Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.69 (APC)
 16,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lupus anticoagulant, concentrations of anticardiolipin antibodies, antithrombin III, plasminogen, (free) protein S, protein C, prothrombin, platelet counts, and bleeding times were determined in 74 lupus patients (58 with systemic lupus erythematosus; 16 with lupus-like disease) to establish the presence of risk factors for thrombosis in these patients. Of the variables evaluated, lupus anticoagulant had the strongest association with a history of thrombosis. Both positive anticardiolipin antibody concentrations and the presence of (mild) thrombocytopenia were significantly associated with a history of thrombosis and the presence of lupus anticoagulant. Reduced concentrations of antithrombin III, plasminogen, (free) protein S, and protein C were found in some patients but were not associated with either thrombosis or lupus anticoagulant. Mean concentrations of total protein S were significantly lower in patients with thrombosis than in those without and in patients with lupus anticoagulant than in those without. The antigenic concentration of prothrombin was reduced in 3/74 (4%) lupus patients. These three patients had lupus anticoagulant but no history of thrombosis, which suggests that a low prothrombin concentration protects patients with lupus anticoagulant from the development of thrombosis. A prolonged bleeding time was associated with the presence of lupus anticoagulant but not with a history of thrombosis. Analysis by stepwise logistic regression did not disclose additional risk factors for thrombosis in lupus patients with lupus anticoagulant. Increased antithrombin III concentrations and decreased free protein S concentrations are often found in lupus patients, unrelated to lupus anticoagulant or thrombosis.
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PMID:Risk factors for thrombosis in lupus patients. 251 63

The profile of blood coagulation and fibrinolysis was studied in detail in eight patients with acute thrombotic thrombocytopenic purpura (TTP). In the majority of the patients, fibrinogen, factor XIII, antithrombin III, alpha 2-plasmin inhibitor, plasminogen, and alpha 2-macroglobulin were normal, whereas FDP, plasmin-alpha 2-plasmin inhibitor complex, and tissue-type plasminogen activator antigen were marginally or moderately elevated. Low fibronectin values were observed in four patients. Protein C and C4b-binding protein were nearly normal, whereas total protein S and free protein S were reduced in five and six patients, respectively. A positive correlation was found between total protein S and C4 and between free protein S and C3. von Willebrand factor antigen (vWf:Ag) and ristocetin cofactor (RCof) were either normal or elevated, but RCof/vWf:Ag ratio was decreased in seven patients. Crossed immunoelectrophoresis and sodium dodecyl sulfate (SDS)-agarose gel electrophoresis revealed that the large vWf multimers were either absent from or relatively decreased in all patients except one. In addition, one patient had unusually large vWf multimers, and a low-molecular-weight vWf fragment was apparently observed in three patients. These findings indicate that the intravascular generation of thrombin and plasmin was minimal in TTP and suggest that the alterations of the vWf molecule were caused not only by consumption through its participation in platelet thrombus formation but also by accelerated proteolysis. Low protein S values would be related to the immunological abnormalities underlying TTP.
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PMID:Coagulation studies in thrombotic thrombocytopenic purpura, with special reference to von Willebrand factor and protein S. 252 Dec 76

This study prospectively evaluates hypercoagulable states in patients under 51 years of age undergoing lower extremity revascularization for ischemia and assesses early outcome after operation. Twenty patients whose ages range from 23 to 50 years (mean 40.8 years) were identified prospectively who underwent lower extremity revascularization and evaluation of hypercoagulability. Fifteen patients were male (75%), 10 were black (50%), six had hypertension (30%), and four were diabetic (20%). All but two were cigarette smokers (90%). Seven aortoiliac procedures and 13 infrainguinal procedures were performed. Six patients had one or more abnormalities of regulatory proteins (protein S deficiency, four; protein C deficiency, three; presence of lupus-like anticoagulant, three; plasminogen deficiency, two). Eight of 17 patients in whom platelet aggregation profiles were obtained showed increased reactivity (47%). Only 4 of 17 patients (24%) were normal when tested for all parameters. Arterial or graft thrombosis developed in four of the 20 patients within 30 days after operation. Hypercoagulability was found in all four patients whose revascularizations failed. A high incidence of hypercoagulable states was found in patients under 51 years of age with lower limb ischemia requiring revascularization. Hypercoagulability may have contributed to early postoperative thrombosis of the vascular procedure.
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PMID:Hypercoagulable states and lower limb ischemia in young adults. 252 8

