Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.3.1.108 (TAT)
2,389 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activation of coagulation was studied during the peri-operative period in patients undergoing cardiopulmonary bypass (CPB) surgery using activation markers which have recently become available: prothrombin fragment F1 + 2 (F1 + 2), which is a measure of total thrombin generation, and thrombin-antithrombin complex, which is a measure of inactivation of free thrombin by antithrombin. Levels of the specific marker of fibrin breakdown, D-dimer, were also determined. F1 + 2 levels were assessed using a newly developed ELISA described herein which employs a neoantigen-specific capture antibody raised using a synthetic peptide; the latter antibody has been pre-adsorbed against prothrombin to ensure high specificity for F1 + 2. Increased generation of thrombin during surgery was clearly demonstrated despite maintenance of a high concentration of heparin during the period of extracorporeal blood circulation. There was a close association (r = 0.882) between the generation of thrombin (F1 + 2 levels) and its inhibition (TAT levels). Differences were noted, however, between the information provided by F1 + 2 and TAT, which are interpreted with regard to the different in vivo fates of F1 + 2 and thrombin. The enhanced activation and inhibition of coagulation observed during CPB was suppressed once physiological blood circulation was restored, with F1 + 2 returning to pre-surgical levels within 24 h after surgery. During the post-operative period D-dimer levels, which rose in concert with F1 + 2 and TAT levels, remained highly elevated, suggesting that not all of the generated thrombin was inactivated by antithrombin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Thrombin production, inactivation and expression during open heart surgery measured by assays for activation fragments including a new ELISA for prothrombin fragment F1 + 2. 823 30

The coagulation and fibrinolysis profile was evaluated in 40 patients with newly diagnosed untreated colorectal carcinoma (24 males, 16 females; 29 patients without and 11 patients with metastases). Fibrinogen, von Willebrand factor antigen, FVIII:C, thrombin-antithrombin III complex (TAT III), fibrin monomers (FM), plasminogen activator inhibitor-1 (PAI-1) and D-dimers were tested. None of the patients had clinical or laboratory evidence of serious hemorrhage or thrombosis. The results of global routine coagulation tests (aPTT, PT) were not significantly changed. Significant elevations were found for median fibrinogen, von Willebrand factor antigen, FVIII:C, TAT III and D-dimers, compared with a healthy reference group. These results confirm earlier reports of an enhanced level of both coagulation and fibrinolysis markers in carcinoma patients and might be helpful in trying to understand the impact of several relatively new sensitive coagulation and fibrinolysis parameters in colorectal cancer. Moreover the position of the coagulation/fibrinolysis balance might be an explanation for the elevated incidence of thrombotic events in patients with cancer.
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PMID:Evaluation of the coagulation/fibrinolysis balance in patients with colorectal cancer. 827 20

Pediatric patients with acute lymphoblastic leukemia (ALL) are at an increased risk of thromboembolic events. Potential responsible mechanisms include the disease process itself, treatment with chemotherapeutic agents (particularly L-Asparaginase [ASP]), or a combination of the disease and treatment. We studied thrombin regulation in 26 consecutive children with ALL and 14 healthy age-matched controls by: (1) plasma concentrations of prothrombin; (2) plasma inhibition of 125I-alpha-thrombin; and (3) four biochemical markers of in vivo thrombin activation (thrombin complexed to its inhibitor antithrombin III [ATIII; TAT], prothrombin fragment 1.2 (F1.2), activated protein C complexed to the inhibitors alpha 1 antitrypsin [APCAT]), and protein C inhibitor (APC-PCI). Measurements were made at presentation before treatment, after treatment with ASP alone, and during combination chemotherapy with and without ASP. At presentation, the capacity to generate thrombin (reflected by plasma prothrombin concentrations) and the capacity to inhibit thrombin (125I-alpha-thrombin--inhibitor complex formation) were similar in children with ALL compared with that for healthy children. After ASP alone or as part of combination chemotherapy, prothrombin levels were preserved, whereas plasma inhibition of 125I-alpha-thrombin decreased significantly because of a decrease in plasma concentrations of inhibitors, most importantly ATIII. After combination chemotherapy without ASP, plasma concentrations of ATIII and the capacity to inhibit 125I-alpha-thrombin returned to normal values, whereas prothrombin levels increased above control values. Thrombin generation in vivo also differed from healthy controls. At presentation, plasma concentrations of three of four markers of in vivo thrombin activity (TAT, F1.2, APCAT, but not APC-PCI) were increased in children with ALL. Neither ASP alone nor combination chemotherapy with or without ASP significantly altered values of these three markers. In summary, although the in vitro capacity to generate thrombin was preserved, the in vitro capacity to inhibit 125I-alpha-thrombin decreased after ASP therapy. Evidence for increased endogenous thrombin generation was documented in children with ALL at presentation and throughout treatment. We speculate that poor regulation of this thrombin may contribute to thrombotic complications in children with ALL.
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PMID:Increased endogenous thrombin generation in children with acute lymphoblastic leukemia: risk of thrombotic complications in L'Asparaginase-induced antithrombin III deficiency. 828 39

