WorldWideScience

Sample records for thrombin topical recombinant

  1. 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 

  2. Development of gel-forming lyophilized formulation with recombinant human thrombin.

    Science.gov (United States)

    Murányi, Andrej; Bartoš, Peter; Tichý, Eduard; Lazová, Jana; Pšenková, Jana; Žabka, Marián

    2015-09-01

    The objective of this work was development and evaluation of gel-forming lyophilized formulation with recombinant human thrombin for topical administration. The influence of pH, ionic strength and buffer type on protein stability was evaluated as part of the pre-formulation screening studies. Results indicated an optimal pH from 6.0 to 7.0 and increased stability with increasing content of sodium chloride. The tested buffer types had no significant effect on thrombin stability. For further development, thermosensitive Pluronic® F-127 was employed as a bulking and gelling agent. Physical and mechanical characterization and viscosity measurement confirmed the gel-forming properties of the formulation at the application temperature of 32?°C. Several techniques (addition of well-soluble polyols, different freezing protocols and reconstitution under vacuum) were tested to decrease the reconstitution time. The obtained results revealed that a vacuum in the vial headspace is crucial for acceptable reconstitution. The freeze drying process has no negative impact on recombinant thrombin stability, and this was confirmed by reverse-phase-HPLC, activity assay and optical density measurements. PMID:25347143

  3. Clinical use of topical thrombin as a surgical hemostat

    OpenAIRE

    Lew, Wesley K.; Weaver, Fred A.

    2008-01-01

    Wesley K Lew1, Fred A Weaver21University of Southern California, Department of Surgery, Los Angeles, CA, USA; 2CardioVascular Thoracic Institute at the University of Southern California, Los Angeles, CA, USAAbstract: When surgical ligation of bleeding fails, or is not possible, surgeons rely on a number of hemostatic aids, including thrombin. This review discusses the history, pharmacology and clinical application of thrombin as a surgical hemostat. The initial thrombin was bovine in origin, ...

  4. Recombinant thrombin: safety and immunogenicity in burn wound excision and grafting.

    Science.gov (United States)

    Greenhalgh, David G; Gamelli, Richard L; Collins, Jay; Sood, Rajiv; Mozingo, David W; Gray, Todd E; Alexander, W Allan

    2009-01-01

    This study evaluated the safety, immunogenicity, and hemostatic effect of recombinant human Thrombin (rThrombin), in patients undergoing skin grafting for burns. This was a phase 2 multiple site, single-arm, open-label study in patients receiving partial- or full-thickness autologous grafts. rThrombin was applied using a spray applicator to newly excised wounds of 1 to 4% body surface area at 5 minutes intervals for up to 20 minutes, after point source bleeding was stopped. Adverse events, skin graft survival, and formation of anti-rThrombin antibodies were measured at baseline and Day 29. There were no deaths or study drug discontinuations. Adverse events occurred in 63 of 72 patients (88%), and were typical of sequelae of skin grafting. Hemostasis was achieved within 20 minutes after application of rThrombin in 65 of 71 patients (91.5%). Skin graft failure occurred in 4 patients (6%). At the day 29 evaluation, for those patients who returned, 88.9% had > or =90% graft survival. One patient (1 of 70, 1.4%) had specific, low titer antibodies to rThrombin at baseline, but no increase in titer posttreatment; a second patient (1 of 62, 1.6%), developed antibodies to rThrombin at day 29. None of the antibodies neutralized native human thrombin. In excised burn wounds, hemostasis at 20 minutes was achieved in 91.5% of patients and skin graft survival was excellent. There was a low rate of antibodies to rThrombin at baseline (1.4%) and a low rate of anti-rThrombin antibody formation at day 29 (1.6%). rThrombin was well tolerated when administered with a pump spray. PMID:19349898

  5. Thrombin cleaves recombinant human thrombopoietin: One of the proteolytic events that generates truncated forms of?thrombopoietin

    OpenAIRE

    Kato, Takashi; Oda, Atsushi; Inagaki, Yoshimasa; Ohashi, Hideya; MATSUMOTO, ATSUSHI; Ozaki, Katsutoshi; Miyakawa, Yoshitaka; Watarai, Hiroshi; Fuju, Kazumi; Kokubo, Atsuko; Kadoya, Toshihiko; IKEDA, YASUO; Miyazaki, Hiroshi

    1997-01-01

    A heterogeneity in the molecular weight (Mr) of thrombopoietin (TPO) has been reported. We found several thrombin cleavage sites in human, rat, murine, and canine TPOs, and also found that human TPO undergoes selective proteolysis by thrombin. Recombinant human TPO (rhTPO) was incubated with human platelets in the presence of calcium ions to allow the generation of thrombin, and was cleaved into low Mr peptide fragments. The cleavage was completely inhibited by hirudin, indicating that the pr...

  6. Recombinant DNA Technology. A Topics Course for Undergraduates.

    Science.gov (United States)

    Parson, Kathleen A.

    1988-01-01

    Describes the development of a topics course offered jointly by the chemistry and biology departments at Macalester College (Minnesota). Outlines the syllabus for the course. Discusses teaching and laboratory methods used. (CW)

  7. Nanostructured bioluminescent sensor for rapidly detecting thrombin.

    Science.gov (United States)

    Chen, Longyan; Bao, Yige; Denstedt, John; Zhang, Jin

    2016-03-15

    Thrombin plays a key role in thrombosis and hemostasis. The abnormal level of thrombin in body fluids may lead to different diseases, such as rheumatoid arthritis, glomerulonephritis, etc. Detection of thrombin level in blood and/or urine is one of important methods for medical diagnosis. Here, a bioluminescent sensor is developed for non-invasively and rapidly detecting thrombin in urine. The sensor is assembled through conjugating gold nanoparticles (Au NPs) and a recombinant protein containing Renilla luciferase (pRluc) by a peptide, which is thrombin specific substrate. The luciferase-catalyzed bioluminescence can be quenched by peptide-conjugating Au NPs. In the presence of thrombin, the short peptide conjugating luciferase and Au NPs is digested and cut off, which results in the recovery of bioluminescence due to the release of luciferase from Au NPs. The bioluminescence intensity at 470 nm is observed, and increases with increasing concentration of thrombin. The bioluminescence intensity of this designed sensor is significantly recovered when the thrombin digestion time lasts for 10 min. In addition, a similar linear relationship between luminescence intensity and the concentration of thrombin is found in the range of 8 nM to 8 μM in both buffer and human urine spiked samples. The limit of detection is as low as 80 pM. It is anticipated that our nanosensor could be a promising tool for clinical diagnosis of thrombin in human urine. PMID:26397418

  8. Comparison of mammalian and bacterial expression library screening to detect recombinant alpha-1 proteinase inhibitor variants with enhanced thrombin inhibitory capacity.

    Science.gov (United States)

    Gierczak, Richard F; Bhakta, Varsha; Xie, Michael; Sheffield, William P

    2015-08-20

    Serpins are a widely distributed family of serine proteases. A key determinant of their specificity is the reactive centre loop (RCL), a surface motif of ?20 amino acids in length. Expression libraries of variant serpins could be rapidly probed with proteases to develop novel inhibitors if optimal systems were available. The serpin variant alpha-1 proteinase inhibitor M358R (API M358R) inhibits the coagulation protease thrombin, but at sub-maximal rates compared to other serpins. Here we compared two approaches to isolate functional API variants from serpin expression libraries, using the same small library of API randomized at residue 358 (M358X): flow cytometry of transfected HEK 293 cells expressing membrane-displayed API; and a thrombin capture assay (TCA) performed on pools of bacterial lysates expressing soluble API. No enrichment for specific P1 residues was observed when the RCL codons of the 1% of sorted transfected 293 cells with the highest fluorescent thrombin-binding signals were subcloned and sequenced. In contrast, screening of 16 pools of bacterial API-expressing transformants led to the facile identification of API M358R and M358K as functional variants. Kinetic characterization showed that API M358R inhibited thrombin 17-fold more rapidly than API M358K. Reducing the incubation time with immobilized thrombin improved the sensitivity of TCA to detect supra-active API M358R variants and was used to screen a hypervariable library of API variants expressing 16 different amino acids at residues 352-357. The most active variant isolated, with TLSATP substituted for FLEAI, inhibited thrombin 2.9-fold more rapidly than API M358R. Our results indicate that flow cytometric approaches used in protein engineering of antibodies are not appropriate for serpins, and highlight the utility of the optimized TCA for serpin protein engineering. PMID:26043905

  9. Subconjunctival and topical application of recombinant tissue plasminogen activator in rabbits

    Directory of Open Access Journals (Sweden)

    José Ricardo de Abreu Reggi

    2015-02-01

    Full Text Available Purpose: To quantify fibrin degradation products after topical and subconjunctival administration of recombinant tissue plasminogen activator in rabbits. Methods: Fibrin formation was induced in the anterior chamber in 25 rabbits. Subsequently, five rabbits received an injection of r-TPA (positive control in the anterior chamber, another 10 received a subconjunctival injection of r-TPA, and the remaining 10 received instillations of topical r-TPA. Afterwards, samples of aqueous humor were collected and semi-quantitative analysis of fibrin degradation products (FDP was performed. Results: No statistical differences were noted between the treatment and control groups at any time point. Fibrin degradation products semi-quantification showed statistical improvement in the control group and the subconjunctival group. Conclusion: Fibrin degradation products were observed in the anterior chamber after subconjunctival administration of r-TPA. However, it was probably not sufficient to cause fibrin degradation. Topical r-TPA did not effectively absorb anterior chamber fibrin.

  10. Whole Blood Thrombin: Development of a Process for Intra-Operative Production of Human Thrombin

    Science.gov (United States)

    Kumar, Vijay; Chapman, John R.

    2007-01-01

    Abstract: Thrombin-based clotting agents currently used for topical hemostasis with absorbable sponges, fibrin sealants, and platelet gels are primarily derived from bovine or pooled human plasma sources. Autologous thrombin has important safety advantages in that it does not carry the same safety concerns as pooled plasma-derived products and it avoids exposure to risks associated with bovine-derived proteins. The goal of our research was to develop a rapid, reliable, and simple to perform process to generate autologous human thrombin in the intraoperative setting, from patient whole blood as the starting source material. Using whole blood instead of plasma as the starting material, it is possible to avoid the inherent delay in thrombin availability associated with a primary step of plasma isolation. In this study, we varied several key processing parameters to maximize thrombin production, reproducibility and stability. Autologous thrombin production was generated using a dedicated, single use disposable with a sterile reagent. The disposable consists of a tubular reaction chamber containing glass microsphere beads to activate the alternative pathway of the coagulation cascade. At the end of the process, thrombin-activated serum was harvested from the reaction chamber. The average activity of the thrombin produced at room temperature by this system was 82.8 ± 15.9 IU/mL. The total processing time was <30 minutes. The system was compatible with Anticoagulant Citrate Dextrose-Solution A (ACD-A) (8%–12%). The average volume of thrombin harvested from each aliquot of blood was 7.0 ± 0.3 mL, and the stability of thrombin was observed to be temperature dependent, with cold storage better preserving thrombin activity. Clot times with platelet concentrates at 1:4.3 and 1:11 ratios (thrombin to platelet concentrate) were <10 and 20 seconds, respectively. A process for the preparation of thrombin from whole blood, under conditions compatible with the resources of an operating room, has been developed. The device is simple to use, requires 30 minutes, and can consistently produce thrombin solutions that achieve rapid clotting of platelet concentrates, plasma, and fibrinogen concentrates even when mixed at thrombin to blood product ratios of 1:11. PMID:17486869

  11. 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.

  12. Effect of Electronic Polarization to Human ?-Thrombin

    Science.gov (United States)

    Duan, Li-Li; Li, Zong-Chao; He, Xiang; Zhang, Qing-Gang

    2014-04-01

    The polarized protein-specific charges (PPC) of human ?-thrombin (thrombin) and its inhibitor (L86) are made possible by employing the recently developed molecular fractionation with conjugate caps approach incorporated the Poisson—Boltzmann model. Molecular dynamics (MD) simulations of thrombin have been carried out to investigate the dynamics and stability of the thrombin-inhibitor using PPC and AMBER charges respectively. Detailed analysis and comparison of MD results show that the PPC can correctly describe the polarized state of the thrombin and L86. Especially, the root-mean-square deviation of backbone atoms and the hydrogen bonds using PPC are more stable than the AMBER charge. The present results indicate that protein polarization plays critical roles in maintaining the compact structure of thrombin.

  13. Multiple inhibitory kinetics reveal an allosteric interplay among thrombin functional sites.

    Science.gov (United States)

    Zavyalova, Elena; Kopylov, Alexey

    2015-01-01

    Thrombin is a key blood clotting enzyme; therefore, developing of its inhibitors has become a mainstream in antithrombotic pharmacology. As a result, a wide variety of proteins, peptides, peptidomimetics, DNA, RNA, and carbohydrates were reported to be effective inhibitors of thrombin activities. The majority of described inhibitors were characterized kinetically with amidolytic assay only; though some of them inhibit fibrinogen binding rather than amidolytic activity, e.g. hirugen and nucleic acid aptamers. Per contra, studying the inhibition kinetics of fibrinogen hydrolysis might reveal essential peculiarities of mechanism of action of thrombin inhibitors. In this paper the effect of thrombin inhibitors on fibrinogen hydrolysis has been investigated using improved turbidimetric assay. This technique is highly productive versus fibrinopeptide determination allowing elucidation of inhibition type and apparent constant for different types of thrombin inhibitors. The protein (recombinant hirudin, antithrombin III), peptide (bivalirudin, hirugen), and peptidomimetic (argatroban, PPACK) inhibitors were characterized in terms of inhibition types for the first time. Unexpectedly, for others: heparin, RNA aptamer Toggle-25t, partial inhibition has been shown indicating allosteric interplay between exosites. Improved turbidimetric assay is also applicable for studying the fibrin association inhibitors. Hence, GPRP-peptide was characterized kinetically for the first time. The kinetic study revealed a repertoire of different inhibition types and also close allosteric interplay within the thrombin. The results are undoubtedly important for understanding the enzyme activity regulation, as well as for the rational development of new antithrombotic substances. PMID:25467079

  14. Autologous Thrombin: Intraoperative Production From Whole Blood

    Science.gov (United States)

    Kumar, Vijay; Chapman, John R.

    2008-01-01

    Abstract: Thrombin is routinely combined in surgical practice with a fibrinogen source to prepare fibrin sealant to promote hemostasis or with platelet concentrates to prepare platelet gels to enhance wound healing. The purpose of this study was to evaluate the robustness and reproducibility of a new sterile handheld disposable thrombin-processing device (TPD) to generate autologous human thrombin in the intraoperative setting, using whole blood as the starting source material. By using whole blood instead of plasma as the starting material, it is possible to eliminate the plasma separation step from whole blood and reduce the thrombin production time and increase its availability to the surgical team intraoperatively. Active thrombin was prepared by combining 4 mL of thrombin reagent (a mixture of calcium chloride and ethanol) to 11 mL of blood in a reaction chamber containing negatively charged particles. The whole blood, reagent and particle mixture was incubated for 25 minutes at either 18°C or 24°C (n = 25/group) to assess stability of the thrombin activity. The mean activity of the thrombin produced at 18°C and 24°C was 52 ± 14 (n = 25) and 61 ± 12.2 IU/mL (n = 25), respectively. The average volume of thrombin harvested from each aliquot of blood at 18°C and 24°C was 10 ± 0.4 and 9 ± 0.6 mL, respectively. The thrombin concentration generated was shown to rapidly (<5 seconds) coagulate fibrinogen concentrate and retained clotting activity for 1 hour at room temperature (18–26°C) and up to 4 hours when stored on ice. The results show that the TPD is able to consistently generate high thrombin activity from human whole blood. The device offers a robust and rapid approach for preparing active thrombin from whole blood. PMID:18705544

  15. Investigation of the selectivity of thrombin-binding aptamers for thrombin titration in murine plasma.

    Science.gov (United States)

    Trapaidze, Ana; Hérault, Jean-Pascal; Herbert, Jean-Marc; Bancaud, Aurélien; Gué, Anne-Marie

    2016-04-15

    Detection of thrombin in plasma raises timely challenges to enable therapeutic management of thrombosis in patients under vital threat. Thrombin binding aptamers represent promising candidates as sensing elements for the development of real-time thrombin biosensors; however implementation of such biosensor requires the clear understanding of thrombin-aptamer interaction properties in real-like environment. In this study, we used Surface Plasmon Resonance technique to answer the questions of specificity and sensitivity of thrombin detection by the thrombin-binding aptamers HD1, NU172 and HD22. We systematically characterized their properties in the presence of thrombin, as well as interfering molecular species such as the thrombin precursor prothrombin, thrombin in complex with some of its natural inhibitors, nonspecific serum proteins, and diluted plasma. Kinetic experiments show the multiple binding modes of HD1 and NU172, which both interact with multiple sites of thrombin with low nanomolar affinities and show little specificity of interaction for prothrombin vs. thrombin. HD22, on the other hand, binds specifically to thrombin exosite II and has no affinity to prothrombin at all. While thrombin in complex with some of its inhibitors could not be recognized by any aptamer, the binding of HD1 and NU172 properties is compromised by thrombin inhibitors alone, as well as with serum albumin. Finally, the complex nature of plasma was overwhelming for HD1, but we define conditions for the thrombin detection at 10nM range in 100-fold diluted plasma by HD22. Consequently HD22 showed key advantage over HD1 and NU172, and appears as the only alternative to design an aptasensor. PMID:26594887

  16. Aptamer Based Microsphere Biosensor for Thrombin Detection

    Directory of Open Access Journals (Sweden)

    Xudong Fan

    2006-08-01

    Full Text Available We have developed an optical microsphere resonator biosensor using aptamer asreceptor for the measurement of the important biomolecule thrombin. The sphere surface ismodified with anti-thrombin aptamer, which has excellent binding affinity and selectivityfor thrombin. Binding of the thrombin at the sphere surface is monitored by the spectralposition of the microsphere’s whispering gallery mode resonances. A detection limit on theorder of 1 NIH Unit/mL is demonstrated. Control experiments with non-aptameroligonucleotide and BSA are also carried out to confirm the specific binding betweenaptamer and thrombin. We expect that this demonstration will lead to the development ofhighly sensitive biomarker sensors based on aptamer with lower cost and higher throughputthan current technology.

  17. Subconjunctival and topical application of recombinant tissue plasminogen activator in rabbits / Uso tópico e subconjuntival de ativador de plasminogênio tecidual recombinante em coelhos

    Scientific Electronic Library Online (English)

    José Ricardo de Abreu, Reggi; Richard Yudi, Hida; Milton Massato, Hida; Maria Cristina, Nishiwaki-Dantas; Hisashi, Suzuki.

    2015-02-01

    Full Text Available Objetivo: Quantificar produtos de degradação de fibrina (PDF) após uso tópico e subconjunctival de ativador de plasminogênio tecidual recombinante (r-TPA) em coelhos. Métodos: Formação de fibrina foi induzida na câmara anterior em 25 coelhos. Cinco coelhos foram submetidos a injeção intracameral de [...] r-TPA (controle positivo). Dez coelhos foram submetidos a injeção subconjuntival de r-TPA e dez coelhos foram submetidos a instilação tópica de r-TPA. Amostras de humor aquoso foram coletados e uma análise quantitativa dos produtos de degradação de fibrina foi realizada. Resultados: Não foi observado diferença estatisticamente significativa na degradação de fibrina em nenhum dos momentos estudados quando comparados com o controle. Porém foi observado diferença estatisticamente significante na quantificação do produtos de degradação de fibrina no grupo controle e no grupo subconjuntival. Conclusão: Produtos de degradação de fibrina foi observado nas amostras do grupo subconjunctival, porém, provavelmente não foi suficiente para degradar a fibrin presente. r-TPA tópico não foi efetivo em absorver fibrina na câmara anterior. Abstract in english Purpose: To quantify fibrin degradation products after topical and subconjunctival administration of recombinant tissue plasminogen activator in rabbits. Methods: Fibrin formation was induced in the anterior chamber in 25 rabbits. Subsequently, five rabbits received an injection of r-TPA (positive [...] control) in the anterior chamber, another 10 received a subconjunctival injection of r-TPA, and the remaining 10 received instillations of topical r-TPA. Afterwards, samples of aqueous humor were collected and semi-quantitative analysis of fibrin degradation products (FDP) was performed. Results: No statistical differences were noted between the treatment and control groups at any time point. Fibrin degradation products semi-quantification showed statistical improvement in the control group and the subconjunctival group. Conclusion: Fibrin degradation products were observed in the anterior chamber after subconjunctival administration of r-TPA. However, it was probably not sufficient to cause fibrin degradation. Topical r-TPA did not effectively absorb anterior chamber fibrin.

  18. Percutaneous thrombin injection for pseudoaneurysm treatment

    Directory of Open Access Journals (Sweden)

    Gareth Bydawell

    2013-03-01

    Full Text Available Pseudoaneurysm of the femoral artery is a well-documented complication following arterial access. There are several treatment options, but percutaneous injection of thrombin, using ultrasound guidance, has become increasingly popular worldwide and is the therapy of choice in most vascular centres. This short review highlights the procedure and provides step-by-step guidance for radiologists who are interested in performing thrombin injection.

  19. Thrombin Inhibition by Serpins Disrupts Exosite II*

    OpenAIRE

    Li, Wei; Johnson, Daniel J D; Adams, Ty E.; Pozzi, Nicola; FILIPPIS, Vincenzo DE; Huntington, James A.

    2010-01-01

    Thrombin uses three principal sites, the active site, exosite I, and exosite II, for recognition of its many cofactors and substrates. It is synthesized in the zymogen form, prothrombin, and its activation at the end of the blood coagulation cascade results in the formation of the active site and exosite I and the exposure of exosite II. The physiological inhibitors of thrombin are all serpins, whose mechanism involves significant conformational change in both serpin and protease. It has been...

  20. Skin regeneration in deep second-degree scald injuries either by infusion pumping or topical application of recombinant human erythropoietin gel

    Science.gov (United States)

    Giri, Priya; Ebert, Sabine; Braumann, Ulf-Dietrich; Kremer, Mathias; Giri, Shibashish; Machens, Hans-Günther; Bader, Augustinus

    2015-01-01

    Large doses of recombinant growth factors formulated in solution form directly injected into the body is usual clinical practice in treating second-degree scald injuries, with promising results, but this approach creates side effects; furthermore, it may not allow appropriate levels of the factor to be sensed by the target injured tissue/organ in the specific time frame, owing to complications arising from regeneration. In this research, two delivery methods (infusion pumping and local topical application) were applied to deliver recombinant human erythropoietin (rHuEPO) for skin regeneration. First, rHuEPO was given in deep second-degree scald injury sites in mice by infusion pump. Vascularization was remarkably higher in the rHuEPO pumping group than in controls. Second, local topical application of rHuEPO gel was given in deep second-degree scald injury sites in rats. Histological analysis showed that epithelialization rate was significantly higher in the rHuEPO gel-treated group than in controls. Immunohistochemical studies showed that the rHuEPO gel-treated group showed remarkably higher expression of skin regeneration makers than the control group. An accurate method for visualization and quantification of blood vessel networks in target areas has still not been developed up to this point, because of technical difficulties in detecting such thin blood vessels. A method which utilizes a series of steps to enhance the image, removes noise from image background, and tracks the vessels edges for vessel segmentation and quantification has been used in this study. Using image analysis methods, we were able to detect the microvascular networks of newly formed blood vessels (less than 500 ?m thickness), which participate in the healing process, providing not only nutrition and oxygen to grow tissues but also necessary growth factors to grow tissue cells for complete skin regeneration. The rHuEPO-treated group showed higher expression of stem cell markers (CD 31, CD 90, CD 71, and nestin), which actively contribute to in-wound-healing processes for new hair follicle generation as well as skin regeneration. Collectively, both rHuEPO group pumping into the systemic circulation system, and injection into the local injury area, prompted mice and rats to form new blood vessel networks in scald injury sites, which significantly participate in the scald healing process. These results may lead to the development of novel treatments for scald wounds. PMID:26005333

  1. Skin regeneration in deep second-degree scald injuries either by infusion pumping or topical application of recombinant human erythropoietin gel

    Directory of Open Access Journals (Sweden)

    Giri P

    2015-05-01

    Full Text Available Priya Giri,1 Sabine Ebert,1 Ulf-Dietrich Braumann,2 Mathias Kremer,3 Shibashish Giri,1 Hans-Günther Machens,4 Augustinus Bader1 1Department of Cell Techniques and Applied Stem Cell Biology, Center for Biotechnology and Biomedicine (BBZ, Faculty of Medicine, University of Leipzig, Leipzig, Germany; 2Interdisciplinary Center for Bioinformatics (IZBI, University of Leipzig, Leipzig, Germany; 3Department of Plastic and Hand Surgery, University of Lübeck, Lübeck, Germany; 4Department of Plastic and Hand Surgery, Technical University of Munich, Munich, Germany Abstract: Large doses of recombinant growth factors formulated in solution form directly injected into the body is usual clinical practice in treating second-degree scald injuries, with promising results, but this approach creates side effects; furthermore, it may not allow appropriate levels of the factor to be sensed by the target injured tissue/organ in the specific time frame, owing to complications arising from regeneration. In this research, two delivery methods (infusion pumping and local topical application were applied to deliver recombinant human erythropoietin (rHuEPO for skin regeneration. First, rHuEPO was given in deep second-degree scald injury sites in mice by infusion pump. Vascularization was remarkably higher in the rHuEPO pumping group than in controls. Second, local topical application of rHuEPO gel was given in deep second-degree scald injury sites in rats. Histological analysis showed that epithelialization rate was significantly higher in the rHuEPO gel-treated group than in controls. Immunohistochemical studies showed that the rHuEPO gel-treated group showed remarkably higher expression of skin regeneration makers than the control group. An accurate method for visualization and quantification of blood vessel networks in target areas has still not been developed up to this point, because of technical difficulties in detecting such thin blood vessels. A method which utilizes a series of steps to enhance the image, removes noise from image background, and tracks the vessels edges for vessel segmentation and quantification has been used in this study. Using image analysis methods, we were able to detect the microvascular networks of newly formed blood vessels (less than 500 µm thickness, which participate in the healing process, providing not only nutrition and oxygen to grow tissues but also necessary growth factors to grow tissue cells for complete skin regeneration. The rHuEPO-treated group showed higher expression of stem cell markers (CD 31, CD 90, CD 71, and nestin, which actively contribute to in-wound-healing processes for new hair follicle generation as well as skin regeneration. Collectively, both rHuEPO group pumping into the systemic circulation system, and injection into the local injury area, prompted mice and rats to form new blood vessel networks in scald injury sites, which significantly participate in the scald healing process. These results may lead to the development of novel treatments for scald wounds. Keywords: re-epithelialization, scald wound, skin regeneration, neovascularization, vascularization, segmentation

  2. Fibrinogen and thrombin concentrations are critical for fibrin glue adherence in rat high-risk colon anastomoses

    Scientific Electronic Library Online (English)

    Eliseo Portilla-de, Buen; Abel, Orozco-Mosqueda; Caridad, Leal-Cortés; Gonzalo, Vázquez-Camacho; Clotilde, Fuentes-Orozco; Andrea Socorro, Alvarez-Villaseñor; Michel Dassaejv, Macías-Amezcua; Alejandro, González-Ojeda.

    2014-04-01

    Full Text Available OBJECTIVE: Fibrin glues have not been consistently successful in preventing the dehiscence of high-risk colonic anastomoses. Fibrinogen and thrombin concentrations in glues determine their ability to function as sealants, healers, and/or adhesives. The objective of the current study was to compare [...] the effects of different concentrations of fibrinogen and thrombin on bursting pressure, leaks, dehiscence, and morphology of high-risk ischemic colonic anastomoses using fibrin glue in rats. METHODS: Colonic anastomoses in adult female Sprague-Dawley rats (weight, 250-350 g) treated with fibrin glue containing different concentrations of fibrinogen and thrombin were evaluated at post-operative day 5. The interventions were low-risk (normal) or high-risk (ischemic) end-to-end colonic anastomoses using polypropylene sutures and topical application of fibrinogen at high (120 mg/mL) or low (40 mg/mL) concentrations and thrombin at high (1000 IU/mL) or low (500 IU/mL) concentrations. RESULTS: Ischemia alone, anastomosis alone, or both together reduced the bursting pressure. Glues containing a low fibrinogen concentration improved this parameter in all cases. High thrombin in combination with low fibrinogen also improved adherence exclusively in low-risk anastomoses. No differences were detected with respect to macroscopic parameters, histopathology, or hydroxyproline content at 5 days post-anastomosis. CONCLUSIONS: Fibrin glue with a low fibrinogen content normalizes the bursting pressure of high-risk ischemic left-colon anastomoses in rats at day 5 after surgery.

  3. Investigation of a thrombin-complexing protein associated with platelets

    International Nuclear Information System (INIS)

    A fraction of the 125I-thrombin that binds to human platelets is taken into a sodium dodecyl sulfate-resistant 77k Da complex with a platelet factor. This platelet factor is in several respects similar to protease nexin I (PNI), a fibroblasts thrombin inhibitor. The complexes are of the right size, bind to agarose that has been derivatized with either anti-PNI antibody or heparin, do not form when the thrombin active site has been blocked with diisopropylphosphofluoridate, and do not appear on platelets when heparin is present. The interaction with the platelet surface may modulate the conformation and function of this platelet form of protease nexin I (PNIp) because: (i) an antibody against protease nexi I inhibited released PNIp, but not platelet-bound PNIp from complexing 125I-thrombin, and (ii) whereas PNIp extracted from platelets bound both thrombin and urokinase, platelet-bound PNIp bound only thrombin. In experiments employing several different platelet isolation methods, PNIp accounted for a large fraction of the rapid high affinity binding of 125I-thrombin to platelets. However, platelets isolated and maintained in the presence of metabolic inhibitors failed to take added thrombin into 125I-thrombine-PNIp complexes

  4. Thrombin generation in a patient with an acquired high-titre factor V inhibitor.

    Science.gov (United States)

    Schmidt, David E; Steinhagen, Friederike; Schnabel, Claudia; Spath, Brigitte; Holstein, Katharina; Fiedler, Walter; Bokemeyer, Carsten; Renné, Thomas; Langer, Florian

    2015-01-01

    The management of patients with acquired factor V inhibitors is challenging, because their bleeding risk is highly variable and only poorly correlated with routine coagulation tests. Furthermore, there is no standardized treatment for bleeding control or inhibitor eradication. An 84-year-old white man underwent uneventful surgery for a ruptured intracerebral haemangioma. There were no perioperative coagulation abnormalities. Eight weeks after surgery, however, the prothrombin and the activated partial thromboplastin times were found to be maximally prolonged without signs of acute haemorrhage. A factor V inhibitor of 212 Bethesda units was diagnosed. We used a fluorogenic real-time thrombin generation assay with low concentrations of tissue factor (TF) to analyse the factor V inhibitor for interference with coagulation in platelet-poor plasma. Compared with three bleeding patients with acquired haemophilia A and severely deficient thrombin generation, total thrombin generation capacity was similar in the patient and healthy controls. However, the lag phase was significantly prolonged, suggesting a defect in the initiation/amplification, but not in the propagation phase of TF-triggered thrombin generation. This defect could be fully reproduced by purified patient IgG and largely corrected by ex-vivo addition of activated prothrombin complex concentrate, but not recombinant human FVIIa. Addition of normal platelets to the patient's plasma resulted in a pronounced shortening of the lag phase, suggesting that platelet-derived factor V can escape the inhibitor. Our findings offer an explanation for the absence of spontaneous bleeding in this patient and support the concept of platelet transfusions for the management of acute haemorrhages in patients with acquired factor V inhibitors. PMID:25158984

  5. Skin regeneration in deep second-degree scald injuries either by infusion pumping or topical application of recombinant human erythropoietin gel

    OpenAIRE

    Giri, Priya; Ebert, Sabine; Braumann, Ulf-Dietrich; Kremer, Mathias; Giri, Shibashish; Machens, Hans-Günther; Bader, Augustinus

    2015-01-01

    Large doses of recombinant growth factors formulated in solution form directly injected into the body is usual clinical practice in treating second-degree scald injuries, with promising results, but this approach creates side effects; furthermore, it may not allow appropriate levels of the factor to be sensed by the target injured tissue/organ in the specific time frame, owing to complications arising from regeneration. In this research, two delivery methods (infusion pumping and local topica...

  6. XIMELAGATRAN: A NEW DIRECT THROMBIN INHIBITOR

    Directory of Open Access Journals (Sweden)

    Mehta Hiren R

    2011-04-01

    Full Text Available Venous thromboembolism is a serious illness that affects patient morbidity and mortality and presents a significant management challenge to healthcare providers world-wide. Despite major achievements in the significant reduction of thromboembolic complications, the most common therapies currently used for prevention and treatment of venous thromboembolism – heparins and vitamin K antagonists such as warfarin – have several limitations. Warfarin sodium is an effective oral anticoagulant drug. However, warfarin has a narrow therapeutic window with significant risks of hemorrhage at therapeutic concentrations. Dosing is difficult and requires frequent monitoring. New oral anticoagulant agents are required to improve current anticoagulant therapy. Furthermore, while warfarin is effective in venous disease, it does not provide more than 60% risk reduction compared with placebo in venous thrombosis prophylaxis and considerably lower risk reduction in terms of arterial thrombosis. Unlike warfarin and heparin, these direct thrombin inhibitors are able to inhibit fibrin-bound thrombin and so produce more effective inhibition of coagulation. Importantly, some members of this class of drugs have been developed for oral administration. Ximelagatran is an oral pro-drug of melagatran, a synthetic small peptidomimetic with direct thrombin inhibitory actions and anticoagulant activity. As an oral agent, ximelagatran has a number of desirable properties including a rapid onset of action, fixed dosing, stable absorption, apparent low potential for medication interactions, and no requirement for monitoring of drug levels or dose adjustment. It has a short plasma elimination half-life of about 4 hours in cases of unexpected hemorrhage or need for reversal.

  7. 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.

  8. Label-free impedimetric biosensor for thrombin using the thrombin-binding aptamer as receptor

    International Nuclear Information System (INIS)

    This study presents the further establishment of impedimetric biosensors with aptamers as receptors. Aptamers are short single-stranded oligonucleotides which bind analytes with a specific region of their 3D structure. Electrical impedance spectroscopy is a sensitive method for analyzing changes on the electrode surface, e.g. caused by receptor-ligand-interactions. Fast and inexpensive prototyping of electrodes on the basis of commercially available compact discs having a 24 carat gold reflective layer was investigated. Electrode structures (CDtrodes [1]) in the range from few millimetres down to 100 microns were realized. The well-studied thrombin-binding aptamer (TBA) was used as receptor for characterizing these micro- and macro-electrodes. The impedance signal showed a linear correlation for concentrations of thrombin between 1.0 nM to 100 nM. This range corresponds well with most of the references and may be useful for the point-of-care testing (POCT).

  9. 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.

  10. Altered Flow Changes Thrombin Generation Rate of Circulating Platelets.

    Science.gov (United States)

    Yin, Wei; Bond, Kyle; Rouf, Farzana; Rubenstein, David A

    2015-12-01

    Shear stress affects platelet participation in coagulation. Many numerical models have been developed to describe coagulation kinetics. However, most of those models used rate constants determined under static conditions. Little is known about the effects of flow on coagulation rate constants. In the present study, platelets were exposed to constant or pulsatile shear stress/rate, with or without prothrombin, factor Xa, and factor Va. Thrombin generation was measured using a modified prothrombinase assay, and the overall thrombin generation rate was solved using typical Michaelis-Menten kinetics. Platelet surface P-selectin and phosphatidylserine (PS) expression was measured using flow cytometry. The results demonstrated that the concentration of factor Va had a dominant effect on thrombin generation rate under flow. In comparison, the expression of PS was less sensitive to altered flow. The lumped overall rate constant for prothrombin conversion to thrombin was significantly affected by the shear forces that were applied to the coagulation complex. Constant shear stress/rate induced faster thrombin generation compared to pulsatile shear stress/rate, but elevated shear stress/rate did not necessarily enhance thrombin generation. Therefore, the overall thrombin generation rate is dynamic and must be described as a function of shear stress/rate, shear exposure time and the immediate availability of coagulation proteins. PMID:26036336

  11. Thrombin Preconditioning in Surgical Brain Injury in Rats.

    Science.gov (United States)

    Benggon, Michael; Chen, Hank; Applegate, Richard L; Zhang, John

    2016-01-01

    The surgical brain injury model replicates neurosurgical brain parenchymal damage. Postsurgical brain edema correlates with postoperative neurological dysfunction. Intranasal administration is a proven method of delivering therapies to brain tissue. Thrombin preconditioning decreased brain edema and improved neurological outcomes in models of ischemic brain injury. We hypothesized thrombin preconditioning in surgical brain injury may improve postoperative brain edema and neurological outcomes. Adult male Sprague-Dawley rats (n?=?78) weighing 285-355 g were randomly assigned to sham or pre-injury treatment: one-time pretreatment 1 day prior, one-time pretreatment 5 days prior, and daily preconditioning for 5 days prior. Treatment arms were divided into vehicle or thrombin therapies, and subdivided into intranasal (thrombin 5 units/50 ?L 0.9 % saline) or intracerebral ventricular (thrombin 0.1 unit/10 ?L 0.9 % saline) administration. Blinded observers performed neurological testing 24 h after brain injury followed immediately by measurement of brain water content. There was a significant difference in ipsilateral brain water content and neurological outcomes between all treatment groups and the sham group. However, there was no change in brain water content or neurological outcomes between thrombin- and vehicle-treated animals. Thrombin preconditioning did not significantly improve brain edema or neurological function in surgical brain injury in rats. PMID:26463965

  12. Facile fabrication of an aptasensor for thrombin based on graphitic carbon nitride/TiO2 with high visible-light photoelectrochemical activity.

    Science.gov (United States)

    Fan, Dawei; Guo, Cuijuan; Ma, Hongmin; Zhao, Di; Li, Yina; Wu, Dan; Wei, Qin

    2016-01-15

    A novel aptasensor for thrombin with high visible-light activity was facilely fabricated based on graphitic carbon nitride/TiO2 (g-C3N4/TiO2) photoelectrochemical (PEC) composite. Crystallization of TiO2 nanoparticles (NPs) and their strong interaction with g-C3N4 sheet were confirmed by high-resolution transmission electron microscope (HR-TEM), both of which contributed to the high photocurrent intensity under visible-light irradiation. Carboxyl functionalized thrombin aptamers were first successfully bound to the g-C3N4/TiO2 modified electrode as proven by photoelectrochemical test and electrochemical impedance spectroscopy (EIS) analysis. Ascorbic acid was utilized as the electron donor for scavenging photo-generated holes and inhibiting light driven electron-hole pair recombination. The specific recognition between thrombin aptamer and thrombin led to the linear decrease of photocurrent with the increase of logarithm of thrombin concentration in the range of 5.0×10(-13)molL(-1) to 5.0×10(-9)molL(-1) with a detection limit of 1.2×10(-13)molL(-1). This proposed low-cost, convenient and sensitive aptasensor showed promising applications in biosensor and photoelectrochemical analysis. PMID:26301999

  13. The interaction of thrombin with platelet protease nexin

    International Nuclear Information System (INIS)

    Thrombin interacts with a platelet protein which is immunologically related to fibroblast protease nexin and has been termed platelet protease nexin I (PNI). Conflicting hypotheses about the relationship of the thrombin-PNI complex formation to platelet activation have been proposed. The studies presented here demonstrate that the platelet-associated and supernatant complexes with added 125I-thrombin are formed only under conditions which produce platelet activation in normal and chymotrypsin-modified platelets. The platelet-associated complex is formed prior to the appearance of complexes in supernatants. Appearance of the supernatant complex coincides with the appearance of thrombospondin in the reaction supernatants. Excess native thrombin, dansylarginine N-(3-ethyl-1,5-pentanediyl) amide or hirudin can prevent radiolabeled platelet-associated complex formation if added before 125I-thrombin. DAPA or hirudin can prevent or dissociate complex formation if added up to one minute after thrombin but not at later time points. The surface associated complex is accessible to trypsin although a portion remains with the cytoskeletal proteins when thrombin-activated platelets are solubilized with Triton X 100. The surface-associated complex formation parallels many aspects of the specific measurable thrombin binding, yet it does not appear to involve other identified surface glycoprotein thrombin receptors or substrates. Although the time course of appearance of the complexes in supernatants is consistent with other data which suggest that PNI may be released from platelet granules during platelet activation, other explanations for the appearance of PNI on the platelet surface and in supernatants during platelet activation are possible

  14. Crystallization and preliminary X-ray analysis of the complex of human ?-thrombin with a modified thrombin-binding aptamer

    International Nuclear Information System (INIS)

    The complex between human ?-thrombin and a modified thrombin-binding aptamer has been crystallized. Diffraction data were collected to 2.15 Å resolution, the structure was solved by molecular replacement and refinement of the model is in progress. The thrombin-binding aptamer (TBA) is a consensus DNA 15-mer that binds specifically to human ?-thrombin at nanomolar concentrations and inhibits its procoagulant functions. Recently, a modified TBA (mTBA) containing a 5?–5? inversion-of-polarity site has been shown to be more stable and to possess a higher thrombin affinity than its unmodified counterpart. The structure of the thrombin–TBA complex has previously been determined at low resolution, but did not provide a detailed picture of the aptamer conformation or of the protein–DNA assembly, while that of the complex with mTBA is unknown. Crystallographic analysis of the thrombin–mTBA complex has been attempted. The crystals diffracted to 2.15 Å resolution and belonged to space group I222

  15. Concentration-Dependent Dual Role of Thrombin in Protection of Cultured Rat Cortical Neurons.

    Science.gov (United States)

    García, Paul S; Ciavatta, Vincent T; Fidler, Jonathan A; Woodbury, Anna; Levy, Jerrold H; Tyor, William R

    2015-11-01

    Thrombin's role in the nervous system is not well understood. Under conditions of blood-brain barrier compromise (e.g., neurosurgery or stroke), thrombin can result in neuroapoptosis and the formation of glial scars. Despite this, preconditioning with thrombin has been found to be neuroprotective in models of cerebral ischemia and intracerebral hemorrhage. We investigated the effects of physiologically relevant concentrations of thrombin on cortical neurons using two culture-based assays. We examined thrombin's effect on neurites by quantitative analysis of fluorescently labeled neurons. To characterize thrombin's effects on neuron survival, we spectrophotometrically measured changes in enzymatic activity. Using receptor agonists and thrombin inhibitors, we separately examined the role of thrombin and its receptor in neuroprotection. We found that low concentrations of thrombin (1 nM) enhances neurite growth and branching, neuron viability, and protects against excitotoxic damage. In contrast, higher concentrations of thrombin (100 nM) are potentially detrimental to neuronal health as evidenced by inhibition of neurite growth. Lower concentrations of thrombin resulted in equivalent neuroprotection as the antifibrinolytic, aprotinin, and the direct thrombin inhibitor, argatroban. Interestingly, exogenous application of the species-specific thrombin inhibitor, antithrombin III, was detrimental to neuronal health; suggesting that some endogenous thrombin is necessary for optimal neuron health in our culture system. Activation of the thrombin receptor, protease-activated receptor-1 (PAR-1), via micromolar concentrations of the thrombin receptor agonist peptide, TRAP, did not adversely affect neuronal viability. An optimal concentration of thrombin exists to enhance neuronal health. Neurotoxic effects of thrombin do not involve activation of PAR receptors and thus separate pharmacologic manipulation of thrombin's receptor in the setting of direct thrombin inhibitors could be a potential neuroprotective strategy. PMID:26342829

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

    Science.gov (United States)

    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 ?2Macroglobulin (?2M) 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 ?2M 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, ?2M 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 ?2M 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. PMID:26509437

  17. 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.

  18. Biochemical characterization of bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI

    Directory of Open Access Journals (Sweden)

    Kristensen Torsten

    2009-05-01

    Full Text Available Abstract Background TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI, and recombinant human TAFI have recently been solved. In light of these recent advances, we have characterized authentic bovine TAFI biochemically and compared it to human TAFI. Results The four N-linked glycosylation sequons within the activation peptide were all occupied in bovine TAFI, similar to human TAFI, while the sequon located within the enzyme moiety of the bovine protein was non-glycosylated. The enzymatic stability and the kinetic constants of TAFIa differed somewhat between the two proteins, as did the isoelectric point of TAFI, but not TAFIa. Equivalent to human TAFI, bovine TAFI was a substrate for transglutaminases and could be proteolytically cleaved by trypsin or thrombin/solulin complex, although small differences in the fragmentation patterns were observed. Furthermore, bovine TAFI exhibited intrinsic activity and TAFIa attenuated tPA-mediated fibrinolysis similar to the human protein. Conclusion The findings presented here suggest that the properties of these two orthologous proteins are similar and that conclusions reached using the bovine TAFI may be extrapolated to the human protein.

  19. Aptamer RA36 inhibits of human, rabbit, and rat plasma coagulation activated with thrombin or snake venom coagulases.

    Science.gov (United States)

    Savchik, E Yu; Kalinina, T B; Drozd, N N; Makarov, V A; Zav'yalova, E G; Lapsheva, E N; Mudrik, N N; Babij, A V; Pavlova, G V; Golovin, A V; Kopylov, A M

    2013-11-01

    RA36 DNA aptamer is a direct anticoagulant prolonging clotting time of human, rabbit, and rat plasma in the thrombin time test. Anticoagulant activity of RA36 is lower than that of recombinant hirudin. During inhibition of human plasma clotting activated with echitox (coagulase from Echis multisquamatus venom), the aptamer presumably binds to meisothrombin exosite I. The sensitivity of human plasma to the aptamer 5-fold surpasses that of rat plasma. Analysis of RA36 binding to coagulase of Agkistrodon halys venom (ancistron) is required for proving the effect of aptamer on polymerization of human fibrinogen. PMID:24319726

  20. 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 ?g/mL and from 4.5 to 100 ?g/mL with detection limits of 1.5 ?g/mL and 1.9 ?g/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

  1. 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 ?g/mL and from 4.5 to 100 ?g/mL with detection limits of 1.5 ?g/mL and 1.9 ?g/mL, respectively. Most importantly, this strategy shall allow us to detect different classes of enzymes simultaneously by designing various enzyme-specific peptide substrates.

  2. Estradiol Topical

    Science.gov (United States)

    Estradiol topical gel and emulsion (lotion type mixture) are used to treat and prevent hot flushes (hot ... of life; the end of monthly menstrual periods). Estradiol topical gel is also used to treat vaginal ...

  3. Bexarotene Topical

    Science.gov (United States)

    ... condition may improve as soon as 4 weeks after you begin to use topical bexarotene, or it may ... notice any improvement. Continue to use topical bexarotene after you notice improvement; your condition may continue to improve. ...

  4. Scanning electrochemical microscopy for study of aptamer-thrombin interfacial interactions on gold disk microelectrodes.

    Science.gov (United States)

    Bai, Huei-Yu; del Campo, F Javier; Tsai, Yu-Chen

    2014-03-01

    A feasibility for the determination of thrombin on gold disk microelectrodes (GDMs) using scanning electrochemical microscopy (SECM) is reported. The assembly process step-by-step of thrombin aptasensor on GDMs is monitored by SECM. SECM analysis reveals the immobilization of thrombin aptamers on GDMs. The interaction between thrombin aptamers and thrombin on GDMs is imaged by SECM with feedback mode using ferrocenemethanol as an electrochemical mediator. The formation of thrombin/thrombin aptamer complex on GDMs results in a decrease in the tip peak current on spatial SECM images. This method is able to linearly and selectively detect thrombin over a linear range from 10(-12) to 10(-5)M with a detection limit of 6.07 fM. PMID:24407695

  5. Recombinant activated factor VII: 30 years of research and innovation.

    Science.gov (United States)

    Hedner, Ulla

    2015-06-01

    Recombinant activated factor VII (rFVIIa) was initially developed to treat bleeding episodes in patients with congenital haemophilia and inhibitors. The story of its development began in the 1970s, when FVIIa was identified as one of the activated coagulation factors that has minimal potential for inducing thromboembolic side-effects. Extensive research over the last 30 years has greatly increased our knowledge of the characteristics of FVII, its activation, and the mechanisms by which rFVIIa restores haemostasis. In haemophilia, the haemostatic effect of rFVIIa is mediated via binding to thrombin-activated platelets at the site of injury, thereby enhancing thrombin generation also in the absence of factor (F) VIII or FIX. The mechanism of action of rFVIIa has also allowed its successful use in other clinical scenarios characterised by impaired thrombin generation, and its licensed uses have now been extended to acquired haemophilia, congenital FVII deficiency and Glanzmann's thrombasthenia. PMID:26073368

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

    International Nuclear Information System (INIS)

    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

  7. High-affinity RNA ligands to human alpha-thrombin.

    OpenAIRE

    Kubik, M F; Stephens, A W; Schneider, D; Marlar, R A; Tasset, D

    1994-01-01

    Systematic Evolution of Ligands by EXponential enrichment (SELEX) was used to isolate from a population of 10(13) RNA molecules two classes of high affinity RNAs that bind specifically to human alpha-thrombin. Class I RNAs are represented by a 24-nucleotide RNA (RNA 16.24), and class II RNAs are represented by a 33-nucleotide RNA (RNA 27.33). RNA 16.24 inhibits thrombin-catalyzed fibrin clot formation in vitro. Secondary structures are proposed for these RNAs, revealing a novel stem-loop stru...

  8. 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; M. Bompiani, Kristin; Hansen, Majken Nørgaard; Gothelf, Kurt Vesterager; Sullenger, Bruce A.; Labean, Thomas H.

    2012-01-01

    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 by...

  9. New Approaches to the Role of Thrombin in Acute Coronary Syndromes: Quo Vadis Bivalirudin, a Direct Thrombin Inhibitor?

    Science.gov (United States)

    Esteve-Pastor, María Asunción; Hernández-Romero, Diana; Valdés, Mariano; Marín, Francisco

    2016-01-01

    The pathophysiology of acute coronary syndrome (ACS) involves platelet activation and thrombus formation after the rupture of atherosclerotic plaques. Thrombin is generated at the blood-plaque interface in association with cellular membranes on cells and platelets. Thrombin also amplifies the response to the tissue injury, coagulation and platelet response, so the treatment of ACS is based on the combined use of both antiplatelet (such as aspirin, clopidogrel, prasugrel and ticagrelor) and antithrombotic drugs (unfractionated heparin, enoxaparin, fondaparinux and bivalirudin). Bivalirudin competitively inhibits thrombin with high affinity, a predictable response from its linear pharmacokinetics and short action. However, a present remarkable controversy exists between the latest main Guidelines in Clinical Practice and the key trials evaluating the use of bivalirudin in ACS. The aim of this review is to update the development of bivalirudin, including pharmacological properties, obtained information from clinical trials evaluating efficacy and safety of bivalirudin in ACS; as well as the recommendations of clinical Guidelines. PMID:26927051

  10. 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. PMID:26840958

  11. A Guided Mode Resonance Aptasensor for Thrombin Detection

    Directory of Open Access Journals (Sweden)

    Wen-Yih Chen

    2011-09-01

    Full Text Available Recent developments in aptamers have led to their widespread use in analytical and diagnostic applications, particularly for biosensing. Previous studies have combined aptamers as ligands with various sensors for numerous applications. However, merging the aptamer developments with guided mode resonance (GMR devices has not been attempted. This study reports an aptasensor based home built GMR device. The 29-mer thrombin aptamer was immobilized on the surface of a GMR device as a recognizing ligand for thrombin detection. The sensitivity reported in this first trial study is 0.04 nm/?M for thrombin detection in the concentration range from 0.25 to 1 ?M and the limit of detection (LOD is 0.19 ?M. Furthermore, the binding affinity constant (Ka measured is in the range of 106 M?1. The investigation has demonstrated that such a GMR aptasensor has the required sensitivity for the real time, label-free, in situ detection of thrombin and provides kinetic information related to the binding.

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

    International Nuclear Information System (INIS)

    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

  13. AI Topics

    OpenAIRE

    Buchanan, Bruce G; Glick, Jonathan

    2002-01-01

    The debut of the AI in the News column elsewhere in this issue of AI Magazine created a good opportunity to introduce the professional community to the AI Topics web site, home of the AI in the news virtual page. Although AI Topics is designed for the lay public, it serves a much larger audience.

  14. Thrombin mutant W215A/E217A treatment improves neurological outcome and attenuates central nervous system damage in experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Verbout, Norah G; Yu, Xiaolin; Healy, Laura D; Phillips, Kevin G; Tucker, Erik I; Gruber, András; McCarty, Owen J T; Offner, Halina

    2015-02-01

    Multiple sclerosis (MS) is a neuroinflammatory disease characterized by demyelination and axonal damage of the central nervous system. The pathogenesis of MS has also been linked to vascular inflammation and local activation of the coagulation system, resulting in perivascular fibrin deposition. Treatment of experimental autoimmune encephalomyelitis (EAE), a model of human MS, with antithrombotic and antiinflammatory activated protein C (APC) reduces disease severity. Since recombinant APC (Drotecogin alfa), originally approved for the treatment of severe sepsis, is not available for human MS studies, we tested the hypothesis that pharmacologic activation of endogenous protein C could likewise improve the outcome of EAE. Mice were immunized with murine myelin oligodendrocyte glycoprotein (MOG) peptides and at the onset of EAE symptoms, were treated every other day with either WE thrombin (25 ?g/kg; i.v.), a selective recombinant protein C activator thrombin analog, or saline control. Mice were monitored for changes in disease score until euthanized for ex vivo analysis of inflammation. Administration of WE thrombin significantly ameliorated clinical severity of EAE, reduced inflammatory cell infiltration and demyelination, suppressed the activation of macrophages comprising the CD11b + population and reduced accumulation of fibrin (ogen) in the spinal cord. These data suggest that symptomatic MS may respond to a treatment strategy that involves temporal pharmacological enhancement of endogenous APC generation. PMID:24810631

  15. Thrombin as a multi-functional enzyme. Focus on in vitro and in vivo effects.

    Science.gov (United States)

    Siller-Matula, Jolanta M; Schwameis, Michael; Blann, Andrew; Mannhalter, Christine; Jilma, Bernd

    2011-12-01

    Thrombin is the central protease in the coagulation cascade and one of the most extensively studied of all enzymes. In addition to its recognised role in the coagulation cascade and haemostasis, thrombin is known to have multiple pleiotropic effects, which mostly have been shown only in in vitro studies: it plays a role in inflammation and cellular proliferation and displays a mitogen activity on smooth muscle cells and endothelial cells, predominantly by activation of angiogenesis. In vivo , thrombin effects were examined in animal models of intravenous or intraarterial thrombin infusion. An extensive literature search regarding in vivo data showed that i) thrombin administered as a bolus causes microembolism, ii) thrombin infused slowly at steady-state conditions (up to 1.6 U/kg/min) leads to bleeds but not to intravascular clotting, iii) large quantity of thrombin infused at low rates (0.05 U/kg/min) does not have any measurable effect, and iv) thrombin increases vascular permeability leading to tissue damage. Although several decades of research on thrombin functions have provided a framework for understanding the biology of thrombin, animal and human studies with use of newer laboratory techniques are still needed to confirm the pleiotropic thrombin functions shown in in vitro studies. PMID:21979864

  16. Clindamycin Topical

    Science.gov (United States)

    ... slowing or stopping the growth of bacteria that cause acne and by decreasing swelling. ... or bloody stools stomach cramps Topical clindamycin may cause other side ... the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting ...

  17. Tacrolimus Topical

    Science.gov (United States)

    Tacrolimus ointment is used to treat the symptoms of eczema (atopic dermatitis; a skin disease that causes ... whose eczema has not responded to another medication. Tacrolimus is in a class of medications called topical ...

  18. Diphenhydramine Topical

    Science.gov (United States)

    Diphenhydramine, an antihistamine, is used to relieve the itching of insect bites, sunburns, bee stings, poison ivy, ... Diphenhydramine topical comes in cream, lotion, gel, and spray to be applied to the skin. It is ...

  19. Interactions of liver Grp78 and Escherichia coli recombinant Grp78 with ATP: multiple species and disaggregation.

    OpenAIRE

    A. Carlino; Toledo, H; Skaleris, D; DeLisio, R; Weissbach, H; Brot, N

    1992-01-01

    The hamster gene encoding the 78-kDa glucose-regulated protein (Grp78) was expressed in Escherichia coli as a fusion protein with glutathione S-transferase. After induction with isopropyl beta-D-thiogalactopyranoside, the recombinant Grp78 was purified to homogeneity by affinity column chromatography of the fusion protein followed by thrombin cleavage. The purified recombinant protein was compared with liver Grp78 for its ability to interact with ATP. Like liver Grp78, the recombinant protein...

  20. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as...... well as the cellular organization of the process of homologous recombination. Herein we review the cell biological aspects of mitotic homologous recombination with a focus on Saccharomyces cerevisiae and mammalian cells, but will also draw on findings from other experimental systems. Key topics of this...

  1. Stimulation of phosphoinositide hydrolysis by thrombin in embryonic chick heart cells

    International Nuclear Information System (INIS)

    The authors have shown that muscarinic receptor stimulation results in phosphoinositide (PI) hydrolysis in dissociated embryonic chick heart cells, with maximal stimulation produced by 1 mM carbachol. In an effort to identify other stimulators of PI turnover, they studied the effects of thrombin in primary cultures of 13-day embryonic chick heart cells. Thrombin increased PI hydrolysis, as measured by the accumulation of [3H]inositol 1-phosphate in the presence of 10 mM LiCl. Stimulation occurred in a dose-dependent manner with half-maximal stimulation obtained at 0.07 U/ml and maximal stimulation at 0.3 U/ml thrombin. The effects of maximal doses of carbachol and thrombin were additive, suggesting different mechanisms of action or different populations of cells. Effects of both hormones were inhibited by pretreatment of the monolayer cultures with 4?-phorbol 12 ?-myristate 13?-acetate. The simultaneous addition of hirudin with thrombin blocked thrombin-stimulated PI turnover. An active-site-blocked derivative of thrombin was ineffective in stimulating IP formation. These data indicate a proteolytic action of thrombin in stimulation of the PI response. To their knowledge, these are the first data suggesting that there may be thrombin receptors or effects of thrombin on heart cells

  2. Evaluation of DNA aptamers directed to thrombin as potential thrombus imaging agents

    International Nuclear Information System (INIS)

    Two DNA aptamers directed against two separate exosites on human ?-thrombin were evaluated for thrombus-imaging potential. Aptamer ODN 1 is directed to the thrombin substrate binding site (exosite 1). Our finding that ODN 1 competes with fibrin for binding to exosite 1 on thrombin suggests that ODN 1 will not be useful for thrombus imaging. Aptamer ODN 2 is directed against the thrombin heparin binding site (exosite 2). ODN 2 bound to model thrombi that were formed either by clotting purified fibrinogen with thrombin, or by recalcifying citrated plasma. As the thrombin content of thrombi was increased the rate of ODN 2 uptake into preformed thrombi increased, whereas the rate of release of ODN 2 out of preformed thrombi decreased. This in vitro data suggested that ODN 2 might be useful for thrombus imaging because it can bind to exosite 2 on fibrin-bound thrombin. However, in a rabbit jugular vein model using thrombus supplemented with human thrombin, ODN 2 uptake was equal to the ovalbumin control, and did not reflect thrombin content. While the in vitro results with ODN 2 were consistent with thrombus imaging, the rapid clearance of ODN 2 from circulation, combined with slow mass transfer in the clot, seem to work against in vivo thrombin-dependent imaging or washout analysis

  3. A novel histochemical method for the visualization of thrombin activity in the nervous system.

    Science.gov (United States)

    Bushi, D; Gera, O; Kostenich, G; Shavit-Stein, E; Weiss, R; Chapman, J; Tanne, D

    2016-04-21

    Although thrombin has an important role in both central and peripheral nerve diseases, characterization of the anatomical distribution of its proteolytic activity has been limited by available methods. This study presents the development, challenges, validation and implementation of a novel histochemical method for visualization of thrombin activity in the nervous system. The method is based on the cleavage of the substrate, Boc-Asp(OBzl)-Pro-Arg-4M?NA by thrombin to liberate free 4-methoxy-2-naphthylamine (4M?NA). In the presence of 5-nitrosalicylaldehyde, free 4M?NA is captured, yielding an insoluble yellow fluorescent precipitate which marks the site of thrombin activity. The sensitivity of the method was determined in vitro using known concentrations of thrombin while the specificity was verified using a highly specific thrombin inhibitor. Using this method we determined the spatial distribution of thrombin activity in mouse brain following transient middle cerebral artery occlusion (tMCAo) and in mouse sciatic nerve following crush injury. Fluorescence microscopy revealed well-defined thrombin activity localized to the right ischemic hemisphere in cortical areas and in the striatum compared to negligible thrombin activity contralaterally. The histochemical localization of thrombin activity following tMCAo was in good correlation with the infarct areas per triphenyltetrazolium chloride staining and to thrombin activity measured biochemically in tissue punches (85±35 and 20±3mU/ml, in the cortical and striatum areas respectively, compared to 7±2 and 13±2mU/ml, in the corresponding contralateral areas; mean±SEM; p<0.05). In addition, 24h following crush injury, focal areas of highly elevated thrombin activity were detected in teased sciatic fibers. This observation was supported by the biochemical assay and western blot technique. The histochemical method developed in this study can serve as an important tool for studying the role of thrombin in physiological and pathological conditions. PMID:26851772

  4. 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.

  5. Testosterone Topical

    Science.gov (United States)

    ... amount of testosterone in your blood during your treatment.Testosterone topical may control your symptoms but will not ... of low testosterone in men who have low testosterone due to aging ('age-related hypogonadism').This medication may be prescribed ...

  6. Aptamer-Crosslinked Microbubbles: Smart Contrast Agents for Thrombin-Activated Ultrasound Imaging

    OpenAIRE

    Nakatsuka, Matthew A.; Mattrey, Robert F.; Esener, Sadik C.; Cha, Jennifer N.; Goodwin, Andrew P.

    2012-01-01

    Thrombosis, or malignant blood clotting, is associated with numerous cardiovascular diseases and cancers. This report describes a microbubble contrast agent that produces ultrasound harmonic signal only when exposed to elevated thrombin levels. Silenced initially, microbubbles activated in the presence of both thrombin-spiked and freshly clotting blood in three minutes with detection limits of 20 nM thrombin and 2 aM microbubbles.

