Sample records for activatable fibrinolysis inhibitor

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

    Valnickova, Zuzana; Thaysen-Andersen, Morten; Højrup, Peter;


    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...

  2. Reduced activity of TAFI (thrombin-activatable fibrinolysis inhibitor) in acute promyelocytic leukaemia

    Meijers, JCM; Oudijk, EJD; Mosnier, LO; Nieuwenhuis, HK; Fijnheer, R; Bouma, Bonno N.; Bos, R


    Acute promyelocytic leukaemia (APL) is a disease that is distinguished from other leukaemias by the high potential for early haemorrhagic death. Several processes are involved, such as disseminated intravascular coagulation and hyperfibrinolysis. Recently, TAFI (thrombin-activatable fibrinolysis inh

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

    Kristensen Torsten


    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.

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

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


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

  5. Activated thrombin-activatable fibrinolysis inhibitor (TAFIa) attenuates breast cancer cell metastatic behaviors through inhibition of plasminogen activation and extracellular proteolysis

    Bazzi, Zainab A.; Lanoue, Danielle; El-Youssef, Mouhanned; Romagnuolo, Rocco; Tubman, Janice; Cavallo-Medved, Dora; Porter, Lisa A.; Boffa, Michael B.


    Background Thrombin activatable fibrinolysis inhibitor (TAFI) is a plasma zymogen, which can be converted to activated TAFI (TAFIa) through proteolytic cleavage by thrombin, plasmin, and most effectively thrombin in complex with the endothelial cofactor thrombomodulin (TM). TAFIa is a carboxypeptidase that cleaves carboxyl terminal lysine and arginine residues from protein and peptide substrates, including plasminogen-binding sites on cell surface receptors. Carboxyl terminal lysine residues ...

  6. Association between thrombin-activatable fibrinolysis inhibitor gene polymorphisms and venous thrombosis risk: a meta-analysis.

    Wang, Wei; Ma, He; Lu, Lili; Sun, Guixiang; Liu, Dang; Zhou, Yunti; Tong, Yue; Lu, Zhaojun


    Thrombin-activatable fibrinolysis inhibitor (TAFI) is an important antifibrinolytic factor that has been shown in increased concentrations to be associated with an increased risk for venous thrombosis. However, the effect of TAFI gene polymorphisms on the risk of venous thrombosis remains debatable. The aim of the current study was to evaluate the association of three single nucleotide polymorphisms: 505G>A (rs3742264), 1040 C>T (rs1926447) and -438G>A (rs2146881) with venous thrombosis risk using a meta-analysis. A systematic literature search for eligible studies published before 20 January 2015 was conducted in PubMed, EMBASE, Web of Science, WanFang database and Chinese National Knowledge Infrastructure. We assessed the possible association by pooled odds ratio and its 95% confidence interval. A total of 14 independent case-control studies including 2970 cases and 3049 controls were enrolled in the final meta-analysis. A significant reduction of venous thrombosis risk in the 505G>A polymorphism was observed under allele comparison, homozygote comparison and recessive models, but opposite results were seen in Asians. Likewise, there was a significant decreased susceptibility to venous thrombosis in the 1040C>T polymorphism in homozygote comparison and recessive models. In the subgroup analysis, the nonvenous thromboembolism disease group showed a significantly increased venous thrombosis risk. Pooled estimates did not show evidence of association between -438G>A and venous thrombosis risk in any genetic model. This meta-analysis suggested that although the -438G>T polymorphism is not correlated with venous thrombosis risk in all models, a trend toward reduced risk still could be observed. The A allele and AA genotype of 505G>A in whites and the TT genotype of 1040C>T were significantly associated with a decreased risk of venous thrombosis, except in the non-venous thromboembolism group. PMID:26656901

  7. Thrombin-activatable fibrinolysis inhibitor Thr325Ile polymorphism and plasma level in breast cancer: A pilot study

    Manal S. Fawzy


    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.

  8. Isolation, Co-Crystallization and Structure-Based Characterization of Anabaenopeptins as Highly Potent Inhibitors of Activated Thrombin Activatable Fibrinolysis Inhibitor (TAFIa).

    Schreuder, Herman; Liesum, Alexander; Lönze, Petra; Stump, Heike; Hoffmann, Holger; Schiell, Matthias; Kurz, Michael; Toti, Luigi; Bauer, Armin; Kallus, Christopher; Klemke-Jahn, Christine; Czech, Jörg; Kramer, Dan; Enke, Heike; Niedermeyer, Timo H J; Morrison, Vincent; Kumar, Vasant; Brönstrup, Mark


    Mature thrombin activatable fibrinolysis inhibitor (TAFIa) is a carboxypeptidase that stabilizes fibrin clots by removing C-terminal arginines and lysines from partially degraded fibrin. Inhibition of TAFIa stimulates the degradation of fibrin clots and may help to prevent thrombosis. Applying a lead finding approach based on literature-mining, we discovered that anabaenopeptins, cyclic peptides produced by cyanobacteria, were potent inhibitors of TAFIa with IC50 values as low as 1.5 nM. We describe the isolation and structure elucidation of 20 anabaenopeptins, including 13 novel congeners, as well as their pronounced structure-activity relationships (SAR) with respect to inhibition of TAFIa. Crystal structures of the anabaenopeptins B, C and F bound to the surrogate protease carboxypeptidase B revealed the binding modes of these large (~850 Da) compounds in detail and explained the observed SAR, i.e. the strong dependence of the potency on a basic (Arg, Lys) exocyclic residue that addressed the S1' binding pocket, and a broad tolerance towards substitutions in the pentacyclic ring that acted as a plug of the active site. PMID:27604544

  9. Posttranslational Modifications of Human Thrombin Activatable Fibrinolysis Inhibitor (TAFI): Evidence for a large shift in isoelectric point and reduced solubility upon activation

    Valnickova, Zuzana; Christensen, Trine; Skottrup, Peter; Thøgersen, Ida; Højrup, Peter; Enghild, Jan Johannes


    Thrombin-activable fibrinolysis inhibitor (TAFI) is distinct from pancreatic procarboxypeptidase B in several ways. The enzymatic activity of TAFIa is unstable and decays with a half-life of a few minutes. During this study, we observed that (i) the isoelectric point (pI) of TAFI shifts dramatica......Thrombin-activable fibrinolysis inhibitor (TAFI) is distinct from pancreatic procarboxypeptidase B in several ways. The enzymatic activity of TAFIa is unstable and decays with a half-life of a few minutes. During this study, we observed that (i) the isoelectric point (pI) of TAFI shifts...... cysteine residues, of which two, Cys69 and Cys383, are not involved in disulfides and contain free sulfhydryl groups. The remaining six cystines form disulfides, including Cys156-Cys169, Cys228-Cys252, and Cys243-Cys257. This pattern is homologous to pancreatic procarboxypeptidase B, and it is therefore...

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

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


    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 and from 35 dogs with various diseases were analyzed using a commercial chromogenic assay that...

  11. Effect of heparin on TAFI-dependent inhibition of fibrinolysis: relative importance of TAFIa generated by clot-bound and fluid phase thrombin.

    Colucci, Mario; Pentimone, Anna; Binetti, Bianca M; Cramarossa, Marialisa; Piro, Donatella; Semeraro, Nicola


    Heparin has been proposed to enhance thrombolysis by inhibiting thrombin-dependent generation of activated TAFI (thrombin activatable fibrinolysis inhibitor), a carboxypeptidase that inhibits fibrinolysis. We evaluated the effect of heparin in an in vitro thrombolysis model consisting of a radiolabelled blood clot submerged in defibrinated plasma. Fibrinolysis was induced by adding t-PA (250 ng/ml) and calcium to the plasma bath. Control experiments indicated that thrombin generation induced by recalcification caused significant TAFI activation and inhibited clot lysis. Heparin (up to 1 U/ml), added to the plasma bath, failed to enhance clot lysis. Thrombin generation in the fluid phase was totally inhibited by heparin at concentrations > 0.5 U/ml. In contrast, thrombin generation on the clot surface was not inhibited by heparin (1 U/ml). TAFIa generation did occur in heparin-containing samples (1 U/ml) and amounted to about 10% of TAFIa formed in control samples. This low amount of TAFIa did exert antifibrinolytic activity as indicated by the observation that the addition of a specific TAFIa inhibitor (PTI) along with heparin enhanced clot lysis. Hirudin (10 micrograms/ml), at variance with heparin, inhibited clot-bound thrombin and enhanced clot lysis. These data show that heparin is unable to stimulate fibrinolysis through a TAFI-dependent mechanism, most likely because of its inefficiency in inhibiting thrombin generation on the clot surface. Moreover, they suggest that clot-bound thrombin plays a major role in TAFI-mediated inhibition of fibrinolysis through "localized" TAFIa generation. PMID:12195701

  12. Relationship Between Hypothyroidism and Coagulation - fibrinolysis%甲状腺功能减低与凝血和纤溶的关系

    徐静梅; 孙玉倩


    The definition of hypothyroidism: as a low metabolism syndrome which is induced by low synthesis and secretion of thyroid hormone or lack of organization use. The prevalence of clinical hypothyroidism is 1 % which is rising by age and female is more than male. Recent years, the incidence of hypothyroidism is rising year by year, lots of researches demonstrated that: hypothyroidism can accelerate the occurrence and progress of atherosclerosis, hypothyroidism can affect the biochemical indicators of coagulation- fibrinolysis system besides blood fat and then increase the risk of atherosclerosis and thrombosis. Hypothyroidism modified the coagulation - fibrinolytic balance through the effect to biochemical indicators of coagulation - fibrinolysis system, such as: fibrinogen, thrombin - activatable fibrinolysis inhibitor (TAFI), plasminogen activator inhibnitor typel (PAI - 1), D - Dimer (DDI), von willebrand disease factor (VWF) and then induced thrombosis or hemorrhagic tendency. Now the effect of hypothyroidism on fibrinogen, TAFI, and PAI - 1 is summed up.%甲状腺功能减退症(简称甲减)的定义:是由于甲状腺激素合成和分泌减少或组织利用不足导致的全身代谢减低综合征.临床甲减的患病率为1%左右,女性较男性多见,随年龄增加患病率上升.近几年甲减的发病率逐年上升,众多研究表明甲减加速动脉粥样硬化的发生发展,甲减除了可引起血脂异常外,还对凝血和纤溶系统的生化指标产生影响进而增加动脉粥样硬化、血栓形成的风险.甲减可通过对凝血和纤溶系统的生化指标如:纤维蛋白原、血管性血友病因子(VWF)、凝血酶激活的纤溶抑制物(TAFI)、纤溶酶原激活物抑制剂-1(PAI-1)、D-二聚体(DDI)的影响而改变血液的凝血纤溶平衡,进而促进血栓形成或有出血倾向.现将甲减对纤维蛋白原、TAFI、VWF、PAI -1、DDI的影响综述如下.

  13. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Minet, Valentine, E-mail:; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)


    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  14. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations

  15. [Fibrinolysis in acute myocardial infarct].

    Bleifeld, W


    Fibrinolysis has opened up a new avenue in the treatment of acute myocardial infarction (AMI). In principle, the rate of reperfusion depends on the type of compound used, the mode of administration and the time between onset of symptoms and the beginning of treatment. With intracoronary streptokinase the reperfusion rate is of the order of 85%. Intravenous urokinase administered as a bolus results in a reopening rate of 50-60%; a similar rate of reperfusion is achieved with rt-PA as infusion, while i.v. streptokinase produces about 50% reopened coronary vessels. The final infarct size is decreased in 70% of patients if fibrinolysis is initiated within 2.5 hours after the onset of symptoms and followed by reopening of the occluded vessel. This results in a lowering of in-hospital mortality, which in various studies is of the order of 45-60%.- Bearing in mind the contraindications, fibrinolysis should be initiated within 3 hours. Hemodynamic improvement by a decrease of infarct size may also be achieved beyond 3 hours in large anterior myocardial infarctions and in posterior infarctions with cardiogenic shock. Early initiation of thrombolysis is of major importance in improving left ventricular function and lowering mortality following acute myocardial infarction. Therefore, prehospital thrombolytic therapy should be considered. - In the postinfarction phase coronary angiography is indicated in patients with angina at rest, stable angina of ECG signs of ischemia. In this situation transfer to a specialized cardiology division for possible percutaneous transluminal angioplasty is indicated. - Reocclusion after successful thrombolysis occurs in 20-30%, and it is therefore important to avoid reinfarction to improve the long term prognosis after AMI.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3321420

  16. Impaired Fibrinolysis in the Antiphospholipid Syndrome

    Krone, Katie A.; Allen, Kristi L.; McCrae, Keith R.


    The antiphospholipid syndrome (APS) is characterized by venous and/or arterial thrombosis, or recurrent fetal loss, in the presence of antiphospholipid antibodies (APL). The pathogenesis of APS is multifaceted and involves numerous mechanisms including activation of endothelial cells, monocytes, and/or platelets; inhibition of natural anticoagulant pathways such as protein C, tissue factor inhibitor, and annexin A5; activation of the complement system; and impairment of the fibrinolytic system. Fibrinolysis—the process by which fibrin thrombi are remodeled and degraded—involves the conversion of plasminogen to plasmin by tissue plasminogen activator (tPA) or urokinase-type plasminogen activator, and is tightly regulated. Although the role of altered fibrinolysis in patients with APS is relatively understudied, several reports suggest that deficient fibrinolytic activity may contribute to the pathogenesis of disease in these patients. This article discusses the function of the fibrinolytic system and reviews studies that have reported alterations in fibrinolytic pathways that may contribute to thrombosis in patients with APL. Some of these mechanisms include elevations in plasminogen activator inhibitor-1 levels, inhibitory antibodies against tPA or other components of the fibrinolytic system, antibodies against annexin A2, and finally, antibodies to β2-glycoprotein-I (β2GPI) that block the ability of β2GPI to stimulate tPA-mediated plasminogen activation. PMID:20425534

  17. Molecular Imaging with Activatable Reporter Systems

    Gang Niu, Xiaoyuan Chen


    Full Text Available Molecular imaging is a newly emerged multiple disciplinary field that aims to visualize, characterize and quantitatively measure biological processes at cellular and molecular levels in humans and other living systems. A reporter gene is a piece of DNA encoding reporter protein, which presents as a readily measurable phenotype that can be distinguished easily from the background of endogenous protein. After being transferred into cells of organ systems (transgenes, the reporter gene can be utilized to visualize transcriptional and posttranscriptional regulation of gene expression, protein-protein interactions, or trafficking of proteins or cells in living subjects. Herein, we review previous classification of reporter genes and regroup the reporter gene based imaging as basic, inducible and activatable, based on the regulation of reporter gene transcription and post-translational modification of reporter proteins. We then focus on activatable reporters, in which the signal can be activated at the posttranslational level for visualizing protein-protein interactions, protein phosphorylation or tertiary structure changes. The applications of several types of activatable reporters will also be summarized. We conclude that activatable reporter imaging can benefit both basic biomedical research and drug development.

  18. Blood coagulation and fibrinolysis after long-duration treadmill exercise controlled by individual anaerobic threshold.

    Hilberg, Thomas; Gläser, Doreen; Reckhart, Carsten; Prasa, Dagmar; Stürzebecher, Jörg; Gabriel, Holger H W


    For rehabilitation training it is recommended that the intensity of exercise should be clearly below the individual anaerobic threshold (IAT). We investigated blood coagulation, particularly endogenous thrombin potential (ETP) and fibrinolysis following a standardized treadmill (TR) ergometer test at 90% IAT for 60-120 min. Sixteen healthy male non-smokers underwent the TR test. Blood samples were taken after a 30-min rest, immediately after exercise, and 2 h after exercise completion. Extrinsic and intrinsic total (TTP(ex+in)) and endogenous (ETP(ex+in)) thrombin potential, prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), plasmin-alpha2-antiplasmin complex (PAP), D-dimer, tissue plasminogen activator antigen and activity (tPA-AG and tPA-ACT) and plasminogen activator inhibitor type 1 antigen and activity (PAI-1-AG and PAI-1-ACT) were measured. Immediately after TR, F1+2, TAT and TTP(ex+in) were increased ( PIAT (90%) on a TR ergometer only implicates a small increase in thrombin generation markers and total (free and alpha(2)-macroglubulin-bound thrombin), but not in endogenous (free) thrombin potential alone. In contrast, fibrinolysis is distinctly increased after this type of exercise. Endurance exercise with an intensity below 90% IAT and a duration below 2 h generates a more favourable condition for fibrinolysis than for blood coagulation in healthy young subjects. Data are given as mean (SD). PMID:12883904

  19. Regulation of Plasminogen Activator Inhibitor-1 Expression in Endothelial Cells with Exposure to Metal Nanoparticles

    Yu, Min; Mo, Yiqun; Wan, Rong; Chien, Sufan; Zhang, Xing; Zhang, Qunwei


    Recent studies demonstrated that exposure to nanoparticles could enhance the adhesion of endothelial cells and modify the membrane structure of vascular endothelium. The endothelium plays an important role in the regulation of fibrinolysis, and imbalance of the fibrinolysis system potential contributes to the development of thrombosis. Plasminogen activator inhibitor-1 (PAI-1) is the most potent endogenous inhibitor of fibrinolysis and is involved in the pathogenesis of several cardiovascular...

  20. Thrombin Avtivable Fibrinolysis Inhibitor in Venous and Arterial Thrombosis

    Bruijne, E.L.E.


    textabstractVenous and arterial thromboses are major causes of morbidity and mortality. Venous thrombosis is the result of pathological occlusive clot formation in the veins. It occurs mainly in the deep veins of the leg (deep vein thrombosis), from which parts of the clot frequently embolize to the lungs (pulmonary embolism). Less than 5% of all venous thromboses occur at other sites (e.g. arm or cerebral veins). Rarely occurring, but often life-threathening venous thrombosis is splanchnic v...

  1. Haemostatic factors and intraluminal thrombus thickness in abdominal aortic aneurysm. Is secondary fibrinolysis relevant?

    Siennicka, A; Drozdzynska, M; Chelstowski, K; Cnotliwy, M; Jastrzebska, M


    Many circulating haemostatic markers have been investigated in relation to the abdominal aortic aneurysm (AAA) size, growth as well as intraluminal thrombus (ILT) size. However, the results of these studies seem to be uncertain and inconsistent. The first aim of the present study was to compare the haemostatic parameters of fibrinolysis and some of thrombotic markers in patients with AAA and controls. We also examined the relationship between those parameters and both maximum aneurysm diameter and intraluminal thrombus thickness. Tissue plasminogen activator (t-PA), plasminogen activator inhibitor (PAI-1), fibrinogen (Fb), D-dimer, prothrombin fragments 1 and 2 (F1+2), thromboxane B2 (TXB2) and lipids profile were measured in 36 patients with AAA and 30 controls. The mean maximum aortic diameter in patients with the AAA was 59±12 mm (range 42-100). The mean ILT thickness was 32±10 mm (range 8-56). Among haemostatic factors, t-PA and D-dimer levels, but not PAI-1, were significantly higher in subjects with the AAA. There was a strong positive correlation between thickness of intraluminal thrombus and maximum aneurysm size (r=0.69, paneurysm diameter (r= -0.38, p=0.023). Higher plasma concentrations of t-PA and D-dimer support the hypothesis that the secondary fibrinolysis plays an important role in the pathogenesis of the aortic abdominal aneurysm formation. In addition, the negative correlation between t-PA plasma level and ILT thickness suggests that thrombotic/fibrinolysis imbalance may favour accelerated formation of intraluminal thrombus and possibly aneurysm progression. PMID:23959729

  2. Changes of coagulation and fibrinolysis in middle-old aged patients with nonvalvular atrial fibrillation

    Objective: To evaluate the changes of coagulation and fibrinolysis function in the middle-old aged patients with nonvalvular atrial fibrillation. Methods: The levels of D-Dimer and tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) were detected in 92 middle-aged patients with nonvalvular atrial fibrillation (AF group) and 60 patients with sinus rhythm (control group) by immune turbidimetry and enzyme linked immunoadsorbent assay (ELISA). Univariate analysis was used to determine the differences between two groups, and covariance analysis was used to determine the factors which might affect coagulation and fibrinolysis indexes. Results: 1)The plasma levels of D-Dimer [(0.16±0.10) mg·L-1] and t-PA [(42.58± 30.28) μg·L-1] and PAI-1 [(86.03 ± 21.43) μg·L-1] in AF group were significantly higher than those in the control group [(0.10 ± 0.08) mg·L-1, (26.02±13.84) μg·L-1, (64.94±24.35) μg·L-1] (P<0.05 or P <0.001). The ratio of PAI-1/t-PA in AF group was higher than that in control group slightly. 2) After adjustment of the factors which included sex, age and plasma creatinine, uric acid, blood sugar, triglyceride and cholesterol, the levels of D-Dimer (P=0.047), t-PA (P=0.264) and PAI-1 (P=0.001) in AF group were higher than those in the control group. Conclusion: The middle-old aged patients with nonvalvular atrial fibrillation lose their balance of coagulation and fibrinolysis in the state of hypercoagulated and hypofibrinolysis. (authors)

  3. Usefulness of human coagulation and fibrinolysis assays in domestic pigs

    Münster, Anna-Marie Bloch; Olsen, Aage Kristian; Bladbjerg, Else-Marie


    Pigs are often used as animal models in research on blood coagulation and fibrinolysis. The usefulness of the assays applied within this field, and the knowledge of reference intervals are therefore essential and of utmost importance. In the study reported here, we investigated the applicability of...... commercial human coagulation and fibrinolysis assays for use with porcine plasma. In total, 22 functional and immunologic assays were applied to plasma obtained from domestic pigs, and the following blood coagulation and fibrinolysis variables were measured: prothrombin time, activated partial thromboplastin...... that 11 of 12 functional assays, but only 3 of 10 immunoassays, were applicable to porcine plasma, and we determined the normal range of these variables. We conclude that human functional assays are useful in porcine plasma, whereas only a few immunologic assays can be used. However, precautions must...

  4. Effect of nonionic and ionic contrast media on fibrinolysis in patients undergoing angiography

    Radiological contrast media may influence processes of hemostasis resulting in increased thrombotic or bleeding tendency. A number of clinical case reports suggest that the use of nonionic contrast media is associated with thrombotic complications. In vitro studies have indicated that nonionic contrast media may induce generation of thrombin in blood whereas ionic contrast agents do not show such an effect. Not much is known about the effects of contrast media on the coagulation and fibrinolytic systems in vivo. The aim of this study was to evaluate the systemic effects of markers for activation of fibrinolysis with a nonionic contrast medium (Iopromid/Ultravist-300/Schering AG) and ionic contrast medium (Uropolinum, Polfa) in 82 patients undergoing angiography. We measured tissue plasminogen activator (t-PA) and tissue plasminogen activator inhibitor (PAI), using COA-SET, t-PA and COA-TEST PAI (Chromogenix). Fibrinogen concentration and euglobulin lysis time (ELT) were also estimated. Both contrast agents caused a significant decrease in fibrinogen concentrations. A marked difference was seen for PAI activity. A statistically significant increase was seen in the Iopromid group and no statistically significant rise was seen in the Uropolinum group. t-PA activity remained virtually unchanged in both groups. ELT has been significantly prolonged in patients who received Iopromid but not in those who received Uropolinum. It is likely that nonionic contrast medium could release PAI from platelets and endothelial cells. The changes in fibrinolysis may result from endothelial cell dysfunction. (author)

  5. Impaired Fibrinolysis in the Antiphospholipid Syndrome

    Krone, Katie A.; Allen, Kristi L.; McCrae, Keith R


    The antiphospholipid syndrome (APS) is characterized by venous and/or arterial thrombosis, or recurrent fetal loss, in the presence of antiphospholipid antibodies (APL). The pathogenesis of APS is multifaceted and involves numerous mechanisms including activation of endothelial cells, monocytes, and/or platelets; inhibition of natural anticoagulant pathways such as protein C, tissue factor inhibitor, and annexin A5; activation of the complement system; and impairment of the fibrinolytic syste...

  6. Vino, fibrinolisis y salud Wine, fibrinolysis and health

    Consuelo Pasten; Hernán Grenett


    Cardiovascular diseases are the leading cause of death in both men and women in the world. Epidemiological and experimental studies have associated moderate wine consumption (1 to 2 glasses/day) with a decrease in cardiovascular diseases. This decrease is probably due to the effect of ethanol and polyphenols present in the wine. The cardioprotective benefit of wine may be due, in part, to a modulation of the expression of proteins involved in fibrinolysis. Endothelial cells (ECs) play a major...

  7. Local Intra-Arterial Fibrinolysis in Acute Basilar Artery Occlusion

    Enomoto, Y.; Yoshimura, S.; Kitajima, H.; Tamakawa, N.; Iwama, T


    Acute basilar artery (BA) occlusion is typically associated with poor outcome; however newer diagnostic and treatment modalities have the potential to improve prognosis. In this study, six patients with acute BA occlusion were followed and the effectiveness of local intra-arterial fibrinolysis (LIF) and subsequent percutaneous transluminal angioplasty (PTA) with a balloon catheter were assessed. Of the six patients with BA occlusion observed in this study, two had extended brain stem infarcti...

  8. Novel Bioluminescent Activatable Reporter for Src Tyrosine Kinase Activity in Living Mice.

    Leng, Weibing; Li, Dezhi; Chen, Liang; Xia, Hongwei; Tang, Qiulin; Chen, Baoqin; Gong, Qiyong; Gao, Fabao; Bi, Feng


    Aberrant activation of the Src kinase is implicated in the development of a variety of human malignancies. However, it is almost impossible to monitor Src activity in an in vivo setting with current biochemical techniques. To facilitate the noninvasive investigation of the activity of Src kinase both in vitro and in vivo, we developed a genetically engineered, activatable bioluminescent reporter using split-luciferase complementation. The bioluminescence of this reporter can be used as a surrogate for Src activity in real time. This hybrid luciferase reporter was constructed by sandwiching a Src-dependent conformationally responsive unit (SH2 domain-Srcpep) between the split luciferase fragments. The complementation bioluminescence of this reporter was dependent on the Src activity status. In our study, Src kinase activity in cultured cells and tumor xenografts was monitored quantitatively and dynamically in response to clinical small-molecular kinase inhibitors, dasatinib and saracatinib. This system was also applied for high-throughput screening of Src inhibitors against a kinase inhibitor library in living cells. These results provide unique insights into drug development and pharmacokinetics/phoarmocodynamics of therapeutic drugs targeting Src signaling pathway enabling the optimization of drug administration schedules for maximum benefit. Using both Firefly and Renilla luciferase imaging, we have successfully monitored Src tyrosine kinase activity and Akt serine/threonine kinase activity concurrently in one tumor xenograft. This dual luciferase reporter imaging system will be helpful in exploring the complex signaling networks in vivo. The strategies reported here can also be extended to study and image other important kinases and the cross-talks among them. PMID:26941850

  9. The influence of weather on fibrinolysis and fibrinogenolysis. [in human body

    Marchenko, V. I.


    Analysis of fibrinolysis and fibrinogenolysis indices by month showed an increase in the activity of these processes from winter to summer (1967-1968). At all seasons of the year, fibrinolysis and fibrinogenolysis increase during weather of the cyclonic type with passage of fronts and sharp fluctuations in meteorological factors in the atmosphere.

  10. Inhibitors

    ... wrong place in the body. Immune Tolerance Induction (ITI) Therapy: The goal of ITI therapy is to stop the inhibitor reaction from ... body to accept clotting factor concentrate treatments. With ITI therapy, people receive large amounts of clotting factor ...

  11. The effects of percutaneous coronary interventional therapy on platelet activation and the systems fibrinolysis in patients with coronary artery disease

    Objective: To investigate the effects of percutaneous coronary interventional therapy on platelet activation and the systemic fibrinolysis in patients with coronary artery disease (CAD). Methods: The plasma concentration of platelet alpha-granule membrane glycoprotein-140 (GMP-140), plasminogen activator inhibitor-1 (PAI-1), tissue-type plasminogen activator (t-PA), von Willebrand factor (vWF) and D-dimer (D-D) of the blood sampled from vein according to the schedule were measured by ELISA. Results: In the sixty-five patients with CAD, at 10 minutes after the procedure, plasma levels of GMP-140, t-PA and D-D were significantly higher than the previous ones; and at 24 h, plasma levels of PAI-1 and vWF were also increased significantly. Conclusions: The activation of platelet and impaired fibrinolytic activity were occurred after PCI in the patients with CAD

  12. The effects of ropivacaine hydrochloride on coagulation and fibrinolysis. An assessment using thromboelastography.

    Porter, J M


    Amide local anaesthetics impair coagulation by inhibition of platelet function and enhanced fibrinolysis. The potential therefore exists that the presence of amide local anaesthetics in the epidural space could contribute to the therapeutic failure of an epidural autologous blood patch. Ropivacaine is an aminoamide local anaesthetic increasingly used for epidural analgesia and anaesthesia, particularly in obstetric practice. This study was undertaken to investigate whether concentrations of ropivacaine in blood, which could occur clinically in the epidural space, alter coagulation or fibrinolysis. Thromboelastography was used to assess clotting and fibrinolysis of blood to which ropivacaine had been added. Although modest alterations in maximum amplitude, coagulation time and alpha angle were observed, the effect of ropivacaine on clotting and fibrinolysis was not clinically significant. We conclude that it is unlikely that the presence of ropivacaine in the epidural space would reduce the efficacy of an early or prophylactic epidural blood patch.

  13. A Novel Serine Protease Secreted by Medicinal Maggots Enhances Plasminogen Activator-Induced Fibrinolysis

    van der Plas, Mariena J. A.; Andersen, Anders S.; Nazir, Sheresma; van Tilburg, Nico H.; Oestergaard, Peter R.; Krogfelt, Karen A.; van Dissel, Jaap T.; Hensbergen, Paul J.; Rogier M Bertina; Nibbering, Peter H.


    Maggots of the blowfly Lucilia sericata are used for the treatment of chronic wounds. As haemostatic processes play an important role in wound healing, this study focused on the effects of maggot secretions on coagulation and fibrinolysis. The results showed that maggot secretions enhance plasminogen activator-induced formation of plasmin and fibrinolysis in a dose- and time-dependent manner. By contrast, coagulation was not affected by secretions. Biochemical studies indicated that a novel s...

