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)

To evaluate the occurrence of hypercoagulability during treatment with L-asparaginase (L-ase), thrombin-antithrombin complex (TAT) and D-dimer levels in plasma were serially measured in 15 consecutive adult patients with acute lymphoblastic leukaemia or lymphoblastic lymphoma who had recently completed a chemotherapy cycle with cytosine arabinoside and methotrexate. The first eight patients (group A) received i.v. L-ase alone (20,000 U/m2 on alternate days over 10 d); the last seven patients (group B) received, in addition to L-ase, bolus injection of antithrombin concentrate (2000 U) on alternate days for a total of six administrations, beginning with the second L-ase infusion. Increased levels of TAT (P less than 0.05) and D-dimer (P less than 0.01) were observed prior to L-ase, possibly related to inflammation and cytolysis secondary to previous chemotherapy. In patients treated with L-ase alone, further elevation of TAT (P less than 0.05) and persistence of increased D-dimer were observed, associated with marked reduction of the anticoagulant activities of protein C, protein S and antithrombin III. At variance, in patients receiving antithrombin III supplementation there was no increase of TAT and a normalization of D-dimer levels occurred during L-ase treatment. In these patients, mean plasma antithrombin III activity was maintained at levels higher than 70% of normal throughout the treatment. The rate of decline of fibrinogen, factor IX, protein C and protein S was unaffected by antithrombin III supplementation, indicating that hypercoagulability has little if any relevance for the reduction of coagulation factors and inhibitors induced by L-ase treatment. The usefulness of antithrombin III concentrates in preventing thromboembolic complications in patients submitted to L-ase treatment remains to be determined.
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PMID:Hypercoagulability during L-asparaginase treatment: the effect of antithrombin III supplementation in vivo. 218 89

The concept of the haemostatic balance was reviewed, and its potential role in the regulation of tissue repair and the pathogenesis of thrombotic processes was surveyed. Physiological activation of coagulation appears to be dominated by effects of degenerated and injured cells of the vascular wall causing local release of thromboplastin and exposition of activating surfaces. Inhibition of coagulation impairs its progression and the non-thrombogenic nature of the normal endothelium is chiefly caused by the binding of inhibitory components (antithrombin-III, protein C) to specific receptor sites. Physiological activation of fibrinolysis appears to be triggered by and limited to the fibrin because of a specific affinity to fibrin of plasminogen and plasminogen activators. Systemic activation of fibrinolysis is prevented by primary (alpha 2-antiplasmin) and secondary (alpha 2-macroglobulin, alpha 1-antitrypsin) plasmin inhibitors. A plasminogen binding protein (histidine-rich glycoprotein), plasmin inhibitors and activator inhibitors appear to contribute to the regulation of the initial phase of fibrinolysis. A deviation from normal of the dynamic balance, regulating fibrin formation and resolution, may lead to a haemorrhagic and/or a thrombophilic state. Described were the optimization of selected methods for assessment of variables involved in the haemostatic balance. An overestimation of plasminogen concentrations in plasma may occur in patients with elevated levels of fibrinogen or fibrin degradation products, when using assays based on the activation of plasminogen by streptokinase followed by the hydrolysis of a synthetic chromogenic substrate. This source of error could be eliminated by presence of fibrinogen in excess in the plasminogen assay, thereby securing maximum stimulation of the plasminogen-streptokinase complex. The presence of cryoglobulin in plasma interferes with the assessment in euglobulins of plasminogen activator activities. Experiments indicate that tissue-type plasminogen activator adsorb cryoglobulins and that a cold-promoted activation of the factor XII-dependent proactivator system of fibrinolysis is related to the presence of cryoglobulins. Experiments supported the existence of an as yet not characterized factor XII-dependent proactivator. Strictly optimized procedures for the preparation of euglobulins for the accurate determination of plasminogen activators were recommended. The determination of plasminogen activator inhibition in plasma was optimized and simplified. The amidolytic assay of antithrombin-III was shown to be influenced by adsorption to laboratory utensils and aggregation of thrombin. This error could be corrected by protection with additives (Tween 80, polyethyleneglycol 6,000), which also improved the solubility of the chromogenic substrates in aqueous media. The role of thrombosis in myocardial infarction was reviewed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The haemostatic balance in groups of thrombosis-prone patients. With particular reference to fibrinolysis in patients with myocardial infarction. 219 35

Early diagnosis and immediate treatment of the disease responsible for DIC are most important for successful therapy of DIC. Furthermore, it is also necessary to use anticoagulant agents in most cases of DIC. The agents may be classified on the basis of their mode of anticoagulant action into three groups: ones with antithrombin effect, ones with anti-Xa effect or ones with both effect, and each agent is hoped to be chosen appropriately for development of DIC in near future. At present, such anticoagulant agents as standard heparin, antithrombin-III concentrate, gabexate mesilate, nafamostat mesilate, MD-805, low molecular weight heparin, heparan sulfate, activated protein C, are known as drugs for DIC, and each of them was effective for improvement from DIC in our experience. Antifibrinolytic agents, which have been considered to be contraindicated for therapy of DIC, may be good indication for selected cases of DIC with enhanced fibrinolysis such cases as acute promyelocytic leukemia. Antiplatelet agents may be available for some cases of chronic DIC.
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PMID:[Treatment of disseminated intravascular coagulation]. 221 66

