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)

Mesenteric venous thrombosis is a rare insidious event that is difficult to diagnose. Approximately half the cases in the past were deemed "primary" or "idiopathic." These cases were also frequently associated with a previous history of thromboembolism and a family history positive for thromboembolism. Inherited hypercoagulable disorders, such as deficiency of protein C, protein S, or antithrombin III, will probably explain many "primary" cases. Prompt diagnosis, especially with modern imaging techniques, and prompt anticoagulant therapy decrease mortality.
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PMID:Evolution of our understanding of the pathophysiology of primary mesenteric venous thrombosis. 153 72

Hypercoagulable states are disorders of blood coagulation, which include deficiencies of natural anticoagulants, disorders of the fibrinolytic system, presence of antiphospholipid antibody and abnormalities of platelet function. These disorders are well known causes of venous thromboembolic disease and are being recognized in association with arterial thromboembolic occurrences with increasing frequency. The performance of standard prosthetic vascular reconstructions may result in disastrous outcomes in patients with unrecognized and untreated hypercoagulable states. From 1986 to 1990, we identified 12 patients with hypercoagulable states, six of whom presented with evidence of arterial thromboembolism. All of the patients were men who smoked and were somewhat younger than the usual patient with atherosclerosis. Their ages ranged from 41 to 62 years. Four patients presented with ischemic rest pain, one patient with blue toe syndrome and one with rapidly progressive claudication. Four patients had undergone prior vascular reconstruction and two had previous pulmonary emboli. Evaluation of these patients to identify hypercoagulability included determinations of prothrombin time (PT) and partial thromboplastin time (PTT), platelet count, antithrombin III, protein C, free protein S and total protein S levels, along with platelet aggregometry. Two patients had protein S deficiency, one had protein C deficiency, one patient had protein C and S deficiency and two patients had hyperaggregable platelets. Four patients had prosthetic reconstructions and two had autogenous reconstructions. Three of the four patients undergoing prosthetic reconstructions had subsequent loss of limb and one patient died. Only one patient with prosthetic reconstruction had a patent graft on long term anticoagulation. Both patients undergoing autogenous procedures had successful revascularization with limb salvage.
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PMID:Hypercoagulable states in arterial thromboembolism. 154 37

Hereditary protein S deficiency is an established risk factor for venous thrombosis. The common sites of thrombosis are the deep leg and pelvic veins. We report on a 38-year-old female patient with hereditary protein S deficiency and a previous history of deep leg vein thrombosis, who developed thrombosis of the cerebral straight and superior sagittal sinus while taking oral contraceptives. The diagnosis was established by computerized tomography and carotid angiography. Lysis of the thrombus occurred during heparin treatment. The hereditary nature of protein S deficiency was documented by family studies, since nine additional family members deficient in protein S were identified. Nineteen published cases of cerebral vein thrombosis and a deficiency of either anti-thrombin III, protein C, or protein S were reviewed. Compared with patients without a deficiency state, the clinical features of cerebral vein thrombosis were similar except for an earlier onset and a positive medical history of venous thromboembolic events in a considerable number of patients.
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PMID:Cerebral sinus thrombosis in a patient with hereditary protein S deficiency: case report and review of the literature. 155 92

In a study of 20 patients with hypercholesterolemia (type IIa) the effects of lovastatin (20-80 mg/day) on various clotting and thrombosis parameters were monitored for 12 months. On 11 occasions various cholesterol fractions and clotting parameters were determined in each patient. In addition, the clotting inhibitors AT III, protein C, protein S, and C1-esterase inhibitor and the fibrinolysis parameters plasminogen and alpha 2-antiplasmin were examined. Platelet function was monitored on the basis of spontaneous and induced (collagen, ADP, epinephrine, ristocetin) aggregation. Lovastatin in the above dosage brought about a 66 mg/dl (from 320 +/- 12.6 to 254 +/- 12.0 mg/dl) reduction in the total cholesterol level and a 56 mg/dl (from 244 +/- 11.4 to 188 +/- 12.1 mg/dl) reduction in LDL cholesterol at the end of the study. Fibrinogen showed a significance decrease during the study period, whereas PT and aPTT remained unaffected. The initial slopes of the ADP-induced platelet aggregation revealed a significant decrease. C-reactive protein and platelet count remained within the normal range, indicating no significant change. Thrombin clotting time, AT III, C1-esterase inhibitor, plasminogen, and alpha 2-antiplasmin were not modified. Protein C and S behaved in a contradictory way, but remained within the normal range. Long-term treatment with lovastatin was associated with a significant reduction of fibrinogen levels and platelet aggregation induced by ADP in type-IIa hypercholesterolemic patients. These alterations, as well as their role in cardiovascular disease, should be the subject of further investigations.
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PMID:Effects of long-term treatment with lovastatin on the clotting system and blood platelets. 158 7