  14. Intrapericardial fibrinolysis in purulent pericarditis-case report.

    Dybowska, Małgorzata; Kazanecka, Barbara; Kuca, Paweł; Burakowski, Janusz; Czajka, Cezary; Grzegorczyk, Franciszek; Gralec, Renata; Tomkowski, Witold


    Purulent pericarditis (PP) continues to result in a very serious prognosis and high mortality. The most serious complication of pericarditis is constriction. Intrapericardial administration of fibrinolytic agents, although controversial, can prevent the development of constrictions. We present the case of a 63-year-old man with purulent inflammation of the right knee who was admitted to the intensive care unit (ICU) via emergency room orthopedic evaluation because of purulent pericarditis. Subxiphoid pericardiotomy was urgently performed, with 1200 ml of thick purulent fluid evacuated. As prevention for pericardial constriction, it was decided to administer fibrinolysis to the patient's pericardial cavity. Administration of streptokinase was complicated by the occurrence of a severe retrosternal pain and intrapericardial bleeding. Due to insufficiency of antibiotic therapy, 17 days after complicated fibrinolytic therapy with streptokinase, it was decided to administer 20 mg of r-tPA directly into the pericardium. In the following days, there remained a high drainage of purulent secretions. Fever up to 38 °C was still observed despite the use of antibiotics. Nine days after first administration of r-tPA, it was decided to apply the next dose. Daily drainage decreased from 50 to 20 ml in successive days. No fluid accumulation and symptoms and signs of constrictions were observed in clinical examinations as well as in echocardiography performed during 7 years follow-up after discharge. PMID:26446031

  15. Polypeptide micelles with dual pH activatable dyes for sensing cells and cancer imaging

    Gong, Ping; Yang, Yueting; Yi, Huqiang; Fang, Shengtao; Zhang, Pengfei; Sheng, Zonghai; Gao, Guanhui; Gao, Duyang; Cai, Lintao


    pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence in an alkaline environment. Hence, DPNs exhibited a dual response signal with strong red fluorescence and weak green fluorescence under acidic conditions; in contrast, they showed strong green fluorescence and almost no red fluorescence under alkaline and neutral conditions. The favorable inverse pH responses of the two fluorescent dyes resulted in ratiometric pH determination for DPNs with an optimized pH-sensitive range of pH 4.5-7.5. Quantitative analysis of the intracellular pH of intact MCF-7 cells has been successfully demonstrated with our nanosensor. Moreover, single acid activatable fluorescent dye doped polypeptide nanoparticles that only contained RBLC can distinguish tumor tissue from normal tissue by monitoring the acidic extracellular environment.pH is an important control parameter for maintenance of cell viability and tissue functions. pH monitoring provides valuable information on cell metabolic processes and the living environment. In this study, we prepared dual pH-sensitive, fluorescent dye-loaded polypeptide nanoparticles (DPNs) for ratiometric sensing of pH changes in living cells. DPNs contain two types of dyes: N-(rhodamine B) lactam cystamine (RBLC), an acid activatable fluorescent dye with increased fluorescence in an acidic environment, and fluorescein isothiocyanate (FITC), a base activatable fluorescent dye with enhanced fluorescence

  16. The effect of erythropoietin on platelet function and fibrinolysis in chronic renal failure

    Stenver, Doris Irene; Jeppesen, L; Nielsen, B;


    The influence of erythropoietin therapy on platelet function and fibrinolysis was evaluated in 12 anemic hemodialysis patients. Six months of therapy with human erythropoietin (50 to 80 IU/kg initially) raised the hemoglobin level to 10.8 g/dl but did not increase platelet activity in vivo as mea...

  17. Effect of onion and garlic on blood coagulation and fibrinolysis in vitro.

    Nagda, K K; Ganeriwal, S K; Nagda, K C; Diwan, A M


    The effects of aqueous extracts of onion and garlic as well as of garlic oil were studied on the process of blood coagulation and fibrinolysis in vitro. Only onion was found to exhibit anti-coagulant and fibrinolytic activity while garlic extract as well as garlic oil were inactive. PMID:6885127

  18. A Comparison Study of the Effects Injectable Contraceptive Cyclofem on Blood Coagulation and Fibrinolysis

    孙丹利; 卢凤英; 陈爱军; 沈康元; 蒋海瑛; 童琮


    Forty-six healthy women received Cyclofem (25mg medroxyprogesterone acetate with 5mg estradiol cypionate) and other forty-five women, as control, received oral contraceptive pill (Orttm-Novum 1/35, containing norethisterone enantate 1mg and estradiol valerate 35μg) for nine months. Blood samples were taken during the follicular and luteal phases of pre- treatment, and for Cyclofem group, immediately prior to the 3rd and 9th injections and 1 and 3 weeks after the 3rd and 9th injections; for Ortho-Novum group, blood samples were taken on the irst day of the 3rd and 9th pill cycles and 1 and 3 weeks later in both cycles. For both groups after at least 3 months nonhormonal method of contraception, blood sampling was repeated at follicular and luteal phases of a normal mentrual cycle. Coagulation and fibrinolysis parameter were detected including hemoglobin, platelet count, prothrombin time, APTT, fibrinogen, factor Ⅶ, factor Ⅹ, plasminogen, t-PAL AT Ⅲ(functional and immunological assays) and protein C. In the Cyclofem group, hemoglobin, platelet count, fibrinogen and factor Ⅹ were not changed. Factor Ⅶ significantly reduced. Prothrombin time and APTT showed minor changes. Plasminogen and protein C decreased while t-PAI aad AT Ⅲ increased. These changes showed a dynamic balance between coagulation and fibrinolysis. In Ortho-Novum 1/35 group, platelet count, factor Ⅹ and fibrinogen increased and prothrombin time and APTT accelerated. In fibrinolysis and anticoagutation system, plasminogen increased as well as protein C, but AT Ⅲ declined. Those changes showed a tendency of hyper-eoagutability state, fibrinolysis and anticoagulation were enhanced to a certain extent.The result of our study is that there are slight changes on coagulation and fibrinolysis in Cyclofem injectable contraceptive users.

  19. Effects of radiation therapy on blood coagulation-fibrinolysis system in patients with oral squamous cell carcinoma

    The aims of this study were to clarify the effects of radiotherapy on haemostatic activity in patients with oral squamous cell carcinoma (SCC) and to investigate the differences in the clinical findings. The subjects were 61 patients with primary oral SCC (SCC group) who had undergone preoperative radiotherapy of 34.2±7.2 Gy (mean±SD). These patients were divided into early group (stage I and II) and advanced group (stage III and IV), and the region in the oral cavity. Before and after radiotherapy, activated partial thromboplastin time (APTT), fibrinogen, prothrombin fragment 1+2 (F1+2) and plasmin-α2 plasmin inhibitor complex (PAP) were measured. In SCC group, after the radiotherapy, APTT extended and PAP increased. In the early stage group, PAP increased and in the advanced group, there was the extension of APTT. The regional division of the patients, there was the extension of APTT in oral floor and lower gingiva groups. F1+2 in lower gingiva group increased, and PAP rose in tongue and buccal mucosa groups. These results indicate that irradiation affects blood coagulation fibrinolysis system in patients with oral SCC, but the amount of the activation differs by the clinical findings. (author)

  20. Changes in coagulation-fibrinolysis function in alveolar lavage fluid of endotoxemic dogs after partial removal of peripheral leukocytes

    Shun-gang ZHOU


    Full Text Available Objective To observe the effect of partial removal of peripheral leucocytes on the coagulation-fibrinolysis function of alveolar lavage fluid(ALF in endotoxemic dogs,and explore the influence and mechanisms of activated leucocytes on lung injury in endotoxemic dogs.Methods Thirty male mongrel dogs were involved in present study and randomly divided into 3 groups(10 each: LPS group(group L,sham leukocytapheresis group(group S and leukocytapheresis group(group T.Endotoxemic model was reproduced in group L by administration of LPS(2mg/kg,but the animals did not receive leukocytapheresis.Animals in group T received leukocytapheresis using a continuous-flow blood cell separator 12-14 hours after administration of LPS.Animals in group S received sham leukocytapheresis(the end products were transfused back into the dogs at 12-14 hours after administration of LPS.At 36h after administration of LPS,the lung tissues were harvested to obtain ALF,and the levels of neutrophil elastase(NE,soluble thrombomodulin(sTM,activated protein C(APC and plasminogen activator inhibitor-1(PAI-1 in ALF were determined,the expression of thrombomodulin in lung tissue was observed by immunohistochemical staining,while the routine pathological examination and wet/dry ratio of lung tissue were performed.Results The APC level in ALF was significantly higher,while the NE,sTM and PAI-1 levels in ALF and wet/dry ratio of lung tissue were significantly lower in group T than in group L and group S(P < 0.05.Immunohistochemical examination revealed that the expression of thrombomodulin in lung tissue was higher in group T than in group L and group S.No significant difference was found between group L and group S in the indexes mentioned above.Pathological observation showed the incidence of acute lung injury was significantly lower in group T(2/10 than in group L(7/10 and group S(8/10,P < 0.05.Conclusion Partial removal of peripheral leukocytes may lower the level of NE in ALF

  1. Percutaneous coronary intervention for acute MI does not prevent in-hospital development of cardiogenic shock compared to fibrinolysis

    Lindholm, Matias G; Boesgaard, Søren; Thune, Jens Jakob; Kelbaek, Henning; Andersen, Henning Rud; Køber, Lars Valeur


    acute MI compared to fibrinolysis. Cardiogenic shock is still the leading cause of death in patients hospitalised for acute MI. There was no difference in mortality, with regards to treatment strategy in patients developing cardiogenic shock after the initial treatment.......BACKGROUND: It has been speculated that invasive revascularization prevents development of cardiogenic shock. Data from randomised trials comparing angioplasty with fibrinolysis on the development of cardiogenic shock are lacking. AIMS: To elucidate the effect of angioplasty on in......-hospital development of cardiogenic shock compared to fibrinolysis. To evaluate whether mortality in patients who develop cardiogenic shock after treatment is dependent on revascularization strategy. METHODS AND RESULTS: DANAMI-2 randomly assigned 1572 STEMI patients to fibrinolysis (782 patients) or angioplasty (790...

  2. Activatable thermo-sensitive ICG encapsulated pluronic nanocapsules for temperature sensitive fluorescence tomography

    Kwong, Tiffany C.; Nouizi, Farouk; Sampathkumaran, Uma; Zhu, Yue; Alam, Maksudul M.; Gulsen, Gultekin


    Fluorescent tomography has been hindered by poor tissue penetration and weak signal which results in poor spatial resolution and quantification accuracy. Recently, it has been reported that activatable temperature responsive fluorescent probes which respond to focused ultrasound heating can improve the resolution and quantification of fluorescent tomography in deep tissue. This has lead to a new imaging modality, "Temperature-modulated fluorescent tomography." This technique relies on activatable thermo-sensitive fluorescent nanocapsules for whose fluorescence quantum efficiency is temperature dependent. Within a 4-5° C temperature range, the fluorescent signal increase more than 10-fold. In this molecular probe, Indocyanine Green (ICG) is encapsulated inside the core of a thermo-reversible pluronic micelle. Here we show the fluorescence response and temperature range of the nanocapsules which have been optimized for a higher temperature range to be used for in vivo animal imaging. We report on the feasibility of these temperature-sensitive reversible nanocapsules for in vivo applications by studying the pharmacokinetics in a subcutaneous mouse tumor model in vivo.

  3. Plasmin-driven fibrinolysis facilitates skin tumor growth in a gender-dependent manner

    Hald, Andreas; Eickhardt, Hanne; Maerkedahl, Rasmus Baadsgaard;


    Rearrangement of the skin during wound healing depends on plasmin and plasminogen, which serve to degrade fibrin depositions in the provisional matrix and thereby facilitate keratinocyte migration. In the current study, we investigated whether plasmin and plasminogen likewise played a role during...... by superimposing heterozygous fibrinogen deficiency on Plg(-)(/)(-) mice. Tumors derived from these Fib(-)(/+);Plg(-)(/)(-) mice displayed a significantly decreased level of tumor thrombosis compared with Plg(-)(/)(-) mice. In summary, these data indicate that plasmin-driven fibrinolysis facilitates tumor growth...... by maintaining patency of the tumor vasculature.-Hald, A., Eickhardt, H., Maerkedahl, R. B., Feldborg, C. W., Egerod, K. L., Engelholm. L. H., Laerum, O. D., Lund, L. R., Rønø, B. Plasmin-driven fibrinolysis facilitates skin tumor growth in a gender-dependent manner....

  4. Coagulation and fibrinolysis systems in bronchoalveolar lavage fluid in irradiated lung of rabbits

    Sawada, Midori (Hirosaki Univ., Aomori (Japan). School of Medicine)


    Pulmonary fibrin deposition suggests the involvement of coagulation and fibrinolysis in pulmonary inflammation. The present study was designed to investigate the alterations of coagulation and fibrinolysis in rabbits that received thoracic irradiation. Serial bronchoalveolar lavage (BAL) was performed after the irradiation, and procoagulant activity (PCA) and tissue plasminogen activator (r-PA) were measured in BAL fluids. PCA increased from 2 to 8 weeks after irradiation with increased number of macrophages and increased PCA per macrophage. T-PA also increased with a significant difference at 4 weeks compared to controls. Although irradiation activated both PCA and t-PA, PCA increased prior to t-PA and the elevation lasted longer. It was concluded that activation of the coagulation system promotes pulmonary fibrin deposition and may contribute to the progression of pulmonary injury. (author).

  5. Blood pressure lowering, fibrinolysis enhancing and antioxidant activities of cardamom (Elettaria cardamomum).

    Verma, S K; Jain, Vartika; Katewa, S S


    Elettaria cardamomum (L.) Maton. (Small cardamom) fruit powder was evaluated for its antihypertensive potential and its effect on some of the cardiovascular risk factors in individuals with stage 1 hypertension. Twenty, newly diagnosed individuals with primary hypertension of stage 1 were administered 3 g of cardamom powder in two divided doses for 12 weeks. Blood pressure was recorded initially and at 4 weeks interval for 3 months. Blood samples were also collected initially and at 4 weeks interval for estimation of lipid profile, fibrinogen and fibrinolysis. Total antioxidant status, however, was assessed initially and at the end of the study. Administration of 3 g cardamom powder significantly (pcardamom effectively reduces blood pressure, enhances fibrinolysis and improves antioxidant status, without significantly altering blood lipids and fibrinogen levels in stage 1 hypertensive individuals. PMID:20361714

  6. Association between sympathoadrenal activation, fibrinolysis, and endothelial damage in septic patients

    Johansson, Pär I; Haase, Nicolai; Perner, Anders;


    ), whereas no other baseline preintervention biomarkers differed. In the 53 patients not receiving catecholamines at blood sampling, endogenous p-noradrenaline correlated positively with adrenaline, syndecan 1, soluble vascular endothelial growth factor receptor 1, soluble CD40 ligand, tissue...... damage, natural anticoagulation, fibrinolysis, cell damage, and platelet activation. RESULTS: Sixty-seven patients were included, of whom 14 turned out to receive noradrenaline infusion at blood sampling. These 14 patients had p-noradrenaline 5-fold higher than patients not receiving catecholamines (n=53......). CONCLUSIONS: In septic patients, endogenous noradrenaline was independently associated with biomarkers of endothelial activation, damage, fibrinolysis and mortality, comparable with findings in trauma and myocardial infarction patients. The catecholamine surge in critical illness may contribute to balance...

  7. [Puncture aspiration and local fibrinolysis in the surgery of primary non-traumatic intracranial hemorrhages].

    Krylov, V V; Burov, S A; Dash'ian, V G; Galankina, I E


    A possibility of evacuation of primary non-traumatic intracranial hematomas with less traumatic effect using puncture aspiration and local fibrinolysis has been studied in 73 patients aged 23-69 years. It has been shown that this method allows an effective (up to 95% of initial volume) evacuation of hypertensive hematomas in most patients. The evacuation of hemorrhage is accompanied by the significant regress of movement disorders already in the early post-operative period that promotes shortening of treatment time in patients with hemorrhage stroke. The positive changes of neurological status are supported by the morphological data on the induction of reparative processes in the perifocal brain tissue against the background of focal fibrinolysis. The reduction of post-operative fatal cases (from 35 to 23%) allows a recommendation of the method described in surgery of hypertensive hemorrhages. PMID:19008848

  8. Fibrinolysis or Primary PCI in ST-Segment Elevation Myocardial Infarction

    Armstrong, Paul W.; Gershlick, Anthony H; Goldstein, Patrick; Wilcox, Robert; Danays, Thierry; Lambert, Yves; Sulimov, Vitaly; Rosell Ortiz, Fernando; Ostojic, Miodrag; Welsh, Robert C.; Carvalho, Antonio C.; Nanas, John; Arntz, Hans-Richard; Halvorsen, Sigrun; Huber, Kurt


    BACKGROUND It is not known whether prehospital fibrinolysis, coupled with timely coronary angiography, provides a clinical outcome similar to that with primary percutaneous coronary intervention (PCI) early after acute ST-segment elevation myocardial infarction (STEMI). METHODS Among 1892 patients with STEMI who presented within 3 hours after symptom onset and who were unable to undergo primary PCI within 1 hour, patients were randomly assigned to undergo either primary PCI or fibrinolytic th...

  9. Exposure of endothelial cells to physiological levels of myeloperoxidase-modified LDL delays pericellular fibrinolysis.

    Karim Zouaoui Boudjeltia

    Full Text Available BACKGROUND: Blood fluidity is maintained by a delicate balance between coagulation and fibrinolysis. The endothelial cell surface is a key player in this equilibrium and cell surface disruptions can upset the balance. We investigated the role of pericellular myeloperoxidase oxidized LDLs (Mox-LDLs in this balance. METHODS AND RESULTS: We designed a technical device that enabled us to monitor fibrinolysis in real-time at the surface of an endothelial cell line (EA.hy926, and showed that Mox-LDL decreased pericellular fibrinolysis. There were no changes in fibrinolysis when EA.hy926 endothelial cells were exposed to native LDL (24 hours at doses of 10, 50, 100 and up to 1250 µg/ml. However, treatment of EA.hy926 endothelial cells with 10 and 50 µg/ml of Mox-LDL (physiological serum concentrations increased the lysis time by 15 and 13%, respectively (p<0.001, although this effect was not present at higher concentrations of 100 µg/ml. This effect was not correlated with any changes in PAI-1 or t-PA or PA Receptor (PAR expression. No effect was observed at the surface of smooth muscle cells used as controls. CONCLUSION: Our data link the current favorite hypothesis that modified LDL has a causal role in atheroma plaque formation with an old suggestion that fibrin may also play a causal role. Our data help complete the paradigm of atherosclerosis: Modified LDL locally enhances fibrin deposition (present work; fibrin deposits enhance endothelial permeability; this effect allows subendothelial accumulation of lipid and foam cells.

  10. [Extravasation of contrast medium in local intra-arterial fibrinolysis of the carotid territory].

    Urbach, H; Bendszus, M; Brechtelsbauer, D; Solymosi, L


    The safety of fibrinolytic therapy is determined with the incidence of intraparenchymatous hemorrhage. When interpreting CT studies after local intra-arterial fibrinolysis (LIF) in the carotid territory, one must consider that a hyperdense lesion may also be caused by extravasation of contrast material during angiography. In this study we retrospectively analyzed CT scans of 24 patients performed within 24 h after LIF and correlated the results with clinical and angiographic findings before and after therapy. Three of 24 patients (12.5%) showed striatocapsular parenchymal hematomas, 2 patients died and 1 showed marked clinical deterioration. Fifteen of 24 patients (62.5%) showed hyperdense lesions without space-occupying effect within striatocapsular infarctions. In 6 of these patients (25%) these lesions were attributable to an extravasation of contrast medium during angiography. This extravasation required at least partial recanalization of the middle cerebral artery and always occurred within a striatocapsular infarction. The pathogenesis of extravasation of contrast medium during local intra-arterial fibrinolysis is unknown. The identification of these lesions, however, is essential for the assessment of safety of local intra-arterial fibrinolysis. PMID:9673972

  11. Vascular surgical society of great britain and ireland: inhibition of systemic fibrinolysis is associated with myocardial injury in patients operated on for ruptured abdominal aortic aneurysm

    Adam; Evans; Ludlam; Bradbury


    BACKGROUND: Previous work has demonstrated that ruptured abdominal aortic aneurysm (AAA) is associated with systemic thrombin generation and inhibition of systemic fibrinolysis. The procoagulant and hypofibrinolytic state associated with ruptured AAA predisposes to microvascular and macrovascular thrombosis and subsequent myocardial injury. The aim of this study was to determine the relationship between haemostatic derangement and biochemical evidence of myocardial injury in patients operated on for ruptured AAA. METHODS: Ten patients undergoing repair of ruptured AAA were studied. Tissue plasminogen activator (tPA) activity, plasminogen activator inhibitor (PAI) activity, prothrombin fragment (PF) 1 + 2, D-dimer and fibrinogen levels were measured before operation, and immediately before and 5 min after aortic clamp release. Plasma levels of cardiac troponin (cTn) I were measured before operation, and 6 and 24 h after aortic clamp release. RESULTS: There was no relationship between tPA activity, PF 1 + 2, D-dimer or fibrinogen and cTn-I levels at any sampling point. There was, however, a significant positive correlation (Spearman rank test) between PAI activity immediately before (median 38.6 (range 13.0-39.4) units ml-1) and 5 min after (37.2 (10.6-39.4) units ml-1) aortic clamp release, and cTn-I at 6 h (median 3.17 (range less than 0.5 to 71.1) ng ml-1) and 24 h (5.55 (range less than 0.5 to 110) ng ml-1) after aortic clamp release. CONCLUSION: These data strongly support the hypothesis that the inhibition of systemic fibrinolysis which occurs in response to ischaemia and reperfusion during ruptured AAA repair contributes to the development of subsequent myocardial injury. PMID:10361322

  12. Primary percutaneous coronary intervention compared with fibrinolysis for myocardial infarction in diabetes mellitus - Results from the primary coronary angioplasty vs thrombolysis-2 trial

    Timmer, Jorik R.; Ottervanger, Jan Paul; de Boer, Menko-Jan; Boersma, Eric; Grines, Cindy L.; Westerhout, Cynthia M.; Simes, John; Granger, Christopher B.; Zijlstra, Felix


    Background: There is growing evidence for a clinical benefit of primary percutaneous coronary intervention (PCI) compared with fibrinolysis; however, whether the treatment effect is consistent among patients with diabetes mellitus is unclear. We compared PCI with fibrinolysis for treatment of ST-seg

  13. [Local fibrinolysis in surgical treatment of non-traumatic intracranial hemorrhages].

    Krylov, V V; Burov, S A; Dash'ian, V G; Galankina, I E


    More than 70% of hypertensive hemorrhages are located in deep brain structures. The removal of such hematomas using encephalotomy is accompanied by additional cerebral trauma and often results in unsatisfactory outcomes. The puncture aspiration with local fibrinolysis is one of the minimal invasive methods for treatment of intracerebral hematomas (ICH). The puncture and aspiration of liquid part of ICH (not more than 20% of ICH volume) is performed via small burr hole. Afterward the catheter is placed into ICH cavity and fibrinolytic is injected via this catheter in postoperative period for lysis of ICH solid part. The lysed blood is aspirated within 1-4 days. The last generations of fibrinolytics are very effective concerning intensity of blood clot lysis and practically have no systematic effect on blood coagulation system during their local usage. Morphological examinations showed that usage of fibrinolysis leads to formation of smaller cysts in the region of former hematoma as well as reparative processes in perihemorrhagical zone are expressed better comparing with treatment methods without usage of fibrinolytics. The morphological pattern is also confirmed by clinical signs of neurological deficit regress corresponding to damage focus. We operated 124 patients with parenchymal hemorrhages and 28 patients with intraventricular hemorrhages using described minimally invasive method at the base of Scientific Research Institute of Emergency Care n.a. N. V. Sklifosovsky. The applied method allowed decreasing lethality from 35% to 21% among patients with parenchymal ICH and from 98% to 48%--among patients with ventricular hemotamponade underwent usage of ventricular drainage combined with local fibrinolysis. PMID:24340958

  14. Effects of an oral dose of isosorbide dinitrate on platelet function and fibrinolysis in healthy volunteers.

    Wallén, N H; Larsson, P T; Bröijersén, A; Andersson, A; Hjemdahl, P


    1. A randomised double-blind placebo-controlled study was performed to investigate the effects of isosorbide dinitrate (ISDN; 20 mg orally) on various aspects of platelet function and fibrinolysis in vivo in 12 healthy volunteers. 2. Measurements were performed at rest (before and after tablet ingestion) and during platelet activation by adrenaline (0.4 nmol kg-1 min-1; 30 min infusion). 3. At rest, ISDN did not alter plasma concentrations of beta-thromboglobulin (beta TG). EC50 values for AD...

  15. A serine protease inhibitor from hemolymph of green mussel, Perna viridis

    Khan, M.S.; Goswami, U.; Rojatkar, S.R.; Khan, M.I.

    of qua to respectively. that and innate immune mecha- memory following the first have is constituted perform ly, natural invertebrates, serine proteases and their inhibitors are also in- volved in parallel physiological processes, for example, the blood...- sin and are novel anticoagulants isolated from the marine animals. 5 In vertebrates, serine protease inhibitors have been studied extensively and they are known to be involved in phagocytosis, coagulation, complement activation, fibrinolysis, blood...

  16. Fluorescence in vivo imaging of live tumor cells with pH-activatable targeted probes via receptor-mediated endocytosis

    Asanuma, Daisuke; Urano, Yasuteru; Nagano, Tetsuo; Hama, Yukihiro; Koyama, Yoshinori; Kobayashi, Hisataka


    One goal of molecular imaging is to establish a widely applicable technique for specific detection of tumors with minimal background. Here, we achieve specific in vivo tumor visualization with a newly-designed "activatable" targeted fluorescence probe. This agent is activated after cellular internalization by sensing the pH change in the lysosome. Novel acidic pH-activatable probes based on the BODIPY fluorophore were synthesized, and then conjugated to a cancer-targeting monoclonal antibody, Trastuzumab, or galactosyl serum albumin (GSA). As proof of concept, ex and in vivo imaging of two different tumor mouse models was performed: HER2-overexpressed lung metastasis tumor with Trastuzumab-pH probe conjugates and lectin-overexpressed i.p. disseminated tumor with GSA-pH probe conjugates. These pH-activatable targeted probes were highly specific for tumors with minimal background signal. Because the acidic pH in lysosomes is maintained by the energy-consuming proton pump, only viable cancer cells were successfully visualized. Furthermore, this strategy was also applied to fluorescence endoscopy in tumor mouse models, resulting in specific visualization of tumors as small as submillimeter in size that could hardly detected by naked eyes because of their poor contrast against normal tissues. The design concept can be widely adapted to cancer-specific cell-surface-targeting molecules that result in cellular internalization.

  17. CpG expedites regression of local and systemic tumors when combined with activatable nanodelivery.

    Kheirolomoom, Azadeh; Ingham, Elizabeth S; Mahakian, Lisa M; Tam, Sarah M; Silvestrini, Matthew T; Tumbale, Spencer K; Foiret, Josquin; Hubbard, Neil E; Borowsky, Alexander D; Murphy, William J; Ferrara, Katherine W


    Ultrasonic activation of nanoparticles provides the opportunity to deliver a large fraction of the injected dose to insonified tumors and produce a complete local response. Here, we evaluate whether the local and systemic response to chemotherapy can be enhanced by combining such a therapy with locally-administered CpG as an immune adjuvant. In order to create stable, activatable particles, a complex between copper and doxorubicin (CuDox) was created within temperature-sensitive liposomes. Whereas insonation of the CuDox liposomes alone has been shown to produce a complete response in murine breast cancer after 8 treatments of 6 mg/kg delivered over 4 weeks, combining this treatment with CpG resolved local cancers within 3 treatments delivered over 7 days. Further, contralateral tumors regressed as a result of the combined treatment, and survival was extended in systemic disease. In both the treated and contralateral tumor site, the combined treatment increased leukocytes and CD4+ and CD8+ T-effector cells and reduced myeloid-derived suppressor cells (MDSCs). Taken together, the results suggest that this combinatorial treatment significantly enhances the systemic efficacy of locally-activated nanotherapy. PMID:26471394

  18. Southern copperhead venom enhances tissue-type plasminogen activator induced fibrinolysis but does not directly lyse human plasma thrombi.

    Nielsen, Vance G


    In addition to degrading fibrinogen as a source of consumptive coagulopathy, purified fractions of southern copperhead (Agkistrodon contortrix contortrix; A. c. contortrix) venom has been demonstrated to enhance fibrinolysis. The goal of this investigation was to characterize the kinetic fibrinolytic profile of A. c. contortrix venom in the absence and presence of tissue-type plasminogen activator (tPA) to determine if intact venom had tPA independent fibrinolytic properties. Utilizing thrombelastographic methods, the coagulation and fibrinolytic kinetic profiles of human plasma exposed to A. c. contortrix venom (0-6 μg/ml) were determined in the absence or presence of tPA (0-100 IU/ml). Then, plasma was exposed to 0-6 μg/ml of venom without tPA added and coagulation observed for 3 h. Venom significantly prolonged the onset of coagulation, decreased the velocity of thrombus growth but did not significantly decrease clot strength. In the presence of tPA, venom significantly decreased clot strength, shortened the time of onset of fibrinolysis, decreased clot lysis time but did not significantly affect the maximum rate of lysis. Lastly, while venom exposure in the absence of tPA significantly prolonged the onset of coagulation and decreased the velocity of clot growth, venom exposure did not result in detectable fibrinolysis over the 3 h observation period. A. c. contortrix venom enhances tPA mediated fibrinolysis by degrading plasma coagulation kinetics. Intact A. c. contortrix venom does not possess sufficient fibrinolytic activity to cause fibrinolysis in human plasma at the concentration tested. PMID:26407681

  19. Transition-Metal-Free CO-Releasing BODIPY Derivatives Activatable by Visible to NIR Light as Promising Bioactive Molecules.

    Palao, Eduardo; Slanina, Tomáš; Muchová, Lucie; Šolomek, Tomáš; Vítek, Libor; Klán, Petr


    Carbon monoxide-releasing molecules (CORMs) are chemical agents used to administer CO as an endogenous, biologically active molecule. A precise spatial and temporal control over the CO release is the major requirement for their applications. Here, we report the synthesis and properties of a new generation of transition-metal-free carbon monoxide-releasing molecules based on BODIPY chromophores (COR-BDPs) activatable by visible-to-NIR (up to 730 nm) light. We demonstrate their performance for both in vitro and in vivo experimental settings, and we propose the mechanism of the CO release based on steady-state and transient spectroscopy experiments and quantum chemical calculations. PMID:26697725

  20. Design and synthesis of phospholipase C and A2-activatable near-infrared fluorescent smart probes.

    Popov, Anatoliy V; Mawn, Theresa M; Kim, Soungkyoo; Zheng, Gang; Delikatny, E James


    The primary focus of this work was to develop activatable probes suitable for in vivo detection of phospholipase activity. Phospholipases (PLs) are ubiquitous enzymes that perform a number of critical regulatory functions. They catalyze phospholipid breakdown and are categorized as A(1), A(2) (PLA(2)), C (PLC), and D (PLD) based on their site of action. Here, we report the design, synthesis, and characterization of self-quenching reporter probes that release fluorescent moieties upon cleavage with PLA(2) or PLC. A series of phospholipids were synthesized bearing the NIR fluorophore pyropheophorbide a (Pyro) at the sn-2 position. Fluorescence quenching was achieved by attachment of either a positively charged black hole quencher-3 (BHQ-3) to the phospholipid headgroup or another neutral Pyro moiety at the sn-1 position. The specificity to different phospholipases was modulated by insertion of spacers (C(6), C(12)) between Pyro and the lipid backbone. The specificity of the quenched fluorescent phospholipids was assayed on a plate reader against a number of phospholipases and compared with two commercial probes bearing the visible fluorophore BODIPY. While PyroC(6)-PyroC(6)-PtdCho revealed significant background fluorescence, and a 10% fluorescence increase under the action of PLA(2), Pyro-PtdEtn-BHQ demonstrated high selective sensitivity to PLC, particularly to the PC-PLC isoform, and its sensitivity to PLA(2) was negligible due to steric hindrance at the sn-2 position. In contrast, the C(12)-spacered PyroC(12)-PtdEtn-BHQ demonstrated a remarkable selectivity for PLA(2) and the best relative PLA(2)/PLC sensitivity, significantly outperforming previously known probes. These results open an avenue for future in vivo experiments and for new probes to detect PL activity. PMID:20882956

  1. Utilization of Extracorporeal Pump during Local Intra-arterial Fibrinolysis in the Treatment of Acute Cerebral Arterial Occlusion: A Case Report

    Matsumaru, Y; Sonobe, M.; Mashiko, R.; Sugimorp, M.; Takahashi, S.; Nose, T


    Local intra-arterial fibrinolysis may improve the outcome of patients with ischemic cerebrovascular disease. A favorable prognosis is thought to be related to early re-establishment of blood flow into the affected brain. To minimize the time to revascularization during local intraarterial fibrinolysis, we employed an extracorporeal pump to deliver oxygenated blood into the affected brain through a microcatheter. The patient, a 57-year-old man, showed disturbance of consciousness with left hem...

