Search results for "Thrombin"
showing 10 items of 201 documents
Anticoagulation with argatroban for elective percutaneous coronary intervention: population pharmacokinetics and pharmacokinetic-pharmacodynamic rela…
2010
The synthetic direct thrombin inhibitor argatroban has a rapid onset and offset of anticoagulation. However, there are no data about the pharmacokinetic-pharmacodynamic (PK-PD) relationship of argatroban in patients undergoing contemporary percutaneous coronary intervention (PCI) and no data about other coagulation parameters than activated clotting time (ACT) in this setting. In the ARG-E04-trial, 140 patients were randomly assigned to argatroban (250, 300, or 350 μg/kg as bolus before PCI, followed by 15, 20, or 25 μg/kg/min infusion) or unfractionated heparin (70-100 IU/kg bolus). A 2-compartment model with first-order elimination adequately described the pharmacokinetic profile of argat…
Mapping the fluorophilicity of a hydrophobic pocket: synthesis and biological evaluation of tricyclic thrombin inhibitors directing fluorinated alkyl…
2006
In the completion of our fluorine scan of tricyclic inhibitors to map the fluorophilicity/fluorophobicity of the thrombin active site, a series of 11 new ligands featuring alkyl, alkenyl, and fluoroalkyl groups was prepared to explore fluorine effects on binding into the hydrophobic proximal (P) pocket, lined by Tyr 60A and Trp 60D, His 57, and Leu 99. The synthesis of the tricyclic scaffolds was based on the 1,3-dipolar cycloaddition of azomethine ylides, derived from L-proline and 4-bromobenzaldehyde, with N-(4-fluorobenzyl)maleimide. Introduction of alkyl, alkenyl, and partially fluorinated alkyl residues was achieved upon substitution of a sulfonyl group by mixed Mg/Zn organometallics f…
A Fluorine Scan at the Catalytic Center of Thrombin: CF, COH, and COMe Bioisosterism and Fluorine Effects on pKa and logD Values
2006
A series of 16 tricyclic thrombin inhibitors was prepared by using the 1,3-dipolar cycloaddition of azomethine ylides derived from 3- or 4-hydroxyproline and 4-bromobenzaldehyde, with N-(4-fluorobenzyl)maleimide as the key step. The terminal pyrrolidine ring of the inhibitors was systematically substituted to explore the potential bioisosteric behavior of C-F, C-OH, and C-OMe residues pointing into the environment of the catalytic center of a serine protease. X-ray crystal structure analyses revealed a distinct puckering preference of this ring. Substitution by F, HO, and MeO has a strong effect on the basicity of the adjacent pyrrolidine nitrogen center which originates from two sigma-indu…
Thrombin generation - a potentially useful biomarker of thrombotic risk in Philadelphia-negative myeloproliferative neoplasms.
