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)

Protein C is, after activation by thrombin, a potent inhibitor of blood coagulation. An isolated deficiency of protein C increases the risk of thrombosis. The two forms of protein C deficiency, the heterozygous and the homozygous deficiency state, have different clinical features. Patients with heterozygous protein C deficiency are at a high risk to develop venous thrombosis and pulmonary embolism. In newborns with homozygous protein C deficiency with very low protein C levels (1%) a purpura fulminans like syndrome was observed. Heparin and coumarin derivatives are effective drugs in heterozygous protein C deficiency, homozygous patients may be treated either by replacement of protein C or coumarin derivatives. Decreased protein C levels were observed in various other diseases: Chronic and acute liver disease, disseminated intravascular coagulation, malignancy, postoperatively and during treatment with asparaginase. The role of protein C in these diseases to trigger thrombosis is not yet established.
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PMID:Clinical relevance of protein C. 352 11

A rapid assay for protein C activity in whole plasma using a protein C activator from the venom of Agkistrodon contortrix is described. Plasma samples are incubated with venom activator in the presence and absence of anti-protein C antibody for 8 minutes at 37 degrees C in microtiter plate wells, followed by addition of a chromogenic substrate for activated protein C and measurement of the absorbance at 405 nm after 10-20 minutes incubation at 37 degrees C. The difference in absorbance between plasma assayed in the presence and absence of anti-protein C antibody is used to calculate the protein C activity by reference to a dilution curve of normal plasma. With this assay, mean protein C activity in 33 normal subjects was 87%. Thirty-eight patients receiving warfarin had a mean protein C of 34%. Twenty-four patients with disseminated intravascular coagulation had a mean protein C of 24%. The venom activator appears to preferentially activate gamma-carboxylated protein C, indicating specificity for the physiologically active form of the molecule.
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PMID:Rapid amidolytic assay of protein C in whole plasma using an activator from the venom of Agkistrodon contortrix. 357 35

We have developed a variation of the solid-phase enzyme-linked immunosorbent assay (ELISA) to enable measurement of the activity and antigen levels of protein C (PC) in human plasma. With this assay it is possible to do both tests with the same sample and same microtiter plate coated with anti-PC monoclonal antibody (MCA)JTC-4, which inhibited neither activation of PC nor activity of activated PC (APC). Even in patients undergoing heparin treatment for severe disseminated intravascular coagulation, there were no detectable differences between amidolytic activity and antigen levels of PC in patients' plasma. In addition, there was a strong correlation between the immunologic levels of PC in patients' plasma determined both by polyclonal ELISA using peroxidase-labeled immunopurified antiprotein C-IgG and those found with MCA ELISA using peroxidase-labeled MCAJTC-5, which does not bind to APC. In contrast, when oral anticoagulation therapy was started, immunologic levels of plasma PC estimated by peroxidase-labeled MCAJTC-1, a MCA that recognizes a gamma-carboxyglutamic acid domain-related conformational change of PC induced by metal ions, decreased more rapidly than did either the PC level determined by polyclonal ELISA or the percent prothrombin time. This suggested that comparison of MCAJTC-1-recognized PC levels and prothrombin time may be necessary at the beginning of oral anticoagulation therapy to treat patients safely.
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PMID:Level of protein C determined by combined assays during disseminated intravascular coagulation and oral anticoagulation. 358 May 75

Five functional assays and two immunoassays for protein C (PC) were evaluated in parallel for the same plasma samples collected from healthy subjects, patients with congenital and acquired PC deficiencies or patients with conditions associated with high PC levels. For 7 patients starting warfarin therapy and for 15 patients during stabilized warfarin therapy, there were significant between-assay differences. For these groups immunoassays gave higher values than most functional assays and the latter also gave varied results, probably depending on their respective capacity for recognizing a carboxylated PC. On the other hand, there were no significant between-assay differences nor discrepancies between PC activity and antigen levels for healthy subjects (n = 39), patients with congenital PC deficiency (n = 10), myocardial infarction (n = 25), chronic liver disease (n = 19), disseminated intravascular coagulation (n = 35), in the post-operative period (n = 20) or in women taking oral contraceptives (n = 20). This comparison of PC assays indicates that PC levels measured by different functional or immunological assays are very close in the majority of clinical conditions, but not for patients on oral anticoagulants.
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PMID:Multicenter comparison of five functional and two immunological assays for protein C. 359 79