  7. Evaluation of Antithrombotic Activity of Thrombin DNA Aptamers by a Murine Thrombosis Model

    OpenAIRE

    Zavyalova, Elena; Samoylenkova, Nadezhda; Revishchin, Alexander; Golovin, Andrey; Pavlova, Galina; Kopylov, Alexey

    2014-01-01

    Aptamers are nucleic acid based molecular recognition elements with a high potential for the theranostics. Some of the aptamers are under development for therapeutic applications as promising antithrombotic agents; and G-quadruplex DNA aptamers, which directly inhibit the thrombin activity, are among them. RA-36, the 31-meric DNA aptamer, consists of two thrombin binding pharmacophores joined with the thymine linker. It has been shown earlier that RA-36 directly inhibits thrombin in the react...

  8. 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.

  9. Percutaneous Ultrasound-Guided Thrombin Injection in Iatrogenic Arterial Pseudoaneurysms: Effectiveness and Complications

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Young Hwan [Boramae Hospital, Seoul (Korea, Republic of); Kim, Hak Soo; Kim, Hyung Sik; Min, Seung Kee [Gachon Medical School, Incheon (Korea, Republic of)

    2005-09-15

    To evaluate and describe the efficacy and side effects of a percutaneous thrombin injection under ultrasonography guidance for the treatment of iatrogenic pseudo aneurysms Eighteen consecutive iatrogenic pseudo aneurysm cases were treated with a thrombin injection. The thrombin was injected into the pseudo aneurysm cavity using a 22-gauge needle under ultrasonographic guidance. The causes of the pseudo aneurysms are as follows: post coronary angiography (9 cases), percutaneous coronary balloon angioplasty (5 cases), cerebral angiography (1 case), transhepatic chemo embolization (1 case), percutaneous trans femoral arterial stent insertion (1 case) and bone marrow aspiration for a marrow transplant (1 case). Only one case required a secondary thrombin injection due to recurrent flow in the pseudo aneurysm lumen, which was detected at the follow up Doppler ultrasound. Other seventeen cases were successfully treated on the first trial. There were no technical failures or complication related to the procedure. The average amount of thrombin injected was 733 IU. Nine out of 18 treated patients (50%) showed mild reactions to the thrombin including mild fever (4 cases), chilling sensation (3 cases), a chilling sensation with mild dyspnea (1 case), mild chest discomfort (1 case) after the thrombin injection. All these side effects were transient and improved several hours later. All the iatrogenic pseudo aneurysms were treated successfully with an ultrasound-guided percutaneous thrombin injection. There was a high rate of hypersensitivity to the bovine thrombin, which precaution should be taken to prevent more serious side effects

  10. 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 ?l). 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?stress marker, and microglial activation in the periventricular white matter. These changes were significantly reduced in HCR rats. Intraventricular injection of thrombin caused more white matter damage and 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. PMID:26463978

  11. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  12. Thrombin and fibrinogen ?' 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 ?' 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 ?' 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 ?' showed reduced protofibril packing over a range of thrombin concentrations. High-magnification electron microscopy demonstrated reduced protofibril packing in ?' 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 ?' fibrinogen. These findings demonstrate that, in fully hydrated conditions, thrombin and fibrinogen ?' 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 ?' modulate fibrin clot structure and strength. PMID:26608329

  13. Thrombin Induces Tumor Invasion through the Induction and Association of Matrix Metalloproteinase-9 and ?1-Integrin on the Cell Surface*

    OpenAIRE

    Radjabi, A. Reza; Sawada, Kenjiro; Jagadeeswaran, Sujatha; Eichbichler, Alfred; Kenny, Hilary A; Montag, Anthony; Bruno, Katharina; Lengyel, Ernst

    2007-01-01

    The procoagulatory serine protease, thrombin, is known to induce invasion and metastasis in various cancers, but the mechanisms by which it promotes tumorigenesis are poorly understood. Because the 92-kDa gelatinase (MMP-9) is a known mediator of tumor cell invasion, we sought to determine whether and how thrombin regulates MMP-9. The thrombin receptor, PAR-1, and MMP-9 are expressed in osteosarcomas, as determined by immunohistochemistry. Stimulation of U2-OS osteosarcoma cells with thrombin...

  14. Topical corticosteroids

    Directory of Open Access Journals (Sweden)

    Laleh Vaziri

    2015-07-01

    Full Text Available Topical corticosteroids (TCs are very useful in the treatment of some skin disorders such as eczema and psoriasis. TCs exhibit potent anti-inflammatory and anti-proliferative effects responsible for their efficacy in the treatment of skin disorders. TCs can be classified into different groups according to their potency; that depends on the intrinsic activity of the corticosteroid molecule, the characteristics of the vehicle (cream, ointment, lotion that directly influence patient’s compliance and may modify penetration through the skin. British National Formulary classified them into four potency groups with Class I grouping the most potent molecules (e.g. clobetasol propionate and Class IV the least potent (e.g. hydrocortisone. In contrast, the American classification considers seven potency groups, with super potent, potent, upper mid-strength, mid-strength, lower mid-strength, mild and least potent.

  15. Kinetic characterization of inhibition of human thrombin with DNA aptamers by turbidimetric assay.

    Science.gov (United States)

    Zavyalova, Elena G; Protopopova, Anna D; Yaminsky, Igor V; Kopylov, Aleksey M

    2012-02-01

    A sensitive turbidimetric method for detecting fibrin association was used to study the kinetics of fibrinogen hydrolysis with thrombin. The data were complemented by high-performance liquid chromatography (HPLC) measurements of the peptide products, fibrinopeptides released during hydrolysis. Atomic force microscopy (AFM) data showed that the fibril diameter is the main geometric parameter influencing the turbidity. The turbidimetric assay was validated using thrombin with the standard activity. To study thrombin inhibitors, a kinetic model that allows estimating the inhibition constants and the type of inhibition was proposed. The kinetic model was used to study the inhibitory activity of the two DNA aptamers 15-TBA (thrombin-binding aptamer) and 31-TBA, which bind to thrombin exosites. For the first time, 31-TBA was shown to possess the competitive inhibition type, whereas the shortened aptamer 15-TBA has the noncompetitive inhibition type. PMID:22056408

  16. Detection of thrombin using an excimer aptamer switch labeled with dual pyrene molecules.

    Science.gov (United States)

    Zhao, Qiang; Cheng, Lin

    2013-10-01

    We constructed an excimer aptamer probe containing one pyrene molecule at each end of a DNA aptamer to achieve the detection of thrombin, which binds to the heparin-binding site of thrombin with high binding affinity. The specific binding of thrombin to the excimer aptamer probe brought the two pyrene molecules at the termini of the duplex of the aptamer into close proximity, generating an excimer. The excimer emitted a distinct fluorescence peak, and fluorometric measurement of excimer allowed the sensitive detection of thrombin. The effects of experimental conditions like pH, ionic strength, and cations were investigated and optimized. The detection limit for thrombin was about 42 pM. This aptamer switch has potential in the study of molecular interactions and protein sensing with other switch-based detection strategy. PMID:23912830

  17. 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.

  18. Platelet activation and aggregation : the importance of thrombin activity--a laboratory model

    DEFF Research Database (Denmark)

    Jensen, Maria Sander; Larsen, O H

    2013-01-01

    This study introduces a new laboratory model of whole blood platelet aggregation stimulated by endogenously generated thrombin, and explores this aspect in haemophilia A in which impaired thrombin generation is a major hallmark. The method was established to measure platelet aggregation initiated by tissue factor evaluated by means of impedance aggregometry. Citrated whole blood from healthy volunteers and haemophilia A patients with the addition of inhibitors of the contact pathway and fibrin polymerization was evaluated. In healthy persons, a second wave of platelet aggregation was found to coincide with the thrombin burst and to be abolished by thrombin inhibitors. In this system, platelet aggregation in severe haemophilia A (n = 10) was found to be significantly decreased as compared with healthy individuals (912 ± 294 vs. 1917 ± 793 AU × min, P = 0.003), most probably due to the weak level of thrombin generation. For the first time, analysis of platelet aggregation as induced by endogenously generated thrombin was demonstrated. The new method makes it possible to explore the influence of the coagulation system on platelet function. In contrast to the general understanding, the data suggest that the impaired thrombin generation in haemophilia may affect platelet activation. Future studies will address whether our results may contribute to understanding differences in bleeding phenotypes and response to haemostatic substitution observed among patients.

  19. Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces

    Science.gov (United States)

    Wheatley Myerson, Jacob; He, Li; Allen, John Stacy; Williams, Todd; Lanza, Gregory; Tollefsen, Douglas; Caruthers, Shelton; Wickline, Samuel

    2014-09-01

    Restoring an antithrombotic surface to suppress ongoing thrombosis is an appealing strategy for treatment of acute cardiovascular disorders such as erosion of atherosclerotic plaque. An antithrombotic surface would present an alternative to systemic anticoagulation with attendant risks of bleeding. We have designed thrombin-targeted nanoparticles (NPs) that bind to sites of active clotting to extinguish local thrombin activity and inhibit platelet deposition while exhibiting only transient systemic anticoagulant effects. Perfluorocarbon nanoparticles (PFC NP) were functionalized with thrombin inhibitors (either D-phenylalanyl-L-prolyl-L-arginyl-chloromethyl ketone or bivalirudin) by covalent attachment of more than 15 000 inhibitors to each PFC NP. Fibrinopeptide A (FPA) ELISA demonstrated that thrombin-inhibiting NPs prevented cleavage of fibrinogen by both free and clot-bound thrombin. Magnetic resonance imaging (MRI) confirmed that a layer of thrombin-inhibiting NPs prevented growth of clots in vitro. Thrombin-inhibiting NPs were administered in vivo to C57BL6 mice subjected to laser injury of the carotid artery. NPs significantly delayed thrombotic occlusion of the artery, whereas an equivalent bolus of free inhibitor was ineffective. For thrombin-inhibiting NPs, only a short-lived (˜10 min) systemic effect on bleeding time was observed, despite prolonged clot inhibition. Imaging and quantification of in vivo antithrombotic NP layers was demonstrated by MRI of the PFC NP. 19F MRI confirmed colocalization of particles with arterial thrombi, and quantitative 19F spectroscopy demonstrated specific binding and retention of thrombin-inhibiting NPs in injured arteries. The ability to rapidly form and image a new antithrombotic surface in acute vascular syndromes while minimizing risks of bleeding would permit a safer method of passivating active lesions than current systemic anticoagulant regimes.

  20. Thrombin-inhibiting nanoparticles rapidly constitute versatile and detectable anticlotting surfaces

    International Nuclear Information System (INIS)

    Restoring an antithrombotic surface to suppress ongoing thrombosis is an appealing strategy for treatment of acute cardiovascular disorders such as erosion of atherosclerotic plaque. An antithrombotic surface would present an alternative to systemic anticoagulation with attendant risks of bleeding. We have designed thrombin-targeted nanoparticles (NPs) that bind to sites of active clotting to extinguish local thrombin activity and inhibit platelet deposition while exhibiting only transient systemic anticoagulant effects. Perfluorocarbon nanoparticles (PFC NP) were functionalized with thrombin inhibitors (either D-phenylalanyl-L-prolyl-L-arginyl-chloromethyl ketone or bivalirudin) by covalent attachment of more than 15 000 inhibitors to each PFC NP. Fibrinopeptide A (FPA) ELISA demonstrated that thrombin-inhibiting NPs prevented cleavage of fibrinogen by both free and clot-bound thrombin. Magnetic resonance imaging (MRI) confirmed that a layer of thrombin-inhibiting NPs prevented growth of clots in vitro. Thrombin-inhibiting NPs were administered in vivo to C57BL6 mice subjected to laser injury of the carotid artery. NPs significantly delayed thrombotic occlusion of the artery, whereas an equivalent bolus of free inhibitor was ineffective. For thrombin-inhibiting NPs, only a short-lived (?10 min) systemic effect on bleeding time was observed, despite prolonged clot inhibition. Imaging and quantification of in vivo antithrombotic NP layers was demonstrated by MRI of the PFC NP. 19F MRI confirmed colocalization of particles with arterial thrombi, and quantitative 19F spectroscopy demonstrated specific binding and retention of thrombin-inhibiting NPs in injured arteries. The ability to rapidly form and image a new antithrombotic surface in acute vascular syndromes while minimizing risks of bleeding would permit a safer method of passivating active lesions than current systemic anticoagulant regimes. (paper)

  1. Thrombostatin FM compounds: direct thrombin inhibitors ? mechanism of action in vitro and in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Nieman, M.T.; Burke, F.; Warnock, M.; Zhou, Y.; Sweigart, J.; Chen, A.; Ricketts, D.; Lucchesi, B.R.; Chen, Z.; Cera, E.Di; Hilfinger, J.; Kim, J.S.; Mosberg, H.I.; Schmaier, A.H. (Case Western); (Michigan); (TSRL); (WU-MED)

    2008-04-29

    Novel pentapeptides called Thrombostatin FM compounds consisting mostly of D-isomers and unusual amino acids were prepared based upon the stable angiotensin converting enzyme breakdown product of bradykinin - RPPGF. These peptides are direct thrombin inhibitors prolonging the thrombin clotting time, activated partial thromboplastin time, and prothrombin time at {>=}0.78, 1.6, and 1.6 {mu}m, respectively. They competitively inhibit {alpha}-thrombin-induced cleavage of a chromogenic substrate at 4.4--8.2 {mu}m. They do not significantly inhibit plasma kallikrein, factor (F) XIIa, FXIa, FIXa, FVIIa-TF, FXa, plasmin or cathepsin G. One form, FM19 [rOicPaF(p-Me)], blocks {alpha}-thrombin-induced calcium flux in fibroblasts with an IC{sub 50} of 6.9 {+-} 1.2 {mu}m. FM19 achieved 100% inhibition of threshold {alpha}- or {gamma}-thrombin-induced platelet aggregation at 8.4 {+-} 4.7 {mu}m and 16 {+-} 4 {mu}m, respectively. The crystal structure of thrombin in complex with FM19 shows that the N-terminal D-Arg retrobinds into the S1 pocket, its second residue Oic interacts with His-57, Tyr-60a and Trp-60d, and its C-terminal p-methyl Phe engages thrombin's aryl binding site composed of Ile-174, Trp-215, and Leu-99. When administered intraperitoneal, intraduodenal, or orally to mice, FM19 prolongs thrombin clotting times and delays carotid artery thrombosis. FM19, a low affinity reversible direct thrombin inhibitor, might be useful as an add-on agent to address an unmet need in platelet inhibition in acute coronary syndromes in diabetics and others who with all current antiplatelet therapy still have reactive platelets.

  2. Topical haemostatic agents for skin wounds: a systematic review

    Directory of Open Access Journals (Sweden)

    Ubbink Dirk T

    2011-07-01

    Full Text Available Abstract Background Various agents and techniques have been introduced to limit intra-operative blood loss from skin lesions. No uniformity regarding the type of haemostasis exists and this is generally based on the surgeon's preference. To study the effectiveness of haemostatic agents, standardized wounds like donor site wounds after split skin grafting (SSG appear particularly suitable. Thus, we performed a systematic review to assess the effectiveness of haemostatic agents in donor site wounds. Methods We searched all randomized clinical trials (RCTs on haemostasis after SSG in Medline, Embase and the Cochrane Library until January 2011. Two reviewers independently assessed trial relevance and quality and performed data analysis. Primary endpoint was effectiveness regarding haemostasis. Secondary endpoints were wound healing, adverse effects, and costs. Results Nine relevant RCTs with a fair methodological quality were found, comparing epinephrine, thrombin, fibrin sealant, alginate dressings, saline, and mineral oil. Epinephrine achieved haemostasis significantly faster than thrombin (difference up to 2.5 minutes, saline or mineral oil (up to 6.5 minutes. Fibrin sealant also resulted in an up to 1 minute quicker haemostasis than thrombin and up to 3 minutes quicker than placebo, but was not directly challenged against epinephrine. Adverse effects appeared negligible. Due to lack of clinical homogeneity, meta-analysis was impossible. Conclusion According to best available evidence, epinephrine and fibrin sealant appear superior to achieve haemostasis when substantial topical blood loss is anticipated, particularly in case of (larger SSGs and burn debridement.

  3. Thrombin promotes epithelial ovarian cancer cell invasion by inducing epithelial-mesenchymal transition

    OpenAIRE

    Zhong, Yi-Cun; Zhang, Ting; Di, Wen; LI, WEI-PING

    2013-01-01

    Objective Over-expression of thrombin in ovarian cancer cells is associated with poor prognosis. In this study, we investigated the role of thrombin in inducing epithelial-mesenchymal transition (EMT) in SKOV3 epithelial ovarian cancer cells. Methods After thrombin treatment SKOV3 cells were subjected to western blots, reverse-transcription PCR, and enzyme-linked immunosorbent assay to quantify EMT-related proteins, mRNA expression of SMAD2, DKK1, and sFRP1, and the secretion of matrix metall...

  4. Detection of a new heparin-dependent inhibitor of thrombin in human plasma.

    OpenAIRE

    Tollefsen, D.M.; Blank, M K

    1981-01-01

    We have demonstrated that human plasma contains a heparin-dependent inhibitor of thrombin that is distinguishable from antithrombin III (AT III). When a 1:50 dilution of plasma was incubated with greater than or equal to 0.01 U/ml heparin and 1 U/ml 125I-thrombin, the labeled thrombin B-chains became incorporated into two complexes of Mr-96,000 and Mr-85,000 that were separated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and beta-mercaptoethanol. Neither co...

  5. A fluorescent sandwich assay for thrombin using aptamer modified magnetic beads and quantum dots

    International Nuclear Information System (INIS)

    We describe an aptamer-based sandwich assay for thrombin by using a pair of thrombin-binding aptamers, namely one 15-mer aptamer (denoted as Apt15) and one 29-mer aptamer (denoted as Apt29). Either Apt29 or Apt15 can be used as capture aptamers on magnetic beads or reporter aptamers on the quantum dots to form the sandwich complex. Detection of thrombin is achieved by the fluorescent measurement of quantum dots in the sandwich complex. The choice of capture aptamers and reporter aptamers, and the effect of the addition order of the aptamers modified magnetic beads and the aptamers modified quantum dots were investigated. Detection of 0.05 nM thrombin was accomplished. The proteins hemoglobin, lysozyme, and transferrin did not interfere in this assay. (author)

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

    International Nuclear Information System (INIS)

    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 125I-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 125I fibrinogen was transformed after ancrod exposure into a non-coagulating fraction of fibrinogen derivatives which produces no fibrinolytic decomposition products. (orig./AJ)

  7. Plasma from chronic liver disease subjects exhibit differential ability to generate thrombin.

    Science.gov (United States)

    Yang, Zhineng J; Sheth, Siddharth H; Smith, Chad H; Schmotzer, Amy R; Lippello, Anita L; Al-Khafaji, Ali; Chopra, Kapil B; Smith, Roy E

    2015-10-01

    Liver fibrosis in chronic liver disease (CLD) results in complex alterations in procoagulant and anticoagulant proteins. Although an elevated international normalized ratio (INR) is a prominent feature of progressive fibrosis, the utility of the INR to accurately reflect the net effect of these changes on the coagulation system is uncertain. In subjects with CLD, elevated INRs have been observed in both bleeding and thrombotic complications, suggesting limitations of the INR in characterizing the coagulation status. Unlike the INR, which is preferentially sensitive to the extrinsic pathway, the direct measurement of thrombin generation better captures the global coagulation cascade. We conducted a pilot study measuring the INR, chromogenic factor X and thrombin generation in CLD subjects and compared them with control subjects and subjects on warfarin anticoagulation. We observed a large interquartile range in thrombin generation among compensated CLD subjects across a narrow INR range, suggesting that the INR is a suboptimal surrogate measure of thrombin generation in CLD subjects. PMID:26200653

  8. The tick-derived anticoagulant madanin is processed by thrombin and factor Xa.

    Science.gov (United States)

    Figueiredo, Ana C; de Sanctis, Daniele; Pereira, Pedro José Barbosa

    2013-01-01

    The cysteine-less peptidic anticoagulants madanin-1 and madanin-2 from the bush tick Haemaphysalis longicornis are the founding members of the MEROPS inhibitor family I53. It has been previously suggested that madanins exert their functional activity by competing with physiological substrates for binding to the positively charged exosite I (fibrinogen-binding exosite) of ?-thrombin. We hereby demonstrate that competitive inhibition of ?-thrombin by madanin-1 or madanin-2 involves binding to the enzyme's active site. Moreover, the blood coagulation factors IIa and Xa are shown to hydrolyze both inhibitors at different, although partially overlapping cleavage sites. Finally, the three-dimensional structure of the complex formed between human ?-thrombin and a proteolytic fragment of madanin-1, determined by X-ray crystallography, elucidates the molecular details of madanin-1 recognition and processing by the proteinase. Taken together, the current findings establish the mechanism of action of madanins, natural anticoagulants that behave as cleavable competitive inhibitors of thrombin. PMID:23951260

  9. Thrombin inhibits the anti-myeloperoxidase and ferroxidase functions of ceruloplasmin: relevance in rheumatoid arthritis.

    Science.gov (United States)

    Sokolov, Alexej V; Acquasaliente, Laura; Kostevich, Valeria A; Frasson, Roberta; Zakharova, Elena T; Pontarollo, Giulia; Vasilyev, Vadim B; De Filippis, Vincenzo

    2015-09-01

    Human ceruloplasmin (CP) is a multifunctional copper-binding protein produced in the liver. CP oxidizes Fe(2+) to Fe(3+), decreasing the concentration of Fe(2+) available for generating harmful oxidant species. CP is also a potent inhibitor of leukocyte myeloperoxidase (MPO) (Kd=130nM), a major source of oxidants in vivo. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease affecting flexible joints and characterized by activation of both inflammatory and coagulation processes. Indeed, the levels of CP, MPO, and thrombin are markedly increased in the synovial fluid of RA patients. Here we show that thrombin cleaves CP in vitro at (481)Arg-Ser(482) and (887)Lys-Val(888) bonds, generating a nicked species that retains the native-like fold and the ferroxidase activity of the intact protein, whereas the MPO inhibitory function of CP is abrogated. Analysis of the synovial fluid of 24 RA patients reveals that CP is proteolytically degraded to a variable extent, with a fragmentation pattern similar to that observed with thrombin in vitro, and that proteolysis is blocked by hirudin, a highly potent and specific thrombin inhibitor. Using independent biophysical techniques, we show that thrombin has intrinsic affinity for CP (Kd=60-270nM), independent of proteolysis, and inhibits CP ferroxidase activity (KI=220±20nM). Mapping of thrombin binding sites with specific exosite-directed ligands (i.e., hirugen, fibrinogen ?'-peptide) and thrombin analogues having the exosites variably compromised (i.e., prothrombin, prethrombin-2, ?T-thrombin) reveals that the positively charged exosite-II of thrombin binds to the negatively charged upper region of CP, while the protease active site and exosite-I remain accessible. These results suggest that thrombin can exacerbate inflammation in RA by impairing the MPO inhibitory function of CP via proteolysis and by competitively inhibiting CP ferroxidase activity. Notably, local administration of hirudin, a highly potent and specifc thrombin inhibitor, reduces the concentration of active MPO in the synovial fluid of RA patients and has a beneficial effect on the clinical symptoms of the disease. PMID:26001728

  10. Percutaneous ultrasound-guided thrombin injection for the treatment of iatrogenic femoral artery pseudoaneurysms

    Energy Technology Data Exchange (ETDEWEB)

    Vlachou, Paraskevi A. [Department of Radiology, Leicester Royal Infirmary, Leicester (United Kingdom); Karkos, Christos D., E-mail: ckarkos@hotmail.com [Department of Vascular and Endovascular Surgery, Leicester Royal Infirmary, Leicester (United Kingdom); Bains, Salena; McCarthy, Mark J. [Department of Vascular and Endovascular Surgery, Leicester Royal Infirmary, Leicester (United Kingdom); Fishwick, Guy; Bolia, Amman [Department of Radiology, Leicester Royal Infirmary, Leicester (United Kingdom)

    2011-01-15

    Purpose: To audit our experience with ultrasound-guided thrombin injection for the treatment of iatrogenic femoral artery pseudoaneurysms. Methods: A retrospective study of 85 consecutive patients undergoing percutaneous ultrasound-guided thrombin injection of post-catheterization femoral pseudoaneurysms during the period January 2002 to May 2007. Results: Pseudoaneurysms had a mean maximum diameter of 3.3 cm (range 1.0-7.6 cm) and a mean neck width of 3.4 mm (range 1.0-7.0 mm). No statistically significant correlation existed between maximum diameter and neck width (Kendall's rank correlation tau b = -0.09, p = 0.5). The median dose of thrombin injected was 425 U (range 100-1500 U). The procedure resulted in complete sac thrombosis in 81 (95%) patients. Seventy-nine pseudoaneurysms thrombosed immediately after one injection, whereas two required a second thrombin injection. There were no procedural complications. The maximum diameter of the pseudoaneurysm was predictive of procedural success (Wilcoxon's rank sum test, p = 0.001) and of the 5 patients with a pseudoaneurysm measuring {>=}6 cm, ultrasound-guided thrombin injection was unsuccessful in 4 (4/5 versus 0/80, p < 0.0001, Fisher's exact test). Three of these necessitated implantation of a stent-graft, whereas one required repeated thrombin injection and coil placement. In contrast, the pseudoaneurysm neck width did not seem to relate to the success of the procedure. Conclusion: Percutaneous ultrasound-guided thrombin injection of is a quick, effective and safe treatment for iatrogenic femoral pseudoaneurysms. For larger pseudoaneurysms, although it is worth attempting more than one thrombin injection, endovascular repair may eventually be required.

  11. A novel purification method for histidine-tagged proteins containing a thrombin cleavage site

    OpenAIRE

    Hefti, M.H.; Vugt-Toorn, C.J., van der; Dixon, R.; Vervoort, J. J. M.

    2001-01-01

    A general procedure for the purification of histidine-tagged proteins has been developed using immobilized metal-ion affinity chromatography. This two-step purification method can be used for proteins containing a hexahistidine tag and a thrombin cleavage site, yielding high amounts of purified protein. The advantage of this method is that thrombin is used instead of imidazole in the final purification step. Imidazole can influence NMR experiments, competition studies, or crystallographic tri...

  12. Thrombin related peptide TP508 promoted fracture repair in a mouse high energy fracture model

    OpenAIRE

    Pan Xiao-Hua; Ryaby James T; Hanratty Brain M; Li Gang

    2009-01-01

    Abstract Background Thrombin related peptide (TP508) is a 23 amino-acid synthetic peptide that represents a portion of the receptor-binding domain of thrombin molecule. Previous studies have shown that TP508 can accelerate musculoskeletal tissue repair including fracture healing. Objectives The aim of this study was to investigate the effect of TP508 on fracture healing in a murine fracture model representing high energy fracture situation. Methods Eighty CD 1 mice underwent controlled quadri...

  13. Thrombin induction of plasminogen activator-inhibitor in cultured human endothelial cells.

    OpenAIRE

    Gelehrter, T. D.; Sznycer-Laszuk, R

    1986-01-01

    We have examined the effect of thrombin on the activity of plasminogen activator (PA) and plasminogen activator-inhibitor (PA-I) in medium conditioned by primary cultures of human umbilical vein endothelial cells. PA activity was measured by fibrinolytic and esterolytic assays, and total tissue-type PA (tPA) antigen by radioimmunoassay. Net PA-I activity was assayed by titration of human urokinase esterolytic activity. Incubation of confluent endothelial cell cultures with thrombin for 24 h c...

  14. Induction of KDR expression in bovine arterial endothelial cells by thrombin: involvement of nitric oxide.

    Science.gov (United States)

    Wang, Jie; Morita, Ikuo; Onodera, Mitsue; Murota, Sei-Itsu

    2002-02-01

    Thrombin, a multifunctional serine protease, is generated at the site with vascular injuries. It not only participates in the coagulation cascade, but also can induce a lot of events related to cell mitogenesis and migration. In this study, we investigated the effect of thrombin on endothelial cell proliferation induced by vascular endothelial growth factor (VEGF). Thrombin promoted proliferation of cultured bovine carotid endothelial cells in a time- and dose-dependent manner. Moreover, it drastically enhanced the cell growth stimulated by VEGF. This stimulatory effect was reduced by inhibitors of either protein kinase C (PKC) or mitogen-activated protein kinase kinase (MAPKK). Thrombin induced a significant increase in the level of mRNA of the kinase domain-containing receptor (KDR), but not tms-like tyrosine kinase (Flt-1), in a time-dependent manner, which reached the maximum after 24 h of stimulation. This increase coincides well with the KDR protein expression. The luciferase assay showed that thrombin induced an about 7.5-fold increase in the KDR promoter activity compared with the control. This enhanced KDR promoter activity was also abolished by inhibitors of either PKC or MAPKK. The deletion analyses indicated that the region between -115 and -97 (containing Sp1 binding region) within the KDR promoter gene was required for the enhanced KDR expression induced by thrombin and VEGF. Moreover, the nitric oxide synthase (NOS) inhibitor abolished both the accelerated cell proliferation and the increased KDR expression induced by thrombin and VEGF. This inhibition was abrogated by DETA NONOate, a NO donor with long half-life. These findings suggest that thrombin might potentiate the VEGF-induced angiogenic activity through increasing the level of the VEGF receptor KDR, in which production of NO is involved. PMID:11807828

  15. A label-free electrochemical aptasensor for sensitive thrombin detection in whole blood

    International Nuclear Information System (INIS)

    In this paper, we reported a novel label-free electrochemical aptasensors for thrombin detection in whole blood using self-assembled multilayers with carboxymethyl-PEG-carboxymethyl (CM-PEG-CM) and thrombin-binding aptamer (TBA). In the sensing strategy, CM-PEG-CM and TBA were assembled on the electrode surface via covalent binding. In the presence of target, the TBA on the outermost layer of the self-assembled multilayer would catch the target on the electrode interface, which makes a barrier for electrons and inhibits the electro-transfer, resulting in the decreased DPV signals. Using this strategy, a wide detection range (1 pM–160 nM) for target thrombin was obtained, with a low detection limit of 1.56 × 10−14 M. The control experiments were also carried out by using bull serum albumin (BSA) and lysozyme in the absence of thrombin. The results showed that the aptasensors had good specificity, stability and reproducibility to thrombin. Moreover, the aptasensors could be used for detection of thrombin in whole blood which could provide a promising platform for fabrication of aptamer based biosensors in clinical application

  16. Leptospira interrogans reduces fibrin clot formation by modulating human thrombin activity via exosite I.

    Science.gov (United States)

    Fernandes, Luis G; de Morais, Zenaide M; Vasconcellos, Silvio A; Nascimento, Ana L T O

    2015-06-01

    Pathogenic bacteria of the genus Leptospira are the etiological agents of leptospirosis, a disease that affects humans and animals worldwide. Although there are an increasing number of studies on the biology of Leptospira, the mechanisms of pathogenesis are not yet understood. We report in this work that Leptospira interrogans FIOCRUZ L1-130 virulent, M20 culture attenuated and the saprophyte L. biflexa Patoc 1 strains do not bind prothrombin. Leptospiral binding to thrombin was detected with the virulent, followed by culture-attenuated M20, and practically none was observed with the saprophyte strain. The interaction of Leptospira with thrombin mostly occurs via exosite I, with a minor participation of catalytic site, as determined by employing the thrombin inhibitors hirugen, hirudin and argatroban. Leptospira interrogans binding to thrombin inhibits its catalytic activity reducing fibrin clot formation in thrombin-catalyzed reaction of fibrinogen. This inhibition was more efficient with the virulent FIOCRUZ L1-130 than with the M20 culture attenuated, while none was seen with the saprophyte strain, suggesting that this binding might be important for bacterial virulence. This is the first study reporting the binding of pathogenic Leptospira to thrombin promoting a decrease in fibrin clotting that could lead to hemorrhage, helping bacteria dissemination. PMID:25834144

  17. Thrombin Production and Human Neutrophil Elastase Sequestration by Modified Cellulosic Dressings and Their Electrokinetic Analysis

    Directory of Open Access Journals (Sweden)

    Nicolette Prevost

    2011-12-01

    Full Text Available Wound healing is a complex series of biochemical and cellular events. Optimally, functional material design addresses the overlapping acute and inflammatory stages of wound healing based on molecular, cellular, and bio-compatibility issues. In this paper the issues addressed are uncontrolled hemostasis and inflammation which can interfere with the orderly flow of wound healing. In this regard, we review the serine proteases thrombin and elastase relative to dressing functionality that improves wound healing and examine the effects of charge in cotton/cellulosic dressing design on thrombin production and elastase sequestration (uptake by the wound dressing. Thrombin is central to the initiation and propagation of coagulation, and elastase is released from neutrophils that can function detrimentally in a stalled inflammatory phase characteristic of chronic wounds. Electrokinetic fiber surface properties of the biomaterials of this study were determined to correlate material charge and polarity with function relative to thrombin production and elastase sequestration. Human neutrophil elastase sequestration was assessed with an assay representative of chronic wound concentration with cotton gauze cross-linked with three types of polycarboxylic acids and one phosphorylation finish; thrombin production, which was assessed in a plasma-based assay via a fluorogenic peptide substrate, was determined for cotton, cotton-grafted chitosan, chitosan, rayon/polyester, and two kaolin-treated materials including a commercial hemorrhage control dressing (QuickClot Combat Gauze. A correlation in thrombin production to zeta potential was found. Two polycarboxylic acid cross linked and a phosphorylated cotton dressing gave high elastase sequestration.

  18. Regulation of fibrin-mediated tumor cell adhesion to the endothelium using anti-thrombin aptamer.

    Science.gov (United States)

    Gaddes, Erin R; Lee, Deborah; Gydush, Gregory; Wang, Yong; Dong, Cheng

    2015-12-10

    Molecular intervention during transient stages of various metastatic pathways may lead to development of promising therapeutic technologies. One of such involves soluble fibrin (sFn) that has been implicated as a cross-linker between circulating blood or tumor cells and endothelial cell receptors, promoting cell arrest on the endothelium during circulation. sFn generation is a result of thrombin-mediated fibrinogen (Fg) cleavage due to either vascular injuries or a tumor microenvironment. For cancer therapy, thrombin-mediated conversions of Fg to sFn thus serve as potential intervention points to decrease circulating tumor cell adhesion to the endothelium and subsequent metastatic events. The purpose of this work was to investigate the function of an anti-thrombin oligonucleotide aptamer in reducing tumor cell arrest. Both molecular and cellular interactions were examined to demonstrate the binding and inhibitory effects of anti-thrombin aptamer. The results show that the aptamer is capable of inhibiting thrombin-mediated Fg conversion, thereby reducing sFn-mediated tumor cell adhesion in a concentration-dependent manner. Notably, the aptamer is able to bind thrombin under dynamic flow conditions and reduce tumor cell adhesive events at various physiological shear rates. This study further indicates that oligonucleotide aptamers hold great promise as therapeutic regulators of tumor cell adhesion, and consequently, metastatic activity. PMID:26481421

  19. Pulsatile equibiaxial stretch inhibits thrombin-induced RhoA and NF-?B activation

    International Nuclear Information System (INIS)

    This study investigated interactions between the effects of mechanical stretch and thrombin on RhoA activation in rat aortic smooth muscle cells (RASMC). Equibiaxial, pulsatile stretch, or thrombin produced a significant increase in RhoA activation. Surprisingly, in combination, 30 min of stretch inhibited the ability of thrombin to activate RhoA. NO donors and 8-bromo-cGMP significantly inhibited thrombin-induced RhoA activation. Interestingly, the nitric oxide synthase (NOS) inhibitor L-NAME increased basal RhoA activity, suggesting that NOS activity exerts a tonic inhibition on RhoA. Stretching RASMC increases nitrite production, consistent with the idea that NO contributes to the inhibitory effects of stretch. Thrombin stimulates MAP kinase and NF-?B pathways through Rho and these responses were blocked by 8-bromo-cGMP or stretch and restored by L-NAME. These data suggest that stretch, acting through NO and cGMP, can prevent the ability of thrombin to stimulate Rho signaling pathways that contribute to pathophysiological proliferative and inflammatory responses

  20. How does association process affect fibrinogen hydrolysis by thrombin?

    Science.gov (United States)

    Zavyalova, Elena; Kopylov, Alexey

    2014-12-01

    Thrombin, a key enzyme in the blood coagulation cascade, hydrolyzes fibrinogen into fibrin, which specifically associates into the fibers that build up a thrombus scaffold. The assembly of fibrin involves a set of stepwise reactions, for which a complete and detailed kinetic portrait is needed. Existing kinetic models focus on particular parts of the process, for example the mechanism of enzyme action itself or the kinetics of formation of fibrin assemblies. The current study considers a thorough model of the process from fibrinogen hydrolysis to the assembly of fibrin. Composing the model requires taking into account several reaction intermediates, stepwise removal of fibrinopeptides, and association of partially hydrolyzed fibrin, in particular desAA fibrin. The model is versatile enough to adopt new data both on fibrinogen hydrolysis and fibrin association. In addition, the model could be considered as an example of a kinetic description of other complex enzyme systems having several intermediates and feedbacks, such as the blood coagulation cascade and signal transduction. PMID:25239831

  1. Thrombin generation as a predictor of radiotherapy induced skin erythema

    International Nuclear Information System (INIS)

    Background and purpose: Biological mechanisms underlying radiation induced erythema remain largely unknown, with no simple way to accurately predict or prevent extreme cases. Based on the recent findings in patients suffering from chronic urticaria, we sought to determine if similar mechanisms of hypercoagulation contributed to comparable skin reactions during radiotherapy. Materials and methods: Plasma levels of prothrombin factor 1+2 (F1+2), D-dimers and plasminogen activator inhibitor-1 (Pai-1) were tested in 32 women undergoing irradiation following breast conserving surgery for early breast cancer. Reflectance spectrophotometry was used to objectively assess erythema throughout the treatment by measuring the amount of light reflected from the skin surface as a function of wavelength. Correlations between peak levels of erythema and plasma biomarkers were then assessed. Results: Individual peak reflectance readings generally occurred between day 29 of treatment and 2 weeks post radiotherapy, and represented a median increase of 66% (range: 11-146%; p < 0.001) from baseline. Peak reflectance correlated with F1+2 and Pai-1 levels measured both at baseline and day 29 of treatment, and multivariate analysis indicated that these two baseline measurements were the best predictors of peak reflectance, accounting for 59% of the variability in erythema (p = 0.000004). Conclusions: Patients with signs of intravascular thrombin generation are at higher risk of radiotherapy-induced skin reactions, providing a new therapeutic avenue for possibly predicting and preventing this side effect of cancer treatment

  2. Design, synthesis and evaluation of graftable thrombin inhibitors for the preparation of blood-compatible polymer materials.

    OpenAIRE

    Salvagnini, Claudio; Michaux, Catherine; Remiche, Julie; Wouters, Johan; Charlier, Paulette; Marchand-Brynaert, Jacqueline

    2005-01-01

    Piperazinyl-amide derivatives of N-alpha-(3-trifluoromethyl-benzenesulfonyl)-L-arginine (1) were synthesized as graftable thrombin inhibitors. The possible disturbance of biological activity due to a variable spacer-arm fixed on the N-4 piperazinyl position was evaluated in vitro, against human alpha-thrombin, and in blood coagulation assay. Molecular modelling (in silico analysis) and X-ray diffraction studies of thrombin-inhibitor complexes were also performed. The fixation of bioactive mol...

  3. Effects of alpha(2)-macroglobulin and antithrombin on thrombin generation and inhibition in cord and adult plasma.

    Science.gov (United States)

    Cvirn, G; Gallistl, S; Muntean, W

    2001-02-01

    Thromboembolic complications rarely occur during infancy and childhood. It has been reported that increased capacity of cord plasma to inhibit thrombin due to elevated alpha(2)-macroglobulin (alpha(2)-M) levels may in part provide protection from thrombosis. In antithrombin (AT)-deficient plasma, alpha(2)-M exhibits anticoagulant action by complexing substantial amounts of generated free thrombin. It has been suggested that alpha(2)-M has the same impact on thrombin inhibition as AT, the most important thrombin inhibitor in adult plasma. The aim of our study was to examine this assumption by determining time-courses of free thrombin generation and prothrombin activation. Additionally, the amount of thrombin complexed to alpha(2)-M was assessed by comparing the heights of the end-level of amidolytic activity curves (AACs) after extrinsic activation of platelet poor plasma in the presence of different concentrations of AT or alpha(2)-M. Increasing the AT content by 30% resulted in significantly suppressed generation of free thrombin and prothrombin fragment 1+2 (F1+2) in cord and adult plasma. In contrast, increasing the alpha(2)-M content in plasma containing physiologic amounts of AT by the same percentage had no effect on free thrombin generation and on F1+2 generation in both cord and adult plasma. In addition, the effect of AT supplementation on the end-level of the AACs was significantly higher compared to the effect of alpha(2)-M supplementation. Since alpha(2)-M, in contrast to AT, had no effect on free thrombin generation and prothrombin activation, our study suggests that the action between alpha(2)-M and thrombin might not be fast enough to prevent thrombin from its feedback activation in both cord and adult plasma and, therefore, in cord and adult plasma containing physiological amounts of AT alterations of the alpha(2)-M content had no effect on thrombin generation and inhibition. PMID:11228341

  4. Acceleration of the thrombin inactivation of single chain urokinase-type plasminogen activator (pro-urokinase) by thrombomodulin.

    OpenAIRE

    de Munk, G A; Groeneveld, E; Rijken, D.C.

    1991-01-01

    The in vitro effects of thrombomodulin on the inactivation of single chain urokinase-type plasminogen activator (scu-PA) by thrombin were investigated by incubating scu-PA with varying concentrations of human thrombin, in both the absence and presence of soluble rabbit thrombomodulin. 50% inactivation of scu-PA occurred in 45 min at 160 ng/ml thrombin in the absence of thrombomodulin and at 4.6 ng/ml thrombin in the presence of thrombomodulin. No difference was found in either the absence or ...

  5. 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. PMID:25314620

  6. Design and characterization of hirulogs: A novel class of bivalent peptide inhibitors of thrombin

    International Nuclear Information System (INIS)

    A novel class of synthetic peptides has been designed that inhibit the thrombin catalytic site and exhibit specificity for the anion-binding exosite (ABE) of ?-thrombin. These peptides, called hirulogs, consist of (i) an active-site specificity sequence with a restricted Arg-Pro scissile bond, (ii) a polymeric linker of glycyl residues from 6 to 18 angstrom in length, and (iii) an ABE recognition sequence such as that in the hirudin C-terminus. Hirulog-1 [(D-Phe)-Pro-Arg-Pro-(Gly)4-Asn-Gly-Asp-Phe-Glu-Glu-Ile-Pro-Glu-Tyr-Leu] inhibits the thrombin-catalyzed hydrolysis of a tripeptide p-nitroanilide substrate with Ki = 2.3 nM. In contrast, the synthetic C-terminal hirudin peptide S-Hir53-64, which binds to the thrombin ABE, blocked the fibrinogen clotting activity of the enzyme with Ki = 144 nM but failed to inhibit the hydrolysis of p-nitroanilide substrates at concentrations as high as 1 mM. Hirulog-1, but not S-Hir53-64, was found to inhibit the incorporation of [14C]diisopropyl fluorophosphate in thrombin. Hirulog-1 appears specific for thrombin as it lacks inhibitory activities toward human factor Xa, human plasmin, and bovine trypsin at inhibitor:enzyme concentrations 3 orders of magnitude higher than those required to inhibit thrombin. The optimal inhibitory activity of hirulog-1 depends upon all three components of its structure. Comparison of anticoagulant activities of hirulog-1, hirudin, and S-Hir53-64 showed that the synthetic hirulog-1 is 2-fold more potent than hirudin and 100-fold more active than S-Hir53-64 in increasing the activated partial thromboplastin time of normal human plasma

  7. Percutaneous treatment of femoral pseudoaneurysms: comparison of fibrin sealant against thrombin

    Directory of Open Access Journals (Sweden)

    Daniel Mendes Pinto

    2013-12-01

    Full Text Available INTRODUCTION: Femoral pseudoaneurysms are a complication that occurs in connection with up to 8% of percutaneous procedures. Of the available treatments, ultrasound guided thrombin injection has a high success rate and is well-tolerated by patients. The combination of thrombin and fibrinogen known as fibrin sealant forms a stable clot and can be used to treat pseudoaneurysms, particularly those with complex anatomy and larger size. OBJECTIVE: To compare the results of treating femoral pseudoaneurysm in two ways: Group T was treated with thrombin alone and Group T+F was treated with fibrin sealant (thrombin+fibrinogen. METHODS: A retrospective analysis was conducted of femoral pseudoaneurysm cases treated between January 2005 and December 2012. RESULTS: Twenty-eight patients were treated, 21 with thrombin alone and seven with fibrin sealant. All patients in group T were treated successfully, but only four patients in group T+F were treated successfully (57.1% success rate in Group T+F, p<0.01. The three cases of failure in group T+F needed surgery and in one of these cases the complication was embolization to the femoral bifurcation. The pseudoaneurysms that were treated with fibrin sealant were larger (25 cm3 in Group T and 57.7 cm3 in Group T+F, p=0.02 and required larger volumes of thrombin (0.5 mL in Group T and 1.0 mL in Group T+F, p<0.01. There was one complication in Group T and two complications in Group T+F (p<0.01. CONCLUSIONS: Irrespective of the small number of cases reviewed, treatment with thrombin alone was superior to treating with fibrin sealant, since it caused few complications and was more effective at correcting pseudoaneurysms.

  8. The effect of resveratrol on the platelet secretory process induced by endotoxin and thrombin.

    Science.gov (United States)

    Olas, B; Wachowicz, B; Szewczuk, J; Saluk-Juszczak, J; Kaca, W

    2001-01-01

    The effect of resveratrol (trans-3,4',5-trihydroxystilbene) on the release of adenine nucleotides and proteins from blood platelets activated by lipopolysaccharide (LPS), from Proteus mirabilis and by thrombin, were studied. Thrombin stimulated the release of adenine nucleotides from dense granules and proteins from alpha-granules. The LPS (0.3 microg/10(8) platelets, 5 min, 37 degrees C), like thrombin (2.5 U/10(8) platelets, 5 min, 37 degrees C) was found to cause a release of adenine nucleotides and proteins (p <0.05). Resveratrol (6.25-100 microg/ml, 30 min, 37 degrees C) had a different effect on the platelet release reaction caused by either LPS or thrombin. The results indicated that resveratrol inhibited, in dose-dependent manner, the secretory process (release of adenine nucleotides and proteins) induced by thrombin (p <0.05), but it significantly stimulated the liberation of proteins from blood platelets activated by LPS (p <0.05). PMID:11368092

  9. Gold nanocluster-encapsulated glucoamylase as a biolabel for sensitive detection of thrombin with glucometer readout

    International Nuclear Information System (INIS)

    This article reports on a sensitive aptamer-based assay for thrombin. The assay includes the following steps: (a) a first thrombin-specific aptamer (P1) was immobilized on the surface of the wells of a microtiter plate via biotin-streptavidin interaction; (b) gold nanoclusters (GNCs) were used to cover the enzyme glucoamylase via a reverse micelle method; (c) the GNCs were then coated with the second aptamer (P2) via thiol chemistry; (d) addition of a solution containing thrombin to the well, and (e) subsequent addition of amylopectin. The glucoamylase in the GNC label catalytically hydrolyzes the amylopectin to form glucose which then is quantified with a glucometer. Under optimal conditions, the signal for glucose increases with the concentration of thrombin in range from 0.05 to 100 nM, and the detection limit is as low as 10 pM. The assay has a good repeatability and displays an intermediate precision of down to 11 %. Nonspecific adsorption was not observed in a series of analyses. The method was applied to the determination of thrombin in spiked serum samples, and the recoveries ranged from 94 to 110 %. The method is assumed to have a wide scope in that it may be extended to numerous other analytes for which appropriate aptamers are available. (author)

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

    Science.gov (United States)

    Ocaña, Cristina; Del Valle, Manel

    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). PMID:26920780

  11. Genetic Determinants of Thrombin Generation and Their Relation to Venous Thrombosis: Results from the GAIT-2 Project

    Science.gov (United States)

    Martin-Fernandez, Laura; Ziyatdinov, Andrey; Carrasco, Marina; Millon, Juan Antonio; Martinez-Perez, Angel; Vilalta, Noelia; Brunel, Helena; Font, Montserrat; Hamsten, Anders; Souto, Juan Carlos; Soria, José Manuel

    2016-01-01

    Background Venous thromboembolism (VTE) is a common disease where known genetic risk factors explain only a small portion of the genetic variance. Then, the analysis of intermediate phenotypes, such as thrombin generation assay, can be used to identify novel genetic risk factors that contribute to VTE. Objectives To investigate the genetic basis of distinct quantitative phenotypes of thrombin generation and its relationship to the risk of VTE. Patients/Methods Lag time, thrombin peak and endogenous thrombin potential (ETP) were measured in the families of the Genetic Analysis of Idiopathic Thrombophilia 2 (GAIT-2) Project. This sample consisted of 935 individuals in 35 extended families selected through a proband with idiopathic thrombophilia. We performed also genome wide association studies (GWAS) with thrombin generation phenotypes. Results The results showed that 67% of the variation in the risk of VTE is attributable to genetic factors. The heritabilities of lag time, thrombin peak and ETP were 49%, 54% and 52%, respectively. More importantly, we demonstrated also the existence of positive genetic correlations between thrombin peak or ETP and the risk of VTE. Moreover, the major genetic determinant of thrombin generation was the F2 gene. However, other suggestive signals were observed. Conclusions The thrombin generation phenotypes are strongly genetically determined. The thrombin peak and ETP are significantly genetically correlated with the risk of VTE. In addition, F2 was identified as a major determinant of thrombin generation. We reported suggestive signals that might increase our knowledge to explain the variability of this important phenotype. Validation and functional studies are required to confirm GWAS results. PMID:26784699

  12. A Universal Base in a Specific Role: Tuning up a Thrombin Aptamer with 5-Nitroindole

    Science.gov (United States)

    Tsvetkov, Vladimir B.; Varizhuk, Anna M.; Pozmogova, Galina E.; Smirnov, Igor P.; Kolganova, Natalia A.; Timofeev, Edward N.

    2015-11-01

    In this study we describe new modified analogs of the thrombin binding aptamer (TBA) containing 5-nitroindole residues. It has been shown that all modified TBAs form an anti-parallel G-quadruplex structure and retain the ability to inhibit thrombin. The most advanced TBA variant (TBA-N8) has a substantially increased clotting time and two-fold lower IC50 value compared to the unmodified prototype. Molecular modelling studies suggest that the improved anticoagulant properties of TBA-N8 result from changes in the binding mode of the analog. A modified central loop in TBA-N8 is presumed to participate in the binding of the target protein. Studies of FAM labelled TBA and TBA-N8 showed an improved binding affinity of the modified aptamer and provided evidence of a direct interaction between the modified central loop and thrombin. Our findings have implications for the design of new aptamers with improved binding affinities.

  13. Development of Orally Active Thrombin Inhibitors for the Treatment of Thrombotic Disorder Diseases

    Directory of Open Access Journals (Sweden)

    Li-Wei He

    2015-06-01

    Full Text Available Thrombotic disorders represent the major share of the various cardiovascular diseases, and significant progress has been made in the development of synthetic thrombin inhibitors as new anticoagulants. In addition to the development of highly potent and selective inhibitors with improved safety and suitable half-life, several allosteric inhibitors have been designed and synthesized, that did not fully nullify the procoagulant signal and thus could result in reduced bleeding complications. Furthermore, natural products with thrombin inhibitory activity have been isolated, and some natural products have been modified in order to improve their inhibitory activity and metabolic stability. This review summarizes the development of orally active thrombin inhibitors for the treatment of thrombotic disorder diseases, which could serve as a reference for the interested researchers.

  14. Discovery and evaluation of potent P1 aryl heterocycle-based thrombin inhibitors.

    Science.gov (United States)

    Young, Mary Beth; Barrow, James C; Glass, Kristen L; Lundell, George F; Newton, Christina L; Pellicore, Janetta M; Rittle, Kenneth E; Selnick, Harold G; Stauffer, Kenneth J; Vacca, Joseph P; Williams, Peter D; Bohn, Dennis; Clayton, Franklin C; Cook, Jacquelynn J; Krueger, Julie A; Kuo, Lawrence C; Lewis, S Dale; Lucas, Bobby J; McMasters, Daniel R; Miller-Stein, Cynthia; Pietrak, Beth L; Wallace, Audrey A; White, Rebecca B; Wong, Bradley; Yan, Youwei; Nantermet, Philippe G

    2004-06-01

    In an effort to discover potent, clinically useful thrombin inhibitors, a rapid analogue synthetic approach was used to explore the P(1) region. Various benzylamines were coupled to a pyridine/pyrazinone P(2)-P(3) template. One compound with an o-thiadiazole benzylic substitution was found to have a thrombin K(i) of 0.84 nM. A study of ortho-substituted five-membered-ring heterocycles was undertaken and subsequently demonstrated that the o-triazole and tetrazole rings were optimal. Combination of these potent P(1) aryl heterocycles with a variety of P(2)-P(3) groups produced a compound with an extraordinary thrombin inhibitory activity of 1.4 pM. It is hoped that this potency enhancement in P(1) will allow for more diversification in the P(2)-P(3) region to ultimately address additional pharmacological concerns. PMID:15163182

  15. Topical report review status

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-08-01

    This report provides industry with procedures for submitting topical reports, guidance on how the U.S. Nuclear Regulatory Commission (NRC) processes and responds to topical report submittals, and an accounting, with review schedules, of all topical reports currently accepted for review schedules, of all topical reports currently accepted for review by the NRC. This report will be published annually. Each sponsoring organization with one or more topical reports accepted for review copies.

  16. Topical report review status

    International Nuclear Information System (INIS)

    This report provides industry with procedures for submitting topical reports, guidance on how the U.S. Nuclear Regulatory Commission (NRC) processes and responds to topical report submittals, and an accounting, with review schedules, of all topical reports currently accepted for review schedules, of all topical reports currently accepted for review by the NRC. This report will be published annually. Each sponsoring organization with one or more topical reports accepted for review copies

  17. Salmon-derived thrombin inhibits development of chronic pain through an endothelial barrier protective mechanism dependent on APC.

    Science.gov (United States)

    Smith, Jenell R; Galie, Peter A; Slochower, David R; Weisshaar, Christine L; Janmey, Paul A; Winkelstein, Beth A

    2016-02-01

    Many neurological disorders are initiated by blood-brain barrier breakdown, which potentiates spinal neuroinflammation and neurodegeneration. Peripheral neuropathic injuries are known to disrupt the blood-spinal cord barrier (BSCB) and to potentiate inflammation. But, it is not known whether BSCB breakdown facilitates pain development. In this study, a neural compression model in the rat was used to evaluate relationships among BSCB permeability, inflammation and pain-related behaviors. BSCB permeability increases transiently only after injury that induces mechanical hyperalgesia, which correlates with serum concentrations of pro-inflammatory cytokines, IL-7, IL-12, IL-1? and TNF-?. Mammalian thrombin dually regulates vascular permeability through PAR1 and activated protein C (APC). Since thrombin protects vascular integrity through APC, directing its affinity towards protein C, while still promoting coagulation, might be an ideal treatment for BSCB-disrupting disorders. Salmon thrombin, which prevents the development of mechanical allodynia, also prevents BSCB breakdown after neural injury and actively inhibits TNF-?-induced endothelial permeability in vitro, which is not evident the case for human thrombin. Salmon thrombin's production of APC faster than human thrombin is confirmed using a fluorogenic assay and APC is shown to inhibit BSCB breakdown and pain-related behaviors similar to salmon thrombin. Together, these studies highlight the impact of BSCB on pain and establish salmon thrombin as an effective blocker of BSCB, and resulting nociception, through its preferential affinity for protein C. PMID:26708087

  18. Evaluation of antithrombotic activity of thrombin DNA aptamers by a murine thrombosis model.

    Science.gov (United States)

    Zavyalova, Elena; Samoylenkova, Nadezhda; Revishchin, Alexander; Golovin, Andrey; Pavlova, Galina; Kopylov, Alexey

    2014-01-01

    Aptamers are nucleic acid based molecular recognition elements with a high potential for the theranostics. Some of the aptamers are under development for therapeutic applications as promising antithrombotic agents; and G-quadruplex DNA aptamers, which directly inhibit the thrombin activity, are among them. RA-36, the 31-meric DNA aptamer, consists of two thrombin binding pharmacophores joined with the thymine linker. It has been shown earlier that RA-36 directly inhibits thrombin in the reaction of fibrinogen hydrolysis, and also it inhibits plasma and blood coagulation. Studies of both inhibitory and anticoagulation effects had indicated rather high species specificity of the aptamer. Further R&D of RA-36 requires exploring its efficiency in vivo. Therefore the development of a robust and adequate animal model for effective physiological studies of aptamers is in high current demand. This work is devoted to in vivo study of the antithrombotic effect of RA-36 aptamer. A murine model of thrombosis has been applied to reveal a lag and even prevention of thrombus formation when RA-36 was intravenous bolus injected in high doses of 1.4-7.1 µmol/kg (14-70 mg/kg). A comparative study of RA-36 aptamer and bivalirudin reveals that both direct thrombin inhibitors have similar antithrombotic effects for the murine model of thrombosis; though in vitro bivalirudin has anticoagulation activity several times higher compared to RA-36. The results indicate that both RA-36 aptamer and bivalirudin are direct thrombin inhibitors of different potency, but possible interactions of the thrombin-inhibitor complex with other components of blood coagulation cascade level the physiological effects for both inhibitors. PMID:25192011

  19. Real-time detection of ?-thrombin binding to single-strand DNA aptamers by a highly sensitive Si-based waveguide SPR biosensor

    Science.gov (United States)

    Huang, Chi-Chieh; Hsu, Hsin-Feng; Chen, Sz-Hau; Tsai, Kun-Yu; Huang, Yang-Tung; Lin, Chih-Sheng; Hsu, Shih-Hsin

    2012-02-01

    ?In this paper, real-time characterization of ?-thrombin binding to single-strand DNA (ssDNA) aptamers by novel Si-based waveguide SPR biosensors has been investigated. The gold nanoparticles (AuNPs) modified with anti-thrombin antibodies were employed to bind with ?-thrombin via strong antibody/antigen affinity for SPR signal amplification. The detection limit of 1 pM for -thrombin detection was achieved.

  20. Saccular aneurysm of superior vena cava treated with percutaneous, transcatheter thrombin injection.

    Science.gov (United States)

    Jargiello, Tomasz; Durakiewicz, Marek; Sojka, Micha?; Czekajska-Chehab, Elzbieta; Szczerbo-Trojanowska, Malgorzata

    2014-04-01

    We report the case of successful endovascular treatment of large saccular aneurysm of SVC in a patient with vascular malformation of right hand and chest. Considering the high risk of surgery, the patient was referred for percutaneous intervention. Venography showed communication between the aneurysm and SVC, just below brachiocephalic confluence. That is why the decision of balloon-protected transcatheter thrombin injection was made. Selective catheter was placed in the aneurysm and balloon occlusion catheter in SVC. Both catheters were withdrawn right after thrombin injection. During follow-up, aneurysm slightly enlarged in early observation and after a year shrinkage was observed. PMID:23737024

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

    International Nuclear Information System (INIS)

    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

  2. Biochemical characterization of bovine plasma thrombin-activatable fibrinolysis inhibitor (TAFI)

    DEFF Research Database (Denmark)

    Valnickova, Zuzana; Thaysen-Andersen, Morten; Højrup, Peter; Christensen, Trine; Sanggaard, Kristian W; Kristensen, Torsten; Enghild, Jan J

    2009-01-01

    BACKGROUND: TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa) in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin-activatable fib......BACKGROUND: TAFI is a plasma protein assumed to be an important link between coagulation and fibrinolysis. The three-dimensional crystal structures of authentic mature bovine TAFI (TAFIa) in complex with tick carboxypeptidase inhibitor, authentic full lenght bovine plasma thrombin...

  3. Application of thrombin powder after tooth extraction in patients receiving anticoagulant therapy

    Directory of Open Access Journals (Sweden)

    Marjanovi? Marjan

    2002-01-01

    Full Text Available Patients with extreme hypocoagulation, which occurs either as an effect of some diseases with coagulation deficiency or because of the anticoagulant therapy (ACT, are a risk group for oral surgery. In the last decades decision to change or interrupt ACT before and after the procedure was abandoned and more often local hemostasis was being achieved by combining chemical and biological substances. The success of the surgical hemostasis and thrombin powder combination was tested on the group of 20 patients with ACT. The results were satisfactory despite thrombin powder solubility in the moist oral environment.

  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.; Bochsen, L.; Kristensen, Annemarie Thuri

    2008-01-01

    thrombin) and endogenous thrombin potential (ETP; nm thrombin*min) were registered. Clot formation was evaluated by TEG and the R time (min), maxial amplitude (MA; mm), time to maximum thrombus generation (TMG; min) and maximum thrombus generation (MTG; dynes cm(-2) s(-1)) and total thrombus generation...

  5. 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.

