Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.5 (thrombin)
 33,306 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The potential differences in hematologic profiles of blood samples drawn simultaneously from the right utero-ovarian vein and from the upper extremity were investigated in four patients with uncomplicated molar pregnancy in stable obstetric conditions. The patients had undergone no previous chemotherapy and were scheduled for total abdominal hysterectomies. The dominant abnormalities in uterine venous blood were prolongation of thrombin time; shortening of activated partial thromboplastin time; positive protamine sulfate test; and increase in coagulation factors II and VII, with a tendency to low values in factor V. Peripheral samples gave almost parallel results in all altered and normal tests, except in one case with very striking differences in factors II, V, VII and X. Several local and systemic influences are discussed. It is concluded that molar pregnancy seems to have important systemic mechanisms affecting the stability of the blood coagulation homeostasis, which act in addition to those at a local level.
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PMID:Uterine and peripheral hematologic profiles in molar pregnancy. 3 41

An 'artificial' plasma for one-stage factor-VIII assays is made by incubating human plasma with EDTA, to destroy factor VIII, and afterwards removing the anticoagulant by dialysis. Bovine factor V is then added to a given level. In the assay, contact activation is controlled by adding contact product. It was confirmed that factor-VIII activity was destroyed and that the EDTA was freely dialysable. The fibrinogen in the treated plasma clotted normally with thrombin. Likely variation in the factor-V activity was found not to be critical. The concentration of fibrinogen and other factors was adequate. Variation between batches was small. The artificial plasma yielded assay results closely comparable to haemophilic plasma in samples with factor-VIII activities in the range 0.01--20.0 iu/ml; the mean results in the artificial system were estimated to be 0.997 x those in haemophilic plasma, with a 95% confidence interval of 0.901--1.103. Biological variability in individual assays was smaller in the artificial system than when haemophilic plasma was used. Instability at the bench was more often detected in the artificial system than in haemophilic plasma assays, but the effect was eliminated from the results by obtaining duplicated readings in a balanced order.
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PMID:An artificial 'haemophilic' plasma for one-stage factor-VIII assay. 10 60

With human urine a very active procoagulant is excreted which converts prothrombin into thrombin in the presence of factor V, phospholipids and calcium chloride. In kidney diseases, its excretion is considerably reduced or totally absent. A negative correlation exists between these diseases and protein excretion. Kidney transplantation results in a normalization, however showing a trend which is not always parallel with the normalization of the blood creatinine levels. During the post-transplantation period, an occasional temporary, but very clear reduction with abnormal values of the kidney function tests can be observed. It is presumed that the procoagulant excretion could represent a hitherto unexplored function of the tubuli.
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PMID:[On the normalization of the content of human urine of procoagulant after renal transplantation (author's transl)]. 34 13

A prospective study of hemostatic abnormalities in 108 cancer patients was undertken at an oncology clinic in a university teaching hospital. Tests included Quick prothrombin time, activated partial thromboplastin time, thrombin time, platelet count, modified Ivy bleeding time, fibrinogen, fibrin degradation products (FDP), euglobulin lysis time, protamine sulfate test, and factor V, VII, VIII and X assays. Ninety-eight per cent of the patients had one or more abnormal coagulation tests. The commonest abnormalities were elevated fibrin degradation products and prolonged thrombin time. Thrombocytosis occurred in 57% of patients, hyperfibrinogenemia in 46%, thrombocytopenia in 11%, and non had hypofibrinogenmia. It is suggested that platelet count, fibrinogen concentration, and serum FDP assay are the most useful tests in assessing the hemostatic abnormalities in cancer patients, although thrombin time, factor V assay, and bleeding time may also be helpful. The peripheral blood smears of 53 patients were reviewed, and only one showed microangiopathic hemolytic anemia. The data illustrate that subclinical coagulopathy is relatively frequent in patients with malignancy.
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PMID:Hemostatic abnormalities in malignancy, a prospective study of one hundred eight patients. Part I. Coagulation studies. 42 Jan 61

Factor V was isolated from human citrate plasma by very mild purification steps. Cryoprecipitation, fractionation with polyethylene glycol 6000, gel filtration of AcA 44 and adsorption of haptoglobin to immobilized hemoglobin were applied successively, resulting in factor V preparations with a specific activity of 14.5 unit/mg. The yield was 28 percent. A molecular weight of 296 000 was determined by gel filtration and the apparent sedimentation constant found by ultracentrifugation in a sucrose gradient was 7.8 S. Parallel experiments with citrate plasma resulted in the same molecular weight and sedimentation constant. Polyacrylamide gel electrophoresis of factor V in the presence or absence of sodium dodecyl sulfate showed a single protein band. Incubation with human thrombin resulted in an 8-fold activation of the purified factor V.
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PMID:Isolation and partial characterization of human factor V. 45 68

