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)

Solvent/detergent virus-inactivated plasma (VIP) contains markedly reduced protein S (PS) and alpha 2-antiplasmin (APL) beside other slightly decreased inhibitors. This could possibly be critical for the balance of hemostasis in diseases in which plasma inhibitors are reduced. A heterogeneous group of 14 patients with 18 plasma transfusions (12 FFP/24 VIP, 2 units per transfusion) was investigated. The patients suffered from dilution coagulopathy, liver disease, disseminated intravascular coagulation (DIC), hyperfibrinolysis, or received massive transfusions. Prothrombin fragment 1 + 2, fibrin monomers, D-Dimers, thrombin-AT III complexes, antiplasmin-plasmin complexes and fibrinogen degradation products as markers of activated coagulation (MAC) were measured. Blood samples were taken before and after plasma replacement. Significant differences between VIP and FFP should be recognized by comparing the ratio of MAC after/MAC before plasma transfusion. Patients showed an average inhibitor plasma level of AT III 51%, protein C 44%, PS 63%, and APL 52%. Only the F 1 + 2 ratio was obviously higher in the VIP group but not significantly. So the remaining MAC ratios did not show any significant difference. Our preliminary data showed no indication for a higher state of activation of coagulation in patients receiving VIP in comparison with those receiving FFP, if the VIP had the quality required. Solvent/detergent (SD) inactivation of transfusion-relevant viruses in plasma was successfully performed by Horowitz et al. [1]. The procedure leads to a partial reduction of the activity of clotting factors [2]. PS and APL are more severely affected. Therefore, treatment with VIP might activate or at least increase the activation of coagulation, especially in patients with reduced plasma inhibitors. To clarify this problem, the following disorders with the indication for plasma replacement were included in a prospective randomized study of FFP vs. VIP: massive transfusion; dilution coagulopathy; disturbance in liver synthesis; disseminated intravascular coagulation (DIC); primary hyperfibrinolysis. Low PS levels could induce hypercoagulability by reduced F VIII and FV inhibition, and low APL could induce hyperfibrinolysis by reduced plasmin inhibition.
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PMID:Protocol and preliminary results of a clinical study for comparison of solvent/detergent-inactivated plasma VIP versus FFP with special consideration of the balance of hemostasis. 942 23

Activated protein C (APC) is a potent physiologic anticoagulant with profibrinolytic properties, and has been shown to prevent thrombosis in different experimental models. We investigated the effect of human APC on thrombin-induced thromboembolism in mice, a model of acute intravascular fibrin deposition leading to death within minutes. APC given intravenously (i.v.) as a bolus 2 min before thrombin challenge (1,250 U/kg) reduced mortality in a dose-dependent manner despite the lack of thrombin inhibitor activity. Significant inhibition of thrombin-induced death was observed at the dose of 0.05 mg/kg, and maximal protection was obtained with 2 mg/kg (> 85% reduction in mortality rate). Histology of lung tissue revealed that APC treatment (2 mg/kg) reduced significantly vascular occlusion rate (from 89.2 to 46.6%, P < 0.01). The protective effect of APC was due to the inhibition of endogenous thrombin formation as indicated by the fact that (a) the injection of human thrombin caused a marked decrease in the coagulation factors of the intrinsic and common pathways (but not of Factor VII), suggesting the activation of blood clotting via the contact system; (b) APC pretreatment reduced markedly prothrombin consumption; (c) the lethal effect of thrombin was almost abolished when the animals were made deficient in vitamin K-dependent factors by warfarin treatment, and could be restored only by doubling the dose of thrombin, indicating that the generation of endogenous thrombin contributes significantly to death; and (d) APC failed to protect warfarin-treated animals, in which mortality is entirely due to injected thrombin, even after protein S supplementation. Other results suggest that APC protects from thrombin-induced thromboembolism by rendering the formed fibrin more susceptible to plasmin degradation rather than by reducing fibrin formation: in thrombin-treated mice, fibrinogen consumption was not inhibited by APC; and inhibition of endogenous fibrinolysis by epsilon-aminocaproic or tranexamic acid resulted in a significant reduction of the protective effect of APC. Since APC did not enhance plasma fibrinolytic activity, as assessed by the measurement of plasminogen activator (PA) or PA inhibitor (PAI) activities, PAI-1 antigen, or 125I-fibrin degrading activity, we speculate that the inhibition of additional (endogenous) thrombin formation by APC interrupts thrombin-dependent mechanisms that make fibrin clots more resistant to lysis, so that the intravascular deposited fibrin can be removed more rapidly by the endogenous fibrinolytic system.
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PMID:Activated human protein C prevents thrombin-induced thromboembolism in mice. Evidence that activated protein c reduces intravascular fibrin accumulation through the inhibition of additional thrombin generation. 944 1