The prospective study reported here evaluated the relationship between coagulopathy, catecholamines, and outcome in severe head trauma. Thirty-six trauma patients (10 with penetrating injuries, 26 with blunt injuries, 50% overall mortality) were evaluated. These patients had severe head trauma (Glasgow Coma Scale score less than 9). Blood was analyzed for platelet count, prothrombin time (PT), partial thromboplastin time (PTT), and fibrinogen, D-dimer, antithrombin III, protein C, and protein S levels. A 24-hour urine sample was collected for vanillylmandelic acid (VMA), normetanephrine, and metanephrine determinations. A control group of five patients undergoing elective neurosurgery was also studied. Statistically significant differences between head injury survivors and nonsurvivors were present for platelet count, PT, and fibrinogen activity. There were no differences in the results of the other coagulation tests or in urinary catecholamine levels. The trauma patients differed from the elective neurosurgery patients with regard to D-dimer levels, PT, PTT, protein C levels, and urinary normetanephrine concentrations. Head trauma patients have a coagulopathy that is absent in patients following elective neurosurgical procedures. The coagulopathy may correlate with poor survival in head trauma and may be related to a catecholamine surge.
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PMID:Coagulopathy and catecholamines in severe head injury. 158 49

Protein C together with its plasmatic cofactor protein S and antithrombin III probably represent the most important plasmatic inhibitor in coagulation. Protein C deficiency constitutes a high risk factor for venous thrombosis. Cerebral venous thrombosis is a manifestation which is scarcely referred to in protein C deficiency. The case of a 32 year old patient with protein C deficiency is presented. The patient was admitted for an endocraneal hypertension syndrome. CT and MR demonstrated multiple hemorrhagic cerebral infarctions. Arteriography confirmed vertebral venous thrombosis. Only six cases sufficiently documenting cerebral venous thrombosis due to protein C deficiency were found in the literature. In most cases coadjuvant factors exist predisposing thromboembolic disease. The present clinical case demonstrates the importance of considering protein C deficiency in the diagnosis of cerebral venous thrombosis in young adults.
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PMID:[Cerebral venous thrombosis and hereditary protein C deficiency]. 159 2

The effect of subcutaneous administration of recombinant human erythropoietin (rHuEPO) on plasma natural coagulation inhibitors (protein C, protein S, and antithrombin III) was evaluated in 10 uremic patients on continuous ambulatory peritoneal dialysis (CAPD). These patients were commenced on a 16 week-course of twice weekly rHuEPO by the subcutaneous route. The hemoglobin increased significantly from 6.9 +/- 1.3 g/dl to 9.6 +/- 1.9 g/dl after subcutaneous rHuEPO treatment (p less than 0.01) at an average dose of 84 +/- 9 U/kg body wt/week. With rHuEPO therapy, a significant increase in platelet counts was observed, albeit within the normal range. A significant increase in the prothrombin time was demonstrated at 6 weeks after treatment and increased activated partial thromboplastin time was observed at 6 weeks and 16 weeks after rHuEPO administration although these measurements still remained in normal range. CAPD patients have comparable or even higher plasma levels of natural coagulation inhibitors compared with healthy controls supporting our previous findings that patients on CAPD have normal plasma levels due to an effective compensatory production despite peritoneal losses of these proteins with CAPD. No change in either the immunological or the functional activity of these natural coagulation inhibitors was demonstrated with rHuEPO therapy and clinical thrombosis was not observed during and after rHuEPO therapy. We conclude that there is no laboratory evidence of increased risk of thrombogenesis due to reduction of natural coagulation inhibitors with rHuEPO therapy.
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PMID:Effect of subcutaneous administration of recombinant human erythropoietin on plasma protein C, protein S, and antithrombin III levels in patients on continuous ambulatory peritoneal dialysis. 160 9