  6. (-)-Epigallocatechin-3-gallate decreases thrombin/paclitaxel-induced endothelial tissue factor expression via the inhibition of c-Jun terminal NH2 kinase phosphorylation

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huang-Joe [Institute of Biotechnology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan (China); Division of Cardiology, Department of Medicine, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan (China); Lo, Wan-Yu [Department of Medical Research, China Medical University Hospital, No. 2, Yuh-Der Road, Taichung 40447, Taiwan (China); Graduate Integration of Chinese and Western Medicine, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan (China); Lu, Te-Ling [School of Pharmacy, China Medical University, No. 91, Hsueh-Shih Road, Taichung 40402, Taiwan (China); Huang, Haimei, E-mail: hmhuang@life.nthu.edu.tw [Institute of Biotechnology, National Tsing Hua University, No. 101, Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan (China)

    2010-01-01

    Patients with paclitaxel-eluting stents are concerned with stent thrombosis caused by premature discontinuation of dual antiplatelet therapy or clopidogrel resistance. This study investigates the effect of (-)-epigallocatechin-3-gallate (EGCG) on the expression of thrombin/paclitaxel-induced endothelial tissue factor (TF) expressions in human aortic endothelial cells (HAECs). EGCG was nontoxic to HAECs at 6 h up to a concentration of 25 {mu}mol/L. At a concentration of 25 {mu}mol/L, EGCG pretreatment potently inhibited both thrombin-stimulated and thrombin/paclitaxel-stimulated endothelial TF protein expression. Thrombin and thrombin/paclitaxel-induced 2.6-fold and 2.9-fold increases in TF activity compared with the control. EGCG pretreatment caused a 29% and 38% decrease in TF activity on thrombin and thrombin/paclitaxel treatment, respectively. Real-time polymerase chain reaction (PCR) showed that thrombin and thrombin/paclitaxel-induced 3.0-fold and 4.6-fold TF mRNA expressions compared with the control. EGCG pretreatment caused an 82% and 72% decrease in TF mRNA expression on thrombin and thrombin/paclitaxel treatment, respectively. The c-Jun terminal NH2 kinase (JNK) inhibitor SP600125 reduced thrombin/paclitaxel-induced TF expression. Furthermore, EGCG significantly inhibited the phosphorylation of JNK to 49% of thrombin/paclitaxel-stimulated HAECs at 60 min. Immunofluorescence assay did not show an inhibitory effect of EGCG on P65 NF-{kappa}B nuclear translocation in the thrombin/paclitaxel-stimulated endothelial cells. In conclusion, EGCG can inhibit TF expression in thrombin/paclitaxel-stimulated endothelial cells via the inhibition of JNK phosphorylation. The unique property of EGCG may be used to develop a new drug-eluting stent by co-coating EGCG and paclitaxel.

  7. (-)-Epigallocatechin-3-gallate decreases thrombin/paclitaxel-induced endothelial tissue factor expression via the inhibition of c-Jun terminal NH2 kinase phosphorylation

    International Nuclear Information System (INIS)

    Patients with paclitaxel-eluting stents are concerned with stent thrombosis caused by premature discontinuation of dual antiplatelet therapy or clopidogrel resistance. This study investigates the effect of (-)-epigallocatechin-3-gallate (EGCG) on the expression of thrombin/paclitaxel-induced endothelial tissue factor (TF) expressions in human aortic endothelial cells (HAECs). EGCG was nontoxic to HAECs at 6 h up to a concentration of 25 ?mol/L. At a concentration of 25 ?mol/L, EGCG pretreatment potently inhibited both thrombin-stimulated and thrombin/paclitaxel-stimulated endothelial TF protein expression. Thrombin and thrombin/paclitaxel-induced 2.6-fold and 2.9-fold increases in TF activity compared with the control. EGCG pretreatment caused a 29% and 38% decrease in TF activity on thrombin and thrombin/paclitaxel treatment, respectively. Real-time polymerase chain reaction (PCR) showed that thrombin and thrombin/paclitaxel-induced 3.0-fold and 4.6-fold TF mRNA expressions compared with the control. EGCG pretreatment caused an 82% and 72% decrease in TF mRNA expression on thrombin and thrombin/paclitaxel treatment, respectively. The c-Jun terminal NH2 kinase (JNK) inhibitor SP600125 reduced thrombin/paclitaxel-induced TF expression. Furthermore, EGCG significantly inhibited the phosphorylation of JNK to 49% of thrombin/paclitaxel-stimulated HAECs at 60 min. Immunofluorescence assay did not show an inhibitory effect of EGCG on P65 NF-?B nuclear translocation in the thrombin/paclitaxel-stimulated endothelial cells. In conclusion, EGCG can inhibit TF expression in thrombin/paclitaxel-stimulated endothelial cells via the inhibition of JNK phosphorylation. The unique property of EGCG may be used to develop a new drug-eluting stent by co-coating EGCG and paclitaxel.

  8. Freshman Health Topics

    Science.gov (United States)

    Hovde, Karen

    2011-01-01

    This article examines a cluster of health topics that are frequently selected by students in lower division classes. Topics address issues relating to addictive substances, including alcohol and tobacco, eating disorders, obesity, and dieting. Analysis of the topics examines their interrelationships and organization in the reference literature.…

  9. Improved thrombin binding aptamer by incorporation of a single unlocked nucleic acid monomer

    DEFF Research Database (Denmark)

    Pasternak, Anna; Hernandez, Frank J; Rasmussen, Lars Melholt; Vester, Birte; Wengel, Jesper

    2011-01-01

    A 15-mer DNA aptamer (named TBA) adopts a G-quadruplex structure that strongly inhibits fibrin-clot formation by binding to thrombin. We have performed thermodynamic analysis, binding affinity and biological activity studies of TBA variants modified by unlocked nucleic acid (UNA) monomers. UNA-U ...

  10. Prolyl endopeptidase and thrombin inhibitory diterpenoids from the bark of Xylopia aethiopica.

    Science.gov (United States)

    Diderot, Noungoue Tchamo; Silvere, Ngouela; Yasin, Amsha; Zareen, Seema; Fabien, Zelefack; Etienne, Tsamo; Choudhary, M Iqbal; Atta-Ur-Rahman

    2005-09-01

    The inhibitory effects of seven diterpenes, belonging to three different structural classes and isolated from the bark of Xylopia aethiopica, were investigated against the enzymes prolyl endopeptidase (PEP) and alpha-thrombin. Five compounds exhibited inhibitory activity against them. PMID:16195597

  11. Rac inhibits thrombin-induced Rho activation: evidence of a Pak-dependent GTPase crosstalk

    Directory of Open Access Journals (Sweden)

    Rosenfeldt Hans

    2006-12-01

    Full Text Available Abstract The strict spatio-temporal control of Rho GTPases is critical for many cellular functions, including cell motility, contractility, and growth. In this regard, the prototypical Rho family GTPases, Rho, Rac, and Cdc42 regulate the activity of each other by a still poorly understood mechanism. Indeed, we found that constitutively active forms of Rac inhibit stress fiber formation and Rho stimulation by thrombin. Surprisingly, a mutant of Rac that is unable to activate Pak1 failed to inhibit thrombin signaling to Rho. To explore the underlying mechanism, we investigated whether Pak1 could regulate guanine nucleotide exchange factors (GEFs for Rho. We found that Pak1 associates with P115-RhoGEF but not with PDZ-RhoGEF or LARG, and knock down experiments revealed that P115-RhoGEF plays a major role in signaling from thrombin receptors to Rho in HEK293T cells. Pak1 binds the DH-PH domain of P115-RhoGEF, thus suggesting a mechanism by which Rac stimulation of Pak1 may disrupt receptor-dependent Rho signaling. In agreement, expression of a dominant-negative Pak-Inhibitory Domain potentiated the activation of Rho by thrombin, and prevented the inhibition of Rho by Rac. These findings indicate that Rac interferes with receptor-dependent Rho stimulation through Pak1, thus providing a mechanism for cross-talk between these two small-GTPases.

  12. Thrombin detection in murine plasma using engineered fluorescence resonance energy transfer aptadimers

    Science.gov (United States)

    Trapaidze, Ana; Brut, Marie; Mazères, Serge; Estève, Daniel; Gué, Anne-Marie; Bancaud, Aurélien

    2015-12-01

    Biodetection strategies, in which two sides of one target protein are targeted simultaneously, have been shown to increase specificity, selectivity, and affinity, and it has been suggested that they constitute excellent candidates for protein sensing in complex media. In this study we propose a method to engineer the sequence of a DNA construct dedicated to reversible thrombin detection. This construct, called Fluorescence Resonance Energy Transfer (FRET) aptadimer, is assembled with two aptamers, which target different epitopes of thrombin, interconnected with a DNA linker that contains a FRET couple and a reversible double helix stem. In the absence of target, the stem is stable maintaining a FRET couple in close proximity, and fluorescence is unquenched upon thrombin addition due to the dehybridization of the stem. We define design rules for the conception of FRET aptadimers, and develop a software to optimize their functionality. One engineered FRET aptadimer sequence is subsequently characterized experimentally by temperature scanning fluorimetry, demonstrating the relevance of our technology for thrombin sensing in bulk and diluted murine plasma.

  13. 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. PMID:26203764

  14. Microfluidic chip-based silver nanoparticles aptasensor for colorimetric detection of thrombin.

    Science.gov (United States)

    Zhao, Yaju; Liu, Xiaohui; Li, Jie; Qiang, Weibing; Sun, Liang; Li, Hui; Xu, Danke

    2016-04-01

    In this paper, a colorimetric silver nanoparticles aptasensor (aptamer-AgNPs) was developed for simple and straightforward detection of protein in microfluidic chip. Surface-functionalized microfluidic channels were employed as the capture platform. Then the mixture of target protein and aptamer-AgNPs were injected into the microfluidic channels for colorimetric detection. To demonstrate the performance of this detection platform, thrombin was chosen as a model target protein. Introduction of thrombin could form a sandwich-type complex involving immobilized AgNPs. The amount of aptamer-AgNPs on the complex augmented along with the increase of the thrombin concentration causing different color change that can be analyzed both by naked eyes and a flatbed scanner. This method is featured with low sample consumption, simple processes of microfluidic platform and straightforward colorimetric detection with aptamer-AgNPs. Thrombin at concentrations as low as 20pM can be detected using this aptasensor without signal amplification. This work demonstrated that it had good selectivity over other proteins and it could be a useful strategy to detect other targets with two affinity binding sites for ligands as well. PMID:26838384

  15. Reversible regulation of thrombin adsorption and desorption based on photoresponsive-aptamer modified gold nanoparticles.

    Science.gov (United States)

    Yu, Jiemiao; Yang, Liangrong; Liang, Xiangfeng; Dong, Tingting; Liu, Huizhou

    2015-11-01

    In the protein separation, adsorption and desorption of target protein have been using different buffer condition. Different buffer will change the structure and activity of target protein in some cases. This work describes the use of different wavelength light for remote regulation of adsorption and desorption of target protein in the same buffer solutions. A dynamic system that captured and released protein in response to light is reported. Matrix gold nanoparticles and light-responsive affinity ligand comprising thrombin aptamer (APT15), polyethylene glycol linker, and azobenzene-modified complementary sequence were used. UV light induced a trans-cis isomerization of the azobenzene that destabilized the duplex of aptamer and azobenzene-modified complementary sequence, resulting in thrombin binding to aptamer sequence. Visible light irradiation resulted in DNA duplex rehybridization and thrombin released. Our work demonstrates that different light wavelengths effectively regulated the adsorption and desorption of thrombin in the same buffer, and this system also can capture and release prothrombin from plasma with different wavelength light. Furthermore, this method can be widely applied to a variety of different protein separation process. PMID:26452827

  16. Early thrombin generation and impaired fibrinolysis after SCT associate with acute GVHD.

    Science.gov (United States)

    Pinomäki, A; Volin, L; Joutsi-Korhonen, L; Virtanen, J O; Lemponen, M; Ruutu, T; Lassila, R

    2010-04-01

    The evolution of coagulation and fibrinolysis has not been thoroughly evaluated in allogeneic SCT. In this pilot study, we characterized the adaptive mechanisms of coagulation and fibrinolysis during allogeneic SCT and 3-month follow-up and studied possible associations with outcome, including acute GVHD. Thirty patients underwent SCT for a haematological malignancy after myeloablative conditioning. Nineteen patients received the transplant from an HLA-identical sibling and 11 from an unrelated donor. GVHD prophylaxis consisted of CYA and MTX, with methylprednisolone in sibling transplants. Serial coagulation and fibrinolytic activity markers were assessed, including prothrombin fragments 1+2 (F1+2), thrombin time, D-dimer, tissue-type plasminogen-activator (tPA) and plasminogen-activator inhibitor (PAI-1). Early during conditioning therapy, F1+2 and D-dimer increased threefold indicating thrombin generation and fibrin turnover. TPA activity peaked before engraftment, concurring with diminished PAI-1. At 10 days after transplantation shortened thrombin time (<15 s), F1+2 exceeding 0.7 nmol/L and PAI-1 3.0 IU/mL were associated with the development of GVHD. In conclusion, early maladaptation, that is, upregulated thrombin generation and inhibition of fibrinolysis, occurred in one-third of the SCT patients associating with the development of GVHD, a finding suggesting an interplay between coagulation and immunology during SCT. PMID:19718071

  17. Crystallization and preliminary crystallographic characterization of three peptidic inhibitors in complex with ?-thrombin

    OpenAIRE

    Carvalho Figueiredo, Ana; Clement, Cristina C.; Philipp, Manfred; Barbosa Pereira, Pedro José

    2010-01-01

    Human ?-thrombin was crystallized in complex with specific peptide inhibitors of general sequence d-Phe-Pro-d-Arg-P1?-CONH2. The crystals belonged to the orthorhombic space group P212121 and diffracted to beyond 1.3?Å resolution.

  18. An aptamer-based single particle method for sensitive detection of thrombin using fluorescent quantum dots as labeling probes.

    Science.gov (United States)

    Yin, Jinjin; Zhang, Aidi; Dong, Chaoqing; Ren, Jicun

    2015-11-01

    In this study, an aptamer-based single particle method was developed for the thrombin detection in human serum samples using fluorescence correlation spectroscopy (FCS). In this method, quantum dots (QDs) were used as the fluorescent probes and thrombin-binding aptamer (TBA) was used as molecular recognition unit. When two QDs probes labeled with TBA (QD-TBA1 and QD-TBA2) are mixed in a sample containing thrombin targets, the binding of targets will cause QDs to form dimers (or oligomers) with bigger sizes, which leads to the nearly double increase in the characteristic diffusion time of QDs in the detection volume of FCS. FCS method can detect the change in the characteristic diffusion time of QDs. Firstly, the diffusion and blinking behaviors of QD-TBA probes in the presence of thrombin were investigated by FCS and total internal reflection fluorescence microscopy (TIRFM) imaging system, and the experimental results documented that QD-TBAs were bound together with "one-by-one" structure when thrombin were added into the solution. And then, the assay conditions were optimized in order to improve the sensitivity and specificity of this method. Under the optimized conditions, the linear range of the method is from 5.0nM to 500nM of thrombin, and the limit of detection is about 2.6nM. Finally, this method was applied to homogeneous determination of thrombin in human serum samples. PMID:26452786

  19. Recombinant Technology and Probiotics

    Directory of Open Access Journals (Sweden)

    Icy D’Silva

    2011-09-01

    Full Text Available Recombinant technology has led the way to monumental advances in the development of useful molecules, including the development of safe probiotics. The development of novel approaches using recombinant technology and probiotics that allow accurate targeting of therapeutics to the mucosa is an interesting area of research. The creation and use of recombinant probiotics expressing recombinantovalbumin, recombinant ovalbumin mutants and yet-to-be-designed recombinant hypo/non-allergenic molecules offer the opportunity to further investigate their effects for food, nutrition, environment andhealth. This review highlights advances in native probiotics and recombinant probiotics expressing native and recombinant molecules for food, nutrition, environment and health.

  20. A balance between TFPI and thrombin-mediated platelet activation is required for murine embryonic development.

    Science.gov (United States)

    Ellery, Paul E R; Maroney, Susan A; Cooley, Brian C; Luyendyk, James P; Zogg, Mark; Weiler, Hartmut; Mast, Alan E

    2015-06-25

    Tissue factor pathway inhibitor (TFPI) is a critical anticoagulant protein present in endothelium and platelets. Mice lacking TFPI (Tfpi(-/-)) die in utero from disseminated intravascular coagulation. They are rescued by concomitant tissue factor (TF) deficiency, demonstrating that TFPI modulates TF function in vivo. Recent studies have found TFPI inhibits prothrombinase activity during the initiation of coagulation and limits platelet accumulation during thrombus formation, implicating TFPI in modulating platelet procoagulant activity. To examine whether altered platelet function would compensate for the lack of TFPI and rescue TFPI-null embryonic lethality, Tfpi(+/-) mice lacking the platelet thrombin receptor, protease activated receptor 4 (PAR4; Par4(-/-)), or its coreceptor, PAR3, were mated. PAR3 deficiency did not rescue Tfpi(-/-) embryos, but >40% of expected Tfpi(-/-):Par4(-/-) offspring survived to adulthood. Adult Tfpi(-/-):Par4(-/-) mice did not exhibit overt thrombosis. However, they had focal sterile inflammation with fibrin(ogen) deposition in the liver and elevated plasma thrombin-antithrombin complexes, indicating activation of coagulation at baseline. Tfpi(-/-):Par4(-/-) mice have platelet and fibrin accumulation similar to Par4(-/-) mice following venous electrolytic injury but were more susceptible than Par4(-/-) mice to TF-induced pulmonary embolism. In addition, ?30% of the Tfpi(-/-):Par4(-/-) mice were born with short tails. Tfpi(-/-):Par4(-/-) mice are the first adult mice described that lack TFPI with unaltered TF. They demonstrate that TFPI physiologically modulates thrombin-dependent platelet activation in a manner that is required for successful embryonic development and identify a role for TFPI in dampening intravascular procoagulant stimuli that lead to thrombin generation, even in the absence of thrombin-mediated platelet activation. PMID:25954015

  1. Expression and functional characterization of boophilin, a thrombin inhibitor from Rhipicephalus (Boophilus) microplus midgut.

    Science.gov (United States)

    Soares, Tatiane Sanches; Watanabe, Renata Midori Okuta; Tanaka-Azevedo, Anita Mitico; Torquato, Ricardo José Soares; Lu, Stephen; Figueiredo, Ana Carvalho; Pereira, Pedro José Barbosa; Tanaka, Aparecida S

    2012-07-01

    Rhipicephalus (Boophilus) microplus is an ectoparasite responsible for an important decrease in meat, milk and leather production, caused both by cattle blood loss and by the transmission of anaplasmosis and babesiosis. R. microplus is a rich source of serine protease inhibitors, including the trypsin inhibitors BmTI-A and BmTI-6, the subtilisin inhibitor BmSI, and the recently described thrombin inhibitor, boophilin. Boophilin is a double Kunitz-type thrombin inhibitor, with the unusual ability to form a ternary complex with a second (non-thrombin) serine proteinase molecule. The large-scale expression and purification of boophilin and of its isolated N-terminal (D1) domain in Pichia pastoris, its expression profile, and the effect of RNAi-mediated gene silencing in tick egg production are reported. Full-length boophilin and D1 were expressed at 21 and 37.5mg/L of culture, respectively. Purified boophilin inhibited trypsin (K(i) 0.65 nM), neutrophil elastase (K(i) 21 nM) and bovine thrombin (K(i) 57 pM), while D1 inhibited trypsin and neutrophil elastase (K(i) of 2.0 and 129 nM, respectively), but not thrombin. Boophilin gene silencing using RNAi resulted in 20% reduction in egg weight production, suggesting that the expression of boophilin in this life stage would be important but not vital, probably due to functional overlap with other serine proteinase inhibitors in the midgut of R. microplus. Considering our data, Boophilin could be combining with other antigen in a vaccine production for tick control. PMID:22341830

  2. Topical treatment of ichthyoses.

    Science.gov (United States)

    Fleckman, Philip; Newell, Brandon D; van Steensel, Maurice A; Yan, Albert C

    2013-01-01

    Management of ichthyoses is a complex and continuously dynamic process. Primary treatments of ichthyosis are by means of topical moisturizers and topical medications. Patients and families need to have reasonable and realistic expectations when it comes to topical therapy. Topical medications cannot cure the scaling, but can gradually reduce it and thus improve their condition. No one treatment regimen works for everyone, and the best topical therapy for each patient may be the result of months (or years) of painstaking effort on both the physician's and the patient's behalf. As patients get older and their activities and lifestyles change, so should their topical treatment regimen. Bear in mind that the more complex the skin care regimen and costly the topical treatments, the less likely a patient and their family will be compliant. PMID:23384017

  3. Recombinant Technology and Probiotics

    OpenAIRE

    Icy D’Silva

    2011-01-01

    Recombinant technology has led the way to monumental advances in the development of useful molecules, including the development of safe probiotics. The development of novel approaches using recombinant technology and probiotics that allow accurate targeting of therapeutics to the mucosa is an interesting area of research. The creation and use of recombinant probiotics expressing recombinantovalbumin, recombinant ovalbumin mutants and yet-to-be-designed recombinant hypo/non-allergenic molecule...

  4. Crystallographic determination of the structures of human alpha-thrombin complexed with BMS-186282 and BMS-189090.

    OpenAIRE

    Malley, M. F.; Tabernero, L; Chang, C.Y.; Ohringer, S. L.; Roberts, D.G.; J Das; Sack, J. S.

    1996-01-01

    The crystallographic structures of the ternary complexes of human alpha-thrombin with hirugen (a sulfated hirudin fragment) and the small-molecule active site thrombin inhibitors BMS-186282 and BMS-189090 have been determined at 2.6 and 2.8 A. In both cases, the inhibitors, which adopt very similar bound conformations, bind in an antiparallel beta-strand arrangement relative to the thrombin main chain in a manner like that reported for PPACK, D-Phe-Pro-Arg-CH2Cl. They do, however, exhibit dif...

  5. Inositol cyclic triphosphate [inositol 1,2-(cyclic)-4,5-triphosphate] is formed upon thrombin stimulation of human platelets.

    OpenAIRE

    Ishii, H; Connolly, T M; Bross, T E; Majerus, P W

    1986-01-01

    Cleavage of polyphosphoinositides in vitro by phospholipase C results in formation of both cyclic and noncyclic inositol phosphates. We have now isolated the cyclic product of phosphatidylinositol 4,5-bisphosphate cleavage, inositol 1,2(cyclic)-4,5-triphosphate [cIns(1:2,4,5)P3], from thrombin-treated platelets. We found 0.2-0.4 nmol of cIns-(1:2,4,5)P3 per 10(9) platelets at 10 sec after thrombin; none was found in unstimulated platelets or in platelets 10 min after thrombin addition. We con...

  6. Autocrine production of basic fibroblast growth factor translated from novel synthesized mRNA mediates thrombin-induced mitogenesis in smooth muscle cells.

    Science.gov (United States)

    Cucina, Alessandra; Borrelli, Valeria; Lucarelli, Marco; Sterpetti, Antonio V; Cavallaro, Antonino; Strom, Roberto; Santoro-D'Angelo, Luciana; Scarpa, Sigfrido

    2002-03-01

    Thrombin is known to stimulate smooth muscle cell (SMC) growth in culture but the mechanisms underlying growth stimulation remain unclear. Previous works have observed a significant increase in platelet-derived growth factor AA and basic fibroblast growth factor (bFGF) release by bovine aortic SMC after addition of thrombin. The aim of this study was to clarify the link between thrombin, bFGF and SMC proliferation by examining the kinetics of autocrine production of bFGF by thrombin-stimulated SMC and its contribution to thrombin-induced mitogenesis. Experiments were performed to assess the dynamics of thrombin-induced bFGF mRNA transcription and to distinguish, following thrombin stimulus, between the activation of 'old' bFGF protein and/or bFGF mRNA, or novel mRNA synthesis and subsequent translation. Bovine aortic SMCs were stimulated with thrombin in serum-free culture. bFGF mRNA expression was determined by RT-PCR. Mitogenic activity of thrombin was determined by 3H-thymidine uptake. Our results demonstrate that the peak of bFGF mRNA expression occurred 24 h after thrombin stimulation. Experiments performed with cycloheximide, a translation inhibitor, revealed a translation peak later than 24 h after thrombin stimulation. Thrombin-induced mitogenic activity in SMCs was partially inhibited by the addition of anti-bFGF antibody (p<0.001) and of hirudin (p<0.001). When hirudin was added 24 h after stimulation, thrombin-induced mitogenic activity was not inhibited. In conclusion, thrombin-induced mitogenesis was partially mediated by the autocrine production of bFGF, mainly due to protein synthesis by novel mRNA with a transcription peak at 24 h and a later translation peak. PMID:11835269

  7. Topical report review status

    International Nuclear Information System (INIS)

    A Topical Report Review Status is scheduled to be published semi-annually. The primary purpose of this document is to provide periodic progress reports of on-going topical report reviews, to identify those topical reports for which the Nuclear Regulatory Commission (NRC) staff review has been completed and, to the extent practicable, to provide NRC management with sufficient information regarding the conduct of the topical report program to permit taking whatever actions deemed necessary or appropriate. This document is also intended to be a source of information to NRC Licensing Project Managers and other NRC personnel regarding the status of topical reports which may be referenced in applications for which they have responsibility. This status report is published primarily for internal NRC use in managing the topical report program, but is also used by NRC to advise the industry of report review status

  8. Contrastive topics decomposed

    OpenAIRE

    Michael Wagner

    2012-01-01

    The analysis of contrastive topics introduced in Büring 1997b and further developed in Büring 2003 relies on distinguishing two types of constituents that introduce alternatives: the sentence focus, which is marked by a FOC feature, and the contrastive topic, which is marked by a CT feature. A non-compositional rule of interpretation that refers to these features is used to derive a topic semantic value, a nested set of sets of propositions. This paper presents evidence for a correlation betw...

  9. [Topical therapy of rosacea].

    Science.gov (United States)

    Schöfer, H

    2013-07-01

    Metronidazole and azelaic acid are the only topical medications approved for rosacea. All other topical treatments for rosacea and its special forms are used off-label. Topical steroids are not indicated in rosacea, because of their side effects (induction of steroid rosacea, high risk of facial skin atrophy, and high risk of rebound after cessation of therapy). Topical as well as systemic steroids are allowed only as initial and short term therapy for acute forms of rosacea (e.g. rosacea fulminans). Papular and pustular rosacea is the major indication for topical therapy. Sebaceous gland and connective tissue hyperplasia in glandular-hypertrophic rosacea as well as erythema in erythematous rosacea do not respond well to topical measures. A new active substance, the alpha-2-adrenoreceptor agonist brimonidine, will be approved soon for the topical treatment of erythema in rosacea. All severe forms of rosacea should initially be treated with a combination of topical and systemic agents. After improvement of the clinical symptoms, topical treatment alone is usually adequate to maintain the control. PMID:23780475

  10. Evaluation of the Profile of Thrombin Generation during the Process of Whole Blood Clotting as Assessed by Thromboelastography

    OpenAIRE

    Rivard, Georges E; Brummel, Kathleen; Mann, Kenneth G.; Fan, Li; Hofer, Angélique; Cohen, Eli

    2005-01-01

    Thromboelastography is useful for assessment of whole blood coagulation. The objective of this study was to evaluate the possibility of linking the tracing of whole blood clotted in a thromboelastograph TEG with the generation of thrombin assessed by thrombin/antithrombin complex (TAT). Citrated whole blood containing corn trypsin inhibitor from volunteers was clotted in the presence of CaCl2 and tissue factor. Clotting was monitored with 8 channels of a TEG system. At different time points t...

  11. The protective role of (?)-epigallocatechin-3-gallate in thrombin-induced neuronal cell apoptosis and JNK-MAPK activation

    OpenAIRE

    He, Qianqian; Bao, Lei; Zimering, Jeffrey; Zan, Kun; Zhang, Zuohui; Shi, Hongjuan; Zu, Jie; YANG, XINXIN; Hua, Fang; Ye, Xinchun; Cui, Guiyun

    2015-01-01

    (?)-Epigallocatechin-3-gallate (EGCG), the major polyphenolic component of green tea, has anti-inflammatory and antioxidant properties and provides neuroprotection against central nervous system diseases. Yet, it is not known whether EGCG may be neuroprotective against intracerebral hemorrhage. In this study, we used a simplified in-vitro model of thrombin neurotoxicity to test whether EGCG provides neuroprotection against thrombin-associated toxicity. Exposure of primary cortical neurons to ...

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

    International Nuclear Information System (INIS)

    The binding of ?2-macroglobulin (?2M) 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 125I-labeled ?2M. 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 00C showed that monocytes bound the ?2M-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 ?2M in a manner similar to ?2M-thrombin. Competitive binding studies showed that ?2M-thrombin and methylamine-treated ?2M bound to the same sites on the monocyte. In contrast, native ?2M did not compete with ?2M-thrombin for the site. Studies done at 370C suggested that after binding, the monocyte internalized and degraded ?2M-thrombin and excreted the degradation products. Receptor turnover and degradation of ?2M-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 ?2M-thrombin and methylamine-treated ?2M which may function to clear ?2M-proteinase complexes from the circulation

  13. Staphylocidal action of thrombin-induced platelet microbicidal protein is influenced by microenvironment and target cell growth phase.

    OpenAIRE

    Koo, S P; Yeaman, M R; Bayer, A S

    1996-01-01

    Thrombin-induced platelet microbicidal protein (tPMP) is a small, cationic peptide released from rabbit platelets following exposure to thrombin in vitro. This peptide exerts potent in vitro microbicidal activity against a broad spectrum of bloodstream pathogens, including Staphylococcus aureus. It is known that the microbicidal actions of other cationic antimicrobial peptides (e.g., neutrophil defensins) are influenced by environmental factors and target cell growth phase. However, whether t...

  14. Balloon-assisted ultrasound-guided thrombin injection of a pseudoaneurysm in the posterior tibial artery: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Taeg Ki; Jeon, Yong Sun; Hong, Kee Chun; Cho, Soon Gu; Kim, Eu Gene [Inha University School of Medicine, Incheon (Korea, Republic of)

    2014-05-15

    An ultrasound-guided direct injection of thrombin is currently the first choice of treatment for the postcatheterization pseudoaneurysm, mainly in the femoral artery. A pseudoaneurysm in the posterior tibial artery is very rare, so there are not enough reports about proper treatment yet. We report a case of a balloon-assisted injection of thrombin under ultrasonography-guidance to manage a pseudoaneurysm in the posterior tibial artery and concurrently to prevent a distal artery embolization.

  15. Syntacticized topics in Kurmuk

    DEFF Research Database (Denmark)

    Andersen, Torben

    2015-01-01

    This article argues that Kurmuk, a little-described Western Nilotic language, is characterized by a syntacticized topic whose grammatical relation is variable. In this language, declarative clauses have as topic an obligatory preverbal NP which is either a subject, an object or an adjunct. The gr...

  16. Syntacticized topics in Kurmuk

    DEFF Research Database (Denmark)

    Andersen, Torben

    This article argues that Kurmuk, a little-described Western Nilotic language, is characterized by a syntacticized topic whose grammatical relation is variable. In this language, declarative clauses have as topic an obligatory preverbal NP which is either a subject, an object or an adjunct. The gr...

  17. Spectroscopic and Electrochemical Detection of Thrombin/5'-SH or 3'-SH Aptamer Immobilized on (porous) Gold Substrates

    International Nuclear Information System (INIS)

    Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer. Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film

  18. Relationship between calcium mobilization and platelet ?- and ?-granule secretion. A role for TRPC6 in thrombin-evoked ?-granule exocytosis.

    Science.gov (United States)

    Lopez, E; Bermejo, N; Berna-Erro, A; Alonso, N; Salido, G M; Redondo, P C; Rosado, J A

    2015-11-01

    Changes in cytosolic Ca(2+) concentration ([Ca(2+)]c) regulate granule secretion in different cell types. Thrombin activates PAR1 and PAR4 receptors and promotes release of Ca(2+) from distinct intracellular stores, which, in turn, activates store-operated Ca(2+) entry (SOCE). A crucial step during platelet function is the release of physiological agonists stored in secretory granules to the extracellular compartment during activation. We aim to study the role of Ca(2+) mobilization from the extracellular compartment or from different intracellular stores in platelet granule secretion. By using flow cytometry, we have found that ?- and ?-granules are secreted in thrombin-stimulated platelets in the absence of extracellular Ca(2+), and in a concentration-dependent manner. Our findings show that thrombin-stimulated granule secretion depends on Ca(2+) mobilization from intracellular stores. Analysis of the kinetics of granule secretion reveals that platelet stimulation with thrombin results in rapid release of ?-granules which precedes the secretion of ?-granules. Incubation of platelets with a specific antibody, which recognizes the extracellular amino acid sequence 573-586 of TRPC6, inhibited thrombin-evoked ?-granule exocytosis. Our results indicate that the mechanisms underlying thrombin-induced ?- and ?-granule secretion show differences in dependency on Ca(2+) mobilization. PMID:26386308

  19. Deletion of the thrombin cleavage domain of osteopontin mediates breast cancer cell adhesion, proteolytic activity, tumorgenicity, and metastasis

    Directory of Open Access Journals (Sweden)

    Postenka Carl O

    2011-01-01

    Full Text Available Abstract Background Osteopontin (OPN is a secreted phosphoprotein often overexpressed at high levels in the blood and primary tumors of breast cancer patients. OPN contains two integrin-binding sites and a thrombin cleavage domain located in close proximity to each other. Methods To study the role of the thrombin cleavage site of OPN, MDA-MB-468 human breast cancer cells were stably transfected with either wildtype OPN (468-OPN, mutant OPN lacking the thrombin cleavage domain (468-?TC or an empty vector (468-CON and assessed for in vitro and in vivo functional differences in malignant/metastatic behavior. Results All three cell lines were found to equivalently express thrombin, tissue factor, CD44, ?v?5 integrin and ?1 integrin. Relative to 468-OPN and 468-CON cells, 468-?TC cells expressing OPN with a deleted thrombin cleavage domain demonstrated decreased cell adhesion (p in vitro. Furthermore, injection of 468-?TC cells into the mammary fat pad of nude mice resulted in decreased primary tumor latency time (p Conclusions The results presented here suggest that expression of thrombin-uncleavable OPN imparts an early tumor formation advantage as well as a metastatic advantage for breast cancer cells, possibly due to increased proteolytic activity and decreased adhesion and apoptosis. Clarification of the mechanisms responsible for these observations and the translation of this knowledge into the clinic could ultimately provide new therapeutic opportunities for combating breast cancer.

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

    Science.gov (United States)

    White, Michael J V; Gomer, Richard H

    2015-01-01

    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. PMID:26407067

  1. Recombinant DNA in Medicine

    OpenAIRE

    Cederbaum, Stephen D.; Fareed, George C.; Lovett, Michael A.; Shapiro, Larry J.

    1984-01-01

    Studies in bacteria and bacterial viruses have led to methods to manipulate and recombine DNA in unique and reproducible ways and to amplify these recombined molecules millions of times. Once properly identified, the recombinant DNA molecules can be used in various ways useful in medicine and human biology. There are many applications for recombinant DNA technology. Cloned complementary DNA has been used to produce various human proteins in microorganisms. Insulin and growth hormone have been...

  2. Improving baculovirus recombination

    OpenAIRE

    Zhao, Yuguang; Chapman, David A.G.; Jones, Ian M

    2003-01-01

    Recombinant baculoviruses have established themselves as a favoured technology for the high-level expression of recombinant proteins. The construction of recombinant viruses, however, is a time consuming step that restricts consideration of the technology for high throughput developments. Here we use a targeted gene knockout technology to inactivate an essential viral gene that lies adjacent to the locus used for recombination. Viral DNA prepared from the knockout fails to initiate an infecti...

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

    DEFF Research Database (Denmark)

    Jessen, Lisbeth Rem; Wiinberg, Bo; Kjelgaard-Hansen, Mads; Jensen, Asger Lundorff; Rozanski, Elizabeth; Kristensen, Annemarie Thuri

    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 spontaneous disease. Objective: The aim of this study was to compare TAFI activity in healthy dogs with TAFI activity in dogs with spontaneous disease. Methods: Plasma samples from 20 clinically healthy Beagles...

  4. 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.

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

    OpenAIRE

    White, Michael J. V.; Gomer, Richard H

    2015-01-01

    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, potent...

  6. Thrombelastograph (TEG®) Analysis of Platelet Gel Formed With Different Thrombin Concentrations

    Science.gov (United States)

    Ellis, William Cory; Cassidy, Linsay K.; Finney, Angela S.; Spiwak, Allison J.; Riley, Jeffrey B.

    2005-01-01

    Abstract: Autologous blood transfusion is the safest and most successful way to decrease transfusion-related risks such as post-operative infections, allo-immunization, and short- and long-term immunosuppression. In addition, these fibrin sealants are known to provide coagulation support at the surgical site and act as an adjunct to the control of postoperative bleeding. The physical formation of autologous platelet fibrin gel clot is dependent on both the common pathway of the coagulation cascade and platelet activation. Platelet gel can help provide control of intraoperative and postoperative bleeding. The Thrombelastograph Hemostasis Analyzer (TEG®) measures the viscoelastic properties of a clot as it forms. Based on the information that the TEG provides, it promises to be a good choice for point of care measurement of the integrity of thrombus formed by platelet gels. Bovine blood from a single donor was sequestered into platelet-rich plasma and was made into platelet gel using calcium and three different concentrations of thrombin. The platelet gel samples were then analyzed with the TEG analyzer. The results for MA, tMA, CI, and angle were recorded and statistical analysis was performed to accept or reject the null hypothesis, which is: There is no difference between TEG parameters when analyzing platelet gels formed with calcium chloride, platelet-rich plasma and three different concentrations of thrombin A one-way analysis of variance test was performed between thrombin concentrations for MA (p = 0.19), tMA (p = 0.443), CI (p = 0.257), and angle (p = 0.323). The results showed that thrombin concentration did not affect the MA, tMA, CI, or angle as measured by the TEG analyzer. The null hypothesis was accepted. Based on a one-way analysis of variance test for MA, tMA, CI, and angle there was no significant statistical difference for the TEG samples in this experiment as reported with a 95% confidence interval. PMID:15804158

  7. In vivo fluorescence imaging of atherosclerotic plaques with activatable cell-penetrating peptides targeting thrombin activity†

    OpenAIRE

    Olson, Emilia S; Whitney, Michael A.; Friedman, Beth; Aguilera, Todd A.; Crisp, Jessica L; Baik, Fred M.; Jiang, Tao; Baird, Stephen M.; Tsimikas, Sotirios; Tsien, Roger Y.; Nguyen, Quyen T.

    2012-01-01

    Thrombin and other coagulation enzymes have been shown to be important during atherosclerotic disease development. Study of these proteases is currently limited because of lack of robust molecular imaging agents for imaging protease activity in vivo. Activatable cell penetrating peptides (ACPPs) have been used to monitor MMP activity in tumors and, in principle, can be modified to detect other proteases. We have developed a probe that incorporates the peptide sequence DPRSFL from the proteina...

  8. Insights into the molecular inactivation mechanism of human activated thrombin-activatable fibrinolysis inhibitor

    DEFF Research Database (Denmark)

    Sanglas, L; Arolas, J L; Valnickova, Z; Aviles, F X; Enghild, J J; Gomis-Rüth, F X

    2010-01-01

    SUMMARY BACKGROUND: Thrombin-activatable fibrinolysis inhibitor (TAFI) is a validated target for thrombotic diseases. TAFI is converted in vivo to activated TAFI (TAFIa) by removal of its pro-domain. Whereas TAFI is stable and persists in the circulation, possibly in complex with plasminogen, TAFIa is unstable and poorly soluble, with a half-life of minutes. OBJECTIVES: In order to study the molecular determinants of this instability, we studied the influence of protein inhibitors on human TAFIa...

  9. Effect of resveratrol, a natural polyphenolic compound, on platelet activation induced by endotoxin or thrombin.

    Science.gov (United States)

    Olas, Beata; Wachowicz, Barbara; Saluk-Juszczak, Joanna; Zieli?ski, Tomasz

    2002-08-15

    Resveratrol (3, 4', 5-trihydroxystilbene), a natural polyphenol, is found in some plants that are used in human nutrition. Grapes are a major source for resveratrol, and a significant amount can also be found in red wine. Several experimental studies have demonstrated biological properties of resveratrol, especially its anti-inflammatory, antioxidant, anti-platelet and antitumor effects. In the present study, we investigated the first step of platelet activation-platelet adhesion stimulated by lipopolysaccharide (LPS) from Proteus mirabilis (weak stimulator) and thrombin (strong activator) in the presence of resveratrol. Our studies show that endotoxin (0.3 microg/10(8) platelets), like thrombin (0.2 U/10(8) platelets), induced the adhesion of platelets (expressed as absorbance of cell attached proteins) to collagen and fibrinogen. Preincubation of washed platelets with resveratrol at physiological plasma concentrations (25-100 microg/ml, 30 min, 37 degrees C) had an inhibitory effect on adhesion of platelets to collagen after activation by LPS alone or LPS with thrombin. The strongest effect on this process was caused by resveratrol at the concentration of 100 microg/ml. Pretreatment of platelets with resveratrol (25-100 microg/ml, 30 min, 37 degrees C) had also inhibitory effects on adhesion of platelets to fibrinogen after stimulation of these cells by LPS alone or by LPS with thrombin at the same concentration. In conclusion, we suggest that resveratrol present in human diet may be an important compound responsible for the reduction of platelet adhesion and changed reactivity of blood platelets in inflammatory process. PMID:12431480

  10. 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.

  11. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  12. Electrochemical Raduction Potential Shifts of Graphene Oxide Employed in Thrombin Detection

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hanall; Hwang, Shinjae; Kim, Kyuwon [Incheon National Univ., Incheon (Korea, Republic of)

    2014-06-15

    We have reported a feasibility study on thrombin detection by the measurement of peak potentials shifts for the electrochemical reduction of GO. Our novel strategy has demonstrated that the shifts are fairly dependent upon the concentration of target thrombin. We are extending this result to determine quantitatively various target material such as proteins, DNA, metal ions. The development of electrochemical biosensor is currently under the intense investigation owing to their great promise for rapid, convenience and low-cost detection of analytes. Especially, graphene oxide (GO), an oxygen-rich carbonaceous layered material, has attracted strong interest as an substrate material because of its own unique characteristics. Based on recent studies GO consists of intact graphitic regions interspersed with sp{sup 3}-hybridized carbons containing hydroxyl and epoxy functional groups on the top and bottom surfaces of each sheet and sp{sup 2}-hybridized carbons containing carboxylate and carbonyl groups principally at the sheet edges. The intrinsic oxygen-containing functional groups have been used as initial sites for deposition of biomolecules such as DNA and proteins on the GO sheets and provide the possibility to be an ideal platform for detecting of target materials. In addition, GO is electrochemically reducible, which enables it as an indicator or label for electrochemical sensor applications. Several studies have employed the GO-indicator to determine DNA, Hg{sup 2+}, and thrombin.

  13. Electrochemiluminescence biosensor based on CdSe quantum dots for the detection of thrombin

    International Nuclear Information System (INIS)

    A novel QDs electrochemiluminescence (ECL) biosensor for the determination of thrombin was described. The CdSe QDs solution was dripped onto the clear surface of the ITO and then immersed in PBS which contained EDC and NHS as a coupling agent to activate the carboxyl-terminated surface of the CdSe QDs. The ITO electrode was immersed in the PBS containing 0.4 ?M aptamer, followed by rinsing with PBS and dried with N2 again, then dipped in the BSA solution for 30 min to decrease the non-specific binding. After that, the aptamer modified ITO was soaked in PBS to remove unbound aptamer. Under optimal conditions, the linear range was obtained from 0 to 64 ?g mL?1 with a correlation coefficient of 0.9986 (n = 16). The control experiment was also carried out by using BSA, lysozyme and IgG in the absence of thrombin. The results showed that the aptasensor had good specificity, stability and reproducibility to the thrombin. Moreover, the aptasensor could be used for detection of real sample with consistent results in comparison with those obtained by electrochemical method which could provide a promising platform for fabrication of aptamer based biosensors.

  14. Aptamer-conjugated gold functionalized graphene oxide nanocomposites for human ?-thrombin specific recognition.

    Science.gov (United States)

    Deng, Nan; Jiang, Bo; Chen, Yuanbo; Liang, Zhen; Zhang, Lihua; Liang, Yu; Yang, Kaiguang; Zhang, Yukui

    2016-01-01

    The specific recognition toward target proteins from complex biological samples has great potential in clinical diagnostics and therapeutics, receiving more and more attention. Herein, we achieved the specific detection of human ?-thrombin from human serum by aptamer-conjugated gold functionalized graphene oxide nanocomposites (denoted as Apt/Au/PEI/GO nanocomposites). Gold functionalized graphene oxide nanocomposites were synthesized by in situ growth of Au nanoparticles on graphene oxide surface using polyethylenimine as reducing and stabilizing reagents, and then it was used as support for aptamer immobilization through forming an Au-S bonding. The obtained Apt/Au/PEI/GO nanocomposites inherited not only the large surface area which made the immobilizing amount of aptamer up to 36.1nmol/mg, but also the excellent hydrophilicity which showed remarkable selectivity for human ?-thrombin specific recognition, even with the interference of 3000 fold human serum proteins. Furthermore, with its superior properties, Apt/Au/PEI/GO nanocomposites showed advantages of high capture efficiency (>86%) and excellent recognition repeatability. Finally, the Apt/Au/PEI/GO nanocomposites were successfully applied for human ?-thrombin specific recognition in human serum, verifying its great potential in clinical applications. PMID:26689824

  15. [Heparin cofactor II, a thrombin inhibitor with a still not clarified physiologic role].

    Science.gov (United States)

    Rossi, E B; Duboscq, C L; Kordich, L C

    1999-01-01

    Heparin Cofactor II (HCII) is a glycoprotein in human plasma which inactivates thrombin rapidly in the presence of dermatan sulfate. Inhibition occurs by formation of a stable equimolar complex between HCII and thrombin. HCII association with thrombotic events has not always been observed, thus decreased HCII does not appear to be a strong risk factor for thromboembolic events. Reduced HCII levels have been detected in different clinical conditions, such as hepatic failure, disseminated intravascular coagulation, thalasemina, sickle cell anemia. Increased physiological levels have been found in pregnant women and oral contraception. In our laboratory, we measured HCII plasmatic levels in the normal Buenos Aires city population and in patients under different clinical conditions, such as sepsis, diabetis, burns, oral anticoagulation and in patients treated with heparin, hyperhomcysteinemia in whom septic and diabetic patients showed decreased values. HCII thrombin inhibition possibly takes place in extravascular sites where dermatan sulfate is present. HCII activity would be important in the regulation of wound healing, inflammation, or neuronal development. PMID:10349131

  16. 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.

  17. Direct thrombin inhibitor-bivalirudin functionalized plasma polymerized allylamine coating for improved biocompatibility of vascular devices.

    Science.gov (United States)

    Yang, Zhilu; Tu, Qiufen; Maitz, Manfred F; Zhou, Shuo; Wang, Jin; Huang, Nan

    2012-11-01

    The direct thrombin inhibitor of bivalirudin (BVLD), a short peptide derived from hirudin, has drawn an increasing attention in clinical application because it is safer and more effective than heparin for diabetic patients with moderate- or high-risk for acute coronary syndromes (ACS). In this study, BVLD was covalently conjugated on plasma polymerized allylamine (PPAam) coated 316L stainless steel (SS) to develop an anticoagulant surface. QCM-D real time monitoring result shows that 565±20 ng/cm2 of BVLD was bound to the PPAam surface. Infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS) confirmed the immobilization of BVLD. The conjugation of BVLD onto the PPAam coating led to enhanced binding of thrombin, and the activity of the thrombin adsorbed on its surface was effectively inhibited. As a result, the BVLD immobilized PPAam (BVLD-PPAam) substrate prolonged the clotting times, and exhibited inhibition in adhesion and activation of platelets and fibrinogen. We also found that the BVLD-PPAam coating significantly enhanced endothelial cell adhesion, proliferation, migration and release of nitric oxide (NO) and secretion of prostaglandin I2 (PGI2). In vivo results indicate that the BVLD-PPAam surface restrained thrombus formation by rapidly growing a homogeneous and intact endothelium on its surface. These data suggest the potential of this multifunctional BVLD-PPAam coating for the application not only in general vascular devices such as catheters, tubes, oxygenator, hemodialysis membranes but also vascular grafts and stents. PMID:22877639

  18. Isolation and characterization of the thrombin-like enzyme from Cryptelytrops purpureomaculatus venom.

    Science.gov (United States)

    Tan, Nget Hong

    2010-01-01

    A thrombin-like enzyme, purpurase, was purified from the Cryptelytrops purpureomaculatus (mangrove pit viper) venom using high performance ion-exchange and gel filtration chromatography. The purified sample (termed purpurase) yielded a homogeneous band in SDS-polyacrylamide gel electrophoresis with a molecular weight of 35,000. The N-terminal sequence of purpurase was determined to be VVGGDECNINDHRSLVRIF and is homologous to many other venom thrombin-like enzymes. Purpurase exhibits both arginine ester hydrolase and amidase activities. Kinetic studies using tripeptide chromogenic anilide substrates showed that purpurase is not fastidious towards its substrate. The clotting times of fibrinogen by purpurase were concentration dependent, with optimum clotting activity at 3mg fibronogen/mL. The clotting activity by purpurase was in the following decreasing order: cat fibrinogen>human fibrinogen>dog fibrinogen>goat fibrinogen>rabbit fibrinogen. Reversed-phase HPLC analysis of the products of action of purpurase on bovine fibrinogen showed that only fibrinopeptide A was released. Indirect ELISA studies showed that anti-purpurase cross-reacted strongly with venoms of most crotalid venoms, indicating the snake venom thrombin-like enzymes generally possess similar epitopes. In the more specific double-sandwich ELISA, however, anti-purpurase cross-reacted only with venoms of certain species of the Trimeresurus complex, and the results support the recent proposed taxonomy changes concerning the Trimeresurus complex. PMID:19770070

  19. Whole blood coagulation in children with thrombocytopenia and the response to platelet replacement, recombinant factor VIIa, and a potent factor VIIa analogue

    DEFF Research Database (Denmark)

    Larsen, Ole Halfdan; Clausen, Niels; Persson, Egon; Ezban, Mirella; Ingerslev, Jørgen; Sørensen, Benny

    2008-01-01

    The present study evaluated dynamic coagulation profiles, platelet aggregation, and thrombin generation in whole blood (WB) from eight children with thrombocytopenia during chemotherapy, and the haemostatic potential of platelets (+60 x 10(9)/l), recombinant factor VIIa (rFVIIa - NovoSeven), and a potent rFVIIa analogue (NN1731) both at 1 and 4 microg/ml. Dynamic WB coagulation profiles were recorded by thrombelastometry employing activation with tissue factor (TF - Innovin) at low concentration...

  20. Thrombin-induced intracellular calcium rise identifies oligodendrocytes derived from SVZ cultures

    Directory of Open Access Journals (Sweden)

    S. Grade

    2009-08-01

    Full Text Available Glial cell transplantation arises as a promising complementary strategy to challenge oligodendrocytes loss occurring in the demyelinated brain. Recent advances in stem cell biology, namely concerning subventricular zone (SVZ stem cells have been giving new hopes offering a source of new oligodendrocytes for cell replenishment in MS brains. However, there are yet no good methods for the functional identification of differentiating oligodendrocytes, and pharmacological analysis in these cells prior transplantation.In the present study, we questioned whether SVZ-derived oligodendrocytes could be functionally discriminated on the basis of variations of intracellular calcium levels ([Ca2+]i following 50 mM KCl, 100 ?M histamine or 0,1 U/ml thrombin stimulations. For this purpose, P1-3 C57/BL6 mice SVZ cultures were treated with triiodo-L-thyronine (T3 to promote oligodendrocytic differentiation before functional analysis of the heterogeneous population. Our group has previously shown that SVZ-derived neurons and immature cells can be discriminated due to their selective [Ca2+]i rise upon KCl and histamine stimulations, respectively. Herein, we demonstrate that O4-oligodendrocytes, as observed previously in astrocytes, do not respond to these stimuli. Nonetheless, O4-oligodendrocytes display an increase in [Ca2+]i following thrombin stimulation whereas all the other cell types in the culture were insensitive to thrombin. Thus, oligodendrocytes can be distinguished according to the uniqueness of their response to thrombin.We further show that thrombin-induced calcium increase in SVZ-derived oligodendrocytes is mediated by protease-activated receptor-1 activation with the downstream involvement of Gq/11 and PLC, resulting in the mobilization of calcium from the cellular internal stores.This method allows the analysis of functional properties of the oligodendrocytic cell population in living SVZ cultures which is of major interest for the development of efficient grafting strategies in the demyelinated brain. Furthermore, this technique opens new perspectives for the search of new pro-oligodendrogenic factors to be used prior grafting. Ackowledgments:PTDC/SAU-NEU/68465/2006, FEDER

  1. Topical photodynamic therapy

    Directory of Open Access Journals (Sweden)

    Polja?ki Mirjana

    2006-01-01

    Full Text Available Topical photodynamic therapy is a therapeutic modality in development, thus arises grate interest among dermatologists worldwide. It is an effective therapy for actinic keratosis, superficial BCC and Bowenos disease. Treatment efficacy, good cosmetics, low risk of skin cancer, low invasiveness, low rate of adverse events, facility for treating multiple or large lesions, especially in poor healing sites and, for penile, digital and facial involvement, low general toxicity and possibility of repeating the treatments with the same efficiency, enable topical photodynamic therapy to become increasingly practiced treatment modality. Researching aimed topical photodynamic therapy to prove as a treatment modality for clinical use in other dermatoses, is in experimental phase. To answer the question when dermatologist should consider using topical photodynamic therapy treatment modatility, we are present available date.

  2. Diclofenac Topical (osteoarthritis pain)

    Science.gov (United States)

    ... gel (Voltaren) is used to relieve pain from osteoarthritis (arthritis caused by a breakdown of the lining ... Diclofenac topical liquid (Pennsaid) is used to relieve osteoarthritis pain in the knees. Diclofenac is in a ...

  3. Topics in Nuclear Astrophysics

    International Nuclear Information System (INIS)

    Some topics in nuclear astrophysics are discussed, e.g.: highly evolved stellar cores, stellar evolution (through the temperature analysis of stellar surface), nucleosynthesis and finally the solar neutrino problem. (L.C.)

  4. Contrastive topics decomposed

    Directory of Open Access Journals (Sweden)

    Michael Wagner

    2012-12-01

    Full Text Available The analysis of contrastive topics introduced in Büring 1997b and further developed in Büring 2003 relies on distinguishing two types of constituents that introduce alternatives: the sentence focus, which is marked by a FOC feature, and the contrastive topic, which is marked by a CT feature. A non-compositional rule of interpretation that refers to these features is used to derive a topic semantic value, a nested set of sets of propositions. This paper presents evidence for a correlation between the restrictive syntax of nested focus operators and the syntax of contrastive topics, a correlation which is unexpected under this analysis. A compositional analysis is proposed that only makes use of the flatter focus semantic values introduced by focus operators. The analysis aims at integrating insights from the original analysis while at the same time capturing the observed syntactic restrictions. http://dx.doi.org/10.3765/sp.5.8 BibTeX info

  5. Can autologous thrombin with a rest fraction of ethanol be used safely for activation of concentrated autologous platelets applied on nerves?

    OpenAIRE

    de Somer, Filip; De Brauwer, Veerle; Vandekerckhove, Maxence; Ducatelle, Richard; Uyttendaele, Dirk; Nooten, Guido Van

    2005-01-01

    The use of concentrated platelet-rich plasma (cPRP) as a source of growth factors is reported to be beneficial for an enhanced osteogenesis in spine surgery. Today both bovine and autologous thrombin is used for activating the platelets and thus releasing the growth factors. In order to prevent transmission of organisms and the development of antibodies, autologous thrombin seems to be the logical choice. However, the preparation of autologous thrombin is cumbersome and consumes a part of the...

  6. Direct Thrombin Inhibition Reduces Lung Collagen, Accumulation, and Connective Tissue Growth Factor mRNA Levels in Bleomycin-Induced Pulmonary Fibrosis

    OpenAIRE

    Howell, David C.J.; Goldsack, Neil R.; Richard P. Marshall; McAnulty, Robin J; Starke, Richard; Purdy, Gordon; Laurent, Geoffrey J.; Chambers, Rachel C

    2001-01-01

    Dramatic activation of the coagulation cascade has been extensively documented for pulmonary fibrosis associated with acute and chronic lung injury. In addition to its role in hemostasis, thrombin exerts profibrotic effects via activation of the major thrombin receptor, protease-activated receptor-1. In this study, we examined the effect of the direct thrombin inhibitor, UK-156406 on fibroblast responses in vitro and on bleomycin-induced pulmonary fibrosis in rats. UK-156406 significantly inh...

  7. Recombination in RNA.

    Science.gov (United States)

    King, A M; McCahon, D; Slade, W R; Newman, J W

    1982-07-01

    The aphthovirus genome consists of a single molecule of single-stranded RNA that encodes all the virus-induced proteins. We isolated recombinant aphthoviruses from cells simultaneously infected with temperature-sensitive mutants of two different subtype strains. Analysis of the proteins induced by 16 independently generated recombinants revealed two types of protein pattern, which were consistent with single genetic crossovers on the 5' side and 3' side, respectively, of the central P34-coding region. Recombinants invariably inherited all four coat proteins from the same parent, and novel recombinant proteins were not observed. RNAase T1 fingerprints of virus RNA, prepared from representatives of each recombinant type, confirmed the approximate crossover sites that had been deduced from the inheritance of proteins. These fingerprints provide molecular evidence of recombination at the level of RNA and demonstrate the potential of RNA recombination for producing genetic diversity among picornaviruses. PMID:6295637

  8. Towards Big Topic Modeling

    OpenAIRE

    Yan, Jian-feng; Zeng, Jia; Liu, Zhi-qiang; GAO, YANG

    2013-01-01

    To solve the big topic modeling problem, we need to reduce both time and space complexities of batch latent Dirichlet allocation (LDA) algorithms. Although parallel LDA algorithms on the multi-processor architecture have low time and space complexities, their communication costs among processors often scale linearly with the vocabulary size and the number of topics, leading to a serious scalability problem. To reduce the communication complexity among processors for a better scalability, we p...

  9. 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.

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

    International Nuclear Information System (INIS)

    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

  11. Topical Drugs for Pain Relief

    Directory of Open Access Journals (Sweden)

    Anjali Srinivasan

    2015-03-01

    Full Text Available Topical therapy helps patients with oral and perioral pain problems such as ulcers, burning mouth syndrome, temporomandibular disorders, neuromas, neuropathies and neuralgias. Topical drugs used in the field of dentistry are topical anaesthetics, topical analgesics, topical antibiotics and topical corticosteroids. It provides symptomatic/curative effect. Topical drugs are easy to apply, avoids hepatic first pass metabolism and more sites specific. But it can only be used for medications that require low plasma concentrations to achieve a therapeutic effect.

  12. Design, synthesis and antithrombotic evaluation of novel dabigatran etexilate analogs, a new series of non-peptides thrombin inhibitors.

    Science.gov (United States)

    Chen, Dongxing; Wang, Shaochi; Diao, Xiaojuan; Zhu, Qihua; Shen, Huiliang; Han, Xueqing; Wang, Yiwei; Gong, Guoqing; Xu, Yungen

    2015-12-01

    Thrombin is a serine protease that plays a key role in blood clotting, which makes it a promising target for the treatment of thrombotic diseases. Dabigatran is direct potent thrombin inhibitor. Based on bioisosteric and scaffold hopping principle, two dabigatran mimics (I-1 and II-1) in which the benzamidine moiety of dabigatran was replaced by a tricyclic fused scaffold were designed, synthesized and evaluated for their in vitro activities for inhibiting thrombin. The results reveal that compounds I-1 (IC50=9.20nM) and II-1 (IC50=7.48nM) are potent direct thrombin inhibitors and the activity is in the range of reference drug. On this basis, twenty-two ester and carbamate derivatives of I-1 or II-1 were prepared and evaluated for their anticoagulant activity. Prodrugs I-4a (IC50=0.73?M), I-4b (IC50=0.75?M), II-2a (IC50=1.44?M) and II-2b (IC50=0.91?M) display excellent effects of inhibiting thrombin induced-platelet aggregation. Moreover, compounds I-9 and II-4, which contain a cleavable moiety with anti-platelet activity, show the best anticoagulant efficacy among the tested compounds in the rat venous thrombosis model. The compounds which have better in vitro and in vivo activity were subjected to rat tail bleeding test, and the result demonstrates that compound I-9 is less likely to have bleeding risk than dabigatran etexilate. PMID:26537784

  13. Apoferritin Protein Nanoparticles Dually labeled with Aptamer and Horseradish Peroxidase as a Sensing Probe for Thrombin Detection

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jie; Liu, Meiling; Zhang, Youyu; Li, Haitao; Lin, Yuehe; Yao, Shouzhuo

    2013-01-08

    A sandwich-type electrochemical aptasensor has been developed for the detection of thrombin, based on dual signal-amplification using HRP and apoferritin. Aptamer1 (Apt1) loaded on core/shell Fe3O4/Au magnetic nanoparticle (AuMNP) was used as recognition elements, and apoferritin dually labeled with Aptamer2 (Apt2) and HRP was used as a detection probe. Sandwich-type complex, Apt1/thrombin/Apt2–apoferritin NPs–HRP was formed by the affinity reactions between AuMNPs–Apt1, thrombin, and Apt2–apoferritin–HRP. The complex was anchored on a screen-printed carbon electrode (SPCE). Differential pulse voltammetry (DPV) was used to monitor the electrode response. The proposed aptasensor yielded a linear current response to thrombin concentrations over a broad range of 0.5 pM to 100 pM with a detection limit of 0.07 pM (S/N = 3). The detection signal was amplified by using apoferritin and HRP. This nanoparticle-based aptasensor offers a new method for rapid, sensitive, selective, and inexpensive quantification of thrombin, and offers a promising potential in biomarker detection and disease diagnosis. --------------------------------------------------------------------------------

  14. Fluorescence correlation spectroscopy of gold nanoparticles, and its application to an aptamer-based homogeneous thrombin assay

    International Nuclear Information System (INIS)

    We have studied the fluorescence properties and diffusion behaviors of gold nanoparticles (GNPs) in solution by using fluorescence correlation spectroscopy (FCS) at single molecule level. The GNPs display a high photo-saturation feature. Under illumination with strong laser light, they display higher brightness per particle (BPP) despite their low quantum yields. Based on the unique fluorescence properties and diffusion behaviors of GNPs, we have developed a sensitive and homogenous thrombin assay. It is based on a sandwich strategy and is making use of GNPs to which two different aptamers are conjugated. When the differently aptamer-labeled GNPs are mixed with solutions containing thrombin, the affinity reaction causes the GNPs to form dimers or oligomers. This leads to an increase in the diffusion time of the GNPs in the detection volume that is seen in FCS. The FCS method enables sensitive detection of the change in the characteristic diffusion time of the GNPs before and after the affinity reaction. Quantitative analysis of thrombin is based on the measurement of the change in the diffusion time. Under optimal conditions, the calibration plot is linear in the 0.5 nM to 110 nM thrombin concentration range, and the detection limit is 0.5 nM. The method was successfully applied to the direct determination of thrombin in human plasma. (author)

  15. Thrombin inhibits HMGB1-mediated proinflammatory signaling responses when endothelial protein C receptor is occupied by its natural ligand

    Directory of Open Access Journals (Sweden)

    Jong-Sup Bae

    2013-11-01

    Full Text Available High mobility group box 1 (HMGB1 is involved in thepathogenesis of vascular diseases. Unlike activated protein C(APC, the activation of PAR-1 by thrombin is known to elicitproinflammatory responses. To determine whether the occupancyof EPCR by the Gla-domain of APC is responsible for thePAR-1-dependent antiinflammatory activity of the protease, wepretreated HUVECs with the PC zymogen and then activatedPAR-1 with thrombin. It was found that thrombin downregulatesthe HMGB1-mediated induction of both TNF-? andIL-6 and inhibits the activation of both p38 MAPK and NF-?B inHUVECs pretreated with PC. Furthermore, thrombin inhibitedHMGB1-mediated hyperpermeability and leukocyte adhesion/migration by inhibiting the expression of cell adhesion moleculesin HUVECs if EPCR was occupied. Collectively, theseresults suggest the concept that thrombin can initiate proinflammatoryresponses in vascular endothelial cells through theactivation of PAR-1 may not hold true for normal vesselsexpressing EPCR under in vivo conditions. [BMB Reports 2013;46(11: 544-549

  16. 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.

