatment also permitted direct inspection by scanning electron microscopy (SEM). - Highlights: • Aptasensor to detect thrombin reaching the femtomolar level. • Biosensing protocol employs two thrombin aptamers in a sandwich capture scheme. • Use of second biotinylated aptamer allows many amplification and detection variants. • Precipitation reaction provides the highest signal amplification of ca. 3 times. • Double recognition event improves remarkably selectivity for thrombin detection.

  8. Thrombolysis by intravenous tissue plasminogen activator (t-PA). Current status and future direction

    International Nuclear Information System (INIS)

    Tanahashi, Norio

    2009-01-01

    In Japan, the intravenous tissue plasminogen activator (t-PA) Alteplase (0.6 mg/kg) administration of the within 3 h of the onset of acute ischemic stroke was approved for therapeutic use in the year 2006. t-PA induces thrombolysis in patients with acute ischemic stroke, and this method has gradually gained recognition among physicians and the general population. However, the number of patients who were treated using Alteplase is low (4,000-5,000 patients/year), and this figure accounts for only 2-3% of the annual number of cases of ischemic stroke. There is little doubt that Alteplase treatment is a potentially effective modality for some patients with acute ischemic stroke. The post-marketing surveillance of 4,749 Japanese patients treated using Alteplase showed that 33% of the patients had modified Rankin scale (mRS) scores of 0-1, 17% of patients died and 4.5% presented with symptomatic intracerebral hemorrhage (ICH); these results were comparable to those from other countries. The expansion of the therapeutic time window has been a matter of concern. The investigators of the European Cooperative Acute Stroke Study (ECASS) have reported that there was significant improvement in the clinical outcomes of patients with acute ischemie stroke when Alteplase was administered 3-4.5 h after the onset of the symptoms. Mismatches in perfusion- and diffusion-weighted (DW) magnetic resonance imaging (MRI) images have been used for selecting patients 3 h after the onset of symptoms, and the findings from MRI, dwimages (DWI) and MR angiography are practical predictors of t-PA therapy within 3 h of onset. The Middle Cerebral Artery Embolism Local Fibrinolytic Intervention Trial (MELT) Japan study showed that local intra-arterial fibrinolysis is effective in patients with embolic MCA occlusion within 6 h of the onset of symptoms. Combining the initiation of intravenous t-PA administration with further intra-arterial fibrinolysis or mechanical thrombolectomy may improve the

  9. Inhibition of Intrinsic Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Thomas W. Stief MD

    2006-01-01

    Full Text Available Background The contact phase of coagulation is of physiologic/pathophysiologic importance, whenever unphysiologic polynegative substances such as cell fragments (microparticles get in contact with blood. There are several clinically used inhibitors of intrinsic thrombin generation. Here the inhibitory concentrations 50% (IC50 of these anticoagulants are measured by the highly specific thrombin generation assay INCA. Methods Unfrozen pooled normal citrated plasma in polystyrole tubes was supplemented at 23°C in duplicate with 0–2 IU/ml low molecular weight heparin (dalteparin, 0–2 IU/ml unfractionated heparin, 0–500 KIU/ml aprotinin, or 0–40 mM arginine. 50 μl plasma or 1 IU/ml thrombin standard were pipetted into a polystyrole microtiter plate with flat bottom. 5 μl SiO 2 /CaCl 2 - reagent (INCA activator were added and after 0–30 min incubation at 37°C 100 μl 2.5 M arginine, pH 8.6, were added; arginine inhibits hemostasis activation and depolymerizes generated fibrin within 20 min at 23°C. The in the physiologic 37°C incubation phase generated thrombin was then chromogenically detected. The intra-assay CV values were < 5%. Results and Discussion The approximate IC50 were 0.01 IU/ml dalteparin, 0.02 IU/ml heparin, 25 KIU/ml aprotinin, and 12 mM arginine. The efficiency of any anticoagulant on intrinsic thrombin generation should be measured for each individual patient. Abbreviations IIa, thrombin; δA, increase in absorbance; APTT, activated partial thromboplastin time; CRT, coagulation reaction time (at 37°C in water-bath; F-wells, polystyrole microtiter plates with flat bottom; IC50, inhibitory concentration 50%; INCA, intrinsic coagulation activity assay; IU, international units; KIU, kallikrein inhibiting unis; LMWH, low molecular weight heparin; mA, milli-absorbance units; PSL, pathromtin SL®; RT, room temperature (23°C; U-wells, polystyrole microtiter plates with round bottom.

  10. RADIOLOGICAL TIPS Percutaneous thrombin injection for ...

    African Journals Online (AJOL)

    pseudoaneurysm sac has a typical 'yin-yang' sign. The neck is normally seen posteriorly and is usually thin and longitudinal. A large neck diameter (e.g. >10 mm) is a relative contra-indication for thrombin injection because of a slightly higher risk of distal embolisation. There are several thrombin preparations available.

  11. Synergism between thrombin and adrenaline (epinephrine) in human platelets. Marked potentiation of inositol phospholipid metabolism.

    Science.gov (United States)

    Steen, V M; Tysnes, O B; Holmsen, H

    1988-01-01

    We have studied synergism between adrenaline (epinephrine) and low concentrations of thrombin in gel-filtered human platelets prelabelled with [32P]Pi. Suspensions of platelets, which did not contain added fibrinogen, were incubated at 37 degrees C to measure changes in the levels of 32P-labelled phosphatidylinositol 4,5-bisphosphate (PIP2), phosphatidylinositol 4-phosphate (PIP) and phosphatidate (PA), aggregation and dense-granule secretion after stimulation. Adrenaline alone (3.5-4.0 microM) did not cause a change in any parameter (phosphoinositide metabolism, aggregation and dense-granule secretion), but markedly enhanced the thrombin-induced responses over a narrow range of thrombin concentrations (0.03-0.08 units/ml). The thrombin-induced hydrolysis of inositol phospholipids by phospholipase C, which was measured as the formation of [32P]PA, was potentiated by adrenaline, as was the increase in the levels of [32P]PIP2 and [32P]PIP. The presence of adrenaline caused a shift to the left for the thrombin-induced changes in the phosphoinositide metabolism, without affecting the maximal levels of 32P-labelled compounds obtained. A similar shift by adrenaline in the dose-response relationship was previously demonstrated for thrombin-induced aggregation and dense-granule secretion. Also, the narrow range of concentrations of thrombin over which adrenaline potentiates thrombin-induced platelet responses is the same for changes in phosphoinositide metabolism and physiological responses (aggregation and dense-granule secretion). Our observations clearly indicate that adrenaline directly or indirectly influences thrombin-induced changes in phosphoinositide metabolism. PMID:2845924

  12. Management of major bleeding complications and emergency surgery in patients on long-term treatment with direct oral anticoagulants, thrombin or factor-Xa inhibitors: proposals of the working group on perioperative haemostasis (GIHP) - March 2013.

    Science.gov (United States)

    Pernod, Gilles; Albaladejo, Pierre; Godier, Anne; Samama, Charles M; Susen, Sophie; Gruel, Yves; Blais, Normand; Fontana, Pierre; Cohen, Ariel; Llau, Juan V; Rosencher, Nadia; Schved, Jean-François; de Maistre, Emmanuel; Samama, Meyer M; Mismetti, Patrick; Sié, Pierre

    2013-01-01

    Direct new oral anticoagulants (NOACs) - inhibitors of thrombin or factor Xa - are intended to be used largely in the treatment of venous thromboembolic disease or the prevention of systematic embolism in atrial fibrillation, instead of vitamin K antagonists. Like any anticoagulant treatment, they are associated with spontaneous or provoked haemorrhagic risk. Furthermore, a significant proportion of treated patients are likely to be exposed to emergency surgery or invasive procedures. Given the absence of a specific antidote, the action to be taken in these situations must be defined. The lack of data means that it is only possible to issue proposals rather than recommendations, which will evolve according to accumulated experience. The proposals presented here apply to dabigatran (Pradaxa(®)) and rivaroxaban (Xarelto(®)); data for apixaban and edoxaban are still scarce. For urgent surgery with haemorrhagic risk, the drug plasma concentration should be less or equal to 30ng/mL for dabigatran and rivaroxaban should enable surgery associated with a high bleeding risk. Beyond that, if possible, the intervention should be postponed by monitoring the drug concentration. The course to follow is then defined according to the NOAC and its concentration. If the anticoagulant dosage is not immediately available, worse propositions, based on the usual tests (prothrombin time and activated partial thromboplastin time), are presented. However, these tests do not really assess drug concentration or the risk of bleeding that depends on it. In case of serious bleeding in a critical organ, the effect of anticoagulant therapy should be reduced using a non-specific procoagulant drug as a first-line approach: activated prothrombin complex concentrate (aPCC) (FEIBA(®) 30-50U/kg) or non-activated PCC (50U/kg). In addition, for any other type of severe haemorrhage, the administration of a procoagulant drug, which is potentially thrombogenic in these patients, is discussed according

  13. Endogenous thrombin potential in polycystic ovary syndrome

    DEFF Research Database (Denmark)

    Aziz, Mubeena; Sidelmann, Johannes J; Wissing, Marie Louise Muff

    2015-01-01

    OBJECTIVES: The objective of this study is to investigate plasma endogenous thrombin generation in four different phenotypes of polycystic ovary syndrome (PCOS) defined by Body Mass Index (BMI) and insulin resistance (IR). PCOS is diagnosed according to the Rotterdam criteria. DESIGN: Multicenter......: Endogenous thrombin potential (ETP). RESULTS: PCOS women with phenotype BMI > 25 + IR have increased potential of thrombin generation. ETP is associated with total body fat mass, IR, and CRP. CONCLUSIONS: Obese and insulin resistant women with PCOS have elevated level of ETP corresponding to increased risk...

  14. Thrombin impairs human endometrial endothelial angiogenesis; implications for progestin-only contraceptive-induced abnormal uterine bleeding.

    Science.gov (United States)

    Shapiro, John P; Guzeloglu-Kayisli, Ozlem; Kayisli, Umit A; Semerci, Nihan; Huang, S Joseph; Arlier, Sefa; Larsen, Kellie; Fadda, Paolo; Schatz, Frederick; Lockwood, Charles J

    2017-06-01

    Progestin-only contraceptives induce abnormal uterine bleeding, accompanied by prothrombin leakage from dilated endometrial microvessels and increased thrombin generation by human endometrial stromal cell (HESC)-expressed tissue factor. Initial studies of the thrombin-treated HESC secretome identified elevated levels of cleaved chondroitin sulfate proteoglycan 4 (CSPG4), impairing pericyte-endothelial interactions. Thus, we investigated direct and CSPG4-mediated effects of thrombin in eliciting abnormal uterine bleeding by disrupting endometrial angiogenesis. Liquid chromatography/tandem mass spectrometry, enzyme-linked immunosorbent assay (ELISA) and quantitative real-time-polymerase chain reaction (PCR) evaluated conditioned medium supernatant and cell lysates from control versus thrombin-treated HESCs. Pre- and post-Depo medroxyprogesterone acetate (DMPA)-administered endometria were immunostained for CSPG4. Proliferation, apoptosis and tube formation were assessed in human endometrial endothelial cells (HEECs) incubated with recombinant human (rh)-CSPG4 or thrombin or both. Thrombin induced CSPG4 protein expression in cultured HESCs as detected by mass spectrometry and ELISA (pabnormal uterine bleeding in DMPA users. Mass spectrometry analysis identified several HESC-secreted proteins regulated by thrombin. Therapeutic agents blocking angiogenic effects of thrombin in HESCs can prevent or minimize progestin-only contraceptive-induced abnormal uterine bleeding. Copyright © 2017. Published by Elsevier Inc.

  15. Low thrombin generation predicts poor prognosis in ischemic stroke patients after thrombolysis.

    Directory of Open Access Journals (Sweden)

    Renáta Hudák

    Full Text Available Thrombolysis by intravenous recombinant tissue plasminogen activator (rt-PA is an effective therapy in acute ischemic stroke (AIS. Thrombin generation test (TGT is a global hemostasis test providing information about the speed and amount of generated thrombin in plasma. Here we aimed to find out whether results of this test before the initiation of thrombolysis might predict outcomes. Study population included 120 consecutive AIS patients, all within 4.5 hours of their symptom onset, who underwent thrombolysis by rt-PA. Blood samples were collected from all patients upon admission and TGT was performed using platelet poor plasma. Clinical data of patients including the NIHSS were registered at admission, day 1 and 7 after therapy. The ASPECT score was assessed using CT images taken before and 24 hours after thrombolysis. Long-term functional outcome was defined 3 months after the event by the modified Rankin Scale. Endogenous Thrombin Potential (ETP and Peak Thrombin were significantly lower in patients with cardioembolic IS. Symptomatic intracranial hemorrhage (SICH was found in 6 patients and was significantly associated with low ETP and Peak Thrombin levels. A multiple logistic regression model revealed that an ETP result in the lower quartile is an independent predictor of mortality within the first two weeks (OR: 6.03; 95%CI: 1.2-30.16, p<0.05 and three months after the event (OR: 5.28; 95%CI: 1.27-21.86, p<0.05. Low levels of ETP and Peak Thrombin parameters increase the risk of therapy associated SICH. A low ETP result is an independent predictor of short- and long-term mortality following thrombolysis.

  16. Thrombin Generation in Acute Ischaemic Stroke

    Directory of Open Access Journals (Sweden)

    Ibrahim O. Balogun

    2016-01-01

    Full Text Available Introduction. Stroke remains a global leading cause of death and disability. Traditional description of plasma biology in the aftermath of acute ischaemic stroke favours development of hypercoagulability, resulting from complex interplay between plasma and endothelial factors. However, no single assay measures the overall global coagulation process. We postulate that thrombin generation would assist in identifying coagulation abnormalities after acute stroke. Aim. To investigate the coagulation abnormalities after acute ischaemic stroke using thrombin generation. Methods. We evaluated thrombin generation, measured with calibrated automated thrombography in stroke of different aetiological types (n=170 within 48 hours of symptoms onset (baseline and in the second week (time 2 and in normal healthy volunteers (n=71. Results. Two-point thrombin generation assays showed prolonged lag time and time to peak at baseline (3.3 (2.9, 4.0 versus 3.6 (3.2, 4.7; p=0.005 and (3.3 (2.9, 4.0 versus 3.6 (3.2, 4.7; p=0.002, respectively, and at time 2 (3.5 (2.9, 4.2 versus 4.0 (3.1, 4.9; p=0.004 and (5.9 (5.3, 6.6 versus 6.8 (5.8, 7.7 p=0.05, respectively, in cardioembolic stroke (n=39, when compared to noncardioembolic stroke (n=117. The result was reproduced in multiple comparisons between acute ischaemic stroke subgroups and normal healthy volunteers. Endogenous thrombin potential and peak thrombin did not indicate hypercoagulability after acute ischaemic stroke, and thrombolytic therapy did not affect thrombin generation assays. Conclusion. Our findings suggest that thrombin generation in platelet poor plasma is not useful in defining hypercoagulability in acute ischaemic stroke. This is similar to observed trend in coronary artery disease and contrary to other hypercoagulable states.

  17. [Application of direct electric current and intravenous ozone therapy in the complex treatment of destructive forms of acute pancreatitis in experiment].

    Science.gov (United States)

    Zhakiev, B S; Zhumabaeva, A N; Kaliev, A A; Kazbekova, G A

    2013-01-01

    The results of experimental study which have carried out on 40 outbread dogs were analyzed in this thesis. Modeling of destructive pancreatitis in animals has been achieved via canalicular-hypertensive model by S.A. Shalimov. 4 series of experimental study were made to achieve the targeted goal. The first series 10 dogs without treatment, the second series 10 dogs in which conventional conservative therapy was used for the treatment of acute experimental destructive pancreatitis in animals, the third series 10 dogs that underwent intravenous ozone therapy in the complex together with medication therapy, the forth series the effectiveness of combined administration of intravenous ozone therapy and small doses of direct current in 10 dogs was evaluated. Combined administration of small doses of DC and intravenous ozone therapy in the complex treatment of destructive pancreatitis shows antiphlogistic action, favors accelerated rejection of necrotic tissue, remits inflammatory process as well as encourages regeneration process in pancreas whereby allows to decrease the mortality in experimental animals from 60% to 20%.

  18. Topical thrombin-related corneal calcification.

    Science.gov (United States)

    Kiratli, Hayyam; Irkeç, Murat; Alaçal, Sibel; Söylemezoğlu, Figen

    2006-09-01

    To report a highly unusual case of corneal calcification after brief intraoperative use of topical thrombin. A 44-year-old man underwent sclerouvectomy for ciliochoroidal leiomyoma, during which 35 UNIH/mL lyophilized bovine thrombin mixed with 9 mL of diluent containing 1500 mmol/mL calcium chloride was used. From the first postoperative day, corneal and anterior lenticular capsule calcifications developed, and corneal involvement slightly enlarged thereafter. A year later, 2 corneal punch biopsies confirmed calcification mainly in the Bowman layer. Topical treatment with 1.5% ethylenediaminetetraacetic acid significantly restored corneal clarity. Six months later, a standard extracapsular cataract extraction with intraocular lens placement improved visual acuity to 20/60. This case suggests that topical thrombin drops with elevated calcium concentrations may cause acute corneal calcification in Bowman layer and on the anterior lens capsule.

  19. Ethanol interferes with thrombin mediated changes in the morphology and cytoskeleton of human vascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pratt, K.J.; Rubin, R.; Hoek, J.; Williams, S.K. (Thomas Jefferson Univ., Philadelphia, PA (United States))

    1991-03-15

    The effect of physiological concentrations of ethanol (EtOH) on the response of human vascular endothelial cells (EC) to thrombin was examined Treatment of EC with EtOH concentrations of 20-85mM for 2-10 min. produced no significant changes in the morphology of 3- and 4-day monolayers established on fibronectin coated polystyrene. When examined immunofluorescently no significantly changes in the microfilament or microtubule structures were seen. Exposure of EC monolayers to 0.5 and 1 U/ml of thrombin for 1-60 minutes causes a concentration and time dependent monolayer retraction, evidenced by a general decrease in cell size, increase in visible gaps in the monolayer and redistribution of the microtubule and microfilament networks. Pretreatment of EC monolayers with EtOH for 3-5 minutes prior to addition of thrombin prevents the changes seen with thrombin alone. Immunofluorescent examination of the microfilament and microtubule structures suggests than EtOH may act in part via the microtubule network, which appears to be disorganized/disrupted when the EC are exposed to EtOH and then thrombin. Colchicine studies show that EC which have been pretreated with EtOH respond to colchicine differently then cells which have not previously seen EtOH. These data suggest that EtOH may alter EC monolayer responsiveness either by indirect changes which are reflected in cytoskeletal disorganization or possibly by direct influence on the cytoskeleton.

  20. Percutaneous Thrombin Injection to Complete SMA Pseudoaneurysm Exclusion After Failing of Endograft Placement

    International Nuclear Information System (INIS)

    Szopinski, Piotr; Ciostek, Piotr; Pleban, Eliza; Iwanowski, Jaroslaw; Krol, Malgorzata Serafin-; Marianowska, Agnieszka; Noszczyk, Wojciech

    2005-01-01

    Visceral aneurysms are potentially life-threatening vascular lesions. Superior mesenteric artery (SMA) pseudoaneurysms are a rare but well-recognized complication of chronic pancreatitis. Open surgical repair of such an aneurysm, especially in patients after previous surgical treatment, might be dangerous and risky. Stent graft implantation makes SMA pseudoaneurysm exclusion possible and therefore avoids a major abdominal operation. Percutaneous direct thrombin injection is also one of the methods of treating aneurysms in this area. We report a first case of percutaneous ultrasound-guided thrombin injection to complete SMA pseudoaneurysm exclusion after an unsuccessful endograft placement. Six-month follow-up did not demonstrate any signs of aneurysm recurrence

  1. Decreased prothrombin conversion and reduced thrombin inactivation explain rebalanced thrombin generation in liver cirrhosis.

    Directory of Open Access Journals (Sweden)

    Romy M W Kremers

    Full Text Available Impaired coagulation factor synthesis in cirrhosis causes a reduction of most pro- and anticoagulant factors. Cirrhosis patients show no clear bleeding or thrombotic phenotype, although they are at risk for both types of hemostatic event. Thrombin generation (TG is a global coagulation test and its outcome depends on underlying pro- and anticoagulant processes (prothrombin conversion and thrombin inactivation. We quantified the prothrombin conversion and thrombin inactivation during TG in 30 healthy subjects and 52 Child-Pugh (CP- A, 15 CP-B and 6 CP-C cirrhosis patients to test the hypothesis that coagulation is rebalanced in liver cirrhosis patients. Both prothrombin conversion and thrombin inactivation are reduced in cirrhosis patients. The effect on pro- and anticoagulant processes partially cancel each other out and as a result TG is comparable at 5 pM tissue factor between healthy subjects and patients. This supports the hypothesis of rebalanced hemostasis, as TG in cirrhosis patients remains within the normal range, despite large changes in prothrombin conversion and thrombin inactivation. Nevertheless, in silico analysis shows that normalization of either prothrombin conversion or thrombin inactivation to physiological levels, by for example the administration of prothrombin complex concentrates would cause an elevation of TG, whereas the normalization of both simultaneously maintains a balanced TG. Therefore, cirrhosis patients might require adapted hemostatic treatment.

  2. Binding of α2-macroglobulin-thrombin complexes and methylamine-treated α2-macroglobulin to human blood monocytes

    International Nuclear Information System (INIS)

    Straight, D.L.; Jakoi, L.; McKee, P.A.; Snyderman, R.

    1988-01-01

    The binding of α 2 -macroglobulin (α 2 M) to human peripheral blood monocytes was investigated. Monocytes, the precursors of tissue macrophages, were isolated from fresh blood by centrifugal elutriation or density gradient centrifugation. Binding studies were performed using 125 I-labeled α 2 M. Cells and bound ligand were separated from free ligand by rapid vacuum filtration. Nonlinear least-squares analysis of data obtained in direct binding studies at 0 0 C showed that monocytes bound the α 2 M-thrombin complex with a K/sub d/ 3.0 +- .09 nM and the monocyte had 1545 +- 153 sitescell. Thrombin alone did not compete for the site. Binding was divalent cation dependent. Direct binding studies also demonstrated that monocytes bound methylamine-treated α 2 M in a manner similar to α 2 M-thrombin. Competitive binding studies showed that α 2 M-thrombin and methylamine-treated α 2 M bound to the same sites on the monocyte. In contrast, native α 2 M did not compete with α 2 M-thrombin for the site. Studies done at 37 0 C suggested that after binding, the monocyte internalized and degraded α 2 M-thrombin and excreted the degradation products. Receptor turnover and degradation of α 2 M-thrombin complexes were blocked in monocytes treated with chloroquine, an inhibitor of lysosomal function. The results indicate that human monocytes have a divalent cation dependent, high-affinity binding site for α 2 M-thrombin and methylamine-treated α 2 M which may function to clear α 2 M-proteinase complexes from the circulation

  3. Thrombin-specific inactivation of endothelial cell derived plasminogen activator

    International Nuclear Information System (INIS)

    Highsmith, R.F.; Gallaher, M.J.

    1986-01-01

    Although thrombin (T) has diverse functions in the overall hemostatic mechanism, relatively little is known about its direct effect on components of the fibrinolytic enzyme system. The authors have investigated the interaction of T with plasminogen activators (PA) derived from bovine aortic endothelial cells (EC) in culture (2-5th passage, preconfluent monolayers). Varying concentrations of purified bovine or human thrombin were added to EC-conditioned media (CM). CM + T mixtures were assayed at various times for PA activity using purified plasminogen and a sensitive 125 I-fibrinogenolytic or caseinolytic assay. T (5 nM), but not plasmin or trypsin at equivalent concentrations, resulted in a time-dependent inhibition of the PA activity in CM. T had no effect on the PA activity of urokinase, streptokinase or preformed plasmin. The ability of T to inactivate the EC-derived PA was abolished by prior treatment of T with active site-directed reagents. SDS-PAGE and zymography with copolymerized fibrinogen and plasminogen revealed further specificity in that only one of the multiple-molecular weight forms of PA present in EC-CM was inactivated by T. The authors conclude that in a highly specific fashion, T inactivates the predominant PA present in EC-CM by limited proteolysis. Thus, another potentially important function of T is suggested which may have particular significance in the temporal regulation of coagulation and fibrinolysis at the blood-endothelium interface

  4. Thrombin-specific inactivation of endothelial cell derived plasminogen activator

    Energy Technology Data Exchange (ETDEWEB)

    Highsmith, R.F.; Gallaher, M.J.

    1986-03-05

    Although thrombin (T) has diverse functions in the overall hemostatic mechanism, relatively little is known about its direct effect on components of the fibrinolytic enzyme system. The authors have investigated the interaction of T with plasminogen activators (PA) derived from bovine aortic endothelial cells (EC) in culture (2-5th passage, preconfluent monolayers). Varying concentrations of purified bovine or human thrombin were added to EC-conditioned media (CM). CM + T mixtures were assayed at various times for PA activity using purified plasminogen and a sensitive /sup 125/I-fibrinogenolytic or caseinolytic assay. T (5 nM), but not plasmin or trypsin at equivalent concentrations, resulted in a time-dependent inhibition of the PA activity in CM. T had no effect on the PA activity of urokinase, streptokinase or preformed plasmin. The ability of T to inactivate the EC-derived PA was abolished by prior treatment of T with active site-directed reagents. SDS-PAGE and zymography with copolymerized fibrinogen and plasminogen revealed further specificity in that only one of the multiple-molecular weight forms of PA present in EC-CM was inactivated by T. The authors conclude that in a highly specific fashion, T inactivates the predominant PA present in EC-CM by limited proteolysis. Thus, another potentially important function of T is suggested which may have particular significance in the temporal regulation of coagulation and fibrinolysis at the blood-endothelium interface.

  5. Intravenous Leiomyomatosis

    African Journals Online (AJOL)

    Hemostasis was well achieved. The tumor weighed 6.7 kg. The postoperative course. Intravenous Leiomyomatosis. Narayanaswamy Mariyappa, Uday Kumar Manikyam1, Dinesh Krishnamurthy2, Preeti K,. Yamini Agarwal, Prakar U. Departments of Obstetrics and Gynaecology, 1Pathology and 2Anaesthesia, Sri Devaraj ...

  6. The use of thrombin in the radiology department.

    LENUS (Irish Health Repository)

    Ward, E

    2009-03-01

    Thrombin is a naturally occurring coagulation protein that converts soluble fibrinogen into insoluble fibrin and plays a vital role in the coagulation cascade and in turn haemostasis. Thrombin also promotes platelet activation. In the last few years, there has been a rapid increase in the use of thrombin by radiologists in a variety of clinical circumstances. It is best known for its use in the treatment of pseudoaneurysms following angiography. However, there are now a variety of cases in the literature describing the treatment of traumatic, inflammatory and infected aneurysms with thrombin in a variety of locations within the human body. There have even been recent reports describing the use of thrombin in conventional aneurysms as well as ruptured aneurysms. Its use has also been described in the treatment of endoleaks (type II) following aneurysm repair. In nearly all of these cases, treatment with thrombin requires imaging guidance. Recently, thrombin has also been used as a topical treatment post-percutaneous intervention to reduce or stop bleeding. Most radiologists have only a limited knowledge of the pharmacodynamics of thrombin, its wide range of utilisation and its limitations. Apart from a few case reports and case series, there is little in the radiological literature encompassing the wide range of applications that thrombin may have in the radiology department. In this review article, we comprehensively describe the role and pathophysiology of thrombin, describing with examples many of its potential uses. Techniques of usage as well as pitfalls and limitations are also described.

  7. Thrombin-Inhibiting Anticoagulant Liposomes: Development and Characterization.

    Science.gov (United States)

    Endreas, Wegderes; Brüßler, Jana; Vornicescu, Doru; Keusgen, Michael; Bakowsky, Udo; Steinmetzer, Torsten

    2016-02-04

    Many peptides and peptidomimetic drugs suffer from rapid clearance in vivo; this can be reduced by increasing their size through oligomerization or covalent conjugation with polymers. As proof of principle, an alternative strategy for drug oligomerization is described, in which peptidomimetic thrombin inhibitors are incorporated into the liposome surface. For this purpose, the inhibitor moieties were covalently coupled to a palmitic acid residue through a short bifunctionalized ethylene glycol spacer. These molecules were directly added to the lipid mixture used for liposome preparation. The obtained liposomes possess strong thrombin inhibitory potency in enzyme kinetic measurements and anticoagulant activity in plasma. Their strong potency and positive ζ potential indicate that large amounts of the benzamidine-derived inhibitors are located on the surface of the liposomes. This concept should be applicable to other drug molecules that suffer from rapid elimination and allow covalent modification with a suitable fatty acid residue. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. THROMBIN GENERATION AND BLEEDING IN HEMOPHILIA A

    Science.gov (United States)

    Brummel-Ziedins, Kathleen E.; Whelihan, Matthew F.; Gissel, Matthew; Mann, Kenneth G.; Rivard, Georges E.

    2012-01-01

    Introduction Hemophilia A displays phenotypic heterogeneity with respect to clinical severity. Aim To determine if tissue factor (TF)-initiated thrombin generation profiles in whole blood in the presence of corn trypsin inhibitor (CTI) are predictive of bleeding risk in hemophilia A. Methods We studied factor(F) VIII deficient individuals (11 mild, 4 moderate and 12 severe) with a well-characterized five-year bleeding history that included hemarthrosis, soft tissue hematoma and annual FVIII concentrate usage. This clinical information was used to generate a bleeding score. The bleeding scores (range 0–32) were separated into three groups (bleeding score groupings: 0, 0 and ≤9.6, >9.6), with the higher bleeding tendency having a higher score. Whole blood collected by phlebotomy and contact pathway suppressed by 100μg/mL CTI was stimulated to react by the addition of 5pM TF. Reactions were quenched at 20min by inhibitors. Thrombin generation, determined by ELISA for thrombin – antithrombin was evaluated in terms of clot time (CT), maximum level (MaxL) and maximum rate (MaxR) and compared to the bleeding score. Results Data are shown as the mean±SD. MaxL was significantly different (phemophilia A. PMID:19563500

  9. Reproducibility, stability, and biological variability of thrombin generation using calibrated automated thrombography in healthy dogs.

    Science.gov (United States)

    Cuq, Benoît; Blois, Shauna L; Wood, R Darren; Monteith, Gabrielle; Abrams-Ogg, Anthony C; Bédard, Christian; Wood, Geoffrey A

    2018-03-26

    Thrombin plays a central role in hemostasis and thrombosis. Calibrated automated thrombography (CAT), a thrombin generation assay, may be a useful test for hemostatic disorders in dogs. To describe CAT results in a group of healthy dogs, and assess preanalytical variables and biological variability. Forty healthy dogs were enrolled. Lag time (Lag), time to peak (ttpeak), peak thrombin generation (peak), and endogenous thrombin potential (ETP) were measured. Direct jugular venipuncture and winged-needle catheter-assisted saphenous venipuncture were used to collect samples from each dog, and results were compared between methods. Sample stability at -80°C was assessed over 12 months in a subset of samples. Biological variability of CAT was assessed via nested ANOVA using samples obtained weekly from a subset of 9 dogs for 4 consecutive weeks. Samples for CAT were stable at -80°C over 12 months of storage. Samples collected via winged-needle catheter venipuncture showed poor repeatability compared to direct venipuncture samples; there was also poor agreement between the 2 sampling methods. Intra-individual variability of CAT parameters was below 25%; inter-individual variability ranged from 36.9% to 78.5%. Measurement of thrombin generation using CAT appears to be repeatable in healthy dogs, and samples are stable for at least 12 months when stored at -80°C. Direct venipuncture sampling is recommended for CAT. Low indices of individuality suggest that subject-based reference intervals are more suitable when interpreting CAT results. © 2018 American Society for Veterinary Clinical Pathology.

  10. Topical thrombin preparations and their use in cardiac surgery

    Directory of Open Access Journals (Sweden)

    Brianne L Dunn

    2009-10-01

    Full Text Available Brianne L Dunn1, Walter E Uber1, John S Ikonomidis21Department of Pharmacy Services and 2Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, South Carolina, USAAbstract: Coagulopathic bleeding may lead to increased morbidity and mortality after cardiac surgery. Topical bovine thrombin has been used to promote hemostasis after surgical procedures for over 60 years and is used frequently as a topical hemostatic agent in cardiac surgery. Recently, use of bovine thrombin has been reported to be associated with increased risk for anaphylaxis, thrombosis, and immune-mediated coagulopathy thought secondary to the production of antifactor V and antithrombin antibodies. In patients who develop bovine thrombin-induced immune-mediated coagulopathy, clinical manifestations may range from asymptomatic alterations in coagulation tests to severe hemorrhage and death. Patients undergoing cardiac surgical procedures may be at increased risk for development of antibodies to bovine thrombin products and associated complications. This adverse immunologic profile has led to the development of alternative preparations including a human and a recombinant thrombin which have been shown to be equally efficacious to bovine thrombin and have reduced antigenicity. However, the potential benefit associated with reduced antigenicity is not truly known secondary to the lack of long-term experience with these products. Given the potentially higher margin of safety and less stringent storage concerns compared to human thrombin, recombinant thrombin may be the most reasonable approach in cardiac surgery.Keywords: bovine thrombin, human thrombin, recombinant thrombin, immune-mediated coagulopathy, topical hemostatic agents, thrombin 

  11. Human Thrombin Injection for the Percutaneous Treatment of Iatrogenic Pseudoaneurysms

    International Nuclear Information System (INIS)

    Elford, Julian; Burrell, Christopher; Freeman, Simon; Roobottom, Carl

    2002-01-01

    Purpose: Thrombin injection is becoming well established for the percutaneous management of iatrogenic pseudoaneurysms. All the published series to date use bovine thrombin,and there have been reports of adverse immunologic effects following its use. Our study aimed to assess the efficacy of human thrombin injection for pseudoaneurysm occlusion. Methods:Fourteen patients with iatrogenic pseudoaneurysms underwent a color Doppler ultrasound examination to assess their suitability for percutaneous human thrombin injection. Human thrombin 1000 IU was then injected into the pseudoaneurysm sac under sterile conditions and with ultrasound guidance. A further color Doppler ultrasound examination was performed 24 hr later to confirm occlusion. Results: All 14 pseudoaneurysms were successfully occluded by human thrombin injection. In two cases a second injection of thrombin was required,but there were no other complications, and all pseudoaneurysms remained occluded at 24 hr. Conclusion: Ultrasound-guided human thrombin injection is simple to perform, effective and safe. We recommend that human thrombin becomes the agent of choice for percutaneous injection into iatrogenic pseudoaneurysms

  12. Ex vivo reversal of effects of rivaroxaban evaluated using thromboelastometry and thrombin generation assay

    Science.gov (United States)

    Schenk, B.; Würtinger, P.; Streif, W.; Sturm, W.; Fries, D.; Bachler, M.

    2016-01-01

    Background In major bleeding events, the new direct oral anticoagulants pose a great challenge for physicians. The aim of the study was to test for ex vivo reversal of the direct oral anticoagulant rivaroxaban with various non-specific reversal agents: prothrombin complex concentrate (PCC), activated prothrombin complex concentrate (aPCC), recombinant activated factor VII (rFVIIa), and fibrinogen concentrate (FI). Methods Blood was obtained from healthy volunteers and from patients treated with rivaroxaban. Blood samples from healthy volunteers were spiked with rivaroxaban to test the correlation between rivaroxaban concentration and coagulation tests. Patient blood samples were spiked with various concentrations of the above-mentioned agents and analysed using thromboelastometry and thrombin generation. Results When added in vitro, rivaroxaban was significantly (P<0.05) correlated with ROTEM® thromboelastometry EXTEM (extrinsic coagulation pathway) clotting time (CT), time to maximal velocity (MaxV−t), and with all measured thrombin generation parameters. In vivo, CT, MaxV−t, lag time, and peak thrombin generation (Cmax) were significantly correlated with rivaroxaban concentrations. Regarding reversal of rivaroxaban, all tested agents significantly (P<0.05) reduced EXTEM CT, but to different extents: rFVIIa by 68%, aPCC by 47%, PCC by 17%, and FI by 9%. Only rFVIIa reversed EXTEM CT to baseline values. Both PCC (+102%) and aPCC (+232%) altered overall thrombin generation (area under the curve) and increased Cmax (+461% for PCC, +87.5% for aPCC). Conclusions Thromboelastometry and thrombin generation assays do not favour the same reversal agents for rivaroxaban anticoagulation. Controlled clinical trials are urgently needed to establish doses and clinical efficacy of potential reversal agents. Clinical trial registration EudracCT trial no. 213-00474-30. PMID:27623677

  13. Thrombin-receptor antagonist vorapaxar in acute coronary syndromes

    DEFF Research Database (Denmark)

    Tricoci, Pierluigi; Huang, Zhen; Held, Claes

    2012-01-01

    Vorapaxar is a new oral protease-activated-receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation.......Vorapaxar is a new oral protease-activated-receptor 1 (PAR-1) antagonist that inhibits thrombin-induced platelet activation....

  14. Hypersensitivity to thrombin of platelets from hypercholesterolemic rats

    International Nuclear Information System (INIS)

    Winocour, P.D.; Rand, M.L.; Kinlough-Rathbone, R.L.; Mustard, J.F.

    1986-01-01

    Hypersensitivity of platelets to thrombin has been associated with hypercholesterolemia. The authors have examined the mechanisms involved in this hypersensitivity. Rats were given diets rich in milk fat and containing added cholesterol and taurocholate to produce hypercholesterolemia (HC) (262 +/- 25 mg%) or added sitosterol as a normocholesterolemic control (NC) (89 +/- 6 mg%). Washed platelets were prelabelled with 14 C-serotonin. In the presence of acetylsalicyclic acid (ASA) (to inhibit thromboxane A 2 (TXA 2 ) formation) and creatine phosphate/creatine phosphokinase (CP/CPK) (to remove released ADP), HC platelets aggregated more (26 +/- 1%) and released more 14 C (9.1 +/- 2.0%) than NC platelets (aggregation: 0%, p 14 C release: 1.5 +/- 0.5%, p 2 formation is involved in the hypersensitivity of HC platelets to thrombin. Total binding of 125 I-thrombin to HC platelets was less than that to NC platelets but HC platelets were smaller and had less protein than NC platelets; the thrombin binding per mg platelet protein was the same for HC and NC platelets, indicating that hypersensitivity to thrombin of HC platelets does not result from increased thrombin binding. Thus, hypersensitivity of HC platelets to thrombin is not due to TXA 2 formation, the action of released ADP or increased thrombin binding

  15. Acidosis, magnesium and acetylsalicylic acid: Effects on thrombin

    Science.gov (United States)

    Borisevich, Nikolaj; Loznikova, Svetlana; Sukhodola, Aleksandr; Halets, Inessa; Bryszewska, Maria; Shcharbin, Dzmitry

    2013-03-01

    Thrombin, an enzyme from the hydrolase family, is the main component of the blood coagulation system. In ischemic stroke it acts as a serine protease that converts soluble fibrinogen into insoluble strands of fibrin forming blood clots in the brain. It has been found to phosphoresce at room temperature in the millisecond and microsecond ranges. The phosphorescence of thrombin was studied under physiological conditions, in acidosis (decrease of pH from 8.0 to 5.0) and on the addition of salts (magnesium sulfate and sodium chloride) and of acetylsalicylic acid, and its connection with thrombin function is discussed. Acidosis significantly increased the internal dynamics of thrombin. We propose that lactate-acidosis plays a protective role in stroke, preventing the formation of clots. The addition of NaCl and MgSO4 in different concentrations increased the internal dynamics of thrombin. Also, the addition of MgSO4 decreased thrombin-induced platelet aggregation. However, magnesium sulfate and acetylsalicylic acid in the therapeutic concentrations used for treatment of ischemic stroke had no effect on thrombin internal dynamics. The data obtained will help to elucidate the conformational stability of thrombin under conditions modulating lactate-acidosis and in the presence of magnesium sulfate.

  16. Computed tomography intravenous cholangiography

    International Nuclear Information System (INIS)

    Nascimento, S.; Murray, W.; Wilson, P.

    1997-01-01

    Indications for direct visualization of the bile ducts include bile duct dilatation demonstrated by ultrasound or computed tomography (CT) scanning, where the cause of the bile duct dilatation is uncertain or where the anatomy of bile duct obstruction needs further clarification. Another indication is right upper quadrant pain, particularly in a post-cholecystectomy patient, where choledocholithiasis is suspected. A possible new indication is pre-operative evaluation prior to laparoscopic cholecystectomy. The bile ducts are usually studied by endoscopic retrograde cholangiopancreatography (ERCP), or, less commonly, trans-hepatic cholangiography. The old technique of intravenous cholangiography has fallen into disrepute because of inconsistent bile-duct opacification. The advent of spiral CT scanning has renewed interest in intravenous cholangiography. The CT technique is very sensitive to the contrast agent in the bile ducts, and angiographic and three-dimensional reconstructions of the biliary tree can readily be obtained using the CT intravenous cholangiogram technique (CT IVC). Seven patients have been studied using this CT IVC technique, between February 1995 and June 1996, and are the subject of the present report. Eight further studies have since been performed. The results suggest that CT IVC could replace ERCP as the primary means of direct cholangiography, where pancreatic duct visualization is not required. (authors)

  17. Computed tomography intravenous cholangiography

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, S.; Murray, W.; Wilson, P. [Pittwater Radiology, Dee Why, NSW, (Australia)

    1997-08-01

    Indications for direct visualization of the bile ducts include bile duct dilatation demonstrated by ultrasound or computed tomography (CT) scanning, where the cause of the bile duct dilatation is uncertain or where the anatomy of bile duct obstruction needs further clarification. Another indication is right upper quadrant pain, particularly in a post-cholecystectomy patient, where choledocholithiasis is suspected. A possible new indication is pre-operative evaluation prior to laparoscopic cholecystectomy. The bile ducts are usually studied by endoscopic retrograde cholangiopancreatography (ERCP), or, less commonly, trans-hepatic cholangiography. The old technique of intravenous cholangiography has fallen into disrepute because of inconsistent bile-duct opacification. The advent of spiral CT scanning has renewed interest in intravenous cholangiography. The CT technique is very sensitive to the contrast agent in the bile ducts, and angiographic and three-dimensional reconstructions of the biliary tree can readily be obtained using the CT intravenous cholangiogram technique (CT IVC). Seven patients have been studied using this CT IVC technique, between February 1995 and June 1996, and are the subject of the present report. Eight further studies have since been performed. The results suggest that CT IVC could replace ERCP as the primary means of direct cholangiography, where pancreatic duct visualization is not required. (authors). 11 refs., 6 figs.

  18. APTAMER-BASED SERRS SENSOR FOR THROMBIN DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H; Baker, B R; Wachsmann-Hogiu, S; Pagba, C V; Laurence, T A; Lane, S M; Lee, L P; Tok, J B

    2008-07-02

    We describe an aptamer-based Surface Enhanced Resonance Raman Scattering (SERRS) sensor with high sensitivity, specificity, and stability for the detection of a coagulation protein, human a-thrombin. The sensor achieves high sensitivity and a limit of detection of 100 pM by monitoring the SERRS signal change upon the single step of thrombin binding to immobilized thrombin binding aptamer. The selectivity of the sensor is demonstrated by the specific discrimination of thrombin from other protein analytes. The specific recognition and binding of thrombin by the thrombin binding aptamer is essential to the mechanism of the aptamer-based sensor, as shown through measurements using negative control oligonucleotides. In addition, the sensor can detect 1 nM thrombin in the presence of complex biofluids, such as 10% fetal calf serum, demonstrating that the immobilized, 5{prime}-capped, 3{prime}-capped aptamer is sufficiently robust for clinical diagnostic applications. Furthermore, the proposed sensor may be implemented for multiplexed detection using different aptamer-Raman probe complexes.

  19. Label-free aptamer biosensor for selective detection of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Na, Weidan; Liu, Xiaotong; Wang, Lei; Su, Xingguang, E-mail: suxg@jlu.edu.cn

    2015-10-29

    We fabricated a novel fluorescence biosensor for the selective detection of thrombin by using bovine serum albumin-capped CdS quantum dots (BSA-CdS QDs). Two kinds of designed DNA (DNA1 and DNA2) could bind to CdS QDs through the electrostatic interaction between DNA and Cd{sup 2+} on the surface of CdS QDs. The obtained DNA/BSA-CdS QDs kept stable in the solution with the fluorescence intensity obviously enhanced. Hairpin structure of DNA1contained two domains, one is the aptamer sequence of thrombin and the other is the complementary sequence of DNA2. When thrombin was added, it would bind to DNA1 and induce the hairpin structure of DNA1 changed into G-quadplex structure. Meanwhile, DNA2 would transfer from the surface of CdS QDs to DNA1 via hybridization, which resulted in the removal of DNA1 and DNA2 from the surface of CdS QDs, and led to the fluorescence intensity of CdS QDs reduced. Thus, the determination of thrombin could be achieved by monitoring the change of the fluorescence intensity of CdS QDs. The present method is simple and fast, and exhibits good selectivity for thrombin over other proteins. We have successfully detected thrombin in human serum samples with satisfactory results. - Highlights: • A novel strategy for the detection of thrombin was established based on BSA-CdS QDs. • DNA could serve as the co-ligands to stabilize CdS QDs and enhance the fluorescence intensity. • Thrombin could change the structure of DNA1 and quench the fluorescence of CdS QDs. • Thrombin in real sample was detected with satisfactory results.

  20. [Human thrombin: enzymatic properties, stability and standardization of preparation].

    Science.gov (United States)

    Kolodzeĭskaia, M V; Chernyshenko, T M

    2002-01-01

    The work deals with estimation of thrombin preparation having such features as: sedimentation activity 3000-3200 NIH un. per 1 mg of protein and 97% of active centres. The enzyme isolated has been estimated according to the amidolytic activity on synthetic substrates S-2160 and BAPNA being equal 5200 and 185 milli un/mg of protein, respectively. According to the electrophoresis in PAAG in the presence of Ds-Na the preparation is homogenous, its molecular mass is 36000. The fibrinogen sedimentation time dependence on the isolated thrombin concentration has been estimated as well as the comparative analysis with the thrombin of the firm "Sigma" with the previously calibrated activity using the international standartion (coded P4) has been conducted. The absence of proportionality between the substrate sedimentation time and the preparation concentration has been determined. It has been revealed, that if the experimental findings are presented in the units 1/t against the thrombin units NIH the right lines are received within the limits used. The defreezing and secondary freezing of the preparation preserved under -20 degrees C have been showed as rendering an essential effect on thrombin activity. In order of the enzyme stabilizing at preserving the thrombin isolated has been concentrated applying the amycon membranes (MWCo: 30,000). While applying the thrombin water-saline solution in the conditions selected the preparation has showed itself practically stable during a year without utilizing any admixtures. The essential effect on thrombin has been found from the side of 1% glycin, 0.5% PEG, 1% saccharose and so on. The thrombin isolated high functional homogeneity, its stability permit to recommend the preparation as an operative standard.

  1. Purification and Characterization of Human Thrombin Activatable Fibrinolysis Inhibitor (TAFI)

    DEFF Research Database (Denmark)

    Christensen, Trine; Skottrup, Peter Durand; Valnickova, Zuzana

    Thrombin Activatable Fibrinolysis inhibitor (TAFI) is a basic carboxypeptidase, circulating in plasma as an enzymatic inactive precursor. TAFI shares ~40% overall sequence identity with pancreas Carboxypeptidase B (PCPB) with the activation peptide being less conserved. Following activation of TA...

  2. Thrombin Generating Capacity and Phenotypic Association in ABO Blood Groups.

    Science.gov (United States)

    Kremers, Romy M W; Mohamed, Abdulrahman B O; Pelkmans, Leonie; Hindawi, Salwa; Hemker, H Coenraad; de Laat, H Bas; Huskens, Dana; Al Dieri, Raed

    2015-01-01

    Individuals with blood group O have a higher bleeding risk than non-O blood groups. This could be explained by the lower levels of FVIII and von Willebrand Factor (VWF) levels in O individuals. We investigated the relationship between blood groups, thrombin generation (TG), prothrombin activation and thrombin inactivation. Plasma levels of VWF, FVIII, antithrombin, fibrinogen, prothrombin and α2Macroglobulin (α2M) levels were determined. TG was measured in platelet rich (PRP) and platelet poor plasma (PPP) of 217 healthy donors and prothrombin conversion and thrombin inactivation were calculated. VWF and FVIII levels were lower (75% and 78%) and α2M levels were higher (125%) in the O group. TG is 10% lower in the O group in PPP and PRP. Less prothrombin was converted in the O group (86%) and the thrombin decay capacity was lower as well. In the O group, α2M plays a significantly larger role in the inhibition of thrombin (126%). In conclusion, TG is lower in the O group due to lower prothrombin conversion, and a larger contribution of α2M to thrombin inactivation. The former is unrelated to platelet function because it is similar in PRP and PPP, but can be explained by the lower levels of FVIII.

  3. [Management of major bleeding complications and emergency surgery in patients on long-term treatment with direct oral anticoagulants, thrombin or factor-Xa inhibitors. Proposals of the Working Group on Perioperative Haemostasis (GIHP) - March 2013].

    Science.gov (United States)

    Pernod, G; Albaladejo, P; Godier, A; Samama, C M; Susen, S; Gruel, Y; Blais, N; Fontana, P; Cohen, A; Llau, J V; Rosencher, N; Schved, J F; de Maistre, E; Samama, M M; Mismetti, P; Sié, P

    2013-10-01

    New direct oral anticoagulants (NOAC), inhibitors of factor IIa or Xa, are expected to be widely used for the treatment of venous thromboembolic disease, or in case of atrial fibrillation. Such anticoagulant treatments are known to be associated with haemorrhagic complications. Moreover, it is likely that such patients on long-term treatment with NOAC will be exposed to emergency surgery or invasive procedures. Due to the present lack of experience in such conditions, we cannot make recommendations, but only propose management for optimal safety as regards the risk of bleeding in such emergency conditions. In this article, only dabigatran and rivaroxaban were discussed. For emergency surgery at risk of bleeding, we propose to dose the plasmatic concentration of drug. Levels inferior or equal to 30ng/mL for both dabigatran and rivaroxaban, should enable the realization of a high bleeding risk surgery. For higher concentration, it was proposed to postpone surgery by monitoring the evolution of the drug concentration. Action is then defined by the kind of NOAC and its concentration. If the dosage of the drug is not immediately available, proposals only based on the usual tests, PT and aPTT, also are presented. However, these tests do not really assess drug concentration or bleeding risk. In case of severe haemorrhage in a critical organ, it is proposed to reduce the effect of anticoagulant therapy using a nonspecific procoagulant drug (activated prothrombin concentrate, FEIBA, 30-50U/kg, or non-activated 4-factors prothrombin concentrates 50U/kg). For any other type of severe haemorrhage, the administration of such a procoagulant drug, potentially thrombogenic in these patients, will be discussed regarding concentration of NACO and possibilities for mechanical haemostasis. Copyright © 2013 Société française d’anesthésie et de réanimation (Sfar). Published by Elsevier SAS. All rights reserved.

  4. Thrombin generation in abdominal sepsis is Rho-kinase-dependent.

    Science.gov (United States)

    Wang, Yongzhi; Braun, Oscar Ö; Zhang, Su; Norström, Eva; Thorlacius, Henrik

    2015-05-08

    Sepsis causes severe derangements of the coagulation system. However, the signaling mechanisms regulating sepsis-induced thrombin generation remain elusive. Herein, we hypothesized that Rho-kinase might be an important regulator of thrombin generation in abdominal sepsis. Abdominal sepsis was induced by cecal ligation and puncture (CLP) in C57Bl/6 mice. Thrombin generation, coagulation factors, lung histology and myeloperoxidase (MPO) activity were determined 6 h and 24 h after induction of CLP. Induction of CLP triggered a systemic inflammatory response characterized by neutrophil accumulation and tissue injury in the lung as well as thrombocytopenia and leukocytopenia. Administration of Y-27632, a Rho-kinase inhibitor, attenuated these markers of systemic inflammation in CLP animals. Moreover, peak thrombin formation was decreased by 77% and 81% in plasma from mice 6 h and 24 h after induction of CLP. Total thrombin generation was reduced by 64% and 67% 6 h and 24 h after CLP induction, respectively. Notably, administration of Y-27632 increased peak formation by 99% and total thrombin generation by 66% in plasma from septic animals. In addition, CLP markedly decreased plasma levels of prothrombin, factor V and factor X at 6 h and 24 h. Interestingly, Rho-kinase inhibition significantly enhanced levels of prothrombin, factor V and factor X in plasma from septic mice. In addition, inhibition of Rho-kinase decreased CLP-induced elevations of CXCL2 by 36% and interleukin-6 by 38%. These novel findings suggest that sepsis-induced thrombin generation is regulated by Rho-kinase. Moreover, inhibition of Rho-kinase reverses sepsis-evoked consumption of coagulation factors. Thus, our results show that targeting Rho-kinase signaling might protect against coagulation dysfunction in abdominal sepsis. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. A Novel Photoelectrochemical Biosensor for Tyrosinase and Thrombin Detection

    Science.gov (United States)

    Chen, Jiexia; Liu, Yifan; Zhao, Guang-Chao

    2016-01-01

    A novel photoelectrochemical biosensor for step-by-step assay of tyrosinase and thrombin was fabricated based on the specific interactions between the designed peptide and the target enzymes. A peptide chain with a special sequence which contains a positively charged lysine-labeled terminal, tyrosine at the other end and a cleavage site recognized by thrombin between them was designed. The designed peptide can be fixed on surface of the CdTe quantum dots (QDs)-modified indium-tin oxide (ITO) electrode through electrostatic attraction to construct the photoelectrochemical biosensor. The tyrosinase target can catalyze the oxidization of tyrosine by oxygen into ortho-benzoquinone residues, which results in a decrease in the sensor photocurrent. Subsequently, the cleavage site could be recognized and cut off by another thrombin target, restoring the sensor photocurrent. The decrease or increase of photocurrent in the sensor enables us to assay tyrosinase and thrombin. Thus, the detection of tyrosinase and thrombin can be achieved in the linear range from 2.6 to 32 μg/mL and from 4.5 to 100 μg/mL with detection limits of 1.5 μg/mL and 1.9 μg/mL, respectively. Most importantly, this strategy shall allow us to detect different classes of enzymes simultaneously by designing various enzyme-specific peptide substrates. PMID:26805846

  6. Exploring potential anticoagulant drug formulations using thrombin generation test

    Directory of Open Access Journals (Sweden)

    Elena Zavyalova

    2016-03-01

    The thrombin generation test was used to assess the whole coagulation cascade in normal and factor-deficient human blood plasma. Potential therapeutic windows were estimated for coagulation factors, ranking them as targets for anticoagulant drugs. Thrombin and factor Xa have been revealed as the most promising targets, which fully agrees with the current drug development strategy. Inhibitors of factors Va and VIIa are expected to have narrow therapeutic windows. Inhibitors of factors VIIIa and IXa are expected to have a moderate anticoagulant effect. Factors XI and XII are poor targets for anticoagulant drugs. Compared with plasma that is deficient in factor II, the thrombin inhibitors bivalirudin and aptamer HD1 had increased activity. Both inhibitors were tested in deficient plasma providing a model of potential drug combination. The most promising combinations were anti-thrombin with anti-V/Va and also anti-thrombin with anti-IX/IXa. Each combination had an incremental dose-effect dependence that is promising from the standpoint of the therapeutic window.

  7. A Novel Photoelectrochemical Biosensor for Tyrosinase and Thrombin Detection

    Directory of Open Access Journals (Sweden)

    Jiexia Chen

    2016-01-01

    Full Text Available A novel photoelectrochemical biosensor for step-by-step assay of tyrosinase and thrombin was fabricated based on the specific interactions between the designed peptide and the target enzymes. A peptide chain with a special sequence which contains a positively charged lysine-labeled terminal, tyrosine at the other end and a cleavage site recognized by thrombin between them was designed. The designed peptide can be fixed on surface of the CdTe quantum dots (QDs-modified indium-tin oxide (ITO electrode through electrostatic attraction to construct the photoelectrochemical biosensor. The tyrosinase target can catalyze the oxidization of tyrosine by oxygen into ortho-benzoquinone residues, which results in a decrease in the sensor photocurrent. Subsequently, the cleavage site could be recognized and cut off by another thrombin target, restoring the sensor photocurrent. The decrease or increase of photocurrent in the sensor enables us to assay tyrosinase and thrombin. Thus, the detection of tyrosinase and thrombin can be achieved in the linear range from 2.6 to 32 μg/mL and from 4.5 to 100 μg/mL with detection limits of 1.5 μg/mL and 1.9 μg/mL, respectively. Most importantly, this strategy shall allow us to detect different classes of enzymes simultaneously by designing various enzyme-specific peptide substrates.

  8. Implication of Free Fatty Acids in Thrombin Generation and Fibrinolysis in Vascular Inflammation in Zucker Rats and Evolution with Aging

    Directory of Open Access Journals (Sweden)

    Jérémy Lagrange

    2017-11-01

    Full Text Available Background: The metabolic syndrome (MetS and aging are associated with modifications in blood coagulation factors, vascular inflammation, and increased risk of thrombosis.Objectives: Our aim was to determine concomitant changes in thrombin generation in the blood compartment and at the surface of vascular smooth muscle cells (VSMCs and its interplay with adipokines, free fatty acids (FFA, and metalloproteinases (MMPs in obese Zucker rats that share features of the human MetS.Methods: Obese and age-matched lean Zucker rats were compared at 25 and 80 weeks of age. Thrombin generation was assessed by calibrated automated thrombography (CAT.Results: Endogenous thrombin potential (ETP was increased in obese rats independent of platelets and age. Clot half-lysis time was delayed with obesity and age. Interleukin (IL-1β and IL-13 were increased with obesity and age respectively. Addition of exogenous fibrinogen, leptin, linoleic, or palmitic acid increased thrombin generation in plasma whereas adiponectin had an opposite effect. ETP was increased at the surface of VSMCs from obese rats and addition of exogenous palmitic acid further enhanced ETP values. Gelatinase activity was increased in aorta at both ages in obese rats and MMP-2 activity was increased in VSMCs from obese rats.Conclusions: Our study demonstrated in MetS an early prothrombotic phenotype of the blood compartment reinforced by procoagulant properties of dedifferentiated and inflammatory VSMCs. Mechanisms involved (1 increased fibrinogen and impaired fibrinolysis and (2 increased saturated fatty acids responsible for additive procoagulant effects. Whether specifically targeting this hypercoagulability using direct thrombin inhibitors would improve outcome in MetS is worth investigating.

  9. Horn fly (Diptera: Muscidae) saliva targets thrombin action in hemostasis.

    Science.gov (United States)

    Cupp, M S; Zhang, D; Cupp, E W

    2000-05-01

    The horn fly, Hematobia irritans (L.), is an important pest of livestock because the adult stage of both sexes are aggressive blood-feeders. Remarkably, even though horn fly adults feed recurrently on their hosts as ectoparasites, these flies lack the ADP-responsive antiplatelet aggregation and vasodilatory antihemostatic systems described for other blood-feeding Diptera. Horn fly salivary gland extracts do interfere with the normal coagulation process as demonstrated by the recalcification time assay. Using this as a baseline, the effects of saliva on recalcification time, activated partial thromboplastin time, prothrombin time, and thrombin time were measured to determine which arm(s) of the coagulation cascade might be impacted. Factor-deficient plasma assays also were used to measure possible perturbations in clotting. Gland-free saliva delayed the recalcification time as well as the activated partial thromboplastin time, prothrombin time, and thrombin time. Saliva also further delayed clotting times of plasmas deficient in factor V, factor VIII, and factor XIII, indicating that other factors in the coagulation cascade were inhibited. Although horn fly saliva did not alter the ability of deficient plasma reconstituted with factor X to clot, it did inhibit deficient plasma reconstituted with factor II (thrombin). Antithrombin activity in saliva was confirmed by its ability to interfere with thrombin hydrolysis of fibrinogen, its normal substrate, and by its inhibition of thrombin action on a chromagenic substrate that mimics the hydrolytic site of fibrinogen. Thus, horn fly saliva contains a factor that specifically targets thrombin, a key component in the coagulation cascade. While the biochemical mechanisms of inhibition may vary, this antihemostatic characteristic is shared with other zoophilic Diptera such as black flies, Simulium spp., and tsetse, Glossina morsitans morsitans Westwood, that feed on ungulates.

  10. Activation of human factor V by factor Xa and thrombin

    International Nuclear Information System (INIS)

    Monkovic, D.D.; Tracy, P.B.

    1990-01-01

    The activation of human factor V by factor Xa and thrombin was studied by functional assessment of cofactor activity and sodium dodecyl sulfate-polycarylamide gel electrophoresis followed by either autoradiography of 125 I-labeled factor V activation products or Western blot analyses of unlabeled factor V activation products. Cofactor activity was measured by the ability of the factor V/Va peptides to support the activation of prothrombin. The factor Xa catalyzed cleavage of factor V was observed to be time, phospholipid, and calcium ion dependent, yielding a cofactor with activity equal to that of thrombin-activated factor V (factor Va). The cleavage pattern differed markedly from the one observed in the bovine system. The factor Xa activated factor V subunits expressing cofactor activity were isolated and found to consist of peptides of M r 220,000 and 105,000. Although thrombin cleaved the M r 220,000 peptide to yield peptides previously shown to be products of thrombin activation, cofactor activity did not increase. N-Terminal sequence analysis confirmed that both factor Xa and thrombin cleave factor V at the same bond to generate the M r 220,000 peptide. The factor Xa dependent functional assessment of 125 I-labeled factor V coupled with densitometric analyses of the cleavage products indicated that the cofactor activity of factor Xa activated factor V closely paralleled the appearance of the M r 220,000 peptide. The data indicate that factor Xa is as efficient an enzyme toward factor V as thrombin

  11. Multiple active forms of thrombin. IV. Relative activities of meizothrombins

    International Nuclear Information System (INIS)

    Doyle, M.F.; Mann, K.G.

    1990-01-01

    The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes

  12. Multiple active forms of thrombin. IV. Relative activities of meizothrombins

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, M.F.; Mann, K.G. (Univ. of Vermont College of Medicine, Burlington (USA))

    1990-06-25

    The prothrombin activation intermediates meizothrombin and meizothrombin(desF1) (meizothrombin that has been autoproteolyzed to remove fragment 1) have been obtained in a relatively pure, active form with minimal autolysis, making them suitable for enzymatic characterization. When compared at equimolar concentrations, alpha-thrombin, fragment 1.2+ alpha-thrombin, meizothrombin(desF1), and meizothrombin have approximately 100, 100, 10, and 1% activity, respectively, toward the macromolecular substrates factor V, fibrinogen, and platelets. The difference in activity of these four enzymes cannot be attributed to alterations in the catalytic triad, as all four enzymes have nearly identical catalytic efficiency toward the chromogenic substrate S2238. Further, the ability of meizothrombin and meizothrombin(desF1) to activate protein C was 75% of the activity exhibited by alpha-thrombin or fragment 1.2+ alpha-thrombin. All four enzymes bind to thrombomodulin, as judged by the enhanced rate of protein C activation upon preincubation of the enzymes with thrombomodulin. The extent of rate enhancement varied, with meizothrombin/thrombomodulin exhibiting only 50% of the alpha-thrombin/thrombomodulin rate. This difference in rate is not due to a decreased affinity of the meizothrombin for thrombomodulin since the apparent dissociation constants for the alpha-thrombin-thrombomodulin complex and the meizothrombin-thrombomodulin complex are virtually identical. The difference in the observed rate is due in part to the higher Km for protein C exhibited by the meizothrombin-thrombomodulin complex. Incubation of the thrombomodulin-enzyme complex with phospholipid vesicles caused an increase in the protein C activation rates. The kinetic constants for protein C activation in the presence of phospholipid are virtually identical for these enzyme-thrombomodulin complexes.

  13. Endotoxin, thrombin, and the Limulus amebocyte lysate test.

    Science.gov (United States)

    Yin, E T

    1975-09-01

    The Limulus amebocyte lysate, a proteinaceous composite isolated from the hemolymph cells of the horseshoe crab (Limulus polyphemus) is sensitive to picogram quantities of Gram-negative bacterial lipopolysaccharides. However, a controversy currently exists as to whether the Limulus amebocyte lysate is specifically sensitive to Gram-negative bacterial endotoxins as a result of a recent report that the blood coagulation protease, thrombin, can mimic endotoxins in the Limulus amebocyte lysate test. Experiments including those employing two highly purified fractions isolated from the Limulus lystae have provided us with evidence that thrombin per se is unable to mimic endotoxin.

  14. Aggregation of thrombin-derived C-terminal fragments as a previously undisclosed host defense mechanism

    DEFF Research Database (Denmark)

    Petrlova, Jitka; Hansen, Finja C; van der Plas, Mariena J A

    2017-01-01

    Effective control of endotoxins and bacteria is crucial for normal wound healing. During injury, the key enzyme thrombin is formed, leading to generation of fibrin. Here, we show that human neutrophil elastase cleaves thrombin, generating 11-kDa thrombin-derived C-terminal peptides (TCPs), which ...

  15. Thrombin-induced, TNFR-dependent miR-181c downregulation promotes MLL1 and NF-κB target gene expression in human microglia.

    Science.gov (United States)

    Yin, Min; Chen, Zhiying; Ouyang, Yetong; Zhang, Huiyan; Wan, Zhigang; Wang, Han; Wu, Wei; Yin, Xiaoping

    2017-06-29

    Controlling thrombin-driven microglial activation may serve as a therapeutic target for intracerebral hemorrhage (ICH). Here, we investigated microRNA (miRNA)-based regulation of thrombin-driven microglial activation using an in vitro thrombin toxicity model applied to primary human microglia. A miRNA array identified 22 differential miRNA candidates. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) identified miR-181c as the most significantly downregulated miRNA. TargetScan analysis identified mixed lineage leukemia-1 (MLL1) as a putative gene target for miR-181c. qRT-PCR was applied to assess tumor necrosis factor-alpha (TNF-α), miR-181c, and MLL1 levels following thrombin or proteinase-activated receptor-4-specific activating peptide (PAR4AP) exposure. Anti-TNF-α antibodies and tumor necrosis factor receptor (TNFR) silencing were employed to test TNF-α/TNFR dependence. A dual-luciferase reporter system and miR-181c mimic transfection assessed whether mir-181c directly binds to and negatively regulates MLL1. Nuclear factor kappa-B (NF-κB)-dependent luciferase reporter assays and NF-κB target gene expression were assessed in wild-type (MLL1+) and MLL1-silenced cells. Thrombin or PAR4AP-induced miR-181c downregulation (p < 0.05) and MLL1 upregulation (p < 0.05) that were dependent upon TNF-α/TNFR. miR-181c decreased wild-type MLL1 3'-UTR luciferase reporter activity (p < 0.05), and a miR-181c mimic suppressed MLL1 expression (p < 0.05). Thrombin treatment increased, while miR-181c reduced, NF-κB activity and NF-κB target gene expression in both wild-type (MLL1+) and MLL1-silenced cells (p < 0.05). Thrombin-induced, TNF-α/TNFR-dependent miR-181c downregulation promotes MLL1 expression, increases NF-κB activity, and upregulates NF-κB target gene expression. As miR-181c opposes thrombin's stimulation of pro-inflammatory NF-κB activity, miR-181c mimic therapy may show promise in controlling thrombin

  16. Phage display of the serpin alpha-1 proteinase inhibitor randomized at consecutive residues in the reactive centre loop and biopanned with or without thrombin.

    Directory of Open Access Journals (Sweden)

    Benjamin M Scott

    Full Text Available In spite of the power of phage display technology to identify variant proteins with novel properties in large libraries, it has only been previously applied to one member of the serpin superfamily. Here we describe phage display of human alpha-1 proteinase inhibitor (API in a T7 bacteriophage system. API M358R fused to the C-terminus of T7 capsid protein 10B was directly shown to form denaturation-resistant complexes with thrombin by electrophoresis and immunoblotting following exposure of intact phages to thrombin. We therefore developed a biopanning protocol in which thrombin-reactive phages were selected using biotinylated anti-thrombin antibodies and streptavidin-coated magnetic beads. A library consisting of displayed API randomized at residues 357 and 358 (P2-P1 yielded predominantly Pro-Arg at these positions after five rounds of thrombin selection; in contrast the same degree of mock selection yielded only non-functional variants. A more diverse library of API M358R randomized at residues 352-356 (P7-P3 was also probed, yielding numerous variants fitting a loose consensus of DLTVS as judged by sequencing of the inserts of plaque-purified phages. The thrombin-selected sequences were transferred en masse into bacterial expression plasmids, and lysates from individual colonies were screening for API-thrombin complexing. The most active candidates from this sixth round of screening contained DITMA and AAFVS at P7-P3 and inhibited thrombin 2.1-fold more rapidly than API M358R with no change in reaction stoichiometry. Deep sequencing using the Ion Torrent platform confirmed that over 800 sequences were significantly enriched in the thrombin-panned versus naïve phage display library, including some detected using the combined phage display/bacterial lysate screening approach. Our results show that API joins Plasminogen Activator Inhibitor-1 (PAI-1 as a serpin amenable to phage display and suggest the utility of this approach for the selection

  17. Rigidification of the autolysis loop enhances Na(+) binding to thrombin.

    Science.gov (United States)

    Pozzi, Nicola; Chen, Raymond; Chen, Zhiwei; Bah, Alaji; Di Cera, Enrico

    2011-11-01

    Binding of Na(+) to thrombin ensures high activity toward physiological substrates and optimizes the procoagulant and prothrombotic roles of the enzyme in vivo. Under physiological conditions of pH and temperature, the binding affinity of Na(+) is weak due to large heat capacity and enthalpy changes associated with binding, and the K(d)=80 mM ensures only 64% saturation of the site at the concentration of Na(+) in the blood (140 mM). Residues controlling Na(+) binding and activation have been identified. Yet, attempts to improve the interaction of Na(+) with thrombin and possibly increase catalytic activity under physiological conditions have so far been unsuccessful. Here we report how replacement of the flexible autolysis loop of human thrombin with the homologous rigid domain of the murine enzyme results in a drastic (up to 10-fold) increase in Na(+) affinity and a significant improvement in the catalytic activity of the enzyme. Rigidification of the autolysis loop abolishes the heat capacity change associated with Na(+) binding observed in the wild-type and also increases the stability of thrombin. These findings have general relevance to protein engineering studies of clotting proteases and trypsin-like enzymes. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Rigidification of the autolysis loop enhances Na+ binding to thrombin

    Science.gov (United States)

    Pozzi, Nicola; Chen, Raymond; Chen, Zhiwei; Bah, Alaji; Di Cera, Enrico

    2011-01-01

    Binding of Na+ to thrombin ensures high activity toward physiological substrates and optimizes the procoagulant and prothrombotic roles of the enzyme in vivo. Under physiological conditions of pH and temperature, the binding affinity of Na+ is weak due to large heat capacity and enthalpy changes associated with binding, and the Kd=80 mM ensures only 64% saturation of the site at the concentration of Na+ in the blood (140 mM). Residues controlling Na+ binding and activation have been identified. Yet, attempts to improve the interaction of Na+ with thrombin and possibly increase catalytic activity under physiological conditions have so far been unsuccessful. Here we report how replacement of the flexible autolysis loop of human thrombin with the homologous rigid domain of the murine enzyme results in a drastic (up to 10-fold) increase in Na+ affinity and a significant improvement in the catalytic activity of the enzyme. Rigidification of the autolysis loop abolishes the heat capacity change associated with Na+ binding observed in the wild-type and also increases the stability of thrombin. These findings have general relevance to protein engineering studies of clotting proteases and trypsin-like enzymes. PMID:21536369

  19. Increased thrombin generation in women with polycystic ovary syndrome

    DEFF Research Database (Denmark)

    Glintborg, Dorte; Sidelmann, Johannes Jakobsen; Lambaa Altinok, Magda

    2015-01-01

    Objective. Polycystic ovary syndrome (PCOS) is associated with risk factors for cardiovascular disease (CVD) which may be modified by the use of metformin and oral contraceptives (OC). Thrombin generation (TG) measures are risk markers of CVD and address the composite of multiple factors...