We studied the coagulation cascade, fibrinolytic system and naturally occurring anticoagulants in a group of 14 patients with end-stage renal disease maintained on continuous ambulatory peritoneal dialysis (CAPD). The results were compared with those obtained in a group of ten normal volunteers. Plasma procoagulant activities of factors XII, XI, IX, VIII, VII, X and II were significantly greater in the CAPD group as compared to the normal control group. Likewise plasma concentrations of total and free protein S were increased in the CAPD group. Although the mean value for plasma factor V activity in the CAPD group was higher than that found in the control group the difference did not attain statistical significance. In addition plasma fibrinogen concentration and factor VIII-related antigen level were significantly increased in CAPD patients. No significant difference was found between the CAPD patients and the control group with respect to plasma levels of protein C, antithrombin III, plasminogen or alpha 2-antiplasmin. In summary, the results demonstrate a tendency for increased levels of various coagulation factors and protein S in CAPD patients with no significant alterations in the levels of various fibrinolytic and endogenous anticoagulant agents, i.e. antithrombin III and protein C. The clinical significance and the mechanism responsible for the observed changes require further investigation.
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PMID:Coagulation cascade, fibrinolytic system, antithrombin III, protein C and protein S in patients maintained on continuous ambulatory peritoneal dialysis. 252 49

The observation of protein S deficiency in a family six members of which had recurrent cerebral strokes prompted a prospective study so far including 33 patients (23 women, 10 men) with cerebral arterial thrombosis at the age of 19 to 57 years (mean 31 years) admitted to the neurological departments of several hospitals. Diseases associated with cerebral arterial occlusions, such as arterial embolism or hematological, infectious and immunological disorders were not found. The following parameters were tested: antithrombin III, protein C, plasminogen, fibrinolytic capacity after infusion of DDAVP, and free and total protein S. Prothrombin times of all patients were within normal ranges; no woman had taken oral contraceptives for at least 3 months before examination. In 9 patients (8 women, 1 man) a decrease of free and total protein S was found; in 4 additional patients (2 women, 2 men) only the free protein S was reduced. Protein S deficiency was confirmed as an inherited defect in 5 cases by family studies, but excluded in one (both parents normal). Protein S deficiency was combined with protein C deficiency in 3 cases, plasminogen deficiency in 2 cases and reduced fibrinolytic capacity in two. Venous thromboembolism occurred only in one of the 13 patients with protein S deficiency and cerebral arterial thrombosis. Protein S deficiency may be found-mainly as a familial trait-in a substantial percentage of younger patients with "idiopathic" cerebral arterial thrombosis.
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PMID:[Protein-S deficiency in young patients with thrombotic brain infarction]. 252 95

55 consecutive patients (28 males and 27 females) who had suffered from (recurrent) venous and/or arterial thromboembolism were evaluated for laboratory findings of thrombophilia. At the time of investigation, 15 patients were taking oral anticoagulants. In addition to patient and family history and clinical examination, a coagulation profile, euglobulin clot lysis time before and after venous occlusion, assays of plasminogen, antithrombin III, protein C (PC), free protein S (PS[f]), and C4b binding protein bound protein S (PS[b]) were obtained. 2 patients not orally anticoagulated had partial PD deficiency with functional PC activity values of 53% and 57% respectively, as compared to normal human plasma (NHP). Functionally active PS(f) was found to be lower than normal in 14 patients not taking oral anticoagulants and without signs of hepatopathy. In 4 of these 14 patients partial PS deficiency was present (PS[f] between 7 and 37% of NHP, and PS[b] between 51 and 86% of NHP). In one of these 4 subjects the hereditary nature of PS deficiency was proven by investigation of family members. In 3 of the 14 patients a shift from PS(f) (between 34 and 66%) towards PS(b) (124-141%) was found. The remaining 7 patients showed subnormal PS(f) values (56-64%) and normal PS(b) values (78-105%). In the patients receiving oral anticoagulant therapy, PC and PS levels were diminished. Statistically there was no close relationship between PC and PS levels on the one hand and prothrombin time values on the other. In anticoagulated patients, therefore, PC or PS deficiency can only be diagnosed by investigation of members of the propositus's family.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Hemostasis parameters in 55 patients with venous and/or arterial thromboembolisms]. 252 96