  2. Percutaneous Coronary Intervention after Fibrinolysis for ST-Segment Elevation Myocardial Infarction Patients: An Updated Systematic Review and Meta-Analysis

    Feng Liu; Qinglong Guo; Guoqiang Xie; Han Zhang; Yaxi Wu; Lixia Yang


    Background Percutaneous coronary intervention (PCI), fibrinolysis and the combination of both methods are current therapeutic options for patients with ST-segment elevation myocardial infarction (STEMI). Methods We searched PubMed, EMBASE, Google scholar and Cochrane Controlled Trials Register for randomized controlled trials (RCTs) evaluating the efficacy and safety of PCI after fibrinolysis within 24 hours, which was compared with primary PCI alone and ischemia-guided or delayed PCI. Meta-a...

  3. XTEN as Biological Alternative to PEGylation Allows Complete Expression of a Protease-Activatable Killin-Based Cytostatic.

    Haeckel, Akvile; Appler, Franziska; Ariza de Schellenberger, Angela; Schellenberger, Eyk


    Increased effectiveness and reduced side effects are general goals in drug research, especially important in cancer therapy. The aim of this study was to design a long-circulating, activatable cytostatic drug that is completely producible in E. coli. Crucial for this goal was the novel unstructured polypeptide XTEN, which acts like polyethylene glycol (PEG) but has many important advantages. Most importantly, it can be produced in E. coli, is less immunogenic, and is biodegradable. We tested constructs containing a fragment of Killin as cytostatic/cytotoxic element, a cell-penetrating peptide, an MMP-2 cleavage site for specific activation, and XTEN for long blood circulation and deactivation of Killin. One of three sequence variants was efficiently expressed in E. coli. As typical for XTEN, it allowed efficient purification of the E. coli lysate by a heat step (10 min 75°C) and subsequent anion exchange chromatography using XTEN as purification tag. After 24 h XTEN-Killin reduced the number of viable cells of HT-1080 tumor cell line to 3.8 ±2.0% (p<0.001) compared to untreated controls. In contrast, liver derived non-tumor cells (BRL3A) did not show significant changes in viability. Our results demonstrate the feasibility of completely producing a complex protease-activatable, potentially long-circulating cytostatic/cytotoxic prodrug in E. coli-a concept that could lead to efficient production of highly multifunctional drugs in the future. PMID:27295081

  4. Activatable albumin-photosensitizer nanoassemblies for triple-modal imaging and thermal-modulated photodynamic therapy of cancer.

    Hu, Dehong; Sheng, Zonghai; Gao, Guanhui; Siu, Fungming; Liu, Chengbo; Wan, Qian; Gong, Ping; Zheng, Hairong; Ma, Yifan; Cai, Lintao


    Photodynamic therapy (PDT) is a noninvasive and effective approach for cancer treatment. The main bottlenecks of clinical PDT are poor selectivity of photosensitizer and inadequate oxygen supply resulting in serious side effects and low therapeutic efficiency. Herein, a thermal-modulated reactive oxygen species (ROS) strategy using activatable human serum albumin-chlorin e6 nanoassemblies (HSA-Ce6 NAs) for promoting PDT against cancer is developed. Through intermolecular disulfide bond crosslinking and hydrophobic interaction, Ce6 photosensitizer is effectively loaded into the HSA NAs, and the obtained HSA-Ce6 NAs exhibit excellent reduction response, as well as enhanced tumor accumulation and retention. By the precision control of the overall body temperature instead of local tumor temperature increasing from 37 °C to 43 °C, the photosensitization reaction rate of HSA-Ce6 NAs increases 20%, and the oxygen saturation of tumor tissue raise 52%, significantly enhancing the generation of ROS for promoting PDT. Meanwhile, the intrinsic fluorescence and photoacoustic properties, and the chelating characteristic of porphyrin ring can endow the HSA-Ce6 NAs with fluorescence, photoacoustic and magnetic resonance triple-modal imaging functions. Upon irradiation of low-energy near-infrared laser, the tumors are completely suppressed without tumor recurrence and therapy-induced side effects. The robust thermal-modulated ROS strategy combined with albumin-based activatable nanophotosensitizer is highly potential for multi-modal imaging-guided PDT and clinical translation. PMID:27061266

  5. Microbial light-activatable proton pumps as neuronal inhibitors to functionally dissect neuronal networks in C. elegans.

    Steven J Husson

    Full Text Available Essentially any behavior in simple and complex animals depends on neuronal network function. Currently, the best-defined system to study neuronal circuits is the nematode Caenorhabditis elegans, as the connectivity of its 302 neurons is exactly known. Individual neurons can be activated by photostimulation of Channelrhodopsin-2 (ChR2 using blue light, allowing to directly probe the importance of a particular neuron for the respective behavioral output of the network under study. In analogy, other excitable cells can be inhibited by expressing Halorhodopsin from Natronomonas pharaonis (NpHR and subsequent illumination with yellow light. However, inhibiting C. elegans neurons using NpHR is difficult. Recently, proton pumps from various sources were established as valuable alternative hyperpolarizers. Here we show that archaerhodopsin-3 (Arch from Halorubrum sodomense and a proton pump from the fungus Leptosphaeria maculans (Mac can be utilized to effectively inhibit excitable cells in C. elegans. Arch is the most powerful hyperpolarizer when illuminated with yellow or green light while the action spectrum of Mac is more blue-shifted, as analyzed by light-evoked behaviors and electrophysiology. This allows these tools to be combined in various ways with ChR2 to analyze different subsets of neurons within a circuit. We exemplify this by means of the polymodal aversive sensory ASH neurons, and the downstream command interneurons to which ASH neurons signal to trigger a reversal followed by a directional turn. Photostimulating ASH and subsequently inhibiting command interneurons using two-color illumination of different body segments, allows investigating temporal aspects of signaling downstream of ASH.

  6. Microbial light-activatable proton pumps as neuronal inhibitors to functionally dissect neuronal networks in C. elegans.

    Husson, Steven J; Liewald, Jana F; Schultheis, Christian; Stirman, Jeffrey N; Lu, Hang; Gottschalk, Alexander


    Essentially any behavior in simple and complex animals depends on neuronal network function. Currently, the best-defined system to study neuronal circuits is the nematode Caenorhabditis elegans, as the connectivity of its 302 neurons is exactly known. Individual neurons can be activated by photostimulation of Channelrhodopsin-2 (ChR2) using blue light, allowing to directly probe the importance of a particular neuron for the respective behavioral output of the network under study. In analogy, other excitable cells can be inhibited by expressing Halorhodopsin from Natronomonas pharaonis (NpHR) and subsequent illumination with yellow light. However, inhibiting C. elegans neurons using NpHR is difficult. Recently, proton pumps from various sources were established as valuable alternative hyperpolarizers. Here we show that archaerhodopsin-3 (Arch) from Halorubrum sodomense and a proton pump from the fungus Leptosphaeria maculans (Mac) can be utilized to effectively inhibit excitable cells in C. elegans. Arch is the most powerful hyperpolarizer when illuminated with yellow or green light while the action spectrum of Mac is more blue-shifted, as analyzed by light-evoked behaviors and electrophysiology. This allows these tools to be combined in various ways with ChR2 to analyze different subsets of neurons within a circuit. We exemplify this by means of the polymodal aversive sensory ASH neurons, and the downstream command interneurons to which ASH neurons signal to trigger a reversal followed by a directional turn. Photostimulating ASH and subsequently inhibiting command interneurons using two-color illumination of different body segments, allows investigating temporal aspects of signaling downstream of ASH. PMID:22815873

  7. Plasma pentraxin-3 and coagulation and fibrinolysis variables during acute Puumala hantavirus infection and associated thrombocytopenia.

    Laine, Outi K; Koskela, Sirpa M; Outinen, Tuula K; Joutsi-Korhonen, Lotta; Huhtala, Heini; Vaheri, Antti; Hurme, Mikko A; Jylhävä, Juulia; Mäkelä, Satu M; Mustonen, Jukka T


    Thrombocytopenia and altered coagulation characterize all hantavirus infections. To further assess the newly discovered predictive biomarkers of disease severity during acute Puumala virus (PUUV) infection, we studied the associations between them and the variables reflecting coagulation, fibrinolysis and endothelial activation. Nineteen hospital-treated patients with serologically confirmed acute PUUV infection were included. Acutely, plasma levels of pentraxin-3 (PTX3), cell-free DNA (cf-DNA), complement components SC5b-9 and C3 and interleukin-6 (IL-6) were recorded as well as platelet ligands and markers of coagulation and fibrinolysis. High values of plasma PTX3 associated with thrombin formation (prothrombin fragments F1+2; r = 0.46, P = 0.05), consumption of platelet ligand fibrinogen (r = -0.70, P < 0.001) and natural anticoagulants antithrombin (AT) (r = -0.74, P < 0.001), protein C (r = -0.77, P < 0.001) and protein S free antigen (r = -0.81, P < 0.001) and a decreased endothelial marker ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 domain 13) (r = -0.48, P = 0.04). Plasma level of AT associated with C3 (r = 0.76, P < 0.001), IL-6 (r = -0.56, P = 0.01) and cf-DNA (r = -0.47, P = 0.04). High cf-DNA coincided with increased prothrombin fragments F1+2 (r = 0.47, P = 0.04). Low C3 levels reflecting the activation of complement system through the alternative route predicted loss of all natural anticoagulants (for protein C r = 0.53, P = 0.03 and for protein S free antigen r = 0.64, P = 0.004). Variables depicting altered coagulation follow the new predictive biomarkers of disease severity, especially PTX3, in acute PUUV infection. The findings are consistent with the previous observations of these biomarkers also being predictive for low platelet count and underline the cross-talk of inflammation and coagulation systems in acute PUUV infection. PMID:24751477

  8. Effects of Acute Normovolemic Hemodilution on Perioperative Coagulation and Fibrinolysis in Elderly Patients Undergoing Hepatic Carcinectomy

    Jian-rong Guo; Jun Yu; Xiao-ju Jin; Jin-man Du; Wei Guo; Xiao-hong Yuan


    Objective To observe the effects of acute normovolemie hemodilution (ANH) on coagulation func-tion and fibrinolysis in elderly patients undergoing hepatic carcinectomy.Methods Thirty elderly patients (aged 60-70 years) with liver cancer (American Society of Anesthe-siologists physical status Ⅰ-Ⅱ) scheduled for hepatic carcinectomy from February 2007 to February 2008 were randomly divided into ANH group (n= 15) and control group (n= 15). After tracheal intubation, patients in ANH group and control group were infused with 6% hydroxyethyl starch (HES) (130/0.4), and basic liquid containing 6% HES and routine Ringer's solution, respectively. In all the studied patients, blood samples were drawn at five different time points: before anesthesia induction (T1), 30 minutes after ANH (T2), I hour after start of operation (T3), immediately after operation (T4), and 24 hours after operation (T5). Then co-agulation function, soluble fibrin monomer complex (SFMC), prothrombin fragment (F1+2), and platelet membrane glycoprotein (activated GPIIb/GPIIIa and P-selectin) were measured.Results The perioperative blood loss was not significantly different between the two groups (P> 0.05). The volume of allogeneic blood transfusion in ANH group was significantly smaller than that in control group (350.5±70.7 mL vs. 457.8±181.3 mL, P0.05). SFMC and F1 +2 increased in both groups, but without statistical significance. P-selectin expression on the platelet surface of ANH group was significantly low-ered at T2 and T3 compared with the level at T1 (P< 0.05). Compared with control group, P-selectin was sig-nificandy lower in ANH group at T2-T5 (all P<0.05).Conclusions In elderly patients undergoing resection of liver cancer, ANH may not hamper fibri-nolysis and coagulation function. It could therefore be safe to largely reduce allogeneic blood transfusion.

  9. Interaction of Plasminogen Activator Inhibitor Type-1 (PAI-1) with Vitronectin

    Schröck, Florian Rudolf


    The serpin plasminogen activator inhibitor type-1 (PAI-1) is of importance in physiological processes such as fibrinolysis and thrombolysis as well as in pathophysiological processes like thrombosis, tumor cell adhesion or invasion, and metastasis. The interaction of PAI-1 with the extracellular matrix protein vitronectin (Vn) was implicated to play an important role in several of these processes and is therefore a possible target for therapeutic strategies. Understanding the PAI-1/Vn interac...

  10. Perturbed blood coagulation and fibrinolysis in rabbits after irradiation to the liver

    Effects of X-ray irradiation to the liver were studied in rabbits with special reference to the free radicals induced by the irradiation at various doses of 5, 10, 20 and 40 Gy. Results were summarized as follows: (1) APTT and PT significantly prolonged immediately after irradiation and on day 1, and recovered thereafter to the control levels. (2) Levels of blood coagulation factors I, II and plasminogen, t-PA and plasma prekallikrein showed similar trends, namely, an initial rapid decrease immediately after irradiation, followed by a transient increase on day 3 and a subsequent recovery to the control level on days 7 and 10. These changes coincided with the prolongation of ATPP and PT. (3) The SOD activity and the plasma albumin level also decreased immediately after irradiation, recovered once from 3 to 7 days and decreased again on days 10. The decreased SOD activity noted immediately after irradiation indicates production of free radicals induced by the irradiation. This finding may suggest that the free radicals thus produced may have perturbed blood coagulation and fibrinolysis, at least in part, by blocking the secretion of relevant proteins from the hepatocytes. (author)

  11. Polypyrrole-based nanotheranostics for activatable fluorescence imaging and chemo/photothermal dual therapy of triple-negative breast cancer

    Park, Dongjin; Ahn, Kyung-Ohk; Jeong, Kyung-Chae; Choi, Yongdoo


    Here, we fabricated polypyrrole nanoparticles (PPys) (termed HA10-PPy, HA20-PPy, and HA40-PPy) doped with different average molecular weight hyaluronic acids (HAs) (10, 20, and 40 kDa, respectively), and evaluated the effect of molecular weight of doped HA on photothermal induction, fluorescence quenching, and drug loading efficiencies. Doxorubicin-loaded HA-doped PPys (DOX@HA-PPys) could be used for imaging and therapy of triple-negative breast cancer (TNBC). Fluorescence turn-on, stimuli-responsive drug release, and photo-induced heating of DOX@HA-PPys enabled not only activatable fluorescence imaging but also subsequent chemo/photothermal dual therapy for TNBC. In particular, we illustrated the potential usefulness of the photothermal effect of the nanoparticles for overcoming chemoresistance in TNBC.

  12. Thiol-Activatable Triplet-Triplet Annihilation Upconversion with Maleimide-Perylene as the Caged Triplet Acceptor/Emitter.

    Mahmood, Zafar; Zhao, Jianzhang


    Efficient thiol-activated triplet-triplet annihilation (TTA) upconversion system was devised with maleimide-caged perylene (Py-M) as the thiol-activatable triplet acceptor/emitter and with diiodoBodipy as the triplet photosensitizer. The photophysical processes were studied with steady-state UV-vis absorption spectroscopy, fluorescence spectroscopy, electrochemical properties, and nanosecond transient absorption spectroscopy. The triplet acceptor/emitter Py-M shows week fluorescence (ΦF = 0.8%), and no upconversion (ΦUC = 0%) was observed. The quenching of fluorescence of Py-M is due to photoinduced electron-transfer (PET) process from perylene to maleimide-caging unit, which quenches the singlet excited state of perylene. The fluorescence of Py-M was enhanced by 200-fold (ΦF = 97%) upon addition of thiols such as 2-mercaptoethanol, and the ΦUC was increased to 5.9%. The unique feature of this thiol-activated TTA upconversion is that the activation is based on addition reaction of the thiols with the caged acceptor/emitter, and no side products were formed. The previously reported cleavage approach gives side products which are detrimental to the TTA upconversion. With nanosecond transient absorption spectroscopy, we found that the triplet excited state of Py-M was not quenched by any PET process, which is different from singlet excited state (fluorescence) of Py-M. The results are useful for study of the triplet excited states of organic chromophores and for activatable TTA upconversion. PMID:26694534

  13. Endovascular recanalization of acute intracranial vertebrobasilar artery occlusion using local fibrinolysis and additional balloon angioplasty

    Vertebrobasilar artery occlusion (VBO) produces high mortality and morbidity due to low recanalization rate utilization in endovascular therapy. The use of percutaneous transluminal angioplasty (PTA) to improve recanalization rate additional to local intra-arterial fibrinolysis (LIF) was investigated in this study. Results obtained following recanalization therapy in acute intracranial VBO are reported. Eighteen consecutive patients with acute VBO underwent LIF with or without PTA, from August 2000 to May 2006. Eight patients were treated using LIF alone, and ten required additional PTA. Rate of recanalization, neurological status before treatment, and clinical outcomes were evaluated. Of 18 patients, 17 achieved recanalization. One procedure-related complication of subarachnoid hemorrhage occurred. Overall survival rate was 94.4% at discharge. Seven patients achieved good outcomes [modified Rankin scale (mRS) 0-2], and the other 11 had poor outcomes (mRS 3-6). Five of six patients who scored 9-14 on the Glasgow Coma Scale (GCS) before treatment displayed good outcomes, whereas ten of 12 patients who scored 3-8 on the GCS showed poor outcomes. GCS prior to treatment showed a statistically significant correlation to outcomes (p < 0.05). Moreover, the National Institutes of Health Stroke Scale (NIHSS) before treatment correlated well with mRS (correlation coefficient 0.487). No statistical difference between the good and poor outcome groups was observed for the duration of symptoms, age, etiology, and occlusion site. Endovascular recanalization can reduce mortality and morbidity of acute VBO. Good GCS and NIHSS scores prior to treatment can predict the efficacy of endovascular recanalization. (orig.)

  14. Endovascular recanalization of acute intracranial vertebrobasilar artery occlusion using local fibrinolysis and additional balloon angioplasty

    Kashiwagi, Junji; Okahara, Mika [Shinbeppu Hospital, Department of Radiology, Beppu, Oita (Japan); Kiyosue, Hiro; Tanoue, Shuichi; Sagara, Yoshiko; Mori, Hiromu [Oita University Faculty of Medicine, Department of Radiology, Yufu, Oita (Japan); Hori, Yuzo [Nagatomi Neurosurgical Hospital, Department of Radiology, Oita, Oita (Japan); Abe, Toshi [Kurume University School of Medicine, Department of Radiology, Kurume, Fukuoka (Japan)


    Vertebrobasilar artery occlusion (VBO) produces high mortality and morbidity due to low recanalization rate utilization in endovascular therapy. The use of percutaneous transluminal angioplasty (PTA) to improve recanalization rate additional to local intra-arterial fibrinolysis (LIF) was investigated in this study. Results obtained following recanalization therapy in acute intracranial VBO are reported. Eighteen consecutive patients with acute VBO underwent LIF with or without PTA, from August 2000 to May 2006. Eight patients were treated using LIF alone, and ten required additional PTA. Rate of recanalization, neurological status before treatment, and clinical outcomes were evaluated. Of 18 patients, 17 achieved recanalization. One procedure-related complication of subarachnoid hemorrhage occurred. Overall survival rate was 94.4% at discharge. Seven patients achieved good outcomes [modified Rankin scale (mRS) 0-2], and the other 11 had poor outcomes (mRS 3-6). Five of six patients who scored 9-14 on the Glasgow Coma Scale (GCS) before treatment displayed good outcomes, whereas ten of 12 patients who scored 3-8 on the GCS showed poor outcomes. GCS prior to treatment showed a statistically significant correlation to outcomes (p < 0.05). Moreover, the National Institutes of Health Stroke Scale (NIHSS) before treatment correlated well with mRS (correlation coefficient 0.487). No statistical difference between the good and poor outcome groups was observed for the duration of symptoms, age, etiology, and occlusion site. Endovascular recanalization can reduce mortality and morbidity of acute VBO. Good GCS and NIHSS scores prior to treatment can predict the efficacy of endovascular recanalization. (orig.)

  15. Photoacoustic Imaging: Semiconducting Oligomer Nanoparticles as an Activatable Photoacoustic Probe with Amplified Brightness for In Vivo Imaging of pH (Adv. Mater. 19/2016).

    Miao, Qingqing; Lyu, Yan; Ding, Dan; Pu, Kanyi


    Despite the great potential of photoacoustic imaging in the life sciences, the development of smart activatable photoacoustic probes remains elusive. On page 3662, K. Pu and co-workers report a facile nanoengineering approach based on semiconducting oligomer nano-particles to develop ratiometric photoacoustic probes with amplified brightness and enhanced sensing capability for accurate photoacoustic mapping of pH in the tumors of living mice. PMID:27167028

  16. Imaging Dendrimer-Grafted Graphene Oxide Mediated Anti-miR-21 Delivery With an Activatable Luciferase Reporter.

    Wang, Fu; Zhang, Beilei; Zhou, Lin; Shi, Yaru; Li, Zhiqiang; Xia, Yuqiong; Tian, Jie


    MicroRNAs (miRNAs) are a class of post-transcriptional gene regulators involved in various physiological processes including carcinogenesis, and they have emerged as potential targets for tumor theranostics. However, the employment of antisense oligonucleotides, termed anti-miRs, for antagonizing miRNA functions in vivo has largely been impeded by a lack of effective delivery carriers. Here, we describe the development of polyamidoamine (PAMAM) dendrimer and polyethylene glycol (PEG)-functionalized nanographene oxide (NGO) conjugate (NGO-PEG-dendrimer) for the efficient delivery of anti-miR-21 into non-small-cell lung cancer cells. To monitor the delivery of anti-miR-21 into cells and tumors, we also constructed an activatable luciferase reporter (Fluc-3xPS) containing three perfectly complementary sequences against miR-21 in the 3' untranslated region (UTR) of the reporter. Compared with bare dendrimer and Lipofectamine 2000 (Lipo2000), NGO-PEG-dendrimer showed considerably lower cytotoxicity and higher transfection efficiency. As demonstrated by in vitro bioluminescence imaging and Western blotting assays, NGO-PEG-dendrimer effectively delivered anti-miR-21 into the cytoplasm and resulted in the upregulation of luciferase intensity and PTEN target protein expression in a dose-dependent manner. Moreover, transfection with anti-miR-21 by NGO-PEG-dendrimer led to stronger inhibition of cell migration and invasion than did bare dendrimer or Lipo2000 transfection. The intravenous delivery of anti-miR-21 via NGO-PEG-dendrimer induced a significant increase in the bioluminescence signal within the Fluc-3xPS reporter-transplanted tumor areas. These results suggest that NGO-PEG-dendrimer could be an efficient and a potential nanocarrier for delivering RNA oligonucleotides. In addition, the strategy of combining NGO-PEG-dendrimer with an activatable luciferase reporter allows the image-guided monitoring of the delivery process, which can provide insights into the RNA

  17. Clinical outcome, and survival between primary percutaneous coronary intervention versus fibrinolysis in patients older than 60 years with acute myocardial infarction

    H Falsoleiman


    Conclusion: The higher rates of heart failure and need for revascularization in the fibrinolysis group reinforces benefits of PPCI in patients older than 60 years. PPCI in those who are 60 years and above with AMI is safe and cost effective.

  18. The construction and in vitro testing of photo-activatable cancer targeting folated anti-CD3 conjugates

    The construction and in vitro testing of a photo-activatable anti-tumour immuno-regulatory antibody is described. In this 'cloaked' folated anti-CD3 antibody conjugate, the folate portion of the conjugate is free to bind to folate receptor expressing cancer cells, whilst the anti-CD3 activity is effectively rendered inert by a coating of photo-labile 2-nitrobenzyl groups. On irradiation with UV-A light the activity of the anti-CD3 antibody is restored, not only when it is required, but more importantly, only where it is required. The conjugate can then attract killer T-cells to the surface of the tumour cells and kill them. Unirradiated normal tissues, to which the conjugate has been targeted by specific and non-specific binding, remain unharmed. We believe that these 'photo-switchable' conjugates could be used to markedly improve the targeting of the immune response to folate receptor (FR) expressing ovarian and breast cancers whilst minimising the side effects in the rest of the body

  19. Large-scale preparation of active caspase-3 in E. coli by designing its thrombin-activatable precursors

    Park Sung


    Full Text Available Abstract Background Caspase-3, a principal apoptotic effector that cleaves the majority of cellular substrates, is an important medicinal target for the treatment of cancers and neurodegenerative diseases. Large amounts of the protein are required for drug discovery research. However, previous efforts to express the full-length caspase-3 gene in E. coli have been unsuccessful. Results Overproducers of thrombin-activatable full-length caspase-3 precursors were prepared by engineering the auto-activation sites of caspase-3 precursor into a sequence susceptible to thrombin hydrolysis. The engineered precursors were highly expressed as soluble proteins in E. coli and easily purified by affinity chromatography, to levels of 10–15 mg from 1 L of E. coli culture, and readily activated by thrombin digestion. Kinetic evaluation disclosed that thrombin digestion enhanced catalytic activity (kcat/KM of the precursor proteins by two orders of magnitude. Conclusion A novel method for a large-scale preparation of active caspase-3 was developed by a strategic engineering to lack auto-activation during expression with amino acid sequences susceptible to thrombin, facilitating high-level expression in E. coli. The precursor protein was easily purified and activated through specific cleavage at the engineered sites by thrombin, generating active caspase-3 in high yields.


    Heng Hong; Zhi-min Xu; Bao-sen Pang; Liang Cui; Yu Wei; Wen-jing Guo; Yan-ling Mao; Xin-chun Yang


    Objective To evaluate the effects of simvastatin combined with omega-3 fatty acids on high sensitive C-reactive protein (HsCRP), lipidemia, and fibrinolysis in coronary heart disease (CHD) and CHD risk equivalent patients with mixed dyslipidemia.Methods A randomized, double-blind placebo controlled and parallel group trial was conducted. Patients with CHD and CHD risk equivalents with mixed dyslipidemia were treated with 10 or 20 mg simvastatin for 6-12 weeks. Following with the treatment of patients whose low-density lipoprotein cholesterol (LDL-ch) reaching goal level (< 100 mg/dL) or close to the goal (< 130 mg/dL), while triglyceride (TG) ≥ 200 mg/dL and < 500 mg/dL, was combined with omega-3fatty acids (3 g/d) or a placebo for 2 months. The effects of the treatment on HsCRP, total cholesterol (TC), LDL-ch, highdensity lipoprotein cholesterol (HDL-ch), TG, lipoprotein (a) [LP (a)], apolipoprotein Al (apoAl), apolipoprotein B (apoB),plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (tPA) were investigated. Forty patients finished the study with each group consisting of twenty patients.Results (1) There were significant reductions of HsCRP, TG, TC, and TC/HDL-ch, which decreased by 2.16 ± 2.77mg/L (38.5%), 94.0± 65.4 mg/dL (31.1%), 13.3 ± 22.3 mg/dL (6.3%), 0.78 ± 1.60 respectively in the omega-3 fatty acids group (P < 0.01, < 0.001, < 0.05, < 0.05) compared to the baseline. HsCRP and triglyceride reduction were more significant in omega-3 fatty acids group compared to the placebo group (P= 0.021 and 0.011 respectively). (2) In the omega-3 fatty acids group, the values and percentage of TG reduction had a significantly positive relation with HsCRP reduction (r = 0.51and 0.45, P=0.021 and 0.047 respectively).Conclusion In CHD and CHD risk equivalent patients with mixed dyslipidemia, dyslipidemia's therapeutic effect using simvastatin and omega-3 fatty acids may result from not only the combination of lipid adjustment

  1. Design and study of activatable ("OFF/ON") quantum dots (Qdots): ligand selection for Qdot surface modification for controlling Qdot fluorescence quenching and restoration

    Teblum, Andrew; Basumallick, Srijita; Shah, Rikhav; Mitra, Rajendra N.; Banerjee, Subhash; Santra, Swadeshmukul


    We report design and synthesis of a series of activatable "OFF/ON" CdS:Mn/ZnS quantum dot (Qdot) based sensing probes. The Qdot "OFF" state represent the "quenched state" where the Qdot fluorescence is quenched by ligands attached to Qdot surface. Fluorescence quenching is likely due to ligand assisted electron transfer process. Qdot fluorescence is restored when the electron transfer process is stopped. Using this activatable Qdots, we have successfully demonstrated usefulness of these Qdot probes for reliable detection of toxic cadmium ions in solution, selective detection of glutathione and sensitive detection of intracellular cancer drug release event. In this paper, we will discuss a simple but robust method of making water-soluble CdS:Mn/ZnS Qdots at the room-temperature. Two different water-soluble biomolecules, the N-acetyl cysteine (NAC) and the glutathione (GSH) were used as surface coating ligands. This is a singlestep, one-pot synthesis where the Qdot nanocrystals were grown in the presence of the biomolecules. These Qdots were characterized by fluorescence spectroscopy. Stability of the GSH coated Qdots and the NAC coated Qdots were studied by treating with ethylenediaminetetraacetic acid (EDTA, a strong chelating agent for Zn and Cd ions). Our results show that fluorescence properties of Qdots are affected by the type of surface coated ligands. In comparison to the GSH coated Qdots, the NAC coated Qdots show broad but strong emission towards near infra-red region. When treated with EDTA, fluorescence property of the GSH coated Qdot was affected less than the NAC coated Qdots. This preliminary study shows that NAC coated Qdots could potentially be used to develop activatable ("OFF/ON") probes for potential deep-tissue imaging applications. Similarly, the GSH coated Qdots could be applied for probing desired analytes or for bioimaging purposes in environmentally harsh conditions.

  2. Au@Ag/Au nanoparticles assembled with activatable aptamer probes as smart ``nano-doctors'' for image-guided cancer thermotherapy

    Shi, Hui; Ye, Xiaosheng; He, Xiaoxiao; Wang, Kemin; Cui, Wensi; He, Dinggeng; Li, Duo; Jia, Xuekun


    Although nanomaterial-based theranostics have increased positive expectations from cancer treatment, it remains challenging to develop in vivo ``nano-doctors'' that provide high-contrast image-guided site-specific therapy. Here we designed an activatable theranostic nanoprobe (ATNP) via self-assembly of activatable aptamer probes (AAPs) on Au@Ag/Au nanoparticles (NPs). As both quenchers and heaters, novel Au@Ag/Au NPs were prepared, showing excellent fluorescence quenching and more effective near-infrared photothermal therapy than Au nanorods. The AAP comprised a thiolated aptamer and a fluorophore-labeled complementary DNA; thus, the ATNP with quenched fluorescence in the free state could realize signal activation through target binding-induced conformational change of the AAP, and then achieve on-demand treatment under image-guided irradiation. By using S6 aptamer as the model, in vitro and in vivo studies of A549 lung cancer verified that the ATNP greatly improved imaging contrast and specific destruction, suggesting a robust and versatile theranostic strategy for personalized medicine in future.Although nanomaterial-based theranostics have increased positive expectations from cancer treatment, it remains challenging to develop in vivo ``nano-doctors'' that provide high-contrast image-guided site-specific therapy. Here we designed an activatable theranostic nanoprobe (ATNP) via self-assembly of activatable aptamer probes (AAPs) on Au@Ag/Au nanoparticles (NPs). As both quenchers and heaters, novel Au@Ag/Au NPs were prepared, showing excellent fluorescence quenching and more effective near-infrared photothermal therapy than Au nanorods. The AAP comprised a thiolated aptamer and a fluorophore-labeled complementary DNA; thus, the ATNP with quenched fluorescence in the free state could realize signal activation through target binding-induced conformational change of the AAP, and then achieve on-demand treatment under image-guided irradiation. By using S6 aptamer as

  3. Redoxable heteronanocrystals functioning magnetic relaxation switch for activatable T1 and T2 dual-mode magnetic resonance imaging.