This study analyzed the coagulation changes in twenty patients after orthotopic liver transplantation. The procoagulant, anticoagulant, and fibrinolytic systems were studied during the first two postoperative weeks. Within the first postoperative day all extrinsic and intrinsic pathway factors became normal except factors IX, VII, and X, which recovered within the next 24 hr. Of interest are the changes in factor VIII, which reached a high concentration with an increase in its antigenic fraction during the study. However, coagulation inhibitors showed a different pattern. In fact, antithrombin III (AT-III) and protein C (PC) needed from 7 to 14 days to reach normal values. Total protein S (TPS) and free protein S (FPS) did not recover until day 7, whereas heparin cofactor II (HC-II) remained at subnormal levels throughout the study. Thrombin-antithrombin III complex (TAT) values were strikingly elevated in the immediate postoperative period. Fibrinolysis parameters showed plasminogen (PL) levels in the normal range until day 4. Antiplasmin (AP) followed a curve parallel to that of plasminogen but its levels were higher during this observation period. Similarly the initial elevation in plasminogen activator inhibitor 1 endothelial type (PAI-1) levels remained high until days 4 and 7. In summary, it can be concluded that during the postoperative phase after OLT a hypercoagulable state is developed as a result of diminished anticoagulant and fibrinolytic activity. This coagulation might be a nontechnical factor contributing to the thrombotic vascular complications of some liver recipients.
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PMID:Diminished anticoagulant and fibrinolytic activity following liver transplantation. 160 81

A simple and fast method for the quantitative determination of protein C activity in plasma is here described. The first step consists in the conversion of protein C in the test sample into activated protein C by means of an activator isolated from Southern Copperhead venom. Subsequently, the degradation of factor Va, in presence of protein C-deficient plasma, is measured by the prolongation of the prothrombin time which is proportional to the amount of protein C in the sample. The dose-response curve showed a linear relationship from 6 to 150% protein C activity and the inter- and intra-assay reproducibility was 3.5% and 5.6% respectively. In normal subjects, a mean of protein C level of 98 +/- 15% of normal pooled plasma was found. Comparison with the anticoagulant assay in samples of patients with oral anticoagulant, liver cirrhosis, disseminated intravascular coagulation and severe preeclampsia revealed an excellent correlation (r = 0.94, p less than 0.001). Also, a similar correlation (r = 0.93, p less than 0.001) existed between amidolytic assay and the method here proposed for all the samples studied without including the oral anticoagulant group. These results allowed us to infer that this method evaluates the ability of protein C to interact with protein S, phospholipids, calcium ions and factor Va.
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PMID:A novel functional assay of protein C in human plasma and its comparison with amidolytic and anticoagulant assays. 161 82

Thrombotic events occur frequently in myeloproliferative disorders, namely polycythaemia vera and essential thrombocythaemia. Standard diagnostic criteria are designed quite stringent, so that a number of patients could be underdiagnosed. Spontaneous erythroid colonies formation from bone marrow or peripheral blood in the absence of exogenous erythropoietin is considered a reliable index of myeloproliferative disorder even at early stages. Endogenous erythroid colonies (EECs) formation was assessed in 43 patients having recently suffered from venous thrombosis prior to 45 years and without a previous diagnosis of hematological disease favouring thrombosis. A screening for coagulative abnormalities associated with thrombophilia was also carried out: in 5 patients (11.6%) a plasmatic thrombogenic defect was found (quantitative deficiency of antithrombin III, 1 case, protein C, 2 cases, protein S, 1 case, and plasminogen, 1 case). In 10 patients (2 males and 8 females) (23.2%) EECs assay was positive, allowing diagnosis of myeloproliferative disease even though 7 of them did not fulfill standard diagnostic criteria. In the other 3 patients who met the criteria for diagnosis of overt myeloproliferative disease the thrombotic event was the inaugural manifestation. In all these EECs-positive patients thrombosis involved mesenteric and portal veins (n = 4), hepatic veins (n = 3), portal vein (n = 2), mesenteric vein (n = 1). One of them was simultaneously affected from congenital protein C deficiency. Thus latent or atypical forms of myeloproliferative disease as well as the overt stages were the most frequent recognized cause of splanchnic venous thrombosis, accounting for 55% of the cases of our series. On the contrary no EECs-positive subject was found among the 25 patients with other sites of thrombosis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hematological causes of venous thrombosis in young people: high incidence of myeloproliferative disorder as underlying disease in patients with splanchnic venous thrombosis. 164 18


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