2017
The diagnosis of essential thrombocythemia and polycythemia vera is often made during a thrombotic event which can be serious. Philadelphia-negative chronic myeloproliferative neoplasia patients have an increased thrombotic risk. This is assessed using various scoring systems but these are far from ideal and individual risk. The currend trend to personalised medicine requires finding the most useful thrombotic risk biomarker in these patients. Routine tests for coagulation do not take account of both pro- and anti-coagulant factors which is why these tests are not useful in patients with Philadelphia-negative myeloproliferative neoplasms. Thrombin generation reflects more accurately the bal…
Clinical Applications, Pitfalls, and Uncertainties of Thrombin Generation in the Presence of Platelets
2019
Platelet-dependent thrombin generation is a helpful tool to assess ex vivo the interaction between platelets and plasma coagulation factors in the initiation, amplification, and inhibition of thrombin generation (TG). This review article discusses the most relevant available data on the clinical applications of fluorogenic TG, the most widely used TG assay, performed in the presence of platelets, i.e., in platelet-rich plasma. With respect to prothrombotic states, arterial hypertension and obesity were the most prominent cardiovascular conditions linked to increased platelet-dependent TG. In addition, platelet-associated hypercoagulability, assessed by the TG assay, has been shown in indivi…
Scalable Bio Marker Combinations for Early Stroke Diagnosis: A Systematic Review
2021
Background: Acute stroke treatment is a time-critical process in which every minute counts. Laboratory biomarkers are needed to aid clinical decisions in the diagnosis. Although imaging is critical for this process, these biomarkers may provide additional information to distinguish actual stroke from its mimics and monitor patient condition and the effect of potential neuroprotective strategies. For such biomarkers to be effectively scalable to public health in any economic setting, these must be cost-effective and non-invasive. We hypothesized that blood-based combinations (panels) of proteins might be the key to this approach and explored this possibility through a systematic review.Metho…
Abstract 147: The Role of Thrombin Generation in Cardiovascular Disease and Mortality - Results from the Population-based Gutenberg Health Study
2018
Background: Thrombin formation is one of the key enzymatic processes that direct the activity of the hemostatic system. Thrombin generation (TG), a method addressing the overall potential of a given plasma sample to form thrombin, may be a potential tool to improve risk stratification for cardiovascular diseases (CVD). This study aims to explore the relation between TG and cardiovascular risk factors (CVRFs), CVD, and total mortality. Methods: For this study, N=5000 subjects from the population-based Gutenberg Health Study were analyzed in a highly standardized setting. TG was measured by the Calibrated Automated Thrombogram method at 1 and 5 pM tissue factor (TF) trigger in platelet poor …
Adverse Events in Treatment of Inherited Factor VII Deficiency: Final Analysis of the STER
2012
Abstract Abstract 2279 Introduction No evidence-based guidelines are available for the treatment of Factor VII deficiency. Replacement therapy (RT) is still influenced by different factors as rarity of the disorder, availability and supply of products and economic reasons. All RTs are not exempt of side effects and scanty data is available about the safety of the products currently used. Aim of this study was to analyze adverse events (AEs) of RTs for congenital Factor VII deficiency, as reported in Seven Treatment Evaluation Registry (STER). Design and Methods FVII deficiency patients treated for bleeding episodes, prophylaxis, and surgery were investigated for RT-related AEs over a period…
Permeabilit�ts�nderungen durch Dicumarol unabh�ngig von �nderungen der Prothrombinzeit
1950
Bei Mausen wurde nach Dicumarol per os in Dosen von 0,05–1 mg/g zirka 1–25 Std nach der Dicumarol-Gabe die Prothrombinzeit bestimmt und kurz danach die Odembildung der Hinterbeine bei der Durchstromung mit Tyrodelosung untersucht. In den meisten Fallen war innerhalb der ersten 7 Std die Prothrombinzeit unverandert, dagegen war eine erhohte Kapillarpermeabilitat eingetreten. Von 11 Std aufwarts war die Prothrombinzeit fast immer erhoht, wahrend die Gefaspermeabilitat in der Mehrzahl der Falle nicht mehr erhoht war. Nach akut nicht todlich wirkenden Gaben von 0,1–0,3 mg/g Dicumarol war die Permeabilitat nach Ablauf von 7 Std in der Mehrzahl der Falle sogar vermindert. Aus den Versuchen ist zu…
Sodium/hydrogen exchange inhibition with cariporide reduces leukocyte adhesion via P-selectin suppression during inflammation
2008
Background and purpose: The Na+/H+ exchange (NHE) inhibitor cariporide is known to ameliorate ischaemia/reperfusion (I/R) injury by reduction of cytosolic Ca2+ overload. Leukocyte activation and infiltration also mediates I/R injury but whether cariporide reduces I/R injury by affecting leukocyte activation is unknown. We studied the effect of cariporide on thrombin and I/R induced leukocyte activation and infiltration models and examined P-selectin expression as a potential mechanism for any identified effects. Experimental approach: An in vivo rat mesenteric microcirculation microscopy model was used with stimulation by thrombin (0.5 μ ml−1) superfusion or ischaemia (by haemorrhagic shock…