  20. Tyrosine sulfation modulates activity of tick-derived thrombin inhibitors

    Science.gov (United States)

    Thompson, Robert E.; Liu, Xuyu; Ripoll-Rozada, Jorge; Alonso-García, Noelia; Parker, Benjamin L.; Pereira, Pedro José Barbosa; Payne, Richard J.

    2017-09-01

    Madanin-1 and chimadanin are two small cysteine-free thrombin inhibitors that facilitate blood feeding in the tick Haemaphysalis longicornis. Here, we report a post-translational modification—tyrosine sulfation—of these two proteins that is critical for potent anti-thrombotic and anticoagulant activity. Inhibitors produced in baculovirus-infected insect cells displayed heterogeneous sulfation of two tyrosine residues within each of the proteins. One-pot ligation-desulfurization chemistry enabled access to homogeneous samples of all possible sulfated variants of the proteins. Tyrosine sulfation of madanin-1 and chimadanin proved crucial for thrombin inhibitory activity, with the doubly sulfated variants three orders of magnitude more potent than the unmodified inhibitors. The three-dimensional structure of madanin-1 in complex with thrombin revealed a unique mode of inhibition, with the sulfated tyrosine residues binding to the basic exosite II of the protease. The importance of tyrosine sulfation within this family of thrombin inhibitors, together with their unique binding mode, paves the way for the development of anti-thrombotic drug leads based on these privileged scaffolds.

  1. Thrombin induces rapid PAR1-mediated non-classical FGF1 release

    International Nuclear Information System (INIS)

    Duarte, Maria; Kolev, Vihren; Soldi, Raffaella; Kirov, Alexander; Graziani, Irene; Oliveira, Silvia Marta; Kacer, Doreen; Friesel, Robert; Maciag, Thomas; Prudovsky, Igor

    2006-01-01

    Thrombin induces cell proliferation and migration during vascular injury. We report that thrombin rapidly stimulated expression and release of the pro-angiogenic polypeptide fibroblast growth factor 1 (FGF1). Thrombin failed to induce FGF1 release from protease-activated receptor 1 (PAR1) null fibroblasts, indicating that this effect was dependent on PAR1. Similarly to thrombin, FGF1 expression and release were induced by TRAP, a specific oligopeptide agonist of PAR1. These results identify a novel aspect of the crosstalk between FGF and thrombin signaling pathways which both play important roles in tissue repair and angiogenesis

  2. Renal function and plasma dabigatran level measured at trough by diluted thrombin time assay

    Directory of Open Access Journals (Sweden)

    Marta E. Martinuzzo

    2017-02-01

    Full Text Available Dabigatran etexilate (direct thrombin inhibitor is effective in preventing embolic stroke in patients with atrial fibrillation. It does not require laboratory control, but given the high renal elimination, its measurement in plasma is important in renal failure. The objectives of the study were to verify the analytical quality of the diluted thrombin time assay for measurement of dabigatran plasma concentration (cc, correlate cc with classic coagulation assays, prothrombin time (PT and activated partial thromboplastin time (APTT, and evaluate them according to the creatinine clearance (CLCr. Forty plasma samples of patients (34 consecutive and 6 suspected of drug accumulation receiving dabigatran at 150 (n = 19 or 110 (n = 21 mg/12 hours were collected. Blood samples were drawn at 10-14 hours of the last intake. Dabigatran concentration was determined by diluted thrombin time (HemosIl DTI, Instrumentation Laboratory (IL. PT and APTT (IL were performed on two fotooptical coagulometers, ACL TOP 300 and 500 (IL. DTI presented intra-assay coefficient of variation < 5.4% and inter-assay < 6%, linearity range 0-493 ng/ml. Patients' cc: median 83 (4-945 ng/ml. Individuals with CLCr in the lowest tertile (22.6-46.1 ml/min showed significantly higher median cc: 308 (49-945, compared to the average 72 (12-190 and highest tertile, 60 (4-118 ng/ml. Correlation between cc and APTT or PT were moderate, r2 = 0.59 and -0.66, p < 0.0001, respectively. DTI test allowed us to quantify plasma dabigatran levels, both in patients with normal or altered renal function, representing a useful tool in clinical situations such as renal failure, pre surgery or emergencies

  3. Intentional intravenous mercury injection

    African Journals Online (AJOL)

    In this case report, intravenous complications, treatment strategies and possible ... Mercury toxicity is commonly associated with vapour inhalation or oral ingestion, for which there exist definite treatment options. Intravenous mercury ... personality, anxiousness, irritability, insomnia, depression and drowsi- ness.[1] However ...

  4. Isolation and characterization of a serine proteinase with thrombin-like activity from the venom of the snake Bothrops asper

    Directory of Open Access Journals (Sweden)

    A.V Pérez

    2008-01-01

    Full Text Available A serine proteinase with thrombin-like activity was isolated from the venom of the Central American pit viper Bothrops asper. Isolation was performed by a combination of affinity chromatography on aminobenzamidine-Sepharose and ion-exchange chromatography on DEAE-Sepharose. The enzyme accounts for approximately 0.13% of the venom dry weight and has a molecular mass of 32 kDa as determined by SDS-PAGE, and of 27 kDa as determined by MALDI-TOF mass spectrometry. Its partial amino acid sequence shows high identity with snake venom serine proteinases and a complete identity with a cDNA clone previously sequenced from this species. The N-terminal sequence of the enzyme is VIGGDECNINEHRSLVVLFXSSGFL CAGTLVQDEWVLTAANCDSKNFQ. The enzyme induces clotting of plasma (minimum coagulant dose = 4.1 µg and fibrinogen (minimum coagulant dose = 4.2 µg in vitro, and promotes defibrin(ogenation in vivo (minimum defibrin(ogenating dose = 1.0 µg. In addition, when injected intravenously in mice at doses of 5 and 10 µg, it induces a series of behavioral changes, i.e., loss of the righting reflex, opisthotonus, and intermittent rotations over the long axis of the body, which closely resemble the `gyroxin-like' effect induced by other thrombin-like enzymes from snake venoms.

  5. Isolation and characterization of a serine proteinase with thrombin-like activity from the venom of the snake Bothrops asper.

    Science.gov (United States)

    Pérez, A V; Rucavado, A; Sanz, L; Calvete, J J; Gutiérrez, J M

    2008-01-01

    A serine proteinase with thrombin-like activity was isolated from the venom of the Central American pit viper Bothrops asper. Isolation was performed by a combination of affinity chromatography on aminobenzamidine-Sepharose and ion-exchange chromatography on DEAE-Sepharose. The enzyme accounts for approximately 0.13% of the venom dry weight and has a molecular mass of 32 kDa as determined by SDS-PAGE, and of 27 kDa as determined by MALDI-TOF mass spectrometry. Its partial amino acid sequence shows high identity with snake venom serine proteinases and a complete identity with a cDNA clone previously sequenced from this species. The N-terminal sequence of the enzyme is VIGGDECNINEHRSLVVLFXSSGFL CAGTLVQDEWVLTAANCDSKNFQ. The enzyme induces clotting of plasma (minimum coagulant dose = 4.1 microg) and fibrinogen (minimum coagulant dose = 4.2 microg) in vitro, and promotes defibrin(ogen)ation in vivo (minimum defibrin(ogen)ating dose = 1.0 microg). In addition, when injected intravenously in mice at doses of 5 and 10 microg, it induces a series of behavioral changes, i.e., loss of the righting reflex, opisthotonus, and intermittent rotations over the long axis of the body, which closely resemble the ;gyroxin-like' effect induced by other thrombin-like enzymes from snake venoms.

  6. Thrombin generation, ProC(®)Global, prothrombin time and activated partial thromboplastin time in thawed plasma stored for seven days and after methylene blue/light pathogen inactivation.

    Science.gov (United States)

    Thiele, Thomas; Hron, Gregor; Kellner, Sarah; Wasner, Christina; Westphal, Antje; Warkentin, Theodore E; Greinacher, Andreas; Selleng, Kathleen

    2016-01-01

    Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC(®)Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC(®)Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations.

  7. Feedback activation of factor XI by thrombin in plasma results in additional formation of thrombin that protects fibrin clots from fibrinolysis

    NARCIS (Netherlands)

    von dem Borne, P. A.; Meijers, J. C.; Bouma, B. N.

    1995-01-01

    Recently, an alternative pathway for factor XI activation has been described in which factor XI is activated by thrombin. Patients with a factor XI deficiency bleed mostly from tissues with high local fibrinolytic activity. Therefore, the role of thrombin-mediated factor XI activation in both fibrin

  8. Thrombin-activatable fibrinolysis inhibitor is degraded by Salmonella enterica and Yersinia pestis.

    Science.gov (United States)

    Valls Serón, M; Haiko, J; DE Groot, P G; Korhonen, T K; Meijers, J C M

    2010-10-01

     Pathogenic bacteria modulate the host coagulation system to evade immune responses or to facilitate dissemination through extravascular tissues. In particular, the important bacterial pathogens Salmonella enterica and Yersinia pestis intervene with the plasminogen/fibrinolytic system. Thrombin-activatable fibrinolysis inhibitor (TAFI) has anti-fibrinolytic properties as the active enzyme (TAFIa) removes C-terminal lysine residues from fibrin, thereby attenuating accelerated plasmin formation.  Here, we demonstrate inactivation and cleavage of TAFI by homologous surface proteases, the omptins Pla of Y. pestis and PgtE of S. enterica. We show that omptin-expressing bacteria decrease TAFI activatability by thrombin-thrombomodulin and that the anti-fibrinolytic potential of TAFIa was reduced by recombinant Escherichia coli expressing Pla or PgtE. The functional impairment resulted from C-terminal cleavage of TAFI by the omptins.  Our results indicate that TAFI is degraded directly by the omptins PgtE of S. enterica and Pla of Y. pestis. This may contribute to the ability of PgtE and Pla to damage tissue barriers, such as fibrin, and thereby to enhance spread of S. enterica and Y. pestis during infection. © 2010 International Society on Thrombosis and Haemostasis.

  9. Thrombin generation and fibrin clot formation under hypothermic conditions: an in vitro evaluation of tissue factor initiated whole blood coagulation.

    Science.gov (United States)

    Whelihan, Matthew F; Kiankhooy, Armin; Brummel-Ziedins, Kathleen E

    2014-02-01

    Despite trauma-induced hypothermic coagulopathy being familiar in the clinical setting, empirical experimentation concerning this phenomenon is lacking. In this study, we investigated the effects of hypothermia on thrombin generation, clot formation, and global hemostatic functions in an in vitro environment using a whole blood model and thromboelastography, which can recapitulate hypothermia. Blood was collected from healthy individuals through venipuncture and treated with corn trypsin inhibitor, to block the contact pathway. Coagulation was initiated with 5pM tissue factor at temperatures 37°C, 32°C, and 27°C. Reactions were quenched over time, with soluble and insoluble components analyzed for thrombin generation, fibrinogen consumption, factor (f)XIII activation, and fibrin deposition. Global coagulation potential was evaluated through thromboelastography. Data showed that thrombin generation in samples at 37°C and 32°C had comparable rates, whereas 27°C had a much lower rate (39.2 ± 1.1 and 43 ± 2.4 nM/min vs 28.6 ± 4.4 nM/min, respectively). Fibrinogen consumption and fXIII activation were highest at 37°C, followed by 32°C and 27°C. Fibrin formation as seen through clot weights also followed this trend. Thromboelastography data showed that clot formation was fastest in samples at 37°C and lowest at 27°C. Maximum clot strength was similar for each temperature. Also, percent lysis of clots was highest at 37°C followed by 32°C and then 27°C. Induced hypothermic conditions directly affect the rate of thrombin generation and clot formation, whereas global clot stability remains intact. © 2013.

  10. Stabilization of the E* Form Turns Thrombin into an Anticoagulant

    Energy Technology Data Exchange (ETDEWEB)

    Bah, Alaji; Carrell, Christopher J.; Chen, Zhiwei; Gandhi, Prafull S.; Di Cera, Enrico; (WU-MED)

    2009-07-31

    Previous studies have shown that deletion of nine residues in the autolysis loop of thrombin produces a mutant with an anticoagulant propensity of potential clinical relevance, but the molecular origin of the effect has remained unresolved. The x-ray crystal structure of this mutant solved in the free form at 1.55 {angstrom} resolution reveals an inactive conformation that is practically identical (root mean square deviation of 0.154 {angstrom}) to the recently identified E* form. The side chain of Trp215 collapses into the active site by shifting >10 {angstrom} from its position in the active E form, and the oxyanion hole is disrupted by a flip of the Glu192-Gly193 peptide bond. This finding confirms the existence of the inactive form E* in essentially the same incarnation as first identified in the structure of the thrombin mutant D102N. In addition, it demonstrates that the anticoagulant profile often caused by a mutation of the thrombin scaffold finds its likely molecular origin in the stabilization of the inactive E* form that is selectively shifted to the active E form upon thrombomodulin and protein C binding.

  11. Infection-Induced Thrombin Production: A Potential Novel Mechanism for Preterm Premature Rupture of Membranes (PPROM).

    Science.gov (United States)

    Feng, Liping; Allen, Terrence K; Marinello, William P; Murtha, Amy P

    2018-04-13

    Preterm premature rupture of membranes (PPROM) is a leading contributor to maternal and neonatal morbidity and mortality. Epidemiologic and experimental studies have demonstrated that thrombin causes fetal membrane weakening and subsequently PPROM. Although blood is suspected as the likely source of thrombin in fetal membranes and amniotic fluid of patients with PPROM, this has not been proven. Ureaplasma Parvum (U. parvum) is emerging as a pathogen involved in prematurity, including PPROM, but until now, prothrombin production directly induced by bacteria in fetal membranes has not been described. This study was designed to investigate whether U. parvum exposure can induce prothrombin production in fetal membranes cells. Primary fetal membrane cells (amnion epithelial, chorion trophoblast, and decidua stromal) or full-thickness fetal membrane tissue explants from elective, term, uncomplicated cesarean deliveries were harvested. Cells or tissue explants were infected with live U. parvum (1 x 10 5 , 1 x 10 6 , or 1 x 10 7 colony forming units (cfu)/ml) or lipopolysaccharide (Escherichia coli J5, L-5014, Sigma, 100 ng/ml or 1000 ng/ml) for 24 hours. Tissue explants were fixed for immunohistochemistry staining of thrombin/prothrombin. Fetal membrane cells were fixed for confocal immunofluorescent staining of the biomarkers of fetal membrane cell types and thrombin/prothrombin. Protein and mRNA were harvested from the cells and tissue explants for Western blot or qRT-PCR to quantify thrombin/prothrombin protein or mRNA production, respectively. Data are presented as mean values ± standard errors of mean. Data were analyzed using one-way ANOVA with post hoc Dunnett's test. Prothrombin production and localization was confirmed by Western blot and immunostainings in all primary fetal membrane cells and tissue explants. Immunofluorescence observations revealed a perinuclear localization of prothrombin in amnion epithelial cells. Localization of prothrombin in chorion and

  12. Thrombin preferentially induces autophagy in glia cells in the rat central nervous system.

    Science.gov (United States)

    Hu, Shukun; Wu, Gang; Ding, Xin; Zhang, Yi

    2016-09-06

    Autophagy widely occurs after intracerebral hemorrhage (ICH). In our previous study, we demonstrated that thrombin, a serine protease produced after hematoma, contributes to ICH-induced autophagy. However, whether thrombin plays a neuronal and/or astrocytic role in autophagy induction is largely unknown. Here, we examined the autophagic role of thrombin on neurons and glia cells, respectively. In vivo, we found that intracaudate injection of thrombin specifically elevated the astrocytic expression of beclin-1 and LC3, two autophagic markers, and promoted the formation of autophagic vacuoles within astrocytes rather than neurons in the ipsilateral basal ganglia. Consistent with this, thrombin enhanced the LC3-II level and increased the number of MDC-labeled autophagic vacuoles in cultured astrocytes. These results indicated that thrombin preferentially activated astrocytic autophagy after ICH, and therefore provided novel insights into the pathophysiological mechanisms and therapeutic targets for hemorrhage stroke and brain trauma. Copyright © 2016. Published by Elsevier Ireland Ltd.

  13. Analysis of blood coagulation in mice: pre-analytical conditions and evaluation of a home-made assay for thrombin-antithrombin complexes

    Directory of Open Access Journals (Sweden)

    Meijers Joost CM

    2005-08-01

    Full Text Available Abstract Background The use of mouse models for the study of thrombotic disorders has gained increasing importance. Methods for measurement of coagulation activation in mice are, however, scarce. The primary aim of this study was to develop a specific mouse thrombin-antithrombin (TAT ELISA for measurement of coagulation activation and to compare it with two commercially available assays for human TAT complexes. In addition, we aimed to improve methods for mouse plasma anticoagulation and preparation. Methods and results First, for the measurement of TAT-complexes in plasma a mouse specific TAT-ELISA was developed using rabbit polyclonal antibodies raised against mouse thrombin and rat antithrombin, respectively. This ELISA detected an increase in TAT levels in a mouse model of endotoxemia. Two commercial human TAT ELISAs appeared to be less specific for mouse thrombin-rat antithrombin complexes. Second, to prevent clotting of mouse blood sodium citrate was either mixed with blood during collection in a syringe or was injected intravenously immediately prior to blood collection. Intravenous sodium citrate completely inhibited blood coagulation resulting in plasma with consistently low TAT levels. Sodium citrate mixed with blood during collection resulted in increased TAT levels in 4 out of 16 plasma samples. Third, heparinase was added to plasma samples after in vivo injection of different heparin doses to test its neutralizing effect. Heparinase neutralized up to a 20 U of heparin/mouse and resulted in accurate APTT and factor VIII determinations. Conclusion These procedures and reagents for plasma preparation and coagulation testing will improve studies on thrombotic disorders in mice.

  14. Thrombin Maybe Plays an Important Role in MK Differentiation into Platelets

    Directory of Open Access Journals (Sweden)

    Xiao-Lei Yang

    2016-01-01

    Full Text Available Objectives. After development and differentiation, megakaryocytes (MKs can produce platelets. As is well known, thrombopoietin (TPO can induce MKs to differentiate. The effect of thrombin on MKs differentiation is not clear. In this study, we used a human megakaryoblastic leukemia cell line (Meg-01 to assess the effect of thrombin on MKs differentiation. Methods. In order to interrogate the role of thrombin in Meg-01 cells differentiation, the changes of morphology, cellular function, and expression of diverse factors were analyzed. Results. The results show that thrombin suppresses Meg-01 cells proliferation and induces apoptosis and cell cycle arrest. Thrombin upregulates the expression of CD41b, which is one of the most important MK markers. Globin transcription factor 1 (GATA-1, an important transcriptional regulator, controls MK development and maturation. The expression of GATA-1 is also upregulated by thrombin in Meg-01 cells. The expression of B-cell lymphoma 2 (Bcl-2, an apoptosis-inhibitory protein, is downregulated by thrombin. Phosphorylated protein kinase B (p-AKT and phosphorylated extracellular signal-regulated kinase (p-ERK were upregulated by thrombin in Meg-01 cells. All the results are consistent with Meg-01 cells treated with TPO. Discussion and Conclusion. In conclusion, all these data indicate that thrombin maybe plays an important role in MK differentiation into platelets. However, whether the platelet-like particles are certainly platelets remains unknown.

  15. Changes in thrombin generation in children after cardiac surgery and ex-vivo response to blood products and haemostatic agents

    DEFF Research Database (Denmark)

    Andreasen, Jo B; Ravn, Hanne B; Hvas, Anne-Mette

    2016-01-01

    surgery including cardiopulmonary bypass. Thrombin generation was analysed both in platelet-poor plasma and platelet-rich plasma. Analysis of the thrombin generation showed a significantly prolonged lag time (Pplatelet-poorandplatelet-richplasma ... thrombin generation significantly (all P platelet concentrate. The present study showed that thrombin generation was significantly reduced after cardiopulmonary bypass in children, both when analysed in platelet-poor and platelet-rich plasma...... to test the hypothesis that thrombin generation reveals an impaired haemostasis after paediatric cardiac surgery and that ex-vivo addition of platelet concentrate and haemostatic agents improves thrombin generation. The study comprised 29 children with congenital heart disease, who underwent corrective...

  16. Differential inhibitory action of apixaban on platelet and fibrin components of forming thrombi: Studies with circulating blood and in a platelet-based model of thrombin generation.

    Directory of Open Access Journals (Sweden)

    Lluis Pujadas-Mestres

    Full Text Available Mechanisms of action of direct oral anticoagulants (DOAC suggest a potential therapeutic use in the prevention of thrombotic complications in arterial territories. However, effects of DOACs on platelet activation and aggregation have not been explored in detail. We have investigated the effects of apixaban on platelet and fibrin components of thrombus formation under static and flow conditions.We assessed the effects of apixaban (10, 40 and 160 ng/mL on: 1 platelet deposition and fibrin formation onto a thrombogenic surface, with blood circulating at arterial shear-rates; 2 viscoelastic properties of forming clots, and 3 thrombin generation in a cell-model of coagulation primed by platelets.In studies with flowing blood, only the highest concentration of apixaban, equivalent to the therapeutic Cmax, was capable to significantly reduce thrombus formation, fibrin association and platelet-aggregate formation. Apixaban significantly prolonged thromboelastometry parameters, but did not affect clot firmness. Interestingly, results in a platelet-based model of thrombin generation under more static conditions, revealed a dose dependent persistent inhibitory action by apixaban, with concentrations 4 to 16 times below the therapeutic Cmax significantly prolonging kinetic parameters and reducing the total amount of thrombin generated.Our studies demonstrate the critical impact of rheological conditions on the antithrombotic effects of apixaban. Studies under flow conditions combined with modified thrombin generation assays could help discriminating concentrations of apixaban that prevent excessive platelet accumulation, from those that deeply impair fibrin formation and may unnecessarily compromise hemostasis.

  17. Activation of PAR-1/NADPH Oxidase/ROS Signaling Pathways is Crucial for the Thrombin-Induced sFlt-1 Production in Extravillous Trophoblasts: Possible Involvement in the Pathogenesis of Preeclampsia

    Directory of Open Access Journals (Sweden)

    Qi-tao Huang

    2015-03-01

    Full Text Available Backgrounds/Aims: Preeclampsia was characterized by excessive thrombin generation in placentas and previous researches showed that thrombin could enhance soluble Fms-like tyrosine kinase 1 (sFlt-1 expression in first trimester trophoblasts. However, the detailed mechanism for the sFlt-1 over-production induced by thrombin was largely unknown. The purpose of this study was to explore the possible signaling pathway of thrombin-induced sFlt-1 production in extravillous trophoblasts (EVT. Methods: An EVT cell line (HRT-8/SVneo was treated with various concentrations of thrombin. The mRNA expression and protein secretion of sFlt-1 in EVT were detected with real-time polymerase chain reaction and ELISA, respectively. The levels of intracellular reactive oxygen species (ROS production were determined by DCFH-DA. Results: Exposure of EVT to thrombin induced increased intracellular ROS generation and overexpression of sFlt-1 at both mRNA and protein levels in a dose dependent manner. Short interfering RNA (siRNA directed against PAR-1 or apocynin (an inhibitor of NADPH oxidase could decrease the intracellular ROS generation and subsequently suppressed the production of sFlt-1 at mRNA and protein levels. Conclusions: Our results suggested that thrombin increased sFlt-1 production in EVT via the PAR-1 /NADPH oxidase /ROS signaling pathway. This also highlights the PAR-1 / NADPH oxidase / ROS pathway might be a potential therapeutic target for the prevention of preeclampsia in the future.

  18. Pain management in emergency department: intravenous morphine vs. intravenous acetaminophen

    Directory of Open Access Journals (Sweden)

    Morteza Talebi Doluee

    2015-01-01

    Full Text Available Pain is the most common complaint in emergency department and there are several methods for its control. Among them, pharmaceutical methods are the most effective. Although intravenous morphine has been the most common choice for several years, it has some adverse effects. There are many researches about intravenous acetaminophen as an analgesic agent and it appears that it has good analgesic effects for various types of pain. We searched some electronic resources for clinical trials comparing analgesic effects of intravenous acetaminophen vs. intravenous morphine for acute pain treatment in emergency setting.In two clinical trials, the analgesic effect of intravenous acetaminophen has been compared with intravenous morphine for renal colic. The results revealed no significant difference between analgesic effects of two medications. Another clinical trial revealed that intravenous acetaminophen has acceptable analgesic effects on the post-cesarean section pain when combined with other analgesic medications. One study revealed that administration of intravenous acetaminophen compared to placebo before hysterectomy decreased consumption of morphine via patient-controlled analgesia pump and decreased the side effects. Similarly, another study revealed that the infusion of intravenous acetaminophen vs. placebo after orthopedic surgery decreased the consumption of morphine after the surgery. A clinical trial revealed intravenous acetaminophen provided a level of analgesia comparable to intravenous morphine in isolated limb trauma, while causing less side effects than morphine.It appears that intravenous acetaminophen has good analgesic effects for visceral, traumatic and postoperative pains compare with intravenous morphine.

  19. A chemiluminescence biosensor for the detection of thrombin based on the aptamer composites

    Science.gov (United States)

    Lin, Yanna; Li, Jianbo; Wang, Yanhui; Sun, Yuanling; Ding, Chaofan; Sun, Weiyan; Luo, Chuannan

    2018-03-01

    An efficient, rapid, simple and ultrasensitive chemiluminescence (CL) approach was proposed for thrombin detection based on the aptamer-thrombin recognition. The aptamer composites were synthesized in this work using graphene oxide (GO) as the backing material. The thrombin was adsorbed on the aptamer composites based on the aptamer-thrombin recognition. Thus, thrombin could be quantified by the difference value of the CL intensity between supernate of the sample and the mixture which composed of thrombin and coexisted substances. The CL intensity exhibits a stable response to thrombin over a concentration range from 2.5 × 10- 10 to 1 × 10- 9 mol·L- 1 with a detection limit as low as 8.3 × 10- 11 mol·L- 1, the relative standard deviation (RSD) was found to be 4.9% for 11 determinations of 1.25 × 10- 9 mol·L- 1 thrombin. Finally, the applicability of the method was verified by applying to serum samples. The recoveries were in the range of 90.3-101.0% with RSD of 2.6-3.2%.

  20. Probing the hirudin-thrombin interaction by incorporation of noncoded amino acids and molecular dynamics simulation

    NARCIS (Netherlands)

    De Filippis, [No Value; Colombo, G; Russo, [No Value; Spadari, B; Fontana, A

    2002-01-01

    Thrombin is a primary target for the development of novel anticoagulants, since It plays two important and opposite roles in hemostasis: procoagulant and anticoagulant. All thrombin functions are influenced by Na+ binding, which triggers the transition of this enzyme from an anticoagulant (slow)

  1. Effects of Aerobic Capacity on Thrombin-Induced Hydrocephalus and White Matter Injury.

    Science.gov (United States)

    Ni, Wei; Gao, Feng; Zheng, Mingzhe; Koch, Lauren G; Britton, Steven L; Keep, Richard F; Xi, Guohua; Hua, Ya

    2016-01-01

    We have previously shown that intracerebral hemorrhage-induced brain injury is less in rats bred for high aerobic capacity (high capacity runners; HCR) compared with those bred for low aerobic capacity (low capacity runners; LCRs). Thrombin, an essential component in the coagulation cascade, is produced after cerebral hemorrhage. Intraventricular injection of thrombin causes significant hydrocephalus and white matter damage. In the present study, we examined the effect of exercise capacity on thrombin-induced hydrocephalus and white matter damage. Mid-aged (13-month-old) female LCRs (n = 13) and HCRs (n = 12) rats were used in this study. Rats received an intraventricular injection of thrombin (3 U, 50 μl). All rats underwent magnetic resonance imaging (MRI) at 24 h and were then euthanized for brain histology and Western blot. The mortalities were 20 % in LCRs and 33 % in HCRs after thrombin injection (p > 0.05). No rats died after saline injection. Intraventricular thrombin injection resulted in hydrocephalus and periventricular white matter damage as determined on MRI. In LCR rats, thrombin induced significant ventricle enlargement (23.0 ± 2.3 vs12.8 ± 1.9 mm(3) in LCR saline group; p hydrocephalus in rats with low aerobic capacity. A differential effect of thrombin may contribute to differences in the effects of cerebral hemorrhage with aerobic capacity.

  2. Thrombin contributes to protective immunity in pneumonia-derived sepsis via fibrin polymerization and platelet-neutrophil interactions

    NARCIS (Netherlands)

    Claushuis, T. A. M.; de Stoppelaar, S. F.; Stroo, I.; Roelofs, J. J. T. H.; Ottenhoff, R.; van der Poll, T.; van't Veer, C.

    2017-01-01

    Essentials Immunity and coagulation are linked during sepsis but the role of thrombin is not fully elucidated. We investigated the effect of thrombin inhibition on murine Klebsiella pneumosepsis outcome. Thrombin is crucial for survival and limiting bacterial growth in pneumonia derived sepsis.

  3. Enzyme binding selectivity prediction: alpha-thrombin vs trypsin inhibition.

    Science.gov (United States)

    Mlinsek, G; Novic, M; Kotnik, M; Solmajer, T

    2004-01-01

    In the present work we explore the possibility of an in-depth computational analysis of available experimental X-ray structures in the specific case of a series of alpha-thrombin and trypsin complexes with their respective inhibitors for the development of a novel scoring function based on molecular electrostatic potential computed at the contact surface in the enzyme-inhibitor molecular complex. We subsequently employ the chemometrical approach to determine which are the interactions in the large volume of data that determine the resulting experimental binding constant between ligand and receptor. The results of the model evaluated with molecules in the independent validation set show that a reasonable average error of 1.30 log units of the difference between experimental and calculated binding constants was achieved in the system thrombin-trypsin, which is comparable with those of methods from the literature. Furthermore, by a careful preparation of the Kohonen top layer in the artificial neural network approach that is normally perceived as a "black box device", we have been able to follow the implications of the structure of the inhibitor-enzyme complex for the inhibitor's binding constant. The method appears to be suitable for evaluation of selectivity in structurally similar enzymatic systems, which is currently an important problem in drug design. Copyright 2004 American Chemical Society

  4. Administration and monitoring of intravenous anesthetics

    NARCIS (Netherlands)

    Sahinovic, Marko M.; Absalom, Anthony R.; Struys, Michel M. R. F.

    2010-01-01

    Purpose of review The importance of accuracy in controlling the dose-response relation for intravenous anesthetics is directly related to the importance of optimizing the efficacy and quality of anesthesia while minimizing adverse drug effects. Therefore, it is important to measure and control all

  5. Effects of thrombin inhibition with melagatran on renal hemodynamics and function and liver integrity during early endotoxemia.

    Science.gov (United States)

    Nitescu, Nicoletta; Grimberg, Elisabeth; Ricksten, Sven-Erik; Marcussen, Niels; Nordlinder, Hans; Guron, Gregor

    2007-03-01

    Sepsis is associated with an activation of the coagulation system and multiorgan failure. The aim of the study was to examine the effects of selective thrombin inhibition with melagatran on renal hemodynamics and function, and liver integrity, during early endotoxemia. Endotoxemia was induced in thiobutabarbital-anesthetized rats by an intravenous bolus dose of lipopolysaccharide (LPS; 6 mg/kg). Sham-Saline, LPS-Saline, and LPS-Melagatran study groups received isotonic saline or melagatran immediately before (0.75 micromol/kg iv) and continuously during (0.75 micromol.kg(-1).h(-1) iv) 4.5 h of endotoxemia. Kidney function, renal blood flow (RBF), and intrarenal cortical and outer medullary perfusion (OMLDF) measured by laser-Doppler flowmetry were analyzed throughout. Markers of liver injury and tumor necrosis factor (TNF)-alpha were measured in plasma after 4.5 h of endotoxemia. In addition, liver histology and gene expression were examined. Melagatran treatment prevented the decline in OMLDF observed in the LPS-Saline group (P < 0.05, LPS-Melagatran vs. LPS-Saline). However, melagatran did not ameliorate reductions in mean arterial pressure, RBF, renal cortical perfusion, and glomerular filtration rate or attenuate tubular dysfunctions during endotoxemia. Melagatran reduced the elevated plasma concentrations of aspartate aminotransferase (-34 +/- 11%, P < 0.05), alanine aminotransferase (-21 +/- 7%, P < 0.05), bilirubin (-44 +/- 9%, P < 0.05), and TNF-alpha (-32 +/- 14%, P < 0.05) in endotoxemia. Melagatran did not diminish histological abnormalities in the liver or the elevated hepatic gene expression of TNF-alpha, intercellular adhesion molecule-1, and inducible nitric oxide synthase in endotoxemic rats. In summary, thrombin inhibition with melagatran preserved renal OMLDF, attenuated liver dysfunction, and reduced plasma TNF-alpha levels during early endotoxemia.

  6. Update on pharmacologic approaches to prevent thromboembolism in atrial fibrillation: are thrombin and factor Xa inhibitors the ultimate answer?

    Science.gov (United States)

    Wolfram, Oliver; Hammwoehner, Matthias; Gramley, Felix; Goette, Andreas

    2011-05-01

    Atrial fibrillation (AF) is the most common clinically relevant cardiac arrhythmia. Prevalence and incidence rates are rising with the advancing population age. A severe complication of untreated AF is thrombus formation in the left atrial appendage with consecutive peripheral thromboembolism. Thus, AF is a major contributor to thromboembolic events, especially in the elderly. Depending on the CHADS2 score for thromboembolic events that takes into account congestive heart failure, hypertension, age, diabetes mellitus and stroke as risk factors, oral anticoagulation therapy with vitamin K antagonists is currently the treatment of choice for the prevention of thromboembolism. However, due to drawbacks of current anticoagulation therapy new substances for oral therapy are currently evaluated in various clinical studies. This article provides an up to date overview of orally active compounds for the future treatment of AF. Emphasis lies on comparison of direct thrombin inhibitors with factor Xa inhibitors that are currently investigated in clinical phase III studies for the treatment of non-valvular AF. The direct thrombin inhibitor dabigatran will be compared with factor Xa inhibitors like rivaroxaban and apixaban. Other promising agents currently investigated in phase II trials such as direct factor Xa inhibitors DU-176b (edoxaban) and YM150, will also be discussed.

  7. Shc adaptor proteins are key transducers of mitogenic signaling mediated by the G protein-coupled thrombin receptor

    DEFF Research Database (Denmark)

    Chen, Y; Grall, D; Salcini, A E

    1996-01-01

    of the thrombin receptor in growth-responsive CCL39 fibroblasts. Shc phosphorylation by thrombin or the thrombin receptor agonist peptide is maximal by 15 min and persists for > or = 2 h. Following thrombin stimulation, phosphorylated Shc is recruited to Grb2 complexes. One or more pertussis toxin......-insensitive proteins appear to mediate this effect, since (i) pertussis toxin pre-treatment of cells does not blunt the action of thrombin and (ii) Shc phosphorylation on tyrosine can be stimulated by the muscarinic m1 receptor. Shc phosphorylation does not appear to involve protein kinase C, since the addition of 4...

  8. The Organophosphate Paraoxon and Its Antidote Obidoxime Inhibit Thrombin Activity and Affect Coagulation In Vitro

    Science.gov (United States)

    Golderman, Valery; Shavit-Stein, Efrat; Tamarin, Ilia; Rosman, Yossi; Shrot, Shai; Rosenberg, Nurit

    2016-01-01

    Organophosphates (OPs) are potentially able to affect serine proteases by reacting with their active site. The potential effects of OPs on coagulation factors such as thrombin and on coagulation tests have been only partially characterized and potential interactions with OPs antidotes such as oximes and muscarinic blockers have not been addressed. In the current study, we investigated the in vitro interactions between coagulation, thrombin, the OP paraoxon, and its antidotes obidoxime and atropine. The effects of these substances on thrombin activity were measured in a fluorescent substrate and on coagulation by standard tests. Both paraoxon and obidoxime but not atropine significantly inhibited thrombin activity, and prolonged prothrombin time, thrombin time, and partial thromboplastin time. When paraoxon and obidoxime were combined, a significant synergistic effect was found on both thrombin activity and coagulation tests. In conclusion, paraoxon and obidoxime affect thrombin activity and consequently alter the function of the coagulation system. Similar interactions may be clinically relevant for coagulation pathways in the blood and possibly in the brain. PMID:27689805

  9. Protamine sulfate down-regulates thrombin generation by inhibiting factor V activation.

    LENUS (Irish Health Repository)

    Ni Ainle, Fionnuala

    2009-08-20

    Protamine sulfate is a positively charged polypeptide widely used to reverse heparin-induced anticoagulation. Paradoxically, prospective randomized trials have shown that protamine administration for heparin neutralization is associated with increased bleeding, particularly after cardiothoracic surgery with cardiopulmonary bypass. The molecular mechanism(s) through which protamine mediates this anticoagulant effect has not been defined. In vivo administration of pharmacologic doses of protamine to BALB\\/c mice significantly reduced plasma thrombin generation and prolonged tail-bleeding time (from 120 to 199 seconds). Similarly, in pooled normal human plasma, protamine caused significant dose-dependent prolongations of both prothrombin time and activated partial thromboplastin time. Protamine also markedly attenuated tissue factor-initiated thrombin generation in human plasma, causing a significant decrease in endogenous thrombin potential (41% +\\/- 7%). As expected, low-dose protamine effectively reversed the anticoagulant activity of unfractionated heparin in plasma. However, elevated protamine concentrations were associated with progressive dose-dependent reduction in thrombin generation. To assess the mechanism by which protamine mediates down-regulation of thrombin generation, the effect of protamine on factor V activation was assessed. Protamine was found to significantly reduce the rate of factor V activation by both thrombin and factor Xa. Protamine mediates its anticoagulant activity in plasma by down-regulation of thrombin generation via a novel mechanism, specifically inhibition of factor V activation.

  10. Loop Electrostatics Asymmetry Modulates the Preexisting Conformational Equilibrium in Thrombin.

    Science.gov (United States)

    Pozzi, Nicola; Zerbetto, Mirco; Acquasaliente, Laura; Tescari, Simone; Frezzato, Diego; Polimeno, Antonino; Gohara, David W; Di Cera, Enrico; De Filippis, Vincenzo

    2016-07-19

    Thrombin exists as an ensemble of active (E) and inactive (E*) conformations that differ in their accessibility to the active site. Here we show that redistribution of the E*-E equilibrium can be achieved by perturbing the electrostatic properties of the enzyme. Removal of the negative charge of the catalytic Asp102 or Asp189 in the primary specificity site destabilizes the E form and causes a shift in the 215-217 segment that compromises substrate entrance. Solution studies and existing structures of D102N document stabilization of the E* form. A new high-resolution structure of D189A also reveals the mutant in the collapsed E* form. These findings establish a new paradigm for the control of the E*-E equilibrium in the trypsin fold.

  11. Intravenous lidocaine infusion.

    Science.gov (United States)

    Soto, G; Naranjo González, M; Calero, F

    2018-02-26

    Systemic lidocaine used in continuous infusion during the peri-operative period has analgesic, anti-hyperalgesic, as well as anti-inflammatory properties. This makes it capable of reducing the use of opioids and inhalational anaesthetics, and the early return of bowel function, and patient hospital stay. The aim of this narrative review was to highlight the pharmacology and indications for clinical application, along with new and interesting research areas. The clinical applications of peri-operative lidocaine infusion have been reviewed in several recent systematic reviews and meta-analyses in patients undergoing open and laparoscopic abdominal procedures, ambulatory procedures, and other types of surgery. Peri-operative lidocaine infusion may be a useful analgesic adjunct in enhanced recovery protocols. Potential benefits of intravenous lidocaine in chronic post-surgical pain, post-operative cognitive dysfunction, and cancer recurrence are under investigation. Due to its immunomodulation properties over surgical stress, current evidence suggests that intravenous lidocaine could be used in the context of multimodal analgesia. Copyright © 2018 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  12. Increased anticoagulant activity of thrombin-binding DNA aptamers by nanoscale organization on DNA nanostructures

    DEFF Research Database (Denmark)

    Rangnekar, Abhijit; Zhang, Alex M.; Shiyuan Li, Susan

    2012-01-01

    by a flexible single-strand linker, have been shown to possess anticoagulant activity. Here, we link multiple aptamers at programmed positions on DNA nanostructures to optimize spacing and orientation of the aptamers and thereby to maximize anticoagulant activity in functional assays. By judicious engineering...... of the DNA nanostructures, we have created a novel, functional DNA nanostructure, which is a multi-aptamer inhibitor with activity eightfold higher than free aptamer. Reversal of the thrombin inhibition was also achieved by the use of single-stranded DNA antidotes, thus enabling significant control over......Control over thrombin activity is much desired to regulate blood clotting in surgical and therapeutic situations. Thrombin-binding RNA and DNA aptamers have been used to inhibit thrombin activity and thus the coagulation cascade. Soluble DNA aptamers, as well as two different aptamers tethered...

  13. Human Thrombin Detection Through a Sandwich Aptamer Microarray: Interaction Analysis in Solution and in Solid Phase

    Science.gov (United States)

    Sosic, Alice; Meneghello, Anna; Cretaio, Erica; Gatto, Barbara

    2011-01-01

    We have developed an aptamer-based microarray for human thrombin detection exploiting two non-overlapping DNA thrombin aptamers recognizing different exosites of the target protein. The 15-mer aptamer (TBA1) binds the fibrinogen-binding site, whereas the 29-mer aptamer (TBA2) binds the heparin binding domain. Extensive analysis on the complex formation between human thrombin and modified aptamers was performed by Electrophoresis Mobility Shift Assay (EMSA), in order to verify in solution whether the chemical modifications introduced would affect aptamers/protein recognition. The validated system was then applied to the aptamer microarray, using the solid phase system devised by the solution studies. Finally, the best procedure for Sandwich Aptamer Microarray (SAM) and the specificity of the sandwich formation for the developed aptasensor for human thrombin were optimized. PMID:22163703

  14. Comparing thrombin generation in patients with hemophilia A and patients on vitamin K antagonists

    NARCIS (Netherlands)

    de Koning, M L Y; Fischer, K; de Laat, B; Huisman, A; Ninivaggi, M; Schutgens, R E G

    Essentials: It is unknown if hemophilia patients with atrial fibrillation need anticoagulation. Endogenous thrombin potentials (ETP) in hemophilia patients and patients on coumarins were compared. Severe hemophilia patients had comparable ETP to therapeutic international normalized ratio (INR). In

  15. Impaired healing of cutaneous wounds and colonic anastomoses in mice lacking thrombin-activatable fibrinolysis inhibitor

    NARCIS (Netherlands)

    te Velde, E. A.; Wagenaar, G. T. M.; Reijerkerk, A.; Roose-Girma, M.; Borel Rinkes, I. H. M.; Voest, E. E.; Bouma, B. N.; Gebbink, M. F. B. G.; Meijers, J. C. M.

    2003-01-01

    Plasmin and other components of the plasminogen activation system play an important role in tissue repair by regulating extracellular matrix remodeling, including fibrin degradation. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a procarboxypeptidase that, after activation, can attenuate

  16. Active but inoperable thrombin is accumulated in a plasma protein layer surrounding Streptococcus pyogenes

    NARCIS (Netherlands)

    Naudin, Clément; Hurley, Sinead M.; Malmström, Erik; Plug, Tom; Shannon, Oonagh; Meijers, Joost C. M.; Mörgelin, Matthias; Björck, Lars; Herwald, Heiko

    2015-01-01

    Activation of thrombin is a critical determinant in many physiological and pathological processes including haemostasis and inflammation. Under physiological conditions many of these functions are involved in wound healing or eradication of an invading pathogen. However, when activated systemically,

  17. Histopathology of Lesions in Swine Exposed to a Hemostatic Bandage Composed of Salmon Thrombin and Fibrinogen

    National Research Council Canada - National Science Library

    Szabo, Kathleen A; Flournoy, William S; Dorsey, Evelyn Sawyer ;David Simpson ;Gary Cadd ;Jennifer; Rothwell, Stephen W

    2006-01-01

    .... However, because of concern that these foreign proteins may induce an immune response in the patients, we investigated the inflammatory response in pigs exposed to salmon thrombin/fibrinogen dressings...

  18. Thrombin-linked aptamer assay for detection of platelet derived growth factor BB on magnetic beads in a sandwich format.

    Science.gov (United States)

    Guo, Limin; Zhao, Qiang

    2016-09-01

    Here we describe a thrombin-linked aptamer assay (TLAA) for protein by using thrombin as an enzyme label, harnessing enzyme activity of thrombin and aptamer affinity binding. TLAA converts detection of specific target proteins to the detection of thrombin by using a DNA sequence that consists of two aptamers with the first aptamer binding to the specific target protein and the second aptamer binding to thrombin. Through the affinity binding, the thrombin enzyme is labeled on the protein target, and thrombin catalyzes the hydrolysis of small peptide substrate into product, generating signals for quantification. As a proof of principle, we show a sandwich TLAA for platelet derived growth factor BB (PDGF-BB) by using anti-PDGF-BB antibody coated on magnetic beads and an oligonucleotide containing the aptamer for PDGF-BB and the aptamer for thrombin. The binding of PDGF-BB to both the antibody and the aptamer results in labeling the complex with thrombin. We achieved detection of PDGF-BB at 16 pM. This TLAA contributes a new application of thrombin and its aptamer in bioanalysis, and shows potentials in assay developments. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Thrombin and fibrinogen γ' impact clot structure by marked effects on intrafibrillar structure and protofibril packing.

    Science.gov (United States)

    Domingues, Marco M; Macrae, Fraser L; Duval, Cédric; McPherson, Helen R; Bridge, Katherine I; Ajjan, Ramzi A; Ridger, Victoria C; Connell, Simon D; Philippou, Helen; Ariëns, Robert A S

    2016-01-28

    Previous studies have shown effects of thrombin and fibrinogen γ' on clot structure. However, structural information was obtained using electron microscopy, which requires sample dehydration. Our aim was to investigate the role of thrombin and fibrinogen γ' in modulating fibrin structure under fully hydrated conditions. Fibrin fibers were studied using turbidimetry, atomic force microscopy, electron microscopy, and magnetic tweezers in purified and plasma solutions. Increased thrombin induced a pronounced decrease in average protofibril content per fiber, with a relatively minor decrease in fiber size, leading to the formation of less compact fiber structures. Atomic force microscopy under fully hydrated conditions confirmed that fiber diameter was only marginally decreased. Decreased protofibril content of the fibers produced by high thrombin resulted in weakened clot architecture as analyzed by magnetic tweezers in purified systems and by thromboelastometry in plasma and whole blood. Fibers produced with fibrinogen γ' showed reduced protofibril packing over a range of thrombin concentrations. High-magnification electron microscopy demonstrated reduced protofibril packing in γ' fibers and unraveling of fibers into separate protofibrils. Decreased protofibril packing was confirmed in plasma for high thrombin concentrations and fibrinogen-deficient plasma reconstituted with γ' fibrinogen. These findings demonstrate that, in fully hydrated conditions, thrombin and fibrinogen γ' have dramatic effects on protofibril content and that protein density within fibers correlates with strength of the fibrin network. We conclude that regulation of protofibril content of fibers is an important mechanism by which thrombin and fibrinogen γ' modulate fibrin clot structure and strength. © 2016 by The American Society of Hematology.

  20. Comparison by sex between thrombin generation and fibrin network characteristics in a healthy population.

    Science.gov (United States)

    Marchi, R; Marcos, L; Paradisi, I

    2015-02-20

    The aim of the present work was to compare sex differences in thrombin generation and fibrin network characteristics in a young healthy population, and correlate thrombin generation parameters with fibrin network characteristics. Sixty individuals aged 21 y (18-26), 50% men and 50% women were selected. Thrombin generation was performed with the Technothrombin TGA kit. Plasma fibrin formation kinetic was followed by turbidity at 350 nm, and the fibrin elastic modulus was measured with the Hemodyne. In addition, the prothrombin polymorphism G20210A was assessed. Thrombin generation in men was: lag time (LT): 12.5 ± 3.0 min, peak thrombin: 257 ± 135 nmol/l, and endogenous thrombin potential (ETP): 3459 ± 449 nmol/l·min, while in women the LT was shortened (9.7 ± 2.8 min, pgeneration between women and men were not related to prothrombin concentration, prothrombin polymorphism G20210A or fibrinogen concentration. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. The Phosphatase Inhibitor Calyculin-A Impairs Clot Retraction, Platelet Activation, and Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Renáta Hudák

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of the serine/threonine protein phosphatase inhibitor, calyculin-A (CLA, on clot formation and on the procoagulant activity of human platelets. Platelet-rich plasma (PRP samples were preincubated with buffer or CLA and subsequently platelets were activated by the protease-activated receptor 1 (PAR-1 activator, thrombin receptor activating peptide (TRAP. Clot retraction was detected by observing clot morphology up to 1 hour, phosphatidylserine- (PS- expression was studied by flow cytometry, and thrombin generation was measured by a fluorimetric assay. For the intracellular Ca2+ assay, platelets were loaded with calcium-indicator dyes and the measurements were carried out using a ratiometric method with real-time confocal microscopy. CLA preincubation inhibited clot retraction, PS-expression, and thrombin formation. TRAP activation elicited Ca2+ response and PS-expression in a subset of platelets. The activated PRP displayed significantly faster and enhanced thrombin generation compared to nonactivated samples. CLA pretreatment abrogated PS-exposure and clot retraction also in TRAP-activated samples. As a consequence of the inhibitory effect on calcium elevation and PS-expression, CLA significantly downregulated thrombin generation in PRP. Our results show that CLA pretreatment may be a useful tool to investigate platelet activation mechanisms that contribute to clot formation and thrombin generation.

  2. Synergy in thrombin-graphene sponge for improved hemostatic efficacy and facile utilization.

    Science.gov (United States)

    Li, Guofeng; Quan, Kecheng; Xu, CongCong; Deng, Bo; Wang, Xing

    2018-01-01

    Composites are attractive for its potential synergistic effects that can result in high-performance, but the synergy depends on subtle design. In this study, a hemostatic composite, a thrombin/cross-linked graphene sponge (TCGS), was developed through a facile gradient composite strategy. The porous structure of the CGS assures that the thrombin is stably embedded in the TCGS, avoiding a burst release but maintaining its bioactivity. In the synergy between proper thrombin stimulation and the fast absorption of the sponge, TCGS exhibits outstanding hemostatic performance, ultrafast bleeding cessation, within 100s, which is superior to both CGS and equal amounts of native thrombin. Lower or excessive thrombin dosages prolong the bleeding time. The study revealed that the balance between plasma absorption and thrombin stimulation at the interface is critical for improving hemostatic efficacy. TCGS is also highlighted for its biosafety and stability, even after 6 months of storage in environment. This potentially ultra-long shelf life is conducive to its practical applications. Therefore, TCGS not only provides a new strategy for developing a hemostatic composite but also provides a new method and understanding for the design of hemostatic materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Thrombin-induced microglial activation impairs hippocampal neurogenesis and spatial memory ability in mice.

    Science.gov (United States)

    Yang, Yuan; Zhang, Meikui; Kang, Xiaoni; Jiang, Chen; Zhang, Huan; Wang, Pei; Li, Jingjing

    2015-09-26

    To investigate the effects of microglia/macrophages activation induced by intrastriatal thrombin injection on dentate gyrus neurogenesis and spatial memory ability in mice. The male C57BL/6 mice were divided into 4 groups of 10: sham, intracerebral hemorrhage (ICH), ICH + hirudin (thrombin inhibitor), and ICH + indometacin (Indo, an anti-inflammation drug). ICH model was created by intrastriatal thrombin (1U) injection. BrdU (50 mg/kg) was administrated on the same day after surgery for 6 consecutive days. Motor functions were evaluated with rotarod and beam walking tests. The spatial memory deficit was measured with Morris water maze (MWM). Cell quantification was performed for doublecortin (DCX, immature neuron), BrdU (S-phase proliferating cell population) and CD68 (activated microglia/macrophage) immune-reactive cells. Microglia/macrophages activation induced by intrastriatal thrombin injection reduced hippocampal neurogenesis and impaired spatial memory ability, but did not affect the motor function at 3 and 5 days post-injury. Both hirudin and indometacin reduced microglia/macrophages activation, enhanced hippocampal neurogenesis, and improved spatial memory ability in mice. Microglia/macrophages activation induced by intrastriatal thrombin injection might be responsible for the spatial memory deficit. Targeting both thrombin and inflammation systems in acute phase of ICH might be important in alleviating the significant spatial memory deficits.

  4. Thrombin-Activatable Microbubbles as Potential Ultrasound Contrast Agents for the Detection of Acute Thrombosis.

    Science.gov (United States)

    Lux, Jacques; Vezeridis, Alexander M; Hoyt, Kenneth; Adams, Stephen R; Armstrong, Amanda M; Sirsi, Shashank R; Mattrey, Robert F

    2017-11-01

    Acute deep vein thrombosis (DVT) is the formation of a blood clot in the deep veins of the body that can lead to fatal pulmonary embolism. Acute DVT is difficult to distinguish from chronic DVT by ultrasound (US), the imaging modality of choice, and is therefore treated aggressively with anticoagulants, which can lead to internal bleeding. Here we demonstrate that conjugating perfluorobutane-filled (PFB-filled) microbubbles (MBs) with thrombin-sensitive activatable cell-penetrating peptides (ACPPs) could lead to the development of contrast agents that detect acute thrombosis with US imaging. Successful conjugation of ACPP to PFB-filled MBs was confirmed by fluorescence microscopy and flow cytometry. Fluorescein-labeled ACPP was used to evaluate the efficiency of thrombin-triggered cleavage by measuring the mean fluorescence intensity of ACPP-labeled MBs (ACPP-MBs) before and after incubation at 37 °C with thrombin. Lastly, control MBs and ACPP-MBs were infused through a tube containing a clot, and US contrast enhancement was measured with or without the presence of a thrombin inhibitor after washing the clot with saline. With thrombin activity, 91.7 ± 14.2% of the signal was retained after ACPP-MB infusion and washing, whereas only 16.7 ± 4% of the signal was retained when infusing ACPP-MBs in the presence of hirudin, a potent thrombin inhibitor.

  5. Active but inoperable thrombin is accumulated in a plasma protein layer surrounding Streptococcus pyogenes.

    Science.gov (United States)

    Naudin, Clément; Hurley, Sinead M; Malmström, Erik; Plug, Tom; Shannon, Oonagh; Meijers, Joost C M; Mörgelin, Matthias; Björck, Lars; Herwald, Heiko

    2015-10-01

    Activation of thrombin is a critical determinant in many physiological and pathological processes including haemostasis and inflammation. Under physiological conditions many of these functions are involved in wound healing or eradication of an invading pathogen. However, when activated systemically, thrombin can contribute to severe and life-threatening conditions by causing complications such as multiple multi-organ failure and disseminated intravascular coagulation. In the present study we investigated how the activity of thrombin is modulated when it is bound to the surface of Streptococcus pyogenes. Our data show that S. pyogenes bacteria become covered with a proteinaceous layer when incubated with human plasma, and that thrombin is a constituent of this layer. Though the coagulation factor is found attached to the bacteria with a functional active site, thrombin has lost its capacity to interact with its natural substrates and inhibitors. Thus, the interaction of bacteria with human plasma renders thrombin completely inoperable at the streptococcal surface. This could represent a host defense mechanism to avoid systemic activation of coagulation which could be otherwise induced when bacteria enter the circulation and cause systemic infection.

  6. Thrombomodulin is a determinant of metastasis through a mechanism linked to the thrombin binding domain but not the lectin-like domain

    Science.gov (United States)

    Horowitz, Netanel A.; Blevins, Elizabeth A.; Miller, Whitney M.; Perry, Ashley R.; Talmage, Kathryn E.; Mullins, Eric S.; Flick, Matthew J.; Queiroz, Karla C. S.; Shi, Kun; Spek, C. Arnold; Conway, Edward M.; Monia, Brett P.; Weiler, Hartmut; Degen, Jay L.

    2011-01-01

    Thrombomodulin (TM) is a predominantly endothelial transmembrane glycoprotein that modulates hemostatic function through a domain that controls thrombin-mediated proteolysis and an N-terminal lectin-like domain that controls inflammatory processes. To test the hypothesis that TM is a determinant of malignancy and dissect the importance of these functional domains in cancer biology, metastatic potential was evaluated in TMPro mice expressing a mutant form of TM with reduced thrombin affinity and TMLeD mice lacking the N-terminal lectin-like domain. Studies of TMPro mice revealed that TM is a powerful determinant of hematogenous metastasis. TMPro mice exhibited a strongly prometastatic phenotype relative to control mice that was found to result from increased survival of tumor cells newly localized to the lung rather than any alteration in tumor growth. The impact of the TMPro mutation on metastasis was dependent on both tumor cell-associated tissue factor and thrombin procoagulant function. In contrast, expression of a mutant form of TM lacking the lectin-like domain had no significant impact on metastasis. These studies directly demonstrate for the first time that TM-mediated regulation of tumor cell-driven procoagulant function strongly influences metastatic potential and suggest that endothelial cell-associated modulators of hemostasis may represent novel therapeutic targets in limiting tumor dissemination. PMID:21788337

  7. Intravenous fluids: balancing solutions.

    Science.gov (United States)

    Hoorn, Ewout J

    2017-08-01

    The topic of intravenous (IV) fluids may be regarded as "reverse nephrology", because nephrologists usually treat to remove fluids rather than to infuse them. However, because nephrology is deeply rooted in fluid, electrolyte, and acid-base balance, IV fluids belong in the realm of our specialty. The field of IV fluid therapy is in motion due to the increasing use of balanced crystalloids, partly fueled by the advent of new solutions. This review aims to capture these recent developments by critically evaluating the current evidence base. It will review both indications and complications of IV fluid therapy, including the characteristics of the currently available solutions. It will also cover the use of IV fluids in specific settings such as kidney transplantation and pediatrics. Finally, this review will address the pathogenesis of saline-induced hyperchloremic acidosis, its potential effect on outcomes, and the question if this should lead to a definitive switch to balanced solutions.

  8. Intravenous versus oral etoposide

    DEFF Research Database (Denmark)

    Ali, Abir Salwa; Grönberg, Malin; Langer, Seppo W.

    2018-01-01

    High-grade gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs, G3) are aggressive cancers of the digestive system with poor prognosis and survival. Platinum-based chemotherapy (cisplatin/carboplatin + etoposide) is considered the first-line palliative treatment. Etoposide is frequently...... administered intravenously; however, oral etoposide may be used as an alternative. Concerns for oral etoposide include decreased bioavailability, inter- and intra-patient variability and patient compliance. We aimed to evaluate possible differences in progression-free survival (PFS) and overall survival (OS......) in patients treated with oral etoposide compared to etoposide given as infusion. Patients (n = 236) from the Nordic NEC study were divided into three groups receiving etoposide as a long infusion (24 h, n = 170), short infusion (≤ 5 h, n = 33) or oral etoposide (n = 33) according to hospital tradition. PFS...

  9. Adenosine opposes thrombin-induced inhibition of intercellular calcium wave in corneal endothelial cells.

    Science.gov (United States)

    D'hondt, Catheleyne; Srinivas, Sangly P; Vereecke, Johan; Himpens, Bernard

    2007-04-01

    In corneal endothelial cells, intercellular Ca(2+) waves elicited by a mechanical stimulus involve paracrine intercellular communication, mediated by ATP release via connexin hemichannels, as well as gap junctional intercellular communication. Both mechanisms are inhibited by thrombin, which activates RhoA and hence results in myosin light chain phosphorylation. This study was conducted to examine the effects of adenosine, which is known to oppose thrombin-induced RhoA activation, thereby leading to myosin light chain dephosphorylation, on gap junctional intercellular communication and paracrine intercellular communication in cultured bovine corneal endothelial cells. An intercellular Ca(2+) wave was elicited by applying a mechanical stimulus to a single cell in a confluent monolayer. The area of Ca(2+) wave propagation was measured by [Ca(2+)](i) imaging using the fluorescent dye Fluo-4. Gap junctional intercellular communication was assessed by fluorescence recovery after photobleaching. Activity of hemichannels was determined by uptake of the hydrophilic dye Lucifer yellow in a Ca(2+)-free medium containing 2 mM EGTA. Adenosine triphosphate (ATP) release in response to mechanical stimulation was measured using the luciferin-luciferase technique. Gap26, a connexin mimetic peptide, was used to block hemichannels. Exposure to thrombin or TRAP-6 (a selective PAR-1 agonist) inhibited the Ca(2+) wave propagation by 70%. Pretreatment with adenosine prevented this inhibitory effect of thrombin. NECA (a potent A2B agonist) and forskolin, agents known to elevate cAMP in bovine corneal endothelial cells, also suppressed the effect of thrombin. The A1 receptor agonist CPA failed to inhibit the effect of thrombin. Similar to the effects on Ca(2+) wave propagation, adenosine prevented the thrombin-induced reduction in the fluorescence recovery during photobleaching experiments. Furthermore, pretreatment with adenosine prevented both thrombin and TRAP-6 from blocking the

  10. Thrombin-Binding Aptamer Quadruplex Formation: AFM and Voltammetric Characterization

    Directory of Open Access Journals (Sweden)

    Victor Constantin Diculescu

    2010-01-01

    Full Text Available The adsorption and the redox behaviour of thrombin-binding aptamer (TBA and extended TBA (eTBA were studied using atomic force microscopy and voltammetry at highly oriented pyrolytic graphite and glassy carbon. The different adsorption patterns and degree of surface coverage were correlated with the sequence base composition, presence/absence of K+, and voltammetric behaviour of TBA and eTBA. In the presence of K+, only a few single-stranded sequences present adsorption, while the majority of the molecules forms stable and rigid quadruplexes with no adsorption. Both TBA and eTBA are oxidized and the only anodic peak corresponds to guanine oxidation. Upon addition of K+ ions, TBA and eTBA fold into a quadruplex, causing the decrease of guanine oxidation peak and occurrence of a new peak at a higher potential due to the oxidation of G-quartets. The higher oxidation potential of G-quartets is due to the greater difficulty of electron transfer from the inside of the quadruplex to the electrode surface than electron transfer from the more flexible single strands.

  11. The myosin II ATPase inhibitor blebbistatin prevents thrombin-induced inhibition of intercellular calcium wave propagation in corneal endothelial cells.

    Science.gov (United States)

    Ponsaerts, Raf; D'hondt, Catheleyne; Bultynck, Geert; Srinivas, Sangly P; Vereecke, Johan; Himpens, Bernard

    2008-11-01

    Thrombin inhibits intercellular Ca(2+) wave propagation in bovine corneal endothelial cells (BCECs) through a mechanism dependent on myosin light chain (MLC) phosphorylation. In this study, blebbistatin, a selective myosin II ATPase inhibitor, was used to investigate whether the effect of thrombin is mediated by enhanced actomyosin contractility. BCECs were exposed to thrombin (2 U/mL) for 5 minutes. MLC phosphorylation was assayed by immunocytochemistry. Ca(2+) waves were visualized by confocal microscopy with Fluo-4AM. Fluorescence recovery after photobleaching (FRAP) was used to investigate intercellular communication (IC) via gap junctions. ATP release was measured by luciferin-luciferase assay. Lucifer yellow (LY) uptake was used to investigate hemichannel activity, and Fura-2 was used to assay thrombin- and ATP-mediated Ca(2+) responses. Pretreatment with blebbistatin (5 microM for 20 minutes) or its nitro derivative prevented the thrombin-induced inhibition of the Ca(2+) wave. Neither photo-inactivated blebbistatin nor the inactive enantiomers prevented the thrombin effect. Blebbistatin also prevented thrombin-induced inhibition of LY uptake, ATP release and FRAP, indicating that it prevented the thrombin effect on paracrine and gap junctional IC. In the absence of thrombin, blebbistatin had no significant effect on paracrine or gap junctional IC. The drug had no influence on MLC phosphorylation or on [Ca(2+)](i) transients in response to thrombin or ATP. Blebbistatin prevents the inhibitory effects of thrombin on intercellular Ca(2+) wave propagation. The findings demonstrate that myosin II-mediated actomyosin contractility plays a central role in thrombin-induced inhibition of gap junctional IC and of hemichannel-mediated paracrine IC.

  12. Dynamic affinity chromatography in the separation of sulfated lignins binding to thrombin

    Science.gov (United States)

    Liang, Aiye; Thakkar, Jay N.; Hindle, Michael; Desai, Umesh R.

    2013-01-01

    Sulfated low molecular weight lignins (LMWLs), a mixture of chemo-enzymatically prepared oligomers, have been found to be potent antagonists of coagulation. However, structures that induce anticoagulation remain unidentified. The highly polar sulfate groups on these molecules and the thousands of different structures present in these mixtures make traditional chromatographic resolution of sulfated LMWLs difficult. We performed dynamic thrombin affinity chromatography monitored using chromogenic substrate hydrolysis assay to isolate sulfated LMWL fractions that differed significantly in their biophysical and biochemical properties. Three fractions, I35, I55 and Peak II, were isolated from the starting complex mixture. Independent plasma clotting assays suggested that I35 possessed good anticoagulation potential (APTT = 4.2 μM; PT = 6.8 μM), while I55 and Peak II were approximately 10- and 100-fold less potent. The ESI-MS spectrum of this oligomeric fraction showed multiple peaks at 684.8, 610.6, 557.4, 541.4, 536.5, and 519.4 m/z, which most probably arise from variably functionalized (β-O4—β-β-linked trimers and/or a β-O4—β-O4-linked dimers. The first direct observation of these structures in sulfated LMWLs will greatly assist in the discovery of more potent sulfated LMWL-based anticoagulants. PMID:23122400

  13. Development of a sandwich ELISA for the thrombin light chain identified by serum proteome analysis

    Directory of Open Access Journals (Sweden)

    Kazuyuki Sogawa

    2017-08-01

    Full Text Available We previously identified novel biomarker candidates in biliary tract cancer (BTC using serum proteome analysis. Among several candidates, we focused on thrombin light chain which is a 4204 Da peptide as the most promising biomarker for BTC. To move thrombin light chain toward potential diagnostic use, we developed an enzyme immunoassay that enables to measure serum thrombin light chain levels.Both one monoclonal antibody specific to the N-termini and one polyclonal antibody were used to develop a sandwich ELISA for thrombin light chain. The assay was evaluated by comparing the results with those obtained by the ClinProt™ system. Serum samples were obtained from 20 patients with BTC, 20 patients with BBTDs and 20 HVs using the ClinProt™ system and ELISA.The results of the established ELISA showed a positive correlation with the findings by ClinProt™ system (slope=0.3386, intercept=34.901, r2=0.9641. The performance of the ELISA was satisfactory in terms of recovery (97.9–102.5% and within-run (1.5–4.8% and between-day (1.9–6.7% reproducibility. Serum thrombin light chain levels were significantly greater in BTC (176.5±47.2 ng/mL than in BBTDs (128.6±17.4 ng/mL and HVs (127.6±16.0 ng/mL (p<0.001.The sandwich ELISA developed in this study will be useful for validation of the diagnostic significance of serum thrombin light chain levels in various cancers. Keywords: Thrombin light chain, Biliary tract cancer, Sandwich ELISA, Serum biomarker

  14. Construction of photoelectrochemical thrombin aptasensor via assembling multilayer of graphene-CdS nanocomposites.

    Science.gov (United States)

    Shangguan, Li; Zhu, Wei; Xue, Yanchun; Liu, Songqin

    2015-02-15

    A photoelectrochemical (PEC) aptasensor for highly sensitive and specific detection of thrombin was developed by using graphene–CdS nanocomposites multilayer as photoactive species and electroactive mediator hexaammineruthenium(III) chloride (Ru(NH(3))(6)(3+)) as signal enhancer. Graphene–CdS nanocomposites (G–CdS) were synthesized by one-pot reduction of oxide graphene and CdCl2 with thioacetamide. The photoactive multilayer was prepared by alternative assembly of the negatively charged 3-mercaptopropionic acid modified graphene–CdS nanocomposites (MPA-G–CdS) and the positively charged polyethylenimine (PEI) on ITO electrode. This layer-by-layer assembly method enhanced the stability and homogeneity of the photocurrent readout of G–CdS. Thrombin aptamer was covalently bound to the multilayer by using glutaraldehyde as cross-linking. Electroactive mediator (Ru(NH(3))(6)(3+)) could interact with the DNA phosphate backbone and thus facilitated the electron transfer between G–CdS multilayer and electrode and enhanced the photocurrent. Hybridizing of a long complementary DNA with thrombin aptamer could increase the adsorption amount of (Ru(NH(3))(6)(3+)), which in turn boosted the signal readout. In the presence of target thrombin, the affinity interaction between thrombin and its aptamer resulted in the long complementary DNA releasing from the G–CdS multilayer and decreasing of photocurrent signal. On the basis of G–CdS multilayer as the photoactive species, (Ru (NH(3))(6)(3+)) as an electroactive mediator, and aptamer as a recognition module, a high sensitive PEC aptasensor for thrombin detection was proposed. The thrombin aptasensor displayed a linear range from 2.0 pM to 600.0 pM and a detection limit of 1.0 pM. The present strategy provided a promising ideology for the future development of PEC biosensor. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Nanocomplexation of thrombin with cationic amylose derivative for improved stability and hemostatic efficacy

    Directory of Open Access Journals (Sweden)

    Zhuang B

    2015-01-01

    Full Text Available Baoxiong Zhuang,1,* Zhihua Li,1,* Jiadong Pang,2,* Wenbin Li,1 Pinbo Huang,1 Jie Wang,1 Yu Zhou,1 Qing Lin,1 Quanbo Zhou,1 Xiao Ye,1 Huilin Ye,1 Yimin Liu,1 Li-Ming Zhang,2 Rufu Chen1 1Department of Hepato-Pancreato-Billiary Surgery, Department of Medical Oncology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, People’s Republic of China; 2DSAPM Lab and PCFM Lab, Institute of Polymer Science, Department of Polymer and Materials Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, People’s Republic of China *Authors share co-first authorship Abstract: As a topical hemostatic agent, thrombin has wide application for many surgical treatments. However, native thrombin always suffers from its physical and chemical instabilities. In this work, a nanocomplexation strategy was developed for modifying the stability and hemostatic efficacy of thrombin, in which a water-soluble cationic amylose derivative containing poly(l-lysine dendrons was prepared by a click reaction and then used to complex thrombin in an aqueous system. For resultant thrombin nanocomplexes, their morphology and particle size distribution were investigated. Their stabilities were studied in terms of activity retention percentages under different storage time, pH values, and illumination time. In addition, their ability to achieve in vitro fibrinogen and blood coagulation were evaluated. Via a rat hepatic hemorrhage model and a rat iliac artery hemorrhage model, these thrombin nanocomplexes were confirmed to have good tissue biocompatibility and in vivo hemostatic effectiveness. Keywords: thrombin, nanoparticles, amylose derivative, complexation, stability, hemostatic activity

  16. FAK phosphorylation plays a central role in thrombin-induced RPE cell migration.

    Science.gov (United States)

    Aguilar-Solis, E D; Lee-Rivera, I; Álvarez-Arce, A; López, E; López-Colomé, A M

    2017-08-01

    The migration of retinal pigment epithelial (RPE) cells is an important step in various pathologic conditions including subretinal neovascularization (SRN), proliferative vitreoretinopathy (PVR) and, importantly, as a consequence of retinal surgery. Therefore, the elucidation of the mechanisms underlying RPE trans-differentiation and migration is essential for devising effective treatments aimed to the prevention of these disorders. A common event in these pathologies is the alteration of the blood-retina barrier (BRB), which allows the interaction of RPE cells with thrombin, a pro-inflammatory protease contained in serum. Our previous work has demonstrated that thrombin induces RPE cell cytoskeletal remodeling and migration, hallmark processes in the development of PVR; however, the molecular mechanisms involved are still unclear. Cell migration requires the disassembly of focal adhesions induced by Focal Adhesion Kinase (FAK) phosphorylation, together with the formation of actin stress fibers. The aim of the present work was to identify thrombin-activated signaling pathways leading to FAK phosphorylation and to determine FAK participation in thrombin-induced RPE cell migration. Results demonstrate that the activation of PAR1 by thrombin induces FAK autophosphorylation at Y397 and the subsequent phosphorylation of Y576/577 within the activation loop. FAK phosphorylation was shown to be under the control of c/nPKC and PI3K/PKC-ζ, as well as by Rho/ROCK, since the inhibition of these pathways prevented thrombin-induced FAK phosphorylation and the consequent disassembly of focal adhesions, in parallel to FAK-dependent actin stress fiber formation and RPE cell migration. These findings demonstrate, for the first time, that thrombin stimulation of RPE cell transformation and migration are regulated by FAK tyrosine phosphorylation. Thus, targeting FAK phosphorylation may provide a strategical basis for PVR treatment. Copyright © 2017. Published by Elsevier Inc.