  17. A brief exposure to tryptase or thrombin potentiates fibrocyte differentiation in the presence of serum or serum amyloid p.

    Science.gov (United States)

    White, Michael J V; Galvis-Carvajal, Elkin; Gomer, Richard H

    2015-01-01

    A key question in both wound healing and fibrosis is the trigger for the initial formation of scar tissue. To help form scar tissue, circulating monocytes enter the tissue and differentiate into fibroblast-like cells called fibrocytes, but fibrocyte differentiation is strongly inhibited by the plasma protein serum amyloid P (SAP), and healthy tissues contain very few fibrocytes. In wounds and fibrotic lesions, mast cells degranulate to release tryptase, and thrombin mediates blood clotting in early wounds. Tryptase and thrombin are upregulated in wound healing and fibrotic lesions, and inhibition of these proteases attenuates fibrosis. We report that tryptase and thrombin potentiate human fibrocyte differentiation at biologically relevant concentrations and exposure times, even in the presence of concentrations of serum and SAP that normally completely inhibit fibrocyte differentiation. Fibrocyte potentiation by thrombin and tryptase is mediated by protease-activated receptors 1 and 2, respectively. Together, these results suggest that tryptase and thrombin may be an initial trigger to override SAP inhibition of fibrocyte differentiation to initiate scar tissue formation. PMID:25429068

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

    International Nuclear Information System (INIS)

    We describe a sensitive biosensing system combining magnetic relaxation switch diagnosis and colorimetric detection of human ?-thrombin, based on the aptamer-protein interaction induced aggregation of Fe3O4-Au nanoparticles. To demonstrate the concept, gold-coated iron oxide nanoparticle was synthesized by iterative reduction of HAuCl4 onto the dextran-coated Fe3O4 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 ?-thrombin were conjugated separately to two distinct nanorose populations. Once a solution containing human ?-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 (T2) as well as the UV-Vis absorption spectra of the solution. Thus the qualitative and quantitative detection method for human ?-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 T2 change is observed with 1.0 nM human ?-thrombin, and the detection range is from 1.6 nM to 30.4 nM.

  19. 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.

  20. Characters and Topical Diversity

    DEFF Research Database (Denmark)

    Eriksson, Rune

    2014-01-01

    The purpose of this article is to contribute to our understanding of the difference between the bestseller and the non-bestseller in nonfiction. It is noticed that many bestsellers in nonfiction belongs to the sub-genre of creative nonfiction, but also that the topics in this kind of literature is largely ignored by the critics. Thus, the article tests how topics may work in creative nonfiction. Two Danish bestsellers belonging to the genre, Frank’s Mit smukke genom ( My Beautiful Genome), about...

  1. (Photoexcited charge pair escape and recombination)

    Energy Technology Data Exchange (ETDEWEB)

    Braun, C.L.

    1990-01-01

    Progress in four research areas on this project are summarized under the following topics: (1) Geminate charge pair recombination in hexane; (2) Fast current measurements resulting from excitation of charge transfer (CT) states; (3) Measurement of the dipole moment of excited states by DC conductivity; and (4) Charge separation at macroscopic interfaces between electron donor and acceptor solids. In a final section, personnel who have contributed to the project during the past budget period are described.

  2. Recombination and Genetic Diversity

    Scientific Electronic Library Online (English)

    T. C., Coutinho; T.T.da, Silva; G.L., Toledo.

    2012-12-01

    Full Text Available In this paper we present a spatial stochastic model for genetic recombination, that answers if diversity is preserved in an infinite population of recombinat-ing individuals distributed spatially. We show that, for finite times, recombination may maintain all the various potential different types, b [...] ut when time grows infinitely, the diversity of individuals extinguishes off. So under the model premisses, recombination and spatial localization alone are not enough to explain diversity in a population. Further we discuss an application of the model to a controversy regarding the diversity of "Major Histocompatibility Complex" (MHC).

  3. Topical Acne Treatments and Pregnancy

    Science.gov (United States)

    Topical Acne Treatments and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of having ... from your health care provider. What are topical acne treatments? Topical acne treatments are medications applied directly ...

  4. Thrombin related peptide TP508 promoted fracture repair in a mouse high energy fracture model

    Directory of Open Access Journals (Sweden)

    Pan Xiao-Hua

    2009-01-01

    Full Text Available Abstract Background Thrombin related peptide (TP508 is a 23 amino-acid synthetic peptide that represents a portion of the receptor-binding domain of thrombin molecule. Previous studies have shown that TP508 can accelerate musculoskeletal tissue repair including fracture healing. Objectives The aim of this study was to investigate the effect of TP508 on fracture healing in a murine fracture model representing high energy fracture situation. Methods Eighty CD 1 mice underwent controlled quadriceps muscle crush and open transverse mid diaphyseal femoral fracture that was then fixed with an external fixator. Animals were randomised into four groups to receive an intra-operative dose of either 100 ?g TP508 into the fracture gap; 100 ?g TP508 into the surrounding damaged muscle tissues; 10 ?g TP508 into the fracture gap, or control equal amount of saline into the fracture gap. Radiographic assessment was performed weekly for 5 weeks; histological analysis was at 3 and 5 weeks post fracture and biomechanical testing of the fractured bone was performed at 5 weeks post fracture. Results Mechanical testing data showed that the fracture stiffness was significantly higher in the group receiving 100 ?g TP508 into the fracture gap than other groups. Histological and radiographic analysis revealed a trend of increase in bone formation in the 100 ?g TP508 injected into the fracture gap group compared to the saline control group. It was noted that the scar tissues was significantly less in Group II comparing with the saline control group and there was increased blood vessel formation in the crushed muscles and fracture gap areas in the groups receiving TP508 comparing to the saline control group. Conclusion The results from this study demonstrated the use of thrombin related peptide TP508 in the situation of a high energy fracture can promote fracture healing and reduce the potential complications such as muscle fibrosis and fracture delayed or non-union.

  5. Physicochemical characterisation of rVIII-SingleChain, a novel recombinant single-chain factor VIII.

    Science.gov (United States)

    Schmidbauer, Stefan; Witzel, Reinhild; Robbel, Lars; Sebastian, Petra; Grammel, Nicolas; Metzner, Hubert J; Schulte, Stefan

    2015-08-01

    rVIII-SingleChain is a novel recombinant single-chain factor VIII (FVIII) construct, comprising covalently bonded heavy and light chains. Post-translational modifications of FVIII affect physicochemical parameters, including hydrophobicity and charge. The most relevant post-translational modifications of FVIII products are N-glycosylation of asparagine residues and tyrosine sulphations. Here, the physicochemical properties, thrombin cleavage products and post-translational modifications of rVIII-SingleChain were investigated and compared against commercially available recombinant FVIII (rFVIII) products with a predominant two-chain structure (B-domain deleted rFVIII and full-length rFVIII). rVIII-SingleChain was expressed in Chinese hamster ovary (CHO) cells and purified by chromatographic methods. Physicochemical properties of rVIII-SingleChain or thrombin-derived cleavage products were assessed using size-exclusion chromatography, reversed-phase chromatography and sodium dodecyl sulphate polyacrylamide gel electrophoresis. Analysis of the respective carbohydrate structures was performed after release of N-glycans by PNGase F followed by fluorescence labelling and high-performance liquid chromatography. Proteolysis by trypsin generated the corresponding peptides, which were analysed for sulphated tyrosines by liquid chromatography-electrospray ionisation time of flight-mass spectrometry. rVIII-SingleChain was shown to be of high purity and homogeneity, and presented a well-defined single-chain molecule with predominant ?-sheet conformation. The coagulation-relevant thrombin-activation products of rVIII-SingleChain were comparable with those obtained by activation of commercially available rFVIII products. rVIII-SingleChain post-translational modifications were similar to other CHO cell-derived rFVIII products for N-glycopattern and tyrosine sulphation. In conclusion, rVIII-SingleChain is of high homogeneity and purity, and provides an expected cleavage pattern on activation, setting the basis for optimal efficacy in the patient. PMID:26037285

  6. Advanced Topics in Aerodynamics

    DEFF Research Database (Denmark)

    Filippone, Antonino

    1999-01-01

    "Advanced Topics in Aerodynamics" is a comprehensive electronic guide to aerodynamics,computational fluid dynamics, aeronautics, aerospace propulsion systems, design and relatedtechnology. We report data, tables, graphics, sketches,examples, results, photos, technical andscientific literature, for higher education, learning, reference, research and engineering services.

  7. Topics for Mathematics Clubs.

    Science.gov (United States)

    Dalton, LeRoy C., Ed.; Snyder, Henry D., Ed.

    The ten chapters in this booklet cover topics not ordinarily discussed in the classroom: Fibonacci sequences, projective geometry, groups, infinity and transfinite numbers, Pascal's Triangle, topology, experiments with natural numbers, non-Euclidean geometries, Boolean algebras, and the imaginary and the infinite in geometry. Each chapter is…

  8. Selected topics in magnetism

    CERN Document Server

    Gupta, L C

    1993-01-01

    Part of the ""Frontiers in Solid State Sciences"" series, this volume presents essays on such topics as spin fluctuations in Heisenberg magnets, quenching of spin fluctuations by high magnetic fields, and kondo effect and heavy fermions in rare earths amongst others.

  9. 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.; Rasmussen, Lars M.; Andresen, Thomas Lars; Wengel, Jesper; Pasternak, Anna

    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...

  10. Deletion of the thrombin cleavage domain of osteopontin mediates breast cancer cell adhesion, proteolytic activity, tumorgenicity, and metastasis

    International Nuclear Information System (INIS)

    Osteopontin (OPN) is a secreted phosphoprotein often overexpressed at high levels in the blood and primary tumors of breast cancer patients. OPN contains two integrin-binding sites and a thrombin cleavage domain located in close proximity to each other. To study the role of the thrombin cleavage site of OPN, MDA-MB-468 human breast cancer cells were stably transfected with either wildtype OPN (468-OPN), mutant OPN lacking the thrombin cleavage domain (468-?TC) or an empty vector (468-CON) and assessed for in vitro and in vivo functional differences in malignant/metastatic behavior. All three cell lines were found to equivalently express thrombin, tissue factor, CD44, ?v?5 integrin and ?1 integrin. Relative to 468-OPN and 468-CON cells, 468-?TC cells expressing OPN with a deleted thrombin cleavage domain demonstrated decreased cell adhesion (p < 0.001), decreased mRNA expression of MCAM, maspin and TRAIL (p < 0.01), and increased uPA expression and activity (p < 0.01) in vitro. Furthermore, injection of 468-?TC cells into the mammary fat pad of nude mice resulted in decreased primary tumor latency time (p < 0.01) and increased primary tumor growth and lymph node metastatic burden (p < 0.001) compared to 468-OPN and 468-CON cells. The results presented here suggest that expression of thrombin-uncleavable OPN imparts an early tumor formation advantage as well as a metastatic advantage for breast cancer cells, possibly due to increased proteolytic activity and decreased adhesion and apoptosis. Clarification of the mechanisms responsible for these observations and the translation of this knowledge into the clinic could ultimately provide new therapeutic opportunities for combating breast cancer

  11. Do avian mitochondria recombine?

    Science.gov (United States)

    Berlin, Sofia; Smith, Nick G C; Ellegren, Hans

    2004-02-01

    The dogma of strict maternal inheritance of mitochondria is now being tested with population genetics methods on sequence data from many species. In this study we investigated whether recombination occurs in the mitochondria of the blue tit ( Parus caeruleus) by studying polymorphisms in the mitochondrial control region and in a recently identified (A)(n) microsatellite on the W chromosome. The female heterogamety of avian sex chromosomes allows a test of whether mitochondrial recombination affects genealogical inference by comparison of mitochondrial and W-linked sequence variation. There is no discrepancy between mitochondrial and W-linked genealogies in blue tits, consistent with no recombination. We also analyzed mitochondrial sequence variation in both blue tits and peregrine falcons ( Falco peregrinus) using a coalescent-based approach which accounts for recurrent mutation; in neither bird species did we find evidence of recombination. We conclude that it is unlikely that mitochondrial recombination has large effects on mitochondrial genetic variability in birds. PMID:15042336

  12. [New hemostatic therapy of bleeding of bladder by technique of drip-irrigation using a thrombin solution].

    Science.gov (United States)

    Kimura, S; Nakamura, S; Nakai, H

    1986-02-01

    To control the bleeding from the bladder caused by radiation cystitis or transurethral surgery, drip-irrigation of bladder by indwelling a three-way Foley catheter using a thrombin solution, as a clotting agent, was done in 10 patients. Five hundreds ml of solution containing 25,000 units of thrombin was dripped out within 3 hours and repeated 2 times a day for 2 to 7 days. The results were excellent in 2 cases, good in 6 cases and poor in 2 cases. No remarkable side effects were observed. PMID:3524153

  13. Comparison of antibody and aptamer receptors for the specific detection of thrombin with a nanometer gap-sized impedance biosensor.

    Science.gov (United States)

    Schlecht, U; Malavé, A; Gronewold, T; Tewes, M; Löhndorf, M

    2006-07-28

    Nanogap-impedance biosensors with electrode separations of 75 nm have been fabricated by means of standard optical lithography and a sacrificial layer technique. Due to a large surface-to-volume ratio and high sensitivity, these sensors are superior compared to open interdigitated electrode structures. As a model, the blood coagulation factor thrombin was detected. As specific receptors, either an antibody or a RNA-aptamer have been used. The microwave frequency impedance measurements showed that both ligands were equally suitable for the specific detection of thrombin. PMID:17723506

  14. Pegasparaginase treatment alters thrombin generation by modulating the protein C and S system in acute lymphoblastic leukaemia/lymphoma.

    Science.gov (United States)

    Staddon, Jack H; Smock, Kristi J; Schiffman, Joshua D; Fluchel, Mark N; Engel, Michael E; Weyrich, Andrew S; Campbell, Robert A

    2015-10-01

    Paediatric patients with acute lymphoblastic leukaemia/lymphoma treated with pegasparaginase are at an increased risk of thrombosis. We evaluated changes in thrombin generation in the presence and absence of thrombomodulin using paired plasma samples collected from paediatric patients treated with pegasparaginase. Postpegasparaginase samples were significantly less sensitive to reductions in thrombin generation in the presence of thrombomodulin compared with prepegasparaginase, suggesting reduced protein C and S activity. This corresponded to a significant decrease in protein C and protein S antigen. Alterations in the protein C and S pathway may contribute to the increased risk of thrombosis in patients treated with pegasparaginase. PMID:26196196

  15. Acidic Residues C-Terminal to the A2 Domain Facilitate Thrombin-Catalyzed Activation of Factor VIII

    OpenAIRE

    Newell, Jennifer L.; Fay, Philip J.

    2008-01-01

    Factor VIII is activated by thrombin through proteolysis at Arg740, Arg372, and Arg1689. One region implicated in this exosite-dependent interaction is the factor VIII a2 segment (residues 711-740) separating the A2 and B domains. Residues 717-725 (DYYEDSYED) within this region consist of five acidic residues and three sulfo-Tyr residues, thus representing a high density of negative charge potential. The contributions of these residues to thrombin-catalyzed activation of factor VIII were asse...

  16. Modulation of human uterine smooth muscle cell collagen contractility by thrombin, Y-27632, TNF alpha and indomethacin

    Directory of Open Access Journals (Sweden)

    Smith Terry J

    2009-01-01

    Full Text Available Abstract Background Preterm labour occurs in approximately 10% of pregnancies and is a major cause of infant morbidity and mortality. However, the pathways involved in regulating contractility in normal and preterm labour are not fully elucidated. Our aim was to utilise a human myometrial contractility model to investigate the effect of a number of uterine specific contractility agents in this system. Therefore, we investigated the contractile response of human primary uterine smooth muscle cells or immortalised myometrial smooth muscle cells cultured within collagen lattices, to known mediators of uterine contractility, which included thrombin, the ROCK-1 inhibitor Y-27632, tumour necrosis factor alpha (TNF alpha and the non-steroidal anti-inflammatory indomethacin. Methods Cell contractility was calculated over time, with the collagen gel contraction assay, utilising human primary uterine smooth muscle cells (hUtSMCs and immortalised myometrial smooth muscle cells (hTERT-HM: a decrease in collagen gel area equated to an increase in contractility. RNA was isolated from collagen embedded cells and gene expression changes were analysed by real time fluorescence reverse transcription polymerase chain reaction. Scanning electron and fluorescence microscopy were employed to observe cell morphology and cell collagen gel interactions. Statistical analysis was performed using ANOVA followed by Tukey's post hoc tests. Results TNF alpha increased collagen contractility in comparison to the un-stimulated collagen embedded hUtSMC cells, which was inhibited by indomethacin, while indomethacin alone significantly inhibited contraction. Thrombin augmented the contractility of uterine smooth muscle cell and hTERT-HM collagen gels, this effect was inhibited by the thrombin specific inhibitor, hirudin. Y-27632 decreased both basal and thrombin-induced collagen contractility in the hTERT-HM embedded gels. mRNA expression of the thrombin receptor, F2R was up-regulated in hUtSMCs isolated from collagen gel lattices, following thrombin-stimulated contractility. Conclusion TNF alpha and thrombin increased uterine smooth muscle cell collagen contractility while indomethacin had the opposite effect. Thrombin-induced collagen contractility resulted in F2R activation which may in part be mediated by the ROCK-1 pathway. This study established the in vitro human myometrial model as a viable method to assess the effects of a range of uterotonic or uterorelaxant agents on contractility, and also permits investigation of the complex regulatory pathways involved in mediating myometrial contractility at labour.

  17. PREFACE: CEWQO Topical Issue CEWQO Topical Issue

    Science.gov (United States)

    Bozic, Mirjana; Man'ko, Margarita

    2009-09-01

    This topical issue of Physica Scripta collects selected peer-reviewed contributions based on invited and contributed talks and posters presented at the 15th Central European Workshop on Quantum Optics (CEWQO) which took place in Belgrade 29 May-3 June 2008 (http://cewqo08.phy.bg.ac.yu). On behalf of the whole community took place in Belgrade 29 May-3 June 2008 (http://cewqo08.phy.bg.ac.yu, cewqo08.phy.bg.ac.yu). On behalf of the whole community of the workshop, we thank the referees for their careful reading and useful suggestions which helped to improve all of the submitted papers. A brief description of CEWQO The Central European Workshop on Quantum Optics is a series of conferences started informally in Budapest in 1992. Sometimes small events transform into important conferences, as in the case of CEWQO. Professor Jozsef Janszky, from the Research Institute of Solid State Physics and Optics, is the founder of this series. Margarita Man'ko obtained the following information from Jozsef Janszky during her visit to Budapest, within the framework of cooperation between the Russian and Hungarian Academies of Sciences in 2005. He organized a small workshop on quantum optics in Budapest in 1992 with John Klauder as a main speaker. Then, bearing in mind that a year before Janszky himself was invited by Vladimir Buzek to give a seminar on the same topic in Bratislava, he decided to assign the name 'Central European Workshop on Quantum Optics', considering the seminar in Bratislava to be the first workshop and the one in Budapest the second. The third formal workshop took place in Bratislava in 1993 organized by Vladimir Buzek, then in 1994 (Budapest, by Jozsef Janszky), 1995 and 1996 (Budmerice, Slovakia, by Vladimir Buzek), 1997 (Prague, by Igor Jex), 1999 (Olomouc, Czech Republic, by Zdenek Hradil), 2000 (Balatonfüred, Hungary, by Jozsef Janszky ), 2001 (Prague, by Igor Jex), 2002 (Szeged, Hungary, by Mihaly Benedict), 2003 (Rostock,Germany, by Werner Vogel and Sascha Wallentowitz), 2004 (Trieste, Italy, by Naseem Rahman and Sascha Wallentowitz), 2005 (Bilkent, Ankara, by Alexander Shumovsky), 2006 (Vienna, by Helmut Rauch), 2007 (Palermo, Italy, by Antonino Messina) and 2008 (Belgrade, by Mirjana Bozic). The CEWQO series developed in two directions following the rapid development of quantum optics and the transitional development of the scientific collaboration of Central European researchers with researchers from old and new emerging Central European countries, and from all over the world. The topics discussed at CEWQO 08 were divided into ten groups that aimed to cover the broad scope of modern quantum optics: Fundamental aspects of quantum optics and quantum mechanics Single photons and photon pairs Cavity and circuit QED Atoms in intense fields Neutron, atom and molecular quantum optics Quantum gases and fluids Coherence, entanglement and decoherence Optical properties of condensed matter and nanostructures Open quantum systems and chaos Quantum information processing Central European Workshops on Quantum Optics realize and are consistent with a wider idea, and a social, economical, cultural and political program promoted since 1989 by the Central European Initiative (CEI), the main goal of which was to help transition countries in Central Europe to become closer to the EU. The resulting support of the CEI, first obtained thanks to the scientific reputation, organizing activities, and efforts of Helmut Rauch, has been very important for the organization of the CEWQO in recent years, particularly in 2008. The support of the Sixth and Seventh Framework Programs of the European Commission was also very important. A short review of papers in this topical issue A principal role in this topical issue is played by the photon. Vuletic et al describe the mapping of the photon-polarization state onto a single collective-spin excitation (magnon) shared between two atomic ensembles. A heralded quantum memory based on this mapping is demonstrated. Dodonov derives a formula which predicts a photon generation rate in a cavity due to strong variations of the complex dielectric function in a thin layer near an ideally conducting wall (simulation of the dynamic Casimir effect). Skenderovic reports how photons from two femptosecond laser pulses prepare a large molecule in a coherent superposition of vibrational states. The time evolution of this state is interrogated with a third (delayed) pulse which creates a fourth wave, the signal, giving information on the molecular dynamics. Dimitrova et al present lecture demonstrations of interference and quantum erasing with single photons. By considering electromagnetic energy flow lines as photon paths Davidovic et al explain the emergence of an interference pattern in the process of the accumulation of single photon events behind an interference grating. Atoms in a cavity, atom-atom interactions, interactions of atoms with photons and macroscopic bodies is the next important topic in this topical issue. Khanbekyan et al deal with the problem of the spontaneous emission of an excited atom in a high-Q cavity and investigate the regime when the emitted photon belongs to a wave packet simultaneously located inside and outside the cavity. Sambale et al study the resonant Casimir-Polder potential of an excited atom in front of meta-material half-space and show that for long distances it exhibits attenuated oscillations, while close to the surface the potential becomes attractive or repulsive. Buhmann et al study the nonequilibrium Casimir-Polder force on an atom prepared in an incoherent superposition of internal energy-eigenstates, which is placed in a magnetoelectric environment of nonuniform temperature. Lazarou et al discuss how two atoms, interacting with a single cavity, can be coherently evolved into an entangled state when they are controlled by a sequence of Gaussian pulses, named frequency chirps. Bougouffa et al report on field quantization between two parallel conducting plates (modifications of the decay rate between such plates) and the three-level Jaynes-Cummings dynamics in the single-mode regime. Tomas studies the interaction between two atoms, one excited and the other in its ground state near the interface between two media. It is shown that the nonretarded van der Waals force gets enhanced by almost three orders of magnitude at the surface mode resonance. Vuskovic et al write about the plasma treatment of a bulk Nb surface which is very efficient for producing high-Q factor microwave cavities. Nemeth et al review the theory and experiments of the coherently pumped micromaser. With varied atomic inversion in a coherently pumped micromaser, a sudden switch occurs between two distinctively different field states, with high and low photon numbers. Moi et al show that alkali-metal atoms adsorbed either in organic films or in porous glass are released into the vapor phase (desorbed) under illumination, the action of many photons. Several papers are devoted to matter-wave interference and quantum fluids. By analyzing unavoidable quantum losses as they appear in neutron phase-echo and spin rotation experiments, Rauch concludes that basic quantum irreversibility exists in neutron interferometry. Rauch also shows how entanglement effects in a single particle system demonstrate quantum contextuality, and then argues that a quantum system carries much more information than is usually extracted. The time evolution of the wave function of an atom hit by a photon in a three-grating interferometer is used by Arsenovic et al to interpret the intriguing results of the corresponding experiment by Chapman et al. Grujic et al demonstrate dark Raman resonance due to Ramsey interference in a spatially separated pump and probe laser beams co-propagating through a pure 87Rb vapor cell. Obtained EIT profiles are explained by solving Bloch's equations for an atom in a magnetic field moving through pump and probe laser regions. Gawlik et al present results of experiments on finite-temperature Bose-Einstein condensate of 87Rb atoms in a magnetic trap. In the Thomas-Fermi (TF) regime, the condensate dynamics has a hydrodynamic character. The dynamics of non-TF condensates reflect the interaction between BEC and non-condensed thermal atoms. Atoms in intense fields is the subject of several papers. Gainutdinov et al show that the contribution to the radiative shift of the side bands of the Mollow spectrum is very significant. Using Gell-Mann, Low S-matrix formalism, and QED, Glushkov et al present an approach to study multiphoton processes during the interaction of an atom with a realistic intense laser field. The paper by Khetselius is devoted to two related problems: the calculation of the atomic hyperfine structure of the Li-like ions and an estimation of the effectiveness of the three-step scheme of isotope separation for the case of Cs isotopes. Vvedenskii et al present the results concerning the excitation of a residual quasi-dc current in the plasma, which are based on the solution of the time-dependent Schrödinger equation for the hydrogen atom in a few-cycle laser pulse. Information processing is one of the important aspects of this issue and it is considered in several papers. M Man'ko et al presented a new notion of tomographic entropy and new entropic uncertainty relations applied to the problem of light propagation in optical fibers. Nonlinearity in the quantum-information processing is considered in the paper by Chirkin et al. D'Arrigo et al investigated a very specific semiclassical Hamiltonian model of a quantum memory channel. They evaluated the performance of the three-qubit code error correcting code by means of entanglement fidelity. The fundamental aspects of quantum optics are the subject of several papers, namely, Bell's inequalities are studied in the paper by Andreev, the star-product quantization scheme was discussed by O Man'ko, and probabilistic representation was investigated in the paper by Adam et al. In the paper by V Man'ko et al the diagonal representation of the density operator (usually called P-function of Glauber-Sudarshan) is related to the star-product quantization method and to the tomographic-probability representation of quantum states. Laskowski et al suggest an elegant geometrical criterion for the separability, which is based on the local correlation measurements readily available in the laboratory. Mizrahi describes a method to derive the Pauli-Schrödinger equation starting from a simple model of a qubit carried by a massive particle. By analyzing unavoidable quantum losses as they appear in neutron phase-echo and spin rotation experiments, Rauch concludes that basic quantum irreversibility exists in neutron interferometry. Rauch also shows how entanglement effects in a single particle system demonstrate quantum contextuality, and then argues that a quantum system carries much more information than is usually extracted. Kupczynski advocates various statistical tests which could be used to search for a fine structure in experimental data in order to answer the question: is quantum theory predictably complete? For an ion confined within a Paul trap, Mihalcea constructs an invariant operator based on the Lews and Riesenfeld approach and determines the spectrum of the quasienergy operator. Popov et al construct pair-coherent states of the Barut-Girardello kind for two noninteracting subsystems of pseudoharmonic oscillators and examine their statistical properties in different regions of parameters. The property of entanglement, considered to be the most intriguing property of composite quantum systems, has been an important research subject in recent years. It is considered to be a possible resource for quantum computation and communication. Therefore, a substantial number of papers in this topical issue is devoted to entanglement. Leon et al write that two-photon emission from two atoms initially excited in a common electromagnetic vacuum may generate atom-atom entanglement. Dömötör et al elucidate a connection between entanglement and coherent states. Earlier they proved that in the symmetric subspace of a system of N qubits a pure state is not globally entangled, if and only if, it is a coherent state. Here they extend this proof to a system of N 'quKits' (subsystems of arbitrary finite dimension K). Napoli et al compute exactly localizable entanglement as a function of temperature for the system of three interacting spins in a thermal state. Isar considers entanglement in open quantum dynamics by studying the system of two independent oscillators interacting with the general environment. He proposes some special parameters of the environment that manifest interesting properties (e.g., the environment is entangling initially separable states). Lindén et al study the decay of entanglement in rings of qubits that live in the Markov environment. They use the entanglement of formation as the measure whose time evolution announces (or not) the decay. Jivulescu et al consider the time evolution of a spin-1/2 particle nonuniformly coupled through the Heisenberg interaction to the environment composed of N spins. Considering arbitrary initial conditions the authors determine a numerically manipulative general solution from which information on full dynamics may be extracted. Ferraro et al investigate the entanglement evolution of two qubits interacting with a common environment through a Heisenberg XX mechanism and show that the phenomena of entanglement hidden death and entanglement hidden revival take place. Stochastic processes have been very important in quantum optics. Pascazio et al review and compare three algorithms for the generation of sequences of symmetric stable Levy random variables. They draw conclusions on the efficiency of the algorithms used and on some applications in quantum optics. Hul et al report on the possibilities of explaining the statistical properties of the spectra of irregular quantum systems by invoking the random matrix theory. The authors calculated the spectra, spectral correlation functions, and the distributions of avoided crossings, for two types of idealized model of one-dimensional quantum wires forming a quantum graph. Sirko et al present the experimental study of microwave networks displaying an irregular hexagonal structure. In a sense, these networks model quantum graphs with special properties. Kiss et al consider the recurrence of quantum walks on lattices by studying the properties of the generalized Polya number. The properties of this number are compared for classical and quantum cases. A number of interesting papers are devoted to the optical properties of condensed matter and nanostructures. Gorelik derives analytical expressions for photonic dispersion law in 3D photonic crystals filled by dielectrics or metal. Nemilentsau et al evaluate the photon density of states near a single-wall finite length carbon nanotube. The authors found definite singularities in the density of photon states that may be observable in light-matter interaction, thermal radiation distribution, and micromechanical phenomena related to Casimir forces. Perinova et al pay attention to the interesting relationship between microscopic and macroscopic approaches to the quantization of the electromagnetic field in the medium. They examine the problem of a source atom radiating into a dielectric. Radovanovic et al present an extended approach for estimating the tunneling times through all linear materials, including metamaterials having a negative refractive index. Vasic et al describe the optical design of 2D confined structures with metamaterial layers which is based on coordinate transformations. Using the Green's functions method, Ilic et al analyze the influence of boundaries of the molecular ultrathin film on exciton dispersion law. Jeknic-Dugic proposes the model of optically induced transitions in an electronic subsystem of a bio-molecule that is able to describe relatively slow conformational transitions of a bio-molecule. Stef et al present their goal to grow good quality YbF3-doped and PbF2-codoped CaF2 crystals with high divalent Ytterbium content for investigating the influence of Pb2+ ions on the valence conversion, on the dielectric and optical absorption spectra. Vasile et al present the fabrication and SEM and photoluminescence characterization of zinc gallate doped with Eu and Er ions. The results could be important for photonic applications of spinels. Vasiljevic et al present the process of production of microlenses by irradiation of a tot'hema eosin sensitized gelatin (TESG) layer with a laser beam (2nd Nd:YAG harmonic, 532 nm). Microlenses chemically processed after production with 10% alum solution had near diffraction limited performance. The production and application of microlenses are fast expanding because they are increasingly used in biomedical and general optics. Prizes for the poster presentations Authors under 35 years of age were invited to take part in the poster competition. Two first prizes EX-AEQUOAE were awarded to Zoran Grujic from the Institute of Physics, Belgrade, Serbia, for the poster 'Numerical simulation of Raman-Ramsey effects induced by thermal motion of rubidium atoms' and to Andrey Popov from Altai State Technical University, Bernaul, Russia, for the poster 'Beryllium atoms in intense fields'. The third prize was awarded to Alex Crosse from Imperial College, London, UK, for the poster 'Quantum electrodynamics in absorbing nonlinear media'. Members of the Jury were: Mirjana Bozic (Chairperson), Victor Dodonov, Margarita Man'ko, Helmut Rauch, Saverio Pascazio, Richard Tanas and Philip Walther. Sponsors of the awards were the Institute of Physics, Belgrade, European Physical Journal (EPJ) and John Wiley and Sons. CEWQO 2009 and 2010 The 16th Central European Workshop on Quantum Optics was held in Turku, Finland, 23-27 May 2009. CEWQO09 was chaired by Professor Kalle-Antti Suominen (http://www.congress.utu.fi/cewqo2009). The conference site is the new ICT building at chaired by Professor Kalle-Antti Suominen (http://www.congress.utu.fi/cewqo2009, www.congress.utu.fi/cewqo2009). The conference site was the new ICT building at the University of Turku campus area and the Viking Line ferry boat. Turku is the central city of historical Finland established on the mouth of the river Aura in the 13th century. It is the birthplace of Finnish academic life, since the Academy of Turku was established there in 1640. In 2011, Turku will be one of the cultural capitals of Europe. The city has a strong maritime tradition and is shielded from the Baltic sea by a large and beautiful archipelago. The 17th Central European Workshop on Quantum Optics will be held in 2010 in St Andrews, UK. It will be chaired by Professors Ulf Leonhardt and Natalia Korolkova from the School of Physics and Astronomy, University of St Andrews. St Andrews is home to the first university of Scotland, the third-oldest in the English-speaking world, and is the home of golf. It remains a charming, eccentric seaside town that is sufficiently secluded - the ideal place for a stimulating and thought-provoking conference.

  18. Discovering Health Topics in Social Media Using Topic Models

    OpenAIRE

    Paul, Michael J.; Dredze, Mark

    2014-01-01

    By aggregating self-reported health statuses across millions of users, we seek to characterize the variety of health information discussed in Twitter. We describe a topic modeling framework for discovering health topics in Twitter, a social media website. This is an exploratory approach with the goal of understanding what health topics are commonly discussed in social media. This paper describes in detail a statistical topic model created for this purpose, the Ailment Topic Aspect Model (ATAM...

  19. Topics in molecular interactions

    International Nuclear Information System (INIS)

    This volume deals with a variety of problems in intermolecular interactions. These fall into two groups. The first contains important topics which have not recently been dealt with in an authoritative fashion, such as the information given by studying hindered internal rotation. The second group contains contributions based largely on nuclear magnetic resonance work. Nuclear spin relaxation studies have led to intimate knowledge concerning association effects. The approach developed principally at the Karlsruhe laboratory is described. Also included is a second experimental chapter devoted to the way in which light scattering studies provide information on multipole forces in molecular interactions. Other topics based on NMR studies show how this technique yields valuable information on molecular and ion-molecule interactions respectively. (Auth.)

  20. Topical photodynamic therapy

    OpenAIRE

    Polja?ki Mirjana; Jovanovi? Marina; Matovi? Ljubinka; Lugonja Branislava; Gaji? Branislava; Roš Tatjana

    2006-01-01

    Topical photodynamic therapy is a therapeutic modality in development, thus arises grate interest among dermatologists worldwide. It is an effective therapy for actinic keratosis, superficial BCC and Bowenos disease. Treatment efficacy, good cosmetics, low risk of skin cancer, low invasiveness, low rate of adverse events, facility for treating multiple or large lesions, especially in poor healing sites and, for penile, digital and facial involvement, low general toxicity and possibility of re...

  1. Topics in volatility models

    OpenAIRE

    Yi, Cong

    2010-01-01

    In this thesis I will present my PhD research work, focusing mainly on financial modelling of asset’s volatility and the pricing of contingent claims (financial derivatives), which consists of four topics: 1. Several changing volatility models are introduced and the pricing of European options is derived under these models; 2. A general local stochastic volatility model with stochastic interest rates (IR) is studied in the modelling of foreign exchange (FX) rates. The pricin...

  2. Topics in industrial mathematics

    International Nuclear Information System (INIS)

    Mathematical methods are widely used to solve practical problems arising in modern industry. This article outlines some of the topics relevant to AECL programmes. This covers the applications of transmission and neutron transport tomography to determine density distributions in rocks and two phase flow situations. Another example covered is the use of variational methods to solve the problems of aerosol migration and control theory. (author). 7 refs

  3. Topics on mathematical crystallography

    OpenAIRE

    Sunada, Toshikazu

    2014-01-01

    In July 2012 the General Assembly of the United Nations resolved that 2014 should be the International Year of Crystallography, 100 years since the award of the Nobel Prize for the discovery of X-ray diffraction by crystals. On this special occasion, we address several topics in mathematical crystallography. Especially motivated by the recent development in systematic design of crystal structures by both mathematicians and crystallographers, we discuss interesting relationsh...

  4. Superconductivity elementary topics

    CERN Document Server

    Shrivastava, KN

    2000-01-01

    This book describes the elementary concepts of superconductivity and discusses the topics of flux-lattice melting, magnetization including the para-Meissner effect, microwave absorption, a.c. resistivity along with the London penetration depth, the Mössbauer effect, levitation, fractals and nuclear magnetic resonance. There are appendices covering superconducting compounds, the isotope effect, symmetries, the pseudogap, relativistic superconductivity, the Cherenkov effect and soft vortices. Also included is an appendix on the quantum Hall effect. In all of the chapters, the theoretical descrip

  5. Plasma thrombin-cleaved osteopontin elevation after carotid artery stenting in symptomatic ischemic stroke patients

    International Nuclear Information System (INIS)

    Atherothrombosis is the primary pathophysiology that underlies ischemic cerebral infarction. Osteopontin (OPN) is produced in atherosclerotic lesions and is cleaved by activated thrombin. We hypothesized that the rupture or damage of an unstable atherosclerotic plaque increases plasma levels of thrombin-cleaved OPN (trOPN). This study included 90 patients who received carotid angioplasty with stenting (CAS), 23 patients with essential hypertension (EHT) and 10 patients who were treated with carotid endarterectomy (CEA). The CAS patient group included 36 patients that had pre- and post-operative blood tests, diffusion-weighted imaging (DWI) using cerebral MRIs and estimated thrombus debris within the protection device. Immunohistochemistry of CEA specimens revealed that trOPN was detected around intra-plaque vessels. The highest tertile of plasma trOPN levels in CAS patients was higher than trOPN levels in EHT patients. Post-operative trOPN levels were significantly higher in symptomatic compared with asymptomatic patients (P=0.003). New ipsilateral DWI-positive patients revealed higher post-operative trOPN levels (P=0.003) and a higher grade of thrombi (P<0.001) than DWI-negative patients. TrOPN may be a novel biomarker that reflects the atherothrombotic status in ischemic stroke. (author)

  6. Mechanism of the Anticoagulant Activity of Thrombin Mutant W215A/E217A

    Energy Technology Data Exchange (ETDEWEB)

    Gandhi, Prafull S.; Page, Michael J.; Chen, Zhiwei; Bush-Pelc, Leslie; Di Cera, Enrico; (WU-MED)

    2009-09-15

    The thrombin mutant W215A/E217A (WE) is a potent anticoagulant both in vitro and in vivo. Previous x-ray structural studies have shown that WE assumes a partially collapsed conformation that is similar to the inactive E* form, which explains its drastically reduced activity toward substrate. Whether this collapsed conformation is genuine, rather than the result of crystal packing or the mutation introduced in the critical 215-217 {beta}-strand, and whether binding of thrombomodulin to exosite I can allosterically shift the E* form to the active E form to restore activity toward protein C are issues of considerable mechanistic importance to improve the design of an anticoagulant thrombin mutant for therapeutic applications. Here we present four crystal structures of WE in the human and murine forms that confirm the collapsed conformation reported previously under different experimental conditions and crystal packing. We also present structures of human and murine WE bound to exosite I with a fragment of the platelet receptor PAR1, which is unable to shift WE to the E form. These structural findings, along with kinetic and calorimetry data, indicate that WE is strongly stabilized in the E* form and explain why binding of ligands to exosite I has only a modest effect on the E*-E equilibrium for this mutant. The E* {yields} E transition requires the combined binding of thrombomodulin and protein C and restores activity of the mutant WE in the anticoagulant pathway.

  7. The role of structural information in the discovery of direct thrombin and factor Xa inhibitors.

    Science.gov (United States)

    Nar, Herbert

    2012-05-01

    The quest for novel medications to treat thromboembolic disorders such as venous thrombosis, pulmonary embolism and stroke received a boost when the 3D structures of two major players in the blood coagulation cascade were determined in 1989 and 1993. Structure-guided design of inhibitors of thrombin (factor IIa, fIIa) and factor Xa (fXa) eventually led to the discovery of potent, selective, efficacious, orally active and safe compounds that proved successful in clinical studies. In 2008, the direct thrombin inhibitor dabigatran etexilate developed by Boehringer Ingelheim became the first novel antithrombotic molecular entity to enter the market in 50 years. Additional compounds targeting factor Xa were subsequently granted marketing authorization or are in late-stage clinical studies. In this review, I use selected case studies to describe the discovery of novel fIIa and fXa inhibitors, with a particular emphasis on the pre-eminent role that structural information played in this process. PMID:22503439

  8. Module-activity relationship of G-quadruplex based DNA aptamers for human thrombin.

    Science.gov (United States)

    Zavyalova, E; Golovin, A; Pavlova, G; Kopylov, A

    2013-01-01

    G-quadruplex based DNA aptamers for human thrombin are promising pharmaceuticals as anticoagulants. Initially discovered 15-mer DNA aptamer (15-TBA) has a minimal G-quadruplex structure which is able to inhibit thrombin. 15-TBA was modified and extended to improve aptamer activity and in vivo stability providing 31-TBA, NU172, RA-36, and some others as successful examples. In this paper an interplay between G-quadruplex (pharmacophore module) and additional modules has been studied. An original turbidimetric assay and conventional coagulation tests were applied to evaluate both inhibitory activity and type of inhibiting for aptamers constructed by exchanging the modules between 31- TBA and NU172. Additional modules strongly affect pharmacophore module inhibitory activity either enhancing or reducing it. RA-36 aptamer has two putative pharmacophore entities which also interplay being functionally non-equal. 5'- truncated RA-36 has half of the activity of RA-36, and the same as for 15-TBA. On the contrary 3'-truncated RA-36 has intermediate activity in between 15-TBA and RA-36. These results indicate fine regulation of G-quadruplex inhibitory activity by additional modules, as well as non-trivial behavior of joined pharmacophore modules. PMID:24083606

  9. 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.

  10. Proteome changes in platelets activated by arachidonic acid, collagen, and thrombin

    Directory of Open Access Journals (Sweden)

    Suttnar Ji?í

    2010-11-01

    Full Text Available Abstract Background Platelets are small anucleated blood particles that play a key role in the control of bleeding. Platelets need to be activated to perform their functions and participate in hemostasis. The process of activation is accompanied by vast protein reorganization and posttranslational modifications. The goal of this study was to identify changes in proteins in platelets activated by different agonists. Platelets were activated by three different agonists - arachidonic acid, collagen, and thrombin. 2D SDS-PAGE (pI 4-7 was used to separate platelet proteins. Proteomes of activated and resting platelets were compared with each other by Progenesis SameSpots statistical software; and proteins were identified by nanoLC-MS/MS. Results 190 spots were found to be significantly different. Of these, 180 spots were successfully identified and correspond to 144 different proteins. Five proteins were found that had not previously been identified in platelets: protein CDV3 homolog, protein ETHE1, protein LZIC, FGFR1 oncogene partner 2, and guanine nucleotide-binding protein subunit beta-5. Using spot expression profile analysis, we found two proteins (WD repeat-containing protein 1 and mitochondrial glycerol-3-phosphate dehydrogenase that may be part of thrombin specific activation or signal transduction pathway(s. Conclusions Our results, characterizing the differences within proteins in both activated (by various agonists and resting platelets, can thus contribute to the basic knowledge of platelets and to the understanding of the function and development of new antiplatelet drugs.

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

    International Nuclear Information System (INIS)

    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. 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.

  13. Thrombin-induced IL-8/CXCL8 release is mediated by CK2, MSK1, and NF-?B pathways in human lung epithelial cells.

    Science.gov (United States)

    Lin, Chien-Huang; Shih, Chung-Hung; Chen, Bing-Chang

    2015-11-15

    Airway inflammation plays a major role in the pathophysiology of lung inflammatory diseases such as asthma. Thrombin, a serine protease, is known to mediate central functions in thrombosis and hemostasis and also plays a critical role in lung inflammation via producing chemokine release including interleukin (IL)-8/CXCL8. Our previous studies showed that c-Src- and Rac-dependent nuclear factor (NF)-?B signaling pathways participate in thrombin-induced IL-8/CXCL8 release in human lung epithelial cells. In this study, we further investigated the role of casein kinase 2 (CK2)/mitogen stress-activated protein kinase 1 (MSK1)-dependent p65 phosphorylation in thrombin-induced NF-?B activation and IL-8/CXCL8 release. Thrombin-induced IL-8/CXCL8 release was inhibited by CK2 inhibitors (apigenin and tetrabromobenzotriazole, TBB), small interfering RNA of CK2? (CK2? siRNA), and MSK1 siRNA. Treatment of cells with thrombin caused increases in CK2? phosphorylation at Ser209, which was inhibited by a protein kinase C ? (PKC?) inhibitor (Ro-32-0432). Thrombin-induced MSK1 phosphorylation at Ser581 and Akt phosphorylation at Ser473 were inhibited by apigenin. Moreover, the thrombin-induced increase in IL-8/CXCL8 release was attenuated by p65 siRNA. Stimulation of cells with thrombin resulted in an increase in p65 phosphorylation at Ser276, which was inhibited by apigenin and MSK1 siRNA. Thrombin-induced ?B-luciferase activity was also inhibited by apigenin and MSK1 siRNA. Taken together, these results show that thrombin activates the PKC?/CK2/MSK1 signaling pathways, which in turn initiates p65 phosphorylation and NF-?B activation, and ultimately induces IL-8/CXCL8 release in human lung epithelial cells. PMID:26463037

  14. Thrombin Time

    Science.gov (United States)

    ... as part of an investigation of a possible bleeding disorder or inappropriate blood clot formation ( thrombotic episode ), particularly ... battery of tests typically required to evaluate a bleeding or thrombotic disorder. A significant percentage of people with decreased or ...

  15. Topical Treatment in Rhinology

    Directory of Open Access Journals (Sweden)

    Anamaria Gocea

    2014-02-01

    Full Text Available Far from being exhaustive, this paper aims to review the most illustrative topical therapies in rhinology, to show their patterns of action and their most suggestive characteristics proven by clinical trials and meta-analyses as tools of evidence based medecine. We describe several therapeutic clases: decongestants, antihistaminics, anticholinergics, antibiotics, disinfectants, antimicotics, fitotherapeutics, vitamins, immunotherapy and compounds. Furthermore, the nose is increasingly being used for the delivery of other drugs, ranging from hormone replacement therapy and growth hormone to insulin and anti-migraine medication (sumatriptan. The ability to directly reach the neuronal tissue in the olfactory niche and hence the brain makes this a very attractive challenge.

  16. Topics in field theory

    CERN Document Server

    Karpilovsky, G

    1989-01-01

    This monograph gives a systematic account of certain important topics pertaining to field theory, including the central ideas, basic results and fundamental methods.Avoiding excessive technical detail, the book is intended for the student who has completed the equivalent of a standard first-year graduate algebra course. Thus it is assumed that the reader is familiar with basic ring-theoretic and group-theoretic concepts. A chapter on algebraic preliminaries is included, as well as a fairly large bibliography of works which are either directly relevant to the text or offer supplementary material of interest.

  17. Topics in Nonlinear Dynamics

    DEFF Research Database (Denmark)

    Mosekilde, Erik

    Through a significant number of detailed and realistic examples this book illustrates how the insights gained over the past couple of decades in the fields of nonlinear dynamics and chaos theory can be applied in practice. Aomng the topics considered are microbiological reaction systems, ecological...... food-web systems, nephron pressure and flow regulation, pulsatile secretion of hormones, thermostatically controlled radiator systems, post-stall maneuvering of aircrafts, transfer electron devices for microwave generation, economic long waves, human decision making behavior, and pattern formation in...

  18. Topics in String Unification

    CERN Document Server

    Ibáñez, L E

    1991-01-01

    I discuss several aspects of strings as unified theories. After recalling the difficulties of the simplest supersymmetric grand unification schemes I emphasize the distinct features of string unification. An important role in constraining the effective low energy physics from strings is played by $duality$ symmetries. The discussed topics include the unification of coupling constants (computation of $\\sin ^2\\theta _W$ and $\\alpha _s$ at the weak scale), supersymmetry breaking through gaugino condensation, and properties of the induced SUSY-breaking soft terms. I remark that departures from universality in the soft terms are (in contrast to the minimal SUSY model) generically expected.

  19. Topics in Operator Theory

    CERN Document Server

    Ball, Joseph A; Helton, JWilliam; Rodman, Leiba; Spitkovsky, Iiya

    2010-01-01

    This is the first volume of a collection of original and review articles on recent advances and new directions in a multifaceted and interconnected area of mathematics and its applications. It encompasses many topics in theoretical developments in operator theory and its diverse applications in applied mathematics, physics, engineering, and other disciplines. The purpose is to bring in one volume many important original results of cutting edge research as well as authoritative review of recent achievements, challenges, and future directions in the area of operator theory and its applications.

  20. Topics in circular statistics

    CERN Document Server

    Jammalamadaka, S Rao

    2001-01-01

    This research monograph on circular data analysis covers some recent advances in the field, besides providing a brief introduction to, and a review of, existing methods and models. The primary focus is on recent research into topics such as change-point problems, predictive distributions, circular correlation and regression, etc. An important feature of this work is the S-plus subroutines provided for analyzing actual data sets. Coupled with the discussion of new theoretical research, the book should benefit both the researcher and the practitioner. Contents: Circular Probability Distributions

  1. Superior Mesenteric Artery Pseudoaneurysm Following Pancreaticoduodenectomy: Management by Endovascular Stent-Graft Placement and Transluminal Thrombin Injection

    International Nuclear Information System (INIS)

    Superior mesenteric artery (SMA) pseudoaneurysm formation is a rare and potentially fatal postoperative complication. Herein we present a case of a large post-pancreaticoduodenectomy SMA pseudoaneurysm that required thrombin injection after initial stent-graft deployment to accomplish complete pseudoaneurysm occlusion

  2. Multiphoton Assisted Recombination

    International Nuclear Information System (INIS)

    We have observed multiphoton assisted recombination in the presence of a 38.8 GHz microwave field. Stimulated emission of up to ten microwave photons results in energy transfer from continuum electrons, enabling recombination. The maximum electron energy loss is far greater than the 2Up predicted by the standard 'simpleman's' model. The data are well reproduced by both an approximate analytic expression and numerical simulations in which the combined Coulomb and radiation fields are taken into account

  3. Topics on continua

    CERN Document Server

    Macias, Sergio

    2005-01-01

    Specialized as it might be, continuum theory is one of the most intriguing areas in mathematics. However, despite being popular journal fare, few books have thoroughly explored this interesting aspect of topology. In Topics on Continua, Sergio Macías, one of the field's leading scholars, presents four of his favorite continuum topics: inverse limits, Jones's set function T, homogenous continua, and n-fold hyperspaces, and in doing so, presents the most complete set of theorems and proofs ever contained in a single topology volume. Many of the results presented have previously appeared only in research papers, and some appear here for the first time. After building the requisite background and exploring the inverse limits of continua, the discussions focus on Professor Jones''s set function T and continua for which T is continuous. An introduction to topological groups and group actions lead to a proof of Effros''s Theorem, followed by a presentation of two decomposition theorems. The author then offers an...

  4. A electrochemiluminescence aptasensor for detection of thrombin incorporating the capture aptamer labeled with gold nanoparticles immobilized onto the thio-silanized ITO electrode

    Energy Technology Data Exchange (ETDEWEB)

    Fang Lanyun [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Ningbo Municipal Center for Disease Control and Prevention, Ningbo 315010, Zhejiang (China); Lue Zhaozi [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin (China); Wei Hui [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin (China); Graduate School of the Chinese Academy of Sciences, Beijing 100049 (China); Wang Erkang [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin (China)], E-mail: ekwang@ciac.jl.cn

    2008-10-17

    A novel electrochemiluminescence (ECL) aptasensor was proposed for sensitive and cost-effective detection of the target thrombin adopted an aptamer-based sandwich format. To detect thrombin, capture aptamers labeled with gold nanoparticles (AuNPs) were first immobilized onto the thio-silanized ITO electrode surface through strong Au-S bonds. After catching the target thrombin, signal aptamers tagged with ECL labels were attached to the assembled electrode surface. As a result, an AuNPs-capture-aptamer/thrombin/ECL-tagged-signal-aptamer sandwich type was formed. Treating the resulting electrode surface with tri-n-propylamine (TPA) and applying a swept potential to the electrode, ECL response was generated which realized the detection of target protein. Spectroscopy and electrochemical impedance techniques were used to characterize and confirm the fabrication of the ECL aptasensor. AuNPs amplification and smart sensor fabrication art were implemented for the sensitive and cost-effective detection purpose. Signal-to-dose curve excellently followed a sandwich format equation and could be used to quantify the protein, and the detection limit was estimated to be 10 nM. Other forms of thrombin such as {beta}- and {gamma}-thrombins had negligible response, which indicated a high specificity of {alpha}-thrombin detection. The aptasensor opened up new fields of aptamer applications in ECL domain, a highly sensitive technique, and had a promising perspective to be applied in microarray analysis.

  5. Effect of Locked-Nucleic Acid on a Biologically Active G-Quadruplex. A Structure-Activity Relationship of the Thrombin Aptamer

    Directory of Open Access Journals (Sweden)

    Michael B. Jarstfer

    2008-03-01

    Full Text Available Here we tested the ability to augment the biological activity of the thrombin aptamer, d(GGTTGGTGTGGTTGG, by using locked nucleic acid (LNA to influence its G-quadruplex structure. Compared to un-substituted control aptamer, LNA-containing aptamers displayed varying degrees of thrombin inhibition. Aptamers with LNA substituted in either positions G5, T7, or G8 showed decreased thrombin inhibition, whereas LNA at position G2 displayed activity comparable to un-substituted control aptamer. Interestingly, the thermal stability of the substituted aptamers does not correlate to activity – the more stable aptamers with LNA in position G5, T7, or G8 showed the least thrombin inhibition, while a less stable aptamer with LNA at G2 was as active as the un-substituted aptamer. These results suggest that LNA substitution at sites G5, T7, and G8 directly perturbs aptamer-thrombin affinity. This further implies that for the thrombin aptamer, activity is not dictated solely by the stability of the G-quadruplex structure, but by specific interactions between the central TGT loop and thrombin and that LNA can be tolerated in a biologically active nucleic acid structure albeit in a position dependent fashion.

  6. A electrochemiluminescence aptasensor for detection of thrombin incorporating the capture aptamer labeled with gold nanoparticles immobilized onto the thio-silanized ITO electrode

    International Nuclear Information System (INIS)

    A novel electrochemiluminescence (ECL) aptasensor was proposed for sensitive and cost-effective detection of the target thrombin adopted an aptamer-based sandwich format. To detect thrombin, capture aptamers labeled with gold nanoparticles (AuNPs) were first immobilized onto the thio-silanized ITO electrode surface through strong Au-S bonds. After catching the target thrombin, signal aptamers tagged with ECL labels were attached to the assembled electrode surface. As a result, an AuNPs-capture-aptamer/thrombin/ECL-tagged-signal-aptamer sandwich type was formed. Treating the resulting electrode surface with tri-n-propylamine (TPA) and applying a swept potential to the electrode, ECL response was generated which realized the detection of target protein. Spectroscopy and electrochemical impedance techniques were used to characterize and confirm the fabrication of the ECL aptasensor. AuNPs amplification and smart sensor fabrication art were implemented for the sensitive and cost-effective detection purpose. Signal-to-dose curve excellently followed a sandwich format equation and could be used to quantify the protein, and the detection limit was estimated to be 10 nM. Other forms of thrombin such as ?- and ?-thrombins had negligible response, which indicated a high specificity of ?-thrombin detection. The aptasensor opened up new fields of aptamer applications in ECL domain, a highly sensitive technique, and had a promising perspective to be applied in microarray analysis

  7. GDP beta S enhances the activation of phospholipase C caused by thrombin in human platelets: evidence for involvement of an inhibitory GTP-binding protein

    International Nuclear Information System (INIS)

    Guanosine 5'-O-thiotriphosphate (GTP gamma S) and thrombin stimulate the activity of phospholipase C in platelets that have been permeabilized with saponin and whose inositol phospholipids have been prelabeled with [3H]inositol. Ca2+ has opposite effects on the formation of [3H]inositol phosphates induced by thrombin or GTP gamma S. While the action of GTP gamma S on the formation of [3H]inositol phosphates is inhibited by Ca2+, action of thrombin is stimulated by Ca2+. Guanosine 5'-O-(2-thiodiphosphate) (GDP beta S), which inhibits the function of GTP-binding proteins, also inhibits the effect of GTP gamma S on phospholipase C stimulation but, surprisingly, increases the effect of thrombin. Ca2+ increases the inhibitory effect of GDP beta S on GTP gamma S activation of phospholipase C, but Ca2+ further enhances the stimulatory effect of GDP beta S on the thrombin activation of phospholipase C. This indicates that two mechanisms are responsible for the activation of phospholipase C in platelets. A GTP-binding protein is responsible for regulation of phospholipase C induced by GTP gamma S, while the effect of thrombin on the stimulation of phospholipase C is independent of GTP-binding proteins. However, the effect of thrombin may be modulated by the action of an inhibitory GTP-binding protein

  8. GDP beta S enhances the activation of phospholipase C caused by thrombin in human platelets: evidence for involvement of an inhibitory GTP-binding protein

    Energy Technology Data Exchange (ETDEWEB)

    Oberdisse, E.; Lapetina, E.G.

    1987-05-14

    Guanosine 5'-O-thiotriphosphate (GTP gamma S) and thrombin stimulate the activity of phospholipase C in platelets that have been permeabilized with saponin and whose inositol phospholipids have been prelabeled with (/sup 3/H)inositol. Ca/sup 2 +/ has opposite effects on the formation of (/sup 3/H)inositol phosphates induced by thrombin or GTP gamma S. While the action of GTP gamma S on the formation of (/sup 3/H)inositol phosphates is inhibited by Ca/sup 2 +/, action of thrombin is stimulated by Ca/sup 2 +/. Guanosine 5'-O-(2-thiodiphosphate) (GDP beta S), which inhibits the function of GTP-binding proteins, also inhibits the effect of GTP gamma S on phospholipase C stimulation but, surprisingly, increases the effect of thrombin. Ca/sup 2 +/ increases the inhibitory effect of GDP beta S on GTP gamma S activation of phospholipase C, but Ca/sup 2 +/ further enhances the stimulatory effect of GDP beta S on the thrombin activation of phospholipase C. This indicates that two mechanisms are responsible for the activation of phospholipase C in platelets. A GTP-binding protein is responsible for regulation of phospholipase C induced by GTP gamma S, while the effect of thrombin on the stimulation of phospholipase C is independent of GTP-binding proteins. However, the effect of thrombin may be modulated by the action of an inhibitory GTP-binding protein.

  9. Ultrasensitive electrochemical aptasensor for the detection of thrombin based on dual signal amplification strategy of Au@GS and DNA-CoPd NPs conjugates.

    Science.gov (United States)

    Wang, Yaoguang; Zhang, Yong; Yan, Tao; Fan, Dawei; Du, Bin; Ma, Hongmin; Wei, Qin

    2016-06-15

    In this work, an ultrasensitive electrochemical aptasensor for the detection of thrombin was developed based on Au nanoparticles decorated graphene sheet (Au@GS) and CoPd binary nanoparticles (CoPd NPs). A sulfydryl-labeled thrombin capture probe (Apt1) and a biotin-labeled thrombin reporter probe (Apt2) were designed to achieve a sandwich-type strategy. Au@GS was used as a sensing platform for the facile immobilization of Apt1 through Au-S bond, forming a sensing interface for thrombin. The specific recognition of thrombin induced the attachment of Apt2-CoPd NPs to the electrode. The labeled CoPd NPs showed good catalytic properties toward the reduction of H2O2, resulting in an amperometric signal. The amperometric response was correlated to the thrombin concentration in sample solutions. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) confirmed the successful fabrication of the aptasensor. A linear response to thrombin in the range of 0.01-2.00ngmL(-1) with a low detection limit (5pgmL(-1)) was achieved. The proposed aptasensor showed good selectivity, good reproducibility and acceptable stability. This proposed strategy may find many potential applications in the detection of other biomolecules. PMID:26908183

  10. 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)

    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 procedure is highly effective, cheap and minimally invasive. (authors)

  11. Aptamer-directed lanthanide chelate self-assembly for rapid thrombin detection.

    Science.gov (United States)

    Päkkilä, Henna; Blom, Sami; Kopra, Kari; Soukka, Tero

    2013-09-01

    We report a sensitive assay method for homogeneous thrombin detection. The method is based on lanthanide chelate complementation, where the luminescent complex is split into two separate label moieties, which are intrinsically non-luminescent. A luminescent mixed chelate complex is formed only when the label moieties are brought into close proximity directed by two separate binding events of aptamers to the analyte. This results in high specificity in signal generation while time-resolved fluorescence detection eliminates the short lifetime autofluorescence, which is inherent to many homogeneous assays and limits their applicability. The developed method is also very rapid as the maximum signal is obtained in just five minutes. Lanthanide chelate complementation can be applied for the detection of other proteins when two binders recognizing separate epitopes of the analyte are available. PMID:23807946

  12. Thromboelastography, thrombin generation test and thrombodynamics reveal hypercoagulability in patients with multiple myeloma.

