Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012739 (disseminated intravascular coagulation)
 8,673 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thrombin cleaves single-chain urokinase-type plasminogen activator (scu-PA) into a virtually inactive two-chain form (tcu-PA/T), a process that may protect a blood clot from early fibrinolysis. It is not known under what circumstances tcu-PA/T can be generated in vivo. We have studied the occurrence of tcu-PA/T in human subjects with a varying degree of hypercoagulability. tcu-PA/T was assessed in the plasma of patients with disseminated intravascular coagulation (DIC), endotoxin-treated volunteers, patients with unstable angina pectoris, and patients selected for hip replacement. Relationships between tcu-PA/T and several markers reflecting thrombin generation were examined. tcu-PA/T was observed only in the plasma of patients with DIC and was associated with all thrombin markers and with scu-PA and urokinase antigen. Prothrombin fragment 1 + 2 and urokinase antigen were independent predictors of tcu-PA/T. The fact that tcu-PA/T could not be detected in the other three groups was explained by a lower extent of thrombin generation, a greater inhibition of thrombin by antithrombin, or less available urokinase antigen in these groups. The contribution of scu-PA to total urokinase antigen was decreased in the patients with DIC because of inactivation by thrombin, which may be an additional explanation for the inadequate fibrinolysis observed in these patients. These findings show that scu-PA can be inactivated in the circulation under severe pathophysiologic circumstances and that the process of inactivation depends not only on the generation of thrombin but also on the control of thrombin activity by its inhibitor antithrombin.
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PMID:Inactivation of single-chain urokinase-type plasminogen activator by thrombin in human subjects. 1044 30

In this study, we have established a pig model that can combine extensive hemodynamic monitoring with simultaneous repetitive (serial) blood sampling for the study of multiple variables related to the hemostatic system. Sixteen healthy young pigs were studied to evaluate the influence of continuous endotoxin infusion on hemodynamic patterns and activation of coagulation and fibrinolysis. The chief aim of the study was to investigate the applicability of analytical methods primarily developed for use with human plasma samples in quantification of factors and reaction products of the porcine coagulation and fibrinolytic systems, and further, to use these methods to study the longitudinal changes in the plasma levels of these hemostatic variables as a consequence of endotoxin infusion. We found that acute, controlled endotoxemia induced a hemodynamic state of shock and reduced pulmonary gas exchange. Simultaneously, a gradual increase in peripheral blood mononuclear cell tissue factor activity was demonstrated, and increased maximally 5.5-fold 4 hours after onset of endotoxin infusion. Thrombin-antithrombin complexes increased in plasma to maximum levels after 3 hours, accompanied by an ethanol gelation test that was regularly positive after 1 to 2 hours, and fibrin monomer levels that gradually increased maximally 3.8-fold after 6 hours. These changes were followed by gradual decreases of both fibrinogen and factor VII levels, mainly due to consumption. Plasma levels of tissue type plasminogen activator activity peaked at 1.5 hours (11.3-fold increase), whereas the peak of plasminogen activator inhibitor-1 activity (14-fold increase at 4.5 hours) was delayed compared to tissue plasminogen activator and completely extinguished plasma tissue plasminogen activator activity. The sequential activation of coagulation and fibrinolysis established a procoagulant state favoring disseminated intravascular coagulation and microthrombus formation, potentially leading to multiple organ dysfunction.
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PMID:Hemodynamic changes and systemic activation of coagulation and fibrinolysis during controlled endotoxemia in pigs. 1089 51

Tissue factor pathway inhibitor (TFPI) fractions and coagulation markers were determined in 26 patients with disseminated intravascular coagulation (DIC). Thrombin-antithrombin complex and fibrin monomer values were markedly elevated in all patients (P < 0.01). The median TFPI activity level (2.1 nmol/l) was lower than in normal controls (2.6 nmol/l; P < 0.01). The median free TFPI level was within the normal reference range, but seven patients had levels above and nine patients had levels below normal range. The median activated factor X (FXa)-TFPI complex level in patients (0.13 nmol/l) was lower than in controls (0.18 nmol/l; P < 0.01). Only one patient had a FXa-TFPI complex level above the normal range, while eight patients had levels below. In conclusion, TFPI activity, free TFPI antigen and FXa-TFPI complex levels vary considerably in DIC. Activation of coagulation may increase TFPI levels, as reported by other workers and supported by a positive correlation between tissue factor and free TFPI in the present material. A negative correlation between fibrin monomer and free TFPI (r = -0.46, P = 0.019) might indicate that hyperactive coagulation leads to consumption of TFPI. Subnormal FXa-TFPI levels in DIC, possibly caused by consumption, may imply a reduced capacity to inactivate the triggering factor VIIa-tissue factor complex.
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PMID:Tissue factor pathway inhibitor (TFPI) in disseminated intravascular coagulation: low levels of the activated factor X-TFPI complex. 1108 78