  17. Ultrasonography versus intravenous urography

    International Nuclear Information System (INIS)

    Aslaksen, A.

    1991-01-01

    The present study was performed to compare the clinical value of urography and ultrasonography in a non-selected group of patients referred for urography to a university hospital. The conslusions and clinical implications of the study are as follows: Intravenous urography remains the cornerstone imaging examination in the evaluation of ureteral calculi. Ultrasonography is a valuable adjunct in cases of non- visualization of the kidneys, in distal obstruction and known contrast media allergy. When women with recurrent urinary tract infection are referred for imaging of the urinary tract, ultrasonography should be used. Ultrasonography should replace urography for screening of non-acute hydronephrosis like in female genital cancer and benign prostate hyperplasia. There is good correlation between urography and ultrasonography in assessing the degree of hydronephrosis. However, more researh on the relationship between hydronephrosis and obstruction is necessary. Ultrasonography should be used as the only imaging method of the upper urinary tract in patients with microscopic hematuria. In patients less than 50 years with macroscopic hematuria, ultrasonography should be used as the only imaging of the upper urinary tract, and an examination of the urinary bladder should be included. In patients over 50 years, urography supplied with ultrasonography should be used, but more research is necessary on the subject of imaging method and age. 158 refs

  18. Random Forests Are Able to Identify Differences in Clotting Dynamics from Kinetic Models of Thrombin Generation.

    Directory of Open Access Journals (Sweden)

    Jayavel Arumugam

    Full Text Available Current methods for distinguishing acute coronary syndromes such as heart attack from stable coronary artery disease, based on the kinetics of thrombin formation, have been limited to evaluating sensitivity of well-established chemical species (e.g., thrombin using simple quantifiers of their concentration profiles (e.g., maximum level of thrombin concentration, area under the thrombin concentration versus time curve. In order to get an improved classifier, we use a 34-protein factor clotting cascade model and convert the simulation data into a high-dimensional representation (about 19000 features using a piecewise cubic polynomial fit. Then, we systematically find plausible assays to effectively gauge changes in acute coronary syndrome/coronary artery disease populations by introducing a statistical learning technique called Random Forests. We find that differences associated with acute coronary syndromes emerge in combinations of a handful of features. For instance, concentrations of 3 chemical species, namely, active alpha-thrombin, tissue factor-factor VIIa-factor Xa ternary complex, and intrinsic tenase complex with factor X, at specific time windows, could be used to classify acute coronary syndromes to an accuracy of about 87.2%. Such a combination could be used to efficiently assay the coagulation system.

  19. Progestin and thrombin regulate tissue factor expression in human term decidual cells.

    Science.gov (United States)

    Lockwood, C J; Murk, W; Kayisli, U A; Buchwalder, L F; Huang, S-T; Funai, E F; Krikun, G; Schatz, F

    2009-06-01

    Perivascular cell membrane-bound tissue factor (TF) initiates hemostasis via thrombin generation. The identity and potential regulation of TF-expressing cells at the human maternal-fetal interface that confers hemostatic protection during normal and preterm delivery is unclear. The objective of the study were to identify TF-expressing cells at the maternal-fetal interface in term and preterm decidual sections by immunohistochemistry and evaluate progestin, thrombin, TNF-alpha, and IL-1beta effects on TF expression by cultured human term decidual cells (DCs). Serial placental sections were immunostained for TF. Leukocyte-free term DC monolayers were incubated with 10(-8) M estradiol (E2) or E2 plus 10(-7) M medroxyprogestrone acetate (MPA) +/- thrombin or TNF-alpha or IL-1beta. ELISA and Western blotting assessed TF in cell lysates. Quantitative real-time RT-PCR measured TF mRNA levels. Immunolocalized TF in DC membranes in preterm and term placental sections displayed higher Histologic Scores than villous mesenchymal cells (P term placental sections, DC-expressed TF exceeds that of other cell types at the maternal-fetal interface and is localized at the cell membranes in which it can bind to factor VII and meet the hemostatic demands of labor and delivery via thrombin formation. Unlike the general concept that TF is constitutive in cells that highly express it, MPA and thrombin significantly enhanced TF expression in term DC monolayers.

  20. Platelet- and erythrocyte-derived microparticles trigger thrombin generation via factor XIIa.

    Science.gov (United States)

    Van Der Meijden, P E J; Van Schilfgaarde, M; Van Oerle, R; Renné, T; ten Cate, H; Spronk, H M H

    2012-07-01

    The procoagulant properties of microparticles (MPs) are due to the of the presence of phosphatidylserine (PS) and tissue factor (TF) on their surface. The latter has been demonstrated especially on MPs derived from monocytes. To investigate the relative contribution of TF and factor (F)XII in initiating coagulation on MPs derived from monocytes, platelets and erythrocytes. Microparticles were isolated from calcium ionophore-stimulated platelets, erythrocytes and monocytic THP-1 cells. MPs were quantified, characterized for cell-specific antigens and analyzed for TF, PS exposure and their thrombin-generating potential. The MP number was not proportional to PS exposure and the majority of the MPs exposed PS. TF activity was undetectable on platelet- and erythrocyte-derived MPs (monocyte-derived MPs exposed TF (32 fM nM(-1) PS). Platelet-, erythrocyte- and monocyte-derived MPs, but not purified phospholipids, initiated thrombin generation in normal plasma in the absence of an external trigger (lag time derived MPs, but interfered with monocyte MP-triggered coagulation. Platelet- and erythrocyte-derived MPs completely failed to induce thrombin generation in FXII-deficient plasma. In contrast, monocyte-derived MPs induced similar thrombin generation in normal vs. FXII-deficient plasma. MPs from platelets and erythrocytes not only propagate coagulation by exposing PS but also initiate thrombin generation independently of TF in a FXII-dependent manner. In contrast, monocyte-derived MPs trigger coagulation predominantly via TF. © 2012 International Society on Thrombosis and Haemostasis.

  1. Bufadienolides from Kalanchoe daigremontiana as thrombin inhibitors-In vitro and in silico study.

    Science.gov (United States)

    Kolodziejczyk-Czepas, Joanna; Sieradzka, Malgorzata; Moniuszko-Szajwaj, Barbara; Pecio, Łukasz; Ponczek, Michal B; Nowak, Pawel; Stochmal, Anna

    2017-06-01

    Thrombin is an active plasma coagulation factor II, critical for the formation of fibrin clot during blood coagulation. For that reason, this protein is also a crucial target for different anti-thrombotic therapies. The work is based on in vitro evaluation of the inhibitory effect of bufadienolide-rich fraction, isolated from roots of Kalanchoe daigremontiana (1-50μg/ml) on enzymatic properties of a serine proteinase - thrombin. The efficacy of the inhibition of amidolytic activity of thrombin (measured as a hydrolysis of the chromogenic substrate S-2238, Chromogenix) attained about 10 and 66%, respectively. The IC 50 , established for the examined bufadienolide fraction was 2.79μg/ml, while the IC 50 calculated for argatroban (reference compound) was 0.78μg/ml. Linearization conducted using Lineweaver-Burk plot indicated that the K. daigremontiana fraction contains compounds that are uncompetitive inhibitors of thrombin. K. daigremontiana fraction was also able to reduce the proteolytic activity of thrombin towards its physiological substrate, i.e. fibrinogen. Additionally, this study is supported by in silico analysis of interactions of the most common compounds, identified in the examined in Kalanchoe extract to crystal structure of this enzyme. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Platelet-derived microparticles regulates thrombin generation via phophatidylserine in abdominal sepsis.

    Science.gov (United States)

    Wang, Yongzhi; Zhang, Su; Luo, Lingtao; Norström, Eva; Braun, Oscar Ö; Mörgelin, Matthias; Thorlacius, Henrik

    2018-02-01

    Sepsis is associated with dysfunctional coagulation. Recent data suggest that platelets play a role in sepsis by promoting neutrophil accumulation. Herein, we show that cecal ligation and puncture (CLP) triggered systemic inflammation, which is characterized by formation of IL-6 and CXC chemokines as well as neutrophil accumulation in the lung. Platelet depletion decreased neutrophil accumulation, IL-6, and CXC chemokines formation in septic lungs. Depletion of platelets increased peak thrombin formation and total thrombin generation (TG) in plasma from septic animals. CLP elevated circulating levels of platelet-derived microparticles (PMPs). In vitro generated PMPs were a potent inducer of TG. Interestingly, in vitro wild-type recombinant annexin V abolished PMP-induced thrombin formation whereas a mutant annexin V protein, which does not bind to phosphatidylserine (PS), had no effect. Administration of wild-type, but not mutant annexin V, significantly inhibited thrombin formation in septic animals. Moreover, CLP-induced formation of thrombin-antithrombin complexes were reduced in platelet-depleted mice and in animals pretreated with annexin V. PMP-induced TG attenuated in FXII- and FVII-deficient plasma. These findings suggest that sepsis-induced TG is dependent on platelets. Moreover, PMPs formed in sepsis are a potent inducer of TG via PS exposure, and activation of both the intrinsic and extrinsic pathway of coagulation. In conclusion, these observations suggest that PMPs and PS play an important role in dysfunctional coagulation in abdominal sepsis. © 2017 Wiley Periodicals, Inc.

  3. Binding of poly(amidoamine), carbosilane, phosphorus and hybrid dendrimers to thrombin-Constants and mechanisms.

    Science.gov (United States)

    Shcharbin, Dzmitry; Pedziwiatr-Werbicka, Elzbieta; Vcherashniaya, Aliaksandra; Janaszewska, Anna; Marcinkowska, Monika; Goska, Piotr; Klajnert-Maculewicz, Barbara; Ionov, Maksim; Abashkin, Viktar; Ihnatsyeu-Kachan, Aliaksei; de la Mata, F Javier; Ortega, Paula; Gomez-Ramirez, Rafael; Majoral, Jean-Pierre; Bryszewska, Maria

    2017-07-01

    Thrombin is an essential part of the blood coagulation system; it is a serine protease that converts soluble fibrinogen into insoluble strands of fibrin, and catalyzes many other coagulation-related reactions. Absorption at its surface of small nanoparticles can completely change the biological properties of thrombin. We have analyzed the influence on thrombin of 3 different kinds of small nanoparticles: dendrimers (phosphorus-based, carbosilane based and polyamidoamine) and 2 hybrid systems containing carbosilane, viologen and phosphorus dendritic scaffolds in one single molecule, bearing different flexibility, size and surface charge. There was significant alteration in the rigidity of the rigid dendrimers in contrast to flexible dendrimers. These differences in their action are important in understanding interactions taking place at a bio-nanointerface. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Dabigatran reduces thrombin-induced platelet aggregation and activation in a dose-dependent manner

    DEFF Research Database (Denmark)

    Vinholt, Pernille Just; Nielsen, Christian; Söderström, Anna Cecilia

    2017-01-01

    of dabigatran fully inhibited platelet aggregation for thrombin up to 2 IU/mL, while dabigatran did not affect platelet aggregation by other agonists. Platelet activation (percentage of platelets positive for activated GPIIb/IIIa, CD63, P-selectin) was reduced after thrombin stimulation in samples...... with dabigatran levels ≥500 ng/mL. After stimulation with thrombin, the percentage of activated GPIIb/IIIa-positive platelets was 99.8 ± 0.2% without dabigatran, 14.7 ± 4.7% with 500 ng/mL dabigatran, and 4.2 ± 0.2% with 10,000 ng/mL dabigatran, both p 

  5. Pseudomonas aeruginosa elastase cleaves a C-terminal peptide from human thrombin that inhibits host inflammatory responses

    DEFF Research Database (Denmark)

    van der Plas, Mariena J A; Bhongir, Ravi K V; Kjellström, Sven

    2016-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen known for its immune evasive abilities amongst others by degradation of a large variety of host proteins. Here we show that digestion of thrombin by P. aeruginosa elastase leads to the release of the C-terminal thrombin-derived peptide FYT21...

  6. The inactivation of single-chain urokinase-type plasminogen activator by thrombin in a plasma milieu : effect of thrombomodulin

    NARCIS (Netherlands)

    Braat, E.A.M.; Los, P.; Rijken, D.C.

    1998-01-01

    Thrombin cleaves single-chain urokinase-type plasminogen activator (scu- PA) into a virtually inactive two-chain form (tcu-PA/T), a process which may contribute to the maintenance of a fresh blood clot. We have examined the inactivation of scu-PA by thrombin in a plasma milieu to get more insight in

  7. The suicide substrate reaction between plasminogen activator inhibitor 1 acid thrombin is regulated by the cofactors vitronectin and heparin

    NARCIS (Netherlands)

    van Meijer, M.; Smilde, A.; Tans, G.; Nesheim, M. E.; Pannekoek, H.; Horrevoets, A. J.

    1997-01-01

    The interaction of thrombin with plasminogen activator inhibitor 1 (PAI-1) is shown to result in the simultaneous formation of both cleaved PAI-1 and a sodium dodecyl sulfate-stable thrombin-PAI-1 complex. The kinetics of this reaction can be described by a ''suicide substrate'' mechanism that

  8. Thrombin and PAF stimulate formation of inositol triphosphate from similar pools of phosphatidylinositol-4,5-bisphosphate in platelets

    International Nuclear Information System (INIS)

    Shukla, S.D.; Franklin, C.C.

    1986-01-01

    During platelet activation phospholipase C cleaves phosphatidylinositol-4,5-bisphosphate (PIP 2 ) to generate diacylglycerol and inositol triphosphate (IP 3 ). Production of IP 3 was therefore used as a probe to differentiate between thrombin and platelet activating factor (PAF) sensitive pools of PIP 2 . Stimulation of [ 3 H]inositol labelled rabbit platelets (0.5 x 10 9 cells/ml containing 0.1 mM EGTA and 2 mM LiCl) with thrombin (1 U/ml) caused a maximum 3 to 10 fold increase in [ 3 H]IP 3 in 5 min. Treatment with PAF (1 x 10 -9 M) led to a maximum 3 to 5 fold increase in [ 3 H]IP 3 in 5 s followed by a decrease to basal level in 30 s. Addition of thrombin for 5 min followed by PAF for 5 s showed no further increase in [ 3 H]IP 3 over that obtained with thrombin alone. Various other sequential treatments with thrombin and PAF showed negligible cumulative effect. Simultaneous addition of thrombin and PAF showed a partial additive production of [ 3 H]IP 3 at short time periods but these levels never significantly exceeded those obtained by thrombin at 5 min or PAF at 5 s. It is concluded that in platelets thrombin and PAF (a) differentially activate PIP 2 -phosphodiesterase and (b) stimulate production of IP 3 from similar pools of PIP 2

  9. Influence of single nucleotide polymorphisms on thrombin generation in factor V Leiden heterozygotes.

    Science.gov (United States)

    Segers, O; Simioni, P; Tormene, D; Castoldi, E

    2014-03-03

    Carriership of the factor V (FV) Leiden mutation increases the risk of venous thromboembolism (VTE) ~4-fold, but the individual risk of each FV Leiden carrier depends on several co-inherited risk and protective factors. Under the hypothesis that thrombin generation might serve as an intermediate phenotype to identify genetic modulators of VTE risk, we enrolled 188 FV Leiden heterozygotes (11 with VTE) and determined the following parameters: thrombin generation in the absence and presence of activated protein C (APC); plasma levels of prothrombin, factor X, antithrombin, protein S and tissue factor pathway inhibitor; and the genotypes of 24 SNPs located in the genes encoding these coagulation factors and inhibitors. Multiple regression analysis was subsequently applied to identify the (genetic) determinants of thrombin generation. The endogenous thrombin potential (ETP) showed a striking inter-individual variability among different FV Leiden carriers and, especially when measured in the presence of APC, correlated with VTE risk. Several SNPs in the F2 (rs1799963, rs3136516), F10 (rs693335), SERPINC1 (rs2227589), PROS1 (Heerlen polymorphism) and TFPI (rs5940) genes significantly affected the ETP-APC and/or the ETP+APC in FV Leiden carriers. Most of these SNPs have shown an association with VTE risk in conventional epidemiological studies, suggesting that the genetic dissection of thrombin generation leads to the detection of clinically relevant SNPs. In conclusion, we have identified several SNPs that modulate thrombin generation in FV Leiden heterozygotes. These SNPs may help explain the large variability in VTE risk observed among different FV Leiden carriers.

  10. Thrombin generation assays for global evaluation of the hemostatic system: perspectives and limitations

    Directory of Open Access Journals (Sweden)

    Rita Carolina Figueiredo Duarte

    Full Text Available Abstract The existing techniques to evaluate hemostasis in clinical laboratories are not sensitive enough to detect hypercoagulable and mild hypocoagulable states. Under different experimental conditions, the thrombin generation test may meet these requirements. This technique evaluates the overall balance between procoagulant and anticoagulant forces and has provided new insights in our understanding of the coagulation cascade, as well as of the diagnosis of hypocoagulability and hypercoagulability conditions. Thrombin generated in the thrombin generation test can be quantified as platelet-rich or platelet-poor plasma using the calibrated automated thrombogram method, which monitors the cleavage of a fluorogenic substrate that is simultaneously compared to the known thrombin activity in a non-clotting plasma sample. The calibrated automated thrombogram method is an open system, in which different antibodies, proteins, enzymes and peptides can be introduced to answer specific questions regarding hemostatic processes. The thrombin generation test has great clinical potential, such as in monitoring patients taking anticoagulants and antiplatelet drugs, screening for genetic or acquired thrombotic disorders, and evaluating bleeding risk control in patients with hemophilia using bypass agents or replacement therapy. Different to conventional coagulation tests, the thrombin generation test can be used for an overall evaluation of hemostasis, the results of which can then be used to evaluate specific characteristics of hemostasis, such as prothrombin time, activated partial thromboplastin time, and levels of fibrinogen and other coagulation factors. The introduction of this method will contribute to a better understanding and evaluation of overall hemostatic processes; however, this method still requires standardization and clinical validation.

  11. Thrombin-activatable fibrinolysis inhibitor activity in healthy and diseased dogs

    DEFF Research Database (Denmark)

    Jessen, Lisbeth Rem; Wiinberg, Bo; Kjelgaard-Hansen, Mads

    2010-01-01

    Background: In people, increased thrombin-activatable fibrinolysis inhibitor (TAFI) antigen has been associated with increased risk of thrombosis, and decreased TAFI may contribute to bleeding diathesis. TAFI activity in dogs has been described in experimental models, but not in dogs with spontan......Background: In people, increased thrombin-activatable fibrinolysis inhibitor (TAFI) antigen has been associated with increased risk of thrombosis, and decreased TAFI may contribute to bleeding diathesis. TAFI activity in dogs has been described in experimental models, but not in dogs...

  12. Structural Characterization of a Thrombin-Aptamer Complex by High Resolution Native Top-Down Mass Spectrometry

    Science.gov (United States)

    Zhang, Jiang; Loo, Rachel R. Ogorzalek; Loo, Joseph A.

    2017-09-01

    Native mass spectrometry (MS) with electrospray ionization (ESI) has evolved as an invaluable tool for the characterization of intact native proteins and non-covalently bound protein complexes. Here we report the structural characterization by high resolution native top-down MS of human thrombin and its complex with the Bock thrombin binding aptamer (TBA), a 15-nucleotide DNA with high specificity and affinity for thrombin. Accurate mass measurements revealed that the predominant form of native human α-thrombin contains a glycosylation mass of 2205 Da, corresponding to a sialylated symmetric biantennary oligosaccharide structure without fucosylation. Native MS showed that thrombin and TBA predominantly form a 1:1 complex under near physiological conditions (pH 6.8, 200 mM NH4OAc), but the binding stoichiometry is influenced by the solution ionic strength. In 20 mM ammonium acetate solution, up to two TBAs were bound to thrombin, whereas increasing the solution ionic strength destabilized the thrombin-TBA complex and 1 M NH4OAc nearly completely dissociated the complex. This observation is consistent with the mediation of thrombin-aptamer binding through electrostatic interactions and it is further consistent with the human thrombin structure that contains two anion binding sites on the surface. Electron capture dissociation (ECD) top-down MS of the thrombin-TBA complex performed with a high resolution 15 Tesla Fourier transform ion cyclotron resonance (FTICR) mass spectrometer showed the primary binding site to be at exosite I located near the N-terminal sequence of the heavy chain, consistent with crystallographic data. High resolution native top-down MS is complementary to traditional structural biology methods for structurally characterizing native proteins and protein-DNA complexes. [Figure not available: see fulltext.

  13. Longitudinal assessment of thrombin generation potential in response to alteration of antiplatelet therapy after TIA or ischaemic stroke.

    LENUS (Irish Health Repository)

    Tobin, W O

    2013-02-01

    The impact of changing antiplatelet therapy on thrombin generation potential in patients with ischaemic cerebrovascular disease (CVD) is unclear. We assessed patients within 4 weeks of TIA or ischaemic stroke (baseline), and then 14 days (14d) and >90 days (90d) after altering antiplatelet therapy. Thrombin generation was assessed in platelet poor plasma. Ninety-one patients were recruited. Twenty-four were initially assessed on no antiplatelet therapy, and then after 14d (N = 23) and 90d (N = 8) on aspirin monotherapy; 52 were assessed on aspirin monotherapy, and after 14 and 90 days on aspirin and dipyridamole combination therapy; 21 patients were assessed on aspirin and after 14 days (N = 21) and 90 days (N = 19) on clopidogrel. Peak thrombin generation and endogenous thrombin potential were reduced at 14 and 90 days (p ≤ 0.04) in the overall cohort. We assessed the impact of individual antiplatelet regimens on thrombin generation parameters to investigate the cause of this effect. Lag time and time-to-peak thrombin generation were unchanged at 14 days, but reduced 90 days after commencing aspirin (p ≤ 0.009). Lag time, peak thrombin generation and endogenous thrombin potential were reduced at both 14 and 90 days after adding dipyridamole to aspirin (p ≤ 0.01). Lag time was reduced 14 days after changing from aspirin to clopidogrel (p = 0.045), but this effect was not maintained at 90 days (p = 0.2). This pilot study did not show any consistent effects of commencing aspirin, or of changing from aspirin to clopidogrel on thrombin generation potential during follow-up. The addition of dipyridamole to aspirin led to a persistent reduction in peak and total thrombin generation ex vivo, and illustrates the diverse, potentially beneficial, newly recognised \\'anti-coagulant\\' effects of dipyridamole in ischaemic CVD.

  14. Intravenous pyogenic granuloma or intravenous lobular capillary hemangioma

    Energy Technology Data Exchange (ETDEWEB)

    Ghekiere, Olivier; Galant, Christine; Berg, Bruno Vande [Cliniques Universitaires St. Luc, Department of Radiology, Brussels (Belgium)

    2005-06-01

    Lobular capillary hemangioma is a vascular neoplasm that commonly occurs as a cutaneous tumor. When it involves the skin and mucosal surfaces, ulceration and suppuration may occur, hence the classic term of pyogenic granuloma. Intravenous pyogenic granuloma is a rare solitary form of lobular capillary hemangioma that usually occurs in the veins of the neck and upper extremities. We report the ultrasonographic and magnetic resonance imaging findings of a pyogenic intravenous granuloma localized in the right cephalic vein. The imaging and pathological findings and the differential diagnoses are discussed. (orig.)

  15. Thrombin-induced rabbit platelet microbicidal protein is fungicidal in vitro.

    Science.gov (United States)

    Yeaman, M R; Ibrahim, A S; Edwards, J E; Bayer, A S; Ghannoum, M A

    1993-03-01

    Platelet microbicidal protein (PMP) is released from platelets in response to thrombin stimulation. PMP is known to possess in vitro bactericidal activity against Staphylococcus aureus and viridans group streptococci. To determine whether PMP is active against other intravascular pathogens, we evaluated its potential fungicidal activity against strains of Candida species and Cryptococcus neoformans. Anionic resin adsorption and gel electrophoresis confirmed that the fungicidal activity of PMP resided in a small (approximately 8.5-kDa), cationic protein, identical to previous studies of PMP-induced bacterial killing (M.R. Yeaman, S.M. Puentes, D.C. Norman, and A.S. Bayer, Infect. Immun. 60:1202-1209, 1992). When assayed over a 180-min period in vitro, the susceptibilities of these fungi to PMP varied considerably. Generally, Candida albicans strains (mean survival, 33.5% +/- 6.9% [n = 6]) as well as isolates of Candida glabrata (mean survival, 50.8% +/- 2.9% [n = 2]) were the most susceptible to killing by PMP, while Candida guillermondii and Candida parapsilosis were relatively resistant to PMP-induced killing. Compared with C. albicans, C. neoformans was relatively resistant to the fungicidal activity of PMP, with a mean survival among the isolates studied of 77.4% +/- 12.4% (n = 6). Against C. albicans, PMP-induced fungicidal activity was time dependent (range, 0 to 180 min), PMP concentration dependent (range, 10 to 150 U/ml), and inversely related to the fungal inoculum (range, 5 x 10(3) to 1 x 10(5) CFU/ml). Scanning electron microscopy of PMP-exposed C. albicans and C. neoformans cells revealed extensive surface damage and collapse, suggesting that the site of PMP fungicidal action may directly or indirectly involve the fungal cell envelope.

  16. Orthostatic stability with intravenous levodopa

    Directory of Open Access Journals (Sweden)

    Shan H. Siddiqi

    2015-08-01

    Full Text Available Intravenous levodopa has been used in a multitude of research studies due to its more predictable pharmacokinetics compared to the oral form, which is used frequently as a treatment for Parkinson’s disease (PD. Levodopa is the precursor for dopamine, and intravenous dopamine would strongly affect vascular tone, but peripheral decarboxylase inhibitors are intended to block such effects. Pulse and blood pressure, with orthostatic changes, were recorded before and after intravenous levodopa or placebo—after oral carbidopa—in 13 adults with a chronic tic disorder and 16 tic-free adult control subjects. Levodopa caused no statistically or clinically significant changes in blood pressure or pulse. These data add to previous data that support the safety of i.v. levodopa when given with adequate peripheral inhibition of DOPA decarboxylase.

  17. A sensitive bioimmunoassay for thrombin-cleaved two-chain urokinase-type plasminogen activator (abstract)

    NARCIS (Netherlands)

    Braat, E.A.M.; Nauland, U.; Dooijewaard, G.; Rijken, P.C.

    1996-01-01

    Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a virtually inactive two-chain form (tcu-PA/T). Little is known about the physiological importance of tcu-PA/T. To examine the occurrence of tcu-PA/T in vivo, we developed a sensitive and specific bioimmunoassay (BIA)

  18. Thrombin generation and coagulation factor activities: evaluation and comparison with the international normalized ratio

    DEFF Research Database (Denmark)

    Christensen, Thomas D; Jensen, Claus; Larsen, Torben B

    2009-01-01

    of calibrated automated thrombin generation (CAT) and clotting activity of coagulation factors II, VII, IX and X and to compare these parameters with the INR measured in a central laboratory as well as using portable coagulometers. Twenty-four patients on stable oral anticoagulation therapy with coumarins were...

  19. EFFICACY OF THROMBIN FIBRIN GLUE AND SCLE ROSANT IN THE MANAGEMENT OF BLEEDI NG GASTRIC VARICES

    Directory of Open Access Journals (Sweden)

    Sanjay Gupta

    2015-01-01

    Full Text Available Gastric varices are noted in up to 20 % of patents with portal hypertension , and are more common in those with non - cirrhotic etiology 1 . They bleed at lower portal pressures , bleed more severely and are associated with higher rates of rebleed , encephalopathy and mortality 1,2,3 . Variceal obliteration using tissue adhesives such as N - butyl cyanoacrylate leading to plugging and thrombosis of the gastric varices is currently the first line management option for obliteration of the gastric varices 3 . Although various options have been proposed , gold standard for management of gastric variceal bleeds is yet to be defined. We theorized that injection of the gastric varices using thrombin based glue followed by injection of a sclerosant shall be effective in optimum sclerotherapy and eradication of gastric varices. MATERIAL AND METHODS : All patients presenting with gastric variceal bleed were offered sclerotherapy with Thrombin fibrin based glue and sclerosant (TFG/S . During the study period 18 patients were enrolled in the TGF/S group. 21 patients underwent variceal plugging with n - butyl cyanoacrylate (NBC . There was no significant difference in age/ sex , duration of bleed or time interval between onset of bleed and endotherapy. RESULTS: Patients undergoing endotherapy with TGF/S had less episodes of bleed , and greater eradication of varices. CONCLUSION: The results with thrombin / fibrin glue and sclerotherapy are highly encouraging. Well - designed trials need to be performed KEYWORDS:Gastric varices; Thrombin Sclerotherapy

  20. Protein Z efficiently depletes thrombin generation in disseminated intravascular coagulation with poor prognosis.

    Science.gov (United States)

    Lee, Nuri; Kim, Ji-Eun; Gu, Ja-Yoon; Yoo, Hyun Ju; Kim, Inho; Yoon, Sung-Soo; Park, Seonyang; Han, Kyou-Sup; Kim, Hyun Kyung

    2016-01-01

    Disseminated intravascular coagulation (DIC) is characterized by consumption of coagulation factors and anticoagulants. Thrombin generation assay (TGA) gives useful information about global hemostatic status. We developed a new TGA system that anticoagulant addition can deplete thrombin generation in plasma, which may reflect defective anticoagulant system in DIC. TGAs were measured on the calibrated automated thrombogram with and without thrombomodulin or protein Z in 152 patients who were suspected of having DIC, yielding four parameters including lag time, endogenous thrombin potential, peak thrombin and time-to-peak in each experiment. Nonsurvivors showed significantly prolonged lag time and time-to-peak in TGA-protein Z system, which was performed with added protein Z. In multivariate Cox regression analysis, lag time and time-to-peak in TGA system were significant independent prognostic factors. In TGA-protein Z system, lag time and time-to-peak were revealed as independent prognostic factors of DIC. Protein Z addition could potentiate its anticoagulant effect in DIC with poor prognosis, suggesting the presence of defective protein Z system. The prolonged lag time and time-to-peak in both TGA and TGA-protein Z systems are expected to be used as independent prognostic factors of DIC.

  1. Computational Analysis of Intersubject Variability and Thrombin Generation in Dilutional Coagulopathy

    Science.gov (United States)

    2012-11-01

    Mann15,30-32 and S. Dia- mond ,33,34 as well as by our own research group.16 We used the computational model to calculate the five thrombin generation...approach to modeling dilution did not take into account the specific type of liquid that dilutes the blood. While it is known that the type of

  2. Inhibition of Src family kinases improves cognitive function after intraventricular hemorrhage or intraventricular thrombin.

    Science.gov (United States)

    Liu, Da Zhi; Waldau, Ben; Ander, Bradley P; Zhan, Xinhua; Stamova, Boryana; Jickling, Glen C; Lyeth, Bruce G; Sharp, Frank R

    2017-07-01

    Intraventricular hemorrhage causes spatial memory loss, but the mechanism remains unknown. Our recent studies demonstrated that traumatic brain injury activates Src family kinases, which cause spatial memory loss. To test whether the spatial memory loss was due to blood in the ventricles, which activated Src family kinases, we infused autologous whole blood or thrombin into the lateral ventricles of adult rats to model non-traumatic intraventricular hemorrhage. Hippocampal neuron loss was examined 1 day to 5 weeks later. Spatial memory function was assessed 29 to 33 days later using the Morris water maze. Five weeks after the ventricular injections of blood or thrombin, there was death of most hippocampal neurons and significant memory deficits compared with sham operated controls. These data show that intraventricular thrombin is sufficient to kill hippocampal neurons and produce spatial memory loss. In addition, systemic administration of the non-specific Src family kinase inhibitor PP2 or intraventricular injection of siRNA-Fyn, a Src family kinase family member, prevented hippocampal neuronal loss and spatial memory deficits following intraventricular hemorrhage. The data support the conclusions that thrombin mediates the hippocampal neuronal cell death and spatial memory deficits produced by intraventricular blood and that these can be blocked by non-specific inhibition of Src family kinases or by inhibiting Fyn.

  3. Flow cytometric analysis of microparticle phenotype and their role in thrombin generation.

    Science.gov (United States)

    Macey, M G; Enniks, N; Bevan, S

    2011-01-01

    Microparticles may be generated from a number of cell types and are known to play a role in haemostasis by a variety of mechanisms. We investigated the role of platelet, red cell, and leucocyte-derived microparticles in the measurement of thrombin generation. Four parameters of thrombin generation (the endogenous thrombin potential (ETP), lag time, time to peak, peak height) and microparticle content was determined in 35 plasma samples from normal individuals pre and post filtration to remove microparticles. Immunofluorescent flow cytometry was used to identify and enumerate platelet, leucocyte, monocyte and red cell derived microparticles in plasma samples based on the expression of CD42b, CD45, CD15, and Glycophorin A respectively. Expression of phosphatidylserine and tissue factor by microparticles was determined by Annexin V and anti CD142 binding. The pre and post filtration results were compared. There was a significant decrease in ETP and Peak Height, and an increase in the time to peak post filtration (P microparticles was also observed. The change in CD42b+ microparticles correlated highly with the change in Annexin V+ microparticles (r = 0.68). Whilst the change in ETP correlated best with the change in CD15+ microparticles (r = 0.45) and the change in time to peak correlated with the change in Annexin V binding (r = 0.52) (P < 0.01). The presence of micropartcles in plasma significantly affects thrombin generation. Copyright © 2010 International Clinical Cytometry Society.

  4. Rigidification of the autolysis loop enhances Na[superscript +] binding to thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi, Nicola; Chen, Raymond; Chen, Zhiwei; Bah, Alaji; Di Cera, Enrico (St. Louis-MED)

    2011-09-20

    Binding of Na{sup +} to thrombin ensures high activity toward physiological substrates and optimizes the procoagulant and prothrombotic roles of the enzyme in vivo. Under physiological conditions of pH and temperature, the binding affinity of Na{sup +} is weak due to large heat capacity and enthalpy changes associated with binding, and the K{sub d} = 80 mM ensures only 64% saturation of the site at the concentration of Na{sup +} in the blood (140 mM). Residues controlling Na{sup +} binding and activation have been identified. Yet, attempts to improve the interaction of Na{sup +} with thrombin and possibly increase catalytic activity under physiological conditions have so far been unsuccessful. Here we report how replacement of the flexible autolysis loop of human thrombin with the homologous rigid domain of the murine enzyme results in a drastic (up to 10-fold) increase in Na{sup +} affinity and a significant improvement in the catalytic activity of the enzyme. Rigidification of the autolysis loop abolishes the heat capacity change associated with Na{sup +} binding observed in the wild-type and also increases the stability of thrombin. These findings have general relevance to protein engineering studies of clotting proteases and trypsin-like enzymes.

  5. Interactions between thrombin and natural products of Millettia speciosa Champ. using capillary zone electrophoresis.

    Science.gov (United States)

    Zhang, Shuyu; Yin, Ting; Ling, Xiaomei; Liang, Hong; Zhao, Yuying

    2008-08-01

    In Chinese medicine Suberect Spatholobus Stem is used to treat menoxenia, blood deficiency, numb paralyses, and so on. In folk, Millettia speciosa is often used as a substitute for Suberect Spatholobus Stem in some areas but it has not been reported whether M. speciosa is the eligible substitute for Suberect Spatholobus Stem or not till now. In this study, a capillary zone electrophoretic method was applied to determinate the interactions between natural products isolated from M. speciosa Champ. and thrombin for the first time. Both qualitative and quantitative characterizations of the molecule-enzyme binding were determined. Twenty ingredients were isolated from M. speciosa Champ. and the results showed that compared with positive and negative control, the compounds YT-1, YT-2, YT-3, YT-8, YT-9, YT-10, YT-11, YT-12, YT-14, YT-15, YT-16, and YT-20 interacted with thrombin while the other eight had no binding to thrombin. The binding constants of the interaction between compounds and thrombin were calculated by the Scatchard analysis formula. Because M. speciosa contains these compounds which have different levels of anticoagulant activity, it may be the eligible substitute for Suberect Spatholobus Stem.

  6. Inactivation of single-chain urokinase-type plasminogen activator by thrombin in human subjects

    NARCIS (Netherlands)

    Braat, E. A.; Levi, M. [=Marcel M.; Bos, R.; Haverkate, F.; Lassen, M. R.; de Maat, M. P.; Rijken, D. C.

    1999-01-01

    Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a virtually inactive two-chain form (tcu-PA/T), a process that may protect a blood clot from early fibrinolysis. It is not known under what circumstances tcu-PA/T can be generated in vivo. We have studied the occurrence

  7. Thrombin inhibition with melagatran does not attenuate renal ischaemia-reperfusion injury in rats

    DEFF Research Database (Denmark)

    Nitescu, Nicoletta; Grimberg, Elisabeth; Ricksten, Sven-Erik

    2007-01-01

    BACKGROUND: Renal ischaemia-reperfusion (IR) is associated with activation of the coagulation system and inflammation within the kidney. The aim of the present study was to examine the effects of selective thrombin inhibition with melagatran on kidney morphology and function in rats subjected...

  8. Variable hypocoagulant effect of fish oil intake in humans: Modulation of fibrinogen level and thrombin generation

    NARCIS (Netherlands)

    Schoonbeek, K.van; Feijge, M.A.H.; Paquay, M.; Rosing, J.; Saris, W.; Kluft, C.; Giesen, P.L.A.; Maat, M.P.M.de; Heemskerk, J.W.M.

    2004-01-01

    Objective-The beneficial effect of dietary fish oil, rich in omega-3 polyunsaturated fatty acids (PUFAs), on cardiovascular disease is multifactorial and may partly rely on their anticoagulant action. We studied how fish oil intake influenced thrombin generation in plasma and which factors were

  9. Flebogamma(®) DIF (intravenous immunoglobulin) purification process effectively eliminates procoagulant activities.

    Science.gov (United States)

    José, Marta; Marzo, Núria; Pons, Berta; Herrerias, Aida; López, Laura; Faro, Merche; López, Maite; Jorquera, Juan I

    2013-11-01

    Studies have demonstrated that traces of activated factor XI (FXIa) present in specific brands of intravenous immunoglobulin (IVIG) concentrates may pose a thrombogenic risk. To characterize procoagulant activity during fractionation and the elimination capacity of the Flebogamma(®) DIF (Grifols' IVIG) manufacturing process. Flebogamma(®) DIF fractionation steps included cryoprecipitate supernatant (Cryo/S), Fraction (Fr) I supernatant, and Fr II + III suspension. Purification steps included ultrafiltrate I, acid treatment, and pasteurization. Samples were assessed for total protein, IgG, and procoagulant activation markers. Cryo/S showed no procoagulant activity for prekallikrein activator (PKA), kallikrein-like, and non-activated partial thromboplastin time (NaPTT) with normal (-PPP) or FXI-deficient (-FXI) platelet poor plasma. Thrombin generation test (TGT)-PPP and TGT-FXI were DIF production process is capable of eliminating procoagulant activity because of its purification steps. Copyright © 2013 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  10. Competition-derived FRET-switching cationic conjugated polymer-Ir(III) complex probe for thrombin detection.

    Science.gov (United States)

    Du, Chunnuan; Hu, Yufang; Zhang, Qingqing; Guo, Zhiyong; Ge, Guoping; Wang, Sui; Zhai, Chunyang; Zhu, Mingshan

    2018-02-15

    A novel, label-free and convenient strategy for thrombin assay has been developed based on the fluorescence resonance energy transfer (FRET) from a cationic conjugated polymer (CCP) to Ir(III) complex. The energy donor (CCP) and acceptor (Ir(III) complex) were taken into close proximity through π-π stacking interaction and electrostatic interaction, leading to the occurrence of FRET. However, the introduction of the thrombin aptamer upset the status and blocked the FRET process, but afterwards the reappearance of FRET phenomenon was confirmed by the special binding interaction between aptamer and thrombin, thus achieving the quantitative detection of thrombin. This assay could detect thrombin as low concentration as about 0.05pM and provided a highly specific selectivity among other nonspecific proteins. Moreover, the strategy may allow our platform to provide similar sensitivity toward different targets in an aptamer-structure-independent manner. Furthermore, the assay can be used to detect thrombin in diluted real urine or serum samples with a satisfactory recovery, implying its great potential for rapid detection of thrombin in the clinic. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Affinity capillary electrophoresis with laser induced fluorescence detection for thrombin analysis using nuclease-resistant RNA aptamers.

    Science.gov (United States)

    Hao, Lihua; Bai, Yunlong; Wang, Hailin; Zhao, Qiang

    2016-12-09

    Aptamer affinity capillary electrophoresis coupled with laser-induced fluorescence (CE-LIF) combines the advantages of affinity aptamer, rapid CE separation, and high sensitivity detection. Here we reported an affinity CE-LIF assay for thrombin by using a fluorophore-labeled RNA aptamer containing 2'-fluoro modification in sugar rings of pyrimidine nucleotides (C and U) as affinity ligand. This RNA aptamer has high binding affinity, specificity and biostability. Thrombin at 0.2nM was successfully detected. This RNA aptamer allowed for the detection of thrombin spiked in diluted human serum sample due to the nuclease resistance. The RNA aptamer has comparable binding affinity to a 29-mer DNA aptamer for thrombin, and the binding site of the RNA aptamer on thrombin partially overlaps with the binding site of the 29-mer DNA aptamer on thrombin. It shows the nuclease-resistant RNA aptamers are promising in assays for thrombin. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Thrombin induces epithelial-mesenchymal transition and collagen production by retinal pigment epithelial cells via autocrine PDGF-receptor signaling.

    Science.gov (United States)

    Bastiaans, Jeroen; van Meurs, Jan C; van Holten-Neelen, Conny; Nagtzaam, Nicole M A; van Hagen, P Martin; Chambers, Rachel C; Hooijkaas, Herbert; Dik, Willem A

    2013-12-19

    De-differentiation of RPE cells into mesenchymal cells (epithelial-mesenchymal transition; EMT) and associated collagen production contributes to development of proliferative vitreoretinopathy (PVR). In patients with PVR, intraocular coagulation cascade activation occurs and may play an important initiating role. Therefore, we examined the effect of the coagulation proteins factor Xa and thrombin on EMT and collagen production by RPE cells. Retinal pigment epithelial cells were stimulated with factor Xa or thrombin and the effect on zonula occludens (ZO)-1, α-smooth muscle actin (α-SMA), collagen, and platelet-derived growth factor (PDGF)-B were determined by real-time quantitative-polymerase chain reaction (RQ-PCR), immunofluorescence microscopy, and HPLC and ELISA for collagen and PDGF-BB in culture supernatants, respectively. PDGF-receptor activation was determined by phosphorylation analysis and inhibition studies using the PDGF-receptor tyrosine kinase inhibitor AG1296. Thrombin reduced ZO-1 gene expression (P production of α-SMA and collagen increased. In contrast to thrombin, factor Xa hardly stimulated EMT by RPE. Thrombin clearly induced PDGF-BB production and PDGF-Rβ chain phosphorylation in RPE. Moreover, AG1296 significantly blocked the effect of thrombin on EMT and collagen production. Our findings demonstrate that thrombin is a potent inducer of EMT by RPE via autocrine activation of PDGF-receptor signaling. Coagulation cascade-induced EMT of RPE may thus contribute to the formation of fibrotic retinal membranes in PVR and should be considered as treatment target in PVR.

  13. Effects of fibrin, thrombin, and blood on breast capsule formation in a preclinical model.

    Science.gov (United States)

    Marques, Marisa; Brown, Spencer A; Cordeiro, Natália D S; Rodrigues-Pereira, Pedro; Cobrado, M Luís; Morales-Helguera, Aliuska; Lima, Nuno; Luís, André; Mendanha, Mário; Gonçalves-Rodrigues, Acácio; Amarante, José

    2011-03-01

    The root cause of capsular contracture (CC) associated with breast implants is unknown. Recent evidence points to the possible role of fibrin and bacteria in CC formation. The authors sought to determine whether fibrin, thrombin, and blood modulated the histological and microbiological outcomes of breast implant capsule formation in a rabbit model. The authors carried out a case-control study to assess the influence of fibrin, thrombin, and blood on capsule wound healing in a rabbit model. Eighteen New Zealand white rabbits received four tissue expanders. One expander acted as a control, whereas the other expander pockets received one of the following: fibrin glue, rabbit blood, or thrombin sealant. Intracapsular pressure/volume curves were compared among the groups, and histological and microbiological evaluations were performed (capsules, tissue expanders, rabbit skin, and air). The rabbits were euthanized at two or four weeks. At four weeks, the fibrin and thrombin expanders demonstrated significantly decreased intracapsular pressure compared to the control group. In the control and fibrin groups, mixed inflammation correlated with decreased intracapsular pressure, whereas mononuclear inflammation correlated with increased intracapsular pressure. The predominant isolate in the capsules, tissue expanders, and rabbit skin was coagulase-negative staphylococci. For fibrin and thrombin, both cultures that showed an organism other than staphylococci and cultures that were negative were associated with decreased intracapsular pressure, whereas cultures positive for staphylococci were associated with increased intracapsular pressure. Fibrin application during breast implantation may reduce rates of CC, but the presence of staphylococci is associated with increased capsule pressure even in the presence of fibrin, so care should be taken to avoid bacterial contamination.

  14. Effect of temperature on the association step in thrombin-fibrinogen interaction.

    Science.gov (United States)

    Picozzi, M; De Cristofaro, R

    1993-01-01

    Kinetics of fibrinopeptide A release by human alpha-thrombin at low fibrinogen concentration allowed us to measure the specificity constant, i.e. kcat/Km, for the interaction between the enzyme and human fibrinogen. A study of the dependence of the ratio kcat/Km upon the viscosity of the medium revealed that fibrinogen acts as a 'sticky' substrate, or, in other words, as a substrate that dissociates from the Michaelis complex with a rate comparable with that for acylation of the active site. These experiments allowed us also to compute for the first time the second-order rate constant for thrombin-fibrinogen association. A study of the temperature-dependence of the association rate, carried out over the temperature range spanning from 10 degrees C to 37 degrees C (pH 7.50; I0.15) permitted the estimation of the enthalpy and entropy of activation, delta H++ and delta S++, which were found to be equal to 5.69 +/- 0.77 kJ.mol-1 and -80.25 +/- 1.79 kJ.K-1.mol-1 respectively. In addition, the values of Km for thrombin-fibrinogen reaction were measured at different solution viscosities in order to derive the equilibrium dissociation constant, Ks, of this interaction. These experiments showed that the Ks values for thrombin-fibrinogen binding was equal to 1.8 microM at 25 degrees C. Altogether these results indicated that fibrinogen, though interacting with both the catalytic pocket and the fibrinogen recognition site on the thrombin molecule, dissociates from Michaelis complex with a rate comparable with that shown by amide substrates, which interact only with the catalytic site. PMID:8373370

  15. PAR1 antagonists inhibit thrombin-induced platelet activation whilst leaving the PAR4-mediated response intact.

    Science.gov (United States)

    Judge, Heather M; Jennings, Lisa K; Moliterno, David J; Hord, Edward; Ecob, Rosemary; Tricoci, Pierluigi; Rorick, Tyrus; Kotha, Jayaprakash; Storey, Robert F

    2015-01-01

    Thrombin-induced platelet activation is initiated by PAR1 and PAR4 receptors. Vorapaxar, a PAR1 antagonist, has been assessed in patients with acute coronary syndromes (ACS) and stable atherosclerotic disease in addition to standard-of-care treatment. In clinical trials, vorapaxar has been observed to reduce the frequency of ischaemic events in some subgroups though in others has increased the frequency of bleeding events. Among patients undergoing CABG surgery, which is associated with excess thrombin generation, bleeding was not increased. The aim of these studies was to investigate the effects of selective PAR1 antagonism on thrombin-induced platelet activation in patients receiving vorapaxar or placebo in the TRACER trial and to explore the roles of PAR1 and PAR4 in thrombin-induced platelet activation in healthy volunteers. ACS patients receiving vorapaxar or placebo in the TRACER trial were studied at baseline and 4 hours, 1 and 4 months during drug administration. Thrombin-induced calcium mobilisation in platelet-rich plasma was assessed by flow cytometry. In vitro studies were performed in healthy volunteers using the PAR1 antagonist SCH79797 or PAR4 receptor desensitisation. Vorapaxar treatment significantly inhibited thrombin-induced calcium mobilisation, leaving a residual, delayed response. These findings were consistent with calcium mobilisation mediated via the PAR4 receptor and were reproduced in vitro using SCH79797. PAR4 receptor desensitization, in combination with SCH79797, completely inhibited thrombin-induced calcium mobilisation confirming that the residual calcium mobilisation was mediated via PAR4. In conclusion vorapaxar selectively antagonises the PAR1-mediated component of thrombin-induced platelet activation, leaving the PAR4-mediated response intact, which may explain why vorapaxar is well tolerated in patients undergoing CABG surgery since higher thrombin levels in this setting may override the effects of PAR1 antagonism through PAR4

  16. Intravenous urography and childhood trauma

    OpenAIRE

    Okorie, N. M.; MacKinnon, A. E.

    1982-01-01

    Results of intravenous urography (IVU) in 33 patients suspected of suffering from renal trauma were reviewed. It was concluded that when haematuria is only detected microscopically and clears within 24 hr then an IVU is not necessary, in the absence of other evidence of significant urinary tract injury.

  17. Development of an Efficient G-Quadruplex-Stabilised Thrombin-Binding Aptamer Containing a Three-Carbon Spacer Molecule

    DEFF Research Database (Denmark)

    Aaldering, Lukas J.; Poongavanam, Vasanthanathan; Langkjær, Niels

    2017-01-01

    -modified UNA (amino-UNA) on the structural dynamics and stability of TBA. All three modifications were incorporated at three different loop positions (T3, T7, T12) of the TBA G-quadruplex structure to result in a series of TBA variants and their stability was studied by thermal denaturation; folding...... was studied by circular dichroism spectroscopy and thrombin clotting time. The results showed that spacer-C3 introduction at the T7 loop position (TBA-SP7) significantly improved stability and thrombin clotting time while maintaining a similar binding affinity as TBA to thrombin. Detailed molecular modelling...

  18. Salmon and human thrombin differentially regulate radicular pain, glial-induced inflammation and spinal neuronal excitability through protease-activated receptor-1.

    Directory of Open Access Journals (Sweden)

    Jenell R Smith

    Full Text Available Chronic neck pain is a major problem with common causes including disc herniation and spondylosis that compress the spinal nerve roots. Cervical nerve root compression in the rat produces sustained behavioral hypersensitivity, due in part to the early upregulation of pro-inflammatory cytokines, the sustained hyperexcitability of neurons in the spinal cord and degeneration in the injured nerve root. Through its activation of the protease-activated receptor-1 (PAR1, mammalian thrombin can enhance pain and inflammation; yet at lower concentrations it is also capable of transiently attenuating pain which suggests that PAR1 activation rate may affect pain maintenance. Interestingly, salmon-derived fibrin, which contains salmon thrombin, attenuates nerve root-induced pain and inflammation, but the mechanisms of action leading to its analgesia are unknown. This study evaluates the effects of salmon thrombin on nerve root-mediated pain, axonal degeneration in the root, spinal neuronal hyperexcitability and inflammation compared to its human counterpart in the context of their enzymatic capabilities towards coagulation substrates and PAR1. Salmon thrombin significantly reduces behavioral sensitivity, preserves neuronal myelination, reduces macrophage infiltration in the injured nerve root and significantly decreases spinal neuronal hyperexcitability after painful root compression in the rat; whereas human thrombin has no effect. Unlike salmon thrombin, human thrombin upregulates the transcription of IL-1β and TNF-α and the secretion of IL-6 by cortical cultures. Salmon and human thrombins cleave human fibrinogen-derived peptides and form clots with fibrinogen with similar enzymatic activities, but salmon thrombin retains a higher enzymatic activity towards coagulation substrates in the presence of antithrombin III and hirudin compared to human thrombin. Conversely, salmon thrombin activates a PAR1-derived peptide more weakly than human thrombin. These

  19. Microcosting Study of Rituximab Subcutaneous Injection Versus Intravenous Infusion

    NARCIS (Netherlands)

    Mihajloviç, Jovan; Bax, Pieter; van Breugel, Erwin; Blommestein, Hedwig M.; Hoogendoorn, Mels; Hospes, Wobbe; Postma, Maarten J.

    Purpose: The goal of this study is to identify and compare all direct costs of intravenous and subcutaneous rituximab given to patients with diffuse large B-cell lymphoma in the Netherlands.  Methods: Using a prospective, observational, bottom-up microcosting study, we collected primary data on the

  20. Effects of a transmitted light device for pediatric peripheral venipuncture and intravenous cannulation.

    Science.gov (United States)

    Yamazaki, Shinya; Tomita, Shu; Watanabe, Masahiro; Kawaai, Hiroyoshi; Shimamura, Kazuhiro

    2011-01-01

    Pediatric peripheral venipuncture and intravenous cannulation are difficult. However, successful venipuncture and intravenous cannulation are absolutely required for pediatric clinical risk management. This study assessed the success rate of venipuncture and intravenous cannulation when transmitted light was applied to the pediatric dorsum manus. The subjects included 100 young children who were scheduled for dental treatment or oral surgery under general anesthesia. Anesthesia was induced, and insertion of an intravenous catheter into the dorsum manus was attempted with or without using transmitted light. The patients were evaluated to determine whether the venipuncture was successful, and whether the intravenous cannulation of the external catheter was successful. The success rate of venipuncture was 100% when transmitted light was used, and 83% when the transmitted light was not used (P = 0.000016). In addition, the success rate of intravenous cannulation was 88% when transmitted light was used, and 55% when the transmitted light was not used (P = 0.0000002). The shape of the vein in the dorsum manus can be clearly recognized when transmitted light is used. The use of light significantly increased the success rate of intravenous cannulation, because it allowed direct confirmation of the direction to push the intravenous catheter forward. The use of transmitted light allows for more successful venipuncture and intravenous cannulation in young children.

  1. INVOLVEMENT OF BACTERICIDAL FACTORS FROM THROMBIN-STIMULATED PLATELETS IN CLEARANCE OF ADHERENT VIRIDANS STREPTOCOCCI IN EXPERIMENTAL INFECTIVE ENDOCARDITIS

    NARCIS (Netherlands)

    VANDERWERFF, J; ZAAT, SAJ; JOLDERSMA, W; HESS, J

    Platelets activated with thrombin release bactericidal factors. We studied the role of the susceptibility of viridans streptococci to these bactericidal factors in the development of infective endocarditis (IE). By using the experimental endocarditis rabbit model, the initial adherence and the

  2. Analytical and between-subject variation of thrombin generation measured by calibrated automated thrombography on plasma samples

    DEFF Research Database (Denmark)

    Kristensen, Anne F; Kristensen, Søren R; Falkmer, Ursula

    2018-01-01

    BACKGROUND: The Calibrated Automated Thrombography (CAT) is an in vitro thrombin generation (TG) assay that holds promise as a valuable tool within clinical diagnostics. However, the technique has a considerable analytical variation, and we therefore, investigated the analytical and between...

  3. Plasmid-Mediated Resistance to Thrombin-Induced Platelet Microbicidal Protein in Staphylococci: Role of the qacA Locus

    OpenAIRE

    Kupferwasser, Leon Iri; Skurray, Ronald A.; Brown, Melissa H.; Firth, Neville; Yeaman, Michael R.; Bayer, Arnold S.

    1999-01-01

    Thrombin-induced platelet microbicidal protein 1 (tPMP-1) is a small, cationic peptide released from rabbit platelets following thrombin stimulation. In vitro resistance to this peptide among strains of Staphylococcus aureus correlates with the survival advantage of such strains at sites of endothelial damage in humans as well as in experimental endovascular infections. The mechanisms involved in the phenotypic resistance of S. aureus to tPMP-1 are not fully delineated. The plasmid-encoded st...

  4. Intravenous Antiepileptic Drugs in Russia

    Directory of Open Access Journals (Sweden)

    P. N. Vlasov

    2014-01-01

    Full Text Available Launching four intravenous antiepileptic drugs: valproate (Depakene and Convulex, lacosamide (Vimpat, and levetiracetam (Keppra – into the Russian market has significantly broadened the possibilities of rendering care to patients in seizure emergency situations. The chemi- cal structure, mechanisms of action, indications/contraindications, clinical effectiveness and tolerability, advantages/disadvantages, and adverse events of using these drugs in urgent and elective neurology are discussed. 

  5. Intravenous volume tomographic pulmonary angiography imaging

    Science.gov (United States)

    Ning, Ruola; Strang, John G.; Chen, Biao; Conover, David L.; Yu, Rongfeng

    1999-05-01

    This study presents a new intravenous (IV) tomographic angiography imaging technique, called intravenous volume tomographic digital angiography (VTDA) for cross sectional pulmonary angiography. While the advantages of IV-VTDA over spiral CT in terms of volume scanning time and resolution have been validated and reported in our previous papers for head and neck vascular imaging, the superiority of IV-VTDA over spiral CT for cross sectional pulmonary angiography has not been explored yet. The purpose of this study is to demonstrate the advantage of isotropic resolution of IV-VTDA in the x, y and z directions through phantom and animal studies, and to explore its clinical application for detecting clots in pulmonary angiography. A prototype image intensifier-based VTDA imaging system has been designed and constructed by modifying a GE 8800 CT scanner. This system was used for a series of phantom and dog studies. A pulmonary vascular phantom was designed and constructed. The phantom was scanned using the prototype VTDA system for direct 3D reconstruction. Then the same phantom was scanned using a GE CT/i spiral CT scanner using the routine pulmonary CT angiography protocols. IV contrast injection and volume scanning protocols were developed during the dog studies. Both VTDA reconstructed images and spiral CT images of the specially designed phantom were analyzed and compared. The detectability of simulated vessels and clots was assessed as the function of iodine concentration levels, oriented angles, and diameters of the vessels and clots. A set of 3D VTDA reconstruction images of dog pulmonary arteries was obtained with different IV injection rates and isotropic resolution in the x, y and z directions. The results of clot detection studies in dog pulmonary arteries have also been shown. This study presents a new tomographic IV angiography imaging technique for cross sectional pulmonary angiography. The results of phantom and animal studies indicate that IV-VTDA is

  6. Muscle power during intravenous sedation

    Directory of Open Access Journals (Sweden)

    Nobuyuki Matsuura

    2017-11-01

    Full Text Available Intravenous sedation is effective to reduce fear and anxiety in dental treatment. It also has been used for behavior modification technique in dental patients with special needs. Midazolam and propofol are commonly used for intravenous sedation. Although there have been many researches on the effects of midazolam and propofol on vital function and the recovery profile, little is known about muscle power. This review discusses the effects of intravenous sedation using midazolam and propofol on both grip strength and bite force. During light propofol sedation, grip strength increases slightly and bite force increases in a dose-dependent manner. Grip strength decreases while bite force increases during light midazolam sedation, and also during light sedation using a combination of midazolam and propofol. Flumazenil did not antagonise the increase in bite force by midazolam. These results may suggest following possibilities; (1 Activation of peripheral benzodiazepine receptors located within the temporomandibular joint region and masticatory muscles may be the cause of increasing bite force. (2 Propofol limited the long-latency exteroceptive suppression (ES2 period during jaw-opening reflex. Thus, control of masticatory muscle contraction, which is thought to have a negative feedback effect on excessive bite force, may be depressed by propofol.

  7. Addition of thrombin reduces the recovery of extracellular vesicles from blood plasma

    Directory of Open Access Journals (Sweden)

    Anush Arakelyan

    2016-10-01

    Full Text Available Extracellular vesicles (EVs are widely studied as a system of intercellular communication, as markers of various diseases, as well as a vehicle for delivery of various bioactive molecules to various cells. Investigation of EVs’ structure and function requires their isolation and precise quantification. However, in the current literature, there are significant discrepancies in the estimated numbers of EVs in different body fluids. In part, this discrepancy is due to the difference in EVs isolation protocols used by different investigators. A common protocol that includes ExoQuick ™ is often used to isolate EVs from body fluids and culture medium. Here, we show that in the case of isolation of EVs from blood, thrombin should be omitted from the protocol as clots formed due to the thrombin-triggered coagulation may entrap many EVs thus leading to the underestimation of their numbers.

  8. Addition of thrombin reduces the recovery of extracellular vesicles from blood plasma

    Science.gov (United States)

    Arakelyan, Anush; Fitzgerald, Wendy; Vagida, Murad; Vasilieva, Elena; Grivel, Jean-Charles

    2016-01-01

    Extracellular vesicles (EVs) are widely studied as a system of intercellular communication, as markers of various diseases, as well as a vehicle for delivery of various bioactive molecules to various cells. Investigation of EVs’ structure and function requires their isolation and precise quantification. However, in the current literature, there are significant discrepancies in the estimated numbers of EVs in different body fluids. In part, this discrepancy is due to the difference in EVs isolation protocols used by different investigators. A common protocol that includes ExoQuick™ is often used to isolate EVs from body fluids and culture medium. Here, we show that in the case of isolation of EVs from blood, thrombin should be omitted from the protocol as clots formed due to the thrombin-triggered coagulation may entrap many EVs thus leading to the underestimation of their numbers. PMID:28936260

  9. Inhibition of thermolysin and human alpha-thrombin by cobalt(III) Schiff base complexes.

    Science.gov (United States)

    Takeuchi, T; Böttcher, A; Quezada, C M; Meade, T J; Gray, H B

    1999-05-01

    Cobalt(III) Schiff base complexes have been shown to inhibit the replication of the ocular herpes virus. It is well known that these complexes have a high affinity for nitrogenous donors such as histidine residues, and it is possible that they bind to (and inhibit) an enzyme that is crucial to viral replication. In model studies, we have found that [Co(acacen)(NH3)2]+ is an effective irreversible inhibitor of thermolysin at millimolar concentrations; it also inhibits human alpha-thrombin. Axial ligand exchange with an active-site histidine is the proposed mechanism of inhibition. The activity of thermolysin and thrombin can be protected by binding a reversible inhibitor to the active site before addition of the cobalt(III) complex.

  10. Trypsin, Tryptase, and Thrombin Polarize Macrophages towards a Pro-Fibrotic M2a Phenotype.

    Directory of Open Access Journals (Sweden)

    Michael J V White

    Full Text Available For both wound healing and the formation of a fibrotic lesion, circulating monocytes enter the tissue and differentiate into fibroblast-like cells called fibrocytes and pro-fibrotic M2a macrophages, which together with fibroblasts form scar tissue. Monocytes can also differentiate into classically activated M1 macrophages and alternatively activated M2 macrophages. The proteases thrombin, which is activated during blood clotting, and tryptase, which is released by activated mast cells, potentiate fibroblast proliferation and fibrocyte differentiation, but their effect on macrophages is unknown. Here we report that thrombin, tryptase, and the protease trypsin bias human macrophage differentiation towards a pro-fibrotic M2a phenotype expressing high levels of galectin-3 from unpolarized monocytes, or from M1 and M2 macrophages, and that these effects appear to operate through protease-activated receptors. These results suggest that proteases can initiate scar tissue formation by affecting fibroblasts, fibrocytes, and macrophages.

  11. Gelatin-thrombin hemostatic matrix injection to salvage refractory post-renal graft biopsy bleed

    Directory of Open Access Journals (Sweden)

    V Jain

    2013-01-01

    Full Text Available Post-renal biopsy bleeding refractory to angioembolization usually requires graft nephrectomy as a life-saving measure. Gelatin-thrombin hemostatic matrix injection in the needle tract is a novel attempt to control bleeding in such cases and to salvage the allograft. We hereby describe two cases of post-graft biopsy bleed. Both these patients continued to bleed even after angioembolization. They were shifted to the operating room upon developing hypotension, having received multiple blood transfusions with the intention of performing graft nephrectomy to save their lives. However, bleeding was successfully controlled by using Gelatin-thrombin hemostatic matrix injection in the biopsy needle tract. Patients improved hemodynamically after the procedure. Graft function returned to normal in both the cases. At an average follow-up of 10.4 months, both the patients have shown stable graft functions.

  12. Thrombin effectuates therapeutic arteriogenesis in the rabbit hindlimb ischemia model: A quantitative analysis by computerized in vivo imaging

    International Nuclear Information System (INIS)

    Kagadis, George C.; Karnabatidis, Dimitrios; Katsanos, Konstantinos; Diamantopoulos, Athanassios; Samaras, Nikolaos; Maroulis, John; Siablis, Dimitrios; Nikiforidis, George C.

    2006-01-01

    We report on an experimental mammalian controlled study that documents arteriogenic capacity of thrombin and utilizes computerized algorithms to quantify the newly formed vessels. Hindlimb ischemia was surgically invoked in 10 New Zealand white rabbits. After quiescence of endogenous angiogenesis heterologous bovine thrombin was intramuscularly injected (1500 units) in one hindlimb per rabbit (Group T). Contralateral limbs were infused with normal saline (Group C). Digital subtraction angiography (DSA) of both limbs was performed after thrombin infusion by selective cannulation of the abdominal aorta and digital images were post-processed with computerized algorithms in order to enhance newly formed vessels. Total vessel area and total vessel length were quantified. In vivo functional evaluation included measurements of blood flow volume at the level of the external iliac artery by Doppler ultrasonography both at baseline and at 20 days after thrombin infusion. Total vessel area and length (in pixels) were 14,713+/-1023 and 5466+/-1327 in group T versus 12,015+/-2557 and 4598+/-1269 in group C (p=0.0062 and 0.1526, respectively). Blood flow volumes (ml/min) at baseline and at 20 days after thrombin infusion were 25.87+/-11.09 and 38.06+/-11.72 in group T versus 26.57+/-11.19 and 20.35+/-7.20 in group C (p=0.8898 and 0.0007, respectively). Intramuscular thrombin effectuates an arteriogenic response in the rabbit hindlimb ischemia model. Computerized algorithms may enable accurate quantification of the neovascularization outcome

  13. Posttraumatic pseudoaneurysm of medial plantar artery in a child: treatment with percutaneous thrombin injection

    Directory of Open Access Journals (Sweden)

    Fabrício Neto Ladeira

    2014-03-01

    Full Text Available Pseudoaneurysms of the medial plantar artery are rare. The authors describe a case of a pseudoaneurysm of the medial plantar artery of a child who had suffered a penetrating laceration injury. Diagnosis can be confirmed using Doppler ultrasound and magnetic resonance angiography. As an alternative to the conventional surgery technique, percutaneous Doppler ultrasound-guided thrombin injection is a safe and effective treatment.

  14. Cleavage-based hybridization chain reaction for electrochemical detection of thrombin.

    Science.gov (United States)

    Chang, Yuanyuan; Chai, Yaqin; Xie, Shunbi; Yuan, Yali; Zhang, Juan; Yuan, Ruo

    2014-09-07

    In the present work, we constructed a new label-free "inter-sandwich" electrochemical aptasensor for thrombin (TB) detection by employing a cleavage-based hybridization chain reaction (HCR). The designed single-stranded DNA (defined as binding DNA), which contained the thrombin aptamer binding sequence, a DNAzyme cleavage site and a signal reporter sequence, was first immobilized on the electrode. In the absence of a target TB, the designed DNAzymes could combine with the thrombin aptamer binding sequence via complementary base pairing, and then Cu(2+) could cleave the binding DNA. In the presence of a target TB, TB could combine with the thrombin aptamer binding sequence to predominantly form an aptamer-protein complex, which blocked the DNAzyme cleavage site and prevented the binding DNA from being cleaved by Cu(2+)-dependent DNAzyme. As a result, the signal reporter sequence could leave the electrode surface to trigger HCR with the help of two auxiliary DNA single-strands, A1 and A2. Then, the electron mediator hexaammineruthenium (III) chloride ([Ru(NH3)6](3+)) was embedded into the double-stranded DNA (dsDNA) to produce a strong electrochemical signal for the quantitative measurement of TB. For further amplification of the electrochemical signal, graphene reduced by dopamine (PDA-rGO) was introduced as a platform in this work. With this strategy, the aptasensor displayed a wide linearity in the range of 0.0001 nM to 50 nM with a low detection limit of 0.05 pM. Moreover, the resulting aptasensor exhibited good specificity and acceptable reproducibility and stability. Because of these factors, the fabrication protocol proposed in this work may be extended to clinical application.

  15. P2X1 stimulation promotes thrombin receptor-mediated platelet aggregation.

    Science.gov (United States)

    Erhardt, J A; Toomey, J R; Douglas, S A; Johns, D G

    2006-04-01

    P2X1 receptors are ATP-gated channel demonstrated to be involved in multiple platelet responses, although in vitro analysis has been complicated by the effects of rapid desensitization. To further investigate potential roles of P2X1 receptors in platelet activation, the current study employed methods which maximally preserved P2X1 functionality. In preliminary in vivo studies, P2X1-deficiency reduced thrombus formation following the laser-induced, but not FeCl3-induced injury. Given the multiple potential mechanisms involved in thrombus formation in vivo, including tissue-factor/thrombin generation pathways, subsequent studies were designed to investigate the effects of P2X1 inhibition or stimulation on platelet activation in vitro; specifically, the interaction of P2X1 with thrombin receptor stimulation. Aggregation initiated by low/threshold levels of a protease-activated receptor (PAR)4 agonist was reduced in P2X1-deficient murine platelets, and inhibition of P2X1 in wild-type platelets similarly reduced PAR4-mediated aggregation. In human platelets, aggregation to low/threshold stimulation of PAR1 was inhibited with the P2X1 antagonist MRS2159. In addition, P2X1 stimulation primed human platelet responses, such that subsequent sub-threshold PAR1 responses were converted into significant aggregation. Selective ADP receptor inhibitors attenuated P2X1-mediated priming, suggesting that the synergy between P2X1 and sub-threshold PAR1 stimulation was in part because of enhanced granular release of ADP. Overall, the present study defines a novel interaction between platelet P2X1 and thrombin receptors, with P2X1 functioning to amplify aggregation responses at low levels of thrombin receptor stimulation.