Patients with acute myeloid leukemia have multiple hemostatic and thrombotic complications, which may or may not result from disseminated intravascular coagulation. Previous studies incorporating routine coagulation analyses failed to detect any clinically useful information in most of these patients. In this study, the first comprehensive evaluation of the various aspects of the hemostatic system in a population of patients with acute myeloid leukemia was performed. Eighteen patients (23-71 years of age) were studied at either diagnosis or relapse. Hemostatic studies were performed at onset and on days 3, 7, and 30 after initiation of therapy. The bone marrow blast counts ranged from 8% to 98%; prothrombin time and activated partial thromboplastin time showed only minor prolongations in a few of these patients. However, in all patients measurement of platelet-associated markers revealed elevated platelet factor 4 and thromboxane B2 and normal 6-keto-prostaglandin F1 alpha levels. Fibrinolytic markers showed an increase in D-dimer and tissue plasminogen activator and a decrease in alpha 2-antiplasmin levels. Plasminogen, plasminogen activator inhibitor, and fibrinogen levels were normal. Coagulation markers demonstrated a decrease in protein C and antithrombin III levels and an elevation of the thrombin-antithrombin complex. The pretreatment values for all hemostatic markers studied were similar to the values obtained on days 3, 7, and 30 during treatment. This investigation demonstrated a subclinical activation of the components of the hemostatic system possibly leading to a hypercoagulable state. Although only six patients (33%) experienced hemorrhagic complications, the risk of bleeding and/or thrombosis was strongly evident in all patients. The significance of finding abnormal levels of specific molecular markers of hemostasis will be established in the future application of such markers in clinical evaluations of leukemic patients known to be at risk for coagulation disorders.
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PMID:Global and molecular hemostatic markers in acute myeloid leukemia. 222 Jun 67

In this study, blood coagulation and fibrinolytic parameters were measured in maternal blood and fetal umbilical cord blood in 200 normal pregnant women and in 46 with severe toxemia of pregnancy (Toxemia), and the relationships between fetal growth and concentrations protein C (PC), antithrombin-III (AT-III) and alpha 2-plasmin inhibitor (alpha 2-PI) were studied. 1. Significant increases in fibrin degradation products (FDP) and in plasminogen (Plg), AT-III and PC were found in maternal blood of Toxemia. A significant increase in AT-III and a decrease in alpha 2-PI and PC were observed in cord blood from these patients. 2. The platelet count (Pl) tended to be low in patients with Toxemia complicated by fetal growth retardation (IUGR). 3. Pl and fibrinogen (Fib) tended to be high in Toxemia complicated by normal fetal growth. 4. PC increased from early pregnancy, and a further increase was observed in the puerperium. 5. The PC concentration correlated with the AT-III but not with the alpha 2-PI concentration in maternal blood. 6. PC in cord blood was lower than that in maternal blood, and was correlated with AT-III and alpha 2-PI. 7. In patients with Toxemia, PC was reduced in both maternal and cord blood, and this correlated with AT-III as well as alpha 2-PI in maternal blood. 8. PC was low in Toxemia complicated by hypertension and proteinuria. These results suggest the involvement of FDP, AT-III, PC and Plg in the pathogenesis of Toxemia, and that the Pl, Fib, FDP and alpha 2-PI concentrations are related to fetal growth. Therefore, the PC and AT-III concentrations appeared to be a useful index for the blood coagulation and fibrinolysis in pregnant women and appeared to be important factors in the degree of Toxemia and IUGR.
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PMID:[Blood coagulation and fibrinolytic studies in patients with toxemia of pregnancy]. 227 12

In a longitudinal study the plasma levels of antithrombin-III, alpha 2-macroglobulin, alpha 2-antiplasmin, histidine-rich glycoprotein, and protein C were followed in two groups of patients with acute myocardial infarction (AMI), one with and one without deep vein thrombosis (DVT). None of the sequentially studied periods revealed significant differences between the two groups of patients. However, small but consistently higher levels of histidine-rich glycoprotein in patients with DVT suggested the existence among patients submitted for myocardial infarction of a subgroup with increased thrombophilic potential. It was concluded that the inhibitors studied are of little value as possible indicators of the presence of DVT at early stages of the disease when clinical signs are absent and when antithrombotic prophylaxis should preferably be initiated.
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PMID:On the significance of antithrombin-III, alpha 2-macroglobulin, alpha 2-antiplasmin, histidine-rich glycoprotein, and protein C in patients with acute myocardial infarction and deep vein thrombosis. 241 53