In 78 patients (47 men, 31 women; mean age 53 [22-78] years) 174 dialyses were undertaken within one week of a bleeding episode or a diagnostic or therapeutic procedure which may cause bleeding. Minimal anticoagulation with low molecular weight heparin (LMWH) was the aim, using a biocompatible dialyser. During the dialysis coagulation was controlled by global tests (Quick value/international normalized ratio [INR], partial thromboplastin time, thrombin time, antifactor Xa activity), by molecular markers of clotting activity (thrombin-antithrombin III complex [TAT], D-dimers), as well as measurement of elastase (elastase-alpha 1-protein inhibitor complex). The LMWH dosage averaged 932 units as an initial bolus and 234 units/h as a continuous infusion. In the group of chronic dialysis patients (n = 72) this meant (standard heparin units = 2/3 LMWH units) a reduction to 45 +/- 11% from the previously used routine heparin dosage for a 4-hour dialysis. All dialyses were completed without bleeding complications. Considerable clotting formation in the extracorporeal circulation occurred in 11 dialyses (6.3%). TAT, D-dimer and elastase values proved to be suitable for determining individual clotting activity and for reducing anticoagulation to the minimum.
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PMID:[Minimal heparinization in dialysis patients with increased risk of bleeding]. 828 77

Vascular heparan sulfate proteoglycan (vHSPG) is an important functional component of the microvasculature. Previous studies have demonstrated autoimmunity to vHSPG in systemic lupus erythematosus (SLE). In the current studies, we further investigated the immunospecificity of anti-vHSPG antibodies in SLE sera by enzyme-linked immunoassay (ELISA). In direct binding assays, SLE sera contained IgG antibodies reactive with native vHSPG and with heparan sulfate (HS) glycosaminoglycan in significantly higher titers than controls. Employing purified SLE IgG in liquid-phase competitive immunoinhibition ELISAs, SLE IgG anti-HS antibodies cross-reacted with heparin and DNA, but not with other glycosaminoglycans or anionic phospholipid antigens. Immunochemical studies demonstrated that the immunodominant site on HS recognized by SLE IgG contained 2-O-sulfated uronic acid. Removal of N-sulfated and 6-O-sulfated residues primarily on N-acetyl-glucosamine had no effect on antigenicity, further demonstrating that nonspecific charge interactions which are the result of sulfation do not solely account for the antigenicity of HS. SLE IgG from patients with active SLE was further affinity purified on DNA-cellulose and HS-Sepharose columns for immunospecificity studies. After affinity purification of both anti-DNA and anti-HS antibodies, significant enhancement of direct binding reactivity with HS was noted. In addition, anti-DNA and anti-HS IgG antibody reacted with the cell surface of endothelial cells by a cellular ELISA (CELISA). Immunoinhibition studies of CELISA reactivity confirmed that affinity-purified SLE IgG anti-DNA anti-HS antibody were reactive with endothelial cell surface HS antigens. Furthermore, SLE IgG anti-DNA antibody reactivity with endothelial cells was not reduced by DNase treatment of the cells, but was significantly reduced by heparitinase digestion. Since HS plays an important role in the maintenance of normal anticoagulation on the endothelial cell surface by binding antithrombin III, we investigated the inhibition of heparin-accelerated thrombin-antithrombin III complex formation by SLE IgG. Purified IgG from patients with active SLE, but not from normal controls, inhibited heparin-accelerated formation of TAT complexes. These studies demonstrate the presence of IgG autoantibodies to HS in patients with SLE. Anti-HS antibodies recognize an antigenic site also present in heparin, but not other glycosaminoglycans, bind to the endothelial cell surface, and inhibit the formation of TAT complexes. SLE IgG anti-HS antibodies recognize a sulfated uronic acid epitope containing 2-O-sulfate which is important in certain functions of HS, including antithrombin III binding. Thus, anti-HS antibodies may promote a procoagulant state at the endothelial cell surface.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Autoantibodies to vascular heparan sulfate proteoglycan in systemic lupus erythematosus react with endothelial cells and inhibit the formation of thrombin-antithrombin III complexes. 829 26

This study was designed to elucidate the participation of endothelin-1(ET-1) in vivo and in vitro coagulation. The microvascular hemodynamic changes in terms of intravascular thrombus formation in rat mesentery induced by the superfusion of ET-1 (0.5, 1 and 2 pmol) were visualized by an intravital microscope system assisted by television-video tape recorder system. In addition to vasoconstriction we observed the blockade of circulation by clumps resembling thrombus in a dose dependent fashion by ET-1. Thrombus formation could be attenuated by pretreatment with superfusion of 3.8% Na citrate solution but not by the prior superfusion of 1 to 3 ng of nitroglycerine. Thrombus formation was found after the administration of 10 microliters of CaCl2 (100 nM) solution in Na citrate (3.8%, 20 microliters) and ET-1 treated field. In vitro study, a dose dependent increase in TAT (thrombin-antithrombin complexes) and decrease in AT III (antithrombin III) (%) activity, the prolongation of PT (prothrombin time) and APTT (activated partial thromboplastin time) was found by administering ET-1 immediately in native (unanticoagulated) blood in silicon coated test tubes (p < 0.05; n = 6). However in citrated blood, TAT complexes, AT III (%) activity, PT and APTT were not significantly changed after administration of the same doses of ET-1 (p > 0.05; n = 6). Therefore, this study suggested that endothelin-1 caused intravascular thrombosis and enhanced intra test tube coagulation which could be attenuated by blocking ionic calcium.
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PMID:Coagulation in vivo microcirculation and in vitro caused by endothelin-1. 830 59

Numerous attempts to predict the hazard of bleeding during therapeutic fibrinolysis by means of the analysis of parameters for coagulation or fibrinolytic systems have failed to produce reliable results. In the near future the measurement of markers of enhanced thrombin activity TAT, FPA and, to a lesser extent, F1+2 may provide an important non-invasive diagnostic tool with satisfactory reliability for the prediction of thromboembolic events or rethrombosis after successful recanalization by thrombolytic therapy. Measurement of fibrin(ogen) degradation products, such as D-dimers, FbDP and FgDP may provide important help for the diagnosis of thromboembolic events or the danger of reocclusion, though they still lack specificity and are therefore unsuitable as the solely base for diagnosis or therapeutic decisions. Efficient control of anticoagulation with heparin is practicable through the measurement of aPTT. For the prevention of artifacts correct collection and processing of blood samples is mandatory; sample tubes must contain inhibitors of fibrinolytic action such as PPACK or aprotinin.
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PMID:[Laboratory monitoring of thrombolytic therapy in clinical practice and research]. 832 90

We investigated whether different procedures during general anaesthesia alter platelet activation in vivo and/or activate coagulation and fibrinolysis. Forty-one healthy adult patients, scheduled for elective ophthalmic surgery under general anaesthesia, were studied with regard to changes of plasma beta-thromboglobulin (beta TG, index of platelet activation), thrombin-antithrombin III-complex (TAT, index of activation of coagulation) and d-dimer (index of fibrinolysis) during anaesthesia. The patients underwent either inhalation anaesthesia with enflurane and nitrous oxide or balanced anaesthesia with enflurane (0.5% end-tidal concentration) and alfentanil. Ten minutes after intubation the beta TG level was significantly reduced compared to the preoperative value in both general anaesthesia groups. Balanced anaesthesia caused a moderate but significant increase of TAT values at 10 min after extubation. No significant change in d-dimer levels was seen. Presuming a minimal effect of the surgical procedure on the determined variables, we conclude that none of the anaesthetic procedures induces platelet activation and fibrinolysis. The clinical relevance of the moderate coagulation activation during balanced anaesthesia remains to be investigated.
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PMID:The influence of different procedures of general anaesthesia on platelet function, coagulation and the fibrinolytic system. 835 63

The early stage of the state in which coagulation or fibrinolytic pathway is activated has been difficult to be estimated. Recently, it has become possible to detect an early stage of DIC (pre-DIC) due to the development of highly sensitive methods which quantitate so called "molecular markers". Molecular markers can be classified into three groups: 1) activation fragments of coagulation proteins (e.g. F1+2); 2) protease and its inhibitor complex (e.g. TAT, IXa-AT-III, Xa-AT-III and PIC); 3) degradation products (e.g. FPA, FPB beta, SFMC and D-dimer). Among them, F1+2, TAT, FPA and SFMC reflect in vivo thrombin generation, while PIC, FPB beta and D-dimer reflect in vivo plasmin generation. IXa-AT-III and Xa-AT-III may be useful markers to detect hypercoagulable states in an earlier stage of underlying various disorders. Measurement of circulating levels of the zymogens and protease inhibitors is unable to detect small changes caused by low grade DIC or localized thrombotic events. Monitoring plasma levels of molecular markers, however, gives us more specific and accurate information regarding the onset and time course of hypercoagulable states and enable us to diagnose DIC at an early stage and to evaluate the effect of treatment for patients with DIC, specifically.
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PMID:[Diagnosis of predictive state of disseminated intravascular coagulation]. 843 31

In order to predict a hypercoagulable state in patients with advanced breast cancer receiving medical treatment, the effects of chemoendocrine therapy on the coagulation-fibrinolytic systems were investigated prospectively. The patients were randomly divided into two groups. The ACT group had 38 patients, who received 20 mg/m2 adriamycin (ADM) i.v. on days 1 and 8, 100 mg cyclophosphamide (CPA) p.o. on days 1-14, and 20 mg tamoxifen (TAM) p.o. daily. The ACM group had 44 patients, who received 20 mg/m2 ADM i.v. on days 1 and 8, 100 mg CPA p.o. on days 1-14 and 1200 mg medroxyprogesterone acetate (MPA) p.o. daily. The treatment was repeated every 28 days until there was evidence of progressive disease or until the full ADM dose (550 mg/m2) had been given. The following 9 hematologic parameters were measured every 4 weeks: alpha 2-plasmin inhibitor plasmin complex (PIC), anti-thrombin-III (AT-III), D-dimer (Dd), fibrinogen (Fg), plasminogen (Pg), protein C (PC), thrombin-antithrombin-III complex (TAT-III), tissue plasminogen activator (t-PA), and factor X (FX). Compared to the ACT group, patients in the ACM group showed significantly higher values of AT-III and PC, which exceeded the normal ranges. The levels of Pg, t-PA and FX were significantly higher in the ACM group than in the ACT group, but were still within the normal ranges. The levels of TAT-III, Dd and PIC decreased in the ACT group and were unchanged in the ACM group after the start of treatment. Fg remained unchanged in both groups after the start of treatment. One patient in the ACM group had thrombophlebitis of the lower extremities with high levels of TAT-III, Dd and PIC and a decrease of Fg, but her condition returned to normal after reduction of the MPA dose. Although these data are not directly indicative of a hypercoagulable state in patients receiving chemoendocrine therapy, changes in AT-III, TAT-III, Dd and PIC should be monitored carefully when this type of treatment is given.
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PMID:Effects of chemoendocrine therapy on the coagulation-fibrinolytic systems in patients with advanced breast cancer. Japan Advanced Breast Cancer Study Group and Japan Clinical Oncology Group. 851 13


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