  16. In vitro pharmacological characterization of vorapaxar, a novel platelet thrombin receptor antagonist.

    Science.gov (United States)

    Hawes, Brian E; Zhai, Ying; Hesk, David; Wirth, Mark; Wei, Huijun; Chintala, Madhu; Seiffert, Dietmar

    2015-09-05

    Vorapaxar is a novel protease-activated receptor-1 (PAR1) antagonist recently approved for the reduction of thrombotic cardiovascular events in patients with a history of myocardial infarction or with peripheral arterial disease. The present study provides a comprehensive in vitro pharmacological characterization of vorapaxar interaction with the PAR1 receptor on human platelets. Similar studies were performed with a metabolite of vorapaxar (M20). Vorapaxar and M20 were competitive PAR1 antagonists that demonstrated concentration-dependent, saturable, specific, and slowly reversible binding to the receptor present on intact human platelets. The affinities of vorapaxar and M20 for the PAR1 receptor were in the low nanomolar range, as determined by saturation-, kinetic- and competitive binding studies. The calculated Kd and Ki values for vorapaxar increased in the presence of plasma, indicating a decrease in the free fraction available for binding to the PAR1 receptor on human platelets. Vorapaxar was also evaluated in functional assays using thrombin or a PAR1 agonist peptide (SFLLRN). Vorapaxar and M20 completely blocked thrombin-stimulated PAR1/β-arrestin association in recombinant cells and abolished thrombin-stimulated calcium influx in washed human platelets and vascular smooth muscle cells. Moreover, vorapaxar and M20 inhibited PAR1 agonist peptide-mediated platelet aggregation in human platelet rich plasma with a steep concentration response relationship. Vorapaxar exhibited high selectivity for inhibition of PAR1 over other platelet GPCRs. In conclusion, vorapaxar is a potent PAR1 antagonist exhibiting saturable, reversible, selective binding with slow off-rate kinetics and effectively inhibits thrombin's PAR1-mediated actions on human platelets. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Aptamer/Protein Proximity Binding-Triggered Molecular Machine for Amplified Electrochemical Sensing of Thrombin.

    Science.gov (United States)

    Yang, Jianmei; Dou, Baoting; Yuan, Ruo; Xiang, Yun

    2017-05-02

    The development of convenient and sensitive methods without involving any enzymes or complex nanomaterials for the monitoring of proteins is of great significance in disease diagnostics. In this work, we describe the validation of a new aptamer/protein proximity binding-triggered molecular machinery amplification strategy for sensitive electrochemical assay of thrombin in complex serum samples. The sensing interface is prepared by self-assembly of three-stranded DNA complexes on the gold electrode. The association of two distinct functional aptamers with different sites of thrombin triggers proximity binding-induced displacement of one of the short single-stranded DNAs (ssDNAs) from the surface-immobilized three-stranded DNA complexes, exposing a prelocked toehold domain to hybridize with a methylene blue (MB)-tagged fuel ssDNA strand (MB-DNA). Subsequent toehold-mediated strand displacement by the MB-DNA leads to the release and recycling of the aptamer/protein complexes and the function of the molecular machine. Eventually, a large number of MB-DNA strands are captured by the sensor surface, generating drastically amplified electrochemical responses from the MB tags for sensitive detection of thrombin. Our signal amplified sensor is completely enzyme-free and shows a dynamic range from 5 pM to 1 nM with a detection limit of 1.7 pM. Such sensor also has a high specificity for thrombin assay in serum samples. By changing the affinity probe pairs, the developed sensor can be readily expanded as a more general platform for sensitive detection of different types of proteins.

  18. Elevated Cytokines, Thrombin and PAI-1 in Severe HCPS Patients Due to Sin Nombre Virus

    Directory of Open Access Journals (Sweden)

    Virginie Bondu

    2015-02-01

    Full Text Available Sin Nombre Hantavirus (SNV, Bunyaviridae Hantavirus is a Category A pathogen that causes Hantavirus Cardiopulmonary Syndrome (HCPS with case fatality ratios generally ranging from 30% to 50%. HCPS is characterized by vascular leakage due to dysregulation of the endothelial barrier function. The loss of vascular integrity results in non-cardiogenic pulmonary edema, shock, multi-organ failure and death. Using Electric Cell-substrate Impedance Sensing (ECIS measurements, we found that plasma samples drawn from University of New Mexico Hospital patients with serologically-confirmed HCPS, induce loss of cell-cell adhesion in confluent epithelial and endothelial cell monolayers grown in ECIS cultureware. We show that the loss of cell-cell adhesion is sensitive to both thrombin and plasmin inhibitors in mild cases, and to thrombin only inhibition in severe cases, suggesting an increasing prothrombotic state with disease severity. A proteomic profile (2D gel electrophoresis and mass spectrometry of HCPS plasma samples in our cohort revealed robust antifibrinolytic activity among terminal case patients. The prothrombotic activity is highlighted by acute ≥30 to >100 fold increases in active plasminogen activator inhibitor (PAI-1 which, preceded death of the subjects within 48 h. Taken together, this suggests that PAI-1 might be a response to the severe pathology as it is expected to reduce plasmin activity and possibly thrombin activity in the terminal patients.

  19. Alginate-calcium microsphere loaded with thrombin: a new composite biomaterial for hemostatic embolization.

    Science.gov (United States)

    Rong, Jing-jing; Liang, Ming; Xuan, Feng-qi; Sun, Jing-yang; Zhao, Li-jun; Zhen, Hui-zhen; Tian, Xiao-xiang; Liu, Dan; Zhang, Quan-yu; Peng, Cheng-fei; Yao, Tian-ming; Li, Fei; Wang, Xiao-zeng; Han, Ya-ling; Yu, Wei-ting

    2015-04-01

    To date, transcatheter arterial embolization (TAE) has become a standard treatment to control intracavitary bleeding as an alternative to surgery. Due to excellent biocompatibility and no residual in vivo, biodegradable materials are preferred in TAE. However, gelfoam is the only commercially available biodegradable embolic material used to treat blunt trauma of solid abdominal viscera until now, and controversial on its stability and reliability never stopped in the past five decades. In this study, a new biodegradable macromolecule material (thrombin-loaded alginate-calcium microspheres, TACMs) was prepared using electrostatic droplet techniques and a special method was developed for hemostatic embolization. Thrombin was successfully loaded into microspheres with high encapsulation efficiency and drug loading capacity. A burst release of TACMs was observed at early stage and sustained release later on, with the activity of thrombin preserved well. The strength of TACMs mixed thrombus, which was used as embolic agent, increased in a dose-dependent manner after TACMs were added. In addition, the TACMs were verified to be of no cytotoxicity and systemic toxicity, and biodegradable in vivo. Finally, the results of preliminary applications revealed that the TACMs could serve as an effective and promising embolic material for blunt trauma and hemorrhage of solid abdominal viscera. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Nanogravimetric and Optical Characterizations of Thrombin Interaction with a Self-Assembled Thiolated Aptamer

    Directory of Open Access Journals (Sweden)

    Jane Politi

    2016-01-01

    Full Text Available Efficient biorecognition of thrombin (TB, a serine protease with crucial role in physiological and pathological blood coagulation, is a hot topic in medical diagnostics. In this work, we investigate the ability of synthetic thrombin aptamer (TBA, immobilized on a gold substrate, to bind thrombin by two different label-free techniques: the quartz crystal microbalance (QCM and the spectroscopic ellipsometry (SE. By QCM characterization in the range from 20 to 110 nM, we demonstrate high specificity of TBA-TB interaction and determine affinity constant (Kd of 17.7±0.3 nM, system sensitivity of 0.42±0.03 Hz nM−1, and limit of detection (LOD of 240±20 pM. The interaction between TBA and TB is also investigated by SE, an all-optical method, by quantifying the thickness increase of the TBA film assembled on gold substrate. AFM characterization of TBA and TB molecules deposited on flat silicon surface is also supplied.

  1. Thrombin induces macrophage migration inhibitory factor release and upregulation in urothelium: a possible contribution to bladder inflammation.

    Directory of Open Access Journals (Sweden)

    Pedro L Vera

    2010-12-01

    Full Text Available Macrophage migration inhibitory factor (MIF is a pro-inflammatory cytokine expressed by urothelial cells that mediates bladder inflammation. We investigated the effect of stimulation with thrombin, a Protease Activated Receptor-1 (PAR1 agonist, on MIF release and MIF mRNA upregulation in urothelial cells.MIF and PAR1 expression was examined in normal human immortalized urothelial cells (UROtsa using real-time RT-PCR, Western blotting and dual immunostaining. MIF and PAR1 immunostaining was also examined in rat urothelium. The effect of thrombin stimulation (100 nM on urothelial MIF release was examined in UROtsa cells (in vitro and in rats (in vivo. UROtsa cells were stimulated with thrombin, culture media were collected at different time points and MIF amounts were determined by ELISA. Pentobarbital anesthetized rats received intravesical saline (control, thrombin, or thrombin +2% lidocaine (to block nerve activity for 1 hr, intraluminal fluid was collected and MIF amounts determined by ELISA. Bladder or UROtsa MIF mRNA was measured using real time RT-PCR.UROtsa cells constitutively express MIF and PAR1 and immunostaining for both was observed in these cells and in the basal and intermediate layers of rat urothelium. Thrombin stimulation of urothelial cells resulted in a concentration- and time-dependent increase in MIF release both in vitro (UROtsa; 2.8-fold increase at 1 hr and in vivo (rat; 4.5-fold while heat-inactivated thrombin had no effect. In rats, thrombin-induced MIF release was reduced but not abolished by intravesical lidocaine treatment. Thrombin also upregulated MIF mRNA in UROtsa cells (3.3-fold increase and in the rat bladder (2-fold increase where the effect was reduced (1.4-fold by lidocaine treatment.Urothelial cells express both MIF and PAR1. Activation of urothelial PAR1 receptors, either by locally generated thrombin or proteases present in the urine, may mediate bladder inflammation by inducing urothelial MIF release and

  2. Usefulness of MR cholangiopancreatography after intravenous morphine administration

    International Nuclear Information System (INIS)

    Lee, So Jung; Ko, Ji Ho; Cho, Young Duk; Jung, Mi Hee; Yoon, Byung Chull

    2007-01-01

    We wanted to assess the usefulness of MRCP after intravenous morphine administration in the evaluation of the hepatopancreatic pancreatico-biliary ductal system. We studied 15 patients who were suspected of having disease of hepatopancreatic ductal system and they did not have any obstructive lesion on ultrasonography and/or CT. MRCP was acquired before and after morphine administration (0.04 mg/kg, intravenously). Three radiologists scored the quality of the images of the anatomic structures in the hepatopancreatic ductal system. We directly compared the quality of the images obtained with using the two methods and the improvement of the artifacts by pulsatile vascular compression. The MRCP images obtained after intravenous morphine administration were better than those obtained before morphine administration for visualizing the hepatopancreatic ductal system. On direct comparison, the MRCP images obtained after morphine administration were better in 12 cases, equivocal in two cases, and the images before morphine administration were better in only one case. In three patients, MRCP before morphine injection showed signal loss at the duct across the pulsatile hepatic artery. In two of three patients, MRCP after morphine injection showed no signal loss in this ductal area. MRCP after intravenous morphine administration enables physicians to see the hepatopancreatic ductal system significantly better and the artifacts caused by pulsation of the hepatic artery can be avoided

  3. A label-free and high sensitive aptamer biosensor based on hyperbranched polyester microspheres for thrombin detection

    International Nuclear Information System (INIS)

    Sun, Chong; Han, Qiaorong; Wang, Daoying; Xu, Weimin; Wang, Weijuan; Zhao, Wenbo; Zhou, Min

    2014-01-01

    Highlights: • A label-free thrombin aptamer biosensor applied in whole blood has been developed. • The aptamer biosensor showed a wide detection range and a low detection limit. • The antibiofouling idea utilized for biosensor is significant for diagnostics. - Abstract: In this paper, we have synthesized hyperbranched polyester microspheres with carboxylic acid functional groups (HBPE-CA) and developed a label-free electrochemical aptamer biosensor using thrombin-binding aptamer (TBA) as receptor for the measurement of thrombin in whole blood. The indium tin oxide (ITO) electrode surface modified with HBPE-CA microspheres was grafted with TBA, which has excellent binding affinity and selectivity for thrombin. Binding of the thrombin at the modified ITO electrode surface greatly restrained access of electrons for a redox probe of [Fe(CN) 6 ] 3−/4− . Moreover, the aptamer biosensor could be used for detection of thrombin in whole blood, a wide detection range (10 fM–100 nM) and a detection limit on the order of 0.90 fM were demonstrated. Control experiments were also carried out by using bull serum albumin (BSA) and lysozyme in the absence of thrombin. The good stability and repeatability of this aptamer biosensor were also proved. We expect that this demonstration will lead to the development of highly sensitive label-free sensors based on aptamer with lower cost than current technology. The integration of the technologies, which include anticoagulant, sensor and nanoscience, will bring significant input to high-performance biosensors relevant to diagnostics and therapy of interest for human health

  4. A label-free and high sensitive aptamer biosensor based on hyperbranched polyester microspheres for thrombin detection

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Chong [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Han, Qiaorong [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Wang, Daoying; Xu, Weimin [Institute of Agricultural Products Processing, Jiangsu Academy of Agricultural Sciences, Nanjing 210014 (China); Wang, Weijuan [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhao, Wenbo, E-mail: zhaowenbo@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Materials, Biomedical Functional Materials Collaborative Innovation Center, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023 (China); Zhou, Min, E-mail: zhouminnju@126.com [Department of Vascular Surgery, the Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 210008 (China)

    2014-11-19

    Highlights: • A label-free thrombin aptamer biosensor applied in whole blood has been developed. • The aptamer biosensor showed a wide detection range and a low detection limit. • The antibiofouling idea utilized for biosensor is significant for diagnostics. - Abstract: In this paper, we have synthesized hyperbranched polyester microspheres with carboxylic acid functional groups (HBPE-CA) and developed a label-free electrochemical aptamer biosensor using thrombin-binding aptamer (TBA) as receptor for the measurement of thrombin in whole blood. The indium tin oxide (ITO) electrode surface modified with HBPE-CA microspheres was grafted with TBA, which has excellent binding affinity and selectivity for thrombin. Binding of the thrombin at the modified ITO electrode surface greatly restrained access of electrons for a redox probe of [Fe(CN){sub 6}]{sup 3−/4−}. Moreover, the aptamer biosensor could be used for detection of thrombin in whole blood, a wide detection range (10 fM–100 nM) and a detection limit on the order of 0.90 fM were demonstrated. Control experiments were also carried out by using bull serum albumin (BSA) and lysozyme in the absence of thrombin. The good stability and repeatability of this aptamer biosensor were also proved. We expect that this demonstration will lead to the development of highly sensitive label-free sensors based on aptamer with lower cost than current technology. The integration of the technologies, which include anticoagulant, sensor and nanoscience, will bring significant input to high-performance biosensors relevant to diagnostics and therapy of interest for human health.

  5. Bradykinin and thrombin stimulate release of arachidonic acid and formation of prostanoids in human periodontal ligament cells.

    Science.gov (United States)

    Marklund, M; Lerner, U H; Persson, M; Ransjö, M

    1994-06-01

    Previous reports have demonstrated the importance of prostaglandin formation in orthodontic tooth movement, but the mechanisms involved in the activation of prostaglandin biosynthesis in the periodontal ligament (PDL) are still unclear. There is, however, evidence that inflammatory reactions appear after application of orthodontic forces. In the present study, the effect of bradykinin (BK) and thrombin, two inflammatory mediators, on prostanoid biosynthesis in human PDL-cells was investigated. BK and thrombin caused a time-dependent burst of prostaglandin E2 (PGE2) formation (maximal effect after 2-5 min). The stimulatory actions of BK and thrombin on PGE2 biosynthesis were dose-dependent; seen in PDL-cells isolated from four different patients and abolished by the non-steroidal anti-inflammatory drug indomethacin. BK and thrombin also dose-dependently stimulated the biosynthesis of PGI2. BK agonists, with affinity to the B2 subtype of BK receptors, caused a significant increase of PGE2 biosynthesis in human PDL-cells. In contrast, BK agonists with affinity to BK-B1 receptors did not cause a burst of PGE2 biosynthesis. BK and BK-B2 receptor agonists as well as thrombin, but not BK-B1 receptor agonists, also significantly increased [3H] release in human PDL-cells prelabelled with [3H]-arachidonic acid, indicating that BK and thrombin stimulate prostanoid biosynthesis, at least partly, due to activation of phospholipase A2. These data show that BK via BK-B2 receptors, as well as thrombin, have the capacity to stimulate arachidonic acid release and subsequent prostanoid biosynthesis in human PDL-cells and thus may be implicated in the tissue reactions involved in orthodontic tooth movement.

  6. Factor VIII S373L: mutation at P1' site confers thrombin cleavage resistance, causing mild haemophilia A.

    Science.gov (United States)

    Johnson, D J; Pemberton, S; Acquila, M; Mori, P G; Tuddenham, E G; O'Brien, D P

    1994-04-01

    A novel CRM+ mutation, factor VIII position 373 serine to leucine substitution (FVIII 373-Leu) was identified during a survey of Factor VIII (FVIII) mutations. We have purified the variant protein from the patient's plasma in order to allow further characterisation of the molecule. The CRM+ plasma contained 120% Factor VIII antigen (FVIII:Ag) and 6% Factor VIII coagulant activity (FVIII:C). After purification the mutant FVIII was subjected to thrombin proteolysis, and was thereby activated 5.6-fold compared with 7-fold for wild type molecule. Subsequently, spontaneous inactivation of the mutant was much slower than noted for wild type FVIII. Western blot analysis using monoclonal antibodies demonstrated that thrombin cleavage of FVIII 373-Leu at positions 740 and 1689 were normal but that cleavage at position 372 was completely absent. Crystallographic coordinates of the active site of thrombin complexed to fibrinopeptide A were used to explore possible mechanistic reasons for the failure of thrombin to cleave the mutant FVIII at position 372. Steric hindrance between the mutant side chain and the side chain of the P1 residue was apparent. We conclude that the functional defect of FVIII 373-Leu results from the inability of thrombin to cleave the mutant at position 372-373, and propose that this is due to steric hindrance by the side chain of leucine 373, preventing correct formation of the enzyme substrate complex.

  7. Effects of thrombin, PAR-1 activating peptide and a PAR-1 antagonist on umbilical artery resistance in vitro

    Directory of Open Access Journals (Sweden)

    Elliott John T

    2005-02-01

    Full Text Available Abstract Background The non-thrombotic effects of thrombin in cardiovascular tissues, as mediated via the protease activated receptors (PARs, and particularly PAR-1, have been the focus of much recent research. The aims of this study were to evaluate the effects of thrombin, a specific PAR-1 activating peptide (PAR1-AP, and a PAR-1 antagonist on human umbilical artery tone in vitro. Methods Human umbilical artery samples were obtained from 17 women at term. Arterial rings were suspended under physiologic conditions for isometric recording. The in vitro effects of thrombin (0.5 units/mL to 3 units/mL, PAR1-AP TFLLR-NH2 [10(-9 to 10(-6 M], and PAR-1 antagonist (N-trans cinnamoyl- p-fluoroPhe-p-guanidinoPhe-Leu-Arg-Orn-NH2 [10(-9 M to 10(-5 M] on umbilical artery tone were measured. Results Both thrombin and TFLLR-NH2 exerted a potent cumulative vasodilatory effect on human umbilical artery resistance (P 0.05. Conclusion These findings highlight a potential role for thrombin and PAR-1 receptors in vascular regulation of feto-placental blood flow in normal pregnancy, and in association with the vascular lesions associated with IUGR and pre-eclampsia.

  8. Protocol for obtaining platelet-rich plasma (PRP), platelet-poor plasma (PPP), and thrombin for autologous use.

    Science.gov (United States)

    Franco, Diogo; Franco, Talita; Schettino, Angélica Maria; Filho, João Medeiros Tavares; Vendramin, Fabiel Spani

    2012-10-01

    Plasma has been widely studied and used in many different situations to speed up healing with better tissue adherence and hemostasis. Research projects are now attempting to isolate platelet-rich plasma (PRP) and platelet-poor plasma (PPP), making better use of their properties, particularly during operations and for wounds that are slow to heal. In view of the wide diversity of industrial machines and extraction protocols, together with the variety of industrially produced biologic glues, this article suggests an option for obtaining PRP, PPP, and human thrombin for autologous use. A way of obtaining PRP, PPP, and thrombin is reproduced through a protocol defined and established by the authors. Autologous thrombin and plasma were obtained through the collection and successive centrifugation of ten whole blood samples, until the desired hemocomponents were isolated, followed by quantitative and qualitative analyses of the elements obtained. The mean platelet concentration obtained was 6.03 × 10(8) platelets/ml, with a mean thrombin concentration of 33.54 nM, both values compatible with reports in the literature when different protocols are applied. The protocol described is a good option for the preparation and application of PRP, PPP, and autologous thrombin, particularly as they can be obtained simultaneously, eliminating the possibilities of viral contamination and allergic reactions. Moreover, the cost of this procedure is low, it is easy to perform, and replicable. This journal requires that authors assign a level of evidence to each article.

  9. Magnetic relaxation switch and colorimetric detection of thrombin using aptamer-functionalized gold-coated iron oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Liang Guohai; Cai Shaoyu; Zhang Peng [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China); Peng Youyuan [Department of Chemistry, Quanzhou Normal University, Quanzhou 362000 (China); Chen Hui; Zhang Song [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China); Kong Jilie, E-mail: jlkong@fudan.edu.cn [Department of Chemistry and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433 (China)

    2011-03-18

    We describe a sensitive biosensing system combining magnetic relaxation switch diagnosis and colorimetric detection of human {alpha}-thrombin, based on the aptamer-protein interaction induced aggregation of Fe{sub 3}O{sub 4}-Au nanoparticles. To demonstrate the concept, gold-coated iron oxide nanoparticle was synthesized by iterative reduction of HAuCl{sub 4} onto the dextran-coated Fe{sub 3}O{sub 4} nanoparticles. The resulting core-shell structure had a flowerlike shape with pretty narrow size distribution (referred to as 'nanorose'). The two aptamers corresponding to human {alpha}-thrombin were conjugated separately to two distinct nanorose populations. Once a solution containing human {alpha}-thrombin was introduced, the nanoroses switched from a well dispersed state to an aggregated one, leading to a change in the spin-spin relaxation time (T{sub 2}) as well as the UV-Vis absorption spectra of the solution. Thus the qualitative and quantitative detection method for human {alpha}-thrombin was established. The dual-mode detection is clearly advantageous in obtaining a more reliable result; the detection range is widened as well. By using the dual-mode detection method, a detectable T{sub 2} change is observed with 1.0 nM human {alpha}-thrombin, and the detection range is from 1.6 nM to 30.4 nM.

  10. Rapid and ultrasensitive detection of active thrombin based on the Vmh2 hydrophobin fused to a Green Fluorescent Protein.

    Science.gov (United States)

    Piscitelli, Alessandra; Pennacchio, Anna; Cicatiello, Paola; Politi, Jane; De Stefano, Luca; Giardina, Paola

    2017-01-15

    A fusion protein designed in order to combine the fluorescence emission of the Green Fluorescent Protein (GFP) with the adhesion ability of the class I hydrophobin Vmh2 was heterologously produced in the yeast Pichia pastoris. The Vmh2-GFP fusion protein has proven to be a smart and effective tool for the study of Vmh2 self-assembling. Since the two proteins were linked by the specific cutting site of the thrombin, the fusion protein was used as the active biological element in the realization of a thrombin biosensor. When the thrombin present in the target solution specifically hydrolyzed its cleavage sequence, a consequent decrease in the fluorescence intensity of the sample could be observed. The Vmh2-GFP based assay allowed quantification of thrombin in solution with a detection limit of 2.27aM. The specificity of the assay with respect to other proteases and proteins granted the measurement of thrombin added to healthy human plasma with same high sensitivity and a limit of detection of 2.3aM. Further advantages of the developed biosensor are the simplicity of its design and preparation, and the low requirements in terms of samples, reagents and time. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Extracellular histones promote thrombin generation through platelet-dependent mechanisms: involvement of platelet TLR2 and TLR4

    Science.gov (United States)

    Semeraro, Fabrizio; Ammollo, Concetta T.; Morrissey, James H.; Dale, George L.; Friese, Paul; Esmon, Naomi L.

    2011-01-01

    The release of histones from dying cells is associated with microvascular thrombosis and, because histones activate platelets, this could represent a possible pathogenic mechanism. In the present study, we assessed the influence of histones on the procoagulant potential of human platelets in platelet-rich plasma (PRP) and in purified systems. Histones dose-dependently enhanced thrombin generation in PRP in the absence of any trigger, as evaluated by calibrated automated thrombinography regardless of whether the contact phase was inhibited. Activation of coagulation required the presence of fully activatable platelets and was not ascribable to platelet tissue factor, whereas targeting polyphosphate with phosphatase reduced thrombin generation even when factor XII (FXII) was blocked or absent. In the presence of histones, purified polyphosphate was able to induce thrombin generation in plasma independently of FXII. In purified systems, histones induced platelet aggregation; P-selectin, phosphatidylserine, and FV/Va expression; and prothrombinase activity. Blocking platelet TLR2 and TLR4 with mAbs reduced the percentage of activated platelets and lowered the amount of thrombin generated in PRP. These data show that histone-activated platelets possess a procoagulant phenotype that drives plasma thrombin generation and suggest that TLR2 and TLR4 mediate the activation process. PMID:21673343

  12. A colorimetric aptamer biosensor based on cationic polythiophene derivative as peroxidase mimetics for the ultrasensitive detection of thrombin.

    Science.gov (United States)

    Liu, Mei; Li, Jiao; Li, Baoxin

    2017-12-01

    A colorimetric assay for the ultrasensitive determination of thrombin was presented, in which the cationic polythiophene derivative was used as catalyst of the 3,3',5,5'-tetramethylbenzidine (TMB)-H 2 O 2 reaction and the thrombin-binding aptamer (TBA) was used as inducing polymer's different conformation elements. It was found the cationic polythiophene derivative, poly[3-(3'-N,N,N-triethylamino-1'-propyloxy)-4-methyl-2,5-t-hiophene hydrochloride] (PMNT), can catalyze the oxidation reaction of TMB in the presence of H 2 O 2 to produce a blue color solution. The catalytic activity of PMNT on the TMB-H 2 O 2 reaction was closely relevant to the conformation of PMNT. The absorbance of TMB-H 2 O 2 was distinctly increased in the presence of TBA. With the addition of thrombin, TBA interacted with thrombin to form a G-quadruplex structure. The conformational change weakened the catalytic activity of PMNT and resulted in a decrease in the absorbance. The colorimetric sensor could detect thrombin down to 4pM with high selectivity against other interfering proteins. This work is not only of importance for a better understanding of the unique properties of cationic polythiophenes derivative but also have great potential for medical diagnostics and therapy for human health. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Thrombelastographic characterization of the thrombin-like activity of Crotalus simus and Bothrops asper venoms.

    Science.gov (United States)

    Nielsen, Vance G; Boyer, Leslie V; Redford, Daniel T; Ford, Paul

    2017-04-01

    : 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.g., heparin) in the absence or presence of calcium prior to exposure to 2.0 μg/ml of each viper's venom. These profiles were compared with plasma without venom that had contact activation of coagulation. Coagulation kinetics were determined with thrombelastography. All venoms had thrombin-like activity, with C. s. simus creating a slow growing, weak clot that was likely mediated by metalloproteinases. In contrast, B. asper venoms had rapid onset of coagulation and a high velocity of thrombus growth. Further, B. asper venom activity was calcium-independent, activated prothrombin, activated factor XIII, and independently polymerized fibrinogen. The viscoelastic methods used were able to differentiate subspecies of C. simus and specimens of B. asper, and provide insight into the mechanisms by which the venoms acted on plasma. These methods may be useful in the profiling of similar venoms and perhaps can assist in the assessment of interventions designed to treat envenomation (e.g., antivenom).

  14. Comparing thrombin generation in patients with hemophilia A and patients on vitamin K antagonists.

    Science.gov (United States)

    de Koning, M L Y; Fischer, K; de Laat, B; Huisman, A; Ninivaggi, M; Schutgens, R E G

    2017-05-01

    Essentials It is unknown if hemophilia patients with atrial fibrillation need anticoagulation. Endogenous thrombin potentials (ETP) in hemophilia patients and patients on coumarins were compared. Severe hemophilia patients had comparable ETP to therapeutic international normalized ratio (INR). In non-severe hemophilia, 33% had higher ETP than therapeutic INR and may need anticoagulation. Click to hear Dr Negrier's perspective on global assays for assessing coagulation SUMMARY: Background It is unknown whether patients with hemophilia A with atrial fibrillation require treatment with vitamin K antagonists (VKAs) to the same extent as the normal population. Objective To compare hemostatic potential in hemophilia patients and patients on VKAs using thrombin generation (TG). Methods In this cross-sectional study, TG, initiated with 1pM tissue factor, was measured in 133 patients with severe (FVIII hemophilia A, 97 patients on a VKA with an international normalized ratio (INR) ≥ 1.5 and healthy controls. Endogenous thrombin potential (ETP) (nm*min) was compared according to FVIII level (hemophilia patients and patients on VKAs had lower median ETPs at 304 (196-449) and 176 (100-250), respectively. ETP was quite similar in severe hemophilia patients (185 [116-307]) and patients with a therapeutic INR (156 [90-225]). Compared with patients with therapeutic INR, ETP in patients with FVIII 1-19% and patients with FVIII 20-50% was higher at 296 (203-430) and 397 (219-632), respectively. All patients with therapeutic INR had an ETP hemophilia patients, 70% of patients with FVIII 1-19% and 52% of patients with FVIII 20-50% had an ETP hemophilia patients, TG was comparable to that in patients with a therapeutic INR. In one-third of non-severe hemophilia patients, TG was higher. These results suggest that anticoagulation therapy should be considered in a substantial proportion of non-severe hemophilia patients. © 2017 International Society on Thrombosis and Haemostasis.

  15. Thrombin-activatable fibrinolysis inhibitor influences disease severity in humans and mice with pneumococcal meningitis.

    Science.gov (United States)

    Mook-Kanamori, B B; Valls Serón, M; Geldhoff, M; Havik, S R; van der Ende, A; Baas, F; van der Poll, T; Meijers, J C M; P Morgan, B; Brouwer, M C; van de Beek, D

    2015-11-01

    Mortality and morbidity in patients with bacterial meningitis result from the proinflammatory response and dysregulation of coagulation and fibrinolysis. Thrombin-activatable fibrinolysis inhibitor (TAFI) is activated by free thrombin or thrombin in complex with thrombomodulin, and plays an antifibrinolytic role during fibrin clot degradation, but also has an anti-inflammatory role by inactivating proinflammatory mediators, such as complement activation products. To assess the role of TAFI in pneumococcal meningitis. We performed a prospective nationwide genetic association study in patients with bacterial meningitis, determined TAFI and complement levels in cerebrospinal fluid (CSF), and assessed the function of TAFI in a pneumococcal meningitis mouse model by using Cpb2 (TAFI) knockout mice. Polymorphisms (reference sequences: rs1926447 and rs3742264) in the CPB2 gene, coding for TAFI, were related to the development of systemic complications in patients with pneumococcal meningitis. Higher protein levels of TAFI in CSF were significantly associated with CSF complement levels (C3a, iC3b, and C5b-9) and with more systemic complications in patients with bacterial meningitis. The risk allele of rs1926447 (TT) was associated with higher levels of TAFI in CSF. In the murine model, consistent with the human data, Cpb2-deficient mice had decreased disease severity, as reflected by lower mortality, and attenuated cytokine levels and bacterial outgrowth in the systemic compartment during disease, without differences in the brain compartment, as compared with wild-type mice. These findings suggest that TAFI plays an important role during pneumococcal meningitis, which is likely to be mediated through inhibition of the complement system, and influences the occurrence of systemic complications and inflammation. © 2015 International Society on Thrombosis and Haemostasis.

  16. Factor Xa inhibition by rivaroxaban in the trough steady state can significantly reduce thrombin generation.

    Science.gov (United States)

    Horinaka, Shigeo; Sugawara, Rie; Yonezawa, Yutaka; Ishimitsu, Toshihiko

    2018-01-01

    The aim of the present study was to demonstrate evidence of reduced thrombin generation at the trough plasma rivaroxaban concentration. A single-centre, prospective, nonrandomized, drug-intervention, self-controlled study was conducted in 51 anticoagulation therapy-naïve patients with nonvalvular atrial fibrillation. Plasma rivaroxaban concentration was measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) and the anti-factor Xa chromogenic assay. Partial thrombin time (PT), protein C activity, and protein S antigen, prothrombin fragment 1 + 2 (F1 + 2), D-dimer, thrombomodulin (TM), thrombin-antithrombin complex (TAT), plasminogen activator inhibitor-1 (PAI-1) and tissue factor pathway inhibitor (TFPI) levels were also measured at the trough steady state after 4 weeks of rivaroxaban treatment and compared with baseline. Plasma concentrations obtained by the LC-MS/MS and anti-Xa assays were correlated (r = 0.841, P steady state was 23.6 ng ml -1 , at which F1 + 2, TAT and D-dimer had decreased from the baseline values (P steady state in the first to third quartile groups (+0.79 pg ml -1 , P = 0.048). By contrast, PAI-1, protein C activity, protein S antigen and TM remained within the normal range at the trough steady state. Residual plasma rivaroxaban at the trough steady state may explain the antithrombin effect of rivaroxaban in patients with nonvalvular atrial fibrillation. © 2017 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

  17. Differential proteolytic activation of factor VIII-von Willebrand factor complex by thrombin

    International Nuclear Information System (INIS)

    Hill-Eubanks, D.C.; Parker, C.G.; Lollar, P.

    1989-01-01

    Blood coagulation factor VIII (fVIII) is a plasma protein that is decreased or absent in hemophilia A. It is isolated as a mixture of heterodimers that contain a variably sized heavy chain and a common light chain. Thrombin catalyzes the activation of fVIII in a reaction that is associated with cleavages in both types of chain. The authors isolated a serine protease from Bothrops jararacussu snake venom that catalyzes thrombin-like heavy-chain cleavage but not light-chain cleavage in porcine fVIII as judged by NaDodSO 4 /PAGE and N-terminal sequence analysis. Using a plasma-free assay of the ability of activated 125 I-fVIII to function as a cofactor in the activation of factor X by factor IXa, they found that fVIII is activated by the venom enzyme. The venom enzyme-activated fVIII was isolated in stable form by cation-exchange HPLC. von Willebrand factor inhibited venom enzyme-activated fVIII but not thrombin-activated fVIII. These results suggest that the binding of fVIII to von Willebrand factor depends on the presence of an intact light chain and that activated fVIII must dissociate from von Willebrand factor to exert its cofactor effect. Thus, proteolytic activation of fVIII-von Willebrand factor complex appears to be differentially regulated by light-chain cleavage to dissociate the complex and heavy-chain cleavage to activate the cofactor function

  18. Post-traumatic hepatic artery pseudoaneurysm treated with endovascular embolization and thrombin injection

    Science.gov (United States)

    Francisco, Lloret Estañ; Asunción, López Conesa; Antonio, Capel Alemán; Ricardo, Robles Campos; Manuel, Reus Pintado; Caridad, Marín Hernández

    2010-01-01

    Post-traumatic hepatic artery pseudoaneurysm is uncommon, appearing in approximately 1% of hepatic trauma cases. Most are extrahepatic (80%) and have a late onset. Although they are usually asymptomatic, they should always be treated becasue of the high risk of complications, especially breakage. Currently the treatment of choice is endovascular embolization with coils or the exclusion of the pseudoaneurysm using other intravascular devices. Recently there have been accounts of a treatment that combines embolization with coils and image-guided percutaneous human thrombin injection. We present a case of post-traumatic hepatic artery pseudoaneurysm that was successfully treated using this combined technique. PMID:21160978

  19. Protein kinase C is differentially regulated by thrombin, insulin, and epidermal growth factor in human mammary tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, M.L.; Tellez-Inon, M.T. (Instituto de Ingenieria Genetica y Biologia Molecular, Buenos Aires (Argentina)); Medrano, E.E.; Cafferatta, E.G.A. (Instituto de Investigaciones Bioquimicas Fundacion Campomar, Buenos Aires (Argentina))

    1988-03-01

    The exposure of serum-deprived mammary tumor cells MCF-7 and T-47D to insulin, thrombin, and epidermal growth factor (EGF) resulted in dramatic modifications in the activity and in the translocation capacity of protein kinase C from cytosol to membrane fractions. Insulin induces a 600% activation of the enzyme after 5 h of exposure to the hormone in MCF-7 cells; thrombin either activates (200% in MCF-7) or down-regulates (in T-47D), and EGF exerts only a moderate effect. Thus, the growth factors studied modulate differentially the protein kinase C activity in human mammary tumor cells. The physiological significance of the results obtained are discussed in terms of the growth response elicited by insulin, thrombin, and EGF.

  20. Four-factor prothrombin complex concentrate improves thrombin generation and prothrombin time in patients with bleeding complications related to rivaroxaban: a single-center pilot trial.

    Science.gov (United States)

    Schenk, Bettina; Goerke, Stephanie; Beer, Ronny; Helbok, Raimund; Fries, Dietmar; Bachler, Mirjam

    2018-01-01

    Direct oral anticoagulants (DOACs) pose a great challenge for physicians in life-threatening bleeding events. The aim of this study was to test the efficacy of reversing the DOAC rivaroxaban using four-factor PCC (prothrombin complex concentrate), a non-specific reversing agent. Patients with life-threatening bleeding events during rivaroxaban treatment were included and administered 25 U kg -1 of PCC. Blood samples were collected immediately prior to as well as after PCC treatment at predefined time intervals. The primary endpoint was defined as the difference in thrombin generation (TG) parameters ETP (endogenous thrombin potential) and C max (peak thrombin generation) prior to and ten minutes subsequent to PCC treatment. Thirteen patients, of whom the majority suffered from intra-cranial haemorrhage (ICH) or subdural haemorrhage (SDH), were included and administered PCC. The results show that the ETP (TG) significantly ( p  = 0.001) improved by 68% and C max (TG) by 54% (p = 0.001) during PCC treatment. In addition, the Quick value (prothrombin time: Quick PT ) significantly improved by 28% and the activated partial thromboplastin time (aPTT) was decreased by 7% ten minutes after PCC administration. C max was reduced at baseline, but not ETP, aPTT or Quick PT . Lag time until initiation (TG, t lag ), thromboelastometry clotting time (CT EXTEM ) and time to peak (TG, t max ) correlated best with measured rivaroxaban levels and were out of normal ranges at baseline, but did not improve after PCC administration. In 77% of the patients bleeding (ICH/SDH-progression) ceased following PCC administration. During the study three participants passed away due to other complications not related to PCC treatment. The possibility of thrombosis formation was also evaluated seven days after administering PCC and no thromboses were found. This study shows that use of PCC improved ETP, C max, Quick PT and aPTT. However, of these parameters, only C max was reduced at the

  1. Intravenous Therapy: Hazards, Complications and Their Prevention ...

    African Journals Online (AJOL)

    In this review article, the local and systemic complications of intravenous therapy are highlighted and their preventive measures are discussed. Intravenous therapy exposes the patient to numerous hazards and many of them are avoidable, if the health care provider understands the risks involved and acts appropriately and ...

  2. Intentional intravenous mercury injection | Yudelowitz | South African ...

    African Journals Online (AJOL)

    Intravenous mercury injection is rarely seen, with few documented cases. Treatment strategies are not clearly defined for such cases, although a few options do show benefit. This case report describes a 29-year-old man suffering from bipolar disorder, who presented following self-inflicted intravenous injection of mercury.

  3. Intravenous immunoglobulin prophylaxis in neonates on artificial ...

    African Journals Online (AJOL)

    The efficacy of the prophylactic use of intravenous immunoglobulin (Ig) was evaluated in a double-blind placebo-controlled trial of 21 pairs of ventilated neonates weighing more than 1 500 g, Each infant received 0.4 g/kglday of intravenous Ig or a similar volume of placebo daily for 5 days. Criteria used to assess the ...

  4. Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Svendsen, M.S.; Salado, J.

    2008-01-01

    , in part, depend on its reflection of the dynamics of thrombin generation. MATERIAL AND METHODS: The kinetics of thrombin generation of platelets stored for 2 and 7 days, respectively, was assessed by calibrated automated thrombogram (CAT) and the lag time (min), time to peak (ttPeak; min), peak (nm...

  5. Thermodynamic and biological evaluation of a thrombin binding aptamer modified with several unlocked nucleic acid (UNA) monomers and a 2′-C-piperazino-UNA monomer

    DEFF Research Database (Denmark)

    Jensen, Troels B.; Henriksen, Jonas Rosager; Rasmussen, Bjarne E.

    2011-01-01

    Thrombin binding aptamer is a DNA 15-mer which forms a G-quadruplex structure and possess promising anticoagulant properties due to specific interactions with thrombin. Herein we present the influence of a single 2′-C-piperazino-UNA residue and UNA residues incorporated in several positions on th...

  6. Differential contributions of monocyte- and platelet-derived microparticles towards thrombin generation and fibrin formation and stability.

    Science.gov (United States)

    Aleman, M M; Gardiner, C; Harrison, P; Wolberg, A S

    2011-11-01

    Microparticles (MPs) are sub-micron vesicles shed by activated or apoptotic cells, including platelets and monocytes. Increased circulating MPs are associated with thrombosis; however, their role in thrombogenesis is poorly understood. To determine how MPs promote thrombin generation and modulate fibrin density and stability. Platelets and monocytes were isolated from healthy donors. Platelets were stimulated with calcium ionophore, thrombin receptor agonist peptide (TRAP) or TRAP/convulxin. Monocytes and human monocytic THP-1 cells were stimulated with lipopolysaccharide (LPS). MPs were isolated, washed by high-speed centrifugation and assessed using the following: transmission electron microscopy (TEM), Nanoparticle Tracking Analysis (NTA), flow cytometry, tissue factor (TF) activity, prothrombinase activity, thrombin generation, and clot formation, density and stability. MPs from monocytes (M-MPs) and platelets (PMPs) had similar shapes and diameters (100-300 nm). M-MPs had TF activity (16.7 ± 2.4 pm TF per 10(6) MP), supported prothrombinase activity and triggered shorter thrombin generation lag times than buffer controls (5.4 ± 0.5 vs. 84.2 ± 4.8 min, respectively). Compared with controls, M-MPs supported faster fibrin formation (0.24 ± 0.24 vs. 76.7 ± 15.1 mOD min(-1) , respectively), 38% higher fibrin network density and higher clot stability (3.8-fold higher turbidity in the presence of tissue plasminogen activator). In contrast, PMPs did not have TF activity and supported 2.8-fold lower prothrombinase activity than M-MPs. PMPs supported contact-dependent thrombin generation, but did not independently increase fibrin network density or stability. Interestingly, PMPs increased rates of thrombin generation and fibrin formation (1.7- and 1.3-fold, respectively) when mixed with THP-1-derived MPs. MPs from platelets and monocytes differentially modulate clot formation, structure and stability, suggesting unique contributions to thrombosis. © 2011

  7. Incidence of thromboembolic events after use of gelatin-thrombin-based hemostatic matrix during intracranial tumor surgery.

    Science.gov (United States)

    Gazzeri, Roberto; Galarza, Marcelo; Conti, Carlo; De Bonis, Costanzo

    2018-01-01

    Association between the use of hemostatic agents made from collagen/gelatin mixed with thrombin and thromboembolic events in patients undergoing tumor resection has been suggested. This study evaluates the relationship between flowable hemostatic matrix and deep vein thrombosis in a large cohort of patients treated for brain tumor removal. The authors conducted a retrospective, multicenter, clinical review of all craniotomies for tumor removal performed between 2013 and 2014. Patients were classified in three groups: group I (flowable gelatin hemostatic matrix with thrombin), group II (gelatin hemostatic without thrombin), and group III (classical hemostatic). A total of 932 patients were selected: tumor pathology included 441 gliomas, 296 meningiomas, and 195 metastases. Thromboembolic events were identified in 4.7% of patients in which gelatin matrix with thrombin was applied, in 8.4% of patients with gelatin matrix without thrombin, and in 3.6% of cases with classical methods of hemostasis. Patients with venous thromboembolism had an increased proportion of high-grade gliomas (7.2%). Patients receiving a greater dose than 10 ml gelatin hemostatic had a higher rate of thromboembolic events. Intracranial hematoma requiring reintervention occurred in 19 cases: 4.5% of cases of group III, while reoperation was performed in 1.3 and 1.6% of patients in which gelatin matrix with or without thrombin was applied. Gelatin matrix hemostat is an efficacious tool for neurosurgeons in cases of difficult intraoperative bleeding during cranial tumor surgery. This study may help to identify those patients at high risk for developing thromboembolism and to treat them accordingly.

  8. Heparin modulates chemokines in human endometrial stromal cells by interaction with tumor necrosis factor α and thrombin.

    Science.gov (United States)

    Spratte, Julia; Schönborn, Magdalena; Treder, Nora; Bornkessel, Frauke; Zygmunt, Marek; Fluhr, Herbert

    2015-05-01

    To study the impact of heparins on chemokines in decidualized human endometrial stromal cells (ESCs) in vitro. In vitro experiment. Research laboratory. Premenopausal women undergoing hysterectomy for benign reasons. ESCs were isolated from hysterectomy specimens, decidualized in vitro and incubated with unfractionated heparin and low-molecular-weight heparins (LMWHs) as well as tumor necrosis factor (TNF) α or thrombin with or without heparins. Chemokines CXCL1, CXCL5, CXCL8, CCL2, and CCL5 were measured with the use of ELISA, and CXCL5, CXCL8, CCL2, and CCL5 were detected with the use of real-time reverse-transcription polymerase chain reaction. Cell viability was determined with the use of a fluorometric assay. TNF-α and thrombin stimulated distinct patterns of chemokines in ESCs. Unfractionated heparin and LMWHs attenuated the TNF-α-mediated induction of CXCL8 and enhanced CXCL5, CCL2, and CCL5. The stimulating effect of thrombin on CXCL8 could be inhibited by heparin, whereas heparin had no impact on thrombin-induced CXCL1 and CCL2. Nuclear factor of transcription κB signaling mediated the effects of TNF-α. The effects of thrombin were mediated via extracellular signal-regulated protein kinases 1/2. Heparins have modulating effects on TNF-α- and thrombin-induced endometrial chemokines, which might have implications in the regulation of endometrial receptivity and early implantation. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  9. Role of Thrombin in Soluble Thrombomodulin-Induced Suppression of Peripheral HMGB1-Mediated Allodynia in Mice.

    Science.gov (United States)

    Tsujita, Ryuichi; Tsubota, Maho; Hayashi, Yusuke; Saeki, Haruka; Sekiguchi, Fumiko; Kawabata, Atsufumi

    2017-12-01

    High mobility group box 1 (HMGB1), a nuclear protein, once released into the extracellular space under pathological conditions, plays a pronociceptive role in redox-dependent distinct active forms, all-thiol HMGB1 (at-HMGB1) and disulfide HMGB1 (ds-HMGB1), that accelerate nociception through the receptor for advanced glycation endproducts (RAGE) and Toll-like receptor 4 (TLR4), respectively. Thrombomodulin (TM), an endothelial membrane protein, and soluble TM, known as TMα, promote thrombin-mediated activation of protein C and also sequester HMGB1, which might facilitate thrombin degradation of HMGB1. The present study aimed at clarifying the role of thrombin in TMα-induced suppression of peripheral HMGB1-dependent allodynia in mice. Thrombin-induced degradation of at-HMGB1 and ds-HMGB1 was accelerated by TMα in vitro. Intraplantar (i.pl.) injection of bovine thymus-derived HMGB1 in an unknown redox state, at-HMGB1, ds-HMGB1 or lipopolysaccharide (LPS), known to cause HMGB1 secretion, produced long-lasting mechanical allodynia in mice, as assessed by von Frey test. TMα, when preadministered i.pl., prevented the allodynia caused by bovine thymus-derived HMGB1, at-HMGB1, ds-HMGB1 or LPS, in a dose-dependent manner. The TMα-induced suppression of the allodynia following i.pl. at-HMGB1, ds-HMGB1 or LPS was abolished by systemic preadministration of argatroban, a thrombin-inhibiting agent, and accelerated by i.pl. co-administered thrombin. Our data clearly indicate that TMα is capable of promoting the thrombin-induced degradation of both at-HMGB1 and ds-HMGB1, and suppresses the allodynia caused by either HMGB1 in a thrombin-dependent manner. Considering the emerging role of HMGB1 in distinct pathological pain models, the present study suggests the therapeutic usefulness of TMα for treatment of intractable and/or persistent pain.

  10. High throughput protease profiling comprehensively defines active site specificity for thrombin and ADAMTS13.

    Science.gov (United States)

    Kretz, Colin A; Tomberg, Kärt; Van Esbroeck, Alexander; Yee, Andrew; Ginsburg, David

    2018-02-12

    We have combined random 6 amino acid substrate phage display with high throughput sequencing to comprehensively define the active site specificity of the serine protease thrombin and the metalloprotease ADAMTS13. The substrate motif for thrombin was determined by >6,700 cleaved peptides, and was highly concordant with previous studies. In contrast, ADAMTS13 cleaved only 96 peptides (out of >10 7 sequences), with no apparent consensus motif. However, when the hexapeptide library was substituted into the P3-P3' interval of VWF73, an exosite-engaging substrate of ADAMTS13, 1670 unique peptides were cleaved. ADAMTS13 exhibited a general preference for aliphatic amino acids throughout the P3-P3' interval, except at P2 where Arg was tolerated. The cleaved peptides assembled into a motif dominated by P3 Leu, and bulky aliphatic residues at P1 and P1'. Overall, the P3-P2' amino acid sequence of von Willebrand Factor appears optimally evolved for ADAMTS13 recognition. These data confirm the critical role of exosite engagement for substrates to gain access to the active site of ADAMTS13, and define the substrate recognition motif for ADAMTS13. Combining substrate phage display with high throughput sequencing is a powerful approach for comprehensively defining the active site specificity of proteases.

  11. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Liu, Yan-Hong [Second Affiliated Hospital of Harbin Medical University, 246 Xuefu Road, Harbin, Heilongjiang 150081 (China); Li, Yan; Wang, Jia-Ye [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Hattori, Toshio [Department of Emerging Infectious Diseases, Division of Internal Medicine, Graduate School of Medicine, Tohoku University, Sendai 9808574 (Japan); Ling, Hong, E-mail: lingh@ems.hrbmu.edu.cn [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Department of Parasitology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Key Lab of Heilongjiang Province for Infection and Immunity, Key Lab of Heilongjiang Province Education Bureau for Etiology, Harbin, Heilongjiang 150081 (China); Zhang, Feng-Min, E-mail: fengminzhang@yahoo.com.cn [Department of Microbiology, Harbin Medical University, 194 Xuefu Road, Harbin, Heilongjiang 150081 (China); Key Lab of Heilongjiang Province for Infection and Immunity, Key Lab of Heilongjiang Province Education Bureau for Etiology, Harbin, Heilongjiang 150081 (China)

    2010-01-22

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  12. Thrombin activatable fibrinolysis inhibitor and other hemostatic parameters in patients with polycystic ovary syndrome.

    Science.gov (United States)

    Oral, Baha; Mermi, Betül; Dilek, Müfide; Alanoğlu, Güçhan; Sütçü, Recep

    2009-02-01

    To investigate the plasma levels of thrombin-activatable fibrinolysis inhibitor (TAFI) in women with polycystic ovary syndrome (PCOS) and its correlation with various metabolic, hormonal and hemostatic parameters. Forty-eight women with PCOS and 43 age- and BMI-matched ovulatory controls were recruited during a 20-month study period. Blood samples were drawn for all tests, which included plasma lipids and lipoproteins, reproductive hormones, glucose, insulin, TAFI antigen concentration, plasminogen activator inhibitor-1 (PAI-1) activity, fibrinogen concentration, thrombomodulin, thrombin-antithrombin (TAT) complexes, D-dimer, Protein C Antigen, Protein S Antigen, Antithrombin III (AT III) and activated protein C (APC) resistance. Plasma TAFI levels of PCOS patients were found to be significantly higher than in healthy controls (93.8%+/-30.6%vs. 79.8% +/- 22.4%, p < 0.05). Plasma levels of D-dimer, AT III, PAI-1 and thrombomodulin were also significantly higher in women with PCOS compared with healthy controls. All the other hemostatic parameters (including TAT complexes; Protein C; APC; and Protein S) were comparable between the two study groups. This study showed that plasma levels of TAFI, PAI-1, D-dimer, AT III and thrombomodulin were significantly increased in women with PCOS compared with age- and BMI-matched controls.

  13. FVIIa-sTF and Thrombin Inhibitory Activities of Compounds Isolated from Microcystis aeruginosa K-139.

    Science.gov (United States)

    Anas, Andrea Roxanne J; Mori, Akane; Tone, Mineka; Naruse, Chiaki; Nakajima, Anna; Asukabe, Hirohiko; Takaya, Yoshiaki; Imanishi, Susumu Y; Nishizawa, Tomoyasu; Shirai, Makoto; Harada, Ken-Ichi

    2017-08-30

    The rise of bleeding and bleeding complications caused by oral anticoagulant use are serious problems nowadays. Strategies that block the initiation step in blood coagulation involving activated factor VII-tissue factor (fVIIa-TF) have been considered. This study explores toxic Microcystis aeruginosa K-139, from Lake Kasumigaura, Ibaraki, Japan, as a promising cyanobacterium for isolation of fVIIa-sTF inhibitors. M. aeruginosa K-139 underwent reversed-phase solid-phase extraction (ODS-SPE) from 20% MeOH to MeOH elution with 40%-MeOH increments, which afforded aeruginosin K-139 in the 60% MeOH fraction; micropeptin K-139 and microviridin B in the MeOH fraction. Aeruginosin K-139 displayed an fVIIa-sTF inhibitory activity of ~166 µM, within a 95% confidence interval. Micropeptin K-139 inhibited fVIIa-sTF with EC 50 10.62 µM, which was more efficient than thrombin inhibition of EC 50 26.94 µM. The thrombin/fVIIa-sTF ratio of 2.54 in micropeptin K-139 is higher than those in 4-amidinophenylmethane sulfonyl fluoride (APMSF) and leupeptin, when used as positive controls. This study proves that M. aeruginosa K-139 is a new source of fVIIa-sTF inhibitors. It also opens a new avenue for micropeptin K-139 and related depsipeptides as fVIIa-sTF inhibitors.

  14. Computational study of some benzamidine-based inhibitors of thrombin-like snake venom proteinases

    Science.gov (United States)

    Henriques, Elsa S.; Nascimento, Marco A. C.; Ramos, Maria João

    Pit viper venoms contain a number of serine proteinases that, despite their observed coagulant thrombin-like action in vitro, exhibit a paradoxical benign defibrinogenating (anticoagulant) action in vivo, with clinical applications in preventing thrombi and improved blood circulation. Considering that several benzamidine-based inhibitors, some highly selective to thrombin, also inhibit the enzymatic activity of such venombins, the modeling of their enzyme-inhibitor interactions could provide valuable information on the topological factors that determine the divergences in activity. The first step, and the object of the present study, was to derive the necessary set of parameters, consistent with the CHARMM force field, and to perform molecular dynamics (MD) simulations on a few selected representatives of the inhibitors in question under physiological conditions. Bonding and van der Waals parameters were derived by analogy to similar ones in the existing force field. Net atomic charges were obtained with a restrained fitting to the molecular electrostatic potential generated at B3LYP/6-31G(d) level. The parameters were refined to reproduce the available experimental geometries and crystal data, and the MD simulations of the free inhibitors in aqueous solution at 298 K provided an insightful description of their available conformational space.

  15. Proteolytic signatures define unique thrombin-derived peptides present in human wound fluid in vivo.

    Science.gov (United States)

    Saravanan, Rathi; Adav, Sunil S; Choong, Yeu Khai; van der Plas, Mariena J A; Petrlova, Jitka; Kjellström, Sven; Sze, Siu Kwan; Schmidtchen, Artur

    2017-10-13

    The disease burden of failing skin repair and non-healing ulcers is extensive. There is an unmet need for new diagnostic approaches to better predict healing activity and wound infection. Uncontrolled and excessive protease activity, of endogenous or bacterial origin, has been described as a major contributor to wound healing impairments. Proteolytic peptide patterns could therefore correlate and "report" healing activity and infection. This work describes a proof of principle delineating a strategy by which peptides from a selected protein, human thrombin, are detected and attributed to proteolytic actions. With a particular focus on thrombin-derived C-terminal peptides (TCP), we show that distinct peptide patterns are generated in vitro by the human S1 peptidases human neutrophil elastase and cathepsin G, and the bacterial M4 peptidases Pseudomonas aeruginosa elastase and Staphylococcus aureus aureolysin, respectively. Corresponding peptide sequences were identified in wound fluids from acute and non-healing ulcers, and notably, one peptide, FYT21 (FYTHVFRLKKWIQKVIDQFGE), was only present in wound fluid from non-healing ulcers colonized by P. aeruginosa and S. aureus. Our result is a proof of principle pointing at the possibility of defining peptide biomarkers reporting distinct proteolytic activities, of potential implication for improved diagnosis of wound healing and infection.

  16. FVIIa-sTF and Thrombin Inhibitory Activities of Compounds Isolated from Microcystis aeruginosa K-139

    Directory of Open Access Journals (Sweden)

    Andrea Roxanne J. Anas

    2017-08-01

    Full Text Available The rise of bleeding and bleeding complications caused by oral anticoagulant use are serious problems nowadays. Strategies that block the initiation step in blood coagulation involving activated factor VII-tissue factor (fVIIa-TF have been considered. This study explores toxic Microcystis aeruginosa K-139, from Lake Kasumigaura, Ibaraki, Japan, as a promising cyanobacterium for isolation of fVIIa-sTF inhibitors. M. aeruginosa K-139 underwent reversed-phase solid-phase extraction (ODS-SPE from 20% MeOH to MeOH elution with 40%-MeOH increments, which afforded aeruginosin K-139 in the 60% MeOH fraction; micropeptin K-139 and microviridin B in the MeOH fraction. Aeruginosin K-139 displayed an fVIIa-sTF inhibitory activity of ~166 µM, within a 95% confidence interval. Micropeptin K-139 inhibited fVIIa-sTF with EC50 10.62 µM, which was more efficient than thrombin inhibition of EC50 26.94 µM. The thrombin/fVIIa-sTF ratio of 2.54 in micropeptin K-139 is higher than those in 4-amidinophenylmethane sulfonyl fluoride (APMSF and leupeptin, when used as positive controls. This study proves that M. aeruginosa K-139 is a new source of fVIIa-sTF inhibitors. It also opens a new avenue for micropeptin K-139 and related depsipeptides as fVIIa-sTF inhibitors.

  17. The contamination of intravenous fluids by writing on the infusion bag: Fact or fiction?

    OpenAIRE

    James Daniel Langston; William Patrick Monaghan; Mellissa Bush

    2013-01-01

    Introduction -Laboratory experiments were conducted to ascertain whether Sharpie® brand black permanent marker ink will permeate through intravenous infusion bags. The practice of writing directly on infusion bags is a frequent yet controversial practice. There are no known written standards that exist which pertain to this practice. Methods – Five types of intravenous bags containing different solutions marked with black ink from a fine point felt tipped Sharpie® marker. Sample extraction oc...

  18. Intravenous adenosine SPECT thallium imaging

    International Nuclear Information System (INIS)

    Joyce, J.M.; Grossman, S.J.; Garrett, J.S.; Sharma, B.; Geller, M.; Sweeney, P.J.

    1991-01-01

    This paper determines the safety and efficacy of intravenous (IV) adenosine in females for the evaluation of coronary artery disease, since only limited data are available. Eighty consecutive studies of 78 female subjects (aged 43-83 years) using IV adenosine (0.14 mg/kg per minute) with T1-201 SPECT imaging were reviewed. Fifty-eight (73%) had mild symptoms; mild dyspnea (24%), flushing (23%), chest pain (23%), headache (11%), dizziness (11%), weakness (9%), nausea (8%), abdominal pain (8%), arm pain (6%), chest tightness (4%), neck tightness (4%), dry mouth (4%), and dropped P waves (4%). Four had moderate symptoms: dyspnea requiring Proventil or aminophylline (2%), significant hypotension (1%), and third-degree atrioventicular heart block (1%). Two had severe symptoms (ventricular tachycardia requiring cardioversion (1%) and severe dyspnea requiring epinephrine (1%). Twenty-two (28%) underwent cardiac catheterization that demonstrated coronary artery disease or postangioplasty results. The thallium SPECT images were 94% sensitive and 100% specific in detecting significant disease. The one false-negative result was in a subject who experienced no symptoms for ECG changes during adenosine infusion. Ischemic ECG changes were 35% sensitive and 100% specific. Chest pain was 53% sensitive and 60% specific

  19. Genetic variation in thrombin-activatable fibrinolysis inhibitor (TAFI) is associated with the risk of splanchnic vein thrombosis

    NARCIS (Netherlands)

    de Bruijne, Emile L. E.; Darwish Murad, Sarwa; de Maat, Moniek P. M.; Tanck, Michael W. T.; Haagsma, Elizabeth B.; van Hoek, Bart; Rosendaal, Frits R.; Janssen, Harry L. A.; Leebeek, Frank W. G.

    2007-01-01

    Splanchnic vein thrombosis (SVT) has been associated with a hypercoagulable state. Thrombin-activatable fibrinolysis inhibitor (TAFI) may contribute to a hypercoagulable state, and therefore we were interested in the role of TAFI in SVT. Since the disease is frequently associated with liver

  20. Genetic variation in thrombin-activatable fibrinolysis inhibitor (TAR) is associated with the risk of splanchnic vein thrombosis

    NARCIS (Netherlands)

    de Bruijne, Emile L. E.; Murad, Sarwa Darwish; de Maat, Moniek P. M.; Tanck, Michael W. T.; Haagsma, Elizabeth B.; van Hoeks, Bart; Rosendaal, Frits R.; Janssen, Harry L. A.; Leebeek, Frank W. G.

    Splanchnic vein thrombosis (SVT) has been associated with a hypercoagulable state. Thrombin-activatable fibrinolysis inhibitor (TAFI) may contribute to a hypercoagulable state, and therefore we were interested in the role of TAR in SVT. Since the disease is frequently associated with liver

  1. In vivo increase in thrombin generation by four-factor prothrombin complex concentrate in apixaban-treated healthy volunteers

    NARCIS (Netherlands)

    Cheung, Y. W.; Barco, S.; Hutten, B. A.; Meijers, J. C. M.; Middeldorp, S.; Coppens, M.

    2015-01-01

    Four-factor prothrombin complex concentrate (PCC) (Cofact; Sanquin Blood Supply) 50 IU kg(-1) increased thrombin generation beyond baseline values in healthy, rivaroxaban-treated subjects. To assess whether infusion with doses of 37.5 IU kg(-1) and 25 IU kg(-1) PCC reverses the anticoagulant effect

  2. In vitro effect of hemodilution on activated clotting time and high-dose thrombin time during cardiopulmonary bypass

    NARCIS (Netherlands)

    Huyzen, RJ; vanOeveren, W; Wei, FY; Stellingwerf, P; Boonstra, PW; Gu, YJ

    Background. Extreme dilution of clotting factors, as may occur during pediatric or neonatal cardiopulmonary bypass, often leads to inadequate monitoring of anticoagulation with activated dotting time (ACT). In this study we postulate that the high-dose thrombin time (HiTT) is less influenced by

  3. Alkylation of phosphorothioated thrombin binding aptamers improves the selectivity of inhibition of tumor cell proliferation upon anticoagulation.

    Science.gov (United States)

    Yang, Xiantao; Zhu, Yuejie; Wang, Chao; Guan, Zhu; Zhang, Lihe; Yang, Zhenjun

    2017-07-01

    Recently, aptamers have been extensively researched for therapy and diagnostic applications. Thrombin-binding aptamer is a 15nt deoxyribonucleic acid screened by SELEX, it can specifically bind to thrombin and inhibit blood coagulation. Since it is also endowed with excellent antitumor activity, the intrinsic anticoagulation advantage converted to a main potential side effect for its further application in antiproliferative therapy. Site-specific alkylation was conducted through nucleophilic reaction of phosphorothioated TBAs using bromide reagents. Circular dichroism (CD) spectroscopy and surface plasmon resonance (SPR) measurements were used to evaluate anticoagulation activity, and a CCK-8 assay was used to determine cell proliferation activity. The CD spectra of the modified TBAs were weakened, and their affinity for thrombin was dramatically reduced, as reflected by the K D values. On the other hand, their inhibition of A549 cells was retained. Incorporation of different alkyls apparently disrupted the binding of TBA to thrombin while maintaining the antitumor activity. A new modification strategy was established for the use of TBA as a more selective antitumor agent. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. A sensitive bioimmunoassay for thrombin-cleaved two-chain urokinase-type plasminogen activator in human body fluids

    NARCIS (Netherlands)

    Braat, E.A.M.; Nauland, U.; Dooijewaard, G.; Rijken, D.C.

    1996-01-01

    Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a two-chain form (tcu-PA/T), which is virtually inactive in plasminogen activator assays. Little is known about the physiological importance of tcu-PA/T. To examine the occurrence of tcu-PA/T in vivo, we developed a

  5. Effect of the immobilisation of DNA aptamers on the detection of thrombin by means of surface plasmon resonance

    Czech Academy of Sciences Publication Activity Database

    Hianik, T.; Ostatná, V.; Vaisocherová, Hana; Homola, Jiří

    2008-01-01

    Roč. 391, č. 5 (2008), s. 1861-1869 ISSN 1618-2642 R&D Projects: GA AV ČR KAN200670701 Institutional research plan: CEZ:AV0Z20670512 Keywords : DNA aptamer * thrombin * dendrimers Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.328, year: 2008

  6. Binding characteristics of thrombin-activatable fibrinolysis inhibitor to streptococcal surface collagen-like proteins A and B

    NARCIS (Netherlands)

    Seron, Mercedes Valls; Plug, Tom; Marquart, J. Arnoud; Marx, Pauline F.; Herwald, Heiko; de Groot, Philip G.; Meijers, Joost C. M.

    2011-01-01

    Streptococcus pyogenes is the causative agent in a wide range of diseases in humans. Thrombin-activatable fibrinolysis inhibitor (TAFI) binds to collagen-like proteins ScIA and ScIB at the surface of S. pyogenes. Activation of TAFI at this surface redirects inflammation from a transient to chronic

  7. Effects of thrombin inhibition with melagatran on renal hemodynamics and function and liver integrity during early endotoxemia

    DEFF Research Database (Denmark)

    Nitescu, Nicoletta; Grimberg, Elisabeth; Ricksten, Sven-Erik

    2007-01-01

    Sepsis is associated with an activation of the coagulation system and multiorgan failure. The aim of the study was to examine the effects of selective thrombin inhibition with melagatran on renal hemodynamics and function, and liver integrity, during early endotoxemia. Endotoxemia was induced...

  8. INFECTIVE ENDOCARDITIS IN INTRAVENOUS DRUGS ABUSED PATIENT

    Directory of Open Access Journals (Sweden)

    E. Y. Ponomareva

    2011-01-01

    Full Text Available Three-year observation of acute tricuspid infective endocarditis in intravenous drug abused patient: diagnosis, clinical features, visceral lesions, the possibility of cardiac surgery and conservative treatment, outcome.

  9. Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

    NARCIS (Netherlands)

    Eftimov, Filip; Winer, John B.; Vermeulen, Marinus; de Haan, Rob; van Schaik, Ivo N.

    2013-01-01

    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, developing over at least two months. Uncontrolled studies suggest that intravenous immunoglobulin (IVIg) helps. This review was first published in 2002 and has since

  10. Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy

    NARCIS (Netherlands)

    Eftimov, Filip; Winer, John B.; Vermeulen, Marinus; de Haan, Rob; van Schaik, Ivo N.

    2009-01-01

    Background Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) causes progressive or relapsing weakness and numbness of the limbs, developing over at least two months. Uncontrolled studies suggest that intravenous immunoglobulin (IVIg) helps. Objectives To review systematically the

  11. Intravenous iron-containing products: EMA procrastination.

    Science.gov (United States)

    2014-07-01

    A European reassessment has led to identical changes in the summaries of product characteristics (SPCs) for all intravenous iron-containing products: the risk of serious adverse effects is now highlighted, underlining the fact that intravenous iron-containing products should only be used when the benefits clearly outweigh the harms. Unfortunately, iron dextran still remains on the market despite a higher risk of hypersensitivity reactions than with iron sucrose.

  12. Contrast medium extravasation in intravenous urography

    International Nuclear Information System (INIS)

    Tosch, U.; Becker-Gaab, C.; Hahn, D.

    1984-01-01

    Aetiology and diagnostic procedure of calyceal fornix rupture during intravenous urography are discussed. In the literature the fornix rupture is discribed as a spontaneous event - not so in the four cases presented. In two cases a sudden increase in intrapelvic pressure was due to an ureteric calculus, in the other cases an obstruction of the ureter was secondary to neoplasm. It is recommended to perform a CT as soon as a contrastmedium extravasation in intravenous urography is diagnosed. (orig.) [de

  13. Contrast medium extravasation in intravenous urography

    Energy Technology Data Exchange (ETDEWEB)

    Tosch, U.; Becker-Gaab, C.; Hahn, D.

    1984-09-01

    Aetiology and diagnostic procedure of calyceal fornix rupture during intravenous urography are discussed. In the literature the fornix rupture is discribed as a spontaneous event - not so in the four cases presented. In two cases a sudden increase in intrapelvic pressure was due to an ureteric calculus, in the other cases an obstruction of the ureter was secondary to neoplasm. It is recommended to perform a CT as soon as a contrast medium extravasation in intravenous urography is diagnosed.

  14. Reduced peak, but no diurnal variation, in thrombin generation upon melatonin supplementation in tetraplegia. A randomised, placebo-controlled study.

    Science.gov (United States)

    Iversen, Per Ole; Dahm, Anders; Skretting, Grethe; Mowinckel, Marie-Christine; Stranda, Annicke; Østerud, Bjarne; Sandset, Per Morten; Kostovski, Emil

    2015-11-01

    Tetraplegic patients have increased risk of venous thrombosis despite anti-thrombotic prophylaxis. Moreover, they have blunted plasma variations in melatonin and altered diurnal variation of several haemostatic markers, compared with able-bodied. However, whether healthy individuals and tetraplegic patients, with or without melatonin, display abnormalities in thrombin generation during a 24-hour (h) cycle, is unknown. We therefore used the Calibrated Automated Thrombogram (CAT) assay to examine diurnal variations and the possible role of melatonin in thrombin generation. Six men with long-standing complete tetraplegia were included in a randomised placebo-controlled cross-over study with melatonin supplementation (2 mg, 4 consecutive nights), whereas six healthy, able-bodied men served as controls. Ten plasma samples were collected frequently during a 24-h awake/sleep cycle. No significant diurnal variation of any of the measured CAT indices was detected in the three study groups. Whereas endogenous thrombin potential (ETP) was independent (p > 0.05) of whether the tetraplegic men received melatonin or placebo, melatonin decreased (p = 0.005) peak values in tetraplegia compared with those given placebo. Able-bodied men had lower (p = 0.019) ETP and Lag-Time (p = 0.018) compared with tetraplegics receiving placebo. Neither the Time-to-Peak nor the Start-Tail was affected (p > 0.05) by melatonin in tetraplegia. In conclusion, indices of thrombin generation are not subjected to diurnal variation in healthy able-bodied or tetraplegia, but peak thrombin generation is reduced in tetraplegic men receiving oral melatonin.