To elucidate the relationship between glomerular deposition of protein S (PS) and renal lesions or dysfunction, 30 patients with various glomerulopathies were examined. Glomerular PS deposition was found in 20 patients (group A), and other 10 patients showed no deposition (group B). PS was found mainly along the capillary loops and segmentally in the mesangium. Group A showed significantly more severe proteinuria than group B (p < 0.05). Group A patients showed significant decreases in glomerular filtration rate (p < 0.01). Patients in group A had significantly lower plasma levels of plasmin-alpha2-plasmin inhibitor complexes (p < 0.05) and thrombin-antithrombin III complexes (p < 0.01) than those in group B. Group A showed significant decreases in the mean values of plasma total PS (p < 0.01) and protein C (PC) antigens (p < 0.01) and C4b-binding protein (C4bp; p < 0.05) as compared with group B patients. There was a positive correlation between plasma PS and C4bp (p < 0.02). Histologically, group A showed a significantly higher incidence of glomerular deposition of factor XIII (subunit a), alpha2-plasmin inhibitor, PC (p < 0.05), and C4bp (p < 0.01). The present study demonstrates that glomerular PS deposition indicates the existence of PC and C4bp in the glomeruli and suggests that the glomerular PS deposition may modify the activation of fibrinolytic and coagulation systems within the glomeruli in various glomerulopathies.
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PMID:Significance of glomerular deposition of protein S in various glomerulopathies. 945 2

Thrombomodulin (TM) expressed on endothelial cells binds thrombin and initiates anticoagulant pathways. Soluble functional proteolytic fragments of TM are also present in circulating plasma. Recently, it was reported that TM accelerated thrombin-dependent plasma procarboxypeptidase B (pro-pCPB) activation in a purified system and suggested that TM may inhibit fibrinolysis in crude plasma. The aim of present study was to evaluate any functional role of soluble TM fragments in plasma or purified TM added into plasma to the regulation of coagulation and fibrinolysis. Addition of rabbit TM (1-200 ng/ml) to plasma resulted in a concentration-dependent prolongation of urokinase (UK)- or tissue plasminogen activator (t-PA)-induced clot lysis time. The concentration of TM required for the inhibition of fibrinolysis was lower than that required for the inhibition of coagulation. Addition of anti-rabbit TM IgG or anti-human TM IgG into plasma reduced UK- or t-PA-induced clot lysis time without affecting clotting times, indicating that exogenous TM or soluble TM fragments in normal human plasma participated in regulation of fibrinolysis. Moreover, the TM-dependent inhibition of fibrinolysis was observed only in the presence of thrombin and blocked by addition of carboxypeptidase B inhibitors, but not mediated by protein C activation or direct inhibition of UK, t-PA or plasmin. Analysis of various substrates and inhibitors indicated that TM accelerated thrombin-dependent pro-pCPB activation in plasma. The present results indicate that TM, including soluble TM fragments in plasma, inhibit fibrinolysis via activation of pro-pCPB in plasma.
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PMID:Thrombomodulin in human plasma contributes to inhibit fibrinolysis through acceleration of thrombin-dependent activation of plasma procarboxypeptidase B. 949 93

