Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.7 (plasmin)
 9,023 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study attempted to determine whether fibrin monomer complexes, or other alterations of coagulation factor activities that might predispose to thrombosis, were present in 30 vasectomized Rhesus monkeys that had had bilateral vasectomies 1-11 years earlier. Blood coagulation factors, prothrombin, factors V and VIII, fibrogen, and antithrombin III, are consumed when blood coagulation occurs. If consumption of these factors is in excess of the individual's ability to synthesize them, a decreased concentration results. No significant decreases in activities of any consumable clotting factors were found. If intravascular coagulation is present, certain products of coagulation may be present in the blood even though consumable factors remain normal. Products of intravascular coagulation include fibrin monomer and plasmin digestion products of fibrin. No significant differences in average values of fibrin monomer and fibrin digestion products in control and vasectomized animals were found. 1 animal had increased fibrin monomer, but on postmortem examination, no evidence of intravascular thrombosis was seen.
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PMID:Coagulation changes following vasectomy: a study in primates. 9 98

The relationship between factor VIII (AHF) procoagulant activity and factor VIII-related antigen were examined in patients with disseminated intravascular coagulation (DIC), pulmonary embolism (PE), and coronary artery disease with or without myocardial infarction (MI). It was found that 13 of 13 patients with DIC, 17 of 17 patients with PE, and 10 of 12 patients with MI possessed a significantly elevated factor VIII-related antigen to factor VIII activity ratio (VIII-ratio). The VIII-ratio returned to normal in each of 2 patients with DIC and 1 paitent with PE after treatment with heparin, heparin and alpha-amino-caproic acid, and heparin and coumadin respectively. In contrast, the VIII-ratio was slightly elevated only in 1 of 15 patients with coronary artery insufficiency without MI. In in vitro studies, after treatment of plasma with thrombin or plasmin, factor VIII activity was lost, whereas the amount of factor VIII-related antigen remained the same or was even increased when measured by agarose quantitative immunoelectrophoresis. These observations have led us to conclude that an elevated VIII-ratio is a very sensitive indicator of intravascular coagulation.
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PMID:In vivo and in vitro effects of thrombin and plasmin on human factor VIII (AHF). 13 71

Most of the linkage of atherosclerosis and thrombosis with estrogens is epidemiologic in origin. Although the effects of estrogens on the mechanisms of hemostasis are wide ranging, many are benign; only a few may account for thrombus formation. Platelet function tests have provided extensive but contradictory data, and interpretation is limited because it is uncertain whether a rise in one or more of these parameters is a primary or secondary effect. The most consistent effects of estrogens on coagulation proteins are elevations of fibrinogen; factors II, VII, IX, X, and XII; protein C; and plasminogen. Although these elevations have been attributed to the estrogenic component in oral contraceptives, the progestogen concentration may also influence these increases. Among other coagulation proteins studied, the following are unaffected by oral contraceptive use: factors V, VIII, and XI; prekallikrein; and high-molecular-weight kininogen. In contrast, protein S values are decreased. The plasma concentration of plasmin inhibitor is unchanged, whereas both proteinase inhibitor and macroglobulin are significantly increased by oral contraceptive use. Cl esterase inhibitor is decreased in women taking oral contraceptives and correlates with the increase in Hageman factor. Antithrombin III is one plasma inhibitor for which a decrease in quantity and activity have been associated with a thrombotic tendency in humans. Although data on estrogen-associated changes in the quantity of antithrombin III have been conflicting, the ability of plasma to inhibit factor Xa is significantly reduced in a dose-dependent manner among pre- and postmenopausal estrogen users.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Estrogen-associated thromboembolism. 134 94

A binding domain for Factor VIII (F.VIII) has been previously identified on the N-terminal portion of human von Willebrand Factor (vWF) subunit [amino acids (AA) 1-272]. In order to characterize other possible structures of vWF involved in its capacity to bind and to protect F.VIII against human activated protein C (APC), we used a series of purified vWF fragments overlapping the whole sequence of the subunit. Among those were fragments SpIII (dimer; AA 1-1365), SpII (dimer; AA 1366-2050) and SpI (monomer; AA 911-1365) generated by Staphylococcus aureus V8 proteinase, a P34 species (monomer; AA 1-272) obtained with plasmin, a monomeric 39/34 kDa dispase fragment (AA 480-718) and a tetrameric III-T2 fragment (AA 273-511/674-728) produced from SpIII by trypsin. Three other fragments without precise extremities were located using selected monoclonal antibodies to vWF. Two C-terminal fragments of 270 and 260 kDa, overlapping SpI and SpII, were respectively generated from vWF with trypsin and protease 1 from Crotalus atrox venom. An N-terminal 120 kDa fragment, overlapping P34 and 39/34 kDa fragments, was produced by protease 1. Our results show that vWF bound to F.VIII and protected it from degradation by APC in a dose-dependent way. Among the C-terminal and central vWF fragments (SpII, tryptic 270 kDa, 260 kDa, SpI, 39/34 kDa and III-T2), none had the capacity to bind or to protect F.VIII, even at high concentrations. The three N-terminal fragments (SpIII, 120 kDa and P34) bound to F.VIII in a dose-dependent and saturable fashion. SpIII and the 120 kDa fragment had the capacity to protect F.VIII in a dose-dependent way. In contrast, the P34 species did not significantly protect F.VIII, even when using high concentrations of the fragment. In conclusion, the N-terminal end of vWF subunit (AA 1-272) plays a crucial role in binding to F.VIII, but requires additional structures of the 120 kDa fragment to protect it against APC. In addition, the presence of a secondary binding and/or protecting domain on other portions of the vWF subunit (potentially destroyed during the proteolysis of vWF) is highly unlikely.
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PMID:Evidence that a secondary binding and protecting site for factor VIII on von Willebrand factor is highly unlikely. 153 49