  15. Rapid Upregulation of Orai1 Abundance in the Plasma Membrane of Platelets Following Activation with Thrombin and Collagen Related Peptide

    Directory of Open Access Journals (Sweden)

    Guilai Liu

    2015-11-01

    Full Text Available Background: Blood platelets accomplish primary hemostasis following vascular injury and contribute to the orchestration of occlusive vascular disease. Platelets are activated by an increase of cytosolic Ca2+-activity ([Ca2+]i, which is accomplished by Ca2+-release from intracellular stores and subsequent store operated Ca2+ entry (SOCE through Ca2+ release activated Ca2+ channel moiety Orai1. Powerful activators of platelets include thrombin and collagen related peptide (CRP, which are in part effective by activation of small G- protein Rac1. The present study explored the influence of thrombin and CRP on Orai1 protein abundance and cytosolic Ca2+-activity ([Ca2+]i in platelets drawn from wild type mice. Methods: Orai1 protein surface abundance was quantified utilizing CF™488A conjugated antibodies, and [Ca2+]i was determined with Fluo3-fluorescence. Results: In resting platelets, Orai1 protein abundance and [Ca2+]i were low. Thrombin (0.02 U/ml and CRP (5ug/ml within 2 min increased [Ca2+]i and Orai1 protein abundance at the platelet surface. [Ca2+]i was further increased by Ca2+ ionophore ionomycin (1 µM and by store depletion with the sarcoendoplasmatic Ca2+ ATPase inhibitor thapsigargin (1 µM. However, Orai1 protein abundance at the platelet surface was not significantly affected by ionomycin and only slightly increased by thapsigargin. The effect of thrombin and CRP on Orai1 abundance and [Ca2+]i was significantly blunted by Rac1 inhibitor NSC23766 (50 µM. Conclusion: The increase of [Ca2+]i following stimulation of platelets with thrombin and collagen related peptide is potentiated by ultrarapid Rac1 sensitive translocation of Orai1 into the cell membrane.

  16. iTRAQ quantitative proteomics-based identification of cell adhesion as a dominant phenotypic modulation in thrombin-stimulated human aortic endothelial cells.

    Science.gov (United States)

    Wang, Huang-Joe; Chen, Sung-Fang; Lo, Wan-Yu

    2015-05-01

    The phenotypic changes in thrombin-stimulated endothelial cells include alterations in permeability, cell shape, vasomotor tone, leukocyte trafficking, migration, proliferation, and angiogenesis. Previous studies regarding the pleotropic effects of thrombin on the endothelium used human umbilical vein endothelial cells (HUVECs)-cells derived from fetal tissue that does not exist in adults. Only a few groups have used screening approaches such as microarrays to profile the global effects of thrombin on endothelial cells. Moreover, the proteomic changes of thrombin-stimulated human aortic endothelial cells (HAECs) have not been elucidated. HAECs were stimulated with 2 units/mL thrombin for 5h and their proteome was investigated using isobaric tags for the relative and absolute quantification (iTRAQ) and the MetaCore(TM) software. A total of 627 (experiment A) and 622 proteins (experiment B) were quantified in the duplicated iTRAQ analyses. MetaCore(TM) pathway analysis identified cell adhesion as a dominant phenotype in thrombin-stimulated HAECs. Replicated iTRAQ data revealed that "Cell adhesion_Chemokines and adhesion," "Cell adhesion_Histamine H1 receptor signaling in the interruption of cell barrier integrity," and "Cell adhesion_Integrin-mediated cell adhesion and migration" were among the top 10 statistically significant pathways. The cell adhesion phenotype was verified by increased THP-1 adhesion to thrombin-stimulated HAECs. In addition, the expression of ICAM-1, VCAM-1, and SELE was significantly upregulated in thrombin-stimulated HAECs. Several regulatory pathways are altered in thrombin-stimulated HAECs, with cell adhesion being the dominant altered phenotype. Our findings show the feasibility of the iTRAQ technique for evaluating cellular responses to acute stimulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Errors in the administration of intravenous medication in Brazilian hospitals.

    Science.gov (United States)

    Anselmi, Maria Luiza; Peduzzi, Marina; Dos Santos, Claudia Benedita

    2007-10-01

    To verify the frequency of errors in the preparation and administration of intravenous medication in three Brazilian hospitals in the State of Bahia. The administration of intravenous medications constitutes a central activity in Brazilian nursing. Errors in performing this activity may result in irreparable damage to patients and may compromise the quality of care. Cross-sectional study, conducted in three hospitals in the State of Bahia, Brazil. Direct observation of the nursing staff (nurse technicians, auxiliary nurses and nurse attendants), preparing and administering intravenous medication. When preparing medication, wrong patient error did not occur in any of the three hospitals, whereas omission dose was the most frequent error in all study sites. When administering medication, the most frequent errors in the three hospitals were wrong dose and omission dose. The rates of error found are considered low compared with similar studies. The most frequent types of errors were wrong dose and omission dose. The hospitals studied showed different results with the smallest rates of errors occurring in hospital 1 that presented the best working conditions. Relevance to clinical practice. Studies such as this one have the potential to improve the quality of care.

  18. Historical perspective and contemporary management of acute coronary syndromes: from MONA to THROMBINS2.

    Science.gov (United States)

    Kline, Kristopher P; Conti, C Richard; Winchester, David E

    2015-01-01

    Acute coronary syndrome (ACS) remains a major burden on morbidity and mortality in the United States. Medical professionals and students often use the mnemonic 'MONA' (morphine, oxygen, nitroglycerin and aspirin) to recall treatments for ACS; however, this list of therapies is outdated. We provide a historical perspective on 'MONA,' attempt to uncover its origin in the medical literature, and demonstrate the myriad changes that have occurred over the last 50 years of ACS management. We have developed a novel mnemonic, 'THROMBINS2' (thienopyridines, heparin/enoxaparin, renin-angiotensin system blockers, oxygen, morphine, beta blocker, intervention, nitroglycerin, statin/salicylate) to help bedside clinicians recall all the elements of contemporary ACS management. We demonstrate the mortality benefit for each component of contemporary ACS management, correlating the continued improvement with historical data on mortality after myocardial infarction. We encourage providers to utilize this mnemonic to explore options and guide treatments in ACS patients.

  19. Characterization of Ixophilin, a thrombin inhibitor from the gut of Ixodes scapularis.

    Directory of Open Access Journals (Sweden)

    Sukanya Narasimhan

    Full Text Available Ixodes scapularis, the black-legged tick, vectors several human pathogens including Borrelia burgdorferi, the agent of Lyme disease in North America. Pathogen transmission to the vertebrate host occurs when infected ticks feed on the mammalian host to obtain a blood meal. Efforts to understand how the tick confronts host hemostatic mechanisms and imbibes a fluid blood meal have largely focused on the anticoagulation strategies of tick saliva. The blood meal that enters the tick gut remains in a fluid state for several days during the process of feeding, and the role of the tick gut in maintaining the blood-meal fluid is not understood. We now demonstrate that the tick gut produces a potent inhibitor of thrombin, a key enzyme in the mammalian coagulation cascade. Chromatographic fractionation of engorged tick gut proteins identified one predominant thrombin inhibitory activity associated with an approximately 18 kDa protein, henceforth referred to as Ixophilin. The ixophilin gene was preferentially transcribed in the guts of feeding nymphs. Expression began after 24 hours of feeding, coincident with the flow of host blood into the tick gut. Immunity against Ixophilin delayed tick feeding, and decreased feeding efficiency significantly. Surprisingly, immunity against Ixophilin resulted in increased Borrelia burgdorferi transmission to the host, possibly due to delayed feeding and increased transmission opportunity. These observations illuminate the potential drawbacks of targeting individual tick proteins in a functional suite. They also underscore the need to identify the "anticoagulome" of the tick gut, and to prioritize a critical subset of anticoagulants that could be targeted to efficiently thwart tick feeding, and block pathogen transmission to the vertebrate host.

  20. Comparison of Ultrasound-Guided Thrombin Injection of Iatrogenic Pseudoaneurysms Based on Neck Dimension.

    Science.gov (United States)

    Yang, Ethan Y; Tabbara, Marwan M; Sanchez, Priscila G; Abi-Chaker, Andrew M; Patel, Jaimin; Bornak, Arash; Jones, Keith M; Rey, Jorge

    2018-02-01

    Ultrasound-guided thrombin injection (UGTI) of femoral artery pseudoaneurysms after endovascular procedures is an effective therapy. There is controversy in the literature regarding injecting pseudoaneurysms with short and/or wide necks. This article reports our experience in UGTI of pseudoaneurysms in 1 hospital regarding the efficacy of this treatment in all pseudoaneurysms regardless of the size of the necks. A retrospective review of 46 patients diagnosed between 2011 and 2016 with groin pseudoaneurysms using established duplex ultrasound criteria. Mean age was 68 years (range 27-87). Ten pseudoaneurysms thrombosed spontaneously, 5 were thrombosed by ultrasound-guided compression, and 2 were treated surgically due to disqualifying criteria. In this retrospective review, we analyzed the remaining 29 pseudoaneurysms regarding the dimensions of their neck lengths and outcomes after attempting thrombin injection. The mean aneurysm neck length and width were 1.03 ± 0.9 cm and 0.30 ± 0.1 cm, respectively. All 29 patients were evaluated with respect to pseudoaneurysm size, neck length, neck width, and complexity. Successful treatment of 29 pseudoaneurysms (2 external iliac, 20 common femoral, 2 deep femoral, and 5 superficial femoral) with UGTI was achieved without complications in 100% of the cases, regardless of pseudoaneurysm size, neck dimensions, or complexity. Anticoagulation status did not affect the efficacy of the procedure. Nine of the 29 pseudoaneurysms (31.0%) had neck length less than 0.5 cm. This study demonstrates the safety and efficacy of UGTI in treating iatrogenic pseudoaneurysm in 29 of 29 patients, even in patients with pseudoaneurysm with short neck lengths. Our experiences support injecting all pseudoaneurysms irrespective of dimension. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Thrombin induces Egr-1 expression in fibroblasts involving elevation of the intracellular Ca2+ concentration, phosphorylation of ERK and activation of ternary complex factor

    Directory of Open Access Journals (Sweden)

    Thiel Gerald

    2009-05-01

    Full Text Available Abstract Background The serine protease thrombin catalyzes fibrin clot formation by converting fibrinogen into fibrin. Additionally, thrombin stimulation leads to an activation of stimulus-responsive transcription factors in different cell types, indicating that the gene expression pattern is changed in thrombin-stimulated cells. The objective of this study was to analyze the signaling cascade leading to the expression of the zinc finger transcription factor Egr-1 in thrombin-stimulated lung fibroblasts. Results Stimulation of 39M1-81 fibroblasts with thrombin induced a robust and transient biosynthesis of Egr-1. Reporter gene analysis revealed that the newly synthesized Egr-1 was biologically active. The signaling cascade connecting thrombin stimulation with Egr-1 gene expression required elevated levels of cytosolic Ca2+, the activation of diacylgycerol-dependent protein kinase C isoenzymes, and the activation of extracellular signal-regulated protein kinase (ERK. Stimulation of the cells with thrombin triggered the phosphorylation of the transcription factor Elk-1. Expression of a dominant-negative mutant of Elk-1 completely prevented Egr-1 expression in stimulated 39M1-81 cells, indicating that Elk-1 or related ternary complex factors connect the intracellular signaling cascade elicited by activation of protease-activated receptors with transcription of the Egr-1 gene. Lentiviral-mediated expression of MAP kinase phosphatase-1, a dual-specific phosphatase that dephosphorylates and inactivates ERK in the nucleus, prevented Elk-1 phosphorylation and Egr-1 biosynthesis in thrombin stimulated 39M1-81 cells, confirming the importance of nuclear ERK and Elk-1 for the upregulation of Egr-1 expression in thrombin-stimulated lung fibroblasts. 39M1-81 cells additionally express M1 muscarinic acetylcholine receptors. A comparison between the signaling cascades induced by thrombin or carbachol showed no differences, except that signal transduction via M

  2. Intravenous fluids in acute decompensated heart failure.

    Science.gov (United States)

    Bikdeli, Behnood; Strait, Kelly M; Dharmarajan, Kumar; Li, Shu-Xia; Mody, Purav; Partovian, Chohreh; Coca, Steven G; Kim, Nancy; Horwitz, Leora I; Testani, Jeffrey M; Krumholz, Harlan M

    2015-02-01

    This study sought to determine the use of intravenous fluids in the early care of patients with acute decompensated heart failure (HF) who are treated with loop diuretics. Intravenous fluids are routinely provided to many hospitalized patients. We conducted a retrospective cohort study of patients admitted with HF to 346 hospitals from 2009 to 2010. We assessed the use of intravenous fluids during the first 2 days of hospitalization. We determined the frequency of adverse in-hospital outcomes. We assessed variation in the use of intravenous fluids across hospitals and patient groups. Among 131,430 hospitalizations for HF, 13,806 (11%) were in patients treated with intravenous fluids during the first 2 days. The median volume of administered fluid was 1,000 ml (interquartile range: 1,000 to 2,000 ml), and the most commonly used fluids were normal saline (80%) and half-normal saline (12%). Demographic characteristics and comorbidities were similar in hospitalizations in which patients did and did not receive fluids. Patients who were treated with intravenous fluids had higher rates of subsequent critical care admission (5.7% vs. 3.8%; p fluid treatment varied widely across hospitals (range: 0% to 71%; median: 12.5%). Many patients who are hospitalized with HF and receive diuretics also receive intravenous fluids during their early inpatient care, and the proportion varies among hospitals. Such practice is associated with worse outcomes and warrants further investigation. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  3. Direct oral anticoagulants: An update.

    Science.gov (United States)

    Franco Moreno, Ana Isabel; Martín Díaz, Rosa María; García Navarro, María José

    2017-12-30

    Vitamin K antagonists were the only choice for chronic oral anticoagulation for more than half a century. Over the past few years, direct oral anticoagulants have emerged, including one direct thrombin inhibitor (dabigatran etexilate) and three factor Xa inhibitors (apixaban, edoxaban and rivaroxaban). In randomised controlled trials comparing direct oral anticoagulants with traditional vitamin K antagonists, the direct oral anticoagulants all showed a favourable benefit-risk balance in their safety and efficacy profile, in prevention of thromboembolic events in patients with atrial fibrillation and in the prevention and treatment of venous thromboembolism and acute coronary syndrome. In 2008, dabigatran was the first direct oral anticoagulant approved by the European Medicine Agency. Subsequently, rivaroxaban, apixaban and edoxaban were also authorised. This article reviews the evidence related to the use of these drugs. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  4. In vitro anti-inflammatory and anti-coagulant effects of antibiotics towards Platelet Activating Factor and thrombin

    Science.gov (United States)

    2011-01-01

    Background Sepsis is characterized as a systemic inflammatory response that results from the inability of the immune system to limit bacterial spread during an ongoing infection. In this condition the significant mediator of inflammation Platelet Activating Factor (PAF) and the coagulant factor thrombin are implicated. In animal models, treatment with PAF-antagonists or co-administration of antibiotics with recombinant-PAF-Acetylhydrolase (rPAF-AH) have exhibited promising results. In order to examine the putative anti-inflammatory and/or antithrombotic interactions between antibiotic treatment used in sepsis with PAF and/or thrombin, we studied the in vitro effects of these compounds towards PAF or/and thrombin related activities and towards PAF basic metabolic enzymes. Methods We assessed the inhibitory effect of these drugs against PAF or thrombin induced aggregation on washed rabbit platelets (WRPs) or rabbit Platelet Reach Plasma (rPRP) by evaluating their IC50 values. We also studied their effect on Cholinephosphotransferase of PAF (PAF-CPT)/Lyso-PAF-Acetyltransferase (Lyso-PAF-AT) of rabbit leukocytes (RLs), as well as on rabbit plasma-PAF-AH, the key enzymes of both de novo/remodelling PAF biosynthesis and PAF degradation, respectively. Results Several antibiotics inhibited PAF-induced platelet aggregation of both WRPs and rPRP in a concentration-depended manner, with clarithromycin, azithromycin and amikacin exhibiting the higher inhibitory effect, while when combined they synergistically inhibited PAF. Higher concentrations of all antibiotics tested were needed in order to inhibit PAF induced aggregation of rPRP, but also to inhibit thrombin induced aggregation of WRPs. Concentrations of these drugs similar to their IC50 values against PAF activity in WRPs, inhibited also in vitro PAF-CPT and Lyso-PAF-AT activities of rabbit leukocytes, while only clarithromycin and azithromycin increased rabbit plasma-PAF-AH activity. Conclusions These newly found

  5. What´s cheapest, intravenous iron sucrose- or intravenous iron carboxymaltose treatment in IBD patients?

    DEFF Research Database (Denmark)

    Bager, Palle; Dahlerup, Jens Frederik

      What´s cheapest, intravenous iron sucrose- or intravenous iron carboxymaltose treatment in IBD patients? It dependent on the economic evaluation perspective!   Aim: To evaluate the health care cost for intravenous iron sucrose (Venofer®, Vifor) and intravenous iron carboxymaltose (Ferinject......-cost per mg iron is for iron carboxymaltose approximately double the cost of iron sucrose.   Patients and Methods: Data related to 111 IBD-patients treated with intravenous iron at Aarhus University Hospital from August 2005 until October 2009 was used for the economic evaluation. Analysis included......, utensils and ½ hour spend by a nurse per visit; showed approximately 150€ extra cost per 1000 mg Fe++ administrated, if iron carboxymaltose was chosen. In contrast the CEA including both BIA-values and patient-related costs (transportation and lost income) showed iron carboxymaltose to be more cost...

  6. Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Svendsen, M.S.; Salado, J.

    2008-01-01

    BACKGROUND AND OBJECTIVES: Transfusion based on the Thrombelastograph (TEG) results reduces transfusion requirements in cardiac surgery and in liver transplantation. Taking the pivotal role of thrombin generation in the coagulation process into consideration, the clinical utility of the TEG may...

  7. Electrochemical and circular dichroism spectroscopic evidence of two types of interaction between [Ru(NH3)(6)](3+) and an elongated thrombin binding aptamer G-quadruplex

    Czech Academy of Sciences Publication Activity Database

    De Rache, A.; Kejnovská, Iva; Buess-Herman, C.; Doneux, T.

    2015-01-01

    Roč. 179, OCT 2015 (2015), s. 84-92 ISSN 0013-4686 Institutional support: RVO:68081707 Keywords : Biosensors * Thrombin binding aptamer * Hexaammineruthenium Subject RIV: BO - Biophysics Impact factor: 4.803, year: 2015

  8. Thrombin has biphasic effects on the nitric oxide-cGMP pathway in endothelial cells and contributes to experimental pulmonary hypertension.

    Directory of Open Access Journals (Sweden)

    Katrin F Nickel

    Full Text Available BACKGROUND: A potential role for coagulation factors in pulmonary arterial hypertension has been recently described, but the mechanism of action is currently not known. Here, we investigated the interactions between thrombin and the nitric oxide-cGMP pathway in pulmonary endothelial cells and experimental pulmonary hypertension. PRINCIPAL FINDINGS: Chronic treatment with the selective thrombin inhibitor melagatran (0.9 mg/kg daily via implanted minipumps reduced right ventricular hypertrophy in the rat monocrotaline model of experimental pulmonary hypertension. In vitro, thrombin was found to have biphasic effects on key regulators of the nitric oxide-cGMP pathway in endothelial cells (HUVECs. Acute thrombin stimulation led to increased expression of the cGMP-elevating factors endothelial nitric oxide synthase (eNOS and soluble guanylate cyclase (sGC subunits, leading to increased cGMP levels. By contrast, prolonged exposition of pulmonary endothelial cells to thrombin revealed a characteristic pattern of differential expression of the key regulators of the nitric oxide-cGMP pathway, in which specifically the factors contributing to cGMP elevation (eNOS and sGC were reduced and the cGMP-hydrolyzing PDE5 was elevated (qPCR and Western blot. In line with the differential expression of key regulators of the nitric oxide-cGMP pathway, a reduction of cGMP by prolonged thrombin stimulation was found. The effects of prolonged thrombin exposure were confirmed in endothelial cells of pulmonary origin (HPAECs and HPMECs. Similar effects could be induced by activation of protease-activated receptor-1 (PAR-1. CONCLUSION: These findings suggest a link between thrombin generation and cGMP depletion in lung endothelial cells through negative regulation of the nitric oxide-cGMP pathway, possibly mediated via PAR-1, which could be of relevance in pulmonary arterial hypertension.

  9. A phase I trial of intravenous catumaxomab

    DEFF Research Database (Denmark)

    Mau-Sørensen, Morten; Dittrich, Christian; Dienstmann, Rodrigo

    2015-01-01

    design in epithelial cancers with known EpCAM expression. The dose-limiting toxicity (DLT) period consisted of 4 weeks, with weekly intravenous administration of catumaxomab. Key DLTs were ≥grade 3 optimally treated non-hematological toxicity; ≥grade 3 infusion-related reactions refractory to supportive....... A reversible decrease in liver function test (prothrombin time) at the 7-µg dose level was considered a DLT. The first patient at 10 µg experienced a fatal hepatic failure related to catumaxomab that led to the termination of the study. CONCLUSIONS: The MTD of weekly intravenous catumaxomab was 7 µg. Major...

  10. Intravenous polyclonal human immunoglobulins in multiple sclerosis

    DEFF Research Database (Denmark)

    Sørensen, Per Soelberg

    2008-01-01

    Intravenous immunoglobulin (IVIG) is an established therapy for demyelinating diseases of the peripheral nervous system. IVIG exerts a number of effects that may be beneficial in multiple sclerosis (MS). Four double-blind IVIG trials have been performed in relapsing-remitting MS. A meta-analysis ......Intravenous immunoglobulin (IVIG) is an established therapy for demyelinating diseases of the peripheral nervous system. IVIG exerts a number of effects that may be beneficial in multiple sclerosis (MS). Four double-blind IVIG trials have been performed in relapsing-remitting MS. A meta...

  11. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis

    DEFF Research Database (Denmark)

    Kalle, Martina; Papareddy, Praveen; Kasetty, Gopinath

    2012-01-01

    Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here...... present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin...... sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate...

  12. Three months of strictly controlled daily endurance exercise reduces thrombin generation and fibrinolytic risk markers in younger moderately overweight men

    DEFF Research Database (Denmark)

    Gram, Anne Sofie; Bladbjerg, Else-Marie; Skov, Jane

    2015-01-01

    PURPOSE: Physical activity is associated with a decreased risk of cardiovascular disease, but dose dependency of long-term physical exercise on biomarkers within coagulation and fibrinolysis is unknown. We aimed to investigate effects of two doses of daily endurance exercise on biomarkers...... of 600 kcal/day (HIGH), 300 kcal/day (MOD), or to maintain their habitual lifestyle (CON). Fasting blood samples were collected before and after the intervention and analysed for thrombin generation (endogenous thrombin potential, ETP) and concentrations of tissue-type plasminogen activator (t......-PA), plasminogen activator inhibitor type 1 (PAI-1), and von Willebrand factor (vWF). RESULTS: We observed significant within-group decreases in ETP (MOD 7 %; HIGH 6 %) and in t-PA (MOD 22 %; HIGH 21 %) and PAI-1 (MOD 16 %; HIGH 32 %) in both training groups, and no changes in the CON group. At 3 months, between...

  13. Label-free fluorescent detection of thrombin activity based on a recombinant enhanced green fluorescence protein and nickel ions immobilized nitrilotriacetic acid-coated magnetic nanoparticles.

    Science.gov (United States)

    Wang, Ming; Lei, Chunyang; Nie, Zhou; Guo, Manli; Huang, Yan; Yao, Shouzhuo

    2013-11-15

    Herein, a novel label-free fluorescent assay has been developed to detect the activity of thrombin and its inhibitor, based on a recombinant enhanced green fluorescence protein (EGFP) and Ni(2+) ions immobilized nitrilotriacetic acid-coated magnetic nanoparticles (Ni(2+)-NTA MNPs). The EGFP, containing a thrombin cleavage site and a hexahistidine sequence (His-tag) at its N-terminal, was adsorbed onto Ni(2+)-NTA MNPs through Ni(2+)-hexahistidine interaction, and dragged out of the solution by magnetic separation. Thrombin can selectively digest EGFP accompanied by His-tag peptide sequence leaving, and the resulting EGFP cannot be captured by Ni(2+)-NTA MNPs and kept in supernatant. Hence the fluorescence change of supernatant can clearly represent the activity of thrombin. Under optimized conditions, such assay showed a relatively low detection limit (3.0×10(-4) U mL(-1)), and was also used to detect the thrombin inhibitor, Hirudin, and further applied to detect thrombin activity in serum. Combined with the satisfactory reusability of Ni(2+)-NTA MNPs, our method presents a promising candidate for simple, sensitive, and cost-saving protease activity detecting and inhibitor screening. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Thrombin generation assay as a possible tool for assessment of reduced activity of clotting factors induced by antiphospholipid antibodies and in-vitro evaluation of treatment options.

    Science.gov (United States)

    Livnat, Tami; Zivelin, Ariella; Tamarin, Ilia; Guetta, Victor; Salomon, Ophira

    2009-12-01

    Bleeding is a rare manifestation of antiphospholipid syndrome, unless associated with reduced clotting factors or severe thrombocytopenia. Accurate assessment of the autoantibodies in plasma is very important since the autoantibodies can lead to bleeding or thrombosis. The objective of the present study was to define the inhibitors causing reduced clotting activity in a patient with antiphospholipids antibodies and to assess the potential of thrombin generation assay to assist in establishment of optimal treatment in case of major bleeding. Levels of clotting factors as well as inhibitors to factors II, V, VII, VIII, IX, X and XI were defined. For detection of inhibitors to prothrombin crossed immunoelectrophoresis was used. IgG was purified by commercial protein A column. Thrombin generation was measured using a fluorometric assay in platelet-poor and platelet-rich plasma. Inhibitors toward the activity of factors V, VII, VIII, IX, X and XI were defined and also an inhibitor to prothrombin antigen. No thrombin generation was induced in the patient's plasma by recalcification even in the presence of recombinant factor VIIa or factor VIII inhibitor bypassing activity. In contrast, addition of platelets from either donor or patient or synthetic phospholipids normalized the thrombin generation. The thrombin generation model showed that the addition of platelets and no recombinant factor VIIa or factor VIII inhibitor bypassing activity would correct thrombin generation in vitro. On this basis, platelet concentrates were administered to a patient with bleeding caused by lupus anticoagulant and low clotting factors activity.

  15. α-thrombin-induced inositol phosphate formation in G0-arrested and cycling hamster lung fibroblasts: evidence for a protein kinase C-mediated desensitization response

    International Nuclear Information System (INIS)

    L'allemain, G.; Paris, S.; Magnaldo, I.; Pouyssegur, J.

    1986-01-01

    In resting Chinese hamster fibroblasts (CCL39) α-thrombin rapidly induces the breakdown of phosphoinositides. Accumulation of inositol phosphates (IP), measured in the presence of Li + , is detectable within 5s (seconds) of thrombin stimulation. Formation of inositol tris- and bisphosphates slightly precedes that of inositol monophosphate, indicating that thrombin activates primarily the phospholipase C-mediated generation of inositol trisphosphate from phosphatidylinositol 4,5-bisphosphate. Initial rates of IP production increase with thrombin concentration, with no apparent saturability over the range 10 -4 -10 U/ml. Thrombin-induced phosphoinositide hydrolysis rapidly desensitizes (t/sub 1/2/ > 5 min), but a residual activity, corresponding to about 10% of the initial stimulation is sustained for at least 9 h, in contrast with the undetectable activity of G0-arrested cells. This apparent desensitization may be due to a feedback regulation by protein kinase C, since pretreatment with the phorbol ester 12-O-tetradecanoyl phorbol 13-acetate (TPA) markedly inhibits (by up to 70%) subsequent thrombin-induced inositol phosphate formation. This up regulation was found maximal in A51, a very well growth-arrested CCL39 derivative,and reduced or virtually abolished in two tumoral and growth factor-relaxed derivatives of CCL39. Although preliminary, this observation suggests that a persistent activation of phosphatidyl inositol breakdown might operate in variants selected for autonomous growth

  16. The linkage between binding of the C-terminal domain of hirudin and amidase activity in human alpha-thrombin.

    OpenAIRE

    de Cristofaro, R; Rocca, B; Bizzi, B; Landolfi, R

    1993-01-01

    A method derived from the analysis of viscosity effects on the hydrolysis of the amide substrates D-phenylalanylpipecolyl-arginine-p-nitroaniline, tosylglycylprolylarginine-p-nitroanaline and cyclohexylglycylalanylarginine-p-nitroalanine by human alpha-thrombin was developed to dissect the Michaelis-Menten parameters Km and kcat into the individual rate constants of the binding, acylation and deacylation reactions. This method was used to analyse the effect of the C-terminal hirudin (residues...

  17. Anti-thrombin III, Protein C, and Protein S deficiency in acute coronary syndrome

    Directory of Open Access Journals (Sweden)

    Dasnan Ismail

    2002-06-01

    Full Text Available The final most common pathway for the majority of coronary artery disease is occlusion of a coronary vessel. Under normal conditions, antithrombin III (AT III, protein C, and protein S as an active protein C cofactor, are natural anticoagulants (hemostatic control that balances procoagulant activity (thrombin antithrombin complex balance to prevent thrombosis. If the condition becomes unbalanced, natural anticoagulants and the procoagulants can lead to thrombosis. Thirty subjects with acute coronary syndrome (ACS were studied for the incidence of antithrombin III (AT III, protein C, and protein S deficiencies, and the result were compare to the control group. Among patients with ACS, the frequency of distribution of AT-III with activity < 75% were 23,3% (7 of 30, and only 6,7% ( 2 of 30 in control subject. No one of the 30 control subject have protein C activity deficient, in ACS with activity < 70% were 13,3% (4 of 30. Fifteen out of the 30 (50% control subjects had protein S activity deficiency, while protein S deficiency activity < 70% was found 73.3.% (22 out of 30. On linear regression, the deterministic coefficient of AT-III activity deficiency to the development ACS was 13,25 %, and the deterministic coefficient of protein C activity deficient to the development of ACS was 9,06 %. The cut-off point for AT-III without protein S deficiency expected to contribute to the development of vessel disease was 45%. On discriminant analysis, protein C activity deficiency posed a risk for ACS of 4,5 greater than non deficient subjects, and AT-III activity deficiency posed a risk for ACS of 3,5 times greater than non deficient subjects. On binary logistic regression, protein S activity acted only as a reinforcing factor of AT-III activity deficiency in the development of ACS. Protein C and AT III deficiency can trigger ACS, with determinant coefficients of 9,06% and 13,25% respectively. Low levels of protein C posed a greater risk of

  18. New Insights in Thrombin Inhibition Structure–Activity Relationships by Characterization of Octadecasaccharides from Low Molecular Weight Heparin

    Directory of Open Access Journals (Sweden)

    Pierre A. J. Mourier

    2017-03-01

    Full Text Available Low Molecular Weight Heparins (LMWH are complex anticoagulant drugs that mainly inhibit the blood coagulation cascade through indirect interaction with antithrombin. While inhibition of the factor Xa is well described, little is known about the polysaccharide structure inhibiting thrombin. In fact, a minimal chain length of 18 saccharides units, including an antithrombin (AT binding pentasaccharide, is mandatory to form the active ternary complex for LMWH obtained by alkaline β-elimination (e.g., enoxaparin. However, the relationship between structure of octadecasaccharides and their thrombin inhibition has not been yet assessed on natural compounds due to technical hurdles to isolate sufficiently pure material. We report the preparation of five octadecasaccharides by using orthogonal separation methods including size exclusion, AT affinity, ion pairing and strong anion exchange chromatography. Each of these octadecasaccharides possesses two AT binding pentasaccharide sequences located at various positions. After structural elucidation using enzymatic sequencing and NMR, in vitro aFXa and aFIIa were determined. The biological activities reveal the critical role of each pentasaccharide sequence position within the octadecasaccharides and structural requirements to inhibit thrombin. Significant differences in potency, such as the twenty-fold magnitude difference observed between two regioisomers, further highlights the importance of depolymerisation process conditions on LMWH biological activity.

  19. Intravenous immunoglobulin treatment for secondary recurrent miscarriage

    DEFF Research Database (Denmark)

    Christiansen, O B; Larsen, E C; Egerup, P

    2015-01-01

    OBJECTIVE: To determine whether infusions with intravenous immunoglobulin (IVIg) during early pregnancy increase live birth rate in women with secondary recurrent miscarriage compared with placebo. DESIGN: A single-centre, randomised, double-blind, placebo-controlled trial. SETTING: A tertiary...

  20. Intravenous iron supplementation in children on hemodialysis.

    NARCIS (Netherlands)

    Leijn, E.; Monnens, L.A.H.; Cornelissen, E.A.M.

    2004-01-01

    BACKGROUND: Children with end-stage renal disease (ESRD) on hemodialysis (HD) are often absolute or functional iron deficient. There is little experience in treating these children with intravenous (i.v.) iron-sucrose. In this prospective study, different i.v. iron-sucrose doses were tested in

  1. Intravenous and intramuscular magnesium sulphate regimens in ...

    African Journals Online (AJOL)

    1993-09-03

    Sep 3, 1993 ... parenterally, usually according to one of two popular regimens: the intramuscular (IM) regimen introduced by. Pritchard' and a continuous intravenous (IV) infusion described by Zuspan! Sibai et a/.3 have reported that lower serum magnesium values are achieved with Zuspan's regimen (maintenance dose ...

  2. Clinical Evaluation of Ciprofloxacin Intravenous Preparation ...

    African Journals Online (AJOL)

    The most common site of bacteria infection in humans is the urinary tract. For nosocomial infections it is the catheterized urinary tract. Compromised immune responses in hospitalized patients contribute to the difficulties encountered in treating their infections. In these patients, administration of intravenous antibiotic is ...

  3. A Comparison of Prophylactic Intravenous Glycopyrrolate and ...

    African Journals Online (AJOL)

    Ephedrine is gradually falling out of favour because of the associated tachyarrhythmia and foetal acidosis. This study compared the effect of preoperative administration of intravenous glycopyrrolate and ephedrine on spinal induced maternal hypotension. Patients and Methods: Fifty patients scheduled for elective C/S were ...

  4. Comparative Evaluation of Ultrasonography and Intravenous ...

    African Journals Online (AJOL)

    Background: Renal ultrasonography an easily available procedure was compared to intravenous urogram (IVU) to determine its suitability as an alternative to the latter, which is a relatively invasive test for demonstrating hydronephrosis/ or ureteric obstruction in cervical cancer staging. Study design: Thirty five histologically ...

  5. Intravenous voriconazole after toxic oral administration

    NARCIS (Netherlands)

    Alffenaar, J.W.C.; Van Assen, S.; De Monchy, J.G.R.; Uges, D.R.A.; Kosterink, J.G.W.; Van Der Werf, T.S.

    In a male patient with rhinocerebral invasive aspergillosis, prolonged high-dosage oral administration of voriconazole led to hepatotoxicity combined with a severe cutaneous reaction while intravenous administration in the same patient did not. High concentrations in the portal blood precipitate

  6. Intravenous paracetamol overdose in a paediatric patient

    NARCIS (Netherlands)

    Broeks, Ilse J.; Van Roon, Eric N.; Van Pinxteren-Nagler, Evelyn; De Vries, Tjalling W.

    2013-01-01

    BACKGROUND: Paracetamol is a widely used drug in children. In therapeutic doses, paracetamol has an excellent safety profile. Since the introduction of the intravenous form in 2004, only three reports of accidental overdose in children have been published. The low number probably is due to

  7. Intramuscular compared to intravenous midazolam for paediatric ...

    African Journals Online (AJOL)

    Background: Sedation in children remains a controversial issue in emergency departments (ED). Midazolam, as a benzodiazepine is widely used for procedural sedation among paediatrics. We compared the effectiveness and safety of two forms of midazolam prescription; intramuscular (IM) and intravenous (IV). Patients ...

  8. Intravenous platelet blockade with cangrelor during PCI

    NARCIS (Netherlands)

    Bhatt, Deepak L.; Lincoff, A. Michael; Gibson, C. Michael; Stone, Gregg W.; McNulty, Steven; Montalescot, Gilles; Kleiman, Neal S.; Goodman, Shaun G.; White, Harvey D.; Mahaffey, Kenneth W.; Pollack, Charles V.; Manoukian, Steven V.; Widimsky, Petr; Chew, Derek P.; Cura, Fernando; Manukov, Ivan; Tousek, Frantisek; Jafar, M. Zubair; Arneja, Jaspal; Skerjanec, Simona; Harrington, Robert A.; Bhatt, D. L.; Harrington, R. A.; Lincoff, A. M.; Pollack, C. V.; Gibson, C. M.; Stone, G. W.; Mahaffey, K. W.; Kleiman, N. S.; Montalescot, G.; White, H. D.; Goodman, S. G.; Greenbaum, A.; Simon, D.; Lee, D.; Feit, F.; Dauerman, H.; Gurbel, P.; Berger, P.; Makkar, R.; Becker, R. C.; Manoukian, S.; Jorgova, J.; Chew, D. P.; Storey, R.; Desmet, W.; Cura, F.; Herrmann, H.; Rizik, D.; DeServi, S.; Huber, K.; Jukema, W. J.; Knopf, W.; Steg, P. G.; Schunkert, H.; Widimsky, P.; Betriu, A.; Aylward, P.; Polonestsky, L.; Lima, V.; Kobulia, B.; Navickas, R.; Gasior, Z.; Vasilieva, E.; Bennett, J. M.; Kraiz, I.; Van de Werf, F.; Faxon, D.; Ohman, E. M.; Tijssen, J. G. P.; Verheugt, F.; Weaver, W. D.; Califf, R. M.; Mehta, C.; Hamm, C. W.; Pepine, C. J.; Ware, J.; Wilson, M.; Gorham, C.; Maran, A.; McNulty, S.; Fasteson, D.; Ryan, G.; Bradsher, J.; Connolly, P.; Mehta, R.; Leonardi, S.; Brennan, M.; Patel, M.; Petersen, J.; Bushnel, C.; Jolicoeur, M.; Chan, M.; Dowd, L.; Skinner, P.; Lawrence, G.; Jordon, M.; Dickerson, S.; Meyer, M.; Hartford, S.; Garcia Escudero, Alejandro; Poy, Carlos; Miceli, Miguel; Pocovi, Antonio; Londero, Hugo; Baccaro, Jorge; Polonetsky, Leonid; Karotkin, Aliaksey; Shubau, Leanid; Maffini, Eduardo; Machado, Bruno; Airton, José; Lima, Valter; Martinez Filho, Eulogio; Herdy, Arthur; Tumelero, Rogerio; Precoma, Dalton; Botelho, Roberto; Saad, Jamil; Jatene, Jose; Vilas-Boas, Fabio; Godinho, Antonio; Perin, Marco; Caramori, Paulo; Castro, Iran; Grigorov, Mladen; Milkov, Plamen; Jorgova, Julia; Georgiev, Svetoslav; Rifai, Nizar; Doganov, Alexander; Petrov, Ivo; Hui, William; Lazzam, Charles; Reeves, Francois; Tanguay, Jean-Francois; Richter, Marek; Klimsa, Zdenek; Padour, Michal; Mrozek, Jan; Branny, Marian; Coufal, Zdenek; Simek, Stanislav; Rozsival, Vladimir; Pleva, Leos; Stasek, Josef; Kala, Petr; Groch, Ladislav; Kocka, Viktor; Shaburishvili, Tamaz; Khintibidze, Irakli; Chapidze, Gulnara; Mamatsashvili, Merab; Mohanan, Padinhare; Jain, Rajesh; Parikh, Keyur; Patel, Tejas; Kumar, Sampath; Mehta, Ashwani; Banker, Darshan; Krishna, Lanka; Gadkari, Milind; Joshi, Hasit; Hiremath, Shirish; Grinius, Virgilijus; Norkiene, Sigute; Petrauskiene, Birute; Michels, Rolf; Tjon, Melvin; de Swart, Hans; de Winter, Robbert; White, Harvey; Devlin, Gerard; Abernethey, Malcolm; Osiev, Alexander; Linev, Kirill; Kalinina, Svetlana; Baum, Svetlana; Kosmachova, Elena; Shogenov, Zaur; Markov, Valentin; Boldueva, Svetlana; Barbarash, Olga; Kostenko, Victor; Vasilieva, Elena; Gruzdev, Aleksey; Lusov, Victor; Dovgalevsky, Pavel; Azarin, Oleg; Chernov, Sergey; Smolenskaya, Olga; Duda, Alexey; Fridrich, Viliam; Hranai, Marian; Studencan, Martin; Kurray, Peter; Bennett, John; Blomerus, Pieter; Disler, Laurence; Engelbrecht, Johannes; Klug, Eric; Routier, Robert; Venter, Tjaart; van der Merwe, Nico; Becker, Anthony; Cha, Kwang-Soo; Lee, Seung-Hwan; Han, Sang-Jin; Youn, Tae Jin; Hur, Seung-Ho; Seo, Hong Seog; Park, Hun-Sik; Rhim, Chong-Yun; Pyun, Wook-Bum; Choe, Hyunmin; Jeong, Myung-Ho; Park, Jong-Seon; Shin, Eak-Kyun; Hernández, Felipe; Figueras, Jaume; Hernández, Rosana; López-Minguez, José Ramón; González Juanatey, José Ramón; Palop, Ramón López; Galeote, Guillermo; Chamnarnphol, Noppadol; Buddhari, Wacin; Sansanayudh, Nakarin; Kuanprasert, Srun; Penny, William; Lui, Charles; Grimmett, Garfield; Srinivasan, Venkatraman; Ariani, Kevin; Khan, Waqor; Blankenship, James; Cannon, Louis; Eisenberg, Steven; McLaurin, Brent; Mahoney, Paul; Greenberg, Jerry; Breall, Jeffrey; Chandna, Harish; Hockstad, Eric; Tolerico, Paul; Kao, John; Shroff, Adhir; Nseir, Georges; Greenbaum, Adam; Cohn, Joel; Gogia, Harinder; Nahhas, Ahed; Istfan, Pierre; Orlow, Steve; Spriggs, Douglas; Sklar, Joel; Paulus, Richard; Cochran, David; Smith, Robert; Ferrier, L. Norman; Scott, J. Christopher; Xenopoulos, Nicholaos; Mulumudi, Mahesh; Hoback, James; Ginete, Wilson; Ballard, William; Stella, Joseph; Voeltz, Michele; Staniloae, Cezar; Eaton, Gregory; Griffin, John; Kumar, Krishna; Ebrahimi, Ramin; O'Shaughnessy, Charles; Lundstrom, Lundstrom; Temizer, Dogan; Tam, Kenneth; Suarez, Jose; Raval, Amish; Kaufman, Jay; Brilakis, Emmanouil; Stillabower, Michael; Quealy, Kathleen; Nunez, Boris; Pow, Thomas; Samuels, Bruce; Argenal, Agustin; Srinivas, Vankeepuram; Rosenthal, Andrew; Tummala, Pradyumna; Myers, Paul; LaMarche, Nelson; Chan, Michael; Bach, Richard; Simon, Daniel; Kettelkamp, Richard; Helmy, Tarek; Schaer, Gary; Kosinski, Edward; Buchbinder, Maurice; Sharma, Mukesh; Goodwin, Mark; Horwitz, Phillip; Mann, J. Tift; Holmes, David; Angiolillo, Dominick; Rao, Sunil; Azrin, Michael; Gammon, Roger; Mavromatis, Kreton; Ahmed, Abdel; Kent, Kenneth; Zughaib, Marcel; Westcott, R. Jeffrey; Jain, Ash; Gruberg, Luis; LeGalley, Thomas

    2009-01-01

    BACKGROUND: Intravenous cangrelor, a rapid-acting, reversible adenosine diphosphate (ADP) receptor antagonist, might reduce ischemic events during percutaneous coronary intervention (PCI). METHODS: In this double-blind, placebo-controlled study, we randomly assigned 5362 patients who had not been

  9. Effect of intravenous dexmedetomidine infusion on some ...

    African Journals Online (AJOL)

    Background: This study was designed to evaluate the effect of intravenous dexmedetomidine infusion in patients undergoing major abdominal surgery on stress response markers as plasma interleukin-6, cortisol and blood glucose level. It also assessed its effect on recovery profile and postoperative pain. Methods: Thirty ...

  10. Decrements in the thrombin activatable fibrinolysis inhibitor (TAFI) levels in association with orlistat treatment in obesity.

    Science.gov (United States)

    Guven, Gulay Sain; Kiliçaslan, Alpaslan; Oz, S Gul; Haznedaroglu, Ibrahim C; Kirazli, Serafettin; Aslan, Dilek; Sözen, Tümay

    2006-07-01

    Obesity and its associated metabolic complications can impair the physiologic regulation of fibrinolysis, leading to a hyper coagulable state. We aimed to assess circulating thrombin activatable fibrinolysis inhibitor (TAFI) levels in obese female patients and to test the effects of orlistat-induced weight loss on basal TAFI concentrations. Obese female outpatients age 18 and older, with a body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters) of at least 30, were included into the study. Thirteen nonobese (median BMI, 22.60 kg/m(2)) age-matched females were taken as controls. Plasma TAFI levels were measured before orlistat administration and after 6 months of orlistat treatment in the obese group and only one measurement was done in the control group. Twenty-seven obese patients were recruited into the study. The median TAFI level of the control group was 124.00; this value was significantly lower than the basal TAFI level of the obese group (p < 0.001). TAFI levels after orlistat therapy were statistically significantly lower than basal TAFI levels (p < 0.001) in the obese group. Hemostatic abnormalities including TAFI alterations represent a link between obesity and vascular thrombosis. Effective interventions should be considered in improving the obesity-associated prothrombotic risk profile.

  11. Rapid hemostasis in a sheep model using particles that propel thrombin and tranexamic acid.

    Science.gov (United States)

    R Baylis, James; Finkelstein-Kulka, Andres; Macias-Valle, Luis; Manji, Jamil; Lee, Michael; Levchenko, Elina; Okpaleke, Christopher; Al-Salihi, Salahuddin; Javer, Amin; J Kastrup, Christian

    2017-04-01

    Bleeding during endoscopic sinus surgery and open surgeries can easily obstruct the surgeons' field of view and increase morbidity and risk of intraoperative complications. Intraoperative bleeding could potentially be addressed by a hemostatic agent that safely disperses itself through the escaping blood. We tested the safety and efficacy of a self-propelling formulation of thrombin and tranexamic acid (SPTT) in stopping bleeding in a paranasal sinus injury and in an open surgical carotid injury sheep model. Interventional animal study. SPTT was tested in the sinonasal space following endoscopic injury to the inferior turbinate of six sheep, and to the common carotid artery following open surgical injury in eight sheep. In the nasal cavity, bleeding time and local inflammation were measured and compared to plain gauze. Following carotid arteriotomy, successful hemostasis and markers of thrombosis and coagulopathy were compared to Floseal. SPTT significantly decreased bleeding times in the sinonasal space compared to plain gauze (mean difference = 3.8 minutes, P = .002). All of the carotid bleeds (100%) were successfully controlled with SPTT after 10 minutes of application under pressure, compared to 25% with Floseal. No adverse events were noted, and there was no evidence of thromboembolism. SPTT significantly reduced bleeding time in a sheep model of surgical sinus bleeding and successfully stopped bleeding following catastrophic carotid artery injury, with no adverse events observed. NA Laryngoscope, 127:787-793, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Does Lipid Profile Affect Thrombin Generation During Ramadan Fasting in Patients With Cardiovascular Risks?

    Science.gov (United States)

    Sassi, Mouna; Chakroun, Taher; Chouchène, Saoussen; Hellara, Ilhem; Boubaker, Hamdi; Grissa, Mohamed Habib; Khochtali, Ines; Hassine, Mohsen; Addad, Faouzi; Elalamy, Ismail; Nouira, Semir

    2017-11-01

    There is evidence that diet and variation in lipid metabolism can influence blood coagulation, but little is known about the effect of Ramadan fasting on plasmatic coagulation pattern. We investigated the effect of Ramadan fasting on thrombin generation (TG) in patients with cardiovascular disease (CVD) risks, and we aimed to assess the effect of lipid profile on TG parameters. The study was conducted in 36 adults having at least 2 CVD risks and in 30 healthy controls. Coagulation pattern was assessed by both classical clotting times and TG test. A complete lipid profile was performed simultaneously. Patients were invited 2 times: 1 week before Ramadan and during the last week of the Ramadan. The TG parameters were not different in patients with CVD risks compared to healthy controls. Fasting had no effect on plasmatic coagulation parameters and on TG profile. Individual analysis of the mean rate index (MRI) of TG revealed 3 groups: group 1 with no modification of MRI, group 2 with a significant increase in MRI (81.64 nM/min vs 136.07 nM/min; P fasting did not influence the global coagulation pattern in patients with CVD risks. Whereas, a significant increase in the propagation phase of TG was associated with a significant increase in cholesterol levels, which was not found with the other TG parameters.

  13. Unfolding mechanism of thrombin-binding aptamer revealed by molecular dynamics simulation and Markov State Model.

    Science.gov (United States)

    Zeng, Xiaojun; Zhang, Liyun; Xiao, Xiuchan; Jiang, Yuanyuan; Guo, Yanzhi; Yu, Xinyan; Pu, Xuemei; Li, Menglong

    2016-04-05

    Thrombin-binding aptamer (TBA) with the sequence 5'GGTTGGTGTGGTTGG3' could fold into G-quadruplex, which correlates with functionally important genomic regionsis. However, unfolding mechanism involved in the structural stability of G-quadruplex has not been satisfactorily elucidated on experiments so far. Herein, we studied the unfolding pathway of TBA by a combination of molecular dynamics simulation (MD) and Markov State Model (MSM). Our results revealed that the unfolding of TBA is not a simple two-state process but proceeds along multiple pathways with multistate intermediates. One high flux confirms some observations from NMR experiment. Another high flux exhibits a different and simpler unfolding pathway with less intermediates. Two important intermediate states were identified. One is similar to the G-triplex reported in the folding of G-quadruplex, but lack of H-bonding between guanines in the upper plane. More importantly, another intermediate state acting as a connector to link the folding region and the unfolding one, was the first time identified, which exhibits higher population and stability than the G-triplex-like intermediate. These results will provide valuable information for extending our understanding the folding landscape of G-quadruplex formation.

  14. Noncoded amino acids in protein engineering: Structure-activity relationship studies of hirudin-thrombin interaction.

    Science.gov (United States)

    De Filippis, Vincenzo; Acquasaliente, Laura; Pontarollo, Giulia; Peterle, Daniele

    2018-01-01

    The advent of recombinant DNA technology allowed to site-specifically insert, delete, or mutate almost any amino acid in a given protein, significantly improving our knowledge of protein structure, stability, and function. Nevertheless, a quantitative description of the physical and chemical basis that makes a polypeptide chain to efficiently fold into a stable and functionally active conformation is still elusive. This mainly originates from the fact that nature combined, in a yet unknown manner, different properties (i.e., hydrophobicity, conformational propensity, polarizability, and hydrogen bonding capability) into the 20 standard natural amino acids, thus making difficult, if not impossible, to univocally relate the change in protein stability or function to the alteration of physicochemical properties caused by amino acid exchange(s). In this view, incorporation of noncoded amino acids with tailored side chains, allowing to finely tune the structure at a protein site, would facilitate to dissect the effects of a given mutation in terms of one or a few physicochemical properties, thus much expanding the scope of physical organic chemistry in the study of proteins. In this review, relevant applications from our laboratory will be presented on the use of noncoded amino acids in structure-activity relationships studies of hirudin binding to thrombin. © 2017 International Union of Biochemistry and Molecular Biology, Inc.

  15. Extracellular Histones Increase Tissue Factor Activity and Enhance Thrombin Generation by Human Blood Monocytes.

    Science.gov (United States)

    Gould, Travis J; Lysov, Zakhar; Swystun, Laura L; Dwivedi, Dhruva J; Zarychanski, Ryan; Fox-Robichaud, Alison E; Liaw, Patricia C

    2016-12-01

    Sepsis is characterized by systemic activation of inflammatory and coagulation pathways in response to infection. Recently, it was demonstrated that histones released into the circulation by dying/activated cells may contribute to sepsis pathology. Although the ability of extracellular histones to modulate the procoagulant activities of several cell types has been investigated, the influence of histones on the hemostatic functions of circulating monocytes is unknown. To address this, we investigated the ability of histones to modulate the procoagulant potential of THP-1 cells and peripheral blood monocytes, and examined the effects of plasmas obtained from septic patients to induce a procoagulant phenotype on monocytic cells. Tissue factor (TF) activity assays were performed on histone-treated THP-1 cells and blood monocytes. Exposure of monocytic cells to histones resulted in increases in TF activity, TF antigen, and phosphatidylserine exposure. Histones modulate the procoagulant activity via engagement of Toll-like receptors 2 and 4, and this effect was abrogated with inhibitory antibodies. Increased TF activity of histone-treated cells corresponded to enhanced thrombin generation in plasma determined by calibrated automated thrombography. Finally, TF activity was increased on monocytes exposed to plasma from septic patients, an effect that was attenuated in plasma from patients receiving unfractionated heparin (UFH). Our studies suggest that increased levels of extracellular histones found in sepsis contribute to dysregulated coagulation by increasing TF activity of monocytes. These procoagulant effects can be partially ameliorated in sepsis patients receiving UFH, thereby identifying extracellular histones as a potential therapeutic target for sepsis treatment.

  16. Novel Bronchoscopic Management of Airway Bleeding With Absorbable Gelatin and Thrombin Slurry.

    Science.gov (United States)

    Peralta, A Rolando; Chawla, Mohit; Lee, Robert P

    2018-01-18

    Airway bleeding, either spontaneous or as a result of bronchoscopy, is associated with significant morbidity and mortality. Multiple bronchoscopic techniques are available to achieve complete hemostasis or as a bridge to definitive therapies. We report our experience on the feasibility of endobronchial instillation of an absorbable gelatin and thrombin slurry (GTS) for the treatment of spontaneous hemoptysis and procedure-related bleeding. We identified 13 cases in which GTS was used for endobronchial hemostasis when standard bronchoscopic measures like cold saline, epinephrine, and in some cases balloon occlusion were not successful. GTS was delivered through the working channel of the bronchoscope in 10 cases and through the distal port of a bronchial blocker in the remaining 3 cases. Median age was 69 years (range, 52 to 79 y). Eight cases corresponded to spontaneous hemoptysis and 5 cases to diagnostic or therapeutic procedures. Bleeding was considered severe in 9 (70%) cases. All but 1 case were associated with malignancy. Hemostasis was achieved in 10 (77%) cases by using standard measures in addition to GTS. No patient adverse events at 30 days or damage to the equipment were identified. Bronchoscopic instillation of an absorbable GTS is feasible and may be used in cases of spontaneous or procedure-related bleeding in addition to conventional measures. It can be delivered through the working channel of the bronchoscope or through the distal port available in some bronchial blockers. Controlled studies are necessary to determine the safety and efficacy of this novel technique.

  17. Acceleration of consolidation period by thrombin peptide 508 in tibial distraction osteogenesis in rats.

    Science.gov (United States)

    Cakarer, S; Olgac, V; Aksakalli, N; Tang, A; Keskin, C

    2010-12-01

    We aimed to find out whether a single local injection of two different doses of thrombin peptide 508 (TP508) could accelerate consolidation of bone in sites of tibial distraction osteogenesis in rats. Forty-eight adult male Sprague-Dawley rats were divided equally (n=16 in each group) into controls (given saline alone), and two experimental groups, given injections of TP508 10μg or 100 μg. The animals were killed on days 14 and 28 after distraction. Histomorphometric evaluation showed that the TP508 resulted in significantly larger areas of newly formed bone (pbone had formed in the group given TP508 100 μg than in the group given 10 μg, but the difference was not significant (p=0.8). However, the difference was significant at 4 weeks (p=0.03). These findings suggest that a single injection of TP508 given at the end of the distraction period increased the degree of consolidation. The higher dose was more effective at the later time point. Copyright © 2009 The British Association of Oral and Maxillofacial Surgeons. All rights reserved.

  18. Direct oral anticoagulants and venous thromboembolism

    Directory of Open Access Journals (Sweden)

    Massimo Franchini

    2016-09-01

    Full Text Available Venous thromboembolism (VTE, consisting of deep vein thrombosis and pulmonary embolism, is a major clinical concern associated with significant morbidity and mortality. The cornerstone of management of VTE is anticoagulation, and traditional anticoagulants include parenteral heparins and oral vitamin K antagonists. Recently, new oral anticoagulant drugs have been developed and licensed, including direct factor Xa inhibitors (e.g. rivaroxaban, apixaban and edoxaban and thrombin inhibitors (e.g. dabigatran etexilate. This narrative review focusses on the characteristics of these direct anticoagulants and the main results of published clinical studies on their use in the prevention and treatment of VTE.

  19. Synergistic interactions of bradykinin, thrombin, interleukin 1 and tumor necrosis factor on prostanoid biosynthesis in human periodontal-ligament cells.

    Science.gov (United States)

    Ransjö, M; Marklund, M; Persson, M; Lerner, U H

    1998-04-01

    Prostaglandins are involved in force-induced orthodontic tooth movement. Bradykinin (BK) and thrombin are known to cause a significant time- and concentration-dependent burst of prostanoid biosynthesis in cultured human periodontal-ligament (PDL) cells. The aim now was to investigate interactive effects between interleukin 1 alpha, -beta (IL-1 alpha, -1 beta), tumour necrosis factor-alpha,-beta (TNF-alpha, -beta) and BK or thrombin on prostaglandin biosynthesis in human PDL cells. IL-1 alpha and -1 beta produced time- and concentration-dependent stimulation of prostanoid biosynthesis [prostaglandin (PG)E2 and 6-keto-PGF1alpha]. Synergistic stimulation of prostanoid biosynthesis was demonstrated when BK or thrombin were added together with IL-1 alpha or -1 beta. BK and IL-1 beta both significantly stimulated the release of [3H]arachidonic acid. No synergistic effect on [3H]arachidonic acid release was seen when BK and IL-1 beta were added simultaneously. These data suggest that the synergistic effect of BK and IL-1 beta on prostanoid biosynthesis is not due to interactions at the receptor level nor to enhanced release of arachidonic acid, but may be due to increased activity of cyclo-oxygenase. Also, TNF-alpha and -beta produced a concentration-dependent stimulation of PGE2 formation in cultured human PDL cells. Synergistic effects of BK and thrombin were demonstrated when PGE2 production was stimulated in combination with TNF-beta. In addition, a synergistic effect on the PGE2 response to IL-1 alpha or -1 beta was demonstrated when added in combination with TNF-alpha. These experiments demonstrate synergistic interactions between BK, thrombin, IL-1 and TNF on prostaglandin biosynthesis in cultured human PDL cells. The findings suggest that inflammatory mediators may act in concert in stimulating prostanoid production in response to pro-inflammatory stimuli. As an inflammatory reaction is seen in the periodontal ligament when teeth are orthodontically treated, this

  20. Cost-effectiveness of oral phenytoin, intravenous phenytoin, and intravenous fosphenytoin in the emergency department.

    Science.gov (United States)

    Rudis, Maria I; Touchette, Daniel R; Swadron, Stuart P; Chiu, Amy P; Orlinsky, Michael

    2004-03-01

    Oral phenytoin, intravenous phenytoin, and intravenous fosphenytoin are all commonly used for loading phenytoin in the emergency department (ED). The cost-effectiveness of each was compared for patients presenting with seizures and subtherapeutic phenytoin concentrations. A simple decision tree was developed to determine the treatment costs associated with each of 3 loading techniques. We determined effectiveness by comparing adverse event rates and by calculating the time to safe ED discharge. Time to safe ED discharge was defined as the time at which therapeutic concentrations of phenytoin (>or=10 mg/L) were achieved with an absence of any adverse events that precluded discharge. The comparative cost-effectiveness of alternatives to oral phenytoin was determined by combining net costs and number of adverse events, expressed as cost per adverse events avoided. Cost-effectiveness was also determined by comparing the net costs of each loading technique required to achieve the time to safe ED discharge, expressed as cost per hour of ED time saved. The outcomes and costs were primarily derived from a prospective, randomized controlled trial, augmented by time-motion studies and alternate-cost sources. Costs included the cost of drugs, supplies, and personnel. Analyses were also performed in scenarios incorporating labor costs and savings from using a lower-urgency area of the ED. The mean number of adverse events per patient for oral phenytoin, intravenous phenytoin, and intravenous fosphenytoin was 1.06, 1.93, and 2.13, respectively. Mean time to safe ED discharge in the 3 groups was 6.4 hours, 1.7 hours, and 1.3 hours. Cost per patient was 2.83 dollars, 21.16 dollars, and 175.19 dollars, respectively, and did not differ substantially in the Labor and Triage (lower-urgency area of ED) scenarios. When the measure of effectiveness was adverse events, oral phenytoin dominated intravenous phenytoin and intravenous fosphenytoin, with a lower cost and number of adverse

  1. A hand-held robotic device for peripheral intravenous catheterization.

    Science.gov (United States)

    Cheng, Zhuoqi; Davies, Brian L; Caldwell, Darwin G; Barresi, Giacinto; Xu, Qinqi; Mattos, Leonardo S

    2017-12-01

    Intravenous catheterization is frequently required for numerous medical treatments. However, this process is characterized by a high failure rate, especially when performed on difficult patients such as newborns and infants. Very young patients have small veins, and that increases the chances of accidentally puncturing the catheterization needle directly through them. In this article, we present the design, development and experimental evaluation of a novel hand-held robotic device for improving the process of peripheral intravenous catheterization by facilitating the needle insertion procedure. To our knowledge, this design is the first hand-held robotic device for assisting in the catheterization insertion task. Compared to the other available technologies, it has several unique advantages such as being compact, low-cost and able to reliably detect venipuncture. The system is equipped with an electrical impedance sensor at the tip of the catheterization needle, which provides real-time measurements used to supervise and control the catheter insertion process. This allows the robotic system to precisely position the needle within the lumen of the target vein, leading to enhanced catheterization success rate. Experiments conducted to evaluate the device demonstrated that it is also effective to deskill the task. Naïve subjects achieved an average catheterization success rate of 88% on a 1.5 mm phantom vessel with the robotic device versus 12% with the traditional unassisted system. The results of this work prove the feasibility of a hand-held assistive robotic device for intravenous catheterization and show that such device has the potential to greatly improve the success rate of these difficult operations.

  2. Acute toxicity of intravenously administered titanium dioxide nanoparticles in mice.

    Directory of Open Access Journals (Sweden)

    Jiaying Xu

    Full Text Available BACKGROUND: With a wide range of applications, titanium dioxide (TiO₂ nanoparticles (NPs are manufactured worldwide in large quantities. Recently, in the field of nanomedicine, intravenous injection of TiO₂ nanoparticulate carriers directly into the bloodstream has raised public concerns on their toxicity to humans. METHODS: In this study, mice were injected intravenously with a single dose of TiO₂ NPs at varying dose levels (0, 140, 300, 645, or 1387 mg/kg. Animal mortality, blood biochemistry, hematology, genotoxicity and histopathology were investigated 14 days after treatment. RESULTS: Death of mice in the highest dose (1387 mg/kg group was observed at day two after TiO₂ NPs injection. At day 7, acute toxicity symptoms, such as decreased physical activity and decreased intake of food and water, were observed in the highest dose group. Hematological analysis and the micronucleus test showed no significant acute hematological or genetic toxicity except an increase in the white blood cell (WBC count among mice 645 mg/kg dose group. However, the spleen of the mice showed significantly higher tissue weight/body weight (BW coefficients, and lower liver and kidney coefficients in the TiO₂ NPs treated mice compared to control. The biochemical parameters and histological tissue sections indicated that TiO₂ NPs treatment could induce different degrees of damage in the brain, lung, spleen, liver and kidneys. However, no pathological effects were observed in the heart in TiO₂ NPs treated mice. CONCLUSIONS: Intravenous injection of TiO₂ NPs at high doses in mice could cause acute toxicity effects in the brain, lung, spleen, liver, and kidney. No significant hematological or genetic toxicity was observed.

  3. Intravenous/oral ciprofloxacin therapy versus intravenous ceftazidime therapy for selected bacterial infections.

    Science.gov (United States)

    Gaut, P L; Carron, W C; Ching, W T; Meyer, R D

    1989-11-30

    The efficacy and toxicity of sequential intravenous and oral ciprofloxacin therapy was compared with intravenously administered ceftazidime in a prospective, randomized, controlled, non-blinded trial. Thirty-two patients (16 patients receiving ciprofloxacin and 16 patients receiving ceftazidime) with 38 infections caused by susceptible Pseudomonas aeruginosa, enteric gram-negative rods, Salmonella group B, Serratia marcescens, Pseudomonas cepacia, and Xanthomonas maltophilia at various sites were evaluable for determination of efficacy. Length of therapy varied from seven to 25 days. Concomitant antimicrobials included intravenously administered beta-lactams for gram-positive organisms, intravenous/oral metronidazole and clindamycin for anaerobes, and intravenous/local amphotericin B for Candida albicans. Intravenous administration of 200 mg ciprofloxacin every 12 hours to 11 patients produced peak serum levels between 1.15 and 3.12 micrograms/ml; trough levels ranged between 0.08 and 0.86 micrograms/ml. Overall response rates were similar for patients receiving ciprofloxacin and ceftazidime. Emergence of resistance was similar in both groups--one Enterobacter cloacae and two P. aeruginosa became resistant after ciprofloxacin therapy and two P. aeruginosa became resistant after ceftazidime therapy. The frequency of superinfection with a variety of organisms was also similar in both groups. Adverse events related to ciprofloxacin included transient pruritus at the infusion site and generalized rash leading to drug discontinuation (one patient each), and with ceftazidime adverse effects included pain at the site of infusion and the development of allergic interstitial nephritis (one patient each). Overall, intravenous/oral ciprofloxin therapy appears to be as safe and effective as intravenous ceftazidime therapy in the treatment of a variety of infections due to susceptible aerobic gram-negative organisms.

  4. Evaluation of the effects of intravenous anaesthesia using a ...

    African Journals Online (AJOL)

    medetomidine for total intravenous anaesthesia were evaluated in six sahel goats. The goats were administered a combination of ketamine (5mg/kg) and medetomidine (0.01mg/kg) intravenously. Baseline measurements of heart rate, respiratory ...

  5. Increased Clot Formation in the Absence of Increased Thrombin Generation in Patients with Peripheral Arterial Disease: A Case–Control Study

    Directory of Open Access Journals (Sweden)

    Marie-Claire F. Kleinegris

    2017-04-01

    Full Text Available BackgroundIn peripheral arterial disease (PAD, activation of the hemostatic system may contribute to atherosclerosis progression and atherothrombotic events.ObjectiveThis case–control study assesses the overall coagulation status in PAD patients by evaluating coagulation markers in combination with thrombin generation potential, whole blood (WB clot formation, and fibrinolysis.MethodsIn blood from 40 PAD patients (n = 20 with cardiovascular event within 1 year after initial diagnosis, n = 20 without and 40 apparently healthy controls, thrombin generation was determined in WB and platelet-poor plasma. Whole blood rotational thromboelastometry (ROTEM measurements were triggered with tissue factor with/without tissue plasminogen activator.ResultsWe observed increased levels of erythrocyte sedimentation rate, leukocytes, eosinophil granulocytes, vWF antigen, fibrinogen, and D-dimer in PAD patients (p < 0.05. Markers of thrombin generation potential showed no difference between patients and healthy controls. In PAD patients with event compared to patients without, WB-thrombin generation showed a lower thrombin potential when triggered with 0 and 2.5 pM tissue factor. The ROTEM clotting assay showed significantly faster clot formation and increased clot firmness in PAD patients compared to controls. No significant differences were found for parameters of clot degradation.ConclusionThere are no significant differences between the thrombin generation profiles of PAD patients and healthy controls. Between PAD patients with and without cardiovascular event, the WB thrombin generation appears to differ. Mechanistically, PAD patients show an increased ability to form a stable clot in WB in comparison to healthy controls. This is most likely due to the increased fibrinogen levels related to the inflammation in atherosclerosis, confirming the importance of the inflammation-coagulation axis.

  6. Optimal timing for intravenous administration set replacement.

    Science.gov (United States)

    Gillies, D; O'Riordan, L; Wallen, M; Morrison, A; Rankin, K; Nagy, S

    2005-10-19

    Administration of intravenous therapy is a common occurrence within the hospital setting. Routine replacement of administration sets has been advocated to reduce intravenous infusion contamination. If decreasing the frequency of changing intravenous administration sets does not increase infection rates, a change in practice could result in considerable cost savings. The objective of this review was to identify the optimal interval for the routine replacement of intravenous administration sets when infusate or parenteral nutrition (lipid and non-lipid) solutions are administered to people in hospital via central or peripheral venous catheters. We searched The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, EMBASE: all from inception to February 2004; reference lists of identified trials, and bibliographies of published reviews. We also contacted researchers in the field. We did not have a language restriction. We included all randomized or quasi-randomized controlled trials addressing the frequency of replacing intravenous administration sets when parenteral nutrition (lipid and non-lipid containing solutions) or infusions (excluding blood) were administered to people in hospital via a central or peripheral catheter. Two authors assessed all potentially relevant studies. We resolved disagreements between the two authors by discussion with a third author. We collected data for the outcomes; infusate contamination; infusate-related bloodstream infection; catheter contamination; catheter-related bloodstream infection; all-cause bloodstream infection and all-cause mortality. We identified 23 references for review. We excluded eight of these studies; five because they did not fit the inclusion criteria and three because of inadequate data. We extracted data from the remaining 15 references (13 studies) with 4783 participants. We conclude that there is no evidence that changing intravenous administration sets more often than every 96 hours

  7. Acute Coronary Syndrome of Embolic Origin in a Patient on Direct Thrombin Inhibitor Three Years After Mechanical Mitral Valve Replacement

    Directory of Open Access Journals (Sweden)

    Andrew Kei-Yan Ng

    2016-01-01

    Full Text Available Dabigatran was shown to be inferior to warfarin for patients with mechanical heart valves. However it was postulated that its inferiority was limited to early post-operative period where the valves had not been adequately endothelialized. We present a case where thromboembolic acute coronary syndrome developed in a patient six months after switching from warfarin to dabigatran, despite three years after mechanical mitral valve replacement. We propose an alternative explanation for dabigatran failure.

  8. Intravenous immunoglobulin therapy for refractory recurrent pericarditis.

    Science.gov (United States)

    del Fresno, M Rosa; Peralta, Julio E; Granados, Miguel Ángel; Enríquez, Eugenia; Domínguez-Pinilla, Nerea; de Inocencio, Jaime

    2014-11-01

    Recurrent pericarditis is a troublesome complication of idiopathic acute pericarditis and occurs more frequently in pediatric patients after cardiac surgery (postpericardiotomy syndrome). Conventional treatment with nonsteroidal antiinflammatory drugs, corticosteroids, and colchicine is not always effective or may cause serious adverse effects. There is no consensus, however, on how to proceed in those patients whose disease is refractory to conventional therapy. In such cases, human intravenous immunoglobulin, immunosuppressive drugs, and biological agents have been used. In this report we describe 2 patients with refractory recurrent pericarditis after cardiac surgery who were successfully treated with 3 and 5 monthly high-dose (2 g/kg) intravenous immunoglobulin until resolution of the effusion. Our experience supports the effectiveness and safety of this therapy. Copyright © 2014 by the American Academy of Pediatrics.