A comparative study on the coagulant activity of snake venoms was carried out in 26 Bothrops species, using specific clotting systems for the thrombin-like and the factor X-activator activities. With only two exceptions (B. erythromelas and B. castelnaudi) all venoms showed thrombin-like activity, since they were able to clot fibrinogen directly. The absence of thrombin-like action of B. erythromelas venom is due to a fibrinogenolytic effect. Five venoms (B. atrox asper, B. bilineatus bilineatus, B. cotiara, B. fonsecai and B. itapetiningae) were unable to produce a prothrombin activator when preincubated with serum, factor V, and phospholipid. None of the venoms seems to require factors VII, VIII, IX, XII and XIII for their complete coagulant action. Direct prothrombin activation was observed in most of the Bothrops venoms, alone or combined with thrombin-like and factor X-activator activities. An anticoagulant activity was exhibited by B. castelnaudi venom, probably due to an anti-Xa action. This study points out that the coagulant activity of snake venoms varies within the same genus and must be characterized for each species. Thus, in Bothrops venoms the thrombin-like and factor X-activator components are not always associated, the coagulant effect may be related only to one of the components.
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PMID:Thrombin-like and factor X-activator components of Bothrops snake venoms. 47 15

Factor V (Va) is essential for binding of factor Xa to the surface of platelets. After thrombin treatment, normal platelets release at least five times more factor Va activity than is required for maximal factor Xa binding. The concentration of factor V activity obtained after thrombin stimulation of 10(7) normal platelets is sufficient to allow half-maximal factor Xa binding to 10(8) platelets (10% normal, 90% factor-V deficient). Therefore, factor Va activity is not limiting in platelet-surface factor Xa binding and prothrombin activation in normal platelets; some other components limit the number of binding sites. We report studies of a patient (M.S.) with a moderate to severe bleeding abnormality whose platelets are deficient in the platelet-surface component required for the factor Va-factor Xa binding. The patient's platelet factor Va activity released after thrombin treatment is normal, but factor Xa binding is 20%-25% of control values at saturation. Abnormal prothrombin consumption in a patient with normal plasma coagulation factors and platelet function suggests a disorder in platelet-surface thrombin formation.
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PMID:Deficiency of factor Xa-factor Va binding sites on the platelets of a patient with a bleeding disorder. 49 93

Evidence of developmental evolution of coagulation can be seen when the studies of 10 thriving extremely premature (EPT) infants are compared to normal full-term (FT) infants. The prothrombin time, partial thromboplastin time, and thrombin time all became shorter with increasing gestational age. Fibrinogen levels and platelet counts appear to be comparable to term infant and adult levels. Fibrin degradation products (FDP) of 10 micrograms/ml or less were found in the thriving EPT infants. When compared to healthy full-term infants, there is a definite gestational dependency of anti-thrombin III levels. Factors II and VII appear to be related to intrauterine maturation after the age of viability (24 wk), but factor VII-X complex does not. The contact factors XI, XII, high molecular weight kininogen (Fitzgerald factor), and prekallikrein (Fletcher factor) are all markedly decreased in thriving EPT infants. The mean factor V level is lower than that found in FT infants. This study confirms a gestational age dependency of factor VIII activity. The ratio of factor VIII antigen to factor VIII clotting activity is increased (2.8 vs 1.01 in FT and adults). Thriving small for gestational age (SGA) infants had coagulation studies which were not statistically different from those of thriving EPT infants. The coagulation changes which occurred in severely ill EPT were mainly in the factors which decrease during intravascular coagulation (factors I, V, and VIII). The present study suggests that because of the high antigen to activity ratio seen in thriving EPT infants, a dysfunctional or fetal factor VIII may have been produced. However, the further elevation of this ratio in the severely ill EPT infants is in keeping with a pathologic proteolysis or increased endothelial release of factor VIII antigen.
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PMID:Coagulation studies in extremely premature infants. 52 93

The anticoagulant activity of the triiodinated X-ray opaque media iodipamide, iothalamate and diatrizoate on standardized normal human pool plasma was investigated in vitro. We found a dose dependent lengthening of the thrombin time, the reptilase time and the partial thromboplastin time together with a dose dependent drop of the calcium thromboplastin and factor V activity. Iodipamide proved to exert the most pronounced anticoagulant activity of the 3 contrast media tested. The results are interpreted as latent disseminated intravascular coagulation with hyperfibrinolysis following the direct interaction of contrast media with the coagulation enzymes.
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PMID:[Anticoagulant activity of triiodinated x-ray opaque media (author's transl)]. 57 82

Studies of 11 patients with haemorrhagic stroke revealed no significant change in kaolin cephalin clotting time, prothrombin time, thrombin time, PF 3 availability, platelet count and factor V and VIII during the first week. Plasma fibrinogen was significantly increased while factors VII + X were decreased (borderline significance). Prolongation of plasma recalcification time and decrease in heparin tolerance reached borderline significance. There was moderate, but significant, increase in serum antithrombin activity and plasma (euglobulin fraction) fibrinolytic activity.
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PMID:Blood coagulation and fibrinolysis in haemorrhagic stroke. 58 May 8


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