Numerous investigators have postulated that a hypercoagulable state exists in humans for a period of time before the development of thrombotic episodes. A clear biochemical definition of the prethrombotic state, however, has proved elusive due in part to the lack of reliable techniques for monitoring pertinent changes in blood coagulability. Based on recent advances in our knowledge of the biochemistry of the coagulation system, a series of highly sensitive and specific immunochemical tools has been developed that can quantitate the activities of various steps of the hemostatic mechanism in vivo at the subnanomolar level. We have established assays for F1+2 and the protein C activation peptide, which measure the cleavage of the prothrombin molecule by factor Xa and the scission of protein C by the thrombin-thrombomodulin complex, respectively. Nossel and coworkers had previously constructed similar assays for fibrinopeptide A (FPA) and fragment B beta 1-42, which monitor the cleavage of fibrinogen by thrombin and the proteolysis of fibrin I by plasmin, respectively. Substantial elevations in the levels of these markers have been found in patients with disseminated intravascular coagulation and many subjects with acute deep venous thrombosis. The F1+2 and FPA assays have been used to demonstrate that significant increments in factor Xa activity but not thrombin activity regularly occur in the blood of nonanticoagulated individuals with congenital deficiencies of antithrombin or protein C. These two disorders are known to be correlated with the subsequent development of thrombosis. Patients with protein C deficiency have also been noted to have significantly reduced plasma levels of protein C activation peptide. By using the immunoassays for FPA and B beta 1-42 in studies of postoperative patients, it has been shown that an imbalance between the procoagulant action of thrombin and the anticoagulant effect of plasmin on fibrin I polymer may induce an acquired thrombotic diathesis. Finally, we have recently demonstrated that prothrombin activation as measured by the F1+2 assay is suppressed by oral anticoagulants in the blood of patients with thrombotic diatheses. These investigations suggest that these assay techniques can be used to improve our understanding of the hypercoagulable state as well as to develop more effective treatment strategies for the prevention of thromboembolic events.
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PMID:The pathophysiology of the prethrombotic state in humans: insights gained from studies using markers of hemostatic system activation. 360 75

Severe and recurrent purpura fulminans developed in a Chinese boy at one day of age. Results of coagulation studies performed on the patient during attacks were compatible with the diagnosis of disseminated intravascular coagulation. Subsequent investigations have revealed that the patient is homozygous and that his parents are heterozygous for protein C deficiency. Cryoprecipitate and fresh frozen plasma induced a remission, and administration of warfarin has been successful in preventing recurrence of attacks for as long as 8 months without infusion of any plasma components. None of the family members who are heterozygous for protein C deficiency have had thrombotic episodes.
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PMID:Purpura fulminans in a Chinese boy with congenital protein C deficiency. 375 34