  9. Retroperitoneal fibrosis with normal intravenous urogram.

    OpenAIRE

    Creagh, F. M.; Stone, T.; Stephenson, T. P.; Lazarus, J. H.

    1985-01-01

    A 58 year old male presented with a two week history of low back pain and malaise. The intravenous urogram (IVU) at presentation was normal but within three months he had developed renal failure with bilateral ureteric obstruction on repeat IVU. Primary retroperitoneal fibrosis was confirmed at operation. This case demonstrates that retroperitoneal fibrosis may progress rapidly to renal failure within a few months of the first symptoms. In addition, the IVU may be normal in the early stages o...

  10. Total intravenous anesthesia for major burn surgery

    OpenAIRE

    Cancio, Leopoldo C; Cuenca, Phillip B; Walker, Stephen C; Shepherd, John M

    2013-01-01

    Total intravenous anesthesia (TIVA) is frequently used for major operations requiring general anesthesia in critically ill burn patients. We reviewed our experience with this approach. Methods: During a 22-month period, 547 major burn surgeries were performed in this center’s operating room and were staffed by full-time burn anesthesiologists. The records of all 123 TIVA cases were reviewed; 112 records were complete and were included. For comparison, 75 cases were selected at random from a t...

  11. Contrast agent choice for intravenous coronary angiography

    International Nuclear Information System (INIS)

    Zeman, H.D.; Siddons, D.P.

    1989-01-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with monochromatic synchrotron radiation x-rays and an iodine containing contrast agent at the Stanford Synchrotron Radiation Laboratory have shown that such an intravenous angiography procedure would be possible with an adequately intense monochromatic x-ray source. Because of the size and cost of synchrotron radiation facilities it would be desirable to make the most efficient use of the intensity available, while reducing as much as possible the radiation dose experienced by the patient. By choosing contrast agents containing elements with a higher atomic number than iodine, it is possible to both improve the image quality and reduce the patient radiation dose, while using the same synchrotron source. By using Si monochromator crystals with a small mosaic spread, it is possible to increase the x-ray flux available for imaging by over an order of magnitude, without any changes in the storage ring or wiggler magnet. The most critical imaging task for intravenous coronary angiography utilizing synchrotron radiation x-rays is visualizing a coronary artery through the left ventricle or aorta which also contains a contrast agent. Calculations have been made of the signal to noise ratio expected for this imaging task for various contrast agents with atomic numbers between that of iodine and bismuth

  12. Intravenous Lipids for Preterm Infants: A Review

    Directory of Open Access Journals (Sweden)

    Ghassan S. A. Salama

    2015-01-01

    Full Text Available Extremely low birth weight infants (ELBW are born at a time when the fetus is undergoing rapid intrauterine brain and body growth. Continuation of this growth in the first several weeks postnatally during the time these infants are on ventilator support and receiving critical care is often a challenge. These infants are usually highly stressed and at risk for catabolism. Parenteral nutrition is needed in these infants because most cannot meet the majority of their nutritional needs using the enteral route. Despite adoption of a more aggressive approach with amino acid infusions, there still appears to be a reluctance to use early intravenous lipids. This is based on several dogmas that suggest that lipid infusions may be associated with the development or exacerbation of lung disease, displace bilirubin from albumin, exacerbate sepsis, and cause CNS injury and thrombocytopena. Several recent reviews have focused on intravenous nutrition for premature neonate, but very little exists that provides a comprehensive review of intravenous lipid for very low birth and other critically ill neonates. Here, we would like to provide a brief basic overview, of lipid biochemistry and metabolism of lipids, especially as they pertain to the preterm infant, discuss the origin of some of the current clinical practices, and provide a review of the literature, that can be used as a basis for revising clinical care, and provide some clarity in this controversial area, where clinical care is often based more on tradition and dogma than science.

  13. Effects of normoxic and hypoxic exercise regimens on monocyte-mediated thrombin generation in sedentary men.

    Science.gov (United States)

    Wang, Jong-Shyan; Chang, Ya-Lun; Chen, Yi-Ching; Tsai, Hsing-Hua; Fu, Tieh-Cheng

    2015-08-01

    Exercise and hypoxia paradoxically modulate vascular thrombotic risks. The shedding of procoagulant-rich microparticles from monocytes may accelerate the pathogenesis of atherothrombosis. The present study explores the manner in which normoxic and hypoxic exercise regimens affect procoagulant monocyte-derived microparticle (MDMP) formation and monocyte-promoted thrombin generation (TG). Forty sedentary healthy males were randomized to perform either normoxic (NET; 21% O2, n=20) or hypoxic (HET; 15% O2, n=20) exercise training (60% VO(2max)) for 30 min/day, 5 days/week for 5 weeks. At rest and immediately after HET (100 W under 12% O2 for 30 min), the MDMP characteristics and dynamic TG were measured by flow cytometry and thrombinography respectively. The results demonstrated that acute 12% O2 exercise (i) increased the release of coagulant factor V (FV)/FVIII-rich, phosphatidylserine (PS)-exposed and tissue factor (TF)-expressed microparticles from monocytes, (ii) enhanced the peak height and rate of TG in monocyte-rich plasma (MRP) and (iii) elevated concentrations of norepinephrine/epinephrine, myeloperoxidase (MPO) and interleukin-6 (IL-6) in plasma. Following the 5-week intervention, HET exhibited higher enhancements of peak work-rate and cardiopulmonary fitness than NET did. Moreover, both NET and HET decreased the FV/FVIII-rich, PS-exposed and TF-expressed MDMP counts and the peak height and rate of TG in MRP following the HET. However, HET elicited more suppression for the HE (hypoxic exercise)-enhanced procoagulant MDMP formation and dynamic TG in MPR and catecholamine/peroxide/pro-inflammatory cytokine levels in plasma than NET. Hence, we conclude that HET is superior to NET for enhancing aerobic capacity. Furthermore, HET effectively suppresses procoagulant MDMP formation and monocyte-mediated TG under severe hypoxic stress, compared with NET.

  14. Comparison of gelatine matrix-thrombin sealants used during laparoscopic partial nephrectomy.

    Science.gov (United States)

    Nogueira, Lucas; Katz, Darren; Pinochet, Rodrigo; Kurta, Jordan M; Coleman, Jonathan A

    2008-12-01

    To compare haemostasis and other outcomes after the use of bovine-derived or porcine-derived gelatine matrix-thrombin sealants (GMTS) in a continuous series of patients during and for 6 months after laparoscopic partial nephrectomy (LPN). Between October 2006 and September 2007, a consecutive sample of 35 patients with renal tumours underwent LPN by a single surgeon at a referral centre. Group 1 (25 patients) received a bovine-derived GMTS and Group 2 (10 patients) a porcine-derived GMTS. All patients underwent LPN and received one of the two GMTS, applied to the resected bed before sutured renorrhaphy over oxidized nitrocellulose bolsters. Surgical and pathology variables, including ischaemia time, blood loss, tumour size, and serum creatinine values before and after LPN, were measured. Glomerular filtration rates were calculated before and after LPN. Haemostasis was ascertained by visual examination. Intraoperative haemostasis was achieved in all cases. No associated complications occurred within 3 weeks of LPN. The two groups were comparable in age (median, 65 vs 69 years, P = 0.62), gender, tumour number and location, median ischaemia time (34 vs 28 min, P = 0.148), and blood loss (200 vs 150 mL, P = 0.518). One patient in Group 1 developed a urinary fistula. One patient in Group 2 experienced self-limited gross haematuria. Both the porcine- and bovine-derived agents provided acceptable haemostasis without adverse events during LPN and in the early postoperative period. Occurrences of delayed haemorrhage and urinary fistula were not likely to be related to the choice of prothrombotic agent.

  15. Monocyte IL-10 produced in response to lipopolysaccharide modulates thrombin generation by inhibiting tissue factor expression and release of active tissue factor-bound microparticles.

    Science.gov (United States)

    Poitevin, Stéphane; Cochery-Nouvellon, Eva; Dupont, Annick; Nguyen, Philippe

    2007-04-01

    Lipopolysaccharide (LPS)-stimulated monocytes are known to have a procoagulant effect. This property is currently explained by the fact that monocytes, in response to LPS, can express tissue factor (TF) and undergo a process of membrane microvesiculation. Interleukin-10 (IL-10) has been shown to downregulate TF expression and inhibit procoagulant activity (PCA). In order to further characterize the inhibitory effect of IL-10 on LPS-induced PCA, we used the integrated system of analysis of kinetics of thrombin generation in normal plasma (thrombinography). For this, we developed an original method of elutriation allowing to obtain a highly purified monocyte preparation, under endotoxin-free conditions. Thrombin generation was measured using a highly sensitive and specific fluorogenic method which we adapted to inhibit the contact factor pathway. Results show that recombinant human IL-10 decreased the kinetics of thrombin generation in a dose-dependent manner. Furthermore, the inhibition of endogenous IL-10 released by monocytes in response to LPS is associated with an increase in the kinetics of thrombin generation. We demonstrated that this effect was a consequence of the up-regulation of TF expression and TF-bound microparticle release. In conclusion, we report that IL-10 can regulate thrombin generation in conditions close to physiology as allowed by thrombinography, and that endogenous IL-10 regulates TF expression and release of active TF-bound microparticles by a negative feed back loop through IL-10 receptor alpha.

  16. Enhanced Effector Function of CD8+ T Cells From Healthy Controls and HIV-Infected Patients Occurs Through Thrombin Activation of Protease-Activated Receptor 1

    Science.gov (United States)

    Hurley, Amanda; Smith, Mindy; Karpova, Tatiana; Hasley, Rebecca B.; Belkina, Natalya; Shaw, Stephen; Balenga, Nariman; Druey, Kirk M.; Nickel, Erin; Packard, Beverly; Imamichi, Hiromi; Hu, Zonghui; Follmann, Dean; McNally, James; Higgins, Jeanette; Sneller, Michael; Lane, H. Clifford; Catalfamo, Marta

    2013-01-01

    Disruption of vascular integrity by trauma and other tissue insults leads to inflammation and activation of the coagulation cascade. The serine protease thrombin links these 2 processes. The proinflammatory function of thrombin is mediated by activation of protease-activated receptor 1 (PAR-1). We found that peripheral blood effector memory CD4+ and CD8+ T lymphocytes expressed PAR-1 and that expression was increased in CD8+ T cells from human immunodeficiency virus (HIV)–infected patients. Thrombin enhanced cytokine secretion in CD8+ T cells from healthy controls and HIV-infected patients. In addition, thrombin induced chemokinesis, but not chemotaxis, of CD8+ T cells, which led to structural changes, including cell polarization and formation of a structure rich in F-actin and phosphorylated ezrin-radexin-moesin proteins. These findings suggest that thrombin mediates cross-talk between the coagulation system and the adaptive immune system at sites of vascular injury through increased T-cell motility and production of proinflammatory cytokines. PMID:23204166

  17. Enhanced effector function of CD8(+) T cells from healthy controls and HIV-infected patients occurs through thrombin activation of protease-activated receptor 1.

    Science.gov (United States)

    Hurley, Amanda; Smith, Mindy; Karpova, Tatiana; Hasley, Rebecca B; Belkina, Natalya; Shaw, Stephen; Balenga, Nariman; Druey, Kirk M; Nickel, Erin; Packard, Beverly; Imamichi, Hiromi; Hu, Zonghui; Follmann, Dean; McNally, James; Higgins, Jeanette; Sneller, Michael; Lane, H Clifford; Catalfamo, Marta

    2013-02-15

    Disruption of vascular integrity by trauma and other tissue insults leads to inflammation and activation of the coagulation cascade. The serine protease thrombin links these 2 processes. The proinflammatory function of thrombin is mediated by activation of protease-activated receptor 1 (PAR-1). We found that peripheral blood effector memory CD4(+) and CD8(+) T lymphocytes expressed PAR-1 and that expression was increased in CD8(+) T cells from human immunodeficiency virus (HIV)-infected patients. Thrombin enhanced cytokine secretion in CD8(+) T cells from healthy controls and HIV-infected patients. In addition, thrombin induced chemokinesis, but not chemotaxis, of CD8(+) T cells, which led to structural changes, including cell polarization and formation of a structure rich in F-actin and phosphorylated ezrin-radexin-moesin proteins. These findings suggest that thrombin mediates cross-talk between the coagulation system and the adaptive immune system at sites of vascular injury through increased T-cell motility and production of proinflammatory cytokines.

  18. Effect of minimally invasive surgery for cerebral hematoma evacuation in different stages on motor evoked potential and thrombin in dog model of intracranial hemorrhage.

    Science.gov (United States)

    Wu, Guofeng; Zhong, Weibin

    2010-03-01

    To observe the effect of minimally invasive surgery for cerebral hematoma evacuation in different stages on motor evoked potential (MEP) and thrombin in dog model of intracranial hemorrhage. Twenty dogs were selected to prepare the intracranial hemorrhage model, which were randomly divided into 6, 12, 18 and 24 hour groups, respectively. The animals in each group underwent a minimally invasive surgery to evacuate the cerebral hematoma after the models were prepared. Before and after procedures, Purdy score, MEP and thrombin in hematoma region were determined and compared. Significant decreases in Purdy score, latency of MEP and thrombin expression were observed in 6 and 12 hour groups as compared with the 18 and 24 hour groups (pintracranial hemorrhage, which was minimally invasive, easy to operate, highly repeated, simulating the pathological and physiological changes of clinical hypertensive intracranial hemorrhage. Both the latency of MEP and the expression of thrombin decreased after evacuation of intracranial hematoma in early stages by minimally invasive procedures, indicating that minimally invasive procedures for cerebral hematoma in ultra-early and early stages might be more effective to limit brain injury and decrease the latency of MEP and thrombin expression.

  19. Plasma centrifugation does not influence thrombin-antithrombin and plasmin-antiplasmin levels but determines platelet microparticles count.

    Science.gov (United States)

    Stępień, Ewa; Gruszczyński, Krzysztof; Kapusta, Przemysław; Kowalik, Artur; Wybrańska, Iwona

    2015-01-01

    Centrifugation is an essential step for plasma preparation to remove residual elements in plasma, especially platelets and platelet-derived microparticles (PMPs). Our working hypothesis was that centrifugation as a preanalytical step may influence some coagulation parameters. Healthy young men were recruited (N=17). For centrifugation, two protocols were applied: (A) the first centrifugation at 2500xg for 15 min and (B) at 2500xg for 20 min at room temperature with a light brake. In protocol (A), the second centrifugation was carried out at 2500xg for 15 min, whereas in protocol (B), the second centrifugation involved a 10 min spin at 13,000 x g. Thrombin-antithrombin (TAT) and plasmin-antiplasmin (PAP) complexes concentrations were determined by enzyme-linked immunosorbent assays. PMPs were stained with CD41 antibody and annexin V, and analyzed by flow cytometry method. Procoagulant activity was assayed by the Calibrated Automated Thrombogram method as a slope of thrombin formation (CAT velocity). Median TAT and PAP concentrations did not differ between the centrifugation protocols. The high speed centrifugation reduced the median (IQR) PMP count in plasma from 1291 (841-1975) to 573 (391-1010) PMP/µL (P=0.001), and CAT velocity from 2.01 (1.31-2.88) to 0.97 (0.82-1.73) nM/min (P=0.049). Spearman's rank correlation analysis showed correlation between TAT and PMPs in the protocol A plasma which was (rho=0.52, PCentrifugation protocols do not influence the markers of plasminogen (PAP) and thrombin (TAT) generation but they do affect the PMP count and procoagulant activity.

  20. International Normalized Ratio (INR), coagulation factor activities and calibrated automated thrombin generation - influence of 24 h storage at ambient temperature

    DEFF Research Database (Denmark)

    Christensen, T D; Jensen, C; Larsen, T B

    2010-01-01

    International Normalized Ratio (INR) measurements are used to monitor oral anticoagulation therapy with coumarins. Single coagulation factor activities and calibrated automated thrombin (CAT) generation are considered as more advanced methods for evaluating overall haemostatic capacity. The aims...... were to assess the variability of INR, coagulation factor activities, and CAT, during 24 h of storage of blood samples at ambient temperature. A total of 24 patients on stable coumarin treatment were followed prospectively for 6 weeks. INR was analyzed at 0, 6 and 24 h after blood sampling and 1-stage...

  1. Mycotic aneurysms in intravenous drug abusers: the utility of intravenous digital subtraction angiography

    International Nuclear Information System (INIS)

    Shetty, P.C.; Krasicky, G.A.; Sharma, R.P.; Vemuri, B.R.; Burke, M.M.

    1985-01-01

    Two-hundred thirteen intravenous digital subtraction angiographic (DSA) examinations were performed on 195 intravenous drug abusers to rule out the possibility of a mycotic aneurysm in a groin, neck, or upper extremity infection. Twenty-three surgically proved cases of mycotic aneurysm were correctly identified with no false positive results. In addition, six cases of major venous occlusion were documented. The authors present the results of their experience and conclude that DSA is an effective and cost-efficient method of examining this high risk patient population

  2. Interaction of the 268-282 region of glycoprotein Ibalpha with the heparin-binding site of thrombin inhibits the enzyme activation of factor VIII.

    Science.gov (United States)

    De Cristofaro, R; De Filippis, V

    2003-01-01

    Activation of factor VIII (FVIII) by thrombin plays a fundamental role in the amplification of the coagulation cascade and takes place through specific proteolytic cleavages at Arg(372), Arg(740) and Arg(1689). Full FVIII activation requires cleavage at Arg(372), a process involving the alpha-thrombin exosite-II; referred to as heparin-binding site (HBS). The present study was aimed at investigating the effect of glycoprotein Ibalpha (GpIbalpha; 1-282 fragment) binding to thrombin HBS on FVIII activation. Similar experiments were also performed using a synthetic peptide modelled on the 268-282 sequence of GpIbalpha, and sulphated successfully at all tyrosine residues present along its sequence, at positions 276, 278 and 279. Both GpIbalpha 1-282 and the sulphated GpIb 268-282 peptides induced a progressive decrease (up to 70%) in activated FVIII generation, assessed by coagulation and FXa-generation assays. Furthermore, SDS/PAGE and Western-blot experiments showed that the specific appearance of the 44 kDa A2 domain on cleavage of the FVIII Arg(372)-Ser(373) peptide bond was delayed significantly in the presence of either GpIbalpha 1-282 or GpIb 268-282 peptide. Moreover, the effect of the latter on thrombin-mediated hydrolysis of a peptide having the sequence 341-376 of FVIII was investigated using reverse-phase HPLC. The k (cat)/ K (m) values of the FVIII 341-376 peptide hydrolysis by thrombin decreased linearly as a function of the GpIbalpha 268-282 peptide concentration, according to a competitive inhibition effect. Taken together, these experiments suggest that the sulphated 268-282 region of GpIbalpha binds to thrombin HBS, and is responsible for the inhibition of the Arg(372)-Ser(373) bond cleavage and activation of FVIII. PMID:12689334

  3. On the specificity of heparin/heparan sulfate binding to proteins. Anion-binding sites on antithrombin and thrombin are fundamentally different.

    Directory of Open Access Journals (Sweden)

    Philip D Mosier

    Full Text Available The antithrombin-heparin/heparan sulfate (H/HS and thrombin-H/HS interactions are recognized as prototypic specific and non-specific glycosaminoglycan (GAG-protein interactions, respectively. The fundamental structural basis for the origin of specificity, or lack thereof, in these interactions remains unclear. The availability of multiple co-crystal structures facilitates a structural analysis that challenges the long-held belief that the GAG binding sites in antithrombin and thrombin are essentially similar with high solvent exposure and shallow surface characteristics.Analyses of solvent accessibility and exposed surface areas, gyrational mobility, symmetry, cavity shape/size, conserved water molecules and crystallographic parameters were performed for 12 X-ray structures, which include 12 thrombin and 16 antithrombin chains. Novel calculations are described for gyrational mobility and prediction of water loci and conservation.The solvent accessibilities and gyrational mobilities of arginines and lysines in the binding sites of the two proteins reveal sharp contrasts. The distribution of positive charges shows considerable asymmetry in antithrombin, but substantial symmetry for thrombin. Cavity analyses suggest the presence of a reasonably sized bifurcated cavity in antithrombin that facilitates a firm 'hand-shake' with H/HS, but with thrombin, a weaker 'high-five'. Tightly bound water molecules were predicted to be localized in the pentasaccharide binding pocket of antithrombin, but absent in thrombin. Together, these differences in the binding sites explain the major H/HS recognition characteristics of the two prototypic proteins, thus affording an explanation of the specificity of binding. This provides a foundation for understanding specificity of interaction at an atomic level, which will greatly aid the design of natural or synthetic H/HS sequences that target proteins in a specific manner.

  4. Intravenous drugs infusion safety through smart pumps

    Directory of Open Access Journals (Sweden)

    C. Gómez-Baraza

    2014-07-01

    Full Text Available Objective: To analyze the role of smart infusion pumps in reducing errors related with the administration of intravenous medications. Method: Retrospective, observational study analyzing the implementation of a system with smart intravenous infusion pumps (Hospira MedNetTM and the role of the safety system for the detection of errors during the administration of drugs, sera, and blood. We included infusions administered at the day-care hospitals of hematology, oncology, rheumatology, and oncopediatrics. We analyzed adherence to the safety system, the number of programming errors detected, the commonly implicated drugs in these errors, and improvement actions. Results: During the study period, 120 smart pumps were implemented and data on 70,028 infusions were gathered. The rate of adherence to the safety program was 62.30% in hematology (6,887 infusions, 60,30% in oncology (28,127 infusions, 46,50% in rheumatology (1,950 infusions and 1.8% in oncopediatrics (139 infusions. 3,481 out of the established limits programming alerts were generated by the pumps: 2,716 of relative limit and 765 of absolute limit. En 807 infusions (2.17%, errors that could have had consequences for the patients could be prevented. These findings allowed implementing a series of strategies aimed at minimizing these errors in the future. Conclusions: The Hospira MedNetTM system detects deviations from the established protocols of intravenous infusion, preventing in this way potential adverse events for the patients. It also allows establishing correction measures and implementing the improvement strategies.

  5. Oral versus intravenous steroids for treatment of relapses in multiple sclerosis.

    Science.gov (United States)

    Burton, Jodie M; O'Connor, Paul W; Hohol, Marika; Beyene, Joseph

    2012-12-12

    This is an updated Cochrane review of the previous version published (Cochrane Database of Systematic Reviews 2009, Issue 3. Art. No.: CD006921. DOI: 10.1002/14651858.CD006921.pub2).Multiple sclerosis (MS), a chronic inflammatory and neurodegenerative disease of the central nervous system (CNS), is characterized by recurrent relapses of CNS inflammation ranging from mild to severely disabling.  Relapses have long been treated with steroids to reduce inflammation and hasten recovery.  However, the commonly used intravenous methylprednisolone (IVMP) requires repeated infusions with the added costs of homecare or hospitalization, and may interfere with daily responsibilities. Oral steroids have been used in place of intravenous steroids, with lower direct and indirect costs. The primary objective was to compare efficacy of oral versus intravenous steroids in promoting disability recovery in MS relapses Multiple Sclerosis and Rare Diseases of the Central Nervous System Group's Trials Register (January 2012), abstracts from meetings of the American Academy of Neurology (2008-2012), the European Federation of Neurological Sciences (2008-2012), the European Committee for Treatment and Research in Multiple Sclerosis and American Committee for Treatment and Research in Multiple Sclerosis (2008-2012) handsearching. No language restrictions were applied. Randomized or quasi-randomized trials comparing oral versus intravenous steroids for acute relapses (Multiple Sclerosis (OMEGA) trial and the "Efficacy and Safety of Methylprednisolone Per os Versus IV for the Treatment of Multiple Sclerosis (MS) Relapses" (COPOUSEP) trial, designed to address such limitations, are currently underway. The analysis of the five included trials comparing intravenous versus oral steroid therapy for MS relapses do not demonstrate any significant differences in clinical (benefits and adverse events), radiological or pharmacological outcomes. Based on the evidence, oral steroid therapy may be a

  6. Understanding the causes of intravenous medication administration errors in hospitals: a qualitative critical incident study.

    Science.gov (United States)

    Keers, Richard N; Williams, Steven D; Cooke, Jonathan; Ashcroft, Darren M

    2015-03-13

    To investigate the underlying causes of intravenous medication administration errors (MAEs) in National Health Service (NHS) hospitals. Two NHS teaching hospitals in the North West of England. Twenty nurses working in a range of inpatient clinical environments were identified and recruited using purposive sampling at each study site. Semistructured interviews were conducted with nurse participants using the critical incident technique, where they were asked to discuss perceived causes of intravenous MAEs that they had been directly involved with. Transcribed interviews were analysed using the Framework approach and emerging themes were categorised according to Reason's model of accident causation. In total, 21 intravenous MAEs were discussed containing 23 individual active failures which included slips and lapses (n=11), mistakes (n=8) and deliberate violations of policy (n=4). Each active failure was associated with a range of error and violation provoking conditions. The working environment was implicated when nurses lacked healthcare team support and/or were exposed to a perceived increased workload during ward rounds, shift changes or emergencies. Nurses frequently reported that the quality of intravenous dose-checking activities was compromised due to high perceived workload and working relationships. Nurses described using approaches such as subconscious functioning and prioritising to manage their duties, which at times contributed to errors. Complex interactions between active and latent failures can lead to intravenous MAEs in hospitals. Future interventions may need to be multimodal in design in order to mitigate these risks and reduce the burden of intravenous MAEs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  7. Effect of intravenous lipid on human pancreatic secretion.

    Science.gov (United States)

    Edelman, K; Valenzuela, J E

    1983-11-01

    Parenteral alimentation, including intravenous fat, is sometimes used in the treatment of patients with pancreatitis, although the effect of intravenous fat on human pancreatic secretion has not been systematically studied. Intravenous fat, however, has been shown to stimulate pancreatic protein secretion in the dog. The purpose of these studies was to clarify the effect of intravenous fat on human pancreatic secretion. Pancreatic secretion was assessed by measurement of enzymes and bicarbonate in duodenal aspirate collected via a double-lumen tube from 6 healthy volunteers. Four studies were randomly conducted on different days. On day 1, graded concentrations of Intralipid (5%, 10%, and 20%) were given intravenously for 1 h each, while secretin (8.2 pmol . kg-1 . h-1) was given as a background. On day 2, the same doses of Intralipid were infused intravenously without secretin. On day 3, the same doses of Intralipid were perfused into the intestine, and, finally, on day 4, 20% Intralipid was given by intestinal infusion for 2 h while 10% Intralipid was infused intravenously during the second hour. Significant stimulation of enzyme secretion was observed only during the infusion of fat into the intestine, not after intravenous infusion at any concentration. Pancreatic enzyme secretion, stimulated by intraintestinal fat, was not significantly modified by simultaneous intravenous lipid infusion. We conclude that since intravenous fat does not stimulate pancreatic secretion, its use in conditions where pancreatic stimulation is undesirable appears safe.

  8. Monitoring low molecular weight heparins at therapeutic levels: dose-responses of, and correlations and differences between aPTT, anti-factor Xa and thrombin generation assays.

    Directory of Open Access Journals (Sweden)

    Owain Thomas

    Full Text Available Low molecular weight heparins (LMWH's are used to prevent and treat thrombosis. Tests for monitoring LMWH's include anti-factor Xa (anti-FXa, activated partial thromboplastin time (aPTT and thrombin generation. Anti-FXa is the current gold standard despite LMWH's varying affinities for FXa and thrombin.To examine the effects of two different LMWH's on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests' concordance.Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR and Hemochron Jr (HCJ and an optical plasma method using two different reagents (ActinFSL and PTT-Automat. Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents.Methods' mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11 and 69s (SD 14 for enoxaparin and between 101s (SD 21 and 140s (SD 28 for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62-0.87, whereas the other aPTT methods had similar correlation coefficients (Rs0.80-0.92.aPTT displays a linear dose-response to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa's present gold standard status. Thrombin generation with tissue factor-rich activator is a promising method for monitoring LMWH's.

  9. Retroperitoneal fibrosis with normal intravenous urogram.

    Science.gov (United States)

    Creagh, F. M.; Stone, T.; Stephenson, T. P.; Lazarus, J. H.

    1985-01-01

    A 58 year old male presented with a two week history of low back pain and malaise. The intravenous urogram (IVU) at presentation was normal but within three months he had developed renal failure with bilateral ureteric obstruction on repeat IVU. Primary retroperitoneal fibrosis was confirmed at operation. This case demonstrates that retroperitoneal fibrosis may progress rapidly to renal failure within a few months of the first symptoms. In addition, the IVU may be normal in the early stages of the illness. Images Figure 1 Figure 2 PMID:3983053

  10. Pyeloureteral visualization using glucagon during intravenous urography

    International Nuclear Information System (INIS)

    Nepper-Rasmussen, J.; Nielsen, P.H.; Kruse, V.

    1983-01-01

    194 adult patients were subjected to intravenous urography. In order to study the effect of glucagon on the visualization of the pyeloureteral system, IVU's were performed in four different ways: I. with abdominal compression, II. with glucagon 1 mg.i.v., III. without abdominal compression and without glucagon, and IV. with abdominal compression and glucagon 1 mg.i.v. Coded objective and subjective analyses showed significant worsened visualization of the pyelocalyceal systems, when IVU was performed with glucagon alone. Ureteral visualization was equal in all four groups. Glucagon fails as a pharmacological alternative to abdominal compression in adult human subjects. (orig.) [de

  11. Switching between intravenous and subcutaneous trastuzumab

    DEFF Research Database (Denmark)

    Gligorov, Joseph; Curigliano, Giuseppe; Müller, Volkmar

    2017-01-01

    AIM: To assess the safety and tolerability of switching between subcutaneous (SC) and intravenous (IV) trastuzumab in the PrefHer study (NCT01401166). PATIENTS AND METHODS: Patients with HER2-positive early breast cancer completed (neo)adjuvant chemotherapy and were randomised to receive four....... Rates of clinically important events, including grade ≥3 AEs, serious AEs, AEs leading to study drug discontinuation and cardiac AEs, were low and similar between treatment arms (safety signals for trastuzumab were observed. CONCLUSIONS: PrefHer revealed...... that switching from IV to SC trastuzumab (hand-held syringe or SID) or vice versa did not impact the known safety profile of trastuzumab....

  12. Thrombin generation by activated factor VII on platelet activated by different agonists. Extending the cell-based model of hemostasis

    Directory of Open Access Journals (Sweden)

    Herrera Maria

    2006-04-01

    Full Text Available Abstract Background Platelet activation is crucial in normal hemostasis. Using a clotting system free of external tissue factor, we investigated whether activated Factor VII in combination with platelet agonists increased thrombin generation (TG in vitro. Methods and results TG was quantified by time parameters: lag time (LT and time to peak (TTP, and by amount of TG: peak of TG (PTG and area under thrombin formation curve after 35 minutes (AUC→35min in plasma from 29 healthy volunteers using the calibrated automated thrombography (CAT technique. TG parameters were measured at basal conditions and after platelet stimulation by sodium arachidonate (AA, ADP, and collagen (Col. In addition, the effects of recombinant activated FVII (rFVIIa alone or combined with the other platelet agonists on TG parameters were investigated. We found that LT and TTP were significantly decreased (p 35min were significantly increased (p 35min (but not PTG when compared to platelet rich plasma activated with agonists in the absence of rFVIIa. Conclusion Platelets activated by AA, ADP, Col or rFVIIa triggered TG. This effect was increased by combining rFVIIa with other agonists. Our intrinsic coagulation system produced a burst in TG independent of external tissue factor activity an apparent hemostatic effect with little thrombotic capacity. Thus we suggest a modification in the cell-based model of hemostasis.

  13. Inhibition of Cellular Adhesion by Immunological Targeting of Osteopontin Neoepitopes Generated through Matrix Metalloproteinase and Thrombin Cleavage.

    Science.gov (United States)

    Jürets, Alexander; Le Bras, Marie; Staffler, Günther; Stein, Gesine; Leitner, Lukas; Neuhofer, Angelika; Tardelli, Matteo; Turkof, Edvin; Zeyda, Maximilian; Stulnig, Thomas M

    2016-01-01

    Osteopontin (OPN), a secreted protein involved in inflammatory processes and cancer, induces cell adhesion, migration, and activation of inflammatory pathways in various cell types. Cells bind OPN via integrins at a canonical RGD region in the full length form as well as to a contiguous cryptic site that some have shown is unmasked upon thrombin or matrix metalloproteinase cleavage. Thus, the adhesive capacity of osteopontin is enhanced by proteolytic cleavage that may occur in inflammatory conditions such as obesity, atherosclerosis, rheumatoid arthritis, tumor growth and metastasis. Our aim was to inhibit cellular adhesion to recombinant truncated proteins that correspond to the N-terminal cleavage products of thrombin- or matrix metalloproteinase-cleaved OPN in vitro. We specifically targeted the cryptic integrin binding site with monoclonal antibodies and antisera induced by peptide immunization of mice. HEK 293 cells adhered markedly stronger to truncated OPN proteins than to full length OPN. Without affecting cell binding to the full length form, the raised monoclonal antibodies specifically impeded cellular adhesion to the OPN fragments. Moreover, we show that the peptides used for immunization were able to induce antisera, which impeded adhesion either to all OPN forms, including the full-length form, or selectively to the corresponding truncated recombinant proteins. In conclusion, we developed immunological tools to selectively target functional properties of protease-cleaved OPN forms, which could find applications in treatment and prevention of various inflammatory diseases and cancers.

  14. Different approaches toward an automatic structural alignment of drug molecules: Applications to sterol mimics, thrombin and thermolysin inhibitors

    Science.gov (United States)

    Klebe, Gerhard; Mietzner, Thomas; Weber, Frank

    1994-12-01

    A relative comparison of the binding properties of different drug molecules requires their mutual superposition with respect to various alignment criteria. In order to validate the results of different alignment methods, the crystallographically observed binding geometries of ligands in the pocket of a common protein receptor have been used. The alignment function in the program SEAL that calculates the mutual superposition of molecules has been optimized with respect to these references. Across the reference data set, alignments could be produced that show mean rms deviations of approximately 1 Å compared to the experimental situation. For structures with obvious skeletal similarities a multiple-flexible fit, linking common pharmacophoric groups by virtual springs, has been incorporated into the molecular mechanics program MOMO. In order to combine conformational searching with comparative alignments, the optimized SEAL approach has been applied to sets of conformers generated by MIMUMBA, a program for conformational analysis. Multiple-flexible fits have been calculated for inhibitors of ergosterol biosynthesis. Sets of different thrombin and thermolysin inhibitors have been conformationally analyzed and subsequently aligned by a combined MIMUMBA/SEAL approach. Since for these examples crystallographic data on their mutual alignment are available, an objective assessment of the computed results could be performed. Among the generated conformers, one geometry could be selected for the thrombin and thermolysin inhibitors that approached reasonably well the experimentally observed alignment.

  15. Host defense peptides of thrombin modulate inflammation and coagulation in endotoxin-mediated shock and Pseudomonas aeruginosa sepsis.

    Directory of Open Access Journals (Sweden)

    Martina Kalle

    Full Text Available Gram-negative sepsis is accompanied by a disproportionate innate immune response and excessive coagulation mainly induced by endotoxins released from bacteria. Due to rising antibiotic resistance and current lack of other effective treatments there is an urgent need for new therapies. We here present a new treatment concept for sepsis and endotoxin-mediated shock, based on host defense peptides from the C-terminal part of human thrombin, found to have a broad and inhibitory effect on multiple sepsis pathologies. Thus, the peptides abrogate pro-inflammatory cytokine responses to endotoxin in vitro and in vivo. Furthermore, they interfere with coagulation by modulating contact activation and tissue factor-mediated clotting in vitro, leading to normalization of coagulation responses in vivo, a previously unknown function of host defense peptides. In a mouse model of Pseudomonas aeruginosa sepsis, the peptide GKY25, while mediating a modest antimicrobial effect, significantly inhibited the pro-inflammatory response, decreased fibrin deposition and leakage in the lungs, as well as reduced mortality. Taken together, the capacity of such thrombin-derived peptides to simultaneously modulate bacterial levels, pro-inflammatory responses, and coagulation, renders them attractive therapeutic candidates for the treatment of invasive infections and sepsis.

  16. Application of Europium Multiwalled Carbon Nanotubes as Novel Luminophores in an Electrochemiluminescent Aptasensor for Thrombin Using Multiple Amplification Strategies.

    Science.gov (United States)

    Wu, Dan; Xin, Xia; Pang, Xuehui; Pietraszkiewicz, Marek; Hozyst, Robert; Sun, Xian'ge; Wei, Qin

    2015-06-17

    A novel electrochemiluminescent (ECL) aptasensor was proposed for the determination of thrombin (TB) using exonuclease-catalyzed target recycling and hybridization chain reaction (HCR) to amplify the signal. The capture probe was immobilized on an Au-GS-modified electrode through a Au-S bond. Subsequently, the hybrid between the capture probe and the complementary thrombin binding aptamer (TBA) was aimed at obtaining double-stranded DNA (dsDNA). The interaction between TB and its aptamer led to the dissociation of dsDNA because TB has a higher affinity to TBA than the complementary strands. In the presence of exonuclease, aptamer was selectively digested and TB could be released for target recycling. Extended dsDNA was formed through HCR of the capture probe and two hairpin DNA strands (NH2-DNA1 and NH2-DNA1). Then, numerous europium multiwalled carbon nanotubes (Eu-MWCNTs) could be introduced through amidation reaction between NH2-terminated DNA strands and carboxyl groups on the Eu-MWCNTs, resulting in an increased ECL signal. The multiple amplification strategies, including the amplification of analyte recycling and HCR, and high ECL efficiency of Eu-MWCNTs lead to a wide linear range (1.0×10(-12)-5.0×10(-9) mol/L) and a low detection limit (0.23 pmol/L). The method was applied to serum sample analysis with satisfactory results.

  17. Ultrasonography-guided peripheral intravenous access versus traditional approaches in patients with difficult intravenous access.

    Science.gov (United States)

    Costantino, Thomas G; Parikh, Aman K; Satz, Wayne A; Fojtik, John P

    2005-11-01

    We assess the success rate of emergency physicians in placing peripheral intravenous catheters in difficult-access patients who were unsuccessfully cannulated by emergency nurses. A technique using real-time ultrasonographic guidance by 2 physicians was compared with traditional approaches using palpation and landmark guidance. This was a prospective, systematically allocated study of all patients requiring intravenous access who presented to 2 university hospitals between October 2003 and March 2004. Inclusion criterion was the inability of any available nurse to obtain intravenous access after at least 3 attempts on a subgroup of patients who had a history of difficult intravenous access because of obesity, history of intravenous drug abuse, or chronic medical problems. Exclusion criterion was the need for central venous access. Patients presenting on odd days were allocated to the ultrasonographic-guided group, and those presenting on even days were allocated to the traditional-approach group. Endpoints were successful cannulation, number of sticks, time, and patient satisfaction. Sixty patients were enrolled, 39 on odd days and 21 on even days. Success rate was greater for the ultrasonographic group (97%) versus control (33%), difference in proportions of 64% (95% confidence interval [CI] 39% to 71%). The ultrasonographic group required less overall time (13 minutes versus 30 minutes, for a difference of 17 [95% CI 0.8 to 25.6]), less time to successful cannulation from first percutaneous puncture (4 minutes versus 15 minutes, for a difference of 11 [95% CI 8.2 to 19.4]), and fewer percutaneous punctures (1.7 versus 3.7, for a difference of 2.0 [95% CI 1.27 to 2.82]) and had greater patient satisfaction (8.7 versus 5.7, for a difference of 3.0 [95% CI 1.82 to 4.29]) than the traditional landmark approach. Ultrasonographic-guided peripheral intravenous access is more successful than traditional "blind" techniques, requires less time, decreases the number of

  18. Intravenous Carbamazepine for Adults With Seizures.

    Science.gov (United States)

    Vickery, P Brittany; Tillery, Erika E; DeFalco, Alicia Potter

    2018-03-01

    To review the pharmacology, pharmacokinetics, efficacy, safety, dosage and administration, potential drug-drug interactions, and place in therapy of the intravenous (IV) formulation of carbamazepine (Carnexiv) for the treatment of seizures in adult patients. A comprehensive PubMed and EBSCOhost search (1945 to August 2017) was performed utilizing the keywords carbamazepine, Carnexiv, carbamazepine intravenous, IV carbamazepine, seizures, epilepsy, and seizure disorder. Additional data were obtained from literature review citations, manufacturer's product labeling, and Lundbeck website as well as Clinicaltrials.gov and governmental sources. All English-language trials evaluating IV carbamazepine were analyzed for this review. IV carbamazepine is FDA approved as temporary replacement therapy for treatment of adult seizures. Based on a phase I trial and pooled data from 2 open-label bioavailability studies comparing oral with IV dosing, there was no noted indication of loss of seizure control in patients switched to short-term replacement antiepileptic drug therapy with IV carbamazepine. The recommended dose of IV carbamazepine is 70% of the patient's oral dose, given every 6 hours via 30-minute infusions. The adverse effect profile of IV carbamazepine is similar to that of the oral formulation, with the exception of added infusion-site reactions. IV carbamazepine is a reasonable option for adults with generalized tonic-clonic or focal seizures, previously stabilized on oral carbamazepine, who are unable to tolerate oral medications for up to 7 days. Unknown acquisition cost and lack of availability in the United States limit its use currently.

  19. The human experience with intravenous levodopa

    Directory of Open Access Journals (Sweden)

    Shan H Siddiqi

    2016-01-01

    Full Text Available Objective: To compile a comprehensive summary of published human experience with levodopa given intravenously, with a focus on information required by regulatory agencies.Background: While safe intravenous (IV use of levodopa has been documented for over 50 years, regulatory supervision for pharmaceuticals given by a route other than that approved by the U.S. Food and Drug Administration (FDA has become increasingly cautious. If delivering a drug by an alternate route raises the risk of adverse events, an investigational new drug (IND application is required, including a comprehensive review of toxicity data.Methods: Over 200 articles referring to IV levodopa were examined for details of administration, pharmacokinetics, benefit and side effects.Results: We identified 142 original reports describing IVLD use in humans, beginning with psychiatric research in 1959-1960 before the development of peripheral decarboxylase inhibitors. Over 2750 subjects have received IV levodopa, and reported outcomes include parkinsonian signs, sleep variables, hormone levels, hemodynamics, CSF amino acid composition, regional cerebral blood flow, cognition, perception and complex behavior. Mean pharmacokinetic variables were summarized for 49 healthy subjects and 190 with Parkinson’s disease. Side effects were those expected from clinical experience with oral levodopa and dopamine agonists. No articles reported deaths or induction of psychosis.Conclusion: Over 2750 patients have received IV levodopa with a safety profile comparable to that seen with oral administration.

  20. Flank pain: is Intravenous Urogram necessary?

    Science.gov (United States)

    Teh, H S; Lin, M B; Khoo, T K

    2001-09-01

    To determine the diagnostic yield of Intravenous Urogram (IVU) and the values of plain radiograph of kidney, ureter and bladder (KUB) and urinalysis as screening tests, with the objective to improve the cost effectiveness, in the management of patients presenting with flank pain due to urinary lithiasis. All Intravenous Urogram (IVU) request forms and reports for the month of February 1998 were audited. The case notes, urinalysis, KUB and IVU films were traced and reviewed. There were 110 patients investigated, 61.8% (68) had normal IVU, 38.2% (42) had abnormal IVU. The sensitivity and specificity of KUB alone was 79.4% and 90%. The sensitivity using urinalysis alone was 90.9% and its specificity 33.8%. The sensitivity of combined KUB and urinalysis was 100% and its specificity 26%, with a negative predictive value of 100%. All the patients with both negative KUB and urinalysis in our study were found to have negative IVU. Our study shows that in patients with both negative KUB and urinalysis, the yield of IVU is very low and may not be necessary. This is important, as an IVU examination is not without risk. A combination of KUB with urinary analysis and careful evaluation of clinical symptoms will improve the cost-effectiveness of patient management.

  1. Intravenous dynamic nucleography of the brain

    International Nuclear Information System (INIS)

    Rosenthall, L.

    1972-01-01

    The advent of stationary imaging devices has created interest in studying cerebral blood flows and transits with diffusible and nondiffusible radioactive indicators. Much of this has disclosed interesting pathophysiology, but not necessarily of significant diagnostic import to include in routine patient workup. The conventional static brain scan is one of the more useful tests in the nuclear medicine armamentarium for uncovering and localizing intracranial disease. Unfortunately, it does not as a rule clearly distinguish cerebral vascular accidents, neoplasms, arteriovenous malformations, and so forth, which is important from the standpoint of patient management. Aside from clinical impressions a diagnosis is often based on the appearance of the radiocontrast angiogram, which is not always desirable because of the implicit hazards. Thus it is incumbent upon investigators to search for innocuous intravenous methods of identifying the various intracranial afflictions. Intravenous 99 /sup m/Tc-pertechnetate comparisons of brain hemisphere perfusion as a routine complement to static brain imaging are useful. Estimations of disparate radioactive transits are made qualitatively from serial 4 to 5 sec exposure scintiphotographs. (U.S.)

  2. Intravenous polyclonal human immunoglobulins in multiple sclerosis

    DEFF Research Database (Denmark)

    Sørensen, Per Soelberg

    2008-01-01

    Intravenous immunoglobulin (IVIG) is an established therapy for demyelinating diseases of the peripheral nervous system. IVIG exerts a number of effects that may be beneficial in multiple sclerosis (MS). Four double-blind IVIG trials have been performed in relapsing-remitting MS. A meta-analysis ......Intravenous immunoglobulin (IVIG) is an established therapy for demyelinating diseases of the peripheral nervous system. IVIG exerts a number of effects that may be beneficial in multiple sclerosis (MS). Four double-blind IVIG trials have been performed in relapsing-remitting MS. A meta......-analysis of the four trials has shown that IVIG reduces the relapse rate and, possibly, disease progression. In patients with a first episode of demyelinating disease, IVIG delays the time to the second relapse and thereby to the diagnosis of definite MS. In patients with an acute MS relapse, IVIG as add-on therapy...... to methylprednisolone does not make remission of symptoms faster or more complete. IVIG does not seem to be of any benefit to chronic visual or motor symptoms in MS. In secondary progressive MS, IVIG has not shown any effect on disease progression, relapses or new magnetic resonance imaging lesions. Experimental...

  3. Adverse reactions to iotroxate at intravenous cholangiography

    International Nuclear Information System (INIS)

    Nilsson, U.

    1987-01-01

    The number and type of adverse reactions to meglumine iotroxate at intravenous infusion cholangiography, performed one day prior to elective cholecystectomy, were recorded in a prospective investigation of 196 asymptomatic, anicteric patients. One hundred ml (50 mg I/ml) of contrast medium was infused over a period of 30 minutes. Only 2 minor (1%) and no severe or fatal reactions were noted. A review of the literature on the use of iotroxate in 2492 patients, including those in the present investigation, revealed a complication rate of 3.5% (3.0% minor, 0.3% moderate and 0.2% severe reactions) at infusion of iotroxate (5.0-8.0 g I) over a period of 30 to 120 minutes. This compared favourably with the 5% complication rate (4% minor, 0.5% moderate and 0.5% severe reactions) at infusion of iodoxamate and the 9% complication rate (5% minor, 1% moderate and 3% severe reactions) at infusion of ioglycamide. Irrespective of the contrast agent used, the frequency of adverse reactions at infusion was found to be 3 times lower than when equal amounts (5.0-5.6 g I) of the same medium were injected. It is concluded that, at present, infusion of iotroxate in an amount which approximates to the transportation maximum of the liver is the least toxic way of performing intravenous cholangiography with an optimum filling of the bile ducts. (orig.)

  4. A tomographic approach to intravenous coronary arteriography

    International Nuclear Information System (INIS)

    Ritman, E.L.; Bove, A.A.

    1986-01-01

    Coronary artery anatomy can be visualized using high speed, volume scanning X-ray CT. A single scan during a bolus injection of contrast medium provides image data for display of all angles of view of the opacified coronary arterial tree. Due to the tomographic nature of volume image data the superposition of contrast filled cardiac chambers, such as would occur in the levophase of an intravenous injection of contrast agent, can be eliminated. Data are presented which support these statements. The Dynamic Spatial Reconstructor (DSR) was used to scan a life-like radiologic phantom of an adult human thorax in which the left atrial and ventricular chambers and the major epicardial coronary arteries were opacified so as to simulate the levophase of an intravenous injection of contrast agent. A catheter filled with diluted contrast agent and with regions of luminal narrowing (i.e. 'stenoses') was advanced along a tract equivalent to a right ventricular catheterization. Ease of visualization of the catheter 'stenoses' and the accuracy with which they can be measured are presented. (Auth.)

  5. Panlobular emphysema in young intravenous Ritalin abusers

    International Nuclear Information System (INIS)

    Schmidt, R.A.; Glenny, R.W.; Godwin, J.D.; Hampson, N.B.; Cantino, M.E.; Reichenbach, D.D.

    1991-01-01

    We studied a distinctive group of young intravenous Ritalin abusers with profound obstructive lung disease. Clinically, they seemed to have severe emphysema, but the pathologic basis of their symptoms had not been investigated previously. Seven patients have died and been autopsied: in four, the lungs were fixed, inflated, dried, and examined in detail radiologically, grossly, microscopically, and by electron probe X-ray microanalysis. All seven patients had severe panlobular (panacinar) emphysema that tended to be more severe in the lower lung zones and that was associated with microscopic talc granulomas. Vascular involvement by talc granulomas was variable, but significant interstitial fibrosis was not present. Five patients were tested for alpha-1-antitrypsin deficiency and found to be normal, as were six similar living patients. These findings indicate that some intravenous drug abusers develop emphysema that clinically, radiologically, and pathologically resembles that caused by alpha-1-antitrypsin deficiency but which must have a different pathogenesis. Talc from the Ritalin tablets may be important, but the mechanism remains to be elucidated

  6. Intravenous immunoglobulin therapy and systemic lupus erythematosus.

    Science.gov (United States)

    Zandman-Goddard, Gisele; Levy, Yair; Shoenfeld, Yehuda

    2005-12-01

    Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with diverse manifestations. We suggest that intravenous immunoglobulin (IVIg) therapy may be beneficial and safe for various manifestations in SLE. A structured literature search of articles published on the efficacy of IVIg in the treatment of SLE between 1983 and 2005 was conducted. We searched the terms "IVIg," "intravenous immunoglobulin," "lupus," "SLE," and "systemic lupus erythematosus." The various clinical manifestations of SLE that were reported to be successfully treated by IVIg in case reports include autoimmune hemolytic anemia, acquired factor VIII inhibitors, acquired von Willebrand disease, pure red cell aplasia, thrombocytopenia, pancytopenia, myelofibrosis, pneumonitis, pleural effusion, pericarditis, myocarditis, cardiogenic shock, nephritis, end-stage renal disease, encephalitis, neuropsychiatric lupus, psychosis, peripheral neuropathy, polyradiculoneuropathy, and vasculitis. The most extensive experience is with lupus nephritis. There are only a few case series of IVIg use in patients with SLE with various manifestations, in which the response rate to IVIg therapy ranged from 33 to 100%. We suggest that IVIg devoid of sucrose, at a dose of 2 g/kg over a 5-d period given uniformly and at a slow infusion rate in patients without an increased risk for thromboembolic events or renal failure, is a safe and beneficial adjunct therapy for cases of SLE that are resistant to or refuse conventional treatment. The duration of therapy is yet to be established. Controlled trials are warranted.

  7. Association of hemolysis with high dose intravenous immunoglobulin therapy in pediatric patients: An open-label prospective trial.

    Science.gov (United States)

    Akman, Alkim Oden; Kara, Fatma Karaca; Koksal, Tulin; Cakir, Bahar Cuhaci; Karagol, Cuneyt; Sayli, Tulin

    2017-08-01

    Immunoglobulin therapy can be used to treat a wide variety of diseases. However, intravenous immunoglobin products can cause several adverse reactions, including hemolysis. The objective of this study was to determine the extent of anemia and hemolysis after high dose intravenous immunoglobin (2g/kg) and its relationship to the ABO blood type system and hemolytic anemia blood parameters in pediatric patients. Incidence of 'Intravenous immunoglobulin related hemolysis' was %19 (6/31) after high dose intravenous immunoglobulin therapy. The blood parameters were measured before IVIG infusion (1-24h before infusion) and 3-10 days after the first day of infusion. In terms of decrease in Hb levels; decline of 2g/dL (severe hemolysis) in 4 patients (12.9%) after infusion. The decrease in hemoglobin, haptoglobin levels, the increase of reticulocyte count or direct bilirubin were statistically significant after infusion. Five of 6 hemolysis patients had non-O blood group, however statistically significant difference was not noted between these two groups. Also, intravenous immunoglobulin-related hemolysis was determined significantly higher in female than male patients. Mild to moderate hemolysis may be undetected after infusion and the true incidence of such reactions is difficult to document without careful clinical and laboratory follow-up. A careful risk assessment analysis should be performed before intravenous immunoglobulin infusion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Intravenous immunoglobulin in ABO and Rh hemolytic diseases of newborn.

    Science.gov (United States)

    Nasseri, Fatemeh; Mamouri, Gholam A; Babaei, Homa

    2006-12-01

    To evaluate whether the use of intravenous immunoglobulin in newborn infants with isoimmune hemolytic jaundice due to Rh and ABO incompatibility is an effective treatment in reducing the need for exchange transfusion. This study included all direct Coombs' test positive Rh and ABO isoimmunized babies, who admitted in the Neonatal Intensive Care Unit of Ghaem Hospital of Mashhad University of Medical Sciences, Iran, from October 2003 to October 2004. Significant hyperbilirubinemia was defined as rising by >or=0.5 mg/dl per hour. Babies were randomly assigned to received phototherapy with intravenous immunoglobulin (IVIg) 0.5 g/kg over 4 hours, every 12 hours for 3 doses (study group) or phototherapy alone (control group). Exchange transfusion was performed in any group if serum bilirubin exceeded >or=20mg/dl or rose by >or=1mg/dl/h. A total of 34 babies were eligible for this study (17 babies in each group). The number of exchange transfusion, duration of phototherapy and hospitalization days, were significant shorter in the study group versus control group. When we analyzed the outcome results in ABO and Rh hemolytic disease separately, the efficacy of IVIg was significantly better in Rh versus ABO isoimmunization. Late anemia was more common in the IVIg group 11.8% versus 0%, p=0.48. Adverse effects were not observed during IVIg administration. Administration of IVIg to newborns with significant hyperbilirubinemia due to Rh hemolytic disease reduced the need for exchange transfusion but in ABO hemolytic disease there was no significant difference between IVIg and double surface blue light phototherapy.

  9. Effects of intravenous diclofenac on postoperative sore throat in ...

    African Journals Online (AJOL)

    Effects of intravenous diclofenac on postoperative sore throat in patients undergoing laparoscopic surgery at Aga Khan University Hospital, Nairobi: A prospective, randomized, double blind controlled trial.

  10. Intravenous methylprednisolone pulse therapy for children with epileptic encephalopathy

    OpenAIRE

    Pera, Maria Carmela; Randazzo, Giovanna; Masnada, Silvia; Dontin, Serena Donetti; De Giorgis, Valentina; Balottin, Umberto; Veggiotti, Pierangelo

    2015-01-01

    The aim of this retrospective study of children affected by epileptic encephalopathy was to evaluate seizure frequency, electroencephalographic pattern and neuropsychological status, before and after intravenous methylprednisolone therapy.

  11. Fibrinogen Matsumoto V: a variant with Aalpha19 Arg-->Gly (AGG-->GGG). Comparison between fibrin polymerization stimulated by thrombin or reptilase and fibrin monomer polymerization.

    Science.gov (United States)

    Tanaka, H; Terasawa, F; Ito, T; Tokunaga, S; Ishida, F; Kitano, K; Kiyosawa, K; Okumura, N

    2001-01-01

    Fibrinogen Matsumoto V (M-V) is a dysfibrinogen identified in a 52-year-old woman with systemic lupus erythematous. The triplet AGG encoding the amino acid residue Aalpha19 was replaced by GGG, resulting in the substitution of Arg-->Gly. Residue Aalpha19 has been shown to be one of the most important amino acids in the so-called 'A' site or alpha-chain knob. The thrombin-catalyzed release of fibrinopeptide A from M-V fibrinogen was only slightly delayed yet release of fibrinopeptide B was significantly delayed. Both thrombin-catalyzed fibrin polymerization and fibrin monomer polymerization were markedly impaired compared to normal fibrinogen. In addition, reptilase-catalyzed fibrin polymerization of M-V was much more impaired than thrombin-catalyzed fibrin polymerization. These results indicate 'B' and/or 'b' site of M-V fibrinogen play a more important role in thrombin-catalyzed fibrin polymerization than that of normal control fibrinogen.

  12. The Anopheles gambiae cE5, a tight- and fast-binding thrombin inhibitor with post-transcriptionally regulated salivary-restricted expression

    Czech Academy of Sciences Publication Activity Database

    Ronca, R.; Kotsyfakis, Michalis; Lombardo, F.; Rizzo, C.; Currà, C.; Ponzi, M.; Fiorentino, G.; Ribeiro, J.M.C.; Arcà, B.

    2012-01-01

    Roč. 42, č. 9 (2012), s. 610-620 ISSN 0965-1748 R&D Projects: GA ČR GAP502/12/2409 Institutional research plan: CEZ:AV0Z60220518 Keywords : Anopheles * Salivary protein * Anti-thrombin * Anophelin * Hematophagy * Post-transcriptional regulation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2012

  13. Use of a Fibrinogen/Thrombin-Based Collagen Fleece (TachoComb, TachoSil) With a Stapled Closure to Prevent Pancreatic Fistula Formation Following Distal Pancreatectomy.

    Science.gov (United States)

    Mita, Kazuhito; Ito, Hideto; Murabayashi, Ryo; Asakawa, Hideki; Nabetani, Masashi; Kamasako, Akira; Koizumi, Kazuya; Hayashi, Takashi

    2015-12-01

    Postoperative pancreatic fistula formation remains a source of significant morbidity following distal pancreatectomy. The aim of this study was to evaluate the rate of clinically significant fistulas (International Study Group on Pancreatic Fistula grade B and grade C) after distal pancreatectomy using a fibrinogen/thrombin-based collagen fleece (TachoComb, TachoSil) with a stapled closure. Seventy-five patients underwent distal pancreatectomy at our institution between January 2005 and March 2014. A fibrinogen/thrombin-based collagen fleece was applied to the staple line of the pancreas before stapling. Twenty-six patients (34.7%) developed a pancreatic fistula, 8 patients (10.7%) developed a grade B fistula, and no patients developed a grade C fistula. The duration of the drain was significantly different in patients with or without a pancreatic fistula (8.0 ± 4.5 vs. 5.4 ± 1.3 days, P = .0003). Histological analysis showed that there was a tight covering with the fibrinogen/thrombin-based collagen fleece. The fibrinogen/thrombin-based collagen fleece (TachoComb, TachoSil) with a stapled closure has low rates of fistula formation and provides a safe alternative to the conventional stapled technique in distal pancreatectomy. © The Author(s) 2015.

  14. The Thrombin-Derived Host Defense Peptide GKY25 Inhibits Endotoxin-Induced Responses through Interactions with Lipopolysaccharide and Macrophages/Monocytes

    DEFF Research Database (Denmark)

    Hansen, Finja C; Kalle-Brune, Martina; van der Plas, Mariena J A

    2015-01-01

    Host defense peptides have recently gained much interest as novel anti-infectives owing to their ability to kill bacteria and simultaneously modulate host cell responses. The cationic host defense peptide GKY25 (GKYGFYTHVFRLKKWIQKVIDQFGE), derived from the C terminus of human thrombin, inhibits p...

  15. mRNA expression of genes involved in inflammation and haemostasis in equine fibroblast-like synoviocytes following exposure to lipopolysaccharide, fibrinogen and thrombin

    DEFF Research Database (Denmark)

    Andreassen, Stine Mandrup; Berg, Lise Charlotte; Nielsen, Søren Saxmose

    2015-01-01

    to lipopolysaccharide (LPS), fibrinogen and thrombin. Synovial membranes were collected from metacarpo-phalangeal joints of 6 skeletally mature horses euthanized for non-orthopaedic reasons. Passage 4 fibroblast-like synoviocytes were left non-treated or treated with either 0.1 μ g/ml LPS, 5 mg/ml fibrinogen or 5 U...

  16. Posttranslational Modifications of Human Thrombin Activatable Fibrinolysis Inhibitor (TAFI): Evidence for a large shift in isoelectric point and reduced solubility upon activation

    DEFF Research Database (Denmark)

    Valnickova, Zuzana; Christensen, Trine; Skottrup, Peter Durand

    2006-01-01

    Thrombin-activable fibrinolysis inhibitor (TAFI) is distinct from pancreatic procarboxypeptidase B in several ways. The enzymatic activity of TAFIa is unstable and decays with a half-life of a few minutes. During this study, we observed that (i) the isoelectric point (pI) of TAFI shifts dramatica...

  17. cGMP and nitric oxide modulate thrombin-induced endothelial permeability : Regulation via different pathways in human aortic and umbilical vein endothelial cells

    NARCIS (Netherlands)

    Draijer, R.; Atsma, D.E.; Laarse, A. van der; Hinsbergh, V.W.M. van

    1995-01-01

    Previous studies have demonstrated that cGMP and cAMP reduce the endothelial permeability for fluids and macromolecules when the endothelial permeability is increased by thrombin. In this study, we have investigated the mechanism by which cGMP improves the endothelial barrier function and examined

  18. Optimizing electrode-attached redox-peptide systems for kinetic characterization of protease action on immobilized substrates. Observation of dissimilar behavior of trypsin and thrombin enzymes.

    Science.gov (United States)

    Anne, Agnès; Chovin, Arnaud; Demaille, Christophe

    2012-06-12

    In this work, we experimentally address the issue of optimizing gold electrode attached ferrocene (Fc)-peptide systems for kinetic measurements of protease action. Considering human α-thrombin and bovine trypsin as proteases of interest, we show that the recurring problem of incomplete cleavage of the peptide layer by these enzymes can be solved by using ultraflat template-stripped gold, instead of polished polycrystalline gold, as the Fc-peptide bearing electrode material. We describe how these fragile surfaces can be mounted in a rotating disk configuration so that enzyme mass transfer no longer limits the overall measured cleavage kinetics. Finally, we demonstrate that, once the system has been optimized, in situ real-time cyclic voltammetry monitoring of the protease action can yield high-quality kinetic data, showing no sign of interfering effects. The cleavage progress curves then closely match the Langmuirian variation expected for a kinetically controlled surface process. Global fit of the progress curves yield accurate values of the peptide cleavage rate for both trypsin and thrombin. It is shown that, whereas trypsin action on the surface-attached peptide closely follows Michaelis-Menten kinetics, thrombin displays a specific and unexpected behavior characterized by a nearly enzyme-concentration-independent cleavage rate in the subnanomolar enzyme concentration range. The reason for this behavior has still to be clarified, but its occurrence may limit the sensitivity of thrombin sensors based on Fc-peptide layers.

  19. Human fibrinogen and thrombin patch for extraluminal protection of intestinal anastomosis

    Directory of Open Access Journals (Sweden)

    Paulo Gustavo Kotze

    2013-07-01

    Full Text Available In spite of recent advances regarding equipment and surgical techniques in colorectal surgery, rates of anastomotic dehiscence (AD have remained stable throughout the years. The development of products to protect anastomosis aiming the reduction of AD rates has shown to be promising. Human fibrinogen and thrombin patch (HFTP Tachosil® have been used in experimental studies in animals and small case series in humans, with promising results. In this study, the authors describe the technique of HFTP use in details, aiming the protection of colorectal anastomosis, and retrospectively demonstrate the preliminary results in a pilot case series. HFTP was used in 4 patients submitted to conventional surgery. The procedures performed were: left colon resection, segmental colectomy (both for colorectal cancer, enteral anastomosis for fistula closure and right ileocolectomy. Anastomotic healing and absence of complications were observed in 3 patients, and the patient submitted to right ileocolectomy developed AD and died after reoperation. The use of HFTP is safe and can be indicated in selected cases. However, AD can occur even after the use of this strategy. Randomized controlled trials with larger samples of patients are needed in order to properly define the real benefits of this strategy in dehiscence prevention Resumo: Apesar dos avanços em equipamentos e técnica cirúrgica na cirurgia colorretal, os índices de deiscência de anastomose (DA tem permanecido estáveis nos últimos anos. O desenvolvimento de produtos que visam proteção das anastomoses para redução das taxas de DA tem se mostrado promissor. A membrana de fibrinogênio e trombina humanos (MFTH vem sendo utilizada em estudos experimentais e em pequenas séries de casos em humanos, com resultados promissores. Neste artigo os autores detalham a descrição técnica da utilização da MFTH na proteção de anastomoses colorretais, e demonstram os resultados preliminares em uma s

  20. Anaphylaxis after intravenous infusion of dexketoprofen trometamol

    Directory of Open Access Journals (Sweden)

    Sertac Guler

    2016-09-01

    Full Text Available Dexketoprofen trometamol (DT, a nonsteroidal anti-inflammatory drug, is a highly water-soluble salt and active enantiomer of rac-ketoprofen. Its parenteral form is commonly used for acute pain management in emergency departments of our country. Side effects such as diarrhea, indigestion, nausea, stomach pain, and vomiting may be seen after the use of DT. Anaphylactic shock (AS secondary to infusion of DT is very rare and, to our knowledge, it is the first case report describing this side effect. This case report was presented to emphasize that AS may be seen after the use of DT. Keywords: Anaphylactic shock, Dexketoprofen trometamol, Intravenous infusion (MeSH database

  1. Intravenous urography in children and youth

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, H.K.; Gudmundsen, T.E.; Oestensen, H.; Pape, J.F.

    1987-10-01

    This report derives from Tromsoe in northern Norway. In a retrospective study of the indications for intravenous urography (IU) and the findings at IU in 740 patients (451 girls and 289 boys) aged 0-19 years, we found that urinary tract infections accounted for 69.4% of the IU in females and 30.1% of the IU in males, most often seen in the youngest patients. The pathological findings most frequently seen were anomalies (17 females and 10 males) and urinary tract obstruction (3 females and 15 males). The present study indicates the following: first, that the yield of IU in the primary investigation of children and youth suffering from enuresis and non-specific abdominal disturbancies is small; and second, that the use of IU in children and youth with urinary tract infection and haematuria should be questioned and reconsidered.

  2. Renal trauma and the intravenous urogram.

    Science.gov (United States)

    Oakland, C D; Britton, J M; Charlton, C A

    1987-01-01

    A retrospective analysis of all patients with blunt abdominal trauma associated with haematuria admitted to one hospital (Royal United, Bath) in a 10-year period was conducted to establish the contribution of the intravenous urogram (IVU) in their management. Eighty-one case records were analysed. Of 35 IVUs performed in patients with microscopic (reagentstrip positive) haematuria, only one was abnormal. In contrast, 27 IVUs performed in patients with macroscopic (naked eye) haematuria revealed 17 major injuries and 5 previously unrecognized congenital abnormalities. It is concluded that an IVU is an unnecessary and non-contributory investigation in patients with microscopic haematuria and guidelines are suggested for the role of IVU in patients with blunt abdominal trauma associated with haematuria. PMID:3560121

  3. Retrocaval ureter: the importance of intravenous urography.

    Science.gov (United States)

    Hassan, Radhiana; Aziz, Azian Abd; Mohamed, Siti Kamariah Che

    2011-10-01

    Retrocaval ureter is a rare cause of hydronephrosis. Its rarity and non-specific presentation pose a challenge to surgeons and radiologists in making the correct diagnosis. Differentiation from other causes of urinary tract obstruction, especially the more common urolithiasis, is important for successful surgical management. Current practice has seen multislice computed tomography (MSCT) rapidly replaces intravenous urography (IVU) in the assessment of patients with hydronephrosis due to suspected urolithiasis, especially ureterolithiasis. However, MSCT, without adequate opacification of the entire ureter, may allow the physician to overlook a retrocaval ureter as the cause of hydronephrosis. High-resolution IVU images can demonstrate the typical appearance that leads to the accurate diagnosis of a retrocaval ureter. We reported a case that illustrates this scenario and highlights the importance of IVU in the assessment of a complex congenital disorder involving the urinary tract.

  4. Intravenous immunoglobulin, pharmacogenomics, and Kawasaki disease.

    Science.gov (United States)

    Kuo, Ho-Chang; Hsu, Yu-Wen; Wu, Mei-Shin; Chien, Shu-Chen; Liu, Shih-Feng; Chang, Wei-Chiao

    2016-02-01

    Kawasaki disease (KD) is a systemic vasculitis of unknown etiology and it is therefore worth examining the multifactorial interaction of genes and environmental factors. Targeted genetic association and genome-wide association studies have helped to provide a better understanding of KD from infection to the immune-related response. Findings in the past decade have contributed to a major breakthrough in the genetics of KD, with the identification of several genomic regions linked to the pathogenesis of KD, including ITPKC, CD40, BLK, and FCGR2A. This review focuses on the factors associated with the genetic polymorphisms of KD and the pharmacogenomics of the response to treatment in patients with intravenous immunoglobulin resistance. Copyright © 2014. Published by Elsevier B.V.

  5. [Use of intravenous immunoglobulins in pediatrics].

    Science.gov (United States)

    Duse, M; Plebani, A; Crispino, P; Ugazio, A G

    1991-01-01

    Intramuscular Immunoglobulin (IMIG) have been used for 40 years in substitution therapy for antibody deficiencies and as prophylaxis for and treatment of several infectious diseases. Modified and intact intravenous immunoglobulin preparations (IVIG) have now been available for more than 10 years: only the intact product express full Fc- mediated functions with a biological half-life of IgG (3-4 weeks). These preparations have constituted an important achievement in the treatment of humoral immunodeficiencies also resulting in a dramatic improvement of the prognosis. The use of IVIG has also modified the therapeutic approach to several secondary and acquired immunodeficiencies. Treatment with IVIG for immune modulation in several diseases is investigated: substantial data indicate a useful role in selected cases of idiopathic thrombocytopenic purpura, Kawasaky disease and in some neurologic diseases. IVIG are substantially safe and severe side effects have been rarely reported.

  6. Intravenous urography in children and youth

    International Nuclear Information System (INIS)

    Pedersen, H.K.; Gudmundsen, T.E.; Oestensen, H.; Pape, J.F.

    1987-01-01

    This report derives from Tromsoe in northern Norway. In a retrospective study of the indications for intravenous urography (IU) and the findings at IU in 740 patients (451 girls and 289 boys) aged 0-19 years, we found that urinary tract infections accounted for 69.4% of the IU in females and 30.1% of the IU in males, most often seen in the youngest patients. The pathological findings most frequently seen were anomalies (17 females and 10 males) and urinary tract obstruction (3 females and 15 males). The present study indicates the following: first, that the yield of IU in the primary investigation of children and youth suffering from enuresis and non-specific abdominal disturbancies is small; and second, that the use of IU in children and youth with urinary tract infection and haematuria should be questioned and reconsidered. (orig.)

