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:3.4.21.7 (plasmin)
9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of various concentrations of plasmin and activated protein C on the factor VIII procoagulant activity (VIII:C) and coagulant antigen (VIII:CAg) were studied in factor VIII concentrates and normal plasma. Small amounts (0.1 CTA U/ml) of plasmin rapidly destroyed VIII:C, and affected, but did not destroy VIII:CAg, in factor VIII concentrates. In normal plasma larger amounts of plasmin (1.8 CTA U/ml) was required to inactivate VIII:C in order to exceed the neutralizing capacity of alpha 2-antiplasmin. VIII:CAg was unchanged indicating a limited proteolysis. The difference between VIII:C and VIII:CAg was found also in urokinase-activated plasma. Activated protein C (5 micrograms/ml), in the presence of Ca2+ and phospholipids, inactivated VIII:C without affecting VIII:CAg in a high purity factor VIII concentrate. Higher concentrations of activated protein C (25 micrograms/ml) caused a slight decrease of VIII:CAg, even in the absence of Ca2+ and phospholipids, but did not change VIII:CAg in normal plasma or serum.
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PMID:The effects of plasmin and protein Ca on factor VIII:C and VIII:CAg. 622 18

Prolonged clotting times and reduced levels of clotting factors have been reported in hematin-treated patients. This effect persists for up to 5 hr after hematin infusion, associated with plasma levels ranging from 0.01 to 0.04 mg/ml. Therefore we performed in vitro studies to investigate the effects of hematin on fibrinogen, thrombin, factor VIII:C, and plasmin. Hematin in a final concentration of 0.01 mg/ml inhibited the clotting of bovine fibrinogen (1.3 to 2.6 mg/ml) by bovine thrombin (0.12 U/ml) and inhibited the hydrolysis of a synthetic substrate by human thrombin. However, if the hematin was first mixed with albumin (25 mg/ml), fourfold higher concentrations were required to prolong the thrombin clotting time. Hematin, 0.035 mg/ml, reduced VIII:C activity from 0.88 to 0.40 U/ml as measured by two-stage assay. Hematin (0.05 mg/ml) also inhibited the activation of VIII:C by thrombin (0.04 U/ml): baseline activity, 0.84 U/ml; thrombin-activated, 2.94 U/ml; with hematin added, 1.33 U/ml. Hematin also inhibited clot lysis. The inclusion of hematin (0.03 mg/ml) in the diluting buffer reduced the lysis of whole blood clots from 86% +/- 5 to 23% +/- 5 (p less than 0.001, mean +/- S.D. of four determinations) and decreased the lysis of 125I-fibrin clots induced by plasmin (0.02 CTA U/ml) from 100% to 27%. In concentrations as low as 0.09 microgram/ml, hematin inhibited the hydrolysis of a synthetic substrate by plasmin. Hematin was mixed with fibrinogen, albumin, or thrombin, and the mixtures applied to Sephadex G-200 columns. Adherence of the hematin to Sephadex was prevented by either prerinsing the column with albumin or using borate buffer at pH 9.2. Hematin co-eluted with each protein applied to the column and, in the case of fibrinogen, altered its electrophoretic mobility and markedly prolonged the thrombin clotting time of the eluted fibrinogen. We conclude that hematin binds to a variety of hemostatic proteins, inhibiting their biologic activity.
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PMID:The inactivation of hemostatic factors by hematin. 641 43

Blood collected into different anticoagulants was stored in small tubes at +4 degrees C for up to 26 h. Seven blood coagulation analyses were performed under standardized conditions. High yield and stability of factor VIII:C were found for ACD and CPD-adenine. No changes could be found in the other six parameters tested. Whole blood in blood bags could be stored for 2-4 h at +4 degrees C with maximal yield of F VIII:C, with blood stored overnight the recovery was 65%. In plasma F VIII:C was stable for at least 2 h at room temperature. F VIIIR:Ag and F VIIIR:RCoF were stable in both whole blood and plasma. No activation by plasmin as measured by B beta 15-42 could be demonstrated. The initial FPA levels, reflecting thrombin activation, in the donated blood differed individually and in some blood bags very high concentrations were found. The levels of FPA were not correlated to the time for collection of a bag of blood.
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PMID:Improvement of plasma quality as raw material for factor VIII:C concentrates. Storage of whole blood and plasma and interindividual plasma levels of fibrinopeptide A. 641 86