Six coagulation proteins were measured in 79 consecutive patients referred to the coagulation service for suspected disseminated intravascular coagulation. Antithrombin III, plasminogen, and alpha 2-plasmin inhibitor were measured with fluorescent substrate assays. Fibronectin, prothrombin, and protein C were measured with electroimmunoassays. Using history and physical findings and the results of a coagulation screen (prothrombin time, partial thromboplastin time, fibrinogen, fibrin[ogen] degradation products, platelet count, and peripheral smear), the 79 patients were classified into five categories: no disseminated intravascular coagulation (n = 21), elevated fibrin(ogen) degradation products without other evidence of coagulopathy (n = 44), defibrination syndrome (n = 9), microangiopathic thrombocytopenic purpura (n = 4), and primary fibrinolysis (n = 1). Because the sensitivity and specificity of each of the proteins could not easily be compared, receiver operating characteristic (ROC) curves and areas under the ROC curves were calculated for each of the six proteins as well as for the tests of the coagulation screen. The ROC curves indicated that, apart from plasminogen, the other coagulation proteins provided little additional information about the classification of the coagulopathy.
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PMID:Diagnostic efficacy of six plasma proteins in evaluating consumptive coagulopathies. Use of receiver operating characteristic curves to compare antithrombin III, plasminogen, alpha 2-plasmin inhibitor, fibronectin, prothrombin, and protein C. 376 44

We studied functional protein C activity, both anticoagulant and amidolytic, as well as protein C antigen in 30 normal subjects, several members of a family with congenital protein C deficiency, 18 patients with severe preeclampsia, 27 patients with coronary heart disease, including 15 patients with myocardial infarction and 12 with angina pectoris, 20 patients on stable oral anticoagulant therapy (thrombotest values: 3-12%) and three patients with disseminated intravascular coagulation. Protein C values measured by the coagulant assay were compared to those obtained with amidolytic and immunochemical assays. In all the groups studied, the activity assays (amidolytic and coagulant) correlated significantly with each other as well as with the immunochemical assay. In patients on oral anticoagulant therapy the coagulant assay gave lower protein C values than amidolytic and immunochemical assays. A good correlation was found between immunological and amidolytic protein C assays (r=0.90, p less than 0.001), immunological and coagulant protein C assays (r=0.93, p less than 0.001), and amidolytic and coagulant protein C assays (r=0.95, p less than 0.001) in all the samples studied without including the protein C values of patients on oral anticoagulant therapy. These results allow us to recommend the functional protein C coagulant assay in patients on stable oral anticoagulant therapy because only this assay evaluates the "in vivo" protein C function in these patients.
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PMID:Assay of protein C in human plasma: comparison of amidolytic, coagulation, and immunochemical assays. 379 19

Severe homozygous protein C deficiency is a rare but serious problem in the newborn, with a clinical presentation of purpura fulminans. We have presented such a case in an 1,870 gm female neonate. Salient clinical findings in this case include DIC associated with extensive ecchymosis and subsequent gangrene of the skin, thrombotic complications that began on the third day of life. There was no precipitating infection. The progressive gangrenous necrosis of heel and toes was refractory to heparin therapy, but there was clinical improvement after treatment with fresh frozen plasma. Our patient's level of protein C antigen was less than 3% (normal 70% to 130%). Levels of other vitamin-K-dependent factors, as well as factor V, factor VIIIC, and antithrombin III were normal. A heterozygous protein C deficiency was documented in the mother and father. Presently the child is receiving warfarin sodium (Coumadin) therapy and is clinically stable.
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PMID:Protein C deficiency. 381 Feb 23

A 57 year old man presented with apparently spontaneous lower extremity deep vein thrombosis and pulmonary embolism. He was treated in conventional fashion with intravenous heparin and oral warfarin. After 4 daily doses of warfarin the prothrombin and proconvertin (P+P) time was within therapeutic range, and heparin was stopped. Over the next six hours complete defibrination occurred, associated with severe bleeding complications. Functional protein C measured after normalization of routine coagulation tests averaged 40% of normal, and was only 3.5% of normal immediately prior to the episode of defibrination. We conclude that the very low functional protein C levels seen immediately prior to defibrination were caused by a combination of pre-existent protein C deficiency and warfarin therapy, and directly predisposed to defibrination once heparin was stopped, despite "therapeutic" warfarin anticoagulation. Exacerbation of intravascular coagulation should be considered a potential prothrombotic effect of warfarin therapy in protein C deficient individuals.
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PMID:Defibrination during warfarin therapy in a man with protein C deficiency. 383 6


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