  7. Solar urticaria successfully treated with intravenous immunoglobulin.

    LENUS (Irish Health Repository)

    Hughes, R

    2012-02-01

    Idiopathic solar urticaria (SU) is a rare, debilitating photodermatosis, which may be difficult to treat. First-line treatment with antihistamines is effective in mild cases, but remission after phototherapeutic induction of tolerance is often short-lived. Other treatment options include plasma exchange, photopheresis and cyclosporin. We present two cases of severe, idiopathic SU, which were resistant to conventional treatment. Both patients achieved remission after administration of intravenous immunoglobulin (IVIg) and have remained in remission at 13 months and 4 years, respectively. There are only two case reports of successful treatment of solar urticaria with IVIg. In our experience IVIg given at a total dose of 2 g\\/kg over several 5-day courses about a month apart is an effective treatment option for severe idiopathic SU. It is also generally safe, even if certainly subject to significant theoretical risks, such as induction of viral infection or anaphylaxis.

  8. Ceftaroline fosamil: just another intravenous antibiotic.

    Science.gov (United States)

    2013-12-01

    Various antibiotics, especially cephalosporins, are used for empirical treatment of community-acquired pneumonia requiring hospitalisation and intravenous treatment, and for serious infections of the skin and soft tissues. When the infection is caused by bacteria that are resistant to common antibiotics, some antibiotics such as vancomycin are available. Ceftaroline (Zinforo, AstraZeneca) is a new cephalosporin intended for intravenous administration (as ceftaroline fosamil). It is authorised for the treatment of community-acquired pneumonia and for serious infections of the skin and soft tissues. In two double-blind, randomised trials of ceftaroline versus ceftriaxone (a cephalosporin), ceftaroline showed no advantage in patients with community-acquired pneumonia. Note that the results of these trials are undermined by the use of a suboptimal dose of ceftriaxone. Ceftaroline has not been evaluated versus a first-line treatment for serious skin infections. It has been compared with second-line antibiotics in patients with serious skin infections in four randomised trials. None of these trials showed that ceftaroline has superior efficacy. The known adverse effect profile of ceftaroline is similar to that of all cephalosporins, and comprises hypersensitivity reactions (including anaphylaxis) and gastrointestinal disorders (including rare cases of pseudomembranous colitis). A possible excess of haematological and renal adverse effects has also been raised. Given the absence of relevant data, it is best to avoid using ceftaroline during pregnancy. In practice, there is no proof that ceftaroline represents a therapeutic advance for patients with community-acquired pneumonia warranting hospitalisation or with serious skin or soft-tissue infections. It is best to stick with better-known antibiotics.

  9. Phytonadione Content in Branded Intravenous Fat Emulsions.

    Science.gov (United States)

    Forchielli, Maria Luisa; Conti, Matteo; Motta, Roberto; Puggioli, Cristina; Bersani, Germana

    2017-03-01

    Intravenous fat emulsions (IVFE) with different fatty acid compositions contain vitamin E as a by-product of vegetable and animal oil during the refining processes. Likewise, other lipid-soluble vitamins may be present in IVFE. No data, however, exist about phytonadione (vitamin K1) concentration in IVFE information leaflets. Therefore, our aim was to evaluate the phytonadione content in different IVFE. Analyses were carried out in triplicate on 6 branded IVFE as follows: 30% soybean oil (100%), 20% olive-soybean oil (80%-20%), 20% soybean-medium-chain triglycerides (MCT) coconut oil (50%-50%), 20% soybean-olive-MCT-fish oil (30%-25%-30%-15%), 20% soybean-MCT-fish oil (40%-50%-10%), and 10% pure fish oil (100%). Phytonadione was analyzed and quantified by a quali-quantitative liquid chromatography-mass spectrometry (LC-MS) method after its extraction from the IVFE by an isopropyl alcohol-hexane mixture, reverse phase-liquid chromatography, and specific multiple-reaction monitoring for phytonadione and vitamin d3 (as internal standard). This method was validated through specificity, linearity, and accuracy. Average vitamin K1 content was 500, 100, 90, 100, 95, and 70 µg/L in soybean oil, olive-soybean oil, soybean-MCT coconut oil, soybean-olive-MCT-fish oil, soybean-MCT-fish oil, and pure fish oil intravenous lipid emulsions (ILEs), respectively. The analytical LC-MS method was extremely effective in terms of specificity, linearity ( r = 0.99), and accuracy (coefficient of variation <5%). Phytonadione is present in IVFE, and its intake varies according to IVFE type and the volume administered. It can contribute to daily requirements and become clinically relevant when simultaneously infused with multivitamins during long-term parenteral nutrition. LC-MS seems adequate in assessing vitamin K1 intake in IVFE.

  10. Plasma membrane associated phospholipase C from human platelets: Synergistic stimulation of phosphatidylinositol 4,5-bisphosphate hydrolysis by thrombin and guanosine 5'-O-(3-thiotriphosphate)

    International Nuclear Information System (INIS)

    Baldassare, J.J.; Henderson, P.A.; Fisher, G.J.

    1989-01-01

    The effects of thrombin and GTPγS on the hydrolysis of phosphoinositides by membrane-associated phospholipase C (PLC) from human platelets were examined with endogenous [ 3 H]inositol-labeled membranes or with lipid vesicles containing either [ 3 H]phosphatidylinositol or [ 3 H]phosphatidylinositol 4,5-bisphosphate. GTPγS (1 μM) or thrombin (1 unit/mL) did not stimulate release of inositol trisphosphate (IP 3 ), inositol bisphosphate (IP 2 ), or inositol phosphate (IP) from [ 3 H]inositol-labeled membranes. IP 2 and IP 3 , but not IP, from [ 3 H]inositol-labeled membranes were, however, stimulated 3-fold by GTPγS (1 μM) plus thrombin (1 unit/mL). A higher concentration of GTPγS (100 μM) alone also stimulated IP 2 and IP 3 , but not IP, release. In the presence of 1 mM calcium, release of IP 2 and IP 3 was increased 6-fold over basal levels; however, formation of IP was not observed. At submicromolar calcium concentration, hydrolysis of exogenous phosphatidylinositol 4,5-bisphosphate (PIP 2 ) by platelet membrane associated PLC was also markedly enhanced by GTPγS (100 μM) or GTPγS (1 μM) plus thrombin (1 unit/mL). Under identical conditions, exogenous phosphatidylinositol (PI) was not hydrolyzed. The same substrate specificity was observed when the membrane-associated PLC was activated with 1 mM calcium. Thrombin-induced hydrolysis of PIP 2 was inhibited by treatment of the membranes with pertussis toxin or pretreatment of intact platelets with 12-O-tetradecanoyl-13-acetate (TPA) prior to preparation of membranes. Pertussis toxin did not inhibit GTPγS (100 μM) or calcium (1 mM) dependent PIP 2 breakdown, while TPA inhibited GTPγS-dependent but not calcium-dependent phospholipase C activity

  11. Transient receptor potential canonical 3 (TRPC3) mediates thrombin-induced astrocyte activation and upregulates its own expression in cortical astrocytes.

    Science.gov (United States)

    Shirakawa, Hisashi; Sakimoto, Shinya; Nakao, Kenji; Sugishita, Aiko; Konno, Masakazu; Iida, Shota; Kusano, Ayaka; Hashimoto, Emina; Nakagawa, Takayuki; Kaneko, Shuji

    2010-09-29

    Reactive astrogliosis, defined by abnormal morphology and excessive cell proliferation, is a characteristic response of astrocytes to CNS injuries, including intracerebral hemorrhage. Thrombin, a major blood-derived serine protease, leaks into the brain parenchyma upon blood-brain barrier disruption and can induce brain injury and astrogliosis. Transient receptor potential canonical (TRPC) channels, Ca(2+)-permeable, nonselective cation channels, are expressed in astrocytes and involved in Ca(2+) influx after receptor stimulation; however, their pathophysiological functions in reactive astrocytes remain unknown. We investigated the pathophysiological roles of TRPC in thrombin-activated cortical astrocytes. Application of thrombin (1 U/ml, 20 h) upregulated TRPC3 protein, which was associated with increased Ca(2+) influx after thapsigargin treatment. Pharmacological manipulations revealed that the TRPC3 upregulation was mediated by protease-activated receptor 1 (PAR-1), extracellular signal-regulated protein kinase, c-Jun NH(2)-terminal kinase, and nuclear factor-κB signaling and required de novo protein synthesis. The Ca(2+) signaling blockers BAPTA-AM, cyclopiazonic acid, and 2-aminoethoxydiphenyl borate and a selective TRPC3 inhibitor, pyrazole-3, attenuated TRPC3 upregulation, suggesting that Ca(2+) signaling through TRPC3 contributes to its increased expression. Thrombin-induced morphological changes at 3 h upregulated S100B, a marker of reactive astrocytes, at 20 h and increased astrocytic proliferation by 72 h, all of which were inhibited by Ca(2+)-signaling blockers and specific knockdown of TRPC3 using small interfering RNA. Intracortical injection of SFLLR-NH(2), a PAR-1 agonist peptide, induced proliferation of astrocytes, most of which were TRPC3 immunopositive. These results suggest that thrombin dynamically upregulates TRPC3 and that TRPC3 contributes to the pathological activation of astrocytes in part through a feedforward upregulation of its own

  12. Hydrothorax, hydromediastinum and pericardial effusion: a complication of intravenous alimentation.

    Science.gov (United States)

    Damtew, B; Lewandowski, B

    1984-01-01

    Complications secondary to intravenous alimentation are rare but potentially lethal. Massive bilateral pleural effusions and a pericardial effusion developed in a patient receiving prolonged intravenous alimentation. Severe respiratory distress and renal failure ensued. He recovered with appropriate treatment. Images Fig. 1 Fig. 2 Fig. 3 PMID:6428731

  13. Intravenous lipid emulsion and dexmedetomidine for treatment of ...

    African Journals Online (AJOL)

    All cats presented in this study, were treated with intravenous lipid emulsion (ILE) at variable dosages, and dexmedetomidine was also administered by intravenous way. No adverse reaction such as thrombophlebitis, overload circulation or others was noticed during and after administration of ILE. Dexmedetomidine was ...

  14. Clinical effect of intravenous thrombolysis combined with nicorandil ...

    African Journals Online (AJOL)

    Purpose: To evaluate the effectiveness of intravenous thrombolysis in combination with nicorandil in the treatment of acute ST-segment elevation myocardial infarction (STEMI). Methods: Patients who developed acute STEMI and underwent intravenous thrombolysis in the hospital were selected and divided into observation ...

  15. Effects of intravenous diclofenac on postoperative sore throat in ...

    African Journals Online (AJOL)

    EB

    Objective: To evaluate the effect of intravenous diclofenac sodium on the occurrence and severity of postoperative sore throat. Methods: ... Conclusion: Intravenous diclofenac sodium does not reduce the occurrence or severity of postoperative sore throat. .... 8.4% sodium bicarbonate-also a colourless liquid- was added to ...

  16. Cost-minimization of mabthera intravenous versus subcutaneous administration

    NARCIS (Netherlands)

    Bax, P.; Postma, M.J.

    2013-01-01

    Objectives: To identify and compare all costs related to preparing and administrating MabThera for the intravenous and subcutaneous formulations in Dutch hematological patients. The a priori notion is that the costs of subcutaneous MabThera injections are lower compared to intravenous infusion due

  17. Microbiological quality of some brands of intravenous fluids ...

    African Journals Online (AJOL)

    Microbiological quality of some brands of intravenous fluids produced by some pharmaceutical companies in Nigeria was investigated. Membrane filtration method was used for concentration of contaminating organisms in the intravenous fluids. Thioglycollate medium, Tryptone Soya broth, Brilliant Green Agar ...

  18. Shc adaptor proteins are key transducers of mitogenic signaling mediated by the G protein-coupled thrombin receptor

    DEFF Research Database (Denmark)

    Chen, Y; Grall, D; Salcini, A E

    1996-01-01

    The serine protease thrombin activates G protein signaling systems that lead to Ras activation and, in certain cells, proliferation. Whereas the steps leading to Ras activation by G protein-coupled receptors are not well defined, the mechanisms of Ras activation by receptor tyrosine kinases have...... kinase activation, gene induction and cell growth. From these data, we conclude that Shc represents a crucial point of convergence between signaling pathways activated by receptor tyrosine kinases and G protein-coupled receptors....... recently been elucidated biochemically and genetically. The present study was undertaken to determine whether common signaling components are used by these two distinct classes of receptors. Here we report that the adaptor protein Shc, is phosphorylated on tyrosine residues following stimulation...

  19. Label-free monitoring of DNA polymerase activity based on a thrombin-binding aptamer G-quadruplex.

    Science.gov (United States)

    Wang, Jing; Liu, Haisheng; Ma, Changbei; Wang, Jun; Zhong, Linxiu; Wu, Kefeng

    2017-04-01

    We have developed a label-free assay for the detection of DNA polymerase activity based on a thrombin-binding aptamer (TBA) G-quadruplex. In the presence of DNA polymerase, the 3'-OH termini of the hairpin substrate are immediately elongated to replace the TBA, which can be recognized quickly by the ThT dye and results in an increase of fluorescence. This method is highly sensitive with a detection limit of 0.1 U/mL. It is simple and cost-effective without any requirement of labeling with a fluorophore-quencher pair. Furthermore, the proposed method can also be applied to analyze the inhibition of DNA polymerase, which clearly indicates that the proposed method can be applied for screening of potential DNA polymerase inhibitors. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. In vitro dissolution of calcium oxalate stones with ethylenediaminetetraacetic acid and snake venom thrombin-like enzyme.

    Science.gov (United States)

    Zhou, Xiang-Jun; Zhang, Jie; Zhang, Ci; Xu, Chang-Geng

    2014-01-01

    The aim of this study was to determine the feasibility of using snake venom thrombin-like enzyme (SVTLE) and/or ethylenediaminetetraacetic acid (EDTA) to dissolve calcium oxalate stones in vitro. Seven calcium oxalate stones were incubated with various chemolytic agents [EDTA, Tris-HCl/EDTA (TE) buffer or SVTLE diluted in TE buffer]. The pH, calcium concentration, stone weight and stone surface integrity were recorded, as well as related pathological changes to bladder mucosae. Compared to all other solutions, those containing SVTLE and buffered EDTA had higher concentrations of mobilized calcium and caused significantly more stone weight loss, stone fragility and gaps in the calcium crystals. Also, there were no adverse pathological effects on rabbit bladder mucosae from any of the solutions. The data indicate that buffered EDTA and SVTLE can be used to dissolve calcium oxalate stones and, at the concentrations used here, do not damage tissue. 2013 S. Karger AG, Basel.

  1. Course of thrombin activation markers in patients implanted with Palmaz-Schatz stents: first experiences with a post-interventional anticoagulation regimen.

    Science.gov (United States)

    Haushofer, A; Halbmayer, W M; Dittel, M; Prachar, H; Mlczoch, J; Fischer, M

    1994-10-01

    Following implantation of coronary Palmaz-Schatz stents, 29 patients were anticoagulated with a combination of heparin, phenprocoumon and aspirin following a standard protocol. After removing the arterial and venous lines, post-interventional intravenous (i.v.) heparin treatment started with 1500 IU/h for patients > 80 kg and 1250 IU/h for patients < 80 kg. Heparin was monitored by the activated partial thromboplastin time (aPTT) and adjusted by increasing or reducing i.v. heparin by 250 IU/h to maintain the aPTT within the therapeutic range. Phenprocoumon therapy began the day after stent implantation (day 2) and lasted for 3 months. aPTT, Heptest, prothrombin fragment F1 and 2 (F1.2) and thrombin-antithrombin III complexes (TAT) were monitored at standard intervals for 10 days (mean monitoring time: 9.7 +/- 2.3 days). Anticoagulation was efficient with aPTT levels remaining within the therapeutic range on day 9 and the simultaneous, moderate-onset oral anticoagulation within the therapeutic range of the International Normalized Ratio (INR; 2.15-4.80) on day 8 on average, the mean INR being 2.43 +/- 0.76. On day 4, F1.2 levels were significantly higher than on the day of stenting (1.16 +/- 0.30 nmol/l vs 1.04 +/- 0.53 nmol/l; P < 0.005). F1.2 levels fell after day 5, the difference becoming significant from day 8 on (P < 0.05). F1.2 was negatively correlated with the Heptest (P < 0.05) and fell significantly as a function of the INR during phenprocoumon administration (P < 0.001). After phenprocoumon therapy was discontinued over 3 weeks, 25 patients were followed up by angiography. Despite adequate anticoagulation, mean F1.2 levels in patients showing restenosis at follow-up angiography were significantly higher (P < 0.005) than in those without restenosis. In one patient who developed subacute stent thrombosis, clotting factors were determined 20 min before stent occlusion. The levels of F1.2 and TAT were less than all other patients on this day (F1.2: 0.98 nmol

  2. Effects of recombinant human prothrombin on thrombin generation in plasma from patients with hemophilia A and B.

    Science.gov (United States)

    Hansson, K M; Gustafsson, D; Skärby, T; Frison, L; Berntorp, E

    2015-07-01

    The present study was carried out to investigate the impact of FII levels, and their increase, on the hemostatic potential in plasma from hemophilia A and B patients with and without inhibitors. Recombinant human factor (F) II (rhFII) was added ex vivo to plasma from 68 patients with hemophilia A and B, with or without inhibitors. The hemostatic potential as measured by thrombin generation (calibrated automated thrombogram [CAT]) was focused on the endogenous thrombin potential (ETP) as it has been shown to correlate with the clinical phenotype of bleeding in hemophilia patients and has also been used to guide bypassing therapy in hemophilia patients with inhibitors before elective surgery. The factor eight inhibitor bypassing agent (FEIBA(®) ) was used as a reference to the clinical situation. The study shows that rhFII concentration-dependently increased ETP by a similar magnitude in hemophilia A and B, both with and without inhibitors. Compared with FEIBA, rhFII showed a shallower concentration-response curve. In both types of hemophilia 100 mg L(-1) of rhFII roughly doubled the ETP. A corresponding response was obtained by 0.5 U mL(-1) of FEIBA. These data support the theory that FII is one of the major components responsible for the efficacy of FEIBA. The data also indicate that rhFII may be useful, alone or in combination with other coagulation factors, in some of the conditions for which FEIBA is used today, although more data are needed to substantiate this. © 2015 International Society on Thrombosis and Haemostasis.

  3. Plasmid-mediated resistance to thrombin-induced platelet microbicidal protein in staphylococci: role of the qacA locus.

    Science.gov (United States)

    Kupferwasser, L I; Skurray, R A; Brown, M H; Firth, N; Yeaman, M R; Bayer, A S

    1999-10-01

    Thrombin-induced platelet microbicidal protein 1 (tPMP-1) is a small, cationic peptide released from rabbit platelets following thrombin stimulation. In vitro resistance to this peptide among strains of Staphylococcus aureus correlates with the survival advantage of such strains at sites of endothelial damage in humans as well as in experimental endovascular infections. The mechanisms involved in the phenotypic resistance of S. aureus to tPMP-1 are not fully delineated. The plasmid-encoded staphylococcal gene qacA mediates multidrug resistance to multiple organic cations via a proton motive force-dependent efflux pump. We studied whether the qacA gene might also confer resistance to cationic tPMP-1. Staphylococcal plasmids encoding qacA were found to confer resistance to tPMP-1 in an otherwise susceptible parental strain. Deletions which removed the region containing the qacA gene in the S. aureus multiresistance plasmid pSK1 abolished tPMP-1 resistance. Resistance to tPMP-1 in the qacA-bearing strains was inoculum independent but peptide concentration dependent, with the level of resistance decreasing at higher peptide concentrations for a given inoculum. There was no apparent cross-resistance in qacA-bearing strains to other endogenous cationic antimicrobial peptides which are structurally distinct from tPMP-1, including human neutrophil defensin 1, protamine, or the staphylococcal lantibiotics pep5 and nisin. These data demonstrate that the staphylococcal multidrug resistance gene qacA also mediates in vitro resistance to cationic tPMP-1.

  4. Thrombin generation assay and transmission electron microscopy: a useful combination to study tissue factor-bearing microvesicles

    Directory of Open Access Journals (Sweden)

    Damien Gheldof

    2013-03-01

    Full Text Available Introduction. Patients with cancer have a 7- to 10-fold increased risk of developing venous thromboembolism. Circulating microvesicles could be a useful predictive biomarker for venous thromboembolism in cancer. Validated and standardised techniques that could be used to determine the complete microvesicle phenotype are required. These were two-fold: a to characterise tissue factor (TF-bearing microvesicles released by cultured breast cancer cells MDA-MB-231 by flow cytometry (FCM, transmission electron microscopy (TEM and thrombin generation assay (TGA; and b to validate the sensitivity and variability intra/inter-assay of TGA as a useful method to study the procoagulant activity (PCA of microvesicles. Methods. Cultured breast cancer cells MDA-MB-231 were incubated for 45 minutes at 37°C. Samples were then centrifuged or not at 4,500 g for 15 minutes, and cells and MVs or MV-containing supernatants were used for TEM, FCM and TGA. In activity assays, microvesicles (i.e. cell-depleted supernatants were incubated with anti-TF antibodies or with annexin V to assess the contribution of TF and phospholipids to the PCA. Alternatively, supernatants were filtered through 0.1, 0.22, 0.45 or 0.65 µm membranes and subjected to TGA. Results. The majority of the PCA was associated with microvesicles smaller than 0.1 µm, and the mean microvesicle size estimated by TEM after 10,000 g centrifugation was 121±54 nm with a majority of vesicles between 100 and 200 nm. Microvesicles derived from 5,000 MDA-MB-231cells/ml were sufficient to significantly increase the thrombin generation of normal pooled plasma. Conclusions. TEM, FCM and filtration coupled to TGA represent a useful combination to study the PCA of TF-bearing microvesicles, whatever their size. And it will be interesting to implement these techniques in patients.

  5. Immunomodulatory effects of intravenous bis-1 f(ab')(2) administration in renal-cell cancer-patients

    NARCIS (Netherlands)

    Janssen, R. A. J.; Kroesen, B. J.; Mesander, G.; Sleijfer, D. T.; The, T. Hauw; Mulder, N. H.; de Leij, L

    We report the immunomodulatory effects of an intravenous treatment with F(ab')(2) fragments of the bispecific monoclonal antibody BIS-1 during subcutaneous recombinant interleukin 2 (rIL-2) therapy of renal cell cancer (RCC) patients. BIS-1 is directed against both the CD3 antigen on T cells and the

  6. Efficacy and safety of non-intravenous midazolam for the treatment of status epilepticus in children: a Meta-analysis

    Directory of Open Access Journals (Sweden)

    Yan LIN

    2016-02-01

    Full Text Available Objective To evaluate the clinical efficacy and safety of non-intravenous midazolam for treating status epilepticus (SE in children.  Methods Taking midazolam, status epilepticus and children both in Chinese and English as search terms, retrieve in databases such as PubMed, ScienceDirect, China National Knowledge Infrastructure (CNKI, VIP and Wanfang Data, assisted by manual searching and Google Scholar, in order to collect randomized controlled trials (RCTs about non-intravenous midazolam for treating SE in children from January 2000 to January 2015. Jadad Scale was used to evaluate the quality of literatures. Meta-analysis was performed by using RevMan 5.3 software. Results There were a total of 258 records after preliminary searching, and 6 RCTs involving 766 episodes were finally included after excluding duplicate ones and those which did not meet the inclusion criteria. The results were as follows: 1 midazolam via intranasal administration was as effective as intravenous diazepam in achieving seizure control in children (RD = -0.070, 95%CI: -0.200—0.060, P = 0.290. However, non-intravenous (intranasal or buccal midazolam showed better effects on seizure control than rectal diazepam (RD = 0.170, 95% CI: 0.030—0.320; P = 0.020. 2 The mean time from arrival at hospital to cessation was not significantly different between intranasal midazolam and intravenous diazepam (SMD = -1.570, 95%CI: -3.280—0.140; P = 0.070. 3 There was no statistical difference between intranasal midazolam and intravenous diazepam for the time from giving drug to cessation (SMD = 0.240, 95%CI: -0.110—0.590; P = 0.170. 4 There was no statistical difference on the occurrence rate of adverse drug reactions between non-intravenous midazolam and intravenous or non-intravenous diazepam (RD = -0.010, 95% CI: -0.030—0.200; P = 0.500.  Conclusions Non-intravenous midazolam is safe and effective in the treatment for status epilepticus in children. However, the

  7. Cost of opioid intravenous patient-controlled analgesia: results from a hospital database analysis and literature assessment

    Directory of Open Access Journals (Sweden)

    Palmer P

    2014-06-01

    Full Text Available Pamela Palmer,1 Xiang Ji,2 Jennifer Stephens21AcelRx Pharmaceuticals, Inc., Redwood City, CA, 2Pharmerit International, Bethesda, MD, USABackground: Intravenous patient-controlled analgesia (PCA equipment and opioid cost analyses on specific procedures are lacking. This study estimates the intravenous PCA hospital cost for the first 48 postoperative hours for three inpatient surgeries.Methods: Descriptive analyses using the Premier database (2010–2012 of more than 500 US hospitals were conducted on cost (direct acquisition and indirect cost for the hospital, such as overhead, labor, pharmacy services of intravenous PCA after total knee/hip arthroplasty (TKA/THA or open abdominal surgery. Weighted average cost of equipment and opioid drug and the literature-based cost of adverse events and complications were aggregated for total costs.Results: Of 11,805,513 patients, 272,443 (2.3%, 139,275 (1.2%, and 195,062 (1.7% had TKA, THA, and abdominal surgery, respectively, with approximately 20% of orthopedic and 29% of abdominal patients having specific intravenous PCA database cost entries. Morphine (57% and hydromorphone (44% were the most frequently used PCA drugs, with a mean cost per 30 cc syringe of $16 (30 mg and $21 (6 mg, respectively. The mean number of syringes used for morphine and hydromorphone in the first 48 hours were 1.9 and 3.2 (TKA, 2.0 and 4.2 (THA, and 2.5 and 3.9 (abdominal surgery, respectively. Average costs of PCA pump, intravenous tubing set, and drug ranged from $46 to $48, from $20 to $22, and from $33 to $46, respectively. Pump, tubing, and saline required to maintain patency of the intravenous PCA catheter over 48 hours ranged from $9 to $13, from $8 to $9, and from $20 to $22, respectively. Supplemental non-PCA opioid use ranged from $56 for THA to $87 for abdominal surgery. Aggregated mean intravenous PCA equipment and opioid cost per patient were $196 (THA, $204 (TKA, and $243 (abdominal surgery. Total costs, including

  8. Potential intravenous drug interactions in intensive care

    Directory of Open Access Journals (Sweden)

    Maiara Benevides Moreira

    Full Text Available Abstract OBJECTIVE To analyze potential intravenous drug interactions, and their level of severity associated with the administration of these drugs based on the prescriptions of an intensive care unit. METHOD Quantitative study, with aretrospective exploratory design, and descriptive statistical analysis of the ICU prescriptions of a teaching hospital from March to June 2014. RESULTS The sample consisted of 319 prescriptions and subsamples of 50 prescriptions. The mean number of drugs per patient was 9.3 records, and a higher probability of drug interaction inherent to polypharmacy was evidenced. The study identified severe drug interactions, such as concomitant administration of Tramadol with selective serotonin reuptake inhibitor drugs (e.g., Metoclopramide and Fluconazole, increasing the risk of seizures due to their epileptogenic actions, as well as the simultaneous use of Ranitidine-Fentanyl®, which can lead to respiratory depression. CONCLUSION A previous mapping of prescriptions enables the characterization of the drug therapy, contributing to prevent potential drug interactions and their clinical consequences.

  9. Intravenous injection of ioxilan, iohexol and diatrizoate

    Energy Technology Data Exchange (ETDEWEB)

    Thomsen, H.S.; Dorph, S.; Mygind, T.; Sovak, M.; Nielsen, H.; Rygaard, H.; Larsen, S.; Skaarup, P.; Hemmingsen, L.; Holm, J.

    Effects of intravenous ioxilan, a new third generation non-ionic contrast medium, diatrizoate, iohexol and saline on urine profiles were compared. Albumin, glucose, sodium, phosphate, and the enzymes NAG, LDH and GGT were followed in 24 normal rats over 7 days. Diatrizoate significantly affected all profile components during the first two hours. Albuminuria was significantly greater after diatrizoate than after iohexol or ioxilan, and excretion of glucose, LDH and GGT was significantly higher than after ioxilan. Both iohexol and ioxilan increased the excretion of albumin, LDH and GGT, while iohexol also significantly increased excretion of glucose and sodium. There was a greater excretion of glucose and GGT after iohexol than after ioxilan. Saline did not induce any changes. At day 7, serum sodium, urea, creatinine, and albumin were normal for all test substances, and kidney histology revealed no difference between the groups of animals. It is thus concluded that both high osmolar ionic and low osmolar non-ionic contrast media may cause temporary glomerular and tubular dysfunction in rats. In this model, the kidney is affected most by diatrizoate, less by iohexol, and least by ioxilan.

  10. Radiation dose measurements in intravenous pyelography

    International Nuclear Information System (INIS)

    Egeblad, M.; Gottlieb, E.

    1975-01-01

    Intravenous pyelography (IVP) and micturition cystourethrography (MCU) are the standard procedures in the radiological examination of children with urinary tract infections and in the control of these children. Gonad protection against radiation is not possible in MCU, but concerning the girls partly possible in IVP. It is of major importance to know the radiation dose in these procedures, especially since the examination is often repeated in the same patients. All IVP were done by means of the usual technique including possible gonad protection. The thermoluminescence dosimeter was placed rectally in the girls and fixed on the scrota in the boys. A total of 50 children was studied. Gonad dose ranged from 140 to 200mR in the girls and from 20 to 70mR in the boys (mean values). The radiation dose in IVP is very low compared to that of MCU, and from this point of view IVP is a dose saving examination in the control of children with urinary tract infections [fr

  11. Intravenous buprenorphine and norbuprenorphine pharmacokinetics in humans

    Science.gov (United States)

    Huestis, M.A.; Cone, E.J.; Pirnay, S.O.; Umbricht, A.; Preston, K.L.

    2013-01-01

    Background Prescribed sublingual (SL) buprenorphine is sometimes diverted for intravenous (IV) abuse, but no human pharmacokinetic data are available following high-dose IV buprenorphine. Methods Plasma was collected for 72 h after administration of placebo or 2, 4, 8, 12, or 16 mg IV buprenorphine in escalating order (single-blind, double-dummy) in 5 healthy male non-dependent opioid users. Buprenorphine and its primary active metabolite, norbuprenorphine, were quantified by liquid chromatography tandem mass spectrometry with limits of quantitation of 0.1 μg/L. Results Maximum buprenorphine concentrations (mean ± SE) were detected 10 min after 2, 4, 8, 12, 16 mg IV: 19.3±1.0, 44.5±4.8, 85.2±7.7, 124.6±16.6, and 137.7±18.8 μg/L, respectively. Maximum norbuprenorphine concentrations occurred 10–15 min (3.7±0.7 μg/L) after 16 mg IV administration. Conclusions Buprenorphine concentrations increased in a significantly linear dose-dependent manner up to 12 mg IV buprenorphine. Thus, previously demonstrated pharmacodynamic ceiling effects (over 2–16 mg) are not due to pharmacokinetic adaptations within this range, although they may play a role at doses higher than 12 mg. PMID:23246635

  12. Total intravenous anesthesia: advantages for intracranial surgery.

    Science.gov (United States)

    Cole, Chad D; Gottfried, Oren N; Gupta, Dhanesh K; Couldwell, William T

    2007-11-01

    Although volatile anesthetics have been widely accepted in anesthetic management for neurosurgery, they reduce vascular resistance, resulting in increased cerebral blood flow and increased intracranial pressure (ICP). In patients with elevated ICP who undergo craniotomy, the increase in ICP during surgery from inhaled anesthetics can make the surgery more difficult, thereby increasing the risk of ischemic cerebral insults. Total intravenous anesthesia (TIVA) using propofol and analgesic drugs (remifentanil or fentanyl) and excluding simultaneous administration of any inhaled drugs is being used in patients undergoing craniotomy because of its potential to reduce ICP and ease access to the operative site. We reviewed the literature and describe our experience with TIVA, with emphasis on hemodynamic stability, effects on ICP, emergence from anesthesia, extubation times, and return of cognitive function in patients undergoing craniotomy for space-occupying lesions. TIVA with propofol is similar to inhaled anesthetics with regard to hemodynamic stability, emergence times, extubation times, early cognitive function, and adverse events. In several prospective, randomized clinical trials, evidence suggests that ICP is decreased and cerebral perfusion pressure is increased in patients receiving TIVA when compared with those receiving volatile anesthetics during elective craniotomy procedures. The impact of TIVA on ICP, brain swelling, and access to the operative site in patients with severely elevated ICP has yet to be evaluated and is the subject of a future study at our institution.

  13. Infantile Spasms Treated with Intravenous Methypredinsolone Pulse.

    Science.gov (United States)

    Hassanzadeh Rad, Afagh; Aminzadeh, Vahid

    2017-01-01

    Infantile spasms is diagnosed late even by expert pediatricians. Late diagnosis (later than 3 weeks) can have a negative effect on the long-term prognosis. We aimed to investigate infantile spasms treated with intravenous methylprednisolone pulse. In this case series study, 20 infants with infantile spasms in 17-Shahrivar Hospital, Rasht, Iran were enrolled. Drugs were administered based on Mytinger protocol that included 3 days of methylprednisolone pulse and 56 days of oral prednisolone. The control of spasms and the omission of hypsarrhythmia in infants follow-up were the primary and secondary outcomes, respectively. Remission was indicated if the caregivers mentioned no spasms or >50% decrease regarding drug initiation for at least 5 consecutive days and the electroencephalography during sleep period noted the omission of hypsarrhythmia. Eleven female (55%) and 9 male (45%) patients with the mean age of 4.95±1.39 months were enrolled. Mean rapid remission was noted as 4.41±1.50 days. Twelve patients (60%) noted early remission. seizure was controlled in 3(15%) patients completely after 24 months. Five (25%) occasional seizures were noted controlled by routine anticonvulsant drugs after 24 months and 12 (60%) no response was mentioned. Most of the patients (65%) had cryptogenic etiology for infantile spasms. Uncontrolled seizure was mentioned after initial remission. Methyl prednisolone is an appropriate drug based on easy administering, low cost, and its accessibility.

  14. Comparison of analgesic efficacy of intravenous Paracetamol and intravenous dexketoprofen trometamol in multimodal analgesia after hysterectomy.

    Science.gov (United States)

    Unal, Ciğdem; Cakan, Türkay; Baltaci, Bülent; Başar, Hülya

    2013-10-01

    [corrected] We aimed to evaluate analgesic efficacy, opioid-sparing, and opioid-related adverse effects of intravenous paracetamol and intravenous dexketoprofen trometamol in combination with iv morphine after total abdominal hysterectomy. Sixty American Society of Anesthesiologist Physical Status Classification I-II patients scheduled for total abdominal hysterectomy were enrolled to this double-blinded, randomized, placebo controlled, and prospective study. Patients were divided into three groups as paracetamol, dexketoprofen trometamol, and placebo (0.9% NaCl) due to their post-operative analgesic usage. Intravenous patient controlled analgesia morphine was used as a rescue analgesic in all groups. Pain scores, hemodynamic parameters, morphine consumption, patient satisfaction, and side-effects were evaluated. Visual Analog Scale (VAS) scores were not statistically significantly different among the groups in all evaluation times, but decrease in VAS scores was statistically significant after the evaluation at 12(th) h in all groups. Total morphine consumption (morphine concentration = 0.2 mg/ml) in group paracetamol (72.3 ± 38.0 ml) and dexketoprofen trometamol (69.3 ± 24.1 ml) was significantly lower than group placebo (129.3 ± 22.6 ml) (P dexketoprofen trometamol after surgery and the increase in global satisfaction score was significant only in group placebo. Dexketoprofen trometamol and Paracetamol didn't cause significant change on pain scores, but increased patients' comfort. Although total morphine consumption was significantly decreased by both drugs, the incidence of nausea and vomiting were similar among the groups. According to results of the present study routine addition of dexketoprofen trometamol and paracetamol to patient controlled analgesia morphine after hysterectomies is not recommended.

  15. Comparison of analgesic efficacy of intravenous Paracetamol and intravenous dexketoprofen trometamol in multimodal analgesia after hysterectomy

    Directory of Open Access Journals (Sweden)

    Çiğdem Ünal

    2013-01-01

    Full Text Available Backround: We aimed to evaluate analgesic efficacy, opioid-sparing, and opioid-related adverse effects of intravenous paracetamol and intravenous dexketoprofen trometamol in combination with iv morphine after total abdominal hysterectomy. Materials and Methods: Sixty American Society of Anesthesiologist Physical Status Classification I-II patients scheduled for total abdominal hysterectomy were enrolled to this double-blinded, randomized, placebo controlled, and prospective study. Patients were divided into three groups as paracetamol, dexketoprofen trometamol, and placebo (0.9% NaCl due to their post-operative analgesic usage. Intravenous patient controlled analgesia morphine was used as a rescue analgesic in all groups. Pain scores, hemodynamic parameters, morphine consumption, patient satisfaction, and side-effects were evaluated. Results: Visual Analog Scale (VAS scores were not statistically significantly different among the groups in all evaluation times, but decrease in VAS scores was statistically significant after the evaluation at 12 th h in all groups. Total morphine consumption (morphine concentration = 0.2 mg/ml in group paracetamol (72.3 ± 38.0 ml and dexketoprofen trometamol (69.3 ± 24.1 ml was significantly lower than group placebo (129.3 ± 22.6 ml (P < 0.001. Global satisfaction scores of the patients in group placebo was significantly lower than group dexketoprofen trometamol after surgery and the increase in global satisfaction score was significant only in group placebo. Conclusion: Dexketoprofen trometamol and Paracetamol didn′t cause significant change on pain scores, but increased patients′ comfort. Although total morphine consumption was significantly decreased by both drugs, the incidence of nausea and vomiting were similar among the groups. According to results of the present study routine addition of dexketoprofen trometamol and paracetamol to patient controlled analgesia morphine after hysterectomies is not

  16. Contribution of thrombin-reactive brain pericytes to blood-brain barrier dysfunction in an in vivo mouse model of obesity-associated diabetes and an in vitro rat model.

    Directory of Open Access Journals (Sweden)

    Takashi Machida

    Full Text Available Diabetic complications are characterized by the dysfunction of pericytes located around microvascular endothelial cells. The blood-brain barrier (BBB exhibits hyperpermeability with progression of diabetes. Therefore, brain pericytes at the BBB may be involved in diabetic complications of the central nervous system (CNS. We hypothesized that brain pericytes respond to increased brain thrombin levels in diabetes, leading to BBB dysfunction and diabetic CNS complications. Mice were fed a high-fat diet (HFD for 2 or 8 weeks to induce obesity. Transport of i.v.-administered sodium fluorescein and 125I-thrombin across the BBB were measured. We evaluated brain endothelial permeability and expression of tight junction proteins in the presence of thrombin-treated brain pericytes using a BBB model of co-cultured rat brain endothelial cells and pericytes. Mice fed a HFD for 8 weeks showed both increased weight gain and impaired glucose tolerance. In parallel, the brain influx rate of sodium fluorescein was significantly greater than that in mice fed a normal diet. HFD feeding inhibited the decline in brain thrombin levels occurring during 6 weeks of feeding. In the HFD fed mice, plasma thrombin levels were significantly increased, by up to 22%. 125I-thrombin was transported across the BBB in normal mice after i.v. injection, with uptake further enhanced by co-injection of unlabeled thrombin. Thrombin-treated brain pericytes increased brain endothelial permeability and caused decreased expression of zona occludens-1 (ZO-1 and occludin and morphological disorganization of ZO-1. Thrombin also increased mRNA expression of interleukin-1β and 6 and tumor necrosis factor-α in brain pericytes. Thrombin can be transported from circulating blood through the BBB, maintaining constant levels in the brain, where it can stimulate pericytes to induce BBB dysfunction. Thus, the brain pericyte-thrombin interaction may play a key role in causing BBB dysfunction in

  17. [Determination of fibrinogen content in human blood plasma using thrombin-like enzyme of ancistron N and analysis of hemostasis under presence of blood coagulation inhibitors].

    Science.gov (United States)

    Platonova, T N; Sushko, O O; Colovĭov, D O; Iena, Ia M

    1993-01-01

    The cases of non-coagulation or only partial coagulation of blood plasma fibrinogen under the effect of thrombin have been revealed while examining the homeostasis-state in practically healthy elderly and old people and those with hypertonic disease. These cases have been analyzed. It is shown that the suggested method of fibrinogen determination in blood plasma using thrombin-like enzyme ancistrone-H extracted from venom of snakes (Agkistrodon halys halys) permits determining the fibrinogen content in blood plasma even in the cases connected with the presence of circulating coagulation inhibitors in plasma. The determination is not hindered by the introduction of exogenous heparin, including low-molecular heparins of the fraxiparin type.

  18. Characterization of immunoglobulin G fragments in liquid intravenous immunoglobulin products

    NARCIS (Netherlands)

    Diemel, Robert V.; ter Hart, Hendricus G. J.; Derksen, Gerardus J. A.; Koenderman, Anky H. L.; Aalberse, Rob C.

    2005-01-01

    Intravenous immunoglobulin (IVIG) products formulated as a liquid instead of a powder have become commercially available. Preferably, such liquid products should not alter after storage outside the refrigerator. Therefore, a thorough characterization of immunoglobulin G (IgG) fragmentation at

  19. Outcomes of cancer surgery after inhalational and intravenous anesthesia

    DEFF Research Database (Denmark)

    Soltanizadeh, Sinor; Degett, Thea H; Gögenur, Ismail

    2017-01-01

    Perioperative factors are probably essential for different oncological outcomes. This systematic review investigates the literature concerning overall mortality and postoperative complications after cancer surgery with inhalational (INHA) and intravenous anesthesia (TIVA). A search was conducted...

  20. Methods of preparing and using intravenous nutrient compositions

    International Nuclear Information System (INIS)

    Beigler, M.A.; Koury, A.J.

    1983-01-01

    A method for preparing a stable, dry-packaged, sterile, nutrient composition which upon addition of sterile, pyrogen-free water is suitable for intravenous administration to a mammal, including a human, is described. The method comprises providing the nutrients in a specific dry form and state of physical purity acceptable for intravenous administration, sealing the nutrients in a particular type of container adapted to receive and dispense sterile fluids and subjecting the container and its sealed contents to a sterilizing, nondestructive dose of ionizing radiation. The method results in a packaged, sterile nutrient composition which may be dissolved by the addition of sterile pyrogen-free water. The resulting aqueous intravenous solution may be safely administered to a mammal in need of nutrient therapy. The packaged nutrient compositions of the invention exhibit greatly extended storage life and provide an economical method of providing intravenous solutions which are safe and efficacious for use. (author)

  1. Portable Intravenous Fluid Production Device for Ground Use

    Data.gov (United States)

    National Aeronautics and Space Administration — There are several medical conditions require the administration of intravenous (IV) fluids, but limitations of mass, volume, shelf-life, transportation, and local...

  2. Distinct in vitro Complement Activation by Various Intravenous Iron Preparations

    NARCIS (Netherlands)

    Hempel, Julia Cordelia; Poppelaars, Felix; da Costa, Mariana Gaya; Franssen, Casper F. M.; de Vlaam, Thomas P G; Daha, Mohamed R.; Berger, Stefan P.; Seelen, Marc A. J.; Gaillard, Carlo A. J. M.

    2017-01-01

    Background: Intravenous (IV) iron preparations are widely used in the treatment of anemia in patients undergoing hemodialysis (HD). All IV iron preparations carry a risk of causing hypersensitivity reactions. However, the pathophysiological mechanism is poorly understood. We hypothesize that a

  3. Intravenous glutathione for skin lightening: Inadequate safety data ...

    African Journals Online (AJOL)

    protein thiol that protects mammalian cells from oxidative stress. Intravenous (IV) GSH for skin lightening is advertised by clinics in South Africa and internationally online, yet to date no published review on the subject exists. Methods.

  4. Glucagon in intravenous cholangiography - an experimental study on dogs

    International Nuclear Information System (INIS)

    Toetterman, S.; Santavirta, S.; Antila, H.

    1980-01-01

    The present study reports on the effect of glucagon on the excretion of ioglycamate in experimental intravenous cholangiography on dogs. Glucagon increased the bile flow rate highly significantly (p [de

  5. Ultrasound Guidance as a Rescue Technique for Peripheral Intravenous Cannulation

    National Research Council Canada - National Science Library

    Pappas, Nancy L; Michaud, Terese E; Wolbers, Russell M; Steward, James C; Fevurly, Thomas A; Samolitis, Timothy J; Shoneboom, Bruce A; Watts, Dorraine D

    2006-01-01

    Peripheral intravenous (W) cannulation can be difficult to perform using the traditional landmark or visual/palpation technique in patients with access difficulties such as deep, sclerotic, small, or fragile veins...

  6. Plasma kinetics of intravenously administered lactose- in-saline in ...

    African Journals Online (AJOL)

    USER

    2010-05-17

    ) the rapid sequestration of homologous desialylated erythrocytes from the blood stream of rabbits has been considerably inhibited by intravenously administered lactose (Muller et al., 1981). More recently, infusion of lactose ...

  7. Structural dynamics of thrombin-binding DNA aptamer d(GGTTGGTGTGGTTGG) quadruplex DNA studied by large-scale explicit solvent simulations

    Czech Academy of Sciences Publication Activity Database

    Reshetnikov, R.; Golovin, A.; Spiridonova, V.; Kopylov, A.; Šponer, Jiří

    2010-01-01

    Roč. 6, č. 10 (2010), s. 3003-3014 ISSN 1549-9618 R&D Projects: GA AV ČR(CZ) IAA400040802; GA ČR(CZ) GA203/09/1476; GA MŠk(CZ) LC06030 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : molecular dynamics * quadruplex DNA * thrombin Subject RIV: BO - Biophysics Impact factor: 5.138, year: 2010

  8. An evaluation of platelet-rich plasma without thrombin activation with or without anorganic bone mineral in the treatment of human periodontal intrabony defects.

    Science.gov (United States)

    Rodrigues, Silvia V; Acharya, Anirudh B; Thakur, Srinath L

    2011-01-01

    The efficacy of platelet-rich plasma (PRP) in periodontal regeneration is not well understood and the definite clinical viability of blood derived platelets lacks clarity. Also, the use of thrombin for platelet activation is disputed. Hence, the purpose of this study was to evaluate the efficacy of blood derived platelets without thrombin activation, alone or in combination with bovine anorganic bone mineral (ABM), in the treatment of human periodontal intrabony defects. PRP was prepared using a simple tabletop centrifuge and activated using calcium chloride without the addition of thrombin. This PRP was used alone (in Group A) and in combination with bovine ABM (in Group B) in the treatment of human periodontal angular defects. Both the control and the test groups showed definite improvement in clinical parameters. On comparison, however, there was a statistically significant improvement in the probing pocket depths and relative attachment level in Group B over Group A at 3 and 6 months intervals, whereas at the end of 9 months this difference was not statistically significant. There was no statistically significant difference between the groups with respect to the relative defect depth. Within the limitations of this study and the type of PRP used, i.e. without thrombin mediated activation, it can be concluded that both PRP and PRP combined with bovine ABM results in significant clinical improvement. Albeit statistically insignificant, there is a preponderance of better clinical results with the addition of ABM to PRP. Further studies need to be carried out on a larger sample size to confirm the results of the present study.

  9. Does a thrombin-based topical haemostatic agent reduce blood loss and transfusion requirements after total knee revision surgery? A randomized, controlled trial.

    Science.gov (United States)

    Romanò, Carlo L; Monti, Lorenzo; Logoluso, Nicola; Romanò, Delia; Drago, Lorenzo

    2015-11-01

    The aim of the present study was to assess the efficacy of a thrombin-based topical haemostatic in reducing blood requirements after total knee replacement (TKR) revision surgery. This prospective, randomized, controlled study was designed to evaluate the haemostatic efficacy and safety of a thrombin-based topical haemostatic (Floseal) versus standard treatment in patients receiving total knee revision arthroplasty. The decrease in haemoglobin values postsurgery and the blood units transfused were recorded. The decision to transfuse was made by a surgeon blinded to the patient's group allocation. Forty-eight patients were enroled in the study; twenty-four patients each were randomized to the treatment and control groups, respectively. The median decrease in haemoglobin concentration on the first postoperative day was 2.2 g/dL in the treatment group and 2.7 g/dL in the control group. A significant reduction in units of blood transfused was also observed in the treatment group compared with the control group [1.1 ± 1.13 (range 0-4) vs. 1.9 ± 1.41 (range 0-5) blood units; P = 0.04]. No major treatment-related adverse events were recorded in the study. This study shows that a thrombin-based topical haemostatic reduces the need for blood transfusion in TKR revision surgery. A thrombin-based topical haemostatic agent can be an appropriate solution to enhance haemostasis and vessel sealing at the operative site in TKR revision surgery, in order to reduce the need for blood transfusion after surgery. II.

  10. The ATP-gated P2X1 receptor plays a pivotal role in activation of aspirin-treated platelets by thrombin and epinephrine.

    Science.gov (United States)

    Grenegård, Magnus; Vretenbrant-Oberg, Karin; Nylander, Martina; Désilets, Stéphanie; Lindström, Eva G; Larsson, Anders; Ramström, Ida; Ramström, Sofia; Lindahl, Tomas L

    2008-07-04

    Human platelets express protease-activated receptor 1 (PAR1) and PAR4 but limited data indicate for differences in signal transduction. We studied the involvement of PAR1 and PAR4 in the cross-talk between thrombin and epinephrine. The results show that epinephrine acted via alpha(2A)-adrenergic receptors to provoke aggregation, secretion, and Ca(2+) mobilization in aspirin-treated platelets pre-stimulated with subthreshold concentrations of thrombin. Incubating platelets with antibodies against PAR4 or the PAR4-specific inhibitor pepducin P4pal-i1 abolished the aggregation. Furthermore, platelets pre-exposed to the PAR4-activating peptide AYPGKF, but not to the PAR1-activating peptide SFLLRN, were aggregated by epinephrine, whereas both AYPGKF and SFLLRN synergized with epinephrine in the absence of aspirin. The roles of released ATP and ADP were elucidated by using antagonists of the purinergic receptors P2X(1), P2Y(1), and P2Y(12) (i.e. NF449, MRS2159, MRS2179, and cangrelor). Intriguingly, ATP, but not ADP, was required for the epinephrine/thrombin-induced aggregation. In Western blot analysis, a low concentration of AYPGKF, but not SFLLRN, stimulated phosphorylation of Akt on serine 473. Moreover, the phosphatidyl inositide 3-kinase inhibitor LY294002 antagonized the effect of epinephrine combined with thrombin or AYPGKF. Thus, in aspirin-treated platelets, PAR4, but not PAR1, interacts synergistically with alpha(2A)-adrenergic receptors, and the PI3-kinase/Akt pathway is involved in this cross-talk. Furthermore, in PAR4-pretreated platelets, epinephrine caused dense granule secretion, and subsequent signaling from the ATP-gated P2X(1)-receptor and the alpha(2A)-adrenergic receptor induced aggregation. These results suggest a new mechanism that has ATP as a key element and circumvents the action of aspirin on epinephrine-facilitated PAR4-mediated platelet activation.

  11. Advances in the use of intravenous techniques in ambulatory anesthesia

    Directory of Open Access Journals (Sweden)

    Eng MR

    2015-07-01

    Full Text Available Matthew R Eng,1 Paul F White1,2 1Department of Anesthesiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA; 2White Mountain Institute, The Sea Ranch, CA, USA Summary statement: Advances in the use of intravenous techniques in ambulatory anesthesia has become important for the anesthesiologist as the key perioperative physician in outpatient surgery. Key techniques and choices of anesthetics are important in accomplishing fast track goals of ambulatory surgery. Purpose of review: The anesthesiologist in the outpatient environment must focus on improving perioperative efficiency and reducing recovery times while accounting for patients' well-being and safety. This review article focuses on recent intravenous anesthetic techniques to accomplish these goals. Recent findings: This review is an overview of techniques in intravenous anesthesia for ambulatory anesthesia. Intravenous techniques may be tailored to accomplish outpatient surgery goals for the type of surgical procedure and individual patient needs. Careful anesthetic planning and the application of the plans are critical to an anesthesiologist's success with fast-track ambulatory surgery. Conclusion: Careful planning and application of intravenous techniques are critical to an anesthesiologist's success with fast-track ambulatory surgery. Keywords: intravenous anesthesia, outpatient anesthesia, fast-track surgery

  12. Potential intravenous drug interactions in intensive care.

    Science.gov (United States)

    Moreira, Maiara Benevides; Mesquita, Maria Gefé da Rosa; Stipp, Marluci Andrade Conceição; Paes, Graciele Oroski

    2017-07-20

    To analyze potential intravenous drug interactions, and their level of severity associated with the administration of these drugs based on the prescriptions of an intensive care unit. Quantitative study, with aretrospective exploratory design, and descriptive statistical analysis of the ICU prescriptions of a teaching hospital from March to June 2014. The sample consisted of 319 prescriptions and subsamples of 50 prescriptions. The mean number of drugs per patient was 9.3 records, and a higher probability of drug interaction inherent to polypharmacy was evidenced. The study identified severe drug interactions, such as concomitant administration of Tramadol with selective serotonin reuptake inhibitor drugs (e.g., Metoclopramide and Fluconazole), increasing the risk of seizures due to their epileptogenic actions, as well as the simultaneous use of Ranitidine-Fentanyl®, which can lead to respiratory depression. A previous mapping of prescriptions enables the characterization of the drug therapy, contributing to prevent potential drug interactions and their clinical consequences. Analisar as potenciais interações medicamentosas intravenosas e seu grau de severidade associadas à administração desses medicamentos a partir das prescrições do Centro de Terapia Intensiva. Estudo quantitativo, tipologia retrospectiva exploratória, com análise estatística descritiva das prescrições medicamentosas do Centro de Terapia Intensiva de um Hospital Universitário, no período de março-junho/2014. A amostra foi composta de 319 prescrições e subamostras de 50 prescrições. Constatou-se que a média de medicamentos por paciente foi de 9,3 registros, e evidenciou-se maior probabilidade para ocorrência de interação medicamentosa inerente à polifarmácia. O estudo identificou interações medicamentosas graves, como a administração concomitante de Tramadol com medicamentos inibidores seletivos da recaptação da serotonina, (exemplo: Metoclopramida e Fluconazol

  13. Thrombin activatable fibrinolysis inhibitor (TAFI) - A possible link between coagulation and complement activation in the antiphospholipid syndrome (APS).

    Science.gov (United States)

    Grosso, Giorgia; Vikerfors, Anna; Woodhams, Barry; Adam, Mariette; Bremme, Katarina; Holmström, Margareta; Ågren, Anna; Eelde, Anna; Bruzelius, Maria; Svenungsson, Elisabet; Antovic, Aleksandra

    2017-10-01

    Thrombosis and complement activation are pathogenic features of antiphospholipid syndrome (APS). Their molecular link is Plasma carboxypeptidase-B, also known as thrombin activatable fibrinolysis inhibitor (TAFIa), which plays a dual role: anti-fibrinolytic, by cleaving carboxyl-terminal lysine residues from partially degraded fibrin, and anti-inflammatory, by downregulating complement anaphylatoxins C3a and C5a. To investigate the levels of TAFI (proenzyme) and TAFIa (active enzyme) in relation to complement activation, fibrin clot permeability and fibrinolytic function in clinical and immunological subsets of 52 APS patients and 15 controls. TAFI (pAPS patients compared to controls. Furthermore, TAFIa was increased (pAPS patients affected by arterial thrombosis compared to other APS-phenotypes. Positive associations were found between TAFI and age, fibrinogen and C5a, and between TAFIa and age, fibrinogen and thrombomodulin. TAFI and TAFIa levels were increased in patients with APS as a potential response to complement activation. Interestingly, TAFI activation was associated with arterial thrombotic APS manifestations. Thus, TAFIa may be considered a novel biomarker for arterial thrombosis in APS. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Isolation and Biochemical Characterization of a New Thrombin-Like Serine Protease from Bothrops pirajai Snake Venom

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    Kayena D. Zaqueo

    2014-01-01

    Full Text Available This paper presents a novel serine protease (SP isolated from Bothrops pirajai, a venomous snake found solely in Brazil that belongs to the Viperidae family. The identified SP, named BpirSP-39, was isolated by three chromatographic steps (size exclusion, bioaffinity, and reverse phase chromatographies. The molecular mass of BpirSP-39 was estimated by SDS-PAGE and confirmed by mass spectrometry (39,408.32 Da. The protein was able to form fibrin networks, which was not observed in the presence of serine protease inhibitors, such as phenylmethylsulfonyl fluoride (PMSF. Furthermore, BpirSP-39 presented considerable thermal stability and was apparently able to activate factor XIII of the blood coagulation cascade, unlike most serine proteases. BpirSP-39 was capable of hydrolyzing different chromogenic substrates tested (S-2222, S-2302, and S-2238 while Cu2+ significantly diminished BspirSP-39 activity on the three tested substrates. The enzyme promoted platelet aggregation and also exhibited fibrinogenolytic, fibrinolytic, gelatinolytic, and amidolytic activities. The multiple alignment showed high sequence similarity to other thrombin-like enzymes from snake venoms. These results allow us to conclude that a new SP was isolated from Bothrops pirajai snake venom.

  15. Thrombin activatable fibrinolysis inhibitor and clot lysis time in pregnant patients with antiphospholipid syndrome: relationship with pregnancy outcome and thrombosis.

    Science.gov (United States)

    Martinez-Zamora, Maria Angeles; Tassies, Dolors; Carmona, Francisco; Espinosa, Gerard; Cervera, Ricard; Reverter, Juan Carlos; Balasch, Juan

    2009-12-01

    Antiphospholipid syndrome (APS) pregnancies are associated with thrombotic obstetric complications, despite treatment. This study evaluated Thrombin Activatable Fibrinolysis Inhibitor (TAFI) levels, TAFI gene polymorphisms and Clot Lysis Time (CLT) in pregnant patients with APS in relation to pregnancy outcome and thrombosis. Group 1 consisted of 67 pregnant patients with APS. Group 2 included 66 pregnant patients with uneventful term pregnancies and delivery. Patients were sampled during each trimester and at baseline. TAFI antigen and CLT and two polymorphisms of the TAFI gene, Ala147Thr and +1542C/G, were determined. Significantly prolonged CLT was found at baseline in Group 1. Allele distribution of the TAFI gene polymorphisms was similar in both groups. Basal TAFI and CLT in patients with APS having an adverse or a good obstetrical outcome were similar. Comparison of TAFI and CLT baseline levels in patients with APS with or without previous thrombosis showed no statistical differences. Patients with APS have impairment in fibrinolysis evidenced by prolonged CLT at baseline. TAFI and CLT do not seem to be useful as markers of obstetric outcome or risk of thrombosis in patients with APS.

  16. Characterization of a thrombin cleavage site mutation (Arg 1689 to Cys) in the factor VIII gene of two unrelated patients with cross-reacting material-positive hemophilia A.

    Science.gov (United States)

    Arai, M; Higuchi, M; Antonarakis, S E; Kazazian, H H; Phillips, J A; Janco, R L; Hoyer, L W

    1990-01-15

    The molecular defect responsible for moderate and severe hemophilia A has been identified for two unrelated patients with the CRM-positive form of this disorder (factor VIII activity of 0.02 and 0.05 U/mL with factor VIII antigen of 0.87 and 2.20 U/mL). In both cases, the immunopurified dysfunctional factor VIII protein is abnormal, in that the 80 Kd light chain is not cleaved by thrombin at arginine-1689. The basis for this failure was identified by polymerase chain reaction amplification of exon 14 of the variant factor VIII genes and direct sequencing of the amplified products. In both cases, a single base substitution (C to T) was identified that produces an arginine to cysteine substitution at amino acid residue 1689. These data identify the molecular defects of the two identical factor VIII variant proteins. The dysfunctional factor VIII has been designated "Factor VIII-East Hartford," the residence of the patient in whom the defect was first identified.

  17. Intravenous fluids: should we go with the flow?

    Science.gov (United States)

    Kozek-Langenecker, Sibylle A

    2015-01-01

    Sensitive monitoring should be used when prescribing intravenous fluids for volume resuscitation. The extent and duration of tissue hypoperfusion determine the severity of cellular damage, which should be kept to a minimum with timely volume substitution. Optimizing the filling status to normovolaemia may boost the resuscitation success. Macrocirculatory pressure values are not sensitive in this indication. While the Surviving Sepsis Campaign guidelines focus on these conventional pressure parameters, the guidelines from the European Society of Anaesthesiology (ESA) on perioperative bleeding management recommend individualized care by monitoring the actual volume status and correcting hypovolaemia promptly if present. The motto is: 'give what is missing'. The credo of the ESA guidelines is to use management algorithms with predefined intervention triggers. Stop signals should help in avoiding hyper-resuscitation. The high-quality evidence-based S3 guidelines on volume therapy in adults have recently been prepared by 14 German scientific societies. Statements include, for example, repeated clinical inspection including turgor of the skin and mucosa. Adjunctive laboratory parameters such as central venous oxygen saturation, lactate, base excess and haematocrit should be considered. The S3 guidelines propose the use of flow-based and/or dynamic preload parameters for guiding volume therapy. Fluid challenges and/or the leg-raising test (autotransfusion) should be performed. The statement from the Co-ordination group for Mutual Recognition and Decentralized Procedures-Human informs healthcare professionals to consider applying individualized medicine and using sensitive monitoring to assess hypovolaemia. The authorities encourage a personalized goal-directed volume resuscitation technique.

  18. Morbimortality associated with intravenous boarding in very ill pediatrics’ patients

    Directory of Open Access Journals (Sweden)

    Darelys Baños Sánchez

    2018-05-01

    Full Text Available The insertion of intravenous catheters has converted itself in an indispensable procedure in Pediatric Intensive Care Units. The objective is caracterizing the morbimortality associated with intravenous boarding in very ill pediatrics’ patients. Descriptive, longitudinal prospective study, during 2016, in the Intensive Care Unit of the Pepe Portilla Pediatric Hospital, Pinar of the Río, The Universe: It got constituted for 182 patients admitted in the period of study and they required intravenous boarding. The information got from patient's charts and the unit's record of continuous morbility itself, and it was processed with SPSS statistical parcel for Windows, the test of hypothesis of proportions and the percentages were utilized. The intravenous boarding was accomplished to the 51.12% of the admitted patients, 31.46% for femoral road and 60.83% to patients under one year old. Principal use was the administration of medications (100%, the 56.59% had the boarding over 10 days, the 12.08% of patients presented complications, infection was more frequent. The conclusions are high incidence of the application of intravenous boarding exists; infection for catheter is the correlated complication more frequent.

  19. Utilization of a biomedical device (VeinViewer® ) to assist with peripheral intravenous catheter (PIV) insertion for pediatric nurses.

    Science.gov (United States)

    McNeely, Heidi L; Ream, Theresa L; Thrasher, Jodi M; Dziadkowiec, Oliwier; Callahan, Tiffany J

    2018-04-01

    Vascular access in pediatric patients can be challenging even with the currently available technological resources. This nurse-driven research study explored time, cost, and resources for intravenous access to determine if a biomedical device, VeinViewer ® Vision, would facilitate improvements in pediatric access. In addition, this study looked at nurse perceptions of skills and confidence around intravenous insertion and if the use of the VeinViewer ® impacted these perceptions. Literature examining pediatric intravenous access success rates compared with nurse perceived skills and confidence is lacking. Nonblinded randomized control trial of pediatric nurses working in an acute care hospital setting. A preliminary needs assessment solicited feedback from nurses regarding their practice, perceived skills, and confidence with placing peripheral intravenous catheters (PIVs). Due to the results of the preliminary needs assessment, a research study was designed and 40 nurses were recruited to participate. The nurses were randomized into either a VeinViewer ® or standard practice group. Nurse participants placed intravenous catheters on hospitalized pediatric patients using established procedures while tracking data for the study. Needs assessment showed a majority of nurses felt a biomedical device would be helpful in building their intravenous insertion skills and their confidence. The study results did not demonstrate any clinically significant differences between VeinViewer ® use and standard practice for intravenous catheter insertion in pediatric patients for success of placement, number of attempts, or overall cost. In addition, no difference was noted between nurses in either group on perceived skills or confidence with insertion of PIVs. The ongoing need for resources focused on building nurse skills and confidence for PIV insertion was highlighted and organizations should continue to direct efforts toward developing skills and competency for staff that

  20. Efficacy and safety of intravenous fentanyl administered by ambulance personnel

    DEFF Research Database (Denmark)

    Friesgaard, Kristian Dahl; Nikolajsen, Lone; Giebner, Matthias

    2016-01-01

    BACKGROUND: Management of pain in the pre-hospital setting is often inadequate. In 2011, ambulance personnel were authorized to administer intravenous fentanyl in the Central Denmark Region. The aim of this study was to evaluate the efficacy and safety of intravenous fentanyl administered...... by ambulance personnel. METHODS: Pre-hospital medical charts from 2348 adults treated with intravenous fentanyl by ambulance personnel during a 6-month period were reviewed. The primary outcome was the change in pain intensity on a numeric rating scale (NRS) from before fentanyl treatment to hospital arrival....... Secondary outcomes included the number of patients with reduction in pain intensity during transport (NRS ≥ 2), the number of patients with NRS > 3 at hospital arrival, and potential fentanyl-related side effects. RESULTS: Fentanyl reduced pain from before treatment (8, IQR 7-9) to hospital arrival (4, IQR...

  1. Acute Forefoot Phlegmon - A Complication of Intravenous Heroin-Addiction.

    Science.gov (United States)

    Wollina, Uwe; Lotti, Torello; Tchernev, Georgi

    2018-01-25

    Infections of the skin and soft tissues (SSTI) are clinical entities with variable presentations, causes, and levels of clinical severity. They are frequent in emergency departments. The most common pathogen in the Western World is Staphylococcus aureus . SSTI may provide a hint to underlying pathologies such as diabetes and other states of immune compromise. Here we present a 41-year-old non-diabetic male patient with pain and swelling of the left forefoot but not any recent trauma. Microbiology identified streptococci. The medical history was positive for intravenous heroin abuse. The diagnosis of forefoot phlegm due to drug addition was confirmed. Treatment was realised by a combination of intravenous antibiosis and drainage. Intravenous drug addiction is a significant risk factor for SSTI.

  2. An ischemic diabetic eye treated with intravenous prostaglandin E1.

    Science.gov (United States)

    Steigerwalt, Robert D; Belcaro, Gianni; Nebbioso, Marcella; Pascarella, Antonella; De Angelis, Mauro; Cesarone, M Rosaria

    2014-01-01

    To present the use of intravenous prostaglandin E1 (PGE1), a powerful vasodilator of the microcirculation, in the treatment of an ischemic diabetic eye. A 27-year-old diabetic man with ischemic diabetic retinopathy and glaucoma had a decreased visual acuity of no light perception in his right eye and hand motions in his left eye. He was started on intravenous PGE1 and has been treated for over 4.5 years. The visual acuity in his right eye remained unchanged and in his left eye improved gradually to 1.5/30. He has been stable for 4.5 years. Intravenous PGE1 may be useful in ischemic diabetic eyes to improve the ocular blood flow and visual acuity. It is safe and tolerated well.

  3. Intravenous methylprednisolone pulse therapy for children with epileptic encephalopathy.

    Science.gov (United States)

    Pera, Maria Carmela; Randazzo, Giovanna; Masnada, Silvia; Dontin, Serena Donetti; De Giorgis, Valentina; Balottin, Umberto; Veggiotti, Pierangelo

    2015-01-01

    The aim of this retrospective study of children affected by epileptic encephalopathy was to evaluate seizure frequency, electroencephalographic pattern and neuropsychological status, before and after intravenous methylprednisolone therapy. Eleven children with epileptic encephalopathy were administered one cycle of intravenous methylprednisolone (15-30 mg/kg/day for three consecutive days, once a month for four months) in addition to constant dosages of their regular antiepileptic drugs. The treatment resulted in statistically significant reductions of generalized slow spike-and-wave discharges (ptreatment regimen did not cause significant or persistent adverse effects. We suggest that children with epileptic encephalopathy without an underlying structural lesion could be the best candidates for intravenous methylprednisolone pulse therapy.

  4. Clinical Applications of Intravenous Immunoglobulins in Child Neurology.

    Science.gov (United States)

    Gogou, Maria; Papadopoulou-Alataki, Efimia; Spilioti, Martha; Alataki, Sofia; Evangeliou, Athanasios

    2017-11-10

    While there are guidelines for the use of intravenous immunoglobulins in children with Guillain-Barre syndrome and myasthenia gravis based on high-level evidence studies, data are scarce for the majority of neurologic disorders in this age group. Neuronal antibodies are detected in children with seizures of autoimmune etiology. Intravenous immunoglobulins with their broad immunomodulatory mechanism of action could be ideally effective in different forms of immunedysregulated intractable epilepsies such as autoimmune epilepsy and autoimmune Rasmussen encephalitis. We conducted a systematic review of the literature for evidence of the use of intravenous immunoglobulins in a variety of neurologic diseases in childhood. A comprehensive literature search was conducted using Pubmed as the medical database source without date range. Prospective studies in pediatric groups including objective measures of clinical outcomes were systematically selected. A total of 11 prospective studies were identified in the literature demonstrating a favorable effect of this therapeutic option in children with drug-resistant epilepsy and in cases of encephalitis. No serious adverse effects were reported. No prospective studies about the use of intravenous immunoglobulins in children with demyelinating disorders or neurologic paraneoplasmatic syndromes were found. In this review, we summarize the recent advances in the field of intravenous immunoglobulins used in pediatric neurological diseases. Literature data supports a beneficial effect in this age group. Whilst awaiting the results of large scale studies, administration of intravenous immunoglobulins could be justified in refractory child epilepsy. Otherwise, its use should be guided by the individual needs of each child, depending on the underlying neurological disease. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  5. Subcutaneous versus intravenous immunoglobulin in multifocal motor neuropathy

    DEFF Research Database (Denmark)

    Harbo, T; Andersen, Henning; Hess, A

    2009-01-01

    Background and purpose: For treatment of multifocal motor neuropathy (MMN), we hypothesized that (i) infusion of equivalent dosages of subcutaneous immunoglobulin (SCIG) is as effective as intravenous immunoglobulin (IVIG) and that (ii) subcutaneous infusion at home is associated with a better...... at the injection sites for a few weeks. All other adverse effects during SCIG were mild and transient. No differences between treatments of health-related quality of life occurred. Conclusion: In MMN, short-term subcutaneous infusion of immunoglobulin is feasible, safe and as effective as intravenous infusion...

  6. Intravenous adenosine for surgical management of penetrating heart wounds.

    Science.gov (United States)

    Kokotsakis, John; Hountis, Panagiotis; Antonopoulos, Nikolaos; Skouteli, Elian; Athanasiou, Thanos; Lioulias, Achilleas

    2007-01-01

    Accurate suturing of penetrating cardiac injuries is difficult. Heart motion, ongoing blood loss, arrhythmias due to heart manipulation, and the near-death condition of the patient can all affect the outcome. Rapid intravenous injection of adenosine induces temporary asystole that enables placement of sutures in a motionless surgical field. Use of this technique improves surgical conditions, and it is faster than other methods. Herein, we describe our experience with the use of intravenous adenosine to successfully treat 3 patients who had penetrating heart wounds.