    Kim, Myeong-Hoon; Son, Hye-Young; Kim, Ga-Yun; Park, Kwangyeol; Huh, Yong-Min; Haam, Seungjoo


    T1/T2 dual-mode magnetic resonance (MR) contrast agents (DMCAs) have gained much attention because of their ability to improve accuracy by providing two pieces of complementary information with one instrument. However, most of these agents are "always ON" systems that emit MR contrast regardless of their interaction with target cells or biomarkers, which may result in poor target-to-background ratios. Herein, we introduce a rationally designed magnetic relaxation switch (MGRS) for an activatable T1/T2 dual MR imaging system. Redox-responsive heteronanocrystals, consisting of a superparamagnetic Fe3O4 core and a paramagnetic Mn3O4 shell, are synthesized through seed-mediated growth and subsequently surface-modified with polysorbate 80. The Mn3O4 shell acts as both a protector of Fe3O4 in aqueous environments to attenuate T2 relaxation and as a redoxable switch that can be activated in intracellular reducing environments by glutathione. This simultaneously generates large amounts of magnetically decoupled Mn(2+) ions and allows Fe3O4 to interact with the water protons. This smart nanoplatform shows an appropriate hydrodynamic size for the EPR effect (10-100 nm) and demonstrates biocompatibility. Efficient transitions of OFF/ON dual contrast effects are observed by in vitro imaging and MR relaxivity measurements. The ability to use these materials as DMCAs is demonstrated via effective passive tumor targeting for T1- and T2-weighted MR imaging in tumor-bearing mice. PMID:27281684

  4. Plasma fibrinolysis is related to the degree of organ dysfunction but not to the concentration of von Willebrand Factor in critically ill patients

    Vincent Jean-Louis


    Full Text Available Abstract Background Endothelial cell dysfunction, by promoting fibrin deposition, has been implicated in the development of multiple organ failure. Altered fibrinolysis during inflammation may participate in microvascular alterations. We sought to determine whether plasma fibrinolysis was related to the severity of organ dysfunction and/or to the levels of von Willebrand factor (vWF antigen, as a marker of endothelium dysfunction, in critically ill patients. Methods Forty-nine consecutive patients admitted to an adult medico-surgical intensive care unit (ICU with (18 or without sepsis (31 were included. C-reactive protein and vWF levels were measured on ICU admission and plasma fibrinolysis was assessed by the Euglobulin Clot Lysis Time (ECLT. The sequential organ failure assessment (SOFA score and the simplified acute physiology score (SAPS II were calculated on admission. Results ECLT was significantly longer in septic than in non-septic patients [1033 min (871–1372 versus 665 min (551–862, p = 0.001]. There were significant correlations between ECLT and C-reactive protein (CRP concentrations (r = 0.78, p Conclusion ECLT measurement at admission could be a marker of organ dysfunction and a prognostic indicator in critically ill patients.

  5. Therapeutic potential of an orally effective small molecule inhibitor of plasminogen activator inhibitor for asthma.

    Liu, Rui-Ming; Eldridge, Stephanie; Watanabe, Nobuo; Deshane, Jessy; Kuo, Hui-Chien; Jiang, Chunsun; Wang, Yong; Liu, Gang; Schwiebert, Lisa; Miyata, Toshio; Thannickal, Victor J


    Asthma is one of the most common respiratory diseases. Although progress has been made in our understanding of airway pathology and many drugs are available to relieve asthma symptoms, there is no cure for chronic asthma. Plasminogen activator inhibitor 1 (PAI-1), a primary inhibitor of tissue-type and urokinase-type plasminogen activators, has pleiotropic functions besides suppression of fibrinolysis. In this study, we show that administration of TM5275, an orally effective small-molecule PAI-1 inhibitor, 25 days after ovalbumin (OVA) sensitization-challenge, significantly ameliorated airway hyperresponsiveness in an OVA-induced chronic asthma model. Furthermore, we show that TM5275 administration significantly attenuated OVA-induced infiltration of inflammatory cells (neutrophils, eosinophils, and monocytes), the increase in the levels of OVA-specific IgE and Th2 cytokines (IL-4 and IL-5), the production of mucin in the airways, and airway subepithelial fibrosis. Together, the results suggest that the PAI-1 inhibitor TM5275 may have therapeutic potential for asthma through suppressing eosinophilic allergic response and ameliorating airway remodeling. PMID:26702150

  6. A Cell-Based Internalization and Degradation Assay with an Activatable Fluorescence-Quencher Probe as a Tool for Functional Antibody Screening.

    Li, Yan; Liu, Peter Corbett; Shen, Yang; Snavely, Marshall D; Hiraga, Kaori


    For the development of therapeutically potent anti-cancer antibody drugs, it is often important to identify antibodies that internalize into cells efficiently, rather than just binding to antigens on the cell surface. Such antibodies can mediate receptor endocytosis, resulting in receptor downregulation on the cell surface and potentially inhibiting receptor function and tumor growth. Also, efficient antibody internalization is a prerequisite for the delivery of cytotoxic drugs into target cells and is critical for the development of antibody-drug conjugates. Here we describe a novel activatable fluorescence-quencher pair to quantify the extent of antibody internalization and degradation in the target cells. In this assay, candidate antibodies were labeled with a fluorescent dye and a quencher. Fluorescence is inhibited outside and on the surface of cells, but activated upon endocytosis and degradation of the antibody. This assay enabled the development of a process for rapid characterization of candidate antibodies potentially in a high-throughput format. By employing an activatable secondary antibody, primary antibodies in purified form or in culture supernatants can be screened for internalization and degradation. Because purification of candidate antibodies is not required, this method represents a direct functional screen to identify antibodies that internalize efficiently early in the discovery process. PMID:26024945

  7. Extending the cross-linking/mass spectrometry strategy: Facile incorporation of photo-activatable amino acids into the model protein calmodulin in Escherichia coli cells.

    Piotrowski, Christine; Ihling, Christian H; Sinz, Andrea


    Photo-induced cross-linking is a highly promising technique to investigate protein conformations and protein-protein interactions in their natural cellular environment. One strategy relies on the non-directed incorporation of diazirine-containing photo-activatable amino acids into proteins and a subsequent cross-link formation induced by UV-A irradiation. The advantage of this photo-cross-linking strategy is that it is not restricted to lysine residues and that hydrophobic regions in proteins can also be targeted, which is advantageous for investigating membrane proteins. Here, we present a simplified protocol that relies on the use of mineral salts medium without any special requirements for the incorporation of photo-methionines into proteins in Escherichia coli cells. The possibility to perform these experiments in E. coli is especially valuable as it is the major system for recombinant protein production. The method is exemplified for the Ca(2+) regulating protein calmodulin containing nine methionines, which were found to be replaced by their photo-activatable analogues. Our protocol allows the facile and stochastic incorporation of photo-methionines as the basis for conducting photo-cross-linking experiments in E. coli in an efficient manner. PMID:25726908

  8. Fibrinolysis and anticoagulant potential of a metallo protease produced by Bacillus subtilis K42

    Wesam A Hassanein; Essam Kotb; Nadia M Awny; Yehia A El-Zawahry


    In this study, a potent fibrinolytic enzyme-producing bacterium was isolated from soybean flour and identified as Bacillus subtilis K42 and assayed in vitro for its thrombolytic potential. The molecular weight of the purified enzyme was 20.5 kDa and purification increased its specific activity 390-fold with a recovery of 14%. Maximal activity was attained at a temperature of 40°C (stable up to 65°C) and pH of 9.4 (range: 6.5–10.5). The enzyme retained up to 80% of its original activity after pre-incubation for a month at 4°C with organic solvents such as diethyl ether (DE), toluene (TO), acetonitrile (AN), butanol (BU), ethyl acetate (EA), ethanol (ET), acetone (AC), methanol (ME), isopropanol (IP), diisopropyl fluorophosphate (DFP), tosyl-lysyl-chloromethylketose (TLCK), tosyl-phenylalanyl chloromethylketose (TPCK), phenylmethylsulfonylfluoride (PMSF) and soybean trypsin inhibitor (SBTI). Aprotinin had little effect on this activity. The presence of ethylene diaminetetraacetic acid (EDTA), a metal-chelating agent and two metallo protease inhibitors, 2,2′-bipyridine and -phenanthroline, repressed the enzymatic activity significantly. This, however, could be restored by adding Co2+ to the medium. The clotting time of human blood serum in the presence of this enzyme reached a relative PTT of 241.7% with a 3.4-fold increase, suggesting that this enzyme could be an effective antithrombotic agent.

  9. Influence of the laser irradiation on the post-irradiation status of the fibrinolysis and proteolysis in the rats' liver

    The influence of combined action fractionated total X-rayed irradiation in total dose 23,3 mKl/kg and laser (Lambda = 632,8 nm) on status of the fibrinolytic and proteolytic system in nonline male rats liver was studying. Decreasing fibrinolytic system activity after expired 30-days X-rayed mainly by the aget fermentative fibrinolysis have been explored. X-rayed irradiation and combined action X-ray and laser beans appealed rising fibrinolytic system activity. In 20 days after laser and X-ray irradiation were degabling fibrinolytic system activity, which was expressed by the factors combine action. X-rayed, laser irradiation and their combined action called activation unlimited proteolysis system. After action X-rayed beams the upwards of degradation were syned low-molecular proteins (decreasing number of azoalbumin). X-ray irradiation and combined action factors generate more degradation of high-molecular proteins and collagen then action of the X-ray beams. In 20 days in pari causa proteolysis became lower

  10. Altered protein expression in gestational diabetes mellitus placentas provides insight into insulin resistance and coagulation/fibrinolysis pathways.

    Bin Liu

    Full Text Available OBJECTIVE: To investigate the placental proteome differences between pregnant women complicated with gestational diabetes mellitus (GDM and those with normal glucose tolerance (NGT. METHODS: We used two-dimensional electrophoresis (2DE to separate and compare placental protein levels from GDM and NGT groups. Differentially expressed proteins between the two groups were identified by MALDI-TOF/TOF mass spectrometry and further confirmed by Western blotting. The mRNA levels of related proteins were measured by realtime RT-PCR. Immunohistochemistry (IHC was performed to examine the cellular location of the proteins expressed in placenta villi. RESULTS: Twenty-one protein spots were differentially expressed between GDM and NGT placenta villi in the tested samples, fifteen of which were successfully identified by mass spectrometry. The molecular functions of these differentially expressed proteins include blood coagulation, signal transduction, anti-apoptosis, ATP binding, phospholipid binding, calcium ion binding, platelet activation, and tryptophan-tRNA ligase activity. Both protein and mRNA levels of Annexin A2, Annexin A5 and 14-3-3 protein ζ/δ were up-regulated, while the expression of the Ras-related protein Rap1A was down-regulated in the GDM placenta group. CONCLUSION: Placenta villi derived from GDM pregnant women exhibit significant proteome differences compared to those of NGT mothers. The identified differentially expressed proteins are mainly associated with the development of insulin resistance, transplacental transportation of glucose, hyperglucose-mediated coagulation and fibrinolysis disorders in the GDM placenta villi.

  11. Coagulation and fibrinolysis after open infrarenal abdominal aortic aneurysm repair in a long-term perspective.

    Holmberg, A; Bergqvist, D; Siegbahn, A


    In patients with abdominal aortic aneurysms (AAA) the coagulation and fibrinolytic systems have been found to be activated preoperatively. Does the increased activity of the coagulation and fibrinolytic systems persist after AAA surgery in a long-term perspective? Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin complex (TAT), tissue plasminogen activator (tPA), human plasminogen activator inhibitor type 1, and human cross-linked fibrin degradation product (D-dimer) were analysed in 18 patients after open AAA surgery (postop-AAA). The median time between surgery and blood sampling was 19 months (range, 5-37 months). Comparisons were made with both preoperative values of 23 patients with AAA (preop-AAA) as well as 20 age-matched healthy controls (AMC). F1+2, TAT, and D-dimer in preop-AAA were significantly higher compared to AMC (pD-dimer). However, TAT and D-dimer levels were still higher in postop-AAA than in AMC (paneurysmal sac but still higher than in a nonaneurysmal aorta. PMID:10574587

  12. Unraveling the Pivotal Role of Bradykinin in ACE Inhibitor Activity.

    Taddei, Stefano; Bortolotto, L


    Historically, the first described effect of an angiotensin converting enzyme (ACE) inhibitor was an increased activity of bradykinin, one of the substrates of ACE. However, in the subsequent years, molecular models describing the mechanism of action of ACE inhibitors in decreasing blood pressure and cardiovascular risk have focused mostly on the renin-angiotensin system. Nonetheless, over the last 20 years, the importance of bradykinin in regulating vasodilation, natriuresis, oxidative stress, fibrinolysis, inflammation, and apoptosis has become clearer. The affinity of ACE appears to be higher for bradykinin than for angiotensin I, thereby suggesting that ACE inhibitors may be more effective inhibitors of bradykinin degradation than of angiotensin II production. Data describing the effect of ACE inhibition on bradykinin signaling support the hypothesis that the most cardioprotective benefits attributed to ACE inhibition may be due to increased bradykinin signaling rather than to decreased angiotensin II signaling, especially when high dosages of ACE inhibitors are considered. In particular, modulation of bradykinin in the endothelium appears to be a major target of ACE inhibition. These new mechanistic concepts may lead to further development of strategies enhancing the bradykinin signaling. PMID:27260014

  13. The efficacy and safety of complete pericardial drainage by means of intrapericardial fibrinolysis for the prevention of complications of pericardial effusion: a systematic review protocol

    Kakia, Aloysious; Wiysonge, Charles S; Ochodo, Eleanor A; Awotedu, Abolade A; Ristic, Arsen D; Mayosi, Bongani M


    Introduction Intrapericardial fibrinolysis has been proposed as a means of preventing complications of pericardial effusion such as cardiac tamponade, persistent and recurrent pericardial effusion, and pericardial constriction. There is a need to understand the efficacy and safety of this procedure because it shows promise. Methods and analysis We aim to assess the effects of intrapericardial fibrinolysis in the treatment of pericardial effusion. We will search PubMed, the Cochrane Library, African Journals online, Cumulative Index to Nursing and Allied Health Literature, Trip database, Clinical and the WHO International Clinical Trials Registry Platform for studies that evaluate the efficacy and/or safety of complete pericardial fluid drainage by intrapericardial fibrinolysis irrespective of study design, geographical location, language, age of participants, aetiology of pericarditis or types of fibrinolytics. Two authors will do the search independently, screen the search outputs for potentially eligible studies and assess whether the studies meet the inclusion criteria. Discrepancies between the two authors will be resolved through discussion and arbitration by a third author. Data from the selected studies shall be extracted using a standardised data collection form which will be piloted before use. The methodological quality of studies will be assessed using the Cochrane Collaboration's tools for assessing risk of bias for experimental studies and non-randomised studies, respectively. The primary meta-analysis will use random effects models due to expected interstudy heterogeneity. Dichotomous data will be analysed using relative risk and continuous with data mean differences, both with 95% CIs. Ethics and dissemination Approval by an ethics committee is not required for this study as it is a protocol for a systematic review of published studies. The results will be disseminated through a conference presentation and peer-reviewed publication. Review

  14. Addition of Arsenic Trioxide into Induction Regimens Could Not Accelerate Recovery of Abnormality of Coagulation and Fibrinolysis in Patients with Acute Promyelocytic Leukemia.

    Ye Zhang

    Full Text Available All-trans retinoic acid combined to anthracycline-based chemotherapy is the standard regimen of acute promyelocytic leukemia. The advent of arsenic trioxide has contributed to improve the anti-leukemic efficacy in acute promyelocytic leukemia. The objectives of the current study were to evaluate if dual induction by all-trans retinoic acid and arsenic trioxide could accelerate the recovery of abnormality of coagulation and fibrinolysis in patients with acute promyelocytic leukemia.Retrospective analysis was performed in 103 newly-diagnosed patients with acute promyelocytic leukemia. Hemostatic variables and the consumption of component blood were comparably analyzed among patients treated by different induction regimen with or without arsenic trioxide.Compared to patients with other subtypes of de novo acute myeloid leukemia, patients with acute promyelocytic leukemia had lower platelet counts and fibrinogen levels, significantly prolonged prothrombin time and elevated D-dimers (P<0.001. Acute promyelocytic leukemia patients with high or intermediate risk prognostic stratification presented lower initial fibrinogen level than that of low-risk group (P<0.05. After induction treatment, abnormal coagulation and fibrinolysis of patients with acute promyelocytic leukemia was significantly improved before day 10. The recovery of abnormal hemostatic variables (platelet, prothrombin time, fibrinogen and D-dimer was not significantly accelerated after adding arsenic trioxide in induction regimens; and the consumption of transfused component blood (platelet and plasma did not dramatically change either. Acute promyelocytic leukemia patients with high or intermediate risk prognostic stratification had higher platelet transfusion demands than that of low-risk group (P<0.05.Unexpectedly, adding arsenic trioxide could not accelerate the recovery of abnormality of coagulation and fibrinolysis in acute promyelocytic leukemia patients who received all

  15. Domain Modeling: NP_065094.2 [SAHG[Archive

    Full Text Available NP_065094.2 chr8 Crystal structure of Thrombin-Activatable Fibrinolysis Inhibitor (...TAFI) in complex with 2-guanidino-ethyl-mercaptosuccinic acid (GEMSA) p3d68c_ chr8/NP_065094.2/NP_065094.2_a...po_38-435.pdb p3d67a_ chr8/NP_065094.2/NP_065094.2_holo_38-435.pdb blast 38A,39G,54Y,55A,58K,64K,71S,87P,88Q

  16. Optimization of Cyclic Plasmin Inhibitors: From Benzamidines to Benzylamines.

    Hinkes, Stefan; Wuttke, André; Saupe, Sebastian M; Ivanova, Teodora; Wagner, Sebastian; Knörlein, Anna; Heine, Andreas; Klebe, Gerhard; Steinmetzer, Torsten


    New macrocyclic plasmin inhibitors based on our previously optimized P2-P3 core segment have been developed. In the first series, the P4 residue was modified, whereas the 4-amidinobenzylamide in P1 position was maintained. The originally used P4 benzylsulfonyl residue could be replaced by various sulfonyl- or urethane-like protecting groups. In the second series, the P1 benzamidine was modified and a strong potency and excellent selectivity was retained by incorporation of p-xylenediamine. Several analogues inhibit plasmin in the subnanomolar range, and their potency against related trypsin-like serine proteases including trypsin itself could be further reduced. Selected derivatives have been tested in a plasma fibrinolysis assay and are more effective than the reference inhibitor aprotinin. The crystal structure of one inhibitor was determined in complex with trypsin. The binding mode reveals a sterical clash of the inhibitor's linker segment with the 99-hairpin loop of trypsin, which is absent in plasmin. PMID:27280436

  17. Variations in pre-hospital fibrinolysis process of care: insights from the Assessment of the Safety and Efficacy of a New Thrombolytic 3 Plus international acute myocardial infarction pre-hospital care survey.

    Welsh, R.C.; Goldstein, P.; Adgey, J.; Verheugt, F.W.A.; Bestilny, S.A.; Wallentin, L.; Werf, F. van de; Armstrong, P.W.


    The Assessment of the Safety and Efficacy of a New Thrombolytic 3 (ASSENT 3 PLUS) Plus trial (n=1639) was an international trial of pre-hospital fibrinolysis with tenecteplase randomly assigned to enoxaparin or unfractionated heparin, involving 106 sites in 12 countries. Given the potential impact o

  18. Effect of individual dietary fatty acids on postprandial activation of blood coagulation factor VII and fibrinolysis in healthy young men

    Tholstrup, T.; Miller, G.J.; Bysted, Anette; Sandstrom, B.


    Background: Hypertriglyceridemia may represent a procoagulant state involving disturbances to the hemostatic system. Plasminogen activator inhibitor type 1 (PAI-1) is increased in the presence of hypertriglyceridemia. Free fatty acids (FFAs) in plasma may promote factor VII (FVII) activation. Obj...

  19. The effect of "on/off" molecular switching on the photophysical and photochemical properties of axially calixarene substituted activatable silicon(iv)phthalocyanine photosensitizers.

    Güngör, Ömer; Altınbaş Özpınar, Gül; Durmuş, Mahmut; Ahsen, Vefa


    Silicon(iv) phthalocyanines ( and ) bearing two calixarene groups as axial ligands were synthesized. Surprisingly, both phthalocyanines were obtained as two different isomers ( and ) depending on the distance between calixarene benzene groups and the phthalocyanine ring. DFT and TD-DFT computations were performed to model plausible structures of these isomers and to simulate electronic absorption spectra. These isomers converted into each other depending on the polarity of the used solvent, temperature and light irradiation. The photophysical and photochemical properties of each isomer were investigated in dimethylsulfoxide (DMSO) for the determination of photodynamic therapy (PDT) activities of these compounds. The more blue-shifted isomers ( and ) showed higher fluorescence quantum yields and singlet oxygen generation compared to more red-shifted counterparts ( and ). This behavior is extremely important for developing activatable photosensitizers for cancer treatment by PDT. Although these photosensitizers produce lower singlet oxygen in normal cells, they produce higher singlet oxygen (six times higher for ) in cancer cells since these photosensitizers converted to more blue-shifted isomers by using light irradiation. PMID:27052992

  20. [Variations in hemostasis and fibrinolysis during the treatment of acute myocardial infarct (AMI) with tissue-type plasminogen activator (TTPA). A study of 17 cases].

    Izaguirre Avila, R; Ruiz de Chávez Cervantes, A; Villavicencio, R; Gómez Trigos, A; Mar Chavira, R; Spíndola, M del C; Casanova, J M


    The aim of this trial was to estimate changes in the coagulation and fibrinolysis systems during the thrombolytic treatment with recombinant human tissue-type plasminogen activator (rt-PA) in patients with acute myocardial infarction and correlate with hemorrhagic complications. We studied 17 patients with a 3 hours-continuous systemic infusion of 100 mg of rt-PA. Prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen splits products, plasminogen, alfa-2-antiplasmin (a-2AP) and antithrombin III (AT-III) were performed before, during and after infusion. Most patients showed lengthening coagulation times. Fibrinogen and plasminogen were decreased and PDF was increased. No variations in alpha-2AP or AT-III were observed. The recuperation of fibrinogen levels occurred in 3 hours and there was hyperfibrinogenemia after day 3. No hemorrhagic complication was observed in patients with abnormalities in these coagulation or fibrinolytic tests. PMID:8347053

  1. Corrosion inhibitors

    In this paper, we briefly describe the characteristics, cost and electrochemical nature of the corrosion phenomena as well as some of the technologies that are currently employed to minimize its effect. The main subject of the paper however, deals with the description, classification and mechanism of protection of the so-called corrosion inhibitors. Examples of the use of these substances in different aggressive environments are also presented as means to show that these compounds, or their combination, can in fact be used as excellent and relatively cheap technologies to control the corrosion of some metals. In the last part of the paper, the most commonly used techniques to evaluate the efficiency and performance of corrosion inhibitors are presented as well as some criteria to make a careful and proper selection of a corrosion inhibitor technology in a given situation. (Author) 151 refs

  2. Single-cell resolution imaging of retinal ganglion cell apoptosis in vivo using a cell-penetrating caspase-activatable peptide probe.

    Xudong Qiu

    Full Text Available Peptide probes for imaging retinal ganglion cell (RGC apoptosis consist of a cell-penetrating peptide targeting moiety and a fluorophore-quencher pair flanking an effector caspase consensus sequence. Using ex vivo fluorescence imaging, we previously validated the capacity of these probes to identify apoptotic RGCs in cell culture and in an in vivo rat model of N-methyl- D-aspartate (NMDA-induced neurotoxicity. Herein, using TcapQ488, a new probe designed and synthesized for compatibility with clinically-relevant imaging instruments, and real time imaging of a live rat RGC degeneration model, we fully characterized time- and dose-dependent probe activation, signal-to-noise ratios, and probe safety profiles in vivo. Adult rats received intravitreal injections of four NMDA concentrations followed by varying TcapQ488 doses. Fluorescence fundus imaging was performed sequentially in vivo using a confocal scanning laser ophthalmoscope and individual RGCs displaying activated probe were counted and analyzed. Rats also underwent electroretinography following intravitreal injection of probe. In vivo fluorescence fundus imaging revealed distinct single-cell probe activation as an indicator of RGC apoptosis induced by intravitreal NMDA injection that corresponded to the identical cells observed in retinal flat mounts of the same eye. Peak activation of probe in vivo was detected 12 hours post probe injection. Detectable fluorescent RGCs increased with increasing NMDA concentration; sensitivity of detection generally increased with increasing TcapQ488 dose until saturating at 0.387 nmol. Electroretinography following intravitreal injections of TcapQ488 showed no significant difference compared with control injections. We optimized the signal-to-noise ratio of a caspase-activatable cell penetrating peptide probe for quantitative non-invasive detection of RGC apoptosis in vivo. Full characterization of probe performance in this setting creates an important in

  3. Site-specific conjugation of the quencher on peptide's N-terminal for the synthesis of a targeted non-spreading activatable optical probe.

    Simard, Bryan; Mironov, Gleb G; Tomanek, Boguslaw; van Veggel, Frank C J M; Abulrob, Abedelnasser


    Optical imaging offers high sensitivity and portability at low cost. The design of 'smart' or 'activatable' probes can decrease the background noise and increase the specificity of the signal. By conjugating a fluorescent dye and a compatible quencher on each side of an enzyme's substrate, the signal remains in its 'off ' state until it reaches the area where a specific enzyme is expressed. However, the signal can leak from that area unless the dye is attached to a molecule able to bind to a specific target also presented in that area. The aim of this study was to (i) specifically conjugate the quencher on the α-amino group of the peptide's N-terminus, (ii) conjugate the dye on the ε-amino group of a lysine in C-terminus, and (iii) conjugate the carboxyl group of the peptide's C-terminus to an amino group present on an antibody, using carbodiimide chemistry. The use of protecting groups, such as Boc or Fmoc, to allow site-specific conjugation, presents several drawbacks including 'on beads labeling', additional steps required for deprotection and removal from the resin, decreased yield, and dye degradation. A method of preferential labeling of α-amino N-terminal group in slightly acidic solution, proposed by Selo et al. (1996) has partially solved the problem. The present study reports improvements of the method allowing to (i) avoid the homo-bilabeling, (ii) increase the yield of the N-terminal labeling by two folds, and (iii) decrease the cost by 44-fold. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd. PMID:27282138

  4. Long-term prognostic value of ST-segment resolution in patients treated with fibrinolysis or primary percutaneous coronary intervention results from the DANAMI-2 (DANish trial in acute myocardial infarction-2)

    Sejersten, Maria; Valeur, Nana; Grande, Peer;


    . The ST-segment resolution was grouped as follows: 1) complete > or =70%; 2) partial 30% to <70%; and 3) no resolution <30%. End points were 30-day and long-term mortality and reinfarction. RESULTS: The ST-segment resolution at 90 min was more pronounced after pPCI (median 60% vs. 45%, p < 0.0001), and......OBJECTIVES: The purpose of this study was to determine the prognostic value of ST-segment resolution after primary percutaneous coronary intervention (pPCI) versus fibrinolysis. BACKGROUND: Resolution of the ST-segment has been used as a surrogate end point in trials evaluating reperfusion in acute...... a catch-up phenomenon was observed at 4 h. In the fibrinolysis group, 30-day and long-term mortality rates were significantly higher among patients without ST-segment resolution, whereas reinfarction rates were higher with complete ST-segment resolution. The ST-segment resolution was not associated...

  5. Probing intra-cellular drug release event using activatable (OFF/ON) CdS:Mn/ZnS quantum dots (Qdots): spectroscopic studies to investigate interaction of Qdots with quencher

    Tharkur, Jeremy; Teblum, Andrew; Basumallick, Srijita; Shah, Rikhav; Cantarero, Karishma; Maity, Niharika; Rifai, Sara; Doshi, Mona; Gesquiere, Andre J.; Santra, Swadeshmukul


    In recent years, activatable Quantum Dots (AQdots) are gaining popularity in a number of chemical and biological sensing applications. A basic design of AQdot probes involves a suitable quencher which is capable of altering optical properties of the Qdots. In our previous studies we have shown that CdS:Mn/ZnS fluorescence can be effectively quenched using small molecule quenchers (such as dopamine, chemotherapeutic drug) as well as iron oxide nanoparticle via electron/energy transfer process. We have also shown that the quenched Qdot fluorescence can be restored when the Qdots are separated from the quencher. Using Qdot based activatable probes, we detected intracellular drug release event. Qdot fluorescence was restored upon interaction with the intracellular glutathione (GSH). In this paper, we report a GSH induced quenching of water-soluble N-Acetyl Cysteine (NAC) surface-conjugated Cds:Mn/ZnS Qdots. Quenching of NAC-Qdots was due to aggregation of Qdots in solution. This aggregation induced fluorescence quenching phenomenon resembles with the self-quenching phenomenon of traditional organic fluorescence dyes at high concentrations. UV-VIS and fluorescence emission spectroscopy data support the interaction and binding of GSH with the NAC-Qdots. Increase in particle size due to GSH induced aggregation of NAC-Qdots was confirmed by the Dynamic Light Scattering (DLS) data.

  6. Return to normal of sup(99m)Tc-plasmin test after deep venous thrombosis and its relationship to vessel wall fibrinolysis

    Edenbrandt, C.M.; Hedner, U.; Tengborn, L.; Nilsson, J.; Ohlin, P.


    Fourteen patients with deep venous thrombosis (DVT) and a positive sup(99m)Tc-plasmin test were followed up to determine how soon a negative test was obtained. Localization and extension of the thrombi were determined by phlebography. Plasminogen activator activity in vein walls and local fibrinolytic activity after venous occlusion were measured in order to find out what the prerequisites for impaired thrombolysis are. The time required to obtain a negative sup(99m)Tc-plasmin test showed considerable variation, ranging from less than 1 week to more than 6 months. The sup(99m)Tc-plasmin test had returned to normal in 64% of the patients after 6 months. No relationship was found between vessel wall fibrinolysis and time to normalization. Instead, we found an association between the time to normalization of the sup(99m)Tc-plasmin test and the size of the thrombus, according to phlebography, as well as between the time to normalization of the sup(99m)Tc-plasmin test and the extension of leg points with a positive sup(99m)Tc-plasmin test at admission. The finding of abnormal sup(99m)Tc-plasmin test results more than 6 months after acute DVT is of practical importance and warrants caution when evaluating patients with symptoms and signs suggestive of acute recurrent DVT.

  7. Effect of individual dietary fatty acids on postprandial activation of blood coagulation factor VII and fibrinolysis in healthy young men

    Tholstrup, T.; Miller, G.J.; Bysted, Anette;


    Background: Hypertriglyceridemia may represent a procoagulant state involving disturbances to the hemostatic system. Plasminogen activator inhibitor type 1 (PAI-1) is increased in the presence of hypertriglyceridemia. Free fatty acids (FFAs) in plasma may promote factor VII (FVII) activation....... Objective: We tested the hypothesis that FVII activation would be less after consumption of saturated fatty acids than after other fatty acids. Design: The effects of 6 matching dietary test fats, rich in stearic (S), palmitic (P), palmitic + myristic (M), oleic (O), trans 18:1 (T), and linoleic (L) acid......, respectively, on the postprandial lipid and hemostatic profile (after 2, 4, 6, and 8 h) were investigated in 16 young men. High-fat meals (1 g fat/kg body wt; 43% from the test fatty acid) were served in the morning on 6 separate days. Results: All fats increased FVII activation. The S fat resulted in a lower...