Disseminated intravascular coagulation (DIC) is characterized by activation of hemostasis and fibrinolysis resulting in the formation of thrombin and plasmin, and the characteristic effects of these enzymes on plasma fibrinogen can be useful in diagnosis. Thrombin cleaves fibrinopeptides from fibrinogen, forming fibrin monomer that rapidly polymerizes to form a clot. Small amounts can circulate in plasma as "soluble fibrin," which may have a complex composition and include fibrinogen and a variable amount of cross-linking. Plasmic degradation of cross-linked fibrin forms a heterogeneous group of degradation products reactive in assays for D-dimer, and their levels provide a measure of the amount of fibrin formation and lysis. Caution should be exercised in comparing quantitative results using different assays because of problems with standardization and variable reactivity with different molecular forms. Marked elevations of fibrin(ogen) degradation products are a constant finding in experimental animal models of DIC. In human models of DIC resulting from endotoxin infusion, D-dimer is elevated early and high levels persist, reflecting lysis of microvascular fibrin deposits. Elevated levels of D-dimer and soluble fibrin are very sensitive for the diagnosis of DIC, and a normal level has a high negative predictive value. Serial monitoring of soluble fibrin or D-dimer assays may be of value in evaluating the response to therapy and possibly in identifying at-risk patients.
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PMID:Fibrin degradation products, fibrin monomer and soluble fibrin in disseminated intravascular coagulation. 1174 Jun 89

There are global coagulation tests and hemostatic molecular markers in the diagnosis of disseminated intravascular coagulation (DIC). In the global coagulation tests, the sensitivity of prothrombin time ratio and fibrinogen for the diagnosis of DIC is low, but their specificity is high. In platelet count and FDP, the sensitivity for the diagnosis of DIC is good, but the specificity is low. Fibrinogen may be unsuitable for the diagnosis of DIC, because it increases of the inflammatory reaction. It is possible to theoretically diagnose DIC by increased tissue factor production. It is currently considered that hemostatic molecular marker should be utilized to diagnose DIC. Thrombin-antithrombin complex and soluble fibrin are reflected to hypercoagulable state, thrombomodulin to vascular endothelial cell injuries, and plasminogen activator inhibitor-I to hypofibrinolytic state. In leukemia with DIC, hyperfibrinolysis and marked bleeding symptoms are often observed. In septicemia with DIC, hypofibrinolysis and severe organ failure often occur. Early diagnosis and treatment of DIC are important to improve the prognosis, and hemostatic molecular markers should be useful for that purpose.
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PMID:[Hemostatic abnormalities in DIC]. 1237 12

Haemostatic disorders caused by Lonomia obliqua caterpillars has reached epidemic proportions in southern Brazil. Here we evaluated coagulation and fibrinolysis in 105 patients after accidental contact with Lonomia obliqua caterpillars. Global coagulation tests were prolonged in most cases and patients were divided into 3 groups according to fibrinogen (Fg) level: <or=0.5 g/l (group A); 0.51-1.5 g/l (group B), >1.5 g/l (group C). There was a significant reduction of factors V, XIII, VIII and prekallikrein in group A, with no change in factors X, II and von Willebrand factor. Thrombin-antithrombin and prothrombin F1+2 were elevated in most patients. Antithrombin and protein S were not changed whereas protein C levels were reduced in group A. Plasminogen and alfa2-antiplasmin levels were significantly reduced in group A and D-Dimer levels were extremely high in all groups, showing that fibrinolysis had been activated, possibly secondary to fibrin production. Levels of t-PA were normal and PAI-1 was mildly elevated in group A. The platelet count remained above 150 x 109 platelets/ml in 97% of cases. In summary, our results suggest that Lonomia obliqua envenoming is characterized by a consumption coagulopathy and secondary fibrinolysis.
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PMID:Blood coagulation and fibrinolytic factors in 105 patients with hemorrhagic syndrome caused by accidental contact with Lonomia obliqua caterpillar in Santa Catarina, southern Brazil. 1257 17

Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to widespread deposition of fibrin in the circulation. Recent knowledge on important pathogenetic mechanisms that may lead to DIC has resulted in novel preventive and therapeutic approaches to patients with DIC. Thrombin generation proceeds via the (extrinsic) tissue factor/activated factor VII route and simultaneously occurring depression of inhibitory mechanisms, such as antithrombin and the protein C and protein S system. Also, impaired fibrin degradation, due to high circulating levels of plasminogen activator inhibitor type-I, contributes to enhanced intravascular fibrin deposition. Strategies aimed at the inhibition of coagulation activation may theoretically be justified and have been found beneficial in experimental and initial clinical studies. These strategies comprise inhibition of tissue factor-mediated activation of coagulation or restoration of physiological anticoagulant pathways, by means of the administration of antithrombin concentrate or (activated) protein C.
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PMID:Therapeutic intervention in disseminated intravascular coagulation: have we made any progress in the last millennium? 1291 85