The effects of physical training on hemostatic parameters were evaluated in 56 postmyocardial infarction (MI) patients before and after one month of systematic physical training and in 30 control post-MI patients, who did not undergo such training. There were no significant changes in prothrombin time (PT) and alpha 1-antitrypsin (alpha 1AT) at the beginning and end of the study in either group. Levels of fibrinogen, Factor VIII: C (VIII:C) and von Wildebrand antigen (vWf:Ag), and activities of ATIII and plasminogen (Plg) were significantly decreased in the group with physical training (p less than 0.05), while values were unchanged in the control group. Hematocrit, platelet counts, and alpha 2-plasmin inhibitor (alpha 2PI) activities also decreased in the physical training group (p less than 0.05). In contrast, these variables increased in the control group (p less than 0.05). Activated partial thromboplastin time (aPTT) tended to be prolonged in the group with physical training, while it was shortened in the control group. In a subset of 20 patients with physical training, resting levels of plasmin-alpha 2PI complex (PIC), thrombin-antithrombin III complex (TAT), protein-C (P-C:Ag), plasminogen activator inhibitor-1 (PAI-1), VII:C, and P-C activities had significantly decreased after one month of physical training (p less than 0.05), although tissue plasminogen activator activities remained unchanged. Physical training appeared to suppress coagulability as indicated by the decrease in fibrinogen, VIII:C, vWf:Ag, VII:C, and TAT, and prolongation of aPTT. The decrease in plasminogen, t-PA:Ag, alpha 2PI, PAI-1, and PIC after physical training may result from the decreased coagulability. In conclusion, physical training appears to induce a suppression of the coagulation system in patients in the recovery phase of MI.
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PMID:Blood coagulability and fibrinolytic activity before and after physical training during the recovery phase of acute myocardial infarction. 162 56

Clotting within the dialyser is one of the most significant clinical parameters of biocompatibility. A study was designed to evaluate the biocompatibility of two different dialysis membranes (cuprophane and polyacrylonitrile) during therapy with conventional heparin. Transient leukopenia during cuprophane but not during polyacrylonitrile haemodialysis was observed, and elastase release using polyacryonitrile membranes was reduced (P less than 0.001). An elevation in F VIII:C activity during cuprophane haemodialysis has to be taken as an indication of endothelial disturbances. There was a significant (P less than 0.001) platelet activation (beta-thromboglobulin) and combined thrombin/plasmin generation using cuprophane membranes. This new synthetic polyacrylonitrile membrane inactivates the clotting in an extracorporeal system to a sufficient degree and allows a reduction in dosages of heparin. Platelet activation, platelet turnover, disturbances of endothelium, fibrinolysis activation, and granulocyte activation are reproducible parameters of a described interaction model. They also permit a comparison of different haemodialysis membranes.
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PMID:Comparison of blood biocompatibility during haemodialysis with cuprophane and polyacrylonitrile membranes. 839 23

The levels of hemostatic and fibrinolytic parameters and of molecular markers in venous blood before and after 10 minutes of venous occlusion were measured to evaluate vascular endothelial function in 36 patients with old myocardial infarction, and also in 20 healthy subjects. T-PA activity in the venous blood after occlusion was significantly lower in the patient group compared with the control group, and was lowest in patients with diabetes mellitus. These results were considered to be attributable to elevated PAI-1 and alpha 2 PI levels in these patients. The mean levels of t-PA antigen and VIII R: Ag in venous blood before occlusion were significantly higher in the patient group, but the mean amount of release was no higher in patients than in controls. The plasmin.alpha 2PI complex levels before venous occlusion seemed to indicate the presence of secondary fibrinolysis accompanying hypercoagulability, and the level was significantly higher in patients with diabetes mellitus. Venous occlusion induced the release of t-PA and VIII R: Ag without causing a significant difference in the mean amount of increase of these substances in patient and control groups. However, the lower level of t-PA activity after venous occlusion together with the higher levels of VIII: C, VIII R: Ag, alpha 2PI, PAI-1, and plasmin.alpha 2PI complex before venous occlusion in the patients, indicated that the patient group was in a hypercoagulable and hypofibrinolytic state. In those with diabetes mellitus, the changes were more significant.
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PMID:[Changes induced by venous occlusion in coagulation and fibrinolysis in patients with old myocardial infarction]. 202 72