    Science.gov (United States)

    Gracheva, Marina A; Urnova, Evdokiya S; Sinauridze, Elena I; Tarandovskiy, Ivan D; Orel, Elena B; Poletaev, Alexander V; Mendeleeva, Larisa P; Ataullakhanov, Fazoil I; Balandina, Anna N

    2015-12-01

    Patients with multiple myeloma (MM) are at increased risk of venous thromboembolism. Therefore, adequate laboratory control of hemostasis and subsequent adjustments of anticoagulant therapy are necessary. We studied hemostasis changes using thromboelastography (TEG), thrombin generation test (TGT) and thrombodynamics (TD) in primary MM patients (PMMpt, n = 25) and patients in remission (RMMpt, n = 34) during blood stem cell (BSC) mobilization. TD and TEG reveal hypercoagulability in PMMpt (*p < 0.05) in relation to healthy volunteers. There was no difference in any of the tests between PMMpt and RMMpt. We detected no heparin effect in 22% of patients one day after the onset of the prophylactic heparin treatment (500 IU/h) during BSC mobilization; tests shifted toward the hypercoagulability in 75% of patients one day after cyclophosphamide (4 g/m(2)) chemotherapy. Global hemostasis tests were in good agreement with each other, revealed hypercoagulability and heparin "resistance" in patients with MM and may be useful for therapy individualization. PMID:25907422

  13. Topical Acne Treatments and Pregnancy

    Science.gov (United States)

    Topical Acne Treatments and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of having ... This sheet talks about whether exposure to topical acne treatments may increase the risk for birth defects ...

  14. Symbiosis: Rich, Exciting, Neglected Topic

    Science.gov (United States)

    Rowland, Jane Thomas

    1974-01-01

    Argues that the topic of symbiosis has been greatly neglected and underemphasized in general-biology textbooks. Discusses many types and examples of symbiosis, and provides an extensive bibliography of the literature related to this topic. (JR)

  15. Superconcentration and related topics

    CERN Document Server

    Chatterjee, Sourav

    2014-01-01

    A certain curious feature of random objects, introduced by the author as “super concentration,” and two related topics, “chaos” and “multiple valleys,” are highlighted in this book. Although super concentration has established itself as a recognized feature in a number of areas of probability theory in the last twenty years (under a variety of names), the author was the first to discover and explore its connections with chaos and multiple valleys. He achieves a substantial degree of simplification and clarity in the presentation of these findings by using the spectral approach. Understanding the fluctuations of random objects is one of the major goals of probability theory and a whole subfield of probability and analysis, called concentration of measure, is devoted to understanding these fluctuations. This subfield offers a range of tools for computing upper bounds on the orders of fluctuations of very complicated random variables. Usually, concentration of measure is useful when more direct prob...

  16. Topics in orbit equivalence

    CERN Document Server

    Kechris, Alexander S

    2004-01-01

    This volume provides a self-contained introduction to some topics in orbit equivalence theory, a branch of ergodic theory. The first two chapters focus on hyperfiniteness and amenability. Included here are proofs of Dye's theorem that probability measure-preserving, ergodic actions of the integers are orbit equivalent and of the theorem of Connes-Feldman-Weiss identifying amenability and hyperfiniteness for non-singular equivalence relations. The presentation here is often influenced by descriptive set theory, and Borel and generic analogs of various results are discussed. The final chapter is a detailed account of Gaboriau's recent results on the theory of costs for equivalence relations and groups and its applications to proving rigidity theorems for actions of free groups.

  17. 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 M1 muscarinic acetylcholine receptors required the transactivation of the EGF receptor, while thrombin signaling did not. Conclusion This study shows that stimulus-transcription coupling in thrombin-treated lung fibroblasts relies on the elevation of the intracellular Ca2+-concentration and the activation of PKC and ERK. In the nucleus, ternary complex factors function as key proteins linking the intracellular signaling cascade with enhanced transcription of the Egr-1 gene. This study further shows that the dominant-negative Elk-1 mutant is a valuable tool to study Elk-1-mediated gene transcription.

  18. The Polylingual Labeled Topic Model

    OpenAIRE

    Posch, Lisa; Bleier, Arnim; Schaer, Philipp; Strohmaier, Markus

    2015-01-01

    In this paper, we present the Polylingual Labeled Topic Model, a model which combines the characteristics of the existing Polylingual Topic Model and Labeled LDA. The model accounts for multiple languages with separate topic distributions for each language while restricting the permitted topics of a document to a set of predefined labels. We explore the properties of the model in a two-language setting on a dataset from the social science domain. Our experiments show that our model outperform...

  19. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system for assaying recombination using tetrad analysis in a higher eukaryotic system (6). This system enabled the measurement of the frequency and distribution of recombination events at a genome wide level in wild type Arabidopsis (7), construction of genetic linkage maps which include positions for each centromere (8), and modeling of the strength and pattern of interference (9). This proposal extends the use of tetrad analysis in Arabidopsis by using it as the basis for assessing the phenotypes of mutants in genes important for recombination and the regulation of crossover interference and performing a novel genetic screen. In addition to broadening our knowledge of a classic genetic problem - the regulation of recombination by crossover interference - this proposal also provides broader impact by: generating pedagogical tools for use in hands-on classroom experience with genetics, building interdisciplinary collegial partnerships, and creating a platform for participation by junior scientists from underrepresented groups. There are three specific aims: (1) Isolate mutants in Arabidopsis MUS81 homologs using T-DNA and TILLING (2) Characterize recombination levels and interference in mus81 mutants (3) Execute a novel genetic screen, based on tetrad analysis, for genes that regulate meiotic recombination

  20. Recombinant expression and affinity purification of snake venom gland parvalbumin in Escherichia coli.

    Science.gov (United States)

    Jia, Ying; Pérez, John C

    2009-07-01

    Parvalbumins (PV) are small, acidic, water soluble and calcium-binding proteins generally present in muscular and nervous tissues. In the present study, we identified and characterized a cDNA clone encoding PV, named AplPV, from a snake (Agkistrodon piscivorus leucostoma) venom gland cDNA library. AplPV belongs to EF-hand proteins with six alpha-helices constituting three EF-hand domains. The deduced amino acid sequence of AplPV is 91% and 68% identical to the previously characterized PVs of Boa constrictor and Cyprinus carpio, respectively. The full-length cDNA was subcloned into the expression vector pGEX and transformed into Escherichia coli (E.coli) to produce recombinant protein. The bacterially expressed GST-AplPV fusion protein was highly expressed, and effectively purified by Glutathione-Sepharose affinity chromatography. A high concentration of thrombin protease specifically cleaved and removed the GST tag from fusion protein, and further purified by Benzamidine column for removal of thrombin protease. As a result, the 12 kDa AplPV recombinant protein alone was purified. To investigate the tissue-specific biological occurrence of AplPV, a polyclonal antibody (anti-AplPV-antibody) was raised against GST-AplPV fusion protein in rabbit. Western blot analysis revealed that immunoreactive bands were exhibited in both recombinant protein and samples of venom glands, but not in any crude venom. This specific occurrence indicates a specialized function of AplPV in snake venom glands. PMID:19275943

  1. RNA-seq analysis of transcriptomes in thrombin-treated and control human pulmonary microvascular endothelial cells.

    Science.gov (United States)

    Cheranova, Dilyara; Gibson, Margaret; Chaudhary, Suman; Zhang, Li Qin; Heruth, Daniel P; Grigoryev, Dmitry N; Ye, Shui Qing

    2013-01-01

    The characterization of gene expression in cells via measurement of mRNA levels is a useful tool in determining how the transcriptional machinery of the cell is affected by external signals (e.g. drug treatment), or how cells differ between a healthy state and a diseased state. With the advent and continuous refinement of next-generation DNA sequencing technology, RNA-sequencing (RNA-seq) has become an increasingly popular method of transcriptome analysis to catalog all species of transcripts, to determine the transcriptional structure of all expressed genes and to quantify the changing expression levels of the total set of transcripts in a given cell, tissue or organism. RNA-seq is gradually replacing DNA microarrays as a preferred method for transcriptome analysis because it has the advantages of profiling a complete transcriptome, providing a digital type datum (copy number of any transcript) and not relying on any known genomic sequence. Here, we present a complete and detailed protocol to apply RNA-seq to profile transcriptomes in human pulmonary microvascular endothelial cells with or without thrombin treatment. This protocol is based on our recent published study entitled "RNA-seq Reveals Novel Transcriptome of Genes and Their Isoforms in Human Pulmonary Microvascular Endothelial Cells Treated with Thrombin," in which we successfully performed the first complete transcriptome analysis of human pulmonary microvascular endothelial cells treated with thrombin using RNA-seq. It yielded unprecedented resources for further experimentation to gain insights into molecular mechanisms underlying thrombin-mediated endothelial dysfunction in the pathogenesis of inflammatory conditions, cancer, diabetes, and coronary heart disease, and provides potential new leads for therapeutic targets to those diseases. The descriptive text of this protocol is divided into four parts. The first part describes the treatment of human pulmonary microvascular endothelial cells with thrombin and RNA isolation, quality analysis and quantification. The second part describes library construction and sequencing. The third part describes the data analysis. The fourth part describes an RT-PCR validation assay. Representative results of several key steps are displayed. Useful tips or precautions to boost success in key steps are provided in the Discussion section. Although this protocol uses human pulmonary microvascular endothelial cells treated with thrombin, it can be generalized to profile transcriptomes in both mammalian and non-mammalian cells and in tissues treated with different stimuli or inhibitors, or to compare transcriptomes in cells or tissues between a healthy state and a disease state. PMID:23426025

  2. Topics in statistical mechanics

    International Nuclear Information System (INIS)

    This thesis deals with four independent topics in statistical mechanics: (1) the dimer problem is solved exactly for a hexagonal lattice with general boundary using a known generating function from the theory of partitions. It is shown that the leading term in the entropy depends on the shape of the boundary; (2) continuum models of percolation and self-avoiding walks are introduced with the property that their series expansions are sums over linear graphs with intrinsic combinatorial weights and explicit dimension dependence; (3) a constrained SOS model is used to describe the edge of a simple cubic crystal. Low and high temperature results are derived as well as the detailed behavior near the crystal facet; (4) the microscopic model of the lambda-transition involving atomic permutation cycles is reexamined. In particular, a new derivation of the two-component field theory model of the critical behavior is presented. Results for a lattice model originally proposed by Kikuchi are extended with a high temperature series expansion and Monte Carlo simulation. 30 references

  3. Topics in statistical mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Elser, V.

    1984-05-01

    This thesis deals with four independent topics in statistical mechanics: (1) the dimer problem is solved exactly for a hexagonal lattice with general boundary using a known generating function from the theory of partitions. It is shown that the leading term in the entropy depends on the shape of the boundary; (2) continuum models of percolation and self-avoiding walks are introduced with the property that their series expansions are sums over linear graphs with intrinsic combinatorial weights and explicit dimension dependence; (3) a constrained SOS model is used to describe the edge of a simple cubic crystal. Low and high temperature results are derived as well as the detailed behavior near the crystal facet; (4) the microscopic model of the lambda-transition involving atomic permutation cycles is reexamined. In particular, a new derivation of the two-component field theory model of the critical behavior is presented. Results for a lattice model originally proposed by Kikuchi are extended with a high temperature series expansion and Monte Carlo simulation. 30 references.

  4. Advanced verification topics

    CERN Document Server

    Bhattacharya, Bishnupriya; Hall, Gary; Heaton, Nick; Kashai, Yaron; Khan Neyaz; Kirshenbaum, Zeev; Shneydor, Efrat

    2011-01-01

    The Accellera Universal Verification Methodology (UVM) standard is architected to scale, but verification is growing and in more than just the digital design dimension. It is growing in the SoC dimension to include low-power and mixed-signal and the system integration dimension to include multi-language support and acceleration. These items and others all contribute to the quality of the SOC so the Metric-Driven Verification (MDV) methodology is needed to unify it all into a coherent verification plan. This book is for verification engineers and managers familiar with the UVM and the benefits it brings to digital verification but who also need to tackle specialized tasks. It is also written for the SoC project manager that is tasked with building an efficient worldwide team. While the task continues to become more complex, Advanced Verification Topics describes methodologies outside of the Accellera UVM standard, but that build on it, to provide a way for SoC teams to stay productive and profitable.

  5. Dielectronic recombination at nebular temperatures

    International Nuclear Information System (INIS)

    Rate coefficients for dielectronic recombination via low-lying resonance states are calculated for the recombined ions C+, C2+, N2+, N3+ and O4+ at the temperatures and densities appropriate to planetary nebulae. The total dielectronic recombination coefficients obtained are substantially larger than the corresponding radiative recombination coefficients, calculated neglecting resonances, and differ considerably from the dielectronic recombination coefficients generally in use. Effective recombination coefficients are given for spectrum lines that are formed during the cascade process. Some of these lines have been observed in IUE spectra of planetary nebulae. (author)

  6. Experiência inicial com o uso de adesivo tissular contendo trombina para tratamento do pseudo-aneurisma femoral Treatment of femoral pseudoaneurysm with thrombin tissue adhesive: initial experience

    Directory of Open Access Journals (Sweden)

    Daniel Mendes Pinto

    2006-03-01

    Full Text Available O pseudo-aneurisma (PSA após cateterização femoral tem sido diagnosticado com regularidade em serviços com grande movimento de intervenções percutâneas, com incidência variando de 0,05 a 6%. PSA femorais pequenos podem ser acompanhados até a resolução espontânea. As opções de tratamento são: compressão guiada por ultra-som, injeção de trombina para trombose do PSA e tratamento cirúrgico. A injeção percutânea de trombina tem a vantagem de ser um procedimento indolor e rápido. Podem ser utilizados trombina isolada ou preparados contendo trombina associada a fibrinogênio e fatores de coagulação. A experiência inicial dos autores de cinco casos tratados com injeção de adesivo tissular contendo trombina mostrou resultado satisfatório em quatro; um caso necessitou tratamento cirúrgico. Não houve sucesso com uso isolado de trombina humana, porém, ocorreu trombose imediata após injeção de preparado de trombina associada a fibrinogênio/fator XIII. Neste artigo, são discutidas as opções de tratamento dos PSA femorais e a técnica do uso de trombina percutânea.Pseudoaneurysms caused by femoral artery catheterization have been regularly diagnosed in medical units with a great number of percutaneous interventions, with a documented incidence between 0.05 and 6%. Small femoral pseudoaneurysms undergo spontaneous resolution. Treatment options are: ultrasound-guided compression, thrombin injection to induce pseudoaneurysm thrombosis and surgical treatment. Percutaneous thrombin injection has the advantage of being a fast and painless procedure. Both isolated thrombin and thrombin preparations with fibrinogen and coagulation factors can be used. The authors' initial experience with five cases treated with thrombin tissue adhesive showed successful results in four; one case required surgery. There was no success with isolated human thrombin, but immediate thrombosis was achieved after injection of thrombin associated to fibrinogen and factor XIII. In this article, the treatment options for femoral pseudoaneurysms and the technique of percutaneous thrombin are discussed.

  7. Experiência inicial com o uso de adesivo tissular contendo trombina para tratamento do pseudo-aneurisma femoral / Treatment of femoral pseudoaneurysm with thrombin tissue adhesive: initial experience

    Scientific Electronic Library Online (English)

    Daniel Mendes, Pinto; José Olimpio, Dias Júnior; Bernardo Lopes Cançado, Fonseca; Rodrigo Daniel, Moreialvar; Leonardo Ghizoni, Bez; Caetano de Sousa, Lopes.

    2006-03-01

    Full Text Available O pseudo-aneurisma (PSA) após cateterização femoral tem sido diagnosticado com regularidade em serviços com grande movimento de intervenções percutâneas, com incidência variando de 0,05 a 6%. PSA femorais pequenos podem ser acompanhados até a resolução espontânea. As opções de tratamento são: compre [...] ssão guiada por ultra-som, injeção de trombina para trombose do PSA e tratamento cirúrgico. A injeção percutânea de trombina tem a vantagem de ser um procedimento indolor e rápido. Podem ser utilizados trombina isolada ou preparados contendo trombina associada a fibrinogênio e fatores de coagulação. A experiência inicial dos autores de cinco casos tratados com injeção de adesivo tissular contendo trombina mostrou resultado satisfatório em quatro; um caso necessitou tratamento cirúrgico. Não houve sucesso com uso isolado de trombina humana, porém, ocorreu trombose imediata após injeção de preparado de trombina associada a fibrinogênio/fator XIII. Neste artigo, são discutidas as opções de tratamento dos PSA femorais e a técnica do uso de trombina percutânea. Abstract in english Pseudoaneurysms caused by femoral artery catheterization have been regularly diagnosed in medical units with a great number of percutaneous interventions, with a documented incidence between 0.05 and 6%. Small femoral pseudoaneurysms undergo spontaneous resolution. Treatment options are: ultrasound- [...] guided compression, thrombin injection to induce pseudoaneurysm thrombosis and surgical treatment. Percutaneous thrombin injection has the advantage of being a fast and painless procedure. Both isolated thrombin and thrombin preparations with fibrinogen and coagulation factors can be used. The authors' initial experience with five cases treated with thrombin tissue adhesive showed successful results in four; one case required surgery. There was no success with isolated human thrombin, but immediate thrombosis was achieved after injection of thrombin associated to fibrinogen and factor XIII. In this article, the treatment options for femoral pseudoaneurysms and the technique of percutaneous thrombin are discussed.

  8. Dual-colored graphene quantum dots-labeled nanoprobes/graphene oxide: functional carbon materials for respective and simultaneous detection of DNA and thrombin

    International Nuclear Information System (INIS)

    Convenient and simultaneous detection of multiple biomarkers such as DNA and proteins with biocompatible materials and good analytical performance still remains a challenge. Herein, we report the respective and simultaneous detection of DNA and bovine α-thrombin (thrombin) entirely based on biocompatible carbon materials through a specially designed fluorescence on-off-on process. Colorful fluorescence, high emission efficiency, good photostability and excellent compatibility enables graphene quantum dots (GQDs) as the best choice for fluorophores in bioprobes, and thus two-colored GQDs as labeling fluorophores were chemically bonded with specific oligonucleotide sequence and aptamer to prepare two probes targeting the DNA and thrombin, respectively. Each probe can be assembled on the graphene oxide (GO) platform spontaneously by π–π stacking and electrostatic attraction; as a result, fast electron transfer in the assembly efficiently quenches the fluorescence of probe. The presence of DNA or thrombin can trigger the self-recognition between capturing a nucleotide sequence and its target DNA or between thrombin and its aptamer due to their specific hybridization and duplex DNA structures or the formation of apatamer–substrate complex, which is taken advantage of in order to achieve a separate quantitative analysis of DNA and thrombin. A dual-functional biosensor for simultaneous detection of DNA and thrombin was also constructed by self-assembly of two probes with distinct colors and GO platform, and was further evaluated with the presence of various concentrations of DNA and thrombin. Both biosensors serving as a general detection model for multiple species exhibit outstanding analytical performance, and are expected to be applied in vivo because of the excellent biocompatibility of their used materials. (paper)

  9. 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 R; Rasmussen, Leif Bjarne; Rasmussen, Lars M; Andresen, Thomas Lars; Wengel, Jesper; Pasternak, Anna

    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 thermodynamics, kinetics and biological properties of the aptamer. 2'-C-Piperazino-UNA is characterized by more efficient stabilization of quadruplex structure in comparison to regular UNA and increases th...

  10. 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.; Rasmussen, Lars M.; Andresen, Thomas Lars; Wengel, Jesper; Pasternak, Anna

    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 thermodynamics, kinetics and biological properties of the aptamer. 2?-C-Piperazino-UNA is characterized by more efficient stabilization of quadruplex structure in comparison to regular UNA and increases th...

  11. Recombineering Pseudomonas syringae

    Science.gov (United States)

    Here we report the identification of functions that promote genomic recombination of linear DNA introduced into Pseudomonas cells by electroporation. The genes encoding these functions were identified in Pseudomonas syringae pv. syringae B728a based on similarity to the lambda Red Exo/Beta and RecE...

  12. Recombinant hormones in osteoporosis

    DEFF Research Database (Denmark)

    Rejnmark, Lars

    2013-01-01

    For the last 10 years, bone anabolic therapy with the recombinant human parathyroid hormone (rhPTH) analogue, teriparatide (rhPTH[1 - 34]), or full-length rhPTH(1 - 84) has been an option in the treatment of osteoporosis. Both drugs are given as a daily subcutaneous injection. In the USA, only teriparatide is marketed.

  13. Dissociative recombination of NH+

    International Nuclear Information System (INIS)

    We have experimentally investigated dissociative recombination of NH+ with electrons using a merged ion and electron beam configuration in a storage ring. A fast counting and position sensitive imaging detector enabled us to perform fragment imaging measurements over relative electron-ion collision energies from 0 to 12 eV. The results show unprecedented details on product excitation and on the reaction dynamics.

  14. Evidence supporting the use of recombinant activated factor VII in congenital bleeding disorders

    Directory of Open Access Journals (Sweden)

    Pär I Johansson

    2010-06-01

    Full Text Available Pär I Johansson, Sisse R OstrowskiCapital Region Blood Bank, Section for Transfusion Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, DenmarkBackground: Recombinant activated factor VII (rFVIIa, NovoSeven® was introduced in 1996 for the treatment of hemophilic patients with antibodies against coagulation factor VIII or IX.Objective: To review the evidence supporting the use of rFVIIa for the treatment of patients with congenital bleeding disorders.Patients and methods: English-language databases were searched in September 2009 for reports of randomized controlled trials (RCTs evaluating the ability of rFVIIa to restore hemostasis in patients with congenital bleeding disorders.Results: Eight RCTs involving 256 hemophilic patients with antibodies against coagulation factors, also known as inhibitors, were identified. The evidence supporting the use of rFVIIa in these patients was weak with regard to dose, clinical setting, mode of administration, efficacy, and adverse events, given the limited sample size of each RCT and the heterogeneity of the studies.Conclusion: The authors suggest that rFVIIa therapy in hemophilic patients with inhibitors should be based on the individual’s ability to generate thrombin and form a clot, and not on the patient’s weight alone. Therefore, assays for thrombin generation, such as whole-blood thromboelastography, have the potential to significantly improve the treatment of these patients.Keywords: hemophilia, inhibitors, coagulation factor VIII, coagulation factor IX, rFVIIa, NovoSeven, FEIBA, hemostasis, RCT

  15. Recombineering: A Homologous Recombination-Based Method of Genetic Engineering

    OpenAIRE

    Sharan, Shyam K.; Thomason, Lynn C.; Kuznetsov, Sergey G; Court, Donald L.

    2009-01-01

    Recombineering is an efficient method of in vivo genetic engineering applicable to chromosomal as well as episomal replicons in E. coli. This method circumvents the need for most standard in vitro cloning techniques. Recombineering allows construction of DNA molecules with precise junctions without constraints being imposed by restriction enzyme site location. Bacteriophage homologous recombination proteins catalyze these recombineering reactions using double- and single-strand linear DNA sub...

  16. ?-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)

    In resting Chinese hamster fibroblasts (CCL39) ?-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

  17. Spectroscopic and Electrochemical Detection of Thrombin/5'-SH or 3'-SH Aptamer Immobilized on (porous) Gold Substrates

    Energy Technology Data Exchange (ETDEWEB)

    Park, Buem Jin; Sa, Young Seung; Kim, Yong Hwan; Kim, Young Hun [Kwangwoon University, Seoul (Korea, Republic of)

    2012-01-15

    Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer. Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film.

  18. Recent Developments in Dissociative Recombination

    International Nuclear Information System (INIS)

    There have been a number of recent developments in dissociative recombination research as it relates to ITER, that should be highlighted. These concern primarily experimental and modelling issues and this document will not touch upon the topics of the other scientists involved in DR studies that are present at the meeting. The topic of branching ratios in general is a topic fundamental to DR especially how it influences the formation of radical and stable neutral molecules that again might play a role in particle formation. It should be remembered that the reactions of neutral radicals to form cyclic compounds are responsible for the formation of soot in combustion, though the role played by ions in flames is at best uncertain. In the near wall plasma environment, ion processes may well be more important since neutral species are rarer. Modelling studies by Pernot and collaborators at the Universite de Paris-Sud have shown that if one compares the yields of individual neutral species in ion-chemistry models (in this particular case, the ionosphere of Titan), and if one assumes that DR reactions of hydrocarbon ions primarily decay via the ejection of a hydrogen ion (which is assumed by most Titan ionospheric models) and if one compares these predictions with those coming from a model where actual measured branching ratios are used, differences of up to 5 orders of magnitude are found. This shows very clearly the need for branching ratio studies. In early merged beam studies of DR performed in Canada in the 1970's, it was noticed that cross sections for polyatomic species typically displayed a sharp fall-off above 0.1 eV. This has since been seen in many storage ring studies and clearly this has important consequences for ITER chemistry where plasma temperatures are likely to be well above ambient. In a recent analysis, Jungen and Pratt have explained this phenomenon on the basis that the recombination is dominated by the indirect process (initial capture into a vibrationally excited, neutral Rydberg state) in which the propensity rule (+?v=1) dominates the capture. When the electron energy exceeds that between the v'=0 and v'=1 levels of the ion, where the capture must now involve a ?v=2 transition, this will be much less effective and so the cross section drops precipitously. This assumes of course that the recombining ion is primarily in the ground v=0 level. H3+ continues to be an active subject of research and a very recent experiment at the TSR ring in Heidelberg has examined the influence of rotational excitation on the rate of the recombination. This is a very beautiful study but an important outcome is that even though a cryogenically cooled storage trap was used to produce the ions, the internal rotational temperature of the ions was never found to be below 150K. This suggests that ion cooling by storage in the ring leads eventually to an equilibrium value for the internal energy of the ions as they are de-excited/re-excited by passage through the electron cooler. As observed in earlier merged beam experiments in Canada, the extraction field in the ion source plays an important role in determining the excitation state of the ions as collisions outside the source can lead to re-heating. Indeed in the TSR experiments using a conventional Penning source and a normal extraction field, the ions were found to have a rotational temperature of several thousands of degrees. This clearly has important significance for earlier measurements taken in storage rings. Finally, the world will soon have a new storage ring facility for dissociative recombination research and this will be in Langzhou in China. This machine will have a higher magnetic rigidity that previous rings used for DR and so heavier ions and higher mass resolution experiments can be performed there. Experimental operation of this new ring is expected to commence in 2012/2013. (author)

  19. Conventional protein kinase C isoforms differentially regulate ADP- and thrombin-evoked Ca(2+) signalling in human platelets.

    Science.gov (United States)

    Lever, Robert A; Hussain, Azhar; Sun, Benjamin B; Sage, Stewart O; Harper, Alan G S

    2015-12-01

    Rises in cytosolic Ca(2+) concentration ([Ca(2+)]cyt) are central in platelet activation, yet many aspects of the underlying mechanisms are poorly understood. Most studies examine how experimental manipulations affect agonist-evoked rises in [Ca(2+)]cyt, but these only monitor the net effect of manipulations on the processes controlling [Ca(2+)]cyt (Ca(2+) buffering, sequestration, release, entry and removal), and cannot resolve the source of the Ca(2+) or the transporters or channels affected. To investigate the effects of protein kinase C (PKC) on platelet Ca(2+) signalling, we here monitor Ca(2+) flux around the platelet by measuring net Ca(2+) fluxes to or from the extracellular space and the intracellular Ca(2+) stores, which act as the major sources and sinks for Ca(2+) influx into and efflux from the cytosol, as well as monitoring the cytosolic Na(+) concentration ([Na(+)]cyt), which influences platelet Ca(2+) fluxes via Na(+)/Ca(2+) exchange. The intracellular store Ca(2+) concentration ([Ca(2+)]st) was monitored using Fluo-5N, the extracellular Ca(2+) concentration ([Ca(2+)]ext) was monitored using Fluo-4 whilst [Ca(2+)]cyt and [Na(+)]cyt were monitored using Fura-2 and SFBI, respectively. PKC inhibition using Ro-31-8220 or bisindolylmaleimide I potentiated ADP- and thrombin-evoked rises in [Ca(2+)]cyt in the absence of extracellular Ca(2+). PKC inhibition potentiated ADP-evoked but reduced thrombin-evoked intracellular Ca(2+) release and Ca(2+) removal into the extracellular medium. SERCA inhibition using thapsigargin and 2,5-di(tert-butyl) l,4-benzohydroquinone abolished the effect of PKC inhibitors on ADP-evoked changes in [Ca(2+)]cyt but only reduced the effect on thrombin-evoked responses. Thrombin evokes substantial rises in [Na(+)]cyt which would be expected to reduce Ca(2+) removal via the Na(+)/Ca(2+) exchanger (NCX). Thrombin-evoked rises in [Na(+)]cyt were potentiated by PKC inhibition, an effect which was not due to altered changes in non-selective cation permeability of the plasma membrane as assessed by Mn(2+) quench of Fura-2 fluorescence. PKC inhibition was without effect on thrombin-evoked rises in [Ca(2+)]cyt following SERCA inhibition and either removal of extracellular Na(+) or inhibition of Na(+)/K(+)-ATPase activity by removal of extracellular K(+) or treatment with digoxin. These data suggest that PKC limits ADP-evoked rises in [Ca(2+)]cyt by acceleration of SERCA activity, whilst rises in [Ca(2+)]cyt evoked by the stronger platelet activator thrombin are limited by PKC through acceleration of both SERCA and Na(+)/K(+)-ATPase activity, with the latter limiting the effect of thrombin on rises in [Na(+)]cyt and so forward mode NCX activity. The use of selective PKC inhibitors indicated that conventional and not novel PKC isoforms are responsible for the inhibition of agonist-evoked Ca(2+) signalling. PMID:26434503

  20. Secretory products from thrombin-stimulated human platelets exert an inhibitory effect on NK-cytotoxic activity

    DEFF Research Database (Denmark)

    Skov Madsen, P; Hokland, P; Hokland, M

    1987-01-01

    We have investigated the interaction between human platelets and the NK-system, with special emphasis on the action of secretory products from platelets in an NK assay with 51Cr-labelled K562 as target cells. Supernatants from thrombin-stimulated platelets added to the NK assay consistently...... decreased the NK-cytotoxicity by 40% +/- 4.3%, indicating the existence of secreted products from platelets as a source of NK-inhibiting substances. In contrast, no direct cytotoxic effect of these secretory products on the target cells (K562) was seen. Thus, normal human platelets, when stimulated with...... thrombin, are capable of secreting different, yet undefined factors, which significantly inhibit NK activity in vitro. The results also suggest that the role of products from contaminating in vitro activated platelets should be borne in mind when performing conventional NK assays. Udgivelsesdato: 1986-Oct...

  1. Exposure- response for biomarkers of anticoagulant effects by the oral direct thrombin inhibitor AZD0837 in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Rasmussen, Lars H; Olsson, S Bertil; Jensen, Eva; Hamrén, Bengt; Eriksson, Ulf G; Wåhlander, Karin

    2015-01-01

    ) analysis was performed and the effect of AZD0837 therapy on fibrin D-dimer levels was correlated to the PK exposure of AR-H067637, as well as the effect on thrombin generation measured ex vivo, to guide selection of the effective dose regimen for a confirmatory efficacy study in AF patients. PATIENTS AND...... METHODS: Blood samples were obtained from 601 AF patients randomized to receive 1 of 4 doses of AZD0837 (blinded treatment) or dose-adjusted vitamin K antagonists (VKA, open treatment) for 3-9?months. A pharmacodynamic model was developed to describe time course of the AR-H067637 exposure dependent...... effects and the effect of VKA on fibrin D-dimer. The concentration-effect relationship for thrombin generation measured ex vivo in venous plasma was also investigated. RESULTS: AZD0837 was rapidly bioconverted to AR-H067637, showing stable exposure with an estimated interindividual variability of 33% with...

  2. Investigations of the thrombin generation test for the measurement of factor VIII.

    OpenAIRE

    McIntosh, J H

    2005-01-01

    Haemophilia A is a genetic bleeding disorder in which the plasma level of the clotting protein FVHI is reduced or absent Treatment of haemophilia is by replacement of the missing FVTII with FVIII concentrates made from human plasma, or by recombinant technology. The two widely used assays for FVIII measurement (one-stage APTT and chromogenic assay) have disagreements in potency of FVIII concentrates and in post-infusion plasma samples these discrepancies are largest for the recombinant produc...

  3. Topic selection in industry experiments

    OpenAIRE

    Misirli, Ayse Tosun; Erdogmus, Hakan; Juristo Juzgado, Natalia; Dieste Tubio, Oscar

    2014-01-01

    This paper shares our experience with initial negotiation and topic elicitation process for conducting industry experiments in six software development organizations in Finland. The process involved interaction with company representatives in the form of both multiple group discussions and separate face-to-face meetings. Fitness criteria developed by researchers were applied to the list of generated topics to decide on a common topic. The challenges we faced include diversity of proposed topi...

  4. An Automatic Topic Identification Algorithm

    Directory of Open Access Journals (Sweden)

    Hossein S. Baghdadi

    2011-01-01

    Full Text Available Problem statement: Topic is a stream of words which stands for the content of a text. Knowing the topic of a document can help people to be aware from its content and facilitate their searching process. Approach: This paper proposes an automatic algorithm to identify the topic for a textual document based on the chunks corresponding to each sentences in the document. Results and conclusion: We achieved 86% matching for both total and partial matching in our experimental data sample.

  5. Hot topic [editorial

    International Nuclear Information System (INIS)

    There is strong evidence for the human impact on climate change, but we should not ignore those who think otherwise. Unseasonably warm weather in many parts of Europe and North America last month will probably have added to the impression in many people's minds that climate change is a reality and that humans are guilty of warming our planet. The several hundred members of the United Nations' Intergovernmental Panel on Climate Change (IPCC) certainly think that the evidence for anthropogenic climate change is solid. Although Physics World was unable to obtain a copy of the IPCC's latest report on the science of climate change before its release date of 2 February - a clear sign of how sensitive its findings are - hints from those involved in writing the report suggest that the IPCC will have strengthened its conclusions, previously stated in 2001, that humans are heating up the Earth. While most scientists probably share this view, there are some who think otherwise. Many of those are either scientifically ill-informed or have dubious links with the energy industry. But some have genuine doubts. One bona fide sceptic is Richard Lindzen, a climate physicist from the Massachusetts Institute of Technology in the US, who was involved in preparing the IPCC's 2001 scientific report. While he does not dispute that the Earth is getting hotter, Lindzen thinks that, in all probability, the warming is largely the result of natural variations in the Earth's climate. Lindzen believes that climate models, although rooted in physics, contain far too many uncertainties to provide accurate forecasts. Indeed, mainstream climate physicists admit their computer models are far from perfect. Writing in their feature, for example, the chief scientist of the UK's Meteorological Office and colleagues describe how hard it is to incorporate the impact of clouds, which are much smaller than the resolution of the best models. They also warn that if clouds were modelled incorrectly, climate simulations 'would be seriously in error'. One may ask if this magazine should give space to Lindzen or those involved in geoengineering to air their views. Given the uncertainties still present within climate models and the potential costs of dealing with global warming, it would be wrong for Physics World to ignore those outside the mainstream. After all, as Richard Feynman once wrote: 'There is no harm in doubt and scepticism, for it is through these that new discoveries are made'. Physicists should never take anything at face value, not least a topic as important as climate change. (U.K.)

  6. Flexibility of the thrombin-activatable fibrinolysis inhibitor pro-domain enables productive binding of protein substrates

    DEFF Research Database (Denmark)

    Valnickova, Zuzana; Sanglas, Laura; Arolas, Joan L; Petersen, Steen V; Schar, Christine; Otzen, Daniel; Aviles, Francesc X; Gomis-Ruth, F Xavier; Enghild, Jan J

    2010-01-01

    We have previously reported that thrombin-activatable fibrinolysis inhibitor (TAFI) exhibits intrinsic proteolytic activity towards large peptides. The structural basis for this observation was clarified by the crystal structures of human and bovine TAFI. These structures evinced a significant rotation of the pro-domain away from the catalytic moiety when compared to other pro-carboxypeptidases, thus enabling access of large peptide substrates to the active-site cleft. Here we further investigat...

  7. Increased thrombin generation in women with polycystic ovary syndrome. A pilot study on the effect of metformin and oral contraceptives

    DEFF Research Database (Denmark)

    Glintborg, Dorte; Sidelmann, Johannes Jakobsen; Lambaa Altinok, Magda; Mumm, Hanne; Andersen, Marianne

    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 that influence blood coagulation. This prospective, randomized, intervention study evaluated the potential influence of PCOS on TG measures and the effect of OC and/or metformin on TG measures in women with PCOS...

  8. Increased thrombin generation in women with polycystic ovary syndrome. A pilot study on the effect of metformin and oral contraceptives.

    DEFF Research Database (Denmark)

    Glintborg, Dorte; Sidelmann, Johannes Jakobsen

    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 that influence blood coagulation. This prospective, randomized, intervention study evaluated the potential influence of PCOS on TG measures and the effect of OC and/or metformin on TG measures in women with PCOS. Material and methods. Ninety patients with PCOS and 35 controls were included. Patients were randomized to 12 months treatment with metformin, metformin + OC or OC alone. C-reactive protein (CRP), fibrinogen, total cholesterol, trunk fat mass, body mass index, estradiol, testosterone, sex hormone binding globulin (SHBG) as well as TG measures, i.e. the lag time for formation of thrombin, the endogenous thrombin potential (ETP), peak thrombin concentration (peak) and time to peak were determined at baseline and after 12 months of treatment. Results. CRP and total testosterone were significantly higher and SHBG significantly lower in PCOS women than in controls (P=0.012, P0.01). ETP (P=0.006), peak (P=0.003) and lag time (P=0.023) remained increased after adjustment for these potential confounders. Treatment with OC and metformin +OC further increased ETP (P<0.001) and peak (P<0.005) and reduced time to peak (P<0.04). The increase in ETP was significantly lower in the metformin+OC group than in the OC group (P<0.05). Metformin alone did not affect TG significantly. Conclusions. PCOS is associated with increase in TG measures independent of other risk factors of CVD. OC increases TG measures further and may thus add to the increased risk of CVD already present in women with PCOS.

  9. Membrane Changes Associated with Platelet Activation: EXPOSURE OF ACTIN ON THE PLATELET SURFACE AFTER THROMBIN-INDUCED SECRETION

    OpenAIRE

    George, James N; Lyons, Roger M; Morgan, Rebecca K.

    1980-01-01

    The effect of aggregation and secretion on membrane proteins was studied in washed human platelets. Reversible aggregation without secretion was stimulated by ADP and secretion without aggregation was stimulated by thrombin in the presence of EDTA. No loss of platelet surface glycoproteins occurred during reversible ADP-induced platelet aggregation, as measured by quantitative polyacrylamide gel electrophoresis analysis of platelets that were labeled with 125I-diazotized diiodosulfanilic acid...

  10. A brief exposure to tryptase or thrombin potentiates fibrocyte differentiation in the presence of serum or SAP

    OpenAIRE

    White, Michael J. V.; Galvis-Carvajal, Elkin; Gomer, Richard H

    2014-01-01

    A key question in both wound healing and fibrosis is the trigger for the initial formation of scar tissue. To help form scar tissue, circulating monocytes enter the tissue and differentiate into fibroblast-like cells called fibrocytes, but fibrocyte differentiation is strongly inhibited by the plasma protein Serum Amyloid P (SAP), and healthy tissues contain very few fibrocytes. In wounds and fibrotic lesions, mast cells degranulate to release tryptase, and in early wounds thrombin mediates b...

  11. Aptamer-functionalized solid phase microextraction-liquid chromatography/tandem mass spectrometry for selective enrichment and determination of thrombin.

    Science.gov (United States)

    Du, Fuyou; Alam, Md Nazmul; Pawliszyn, Janusz

    2014-10-01

    In this publication, a novel solid phase microextraction (SPME) coating functionalized with a DNA aptamer for selective enrichment of a low abundance protein from diluted human plasma is described. This approach is based on the covalent immobilization of an aptamer ligand on electrospun microfibers made with the hydrophilic polymer poly(acrylonitrile-co-maleic acid) (PANCMA) on stainless steel rods. A plasma protein, human ?-thrombin, was employed as a model protein for selective extraction by the developed Apt-SPME probe, and the detection was carried out with liquid chromatography/tandem mass spectrometry (LC-MS/MS). The SPME probe exhibited highly selective capture, good binding capacity, high stability and good repeatability for the extraction of thrombin. The protein selective probe was employed for direct extraction of thrombin from 20-fold diluted human plasma samples without any other purification. The Apt-SPME method coupled with LC-MS/MS provided a good linear dynamic range of 0.5-50 nM in diluted human plasma with a good correlation coefficient (R(2)=0.9923), and the detection limit of the proposed method was found to be 0.30 nM. Finally, the Apt-SPME coupled with LC-MS/MS method was successfully utilized for the determination of thrombin in clinical human plasma samples. One shortcoming of the method is its reduced efficiency in undiluted human plasma compared to the standard solution. Nevertheless, this new aptamer affinity-based SPME probe opens up the possibility of selective enrichment of a given targeted protein from complex sample either in vivo or ex vivo. PMID:25201271

  12. 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; Marcussen, Niels; Nordlinder, Hans; Guron, Gregor

    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 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 immed...

  13. Continuous Time Dynamic Topic Models

    OpenAIRE

    Wang, Chong; Blei, David; Heckerman, David

    2012-01-01

    In this paper, we develop the continuous time dynamic topic model (cDTM). The cDTM is a dynamic topic model that uses Brownian motion to model the latent topics through a sequential collection of documents, where a "topic" is a pattern of word use that we expect to evolve over the course of the collection. We derive an efficient variational approximate inference algorithm that takes advantage of the sparsity of observations in text, a property that lets us easily handle many time points. In c...

  14. 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 ACS than low levels of AT III. Protein S deficiency was a reinforcing factor on AT-III deficient to development of ACS. The cut-off point of AT-III without protein S deficiency expected to give single vessel disease was 45%, and 9,5% for the development of triple vessel disease. (Med J Indones 2002; 11: 87-92Keywords: acute coronary syndrome, Anti-thrombin III, Protein C, Protein S

  15. A sensitive electrochemical aptasensor based on water soluble CdSe quantum dots (QDs) for thrombin determination

    International Nuclear Information System (INIS)

    A novel aptamer biosensor with easy operation and good sensitivity, specificity, stability and reproducibility was developed by immobilizing the aptamer on water soluble CdSe quantum dots (QDs) modified on the top of the glassy carbon electrode (GCE). Methylene blue (MB) was intercalated into the aptamer sequence and used as an electrochemical marker. CdSe QDs improved the electrochemical signal because of their larger surface area and ion centers of CdSe QDs may also had a major role on amplifying the signal. The higher ion concentration caused more combination of aptamer which caused larger signal. The thrombin was detected by differential pulse voltammetry (DPV) quantitatively. Under optimal conditions, the two linear ranges were obtained from 3 to 13 ?g mL-1 and from 14 to 31 ?g mL-1, respectively. The detection limit was 0.08 ?g mL-1 at 3?. The constructed biosensor had better responses compared with that in the absence of the CdSe QDs immobilizing. The control experiment was also carried out by using BSA, casein and IgG in the absence of thrombin. The results showed that the aptasensor had good specificity, stability and reproducibility to the thrombin. Moreover, the aptasensor could be used for detection of real sample with consistent results in comparison with those obtained by fluorescence method which could provide a promising platform for fabrication of aptamer based biosensors.

  16. A sensitive electrochemical aptasensor based on water soluble CdSe quantum dots (QDs) for thrombin determination

    Energy Technology Data Exchange (ETDEWEB)

    Li Yanfen; Han Min [Jiangsu Laboratory of New Power Batteries, Jiangsu Key Laboratory of Biofuctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Bai Hongyan [Jiangsu Laboratory of New Power Batteries, Jiangsu Key Laboratory of Biofuctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); College of Biological and Chemical Engineering, Jiaxing College, Jiaxing 314001 (China); Wu Yong [Jiangsu Laboratory of New Power Batteries, Jiangsu Key Laboratory of Biofuctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Dai Zhihui, E-mail: daizhihuii@njnu.edu.cn [Jiangsu Laboratory of New Power Batteries, Jiangsu Key Laboratory of Biofuctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China); Bao Jianchun, E-mail: baojianchun@njnu.edu.cn [Jiangsu Laboratory of New Power Batteries, Jiangsu Key Laboratory of Biofuctional Materials, College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210097 (China)

    2011-08-01

    A novel aptamer biosensor with easy operation and good sensitivity, specificity, stability and reproducibility was developed by immobilizing the aptamer on water soluble CdSe quantum dots (QDs) modified on the top of the glassy carbon electrode (GCE). Methylene blue (MB) was intercalated into the aptamer sequence and used as an electrochemical marker. CdSe QDs improved the electrochemical signal because of their larger surface area and ion centers of CdSe QDs may also had a major role on amplifying the signal. The higher ion concentration caused more combination of aptamer which caused larger signal. The thrombin was detected by differential pulse voltammetry (DPV) quantitatively. Under optimal conditions, the two linear ranges were obtained from 3 to 13 {mu}g mL{sup -1} and from 14 to 31 {mu}g mL{sup -1}, respectively. The detection limit was 0.08 {mu}g mL{sup -1} at 3{sigma}. The constructed biosensor had better responses compared with that in the absence of the CdSe QDs immobilizing. The control experiment was also carried out by using BSA, casein and IgG in the absence of thrombin. The results showed that the aptasensor had good specificity, stability and reproducibility to the thrombin. Moreover, the aptasensor could be used for detection of real sample with consistent results in comparison with those obtained by fluorescence method which could provide a promising platform for fabrication of aptamer based biosensors.

  17. Isolation and characterization of the thrombin-like enzyme from Cryptelytrops albolabris (white-lipped tree viper) venom.

    Science.gov (United States)

    Tan, Nget Hong; Fung, Shin Yee; Yap, Yeannie Hui Yeng

    2012-01-01

    A thrombin-like enzyme (termed albolabrase) was isolated in purified form from the venom of Cryptelytrops albolabris (white-lipped tree viper) using high performance anion ion exchange and gel filtration chromatography. The molecular mass of albolabrase was 33.7 kDa as determined by SDS-PAGE and 35.8 kDa as determined by Superose gel filtration chromatography. The N-terminal sequence was determined to be VVGGDECNINE which is homologous to many snake venom thrombin-like enzymes. Albolabrase exhibits both arginine ester hydrolase and arginine amidase activities and the enzyme is fastidious towards tripeptide chromogenic anilide substrates. The fibrinogen clotting activity was optimum at 3mg/mL bovine fibrinogen, and showed distinct species differences in the following decreasing order: bovine fibrinogen>dog fibrinogen?human fibrinogen>goat fibrinogen. The enzyme failed to clot both rabbit and cat fibrinogens. Reversed-phase HPLC analysis on the breakdown products of fibrinogenolytic action of albolabrase indicated that the enzyme belongs to the AB class of snake venom thrombin-like enzyme. In the indirect ELISA, IgG anti-albolabrase reacted extensively with most crotalid venoms, except with Tropidolaemus wagleri and Calloselasma rhodostoma venoms. The double sandwich ELISA, however, showed that anti-albolabrase reacted strongly only with venoms from the Trimeresurus complex, and that the results support the proposed new taxonomy changes concerning the Trimeresurus complex. PMID:21983189

  18. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as well as the cellular organization of the process of homologous recombination. Herein we review the cell biological aspects of mitotic homologous recombination with a focus on Saccharomyces cerevisiae and ...

  19. Updated Topics in Healthcare Informatics

    OpenAIRE

    Takeda, Hiroshi

    2010-01-01

    This key note lecture introduces the role of IMIA, scope of healthcare informatics and some topics in healthcare informatics. Among updated topics, electronic patient record (EPR) and electronic health record (EHR) are featured. A new paradigm of clinical information systems, a document archiving and communication system (DACS) is also described and discussed.

  20. Hot topics for leadership development.

    Science.gov (United States)

    Bleich, Michael R

    2015-02-01

    Three areas stand out from a health systems perspective that should be on the development agenda for all leaders. These topics include population health, predictive analytics, and supply chain management. Together, these topics address access, quality, and cost management. PMID:25633301

  1. Linguistic Extensions of Topic Models

    Science.gov (United States)

    Boyd-Graber, Jordan

    2010-01-01

    Topic models like latent Dirichlet allocation (LDA) provide a framework for analyzing large datasets where observations are collected into groups. Although topic modeling has been fruitfully applied to problems social science, biology, and computer vision, it has been most widely used to model datasets where documents are modeled as exchangeable…

  2. Thrombin and plasmin-like activities in the latices of Cryptostegia grandiflora and Plumeria rubra.

    Science.gov (United States)

    Viana, Carolina A; Oliveira, Jefferson S; Freitas, Cleverson D T; Alencar, Nylane M N; Carvalho, Cristina P S; Nishi, Beatriz C; Ramos, Márcio V

    2013-06-01

    Latex proteins have drawn attention because they have shown several pharmacological activities. Herein, the fibrin(ogen)olytic activity of Cryptostegia grandiflora (CgLP) and Plumeria rubra (PrLP) latices were evaluated and characterized. Ion-exchange chromatography separated CgLP in proteolytic (CgLP PI) and nonproteolytic proteins (CgLP PII). CgLP and CgLP PI hydrolyzed azocasein in a dose-dependent manner, whereas CgLP PII and PrLP showed negligible activities. CgLP and CgLP PI accelerated plasmatic clot formation and digested all fibrinogen chains in a time/dose-dependent manner, though in a nonspecific way. CgLP and CgLP PI did not fully hydrolyze the subunits of the fibrin clot since fibrin ?-chain showed resistance to proteolysis. No fibrinogenolytic activity was noticed after incubation of CgLP and CgLP PI with E-64. These results suggested that fibrinogenolytic and procoagulant activities of C. grandiflora were performed by cysteine proteases and confirm the activity of latex cysteine proteases as thrombin and plasmin-like proteins. PMID:23314383

  3. Selective deacylation of 1-acyl-2-arachidonoyl PC and PE in thrombin-stimulated human platelets

    International Nuclear Information System (INIS)

    Previously the authors have shown that uptake and stimulated release of 3H-arachidonate (AA) in human platelets involves mainly 1-acyl-2-arachidonoyl phospholipids. To determine deacylation of molecular species of 1-acyl-2-arachidonoyl phosphatidylcholine (PC) and phosphatidylethanolamine (PE), phospholipid was extracted by the method of Bligh and Dyer from cells (109/ml) stimulated or not by thrombin (THR, 5 U/ml .370C, 5 min). Total PC and PE were isolated by thin-layer chromatography (TLC) and converted to 1-radyl-2-acyl glycerobenzoates. The 1,2 diacyl glycerobenzoates were separated from other subclasses by TLC. Individual molecular species of 1,2 diacyl glycerobenzoates were resolved by reverse phase HPLC. Mass (O.D.230) and 3H-AA radioactivity (i.e. specific activity) were determined on-line, and changes in individual molecular species could be deduced. Significant deacylation of all 1-acyl-2-arachidonoyl PC and PE molecular species occurred with no apparent deacylation in any non-AA-containing molecular species of 1,2 diacyl PC/PE. At 5 minutes the net deacylation of 1-acyl-2-arachidonoyl PC and PE was approximately 15 and 5 nanomoles, respectively/109 cells. These results indicate that selective deacylation of arachidonoyl-containing molecular species compared to non-arachidonoyl-containing molecular species of PC/PE occurs in THR-stimulated cells. This suggests certain AA-containing phospholipids are compartmentalized with and susceptible to, the action of phospholipase A2

  4. Two related thrombin-like enzymes present in Bothrops atrox venom

    Scientific Electronic Library Online (English)

    J.H., Petretski; M., Kanashiro; C.P., Silva; E.W., Alves; T.L., Kipnis.

    2000-11-01

    Full Text Available This article describes the presence of two new forms of a thrombin-like enzyme, both with apparent molecular masses of 38 kDa, in Bothrops atrox venom. Both share the ability to cleave fibrinogen into fibrin and to digest casein. Both present identical Km on the substrate BApNA. Their N-terminal ami [...] no acid sequences are identical for 26 residues, sharing 80% homology with batroxobin and flavoxobin. Two groups of monoclonal antibodies (mAbs) raised against the purified enzyme forms recognized different epitopes of the putative corresponding enzymes present in B. atrox crude venom. On Western blotting analysis of B. atrox crude venom, mAbs 5DB2C8, 5AA10 and 5CF11, but not mAbs 6CC5 and 6AD2-G5, revealed two or more protein bands ranging from 25 to 38 kDa. By immunoprecipitation assays, the 6AD2-G5 mAb was able to precipitate protein bands of 36-38 kDa from B. atrox, B. leucurus, B. pradoi, B. moojeni, B. jararaca and B. neuwiedii crude venoms. Fibrinogen-clotting activity was inhibited when the same venom specimens were pre-incubated with mAb 6AD2-G5, except for B. jararaca and B. neuwiedii.

  5. Caspases and Thrombin Activity Regulation by Specific Serpin Inhibitors in Bovine Skeletal Muscle.

    Science.gov (United States)

    Gagaoua, Mohammed; Hafid, Kahina; Boudida, Yasmine; Becila, Samira; Ouali, Ahmed; Picard, Brigitte; Boudjellal, Abdelghani; Sentandreu, Miguel Angel

    2015-09-01

    In living cells, after activation, protein inhibitors constitute the last step of proteases activity regulation. This review intends to provide original information about a group of bovine muscle serine proteases inhibitors belonging to the Serpin superfamily and characterized at the gene and protein level. This report is the only one and the first to provide much information on this group of proteases inhibitors of the serpin type and their potential biological functions. Amongst the eight genes identified in bovine, three serpins were purified from the muscle tissue and characterized. These are two members of the bovSERPINA3 family, i.e., bovSERPINA3-1 and A3-3, and the last one is antithrombin III (AT-III or BovSERPINC1). BovSERPINA3 family comprises at least eight protein members encoded by different genes mapped on chromosome 7q23-q26 cluster. BovSERPINA3-1 and A3-3 were shown to locate within muscle cells and are cross-class inhibitors strongly active against trypsin as well as against human initiator and effector caspases 8 and 3. They constitute a key apoptosis control in mammals. They were thus expressed in proliferating and confluent myoblasts phases where cells must be alive but not in myotubes. Antithrombin III inhibits trypsin and, in a heparin dependent manner, thrombin. AT-III and its mRNA were expressed in muscle cells and in differentiating primary myoblasts in culture. PMID:26208691

  6. DIRECT SMEAR VS CELL BLOCK (PLASMA- THROMBIN CLOT METHOD: DIAGNOSTIC VALUE IN SEROSAL CAVITIES FLUIDS CYTOLOGY

    Directory of Open Access Journals (Sweden)

    P MAHZOUNI

    2000-03-01

    Full Text Available Introduction. To improve testing sensitivity, most laboratories use two or more preparation methods but in our laboratories only one method is used which is "direct smear". In this study we tried to evaluate the diagnostic value of cell block as adjunct to direct smear in the cytologic investigation of serosal cavities fluids. Methods. In a clinical trial study 62 specimens of serosal cavity fluids were investigated in AL-Zahrapathology laboratory (Get. 1998 to Get. 1999. Cytologic slides from each specimens were prepared in two methods: direct smear and cell block (plasma- thrombin clot method. Smears and cell blocks were studied separately by the same cytopathologist. The diagnosis were categorized as positive, negative, suspicious or unsatisfactory. Also, the time required for studing of each slides were noted. Findings. The findings indicated that there are discrepancy between direct smear and cell block methods in the number of "suspicious" cases. Also there is significant difference between the mean time needed for studing of direct smear and cell block. Conclusion. It is recommended that the remainer of each specimen should be kept in refrigerator in order to prepare cell blocks in suspicious cases of direct smear. This method facilitates making a more definite diagnosis and reducing the number of suspicious cases.

  7. Thrombin antithrombin complex and IL-18 serum levels in stroke patients

    Directory of Open Access Journals (Sweden)

    Ornella Piazza

    2010-02-01

    Full Text Available The complex picture of inflammation and coagulation alterations comes to life in acute stroke phases. Increasing evidence points to a strong interaction and extensive crosstalk between the inflammation and coagulation systems: the interest towards this relationship has increased since recent experimental research showed that the early administration of antithrombin III (ATIII decreases the volume of ischemia in mice and might be neuroprotective, playing an antiinflammatory role. We aimed to establish the extent of the relationship among markers of inflammation (S100B and IL-18 and procoagulant and fibrinolytic markers (ATIII, thrombin-antithrombin III complex (TAT, Fibrin Degradation Products (FDP, D-dimer in 13 comatose patients affected by focal cerebral ischemia. Plasma levels of TAT, D-dimer and FDP, IL18 and S100B were increased. IL-18 and S100B high serum levels in ischemic patients suggest an early activation of the inflammatory cascade in acute ischemic injury. The basic principles of the interaction between inflammatory and coagulation systems are revised, from the perspective that simultaneous modulation of both coagulation and inflammation, rather than specific therapies aimed at one of these systems could be more successful in stroke therapy.

  8. Exposure- response for biomarkers of anticoagulant effects by the oral direct thrombin inhibitor AZD0837 in patients with atrial fibrillation

    DEFF Research Database (Denmark)

    Lip, Gregory Y H; Rasmussen, Lars H

    2015-01-01

    BACKGROUND: AZD0837 is a novel oral anticoagulant investigated in clinical studies for stroke prevention in patients with atrial fibrillation (AF). It is bioconverted to its active form, AR-H067637, a potent, specific and reversible thrombin inhibitor. OBJECTIVES: A population pharmacokinetic (PK) analysis was performed and the effect of AZD0837 therapy on fibrin D-dimer levels was correlated to the PK exposure of AR-H067637, as well as the effect on thrombin generation measured ex vivo, to guide selection of the effective dose regimen for a confirmatory efficacy study in AF patients. PATIENTS AND METHODS: Blood samples were obtained from 601 AF patients randomized to receive 1 of 4 doses of AZD0837 (blinded treatment) or dose-adjusted vitamin K antagonists (VKA, open treatment) for 3-9?months. A pharmacodynamic model was developed to describe time course of the AR-H067637 exposure dependent effects and the effect of VKA on fibrin D-dimer. The concentration-effect relationship for thrombin generation measured ex vivo in venous plasma was also investigated. RESULTS: AZD0837 was rapidly bioconverted to AR-H067637, showing stable exposure with an estimated interindividual variability of 33% with no or only minor influence of patient demographics or comedications. For all dose groups of AZD0837, D-dimer levels decreased with more rapid onset of effect compared to VKA. The decrease in D-dimer levels correlated to the steady state plasma concentrations (Css) of AR-H067637, with a maximum decrease of baseline D-dimer levels estimated to approximately 60% for both AZD0837 and VKA therapy. Anticoagulant effect measured ex vivo as decreased thrombin generation correlated closely with the plasma concentration of AR-H067637. CONCLUSIONS: Following oral therapy with AZD0837, inhibitory effects on thrombin generation and fibrin D-dimer levels were correlated to the plasma concentration of its active form and provides comparable effects as well-controlled VKA therapy at an exposure at least corresponding to the 300?mg qd dose AZD0837.

  9. Advancements in Topical Antifungal Vehicles.

    Science.gov (United States)

    Kircik, Leon H

    2016-02-01

    The primary treatment for superficial fungal infections is antifungal topical formulations, and allylamines and azoles represent the two major classes of topical formulations that are used to treat these infections. The stratum corneum (SC) is composed of keratinocytes that are surrounded by a matrix of lipids. The efficacy of topically applied formulations depends on their ability to penetrate this lipid matrix, and the vehicle plays an integral role in the penetration of active molecule into skin. There are several challenges to formulating topical drugs, which include the biotransformation of the active molecules as they pass through the SC and the physical changes that occur to the vehicle itself when it is applied to the skin. This article will review current and emerging topical antifungal vehicles. J Drugs Dermatol. 2016;15(Suppl 2):s44-48. PMID:26885798

  10. Hydrogen--oxygen recombiner

    International Nuclear Information System (INIS)

    An apparatus is disclosed for efficiently and safely recombining hydrogen and oxygen gas to form water vapor, the apparatus being particularly adapted for use with a nuclear reactor system in which potentially dangerous hydrogen gas, evolved within the containment vessel during certain postulated accident conditions, can be eliminated. Further, this apparatus also aids in the removal of certain radioactive contaminents from the gases in a containment vessel

  11. Intrachromosomal recombination in plants.

    OpenAIRE

    Peterhans, A; Schlüpmann, H; Basse, C; Paszkowski, J

    1990-01-01

    Molecular evidence for intrachromosomal recombination between closely linked DNA repeats within the plant genome is presented. The non-overlapping complementary deletion derivatives of the selectable neomycin phosphotransferase gene (nptII), when intact conferring kanamycin resistance, were inserted into the genome of Nicotiana tabacum. The functional marker gene was restored with frequencies between 10(-4) and 10(-6) per proliferating cell clone. Prolonged tissue culture prior to kanamycin s...

  12. A Simplified Recombinant PSO

    OpenAIRE

    Bratton, Daniel; Blackwell, Tim M.

    2008-01-01

    Simplified forms of the particle swarm algorithm are very beneficial in contributing to understanding how a particle swarm optimization (PSO) swarm functions. One of these forms, PSO with discrete recombination, is extended and analyzed, demonstrating not just improvements in performance relative to a standard PSO algorithm, but also significantly different behavior, namely, a reduction in bursting patterns due to the removal of stochastic components from the update equations.