We monitored 30 laboratory hemostatic parameters in an attempt to better comprehend alterations in coagulation and fibrinolysis in 10 patients with hematological malignancies subjected to autologous peripheral blood stem cell transplantation (APBSCT). These parameters were assessed before and just after high-dose conditioning chemotherapy, on days 1, 7, 14 and 28. Although, clinical manifestations associated with fibrino-coagulation disorders never occurred, including veno-occlusive disease, a statistically significant increase was seen in 7 of 30 parameters, compared to values seen before conditioning chemotherapy. These were subdivided into early and late phase parameters. The early phase parameters, which increased during the first day after the conditioning chemotherapy was given, then returned to baseline values, included protein C, plasma tissue factor and tissue-plasminogen activator. The late phase parameters, which increased over baseline values during days 7 to 28, included free-protein S, fibrinogen, plasmin-alpha2-plasmin inhibitor complex and soluble-thrombomodulin. The increase of early phase parameters, as produced by the liver and by endothelial cells, may reflect tissue damage by conditioning chemotherapy. Late phase parameters increased in parallel with C-reactive protein, which suggests a correlation with the degree of inflammation, such as the presence of infective disease during neutropenia. These subclinical alterations in coagulation and fibrinolysis which take on a biphasic pattern during the course of APBSCT should be kept in mind by the attending physicians during therapy.
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PMID:Subclinical alterations in coagulation and fibrinolysis in patients undergoing autologous peripheral blood stem cell transplantation. 951 13

Various hemostatic and vascular endothelial cell markers were measured in patients with disseminated intravascular coagulation (DIC), non-DIC, or thrombotic thrombocytopenic purpura (TTP) and in healthy volunteers to examine the relationships between the hemostatic abnormalities or vascular endothelial cell injuries and the patients' outcomes. Although the plasma levels of soluble fibrin monomer, thrombin-antithrombin complex, plasmin-plasmin inhibitor complex, and D-dimer were significantly increased in the DIC patients, there were no significant differences in these markers between the DIC patients who survived and those who died, suggesting that these markers might not be directly related to the patient outcome. The plasma thrombomodulin (TM) levels in the DIC and TTP patients were significantly higher than those in the healthy volunteers, and the plasma TM levels in the patients who died were significantly higher than those in the patients who survived. These findings showed that the TM level reflected the outcome, and that the outcome of the diseases underlying DIC and TTP might depend on vascular endothelial cell injuries. The plasma protein C and antithrombin activities were markedly reduced in the DIC, non-DIC, and TTP patients who died compared to those who survived. These findings suggest that reduced plasma antithrombin and protein C activities are useful markers of systemic vascular endothelial injuries. Although the plasma tissue factor (TF) levels were significantly increased in the DIC patients, there was no significant difference in the plasma TF levels between the DIC patients who died and those who survived. In conclusion, we found that the outcome of the diseases underlying DIC and TTP is related to vascular endothelial cells, and that plasma TM, antithrombin, and protein C are useful markers for systemic vascular endothelial cell injury.
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PMID:Poor outcome in disseminated intravascular coagulation or thrombotic thrombocytopenic purpura patients with severe vascular endothelial cell injuries. 966 69

The changes in various hemostatic parameters were examined within a period from 7 days before the onset of disseminated intravascular coagulation (DIC) in 114 patients (i.e. in their pre-DIC state). The changes in prothrombin time (PT) ratio and fibrinogen levels were not significant before the onset of DIC. Plasma fibrinogen and fibrin degradation products (FDP) levels before the onset of DIC were high, but these changes were already significant in 110 non-DIC patients examined. Plasma thrombin-antithrombin complex (TAT), plasmin-plasmin inhibitor complex (PPIC), D-dimer and soluble fibrin monomer (SFM) levels were high before the onset of DIC. In the 110 leukemic DIC patients, the plasma SFM levels were significantly increased 5 days before, the plasma TAT levels were significantly increased 3 days before, and the D-dimer levels were significantly increased 1 day before the onset of DIC. The plasma tissue factor and plasminogen activator inhibitor-I levels were not significantly changed before the onset of DIC. The PT ratio, fibrinogen, FDP, platelet count, antithrombin, D-dimer, and PPIC levels at 7 days before the onset of DIC were not significantly different from the corresponding values in the non-DIC group, although the hemostatic molecular markers SFM, D-dimer, and TAT are useful for the diagnosis of pre-DIC. Plasma thrombomodulin levels were significantly increased in these patients who died, and plasma antithrombin and protein C activities markedly reduced in the patients who died. The outcome of the diseases underlying DIC is related to vascular endothelial cell injuries.
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PMID:Hemostatic molecular markers before onset of disseminated intravascular coagulation in leukemic patients. 970 63

