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 association between haemostatic parameters and increased risk of myocardial infarction (MI) at a young age, we measured fibrinogen, factor VII, antithrombin III, protein C, protein S, tissue factor (TF), free form tissue factor pathway inhibitor (TFPI), plasminogen, alpha2-antiplasmin, tissue plasminogen activator (tPA), plasminogen activator inhibitor-I (PAI-I), and lipoprotein (a) in 140 young men with MI before age 45 and 150 age-matched healthy men. TF, TF/TFPI ratio, PAI-I, PAI-I/tPA ratio, plasminogen, and lipoprotein (a) in young MI patients were all significantly higher than controls, while TFPI, antithrombin II, and tPA were significantly lower (P <0.001 of each). Significant determinants of MI risk were PAI-I/tPA ratio (R2 = 0.300, P <0.001), TF/TFPI ratio (R2 = 0.049, P <0.001), antithrombin III (R2 = 0.034, P <0.001), hyperlipidaemia (R2 = 0.019, P = 0.004), diabetes (R2 = 0.014, P = 0.015), lipoprotein (a) (R2 = 0.012, P = 0.023), alpha2-antiplasmin (R2= 0.014, P = 0.012), and protein C (R2= 0.012, P = 0.018). We conclude that the imbalances of PAI-I/tPA and TF/TFPI are significantly associated with MI at a young age, perhaps mediated via impaired fibrinolytic activity.
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PMID:Imbalance of plasminogen activator inhibitor-I/ tissue plasminogen activator and tissue factor/tissue factor pathway inhibitor in young Japanese men with myocardial infarction. 1181 7

Hemostatic abnormalities in 26 patients following bone marrow transplantation (BMT) were examined. In the event-free survival group, the plasma levels of antithrombin (AT) and protein C (PC) were significantly decreased 1 and 2 weeks after BMT, and the plasma levels of thrombomodulin (TM) and tissue plasminogen activator-plasminogen activator inhibitor-1 complex (tPA-PAI-I complex) were significantly increased from 4 weeks to 13 weeks after BMT. Excepting AT, there was no significant difference in hemostatic parameters before BMT among the event-free survival, 6-month survival, and death within 6 months groups. On day 0 following BMT, only plasma AT levels were significantly lower in the 6-month survival group than in the death within 6 months group. From 1 to 3 weeks after BMT, plasma levels of AT or PC were significantly lower in the death within 6 months group than in the 6-month survival group. From 1 to 5 weeks after BMT, the plasma levels of TM and tissue type plasminogen activator-plasminogen activator inhibitor-I complex (tPA-PAI-I complex) were significantly higher in the 6-month survival group than in the death within 6 months group. From 1 to 13 weeks after BMT, the plasma levels of D-dimer or soluble fibrin monomer (SFM) were significantly higher in the death within 6 months group than in the 6-month survival group. There was no remarkable difference in plasma levels of thrombin-antithrombin comlex or plasmin-plasmin inhibitor complex following BMT between these groups of patients. These findings suggest that the decrease in the plasma AT or PC level reflects early occurrence of complications of prognostic significance and that the increase in vascular endothelial cell markers such as plasma levels of TM or tPA-PAI-I complex reflects occurrence of complications during the middle course of BMT. Plasma levels of D-dimer and SFM may be useful markers for predicting complications associated with poor prognosis after BMT.
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PMID:Hemostatic abnormalities following bone marrow transplantation. 1212 Oct 52

During normal pregnancy the hemostatic balance changes in the direction of hypercoagulability, thus decreasing bleeding complications in connection with delivery. The most important initial factor for acute hemostasis at delivery is, however, uterine muscle contractions, which interrupt blood flow. Global tests such as Sonoclot signature, the Thromboelastogram, and a new method analyzing overall plasma hemostasis, all show changes representative of hypercoagulability during pregnancy. Increased endogenous thrombin generation, acquired activated protein C resistance, slightly decreased activated partial thromboplastin time (aPTT) and increased prothrombin complex level (PT) measured as international normalized ratio (INR) of less than 0.9 have been reported as well. In normal pregnancy, the platelet count is within normal range except during the third trimester when benign gestational thrombocytopenia, 80 to 150 x 10 9/L, can be observed. Platelet turnover is usually normal. Activation of platelets and release of beta-thromboglobulin and platelet factor 4 are reported. The bleeding time is unchanged during normal pregnancy. Most blood coagulation factors and fibrinogen increase during pregnancy. Factor (F) XI is the only blood coagulation factor that decreases. Blood coagulation inhibitors are mainly unchanged but the level of free protein S decreases markedly and the level of tissue factor pathway inhibitor increases. