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:3.4.21.6 (thromboplastin)
13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied the effects of FR-860 on coagulative and fibrinolytic activities in human plasma compared to conventional unfractionated heparin (UF-heparin). Both FR-860 and UF-heparin dose-dependently prolonged the recalcification time, activated partial thromboplastin time, prothrombin time, factor Xa (F.Xa) clotting time and thrombin time. These effects of FR-860 were weaker than that of UF-heparin. FR-860 showed equipotent efficacy on the anti-F.Xa activity, and weak antithrombin activity compared to UF-heparin. FR-860 had no effects on the activity of ATIII and fibrinolytic activity. UF-heparin shortened the urokinase-activated euglobulin lysis time and showed antiplasmin activity, but did not influence the activities of ATIII, plasminogen and alpha 2-plasmin inhibitor. UF-heparin decreased the fibrinogen level at higher doses. These efficacies of FR-860 were weaker than that of UF-heparin. These results suggest that FR-860 is more efficient and lower in bleeding risk than UF-heparin in clinical use.
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PMID:[Effects of low molecular weight heparin (FR-860) on coagulative and fibrinolytic activities]. 261 5

To investigate causes of the age-dependent increase of thromboembolic events, plasma coagulation parameters were determined in healthy elderly blood donors in comparison with young, and elderly diseased blood donors. Partial thromboplastin and thrombin clotting times were slightly shortened, whereas prothrombin and reptilase clotting times were unaltered. Plasma concentration of clotting factors like F I, VII, VIII: C, X, HMW-kininogen and prekallikrein were increased, whereas the coagulation inhibitor antithrombin III was decreased. Concerning fibrinolysis, plasminogen and alpha-2-antiplasmin were not affected by age, but plasminogen activators in the euglobulin fraction were lower. This shift in the pattern of coagulation factors favors enhanced fibrin formation and delayed fibrinolysis in the elderly. Higher intermediary products demonstrate that activation of coagulation and fibrinolysis happen more often in elderly healthy people. Together with blood stasis and vessel wall damage, this shift of the hemostatic balance contributes to a higher incidence of thromboembolic disorders in the aged.
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PMID:Blood coagulation factors in the elderly. 264 86

Three commercial thrombin preparations used clinically to stop topical bleeding were studied. The specific activities of these preparations were 1,064 U/mg (human); 59 U/mg (bovine) and 147 U/mg (bovine). SDS-PAGE analysis of the human product produced one major band corresponding to a molecular weight of alpha-thrombin and one minor band. The bovine preparations produced several bands in addition to the alpha-thrombin band. One of bovine preparations had the highest amidolytic activity toward synthetic substrates S-2238 and S-2251 and also showed fibrinolytic activity when tested with the plasminogen-free fibrin plate method. Immunological analysis revealed that one preparation (human origin) contained immunoglobulin G, hepatitis B surface (HBs) antibody and human immunodeficiency virus (HIV) antibody. All of the preparations maintained more than 80% of their proteolytic activity for six hours when dissolved in physiological saline solution. It was found that the product A (bovine origin) was the best from the viewpoints of the specific activity, the stability and the purity which was free from factor Xa and plasmin.
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PMID:A study on the properties of commercial thrombin preparations. 265 60

As part of a European multicentre prospective study involving the measurement of a number of haemostatic factors, a quality assessment (QA) scheme was organized. This paper describes the preparation, design and results of the first QA exercise, involving 16 European laboratories and 10 haemostatic assays. The design allowed the investigation, for each assay, of the variability between duplicates and the variability between days within each centre, and of the agreement between centres. A graphical presentation of each centre's performance in comparison to that of others was adopted, which preserved the confidentiality of each centre's results. The factor VIII clotting activity assay (VIII:C) and the rocket immuno-electrophoresis assays of von Willebrand factor related antigen (vWF R:Ag), antithrombin III, protein C and histidine-rich glycoprotein showed the highest between-duplicate and between-day coefficients of variation (CVs), whereas the clotting assays of activated partial thromboplastin time and fibrinogen had the lowest CVs. CVs for the enzymatic assays using synthetic substrates of antithrombin III, plasminogen and alpha-2-antiplasmin were between these extremes. The between-centre CVs were high for both the VIII:C and vWF R:Ag assays. The QA exercise showed that, in multicentre studies involving the measurement of haemostatic factors, it is feasible to undertake analysis locally at each centre.
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PMID:The measurement of haemostatic factors in 16 European laboratories: quality assessment for the Multicentre ECAT Angina Pectoris Study. Report from the European Concerted Action on Thrombosis and Disabilities (ECAT). 266 75

Although the specific anticoagulant activity of dermatan sulphate is seventy times less than that of standard heparin, its venous antithrombotic activity, tested on a great number of experimental models, appears at gravimetric doses which are only seven fold higher. This antithrombotic activity is not correlated with the factor Xa inhibition, but is associated with thrombin generation inhibition and potentiation of heparin cofactor II. Meanwhile, others factors, still non entirely identified, i.e. like the release of endogenous tissue plasminogen activators, must probably be involved in the antithrombotic activity of dermatan sulphate. In contrast to heparin, dermatan sulphate possesses hemorrhagic properties only at doses which are forty times higher than the antithrombotic dose. These hemorrhagic properties seem associated with an inhibition of collagen induced platelet aggregation. Finally, the pharmacokinetic profile of dermatan sulphate after intravenous injection in the rabbit, is different from that of standard heparin, and close to that of low molecular weight heparins.
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PMID:[Dermatan sulfate and the prevention of experimental venous thrombosis]. 267 77

Eighty patients undergoing total hip replacement (THR) were randomly allocated to three groups. Group I (n = 29) received general anaesthesia, Group II (n = 29) epidural anaesthesia and Group III (n = 22) the same epidural as Group II and the same general anaesthesia as Group I but with a lower isoflurane concentration. Prothrombin time (PT), activated thromboplastin time (APTT), fibrinogen (FG), plasminogen (PG), antithrombin III (AT III), protein C (Proc C), alpha-2-antiplasmin (alpha 2AP), Factor VIII coagulating activity (F VIII:C), von Willebrand factor antigen (vWF:Ag), von Willebrand ristocetin cofactor (vWF:Rcof), tissue plasminogen activator (tPA) as antigen and activity were measured before induction (A), at the end of surgery (B), on the first postoperative morning (C) and 7 days postoperatively (D). The most relevant finding was that AT III was equally depressed immediately after surgery in all groups, but returned to normal significantly faster in the epidural group (mean values at C: 96.2% in Group I, 104.1% in Group II, 92.7% in Group III). The faster return to normal of AT III after epidural anaesthesia could be one of the mechanisms responsible for the beneficial effect of this technique on the prevention of thromboembolic complications.
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PMID:Coagulation and fibrinolytic parameters in patients undergoing total hip replacement: influence of the anaesthesia technique. 268 46

There is uncertainty as to which preoperative examinations are necessary before performing regional anesthesia. Therefore an interdisciplinary consensus conference was established to obtain recommendations on some of the open questions related to this topic. Preoperative laboratory examinations are not necessary prior to peripheral nerve blocks near large vessels if these are easy to compress. In patients on anticoagulant therapy direct puncture of the vessel should be avoided. Prior to spinal or epidural anesthesia, no preoperative laboratory examinations are necessary if no anamnestic or clinical evidence of coagulation disorders exists. Otherwise the following examinations are useful: clotting time, prothrombin time, partial thromboplastin time (PTT), and thrombocyte count. Low-dose heparin prophylaxis is no contraindication to spinal or epidural anesthesia. However, in patients at increased risk of bleeding or with low body weight, PTT and thrombocyte count are necessary. Since at present no definite data exist as to the bleeding risk in patients treated with low-molecular-weight heparin prophylaxis, spinal/epidural anesthesia should be performed in controlled studies only under these conditions. This particular precaution seems to be necessary because low-molecular-weight heparin increases levels of plasminogen activators (t-PA) and therefore has fibrinolytic activity. If plasma expanders are administered perioperatively, the highest bleeding risk exists after dextran infusions. There is also an increased bleeding risk if nonsteroidal anti-inflammatory drugs, especially acetylsalicylic acid, are administered repeatedly within 5 days prior to spinal/epidural anesthesia. In these patients preoperative determination of the clotting time appears necessary.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Hemostatic requirements for the performance of regional anesthesia. Workshop on hemostatic problems in regional anesthesia]. 268 21

It is thought that a hypercoagulable state contributes to the pathogenesis of coronary artery disease (CAD), but few sensitive markers have been available for detecting the state. In the present study the plasma level of thrombin-antithrombin III complex (TAT), a specific indicator of thrombin generation in blood, was investigated before and after a submaximal exercise test in 18 patients with CAD and in 12 healthy controls. The mean (+/- SEM) value of plasma TAT before the exercise was 3.30 (0.81) ng/ml in the patient group and 1.49 (0.08) ng/ml in controls, and its level increased to 29.22 (5.74) ng/ml and 12.07 (2.89) ng/ml after the exercise, respectively. Thus, the TAT value in the patient group was higher than that in the controls both before and after the exercise. However, no differences could be found between the groups in the following parameters; prothrombin time, activated partial thromboplastin time, antithrombin III, fibrinogen, FDP, plasminogen, alpha 2-plasmin inhibitor, and alpha 2-macroglobulin. Through these results it was concluded that plasma TAT level could be a sensitive marker for latent activation of blood coagulation, and also that the results of these experiments showed that patients with CAD were in a latent hypercoagulable state.
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PMID:Application of thrombin-antithrombin III complex for detecting a latent hypercoagulable state in patients with coronary artery disease. 269 50

In addition to its antiplatelet effect, aspirin has been reported to have fibrinolytic and hypoprothrombinemic effects. The objective of this study was to investigate possible mechanisms underlying the enhanced fibrinolysis after aspirin. Five healthy subjects received 650 mg of aspirin every 12 hr for 5 days. Blood samples were collected before aspirin (control), and immediately before (0 hr) and 2 hr after (2 hr) the last dose for determinations of clot lysis time, time course of thrombin-induced fibrin aggregation, tissue plasminogen activator activity, intrinsic pathway fibrinolytic activity, plasminogen, fibrinogen, aspirin and salicylic acid, and the coagulation tests activated partial thromboplastin time, thrombin time and prothrombin time. Clot lysis time was shorter after aspirin, control: 9.1 +/- 12.4 min (mean +/- S.D.); 0 hr: 4.6 +/- 4.0 min; 2 hr: 5.7 +/- 6.2 min (P: .04) and the fibrin aggregation curves showed increased relative absorbance at 10 min, control: 8.4 +/- 2.2; 0 hr: 11.2 +/- 0.2; 2 hr: 13.3 +/- 5.4 (P: .02). Control values of tissue plasminogen activator (0.11 +/- 0.04 IU/ml), intrinsic pathway fibrinolytic activity (2.20 +/- 0.54 IU/ml), plasminogen (10.9 +/- 1.0 mg/dl), fibrinogen (288 +/- 37 mg/dl) and the coagulation tests were not different from those after aspirin. Aspirin concentration was below detection limits at 0 hr and 1.63 +/- 0.97 micrograms/ml at 2 hr, whereas salicylic acid concentration was 55.0 +/- 35.8 and 136 +/- 71.9 micrograms/ml at 0 and 2 hr, respectively. In vitro studies using fibrinogen-free plasma and added acetylated fibrinogen showed an inverse relationship between the extent of acetylation and clot lysis time.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Aspirin acetylates fibrinogen and enhances fibrinolysis. Fibrinolytic effect is independent of changes in plasminogen activator levels. 274 95

The clinical course of a patient presenting with thrombocytopenia (86 X 10(3)/L) and signs of intravascular coagulation (prothrombin time, 45%; partial thromboplastin time, 49 s; fibrinogen, 40 mg/dl; antithrombin III, 85%; factor X, 73%; plasminogen, 42%) due to a giant hemangioma of the liver (Kasabach-Merritt syndrome) is reported. Treatment with i.v. heparin, fibrinogen, and fresh-frozen plasma led to significant elevation of fibrinogen (156 mg/dl) and antithrombin III (102%) without changing the decreased activities of the procoagulant factors. Similarly, the signs of hyperfibrinolysis persisted (fibrinogen degradation products, 50 micrograms/dl; plasminogen, 43%; alpha-2 antiplasmin, 74%). The hemangioma was completely removed by excision of the left lobe of the liver. Subsequently, all coagulation parameters returned to normal, indicating a complete reversibility of the coagulation disorder.
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PMID:Giant hemangioma of the liver (Kasabach-Merritt syndrome): successful suppression of intravascular coagulation permitting surgical removal. 275 23


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