Hepatic veno-occlusive disease (VOD) of the liver is a common complication following high-dose cytotoxic therapy for bone marrow transplantation (BMT). The major pathological changes are seen in centrilobular (zone 3) hepatocytes and adjacent endothelium. Glutathione (GSH) becomes depleted following chemotherapy and experimental evidence suggests reduced levels predispose to centrilobular hepatocyte and endothelial cell injury. Animal studies have shown that glutamine infusions can maintain GSH levels and protect against free radical injury. We have prospectively studied the effect of glutamine supplementation during BMT. Thirty-four patients undergoing BMT were randomised to receive either glycl-L-glutamine (n = 18) or an isonitrogenous mixture of non-essential amino acids (n = 16). Glutamine was shown to significantly preserve protein C (days +4 and +7, P < 0.05) and albumin levels (days 0 and +4, P < 0.02). Markers of thrombin and plasmin generation (thrombin-antithrombin, prothrombin fragment F1+2 and plasmin-antiplasmin levels) were not significantly changed between the two groups. These findings suggest that glutamine preserves hepatic function but does not alter thrombin or plasmin generation during BMT. Previous studies have shown reductions in protein C, albumin, factor X and factor VII levels post BMT. Falling protein C levels have been shown to be predictive of severe VOD. These data suggest a role for glutamine in the protection of hepatic function following BMT.
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PMID:Parenteral glutamine protects hepatic function during bone marrow transplantation. 972 Jul 43

A combined hemostatic defect consisting of a reduction in certain procoagulants, anticoagulants (antithrombin III-ATIII-, protein C-PC-) and components of the fibrinolytic system (plasminogen-Plg-) was demonstrated in very-low-birth-weight infants (VLBW <1,500 g) with gestational age 26-32 weeks. Sixteen of them were healthy, 28 were suffering from RDS and 24 from septicemia. The hemostatic defect was more profound in the RDS group, nevertheless increased TAT (thrombin + ATIII complex) and/or PAP values (plasmin + a2-antiplasmin complex) was a more frequent finding in the septicemic group of infants (91.8 vs. 17.9%). Moderate-to-severe thrombocytopenia was detected in a higher percentage in the septicemic (70.8%) than in the RDS group (50%), and increased D-dimers were demonstrated in 34.8 and 28.6% of the infants, respectively. Elevated TAT or PAP values were not always associated with gross coagulation abnormalities, and advanced disseminated intravascular coagulation (DIC) was only documented in 16.7% of the septicemic and 7.1% of the RDS infants. None of the VLBW neonates presented with clinical evidence of thrombosis, although hemorrhagic manifestations were apparent in 34.8 and 14.3% of the neonates with septicemia or RDS, respectively, mainly due to DIC or severe thrombocytopenia. In conclusion, increased TAT and/or PAP values are good indicators of the in vivo activation of the hemostatic system, but still their impact on sick neonates morbidity and mortality remains unknown.
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PMID:Indications of coagulation and/or fibrinolytic system activation in healthy and sick very-low-birth-weight neonates. 974 62

The catalytic triad consisting of His57, Asp102 and Ser195, which is completely conserved within the chymotrypsin-like serine protease family, plays a central role in catalysis. Highly conserved Ala55 also likely plays an important role in catalysis due to its location just behind the catalytic triad. The only exception to the conserved Ala55 in mammalian serine proteases is Val55 in bovine protein C. Interestingly, it has been demonstrated that the replacement of Ala55 with Thr results in the reduced activity of plasmin in patients with venous thrombosis and with retinochoroidal vascular disorders, which indicates the importance of Ala55 in catalysis. In the present study, we constructed a bovine protein C model which shows that Val55 causes no serious rearrangement of the catalytic site structure. We also constructed an A55T variant model of trypsin for comparison. The A55T substitution alters His57 into an inactive conformation, forming an unusual hydrogen bond between Thr55 O gamma 1 and His57 N epsilon 2. The present study shows that the Ala/Val55 residue contributes heavily to the active conformation of His57 and enables His57 to accept a proton from Ser195 O gamma effectively.
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PMID:Effect of exceptional valine replacement for highly conserved alanine-55 on the catalytic site structure of chymotrypsin-like serine protease. 977 31


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