  8. Laboratory assessment of anti-thrombotic therapy in heart failure, atrial fibrillation and coronary artery disease: insights using thrombelastography and a micro-titre plate assay of thrombogenesis and fibrinolysis.

    Lau, Y C; Xiong, Q; Ranjit, P; Lip, G Y H; Blann, A D


    As heart failure, coronary artery disease and atrial fibrillation all bring a risk of thrombosis, anti-thrombotic therapy is recommended. Despite such treatment, major cardiovascular events such as myocardial infarction and stroke still occur, implying inadequate suppression of thrombus formation. Accordingly, identification of patients whose haemostasis remains unimpaired by treatment is valuable. We compared indices for assessing thrombogenesis and fibrinolysis by two different techniques in patients on different anti-thrombotic agents, i.e. aspirin or warfarin. We determined fibrin clot formation and fibrinolysis by a microplate assay and thromboelastography, and platelet marker soluble P selectin in 181 patients with acute or chronic heart failure, coronary artery disease who were taking either aspirin or warfarin. Five thromboelastograph indices and four microplate assay indices were different on aspirin versus warfarin (p < 0.05). In multivariate regression analysis, only microplate assay indices rate of clot formation and rate of clot dissolution were independently related to aspirin or warfarin use (p ≤ 0.001). Five microplate assay indices, but no thrombelastograph index, were different (p < 0.001) in aspirin users. Three microplate assay indices were different (p ≤ 0.002) in warfarin users. The microplate assay indices of lag time and rate of clot formation were abnormal in chronic heart failure patients on aspirin, suggesting increased risk of thrombosis despite anti-platelet use. Soluble P selectin was lower in patients on aspirin (p = 0.0175) but failed to correlate with any other index of haemostasis. The microplate assay shows promise as a tool for dissecting thrombogenesis and fibrinolysis in cardiovascular disease, and the impact of antithrombotic therapy. Prospective studies are required to determine a role in predicting thrombotic risk. PMID:26942726

  9. Plasminogen Activator Inhibitor-1 Controls Vascular Integrity by Regulating VE-Cadherin Trafficking.

    Anna E Daniel

    Full Text Available Plasminogen activator inhibitor-1 (PAI-1, a serine protease inhibitor, is expressed and secreted by endothelial cells. Patients with PAI-1 deficiency show a mild to moderate bleeding diathesis, which has been exclusively ascribed to the function of PAI-1 in down-regulating fibrinolysis. We tested the hypothesis that PAI-1 function plays a direct role in controlling vascular integrity and permeability by keeping endothelial cell-cell junctions intact.We utilized PAI-039, a specific small molecule inhibitor of PAI-1, to investigate the role of PAI-1 in protecting endothelial integrity. In vivo inhibition of PAI-1 resulted in vascular leakage from intersegmental vessels and in the hindbrain of zebrafish embryos. In addition PAI-1 inhibition in human umbilical vein endothelial cell (HUVEC monolayers leads to a marked decrease of transendothelial resistance and disrupted endothelial junctions. The total level of the endothelial junction regulator VE-cadherin was reduced, whereas surface VE-cadherin expression was unaltered. Moreover, PAI-1 inhibition reduced the shedding of VE-cadherin. Finally, we detected an accumulation of VE-cadherin at the Golgi apparatus.Our findings indicate that PAI-1 function is important for the maintenance of endothelial monolayer and vascular integrity by controlling VE-cadherin trafficking to and from the plasma membrane. Our data further suggest that therapies using PAI-1 antagonists like PAI-039 ought to be used with caution to avoid disruption of the vessel wall.

  10. Glycosaminoglycans affect the interaction of human plasma kallikrein with plasminogen, factor XII and inhibitors

    Gozzo A.J.


    Full Text Available Human plasma kallikrein, a serine proteinase, plays a key role in intrinsic blood clotting, in the kallikrein-kinin system, and in fibrinolysis. The proteolytic enzymes involved in these processes are usually controlled by specific inhibitors and may be influenced by several factors including glycosaminoglycans, as recently demonstrated by our group. The aim of the present study was to investigate the effect of glycosaminoglycans (30 to 250 µg/ml on kallikrein activity on plasminogen and factor XII and on the inhibition of kallikrein by the plasma proteins C1-inhibitor and antithrombin. Almost all available glycosaminoglycans (heparin, heparan sulfate, bovine and tuna dermatan sulfate, chondroitin 4- and 6-sulfates reduced (1.2 to 3.0 times the catalytic efficiency of kallikrein (in a nanomolar range on the hydrolysis of plasminogen (0.3 to 1.8 µM and increased (1.9 to 7.7 times the enzyme efficiency in factor XII (0.1 to 10 µM activation. On the other hand, heparin, heparan sulfate, and bovine and tuna dermatan sulfate improved (1.2 to 3.4 times kallikrein inhibition by antithrombin (1.4 µM, while chondroitin 4- and 6-sulfates reduced it (1.3 times. Heparin and heparan sulfate increased (1.4 times the enzyme inhibition by the C1-inhibitor (150 nM.

  11. Effects of perindopril and spironolactone on cardiovascular remodeling and fibrinolysis system in ;hypertensive rats%培哚普利和螺内酯对高血压大鼠心血管重构及纤溶的影响

    邢玉; 高丽; 万国华


    目的:探讨血管紧张素转换酶抑制剂培哚普利( perindopril )和醛固酮受体拮抗剂螺内酯( spironlactone )对实验性高血压大鼠心脏、血管重构的逆转作用及纤溶系统的影响。方法腹主动脉缩窄法建立高血压动物模型,44只雄性Wistar 大鼠随机分为高血压模型组、培哚普利组(2 mg · kg-1· d-1,螺内酯组(20 mg· kg-1· d-1)和假手术组对照组。治疗12周后,各组分别应用超声检测心脏结构和功能,主动脉内径,壁厚,病理检测主动脉形态,测定纤溶酶原激活物抑制物-1(plasminogen activator inhibitor-1, PAI-1),组织纤溶酶原激活剂(tissure plasminogen activator,t-PA)。结果心脏超声结果显示,螺内酯组和培哚普利组同高血压模型组比较,舒张末期室间隔厚度,左心室后壁厚度,相对室壁厚度,左心室质量,左心室内径,左心房内径明显下降( P <0殮.05或<0.01);胸主动脉壁厚明显下降( P <0.01),病理检测胸主动脉内中膜厚度,胸主动脉内中膜厚度/内径明显下降( P <0.01)。血浆PAI-1水平培哚普利组,螺内酯组同假手术组比较明显升高( P <0.01),2组同高血压组比较差异无统计学意义( P >0.05)。 t-PA 4组差异无统计学意义( P >0.05)。结论高血压导致心脏、血管重构,纤溶活性降低,培哚普利和螺内酯均能逆转心脏和血管重构,但对高血压导致的低纤溶状态未产生明显逆转作用。%Objective To investigate the effects of perindopril and spironolactone on cardiovascular remodeling and fibrinolysis system in experimental hypertensive rats .Methods The models of hypertensive rat were established by using the method of abdominal aortic coarctation .The 44 male Wistar rats were randomly divided into 4 groups:hypertension model group , perindopril group ( hypertensive rats subjected to perindopril

  12. Proton pump inhibitors

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by glands in ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This is a ...

  13. Proton pump inhibitors

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This ...

  14. Low toxicity corrosion inhibitors

    This paper discusses the design and testing of low toxicity corrosion inhibitors. New chemistries have been investigated with respect to corrosion protection and impact on the marine environment. The resulting chemicals, while they are effective corrosion inhibitors, present significant improvements in terms of environmental properties over current products. The discussion includes results of the corrosion inhibition, toxicity, biodegradability and partitioning studies

  15. 多囊卵巢综合征患者纤溶系统改变的研究进展%Advances of the study on changes of fibrinolysis system in women with polycystic ovary syndrome

    单育; 王蔼明; 赵勇


    Polycystic ovary syndrome (PCOS) is a female endocrine disease with multipathogen and clinical manifestation of polymorphism. Its characters are insulin resistence (IR) , obesity, dyslipidemia and hyperandrogenism. Recently, it is found that PCOS appears the low-grade chronic inflammation changes. It is evidenced that IR, hyperandrogenism and inflammation can lead to the pathophysiology changes in fihrinolysis system. This review states abnormal phenomena of fibrinolysis system in women with PCOS.%多囊卵巢综合征(PCOS)是一种多病因、临床表现具有多态性的女性内分泌疾病.其基本特征为胰岛素抵抗、肥胖、血脂异常和雄激素过多.近年来发现也会出现慢性炎症的改变.经证实,PCOS患者表现出的胰岛素抵抗、高雄激素血症以及慢性炎症等,都可以导致纤溶系统病理生理性的改变.本文就PCOS患者纤溶系统异常方面的进展做一简要综述.

  16. Characterization of a Kunitz-type protease inhibitor (MjKuPI) reveals the involvement of MjKuPI positive hemocytes in the immune responses of kuruma shrimp Marsupenaeus japonicus.

    Mai, Hung Nam; Nguyen, Ha Thi Nhu; Koiwai, Keiichiro; Kondo, Hidehiro; Hirono, Ikuo


    Serine proteases and their inhibitors play vital roles in biological processes. Serine protease inhibitors, including Kunitz-type protease inhibitors play important roles not only in physiological process (i.e. blood clotting and fibrinolysis) but also in immune responses. In this study, we characterized a Kunitz-type protease inhibitor, designated MjKuPI, from kuruma shrimp Marsupenaeus japonicus. An expression profile showed that MjKuPI was mainly expressed in hemocytes. Immunostaining revealed that some hemocytes expressed MjKuPI (MjKuPI(+) hemocytes) and others did not (MjKuPI(-) hemocytes). Injection of shrimp with Vibrio penaeicida and white spot syndrome virus (WSSV) upregulated the mRNA level of MjKuPI, and a flow cytometry analysis revealed that the proportion of MjKuPI(+) hemocytes increased significantly 24 h after injection. Together, these results suggest that MjKuPI and MjKuPI(+) hemocytes have a role in the innate immune system of kuruma shrimp. PMID:27255219

  17. Small-molecule caspase inhibitors

    The review considers low-molecular weight inhibitors of caspases, cysteine proteases being key contributors to apoptosis (programmed cell death). The inhibitors with aspartic acid residues or various heterocyclic systems (both synthetic and natural) are covered. Their possible mechanisms of action are discussed. Data on inhibitor structure-activity relationship studies are systematically surveyed. The interactions of the non-peptide fragments of an inhibitor with the enzymes are examined. Examples of the use of some inhibitors for apoptosis suppression are provided.

  18. Small-molecule caspase inhibitors

    Zhenodarova, S M [Institute for Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region (Russian Federation)


    The review considers low-molecular weight inhibitors of caspases, cysteine proteases being key contributors to apoptosis (programmed cell death). The inhibitors with aspartic acid residues or various heterocyclic systems (both synthetic and natural) are covered. Their possible mechanisms of action are discussed. Data on inhibitor structure-activity relationship studies are systematically surveyed. The interactions of the non-peptide fragments of an inhibitor with the enzymes are examined. Examples of the use of some inhibitors for apoptosis suppression are provided.

  19. Small-molecule caspase inhibitors

    Zhenodarova, S. M.


    The review considers low-molecular weight inhibitors of caspases, cysteine proteases being key contributors to apoptosis (programmed cell death). The inhibitors with aspartic acid residues or various heterocyclic systems (both synthetic and natural) are covered. Their possible mechanisms of action are discussed. Data on inhibitor structure-activity relationship studies are systematically surveyed. The interactions of the non-peptide fragments of an inhibitor with the enzymes are examined. Examples of the use of some inhibitors for apoptosis suppression are provided.

  20. Inhibitory mechanisms and binding site location for serotonin selective reuptake inhibitors on nicotinic acetylcholine receptors.

    Arias, Hugo R; Feuerbach, Dominik; Bhumireddy, Pankaj; Ortells, Marcelo O


    Functional and structural approaches were used to examine the inhibitory mechanisms and binding site location for fluoxetine and paroxetine, two serotonin selective reuptake inhibitors, on nicotinic acetylcholine receptors (AChRs) in different conformational states. The results establish that: (a) fluoxetine and paroxetine inhibit h alpha1beta1 gammadelta AChR-induced Ca(2+) influx with higher potencies than dizocilpine. The potency of fluoxetine is increased approximately 10-fold after longer pre-incubation periods, which is in agreement with the enhancement of [(3)H]cytisine binding to resting but activatable Torpedo AChRs elicited by these antidepressants, (b) fluoxetine and paroxetine inhibit the binding of the phencyclidine analog piperidyl-3,4-(3)H(N)]-(N-(1-(2 thienyl)cyclohexyl)-3,4-piperidine to the desensitized Torpedo AChR with higher affinities compared to the resting AChR, and (c) fluoxetine inhibits [(3)H]dizocilpine binding to the desensitized AChR, suggesting a mutually exclusive interaction. This is supported by our molecular docking results where neutral dizocilpine and fluoxetine and the conformer of protonated fluoxetine with the highest LUDI score interact with the domain between the valine (position 13') and leucine (position 9') rings. Molecular mechanics calculations also evidence electrostatic interactions of protonated fluoxetine at positions 20', 21', and 24'. Protonated dizocilpine bridges these two binding domains by interacting with the valine and outer (position 20') rings. The high proportion of protonated fluoxetine and dizocilpine calculated at physiological pH suggests that the protonated drugs can be attracted to the channel mouth before binding deeper within the AChR ion channel between the leucine and valine rings, a domain shared with phencyclidine, finally blocking ion flux and inducing AChR desensitization. PMID:20079457

  1. In vitro clot lysis as a potential indicator of thrombus resistance to fibrinolysis--study in healthy subjects and correlation with blood fibrinolytic parameters.

    Colucci, M; Scopece, S; Gelato, A V; Dimonte, D; Semeraro, N


    Using an in vitro model of clot lysis, the individual response to a pharmacological concentration of recombinant tissue plasminogen activator (rt-PA) and the influence on this response of the physiological variations of blood parameters known to interfere with the fibrinolytic/thrombolytic process were investigated in 103 healthy donors. 125I-fibrin labelled blood clots were submersed in autologous plasma, supplemented with 500 ng/ml of rt-PA or solvent, and the degree of lysis was determined after 3 h of incubation at 37 degrees C. Baseline plasma levels of t-PA, plasminogen activator inhibitor 1 (PAI-1), plasminogen, alpha 2-antiplasmin, fibrinogen, lipoprotein (a), thrombomodulin and von Willebrand factor as well as platelet and leukocyte count and clot retraction were also determined in each donor. rt-PA-induced clot lysis varied over a wide range (28-75%) and was significantly related to endogenous t-PA, PAI-1, plasminogen (p < 0.001) and age (p < 0.01). Multivariate analysis indicated that both PAI-1 antigen and plasminogen independently predicted low response to rt-PA. Surprisingly, however, not only PAI-1 but also plasminogen was negatively correlated with rt-PA-induced clot lysis. The observation that neutralization of PAI-1 by specific antibodies, both in plasma and within the clot, did not potentiate clot lysis indicates that the inhibitor, including the platelet-derived form, is insufficient to attenuate the thrombolytic activity of a pharmacological concentration of rt-PA and that its elevation, similarly to the elevation of plasminogen, is not the cause of clot resistance but rather a coincident finding. It is concluded that the in vitro response of blood clots to rt-PA is poorly influenced by the physiological variations of the examined parameters and that factors other than those evaluated in this study interfere with clot dissolution by rt-PA. In vitro clot lysis test might help to identify patients who may be resistant to thrombolytic therapy

  2. Procoagulants and anticoagulants in fetal blood. A literature survey.

    Waldemar Uszyński


    Full Text Available In intrauterine life, hemostasis is maintained by the same components as in extrauterine life (blood platelets, coagulation and fibrinolysis systems, involvement of the vascular wall; in the fetus, however, these components show significant differences of a quantitative/qualitative nature. In the present study, we surveyed the literature on the coagulation system in the fetus. We focused on the velocity of development of the coagulation system, being reflected in the increased concentration of all procoagulants and anticoagulants (a rise from approximately 20% in the middle of pregnancy to about 60% or more in the period of labor; exceptions: factors V, VIII and XIII which in the labor period reach the adult level and screening test results (prothrombin time, aPTT - activated prothrombin time, and thrombin time. Reference values were given for the 19-38 weeks of pregnancy and the labor term. Biochemical features of fetal fibrinogen and PIVKA factors were also discussed. The role of activated protein C (APC in the maintenance of balance between procoagulants and anticoagulants was postulated as well as the role of APC in the formation of thrombin activatable fibrinolysis inhibitor (TAFI.

  3. Cholinesterase inhibitors from botanicals

    Faiyaz Ahmed


    Full Text Available Alzheimer′s disease (AD is a progressive neurodegenerative disease, wherein a progressive loss of cholinergic synapses occurs in hippocampus and neocortex. Decreased concentration of the neurotransmitter, acetylcholine (ACh, appears to be critical element in the development of dementia, and the most appropriate therapeutic approach to treat AD and other form of dementia is to restore acetylcholine levels by inhibiting both major form of cholinesterase: Acetylcholinesterase (AChE and butyrylcholinesterase (BChE. Consequently, researches have focused their attention towards finding cholinesterase inhibitors from natural products. A large number of such inhibitors have been isolated from medicinal plants. This review presents a comprehensive account of the advances in field of cholinesterase inhibitor phytoconstituents. The structures of some important phytoconstituents (collected through are also presented and the scope for future research is discussed.

  4. Phosphodiesterase-5 inhibitors.

    Cockrill, Barbara A; Waxman, Aaron B


    Nitric oxide (NO) signaling plays a key role in modulating vascular tone and remodeling in the pulmonary circulation. The guanylate cyclase/cyclic guanylate monophosphate-signaling pathway primarily mediates nitric oxide signaling. This pathway is critical in normal regulation of the pulmonary vasculature, and is an important target for therapy in patients with pulmonary hypertension. In the pulmonary vasculature, degradation of cGMP is primarily regulated by PDE-5, and inhibition of this enzyme has important effects on pulmonary vasculature smooth muscle tone. Large randomized placebo-controlled trials of PDE-5 inhibitors demonstrated improved exercise capacity, hemodynamics and quality of life in adult patients with PAH. This chapter will discuss the mechanisms of NO signaling in the vasculature, characteristics of the PDE5-inhibitors approved for treatment of PH, and review available data on the use of phosphodiesterase inhibitors in PH. PMID:24092343

  5. Protein protease inhibitors in insects and comparison with mammalian inhibitors.

    Eguchi, M


    1. Studies on insect protein protease inhibitors are summarized. Biochemical, genetic and physiological investigations of the silkworm are performed. 2. In addition, the properties and characteristics of fungal protease inhibitors from the silkworm (Bombyx mori) are described and their importance as defensive functions is emphasized. 3. This review also concerns comparative and evolutionary studies of protease inhibitors from various sources. 4. The biological significance of inhibitors is discussed in view of the extensive experimental results. PMID:8365101

  6. Thymidine Phosphorylase Inhibitors

    Nencka, Radim

    Karachi : Bentham Science Publishers, 2011 - (Atta-ur-Rahman, F.; Choudhary, M.), s. 116-147 ISBN 978-1-60805-162-5 R&D Projects: GA MŠk 1M0508; GA AV ČR 1QS400550501 Institutional research plan: CEZ:AV0Z40550506 Keywords : thymidine phosphorylase inhibitors * angiogenesis * cancer chemotherapy Subject RIV: CC - Organic Chemistry

  7. Sunflower trypsin inhibitor-1.

    Korsinczky, Michael L J; Schirra, Horst Joachim; Craik, David J


    SFTI-1 is a bicyclic 14 amino acid peptide that was originally isolated from the seeds of the sunflower Helianthus annuus. It is a potent inhibitor of trypsin, with a sub-nanomolar K(i) value and is homologous to the active site region of the well-known family of serine protease inhibitors known as the Bowman-Birk trypsin inhibitors. It has a cyclic backbone that is cross-braced by a single disulfide bridge and a network of hydrogen bonds that result in a well-defined structure. SFTI-1 is amenable to chemical synthesis, allowing for the creation of synthetic variants. Alterations to the structure such as linearising the backbone or removing the disulfide bridge do not reduce the potency of SFTI-1 significantly, and minimising the peptide to as few as nine residues results in only a small decrease in reactivity. The creation of linear variants of SFTI-1 also provides a tool for investigating putative linear precursor peptides. The mechanism of biosynthesis of SFTI-1 is not yet known but it seems likely that it is a gene-coded product that has arisen from a precursor protein that may be evolutionarily related to classic Bowman-Birk inhibitors. PMID:15544530

  8. Corrosion inhibitor compositions

    A corrosion inhibitor compositon for hydrocarbon fuels consisting essentially of, by weight, (A) about 75% to 95% of at least one polymerized unsaturated aliphatic monocarboxylic acid, said unsaturated acid having 16 to 18 carbons per molecule, and (B) about 5% to 25% of at least one monoalkenylsuccinic acid in which the alkenyl group as 8 to 18 carbons

  9. Inhibitors of histone demethylases

    Lohse, Brian; Kristensen, Jesper L; Kristensen, Line H; Agger, Karl; Helin, Kristian; Gajhede, Michael; Clausen, Rasmus P


    Methylated lysines are important epigenetic marks. The enzymes involved in demethylation have recently been discovered and found to be involved in cancer development and progression. Despite the relative recent discovery of these enzymes a number of inhibitors have already appeared. Most of the...

  10. Benzoylurea Chitin Synthesis Inhibitors.

    Sun, Ranfeng; Liu, Chunjuan; Zhang, Hao; Wang, Qingmin


    Benzoylurea chitin synthesis inhibitors are widely used in integrated pest management (IPM) and insecticide resistance management (IRM) programs due to their low toxicity to mammals and predatory insects. In the past decades, a large number of benzoylurea derivatives have been synthesized, and 15 benzoylurea chitin synthesis inhibitors have been commercialized. This review focuses on the history of commercial benzolyphenylureas (BPUs), synthetic methods, structure-activity relationships (SAR), action mechanism research, environmental behaviors, and ecotoxicology. Furthermore, their disadvantages of high risk to aquatic invertebrates and crustaceans are pointed out. Finally, we propose that the para-substituents at anilide of benzoylphenylureas should be the functional groups, and bipartite model BPU analogues are discussed in an attempt to provide new insight for future development of BPUs. PMID:26168369

  11. Alpha glucosidase inhibitors.

    Kalra, Sanjay


    Alpha glucosidase inhibitors (AGIs) are a unique class of anti-diabetic drugs. Derived from bacteria, these oral drugs are enzyme inhibitors which do not have a pancreato -centred mechanism of action. Working to delay carbohydrate absorption in the gastrointestinal tract, they control postprandial hyperglycaemia and provide unquestioned cardiovascular benefit. Specially suited for a traditional Pakistani carbohydrate-rich diet, AGIs have been termed the 'untapped diamonds' of diabetology. The use of these oral antidiabetic drugs (OADs) that target pathophysiology in the early stages of type 2 diabetes, notably to reduce postprandial hyperglycaemia and hyperinsulinaemia will inevitably increase with time. This review describes the history of their development, mechanism of action, basic and clinical pharmacology, and suggests practical, evidence-based guidance for their optimal use. PMID:24864650

  12. [JAK2 inhibitors].

    Hernández Boluda, Juan Carlos; Gómez, Montse; Pérez, Ariadna


    Pharmacological inhibition of the kinase activity of JAK proteins can interfere with the signaling of immunomodulatory cytokines and block the constitutive activation of the JAK-STAT pathway that characterizes certain malignancies, including chronic myeloproliferative neoplasms. JAK inhibitors may, therefore, be useful to treat malignancies as well as inflammatory or immune disorders. Currently, the most significant advances have been made in the treatment of myelofibrosis, where these drugs may lead to a remarkable improvement in the control of hyperproliferative manifestations. However, available data suggest that this treatment is not curative of myelofibrosis. In general, JAK2 inhibition induces cytopaenias, with this being considered a class side-effect. By contrast, the extrahaematologic toxicity profile varies significantly among the different JAK inhibitors. At present, there are several clinical trials evaluating the combination of ruxolitinib with other drugs, in order to improve its therapeutic activity as well as reducing haematologic toxicity. PMID:27033437

  13. Update on Aromatase Inhibitors

    Seifert-Klauss V


    Full Text Available Aromatase inhibitors (AI block the last phase of estrogen production in many types of tissues which express the enzym aromatase, among them muscle, liver, adrenal, brain and fat. The enzyme catalyzes the last step of the biosynthesis of the estrogens, i. e. the aromatisation of testosterone to estradiol and of androstendion to estrone. Aromatase is localized in the membrane of the endoplasmatic reticulum and is also produced in the placenta and the gonads. Mutations in the gene CYP19A1, which codes for aromatase, can lead either to lack or excess of aromatase. Gene polymorphisms also influence the amount of bioavailable estrogen and bone Indications: AI are approved for the treatment of postmenopausal women with hormone receptor positive breast cancer, both in the adjuvant setting as well as after recurrence and in progressive disease. In premenopausal and in perimenopausal women AI cause an increased sensitivity of the ovaries to follicle stimulating hormone (FSH and can thereby lead to a boosted estrogen answer – this effect is particularly pronounced in early perimenopausal women – so that these situations demand a combination with GnRH-analogue if AI treatment is to be initiated. Alternatively, tamoxifene may be used in premenopausal patients, with or without GnRH analogues. Treatment of premenopausal patients with hormone receptor positive breast cancer with aromatase inhibiting therapy alone constitutes an absolute contraindication. Aromatase inhibitors do not lead to estrogen receptor downregulation or block the receptor such as tamoxifene. An exceptional application is the application in reproductive medicine in women who do not have hormone receptor positive breast cancer: because of the higher sensitivity induced by AI-co-therapy, FSH-doses and -costs for assisted reproduction are reduced, and ovarian hyperstimulation syndrome (OHSS may be avoided. For premenopausal diseases which are said to be positively affected by

  14. Grupo de trabajo de Leiden sobre fibrinolysis : procedimientos de recogida y manipulación de sangre para la evaluación del activador del plasminógeno de tipo tisular (t-PA) y del inhibidor-1 del activador del plasminógeno (PAI-1) [Leiden fibrinolysis working party : blood collection and handling procedures for assessment of tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1)

    Kluft, C.; Verheijen, J.H.


    Procedures of blood collection and handling are different for the various variables in haemostasis and tend to change gradually with progress in knowledge and methods. The Working Party has gathered background information about procedures and discussed minimal requirements specifically for t-PA and

  15. Inhibitors of lysosomal cysteine proteases

    Lyanna O. L.; Chorna V. I.


    The review is devoted to the inhibitors of cysteine proteinases which are believed to be very important in many biochemical processes of living organisms. They participate in the development and progression of numerous diseases that involve abnormal protein turnover. One of the main regulators of these proteinases is their specific inhibitors: cystatins. The aim of this review was to present current knowledge about endogenous inhibitors of lysosomal cysteine proteases and their synthetic anal...

  16. Inhibitors of lysosomal cysteine proteases

    Lyanna O. L.


    Full Text Available The review is devoted to the inhibitors of cysteine proteinases which are believed to be very important in many biochemical processes of living organisms. They participate in the development and progression of numerous diseases that involve abnormal protein turnover. One of the main regulators of these proteinases is their specific inhibitors: cystatins. The aim of this review was to present current knowledge about endogenous inhibitors of lysosomal cysteine proteases and their synthetic analogs.

  17. Molecular similarity of MDR inhibitors

    Simon Gibbons; Mire Zloh


    Abstract: The molecular similarity of multidrug resistance (MDR) inhibitors was evaluated using the point centred atom charge approach in an attempt to find some common features of structurally unrelated inhibitors. A series of inhibitors of bacterial MDR were studied and there is a high similarity between these in terms of their shape, presence and orientation of aromatic ring moieties. A comparison of the lipophilic properties of these molecules has also been conducted suggesting that this ...


    Pradeep Kumar Arora* and Ashish Chauhan


    Full Text Available Hypertension is a chronic increase in blood pressure, characterized as primary and secondary hypertension. The disorder is associated with various risk factors like obesity, diabetes, age, lack of exercise etc. Hypertension is being treated since ancient times by Ayurvedic, Chinese and Unani medicine. Now various allopathic drugs are available which include diuretics, calcium channel blockers, α-blockers, β-blockers, vasodilators, central sympatholytics and ACE-inhibitors. Non-pharmacological treatments include weight reduction, dietary sodium reduction, increased potassium intake and reduction in alcohol consumption. ACE-inhibitors are widely used in the treatment of hypertension by inhibiting the angiotensin converting enzyme responsible for the conversion of angiotensin I to angiotensin II (responsible for vasoconstriction. Various structure activity relationship studies led to the synthesis of ACE-inhibitors, some are under clinical development. This comprehensive review gives various guidelines on classification of hypertension, hypertension therapy including ancient, pharmacological, non-pharmacological therapies, pharmacoeconomics, historical perspectives of ACE, renin, renin angiotensin system (circulating vs local RAS, mechanism of ACE inhibitors, and development of ACE inhibitors. Review also emphasizes on the recent advancements on ACE inhibitors including drugs in clinical trials, computational studies on ACE-inhibitors, peptidomimetics, dual, natural, multi-functional ACE inhibitors, and conformational requirements for ACE-inhibitors.

  19. Synthesis of Lysine Methyltransferase Inhibitors

    Ye, Tao; Hui, Chunngai


    Lysine methyltransferase which catalyze methylation of histone and nonhistone proteins, play a crucial role in diverse biological processes and has emerged as a promising target for the development of various human diseases, including cancer, inflammation, and psychiatric disorders. However, inhibiting Lysine methyltransferases selectively has presented many challenges to medicinal chemists. During the past decade, lysine methyltransferase inhibitors covering many different structural classes have been designed and developed. In this review, we describe the development of selective, small-molecule inhibitors of lysine methyltransferases with an emphasis on their discovery and chemical synthesis. We highlight the current state of lysine methyltransferase inhibitors and discuss future directions and opportunities for lysine methyltransferase inhibitor discovery.

  20. Acetylcholinesterase Inhibitors: Pharmacology and Toxicology

    Čolović, Mirjana B; Krstić, Danijela Z; Lazarević-Pašti, Tamara D; Bondžić, Aleksandra M; Vasić, Vesna M


    Acetylcholinesterase is involved in the termination of impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine in numerous cholinergic pathways in the central and peripheral nervous systems. The enzyme inactivation, induced by various inhibitors, leads to acetylcholine accumulation, hyperstimulation of nicotinic and muscarinic receptors, and disrupted neurotransmission. Hence, acetylcholinesterase inhibitors, interacting with the enzyme as their primary target, are appl...