Platelet concentrates (PC) are stored for up to 5 days at 22 degrees C prior to infusion. Since considerable suspending plasma is infused with the platelets, we examined the integrity of plasma fibrinogen from stored PC. The concentration of fibrinogen after storage was normal. After purification, fibrinogen from stored PC had normal thrombin time and rate of polymerization of fibrin monomer, and after reduction, its A alpha, B beta, and gamma chains had normal mobility on sodium dodecyl sulfate polyacrylamide gel electrophoresis. Assays of plasma from stored PC for fibrinogen-fibrin degradation products were negative. When 125I-fibrinogen was added to PC prior to storage and supernatant plasma was filtered in a sepharose 4B column after storage, radioactivity eluted in a single, symmetrical peak with no evidence for formation of low or high molecular weight material. These results make it unlikely that thrombin, plasmin, or other proteolytic activity is generated during storage. The levels of factors V and VIII fell to 40 to 65 percent of control values while the activities of factors IX, X, and XI did not change significantly during storage. We conclude that suspending plasma fibrinogen and other coagulation factors are remarkably stable during PC storage. They should be of value during the support of patients with massive hemorrhage.
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PMID:Stability of plasma fibrinogen during storage of platelet concentrates at 22 degrees C. 664 24

Ulcerative colitis and Crohn's disease are associated with a high risk of thromboembolic complications. The questions whether reported risk factors such as low antithrombin III concentrations, thrombocytosis and spontaneous platelet aggregation are merely related to the activity of the inflammatory process remains to be answered. Therefore we investigated 40 patients with an established colitis or Crohn's disease, without signs of active inflammation (normal history, normal ESR and leucocyte count). Of these patients only one patient revealed thrombocytosis, six patients spontaneous platelet aggregation. All patients had normal beta-thromboglobulin and platelet factor 4 plasma levels. No other prethrombotic abnormalities were encountered. There was normal factor VIII C (increased in three patients), normal VIII C/VIII R Ag ratio (1.2), antithrombin III, normal plasminogen and normal alpha 2-antiplasmin. Normal fibrinopeptide A and B beta (15-42) plasma levels (n = 15) in these patients excluded in vivo thrombin or plasmin generation. We conclude that stable chronic inflammatory bowel disease is in general not associated with prethrombotic coagulation abnormalities.
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PMID:No evidence for a prethrombotic state in stable chronic inflammatory bowel disease. 665 71

Blood shed into a closed peritoneal cavity is incoagulable. We have investigated this poorly understood phenomenon in animal experiments. Nonthrombogenic femoral vein-peritoneal cavity shunts were established in five dogs and 10 ml/kg blood admixed with 125I-dog fibrinogen was rapidly drained into the peritoneal cavity. After 1 hr the peritoneal cavity was entered and incoagulable blood aspirated; 125I-fibrinogen Mr distribution was assessed by AGPC, demonstrating complete degradation of fibrinogen into core fragments D and E with no evidence of soluble fibrin complexes or crosslinked fibrin fragments. Peritoneal cavity clotting factors II, V, and VIII and platelets were sharply reduced compared to venous control samples. Plasminogen and antiplasmin levels in peritoneal cavity blood showed mean declines of 17% and 15%, respectively. By comparison, incubation of dog blood with 1 to 2 X 10(3) U/ml urokinase for 1 hr in vitro was insufficient to degrade 125I-dog fibrinogen to core fragments D and E, although plasminogen and antiplasmin were reduced by 66% and 100%, respectively. Pretreatment of dogs with epsilon ACA (0.13 gm/kg, N = 4) resulted in massive intraperitoneal cavity clotting, and aspirated fluid blood contained only small quantities of radiolabel. Heparin treatment (300 U/kg bolus, 150 U/kg/hr infusion; N = 4) eliminated the peritoneal cavity lytic response; analytical gel permeation chromatography consistently demonstrated intact fibrinogen only. Therefore it is apparent that blood in a closed peritoneal cavity undergoes limited clotting followed by brisk plasmin-mediated fibrinolysis as opposed to fibrinogenolysis. The closed peritoneal cavity fibrinolytic response to clotting blood represents a striking example of the efficiency of the "tissue-type" plasminogen activator.
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PMID:Peritoneal fibrinolysis: evidence for the efficiency of the tissue-type plasminogen activator. 668 80