  7. Recurrence of Intravenous Talc Granulomatosis following Single Lung Transplantation

    Directory of Open Access Journals (Sweden)

    Richard C Cook

    1998-01-01

    Full Text Available Advanced pulmonary disease is an unusual consequence of the intravenous injection of oral medications, usually developing over a period of several years. A number of patients with this condition have undergone lung transplantation for respiratory failure. However, a history of drug abuse is often considered to be a contraindication to transplantation in the context of limited donor resources. A patient with pulmonary talc granulomatosis secondary to intravenous methylphenidate injection who underwent successful lung transplantation and subsequently presented with recurrence of the underlying disease in the transplanted lung 18 months after transplantation is reported.

  8. Dose-Response Relationship Between Thrombin-Activatable Fibrinolysis Inhibitor (TAFI) and Stroke: A Chinese Case-Control Study

    Science.gov (United States)

    Dai, Huixu; Shi, Jingpu; He, Qiao; Sun, Hao

    2017-01-01

    Background Because TAFI (thrombin-activatable fibrinolysis inhibitor) antigen varies widely among different populations, we performed this case-control study to explore the relationship between TAFI levels and stroke in a Chinese population. Material/Methods Our population-based case-control study included 217 stroke patients and 218 healthy controls. The plasma TAFI level was measured by immune turbidimetry. Univariate and multivariate logistic regression analyses were used to analyze the association between different TAFI levels and stroke and its subtypes. Restricted cubic spline (RCS) combined with logistic regression analysis were used to explore the dose-response relationship between TAFI levels and stroke. Results The plasma TAFI levels of cases were much higher than in the control group (p=0.038) and this difference persisted even after adjustment (OR=2.2). In the elderly (aged over 60) and female subgroups, TAFI levels in stroke patients were higher than those in controls, and the results were also noted in ischemic stroke. The dose-response curve showed that, as a whole, with the increase of TAFI levels, the relative risk of stroke first increased and then decreased (p=0.0127). Similarly, in general, with the increase of TAFI levels, the curve showed that the relative risk of ischemic stroke first increased and then decreased (p=0.0110). Conclusions There was a definite correlation between TAFI levels and stroke in this Chinese population, and with the increase of TAFI levels, the relative risk of stroke or ischemic stroke first increased and then decreased. PMID:28890533

  9. Differential Contributions of Intrinsic and Extrinsic Pathways to Thrombin Generation in Adult, Maternal and Cord Plasma Samples.

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    Nicklaus T Rice

    Full Text Available Thrombin generation (TG is a pivotal process in achieving hemostasis. Coagulation profiles during pregnancy and early neonatal period are different from that of normal (non-pregnant adults. In this ex vivo study, the differences in TG in maternal and cord plasma relative to normal adult plasma were studied.Twenty consented pregnant women and ten consented healthy adults were included in the study. Maternal and cord blood samples were collected at the time of delivery. Platelet-poor plasma was isolated for the measurement of TG. In some samples, anti-FIXa aptamer, RB006, or a TFPI inhibitor, BAX499 were added to elucidate the contribution of intrinsic and extrinsic pathway to TG. Additionally, procoagulant and inhibitor levels were measured in maternal and cord plasma, and these values were used to mathematically simulate TG.Peak TG was increased in maternal plasma (393.6±57.9 nM compared to adult and cord samples (323.2±38.9 nM and 209.9±29.5 nM, respectively. Inhibitory effects of RB006 on TG were less robust in maternal or cord plasma (52% vs. 12% respectively than in adult plasma (81%. Likewise the effectiveness of BAX499 as represented by the increase in peak TG was much greater in adult (21% than in maternal (10% or cord plasma (12%. Further, BAX499 was more effective in reversing RB006 in adult plasma than in maternal or cord plasma. Ex vivo data were reproducible with the results of the mathematical simulation of TG.Normal parturient plasma shows a large intrinsic pathway reserve for TG compared to adult and cord plasma, while TG in cord plasma is sustained by extrinsic pathway, and low levels of TFPI and AT.

  10. Effects of thromboprophylactic doses of apixaban and rivaroxaban on coagulation and thrombin generation in association with total hip replacement.

    Science.gov (United States)

    Helin, Tuukka A; Virtanen, Lauri; Manninen, Mikko; Leskinen, Jarkko; Leppilahti, Juhana; Joutsi-Korhonen, Lotta; Lassila, Riitta

    2017-05-01

    Factor Xa inhibitors (FXaI) apixaban and rivaroxaban are used for thromboprophylaxis after major elective orthopaedic surgery. Because few patient sample studies exist, we postoperatively assessed patients undergoing unilateral total hip arthroplasty, including 22 treated with apixaban (2.5 mg BID) and 20 treated with rivaroxaban (10 mg OD). We collected blood samples before and 3 h after drug intake at 4 time points, preoperatively, as well as on day 1, week 1 (day 2-8) and day 28 post-operation. APTT and PT were immediately analysed. Calibrated anti-FXa activity, Russel's Viper Venom Time (RVVT) and thrombin generation (TG; Calibrated Automated Thrombogram ® ) captured the effects of FXaI on coagulation and TG. APTT and PT remained within the reference interval throughout, and did not correlate with FXaI levels (PT R 2  = 0.44, APTT R 2  = 0.07). Mean apixaban concentration at the peak varied by eightfold (19-153 ng/mL), but rivaroxaban only by 1.5-fold (111-183 ng/mL). Rivaroxaban, but not apixaban prolonged RVVT at peak levels. Both FXaIs had a prolonged lag time of TG (p < 0.001). Rivaroxaban decreased ETP peak at all time points and reached a minimum at day 28 (540 nM/min at rivaroxaban 184 ng/mL, p < 0.001), while rivaroxaban trough levels were low and ETP values normal. However, with apixaban, after an initial decrease, ETP did not differ between peak and trough levels until decreasing on day 28 at peak (990 nM/min at apixaban 112 ng/mL, p = 0.005). In conclusion, due to different dosing and pharmacology rivaroxaban and apixaban distinctly inhibited TG under postoperative conditions.

  11. Statins but not aspirin reduce thrombotic risk assessed by thrombin generation in diabetic patients without cardiovascular events: the RATIONAL trial.

    Directory of Open Access Journals (Sweden)

    Alejandro Macchia

    Full Text Available The systematic use of aspirin and statins in patients with diabetes and no previous cardiovascular events is controversial. We sought to assess the effects of aspirin and statins on the thrombotic risk assessed by thrombin generation (TG among patients with type II diabetes mellitus and no previous cardiovascular events.Prospective, randomized, open, blinded to events evaluation, controlled, 2×2 factorial clinical trial including 30 patients randomly allocated to aspirin 100 mg/d, atorvastatin 40 mg/d, both or none. Outcome measurements included changes in TG levels after treatment (8 to 10 weeks, assessed by a calibrated automated thrombogram. At baseline all groups had similar clinical and biochemical profiles, including TG levels. There was no interaction between aspirin and atorvastatin. Atorvastatin significantly reduced TG measured as peak TG with saline (85.09±55.34 nmol vs 153.26±75.55 nmol for atorvastatin and control groups, respectively; p = 0.018. On the other hand, aspirin had no effect on TG (121.51±81.83 nmol vs 116.85±67.66 nmol, for aspirin and control groups, respectively; p = 0.716. The effects of treatments on measurements of TG using other agonists were consistent.While waiting for data from ongoing large clinical randomized trials to definitively outline the role of aspirin in primary prevention, our study shows that among diabetic patients without previous vascular events, statins but not aspirin reduce thrombotic risk assessed by TG.ClinicalTrials.gov NCT00793754.

  12. Prothrombotic skeletal muscle myosin directly enhances prothrombin activation by binding factors Xa and Va

    Science.gov (United States)

    Deguchi, Hiroshi; Sinha, Ranjeet K.; Marchese, Patrizia; Ruggeri, Zaverio M.; Zilberman-Rudenko, Jevgenia; McCarty, Owen J. T.; Cohen, Mitchell J.

    2016-01-01

    To test the hypothesis that skeletal muscle myosins can directly influence blood coagulation and thrombosis, ex vivo studies of the effects of myosin on thrombogenesis in fresh human blood were conducted. Addition of myosin to blood augmented the thrombotic responses of human blood flowing over collagen-coated surfaces (300 s−1 shear rate). Perfusion of human blood over myosin-coated surfaces also caused fibrin and platelet deposition, evidencing myosin’s thrombogenicity. Myosin markedly enhanced thrombin generation in both platelet-rich plasma and platelet-poor plasma, indicating that myosin promoted thrombin generation in plasma primarily independent of platelets. In purified reaction mixtures composed only of factor Xa, factor Va, prothrombin, and calcium ions, myosin greatly enhanced prothrombinase activity. The Gla domain of factor Xa was not required for myosin’s prothrombinase enhancement. When binding of purified clotting factors to immobilized myosin was monitored using biolayer interferometry, factors Xa and Va each showed favorable binding interactions. Factor Va reduced by 100-fold the apparent Kd of myosin for factor Xa (Kd ∼0.48 nM), primarily by reducing koff, indicating formation of a stable ternary complex of myosin:Xa:Va. In studies to assess possible clinical relevance for this discovery, we found that antimyosin antibodies inhibited thrombin generation in acute trauma patient plasmas more than in control plasmas (P = .0004), implying myosin might contribute to acute trauma coagulopathy. We posit that myosin enhancement of thrombin generation could contribute either to promote hemostasis or to augment thrombosis risk with consequent implications for myosin’s possible contributions to pathophysiology in the setting of acute injuries. PMID:27421960

  13. Genetic and pharmacological modifications of thrombin formation in apolipoprotein e-deficient mice determine atherosclerosis severity and atherothrombosis onset in a neutrophil-dependent manner.

    Directory of Open Access Journals (Sweden)

    Julian I Borissoff

    Full Text Available BACKGROUND: Variations in the blood coagulation activity, determined genetically or by medication, may alter atherosclerotic plaque progression, by influencing pleiotropic effects of coagulation proteases. Published experimental studies have yielded contradictory findings on the role of hypercoagulability in atherogenesis. We therefore sought to address this matter by extensively investigating the in vivo significance of genetic alterations and pharmacologic inhibition of thrombin formation for the onset and progression of atherosclerosis, and plaque phenotype determination. METHODOLOGY/PRINCIPAL FINDINGS: We generated transgenic atherosclerosis-prone mice with diminished coagulant or hypercoagulable phenotype and employed two distinct models of atherosclerosis. Gene-targeted 50% reduction in prothrombin (FII(-/WT:ApoE(-/- was remarkably effective in limiting disease compared to control ApoE(-/- mice, associated with significant qualitative benefits, including diminished leukocyte infiltration, altered collagen and vascular smooth muscle cell content. Genetically-imposed hypercoagulability in TM(Pro/Pro:ApoE(-/- mice resulted in severe atherosclerosis, plaque vulnerability and spontaneous atherothrombosis. Hypercoagulability was associated with a pronounced neutrophilia, neutrophil hyper-reactivity, markedly increased oxidative stress, neutrophil intraplaque infiltration and apoptosis. Administration of either the synthetic specific thrombin inhibitor Dabigatran etexilate, or recombinant activated protein C (APC, counteracted the pro-inflammatory and pro-atherogenic phenotype of pro-thrombotic TM(Pro/Pro:ApoE(-/- mice. CONCLUSIONS/SIGNIFICANCE: We provide new evidence highlighting the importance of neutrophils in the coagulation-inflammation interplay during atherogenesis. Our findings reveal that thrombin-mediated proteolysis is an unexpectedly powerful determinant of atherosclerosis in multiple distinct settings. These studies suggest that

  14. Ceftriaxone-induced hemolytic anemia in a child successfully managed with intravenous immunoglobulin.

    Science.gov (United States)

    Vehapoğlu, Aysel; Göknar, Nilüfer; Tuna, Rümeysa; Çakır, Fatma Betül

    2016-01-01

    Drug-induced hemolytic anemia is an immune-mediated phenomenon that leads to the destruction of red blood cells. Here, we present a case of life-threatening ceftriaxone-induced hemolytic anemia (CIHA) in a previously healthy 3-year-old girl. We also reviewed the literature to summarize the clinical features and treatment of hemolytic anemia. Acute hemolysis is a rare side effect of ceftriaxone therapy associated with high mortality. Our patient had a sudden loss of consciousness with macroscopic hematuria and her hemoglobin dropped from 10.2 to 2.2 g/dl over 4 hours, indicating that the patient had life-threatening hemolysis after an intravascular dose of ceftriaxone who had previously been treated with ceftriaxone in intramuscular form for six days. CIHA is associated with a positive direct antiglobulin test, revealing the presence of IgG in all cases and C3d in most cases. Our patient's direct antiglobulin test was positive for IgG (3+) and for C3d (4+). The case was managed successfully with supportive measures and intravenous immunoglobulin therapy. Ceftriaxone is used very frequently in children; an early diagnosis and proper treatment of hemolytic anemia are essential to improve the patient outcome. The pathophysiological mechanism is the same as for non-drug autoimmune hemolytic anemia. However, there is still no consensus treatment for CIHA. Intravenous immunoglobulin can be used in clinical emergencies, such as our case, or in refractory cases.

  15. Postarthroscopy analgesia using intraarticular levobupivacaine and intravenous dexketoprofen trometamol.

    Science.gov (United States)

    Sahin, Sevtap Hekimoglu; Memiş, Dilek; Celik, Erkan; Sut, Necdet

    2015-12-01

    The aim of this prospective study was to determine the efficacy of intraarticular levobupivacaine with and without intravenous dexketoprofen trometamol for postarthroscopy analgesia. Sixty patients who underwent arthroscopic knee surgery were randomly assigned to three treatment groups. When the surgical procedure was completed, patients received the following treatments: group I (n = 20) patients received 20 mL intraarticular normal saline and 2 mL intravenous dexketoprofen trometamol (50 mg); group II (n = 20) patients received 20 mL intraarticular 0.5 % levobupivacaine (100 mg) and 2 mL intravenous normal saline; and group III (n = 20) patients received 20 mL intraarticular 0.5 % levobupivacaine (100 mg) and 2 mL intravenous dexketoprofen trometamol (50 mg). The visual analogue scale (VAS) was used, and the total analgesic consumption was assessed at 1, 2, 4, 6, 12, and 24 h post-operatively. The VAS scores at 1, 2, 4, 6, 12, and 24 h post-operatively were significantly increased in group I and group II compared with group III (p dexketoprofen trometamol administration provided better pain relief and less analgesic requirement after arthroscopic knee surgery during the first 24 h than that induced by dexketoprofen alone or levobupivacaine intraarticular alone. II.

  16. Causes of intravenous medication errors: an ethnographic study

    OpenAIRE

    Taxis, K; Barber, N

    2003-01-01

    Background: Intravenous (IV) medication errors are frequent events. They are associated with considerable harm, but little is known about their causes. Human error theory is increasingly used to understand adverse events in medicine, but has not yet been applied to study IV errors. Our aim was to investigate causes of errors in IV drug preparation and administration using a framework of human error theory.

  17. High dose intravenous immunoglobulin in Rh and ABO hemolytic ...

    African Journals Online (AJOL)

    Ehab

    High dose intravenous immunoglobulin in Rh and ABO hemolytic disease of Egyptian neonates. INTRODUCTION. Hemolytic disease of the newborn (HDN) due to red cell alloimmunisation is an important cause of hyperbilirubinemia with significant morbidity in the neonatal period.1,2. Hemolytic disease of the newborn has ...

  18. Intravenous Sedation for Dental Patients with Intellectual Disability

    Science.gov (United States)

    Miyawaki, T.; Kohjitani, A.; Maeda, S.; Egusa, M.; Mori, T.; Higuchi, H.; Kita, F.; Shimada, M.

    2004-01-01

    The poor quality of oral health care for people with intellectual disability (ID) has been recognized, and the strong fears about dental treatment suggested as a major reason for disturbances of visits to dentists by such patients. Intravenous sedation is a useful method for relieving the anxiety and fear of such patients about dental treatment,…

  19. Splenic lipidosis after administration of intravenous fat emulsions.

    Science.gov (United States)

    Forbes, G B

    1978-01-01

    Spleens showing fatty infiltration and necrosis of the pulp were found at necropsy on several patients who had received intravenous fat emulsions during their terminal illnesses. The postmortem findings are described and the clinicopathological correlation is discussed with special reference to the phenomenon of creaming of the emulsion. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:690241

  20. Pattern of intravenous immunoglobulins (IVIG) use in a pediatric ...

    African Journals Online (AJOL)

    EB

    Abstract. Background: Intravenous Immunoglobulin (IVIG) preparations are scarce biological products used for replacement or immunomodulatory effects. Guidelines have been issued by regulatory health authorities to ensure provision of the products for patients who are in severe need. Objectives: The study aimed at ...

  1. AIthesin (eT 1341) - A New Intravenous Anaesthetic Agent*

    African Journals Online (AJOL)

    1973-01-06

    Jan 6, 1973 ... Althesin (CT 1341), a new intravenous steroid anaes':he- tic agent without steroid activity, was given as ... by competent nursing staff who immediately reported any unfavourable side-effects. The time when the ..... A.) (ply) Ltd, for their expert advice, and for the liberal supplies of Althesin. REFERENCES. 1.

  2. Intravenous immunoglobulin in the prevention of recurrent miscarriage

    DEFF Research Database (Denmark)

    Christiansen, Ole B; Nielsen, Henriette Svarre

    2005-01-01

    Immunological disturbances play a role in the majority of patients with recurrent miscarriage (RM) and therefore treatment with intravenous immunoglobulin (IvIg) has been tested in patients with RM in several trials. Seven placebo-controlled trials that were extremely heterogeneous with respect...

  3. Carotid endarterectomy after intravenous thrombolysis for acute cerebral ischaemic attack

    DEFF Research Database (Denmark)

    Rathenborg, Lisbet Knudsen; Jensen, L P; Baekgaard, N

    2013-01-01

    Intravenous thrombolysis (IVT) has proven effective in the treatment of acute cerebral ischaemic attack in selected cases. In the presence of a carotid artery stenosis, such patients may be candidates for carotid endarterectomy (CEA). Few studies have been made on the safety of CEA performed after...

  4. Comparison of Caudal Analgesia and Intravenous Diclofenac for ...

    African Journals Online (AJOL)

    Background: Effective postoperative pain management is a vital determinant to when a child can be safely discharged from the hospital after day case surgery. This study compared the effect of caudal bupivacaine block with intravenous diclofenac for postoperative pain relief in children aged 1-7years undergoing ...

  5. Microbiological quality of some brands of intravenous fluids ...

    African Journals Online (AJOL)

    SERVER

    2007-10-04

    Oct 4, 2007 ... cases of circulation of contaminated intravenous fluids in hospitals in Nigeria. Some deaths and diseases condi- tions have been attributed to use of these microbiolo- gically unfit fluids. The Nigerian National Agency for. Food, Drug Administration and Control (NAFDAC), have on many occasions ordered ...

  6. Ultrastructural Changes in the Liver of Intravenous Heroin Addicts

    Directory of Open Access Journals (Sweden)

    Goran Ilić

    2010-02-01

    Full Text Available The ultrastructural research has a decisive role in gathering the knowledge on the liver’s response to the influence of some drugs. The aim of the study was to perform an ultrastructurai analysis of the liver in chronic intravenous heroin addicts.The study involved the autopsy conducted on 40 bodies of intravenous heroin addicts and 10 control autopsies. The liver tissue was fixed in glutaraldehyde and moulded with epon for investigation purposes of ultrastructural changes. The analysis was performed using the method of transmission electron microscopy.In the group of intravenous heroin addicts, the liver autopsy samples showed degenerative vesicular and fat changes, chronic active and persistent hepatitis, cirrhosis, reduction in the amount of glycogen in hepatocytes, as well as the Kupffer cell’s dominant hypertrophy. Various changes occur in organelles, plasma membrane of hepatocytes and biliary channels as well as in the nucleus.The most important ultrastructural findings include: hyperplasia and hypertrophy of the smooth endoplasmic reticulum, which is histologically proven vesicular degeneration of hepatocyte occurring as a result of the increased synthesis of enzymes of smooth endoplasmic reticulum due to chronic intravenous heroin intake, and the presence of continuous basal membrane followed by transformation of the sinusoids into capillaries (in the cases of chronic active hepatitis and cirrhosis which leads to a disorder of microcirculation and further progress of cirrhosis.

  7. Comparison of intramuscular artemether and intravenous quinine in ...

    African Journals Online (AJOL)

    Objectives: To compare the efficacy of intramuscular artemether and intravenous quinine in the treatment of severe falciparum malaria. Design: An open randomized controlled clinical trial. Setting: New Halfa Teaching Hospital, Eastern Sudan, in the period November 2001-January 2002. Subjects: Forty one male and ...

  8. Pharmacokinetics of Single Dose Intravenous Paracetamol in Children

    African Journals Online (AJOL)

    A new intravenous formulation containing paracetamol is now available and widely used in chil-dren, but with limited paediatric pharmacokinetic data. This study was aimed at determining the effects of age on the pharmacokinetics (PK) of this formulation of paracetamol in children. Blood samples were obtained from 24 ...

  9. The effect of intravenous preemptive paracetamol on postoperative ...

    African Journals Online (AJOL)

    Aim: We investigated the efficacy of intravenous (IV) preemptive paracetamol on postoperative total fentanyl consumption and fentanyl.related side effects in patients undergoing open nephrectomy. Materials and Methods: A total of 60 patients scheduled for elective open nephrectomy under general anesthesia were ...

  10. Optimal composition of intravenous lipids | Kreymann | South African ...

    African Journals Online (AJOL)

    The provision of energy from a lipid source is an essential component of any parenteral nutrition (PN) therapeutic regimen in the appropriate clinical setting. All available sources of intravenous lipid emulsions have a low osmolarity but they strongly differ in their immunologic effects and their effects on oxidative stress, liver ...

  11. Training requirements for the administration of intravenous contrast ...

    African Journals Online (AJOL)

    Background. The administration of intravenous contrast media (IVCM) is one of the key areas currently under investigation for inclusion in the South African (SA) radiographers' scope of practice. However, for the radiographers to legally administer IVCM, training guidelines must first be identified, developed and accredited ...

  12. X-ray diagnostics. Oral and intravenous cholegraphy

    International Nuclear Information System (INIS)

    1981-04-01

    The standard deals with oral and intravenous cholegraphy. It includes information on indications, contraindications, prerequisites and preparations as well as on application and appropriate dosage of contrast media. Parameters on focussing, imaging conditions and on the program of taking radiographies are outlined. The necessity of special examinations according to findings as well as measures concerning radiation protection and hygiene are presented

  13. Enzymuria in neonates receiving continuous intravenous infusion of gentamicin

    DEFF Research Database (Denmark)

    Colding, H; Brygge, K; Brendstrup, L

    1992-01-01

    with non-treatment periods in the same newborn infant (33 infants). The same tendency applied to AAP. Newborn infants receiving continuous intravenous infusion of gentamicin were not found to be at greater risk of nephrotoxicity than those receiving intermittent gentamicin treatment, using NAG and AAP...

  14. Oxalic acid excretion after intravenous ascorbic acid administration

    Science.gov (United States)

    Robitaille, Line; Mamer, Orval A.; Miller, Wilson H.; Levine, Mark; Assouline, Sarit; Melnychuk, David; Rousseau, Caroline; Hoffer, L. John

    2012-01-01

    Ascorbic acid is frequently administered intravenously by alternative health practitioners and, occasionally, by mainstream physicians. Intravenous administration can greatly increase the amount of ascorbic acid that reaches the circulation, potentially increasing the risk of oxalate crystallization in the urinary space. To investigate this possibility, we developed gas chromatography mass spectrometry methodology and sampling and storage procedures for oxalic acid analysis without interference from ascorbic acid and measured urinary oxalic acid excretion in people administered intravenous ascorbic acid in doses ranging from 0.2 to 1.5 g/kg body weight. In vitro oxidation of ascorbic acid to oxalic acid did not occur when urine samples were brought immediately to pH less than 2 and stored at –30°C within 6 hours. Even very high ascorbic acid concentrations did not interfere with the analysis when oxalic acid extraction was carried out at pH 1. As measured during and over the 6 hours after ascorbic acid infusions, urinary oxalic acid excretion increased with increasing doses, reaching approximately 80 mg at a dose of approximately 100 g. We conclude that, when studied using correct procedures for sample handling, storage, and analysis, less than 0.5% of a very large intravenous dose of ascorbic acid is recovered as urinary oxalic acid in people with normal renal function. PMID:19154961

  15. Imaging of chest disease due to intravenous heroin abuse

    International Nuclear Information System (INIS)

    Lian Xuhui; Chen Zhong; Ye Wenqin

    2002-01-01

    Objective: To study the imaging findings of the chest disease due to intravenous heroin abuse. Methods: Twenty-five cases of clinically confirmed chest disease due to intravenous heroin abuse were retrospectively analyzed. 25 cases had conventional X-ray film, 6 cases had CT scanning, and 6 cases had echocardiography scanning. Results: On X-ray and CT, the following signs were found: lung making manifold (n = 5), small patchy shadow (n = 15), pneumatocele (n = 16), small cavity (n = 16), small node (n = 7), pleural effusion (n = 8 ), pneumothorax (n = 2), hydropneumothorax (n = 6), pulmonary edema (n = 2), megacardia (n = 11), multiple-shaped lesion (n = 20). On echocardiography, tricuspid vegetation (n = 4) and tricuspid insufficiency (n = 4) were found. Conclusion: The X-ray and CT manifestations of chest inflammation due to intravenous heroin abuse are multiple. The multiple small cavities and pneumatoceles sign are of some value in the diagnosis of lung inflammation due to intravenous heroin abuse among young patients

  16. ORAL IBOPAMINE SUBSTITUTION IN PATIENTS WITH INTRAVENOUS DOPAMINE DEPENDENCE

    NARCIS (Netherlands)

    GIRBES, ARJ; MILNER, AR; MCCLOSKEY, BV; ZWAVELING, JH; VANVELDHUISEN, DJ; ZIJLSTRA, JG; LIE, KI

    1995-01-01

    In a prospective open study we evaluated whether intravenous dopamine infusions can be safely switched to enterally administered ibopamine in dopamine-dependent patients. Six patients defined as being clinically stable, normovolaemic, but dopamine dependent, i.e. with repeated inability to stop

  17. Classification of chronic orofacial pain using an intravenous diagnostic test

    NARCIS (Netherlands)

    Tjakkes, G. -H. E.; De Bont, L. G. M.; van Wijhe, M.; Stegenga, B.

    The aim of this study was to evaluate the ability of a preliminary intravenous diagnostic test to classify chronic orofacial pain patients into different subgroups. Patients with chronic orofacial pain conditions that could not be unambiguously diagnosed. A retrospective evaluation of series of

  18. Intravenous lipid emulsion and dexmedetomidine for treatment of ...

    African Journals Online (AJOL)

    tulyasys

    2015-08-19

    Aug 19, 2015 ... include intravenous fluid support to maintain electrolyte balance and hydration and to promote diuresis, dermal decontamination with a mild detergent and .... GABAA receptor complex and its activation increases chloride conductance and generates slow inhibitory postsynaptic potentials. This is one of the ...

  19. Illicit intravenous drug use in Johannesburg medical complications ...

    African Journals Online (AJOL)

    Illicit intravenous drug use in Johannesburg medical complications and prevalence of HIV infection. P.G. Williams, S.M. Ansell, F.J. Milne. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Article Metrics. Metrics Loading ... Metrics ...

  20. Intravenous glutamine enhances COX-2 activity giving cardioprotection.

    LENUS (Irish Health Repository)

    McGuinness, Jonathan

    2009-03-01

    Preconditioning, a highly evolutionary conserved endogenous protective response, provides the most powerful form of anti-infarct protection known. We investigated whether acute intravenous glutamine, through an effect on cyclooxygenase (COX)-2 and heat shock protein (HSP) 72, might induce preconditioning.

  1. [Stump pain relieved by continuous intravenous ketamine infusion therapy].

    Science.gov (United States)

    Mizuno, J; Sugimoto, S; Ohmori, T; Itadera, E; Ichikawa, N; Machida, K

    2001-07-01

    We experienced a case of stump pain relieved by continuous intravenous ketamine infusion therapy. A 59-year-old male had his left first through fourth toes amputated because a giant iron plate at work fell on his left foot fifteen years ago. Thereafter he had refractory spontaneous burning pain and night pain on his stump. On examination, we found his left foot skin hard, lustrous, and with sweating disturbance, allodynia and hyperpathia. As intravenous administrations of ketamine 10 mg and thiamylal 50 mg were positive as a drug challenge test, we performed intravenous ketamine infusion at 1 mg.kg-1.hr-1 for 1 hour and a half. After this treatment, his visual analogue scale (VAS) improved dramatically to 0 mm, and night pain, allodynia and hyperpathia disappeared for three days. Thereafter stump pain was relieved to the level of VAS 20 mm. Therefore we diagnosed his stump pain as central pain of neuropathic origin. We suspect that continuous intravenous infusion of ketamine, a noncompetitive blocker of N-methyl-D-aspartic acid receptor, might be an effective and useful alternative treatment in a patient with refractory stump pain.

  2. Treatment of neonatal sepsis with intravenous immune globulin

    DEFF Research Database (Denmark)

    Brocklehurst, Peter; Farrell, Barbara; King, Andrew

    2011-01-01

    Neonatal sepsis is a major cause of death and complications despite antibiotic treatment. Effective adjunctive treatments are needed. Newborn infants are relatively deficient in endogenous immunoglobulin. Meta-analyses of trials of intravenous immune globulin for suspected or proven neonatal sepsis...... suggest a reduced rate of death from any cause, but the trials have been small and have varied in quality....

  3. Intravenous carbon dioxide as an echocardiographic contrast agent

    NARCIS (Netherlands)

    R.S. Meltzer (Richard); P.W.J.C. Serruys (Patrick); P.G. Hugenholtz (Paul); J.R.T.C. Roelandt (Jos)

    1981-01-01

    textabstractIntravenous carbon dioxide (CO2) was employed to cause echocardiographic contrast in 40 patients. One to 3 cc of medically pure CO2 were agitated with 5 to 8 cc of 5% dextrose in water and rapidly injected into an upper extremity vein. Contrast was obtained in all patients. In 33

  4. Intravenous analgesics for pain management in postoperative patients

    African Journals Online (AJOL)

    Purpose: To compare the effectiveness of post-operative pain management and associated adverse effects of ketamine and nefopam. Methods: In total, 78 American Society of Anesthesiologists (ASA) grade 1 and 2 patients who had undergone abdominal surgery were given 3 mg of intravenous (IV) morphine as ...

  5. Time to treatment with intravenous alteplase and outcome in stroke

    DEFF Research Database (Denmark)

    Lees, Kennedy R; Bluhmki, Erich; von Kummer, Rüdiger

    2010-01-01

    BACKGROUND: Early administration of intravenous recombinant tissue plasminogen activator (rt-PA) after ischaemic stroke improves outcome. Previous analysis of combined data from individual patients suggested potential benefit beyond 3 h from stroke onset. We re-examined the effect of time to trea...

  6. Treatment of neonatal sepsis with intravenous immune globulin

    DEFF Research Database (Denmark)

    Brocklehurst, Peter; Farrell, Barbara; King, Andrew

    2011-01-01

    Neonatal sepsis is a major cause of death and complications despite antibiotic treatment. Effective adjunctive treatments are needed. Newborn infants are relatively deficient in endogenous immunoglobulin. Meta-analyses of trials of intravenous immune globulin for suspected or proven neonatal sepsis...

  7. Pattern of intravenous immunoglobulins (IVIG) use in a pediatric ...

    African Journals Online (AJOL)

    Background: Intravenous Immunoglobulin (IVIG) preparations are scarce biological products used for replacement or immunomodulatory effects. Guidelines have been issued by regulatory health authorities to ensure provision of the products for patients who are in severe need. Objectives: The study aimed at description of ...

  8. Intravenous Laser Therapy in Young Children with Thermal Injuries

    Directory of Open Access Journals (Sweden)

    R. V. Bocharov

    2014-01-01

    Full Text Available Objective: to evaluate the laboratory and clinical effects of combined intravenous laser therapy in young children with thermalinjuries in the acute period of burn disease.Subjects and methods. Forty children whose mean age was 2.67±0.35 years were examined; thermal injuries accounted for 25.05±1.01% of the total body surface area; of them degrees IIIaIIIb was 19.04±0.85%. A comparison group (n=15 received conventional therapy without taking into account and correcting baseline and current hemostasiological disorders. On day 1, a study group (n=25 had programmed anticoagulant therapy and intravenous laser therapy at different radiation frequencies with a Mustang 20002+ laser therapy apparatus (patent for invention No. 2482894 in addition to the conventional therapy. The laser therapy cycle was 6 to 16 sessions. The investigators estimated and compared the following examined parameters: white blood cell count; leukocytic index of intoxication; plasma average mass molecules at a wavelength of 254 nm; toxogenic granularity of neutrophils; wound exudate discharge time; surgical plasty area; and hospitalization time.Results. The positive laboratory and clinical effects of the performed combined intravenous laser therapy in the combined therapy of burn disease in young children were comparatively shown in the study group patients. The significant decrease in the level of an inflammatory response and endogenous intoxication led to a rapider burn wound cleansing, active epithelization, and reduced surgical plasty volumes.Conclusion. Combined intravenous laser therapy signif icantly exerts antiinflammatory and detoxifying effects in young children with 40% thermal injuries in the acute period of burn disease. Abolishing a systemic inflammatory response by combined intravenous laser therapy initiated early regenerative processes in the burn wound and caused reductions in surgical plasty volumes and hospitalization time, which optimizes ther

  9. Are postoperative intravenous fluids in patients undergoing elective laparoscopic cholecystectomy a necessity? A randomized clinical trial.

    Science.gov (United States)

    Henriques, Jessimara Ribeiro; Correia, Maria Isabel Toulson Davisson

    2018-04-01

    Intravenous (IV) fluid therapy should be individualized according to each patient's weight, disease, and comorbidities, as well as the type and duration of the operative procedure. Laparoscopic cholecystectomy represents one of the most common, short-duration operations; thus, the aim of this study was to assess the necessity of postoperative administration of IV fluids. A randomized clinical trial with patients undergoing elective laparoscopic cholecystectomy was performed. Patients were randomly assigned to control group (IV fluids at the surgeon's discretion) and study group (no IV fluids after the operation). Body weight and composition, total intravenous fluids, urinary output, creatinine levels, and the presence of thirst and hunger were assessed. Costs related to the administration of postoperative IV fluids were measured. The study and control groups were similar with regard to sex distribution, age, and general characteristics. There was a significant difference in the amount of infused IV fluids (1,600 mL vs 3,000 mL), directly related to the amount offered postoperatively to the control group. Weight, extracellular water, and urinary output (1,257 ± 736 mL vs 888 ± 392 mL; P fluids (r = 0.333). There were no differences in creatinine levels, thirst, hunger, and well-being features. An average of 10.7 minutes per patient of nursing time was required for IV administration. Cost related to IV fluids was increased in the control group. Postoperative intravenous fluids are not necessary in patients undergoing laparoscopic cholecystectomy, and their use is associated with increased nursing time and costs. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Selective screening of a large phage display library of plasminogen activator inhibitor 1 mutants to localize interaction sites with either thrombin or the variable region 1 of tissue-type plasminogen activator.

    Science.gov (United States)

    van Meijer, M; Roelofs, Y; Neels, J; Horrevoets, A J; van Zonneveld, A J; Pannekoek, H

    1996-03-29

    Phage display technology has been exploited to study in detail the interaction between plasminogen activator inhibitor 1 (PAI-1) and either thrombin or an essential positively charged "loop" of tissue-type plasminogen activator (t-PA), denoted variable region 1 (VR1). For this purpose, a PAI-1 mutant phage library was used that served as a reservoir of PAI-1 proteins potentially deficient in the interaction with either VR1 or thrombin. A stringent two-step selection procedure was developed. (i) A negative selection was performed by incubating the pComb3/PAI-1 mutant library with an excess of a thrombin mutant with its VR1 domain substituted with that of t-PA (thrombin-VR1). (ii) The remaining phages were complexed with t-PA (positive selection) and selected by panning with an immobilized anti-t-PA monoclonal antibody. Four consecutive panning rounds yielded an enrichment of pComb3/PAI-1 mutant phages of approximately 50-fold. Sequence analysis of 16 different cDNAs, encoding PAI-1 mutants that are hampered in the binding to thrombin-VR1, revealed the following mutations. Four independent variants share a mutation of the P4' residue (Glu350 --> Lys). Nine independent PAI-1 variants share a substitution of P1' (Met347 --> Lys), whereas three others share a P2 substitution (Ala345 --> Asp). Kinetic analysis of representative PAI-1 mutants provides evidence that the P4' residue is essential for the interaction with the VR1 domain, consistent with the data of Madison et al. (Madison, E.L., Goldsmith, E.J., Gething, M.J., Sambrook, J.F., and Gerard, R.D. (1990) J. Biol. Chem. 265, 21423-21426), whereas the P1' and P2 residues confer thrombin specificity. Concordant with the design of the selection procedure, mutants were obtained that inhibit thrombin-VR1 at least 100-fold slower than wild-type PAI-1, identifying residues that are central to the interaction with either thrombin or VR1. This study demonstrates that phage technology can be used to analyze large numbers of

  11. Thrombostasin: purification, molecular cloning and expression of a novel anti-thrombin protein from horn fly saliva.

    Science.gov (United States)

    Zhang, D; Cupp, M S; Cupp, E W

    2002-03-01

    Thrombostasin (TS), a novel protein found in the saliva of Haematobia irritans (horn fly), was purified by high-performance liquid chromatography from the saliva of field-collected insects. This protein, which inhibits thrombin, accounts for anti-clotting activity in horn fly saliva [J. Med. Entomol. 37 (2000) 416] and is the first purified anti-hemostatic factor described from the Stomoxyinae, a large group of blood-feeding insects that are major pests of livestock world-wide. The purified TS had an apparent molecular weight of 16.7 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and revealed two isoelectric groups with isoelectric points (pIs) of approximately 4.6 and 4.8. Mass spectroscopy analysis, however, resulted in at least three major isoforms that range in mass from 9213 to 9274 Da. A 243-bp coding sequence was obtained from cDNA by using a degenerate primer deduced from the N-terminal sequence of the purified TS. The conceptual translation of the 243-bp sequence showed that the 81-amino-acid peptide, whose first 30 amino acids match those of the N-terminal sequence, had a predicted mass of 9213 Da with pI 4.14. A full-length TS cDNA was generated by rapid amplification of cDNA ends of the 5' and sequential polymerase chain reaction (PCR) amplification. It contained a 5'-end 12-bp segment preceding the putative ATG start codon, followed by a 54-bp sequence corresponding to a secretory signal and an additional 228-bp coding sequence preceding residues revealed by N-terminal sequencing of purified TS. The fidelity of the PCR-generated TS sequence was confirmed in genomic DNA and by biological activity of recombinant TS produced in a baculovirus expression system. Database comparisons revealed no homology between TS and other known molecules. Because of the paucity of other anti-hemostatic factors in horn fly saliva, TS may play a critical role in maintenance of the ectoparasitic lifestyle of horn flies.

  12. Is there any role of thrombin activatable fibrinolysis inhibitor in the development of a hypercoagulable state in gastric cancer

    Directory of Open Access Journals (Sweden)

    Eser Mehmet

    2012-08-01

    Full Text Available Abstract Background The purpose of this study was to investigate plasma levels of thrombin activatable fibrinolysis inhibitor (TAFI and TAFI’s relationship with coagulation markers (prothrombin fragment 1 + 2 in gastric cancer patients. Methods Thirty-three patients with gastric adenocarcinoma and 29 healthy control subjects were prospectively enrolled in the study. Patients who had a history of secondary malignancy, thrombosis related disease, oral contraceptive use, diabetes mellitus, chronic renal failure or similar chronic metabolic disease were excluded from the study. A fasting blood sample was drawn from patients to determine the plasma levels of TAFI and Prothrombin Fragment 1 + 2 (F 1 + 2. In addition, data on patient age, sex, body mass index (BMI and stage of disease were recorded. The same parameters, except stage of disease, were also recorded for the control group. Subsequently, we assessed the difference in the levels of TAFI and F 1 + 2 between the patient and control groups. Moreover, we investigated the relation of TAFI and F 1 + 2 levels with age, sex, BMI and stage of disease in the gastric cancer group. Results There were no statistical differences in any demographic variables (age, gender and BMI between the groups (Table 1. The mean plasma TAFI levels of the gastric cancer group (69.4 ± 33.1 and control group (73.3 ± 27.5 were statistically similar (P = 0.62. The mean plasma F 1 + 2 level in the gastric cancer group was significantly higher than for those in the control group (549.7 ± 325.3 vs 151.9 ± 67.1, respectively; P  Conclusion In our study, TAFI levels of gastric cancer patients were similar to healthy subjects. The results of our study suggest that TAFI does not play a role in pathogenesis of the hypercoagulable state in gastric cancer patients.

  13. Pharmacokinetics of escin Ia in rats after intravenous administration.

    Science.gov (United States)

    Wu, Xiu-Jun; Cui, Xiang-Yong; Tian, Lian-tian; Gao, Feng; Guan, Xin; Gu, Jing-Kai

    2014-10-28

    Escin, a natural mixture of triterpene saponins, is commonly utilized for the treatment of chronic venous insufficiency, hemorrhoids, inflammation and edema. Escin Ia is the chief active ingredient in escin and plays key role in mediating its pharmacological effects. Adequate pharmacokinetic data are essential for proper application of escin agent in clinical practice. However, pharmacokinetic properties of escin Ia are still poorly understood and this conflicts with the growing use of escin agent over the years. The goal of this study is to investigate the pharmacokinetic behavior of escin Ia in rats after low, medium and high-dose intravenous administration. Wistar rats were divided into 3 groups (n=6 per group) and escin Ia was administered via the caudal vein at doses of 0.5, 1.0 and 2.0 mg/kg, respectively. Subsequently, the concentrations of escin Ia and its metabolite isoescin Ia, a positional isomer of escin Ia, in rats׳ plasma were measured by an established liquid chromatography tandem mass spectrometry (LC-MS/MS) method at various time points following the administration of the drug. Main pharmacokinetic parameters were calculated by non-compartmental analysis using the TopFit 2.0 software package (Thomae GmbH, Germany). After intravenous administration, the Cmax and AUC of escin Ia increased in a dose-proportional manner at the dose of 0.5 mg/kg and 1.0 mg/kg, while increased in a more than dose-proportional manner at the doses of 1.0 mg/kg and 2.0 mg/kg. The t₁/₂ was significantly longer with increased intravenous doses, while other parameters such as CL and Vd also exhibit disagreement among three doses. Taken together, our data showed dose-dependent pharmacokinetic profile of escin Ia in rats after intravenous administration at the doses of 0.5-2.0 mg/kg. After intravenous administration, escin Ia was rapidly and extensively converted to isoescin Ia. The results suggested dose-dependent pharmacokinetics of escin Ia at the doses of 0.5-2.0 mg

  14. Intravenous antibiotics for pulmonary exacerbations in people with cystic fibrosis.

    Science.gov (United States)

    Hurley, Matthew N; Prayle, Andrew P; Flume, Patrick

    2015-07-30

    Cystic fibrosis is a multi-system disease characterised by the production of thick secretions causing recurrent pulmonary infection, often with unusual bacteria. Intravenous antibiotics are commonly used in the treatment of acute deteriorations in symptoms (pulmonary exacerbations); however, recently the assumption that exacerbations are due to increases in bacterial burden has been questioned. To establish if intravenous antibiotics for the treatment of pulmonary exacerbations in people with cystic fibrosis improve short- and long-term clinical outcomes. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews and ongoing trials registers.Date of last search of Cochrane trials register: 27 July 2015. Randomised controlled trials and the first treatment cycle of cross-over studies comparing intravenous antibiotics (given alone or in an antibiotic combination) with placebo, inhaled or oral antibiotics for people with cystic fibrosis experiencing a pulmonary exacerbation. The authors assessed studies for eligibility and risk of bias and extracted data. We included 40 studies involving 1717 participants. The quality of the included studies was largely poor and, with a few exceptions, these comprised of mainly small, inadequately reported studies.When comparing treatment with a single antibiotic to a combined antibiotic regimen, those participants receiving a combination of antibiotics experienced a greater improvement in lung function when considered as a whole group across a number of different measurements of lung function, but with very low quality evidence. When limited to the four placebo-controlled studies (n = 214), no difference was observed, again with very low quality evidence. With regard to the review's remaining primary outcomes, there was no effect upon time to next exacerbation and

  15. Platelet associated IgG, platelet mean life span and treatment with intravenous immunoglobulin in idiopathic thrombocytopenic purpura

    Energy Technology Data Exchange (ETDEWEB)

    Nieminen, U.; Syrjaelae, M.; Ikkala, E.; Myllylae, G.

    1988-01-01

    The clinical significance of platelet associated IgG in ITP detected by direct platelet suspension immunofluorescence test (PSIFT) was studied. The platelet mean life span (MLS) was measured with /sup 111/In-labelled platelets in 17 adult patients. All the patients had shortened platelet MLS. The direct PSIFT was positive in 14 patients. Patients were initially treated with prednisone; 12 patients with poor response to the drug were splenectomised. 8 of these 12 patients were treated with intravenous immunoglobulin (IvIg) before splenectomy. The response to IvIg was as good or better in the 3 patients with negative PSIFT, than in the 5 patients with positive PSIFT.

  16. Absorbed Doses to Embryo from Intravenous Urography at Selected Radiological Departments in Slovakia

    International Nuclear Information System (INIS)

    Karkus, R.; Nikodemova, D.; Horvathova, M.

    2003-01-01

    Actual legislation used in radiological protection requires quality assurance program for decreasing radiation load of patients from radiological examinations. The information about irradiation of pregnant women is very important, because the embryo is more radiosensitive as adult organism. On the basis of absence of unified calculations or measurements of absorbed doses to embryo from various radiological examinations in Slovakia we present in this study the values of absorbed doses to embryo from intravenous urography at selected radiological departments in Slovakia. Absorbed doses to embryo were obtained by measurement and calculation using the simulation of irradiation of pregnant woman by intravenous urography. The results of our study indicate, that absorbed doses to embryo were at various radiological departments considerably different, depending on type of X-ray machine and different settings of technical parameters of X-ray machine. In accordance with worldwide trend it is necessary to decrease radiation load of patients as low as possible level. Differences in radiation load between radiological departments indicate, that it is necessary to continue in solving of this problem and perform measurements and calculations of absorbed doses to embryo at different types of X-ray machines and at different examinations, where the embryo is in direct beam of X-ray. (author)

  17. Intravenous digital subtraction angiography in patients with cerebral ischaemia

    International Nuclear Information System (INIS)

    Mantoni, M.; Neergaard, K.

    1989-01-01

    Over a two-year period, 167 patients with symptoms of transient ischaemic attacks or suspected minor stroke underwent intravenous digital subtraction angiography (DSA) of the carotid arteries. There were no major complications. Ninety-six patients had abnormal angiograms, 60 normal studies, and in 11 patients (7%) the examination was not of diagnostic quality, mostly because of motion artifacts. In 86 patients no therapeutic consequences resulted from the DSA examination. Twenty-six patients were referred for vascular surgery, and 34 patients had either anticoagulation or aspirin therapy. In 10 patients a primary medical cause was found for their cerebral vascular symptoms. It is concluded that intravenous DSA of the carotid arteries in patients with transient ischaemic attack is a safe, diagnostically useful procedure, that can also be used on an outpatient basis. (orig.)

  18. Pharmacokinetics of oral and intravenous melatonin in healthy volunteers

    DEFF Research Database (Denmark)

    Andersen, Lars Peter Holst; Werner, Mads Utke; Rosenkilde, Mette Marie

    2016-01-01

    BACKGROUND: The aim was to investigate the pharmacokinetics of oral and iv melatonin in healthy volunteers. METHODS: The study was performed as a cohort crossover study. The volunteers received either 10 mg oral melatonin or 10 mg intravenous melatonin on two separate study days. Blood samples were...... collected at different time points following oral administration and short iv infusion, respectively. Plasma melatonin concentrations were determined by RIA technique. Pharmacokinetic analyses were performed by "the method of residuals" and compartmental analysis. The pharmacokinetic variables: k a, t 1....../2 absorption, t max, C max, t 1/2 elimination, AUC 0-∞, and bioavailability were determined for oral melatonin. C max, t 1/2 elimination, V d, CL and AUC 0-∞ were determined for intravenous melatonin. RESULTS: Twelve male volunteers completed the study. Baseline melatonin plasma levels did not differ...

  19. Pharmacokinetics of high-dose intravenous melatonin in humans

    DEFF Research Database (Denmark)

    Andersen, Lars P H; Werner, Mads U; Rosenkilde, Mette Marie

    2016-01-01

    This crossover study investigated the pharmacokinetics and adverse effects of high-dose intravenous melatonin. Volunteers participated in 3 identical study sessions, receiving an intravenous bolus of 10 mg melatonin, 100 mg melatonin, and placebo. Blood samples were collected at baseline and 0, 60......, 120, 180, 240, 300, 360, and 420 minutes after the bolus. Quantitative determination of plasma melatonin concentrations was performed using a radioimmunoassay technique. Pharmacokinetic parameters were estimated by a compartmental pharmacokinetic analysis. Adverse effects included assessments...... of sedation and registration of other symptoms. Sedation, evaluated as simple reaction times, was measured at baseline and 120, 180, 300, and 420 minutes after the bolus. Twelve male volunteers completed the study. Median (IQR) Cmax after the bolus injections of 10 mg and 100 mg of melatonin were 221...

  20. Candida glabrata olecranon bursitis treated with bursectomy and intravenous caspofungin.

    Science.gov (United States)

    Skedros, John G; Keenan, Kendra E; Trachtenberg, Joel D

    2013-01-01

    Orthopedic surgeons are becoming more involved in the care of patients with septic arthritis and bursitis caused by yeast species. This case report involves a middle-aged immunocompromised female who developed a Candida glabrata septic olecranon bursitis that developed after she received a corticosteroid injection in the olecranon bursa for presumed aseptic bursitis. Candida (Torulopsis) glabrata is the second most frequently isolated Candida species from the bloodstream in the United States. Increased use of fluconazole and other azole antifungal agents as a prophylactic treatment for recurrent Candida albicans infections in immunocompromised individuals is one reason why there appears to be increased resistance of C. glabrata and other nonalbicans Candida (NAC) species to fluconazole. In this patient, this infection was treated with surgery (bursectomy) and intravenous caspofungin, an echinocandin. This rare infectious etiology coupled with this intravenous antifungal treatment makes this case novel among cases of olecranon bursitis caused by yeasts.

  1. Diagnostic value of intravenous cholangiography with regard to laparoscopic cholecystectomy

    International Nuclear Information System (INIS)

    Shoghi, Y.; Georgi, M.

    1996-01-01

    In a retrospective study the accuracy of sonography and intravenous cholangiography (IVC) in respect of pre-operative diagnostics before laparoscopic cholecystectomy was determined. Altogether 267 patients were examined by comparing sonography and IVC results with those under both surgical and histopathological examinations. Ultrasound proved to be superior to IVC detecting cholecystolithiasis in 99.4% versus 94.6%. The choledochus could be perceived in 81.0% by using ultrasound but in 93.6% by using IVC. In diagnosis of choledocholithiasis (CDL) IVC proved to be more suitable. With this method 100% could be recognised whereas sonography showed CDL in 33.3%. Serious side effects caused by intravenous contrast media could not be observed during any IVC examination. In our opinion IVC is a valid and reliable method to detect CDL and should be used in addition to ultrasound in pre-operative diagnostics before laparoscopic cholecystectomy. (orig.) [de

  2. Symptomatic sinus bradycardia: A rare adverse effect of intravenous ondansetron

    Directory of Open Access Journals (Sweden)

    Md Shahnawaz Moazzam

    2011-01-01

    Full Text Available Ondansetron is a serotonin receptor antagonist which has been used frequently to reduce the incidence of post-operative nausea and vomiting in laparoscopic surgery. It has become very popular drug for the prevention of post-operative nausea and vomiting due to its superiority in-terms of efficacy as well as lack of side effects and drug interactions. Although cardiovascular adverse effects of this drug are rare, we found a case of symptomatic sinus bradycardia in a 43-year-old female patient, going for laparoscopic cholecystectomy, who developed the same after she was given intravenous ondansetron in operation theater during premedication. Hence, we report this case, as the rare possibility of encountering bradycardia effect after intravenous administration of ondansetron should be born in mind.

  3. Anaphylactic Shock After Intravenous Fluorescein Administration for Intraoperative Cystoscopy.

    Science.gov (United States)

    Lee, Toy; Sanderson, Derrick; Doyle, Paula; Buchsbaum, Gunhilde

    2018-04-01

    Rates of administration of intravenous sodium fluorescein during cystoscopy have increased since indigotindisulfonate sodium was removed from the market in 2014. Although sodium fluorescein has been extensively evaluated and found to be safe, side effects including anaphylaxis have been observed, with an incidence between 0.05% and 1.0%. We present a case of anaphylactic shock after administration of intravenous sodium fluorescein for the assessment of ureteral efflux in a patient with a history of frequent severe allergic reactions undergoing urethral lysis and cystoscopy for urinary retention. Cardiopulmonary structure and function were evaluated and found to be normal. An elevated serum tryptase level was identified, indicating an anaphylactoid reaction. Timely recognition of symptoms associated with a severe allergic reaction in the setting of hemodynamic instability with prompt supportive and pharmacologic therapy was vital in the patient's recovery. Health care providers must be aware of this potential complication, especially in patients with a history of severe allergic reactions.

  4. Intravenous tranexamic acid for hyperacute primary intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Sprigg, Nikola; Robson, Katie; Bath, Philip

    2016-01-01

    RATIONALE: Outcome after intracerebral hemorrhage remains poor. Tranexamic acid is easy to administer, readily available, inexpensive, and effective in other hemorrhagic conditions. AIM: This randomized trial aims to test the hypothesis that intravenous tranexamic acid given within 8 h...... of spontaneous intracerebral hemorrhage reduces death or dependency. DESIGN: Phase III prospective double-blind randomized placebo-controlled trial. Participants within 8 h of spontaneous intracerebral hemorrhage are randomized to receive either intravenous tranexamic acid 1 g 10 min bolus followed by 1 g 8 h......, and institutionalization. DISCUSSION: This pragmatic trial is assessing efficacy of tranexamic acid after spontaneous intracerebral hemorrhage. Recruitment started in 2013; as of 15th January 2016 1355 participants have been enrolled, from 95 centers in seven countries. Recruitment is due to end in 2017. TICH-2 Trial...

  5. Safety of Intravenous Methamphetamine Administration During Ibudilast Treatment.

    Science.gov (United States)

    DeYoung, Dustin Z; Heinzerling, Keith G; Swanson, Aimee-Noelle; Tsuang, John; Furst, Benjamin A; Yi, Yi; Wu, Ying Nian; Moody, David E; Andrenyak, David M; Shoptaw, Steven J

    2016-08-01

    Methamphetamine dependence is a significant public health concern without any approved medications for treatment. We evaluated ibudilast, a nonselective phosphodiesterase inhibitor, to assess the safety and tolerability during intravenous methamphetamine administration. We conducted a randomized, double-blind, placebo-controlled, within-subjects crossover clinical trial. Participants received ibudilast (20 mg twice daily followed by 50 mg twice daily) and placebo, with order determined by randomization, and then underwent intravenous methamphetamine challenges (15 and 30 mg). We monitored cardiovascular effects, methamphetamine pharmacokinetics, and reported adverse events. Ibudilast treatment had similar rates of adverse events compared with placebo, and there was no significant augmentation of cardiovascular effects of methamphetamine. Pharmacokinetic analysis revealed no clinically significant change in maximum concentration or half-life of methamphetamine with ibudilast. Methamphetamine administration during ibudilast treatment was well tolerated without additive cardiovascular effects or serious adverse events, providing initial safety data to pursue ibudilast's effectiveness for the treatment of methamphetamine dependence.

  6. Accidental intravenous infusion of air: a concise review.

    Science.gov (United States)

    Wilkins, Robert G; Unverdorben, Martin

    2012-01-01

    The unintended intravenous infusion of small volumes of air is common in clinical practice. International Electrotechnical Commission guidelines for infusion pumps permit infusion of up to 1 mL in 15 minutes and discount bubbles smaller than 50 μL. A review of the literature, however, suggests that these limits may be too generous. Neonates and patients with right-to-left cardiac shunts (eg, patent foramen ovale [PFO]) are at risk from lower volumes. Because PFO is prevalent in 20% to 27% of healthy adults and generally asymptomatic, all patients are at risk from small air bubbles, although clinically significant air embolism from intravenous infusion is rare. Attention to good clinical practice and use of an inline air filter should be considered to reduce any risk.

  7. [Intravenous immunoglobulin therapy for kidney diseases in children].

    Science.gov (United States)

    Zwolińska, Danuta

    2011-06-01

    Intravenous immunoglobulin (IVIG) for the treatment of primary immunodeficiency disorders have been administrated for more than 25 years. However, the recognition of the anti-inflammatory and immune-modulatory actions of IVIG resulted broader applications to autoimmunity and systemic inflammatory conditions. The major focus of this review is the usefulness of IVIG therapy in children kidney disease, particularly in severe, atypical hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura, refractory to standard therapy, including plasmaferesis. The role of intravenous immunoglobulins in the treatment and prevention of infection, the most common complication in nephrotic syndrome is also discussed. Probably, in the future, similarly to adults, IVIG will be used for the therapy of some forms of glomerulopathies.

  8. Enucleation following treatment with intravenous pentamidine for Acanthamoeba sclerokeratitis

    Directory of Open Access Journals (Sweden)

    Rebecca A Kuennen

    2010-09-01

    Full Text Available Rebecca A Kuennen, Reynell Harder Smith, Thomas F Mauger, Elson CraigDepartment of Ophthalmology, The Ohio State University, Columbus, Ohio, USAPurpose: To describe the course and outcome of treatment of advanced Acanthamoeba sclerokeratitis with intravenous pentamidine.Methods: A case of advanced Acanthamoeba sclerokeratitis was resistant to conventional therapy and was treated with intravenous pentamidine. The eye was later removed due to incapacitating pain.Results: The eye showed Acanthamoeba organisms within the cornea and evidence of acute and chronic inflammation throughout the remainder of the eye. The patient has survived without orbital recurrence for 2 years.Conclusions: This case demonstrates late inflammation with active Acanthameoba keratitis following systemic pentamidine therapy.Keywords: keratitis, scleritis

  9. Today and tomorrow of intravenous coronary angiography programme in Japan

    International Nuclear Information System (INIS)

    Ando, Masami; Hyodo, Kazuyuki

    1994-01-01

    Development of an intravenous coronary angiography system using monochromated synchrotron radiation at the Photon Factory is described. This comprises an asymmetric cut silicon monochromator crystal to get a larger exposure area, a two dimensional imaging system using an imaging intensifier coupled to a CCD TV camera and a fast video data acquisition system. The whole system is under development using alive dogs. A future system including a dedicated insertion device applicable to alive humans is also proposed. (author)

  10. Total Intravenous Anesthesia (TIVA) in pediatric cardiac anesthesia

    OpenAIRE

    Wong , Grace Lai Sze

    2011-01-01

    Abstract Inhalational anesthesia with moderate to high-dose opioid analgesia has been the mainstay of pediatric cardiac anesthesia but the advances in understanding of pharmacology and availability of new fast-acting drugs coupled with the advanced concepts in pharmacokinetic modeling and computer technology have made total intravenous anesthesia (TIVA) an attractive option. In this article, we review some of the TIVA techniques used in pediatric cardiac anesthesia. gracewong531...

  11. Intravenous ferric carboxymaltose accelerates erythropoietic recovery from experimental malarial anemia

    DEFF Research Database (Denmark)

    Maretty, Lasse; Sharp, Rebecca Emilie; Andersson, Mikael

    2012-01-01

    Iron restriction has been proposed as a cause of erythropoietic suppression in malarial anemia; however, the role of iron in malaria remains controversial, because it may increase parasitemia. To investigate the role of iron-restricted erythropoiesis, A/J mice were infected with Plasmodium chabaudi...... use of iron therapy in malaria and show the need for trials of intravenous ferric carboxymaltose as an adjunctive treatment for severe malarial anemia....

  12. Postoperative analgesic efficacy of intravenous dexketoprofen in lumbar disc surgery.

    Science.gov (United States)

    Yazar, Mehmet Akif; Inan, Nurten; Ceyhan, Aysegul; Sut, Esra; Dikmen, Bayazit

    2011-07-01

    We investigated the postoperative analgesic efficacy and effect on total tramadol consumption of intravenous dexketoprofen trometamol, a new nonsteroidal anti-inflammatory drug, in patients that had undergone lumbar disc surgery. Sixty patients were included in this placebo-controlled, randomized, double-blind study. General anesthesia was applied to both groups. Group D (n=30) received dexketoprofen (50 mg) intravenously 30 minutes before the end of surgery and at the postoperative 12th hour, whereas group C (n=30) received 2 mL of 0.9% NaCL intravenously at the same time points. All patients received a patient controlled analgesia device with a tramadol, 25 mg bolus, 15 minutes lockout protocol, and were followed with visual analog scale, verbal rating scale, modified Aldrete recovery scoring system, and Ramsay sedation scale in the postoperative period. There was no significant difference between the groups for demographic data, duration of surgery, mean arterial pressure, and heart rate. The time to first postoperative analgesic requirement was significantly longer in group D (151.33±81.98 min) than group C (19±5.78 min) (Pdexketoprofen was an effective analgesic for postdiscectomy pain when used alone or in addition to opioids. It is easy to administer and decreases tramadol consumption and opioid-related side effects.

  13. Rhabdomyolysis associated with single-dose intravenous esomeprazole administration

    Science.gov (United States)

    Jeon, Dae-Hong; Kim, Yire; Kim, Min Jeong; Cho, Hyun Seop; Bae, Eun Jin; Chang, Se-Ho; Park, Dong Jun

    2016-01-01

    Abstract Background: Proton pump inhibitors are usually safe, although serious adverse effects can occur. We report the first case of rhabdomyolysis associated with single-dose intravenous esomeprozole administration. Methods: A 45-year-old Korean male visited our emergency room because of persistent lower chest discomfort that started 10 hours before. He had been diagnosed with diabetes and coronary heart disease, but discontinued oral hypoglycemic agents 1 month earlier. He continued to take medications for coronary heart disease. There was no abnormality on an electrocardiogram or in cardiac enzymes. Initial laboratory findings did not show abnormalities for muscle enzymes. Esomeprozole 40 mg was administrated intravenously for the control of his ambiguous chest discomfort. Then, 12 hours later, he complained of abrupt severe right buttock pain. An area of tender muscle swelling 8 cm in diameter was seen on his right buttock area. Creatine kinase and lactate dehydrogenase were elevated to 40,538 and 1326 U/L, respectively. A bone scan using 20 mCi of 99mTc-hydroxymethylene diphosphonate was compatible with rhabdomyolysis. Results: His muscular symptoms, signs, and laboratory findings improved markedly with conservative management, including hydration and urine alkalinization. He is being followed in the outpatient department with no evidence of recurrence. Conclusion: We should keep in mind that single-dose intravenous administration of esomeprazole can induce rhabdomyolysis. PMID:27442680

  14. Intravenous Thrombolysis for Embolic Stroke due to Cardiac Myxoma

    Directory of Open Access Journals (Sweden)

    Mu-Chien Sun

    2011-01-01

    Full Text Available Cardiac myxoma is a rare but curable cause of ischemic stroke. Current guidelines do not address the use of intravenous thrombolysis for embolic stroke caused by cardiac myxoma. The risk of hemorrhage due to occult tumor emboli or microaneurysms is a major concern. We describe a 45-year-old man who had an embolic stroke in the left middle cerebral artery. The initial National Institutes of Health Stroke Scale (NIHSS score was 16. He received intravenous thrombolysis 2 h and 52 min after stroke onset. No intracranial hemorrhage developed. A cardiac mass was found in the left atrium and removed surgically 84 h after stroke. Pathological study showed a myxoma with extensive hemorrhage and thrombus over the surface. At the 3-month follow-up, the NIHSS score was 9 and the modified Rankin scale score was 3. Our experience with this patient supports the hypothesis that intravenous thrombolysis may be safely used in the treatment of embolic stroke due to cardiac myxoma.

  15. A History of Intravenous Anesthesia in War (1656-1988).

    Science.gov (United States)

    Roberts, Matthew; Jagdish, S

    2016-01-01

    The practice of anesthesia in war places significant restraints on the choice of anesthetic technique used; these include, but are not limited to, safety, simplicity, and portability. Ever since intravenous anesthesia became a practical alternative, there have been military doctors who felt that this technique was particularly suited to this environment. The challenge, as in civilian practice, has been to find the appropriate drugs as well as simple and safe delivery systems. The urgency of war has always stimulated innovation in medicine to counteract the ongoing development of weapons of war and their effects on the human body and to achieve improved survival as public expectations rise. This article traces the development of and the use of intravenous anesthesia by military physicians for battle casualties. The story starts long before the era of modern anesthesia, and the discussion concludes in the dog days of the cold war. The rapidly increasing interest in intravenous anesthesia in both civilian and military practice since the early 1990s is left for other authors to examine. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Pharmacokinetics of butafosfan after intravenous and intramuscular administration in piglets.

    Science.gov (United States)

    Sun, F; Wang, J; Yang, S; Zhang, S; Shen, J; Xingyuan, C

    2017-04-01

    The pharmacokinetics and bioavailability of butafosfan in piglets were investigated following intravenous and intramuscular administration at a single dose of 10 mg/kg body weight. Plasma concentration-time data and relevant parameters were best described by noncompartmental analysis after intravenous and intramuscular injection. The data were analyzed through WinNolin 6.3 software. After intravenous administration, the mean pharmacokinetic parameters were determined as T 1/2λz of 3.30 h, Cl of 0.16 L kg/h, AUC of 64.49 ± 15.07 μg h/mL, V ss of 0.81 ± 0.44/kg, and MRT of 1.51 ± 0.27 h. Following intramuscular administration, the C max (28.11 μg/mL) was achieved at T max (0.31 h) with an absolute availability of 74.69%. Other major parameters including AUC and MRT were 48.29 ± 21.67 μg h/mL and 1.74 ± 0.29 h, respectively. © 2016 John Wiley & Sons Ltd.

  17. Efficacy and Tolerability of Intravenous Levetiracetam in Children

    Directory of Open Access Journals (Sweden)

    Jose eAceves

    2013-08-01

    Full Text Available Intractable epilepsy in children poses a serious medical challenge. Acute repetitive seizures and status epilepticus leads to frequent emergency room visits and hospital admissions. Permanent neurological damage can occur if there is delay in treatment. It has been shown that these children continue to remain intractable even after acute seizure management with approved FDA agents. Intravenous levetiracetam, a second-generation anticonvulsant was approved by the FDA in 2006 in patients 16 years and older as an alternative when oral treatment is not an option. It has been shown that oral levetiracetam can be used in the treatment of status epilepticus and acute repetitive seizures. Data have been published showing that intravenous levetiracetam is safe and efficacious, and can be used in an acute inpatient setting. This current review will discuss the recent data about the safety and tolerability of intravenous levetiracetam in children and neonates, and emphasize the need for a larger prospective multicenter trial to prove the efficacy of this agent in acute seizure management.

  18. Clinical and biochemical features of some intravenous iron complexes

    Directory of Open Access Journals (Sweden)

    S. Yu. Abashin

    2013-01-01

    Full Text Available Most anemia cases associated with iron deficiency. There are various therapeutic approaches to compensate iron deficiency. In some cases,a rapid restore of body iron is required, which is only possible with intravenous administration. Now a number of intravenous iron preparations are available, and each of them has not only advantages. Considering the drugs side effects, there was a need for drugs with high efficiency, low immunogenicity, and minimal toxicity. One of the decisions was to create preparations based on maltose and isomaltose. Such new intravenous iron preparations are ferric carboxymaltose and iron isomaltoside. Currently, there are no available clinical data that isomaltose and maltose preparations differ significantly with respect to adverse reactions associated with their immunogenicity. Based on study results isomaltose preparations in patients with dextran sensibilization should be used with caution. This is not completely exclude the possibility that both of these drugs can be an immune response trigger with a different specificity than the one on dextran develops. Preparations based on maltose, sucrose and gluconate were neutral in immunoprecipitation assay with dextran-reactive antibodies that determines their preference for patients with dextran sensibilisation. Other important properties of ferric carboxymaltose are: convenience of application and lack of oxidative stress that are determined by the slow iron release.

  19. Clinical and biochemical features of some intravenous iron complexes

    Directory of Open Access Journals (Sweden)

    S. Yu. Abashin

    2014-07-01

    Full Text Available Most anemia cases associated with iron deficiency. There are various therapeutic approaches to compensate iron deficiency. In some cases,a rapid restore of body iron is required, which is only possible with intravenous administration. Now a number of intravenous iron preparations are available, and each of them has not only advantages. Considering the drugs side effects, there was a need for drugs with high efficiency, low immunogenicity, and minimal toxicity. One of the decisions was to create preparations based on maltose and isomaltose. Such new intravenous iron preparations are ferric carboxymaltose and iron isomaltoside. Currently, there are no available clinical data that isomaltose and maltose preparations differ significantly with respect to adverse reactions associated with their immunogenicity. Based on study results isomaltose preparations in patients with dextran sensibilization should be used with caution. This is not completely exclude the possibility that both of these drugs can be an immune response trigger with a different specificity than the one on dextran develops. Preparations based on maltose, sucrose and gluconate were neutral in immunoprecipitation assay with dextran-reactive antibodies that determines their preference for patients with dextran sensibilisation. Other important properties of ferric carboxymaltose are: convenience of application and lack of oxidative stress that are determined by the slow iron release.

  20. Influence of hirudin and cobra venom factor on the release of 14C-serotonin and 51chromium from human platelets induced by thrombin, collagen, aggregate gammaglobulin and HLA antibody

    International Nuclear Information System (INIS)

    Hagemeyer, G.M.

    1982-01-01

    The present work investigates the influence of hirudin and cobra venom factor on thrombin, collagen, aggregate gammaglobulin and HLA-antibody-induced release of 14 C-serotonin and 51 chromium from human platelets. Besides the platelet-specific release reaction ( 14 C-serotonin) the extent of platelet lysis was determined by measurement of the loss of 51 chromium from the platelets. The results showed the thrombin, collagen and aggregate-gammaglobulin-induced platelet alteration to be a non-complement-dependent reaction of the platelets with release of 14 C-serotonin. Following long-term incubation small quantities of 51 chromium are also released. As this release of 51 chromium cannot be inhibited using cobra venom factor and does not occur in washed platelets either, it is most probably a non-complement-dependent reaction. The HLA-antibody-induced, specific platelet alteration is both complement-dependent and complement-independent. Differentiation is possible by inhibition of the complement-dependent lysis. On the other hand thrombin is of no relevance to the collagen, aggregate gammaglobulin, and HLA-antibody-induced platelet alteration as the interactions of these substances with platelets are not inhibited by hirudin. The above results are confirmed by investigation of the 51 chromium uptake capacity of washed platelets treated previously with thrombin, collagen and HLA antibody. (orig./MG) [de