  13. Recombinant human milk proteins.

    Science.gov (United States)

    Lönnerdal, Bo

    2006-01-01

    Human milk provides proteins that benefit newborn infants. They not only provide amino acids, but also facilitate the absorption of nutrients, stimulate growth and development of the intestine, modulate immune function, and aid in the digestion of other nutrients. Breastfed infants have a lower prevalence of infections than formula-fed infants. Since many women in industrialized countries choose not to breastfeed, and an increasing proportion of women in developing countries are advised not to breastfeed because of the risk of HIV transmission, incorporation of recombinant human milk proteins into infant foods is likely to be beneficial. We are expressing human milk proteins known to have anti-infective activity in rice. Since rice is a normal constituent of the diet of infants and children, limited purification of the proteins is required. Lactoferrin has antimicrobial and iron-binding activities. Lysozyme is an enzyme that is bactericidal and also acts synergistically with lactoferrin. These recombinant proteins have biological activities identical to their native counterparts. They are equally resistant to heat processing, which is necessary for food applications, and to acid and proteolytic enzymes which are needed to maintain their biological activity in the gastrointestinal tract of infants. These recombinant human milk proteins may be incorporated into infant formulas, baby foods and complementary foods, and used with the goal to reduce infectious diseases. PMID:16902336

  14. Dielectronic recombination theory

    International Nuclear Information System (INIS)

    A theory now in wide use for the calculation of dielectronic recombination cross sections (?DR) and rate coefficients (?DR) was one introduced originally by Feshbach for nuclear physics applications, and then later adapted for atomic scattering problems by Hahn. In the following, we briefly review this theory in a very general form, which allows one to account for the effects of overlapping and interacting resonances, as well as continuum-continuum coupling. An extension of our notation will then also allow for the inclusion of the effects of direct radiative recombination, along with a treatment of the interference between radiative and dielectronic recombination. Other approaches to the calculation of ?DR have been described by Fano and by Seaton. We will not consider those theories here. Calculations of ?DR have progressed considerably over the last 25 years, since the early work of Burgess. Advances in the reliability of theoretical predictions have also been promoted recently b a variety of direct laboratory measurements of ?DR. While the measurements of ?DR for ?n ? 0 excitations have tended to agree very well with calculations, the case of ?n = 0 has been much problematic. However, by invoking a mechanism originally proposed by Jacobs, which takes into account the effect of stray electric fields on high Rydberg states (HRS) participating in the DR process, new calculations have improved the agreement between theory and experiment for these cases. Nevertheless, certain discrepancies still remain

  15. Evidence of recombination within human alpha-papillomavirus

    Directory of Open Access Journals (Sweden)

    Carvajal-Rodríguez Antonio

    2007-03-01

    Full Text Available Abstract Background Human papillomavirus (HPV has a causal role in cervical cancer with almost half a million new cases occurring each year. Presence of the carcinogenic HPV is necessary for the development of the invasive carcinoma of the genital tract. Therefore, persistent infection with carcinogenic HPV causes virtually all cervical cancers. Some aspects of the molecular evolution of this virus, as the putative importance of recombination in its evolutionary history, are an opened current question. In addition, recombination could also be a significant issue nowadays since the frequency of co-infection with more than one HPV type is not a rare event and, thus, new recombinant types could be currently being generated. Results We have used human alpha-PV sequences from the public database at Los Alamos National Laboratory to report evidence that recombination may exist in this virus. A model-based population genetic approach was used to infer the recombination signal from the HPV DNA sequences grouped attending to phylogenetic and epidemiological information, as well as to clinical manifestations. Our results agree with recently published ones that use a different methodology to detect recombination associated to the gene L2. In addition, we have detected significant recombination signal in the genes E6, E7, L2 and L1 at different groups, and importantly within the high-risk type HPV16. The method used has recently been shown to be one of the most powerful and reliable procedures to detect the recombination signal. Conclusion We provide new support to the recent evidence of recombination in HPV. Additionally, we performed the recombination estimation assuming the best-fit model of nucleotide substitution and rate variation among sites, of the HPV DNA sequence sets. We found that the gene with recombination in most of the groups is L2 but the highest values were detected in L1 and E6. Gene E7 was recombinant only within the HPV16 type. The topic deserves further study because recombination is an important evolutionary mechanism that could have high impact both in pharmacogenomics (i.e. on the influence of genetic variation on the response to drugs and for vaccine development.

  16. Affinity labeling of lysine-149 in the anion-binding exosite of human ?-thrombin with an N?-(dinitrofluorobenzyl)hirudin C-terminal peptide

    International Nuclear Information System (INIS)

    In order to define structural regions in thrombin that interact with hirudin, the N?-dinitrofluorobenzyl analogue of an undecapeptide was synthesized corresponding to residues 54-64 of hirudin [GDFEEIPEEY(O35SO3)L (DNFB-[35S]Hir54-64)]. DNFB-[35S]Hir54-64 was reacted at a 10-fold molar excess with human ?-thrombin in phosphate-buffered saline at pH 7.4 and 23 degree C for 18 h. Autoradiographs of the product in reducing SDS-polyacrylamide gels revealed a single 35S-labeled band of Mr ?32,500. The labeled product was coincident with a band on Coomassie Blue stained gels migrating slightly above an unlabeled thrombin band at Mr ?31,000. Incorporation of the 35S affinity reagent peptide was found markedly reduced when reaction with thrombin was performed in the presence of 5- and 20-fold molar excesses of unlabeled hirudin peptide, showing that a specific site was involved in complex formation. The human ?-thrombin-DNFB-Hir54-64 complex was reduced, S-carboxymethylated, and treated with pepsin. Peptic fragments were separated by reverse-phase HPLC revealing two major peaks containing absorbance at 310 nm. Automated Edman degradation of the peptide fragments allowed identification of Lys-149 of human thrombin as the major site of DNFB-Hir54-64 derivatization. These data suggest that the anionic C-terminal tail of hirudin interacts with an anion-binding exosite in human thrombin removed 18-20 angstrom from the catalytic apparatus

  17. Topic Model for Graph Mining.

    Science.gov (United States)

    Xuan, Junyu; Lu, Jie; Zhang, Guangquan; Luo, Xiangfeng

    2015-12-01

    Graph mining has been a popular research area because of its numerous application scenarios. Many unstructured and structured data can be represented as graphs, such as, documents, chemical molecular structures, and images. However, an issue in relation to current research on graphs is that they cannot adequately discover the topics hidden in graph-structured data which can be beneficial for both the unsupervised learning and supervised learning of the graphs. Although topic models have proved to be very successful in discovering latent topics, the standard topic models cannot be directly applied to graph-structured data due to the "bag-of-word" assumption. In this paper, an innovative graph topic model (GTM) is proposed to address this issue, which uses Bernoulli distributions to model the edges between nodes in a graph. It can, therefore, make the edges in a graph contribute to latent topic discovery and further improve the accuracy of the supervised and unsupervised learning of graphs. The experimental results on two different types of graph datasets show that the proposed GTM outperforms the latent Dirichlet allocation on classification by using the unveiled topics of these two models to represent graphs. PMID:25616091

  18. Topical steroid-damaged skin

    Directory of Open Access Journals (Sweden)

    Anil Abraham

    2014-01-01

    Full Text Available Topical steroids, commonly used for a wide range of skin disorders, are associated with side effects both systemic and cutaneous. This article aims at bringing awareness among practitioners, about the cutaneous side effects of easily available, over the counter, topical steroids. This makes it important for us as dermatologists to weigh the usefulness of topical steroids versus their side effects, and to make an informed decision regarding their use in each individual based on other factors such as age, site involved and type of skin disorder.

  19. Topics in lightwave transmission systems

    CERN Document Server

    Li, Tingye

    1991-01-01

    Topics in Lightwave Transmission Systems is a second volume of a treatise on optical fiber communications that is devoted to the science, engineering, and application of information transmission via optical fibers. The first volume, published in 1985, dealt exclusively with fiber fabrication. The present volume contains topics that pertain to subsystems and systems. The book contains five chapters and begins with discussions of transmitters and receivers, which are basic to systems now operating in the field. Subsequent chapters cover topics relating to coherent systems: frequency and phase m

  20. Retinoic Acid Promotes Interleukin-4 Plasmid-Dimethylsulfoxide Topical Transdermal Delivery for Treatment of Psoriasis

    OpenAIRE

    Chen, Zhong-Wen; Zhang, Yin-Bing; Chen, Xaing-Jun; Xiao LIU; Wang, Zhen; Zhou, Xi-kun; Qiu, Ji; Zhang, Nan-Nan; Teng, Xiu; MAO, YONG-QIU; Liu, Chang-Yong; WEI, YU-QUAN; Li, Jiong

    2015-01-01

    Background Psoriasis is an autoimmune disease that is caused by a shift in the Th1/Th2 balance toward Th1-dominant immunity. It has been established as an effective treatment to counteract psoriasis by subcutaneous injection of recombinant interleukin (IL)-4, and IL-4 gene therapy by topical transdermal penetration has shown its antipsoriatic effect in mice. Retinoic acid (RA) and dimethylsulfoxide can increase the efficiency of gene transfection in the topical transdermal delivery system. Ob...

  1. Bacterial Recombineering: Genome Engineering via Phage-Based Homologous Recombination.

    Science.gov (United States)

    Pines, Gur; Freed, Emily F; Winkler, James D; Gill, Ryan T

    2015-11-20

    The ability to specifically modify bacterial genomes in a precise and efficient manner is highly desired in various fields, ranging from molecular genetics to metabolic engineering and synthetic biology. Much has changed from the initial realization that phage-derived genes may be employed for such tasks to today, where recombineering enables complex genetic edits within a genome or a population. Here, we review the major developments leading to recombineering becoming the method of choice for in situ bacterial genome editing while highlighting the various applications of recombineering in pushing the boundaries of synthetic biology. We also present the current understanding of the mechanism of recombineering. Finally, we discuss in detail issues surrounding recombineering efficiency and future directions for recombineering-based genome editing. PMID:25856528

  2. HOT TOPICS IN FOOD MICROBIOLOGY

    Science.gov (United States)

    Escherichia coli is a bacterium whose importance ranges from its role as a host for recombinant DNA manipulations to being one of the most well-recognized foodborne pathogens. Most E. coli strains are considered to be part of the normal microflora of the intestinal tract of humans and other warm-bl...

  3. Two topics in quantum chromodynamics

    International Nuclear Information System (INIS)

    The two topics are (1) estimates of perturbation theory coefficients for R(e+e- ? hadrons), and (2) the virtual-photon structure function, with emphasis on the analytic behavior in its squared mass. 20 refs., 4 figs., 2 tabs

  4. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    The collection of abstracts on selected topics in nuclear structure are given. Special attention pays to collective excitations and high-spin states of nuclei, giant resonance structure, nuclear reaction mechanisms and so on

  5. Clindamycin and Benzoyl Peroxide Topical

    Science.gov (United States)

    The combination of clindamycin and benzoyl peroxide is used to treat acne. Clindamycin and benzoyl peroxide are in a class of medications called topical antibiotics. The combination of clindamycin and benzoyl peroxide works by killing the bacteria ...

  6. Iodine Absorption After Topical Administration

    OpenAIRE

    Cruz, Francine Dela; Brown, Deborah Harper; Leikin, Jerrold B.; Franklin, Cory; Hryhorczuk, Daniel O.

    1987-01-01

    Absorption from povidone-iodine preparations after topical administration has been reported to be negligible, but an elderly woman had increased serum iodine levels with possible metabolic complications after povidone-iodine solution was applied to decubitus ulcers.

  7. Present topics of nuclear energy

    International Nuclear Information System (INIS)

    The report is discussing the topics: Reprocessing of spent fuel elements; Final storage of radioactive wastes; Effects of thermal power plants upon the climate; Safeguarding of nuclear facilities and fissionable materials; Properties and possibilities of plutonium. (orig./HP)

  8. Special topics in spectral distributions

    International Nuclear Information System (INIS)

    We discuss two problems which relate to the foundations of the subject, and a third about asymptotic properties of spectral distributions. We give also a brief list of topics which should be further explored

  9. Topics on the FORM software

    International Nuclear Information System (INIS)

    These notes studies the compilation with FORM software as applied to high energy physics, covering the following topics: Command structures, statistics and numbers, Dirac matrices, optimization control, Gamma matrices, errors and polynomial substitution

  10. Recombinant Collagenlike Proteins

    Science.gov (United States)

    Fertala, Andzej

    2007-01-01

    A group of collagenlike recombinant proteins containing high densities of biologically active sites has been invented. The method used to express these proteins is similar to a method of expressing recombinant procollagens and collagens described in U. S. Patent 5,593,859, "Synthesis of human procollagens and collagens in recombinant DNA systems." Customized collagenous proteins are needed for biomedical applications. In particular, fibrillar collagens are attractive for production of matrices needed for tissue engineering and drug delivery. Prior to this invention, there was no way of producing customized collagenous proteins for these and other applications. Heretofore, collagenous proteins have been produced by use of such biological systems as yeasts, bacteria, and transgenic animals and plants. These products are normal collagens that can also be extracted from such sources as tendons, bones, and hides. These products cannot be made to consist only of biologically active, specific amino acid sequences that may be needed for specific applications. Prior to this invention, it had been established that fibrillar collagens consist of domains that are responsible for such processes as interaction with cells, binding of growth factors, and interaction with a number of structural proteins present in the extracellular matrix. A normal collagen consists of a sequence of domains that can be represented by a corresponding sequence of labels, e.g., D1D2D3D4. A collagenlike protein of the present invention contains regions of collagen II that contain multiples of a single domain (e.g., D1D1D1D1 or D4D4D4D4) chosen for its specific biological activity. By virtue of the multiplicity of the chosen domain, the density of sites having that specific biological activity is greater than it is in a normal collagen. A collagenlike protein according to this invention can thus be made to have properties that are necessary for tissue engineering.

  11. Do scientists trace hot topics?

    OpenAIRE

    Tian Wei; Menghui Li; Chensheng Wu; Xiao-Yong Yan; Ying Fan; Zengru Di; Jinshan Wu

    2013-01-01

    Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries,...

  12. Psoriasis: consensus on topical therapies

    DEFF Research Database (Denmark)

    van de Kerkhof, P C M; Barker, J; Griffiths, C E M; Kragballe, K; Mason, J; Menter, A; Papp, K

    2008-01-01

    Objective A consensus conference was convened to evaluate the topical treatment of psoriasis. Participants Members of the International Psoriasis Council (IPC) with broad clinical experience in the treatment of psoriasis and a specialist in meta- and pharmacoeconomic analyses were invited to participate on the consensus panel. Those accepting the invitation convened in Saariselkä, Finland. Evidence An advisory group on topical treatments was nominated by the organizing panel members. All partici...

  13. Pharmacogenetics of ophthalmic topical ?-blockers

    OpenAIRE

    Sidjanin, Duska J.; McCarty, Catherine A.; Patchett, Richard; Smith, Edward; Wilke, Russell A

    2008-01-01

    Glaucoma is the second leading cause of blindness worldwide. The primary glaucoma risk factor is elevated intraocular pressure. Topical ?-blockers are affordable and widely used to lower intraocular pressure. Genetic variability has been postulated to contribute to interpersonal differences in efficacy and safety of topical ?-blockers. This review summarizes clinically significant polymorphisms that have been identified in the ?-adrenergic receptors (ADRB1, ADRB2 and ADRB3). The implications ...

  14. Topics of Bioengineering in Wikipedia

    Directory of Open Access Journals (Sweden)

    Vassia Atanassova

    2009-10-01

    Full Text Available The present report aims to give a snapshot of how topics from the field of bioengineering (bioinformatics, bioprocess systems, biomedical engineering, biotechnology, etc. are currently covered in the free electronic encyclopedia Wikipedia. It also offers insights and information about what Wikipedia is, how it functions, how and when to cite Wikipedian articles, if necessary. Several external wikis, devoted to topics of bioengineering, are also listed and reviewed.

  15. Key Topics in Sports Medicine

    OpenAIRE

    Amir Ali Narvani; Panagiotis Thomas; Burce Lynn

    2006-01-01

    Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1) Sports injuries, rehabilitation and injury prevention, 2) Exercise physiology, fitness testing and training, 3) Drugs in sport, 4) Exercise and health promotion, 5) Sport and exercise for special and clinical populations, 6) The ps...

  16. Primordial magnetogenesis before recombination

    CERN Document Server

    Fabre, Ophélia

    2015-01-01

    The origin of large magnetic fields in the Universe remains currently unknown. We investigate here a mechanism before recombination based on known physics. The source of the vorticity is due to the changes in the photon distribution function caused by the fluctuations in the background photons. We show that the magnetic field generated in the MHD limit, due to the Coulomb scattering, is of the order $10^{-49}$ G. We explicitly show that the magnetic fields generated from this process are sustainable and are not erased by resistive diffusion. We compare the results with current observations and discuss the implications.

  17. A 2D-DIGE-based proteomic analysis reveals differences in the platelet releasate composition when comparing thrombin and collagen stimulations

    Science.gov (United States)

    Vélez, Paula; Izquierdo, Irene; Rosa, Isaac; García, Ángel

    2015-01-01

    Upon stimulation, platelets release a high number of proteins (the releasate). There are clear indications that these proteins are involved in the pathogenesis of several diseases, such as atherosclerosis. In the present study we compared the platelet releasate following platelet activation with two major endogenous agonists: thrombin and collagen. Proteome analysis was based on 2D-DIGE and LC-MS/MS. Firstly, we showed the primary role of thrombin and collagen receptors in platelet secretion by these agonists; moreover, we demonstrated that GPVI is the primary responsible for collagen-induced platelet activation/aggregation. Proteomic analysis allowed the detection of 122 protein spots differentially regulated between both conditions. After excluding fibrinogen spots, down-regulated in the releasate of thrombin-activated platelets, 84 differences remained. From those, we successfully identified 42, corresponding to 37 open-reading frames. Many of the differences identified correspond to post-translational modifications, primarily, proteolysis induced by thrombin. Among others, we show vitamin K-dependent protein S, an anticoagulant plasma protein, is up-regulated in thrombin samples. Our results could have pathological implications given that platelets might be playing a differential role in various diseases and biological processes through the secretion of different subsets of granule proteins and microvesicles following a predominant activation of certain receptors. PMID:25645904

  18. A fully recombinant partial prothrombin complex effectively bypasses fVIII in vitro and in vivo.

    Science.gov (United States)

    Himmelspach, Michèle; Richter, Günter; Muhr, Evelyn; Varadi, Katalin; Turecek, Peter L; Dorner, Friedrich; Schwarz, Hans Peter; Schlokat, Uwe

    2002-12-01

    The development of inhibitory antibodies is a serious complication in hemophilic patients, severely compromising therapeutic success. Bleeding episodes in affected patients are controlled by treatment with a plasma-derived prothrombin complex concentrate (PCC), activated PCC (APCC) or recombinant activated factor VII. We hypothesized that a recombinant two-component agent consisting of recombinant prothrombin (rfII) and activated factor X (rfXa) would have substantial fVIII bypassing activity and could be a safe alternative therapeutic option. To test this hypothesis we assembled an agent in vitro solely consisting of rfII and rfXa at a molar ratio of 37,500:1. These factors are believed to be responsible for the activity of APCC preparations. Recombinant fX, used as the source for fXa generation, and rfII were purified from serum-free and protein-free conditioned media of stably transfected CHO and BHK tissue culture cells, respectively. Activation of rfX to rfXa was accomplished by the plant protease ficin, obviating the need for a protease derived from a human or animal source. We found that in vitro the complex reduced the abnormally prolonged activated partial thromboplastin time (APTT) of a high-titer fVIII inhibitor plasma similar to an APCC preparation. Furthermore, addition of increasing amounts of rfII/rfXa to inhibitor plasma resulted in a linear dose-dependent increase in the rate of thrombin generation. In a rabbit fVIII inhibitor model, treatment with rfII/rfXa statistically significantly reduced the intensity of the abnormal cuticle bleeding. In the Wessler test, rfII/rfXa showed no thrombogenicity. These data show that a well-defined, particularly safe and efficacious agent with fVIII bypassing activity can be generated from recombinant fII and fXa. PMID:12529752

  19. Integrating Document Clustering and Topic Modeling

    OpenAIRE

    Xie, Pengtao; Xing, Eric P.

    2013-01-01

    Document clustering and topic modeling are two closely related tasks which can mutually benefit each other. Topic modeling can project documents into a topic space which facilitates effective document clustering. Cluster labels discovered by document clustering can be incorporated into topic models to extract local topics specific to each cluster and global topics shared by all clusters. In this paper, we propose a multi-grain clustering topic model (MGCTM) which integrates document clusterin...

  20. Anticoagulant profile of iopamidol and meglumine amidotrizoate and their lack of thrombin generation: an in vitro study

    International Nuclear Information System (INIS)

    The aim of this in vitro study was to sketch the subtle anticoagulant profile of iopamidol 300 mg l/ml (low osmolality non ionic contrast medium) and meglumine amidotrizoate 370 mg l/ml (high osmolality ionic contrast medium) in situations where variable amounts of clotting factors are observed and to check whether thrombin-generation significantly occurred in non anti-coagulated blood-contrast materials mixtures. In the first experiment, mixtures of deficient plasmas with a routine plasma pool provided different ranges with a variable amounts of clotting factor II, V, VIII, X, XI and XII. For each clotting factor level studied within these ranges, an activated partial thromboplastin time was determined with either contrast material loaded thromboplastin (5% v/v) used as a control. In the second experiment fibrino-peptide A (FpA) or modified anti-thrombin III (ATM) assays were performed in either (9:1) non anti-coagulated blood contrast materials mixtures or blood-glucose mixtures (control). Differing aPTT prolongation profiles were observed when clotting factors V, VIII, XI and XII were lowered in the plasma. However, neither iopamidol not amidotrizoate induced an aPTT prolongation with decreasing clotting factor II. In the second experiment no significant thrombin generation was observed as both blood - contrast materials mixtures showed significantly lower FpA and ATM levels (p < 0.001) than glucose control after 5 minutes and 10 minutes incubation at room temperature. These findings provide evidence that the use of iopamidol in angiographic procedures does not increase risk of clotting or hemorrhage. (author)

  1. Anticoagulant profile of iopamidol and meglumine amidotrizoate and their lack of thrombin generation: an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Gritli, N.; Nsiri, B.; Mazigh, C.; Ghazouani, E.; M`henni, H.; Machghoul, S.; Gueddiche, M. [Hopital Militaire Principal d`Instruction de Tunis (Tunisia)

    1998-01-01

    The aim of this in vitro study was to sketch the subtle anticoagulant profile of iopamidol 300 mg l/ml (low osmolality non ionic contrast medium) and meglumine amidotrizoate 370 mg l/ml (high osmolality ionic contrast medium) in situations where variable amounts of clotting factors are observed and to check whether thrombin-generation significantly occurred in non anti-coagulated blood-contrast materials mixtures. In the first experiment, mixtures of deficient plasmas with a routine plasma pool provided different ranges with a variable amounts of clotting factor II, V, VIII, X, XI and XII. For each clotting factor level studied within these ranges, an activated partial thromboplastin time was determined with either contrast material loaded thromboplastin (5% v/v) used as a control. In the second experiment fibrino-peptide A (FpA) or modified anti-thrombin III (ATM) assays were performed in either (9:1) non anti-coagulated blood contrast materials mixtures or blood-glucose mixtures (control). Differing aPTT prolongation profiles were observed when clotting factors V, VIII, XI and XII were lowered in the plasma. However, neither iopamidol not amidotrizoate induced an aPTT prolongation with decreasing clotting factor II. In the second experiment no significant thrombin generation was observed as both blood - contrast materials mixtures showed significantly lower FpA and ATM levels (p < 0.001) than glucose control after 5 minutes and 10 minutes incubation at room temperature. These findings provide evidence that the use of iopamidol in angiographic procedures does not increase risk of clotting or hemorrhage. (author)

  2. Effect of the oral thrombin inhibitor dabigatran on allergic lung inflammation induced by repeated house dust mite administration in mice.

    Science.gov (United States)

    de Boer, Johannes D; Berkhout, Lea C; de Stoppelaar, Sacha F; Yang, Jack; Ottenhoff, Roelof; Meijers, Joost C M; Roelofs, Joris J T H; van't Veer, Cornelis; van der Poll, Tom

    2015-10-15

    Asthma is a chronic disease of the airways; asthma patients are hampered by recurrent symptoms of dyspnoea and wheezing caused by bronchial obstruction. Most asthma patients suffer from chronic allergic lung inflammation triggered by allergens such as house dust mite (HDM). Coagulation activation in the pulmonary compartment is currently recognized as a feature of allergic lung inflammation, and data suggest that coagulation proteases further drive inflammatory mechanisms. Here, we tested whether treatment with the oral thrombin inhibitor dabigatran attenuates allergic lung inflammation in a recently developed HDM-based murine asthma model. Mice were fed dabigatran (10 mg/g) or placebo chow during a 3-wk HDM airway exposure model. Dabigatran treatment caused systemic thrombin inhibitory activity corresponding with dabigatran levels reported in human trials. Surprisingly, dabigatran did not lead to inhibition of HDM-evoked coagulation activation in the lung as measured by levels of thrombin-antithrombin complexes and D-dimer. Repeated HDM administration caused an influx of eosinophils and neutrophils into the lungs, mucus production in the airways, and a T helper 2 response, as reflected by a rise in bronchoalveolar IL-4 and IL-5 levels and a systemic rise in IgE and HDM-IgG1. Dabigatran modestly improved HDM-induced lung pathology (P < 0.05) and decreased IL-4 levels (P < 0.01), without influencing other HDM-induced responses. Considering the limited effects of dabigatran in spite of adequate plasma levels, these results argue against clinical evaluation of dabigatran in patients with asthma. PMID:26320153

  3. The hemostatic profile of recombinant activated factor VII. Can low concentrations stop bleeding in off-label indications?

    Directory of Open Access Journals (Sweden)

    de Lourdes Herrera Maria

    2010-05-01

    Full Text Available Abstract Background High concentrations of recombinant activated factor VII (rFVIIa can stop bleeding in hemophilic patients. However the rFVIIa dose needed for stopping haemhorrage in off-label indications is unknown. Since thrombin is the main hemostatic agent, this study investigated the effect of rFVIIa and tissue factor (TF on thrombin generation (TG in vitro. Methods Lag time (LT, time to peak (TTP, peak TG (PTG, and area under the curve after 35 min (AUCo-35 min with the calibrated automated thrombography was used to evaluate TG. TG was assayed in platelet-rich plasma (PRP samples from 29 healthy volunteers under basal conditions and after platelet stimulation with 5.0 ?g/ml, 2.6 ?g/ml, 0.5 ?g/ml, 0.25 ?g/ml, and 0.125 ?g/ml rFVIIa alone and in normal platelet-poor plasma (PPP samples from 22 healthy volunteers, rFVIIa in combination with various concentrations of TF (5.0, 2.5, 1.25 and 0.5 pM. Results In PRP activated by rFVIIa, there was a statistically significant increase in TG compared to basal values. A significant TF dose-dependent shortening of LT and increased PTG and AUCo?35 min were obtained in PPP. The addition of rFVIIa increased the effect of TF in shorting the LT and increasing the AUCo?35 min with no effect on PTG but were independent of rFVIIa concentration. Conclusion Low concentrations of rFVIIa were sufficient to form enough thrombin in normal PRP or in PPP when combined with TF, and suggest low concentrations for normalizing hemostasis in off-label indications.

  4. Challenges of the management of severe hemophilia A with inhibitors: two case reports emphasizing the potential interest of a high-purity human Factor VIII/von Willebrand factor concentrate and individually tailored prophylaxis guided by thrombin-generation test.

    Science.gov (United States)

    Mathieu, Sophie; Crampe, Carine; Dargaud, Yesim; Lavigne-Lissalde, Géraldine; Escuriola-Ettingshausen, Carmen; Tardy, Brigitte; Meley, Roland; Thouvenin, Sandrine; Stephan, Jean L; Berger, Claire

    2015-12-01

    Severe hemophilia A is an X-linked bleeding disorder. Immune tolerance induction (ITI) is the best strategy of treatment when patients develop inhibitors. The objective is to illustrate the benefit of a high-purity human factor VIII/von Willebrand factor (VWF) concentrate (Octanate) in the management of ITI. We also wanted to raise the potential interest of laboratory assays such as thrombin-generation test (TGT) and epitope mapping. Two patients were treated during ITI, first with a recombinant FVIII and then with plasma-derived factor VIII without success, and, finally, with Octanate. Bypassing agents were used based on the results of TGT. Epitope mapping was performed during ITI therapy. These observations suggest the potential contribution of Octanate in the management of ITI in difficult cases. The use of bypassing agents can be necessary in prophylaxis or to treat bleedings, and may be guided by TGT results. Epitope mapping is used to describe the inhibitor. This article shows a decrease of the inhibitor directed against the C2 domain after initiation of Octanate. A high-purity human factor VIII/von Willebrand factor concentrate (Octanate) may be a valuable therapeutical option for ITI therapy. TGT and epitope mapping could be of help in the management of ITI. PMID:26517064

  5. In vitro assessment of Tc-99m labeled bovine thrombin and streptokinase-activated human plasmin: concise communication

    International Nuclear Information System (INIS)

    Bovine thrombin and streptokinase-activated human plasmin have been labeled with Tc-99m using stannous reduction of pertechnetate under physiological conditions (pH 7.4). The binding efficiency of radiotechnetium to these enzymes is greater than 94%, with less than 5% of reduced but unbound Tc-99m (Sn) complex as assayed by ascending paper radiochromatography using ITLC silica gel plate. Free or unbound pertechnetate is less than 1%. In vitro enzymatic analyses of the Tc-99m-labeled enzymes demonstrate no evidence of protein denaturation or significant loss of enzymatic activity after labeling. Both labeled enzymes are biochemically active in vitro with their respective substrates

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

    OpenAIRE

    A.V Pérez; 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 ...

  7. Percutaneous Thrombin Injection of a Femoral Artery Pseudoaneurysm with Simultaneous Venous Balloon Occlusion of a Communicating Arteriovenous Fistula

    International Nuclear Information System (INIS)

    An 82-year-old woman developed acute occlusion of her right coronary artery. She underwent percutaneous coronary stent placement and aortic balloon pump installation. In the postprocedural period, she developed a common femoral artery pseudoaneurysm (PSA) that communicated with the common femoral vein via an arteriovenous fistula (AVF). After unsuccessful ultrasound-guided compression, ultrasound-guided thrombin injection of the PSA was performed, with simultaneous balloon occlusion of the common femoral vein at the level of the AVF. There was complete thrombosis of the PSA and AVF.

  8. Selected topics in radiation dosimetry

    International Nuclear Information System (INIS)

    This report describes four topics, three of which ultimately have found much interest among dosimetrists. The first topic is dedicated to lyoluminescence, a dosimetric method developed on the fact, that dissolving of irradiated inorganic or organic solids in a suitable solvent is accompanied by the emission of light, the amount of which is proportional to the radiation energy absorbed within the solids. The method finds so much attention in particular, because it allows to obtain mixtures of organics with solvents, that exhibit very close tissue equivalence over a wide range of photon energies and also is very suited for neutron dosimetry. The second topic is on passive solid state radiation dosimetry or radiation induced thermally activated current effects, which turned out to be a very sensitive dosimetric method and has led to the development of ultra high purity sapphire dosimeters of high reliability. The third topic concerns the calibration of ionization chambers in units of absorbed dose, avoiding the transformation of the results of exposure measurements into absorbed dose data by utilizing conversion factors. Ionization chambers properly calibrated in units of absorbed dose serve much to simplify dose assessment in tissue equivalent material or in living tissue. The forth topic finally deals with the application of miniature TL-dosimeters in the determination of phosphate diffusion in sediments, work, which has been performed at the European Joint Research Center Ispra recently. (orig.)

  9. Topical agents in burn care

    Directory of Open Access Journals (Sweden)

    Mom?ilovi? Dragan

    2002-01-01

    Full Text Available Introduction Understanding of fluid shifts and recognition of the importance of early and appropriate fluid replacement therapy have significantly reduced mortality in the early post burn period. After the bum patient successfully passes the resuscitation period, the burn wound represents the greatest threat to survival. History Since the dawn of civilization, man has been trying to find an agent which would help burn wounds heal, and at the same time, not harm general condition of the injured. It was not until the XX century, after the discovery of antibiotics, when this condition was fulfilled. In 1968, combining silver and sulfadiazine, fox made silver-sulfadiazine, which is a 1% hydro-soluble cream and a superior agent in topical treatment of burns today. Current topical agents None of the topical antimicrobial agents available today, alone or combined, have the characteristics of ideal prophylactic agents, but they eliminate colonization of burn wound, and invasive infections are infrequent. With an excellent spectrum of activity, low toxicity, and ease of application with minimal pain, silver-sulfadiazine is still the most frequently used topical agent. Conclusion The incidence of invasive infections and overall mortality have been significantly reduced after introduction of topical burn wound antimicrobial agents into practice. In most burn patients the drug of choice for prophylaxis is silver sulfadiazine. Other agents may be useful in certain clinical situations.

  10. Quantum mechanics II advanced topics

    CERN Document Server

    Rajasekar, S

    2015-01-01

    Quantum Mechanics II: Advanced Topics uses more than a decade of research and the authors’ own teaching experience to expound on some of the more advanced topics and current research in quantum mechanics. A follow-up to the authors introductory book Quantum Mechanics I: The Fundamentals, this book begins with a chapter on quantum field theory, and goes on to present basic principles, key features, and applications. It outlines recent quantum technologies and phenomena, and introduces growing topics of interest in quantum mechanics. The authors describe promising applications that include ghost imaging, detection of weak amplitude objects, entangled two-photon microscopy, detection of small displacements, lithography, metrology, and teleportation of optical images. They also present worked-out examples and provide numerous problems at the end of each chapter.

  11. Metabolism-directed optimization of 3-aminopyrazinone acetamide thrombin inhibitors. Development of an orally bioavailable series containing P1 and P3 pyridines.

    Science.gov (United States)

    Burgey, Christopher S; Robinson, Kyle A; Lyle, Terry A; Sanderson, Philip E J; Lewis, S Dale; Lucas, Bobby J; Krueger, Julie A; Singh, Rominder; Miller-Stein, Cynthia; White, Rebecca B; Wong, Bradley; Lyle, Elizabeth A; Williams, Peter D; Coburn, Craig A; Dorsey, Bruce D; Barrow, James C; Stranieri, Maria T; Holahan, Marie A; Sitko, Gary R; Cook, Jacquelynn J; McMasters, Daniel R; McDonough, Colleen M; Sanders, William M; Wallace, Audrey A; Clayton, Franklin C; Bohn, Dennis; Leonard, Yvonne M; Detwiler, Theodore J; Lynch, Joseph J; Yan, Youwei; Chen, Zhongguo; Kuo, Lawrence; Gardell, Stephen J; Shafer, Jules A; Vacca, Joseph P

    2003-02-13

    Recent efforts in the field of thrombin inhibitor research have focused on the identification of compounds with good oral bioavailability and pharmacokinetics. In this manuscript we describe a metabolism-based approach to the optimization of the 3-(2-phenethylamino)-6-methylpyrazinone acetamide template (e.g., 1) which resulted in the modification of each of the three principal components (i.e., P1, P2, P3) comprising this series. As a result of these studies, several potent thrombin inhibitors (e.g., 20, 24, 25) were identified which exhibit high levels of oral bioavailability and long plasma half-lives. PMID:12570369

  12. Urokinase-mediated fibrinolysis in the synovial fluid of rheumatoid arthritis patients may be affected by the inactivation of single chain urokinase type plasminogen activator by thrombin

    OpenAIRE

    Braat, E; Jie, A; Ronday, H; Beekman, B; Rijken, D.

    2000-01-01

    BACKGROUND—Excessive fibrin deposition within the inflamed joints of rheumatoid arthritis (RA) patients suggests that local fibrinolysis is inefficient, which seems to be in contrast with the observed increased levels of urokinase type plasminogen activator (u-PA). Thrombin-mediated inactivation of single chain u-PA (scu-PA) into an inactive form called thrombin-cleaved two chain u-PA (tcu-PA/T) may provide a possible explanation for this contradiction.?AIM—To assess the occurrence of tcu-PA/...

  13. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    The Fourth International Conference on selected topics in nuclear structure was held at Dubna in July 1994 on recent experimental and theoretical investigations in nuclear structure. Topics discussed were the following: nuclear structure at low-energy excitations (collective quasiparticle phenomena, proton-neutron interactions, microscopic and phenomenological theories of nuclear structure; nuclear structure studies with charged particles. heavy ions, neutrons and photons; nuclei at high angular momenta and superdeformation, structure and decay properties of giant resonances, charge-exchange resonances and β-decay; semiclassical approach of large amplitude collective motion and structure of hot nuclei

  14. Topics in millimeter wave technology

    CERN Document Server

    Button, Kenneth

    1988-01-01

    Topics in Millimeter Wave Technology, Volume 1 presents topics related to millimeter wave technology, including fin-lines and passive components realized in fin-lines, suspended striplines, suspended substrate microstrips, and modal power exchange in multimode fibers. A miniaturized monopulse assembly constructed in planar waveguide with multimode scalar horn feeds is also described. This volume is comprised of five chapters; the first of which deals with the analysis and synthesis techniques for fin-lines as well as the various passive components realized in fin-line. Tapers, discontinuities,

  15. Hadron Correlations and Parton Recombination

    OpenAIRE

    Fries, Rainer J.(Cyclotron Institute, Department of Physics & Astronomy, Texas A&M University, College Station, TX, 77843-3366, USA)

    2007-01-01

    Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.

  16. Purification, crystallization and preliminary X-ray diffraction analysis of saxthrombin, a thrombin-like enzyme from Gloydius saxatilis venom

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Wenqing; Zhao, Wei [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230027 (China); Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230027 (China); Wang, Xiaoping [National Conservation of Snake Island and Laotieshan Mountain, Dalian, Liaoning, 116041 (China); Teng, Maikun, E-mail: mkteng@ustc.edu.cn; Niu, Liwen, E-mail: mkteng@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230027 (China); Key Laboratory of Structural Biology, Chinese Academy of Sciences, 96 Jinzhai Road, Hefei, Anhui 230027 (China)

    2007-08-01

    The thrombin-like enzyme saxthrombin has been purified from G. saxatilis snake venom. Crystallization conditions were found and a data set was obtained to 1.43 Å. The snake-venom thrombin-like enzymes (SVTLEs) are a class of serine proteinases that show fibrinogen-clotting and esterolytic activities. Most TLEs convert fibrinogen to fibrin by releasing either fibrinopeptide A or fibrinopeptide B and cannot activate factor XIII. The enzymes hydrolyze fibrinogen to produce non-cross-linked fibrins, which are susceptible to the lytic action of plasmin. Because of these physiological properties, TLEs have important medical applications in myocardial infarction, ischaemic stroke and thrombotic diseases. Here, a three-step chromatography procedure was used to purify saxthrombin (AAP20638) from Gloydius saxatilis venom to homogeneity. Its molecular weight is about 30 kDa as estimated by SDS–PAGE. A saxthrombin crystal was obtained using the hanging-drop vapour-diffusion method and diffracted to a resolution limit of 1.43 Å. The crystal belongs to space group C2, with unit-cell parameters a = 97.23, b = 52.21, c = 50.10 Å, β = 96.72°, and the Matthews coefficient (V{sub M}) was calculated to be 2.13 Å{sup 3} Da{sup −1} with one molecule in the asymmetric unit.

  17. 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.

  18. 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. PMID:17994164

  19. Thrombin-mediated ratiometric two-photon fluorescent probe for selective imaging of endogenous ultratrace glutathione in platelet.

    Science.gov (United States)

    Zhang, Hua; Wang, Caixia; Wang, Ge; Wang, Kui; Jiang, Kai

    2016-04-15

    Ultratrace change of reduced glutathione (GSH) can weaken coagulation function of platelet (PLT). Thus, rapid and sensitive imaging of GSH specific in PLT is beneficial for monitoring coagulation function of PLT. Many fluorescent probes for GSH have been reported, but ratio fluorescent probe with excellent two-photon property for screening PLT from peripheral blood and quantitative imaging of GSH are scarce. In this work, a thrombin-mediated two-photon GSH-specific fluorescent probe (IQDC-L) was reported. Sulfuric diamide, a key group as linker, was introduced into IQDC-L, which resulted in not only specific selectivity for GSH, but also FRET occurring in probe. When IQDC-L encountered GSH, "S-N" in sulfonamide group was cut off, and FRET was inhibited. Furthermore, fluorescence intensities at 520 and 595nm presented linear change on ratio mode in the range of GSH (2.0-65nM). The lowest detection for GSH was as low as 0.083nM. Intriguingly, IQDC-L under thrombin-mediated was able to screen PLT from peripheral blood without any interference. Thus, IQDC-L could be used to screen PLT from peripheral blood, and simultaneously, to in situ image ultratrace GSH. PMID:26649492

  20. Purification, crystallization and preliminary X-ray diffraction analysis of saxthrombin, a thrombin-like enzyme from Gloydius saxatilis venom

    International Nuclear Information System (INIS)

    The thrombin-like enzyme saxthrombin has been purified from G. saxatilis snake venom. Crystallization conditions were found and a data set was obtained to 1.43 Å. The snake-venom thrombin-like enzymes (SVTLEs) are a class of serine proteinases that show fibrinogen-clotting and esterolytic activities. Most TLEs convert fibrinogen to fibrin by releasing either fibrinopeptide A or fibrinopeptide B and cannot activate factor XIII. The enzymes hydrolyze fibrinogen to produce non-cross-linked fibrins, which are susceptible to the lytic action of plasmin. Because of these physiological properties, TLEs have important medical applications in myocardial infarction, ischaemic stroke and thrombotic diseases. Here, a three-step chromatography procedure was used to purify saxthrombin (AAP20638) from Gloydius saxatilis venom to homogeneity. Its molecular weight is about 30 kDa as estimated by SDS–PAGE. A saxthrombin crystal was obtained using the hanging-drop vapour-diffusion method and diffracted to a resolution limit of 1.43 Å. The crystal belongs to space group C2, with unit-cell parameters a = 97.23, b = 52.21, c = 50.10 Å, β = 96.72°, and the Matthews coefficient (VM) was calculated to be 2.13 Å3 Da−1 with one molecule in the asymmetric unit

  1. 3D photonic crystal-based biosensor functionalized with quantum dot-based aptamer for thrombine detection

    Science.gov (United States)

    Lim, Chae Young; Choi, Eunpyo; Park, Youngkyu; Park, Jungyul

    2013-05-01

    In this paper, we propose a new technique for protein detection by using the enhancement of intensity in quantum dots (Qdot) whose emission is guided by 3D photonic crystal (PC) structures. For easy to use, we design the emitted light from the sensor can be recovered, when the chemical antibody (aptamer) conjugated with guard DNA (g-DNA) labeled with a quencher (Black FQ) hybridizes with the target proteins. In detail, we synthesis a Qdot-aptamer complex and then immobilize these complex on the PC surfaces. Next, we perform the hybridization of the Qdot-aptamer complex with g-DNA labeled with the quencher. It induces the quenching effect of fluoresce intensity in the Qdot-aptamer. In presence of target protein (thrombin), the Qdot-aptamer complex prefers to form the thrombin-aptamer complex: this results in the release of Black FQ-g-DNA and the quenched light intensity recovers into the original high intensity with Qdot. The intensity recovery varies quantitatively according to the level of the target protein concentration. This proposed sensor shows much higher detection sensitivity than the general fluorescent detection mechanism, which is functionalized on the flat surfaces because of the light guiding effect from 3D photonic crystal structures.

  2. Recombinant protein scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    New biological materials for tissue engineering are now being developed using common genetic engineering capabilities to clone and express a variety of genetic elements that allow cost-effective purification and scaffold fabrication from these recombinant proteins, peptides or from chimeric combinations of these. The field is limitless as long as the gene sequences are known. The utility is dependent on the ease, product yield and adaptability of these protein products to the biomedical field. The development of recombinant proteins as scaffolds, while still an emerging technology with respect to commercial products, is scientifically superior to current use of natural materials or synthetic polymer scaffolds, in terms of designing specific structures with desired degrees of biological complexities and motifs. In the field of tissue engineering, next generation scaffolds will be the key to directing appropriate tissue regeneration. The initial period of biodegradable synthetic scaffolds that provided shape and mechanical integrity, but no biological information, is phasing out. The era of protein scaffolds offers distinct advantages, particularly with the combination of powerful tools of molecular biology. These include, for example, the production of human proteins of uniform quality that are free of infectious agents and the ability to make suitable quantities of proteins that are found in low quantity or are hard to isolate from tissue. For the particular needs of tissue engineering scaffolds, fibrous proteins like collagens, elastin, silks and combinations of these offer further advantages of natural well-defined structural scaffolds as well as endless possibilities of controlling functionality by genetic manipulation. (topical review)

  3. Topics in optics and music

    Science.gov (United States)

    Sparks, Andrew W.

    2012-10-01

    While the use of optics in the playback of music has been a tremendously successful technology and laser light shows are a common occurrence, other intersections of optics and music tend to be less well known. Topics such as optics-based instruments, performance tools and effects, instrument characterization and manufacturing, recording, playback, and signal processing are explored.

  4. Seven topics in perturbative QCD

    International Nuclear Information System (INIS)

    The following topics of perturbative QCD are discussed: (1) deep inelastic scattering; (2) higher order corrections to e+e- annihilation, to photon structure functions and to quarkonia decays; (3) higher order corrections to fragmentation functions and to various semi-inclusive processes; (4) higher twist contributions; (5) exclusive processes; (6) transverse momentum effects; (7) jet and photon physics

  5. Two topics in quantum chromodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Bjorken, J.D.

    1989-12-01

    The two topics are (1) estimates of perturbation theory coefficients for R(e{sup +}e{sup -} {yields} hadrons), and (2) the virtual-photon structure function, with emphasis on the analytic behavior in its squared mass. 20 refs., 4 figs., 2 tabs.

  6. Topics in Mitigating Radar Bias

    CERN Document Server

    Serakos, Demetrios; Youssef, Hazim

    2008-01-01

    In this paper, we investigate two topics related to mitigating the effect of radar bias in ballistic missile tracking applications. We determine the absolute bias between two radars in polar coordinates when their relative bias is given in rectangular coordinates. Using this result, we then obtain the optimized steady-state filter to handle the random bias.

  7. Selected topics in nuclear structure

    International Nuclear Information System (INIS)

    19. winter school in Zakopane was devoted to selected topics in nuclear structure such as: production of spin resonances, heavy ions reactions and their applications to the investigation of high spin states, octupole deformations, excited states and production of new elements etc. The experimental data are ofen compared with theoretical predictions. Report contains 28 papers. (M.F.W.)

  8. Topic Map for Authentic Travel

    OpenAIRE

    Wandsvik,Atle; Zare, Mehdi

    2007-01-01

    E-business is a new trend in Internet use. Authentic travel is an approach to travel and travel business which helps the traveler experience what is authentic in the travel destination. But how can the traveler find those small authentic spots and organize them together to compose a vacation? E-business techniques, combined withTopic Maps, can help.

  9. Topics on Galactic Chemical Evolution

    OpenAIRE

    Prantzos, Nikos

    2011-01-01

    I discuss three different topics in Galactic chemical evolution:the "puzzling" absence of any observational signature of secondary elements ; the building of the Galactic halo in the framework of hierarchical galaxy formation, as evidenced from its metallicity distribution ; and the potentially important role that radial migration may play in the evolution of galactic disks, according to recent studies.

  10. Psoriasis: consensus on topical therapies

    DEFF Research Database (Denmark)

    van de Kerkhof, P C M; Barker, J; Griffiths, C E M; Kragballe, K; Mason, J; Menter, A; Papp, K

    2008-01-01

    Objective A consensus conference was convened to evaluate the topical treatment of psoriasis. Participants Members of the International Psoriasis Council (IPC) with broad clinical experience in the treatment of psoriasis and a specialist in meta- and pharmacoeconomic analyses were invited to...

  11. The pharmacology of topical analgesics.

    Science.gov (United States)

    Barkin, Robert L

    2013-07-01

    Pain management of patients continues to pose challenges to clinicians. Given the multiple dimensions of pain--whether acute or chronic, mild, moderate, or severe, nociceptive or neuropathic--a multimodal approach may be needed. Fortunately, clinicians have an array of nonpharmacologic and pharmacologic treatment choices; however, each modality must be chosen carefully, because some often used oral agents are associated with safety and tolerability issues that restrict their use in certain patients. In particular, orally administered nonsteroidal antiinflammatory drugs, opioids, antidepressants, and anticonvulsants are known to cause systemic adverse effects in some patients. To address this problem, a number of topical therapies in various therapeutic classes have been developed to reduce systemic exposure and minimize the risks of patients developing adverse events. For example, topical nonsteroidal anti-inflammatory drug formulations produce a site-specific effect (ie, cyclo-oxygenase inhibition) while decreasing the systemic exposure that may lead to undesired effects in patients. Similarly, derivatives of acetylsalicylic acid (ie, salicylates) are used in topical analgesic formulations that do not significantly enter the patient's systemic circulation. Salicylates, along with capsaicin, menthol, and camphor, compose the counterirritant class of topical analgesics, which produce analgesia by activating and then desensitizing epidermal nociceptors. Additionally, patches and creams that contain the local anesthetic lidocaine, alone or co-formulated with other local anesthetics, are also used to manage patients with select acute and chronic pain states. Perhaps the most common topical analgesic modality is the cautious application of cutaneous cold and heat. Such treatments may decrease pain not by reaching the target tissue through systemic distribution, but by acting more directly on the affected tissue. Despite the tolerability benefits associated with avoiding systemic circulation, topically applied analgesics are associated with application-site reactions in patients, such as dryness, erythema, burning, and discoloration. Furthermore, some adverse events that have been observed in patients may be suggestive of some degree of systemic exposure. This article reviews the mechanisms of action, pharmacokinetics, and tolerability of topical treatments for the management of patient pain. PMID:24547599

  12. Delayed recombination and standard rulers

    International Nuclear Information System (INIS)

    Measurements of baryonic acoustic oscillations (BAOs) in galaxy surveys have been recognized as a powerful tool for constraining dark energy. However, this method relies on the knowledge of the size of the acoustic horizon at recombination derived from cosmic microwave background (CMB) anisotropy measurements. This estimate is typically derived assuming a standard recombination scheme; additional radiation sources can delay recombination altering the cosmic ionization history and the cosmological inferences drawn from CMB and BAO data. In this paper we quantify the effect of delayed recombination on the determination of dark energy parameters from future BAO surveys such as the Baryon Oscillation Spectroscopic Survey and the Wide-Field Multi-Object Spectrograph. We find the impact to be small but still not negligible. In particular, if recombination is nonstandard (to a level still allowed by CMB data), but this is ignored, future surveys may incorrectly suggest the presence of a redshift-dependent dark energy component. On the other hand, in the case of delayed recombination, adding to the analysis one extra parameter describing deviations from standard recombination does not significantly degrade the error bars on dark energy parameters and yields unbiased estimates. This is due to the CMB-BAO complementarity.

  13. Iodine chemistry in hydrogen recombiners

    International Nuclear Information System (INIS)

    Hydrogen recombiners, recently introduced in the French nuclear reactor buildings, display high temperature (up to about 900 deg. C) and several thousands square meters of a very reactive surface when operating during a severe accident scenario. Small scale analytical experiments show that cesium and cadmium iodides are unstable, and generate volatile iodine, when heated in an oven that reproduces most physico-chemical parameters of recombiner operation. Based on these results, and due to its potential with regard to the environmental source term of a severe accident, iodine chemistry in hydrogen recombiners deserves close and careful scrutiny. (authors)

  14. Recombining WMAP: constraints on ionizing and resonance radiation at recombination

    OpenAIRE

    Bean, Rachel; Melchiorri, Alessandro; Silk, Joe

    2003-01-01

    We place new constraints on sources of ionizing and resonance radiation at the epoch of the recombination process using the recent CMB temperature and polarization spectra coming from WMAP. We find that non-standard recombination scenarios are still consistent with the current data. In light of this we study the impact that such models can have on the determination of several cosmological parameters. In particular, the constraints on curvature and baryon density appear to be...

  15. 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

    Ro?. 42, ?. 9 (2012), s. 610-620. ISSN 0965-1748 R&D Projects: GA ?R 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

  16. Stimulation of phosphate uptake in human platelets by thrombin and collagen. Changes in specific 32P labeling of metabolic ATP and polyphosphoinositides

    International Nuclear Information System (INIS)

    The uptake of [32P]phosphate by human, gel-filtered blood platelets and its incorporation into cytoplasmic ATP and polyphosphoinositides was studied. In unstimulated platelets, uptake was Na+o-dependent and saturable at approximately 20 nmol/min/10(11) cells with a half-maximal rate at 0.5 mM extracellular phosphate. Upon stimulation with thrombin or collagen, net influx of [32P]Pi was accelerated 5- to 10-fold. With thrombin, [32P]Pi efflux was also increased. After the first 2 min, efflux exceeded influx, resulting in the net release of [32P]Pi from the platelets. Since the stimulus-induced burst in [32P]Pi uptake paralleled the secretory responses, it might be an integral part of stimulus-response coupling in platelets. The stimulus-induced burst in net [32P]Pi uptake led to an enhanced labeling of metabolic ATP, which was already detectable at 5 s after stimulation with thrombin. Concomitantly, the incorporation of [32P]Pi into phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate was accelerated. The thrombin-induced increase in specific 32P radioactivity of cytoplasmic ATP fully accounted for the simultaneous increase in specific 32P radioactivity of these phosphoinositides. In studying the extent of 32P labeling of phosphorylated compounds in response to a cellular stimulus, it is therefore essential to measure the effect of the stimulus on the specific radioactivity of cytoplasmic ATP

  17. Retapamulin: A newer topical antibiotic

    Directory of Open Access Journals (Sweden)

    D Dhingra

    2013-01-01

    Full Text Available Impetigo is a common childhood skin infection. There are reports of increasing drug resistance to the currently used topical antibiotics including fusidic acid and mupirocin. Retapamulin is a newer topical agent of pleuromutilin class approved by the Food and Drug Administration for treatment of impetigo in children and has been recently made available in the Indian market. It has been demonstrated to have low potential for the development of antibacterial resistance and a high degree of potency against poly drug resistant Gram-positive bacteria found in skin infections including Staphylococcus aureus strains. The drug is safe owing to low systemic absorption and has only minimal side-effect of local irritation at the site of application.

  18. Ethical use of topical corticosteroids

    Directory of Open Access Journals (Sweden)

    Abir Saraswat

    2014-01-01

    Full Text Available Dermatologists rely very heavily on corticosteroids for treating many common dermatoses. Concerns about their incorrect use are widely expressed both in lay public and specialist discourse. From the point of view of medical ethics, issues of autonomy, beneficence and non-maleficence are all raised frequently when we prescribe topical corticosteroids to our patients. We need to be aware of situations when conflicts between these issues arise and have a clear thought process about resolving them. This can only be achieved if we have a thorough understanding of the skin disease being treated coupled with expertise in the use of the varied potencies and available dosage forms of topical corticosteroids. A good understanding of human psychology and effective communication is also needed to use these agents optimally.

  19. Do scientists trace hot topics?

    CERN Document Server

    Wei, Tian; Wu, Chensheng; Yan, XiaoYong; Fan, Ying; Di, Zengru; Wu, Jinshan

    2013-01-01

    Do scientists follow hot topics in their scientific investigations? In this paper, by performing analysis to papers published in the American Physical Society (APS) Physical Review journals, it is found that papers are more likely to be attracted by hot fields, where the hotness of a field is measured by the number of papers belonging to the field. This indicates that scientists generally do follow hot topics. However, there are qualitative differences among scientists from various countries, among research works regarding different number of authors, different number of affiliations and different number of references. These observations could be valuable for policy makers when deciding research funding and also for individual researchers when searching for scientific projects.

  20. Recombineering: genetic engineering in bacteria using homologous recombination.

    Science.gov (United States)

    Thomason, Lynn C; Sawitzke, James A; Li, Xintian; Costantino, Nina; Court, Donald L

    2014-01-01

    The bacterial chromosome and bacterial plasmids can be engineered in vivo by homologous recombination using PCR products and synthetic oligonucleotides as substrates. This is possible because bacteriophage-encoded recombination proteins efficiently recombine sequences with homologies as short as 35 to 50 bases. Recombineering allows DNA sequences to be inserted or deleted without regard to location of restriction sites. This unit first describes preparation of electrocompetent cells expressing the recombineering functions and their transformation with dsDNA or ssDNA. It then presents support protocols that describe several two-step selection/counter-selection methods of making genetic alterations without leaving any unwanted changes in the targeted DNA, and a method for retrieving onto a plasmid a genetic marker (cloning by retrieval) from the Escherichia coli chromosome or a co-electroporated DNA fragment. Additional protocols describe methods to screen for unselected mutations, removal of the defective prophage from recombineering strains, and other useful techniques. Curr. Protoc. Mol. Biol. 106:1.16.1-1.16.39. © 2014 by John Wiley & Sons, Inc. PMID:24733238

  1. Topics in clinical oncology. 15

    International Nuclear Information System (INIS)

    The monograph comprising primarily papers on topical subjects of oncology and cancer research, contains also a selection of papers presented at the 2. Congress of the Czechoslovak Society of Nuclear Medicine and Radiation Hygiene. Seven papers were selected on behalf of their subject related to clinical oncology. All of them were iputted in INIS; five of them deal with the scintiscanning of the skeleton of cancer patients, one with radioimmunodetection of tumors, and one with radionuclide lymphography. (A.K.)

  2. Probabilistic analysis and related topics

    CERN Document Server

    Bharucha-Reid, A T

    1983-01-01

    Probabilistic Analysis and Related Topics, Volume 3 focuses on the continuity, integrability, and differentiability of random functions, including operator theory, measure theory, and functional and numerical analysis. The selection first offers information on the qualitative theory of stochastic systems and Langevin equations with multiplicative noise. Discussions focus on phase-space evolution via direct integration, phase-space evolution, linear and nonlinear systems, linearization, and generalizations. The text then ponders on the stability theory of stochastic difference systems and Marko

  3. Topics in Local Economic Development

    OpenAIRE

    Bubbico, Antonio

    2014-01-01

    This thesis contributes to the current debate in literature about local economic development by considering two different topics: quality of institutions, and the role of clusters in innovation and productivity growth. The research is built upon three papers. The first paper deals with the analysis of the effect of administrative continuity on administrative efficiency. The analysis underlines the importance of different typologies of social capital. Findings reveal a positive impact on ...

  4. Topical Ocular Delivery of NSAIDs

    OpenAIRE

    Ahuja, Munish; Dhake, Avinash S.; Sharma, Surendra K; Dipak K. Majumdar

    2008-01-01

    In ocular tissue, arachidonic acid is metabolized by cyclooxygenase to prostaglandins which are the most important lipid derived mediators of inflammation. Presently nonsteroidal anti-inflammatory drugs (NSAIDs) which are cyclooxygenase (COX) inhibitors are being used for the treatment of inflammatory disorders. NSAIDs used in ophthalmology, topically, are salicylic-, indole acetic-, aryl acetic-, aryl propionic- and enolic acid derivatives. NSAIDs are weak acids with pKa mostly between 3.5 a...

  5. Hot topics from the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Glenzinski, D.; /Fermilab

    2008-01-01

    The Tevatron Run-II began in March 2001. To date, both the CDF and D0 experiments have collected 1 fb{sup -1} of data each. The results obtained from this data set were summarized at this conference in 39 parallel session presentations covering a wide range of topics. The author summarizes the most important of those results here and comments on some of the prospects for the future.

  6. Topical Immunotherapy in Alopecia Areata

    OpenAIRE

    Singh, Gurcharan; Lavanya, MS

    2010-01-01

    Alopecia Areata (AA) is a common non-scarring alopecia directed against the anagenic hair follicle. Various treatment modalities have been used for the treatment of severe AA. Topical immunotherapy is the best documented treatment so far for severe and refractory AA. Dinitrochlorobenzene (DNCB), squaric acid dibutylester (SADBE), and diphencyprone (DPCP) are the contact allergens used for this purpose. DNCB has been found to be mutagenic by the Ames test and is largely replaced by DPCP and SA...

  7. Topics on electricity transmission pricing

    OpenAIRE

    Bjørndal, Mette

    2000-01-01

    The efficiency of the power market is heavily affected by the operation and pricing of the transmission system and the topic of this thesis concerns the interaction of the transmission network and the energy markets. After describing different power flow models, we provide an overview of models developed to efficiently coordinate the allocation of transmission resources. The focus is mainly on short-term efficiency, and the survey is only partial, but provides an integrated overview of some o...

  8. Optimization of the purification methods for recovery of recombinant growth hormone from Paralichthys olivaceus

    Science.gov (United States)

    Zang, Xiaonan; Zhang, Xuecheng; Mu, Xiaosheng; Liu, Bin

    2013-03-01

    This study aimed to optimize the purification of recombinant growth hormone from Paralichthys olivaceus. Recombinant flounder growth hormone (r-fGH) was expressed by Escherichia coli in form of inclusion body or as soluble protein under different inducing conditions. The inclusion body was renatured using two recovery methods, i.e., dilution and dialysis. Thereafter, the refolded protein was purified by Glutathione Sepharase 4B affinity chromatography and r-fGH was obtained by cleavage of thrombin. For soluble products, r-fGH was directly purified from the lysates by Glutathione Sepharase 4B affinity chromatography. ELISA-receptor assay demonstrated that despite its low receptor binding activity, the r-fGH purified from refolded inclusion body had a higher yield (2.605 mg L-1) than that from soluble protein (1.964 mg L-1). Of the tested recovery methods, addition of renaturing buffer (pH 8.5) into denatured inclusion body yielded the best recovery rate (17.9%). This work provided an optimized purification method for high recovery of r-fGH, thus contributing to the application of r-fGH to aquaculture.