Thrombin activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme, which is synthesized in the liver and circulates in the blood at a concentration of about 275 nmol/l. Once activated, by thrombin or plasmin, TAFI down regulates fibrinolysis, slowing clot lysis by cleaving the C-terminal lysine and arginine residues from partially degraded fibrin. Thrombomodulin enhances thrombin activation of TAFI by more than 1000-fold, suggesting that the thrombin-thrombomodulin complex is the physiological activator of TAFI. Activated protein C can up-regulate fibrinolysis by limiting the activation of TAFI via the attenuation of thrombin production. While impairment of fibrinolysis may predispose to thrombosis, excessive fibrinolysis may result in a bleeding tendency. In acquired coagulopathies, TAFI antigen levels are reduced in patients with disseminated intravascular coagulation. In focusing on women with major post-partum haemorrhage requiring blood transfusion, a significant reduction in TAFI levels is observed. The precise degree of TAFI activation is currently being characterized using new and more specific assays. The resulting data may provide insight into therapeutic options to treat post-partum haemorrhage, which is associated with significant morbidity.
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PMID:Characterization of thrombin activatable fibrinolysis inhibitor in normal and acquired haemostatic dysfunction. 1456 41

Sepsis almost invariably leads to hemostatic abnormalities, ranging from insignificant laboratory changes to severe disseminated intravascular coagulation (DIC). There is compelling evidence from clinical and experimental studies that DIC is involved in the pathogenesis of microvascular dysfunction and contributes to organ failure. In addition, the massive and ongoing activation of coagulation, may deplete platelets and coagulation factors, which may in turn cause bleeding. Recent insights into important pathogenetic mechanisms that may lead to DIC have resulted in novel preventive and therapeutic approaches to patients with sepsis and a derangement of coagulation. Thrombin generation proceeds via the (extrinsic) tissue factor/factor VIIa route and simultaneously occurring depression of inhibitory mechanisms, such as antithrombin III and the protein C system. Also, impaired fibrin degradation, due to high circulating levels of PAI-1, contributes to enhanced intravascular fibrin deposition. Supportive strategies aimed at the inhibition of coagulation activation may be justified on theoretical grounds and have been found to be beneficial in experimental and initial clinical studies. These strategies comprise inhibition of tissue factor-mediated activation of coagulation or restoration of physiological anticoagulant pathways, by means of the administration of antithrombin concentrate or recombinant human activated protein C.
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PMID:Sepsis and disseminated intravascular coagulation. 1476 Feb 11

A variety of clinical conditions may cause systemic activation of coagulation, ranging from insignificant laboratory changes to severe disseminated intravascular coagulation (DIC). DIC consists of a widespread systemic activation of coagulation, resulting in diffuse fibrin deposition in small and midsize vessels. There is compelling evidence from clinical and experimental studies that DIC is involved in the pathogenesis of microvascular dysfunction and contributes to organ failure. In addition, the massive and ongoing activation of coagulation, may result in depletion of platelets and coagulation factors, which may cause bleeding. Recent understanding of important pathogenetic mechanisms that may lead to DIC has resulted in novel preventive and therapeutic approaches to patients with sepsis and a derangement of coagulation. Thrombin generation proceeds via the (extrinsic) tissue factor/factor VIIa route and simultaneously occurring depression of inhibitory mechanisms, such as antithrombin III and the protein C system. Also, impaired fibrin degradation, due to high circulating levels of the fibrinolytic inhibitor plasminogen activator inhibitor, type 1 (PAI-1), contributes to enhanced intravascular fibrin deposition. Interestingly, an extensive cross-talk between activation of inflammation and coagulation exists, where inflammatory mediators (such as cytokines) not only activate the coagulation system, but vice versa activated coagulation proteases and protease inhibitors may modulate inflammation through specific cell receptors. Supportive strategies aimed at the inhibition of coagulation activation may theoretically be justified and have been found beneficial in experimental and initial clinical studies. These strategies comprise inhibition of tissue factor-mediated activation of coagulation or restoration of physiological anticoagulant pathways, for example by means of the administration of recombinant human activated protein C.
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PMID:New treatment strategies for disseminated intravascular coagulation based on current understanding of the pathophysiology. 1500 Mar 46


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