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)

Deep vein thrombosis (DVT) is a frequent event in patients with spinal cord injury, even with prophylactic anticoagulant therapy. Lower limb paralysis is a known major risk factor for venous thrombosis, supposedly due to the venostasis in relation with total immobility. The main goal of this study was to evaluate the endothelial response to anoxia to determine whether recovery of fibrinolytic potential occurs in patients subjected to forced bedrest because of a spinal cord injury and whether this recovery is related to the incidence and/or evolution of DVT. We evaluated vascular endothelium reactivity in the lower limbs no longer submitted to the hydrostatic pressure of the erected position in 15 patients with paraplegia or tetraplegia and in 10 normal volunteers after venous occlusion produced by the application of 10 cm Hg pressure to the lower limb for 15 min comparatively to the upper limb used as reference. Among the 15 patients, 10 whose spinal cord injury had occurred 1 to 6 months earlier were still receiving prophylactic anticoagulant therapy, whereas the five other patients were not receiving prophylactic anticoagulants because the injury dated back 6 months or more. After venostasis, tissue plasminogen activator (tPA) increased significantly in both patients and controls in the upper limb (tPA levels twofold and threefold respectively in controls and patients) but showed no significant changes in the lower limb; prolonged immobility did not allow recovery in the lower limbs of a level of fibrinolytic responsiveness identical to that in the upper limbs. The plasminogen activator inhibitor (PAI1) remained unchanged after anoxia, although wide interindividual variations were seen. Natural coagulation inhibitors and circulating blood stigmates of hypercoagulability were measured. None of the patients had abnormally low levels of coagulation inhibitors (ie, antithrombin III, protein C and protein S levels were normal). Seventy-five per cent of patients (prophylactically anticoagulated or not) had very high levels of fibrin degradation products (D. Dimer levels sevenfold to eightfold those of the controls), but all patients had normal levels of thrombin-antithrombin complexes and prothrombin fragments 1 + 2. The permanence of the thrombotic process characterized by an increase in D. Dimer levels without recovery of fibrinolytic potential suggests a proposal for the patients an indefinite antithrombotic treatment at curative doses.
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PMID:Endothelial fibrinolytic reactivity and the risk of deep venous thrombosis after spinal cord injury. 907 65

Protein Z is a vitamin-K-dependent plasma glycoprotein synthesized by the liver, showing great structural similarity to other vitamin-K-dependent coagulation factors such as factors II, IX, X and protein C and S. Protein Z seems to assist haemostasis by binding thrombin and promoting its association with phospholipid surfaces, and it downregulates coagulation by forming a complex with the plasma protein-Z-dependent protease inhibitor, which inhibits activated factor Xa. Studies in patients with a bleeding tendency of unknown origin during and after surgery displayed diminished protein-Z-concentrations in about 50 % of the patients with recurrent bleeding. We report about a 19 year old patient, who suffers from a posttraumatic paraplegia subTh 8 since childhood. In 1998 a correction operation in order to reduce scoliosis with restrictive ventilatory defects had to be stopped before successful spondylodesis because of massive bleeding. After a second intraoperative bleeding incident and exclusion of other more frequent thrombocytic or plasmatic causes of hypocoagulability protein-Z-deficiency finally was diagnosed. Under substitution of protein-Z using PPSB (Beriplex P/N) a repeatedly postponed implantation of a sphincter-externus (Brindley-) stimulator could be performed without bleeding complications in 2001, and this was also true for two other urological interventions in 2002. This report about repeated life-threatening intraoperative bleeding in a patient with protein-Z-deficiency, which could be successfully counteracted using selected plasma concentrates with guaranteed protein-Z-amounts, underlines the importance of protein-Z-assessment in some rare cases of bleeding tendency of "unknown origin" and documents the preventive plasma Protein-Z-levels achieved with the substitution of PPSB.
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PMID:[Protein-z-deficiency as a rare case of perioperative bleeding]. 1297 41