  1. Transluminal angioplasty, fibrinolysis, and newer vascular interventions

    This refresher course presents an overview of the current status of transluminal angioplasty in the treatment of peripheral vascular disease, renovascular hypertension, and upper extremity vasculature. Indications for therapy, accepted techniques, and the diagnosis and treatment of complications are major topic areas. Newer areas of increasing application are discussed, particularly popliteal and tibial angioplasty. Newer devices and procedures such as lasers, percutaneous atherectomy, and mechanical recanalization devices are reviewed and their role in the current therapeutic armamentarium discussed. The current status of catheter-directed fibrinolytic techniques is presented, particularly as they relate to the concomitant use of transluminal angioplasty. The choice of lytic agents and newer agents is reviewed. Long-term results and complication rates are discussed by anatomic area

  2. Is There a Tendency for Thrombosis in Gestational Diabetes Mellitus?

    Gorar, Suheyla; Alioglu, Bulent; Ademoglu, Esranur; Uyar, Seyit; Bekdemir, Handan; Candan, Zehra; Saglam, Beylan; Koc, Gonul; Culha, Cavit; Aral, Yalcin


    Context: Impact of gestational diabetes mellitus (GDM) on the coagulation system, dynamics involved at a pathophysiological level and the exact mechanism remain unclear. Aims: To evaluate the association between diabetes-related parameters and hemostatic factors to search for a tendency of thrombosis in GDM. Settings and Design: Nineteen pregnant women who had GDM, 16 healthy pregnant and 13 healthy nonpregnant controls admitted to the Endocrinology outpatient clinics were enrolled in the study. Subjects and Methods: Fasting and postprandial glucose, hemoglobin A1c and insulin levels, and insulin resistance; fructosamine, thrombin activatable fibrinolysis inhibitor (TAFI), tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor Type-1 (PAI-1), tissue-type plasminogen activator (t-PA), fibrinogen, plasminogen and hemoglobin levels, platelet counts, prothrombin time (PT), and activated partial thromboplastin time (aPTT) were studied. Statistical Analysis Used: One-way analysis of variance, Kruskal–Wallis, and post hoc Tukey honestly significant difference or Conover's nonparametric multiple comparison tests for comparison of the study groups. Results: PT and aPTT were significantly lower in GDM patients compared to controls (P diabetes mellitus; but more comprehensive studies with larger sample size are needed to determine the relationship between GDM and hemostasis. PMID:27365919

  3. [Pharmacology of bone resorption inhibitor].

    Menuki, Kunitaka; Sakai, Akinori


    Currently, bone resorption inhibitor is mainly used for osteoporosis. A number of these agents have been developed. These pharmacological action are various. Bisphosphonate inhibit functions of the osteoclasts by inducing apoptosis. On the one hand, RANK-ligand inhibitor and selective estrogen receptor modulator inhibit formation of osteoclasts. It is important to understand these pharmacological action for the selection of the appropriate medicine. PMID:26529923

  4. Copper(II) Ions Increase Plasminogen Activator Inhibitor Type 1 Dynamics in Key Structural Regions That Govern Stability.

    Bucci, Joel C; Trelle, Morten Beck; McClintock, Carlee S; Qureshi, Tihami; Jørgensen, Thomas J D; Peterson, Cynthia B


    Plasminogen activator inhibitor type 1 (PAI-1) regulates the fibrinolysis pathway by inhibiting the protease activity of plasminogen activators. PAI-1 works in concert with vitronectin (VN), an extracellular protein that aids in localization of active PAI-1 to tissues. The Peterson laboratory demonstrated that Cu(II) and other transition metals modulate the stability of PAI-1, exhibiting effects that are dependent on the presence or absence of the somatomedin B (SMB) domain of VN. The study presented here dissects the changes in molecular dynamics underlying the destabilizing effects of Cu(II) on PAI-1. We utilize backbone amide hydrogen/deuterium exchange monitored by mass spectrometry to assess PAI-1 dynamics in the presence and absence of Cu(II) ions with and without the SMB domain of VN. We show that Cu(II) produces an increase in dynamics in regions important for the function and overall stability of PAI-1, while the SMB domain elicits virtually the opposite effect. A mutant form of PAI-1 lacking two N-terminal histidine residues at positions 2 and 3 exhibits similar increases in dynamics upon Cu(II) binding compared to that of active wild-type PAI-1, indicating that the observed structural effects are not a result of coordination of Cu(II) to these histidine residues. Finally, addition of Cu(II) results in an acceleration of the local unfolding kinetics of PAI-1 presumed to be on pathway to the latency conversion. The effect of ligands on the dynamics of PAI-1 adds another intriguing dimension to the mechanisms for regulation of PAI-1 stability and function. PMID:27416303

  5. Microbial inhibitors of cysteine proteases.

    Kędzior, Mateusz; Seredyński, Rafał; Gutowicz, Jan


    Cysteine proteases are one of the major classes of proteolytic enzymes involved in a number of physiological and pathological processes in plants, animals and microorganisms. When their synthesis, activity and localization in mammalian cells are altered, they may contribute to the development of many diseases, including rheumatoid arthritis, osteoporosis and cancer. Therefore, cysteine proteases have become promising drug targets for the medical treatment of these disorders. Inhibitors of cysteine proteases are also produced by almost every group of living organisms, being responsible for the control of intracellular proteolytic activity. Microorganisms synthesize cysteine protease inhibitors not only to regulate the activity of endogenous, often virulent enzymes, but also to hinder the host's proteolytic defense system and evade its immune responses against infections. Present work describes known to date microbial inhibitors of cysteine proteases in terms of their structure, enzyme binding mechanism, specificity and pathophysiological roles. The overview of both proteinaceous and small-molecule inhibitors produced by all groups of microorganisms (bacteria, archaea, fungi, protists) and viruses is provided. Subsequently, possible applications of microbial inhibitors in science, medicine and biotechnology are also highlighted. PMID:27048482

  6. Electrochemical studies of corrosion inhibitors

    Danford, M. D.


    The effect of single salts, as well as multicomponent mixtures, on corrosion inhibition was studied for type 1010 steel; for 5052, 1100, and 2219-T87 aluminum alloys; and for copper. Molybdate-containing inhibitors exhibit an immediate, positive effect for steel corrosion, but an incubation period may be required for aluminum before the effect of a given inhibitor can be determined. The absence of oxygen was found to provide a positive effect (smaller corrosion rate) for steel and copper, but a negative effect for aluminum. This is attributed to the two possible mechanisms by which aluminum can oxidize. Corrosion inhibition is generally similar for oxygen-rich and oxygen-free environments. The results show that the electrochemical method is an effective means of screening inhibitors for the corrosion of single metals, with caution to be exercised in the case of aluminum.

  7. Corrosion inhibitors from expired drugs.

    Vaszilcsin, Nicolae; Ordodi, Valentin; Borza, Alexandra


    This paper presents a method of expired or unused drugs valorization as corrosion inhibitors for metals in various media. Cyclic voltammograms were drawn on platinum in order to assess the stability of pharmaceutically active substances from drugs at the metal-corrosive environment interface. Tafel slope method was used to determine corrosion rates of steel in the absence and presence of inhibitors. Expired Carbamazepine and Paracetamol tablets were used to obtain corrosion inhibitors. For the former, the corrosion inhibition of carbon steel in 0.1 mol L(-1) sulfuric acid solution was about 90%, whereas for the latter, the corrosion inhibition efficiency of the same material in the 0.25 mol L(-1) acetic acid-0.25 mol L(-1) sodium acetate buffer solution was about 85%. PMID:22561212

  8. Positron emitter labeled enzyme inhibitors

    This invention involves a new strategy for imagining and mapping enzyme activity in the living human and animal body using positron emitter-labeled suicide enzyme inactivators or inhibitors which become covalently bound to the enzyme as a result of enzymatic catalysis. Two such suicide inactivators for monoamine oxidase have been labeled with carbon-11 and used to map the enzyme subtypes in the living human and animal body using PET. By using positron emission tomography to image the distribution of radioactivity produced by the body penetrating radiation emitted by carbon-11, a map of functionally active monoamine oxidase activity is obtained. Clorgyline and L-deprenyl are suicide enzyme inhibitors and irreversibly inhibit monoamine oxidase. When these inhibitors are labeled with carbon-11 they provide selective probes for monoamine oxidase localization and reactivity in vivo using positron emission tomography

  9. Retroviral proteinases and their inhibitors

    Sedláček, Juraj


    Roč. 3, 3,4 (2000), s. 23-24. [Proteolytic enzymes and their inhibitors in physiology and pathogenesis.. 14.09.2000, Plzen] Institutional research plan: CEZ:AV0Z5052915 Subject RIV: EB - Genetics ; Molecular Biology

  10. Corrosion Inhibitors for Reinforced Concrete

    ECT Team, Purdue


    Steel corrosion in reinforced concrete structures has been a major problem across the U.S. Steel-reinforced concrete structures are continually subject to attack by corrosion brought on by naturally occurring environmental conditions. FerroGard, a corrosion inhibitor, developed by Sika Corporation, penetrates hardened concrete to dramatically reduce corrosion by 65% and extend the structure's service life.

  11. Biocatalysts with enhanced inhibitor tolerance

    Yang, Shihui; Linger, Jeffrey; Franden, Mary Ann; Pienkos, Philip T.; Zhang, Min


    Disclosed herein are biocatalysts for the production of biofuels, including microorganisms that contain genetic modifications conferring tolerance to growth and fermentation inhibitors found in many cellulosic feedstocks. Methods of converting cellulose-containing materials to fuels and chemicals, as well as methods of fermenting sugars to fuels and chemicals, using these biocatalysts are also disclosed.

  12. Proton pump inhibitors and gastroenteritis

    R.J. Hassing (Robert); A. Verbon (Annelies); H. de Visser (Herman); A. Hofman (Albert); B.H.Ch. Stricker (Bruno)


    textabstractAn association between proton pump inhibitor (PPI) therapy and bacterial gastroenteritis has been suggested as well as contradicted. The aim of this study was to examine the association between the use of PPIs and occurrence of bacterial gastroenteritis in the prospective Rotterdam Study

  13. Less-toxic corrosion inhibitors

    Humphries, T. S.


    Combinations of borates, nitrates, phosphates, silicates, and sodium MBT protect aluminum from corrosion in fresh water. Most effective combinations contained sodium phosphate and were alkaline. These inhibitors replace toxic chromates which are subject to governmental restrictions, but must be used in larger quantities. Experimental exposure times varied from 1 to 14 months depending upon nature of submersion solution.

  14. Proton pump inhibitors and osteoporosis

    Andersen, Bjarne Nesgaard; Johansen, Per Birger; Abrahamsen, Bo


    PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months and a...

  15. PDE-5 inhibitors: clinical points.

    Doumas, Michael; Lazaridis, Antonios; Katsiki, Niki; Athyros, Vasilios


    Erectile dysfunction is usually of vascular origin and is frequently encountered in men with cardiovascular disease. The introduction of phosphodiesterase-5 inhibitors has revolutionized the management of patients with erectile dysfunction. Currently available phosphodiesterase-5 inhibitors have distinct pharmacokinetic and pharmacodynamic properties, thus permitting for tailoring sexual therapy according to patient characteristics and needs. Phosphodiesterase-5 inhibitors possess vasorelaxing properties and exert systemic hemodynamic effects, which need to be taken into account when other cardiovascular drugs are co-administered. Special caution is needed with alpha-blockers, while the co-administration with nitrates is contra-indicated due to the risk of life-threatening hypotension. This review presents the advent of sexual therapy, describes the mechanism of action and the specific characteristics of commercially available phosphodiesterase-5 inhibitors, summarizes the efficacy and safety of these drugs with special emphasis on the cardiovascular system, and discusses the clinical criteria used for the selection of each drug for the individual patient. PMID:25392015

  16. Lipoxygenase inhibitor peptides and their use

    Schurink, M.; Boeriu, C.G.; Berkel, van, A.M.; Wichers, H.J.


    The present invention is in the field of enzyme inhibition. In particular it relates to peptide inhibitors for lipoxygenases. The lipoxygenase peptide inhibitors of have the potential to be used as therapeutic drugs as well as food preservatives.

  17. Kinase Inhibitors from Marine Sponges

    Ana Zivanovic


    Full Text Available Protein kinases play a critical role in cell regulation and their deregulation is a contributing factor in an increasing list of diseases including cancer. Marine sponges have yielded over 70 novel compounds to date that exhibit significant inhibitory activity towards a range of protein kinases. These compounds, which belong to diverse structural classes, are reviewed herein, and ordered based upon the kinase that they inhibit. Relevant synthetic studies on the marine natural product kinase inhibitors have also been included.


    Pradeep Kumar Arora* and Ashish Chauhan


    Hypertension is a chronic increase in blood pressure, characterized as primary and secondary hypertension. The disorder is associated with various risk factors like obesity, diabetes, age, lack of exercise etc. Hypertension is being treated since ancient times by Ayurvedic, Chinese and Unani medicine. Now various allopathic drugs are available which include diuretics, calcium channel blockers, α-blockers, β-blockers, vasodilators, central sympatholytics and ACE-inhibitors. Non-pharmacological...

  19. Thrombin Inhibitors from Different Animals

    Tanaka-Azevedo, A. M.; Morais-Zani, K.; Torquato, R. J. S.; A. S. Tanaka


    Venous and arterial thromboembolic diseases are still the most frequent causes of death and disability in high-income countries. Clinical anticoagulants are inhibitors of enzymes involved in the coagulation pathway, such as thrombin and factor Xa. Thrombin is a key enzyme of blood coagulation system, activating the platelets, converting the fibrinogen to the fibrin net, and amplifying its self-generation by the activation of factors V, VIII, and XI. Thrombin has long been a target for the dev...

  20. Natural Products as Aromatase Inhibitors

    Balunas, Marcy J.; Su, Bin; Brueggemeier, Robert W.; Kinghorn, A. Douglas


    With the clinical success of several synthetic aromatase inhibitors (AIs) in the treatment of postmenopausal estrogen receptor-positive breast cancer, researchers have also been investigating also the potential of natural products as AIs. Natural products from terrestrial and marine organisms provide a chemically diverse array of compounds not always available through current synthetic chemistry techniques. Natural products that have been used traditionally for nutritional or medicinal purpos...

  1. Carbonic anhydrase inhibitors drug design.

    McKenna, Robert; Supuran, Claudiu T


    Inhibition of the metalloenzyme carbonic anhydrase (CA, EC has pharmacologic applications in the field of antiglaucoma, anticonvulsant, antiobesity, and anticancer agents but is also emerging for designing anti-infectives (antifungal and antibacterial agents) with a novel mechanism of action. As a consequence, the drug design of CA inhibitors (CAIs) is a very dynamic field. Sulfonamides and their isosteres (sulfamates/sulfamides) constitute the main class of CAIs which bind to the metal ion in the enzyme active site. Recently the dithiocarbamates, possessing a similar mechanism of action, were reported as a new class of inhibitors. Other families of CAIs possess a distinct mechanism of action: phenols, polyamines, some carboxylates, and sulfocoumarins anchor to the zinc-coordinated water molecule. Coumarins and five/six-membered lactones are prodrug inhibitors, binding in hydrolyzed form at the entrance of the active site cavity. Novel drug design strategies have been reported principally based on the tail approach for obtaining all these types of CAIs, which exploit more external binding regions within the enzyme active site (in addition to coordination to the metal ion), leading thus to isoform-selective compounds. Sugar-based tails as well as click chemistry were the most fruitful developments of the tail approach. Promising compounds that inhibit CAs from bacterial and fungal pathogens, of the dithiocarbamate, phenol and carboxylate types have also been reported. PMID:24146385

  2. Bromodomains and their pharmacological inhibitors.

    Gallenkamp, Daniel; Gelato, Kathy A; Haendler, Bernard; Weinmann, Hilmar


    Over 60 bromodomains belonging to proteins with very different functions have been identified in humans. Several of them interact with acetylated lysine residues, leading to the recruitment and stabilization of protein complexes. The bromodomain and extra-terminal domain (BET) proteins contain tandem bromodomains which bind to acetylated histones and are thereby implicated in a number of DNA-centered processes, including the regulation of gene expression. The recent identification of inhibitors of BET and non-BET bromodomains is one of the few examples in which effective blockade of a protein-protein interaction can be achieved with a small molecule. This has led to major strides in the understanding of the function of bromodomain-containing proteins and their involvement in diseases such as cancer and inflammation. Indeed, BET bromodomain inhibitors are now being clinically evaluated for the treatment of hematological tumors and have also been tested in clinical trials for the relatively rare BRD-NUT midline carcinoma. This review gives an overview of the newest developments in the field, with a focus on the biology of selected bromodomain proteins on the one hand, and on reported pharmacological inhibitors on the other, including recent examples from the patent literature. PMID:24497428

  3. The burden of inhibitors in haemophilia patients.

    Walsh, Christopher E; Jiménez-Yuste, Víctor; Auerswald, Guenter; Grancha, Salvador


    The burden of disease in haemophilia patients has wide ranging implications for the family and to society. There is evidence that having a current inhibitor increases the risk of morbidity and mortality. Morbidity is increased by the inability to treat adequately and its consequent disabilities, which then equates to a poor quality of life compared with non-inhibitor patients. The societal cost of care, or `burden of inhibitors', increases with the ongoing presence of an inhibitor. Therefore, it is clear that successful eradication of inhibitors by immune tolerance induction (ITI) is the single most important milestone one can achieve in an inhibitor patient. The type of factor VIII (FVIII) product used in ITI regimens varies worldwide. Despite ongoing debate, there is in vitro and retrospective clinical evidence to support the use of plasma-derived VWF-containing FVIII concentrates in ITI regimens in order to achieve early and high inhibitor eradication success rates. PMID:27528280

  4. Xylanase inhibitors bind to nonstarch polysaccharides.

    Fierens, Ellen; Gebruers, Kurt; Courtin, Christophe M; Delcour, Jan A


    This study is an in-depth investigation of the interaction between polysaccharides and the proteinaceous xylanase inhibitors, Triticum aestivum xylanase inhibitor (TAXI), xylanase inhibitor protein (XIP), and thaumatin-like xylanase inhibitor (TLXI). The binding affinities of all three known types of xylanase inhibitors from wheat are studied by measuring the residual xylanase inhibition activity after incubation of the inhibitors in the presence of different polysaccharides, such as beta-glucans and (arabino)xylans. The binding affinities of all three xylanase inhibitors for (arabino)xylans increased with a decreasing arabinose/xylose ratio (A/X ratio). This phenomenon was observed both with water-extractable and water-unextractable (arabino)xylans. The inhibitors also interacted with different soluble and insoluble beta-glucans. None of the inhibitors tested had the ability to hydrolyze the polysaccharides investigated. The present findings contribute to the unraveling of the function of xylanase inhibitors in nature and to the prediction of the effect of added xylanases in cereal-based biotechnological processes, such as bread making and gluten-starch separation. PMID:18092758

  5. Inhibitors of Acetylcholinesterase and Butyrylcholinesterase Meet Immunity

    Miroslav Pohanka


    Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE). Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a “cholinergic anti-inflammatory pathway” which raises questions about the role of these inhibitors in the immune system. Thi...

  6. Development of covalent inhibitors that can overcome resistance to first-generation FGFR kinase inhibitors

    Tan, Li; Wang, Jun; Tanizaki, Junko; Huang, Zhifeng; Aref, Amir R.; Rusan, Maria; Zhu, Su-Jie; Zhang, Yiyun; Ercan, Dalia; Liao, Rachel G.; Capelletti, Marzia; Zhou, Wenjun; Hur, Wooyoung; Kim, NamDoo; Sim, Taebo


    Inhibitors of the FGF receptors (FGFRs) are currently under clinical investigation for the treatment of various cancers. All currently approved kinase inhibitors eventually are rendered useless by the emergence of drug-resistant tumors. We used structure-based drug design to develop the first, to our knowledge, selective, next-generation covalent FGFR inhibitors that can overcome the most common form of kinase inhibitor resistance, the mutation of the so-called “gatekeeper” residue located in...

  7. Calcineurin inhibitor minimisation versus continuation of calcineurin inhibitor treatment for liver transplant recipients

    Penninga, Luit; Wettergren, Andre; Chan, An-Wen;


    The therapeutic success of liver transplantation has been largely attributable to the development of effective immunosuppressive treatment regimens. In particular, calcineurin inhibitors were essential in reducing acute rejection and improving early survival. Currently, more than 90% of all liver...... transplant recipients are treated with the calcineurin inhibitor cyclosporine or tacrolimus. Unfortunately, calcineurin inhibitors cause adverse events, such as nephrotoxicity, and because of this, minimisation (reduction and withdrawal) regimens of calcineurin inhibitor have been developed and studied...

  8. The direct thrombin inhibitor hirudin.

    Greinacher, Andreas; Warkentin, Theodore E


    This review discusses the pharmacology and clinical applications of hirudin, a bivalent direct thrombin inhibitor (DTI). Besides the current major indication for hirudin--anticoagulation of patients with heparin-induced thrombocytopenia (HIT)--the experience with hirudin in other indications, especially acute coronary syndromes, are briefly presented. Hirudins have been formally studied prior to their regulatory approval; however, important information on their side effects and relevant preventative measures only became available later. Therefore, current recommendations and dosing schedules for hirudin differ considerably from the information given in the package inserts. Drawbacks of hirudin and important precautions for avoiding potential adverse effects are discussed in detail in the third part of this review. PMID:18449411

  9. Screening for potential inhibitors of influenza neuraminidase

    Ai-linLIU; Guan-huaDU


    AIM: Applying the assay method of neuraminidase(NA) activity established for high throughput screening to find novel inhibitors of influenza virus NA. METHODS: Firstly, a virtual screening strategy was applied to our compound database to select drug-like compounds, and then a high throughput screening model of NA inhibitor was applied to test these compounds. RESULTS:

  10. Angiotensin converting enzyme inhibitor induced hyperkalaemic paralysis

    Dutta., D; Fischler, M; McClung, A


    Secondary hyperkalaemic paralysis is a rare condition often mimicking the Guillain-Barré syndrome. There have been a few case reports of hyperkalaemia caused by renal failure, trauma, and drugs where the presentation has been with muscle weakness. A case of hyperkalaemic paralysis caused by an angiotensin converting enzyme inhibitor is reported.

Keywords: hyperkalaemia; paralysis; ACE inhibitors

  11. Histone deacetylase inhibitors (HDACIs: multitargeted anticancer agents

    Ververis K


    Full Text Available Katherine Ververis,1 Alison Hiong,1 Tom C Karagiannis,1,* Paul V Licciardi2,*1Epigenomic Medicine, Alfred Medical Research and Education Precinct, 2Allergy and Immune Disorders, Murdoch Childrens Research Institute, Melbourne, VIC, Australia*These authors contributed equally to this workAbstract: Histone deacetylase (HDAC inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza and depsipeptide (romidepsin, Istodax. More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the

  12. Potential physiological role of plant glycosidase inhibitors

    Bellincampi, D.; Carmadella, L.; Delcour, J.A.;


    Carbohydrate-active enzymes including glycosidases, transglycosidases, glycosyltransferases, polysaccharide lyases and carbohydrate esterases are responsible for the enzymatic processing of carbohydrates in plants. A number of carbohydrate-active enzymes are produced by microbial pathogens and...... insects responsible of severe crop losses. Plants have evolved proteinaceous inhibitors to modulate the activity of several of these enzymes. The continuing discovery of new inhibitors indicates that this research area is still unexplored and may lead to new exciting developments. To date, the role of the...... inhibitors is not completely understood. Here we review recent results obtained on the best characterised inhibitors, pointing to their possible biological role in vivo. Results recently obtained with plant transformation technology indicate that this class of inhibitors has potential biotechnological...

  13. [Recent development of selective cyclooxygenase-2 inhibitors].

    Kawai, Shinichi


    Nonsteroidal anti-inflammatory drugs(NSAIDs) are clinically effective against the inflammatory symptoms of rheumatoid arthritis. Recent attention has been focused on selective cyclooxygenase(COX)-2 inhibitors, a type of NSAID that inhibits a subtype of COX. Because of the different actions of COX-1 and COX-2, selective COX-2 inhibitors were expected to reduce adverse reactions such as gastrointestinal disorders. Various clinical studies have confirmed that the efficacy of COX-2 inhibitors for RA is similar to that of conventional NSAIDs, but they cause fewer severe gastrointestinal disorders. The incidence of complications related to renal dysfunction, such as edema and hypertension, is not different. Patients using selective COX-2 inhibitors have recently been reported to show an increase in thrombotic complications such as myocardial infarction. Therefore, more data on adverse events should be collected in the future from large-scale clinical studies to further clarify the actual value of selective COX-2 inhibitors. PMID:12510364

  14. Novel peptide-based protease inhibitors

    Roodbeen, Renée

    This thesis describes the design and synthesis of peptide-based serine protease inhibitors. The targeted protease, urokinase-type plasminogen activator (uPA) activates plasminogen, which plays a major role in cancer metastasis. The peptide upain-2 (S 1 ,S 12-cyclo-AcCSWRGLENHAAC-NH2) is a highly...... specific inhibitor of uPA. With the aim of creating better inhibitors based on the upain-2 scaffold, the following three strategies were explored: First, it was attempted to predefine the structure of upain-2 in solution by incorporating turn-inducing sequences and peptidomimetics. Additionally...... bond across the ring. The second bridge was made by a disulfide bridge, amide bond formation or via ring-closing metathesis. A, with upain-2 equipotent, bicyclic inhibitor was obtained and its binding to uPA was studied by ITC, NMR and X-ray. The knowledge of how selective inhibitors bind uPA has been...

  15. Molecular Docking of Aromatase Inhibitors

    Virapong Prachayasittikul


    Full Text Available Aromatase is an enzyme that plays a critical role in the development of estrogen receptor positive breast cancer. As aromatase catalyzes the aromatization of androstenedione to estrone, a naturally occurring estrogen, it is a promising drug target for therapeutic management. The undesirable effects found in aromatase inhibitors (AIs that are in clinical use necessitate the discovery of novel AIs with higher selectivity, less toxicity and improving potency. In this study, we elucidate the binding mode of all three generations of AI drugs to the crystal structure of aromatase by means of molecular docking. It was demonstrated that the docking protocol could reliably reproduce the interaction of aromatase with its substrate with an RMSD of 1.350 Å. The docking study revealed that polar (D309, T310, S478 and M374, aromatic (F134, F221 and W224 and non-polar (A306, A307, V370, L372 and L477 residues were important for interacting with the AIs. The insights gained from the study herein have great potential for the design of novel AIs.

  16. VEGF Inhibitors for Cancer Therapy

    Prakash S. Sukhramani


    Full Text Available Despite significant advances in systemic therapies, radiation oncology, and surgical techniques, many patients with cancer are still incurable. A novel therapeutic approach has been to target the vascular endothelial growth factors (VEGFs which are often mutated and/or over-expressed in many tumors. The ligands and receptors of VEGF family are well established as key regulators of angiogenesis and vasculogenesis processes. VEGF is a homodimeric, basic, 45 kDa glycoprotein specific for vascular endothelial cells. Specifically, VEGF participates in regulation of the female reproductive cycle, wound healing, inflammation, vascular permeability, vascular tone, hematopoiesis and also contributes to pathological angiogenesis disorders such as cancer, rheumatoid arthritis, diabetic retinopathy and the neovascular form of macular degeneration. Thus, the role of VEGF has been extensively studied in the pathogenesis and angiogenesis of human cancers. Clinical trials have anti-VEGF therapies are effective in reducing tumor size, metastasis and blood vessel formation. Clinically, this may result in increased progression free survival, overall patient survival rate and will expand the potential for combinatorial therapies. The aim of present review is on the cellular responses of VEGF inhibitors and their implications for cancer therapy.

  17. ALK inhibitors, a pharmaceutical perspective

    Arturo eGalvani


    Full Text Available In 2007, the ALK tyrosine kinase, already known to be translocated and activated in Anaplastic Large Cell Lymphoma, and a few other rare cancers, was described as a potential therapeutic target for a subset of non small-cell lung cancer (NSCLC patients. Clinical proof of concept, culminating in the recent approval by the FDA of the Pfizer drug Xalkori (crizotinib, formerly known as PF-02341066 followed in record time. The drug was approved together with a companion diagnostic, the Vysis ALK Break Apart FISH Probe Kit (Abbott Molecular, Inc. for detection of eligible patients. This remarkable example of the coming of age of personalized medicine in cancer therapy is hopefully only an auspice of things to come in this rapidly developing field. Perhaps unsurprisingly, however, the appearance of clinical acquired resistance to crizotinib has already been observed early on in clinical testing, with the identification of several ALK secondary point mutations which diminish drug efficacy, and which open the way for development of second-generation inhibitors. It is also emerging that acquired resistance to crizotinib may also occur through ALK-independent mechanisms, which still need to be elucidated in detail.

  18. Vascular calcification: Inducers and inhibitors

    Lee, Donghyun, E-mail: [Department of Biomedical Engineering, Division of Integrative Engineering, Chung-Ang University, 221 Heukseok-Dong, Dongjak-Gu, Seoul 156-756 (Korea, Republic of)


    Highlights: {center_dot} Types of vascular calcification processes. {center_dot} Inducers of vascular calcification. {center_dot} Inhibitors of vascular calcifications. {center_dot} Clinical utility for vascular calcification therapy. {center_dot} Implications for the development of new tissue engineering strategies. - Abstract: Unlike the traditional beliefs, there are mounting evidences suggesting that ectopic mineral depositions, including vascular calcification are mostly active processes, many times resembling that of the bone mineralization. Numbers of agents are involved in the differentiation of certain subpopulation of smooth muscle cells (SMCs) into the osteoblast-like entity, and the activation and initiation of extracellular matrix ossification process. On the other hand, there are factors as well, that prevent such differentiation and ectopic calcium phosphate formation. In normal physiological environments, activities of such procalcific and anticalcific regulatory factors are in harmony, prohibiting abnormal calcification from occurring. However, in certain pathophysiological conditions, such as atherosclerosis, chronic kidney disease (CKD), and diabetes, such balances are altered, resulting in abnormal ectopic mineral deposition. Understanding the factors that regulate the formation and inhibition of ectopic mineral formation would be beneficial in the development of tissue engineering strategies for prevention and/or treatment of such soft-tissue calcification. Current review focuses on the factors that seem to be clinically relevant and/or could be useful in developing future tissue regeneration strategies. Clinical utilities and implications of such factors are also discussed.

  19. Allosteric small-molecule kinase inhibitors

    Wu, Peng; Clausen, Mads Hartvig; Nielsen, Thomas E.


    Small-molecule kinase inhibitors are invaluable targeted therapeutics for the treatment of various human diseases, especially cancers. While the majority of approved and developed preclinical small-molecule inhibitors are characterized as type I or type II inhibitors that target the ATP......-binding pocket of kinases, the remarkable sequential and structural similarity among ATP pockets renders the selective inhibition of kinases a daunting challenge. Therefore, targeting allosteric pockets of kinases outside the highly conversed ATP pocket has been proposed as a promising alternative to overcome...

  20. An Updated Review of Tyrosinase Inhibitors

    Te-Sheng Chang


    Full Text Available Tyrosinase is a multifunctional, glycosylated, and copper-containing oxidase, which catalyzes the first two steps in mammalian melanogenesis and is responsible for enzymatic browning reactions in damaged fruits during post-harvest handling and processing. Neither hyperpigmentation in human skin nor enzymatic browning in fruits are desirable. These phenomena have encouraged researchers to seek new potent tyrosinase inhibitors for use in foods and cosmetics. This article surveys tyrosinase inhibitors newly discovered from natural and synthetic sources. The inhibitory strength is compared with that of a standard inhibitor, kojic acid, and their inhibitory mechanisms are discussed.