The well-known coagulation inhibitors antithrombin and protein C, and the more recently described inhibitors, heparin cofactor II and extrinsic pathway inhibitor, were measured in plasma during a 7-day observation period, from patients with pneumonia (n = 13), and in stroke patients with infarction (n = 9) and haemorrhage (n = 9). In patients with pneumonia, elevated fibrinopeptide A levels and subnormal antithrombin and protein C levels suggested some degree of consumption of the inhibitors. Later, an increase was observed for all the inhibitors, but was most conspicuous for heparin cofactor II which reached high normal values. C-reactive protein, initially markedly elevated, decreased rapidly. This finding suggests that heparin cofactor II might act as a delayed acute phase reactant. In stroke patients only small, not statistically significant, changes occurred during the observation period, except for heparin cofactor II which increased in patients with haemorrhagic stroke.
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PMID:Coagulation inhibitor levels in pneumonia and stroke: changes due to consumption and acute phase reaction. 247 68

Fatal multiple organ failure after severe infection may be related to an early activation of protease cascade systems. This study aimed to relate changes in coagulation, fibrinolysis, and kallikrein to shock and outcome. Of 53 patients with severe infection, 30 did not develop shock, 12 survived septic shock, and 11 died from organ failure after septic shock. No patient had overt disseminated intravascular coagulation. We measured 17 components of the coagulation/fibrinolysis/kallikrein pathways on admission and on the next 2 days. High values for fibrinogen, factor VIII:C, von Willebrand factor antigen, and D-dimer were seen in all patients; factor XII, prekallikrein, factor VII, antithrombin, protein C, and fibronectin were low. The patients thus appeared to be hypercoagulable. These disturbances were more pronounced in septic shock survivors, who also had low plasminogen and antiplasmin, indicating ongoing fibrinolysis. Nonsurvivors of sepsis were distinguished mainly by high plasminogen activator inhibitor values; this suggests an impaired functional fibrinolysis in fatal sepsis, with possible therapeutic implications. Cryoprecipitate infusion increased the fibronectin concentration, but did not influence the other factors studied.
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PMID:Coagulation, fibrinolysis, and kallikrein systems in sepsis: relation to outcome. 250 62

We have evaluated the quantitative relationship between lipopolysaccharide (LPS, endotoxin), fibrinopeptide A (FPA), antithrombin (AT), protein C (PC) and extrinsic pathway inhibitor (EPI) in plasma from 39 consecutively admitted patients with systemic meningococcal disease (SMD). The most severely ill patients with fulminant meningococcal septicemia (n = 13, 6 dead) had significantly (p less than 0.01) higher plasma levels of LPS and FPA and lower levels of PC and AT on admission as compared with the less severe clinical presentations (n = 26, 1 dead). The levels of EPI on admission were significantly (p less than 0.05) higher in nonsurvivors vs survivors with fulminant septicemia. As the disease progressed, the levels of LPS, FPA, AT and PC declined, while the levels of EPI increased. Three of six nonsurviving septicemic patients had levels of EPI greater than 200% within 16 hours of admission vs two of 30 survivors (p = 0.02). The results suggest that increasing levels of LPS in SMD elicit increasing consumption coagulopathy, contributing to the organ pathophysiology. The kinetics of EPI, inhibiting the thromboplastin-FVIIa-FXa complex, differs markedly from the kinetics of AT and PC i.e. increases as opposed to decreases.
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PMID:The quantitative association of plasma endotoxin, antithrombin, protein C, extrinsic pathway inhibitor and fibrinopeptide A in systemic meningococcal disease. 251 Mar 54

In order to carry out a multicenter study aimed at understanding the association of hemostatic factors with atherosclerotic vascular disorders for the Atherosclerosis Risk In Communities (ARIC) Study, we compared a blood collection and processing system developed in our laboratory with the state-of-the-art-procedures. The salient features of our system included the use of a new phlebotomy set for venipuncture, the use of Millipore filters for removing platelet residues in the plasma and the use of a mixture of anticoagulants and antiplatelet agents for inhibiting the in vitro activation of platelets, coagulation and fibrinolytic system. The results derived from systematic evaluations indicate that this newly developed system yields the lowest values of plasma beta TG, PF 4 and FPA when compared with the reported values. The technique also gave reliable values of representative hemostatic measurements such as fibrinogen, factor VII, factor VIII, von Willebrand factor, antithrombin-III, protein C, tissue-type plasminogen activator, and serum thromboxane B2. Further experiments revealed that the samples withstood temporary storage at -70 degrees C and overnight "shipping" manipulations without significant changes in the hemostatic values. We conclude that the described blood collection and processing system may be a valuable asset for conducting multicenter cooperative clinical trials and epidemiologic studies involving blood collection by multiple field centers or clinics.
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PMID:ARIC hemostasis study--I. Development of a blood collection and processing system suitable for multicenter hemostatic studies. 252 84


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