Peritoneal fluid does not clot spontaneously on collection, due to a lack of prothrombin activation, consequent upon a virtual absence of factors V and VIII. Factor VIII related antigen is present in peritoneal fluid in only very small amounts, suggesting that this factor is excluded from the peritoneal cavity, probably by virtue of its size. Slight thrombin activity is demonstrated by the presence of fibrin monomers in the fluid. That peritoneal fluid also contains fibrinolytic activity is shown by high levels of plasminogen and plasmin-antiplasmin complexes, though no plasminogen activator could be detected. No differences were found in clotting and fibrinolytic activities, between fluid taken from these patients with, and those without, laparoscopic evidence of pelvic endometriosis.
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PMID:Clotting and fibrinolytic activities in peritoneal fluid. 677 52

We measured the blood coagulability in pregnancy. Factor XIII, that showed unusual variations in these experiment, was investigated for its biological significance. The results are summarized as follows: 1) Blood coagulation factors XII, IX, VIII, VII and X, prothrombin and plasminogen showed a increasing tendency as the course of pregnancy. These was not very much change in factor V and plasmin activity during pregnancy. Factor XI showed a decreasing tendency. The further dramatic variation appeared in each coagulation factor at the onset of labor. 2) With regards to the factor XIII, XIII-S a carrier protein was inclined to increase from the value of 94.0 +/- 16.0% before pregnancy and reached the value of 109 + 16.3% at the last stage of pregnancy, while XIII-A an active site showed a decreasing tendency from 97.5 + 17.5% before pregnancy to 67.0 + 12.0%. 3) In placenta homogenate XIII-A was observed, but XIII-S absent. In retro-placental blood XIII-S was observed, but no XIII-A was seen. No significant difference between uterine venous blood and maternal peripheral blood was recognized. 4) The placental localization of XIII-A was investigated by the methods of fluorescent antibody technique and enzyme labeled antibody technique. XIII-A appeared in syncitiotrophoblast, but was not found in stroma, vessel wall and fetal side. In regards to decidua region its presence was not confirmed.
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PMID:[Studies on the physiological changes of blood coagulation factor XIII during pregnancy and their significance (author's transl)]. 706 52

Experiments on animals in vitro showed that phosphatidylserine-containing anticoagulant (PhCA) inhibited factors X and VIII, restricted factor V activity and, to a less degree, that of factor VII, decreased the activity of fibrin-stabilizing factor, the degree of clot retraction and its tolerance to fibrinolysin. The activity of factor IX remained virtually unchanged under the influence of PhCA, whereas the contact phase was speeded up by 14%. Anticoagulant activity of PhCA was accounted for by the phosphatidyl molecule residue - glycerylphosphorylserine.
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PMID:[Mechanism of the hypocoagulemic effect and the active principle of a phosphatidylserine-containing anticoagulant]. 728

In 1,800 patients undergoing cardiac surgery over a 2-year period, 11 incidents of abnormal inlet pressure elevations occurred before the membrane oxygenators. In 3 patients, the oxygenators had to be changed during cardiopulmonary bypass. This complication was found to be caused by fibrin formation possibly secondary to precipitation of fibrinogen with other coagulation factors in the heat exchangers of the oxygenators during the cooling phase. Large amounts of fibrin were demonstrated in the heat exchanger of the oxygenators. After careful washing of the apparatus, plasmin was added and fibrin was detected by measuring D-dimer levels. In heat exchangers from uneventful operations, only trace amounts of fibrin were found. Because there were no cold agglutinins demonstrated in the patients before surgery, cryoprecipitation studies were performed soon after surgery. When the patients' plasma samples were studied at different temperatures, from 37 degrees C down to 3 degrees C, cryoprecipitates or a gel (in 1 patient only) were formed. This indicated that there might be something abnormal with regard to fibrinogen-fibrin formation. The study patients were therefore investigated after the acute phase of the operation had ended for various coagulation factors, as well as for fibrin gel network characteristics. The results were compared with those of a control group (n = 10) with uneventful operations. There were no differences between the groups with regard to levels of coagulation factors VII and VIII and von Willebrand factor, although they were increased in both groups. The mean levels of coagulation inhibitors, antithrombin and Protein S, were slightly lower in the study patients. All of these patients had a highly pathologic, ie, tight fibrin gel network, except for the patient in whose sample a gel formed, despite being treated with aspirin or oral anticoagulants. The network was also tighter in some of the controls (v middle-aged reference individuals), although it was significantly tighter in the patients. It is concluded that some individuals who have an increased tendency to form tighter fibrin gel networks might be at increased risk for a severe complication during cardiac surgery performed under hypothermia.
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PMID:Pathologic fibrin formation and cold-induced clotting of membrane oxygenators during cardiopulmonary bypass. 771 53


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