  1. In vitro and in vivo characterisation of the profibrinolytic effect of an inhibitory anti-rat TAFI nanobody.

    Hendrickx, Maarten L V; Zatloukalova, Monika; Hassanzadeh-Ghassabeh, Gholamreza; Muyldermans, Serge; Gils, Ann; Declerck, Paul J


    One of the main disadvantages of current t-PA thrombolytic treatment is the increased bleeding risk. Upon activation, thrombin activatable fibrinolysis inhibitor (TAFI) is a very powerful antifibrinolytic enzyme. Therefore, co-administration of a TAFI inhibitor during thrombolysis could reduce the required t-PA dose without compromising the thrombolytic efficacy. In this study we generated and characterised a nanobody that is inhibitory towards rat TAFI and evaluated its profibrinolytic property in vitro and in vivo. Nanobody VHH-rTAFI-i81 inhibits (at a 16-fold molar ratio nanobody over TAFI) the thrombin/thrombomodulin (T/TM)-mediated activation of rat TAFI (rTAFI) by 83 ± 1.8% with an IC50 of 0.46 (molar ratio nanobody over TAFI). The affinity (KA) of VHH-rTAFI-i81 for rTAFI, as determined by surface plasmon resonance (Biacore®), is 2.5 ± 0.2 x 10(10) M(-1) and illustrates a very strong binding. In an in vitro clot lysis assay, administration of VHH-rTAFI-i81 strongly enhances the degree of lysis and reduces time to reach full lysis of t-PA-mediated clot lysis. Epitope mapping discloses that Lys392 is of primary importance for the nanobody/rTAFI interaction besides minor contributions of Tyr175 and Glu183. In vivo application of VHH-rTAFI-i81 in a tissue factor-induced mouse thromboembolism model significantly decreases fibrin deposition in the lungs in the absence of exogenous administered t-PA. Nanobody VHH-rTAFI-i81 is a very potent inhibitor of T/TM-mediated TAFI activation. Co-administration of this nanobody and t-PA enhances the fibrinolytic efficacy. In an in vivo mouse thromboembolism model, VHH-rTAFI-i81 reduces fibrin deposition in the lungs. PMID:24402608

  2. Kinase inhibitors for advanced medullary thyroid carcinoma

    Martin Schlumberger


    Full Text Available The recent availability of molecular targeted therapies leads to a reconsideration of the treatment strategy for patients with distant metastases from medullary thyroid carcinoma. In patients with progressive disease, treatment with kinase inhibitors should be offered.

  3. Inhibitors of Acetylcholinesterase and Butyrylcholinesterase Meet Immunity

    Miroslav Pohanka


    Full Text Available Acetylcholinesterase (AChE inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE. Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a “cholinergic anti-inflammatory pathway” which raises questions about the role of these inhibitors in the immune system. This review covers research and discussion of the role of the inhibitors in modulating the immune response using as examples the commonly available drugs, donepezil, galantamine, huperzine, neostigmine and pyridostigmine. Major attention is given to the cholinergic anti-inflammatory pathway, a well-described link between the central nervous system and terminal effector cells in the immune system.

  4. Inhibitors of acetylcholinesterase and butyrylcholinesterase meet immunity.

    Pohanka, Miroslav


    Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer's disease and other dementias. More recent use is for myasthenia gravis. Many of these inhibitors interact with the second known cholinesterase, butyrylcholinesterase (BChE). Further, evidence shows that acetylcholine plays a role in suppression of cytokine release through a "cholinergic anti-inflammatory pathway" which raises questions about the role of these inhibitors in the immune system. This review covers research and discussion of the role of the inhibitors in modulating the immune response using as examples the commonly available drugs, donepezil, galantamine, huperzine, neostigmine and pyridostigmine. Major attention is given to the cholinergic anti-inflammatory pathway, a well-described link between the central nervous system and terminal effector cells in the immune system. PMID:24893223

  5. Pharmacophore Identification of Hydroxamate HDAC 1 Inhibitors

    YU,Liqin; LIU,Fei; CHEN,Yadong; YOU,Qidong


    A three-dimensional pharmacophore model was established based on 24 hydroxamate histone deacetylase(HDAC)inhibitors by HypoGen algorithm embedded in Catalyst software.The best pharmacophore hypothesis(Hypol),consisting of four chemical features(one hydrogen-bond acceptor,one aromatic ring and two hydrophobicgroups).has a correlation coefficient of 0.946.The Hypol Was also validated by a test set consisting of 20 othercompounds.Compared with the prior studies towards HDAC inhibitors the detailed chemical features of the"CAP"region in the reported HDAC inhibitors were for the first time depicted,which would be helpful in the further de-signing of novel HDAC inhibitors.

  6. Inhibitors of alanine racemase enzyme: a review.

    Azam, Mohammed Afzal; Jayaram, Unni


    Alanine racemase is a fold type III PLP-dependent amino acid racemase enzyme catalysing the conversion of l-alanine to d-alanine utilised by bacterial cell wall for peptidoglycan synthesis. As there are no known homologs in humans, it is considered as an excellent antibacterial drug target. The standard inhibitors of this enzyme include O-carbamyl-d-serine, d-cycloserine, chlorovinyl glycine, alaphosphin, etc. d-Cycloserine is indicated for pulmonary and extra pulmonary tuberculosis but therapeutic use of drug is limited due to its severe toxic effects. Toxic effects due to off-target affinities of cycloserine and other substrate analogs have prompted new research efforts to identify alanine racemase inhibitors that are not substrate analogs. In this review, an updated status of known inhibitors of alanine racemase enzyme has been provided which will serve as a rich source of structural information and will be helpful in generating selective and potent inhibitor of alanine racemase. PMID:26024289

  7. Strategies for discontinuation of proton pump inhibitors

    Haastrup, Peter; Paulsen, Maja S; Begtrup, Luise M;


    PURPOSE: Proton pump inhibitors (PPIs) are considered to be overprescribed. Consensus on how to attempt discontinuation is, however, lacking. We therefore conducted a systematic review of clinical studies on discontinuation of PPIs. METHODS: Systematic review based on clinical studies investigating...

  8. Cyanobacterial secondary metabolites as acetylcholinesterase inhibitors

    Zelík, Petr; Masojídek, Jiří; Štys, Dalibor; Kopecký, Jiří

    Kunming : Verlag, 2006, s. 52-53. [International Conference on Applied Phycology /10./. Kunming (CN), 24.07.2005-28.07.2005] Institutional research plan: CEZ:AV0Z50200510 Keywords : cyanobacteria * acetylcholinesterase inhibitors Subject RIV: EE - Microbiology, Virology

  9. Progress and prospects on DENV protease inhibitors.

    Timiri, Ajay Kumar; Sinha, Barij Nayan; Jayaprakash, Venkatesan


    New treatments are desperately required to combat increasing rate of dengue fever cases reported in tropical and sub-tropical parts of the world. Among the ten proteins (structural and non-structural) encoded by dengue viral genome, NS2B-NS3 protease is an ideal target for drug discovery. It is responsible for the processing of poly protein that is required for genome replication of the virus. Moreover, inhibitors designed against proteases were found successful in Human Immuno-deficiency Virus (HIV) and Hepatitis C Virus (HCV). Complete molecular mechanism and a survey of inhibitors reported against dengue protease will be helpful in designing effective and potent inhibitors. This review provides an insight on molecular mechanism of dengue virus protease and covers up-to-date information on different inhibitors reported against dengue proteases with medicinal chemistry perspective. PMID:27092412

  10. Effects of multiphase flow on corrosion inhibitor

    Chen, Y.; Jepson, W.P. [Ohio Univ., Athens, OH (United States); Chen, H.J. [Chevron Petroleum Technology Co., La Habra, CA (United States)


    This paper investigates the inhibition performance of a typical imidazoline based inhibitor under multiphase flow. Electrochemical impedance spectroscopy (EIS) measurements were carried out in a 101.6 mm I.D., 15 m long acrylic flow loop using ASTM substitute saltwater and carbon dioxide gas. This flow loop system can generate slug flow, fill pipe flow and other multiphase flow patterns. Effects of different flow conditions on inhibition performance of this typical inhibitor were examined. The system was maintained at a pressure of 0.136 MPa and a temperature of 40 C. EIS measurements for this inhibitor in a Rotating Cylinder Electrode (RCE) system were also conducted. Different equivalent circuit models were used to fit the experiment data for both the RCE and flow loop systems. The high shear stress and turbulence due to the mixing vortex and the bubble impact in multiphase flow can enhance the corrosion or reduce the inhibition performance of inhibitors.

  11. Lipoxygenase inhibitors derived from marine macroalgae.

    Kurihara, Hideyuki; Kagawa, Yoshio; Konno, Remi; Kim, Sang Moo; Takahashi, Koretaro


    The solvent extracts from the algae Sargassum thunbergii (Sargassaceae) and Odonthalia corymbifera (Rhodomelaceae) were subjected to soybean lipoxygenase inhibitory screening. Two hydrophobic inhibitors were obtained from the extracts of S. thunbergii through inhibitory assay-guided fractionation. The inhibitors were identified as known exo-methylenic alkapolyenes (6Z,9Z,12Z,15Z)-1,6,9,12,15-henicosapentaene (1) and (6Z,9Z,12Z,15Z,18Z)-1,6,9,12,15,18-henicosahexaene (2). The alkapolyenes 1 and 2 showed higher inhibitory activity than the known inhibitor nordihydroguaiaretic acid (NDGA). Pheophytin a (3) was obtained from the extract of O. corymbifera. The inhibitor 3 also showed higher inhibitory activity than NDGA. This is the first report on lipoxygenase inhibition of exo-methylenic alkapolyenes and a chlorophyll a-related substance. PMID:24495846

  12. The Broad Stroke of Hsp90 Inhibitors: Painting over the RAF Inhibitor Paradox.

    Vido, Michael J; Aplin, Andrew E


    The novel Hsp90 inhibitor XL888 is undergoing clinical investigation for use in conjunction with the rapidly accelerated fibrosarcoma (RAF) kinase inhibitor vemurafenib to treat unresectable melanoma. The addition of XL888 to current regimens may serve an additional purpose by blocking the RAF inhibitor paradox. Such activity could reduce adverse events in patients and provide a biomarker for the successful inhibition of Hsp90 target proteins. PMID:26358385

  13. The effect of chemical anti-inhibitors on fibrinolytic enzymes and inhibitors

    Sidelmann, Johannes Jakobsen; Jespersen, J; Kluft, C;


    proteases. We studied the influence of chemical anti-inhibitors (chloramine T, flufenamate, sodium lauryl sulfate, and methylamine) on fibrinolytic serine proteases and fibrinolytic enzyme inhibitors using the physiological substrate fibrin as plasmin substrate. Low concentrations of chloramine T (0.01 mmol...... plasminogen activators (apparent recovery > 200%). Sodium lauryl sulfate eliminates the major fibrinolytic enzyme inhibitors, but increases the activity of plasmin (apparent recovery > 200%) and plasminogen activator, urokinase type (apparent recovery 130%). Methylamine affects only plasmin inhibition. We...

  14. Update on TNF Inhibitors in Dermatology.

    Sobell, Jeffrey M


    Emerging data describe new potential indications for tumor necrosis factor (TNF) inhibitors in dermatology, including pediatric psoriasis and hidradenitis suppurativa. New biosimilar TNF agents are in late stages of development and may be available in the United States in the near future. Biosimilar agents are similar but not identical to available TNF inhibitors, and approval requires extensive analytic, toxicity, pharmacokinetic, pharmacodynamic, and clinical testing. Semin Cutan Med Surg 35(supp6):S104-S106. PMID:27537073

  15. Acquired Factor V Inhibitor: A Case Report

    Gaćina, Petar; Kušec, Rajko; Čaržavec, Dubravka; Raić, Biserka; Stančić, Vladimir


    A 19-year-old asymptomatic man who was admitted to our hospital for investigation of prolonged screening coagulation assays, prothrombin time and activated partial thromboplastin time is presented. Further evaluation revealed factor V deficiency and the presence of specific factor V inhibitors. The appearance of these inhibitors may be associated with administration of some antibiotics, topical bovine thrombin preparations containing bovine factor V during surgical or dental procedures, after...

  16. Novel hemagglutinin-based influenza virus inhibitors

    Shen, Xintian; Zhang, Xuanxuan; Liu, Shuwen


    Influenza virus has caused seasonal epidemics and worldwide pandemics, which caused tremendous loss of human lives and socioeconomics. Nowadays, only two classes of anti-influenza drugs, M2 ion channel inhibitors and neuraminidase inhibitors respectively, are used for prophylaxis and treatment of influenza virus infection. Unfortunately, influenza virus strains resistant to one or all of those drugs emerge frequently. Hemagglutinin (HA), the glycoprotein in influenza virus envelope, plays a c...

  17. JAK2 inhibitors: are they the solution?

    Santos, Fabio P S; Verstovsek, Srdan


    The discovery of the JAK2V617F mutation in patients with Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) started the era of targeted therapy for these diseases. Until now, patients had few treatment options available, usually restricted to hydroxyurea, interferon preparations, and chemotherapy in more aggressive cases. JAK2 inhibitors have been developed over the past 5 years, and the results of the first clinical trials with JAK2 inhibitors for patients with myelofibros...

  18. Current use of phosphodiesterase inhibitors in urology

    Hakky, Tariq Said; Jain, Lakshay


    The causes of male erectile dysfunction (ED) are quite variable and are now commonly divided into etiologies such as ischemia, smooth muscle damage, or altered blood flow. Although varying rates of ED have been reported in literature, the number of men with ED is projected to increase worldwide by 2025 to approximately 322 million. Since the introduction of phosphodiesterase 5 (PDE5) inhibitors, there has been a paradigm shift in the treatment of ED because PDE5 inhibitors address a broad spe...

  19. Proton pump inhibitors decrease melanogenesis in melanocytes

    Baek, Seung-Hwa; Lee, Sang-Han


    Proton pump inhibitors (PPIs) are widely used as inhibitors of gastric juice secretion for treatment of gastroesophageal reflux disease. However, there are no previous studies of the effects on melanogenesis resulting from PPI treatments. Therefore, the aim of the present study was to investigate the effects of PPIs on melanogenesis in melan-a cells derived from immortalized mouse melanocytes. Tyrosinase activity and copper-chelating activity were measured spectrophotometrically. In addition,...

  20. Endogenous angiogenesis inhibitors and their therapeutic implications.

    Cao, Y


    A number of endogenous inhibitors targeting the tumor vasculature have recently been identified using in vitro and in vivo antiangiogenesis models. While many of these angiogenesis inhibitors display a broad spectrum of biological actions on several systems in the body, several inhibitors including angiostatin, endostatin, and serpin antithrombin seem to act specifically on the proliferating endothelial cell compartment of the newly formed blood vessels. The discovery of these specific endothelial inhibitors not only increases our understanding of the functions of these molecules in the regulation of physiological and pathological angiogenesis, but may also provide an important therapeutic strategy for the treatment of cancer and other angiogenesis dependent diseases, including diabetic retinopathy and chronic inflammations. Systemic administration of these angiogenesis inhibitors in animals significantly suppresses the growth of a variety of tumors and their metastases. However, their production as functional recombinant proteins has been proven to be difficult. In addition, high dosages of these inhibitors are required to suppress tumor growth in animal studies. Other disadvantages of the antiangiogenic protein therapy include repeated injections, prolonged treatment, transmission of toxins and infectious particles, and high cost for manufacturing large amounts of protein molecules. Thus, alternative strategies need to be developed in order to improve the clinical settings of antiangiogenic therapy. Developments of these strategies are ongoing and they include identification of more potent inhibitors, antiangiogenic gene therapy, improvement of protein/compound half-lives in the circulation, increase of their concentrations at the disease location, and combinatorial therapies with approaches including chemotherapy, radiotherapy, and immunotherapy. Despite the above-mentioned disadvantages, a few inhibitors have entered into the early stages of clinical trials and

  1. Therapeutic Potential of Monoacylglycerol Lipase Inhibitors

    Mulvihill, Melinda M.; Nomura, Daniel K.


    Marijuana and aspirin have been used for millennia to treat a wide range of maladies including pain and inflammation. Both cannabinoids, like marijuana, that exert anti-inflammatory action through stimulating cannabinoid receptors, and cyclooxygenase (COX) inhibitors, like aspirin, that suppress pro-inflammatory eicosanoid production have shown benefitial outcomes in mouse models of neurodegenerative diseases and cancer. Both cannabinoids and COX inhibitors, however, have untoward effects tha...

  2. Aromatase inhibitors in the treatment of endometriosis.

    Słopień, Radosław; Męczekalski, Błażej


    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis. PMID:27095958

  3. Aromatase inhibitors in the treatment of endometriosis

    Męczekalski, Błażej


    Endometriosis is a chronic inflammatory condition in which foci of endometrial tissue grow outside of the uterine cavity. Endometriosis was estimated to affect 176 million women of childbearing potential all over the world in 2010. The presence of extrauterine endometrial tissue is associated with pain and infertility. Typical symptoms of endometriosis include dysmenorrhoea, dyspareunia, heavy menstrual periods (menorrhagia), pelvic pain that is not related to menstrual cycles, dysuria, and chronic fatigue. Medical treatments for endometriosis include combined oral contraceptive pills, danazol, gestrinone, medroxyprogesterone acetate, and gonadotropin-releasing hormone agonists (aGnRHs). A new class of medications called aromatase inhibitors has been identified in recent years as potential therapeutic agents for endometriosis. This article provides general information about aromatase inhibitors, their use in gynaecology, and their adverse effects. In particular, the paper discusses the use of aromatase inhibitors in the treatment of endometriosis in postmenopausal women. Unlike oral contraceptives, gestagens, aGnRHs, and danazol, which suppress ovarian oestrogen synthesis, aromatase inhibitors inhibit mainly extra-ovarian synthesis of oestrogens. Therefore, the use of aromatase inhibitors seems to be particularly relevant in older patients, as most of the body's oestrogen is produced outside the ovaries after menopause. The paper discusses also the use of aromatase inhibitors in the treatment of pain associated with endometriosis and infertility caused by endometriosis. PMID:27095958

  4. Natural inhibitors of tumor-associated proteases

    The turnover and remodelling of extracellular matrix (ECM) is an essential part of many normal biological processes including development, morphogenesis, and wound healing. ECM turnover also occurs in severe pathological situations like artherosclerosis, fibrosis, tumor invasion and metastasis. The major proteases involved in this turnover are serine proteases (especially the urokinase-type plasminogen activator/plasmin system), matrix metalloproteases (a family of about 20 zinc-dependent endopeptidases including collagenases, gelatinases, stromelysins, and membrane-type metalloproteases), and cysteine proteases. In vivo, the activity of these proteases is tightly regulated in the extracellular space by zymogen activation and/or controlled inhibition. In the present review, we give an overview on the structure and biochemical properties of important tumor-associated protease inhibitors such as plasminogen activator inhibitor type 1 and type 2 (PAI-1, PAI-2), tissue inhibitors of metalloproteinases (TIMP-1, -2, -3, and -4), and the cysteine protease inhibitor cystatin C. Interestingly, some of these inhibitors of tumor-associated proteases display multiple functions which rather promote than inhibit tumor progression, when the presence of inhibitors in the tumor tissue is not balanced. (author)

  5. Development of Radiosensitizer using farnesyltransferase inhibitors

    Lim, Jong Seok; Choe, Yong Kyung; Han, Mi Young; Kim, Kwang Dong [Korea Research Institute of Bioscience and Biotechnology, Taejon (Korea)


    We selected some compounds that were reported to have an activity of farneyltransferase inhibitor and tested the hypothesis that they might be used to radiosensitize cells transformed by ras oncogenes. The inhibition of ras processing using some, but not all, inhibitors resulted in higher levels of cell death after {gamma}-irradiation and increased radiosensitivity in H-ras-transformed NIH3T3 cells and MCF-10A human tumor cells. They did not induce additional cell death in control cells that doe not have ras mutation. Furthermore, the treatment of inhibitors alone induced a weak G0/G1 block, whereas inhibitors in combination with {gamma}-irradiation induced an additional enrichment in the G2/M phase of the cell cycle that typically represents irradiation-induced growth arrest. At present, the underling mechanism by which the farnesylltransferase inhibitors exert radiosensitizing effect is not known. In summary, our results suggest and lead to the possibility that some of farnesylation inhibitors may prove clinically useful not only as antitumor agents, but also radiosensitizers of tumors whose growth is dependent on ras function. (author). 15 refs., 10 figs., 4 tabs.

  6. Combined effects of EGFR tyrosine kinase inhibitors and vATPase inhibitors in NSCLC cells

    Jin, Hyeon-Ok [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Hong, Sung-Eun [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Kim, Chang Soon [Department of Microbiological Engineering, Kon-Kuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul, 143–701 (Korea, Republic of); Park, Jin-Ah; Kim, Jin-Hee; Kim, Ji-Young; Kim, Bora [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Chang, Yoon Hwan; Hong, Seok-Il; Hong, Young Jun [Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Park, In-Chul, E-mail: [Division of Radiation Cancer Research, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Lee, Jin Kyung, E-mail: [KIRAMS Radiation Biobank, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of); Department of Laboratory Medicine, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul, 139–706 (Korea, Republic of)


    Despite excellent initial clinical responses of non-small cell lung cancer (NSCLC) patients to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), many patients eventually develop resistance. According to a recent report, vacuolar H + ATPase (vATPase) is overexpressed and is associated with chemotherapy drug resistance in NSCLC. We investigated the combined effects of EGFR TKIs and vATPase inhibitors and their underlying mechanisms in the regulation of NSCLC cell death. We found that combined treatment with EGFR TKIs (erlotinib, gefitinib, or lapatinib) and vATPase inhibitors (bafilomycin A1 or concanamycin A) enhanced synergistic cell death compared to treatments with each drug alone. Treatment with bafilomycin A1 or concanamycin A led to the induction of Bnip3 expression in an Hif-1α dependent manner. Knock-down of Hif-1α or Bnip3 by siRNA further enhanced cell death induced by bafilomycin A1, suggesting that Hif-1α/Bnip3 induction promoted resistance to cell death induced by the vATPase inhibitors. EGFR TKIs suppressed Hif-1α and Bnip3 expression induced by the vATPase inhibitors, suggesting that they enhanced the sensitivity of the cells to these inhibitors by decreasing Hif-1α/Bnip3 expression. Taken together, we conclude that EGFR TKIs enhance the sensitivity of NSCLC cells to vATPase inhibitors by decreasing Hif-1α/Bnip3 expression. We suggest that combined treatment with EGFR TKIs and vATPase inhibitors is potentially effective for the treatment of NSCLC. - Highlights: • Co-treatment with EGFR TKIs and vATPase inhibitors induces synergistic cell death • EGFR TKIs enhance cell sensitivity to vATPase inhibitors via Hif-1α downregulation • Co-treatment of these inhibitors is potentially effective for the treatment of NSCLC.

  7. Proteasome inhibitor treatment in alcoholic liver disease

    Fawzia Bardag-Gorce


    Oxidative stress, generated by chronic ethanol consumption, is a major cause of hepatotoxicity and liver injury. Increased production of oxygen-derived free radicals due to ethanol metabolism by CYP2E1 is principally located in the cytoplasm and in the mitochondria, which does not only injure liver cells, but also other vital organs, such as the heart and the brain. Therefore, there is a need for better treatment to enhance the antioxidant response elements. To date, there is no established treatment to attenuate high levels of oxidative stress in the liver of alcoholic patients. To block this oxidative stress, proteasome inhibitor treatment has been found to significantly enhance the antioxidant response elements of hepatocytes exposed to ethanol. Recent studies have shown in an experimental model of alcoholic liver disease that proteasome inhibitor treatment at low dose has cytoprotective effects against ethanol-induced oxidative stress and liver steatosis. The beneficial effects of proteasome inhibitor treatment against oxidative stress occurred because antioxidant response elements (glutathione peroxidase 2, superoxide dismutase 2, glutathione synthetase, glutathione reductase, and GCLC) were upregulated when rats fed alcohol were treated with a low dose of PS-341 (Bortezomib, Velcade(r)). This is an important finding because proteasome inhibitor treatment up-regulated reactive oxygen species removal and glutathione recycling enzymes, while ethanol feeding alone down-regulated these antioxidant elements. For the first time, it was shown that proteasome inhibition by a highly specific and reversible inhibitor is different from the chronic ethanol feeding-induced proteasome inhibition. As previously shown by our group, chronic ethanol feeding causes a complex dysfunction in the ubiquitin proteasome pathway, which affects the proteasome system, as well as the ubiquitination system. The beneficial effects of proteasome inhibitor treatment in alcoholic liver disease

  8. SGLT2 Inhibitors and the Diabetic Kidney.

    Fioretto, Paola; Zambon, Alberto; Rossato, Marco; Busetto, Luca; Vettor, Roberto


    Diabetic nephropathy (DN) is the most common cause of end-stage renal disease worldwide. Blood glucose and blood pressure control reduce the risk of developing this complication; however, once DN is established, it is only possible to slow progression. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, the most recent glucose-lowering oral agents, may have the potential to exert nephroprotection not only through improving glycemic control but also through glucose-independent effects, such as blood pressure-lowering and direct renal effects. It is important to consider, however, that in patients with impaired renal function, given their mode of action, SGLT2 inhibitors are less effective in lowering blood glucose. In patients with high cardiovascular risk, the SGLT2 inhibitor empagliflozin lowered the rate of cardiovascular events, especially cardiovascular death, and substantially reduced important renal outcomes. Such benefits on DN could derive from effects beyond glycemia. Glomerular hyperfiltration is a potential risk factor for DN. In addition to the activation of the renin-angiotensin-aldosterone system, renal tubular factors, including SGLT2, contribute to glomerular hyperfiltration in diabetes. SGLT2 inhibitors reduce sodium reabsorption in the proximal tubule, causing, through tubuloglomerular feedback, afferent arteriole vasoconstriction and reduction in hyperfiltration. Experimental studies showed that SGLT2 inhibitors reduced hyperfiltration and decreased inflammatory and fibrotic responses of proximal tubular cells. SGLT2 inhibitors reduced glomerular hyperfiltration in patients with type 1 diabetes, and in patients with type 2 diabetes, they caused transient acute reductions in glomerular filtration rate, followed by a progressive recovery and stabilization of renal function. Interestingly, recent studies consistently demonstrated a reduction in albuminuria. Although these data are promising, only dedicated renal outcome trials will clarify whether

  9. Differential Effects of Nebivolol and Metoprolol on Insulin Sensitivity and Plasminogen Activator Inhibitor in the Metabolic Syndrome

    Ayers, Katie; Byrne, Loretta M.; DeMatteo, Anthony; Brown, Nancy J.


    Early generation β-blockers lower blood pressure and reduce cardiovascular morality in coronary artery disease and congestive heart failure, but worsen glucose homeostasis and fibrinolytic balance. Nebivolol is a third-generation β-blocker which increases the bioavailability of nitric oxide. We compared the effect of nebivolol (5mg/d) and the β1-selective antagonist metoprolol (100mg/d) on glucose homeostasis and markers of fibrinolysis in 46 subjects with metabolic syndrome. Subjects underwe...

  10. Selective cell adhesion inhibitors: Barbituric acid based alpha4beta7--MAdCAM inhibitors.

    Harriman, Geraldine C; Brewer, Matthias; Bennett, Robert; Kuhn, Cyrille; Bazin, Marc; Larosa, Greg; Skerker, Paul; Cochran, Nancy; Gallant, Debra; Baxter, Deborah; Picarella, Dominic; Jaffee, Bruce; Luly, Jay R; Briskin, Michael J


    A novel series of barbituric acid derivatives were identified as selective inhibitors of alpha4beta7 MAdCAM (mucosal addressin cell adhesion molecule-1) interactions via a high throughput screening exercise. These inhibitors were optimized to submicromolar potencies in whole cell adhesion assays, retaining their selectivity over alpha4beta1 VCAM. PMID:18331794

  11. Versatile templates for the development of novel kinase inhibitors: Discovery of novel CDK inhibitors

    Dwyer, Michael P.; Paruch, Kamil; Alvarez, Carmen; Doll, Ronald J.; Keertikar, Kerry; Duca, Jose; Fischmann, Thierry O.; Hruza, Alan; Madison, Vincent; Lees, Emma; Parry, David; Seghezzi, Wolfgang; Sgambellone, Nicole; Shanahan, Frances; Wiswell, Derek; Guzi, Timothy J. (SPRI)


    A series of four bicyclic cores were prepared and evaluated as cyclin-dependent kinase-2 (CDK2) inhibitors. From the in-vitro and cell-based analysis, the pyrazolo[1,5-a]pyrimidine core (represented by 9) emerged as the superior core for further elaboration in the identification of novel CDK2 inhibitors.

  12. Polyphenol oxidase inhibitor(s) from German cockroach (Blattella germanica) extract

    An extract from German cockroach appears effective in inhibiting browning on apples and potatoes. Successful identification of inhibitor(s) of PPO from German cockroach would be useful to the fruit and vegetable segments of the food industry, due to the losses they incur from enzymatic browning. Ide...

  13. Janus kinase inhibitors: jackpot or potluck?

    Pavithran Keechilat


    Full Text Available The reports of a unique mutation in the Janus kinase-2 gene (JAK2 in polycythemia vera by several independent groups in 2005 quickly spurred the development of the Janus kinase inhibitors. In one of the great victories of translational research in recent times, the first smallmolecule Janus kinase inhibitor ruxolitinib entered a phase I trial in 2007. With the approval of ruxolitinib by the US Federal Drug Administration in November 2011 for high-risk and intermediate-2 risk myelofibrosis, a change in paradigm has occurred in the management of a subset of myeloproliferative neoplasms (MPN: primary myelofibrosis, post-polycythemia vera myelofibrosis, and post-essential thrombocythemia myelofibrosis. Whereas the current evidence for ruxolitinib only covers high-risk and intermediate-2 risk myelofibrosis, inhibitors with greater potency are likely to offer better disease control and survival advantage in patients belonging to these categories, and possibly to the low-risk and intermediate-1 risk categories of MPN as well. But use of the Janus kinase inhibitors also probably has certain disadvantages, such as toxicity, resistance, withdrawal phenomenon, non-reversal of histology, and an implausible goal of disease clone eradication, some of which could offset the gains. In spite of this, Janus kinase inhibitors are here to stay, and for use in more than just myeloproliferative neoplasms.

  14. Localization and distribution of tissue type and urokinase type plasminogen activators and their inhibitors Type 1 and 2 in human and rhesus monkey fetal membranes.

    Liu, Y X; Hu, Z Y; Liu, K; Byrne, S; Zou, R J; Ny, T; d'Lacey, C; Ockleford, C D


    in the level of abscission. No detectable amount of mRNAs for tPA, uPA, PAI-1 and PAI-2 was found in the fibroblast, reticular and spongy layers. Distribution of the proteins of tPA, uPA and PAI-1 in the fetal membranes of these two species was consistent with the distribution of their mRNA. Anti-PAI-2 immunofluorescence was found to be strongly concentrated in the amniotic epithelium, but PAI-2 mRNA was negative in this layer, suggesting that the epithelium-associated PAI-2 is not of epithelial origin. These findings suggest that a local fibrinolysis in fetal membranes generated by precisely balanced expression of PAs and their inhibitors via paracrine or autocrine mechanisms may play an essential role in fetal membrane development, maturation and in membrane rupture. Following an analysis of the distribution and synthesis of activators and inhibitors it was found that they may play a role in abscission during the third stage of labour. PMID:9548184

  15. Endogenous Matrix-Derived Inhibitors of Angiogenesis

    Hans Petter Eikesdal


    Full Text Available Endogenous inhibitors of angiogenesis are proteins or fragments of proteins that are formed in the body, which can inhibit the angiogenic process. These molecules can be found both in the circulation and sequestered in the extracellular matrix (ECM surrounding cells. Many matrix-derived inhibitors of angiogenesis, such as endostatin, tumstatin, canstatin and arresten, are bioactive fragments of larger ECM molecules. These substances become released upon proteolysis of the ECM and the vascular basement membrane (VBM by enzymes of the tumor microenvironment. Although the role of matrix-derived angiogenesis inhibitors is well studied in animal models of cancer, their role in human cancers is less established. In this review we discuss the current knowledge about these molecules and their potential use as cancer therapeutics and biomarkers.