  9. Stable recombination hotspots in birds.

    Science.gov (United States)

    Singhal, Sonal; Leffler, Ellen M; Sannareddy, Keerthi; Turner, Isaac; Venn, Oliver; Hooper, Daniel M; Strand, Alva I; Li, Qiye; Raney, Brian; Balakrishnan, Christopher N; Griffith, Simon C; McVean, Gil; Przeworski, Molly

    2015-11-20

    The DNA-binding protein PRDM9 has a critical role in specifying meiotic recombination hotspots in mice and apes, but it appears to be absent from other vertebrate species, including birds. To study the evolution and determinants of recombination in species lacking the gene that encodes PRDM9, we inferred fine-scale genetic maps from population resequencing data for two bird species: the zebra finch, Taeniopygia guttata, and the long-tailed finch, Poephila acuticauda. We found that both species have recombination hotspots, which are enriched near functional genomic elements. Unlike in mice and apes, most hotspots are shared between the two species, and their conservation seems to extend over tens of millions of years. These observations suggest that in the absence of PRDM9, recombination targets functional features that both enable access to the genome and constrain its evolution. PMID:26586757

  10. Hydrogen recombiner development at AECL

    International Nuclear Information System (INIS)

    Catalytic recombiners have been developed at AECL for the purpose of hydrogen removal in post-accident nuclear containment buildings. The recombiners are based on a particular catalyst designed by AECL which has extraordinary resistance to fouling from water and water vapour and a large thermodynamic range of operation. The catalysts were developed, originally, for the purpose of heavy water manufacturing by way of a catalytic exchange process. Application of these catalyst materials in recombiners for containment applications began in the late 1980's. The first application was a passive recombiner, qualified for use in control of radiolytic hydrogen in the headspace of a pool-type experimental reactor of AECL design in 1988. The passive, or natural convection recombiner concept has continued development to commercial stage for application in power reactor containments. This paper reviews the AECL recombiner development, describes the current model and shows results from tests of full-scale recombiners in the Large Scale Vented Combustion Test Facility at AECL-WL. The AECL recombiner is designed for compactness and ease of engineering into containment. The design is a simple, open-ended rectangular enclosure with catalyst elements arranged inside to promote optimum convective flow driven by heat of recombination at the catalyst surface. Self start, as evidenced by catalyst heating and initiation of flow, is achieved in less than 1% hydrogen, with available oxygen, at room temperature and 100% relative humidity. This low temperature start-up in condensing atmospheres is viewed as the most challenging condition for wet-proofing effectiveness. Cold start-up is a vital performance requirement in containments, such as CANDU, where engineered air-cooling systems are operating and where long-term hydrogen control is required, after containment atmospheres have cooled. Once started, the removal capacity scales linearly with the inlet cross-section area and the partial pressure of hydrogen. The recombiner also reacts carbon monoxide, in the presence of hydrogen, at approximately the same rate as the hydrogen. The catalyst materials and wet-proofing are unaffected by radiation or high temperatures. Large scale tests confirm self-start behavior and demonstrate strong mixing, irrespective of recombiner placement. (author)

  11. Progenitors of Recombining Supernova Remnants

    OpenAIRE

    Moriya, Takashi J.

    2012-01-01

    Usual supernova remnants have either ionizing plasma or plasma in collisional ionization equilibrium, i.e., the ionization temperature is lower than or equal to the electron temperature. However, the existence of recombining supernova remnants, i.e., supernova remnants with the ionization temperature higher than the electron temperature, is recently confirmed. One suggested way to have recombining plasma in a supernova remnant is to have a dense circumstellar medium at the t...

  12. Eukaryotes arose after genetic recombination

    Directory of Open Access Journals (Sweden)

    Stupar Milanko R.

    2006-01-01

    Full Text Available Division of ancestral prokaryotic pragenome into two circular double-stranded DNA molecules by genetic recombination, is a base for future separate evolution of nuclear and mitochondrial gene compartment. This suggests monophyletic origin of both, mitochondrion and nucleus. Presumed organism which genome undergoes genetic recombination has to be searched among an aerobic, oxygen nonproducing, archaeon with no rigid cell wall, but a plasma membrane. Plastid evolves from an aerobic, oxygen producing protoeukaryote, after mitoplastid genome duplication and subsequent functional segregation.

  13. Eculizumab therapy results in rapid and sustained decreases in markers of thrombin generation and inflammation in patients with PNH independent of its effects on hemolysis and microparticle formation.

    Science.gov (United States)

    Weitz, Ilene C; Razavi, Pedram; Rochanda, Leanne; Zwicker, Jeffrey; Furie, Bruce; Manly, David; Mackman, Nigel; Green, Ralph; Liebman, Howard A

    2012-09-01

    Paroxysmal Nocturnal Hemoglobinuria (PNH) is a clonal bone marrow disorder which results in the loss of glycosylphosphatidyl inositol (GPI) anchors from cell membranes. As a consequence, membrane inhibitors of complement are lost rendering the cells more susceptible to complement mediated destruction. This results in hemolysis, leukopenia, thrombocytopenia and thrombophilia. Eculizumab, a monoclonal antibody to complement protein 5, has been approved for the treatment of PNH and is associated with a significant reduction in hemolysis, thromboembolic events and fatigue. We prospectively studied the effect of Eculizumab therapy on plasma markers of thrombin generation (D-Dimers, TAT), inflammation (IL-6), soluble P-selectin (sP-selectin), antigenic (TFMP) and functional (fTFMP) tissue factor bearing microparticles and total plasma microparticle ex vivo factor Xa generation (MPFXa) in eleven Eculizumab naive PNH patients. Blood sampling occurred day 1, prior to Eculizumab treatment, then on days 8,15,22,29, 43, 90. Our results demonstrate a statistically significant reduction in D-Dimer, TAT, IL-6, sP-selectin, and TFMP during the induction phase of treatment (day 1-29) which was sustained during the maintenance treatment (day 29-90). Although the serum LDH levels decreased rapidly, there was no correlation between the change in LDH and the markers of thrombin generation and inflammation. Although there was a statistically significant decrease in TFMP, this decrease did not correlate with changes in markers of thrombin generation or inflammation. Ex vivo MPFXa generation did not decrease with Eculizumab treatment suggesting continued microparticle formation despite inhibition of hemolysis. Ex vivo total microparticle FXa generation was found to have an inverse correlation with markers of thrombin generation, suggesting that in PNH patients in vivo thrombin generation occurs by a pathway independent of hemolysis and microparticle generation. PMID:22542362

  14. Percutaneous treatment of femoral pseudoaneurysms: comparison of fibrin sealant against thrombin / Tratamento percutaneo do pseudoaneurisma femoral: comparacao entre selante de fibrina e trombina

    Scientific Electronic Library Online (English)

    Daniel Mendes, Pinto; Paulo, Bastianetto.

    2013-12-01

    Full Text Available INTRODUÇÃO: O pseudoaneurisma femoral é complicação descrita em até 8% dos procedimentos percutâneos. Dentre os tratamentos, a injeção de trombina guiada por ultrassom tem alta taxa de sucesso e boa tolerância pelos pacientes. O uso da trombina associada ao fibrinogênio, chamado selante de fibrina [...] , forma um coágulo estável que pode ser usado para o tratamento do pseudoaneurisma, principalmente aqueles de anatomia complexa e maiores. OBJETIVO: Comparar os resultados do tratamento do pseudoaneurisma femoral em dois grupos: Grupo T, tratado com trombina isoladamente, e Grupo T+F, tratado com selante de fibrina (trombina+fibrinogênio). MÉTODO: Análise retrospectiva dos casos de pseudoaneurisma femoral tratados entre janeiro/2005 e dezembro/2012. RESULTADOS: Foram tratados 28 pacientes, 21 com trombina isolada e sete com selante de fibrina. Houve sucesso no tratamento de todos os pacientes do grupo T e somente em quatro casos do grupo T+F (57,1% no Grupo T+F, p Abstract in english INTRODUCTION: Femoral pseudoaneurysms are a complication that occurs in connection with up to 8% of percutaneous procedures. Of the available treatments, ultrasound guided thrombin injection has a high success rate and is well-tolerated by patients. The combination of thrombin and fibrinogen known [...] as fibrin sealant forms a stable clot and can be used to treat pseudoaneurysms, particularly those with complex anatomy and larger size. OBJECTIVE: To compare the results of treating femoral pseudoaneurysm in two ways: Group T was treated with thrombin alone and Group T+F was treated with fibrin sealant (thrombin+fibrinogen). METHODS: A retrospective analysis was conducted of femoral pseudoaneurysm cases treated between January 2005 and December 2012. RESULTS: Twenty-eight patients were treated, 21 with thrombin alone and seven with fibrin sealant. All patients in group T were treated successfully, but only four patients in group T+F were treated successfully (57.1% success rate in Group T+F, p

  15. Percutaneous treatment of femoral pseudoaneurysms: comparison of fibrin sealant against thrombin / Tratamento percutaneo do pseudoaneurisma femoral: comparacao entre selante de fibrina e trombina

    Scientific Electronic Library Online (English)

    Daniel Mendes, Pinto; Paulo, Bastianetto.

    2013-10-21

    Full Text Available INTRODUÇÃO: O pseudoaneurisma femoral é complicação descrita em até 8% dos procedimentos percutâneos. Dentre os tratamentos, a injeção de trombina guiada por ultrassom tem alta taxa de sucesso e boa tolerância pelos pacientes. O uso da trombina associada ao fibrinogênio, chamado selante de fibrina [...] , forma um coágulo estável que pode ser usado para o tratamento do pseudoaneurisma, principalmente aqueles de anatomia complexa e maiores. OBJETIVO: Comparar os resultados do tratamento do pseudoaneurisma femoral em dois grupos: Grupo T, tratado com trombina isoladamente, e Grupo T+F, tratado com selante de fibrina (trombina+fibrinogênio). MÉTODO: Análise retrospectiva dos casos de pseudoaneurisma femoral tratados entre janeiro/2005 e dezembro/2012. RESULTADOS: Foram tratados 28 pacientes, 21 com trombina isolada e sete com selante de fibrina. Houve sucesso no tratamento de todos os pacientes do grupo T e somente em quatro casos do grupo T+F (57,1% no Grupo T+F, p Abstract in english INTRODUCTION: Femoral pseudoaneurysms are a complication that occurs in connection with up to 8% of percutaneous procedures. Of the available treatments, ultrasound guided thrombin injection has a high success rate and is well-tolerated by patients. The combination of thrombin and fibrinogen known [...] as fibrin sealant forms a stable clot and can be used to treat pseudoaneurysms, particularly those with complex anatomy and larger size. OBJECTIVE: To compare the results of treating femoral pseudoaneurysm in two ways: Group T was treated with thrombin alone and Group T+F was treated with fibrin sealant (thrombin+fibrinogen). METHODS: A retrospective analysis was conducted of femoral pseudoaneurysm cases treated between January 2005 and December 2012. RESULTS: Twenty-eight patients were treated, 21 with thrombin alone and seven with fibrin sealant. All patients in group T were treated successfully, but only four patients in group T+F were treated successfully (57.1% success rate in Group T+F, p

  16. 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)

    The effects of thrombin and GTP?S on the hydrolysis of phosphoinositides by membrane-associated phospholipase C (PLC) from human platelets were examined with endogenous [3H]inositol-labeled membranes or with lipid vesicles containing either [3H]phosphatidylinositol or [3H]phosphatidylinositol 4,5-bisphosphate. GTP?S (1 ?M) or thrombin (1 unit/mL) did not stimulate release of inositol trisphosphate (IP3), inositol bisphosphate (IP2), or inositol phosphate (IP) from [3H]inositol-labeled membranes. IP2 and IP3, but not IP, from [3H]inositol-labeled membranes were, however, stimulated 3-fold by GTP?S (1 ?M) plus thrombin (1 unit/mL). A higher concentration of GTP?S (100 ?M) alone also stimulated IP2 and IP3, but not IP, release. In the presence of 1 mM calcium, release of IP2 and IP3 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 (PIP2) by platelet membrane associated PLC was also markedly enhanced by GTP?S (100 ?M) or GTP?S (1 ?M) 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 PIP2 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 GTP?S (100 ?M) or calcium (1 mM) dependent PIP2 breakdown, while TPA inhibited GTP?S-dependent but not calcium-dependent phospholipase C activity

  17. Constraining topic maps : a TMCL declarative implementation

    OpenAIRE

    Ramalho, José Carlos; Librelotto, Giovani Rubert; Henriques, Pedro Rangel

    2005-01-01

    This paper describes the design of an XML language to formally specify constraints over Topic Maps (XTche). This language allows to express contextual conditions on classes of Topic Maps that are further processed by a XSLT based processor. With XTche, a topic map designer defines a set of restrictions that guarantee that a particular topic map is semantically valid. Topic Maps tend to grow quite fast. Most times the designer has some restrictions in mind like: what kind of ...

  18. Delayed recombination and cosmic parameters

    International Nuclear Information System (INIS)

    Current cosmological constraints from cosmic microwave background anisotropies are typically derived assuming a standard recombination scheme, however additional resonance and ionizing radiation sources can delay recombination, altering the cosmic ionization history and the cosmological inferences drawn from the cosmic microwave background data. We show that for recent observations of the cosmic microwave background anisotropy, from the Wilkinson microwave anisotropy probe satellite mission (WMAP) 5-year survey and from the arcminute cosmology bolometer array receiver experiment, additional resonance radiation is nearly degenerate with variations in the spectral index, ns, and has a marked effect on uncertainties in constraints on the Hubble constant, age of the universe, curvature and the upper bound on the neutrino mass. When a modified recombination scheme is considered, the redshift of recombination is constrained to z*=1078±11, with uncertainties in the measurement weaker by 1 order of magnitude than those obtained under the assumption of standard recombination while constraints on the shift parameter are shifted by 1? to R=1.734±0.028. From the WMAP5 data we obtain the following constraints on the resonance and ionization sources parameters: ??i<0.058 at 95% c.l.. Although delayed recombination limits the precision of parameter estimation from the WMAP satellite, we demonstrate that this should not be the case for future, smaller angular scales measurements, such as those by the Planck satellite mission.

  19. Radioiodination and biodistribution study of a thrombin-like enzyme/gyroxin from Lachesis muta muta venom

    Energy Technology Data Exchange (ETDEWEB)

    Pujatti, Priscilla Brunelli; Soares, Marcella Araugio; Silva, Paulo R.O.; Santos, Raquel Gouvea dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: priscillapujatti@yahoo.com.br; Magalhaes, Henrique P.B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Faculdade de Farmacia

    2007-07-01

    Recently, our group isolated and sequenced a thrombin-like enzyme (TLE) of 40kDa from the snake Lachesis muta muta. This protein hydrolyses synthetic substrates with specificity similar to that of trypsin and may be involved in the haemorrhagic, proteolytic and blood-clotting activities of the Lachesis venom. When injected into the tail veins of mice at levels of 0.015-0.130{mu}g/g mouse, the TLE induce temporary episodes of opisthotonus and rapid rolling around the long axis of the animals and that is the reason why it is also called gyroxin. If this gyroxin activity is caused by direct interaction with the brain or by indirect effect remains to be investigated. We report in this work the radioiodination of TLE and the biodistribution of I-TLE in order to investigate its pharmacokinetics and verify if this enzyme are able to penetrate the blood brain barrier to evoke directly the gyroxin effects. (author)

  20. A multifunctional hemin@metal-organic framework and its application to construct an electrochemical aptasensor for thrombin detection

    Science.gov (United States)

    Xie, Shunbi; Ye, Jiawei; Yuan, Yali; Chai, Yaqin; Yuan, Ruo

    2015-10-01

    A new type of multifunctional metal-organic framework (MOF) has been synthesized by encapsulating hemin into the nano-sized Fe-MIL-88 MOFs (hemin@MOFs) and first applied in an electrochemical aptasensor to detect thrombin (TB) with the aid of an enzyme for signal amplification. The gold nanoparticle functionalized hemin@MOFs (Au/hemin@MOFs) have not only simultaneously served as redox mediators and solid electrocatalysts, but have also been utilized as an ideal loading platform to immobilize a large number of biomolecules. In this aptasensor, Au/hemin@MOFs conjugated with glucose oxidase (GOD) and thrombin binding aptamer (TBA II) were used as the secondary aptamer bioconjugates (Au/hemin@MOF-TBA II-GOD bioconjugates), and TB was sandwiched between Au/hemin@MOF-TBA II-GOD bioconjugates and the amino-terminated TBA I which was self-assembled on the gold nanoparticle (AuNP) modified electrode. The GOD could oxidize glucose into gluconic acid accompanied by the generation of H2O2. The generated H2O2 on the electrode surface was further electrocatalyzed by hemin@MOFs to amplify the electrochemical signal of hemin contained in hemin@MOFs. Therefore, the synthesized hemin@MOFs represented a new paradigm for multifunctional materials since it combined three different functions including serving as catalysts, redox mediators and loading platforms within a single material. With such an ingenious design, a wide linear range of 0.0001 nM to 30 nM was acquired with a relatively low detection limit of 0.068 pM for TB detection.A new type of multifunctional metal-organic framework (MOF) has been synthesized by encapsulating hemin into the nano-sized Fe-MIL-88 MOFs (hemin@MOFs) and first applied in an electrochemical aptasensor to detect thrombin (TB) with the aid of an enzyme for signal amplification. The gold nanoparticle functionalized hemin@MOFs (Au/hemin@MOFs) have not only simultaneously served as redox mediators and solid electrocatalysts, but have also been utilized as an ideal loading platform to immobilize a large number of biomolecules. In this aptasensor, Au/hemin@MOFs conjugated with glucose oxidase (GOD) and thrombin binding aptamer (TBA II) were used as the secondary aptamer bioconjugates (Au/hemin@MOF-TBA II-GOD bioconjugates), and TB was sandwiched between Au/hemin@MOF-TBA II-GOD bioconjugates and the amino-terminated TBA I which was self-assembled on the gold nanoparticle (AuNP) modified electrode. The GOD could oxidize glucose into gluconic acid accompanied by the generation of H2O2. The generated H2O2 on the electrode surface was further electrocatalyzed by hemin@MOFs to amplify the electrochemical signal of hemin contained in hemin@MOFs. Therefore, the synthesized hemin@MOFs represented a new paradigm for multifunctional materials since it combined three different functions including serving as catalysts, redox mediators and loading platforms within a single material. With such an ingenious design, a wide linear range of 0.0001 nM to 30 nM was acquired with a relatively low detection limit of 0.068 pM for TB detection. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04532k

  1. Radioiodination and biodistribution study of a thrombin-like enzyme/gyroxin from Lachesis muta muta venom

    International Nuclear Information System (INIS)

    Recently, our group isolated and sequenced a thrombin-like enzyme (TLE) of 40kDa from the snake Lachesis muta muta. This protein hydrolyses synthetic substrates with specificity similar to that of trypsin and may be involved in the haemorrhagic, proteolytic and blood-clotting activities of the Lachesis venom. When injected into the tail veins of mice at levels of 0.015-0.130?g/g mouse, the TLE induce temporary episodes of opisthotonus and rapid rolling around the long axis of the animals and that is the reason why it is also called gyroxin. If this gyroxin activity is caused by direct interaction with the brain or by indirect effect remains to be investigated. We report in this work the radioiodination of TLE and the biodistribution of I-TLE in order to investigate its pharmacokinetics and verify if this enzyme are able to penetrate the blood brain barrier to evoke directly the gyroxin effects. (author)

  2. Synthesis of Fluorescent Potassium Ion-Sensing Probes Based on a Thrombin-Binding DNA Aptamer-Peptide Conjugate.

    Science.gov (United States)

    Takenaka, Shigeori

    2015-01-01

    This unit provides a procedure for synthesis of the potassium-sensing peptide-oligodeoxyribonucleotide conjugate PSO-5 for visualizing potassium ions (K(+) ) in living cells. It is constructed by combining an oligodeoxyribonucleotide carrying a thrombin-binding DNA aptamer (TBA) sequence with an uncharged peptide carrying biotin and the fluorescence tags fluorescein (FAM) and tetramethylrhodamine (TAMRA). The PSO-5 and biotin-modified nuclear export signal peptide are conjugated through streptavidin, and this sensing molecule is introduced into the cell where it is localized in the cytoplasm. The TBA part of PSO-5 shows a conformational change from a random coil to a tetraplex structure induced by K(+) and a change in the fluorescence resonance energy transfer (FRET) efficiency between FAM and TAMRA arising from its conformational change, enabling fluorometric detection of changes in K(+) concentration. © 2015 by John Wiley & Sons, Inc. PMID:26380906

  3. 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

    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 the haemostatic balance in overweight men. METHODS: Haemostatic variables were investigated in 53 healthy, younger (20-40 years), moderately overweight (BMI 25-30 kg/m(2)) men randomly assigned to 3 months of strictly controlled endurance exercise at two different doses corresponding to an energy expenditure 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-group differences were observed for ETP (p = 0.016) and t-PA (p = 0.012) due to significantly lower values in MOD and HIGH compared with CON. Borderline significant between-group differences were observed for PAI-1 (p = 0.082). A significant increase was observed in vWF in HIGH, but with no between-group differences. CONCLUSIONS: Our results demonstrate an effect of 3 months of daily endurance exercise on biomarkers of the haemostatic balance in the direction of reduced cardiovascular risk, independent of exercise dose.

  4. Potential theory—selected topics

    CERN Document Server

    Aikawwa, Hiroaki

    1996-01-01

    The first part of these lecture notes is an introduction to potential theory to prepare the reader for later parts, which can be used as the basis for a series of advanced lectures/seminars on potential theory/harmonic analysis. Topics covered in the book include minimal thinness, quasiadditivity of capacity, applications of singular integrals to potential theory, L(p)-capacity theory, fine limits of the Nagel-Stein boundary limit theorem and integrability of superharmonic functions. The notes are written for an audience familiar with the theory of integration, distributions and basic functional analysis.

  5. Topics in atomic collision theory

    CERN Document Server

    Geltman, Sydney; Brueckner, Keith A

    1969-01-01

    Topics in Atomic Collision Theory originated in a course of graduate lectures given at the University of Colorado and at University College in London. It is recommended for students in physics and related fields who are interested in the application of quantum scattering theory to low-energy atomic collision phenomena. No attention is given to the electromagnetic, nuclear, or elementary particle domains. The book is organized into three parts: static field scattering, electron-atom collisions, and atom-atom collisions. These are in the order of increasing physical complexity and hence necessar

  6. Topics in black hole evaporation

    International Nuclear Information System (INIS)

    Two major aspects of particle creation by gravitational fields of black holes are studied: the neutrino emission from rotating black holes; and interactions between scalar particles emitted by a black hole. Neutrino emission is investigated under three topics: The asymmetry of the angular dependence of neutrino emission from rotating black holes; the production of a local matter excess by rotating black holes in a baryon symmetric universe; and cosmological magnetic field generation by neutrinos from evaporating black holes. Finally the author studies the effects of interactions on the black hole evaporation process

  7. Topics in computational linear optimization

    DEFF Research Database (Denmark)

    Hultberg, Tim Helge

    2000-01-01

    of high quality solvers and the use of algebraic modelling systems to handle the communication between the modeller and the solver. This dissertation features four topics in computational linear optimization: A) automatic reformulation of mixed 0/1 linear programs, B) direct solution of sparse......, repeated sums, index arithmetic and conditional exceptions. Besides the articles the thesis features six introductory chapters, including a description of two real-world applications of linear optimization, in which I have been involved during my Ph.D. study....

  8. Topics in commutative ring theory

    CERN Document Server

    Watkins, John J

    2009-01-01

    Topics in Commutative Ring Theory is a textbook for advanced undergraduate students as well as graduate students and mathematicians seeking an accessible introduction to this fascinating area of abstract algebra. Commutative ring theory arose more than a century ago to address questions in geometry and number theory. A commutative ring is a set-such as the integers, complex numbers, or polynomials with real coefficients--with two operations, addition and multiplication. Starting from this simple definition, John Watkins guides readers from basic concepts to Noetherian rings-one of

  9. Haemophilia B caused by mutation of a potential thrombin cleavage site in factor IX

    Energy Technology Data Exchange (ETDEWEB)

    Winship, P.R. (Univ. of Oxford (England))

    1990-03-11

    Haemophilia B is a blood coagulation disorder caused by mutations in the factor IX gene giving functionally defective or reduced levels of factor IX protein circulating in the plasma. The mutation in the Caucasian patient under investigation, Haemophilia B Oxford h5 (Oxh5), was characterized at the DNA level by constructing a genomic library using leucocyte-derived DNA from the patient. Overlapping recombinant clones spanning the entire factor IX locus were isolated which then allowed the generation of a series of sub-clones across all eight exons (a-h) plus the 5{prime} and 3{prime} flanking sequences known to be important in regulation of the gene and polyadenylation of the mRNA species.

  10. Topic Graph Generation for Query Navigation Use of Frequency Classes for Topic Extraction

    CERN Document Server

    Niwa, Y; Iwayama, M; Takano, A; Nitta, Y; Niwa, Yoshiki; Nishioka, Shingo; Iwayama, Makoto; Takano, Akihiko; Nitta, Yoshihiko

    1997-01-01

    To make an interactive guidance mechanism for document retrieval systems, we developed a user-interface which presents users the visualized map of topics at each stage of retrieval process. Topic words are automatically extracted by frequency analysis and the strength of the relationships between topic words is measured by their co-occurrence. A major factor affecting a user's impression of a given topic word graph is the balance between common topic words and specific topic words. By using frequency classes for topic word extraction, we made it possible to select well-balanced set of topic words, and to adjust the balance of common and specific topic words.

  11. Investigations for designing catalytic recombiners

    International Nuclear Information System (INIS)

    In case of a severe accident in pressurised water reactors (PWR) a high amount of hydrogen up to about 20,000 m3 might be generated and released into the containments. The mixture consisting of hydrogen and oxygen may either burn or detonate, if ignited. In case of detonation the generated shock wave may endanger the components of the plant or the plant itself. Consequently, effective removal of hydrogen is required. The fact that hydrogen and oxygen react exo-thermally on catalytically acting surfaces already at low temperatures generating steam and heat is made use of in catalytic recombiners. They consist of substrates coated with catalyst (mainly platinum or palladium) which are arranged inside a casing. Being passively acting measures, recombiners do not need any additional energy supply. Experimental investigations on catalytic hydrogen recombination are conducted at FZJ (Forschungszentrum Juelich) using three test facilities. The results yield insight in the development potential of contemporary recombiner systems as well as of innovative systems. Detailed investigations on a recombiner section show strong temperature gradients over the surface of a catalytically coated sample. Dependent on the flow velocity, ignition temperature may be reached at the leading edge already at an inlet hydrogen concentration of about 5 vol.-%. The thermal strain of the substrate leads to considerable detachment of catalyst particles probably causing unintended ignition of the flammable mixture. Temperature peaks can be prevented effectively by leaving the first part of the plate uncoated. In order to avoid overheating of the catalyst elements of a recombiner even at high hydrogen concentrations a modular system of porous substrates is proposed. The metallic substrates are coated with platinum at low catalyst densities thus limiting the activity of the single specimen. A modular arrangement of these elements provides high recombination rates over a large hydrogen concentration range without igniting the mixture

  12. Current topics in nail surgery

    Science.gov (United States)

    Alam; Scher

    1999-10-01

    BACKGROUND: Nail surgery can be performed in an office-based dermatology practice with a limited amount of specialized equipment and training. Several excellent reviews have been published in recent years that detail the techniques of nail surgery for both the novice and the experienced practitioner. OBJECTIVE: In this article recent developments in nail surgery are discussed. Topics that are treated include the general principles of nail surgery, including epidemiologic issues, studies of nail anatomy, instrumentation, and anesthesia. The reconstruction of injuries and congenital defects involving the nail is explained, and the role of the hand surgeon clarified. Appropriate removal of tumours and cysts is considered, with special attention to the management of malignant lesions. The controversy regarding more or less conservative management of melanonychia striata is addressed, and the need for early diagnosis of subungual melanoma is emphasized. Other topics are surgical management of ingrown nails and onychomycosis. Newer areas of nail surgery, such as laser surgery of the nail, psychodermatology of the nail, and the role of primary care physicians in simple nail surgery are also examined. PMID:10575165

  13. Recombining WMAP: Constraints on ionizing and resonance radiation at recombination

    International Nuclear Information System (INIS)

    We place new constraints on sources of ionizing and resonance radiation at the epoch of the recombination process using the recent cosmic microwave background temperature and polarization spectra coming from the Wilkinson Microwave Anisotropy Probe (WMAP). We find that non-standard recombination scenarios are still consistent with the current data. In light of this we study the impact that such models can have on the determination of several cosmological parameters. In particular, the constraints on curvature and baryon density appear to be weakly affected by a modified recombination scheme. However, it may affect the current WMAP constraints on inflationary parameters such as the spectral index ns and its running. Physically motivated models, such as those based on primordial black holes or super heavy dark matter decay, are able to provide a good fit to the current data. Future observations in both temperature and polarization will be needed to more stringently test these models

  14. Recombination of H and He in Yang-Mills Gravity

    CERN Document Server

    Katz, Daniel

    2014-01-01

    We investigate some aspects of the thermal history of the early universe according to Yang-Mills Gravity (YMG); a gauge theory of gravity set in flat spacetime. Specifically, equations for the ionization fractions of hydrogen and singly ionized helium during the recombination epoch are deduced analytically and then solved numerically. By considering several approximations we find that the presence of primordial helium and its interaction with Lyman series photons has a much stronger effect on the overall free electron density in YMG than it does in the standard, General Relativity (GR) based, model. Compared to the standard model recombination happens over a much larger range of temperatures, although there is still a very sharp temperature of last scattering around 2000 K. Since the ionization history of the universe is not directly observable we discuss how one may use it to predict the CMB power spectrum and thus test YMG. This topic will be explored in detail in an upcoming paper.

  15. On-line Hot Topic Recommendation Using Tolerance Rough Set Based Topic Clustering

    Directory of Open Access Journals (Sweden)

    Yonghui Wu

    2010-04-01

    Full Text Available In this paper we present our research of online hot topic detection and label extraction method for our hot topic recommendation system. Using a new topical feature selection method, the feature space is compressed suitable for an online system. The tolerance rough set model is used to enriching the small set of topical feature words to a topical approximation space. According to the distance defined on the topical approximation space, the web pages are clustered into groups which will be merged with document overlap. The topic labels are extracted based on the approximation topical space enriched with the useful but high frequency topical words dropped by the clustering process. The experiments show that our method could generate more information abundant classes and more topical class labels, alleviate the topical drift caused by the non-topical and noise words.

  16. Workplace Safety and Health Topics: Safety & Prevention

    Science.gov (United States)

    ... visit this page: About CDC.gov . NIOSH Home Workplace Safety & Health Topics Share Compartir Safety & Prevention Adult ... Z Index What's New on the NIOSH Website Workplace Safety and Health Topics Industries & Occupations Hazards & Exposures ...

  17. Inhomogeneous recombinations during cosmic reionization

    CERN Document Server

    Sobacchi, Emanuele

    2014-01-01

    By depleting the ionizing photon budget available to expand cosmic HII regions, recombining systems (or Lyman limit systems) can have a large impact during (and following) cosmic reionization. Unfortunately, directly resolving such structures in large-scale reionization simulations is computationally impractical. Instead, here we implement a sub-grid prescription for tracking inhomogeneous recombinations in the intergalactic medium. Building on previous work parameterizing photo-heating feedback on star-formation, we present large-scale, semi-numeric reionization simulations which self-consistently track the local (sub-grid) evolution of both sources and sinks of ionizing photons. Our simple, single-parameter model naturally results in both an extended reionization and a modest, slowly-evolving emissivity, consistent with observations. Recombinations are instrumental in slowing the growth of large HII regions, and damping the rapid rise of the ionizing background in the late stages of (and following) reioniza...

  18. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  19. Synergetics introduction and advanced topics

    CERN Document Server

    Haken, Hermann

    2004-01-01

    This book is an often-requested reprint of two classic texts by H. Haken: "Synergetics. An Introduction" and "Advanced Synergetics". Synergetics, an interdisciplinary research program initiated by H. Haken in 1969, deals with the systematic and methodological approach to the rapidly growing field of complexity. Going well beyond qualitative analogies between complex systems in fields as diverse as physics, chemistry, biology, sociology and economics, Synergetics uses tools from theoretical physics and mathematics to construct an unifying framework within which quantitative descriptions of complex, self-organizing systems can be made. This may well explain the timelessness of H. Haken's original texts on this topic, which are now recognized as landmarks in the field of complex systems. They provide both the beginning graduate student and the seasoned researcher with solid knowledge of the basic concepts and mathematical tools. Moreover, they admirably convey the spirit of the pioneering work by the founder of ...

  20. KEY TOPICS IN SPORTS MEDICINE

    Directory of Open Access Journals (Sweden)

    Amir Ali Narvani

    2006-12-01

    Full Text Available Key Topics in Sports Medicine is a single quick reference source for sports and exercise medicine. It presents the essential information from across relevant topic areas, and includes both the core and emerging issues in this rapidly developing field. It covers: 1 Sports injuries, rehabilitation and injury prevention, 2 Exercise physiology, fitness testing and training, 3 Drugs in sport, 4 Exercise and health promotion, 5 Sport and exercise for special and clinical populations, 6 The psychology of performance and injury. PURPOSE The Key Topics format provides extensive, concise information in an accessible, easy-to-follow manner. AUDIENCE The book is targeted the students and specialists in sports medicine and rehabilitation, athletic training, physiotherapy and orthopaedic surgery. The editors are authorities in their respective fields and this handbook depends on their extensive experience and knowledge accumulated over the years. FEATURES The book contains the information for clinical guidance, rapid access to concise details and facts. It is composed of 99 topics which present the information in an order that is considered logical and progressive as in most texts. Chapter headings are: 1. Functional Anatomy, 2. Training Principles / Development of Strength and Power, 3. Biomechanical Principles, 4. Biomechanical Analysis, 5. Physiology of Training, 6. Monitoring of Training Progress, 7. Nutrition, 8. Hot and Cold Climates, 9. Altitude, 10. Sport and Travelling, 11. Principles of Sport Injury Diagnosis, 12. Principles of Sport and Soft Tissue Management, 13. Principles of Physical Therapy and Rehabilitation, 14. Principles of Sport Injury Prevention, 15. Sports Psychology, 16. Team Sports, 17. Psychological Aspects of Injury in Sport, 18. Injury Repair Process, 19. Basic Biomechanics of Tissue Injury, 20. Plain Film Radiography in Sport, 21. Nuclear Medicine, 22. Diagnostic Ultrasound, 23. MRI Scan, 24. Other Imaging, 5. Head Injury, 26. Eye Injury, 27. Injury to the Face, Nose, Ear, 28. Dental Problems, 29. Protective Headwear and Facial Protection in Sport, 30. Spinal Injury: Functional Anatomy and General Biomechanics, 31. Cervical Spine Injuries, 32. Thoracolumbar Spine Injuries, 33. Spine Related Syndromes, 34. Chest Injuries, 35. Abdominal Injuries and Abdominal Wall Injuries, 36. Urinary Tract Injuries, 37. The Shoulder Disorders, 38. Acromioclavicular Joint Disorders, 39. The Elbow Joint, 40. The Forearm and Wrist, 41. Hand Injuries, 42. Neurological Injury Affecting the Upper Limb, 43. Buttock Pain, 44. Groin Pain, 45. Thigh Injuries. ASSESSMENT Based on graduate programme teaching practice and with an international team of contributors, this is a valuable and practical resource for all those interested in sports and exercise medicine, including sports clinicians, general practitioners, team doctors, orthopaedic surgeons, accident and emergency doctors and physiotherapists. It is concise and well organized in its presentation, creating an effective textbook. I believe, therefore, the book will serve as a first-rate teaching tool and reference for students and specialists in sports medicine and rehabilitation, athletic training, physiotherapy. Students will enjoy the format of this book

  1. Topical immunotherapy in alopecia areata.

    Science.gov (United States)

    Singh, Gurcharan; Lavanya, Ms

    2010-01-01

    Alopecia Areata (AA) is a common non-scarring alopecia directed against the anagenic hair follicle. Various treatment modalities have been used for the treatment of severe AA. Topical immunotherapy is the best documented treatment so far for severe and refractory AA. Dinitrochlorobenzene (DNCB), squaric acid dibutylester (SADBE), and diphencyprone (DPCP) are the contact allergens used for this purpose. DNCB has been found to be mutagenic by the Ames test and is largely replaced by DPCP and SADBE. DPCP and SADBE are both known to be non-mutagenic compounds and have comparable efficacy results and relapse rates. SADBE requires special solvents and additives to maintain its potency and is more expensive than the rest. DPCP has a response rate varying from 60% in severe Alopecia Areata to 17% in patients with alopecia totalis or universalis, and shows about 88 to 100% high response rate in patients with patchy Alopecia Areata. PMID:21188022

  2. Neutron transport simulation (selected topics)

    Science.gov (United States)

    Vaz, P.

    2009-10-01

    Neutron transport simulation is usually performed for criticality, power distribution, activation, scattering, dosimetry and shielding problems, among others. During the last fifteen years, innovative technological applications have been proposed (Accelerator Driven Systems, Energy Amplifiers, Spallation Neutron Sources, etc.), involving the utilization of intermediate energies (hundreds of MeV) and high-intensity (tens of mA) proton accelerators impinging in targets of high Z elements. Additionally, the use of protons, neutrons and light ions for medical applications (hadrontherapy) impose requirements on neutron dosimetry-related quantities (such as kerma factors) for biologically relevant materials, in the energy range starting at several tens of MeV. Shielding and activation related problems associated to the operation of high-energy proton accelerators, emerging space-related applications and aircrew dosimetry-related topics are also fields of intense activity requiring as accurate as possible medium- and high-energy neutron (and other hadrons) transport simulation. These applications impose specific requirements on cross-section data for structural materials, targets, actinides and biologically relevant materials. Emerging nuclear energy systems and next generation nuclear reactors also impose requirements on accurate neutron transport calculations and on cross-section data needs for structural materials, coolants and nuclear fuel materials, aiming at improved safety and detailed thermal-hydraulics and radiation damage studies. In this review paper, the state-of-the-art in the computational tools and methodologies available to perform neutron transport simulation is presented. Proton- and neutron-induced cross-section data needs and requirements are discussed. Hot topics are pinpointed, prospective views are provided and future trends identified.

  3. Neutron transport simulation (selected topics)

    International Nuclear Information System (INIS)

    Neutron transport simulation is usually performed for criticality, power distribution, activation, scattering, dosimetry and shielding problems, among others. During the last fifteen years, innovative technological applications have been proposed (Accelerator Driven Systems, Energy Amplifiers, Spallation Neutron Sources, etc.), involving the utilization of intermediate energies (hundreds of MeV) and high-intensity (tens of mA) proton accelerators impinging in targets of high Z elements. Additionally, the use of protons, neutrons and light ions for medical applications (hadrontherapy) impose requirements on neutron dosimetry-related quantities (such as kerma factors) for biologically relevant materials, in the energy range starting at several tens of MeV. Shielding and activation related problems associated to the operation of high-energy proton accelerators, emerging space-related applications and aircrew dosimetry-related topics are also fields of intense activity requiring as accurate as possible medium- and high-energy neutron (and other hadrons) transport simulation. These applications impose specific requirements on cross-section data for structural materials, targets, actinides and biologically relevant materials. Emerging nuclear energy systems and next generation nuclear reactors also impose requirements on accurate neutron transport calculations and on cross-section data needs for structural materials, coolants and nuclear fuel materials, aiming at improved safety and detailed thermal-hydraulics and radiation damage studies. In this review paper, the state-of-the-art in the computational tools and methodologies available to perform neutron transport simulation is presented. Proton- and neutron-induced cross-section data needs and requirements are discussed. Hot topics are pinpointed, prospective views are provided and future trends identified.

  4. On-line Hot Topic Recommendation Using Tolerance Rough Set Based Topic Clustering

    OpenAIRE

    Yonghui Wu; Yuxin Ding; Xiaolong Wang; Jun Xu

    2010-01-01

    In this paper we present our research of online hot topic detection and label extraction method for our hot topic recommendation system. Using a new topical feature selection method, the feature space is compressed suitable for an online system. The tolerance rough set model is used to enriching the small set of topical feature words to a topical approximation space. According to the distance defined on the topical approximation space, the web pages are clustered into groups which will be mer...

  5. Topical tacrolimus as treatment of atopic dermatitis

    OpenAIRE

    Masutaka Furue; Satoshi Takeuchi

    2009-01-01

    Masutaka Furue, Satoshi TakeuchiDepartment of Dermatology, Faculty of Medical Sciences, Kyushu University, Fukuoka, JapanAbstract: Atopic dermatitis (AD) is a common, chronic, relapsing, severely pruritic, eczematous skin disease. The mainstays of treatment for AD are topical tacrolimus and topical steroids. Tacrolimus, a calcineurin inhibitor, not only complements existing treatment options but also overcomes some of the drawbacks of topical steroid therapy when given topically and thus meet...

  6. Dissociative recombination of protonated methanol

    OpenAIRE

    Geppert, Wolf; Hamberg, Mathias; Thomas, Richard D; Österdahl, Fabian; Hellberg, Fredrik; Zhaunerchyk, Vitali; Ehlerding, Anneli; Millar, Tom; Roberts, Helen; Semaniak, Jacek; af Ugglas, Magnus; Källberg, Anders; Simonsson, Ansgar; Kaminska, Magdalena; Larsson, Mats

    2006-01-01

    The branching ratios of the different reaction pathways and the overall rate coefficients of the dissociative recombination reactions of CH3OH2+ and CD3OD2+ have been measured at the CRYRING storage ring located in Stockholm, Sweden. Analysis of the data yielded the result that formation of methanol or deuterated methanol accounted for only 3 and 6% of the total rate in CH3OH2+ and CD3OD2+, respectively. Dissociative recombination of both isotopomeres mainly involves fragmentation of the C–O ...

  7. Selenium incorporation using recombinant techniques

    International Nuclear Information System (INIS)

    An overview of techniques for recombinant incorporation of selenium and subsequent purification and crystallization of the resulting labelled protein. Using selenomethionine to phase macromolecular structures is common practice in structure determination, along with the use of selenocysteine. Selenium is consequently the most commonly used heavy atom for MAD. In addition to the well established recombinant techniques for the incorporation of selenium in prokaryal expression systems, there have been recent advances in selenium labelling in eukaryal expression, which will be discussed. Tips and things to consider for the purification and crystallization of seleno-labelled proteins are also included

  8. Topical report review status: Volume 10

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    This report provides industry with procedures for submitting topical reports, guidance on how the U.S. Nuclear Regulatory Commission (NRC) processes and responds to topical report submittals, and an accounting, with review schedules, of all topical reports currently accepted for review by the NRC. This report is published annually.

  9. [Skin aging and evidence-based topical strategies].

    Science.gov (United States)

    Bayerl, C

    2016-02-01

    Anti-aging in dermatology primarily focuses on the prevention of skin aging with UV protection (clothing and sunsceens), free radical scavengers (synthetic or botanic), and cell-protecting agents such as vitamin B3. For the correction of signs of early skin aging, retinoic acid derivatives in dermatological prescriptions are the best studied substances. Topical hormonal prescriptions are also an option if UV damage has not been the leading culprit for aging. Chemical peeling leads to a marked increase in collagen formation, the deaper the better. Ingredients in cream preparations can reduce superficial skin folds (polyphenols, amino acid peptides). Modulators of regular pigmentation are important for anti-aging preparations. Growth factors (plant extracts, recombinant growth factors) are not thoroughly studied regarding the cost-benefit and risk ratio. Complex precedures such as photodynamic therapy have an impact on the appearance of aged skin. PMID:26683808

  10. 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; Kristensen, Annemarie Thuri; Jacobsen, Stine

    2015-01-01

    Background: Studies in humans have shown that haemostatic and inflammatory pathways both play important roles in the pathogenesis of joint disease. The aim of this study was to assess mRNA expression of haemostatic and inflammatory factors in cultured equine fibroblast-like synoviocytes exposed to....... Conclusion: LPS, fibrinogen and thrombin induced an increased gene expression of inflammatory markers in isolated equine fibroblast-like synoviocytes. LPS caused changes in gene expression promoting increased fibrinolysis, while fibrinogen and thrombin changed the gene expression resulting potentially in...... reduced fibrinolysis. Overall, it appeared that both inflammatory and haemostatic stimuli affected expression of genes involved in inflammatory and haemostatic pathways, supporting their importance in equine joint diseases....

  11. Multilingual Topic Models for Unaligned Text

    CERN Document Server

    Boyd-Graber, Jordan

    2012-01-01

    We develop the multilingual topic model for unaligned text (MuTo), a probabilistic model of text that is designed to analyze corpora composed of documents in two languages. From these documents, MuTo uses stochastic EM to simultaneously discover both a matching between the languages and multilingual latent topics. We demonstrate that MuTo is able to find shared topics on real-world multilingual corpora, successfully pairing related documents across languages. MuTo provides a new framework for creating multilingual topic models without needing carefully curated parallel corpora and allows applications built using the topic model formalism to be applied to a much wider class of corpora.

  12. Design, synthesis and biological evaluation of new peptide-based ureas and thioureas as potential antagonists of the thrombin receptor PAR1

    OpenAIRE

    Ventosa-Andrés, Pilar; Valdivielso, Ángel M.; Pappos, Ioannis; Garcia-Lopez, M. Teresa; Tsopanoglou, Nikos E.; Herranz, Rosario

    2012-01-01

    By applying a diversity oriented synthesis strategy for the search of new antagonists of the thrombin receptor PAR1, a series of peptide-based ureas and thioureas, including analogues of the PAR1 reference antagonist RWJ-58259, has been designed and synthesized. The general synthetic scheme involves reduction of basic amino acid-derived amino nitriles by hydrogen transfer from hydrazine monohydrate in the presence of Raney Ni, followed by reaction with diverse isocyanates and isothiocyanates,...

  13. 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, Ji?í

    2010-01-01

    Ro?. 6, ?. 10 (2010), s. 3003-3014. ISSN 1549-9618 R&D Projects: GA AV ?R(CZ) IAA400040802; GA ?R(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

  14. [Role of exogenous fibrinogen in the processes of degranulation of thrombocytes stimulated with thrombin. Ultrastructural study using fibrinogen labeled with colloidal gold].

    Science.gov (United States)

    Belitser, N V; Anishchuk, M G; Veklich, Iu I; Smekhova, T R; Pozdniakova, T M; Gorkun, O V; Chernyshenko, T M; Moroz, E D

    1992-01-01

    Using colloidal gold-conjugated fibrinogen (F-Au) it is shown that exogenous fibrinogen can participate in the platelet release reaction. In the absence of F-Au, internal secretory vacuoles readily formed in human platelets stimulated with thrombin, but extrusion of their content was delayed. Upon incubation with F-Au, endocytic channels induced by F-Au-receptor interactions, fused with internal vacuoles, thus establishing spatial communications of the latter with the outer medium. PMID:1621283

  15. Lack of nitric oxide- and guanosine 3?:5?-cyclic monophosphate-dependent regulation of ?-thrombin-induced calcium transient in endothelial cells of spontaneously hypertensive rat hearts

    Science.gov (United States)

    Failli, Paola; Fazzini, Alessandro; Ruocco, Carlo; Mazzetti, Luca; Cecchi, Enrica; Giovannelli, Lisa; Marra, Fabio; Milani, Stefano; Giotti, Alberto

    2000-01-01

    While the expression and/or activity of endothelial nitric oxide synthase (eNOS) has been characterized in spontaneously hypertensive (SHR) and normotensive Wistar Kyoto rat (WKY) hearts, in coronary endothelial cells (ECs) from both strains, the effect of NO on intracellular calcium concentration ([Ca2+]i) is still unknown. Coronary microvascular ECs were isolated from SHR and WKY and characterized. Immunocytochemistry and Western blot analysis showed that eNOS was similarly expressed in ECs from both strains. Measuring [Ca2+]i by imaging analysis of fura-2-loaded cells, we demonstrated that ?-thrombin (3?180?U?l?1) induced a superimposable dose-dependent calcium transient in ECs from both strains. In WKY ECs, S-nitroso-N-acetyl-DL-penicillamine (SNAP) dose-dependently (10–100??M) and 0.1??M atrial natriuretic factor (ANF) reduced the maximum and the decay time of ?-thrombin-induced calcium transient. The inhibitory effects of SNAP and ANF were prevented by blocking cyclic GMP-dependent protein kinase. Non selective eNOS inhibitors prolonged the decay time of ?-thrombin-induced calcium transient, while the selective inducible NOS inhibitor 1400?W was ineffective. SNAP (100??M) and 0.1??M ANF increased cyclic GMP content up to 22.9 and 42.3 fold respectively. In SHR ECs, ?-thrombin-induced calcium transient was not modified by SNAP, ANF or eNOS inhibition. SNAP (100??M) and 0.1??M ANF increased cyclic GMP content up to 9.3 and 51 fold respectively. In WKY ECs, SNAP dose-dependently (10–100??M) reduced also bradykinin-induced calcium transient, while in SHR ECs was ineffective. We concluded that in SHR ECs, the cyclic GMP-dependent regulation of calcium transient is lost. PMID:10928946

  16. KEGG PATHWAY / Homologous recombination [KEGG

    Lifescience Database Archive (English)

    Full Text Available PATHWAY: map03440 Entry map03440Pathway Name Homologous recombination Description Homologous rec ... drome mutated) are tumor suppressors that maintain genome ... integrity, at least in part, through HR. Class Gen ... 2MRX complex [PATH:map03440]M00295BRCA1-associated genome ... surveillance complex (BASC) [PATH:map03440] Diseas ...

  17. CRMAGE: CRISPR Optimized MAGE Recombineering.

    Science.gov (United States)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Sommer, Morten O A; Nielsen, Alex Toftgaard

    2016-01-01

    A bottleneck in metabolic engineering and systems biology approaches is the lack of efficient genome engineering technologies. Here, we combine CRISPR/Cas9 and ? Red recombineering based MAGE technology (CRMAGE) to create a highly efficient and fast method for genome engineering of Escherichia coli. Using CRMAGE, the recombineering efficiency was between 96.5% and 99.7% for gene recoding of three genomic targets, compared to between 0.68% and 5.4% using traditional recombineering. For modulation of protein synthesis (small insertion/RBS substitution) the efficiency was increased from 6% to 70%. CRMAGE can be multiplexed and enables introduction of at least two mutations in a single round of recombineering with similar efficiencies. PAM-independent loci were targeted using degenerate codons, thereby making it possible to modify any site in the genome. CRMAGE is based on two plasmids that are assembled by a USER-cloning approach enabling quick and cost efficient gRNA replacement. CRMAGE furthermore utilizes CRISPR/Cas9 for efficient plasmid curing, thereby enabling multiple engineering rounds per day. To facilitate the design process, a web-based tool was developed to predict both the ? Red oligos and the gRNAs. The CRMAGE platform enables highly efficient and fast genome editing and may open up promising prospective for automation of genome-scale engineering. PMID:26797514

  18. Improving recombinant protein purification yield

    Science.gov (United States)

    Production of adequate amounts of recombinant proteins is essential for antibody production, biochemical activity study, and structural determination during the post-genomic era. It’s technologically challenging and a limiting factor for tung oil research because analytical reagents such as high qua...

  19. Recombination of Physical Unclonable Functions

    OpenAIRE

    Devadas, Srinivas; Yu, Meng-Day (Mandel)

    2010-01-01

    A new Physical Unclonable Function (PUF) construction is described, by treating silicon unique features extracted from PUF circuits as “genetic material” unique to each silicon, and recombining this chip-unique material in a way to obtain a combination of advantages not possible with the original PUF circuits, including altering PUF output statistics to better suit PUF-based key generation and authentication.

  20. Recombination luminescence in rigid media

    International Nuclear Information System (INIS)

    When separated ion-pairs result from the ?-irradiation of pure or doped matrices or from solute photoionization, some of the photoejected electrons undergo spontaneous recombination, giving rise to the so-called isothermal luminescence (ITL). Cation-anion recombination takes place when molecular diffusion is possible; that is, it appears mostly in thermoluminescence (TL), upon warming irradiated samples. Electrons are photoextracted from matrix traps or from anions, and the neutralization luminescence is designated as stimulated luminescence (SL). ITL, TL, and SL all constitute very sensitive test for the presence of charged species. ITL decay kinetics throw some light on the recombination mechanism. In TL studies, the maxima of the glow curves correlate with phase transition temperatures (crystal ? crystal or glass ? crystal), providing insight into matrix molecular dynamics. From SL spectra, positive and negative charges can be discriminated, and various characteristics of the negative ions - electrons or anions - can be attained. The global SL irrespective of its spectrum composition, SL emission spectra, and SL excitation spectra or stimulation spectra are reviewed. The SL spectra, being specific of negative charged species, complement optical absorption spectroscopy when cations and anions have undistinguishable spectra. Even though radiative charge recombination constitutes the final step of ion-pair existence, it may serve to track back the successive stages of photoelectron life: electron ejection, matrix trapping or the attachments of electrons to molecules or radicals, and the release of trapped electrons. (Yamashita, S.)

  1. Decision Point 1 Topical Report

    Energy Technology Data Exchange (ETDEWEB)

    Yablonsky, Al; Barsoumian, Shant; Legere, David

    2013-05-01

    This Topical Report addresses accomplishments achieved during Phase 2a of the SkyMine® Carbon Mineralization Pilot Project. The primary objectives of this project are to design, construct, and operate a system to capture CO2 from a slipstream of flue gas from a commercial coal-fired cement kiln, convert that CO2 to products having commercial value (i.e., beneficial use), show the economic viability of the CO2 capture and conversion process, and thereby advance the technology to the point of readiness for commercial scale demonstration and proliferation. The overall process is carbon negative, resulting in mineralization of CO2 that would otherwise be released into the atmosphere. The project will also substantiate market opportunities for the technology by sales of chemicals into existing markets, and identify opportunities to improve technology performance and reduce costs at the commercial scale. The project is being conducted in two phases. The primary objectives of Phase 1 were to elaborate proven SkyMine® process chemistry to commercial pilot-scale operation and complete the preliminary design for the pilot plant to be built and operated in Phase 2, complete a NEPA evaluation, and develop a comprehensive carbon life cycle analysis. The objective of the current Phase (2a) is to complete the detailed design of the pilot plant to be built in Phase 2b.

  2. Topics in theoretical surface science

    International Nuclear Information System (INIS)

    The energetics and structures of clean and adsorbate covered surfaces are investigated in this dissertation. First, the formalism, within the Corrected Effective Medium (CEM) method, for calculating the surface energy of a clean surface is derived. The surface energies for many different metals and their low index surfaces are presented. The minimization of the surface energy is then used to predict the multilayer relaxation of the Al(111), (100), Ni(100), (110) and Fe(100) surfaces. Extensions of the surface CEM formalism to calculate the binding energies of ordered adsorbates on metals surfaces are also derived. The minimization of the binding energy allowed determination of the binding heights, sites and the extent of induced multilayer relaxation for H and N atoms on the Fe(110), (100) and W(110) surfaces. The last topic deals with the dynamics of the epitaxial growth of metals on metal surfaces. The CEM method was first modified by making approximations to enable faster evaluations of the potential and its corresponding forces for molecular dynamics simulations. The goal of these simulations was to identify the important steps in the formation of equilibrium epitaxial structures. 180 refs., 31 figs., 18 tabs

  3. The Virtual Robotics Laboratory; TOPICAL

    International Nuclear Information System (INIS)

    The growth of the Internet has provided a unique opportunity to expand research collaborations between industry, universities, and the national laboratories. The Virtual Robotics Laboratory (VRL) is an innovative program at Oak Ridge National Laboratory (ORNL) that is focusing on the issues related to collaborative research through controlled access of laboratory equipment using the World Wide Web. The VRL will provide different levels of access to selected ORNL laboratory secondary education programs. In the past, the ORNL Robotics and Process Systems Division has developed state-of-the-art robotic systems for the Army, NASA, Department of Energy, Department of Defense, as well as many other clients. After proof of concept, many of these systems sit dormant in the laboratories. This is not out of completion of all possible research topics. but from completion of contracts and generation of new programs. In the past, a number of visiting professors have used this equipment for their own research. However, this requires that the professor, and possibly his/her students, spend extended periods at the laboratory facility. In addition, only a very exclusive group of faculty can gain access to the laboratory and hardware. The VRL is a tool that enables extended collaborative efforts without regard to geographic limitations

  4. Topics in Number Theory Conference

    CERN Document Server

    Andrews, George; Ono, Ken

    1999-01-01

    From July 31 through August 3,1997, the Pennsylvania State University hosted the Topics in Number Theory Conference. The conference was organized by Ken Ono and myself. By writing the preface, I am afforded the opportunity to express my gratitude to Ken for beng the inspiring and driving force behind the whole conference. Without his energy, enthusiasm and skill the entire event would never have occurred. We are extremely grateful to the sponsors of the conference: The National Sci­ ence Foundation, The Penn State Conference Center and the Penn State Depart­ ment of Mathematics. The object in this conference was to provide a variety of presentations giving a current picture of recent, significant work in number theory. There were eight plenary lectures: H. Darmon (McGill University), "Non-vanishing of L-functions and their derivatives modulo p. " A. Granville (University of Georgia), "Mean values of multiplicative functions. " C. Pomerance (University of Georgia), "Recent results in primality testing. " C. ...

  5. Topical subjects of nuclear energy

    International Nuclear Information System (INIS)

    The controversy as regards the introduction of nuclear energy to the energy supply of the Federal Republic of Germany has not subdued yet. However, the discussion has shifted from technical questions more to the field of political argumentation. In addition, questions concerning the back end cycle have come to the fore. The report at hand deals with the topical subjects of fuel reprocessing, ultimate storage of radioactive wastes, the impact of power plants in general and nuclear power plants in particular on the climate, safety and safeguard questions concerning nuclear facilities and fissionable materials, and with the properties and possibilities of plutonium. The authors tried to present technical know-how in an easy comprehensible way. Literature references enable the checking of facts and provide the possibility to deal in more detail with the matter. The seminar report is to give all those interested the opportunity to acquaint themselves with facts and know-how and to acquire knowledge on which to base a personal opinion. (orig.)

  6. Main technical topics in 1999

    International Nuclear Information System (INIS)

    This Safety Authority annual report strives to present current organizational provisions and future trends in nuclear safety supervision in France and to describe the most outstanding occurrences during the past year. A first part presents nine documents concerning the main topics of 1999: aging of nuclear installations, the Offsite Emergency Plans (PPI), the impact of nuclear activities on man and the environment, the criticality hazards, EDF in 1999, the EPR project, the Andra in 1999, the transport incidents, the nuclear safety in eastern Europe. The second part presents the missions and actions of the Nuclear Installations Safety in the domains of the liabilities, the organization of the nuclear safety control, the regulations of the INB, the public information, the international relations, the crisis management, the radioactive materials transportation, the radioactive wastes. The equipment, the radiation protection and the exploitation of the pressurized water reactors are also treated just as the experimental reactors, the fuel cycle installations and the the nuclear installations dismantling. (A.L.B.)

  7. The Anopheles gambiae cE5, a tight- and fast-binding thrombin inhibitor with post-transcriptionally regulated salivary-restricted expression.

    Science.gov (United States)

    Ronca, Raffaele; Kotsyfakis, Michalis; Lombardo, Fabrizio; Rizzo, Cinzia; Currà, Chiara; Ponzi, Marta; Fiorentino, Gabriella; Ribeiro, Josè M C; Arcà, Bruno

    2012-09-01

    Mosquito saliva carries a large number of factors with anti-hemostatic, anti-inflammatory and immuno-modulatory activities. The cE5 protein was initially identified during an Anopheles gambiae salivary gland transcriptome study and later shown to share sequence similarity with anophelin, a thrombin inhibitor from the saliva of the New World mosquito Anopheles albimanus. The cE5 gene was found to encode different mRNA isoforms coexisting in several tissues of both male and female mosquitoes, a highly unusual profile for a gene potentially encoding an anti-thrombin and involved in blood feeding. Expression of the cE5 protein and assessment of its activity and inhibitory properties showed that it is a highly specific and tight-binding thrombin inhibitor, which differs from the A. albimanus orthologue for the fast-binding kinetics. Despite the widespread occurrence of cE5 transcripts in different mosquito tissues the corresponding protein was only found in female salivary glands, where it undergoes post-translational modification. Therefore, tissue-specific restriction of the A. gambiae cE5 is not achieved by transcriptional control, as common for mosquito salivary genes involved in hematophagy, but by post-trascriptional gene regulatory mechanisms. Our observations provide a paradigm of post-transcriptional regulation as key determinant of tissue specificity for a protein from an important disease vector and point out that transcriptomic data should be interpreted with caution in the absence of concomitant proteomic support. PMID:22617725

  8. Genetics Home Reference: Recombinant 8 syndrome

    Science.gov (United States)

    ... this population have been found. What are the genetic changes related to recombinant 8 syndrome? Recombinant 8 ... Center . Where can I find general information about genetic conditions? The Handbook provides basic information about genetics ...

  9. The ?0 polarization and the recombination mechanism

    International Nuclear Information System (INIS)

    We use the recombination and the Thomas Precession Model to obtain a prediction for the ?0 polarization in the p+p ? ?0 + X reaction. We study the effect of the recombination function on the ?0 polarization. (author)

  10. Recent Advances In Topical Therapy In Dermatology

    Directory of Open Access Journals (Sweden)

    Mohan Thappa Devinder

    2003-01-01

    Full Text Available With changing times various newer topical agents are introduced in the field of dermatology. Tacrolimus and pimecrolimus are immunisuppressants, which are effective topically and are tried in the management of atopic dermatitis as well as other disorders including allergic contact dermatitis, atrophic lichen planus, pyoderma gangrenosum. Imiquimod, an immune response modifier, is presently in use for genital warts but has potentials as anti- tumour agent and in various other dermatological conditions when used topically. Tazarotene is a newer addition to the list of topical reginoids, which is effective in psoriasis and has better effect in combination with calcipotriene, phototherapy and topical costicosteroids. Tazarotene and adapelene are also effective in inflammatory acne. Calcipotriol, a vitamin D analogue has been introduced as a topical agent in the treatment of psoriasis. Steroid components are also developed recently which will be devoid of the side effects but having adequate anti-inflammatory effect. Topical photodynamic therapy has also a wide range of use in dermatology. Newer topical agents including cidofovir, capsaicin, topical sensitizers, topical antifungal agents for onychomycosis are also of use in clinical practice. Other promising developments include skin substitutes and growth factors for wound care.