Disorders that predispose children to venous thrombosis include inherited abnormalities of antithrombin III, protein S, protein C, fibrinogen, and plasminogen. Arterial thrombosis may result from disorders that produce endothelial damage, abnormal vascular flow, or increased platelet aggregation. We present here a case of a child who had recurrent thromboses and discuss the evaluation and management of such patients.
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PMID:Inherited hypercoagulable states in children. 252 3

The effect of human skin mast cell tryptase on human plasma proenzymes (prothrombin, coagulation factor XII, complement C1s, protein C and plasminogen) was investigated. Tryptase had no effect on these proenzymes, when incubated with them at 37 degrees C for up to 90 min, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by the ability to hydrolyze specific peptide p-nitroanilide substrates. After prolonged treatment with tryptase, proenzymes could be fully activated with their specific activators. The results indicate that tryptase neither activates these plasma proenzymes nor inactivates the corresponding active enzymes. As a positive control, the tryptase preparation was also incubated with human fibrinogen and rat thymus histones. Prolonged treatment with tryptase increased the thrombin-induced clotting time of fibrinogen. Tryptase also efficiently hydrolyzed histone H1 from rat thymus. Histones H3/H2B and H2A were hydrolyzed less efficiently than H1, and no hydrolysis of histone H4 by tryptase was detected under the experimental conditions.
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PMID:Effect of human mast cell tryptase on human plasma proenzymes. 253 Jan 78

A 38-year-old man of recurrent episodes of multiple cerebral infarctions with protein C abnormality was reported. He had six episodes of visual disturbance within a year. The neurological examination revealed bilateral visual loss and impaired visual field except for small central area. However, there were no abnormalities in the deep tendon reflexes and muscle strength of all extremities and cerebellar examinations. CT scan revealed multiple low density areas in the bilateral posterior lobes, and cerebral angiography demonstrated the severe stenosis of the ganglionic portion and the supraclinoid portion of the right internal carotid artery. Plasma levels of antithrombin-III activity, plasminogen activity, protein C activity, protein C antigen and protein S antigen were 105, 106, 28, 166 and 120%, respectively. Because only protein C activity decreased markedly, a diagnosis of protein C abnormality was established. We started warfarin therapy under the administration of concentrates of factor IX complex, since then there has been no cerebral accident.
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PMID:[A case of recurrent multiple cerebral infarctions with protein C abnormality]. 259 39

Results of histologic, biochemical, and immunologic studies suggest that coagulation and fibrinolysis are possibly important in kidney graft rejection, but there is no information about how or why they are involved. The touchstones of their importance are histologic reports of platelet-fibrin thrombi in glomerular vessels of rejecting kidneys. Most of the nonhistologic studies have made use of functional assays aimed at measuring coagulation changes in blood. Little use has been made of immunoassays, and there are almost no studies of recently described anticoagulant systems, such as the protein C pathway. Endothelial cells form the interface between donor and recipient tissues. Antibody or thrombin-stimulated endothelium produces PAF, and thrombin-stimulated endothelium produces both plasminogen activators and plasminogen-activator inhibitors. As important as these reactions might be, information about them has been obtained with the use of either in vitro experiments or artificial systems, and there is no direct evidence that they are relevant to transplantation. However, these observations do show that tissue factor, PAF and fibrinolytic activities can be immunologically triggered. This opens the possibility that allogeneic recognition may initiate the triggering process. The clotting and fibrinolytic phenomena discussed in this overview were consequences of allogeneic recognition. Such recognition reactions cause monocytes and macrophages to produce tissue factor, which is a potent initiator of coagulation. Endothelial cells also can be stimulated to elaborate tissue factor by immune complexes, interleukin-1, or endotoxin. These observations give cause to speculate that the link between immunity and coagulation in kidney transplantation could be products of allogeneic recognition that activate Factor VII and lead to fibrin deposition. If true, this suggests new approaches to the old problems of diagnosis and treatment of rejection reactions in organ transplantation.
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PMID:Hemostasis and fibrinolysis in renal transplantation. 265 65


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