  16. Synthesis of amino heterocycle aspartyl protease inhibitors.

    Chambers, Rachel K; Khan, Tanweer A; Olsen, David B; Sleebs, Brad E


    Aspartyl proteases are important pharmacological targets. Historically aspartyl proteases have been commonly targeted with transition state derived peptidomimetics. The strategy to develop aspartyl protease inhibitors has undertaken a dramatic paradigm shift in the last 10 years. The pharmaceutical industry in 2005 disclosed several scaffolds or "head groups" that prompted the field to move beyond peptidomimetic derived inhibitors. Since the discovery of the first amino heterocycle aspartyl protease inhibitor, the amino hydantoin, industry and academia have positioned themselves for a foothold on the new molecular space, designing a variety of related "head groups". Both the design and synthetic efforts involved in constructing these scaffolds are varied and complex. Here we highlight the synthetic strategies used to access these amino heterocycle scaffolds. PMID:27143279

  17. Functional non-nucleoside adenylyl cyclase inhibitors.

    Lelle, Marco; Hameed, Abdul; Ackermann, Lisa-Maria; Kaloyanova, Stefka; Wagner, Manfred; Berisha, Filip; Nikolaev, Viacheslav O; Peneva, Kalina


    In this study, we describe the synthesis of novel functional non-nucleoside adenylyl cyclase inhibitors, which can be easily modified with thiol containing biomolecules such as tumour targeting structures. The linkage between inhibitor and biomolecule contains cleavable bonds to enable efficient intracellular delivery in the reductive milieu of the cytosol as well as in the acidic environment within endosomes and lysosomes. The suitability of this synthetic approach was shown by the successful bioconjugation of a poor cell-permeable inhibitor with a cell-penetrating peptide. Additionally, we have demonstrated the excellent inhibitory effect of the compounds presented here in a live-cell Förster resonance energy transfer-based assay in human embryonic kidney cells. PMID:25319071

  18. Paraffin wax deposits and chemical inhibitors

    Mendell, J.L.


    Solutions to this problem becomes necessary with the advent of extremely deep production, offshore production, and the probability of ocean-floor completions. The reasons for paraffin-wax accumulations are many and difficult to pinpoint. Inhibition of these paraffin deposits appears to be the best solution. Paraffin solvents and inhibitors are as follows: solvents, wetting agents, dispersants, and crystal modifiers. Solvents are effective, but can harm a refinery catalyst and create health hazards. Wetting agents and dispersants comprise the majority of chemicals used as paraffin wax inhibitors. Crystal modifiers are relatively new and may provide the most efficient means of reducing deposition. Evaluations of chemical paraffin inhibitors are outlined. Field test results which consider the various chemicals tested may give satisfactory results in determining which particular chemical can solve the problem of the particular situation. (38 refs.)

  19. Cough Syncope due to ACE Inhibitor

    Filiz Koc


    Full Text Available Syncope is defined as a transient loss of consciousness due to sudden temporary decline in cerebral perfusion. Cough syncope is classically seen in middle aged obese men with obstructive pulmonary disease. In patients that use Angiotensin converting enzyme (ACE inhibitors, a dry persistent cough can emerge due to the side effects of this medication. Seventy years old male patient that use ACE inhibitor for hypertension accepted to the clinic with the complaint of syncope. A bout of coughing has developed during electroencephalography recording and 10 seconds in duration of subcortical like epileptiform discharges were viewed. The ACE inhibitor the patient was receiving was replaced with calcium channel blocker and no complaint was observed during the follow up period. [Cukurova Med J 2015; 40(3.000: 619-622

  20. Topoisomerase I inhibitors: camptothecins and beyond.

    Pommier, Yves


    Nuclear DNA topoisomerase I (TOP1) is an essential human enzyme. It is the only known target of the alkaloid camptothecin, from which the potent anticancer agents irinotecan and topotecan are derived. As camptothecins bind at the interface of the TOP1-DNA complex, they represent a paradigm for interfacial inhibitors that reversibly trap macromolecular complexes. Several camptothecin and non-camptothecin derivatives are being developed to further increase anti-tumour activity and reduce side effects. The mechanisms and molecular determinants of tumour response to TOP1 inhibitors are reviewed, and rational combinations of TOP1 inhibitors with other drugs are considered based on current knowledge of repair and checkpoint pathways that are associated with TOP1-mediated DNA damage. PMID:16990856

  1. Use of acetylcholinesterase inhibitors in Alzheimer's disease.

    Moghul, S; Wilkinson, D


    Alzheimer's disease is a growing problem in an aging Western world, estimated to have cost the US economy USD 1.75 trillion. Until recently, the management of Alzheimer's disease largely comprised support for the family, nursing care and the use of unlicensed medication to control behavioral disturbances. The three new acetylcholinesterase inhibitors licensed to treat Alzheimer's disease (donepezil, rivastigmine and galantamine) have provided clinicians with a major impetus to their desire to diagnose and treat this lethal disease. Their effects on cognition are proven. More recent work on the effects of acetylcholinesterase inhibitors on behavioral symptoms, activities of daily living and caregiver burden have also been encouraging. Emerging work indicates their likely efficacy in other dementias (e.g., vascular dementia, dementia with Lewy bodies). This review summarizes the evidence concerning the impact of acetylcholinesterase inhibitors in dementia both currently and over the next 5 years. PMID:19811047

  2. Drug screening for influenza neuraminidase inhibitors

    LIU; Ailin; CAO; Hongpeng; DU; Guanhua


    Neuraminidase (NA) is one of the most important targets to screen the drugs of anti-influenza virus A and B. After virtual screening approaches were applied to a compound database which possesses more than 10000 compound structures, 160 compounds were selected for bioactivity assay, then a High Throughput Screening (HTS) model established for influenza virus NA inhibitors was applied to detect these compounds. Finally, three compounds among them displayed higher inhibitory activities, the range of their IC50 was from 0.1 μmol/L to 3μmol/L. Their structural scaffolds are novel and different from those of NA inhibitors approved for influenza treatment, and will be useful for the design and research of new NA inhibitors. The resuit indicated that the combination of virtual screening with HTS was very significant to drug screening and drug discovery.

  3. Preliminary studies on vigna unguiculata trypsin inhibitor

    Investigation on the presence of trypsin inhibitor in vigna unguiculata at three stages of ripeness, i.e. as young beans obtained from first harvest usually consumed as vegetable, seed from beans picked two weeks after the first harvest and seed from beans picked four weeks after the first harvest, has been carried out. The conclusion drawn from this experiment showed the existence of trypsin inhibitor at those stages of ripeness. It is found that the older the stage of ripeness the greater the specific activity of trypsin inhibitor. Evidently the heated extract loss its antitryptic activity progressively with increasing heatings periods. Extract heated on a water bath at a constant temperature of 78 deg C during 20, 40 and 60 minutes, loss its antitryptic activity of about 53, 78 and 96% respectively. (author)

  4. Green inhibitors. Rare Earth based systems

    Lanthanum, Cerium and Samarium chlorides have been investigated as uniform and pitting corrosion inhibitors of AISI 434 and AISI 304 stainless steels and AA 5083 Al-Mg alloy in 3.5% Na Cl aerated aqueous solutions. Their inhibitor power was evaluated by using electrochemical techniques such as Linear and Cyclic Polarisation. In each case, the highest protection degree was found in the solution dropped with 500 ppm of CeCl3. Similar results were obtained for additions of 500 ppm of LaCl3. Scanning Electron Microscopy and Energy Dispersive Spectroscopy allowed us to confirm the cathodic nature of the inhibition process. (Author) 27 refs

  5. Rational design of protein kinase inhibitors

    Yarmoluk S. M.


    Full Text Available Modern methodological approaches to rational design of low molecular weight compounds with specific activity in relation to predetermined biomolecular targets are considered by example of development of high effective protein kinase inhibitors. The application of new computational methods that allow to significantly improve the quality of computational experiments (in, particular, accuracy of low molecular weight compounds activity prediction without increase of computational and time costs are highlighted. The effectiveness of strategy of rational design is demonstrated by examples of several own investigations devoted to development of new inhibitors that are high effective and selective towards protein kinases CK2, FGFR1 and ASK1.

  6. Small Universal Petri Nets with Inhibitor Arcs

    Ivanov, Sergiu; Pelz, Elisabeth; Verlan, Sergey


    We investigate the problem of construction of small-size universal Petri nets with inhibitor arcs. We consider four descriptional complexity parameters: the number of places, transitions, inhibitor arcs, and the maximal degree of a transition, each of which we try to minimize. We give six constructions having the following values of parameters (listed in the above order): $(30,34,13,3)$, $(14, 31, 51, 8)$, $(11, 31, 79, 11)$, $(21,25,13,5)$, $(67, 64, 8, 3)$, $(58, 55, 8, 5)$ that improve the...

  7. Cerebral venous thrombosis: treatment with local fibrinolysis plus alteplase

    Cerebral venous thrombosis is a rare entity with widely variable clinical signs: thus, a high degree of suspicion is required for diagnosis. It affects the dural sinuses and may or may not invade cerebral veins. The diagnosis has usually been based on an angiographic study although, at the present time, new noninvasive imaging techniques, such as computed tomography, magnetic resonance and magnetic resonance angiography are being employed in a growing number of cases. Treatment should involve symptomatic and etiologic therapy. Although anti coagulation would appear to be a reasonable option in these patients, it remains controversial. As in other processes such as pulmonary embolism and coronary thrombosis, the introduction of novel and increasingly safe fibrinolytic drugs, together with technical innovations in the field of interventional neuroradiology, is changing the perspectives for the management of these patients. We present the case of a 43-year-old woman with right sinus thrombosis who was treated with local thrombolysis plus alteplase (tissue plasminogen activator). The authors describe the technique employed and review the literature. (Author) 16 refs

  8. Fibrinolysis for patients with intermediate-risk pulmonary embolism

    Meyer, Guy; Vicaut, Eric; Danays, Thierry; Agnelli, Giancarlo; Becattini, Cecilia; Beyer-Westendorf, Jan; Bluhmki, Erich; Bouvaist, Helene; Brenner, Benjamin; Couturaud, Francis; Dellas, Claudia; Empen, Klaus; Franca, Ana; Galiè, Nazzareno; Geibel, Annette


    BACKGROUND The role of fibrinolytic therapy in patients with intermediate-risk pulmonary embolism is controversial. METHODS In a randomized, double-blind trial, we compared tenecteplase plus heparin with placebo plus heparin in normotensive patients with intermediate-risk pulmonary embolism. Eligible patients had right ventricular dysfunction on echocardiography or computed tomography, as well as myocardial injury as indicated by a positive test for cardiac troponin I or troponin ...

  9. Synergistic apoptosis induction in leukemic cells by the phosphatase inhibitor salubrinal and proteasome inhibitors.

    Hannes C A Drexler

    Full Text Available BACKGROUND: Cells adapt to endoplasmic reticulum (ER-stress by arresting global protein synthesis while simultaneously activating specific transcription factors and their downstream targets. These processes are mediated in part by the phosphorylation-dependent inactivation of the translation initiation factor eIF2alpha. Following restoration of homeostasis protein synthesis is resumed when the serine/threonine-protein phosphatase PP1 dephosphorylates and reactivates eIF2alpha. Proteasome inhibitors, used to treat multiple myeloma patients evoke ER-stress and apoptosis by blocking the ER-associated degradation of misfolded proteins (ERAD, however, the role of eIF2alpha phosphorylation in leukemic cells under conditions of proteasome inhibitor-mediated ER stress is currently unclear. METHODOLOGY AND PRINCIPAL FINDINGS: Bcr-Abl-positive and negative leukemic cell lines were used to investigate the functional implications of PP1-related phosphatase activities on eIF2alpha phosphorylation in proteasome inhibitor-mediated ER stress and apoptosis. Rather unexpectedly, salubrinal, a recently identified PP1 inhibitor capable to protect against ER stress in various model systems, strongly synergized with proteasome inhibitors to augment apoptotic death of different leukemic cell lines. Salubrinal treatment did not affect the phosphorlyation status of eIF2alpha. Furthermore, the proapoptotic effect of salubrinal occurred independently from the chemical nature of the proteasome inhibitor, was recapitulated by a second unrelated phosphatase inhibitor and was unaffected by overexpression of a dominant negative eIF2alpha S51A variant that can not be phosphorylated. Salubrinal further aggravated ER-stress and proteotoxicity inflicted by the proteasome inhibitors on the leukemic cells since characteristic ER stress responses, such as ATF4 and CHOP synthesis, XBP1 splicing, activation of MAP kinases and eventually apoptosis were efficiently abrogated by the

  10. Polyphenolic Compounds as Pancreatic Lipase Inhibitors.

    Buchholz, Tina; Melzig, Matthias F


    Obesity and its associated diseases such as diabetes mellitus and coronary heart diseases are a major challenge for our society. An important target for the treatment of obesity includes the development of inhibitors of nutrient digestion and absorption. Inhibition of pancreatic lipase and the associated reduction of lipid absorption is an attractive approach for the discovery of potent agents. Currently, the only clinically approved pharmacologic agent as pancreatic lipase inhibitor is Orlistat. However, its usage is compromised by unpleasant gastrointestinal adverse reactions (oily stools, oily spotting, flatulence). The use of botanical materials as a potential source of new drugs is of increasing importance and application. Natural products that are interesting for obesity treatment are generally considered to have less toxic and side effects than totally synthetic drugs. One of the most important sources of potential pancreatic lipase inhibitors represents the class of polyphenols. This article summarizes most studied subclasses of polyphenols including flavonoids, hydroxycinnamic acids, hydroxybenzoic acids and lignans with pancreatic lipase inhibitory effects. A structural comparison of potent inhibitors shows an increased inhibitory effect depending on number and position of phenolic hydroxyl groups, degree of polymerization and elimination of glycosylation during digestion. PMID:26132857

  11. Carborane-based carbonic anhydrase inhibitors

    Brynda, Jiří; Mader, Pavel; Šícha, Václav; Fábry, Milan; Poncová, Kristýna; Bakardjiev, Mario; Grüner, Bohumír; Cígler, Petr; Řezáčová, Pavlína


    Roč. 52, č. 51 (2013), s. 13760-13763. ISSN 1433-7851 R&D Projects: GA TA ČR(CZ) TE01020028; GA AV ČR IAAX00320901 Institutional support: RVO:68378050 ; RVO:61388963 ; RVO:61388980 Keywords : carbonic anhydrases * carboranes * drug discovery * inhibitors * structure elucidation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 11.336, year: 2013

  12. Curcumin derivatives as HIV-1 protease inhibitors

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)


    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  13. A chemotactic inhibitor in synovial fluid.

    Matzner, Y; Partridge, R E; Babior, B M


    Synovial fluid was found to contain an inhibitor of neutrophil chemotaxis. The activity of this inhibitor was masked in native synovial fluid, but could be detected in fluid in which complement had been deactivated by mild heating. The inhibitor was most effective against the chemotactic activity of zymosan-activated serum (C5ades arg). It had little effect when N-formyl-methionyl-leucyl-phenylalanine served as chemoattractant. Inhibition was not the result of a direct effect on the neutrophils, since incubation of cells with synovial fluid did not alter their chemotactic response. The inhibitory activity was destroyed by boiling the synovial fluid or treating it with trypsin, suggesting that it is a protein (or proteins); it was not affected by hyaluronidase treatment. Gel filtration revealed that the inhibitor was present in native as well as decomplemented synovial fluid, and that its molecular weight was in the vicinity of 25,000. It is proposed that this inhibitory activity plays a role in the regulation of the inflammatory response in joints. PMID:6840801

  14. Randomized controlled trials of COX-2 inhibitors

    Stefansdottir, Gudrun; De Bruin, Marie L; Knol, Mirjam J;


    BACKGROUND: Naproxen, ibuprofen and diclofenac are frequently used as comparators in randomized controlled trials (RCTs) on the safety and efficacy of cyclooxygenase (COX)-2 inhibitors. Different comparator doses may influence the results of RCTs. It has been hypothesized that RCTs of COX-2...

  15. Proton pump inhibitors affect the gut microbiome

    Imhann, Floris; Bonder, Marc Jan; Vich Vila, Arnau; Fu, Jingyuan; Mujagic, Zlatan; Vork, Lisa; Tigchelaar, Ettje F; Jankipersadsing, Soesma A; Cenit, Maria Carmen; Harmsen, Hermie J M; Dijkstra, Gerard; Franke, Lude; Xavier, Ramnik J; Jonkers, Daisy; Wijmenga, Cisca; Weersma, Rinse K; Zhernakova, Alexandra


    BACKGROUND AND AIMS: Proton pump inhibitors (PPIs) are among the top 10 most widely used drugs in the world. PPI use has been associated with an increased risk of enteric infections, most notably Clostridium difficile. The gut microbiome plays an important role in enteric infections, by resisting or

  16. Pharmacogenomics of tamoxifen and aromatase inhibitors.

    Ingle, James N


    In selection of therapy for women with breast cancer, the focus has been almost exclusively on the characteristics of the tumor, eg, estrogen receptor (ER) and HER-2. Until recently, essentially no attention has been paid to the host and her genetic makeup as it relates to the metabolism of different drugs. The first real clinical application of pharmacogenetics in breast cancer management relates to tamoxifen's biotransformation to active anticancer metabolites. New information has arisen on the metabolism of tamoxifen to the active metabolite, 4 hydroxy-N-desmethyl-tamoxifen (endoxifen). Endoxifen is a metabolite with antitumor activity and affinity for the ER that is similar to 4-hydroxy-tamoxifen, but 1 that is normally present in substantially higher concentrations. CYP2D6 plays a central role in the metabolism to endoxifen and 1 published study shows that genotypic differences in CYP2D6 and use of CYP2D6 inhibitors has an impact on outcomes of women treated with tamoxifen. The aromatase inhibitors represent a major class of drugs in the armamentarium against breast cancer. The aromatase gene has been resequenced and functional genomics have been performed on the identified nonsynonymous coding single nucleotide polymorphisms showing significant decreases in levels of activity. These findings are consistent with a hypothesis that genetic variation in the CYP19 gene might be important in the activity of aromatase inhibitors. Currently, the emphasis is on examining multiple genes (thus pharmacogenomics) in pharmacodynamic and pharmacokinetic pathways in women receiving aromatase inhibitors for breast cancer. PMID:18072234

  17. Quinazolines as cyclin dependent kinase inhibitors

    Sielecki, Thais M.; Johnson, Tricia L.; Liu, Jie; Muckelbauer, Jodi K.; Grafstrom, Robert H.; Cox, Sarah; Boylan, John; Burton, Catherine R.; Chen, Haiying; Smallwood, Angela; Chang, Chong-Hwan; Boisclair, Michael; Benfield, Pamela A.; Trainor, George L.; Seitza, Steven P. (Dupont)


    Quinazolines have been identified as inhibitors of CDK4/D1 and CDK2/E. Aspects of the SAR were investigated using solution-phase, parallel synthesis. An X-ray crystal structure was obtained of quinazoline 51 bound in CDK2 and key interactions within the ATP binding pocket are defined.

  18. Proton pump inhibitors for irritable infants

    Smith, Christine H.; Israel, David M.; Schreiber, Richard; Goldman, Ran D.


    Question Crying is common in infants; however, caring for infants with inconsolable crying, previously also known as colic or reflux, is often extremely distressing for parents. Is there a benefit to using gastric acid suppression (eg, proton pump inhibitors [PPIs]) in these infants?

  19. Discovery of inhibitors of bacterial histidine kinases

    Velikova, N.R.


    Discovery of Inhibitors of Bacterial Histidine Kinases


    The thesis is on novel antibacterial drug discovery ( Using structure-based and fragment-based dru

  20. Pharmacological caspase inhibitors: Research towards therapeutic perspectives

    Kudělová, J.; Fleischmannová, Jana; Adamová, Eva; Matalová, Eva


    Roč. 66, č. 4 (2015), s. 473-482. ISSN 0867-5910 R&D Projects: GA ČR GB14-37368G Institutional support: RVO:67985904 Keywords : caspase * caspase inhibitor * apoptosis Subject RIV: EA - Cell Biology Impact factor: 2.386, year: 2014

  1. Phenyltriazolinones as potent factor Xa inhibitors.

    Quan, Mimi L; Pinto, Donald J P; Rossi, Karen A; Sheriff, Steven; Alexander, Richard S; Amparo, Eugene; Kish, Kevin; Knabb, Robert M; Luettgen, Joseph M; Morin, Paul; Smallwood, Angela; Woerner, Francis J; Wexler, Ruth R


    We have discovered that phenyltriazolinone is a novel and potent P1 moiety for coagulation factor Xa. X-ray structures of the inhibitors with a phenyltriazolinone in the P1 position revealed that the side chain of Asp189 has reoriented resulting in a novel S1 binding pocket which is larger in size to accommodate the phenyltriazolinone P1 substrate. PMID:20100660

  2. Novel in vitro inhibitory functions of potato tuber proteinaceous inhibitors.

    Fischer, Matthias; Kuckenberg, Markus; Kastilan, Robin; Muth, Jost; Gebhardt, Christiane


    Plant protease inhibitors are a structurally highly diverse and ubiquitous class of small proteins, which play various roles in plant development and defense against pests and pathogens. Particular isoforms inhibit in vitro proteases and other enzymes that are not their natural substrates, for example proteases that have roles in human diseases. Mature potato tubers are a rich source of several protease inhibitor families. Different cultivars have different inhibitor profiles. With the objective to explore the functional diversity of the natural diversity of potato protease inhibitors, we randomly selected and sequenced 9,600 cDNA clones originated from mature tubers of ten potato cultivars. Among these, 120 unique inhibitor cDNA clones were identified by homology searches. Eighty-eight inhibitors represented novel sequence variants of known plant protease inhibitor families. Most frequent were Kunitz-type inhibitors (KTI), potato protease inhibitors I and II (PIN), pectin methylesterase inhibitors, metallocarboxypeptidase inhibitors and defensins. Twenty-three inhibitors were functionally characterized after heterologous expression in the yeast Pichia pastoris. The purified recombinant proteins were tested for inhibitory activity on trypsin, eleven pharmacological relevant proteases and the non-proteolytic enzyme 5-lipoxygenase. Members of the KTI and PIN families inhibited pig pancreas elastase, β-Secretase, Cathepsin K, HIV-1 protease and potato 5-lipoxygenase. Our results demonstrate in vitro inhibitory diversity of small potato tuber proteins commonly known as protease inhibitors, which might have biotechnological or medical applications. PMID:25260821

  3. DNA Methyltransferases Inhibitors from Natural Sources.

    Zwergel, Clemens; Valente, Sergio; Mai, Antonello


    DNA methyltransferases (DNMTs) catalyze the methylation at cytosine-C5 mainly in a CpG dinucleotide context. Although DNA methylation is essential for fundamental processes like embryonic development or differentiation, aberrant expression and/or activities of DNMTs are involved in several pathologies, from neurodegeneration to cancer. DNMTs inhibition can arrest tumor growth, cells invasiveness and induce differentiation, whereas their increased expression is shown in numerous cancer types. Moreover, hypermethylated promoters of tumor suppressor genes lead to their silencing. Hence, the use of specific inhibitors of DNMT might reactivate those genes and stop or even reverse the aberrant cell processes. To date, the only approved DNMTs inhibitors for therapy belong to the nucleoside-based family of drugs, but they display relevant side effects as well as high chemical instability. Thus, there is a keen interest actually exists to develop novel, potent and safe inhibitors possessing a nonnucleoside structure. Increasing literature evidence is highlighting that natural sources could help the researchers to achieve this goal. Indeed, several polyphenols, flavonoids, antraquinones, and others are described able to inhibit DNMTs activity and/or expression, thus decreasing the methylation/silencing of different genes involved in tumorigenesis. These events can lead to re-expression of such genes and to cell death in diverse cancer cell lines. Epigallocatechin-3-gallate (1) and laccaic acid A (11) resulted the most effective DNMT1 inhibitors with submicromolar IC50 values, acting as competitive inhibitors. Compound 1 and 11 both displayed gene demethylation and re-activation in several cancers. However, all of the natural compounds described in this review showed important results, from gene reactivation to cell growth inhibition. Moreover, some of them displayed interesting activity even in rodent cancer models and very recently entered clinical trials. PMID:26303417

  4. Cost of care of haemophilia with inhibitors.

    Di Minno, M N D; Di Minno, G; Di Capua, M; Cerbone, A M; Coppola, A


    In Western countries, the treatment of patients with inhibitors is presently the most challenging and serious issue in haemophilia management, direct costs of clotting factor concentrates accounting for >98% of the highest economic burden absorbed for the healthcare of patients in this setting. Being designed to address questions of resource allocation and effectiveness, decision models are the golden standard to reliably assess the overall economic implications of haemophilia with inhibitors in terms of mortality, bleeding-related morbidity, and severity of arthropathy. However, presently, most data analyses stem from retrospective short-term evaluations, that only allow for the analysis of direct health costs. In the setting of chronic diseases, the cost-utility analysis, that takes into account the beneficial effects of a given treatment/healthcare intervention in terms of health-related quality of life, is likely to be the most appropriate approach. To calculate net benefits, the quality adjusted life year, that significantly reflects such health gain, has to be compared with specific economic impacts. Differences in data sources, in medical practice and/or in healthcare systems and costs, imply that most current pharmacoeconomic analyses are confined to a narrow healthcare payer perspective. Long-term/lifetime prospective or observational studies, devoted to a careful definition of when to start a treatment; of regimens (dose and type of product) to employ, and of inhibitor population (children/adults, low-responding/high responding inhibitors) to study, are thus urgently needed to allow for newer insights, based on reliable data sources into resource allocation, effectiveness and cost-utility analysis in the treatment of haemophiliacs with inhibitors. PMID:19845772

  5. From the selective serotonin transporter inhibitor citalopram to the selective norepinephrine transporter inhibitor talopram

    Eildal, Jonas Nii Nortey; Andersen, Jacob; Kristensen, Anders Skov;


    Citalopram and talopram are structurally closely related, but they have very distinct pharmacological profiles as selective inhibitors of the serotonin and norepinephrine transporters, respectively. A systematic structure-activity relationship study was performed, in which each of the four...

  6. Protein inhibitor of neuronal nitric oxide synthase interacts with protein kinase A inhibitors.

    Yu, Jianqiang; Yu, Long; Chen, Zheng; Zheng, Lihua; Chen, Xiaosong; Wang, Xiang; Ren, Daming; Zhao, Shouyuan


    Protein kinase A (PKA) and neuronal nitric oxide synthase (nNOS) are important signaling molecules. It is well known that PKA can specifically phosphorylate nNOS. But the underlying molecular mechanism is still obscure. Our data indicate that the protein inhibitor of nNOS (PIN) binds to protein kinase A inhibitors (PKIs), which suggests that PKIs, together with PIN, might mediate the phosphorylation of nNOS by PKA. PMID:11978406

  7. Characterizing resistance of Erysiphe necator to fungicides belonging to the quinone outside inhibitors and demethylation inhibitors

    Rallos, Lynn Esther Espada


    Practical resistance of Erysiphe necator to quinone outside inhibitors (QoIs) is now widespread, and resistance to demethylation inhibitors (DMIs) has also developed.  The goal of this research was to characterize fungicide resistance by elucidating resistance mechanisms and determining its stability.  QoI resistance persisted for several years in a field population after QoI application ended.  Resistant isolates were highly competitive in mixed populations in competition assays under labora...

  8. Peptidyl cyclopropenones: Reversible inhibitors, irreversible inhibitors, or substrates of cysteine proteases?

    Cohen, Meital; Bretler, Uriel; Albeck, Amnon


    Peptidyl cyclopropenones were previously introduced as selective cysteine protease reversible inhibitors. In the present study we synthesized one such peptidyl cyclopropenone and investigated its interaction with papain, a prototype cysteine protease. A set of kinetics, biochemical, HPLC, MS, and 13C-NMR experiments revealed that the peptidyl cyclopropenone was an irreversible inhibitor of the enzyme, alkylating the catalytic cysteine. In parallel, this cyclopropenone also behaved as an alter...

  9. ROS inhibitor N-acetyl-L-cysteine antagonizes the activity of proteasome inhibitors.

    Halasi, Marianna; Wang, Ming; Chavan, Tanmay S; Gaponenko, Vadim; Hay, Nissim; Gartel, Andrei L


    NAC (N-acetyl-L-cysteine) is commonly used to identify and test ROS (reactive oxygen species) inducers, and to inhibit ROS. In the present study, we identified inhibition of proteasome inhibitors as a novel activity of NAC. Both NAC and catalase, another known scavenger of ROS, similarly inhibited ROS levels and apoptosis associated with H₂O₂. However, only NAC, and not catalase or another ROS scavenger Trolox, was able to prevent effects linked to proteasome inhibition, such as protein stabilization, apoptosis and accumulation of ubiquitin conjugates. These observations suggest that NAC has a dual activity as an inhibitor of ROS and proteasome inhibitors. Recently, NAC was used as a ROS inhibitor to functionally characterize a novel anticancer compound, piperlongumine, leading to its description as a ROS inducer. In contrast, our own experiments showed that this compound depicts features of proteasome inhibitors including suppression of FOXM1 (Forkhead box protein M1), stabilization of cellular proteins, induction of ROS-independent apoptosis and enhanced accumulation of ubiquitin conjugates. In addition, NAC, but not catalase or Trolox, interfered with the activity of piperlongumine, further supporting that piperlongumine is a proteasome inhibitor. Most importantly, we showed that NAC, but not other ROS scavengers, directly binds to proteasome inhibitors. To our knowledge, NAC is the first known compound that directly interacts with and antagonizes the activity of proteasome inhibitors. Taken together, the findings of the present study suggest that, as a result of the dual nature of NAC, data interpretation might not be straightforward when NAC is utilized as an antioxidant to demonstrate ROS involvement in drug-induced apoptosis. PMID:23772801

  10. Development of covalent inhibitors that can overcome resistance to first-generation FGFR kinase inhibitors.

    Tan, Li; Wang, Jun; Tanizaki, Junko; Huang, Zhifeng; Aref, Amir R; Rusan, Maria; Zhu, Su-Jie; Zhang, Yiyun; Ercan, Dalia; Liao, Rachel G; Capelletti, Marzia; Zhou, Wenjun; Hur, Wooyoung; Kim, NamDoo; Sim, Taebo; Gaudet, Suzanne; Barbie, David A; Yeh, Jing-Ruey Joanna; Yun, Cai-Hong; Hammerman, Peter S; Mohammadi, Moosa; Jänne, Pasi A; Gray, Nathanael S


    The human FGF receptors (FGFRs) play critical roles in various human cancers, and several FGFR inhibitors are currently under clinical investigation. Resistance usually results from selection for mutant kinases that are impervious to the action of the drug or from up-regulation of compensatory signaling pathways. Preclinical studies have demonstrated that resistance to FGFR inhibitors can be acquired through mutations in the FGFR gatekeeper residue, as clinically observed for FGFR4 in embryonal rhabdomyosarcoma and neuroendocrine breast carcinomas. Here we report on the use of a structure-based drug design to develop two selective, next-generation covalent FGFR inhibitors, the FGFR irreversible inhibitors 2 (FIIN-2) and 3 (FIIN-3). To our knowledge, FIIN-2 and FIIN-3 are the first inhibitors that can potently inhibit the proliferation of cells dependent upon the gatekeeper mutants of FGFR1 or FGFR2, which confer resistance to first-generation clinical FGFR inhibitors such as NVP-BGJ398 and AZD4547. Because of the conformational flexibility of the reactive acrylamide substituent, FIIN-3 has the unprecedented ability to inhibit both the EGF receptor (EGFR) and FGFR covalently by targeting two distinct cysteine residues. We report the cocrystal structure of FGFR4 with FIIN-2, which unexpectedly exhibits a "DFG-out" covalent binding mode. The structural basis for dual FGFR and EGFR targeting by FIIN3 also is illustrated by crystal structures of FIIN-3 bound with FGFR4 V550L and EGFR L858R. These results have important implications for the design of covalent FGFR inhibitors that can overcome clinical resistance and provide the first example, to our knowledge, of a kinase inhibitor that covalently targets cysteines located in different positions within the ATP-binding pocket. PMID:25349422