  11. Population inversion in recombining hydrogen plasma

    International Nuclear Information System (INIS)

    The collisional-radiative model is applied to a recombining hydrogen plasma in order to investigate plasma conditions in which a population inversion between the energy levels of hydrogen can be generated. Population inversion is expected in plasmas for which three-body recombination makes a large contribution to the recombining processes and the effective recombination rate is larger than a critical value for a given electron density and temperature. Calculated results are presented in figures and tables. (author)

  12. Variation in hospital resource use and cost among surgical procedures using topical absorbable hemostats

    Directory of Open Access Journals (Sweden)

    Martyn D

    2015-11-01

    Full Text Available Derek Martyn,1 Lisa M Meckley,1 Gavin Miyasato,1 Sangtaeck Lim,2 Jerome B Riebman,3 Richard Kocharian,3 Jillian G Scaife,1 Yajing Rao,1 Mitra Corral2 1Trinity Partners, LLC, Waltham, MA, USA; 2Global Health Economics and Market Access, Ethicon, Inc., Bridgewater, NJ, USA; 3Medical Affairs, Ethicon, Inc., Bridgewater, NJ, USA Background: Adjunctive hemostats are used to assist with the control of intraoperative bleeding. The most common types are flowables, gelatins, thrombins, and oxidized regenerated celluloses (ORCs. In the US, Surgicel® products are the only US Food and Drug Administration-approved ORCs. Objective: To compare the outcomes of health care resource utilization (HRU and costs associated with using ORCs compared to other adjunctive hemostats (OAHs are defined as flowables, gelatins, and topical thrombins for surgical procedures in the US inpatient setting. Patients and methods: A retrospective, US-based cohort study was conducted using hospital inpatient discharges from the 2011–2012 calendar years in the Premier Healthcare Database. Patients with either an ORC or an OAH who underwent a cardiovascular procedure (valve surgery and/or coronary artery bypass graft surgery, carotid endarterectomy, cholecystectomy, or hysterectomy were included. Propensity score matching was used to create comparable groups of ORC and OAH patients. Clinical, economic, and HRU outcomes were compared. Results: The propensity score matching created balanced patient cohorts for cardiovascular procedure (22,718 patients, carotid endarterectomy (10,890 patients, cholecystectomy (6,090 patients, and hysterectomy (9,348 patients. In all procedures, hemostatic agent costs were 28%–56% lower for ORCs, and mean hemostat units per discharge were 16%–41% lower for ORCs compared to OAHs. Length of stay and total procedure costs for patients treated with ORCs were lower for carotid endarterectomy patients (0.3 days and US$700 and for cholecystectomy patients (1 day and US$3,350 (all P<0.001. Conclusion: Costs and HRU for patients treated with ORCs were lower than or similar to patients treated with OAHs. Proper selection of the appropriate hemostatic agents has the potential to influence clinical outcomes and treatment costs. Keywords: hemostatics, hemostatic techniques, blood transfusion, health care costs, surgical blood loss

  13. Dielectronic recombination in laser generated plasmas

    International Nuclear Information System (INIS)

    Dielectronic recombination coefficients have been computed for hydrogenic ions from HeII to FeXVI over a range of conditions typical of laser generated plasma. The results are displayed in a set a graphs together with the corresponding collisional radiative recombination coefficients. A comparison of these results indicates plasma conditions where dielectronic recombination is a significant process. (author)

  14. Quadruplex to Watson-Crick duplex transition of the thrombin binding aptamer: a fluorescence resonance energy transfer study

    International Nuclear Information System (INIS)

    Thermodynamic parameters of closing up of guanine-rich thrombin binding element, upon binding to K+ and Na+ ions to form quadruplexes and opening up of these quadruplexes upon binding to its complementary strand, were investigated. For this purpose, 15 mer deoxynucleotide, d(G2T2G2TGTG2T2G2), labeled with 5'-fluorescein and 3'-tetramethylrhodamine was taken and fluorescence resonance energy transfer was monitored as a function of either metal ions or complementary strand concentrations. Equilibrium association constant obtained from FRET studies demonstrates that K+ ions bind with higher affinity than the Na+ ions. The enthalpy changes, ?H, obtained from temperature dependence of equilibrium association constant studies revealed that formation of quadruplex upon binding of metal ions is primarily enthalpy driven. Binding studies of complementary strand to the quadruplex suggest that opening of a quadruplex in NaCl buffer in presence of the complementary strand is enthalpic as well as entropic driven and can occur easily, whereas opening of the same quadruplex in KCl buffer suffers from enthalpic barrier. Comparison of overall thermodynamic parameters along with kinetics studies indicates that, although quadruplexes cannot efficiently compete with duplex formation at physiological pH, they delay the association of two strands

  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

    2015-01-01

    Background: Studies in humans have shown that haemostatic and inflammatory pathways both play important roles in the pathogenesis of joint disease. The aim of this study was to assess mRNA expression of haemostatic and inflammatory factors in cultured equine fibroblast-like synoviocytes exposed 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 ? g/ml LPS, 5 mg/ml fibrinogen or 5 U/ml thrombin and harvested at time points 0, 6, 24 and 48 h. mRNA expression of serum amyloid A (SAA), interleukin-6 (IL-6), monocyte chemotactic protein 1 (MCP-1), tissue factor (TF), plasminogen activator inhibitor 1 (PAI-1), urokinase plasminogen activator (uPA), vascular endothelial growth factor (VEGF) and protease activator receptor 1 (PAR-1) was assessed using quantitative real time reverse transcriptase PCR. Results: LPS caused a significant increase in mRNA expression of SAA, IL-6, MCP-1 and uPA, and a decrease in TF, PAI-1 and PAR-1 when compared to non-treated cells. Treatment with thrombin resulted in increased mRNA expression of SAA, IL-6, MCP-1 and PAI-1, and a decreased PAR-1 expression compared to non-treated cells. The fibrinogen-treated synoviocytes showed significantly increased mRNA expression of IL-6, MCP-1, TF and PAI-1, and decreased PAR-1 expression compared to non-treated cells. Conclusion: LPS, fibrinogen and thrombin induced an increased gene expression of inflammatory markers in isolated equine fibroblast-like synoviocytes. LPS caused changes in gene expression promoting increased fibrinolysis, while fibrinogen and thrombin changed the gene expression resulting potentially in reduced fibrinolysis. Overall, it appeared that both inflammatory and haemostatic stimuli affected expression of genes involved in inflammatory and haemostatic pathways, supporting their importance in equine joint diseases.

  16. Tracking topic birth and death in LDA.

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Andrew T.; Robinson, David Gerald

    2011-09-01

    Most topic modeling algorithms that address the evolution of documents over time use the same number of topics at all times. This obscures the common occurrence in the data where new subjects arise and old ones diminish or disappear entirely. We propose an algorithm to model the birth and death of topics within an LDA-like framework. The user selects an initial number of topics, after which new topics are created and retired without further supervision. Our approach also accommodates many of the acceleration and parallelization schemes developed in recent years for standard LDA. In recent years, topic modeling algorithms such as latent semantic analysis (LSA)[17], latent Dirichlet allocation (LDA)[10] and their descendants have offered a powerful way to explore and interrogate corpora far too large for any human to grasp without assistance. Using such algorithms we are able to search for similar documents, model and track the volume of topics over time, search for correlated topics or model them with a hierarchy. Most of these algorithms are intended for use with static corpora where the number of documents and the size of the vocabulary are known in advance. Moreover, almost all current topic modeling algorithms fix the number of topics as one of the input parameters and keep it fixed across the entire corpus. While this is appropriate for static corpora, it becomes a serious handicap when analyzing time-varying data sets where topics come and go as a matter of course. This is doubly true for online algorithms that may not have the option of revising earlier results in light of new data. To be sure, these algorithms will account for changing data one way or another, but without the ability to adapt to structural changes such as entirely new topics they may do so in counterintuitive ways.

  17. A Topic Modeling Toolbox Using Belief Propagation

    OpenAIRE

    Zeng, Jia

    2012-01-01

    Latent Dirichlet allocation (LDA) is an important hierarchical Bayesian model for probabilistic topic modeling, which attracts worldwide interests and touches on many important applications in text mining, computer vision and computational biology. This paper introduces a topic modeling toolbox (TMBP) based on the belief propagation (BP) algorithms. TMBP toolbox is implemented by MEX C++/Matlab/Octave for either Windows 7 or Linux. Compared with existing topic modeling packa...

  18. Online Belief Propagation for Topic Modeling

    OpenAIRE

    Zeng, Jia; Liu, Zhi-Qiang; Cao, Xiao-Qin

    2012-01-01

    The batch latent Dirichlet allocation (LDA) algorithms play important roles in probabilistic topic modeling, but they are not suitable for processing big data streams due to high time and space compleixty. Online LDA algorithms can not only extract topics from big data streams with constant memory requirements, but also detect topic shifts as the data stream flows. In this paper, we present a novel and easy-to-implement online belief propagation (OBP) algorithm that infers t...

  19. Mechanisms of sister chromatid recombination

    International Nuclear Information System (INIS)

    Studies using T948 as a model system have been carried out aimed at elucidating the mechanism of sister chromatid recombination (SCR). Characterization of U.V. light- and x-ray-induced SCR, the relationiship between SCR induction and DNA repair using rad mutations, and the relationship between SCR induction and the time of cell division using cdc mutations are presented. It has been supposed that SCR is induced at the phase of S-G2 following DNA replication, that postreplication break of DNA strands is strongly involved in the induction of SCR, and that induction type of SCR, i.e., conversion type or recombination type, is dependent upon the type of molecular damage of DNA. (Namekawa, K.)

  20. Topical tacrolimus as treatment of atopic dermatitis

    Directory of Open Access Journals (Sweden)

    Masutaka Furue

    2009-11-01

    Full Text Available Masutaka Furue, Satoshi TakeuchiDepartment of Dermatology, Faculty of Medical Sciences, Kyushu University, Fukuoka, JapanAbstract: Atopic dermatitis (AD is a common, chronic, relapsing, severely pruritic, eczematous skin disease. The mainstays of treatment for AD are topical tacrolimus and topical steroids. Tacrolimus, a calcineurin inhibitor, not only complements existing treatment options but also overcomes some of the drawbacks of topical steroid therapy when given topically and thus meets the long-term needs of patients in preventing disease progression. Topical tacrolimus has been widely recognized in terms of its short- and long-term efficacies and safety, and it is also accepted as a first-line treatment for inflammation in AD. The recent proactive use of topical tacrolimus may emphasize a long-term benefit of this calcineurin inhibitor for AD treatment. To reduce possible long-term adverse effects, it is important to monitor its topical doses in daily clinics.Keywords: atopic dermatitis, topical tacrolimus, topical steroids, dose, proactive use, adverse effects

  1. Microbial factories for recombinant pharmaceuticals

    OpenAIRE

    Domingo-Espín Joan; Ferrer-Miralles Neus; Corchero José; Vázquez Esther; Villaverde Antonio

    2009-01-01

    Abstract Most of the hosts used to produce the 151 recombinant pharmaceuticals so far approved for human use by the Food and Drug Administration (FDA) and/or by the European Medicines Agency (EMEA) are microbial cells, either bacteria or yeast. This fact indicates that despite the diverse bottlenecks and obstacles that microbial systems pose to the efficient production of functional mammalian proteins, namely lack or unconventional post-translational modifications, proteolytic instability, po...

  2. Recombinant bacteriophage lysins as antibacterials

    OpenAIRE

    Fenton, Mark; Ross, Paul; McAuliffe, Olivia; O'Mahony, Jim; Coffey, Aidan

    2010-01-01

    With the increasing worldwide prevalence of antibiotic resistant bacteria, bacteriophage endolysins (lysins) represent a very promising novel alternative class of antibacterial in the fight against infectious disease. Lysins are phage-encoded peptidoglycan hydrolases which, when applied exogenously (as purified recombinant proteins) to Gram-positive bacteria, bring about rapid lysis and death of the bacterial cell. A number of studies have recently demonstrated the strong potential of these e...

  3. Detection of Quantitative Trait Loci Influencing Recombination Using Recombinant Inbred Lines

    OpenAIRE

    Dole, Jefferey; Weber, David F.

    2007-01-01

    The genetic basis of variation in recombination in higher plants is polygenic and poorly understood, despite its theoretical and practical importance. Here a method of detecting quantitative trait loci (QTL) influencing recombination in recombinant inbred lines (RILs) is proposed that relies upon the fact that genotype data within RILs carry the signature of past recombination. Behavior of the segregational genetic variance in numbers of chromosomal crossovers (recombination) over generations...

  4. Nondisjunction of chromosome 15: Origin and recombination

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, W.P.; Bernasconi, F.; Schinzel, A.A.; Mutirangura, A.; Ledbetter, D.H. (Baylor College of Medicine, Houston, TX (United States)); Langlois, S. (Univ. of Britisch Columbia, Vancouver (Canada)); Morris, M.A.; Malcolm, S.

    1993-09-01

    Thirty-two cases of uniparental disomy (UPD), ascertained from Prader-Willi syndrome patients (N=27) and Angelman syndrome patients (N-5), are used to investigate the pattern of recombination associated with nondisjunction of chromosome 15. In addition, the meiotic stage of nondisjunction is inferred by using markers mapping near the centromere. Two basic approaches to the analysis of recombination in specific pairwise intervals along the chromosome. This method shows a significant reduction in recombination for two of five intervals examined. Second, the observed frequency of each recombinant class (i.e., zero, one, two, three, or more observable crossovers) is compared with expected values. This is useful for testing whether the reduction in recombination can be attributed solely to a proportion of cases with no recombination at all (because of asynapsis), with the remaining groups showing normal recombination (or even excess recombination), or whether recombination is uniformly reduced. Analysis of maternal UPD(15) data shows a slight reduction in the multiple-recombinant classes, with a corresponding increase in both the zero- and one-recombinant classes over expected values. The majority, more than 82%, of the extra chromosomes in maternal UPD(15) cases are due to meiotic I nondisjunction events. In contrast, more paternal UPD(15) cases so far examined appear to have a postzygotic origin of the extra paternal chromosome. 33 refs., 1 fig., 7 tabs.

  5. Homologous Recombination in Negative Sense RNA Viruses

    Directory of Open Access Journals (Sweden)

    Michael Worobey

    2011-08-01

    Full Text Available Recombination is an important process that influences biological evolution at many different levels. More and more homologous recombination events have been reported among negative sense RNA viruses recently. While sporadic authentic examples indicate that homologous recombination does occur, recombination seems to be generally rare or even absent in most negative sense RNA viruses, and most of the homologous recombination events reported in the literature were likely generated artificially due to lab contamination or inappropriate bioinformatics methods. Homologous recombination in negative sense RNA viruses should be reported with caution in the future, and only after stringent quality control efforts. Moreover, co-infection experiments should be performed to confirm whether recombination can occur.

  6. Recombinant factor XIII and congenital factor XIII deficiency: an update from human and animal studies

    Directory of Open Access Journals (Sweden)

    Inbal A

    2013-10-01

    Full Text Available Aida InbalThrombosis and Hemostasis Unit, Hematology Institute, Beilinson Hospital, Rabin Medical Center, Petach Tikva, and Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, IsraelAbstract: Factor XIII (FXIII is a protransglutaminase composed of two catalytic A subunits and two carrier B subunits. An intracellular form of FXIII is present in monocytes/macrophages and platelets as a homodimer of two A subunits. Following activation by thrombin, FXIII becomes plasma transglutaminase, which crosslinks ?-glutamyl-?-lysine residues of fibrin chains and thereby stabilizes the fibrin clot. FXIII deficiency results in a moderate to severe hemorrhagic disorder, abnormal wound healing in about 30% of patients, and recurrent abortion in homozygous females. More than 800 cases of FXIII deficiency have been reported, most of them due to mutation in the FXIII-A gene, resulting in FXIII-A deficiency. Among mutations causing FXIII-A deficiency, 50% are missense mutations. Only 16 mutations in the FXIII-B gene have been published. Routine laboratory tests are normal in patients with FXIII deficiency, and the diagnosis is established by demonstration of decreased FXIII activity and antigen. Plasma-derived, virus-inactivated factor XIII concentrate is the treatment of choice. The low plasma levels of FXIII (about 5% required to control bleeding and its long half-life make monthly prophylactic therapy feasible. Recently, recombinant FXIII concentrate with a half-life similar to that of native FXIII has been developed and tested in a multinational clinical study. This new product appears to be safe and appropriate for lifelong prophylactic treatment of patients with FXIII-A deficiency.Keywords: recombinant FXIII concentrate, FXIII deficiency

  7. Aerodynamics of wind turbines emerging topics

    CERN Document Server

    Amano, R S

    2014-01-01

    Focusing on Aerodynamics of Wind Turbines with topics ranging from Fundamental to Application of horizontal axis wind turbines, this book presents advanced topics including: Basic Theory for Wind turbine Blade Aerodynamics, Computational Methods, and Special Structural Reinforcement Technique for Wind Turbine Blades.

  8. Anesthesia: A Topic for Interdisciplinary Study.

    Science.gov (United States)

    Labianca, Dominick A.; Reeves, William J.

    1977-01-01

    Describes an interdisciplinary approach for teaching the topic of anesthesia as one aspect of a chemistry-oriented course for nonscience majors which focuses on timely topics such as the energy crisis and drugs. Historical treatment with the examination of literature is emphasized in teaching. (HM)

  9. Torpedo: topic periodicity discovery from text data

    Science.gov (United States)

    Wang, Jingjing; Deng, Hongbo; Han, Jiawei

    2015-05-01

    Although history may not repeat itself, many human activities are inherently periodic, recurring daily, weekly, monthly, yearly or following some other periods. Such recurring activities may not repeat the same set of keywords, but they do share similar topics. Thus it is interesting to mine topic periodicity from text data instead of just looking at the temporal behavior of a single keyword/phrase. Some previous preliminary studies in this direction prespecify a periodic temporal template for each topic. In this paper, we remove this restriction and propose a simple yet effective framework Torpedo to mine periodic/recurrent patterns from text, such as news articles, search query logs, research papers, and web blogs. We first transform text data into topic-specific time series by a time dependent topic modeling module, where each of the time series characterizes the temporal behavior of a topic. Then we use time series techniques to detect periodicity. Hence we both obtain a clear view of how topics distribute over time and enable the automatic discovery of periods that are inherent in each topic. Theoretical and experimental analyses demonstrate the advantage of Torpedo over existing work.

  10. Fostering Topic Knowledge: Essential for Academic Writing

    Science.gov (United States)

    Proske, Antje; Kapp, Felix

    2013-01-01

    Several researchers emphasize the role of the writer's topic knowledge for writing. In academic writing topic knowledge is often constructed by studying source texts. One possibility to support that essential phase of the writing process is to provide interactive learning questions which facilitate the construction of an adequate situation…

  11. Severe photosensitivity reaction induced by topical diclofenac

    Directory of Open Access Journals (Sweden)

    Pramod B Akat

    2013-01-01

    Full Text Available Albeit uncommon, photosensitivity reaction induced by diclofenac can be an unfortunate adverse reaction complicating its use as a topical analgesic. We here present a case of a patient who suffered such a reaction as a result of exposure to diclofenac, employed as a topical analgesic for low backache. The lesions healed with conservative management without extensive scarring or other complications.

  12. The Prototypicality of Topic in Mandarin Chinese.

    Science.gov (United States)

    Chu, Chauncey C.

    1993-01-01

    Data from 82 native speakers of Chinese were used to test a hypothesis about the topic in Chinese. The basic characteristics are those of being a nominal and serving as an interclausal link, and the hypothesis is revised to consist of these two as primary attributes. The Chinese prototype and the universal topic are compared. (Contains 20…

  13. Selected topics in nuclear and atomics physics

    International Nuclear Information System (INIS)

    Three topics of current interest are briefly discussed: direct radiative capture of slow neutrons, global systematics of B(E2;01+ ? 21+) values, and advances in the study of heavy-ion-induced x-ray satellite emission. An interested reader is provided with a list of recent references on the above topics. 14 refs., 3 figs

  14. Recent Advances in Topical Ocular Drug Delivery.

    Science.gov (United States)

    Yellepeddi, Venkata Kashyap; Palakurthi, Srinath

    2016-03-01

    Topical ocular drug delivery has been considered to be an ideal route of administration for treatment of ocular diseases related to the anterior segment of the eye. However, topical ocular delivery is a challenging task because of barriers such as nasolacrimal drainage, corneal epithelium, blood-ocular barriers, and metabolism in the eye. Approaches to improve ocular bioavailability include physical approaches such as formulations of drugs as solutions (Zymaxid(™)), suspensions (Zigran(®)), gels (Akten(®)) and chemical approaches such as prodrugs (Xalatan(™)), chemical delivery systems, and soft drugs. The purpose of this review article is to summarize recent advances in topical drug delivery to the anterior segment of the eye. Functional transporters in the corneal epithelium were also discussed as they provide prospects in topical ocular delivery. In addition to conventional delivery systems, novel delivery systems involving nanocarriers were also investigated for topical ocular delivery. Furthermore, due to increased interest, gene therapy applications of topical ocular delivery of genes to the anterior segment of the eye were also discussed. Research in topical ocular delivery is active for more than 50 years and proven to be advantageous for the treatment of many ocular diseases. However, there is scope for innovation in topical drug delivery to develop delivery systems with a high patient safety profile and compliance for effective clinical usefulness. PMID:26666398

  15. Severe photosensitivity reaction induced by topical diclofenac

    OpenAIRE

    Pramod B. Akat

    2013-01-01

    Albeit uncommon, photosensitivity reaction induced by diclofenac can be an unfortunate adverse reaction complicating its use as a topical analgesic. We here present a case of a patient who suffered such a reaction as a result of exposure to diclofenac, employed as a topical analgesic for low backache. The lesions healed with conservative management without extensive scarring or other complications.

  16. Correlated Topic Model for Web Services Ranking

    Directory of Open Access Journals (Sweden)

    Mustapha AZNAG

    2013-07-01

    Full Text Available With the increasing number of published Web services providing similar functionalities, it’s very tedious for a service consumer to make decision to select the appropriate one according to her/his needs. In this paper, we explore several probabilistic topic models: Probabilistic Latent Semantic Analysis (PLSA, Latent Dirichlet Allocation (LDA and Correlated Topic Model (CTM to extract latent factors from web service descriptions. In our approach, topic models are used as efficient dimension reduction techniques, which are able to capture semantic relationships between word-topic and topic-service interpreted in terms of probability distributions. To address the limitation of keywords-based queries, we represent web service description as a vector space and we introduce a new approach for discovering and ranking web services using latent factors. In our experiment, we evaluated our Service Discovery and Ranking approach by calculating the precision (P@n and normalized discounted cumulative gain (NDCGn.

  17. Topical antioxidants in radiodermatitis: a clinical review.

    Science.gov (United States)

    Kodiyan, Joyson; Amber, Kyle T

    2015-09-01

    Radiation-induced skin toxicity is the most prevalent side effect of radiation therapy. Not only does it have a significant effect on patients' quality of life, but it also results in poor follow-up and early termination of radiotherapy treatment. Several skin care practices and topical applications have been studied in the field of radiodermatitis, including skin washing, topical steroids, and mechanical skin barriers. Aside from these methods, many patients turn to complementary and alternative medicine for the prevention and treatment of radiodermatitis. Many of these alternative therapies are topically applied antioxidants. While the rationale behind the use of antioxidants in treating radiodermatitis is strong, clinical studies have been far less consistent. Even in large scale randomised controlled trials, findings have been limited by the inconsistent use of topical vehicles and placebos. In this article, the authors review the role of topical antioxidants to better help the practitioner navigate through different available skin directed antioxidants. PMID:26412275

  18. Staphylocidal action of thrombin-induced platelet microbicidal protein is influenced by microenvironment and target cell growth phase.

    Science.gov (United States)

    Koo, S P; Yeaman, M R; Bayer, A S

    1996-09-01

    Thrombin-induced platelet microbicidal protein (tPMP) is a small, cationic peptide released from rabbit platelets following exposure to thrombin in vitro. This peptide exerts potent in vitro microbicidal activity against a broad spectrum of bloodstream pathogens, including Staphylococcus aureus. It is known that the microbicidal actions of other cationic antimicrobial peptides (e.g., neutrophil defensins) are influenced by environmental factors and target cell growth phase. However, whether these parameters affect tPMP microbicidal activity has not been studied. Thus, we assessed the in vitro bactericidal activity of tPMP against two tPMP-susceptible strains, Bacillus subtilis ATCC 6633 and S. aureus 502A, in various target cell growth phases or under various microenvironmental conditions. The conditions studied included differing bacterial growth phase (logarithmic versus stationary), temperature (range, 4 to 42 degrees C), pH (range, 4.5 to 8.5), cationicity (range, 0.1 mM to 2 M), anionicity (range, 0.08 to 5 microM), and neutral carbohydrates ranging in molecular weight (MW) from 180 to 37,700 (range, 50 to 500 mM) as well as rabbit platelet-free plasma and serum. tPMP staphylocidal activity was greater against logarithmic- than stationary-phase cells. tPMP bactericidal activity against both B. subtilis and S. aureus was directly correlated with temperature and pH, with microbicidal activity exhibited near the physiological range (37 to 42 degrees C and pH 7.2 to 8.5, respectively). The presence of cations (Na+, K+, Ca2+, and Mg2+) decreased tPMP bactericidal activity in a time- and concentration-dependent manner, with complete inhibition at monovalent or divalent cation concentrations of > or = 250 or > or = 10 mM, respectively. Staphylocidal activity of tPMP was also inhibited by the polyanions polyanetholsulfonic acid and polyaspartic acid, at 0.1 and 0.4 microM, respectively. Coincident exposure with low-MW carbohydrates (glucose, sucrose, and melezitose) did not affect tPMP staphylocidal activity. However, higher-MW carbohydrates (raffinose and dextrans) decreased tPMP activity in a manner directly proportional to their concentration and MW. Solute-mediated inhibition of tPMP bactericidal activity was independent of solute osmolality but directly related to the duration of tPMP-solute coexposure. tPMP enhanced the staphylocidal activities of platelet-free plasma and heat-inactivated serum, while the activity of normal serum was not affected. These collective observations suggest that tPMP retains antimicrobial activities under physiological conditions which are likely to be relevant to host defense in vivo. PMID:8751926

  19. Topics on Electricity Transmission Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerndal, Mette

    2000-02-01

    Within the last decade we have experienced deregulation of several industries, such as airlines, telecommunications and the electric utility industry, the last-mentioned being the focus of this work. Both the telecommunications and the electricity sector depend on network facilities, some of which are still considered as natural monopolies. In these industries, open network access is regarded as crucial in order to achieve the gains from increased competition, and transmission tariffs are important in implementing this. Based on the Energy Act that was introduced in 1991, Norway was among the first countries to restructure its electricity sector. On the supply side there are a large number of competing firms, almost exclusively hydro plants, with a combined capacity of about 23000 MW, producing 105-125 TWh per year, depending on the availability of water. Hydro plants are characterized by low variable costs of operation, however since water may be stored in dams, water has an opportunity cost, generally known as the water value, which is the shadow price of water when solving the generator's inter temporal profit maximization problem. Water values are the main factor of the producers' short run marginal cost. Total consumption amounts to 112-117 TWh a year, and consumers, even households, may choose their electricity supplier independent of the local distributor to which the customer is connected. In fact, approximately 10% of the households have actually changed supplier. The web-site www.konkurransetilsynet.no indicates available contracts, and www.dinside.no provides an ''energy-calculator'' where one can check whether it is profitable to switch supplier. If a customer buys energy from a remote supplier, the local distributor only provides transportation facilities for the energy and is compensated accordingly. Transmission and distribution have remained monopolized and regulated by the Norwegian Water Resources and Energy Directorate (NVE). To prevent cross-subsidization, the largest state-owned firm was split to form Statkraft SF, Norway's largest generation company, and Statnett SF, the major transmission company. Statnett is also the system operator of the entire Norwegian power system. Many distribution companies, usually publicly owned, are still part of vertically integrated companies, but there is strict separation of the financial accounts for transmission/distribution and generation/marketing. Trading is accomplished through several channels. The largest organized market is the common Norwegian-Swedish pool, NordPool. NordPool ASA is owned by Statnett Marked (which is a subsidiary of Statnett) and the Swedish grid-company, Svenska Kraftnaet. NordPool also supports the Finnish and Danish markets, thus through cooperation with the grid-companies of Denmark (Eltra) and Finland (Fingrid), locational markets are provided in these countries as well. Unlike England and Wales, only part of actual production is traded on this market. In addition, independent brokers offer various energy-contracts and facilitate bilateral contracts. In 1998 22% of the energy was traded on the hourly day-ahead (spot) market of NordPool. NordPool also organizes a forward and futures market and settles contracts from the regulation market organized by Statnett. The regulation market is a realtime market used to settle imbalances in real time. In total, close to 30% of the energy traded is organized through NordPool, and this share is increasing year by year. The efficiency of the market is heavily affected by the operation and pricing of the transmission system, and the topic of this thesis concerns the interaction of the transmission network and the energy markets. Throughout, the findings are illustrated by means of simple examples. This is to enhance readability and intuition. Chapter 2 is devoted to power flow models, whereas chapter 3 provides an overview of models developed to efficiently coordinate the allocation of transmission resources. The focus is mainly on short-term efficiency, and the survey is only par tial, but provides an integrated overview of some of the theoretical models most frequently cited in the literature. Chapter 4 gives an overview of the Norwegian transmission system, especially the central high voltage grid, and we describe the tariff structure, which applies in this part of the network. In chapter 5 we comment on loop flow and economic modeling. Chapters 6 and 7 concern the implementation of short run marginal cost pricing in the Norwegian transmission system, marginal losses are treated in chapter 6, and in chapter 7 zonal pricing is examined. Loop flow induces seemingly paradoxical situations in power transmission, and in chapter 8 we show that a new line may reduce social surplus, whereas in chapter 9 the competitive effects of a new line are studied. The main contributions of the thesis are found in chapters 5-9. In chapter 10 suggestions for future research are indicated. (author)

  20. Topics in Electricity Transmission Pricing

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerndal, Mette

    2000-02-01

    Within the last decade we have experienced deregulation of several industries, such as airlines, telecommunications and the electric utility industry, the last-mentioned being the focus of this work. Both the telecommunications and the electricity sector depend on network facilities, some of which are still considered as natural monopolies. In these industries, open network access is regarded as crucial in order to achieve the gains from increased competition, and transmission tariffs are important in implementing this. Based on the Energy Act that was introduced in 1991, Norway was among the first countries to restructure its electricity sector. On the supply side there are a large number of competing firms, almost exclusively hydro plants, with a combined capacity of about 23000 MW, producing 105-125 TWh per year, depending on the availability of water. Hydro plants are characterized by low variable costs of operation, however since water may be stored in dams, water has an opportunity cost, generally known as the water value, which is the shadow price of water when solving the generator's inter temporal profit maximization problem. Water values are the main factor of the producers' short run marginal cost. Total consumption amounts to 112-117 TWh a year, and consumers, even households, may choose their electricity supplier independent of the local distributor to which the customer is connected. In fact, approximately 10% of the households have actually changed supplier. The web-site www.konkurransetilsynet.no indicates available contracts, and www.dinside.no provides an ''energy-calculator'' where one can check whether it is profitable to switch supplier. If a customer buys energy from a remote supplier, the local distributor only provides transportation facilities for the energy and is compensated accordingly. Transmission and distribution have remained monopolized and regulated by the Norwegian Water Resources and Energy Directorate (NVE). To prevent cross-subsidization, the largest state-owned firm was split to form Statkraft SF, Norway's largest generation company, and Statnett SF, the major transmission company. Statnett is also the system operator of the entire Norwegian power system. Many distribution companies, usually publicly owned, are still part of vertically integrated companies, but there is strict separation of the financial accounts for transmission/distribution and generation/marketing. Trading is accomplished through several channels. The largest organized market is the common Norwegian-Swedish pool, NordPool. NordPool ASA is owned by Statnett Marked (which is a subsidiary of Statnett) and the Swedish grid-company, Svenska Kraftnaet. NordPool also supports the Finnish and Danish markets, thus through cooperation with the grid-companies of Denmark (Eltra) and Finland (Fingrid), locational markets are provided in these countries as well. Unlike England and Wales, only part of actual production is traded on this market. In addition, independent brokers offer various energy-contracts and facilitate bilateral contracts. In 1998 22% of the energy was traded on the hourly day-ahead (spot) market of NordPool. NordPool also organizes a forward and futures market and settles contracts from the regulation market organized by Statnett. The regulation market is a realtime market used to settle imbalances in real time. In total, close to 30% of the energy traded is organized through NordPool, and this share is increasing year by year. The efficiency of the market is heavily affected by the operation and pricing of the transmission system, and the topic of this thesis concerns the interaction of the transmission network and the energy markets. Throughout, the findings are illustrated by means of simple examples. This is to enhance readability and intuition. To start with, chapter 2 is devoted to power flow models, whereas chapter 3 provides an overview of models developed to efficiently coordinate the allocation of transmission resources. The focus is mainly on short-term efficiency, and the survey is only partial, but provides an integrated overview of some of the theoretical models most frequently cited in the literature. Chapter 4 gives an overview of the Norwegian transmission system, especially the central high voltage grid, and we describe the tariff structure, which applies in this part of the network. In chapter 5 we comment on loop flow and economic modeling. Chapters 6 and 7 concern the implementation of short run marginal cost pricing in the Norwegian transmission system, marginal losses are treated in chapter 6, and in chapter 7 zonal pricing is examined. Loop flow induces seemingly paradoxical situations in power transmission, and in chapter 8 we show that a new line may reduce social surplus, whereas in chapter 9 the competitive effects of a new line are studied. The main contributions of the thesis are found in chapters 5-9. (author)

  1. Topics on Electricity Transmission Pricing

    International Nuclear Information System (INIS)

    Within the last decade we have experienced deregulation of several industries, such as airlines, telecommunications and the electric utility industry, the last-mentioned being the focus of this work. Both the telecommunications and the electricity sector depend on network facilities, some of which are still considered as natural monopolies. In these industries, open network access is regarded as crucial in order to achieve the gains from increased competition, and transmission tariffs are important in implementing this. Based on the Energy Act that was introduced in 1991, Norway was among the first countries to restructure its electricity sector. On the supply side there are a large number of competing firms, almost exclusively hydro plants, with a combined capacity of about 23000 MW, producing 105-125 TWh per year, depending on the availability of water. Hydro plants are characterized by low variable costs of operation, however since water may be stored in dams, water has an opportunity cost, generally known as the water value, which is the shadow price of water when solving the generator's inter temporal profit maximization problem. Water values are the main factor of the producers' short run marginal cost. Total consumption amounts to 112-117 TWh a year, and consumers, even households, may choose their electricity supplier independent of the local distributor to which the customer is connected. In fact, approximately 10% of the households have actually changed supplier. The web-site www.konkurransetilsynet.no indicates available contracts, and www.dinside.no provides an ''energy-calculator'' where one can check whether it is profitable to switch supplier. If a customer buys energy from a remote supplier, the local distributor only provides transportation facilities for the energy and is compensated accordingly. Transmission and distribution have remained monopolized and regulated by the Norwegian Water Resources and Energy Directorate (NVE). To prevent cross-subsidization, the largest state-owned firm was split to form Statkraft SF, Norway's largest generation company, and Statnett SF, the major transmission company. Statnett is also the system operator of the entire Norwegian power system. Many distribution companies, usually publicly owned, are still part of vertically integrated companies, but there is strict separation of the financial accounts for transmission/distribution and generation/marketing. Trading is accomplished through several channels. The largest organized market is the common Norwegian-Swedish pool, NordPool. NordPool ASA is owned by Statnett Marked (which is a subsidiary of Statnett) and the Swedish grid-company, Svenska Kraftnaet. NordPool also supports the Finnish and Danish markets, thus through cooperation with the grid-companies of Denmark (Eltra) and Finland (Fingrid), locational markets are provided in these countries as well. Unlike England and Wales, only part of actual production is traded on this market. In addition, independent brokers offer various energy-contracts and facilitate bilateral contracts. In 1998 22% of the energy was traded on the hourly day-ahead (spot) market of NordPool. NordPool also organizes a forward and futures market and settles contracts from the regulation market organized by Statnett. The regulation market is a realtime market used to settle imbalances in real time. In total, close to 30% of the energy traded is organized through NordPool, and this share is increasing year by year. The efficiency of the market is heavily affected by the operation and pricing of the transmission system, and the topic of this thesis concerns the interaction of the transmission network and the energy markets. Throughout, the findings are illustrated by means of simple examples. This is to enhance readability and intuition. To start with, chapter 2 is devoted to power flow models, whereas chapter 3 provides an overview of models developed to efficiently coordinate the allocation of transmission resources. The focus is mainly on short-term efficiency, and the survey is only par tial, but provides an integrated overview of some of the theoretical models most frequently cited in the literature. Chapter 4 gives an overview of the Norwegian transmission system, especially the central high voltage grid, and we describe the tariff structure, which applies in this part of the network. In chapter 5 we comment on loop flow and economic modeling. Chapters 6 and 7 concern the implementation of short run marginal cost pricing in the Norwegian transmission system, marginal losses are treated in chapter 6, and in chapter 7 zonal pricing is examined. Loop flow induces seemingly paradoxical situations in power transmission, and in chapter 8 we show that a new line may reduce social surplus, whereas in chapter 9 the competitive effects of a new line are studied. The main contributions of the thesis are found in chapters 5-9. In chapter 10 suggestions for future research are indicated. (author)

  2. Topics in combinatorial pattern matching

    DEFF Research Database (Denmark)

    VildhØj, Hjalte Wedel

    2015-01-01

    This dissertation studies problems in the general theme of combinatorial pattern matching. More specifically, we study the following topics: Longest Common Extensions. We revisit the longest common extension (LCE) problem, that is, preprocess a string T into a compact data structure that supports fast LCE queries. An LCE query takes a pair (i, j) of indices in T and returns the length of the longest common prefix of the suffixes of T starting at positions i and j. Such queries are also commonly known as longest common prefix (LCP) queries. We study the time-space trade-offs for the problem, that is, the space used for the data structure vs. the worst-case time for answering an LCE query. Let n be the length of T. Given a parameter ? , 1 ? ? ? n, we show how to achieve either O(n/?? ) space and O(?) query time, or O(n/?) space and O(? log (|LCE(i, j)|/?)) query time, where ?LCE(i, j)| denotes the length of the LCE returned by the query. These bounds provide the first smooth trade-offs for the LCE problem and almost match the previously known bounds at the extremes when ? = 1 or ? = n. We apply the result to obtain improved bounds for several applications where the LCE problem is the computational bottleneck, including approximate string matching and computing palindromes. We also present an efficient technique to reduce LCE queries on two strings to one string. Finally, we give a lower bound on the time-space product for LCE data structures in the non-uniform cell probe model showing that our second trade-off is nearly optimal. Fingerprints in Compressed Strings. The Karp-Rabin fingerprint of a string is a type of hash value that due to its strong properties has been used in many string algorithms. We show how to construct a data structure for a string S of size N compressed by a context-free grammar of size n that supports fingerprint queries. That is, given indices i and j, the answer to a query is the fingerprint of the substring S[i, j]. We present the first O(n) space data structures that answer fingerprint queries without decompressing any characters. For Straight Line Programs (SLP) we get O(log N) query time, and for Linear SLPs (an SLP derivative that captures LZ78 compression and its variations) we get O (log log N) query time. Hence, our data structures has the same time and space complexity as for random access in SLPs. We utilize the fingerprint data structures to solve the longest common extension problem in query time O(log N log e) and O(log e log log e+log log N) for SLPs and Linear SLPs, respectively. Here, e = |LCE(i, j)| denotes the length of the LCE. Sparse Text Indexing. We present efficient algorithms for constructing sparse suffix trees, sparse suffix arrays and sparse positions heaps for b arbitrary positions of a text T of length n while using only O(b) words of space during the construction. Our main contribution is to show that the sparse suffix tree (and array) can be constructed in O(n log² b) time. To achieve this we develop a technique, that allows to efficiently answer b longest common prefix queries on suffixes of T, using only O(b) space. Our first solution is Monte-Carlo and outputs the correct tree with high probability. We then give a Las-Vegas algorithm which also uses O(b) space and runs in the same time bounds with high probability when b = O(?n). Furthermore, additional tradeoffs between the space usage and the construction time for the Monte-Carlo algorithm are given. Finally, we show that at the expense of slower pattern queries, it is possible to construct sparse position heaps in O(n + b log b) time and O(b) space. The Longest Common Substring Problem. Given m documents of total length n, we consider the problem of finding a longest string common to at least d ? 2 of the documents. This problem is known as the longest common substring (LCS) problem and has a classic O(n) space and O(n) time solution (Weiner [FOCS’73], Hui [CPM’92]). However, the use of linear space is impractical in many applications. We show several time-space trade-offs for this probl

  3. 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

    2013-01-01

    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. 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 to experience an MI than their counterparts treated with warfarin (285 of 23,333 vs 133 of 16,024, odds ratio 1.35, 95% confidence interval 1.10 to 1.66, p = 0.005). For secondary analysis, 8 studies (69,615 patients) were identified that compared warfarin with alternative anticoagulant including factor Xa inhibitors, DTIs, aspirin, and clopidogrel. There was no significant advantage in the rate of MIs with the use of warfarin versus comparators (odds ratio 1.06, 95% confidence interval 0.85 to 1.34, p = 0.59). In conclusion, our data suggest that oral DTIs were associated with increased risk of MI. This increased risk appears to be a class effect of these agents, not a specific phenomenon unique to dabigatran or protective effect of warfarin. These findings support the need for enhanced postmarket surveillance of oral DTIs and other novel agents.

  4. Amplified thrombin aptasensor based on alkaline phosphatase and hemin/G-quadruplex-catalyzed oxidation of 1-naphthol.

    Science.gov (United States)

    Yang, Zhe-Han; Zhuo, Ying; Yuan, Ruo; Chai, Ya-Qin

    2015-05-20

    An alkaline phosphatase (ALP)-based biosensor can in situ generate an electroactive product by enzymatic hydrolysis of inactive substrates. To obtain a higher signal-to-background ratio, a chemical redox cycling signal-amplified strategy based on the addition of a strong reducing agent has often be applied in the construction of ALP-based biosensors. However, the strong reducing agent not only affects the activity of ALP but also readily reacts with dissolved oxygen, leading to inaccurate results. In this work, a new signal-amplified strategy for a thrombin (TB) aptasensor based on the catalytic oxidation of ALP-generated products, 1-naphthol (NP), using hemin/G-quadruplex DNAzymes was reported. We implemented gold-nanoparticle-decorated zinc oxide nanoflowers (Au-ZnO) as the matrix for immobilizing ALP and TB aptamer (TBA) and then labeled it with hemin to form hemin/G-quadruplex/ALP/Au-ZnO bioconjugates (TBA II bioconjugates). Through a "sandwich" reaction, TBA II bioconjugates were captured on the electrode surface. The amplified signal was carried out in two steps: (i) an ALP-catalyzed inactive substrate, 1-naphthyl phosphate (NPP), in situ produces NP on the surface of the electrode; (ii) on the one hand, NP as a new reactant could be directly electrooxidized and generated an electrochemical signal, but, on the other hand, NP could be oxidized by hemin/G-quadruplex in the presence of H2O2, resulting in amplification of the electrochemical signal. The proposed TB aptasensor achieved a linear range of 1 pM to 30 nM with a detection limit of 0.37 pM (defined as S/N = 3). PMID:25907268

  5. Effective inhibition of thrombin by Rhipicephalus microplus serpin-15 (RmS-15) obtained in the yeast Pichia pastoris.

    Science.gov (United States)

    Xu, Tao; Lew-Tabor, Ala; Rodriguez-Valle, Manuel

    2016-02-01

    The cattle tick (Rhipicephalus microplus) affects cattle industries in tropical and subtropical countries because it is the vector of babesiosis and anaplasmosis which constitutes a threat to the health of cattle. During blooding feeding, ticks secrete saliva containing a complex of bioactive molecules into the injured site to evade host's defensive responses. Serine protease inhibitors (serpins) are important anti-haemostatic molecules present in tick saliva that are necessary for a successful blood feeding. Several serpin sequences have been reported in R. microplus but there is a gap of information about their functions during host-parasite interactions. In this study, the RmS-15 expressed in the yeast Pichia pastoris was characterised using kinetic assays and in vitro analysis. The inhibitory enzymatic assays conducted showed that RmS-15 is a physiological inhibitor of thrombin with a stoichiometric inhibition (SI) of 1.5 and high inhibition affinity with ka=9.3±0.5×104M(-1)s(-1). RmS-15 delayed the clotting of plasma in a dose-dependent manner as determined in a recalcification time assay. Significant elevated ELISA titres were observed in tick resistant and susceptible cattle on day 28 after the tick infestation (p<0.001). This data suggests direct contact of RmS-15 with the immune system of the host at the tick-feeding site. The present study contributed to the understanding of the biological functions of R. microplus serpins during host-parasite interactions which contributes to the design of future innovative methods for tick control. PMID:26530984

  6. 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.

  7. Thrombin-activatable fibrinolysis inhibitor activity and global fibrinolytic capacity in Type 1 diabetes: evidence for normal fibrinolytic state.

    Science.gov (United States)

    Harmanci, Ayla; Kandemir, Nurgun; Dagdelen, Selcuk; Gonc, Nazli; Buyukasik, Yahya; Alikasifoglu, Ayfer; Kirazli, Serafettin; Ozon, Alev; Gurlek, Alper

    2006-01-01

    Hypofibrinolysis is a state that is commonly observed in type 2 diabetic patients, a finding also possibly related to obesity and insulin resistance. There is little information, however, regarding the status of fibrinolytic system in Type 1 diabetes, in particular as reflected by thrombin-activatable fibrinolysis inhibitor (TAFI) activity and global fibrinolytic capacity (GFC). To provide information in this respect, 30 Type 1 diabetic patients (median age=16) and 28 healthy controls (median age=14) were enrolled in this study. The median duration of diabetes was 7 years, and median HbA(1c) was 8.85% (range: 5.5-11.9%) in the diabetic group. None of the patients had macrovascular complications. Microvascular complications were present in a total of eight patients (nephropathy: n=5; retinopathy: n=3). A comparison of the TAFI activity between the patient (median 84.9, range: 71.5-103.3%) and the control groups (median=83.3, range: 63.7-97.4%) yielded no statistically significant difference (P=.950). Similarly, GFC was comparable between the two groups (median=8.22, range: 0.72-22.38 microg/ml, and median=13.32, range: 3.0-23.22 microg/ml, respectively, in the diabetic and control groups, P=.086). TAFI activity did not significantly correlate with age, albumin excretion, fasting plasma glucose, HbA(1c), D-dimer, and fibrinogen by Spearman rank correlation test. There was as a significant inverse correlation between GFC and TAFI activity (r=-.414, P=.006). Contrary to the previous observations in Type 2 diabetes, our data suggest that fibrinolytic activity is not adversely affected by Type 1 diabetes, and it has no relationship with the degree of metabolic control. PMID:16389166

  8. Thrombin-activatable fibrinolysis inhibitor Thr325Ile polymorphism and plasma level in breast cancer: A pilot study

    Directory of Open Access Journals (Sweden)

    Manal S. Fawzy

    2015-06-01

    Full Text Available This study aimed to investigate thrombin-activatable fibrinolysis inhibitor (TAFI Thr325Ile polymorphism and TAFI antigen (Ag levels in breast cancer (BC in the Egyptian population to clarify their role in relation to BC. A group of 300 females was recruited in this study; of these 150 unrelated patients with different stages of BC and 150 age-matched healthy controls. Plasma TAFI Ag was measured by ELISA and TAFI Thr325Ile (rs1926447 polymorphism was genotyped using TaqMan single nucleotide polymorphism (SNP genotyping assay. The results showed the genotypes of the minor allele; Thr/Ile (CT and Ile/Ile (TT were significantly more frequent in patients compared to control group (50.0% and 22.0% vs. 42.0% and 13.3%, respectively and were also associated with BC susceptibility [OR = 1.9 and 2.6; 95% CI: (1.1–3.3 and (1.3–5.5, respectively P = 0.01]. Ile325 allele carriers were more frequent in cases than in controls (47.0% vs. 34.0% [OR = 1.7, (95% CI = 1.2–2.4, P = 0.001]. However, TAFI Thr325Ile polymorphism was not associated with BC stage or other clincopathological characteristics. TAFI Ag levels were correlated with advanced stages of BC, poor prognosis and risk of recurrence (P = 0.02, P = 0.04 and P  < 0.001, respectively and Thr325Ile SNP was significantly correlated with TAFI antigen levels with the C/C genotype corresponding to the highest and the T/T genotype to the lowest TAFI antigen levels (P < 0.001 in the study groups. In conclusion, this study showed for the first time that TAFI Thr325Ile polymorphism could have a contribution to BC susceptibility in our population. Furthermore, high TAFI plasma levels may serve as a predictor of poor prognosis in patients with BC.

  9. Talking topically to artificial dialog partners: Emulating humanlike topic awareness in a virtual agent

    OpenAIRE

    Breuing, Alexa; Wachsmuth, Ipke

    2013-01-01

    During dialog, humans are able to track ongoing topics, to detect topical shifts, to refer to topics via labels, and to decide on the appropriateness of potential dialog topics. As a result, they interactionally produce coherent sequences of spoken utterances assigning a thematic structure to the whole conversation. Accordingly, an artificial agent that is intended to engage in natural and sophisticated human-agent dialogs should be endowed with similar conversational abilities. This paper pr...

  10. Dissociative Recombination of He_2^+

    Science.gov (United States)

    Coman, L.; Guna, M.; Simons, L.; Hardy, Kenneth A.

    1999-10-01

    The final product states of the dissociative recombination (DR) of He_2^+ have been studied by time of flight (TOF) spectroscopy. DR final product state atoms were seen in six final product states, and from the V = 2,3,4, and 5 vibrational levels of the molecular ion. The energy resolution of the TOF method is sufficient to separate the rotational levels built of these vibrational states. Rotational states up to J=15 were observed. From the rotational states observed, we made the first measurements of the rotational constants of the molecule, and find that the vibrational constants are in reasonable agreement with those predicted by theory.

  11. CRMAGE: CRISPR Optimized MAGE Recombineering

    DEFF Research Database (Denmark)

    Ronda, Carlotta; Pedersen, Lasse Ebdrup; Sommer, Morten Otto Alexander; Nielsen, Alex Toftgaard

    2016-01-01

    A bottleneck in metabolic engineering and systems biology approaches is the lack of efficient genome engineering technologies. Here, we combine CRISPR/Cas9 and λ Red recombineering based MAGE technology (CRMAGE) to create a highly efficient and fast method for genome engineering of Escherichia coli...... assembled by a USER-cloning approach enabling quick and cost efficient gRNA replacement. CRMAGE furthermore utilizes CRISPR/Cas9 for efficient plasmid curing, thereby enabling multiple engineering rounds per day. To facilitate the design process, a web-based tool was developed to predict both the λ Red...

  12. Dissociative recombination in interstellar clouds

    Science.gov (United States)

    Black, John H.; Van Dishoeck, Ewine F.

    1989-01-01

    Molecular ions play a significant role in the chemistry and evolution of interstellar molecular clouds, even though these regions are overwhelmingly neutral. The dissociative recombination (DR) process governs the abundances of many of these ions and of related neutral species. The gas-phase ion-molecule chemistry of the simplest species is summarized, with emphasis on those problems which are most sensitive to uncertain rates or product branching ratios of DR processes. Examples of the kinds of information needed about DR processes are presented. The importance of the H3(+) ion and prospects for its direct observation are discussed.

  13. Pharmacokinetic and galactopoietic response to recombinant variants of bovine growth hormone.

    Science.gov (United States)

    Eppard, P J; White, T C; Birmingham, B K; Hintz, R L; Bentle, L A; Wood, D C; Salsgiver, W J; Rowold, E; Miller, M A; Ganguli, S

    1993-12-01

    Two studies were designed to examine the pharmacokinetic and galactopoietic potency of three molecular variants of recombinant-derived bovine GH (rbGH): [Met1, Leu127]-bGH, [Ala1, Val127]-bGH and [Ala1, Val127, His133]-bGH. Histidine substitution for arginine at residue 133 of rbGH was shown to impart thrombin resistance. In a Latin square design, nine lactating Holstein cows received a 25 mg rbGH bolus infusion via the jugular vein followed by frequent blood sampling over the next 12 h. The serum GH concentration data were found to fit a two-compartment open model. Neither primary nor secondary kinetic parameter estimates differed significantly (P > 0.05) among the three rbGH variants. Thus, the disposition of GH concentration at time t was described by the equation C(t) = (1295.5 micrograms/l) (e-(0.11/min)(t)) + (317.3 micrograms/l)(e-(0.03/min)(t)). Overall averages were: area under the curve = 27.1 mg.min per l, clearance = 0.15 litres/min per 100 kg and volume of distribution of the central compartment = 2.59 litres/100 kg. The t 1/2 for the two compartments averaged 8.2 and 29.1 min. In the second study, 36 lactating Holstein cows received i.m. injections of one of four oil-based formulation treatments: control vehicle or 500 mg of one of the three rbGH variants every 14 days for 42 days. Average and maximum serum GH concentrations and area under the curve estimates were increased by approximately 3-6 micrograms/l, 5-15 micrograms/l and 40-90 micrograms.day per 1 respectively. Ala1, Val127 rbGH treatments elicited greater blood GH concentrations than [Met1, Leu127]-bGH when administered in an oil-based formulation. Blood GH responses did not directly translate into milk response differences, possibly due to differences in biopotency or receptor availability. Thrombin resistance resulting from substitution of histidine at position 127 of rbGH did not affect blood GH pharmacokinetic parameters or milk response over other rbGH variants. PMID:8133211

  14. Effects of nuclear mutations for recombination and repair functions and of caffeine on mitochondrial recombination

    International Nuclear Information System (INIS)

    Studies of both prokaryotic and eukaryotic organisms indicate that pathways governing repair of damage to nuclear DNA caused by x-ray or ultraviolet irradiation overlap with those controlling recombination. Fourteen nuclear mutants of Saccharomyces cerevisiae were tested in order to determine whether these mutant genes affected mitochondrial recombination. None of the mutations studied significantly affected mitochondrial recombination. The nuclear recombination and repair pathways studied do not overlap with the nuclear pathway which controls recombination of mitochondrial DNA. A second set of experiments was designed to test the effect of caffeine on both nuclear and mitochondrial recombination in Saccharomyces cerevisiae. (U.S.)

  15. 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.

  16. Time-dependent inhibitory effects of cGMP-analogues on thrombin-induced platelet-derived microparticles formation, platelet aggregation, and P-selectin expression

    International Nuclear Information System (INIS)

    Highlights: • We investigated the impact of cyclic nucleotide analogues on platelet activation. • Different time dependence were found for inhibition of platelet activation. • Additive effect was found using PKA- and PKG-activating analogues. • Our results may explain some of the discrepancies reported for cNMP signalling. - Abstract: In platelets, nitric oxide (NO) activates cGMP/PKG signalling, whereas prostaglandins and adenosine signal through cAMP/PKA. Cyclic nucleotide signalling has been considered to play an inhibitory role in platelets. However, an early stimulatory effect of NO and cGMP-PKG signalling in low dose agonist-induced platelet activation have recently been suggested. Here, we investigated whether different experimental conditions could explain some of the discrepancy reported for platelet cGMP-PKG-signalling. We treated gel-filtered human platelets with cGMP and cAMP analogues, and used flow cytometric assays to detect low dose thrombin-induced formation of small platelet aggregates, single platelet disappearance (SPD), platelet-derived microparticles (PMP) and thrombin receptor agonist peptide (TRAP)-induced P-selectin expression. All four agonist-induced platelet activation phases were blocked when platelets were costimulated with the PKG activators 8-Br-PET-cGMP or 8-pCPT-cGMP and low-doses of thrombin or TRAP. However, extended incubation with 8-Br-PET-cGMP decreased its inhibition of TRAP-induced P-selectin expression in a time-dependent manner. This effect did not involve desensitisation of PKG or PKA activity, measured as site-specific VASP phosphorylation. Moreover, PKG activators in combination with the PKA activator Sp-5,6-DCL-cBIMPS revealed additive inhibitory effect on TRAP-induced P-selectin expression. Taken together, we found no evidence for a stimulatory role of cGMP/PKG in platelets activation and conclude rather that cGMP/PKG signalling has an important inhibitory function in human platelet activation

  17. Roles of thrombin and platelet membrane glycoprotein IIb/IIIa in platelet-subendothelial deposition after angioplasty in an ex vivo whole artery model

    International Nuclear Information System (INIS)

    Platelet deposition at the site of injury caused by balloon angioplasty is associated with acute closure and restenosis. In a new ex vivo whole artery angioplasty model, the authors examined the roles of thrombin inhibition with D-Phe-Pro-ArgCH2Cl (PPACK) and inhibition of the platelet membrane fibrinogen receptor glycoprotein IIb/IIIa (GPIIb/IIIa) with monoclonal antibody 7E3 on platelet deposition at the site of balloon injury. Fresh rabbit aortas were mounted in a perfusion chamber. One half of the mounted arterial segment was dilated with a standard angioplasty balloon catheter and the uninjured half served as the control segment. The vessels were perfused with human blood at physiological pressure and shear rates of 180-250 second-1 for 30 minutes. Platelet deposition was measured using 111In-labeled platelets and scanning electron microscopy. With heparin (2 units/ml) anticoagulation, 8.2 ± 2.2 x 10(6) platelets/cm2 were deposited at the site of balloon injury compared with 0.7 ± 0.2 x 10(6) platelets/cm2 on uninjured segments (p less than 0.02, n = 7). PPACK was tested at a concentration (10 microM) that totally inhibited platelet aggregation in response to thrombin. 7E3 was tested at a concentration (10 micrograms/ml) that totally inhibited platelet aggregation. Platelet deposition at the site of balloon injury was reduced 47% by PPACK and 70% by 7E3 compared with heparin. At shear rates seen in nonstenotic coronary arteries, PPACK and 7E3 are more effective than heparin in reducing platelet deposition at the site of balloon injury. The significant inhibition of platelet deposition by PPACK demonstrates the importance of heparin-resistant thrombin in platelet thrombus formation

  18. Time-dependent inhibitory effects of cGMP-analogues on thrombin-induced platelet-derived microparticles formation, platelet aggregation, and P-selectin expression

    Energy Technology Data Exchange (ETDEWEB)

    Nygaard, Gyrid [Proteomic Unit at University of Bergen (PROBE), University of Bergen, Bergen (Norway); Department of Biomedicine, University of Bergen, Bergen (Norway); Herfindal, Lars; Kopperud, Reidun [Department of Biomedicine, University of Bergen, Bergen (Norway); Aragay, Anna M. [Department of Biomedicine, University of Bergen, Bergen (Norway); Molecular Biology Institute of Barcelona (IBMB, CSIC), Barcelona (Spain); Holmsen, Holm; Døskeland, Stein Ove; Kleppe, Rune [Department of Biomedicine, University of Bergen, Bergen (Norway); Selheim, Frode, E-mail: Frode.Selheim@biomed.uib.no [Proteomic Unit at University of Bergen (PROBE), University of Bergen, Bergen (Norway); Department of Biomedicine, University of Bergen, Bergen (Norway)

    2014-07-04

    Highlights: • We investigated the impact of cyclic nucleotide analogues on platelet activation. • Different time dependence were found for inhibition of platelet activation. • Additive effect was found using PKA- and PKG-activating analogues. • Our results may explain some of the discrepancies reported for cNMP signalling. - Abstract: In platelets, nitric oxide (NO) activates cGMP/PKG signalling, whereas prostaglandins and adenosine signal through cAMP/PKA. Cyclic nucleotide signalling has been considered to play an inhibitory role in platelets. However, an early stimulatory effect of NO and cGMP-PKG signalling in low dose agonist-induced platelet activation have recently been suggested. Here, we investigated whether different experimental conditions could explain some of the discrepancy reported for platelet cGMP-PKG-signalling. We treated gel-filtered human platelets with cGMP and cAMP analogues, and used flow cytometric assays to detect low dose thrombin-induced formation of small platelet aggregates, single platelet disappearance (SPD), platelet-derived microparticles (PMP) and thrombin receptor agonist peptide (TRAP)-induced P-selectin expression. All four agonist-induced platelet activation phases were blocked when platelets were costimulated with the PKG activators 8-Br-PET-cGMP or 8-pCPT-cGMP and low-doses of thrombin or TRAP. However, extended incubation with 8-Br-PET-cGMP decreased its inhibition of TRAP-induced P-selectin expression in a time-dependent manner. This effect did not involve desensitisation of PKG or PKA activity, measured as site-specific VASP phosphorylation. Moreover, PKG activators in combination with the PKA activator Sp-5,6-DCL-cBIMPS revealed additive inhibitory effect on TRAP-induced P-selectin expression. Taken together, we found no evidence for a stimulatory role of cGMP/PKG in platelets activation and conclude rather that cGMP/PKG signalling has an important inhibitory function in human platelet activation.

  19. A simple, fast, and sensitive assay for the detection of DNA, thrombin, and adenosine triphosphate based on Dual-Hairpin DNA structure.

    Science.gov (United States)

    He, Xiuping; Wang, Guangfeng; Xu, Gang; Zhu, Yanhong; Chen, Ling; Zhang, Xiaojun

    2013-11-19

    In the present study, based on multifunctional Dual-Hairpin DNA structure, a simple, fast and high sensitive assay for the detection of DNA, thrombin and adenosine triphosphate (ATP) was demonstrated. DNA sequence labeled with methylene blue (MB), which was designed as single-stranded DNA (ssDNA) matching with target DNA, thrombin, or ATP aptamer, hybridized to the adjunct probe and formed the dual-hairpin structure on the electrode. With the hybridization of adjunct probe and the hairpin-like capture probe in the stem region, the dual-hairpin was formed with outer and inner hairpins. By the conjugation of the target probe with the adjunct probe in the outer hairpin, the adjunct probe divorced from the dual-hairpin structure. The adjunct probe with signal molecules MB, attaching near or divorcing far from the electrode, produced electrochemical signal change and efficient electron transfer due to the fact that it was in proximity to the electrode. However, upon hybridization with the perfect match target, the redox label with the target probe was forced away from the modified electrode, thus resulting in the change of the Dual-Hairpin DNA conformation, which enables impedance of the efficient electron transfer of MB and, consequently, a detectable change of the electrochemical response. In addition, another highlight of this biosensor is its regenerability and stability owing to the merits of structure. Also, based on this Dual-Hairpin platform, the detection limits of DNA, thrombin, and ATP were 50 nM, 3 pM, and 30 nM, respectively. Moreover, this pattern also demonstrated excellent regenerability, reproducibility, and stability. Additionally, given to its ease-of-use, simplicity in design, easy operations, as well as regenerability and stability, the proposed approach may be applied as an excellent design prompter in the preparation of other molecular sensors. PMID:24079405

  20. Digital Social Network Mining for Topic Discovery

    Science.gov (United States)

    Moradianzadeh, Pooya; Mohi, Maryam; Sadighi Moshkenani, Mohsen

    Networked computers are expanding more and more around the world, and digital social networks becoming of great importance for many people's work and leisure. This paper mainly focused on discovering the topic of exchanging information in digital social network. In brief, our method is to use a hierarchical dictionary of related topics and words that mapped to a graph. Then, with comparing the extracted keywords from the context of social network with graph nodes, probability of relation between context and desired topics will be computed. This model can be used in many applications such as advertising, viral marketing and high-risk group detection.