Urokinase immobilized polymer is highly antithrombotic, which cannot be explained only by fibrinolysis. We immobilized 10 IU/cm2 of urokinase to polyurethane by using maleic anhydride methylvinyl ether copolymer as a carrier. Then we incubated blood in circular tubes made of this material, measured the clotting factors and observed the surface of the tubes after incubation by scanning electronmicroscopy and immunofluorescence microscopy. After 5 min incubation, the relative activities of factors V, VIII, IX, X and XII, fibrinogen, plasminogen and alpha 2 plasmin inhibitor decreased, but the activity of factor VII increased. No platelet adhesion to the surface of the urokinase immobilized polyurethane was observed and there was no significant adsorption of serum proteins, including fibrinogen, fibronectin and vWF antigen, on the surface. Urokinase-immobilized polyurethane catalyzed the digestion of clotting factors as well as fibrinolysis and also inhibited platelet adhesion on its surface probably by inhibiting protein adsorption and its clinical application including vessel prosthesis should be developed further.
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PMID:Antithrombotic mechanisms of urokinase immobilized polyurethane. 202 41

A congenitally abnormal fibrinogen (Vlissingen) was isolated from the blood of a young woman suffering from massive pulmonary embolism. Fibrinogen Vlissingen showed an abnormal clotting time with both thrombin and Reptilase. The release of the fibrino-peptides A and B by thrombin was normal, but fibrin polymerization was impaired both in the presence and absence of Ca2+ ions. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis performed according to Laemmli the gamma-chain of fibrinogen Vlissingen showed two bands, one normal and one having an apparently lower molecular mass of about 1,500 daltons. The previously described protective effect of Ca2+ ions on plasmin degradation of the carboxyl terminus of the gamma-chain of normal fibrinogen was only partially detectable in fibrinogen Vlissingen. In addition the binding of Ca2+ ions was decreased. Fibrinogen Vlissingen bound 2.4 Ca2+ ions per fibrinogen molecule at pH 7.4, whereas normal fibrinogen bound 3.1 Ca2+ ions. At pH 5.8 fibrinogen Vlissingen bound 1.1 Ca2+ ions, whereas normal fibrinogen bound 2.0 Ca2+ ions per molecule fibrinogen in the D-domains, again indicating a structural change in the carboxyl terminus of fibrinogen. The structural defect was determined by sequence analysis of DNA amplified by use of the polymerase chain reaction. Exons VIII, IX, and X of the gamma-chain gene were amplified and the DNA sequence of the amplified fragments was determined. A 6-base deletion was found in 50% of the fragments corresponding to exon VIII, indicating that the patient was heterozygous for the mutation. This deletion codes for amino acids Asn-319 and Asp-320 in the normal fibrinogen gamma-chain. The data indicate that Asn-319 and Asp-320 are crucial for maintaining the integrity of the carboxyl-terminal polymerization sites, the protective effect of Ca2+ ions on plasmin degradation of the carboxyl terminus of the gamma-chain, and the calcium binding domain at the carboxyl terminus of fibrinogen.
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PMID:A congenitally abnormal fibrinogen (Vlissingen) with a 6-base deletion in the gamma-chain gene, causing defective calcium binding and impaired fibrin polymerization. 207 11

The circadian fluctuation of hemostasis related parameters was examined on 16 healthy Japanese adults (male 9, female 7). Twenty one parameters were measured in this study, i.e. fibrinogen, the activity of F.II, F.V., F.VII, F.VIII, F.IX, F.X., F.XI, F.XII, antithrombin III, plasminogen, alpha 2-antiplasmin, as well as the antigen level of F.IX, von Willebrand Factor, protein C, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1), beta-thromboglobulin, platelet factor 4, fibrinopeptide A, plasmin-alpha 2-antiplasmin complex and FDP. Fluctuation was not significant in almost all of the parameters except F.VIII, F.IX, beta-thromboglobulin, platelet factor 4, tPA and PAI-1. Although the fluctuations of F.VIII, F.IX, beta-thromboglobulin and platelet factor 4 were statistically significant, they remained within the normal ranges. On the other hand, tPA and free PAI-1 showed significant circadian fluctuation, of which levels were highest at 9:00. It was postulated that the significant circadian fluctuation of fibrinolytic activity will be regulated by the balance between tPA and PAI-1 in plasma.
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PMID:Reference values of hemostasis related factors of healthy Japanese adults. I: Circadian fluctuation. 208 89


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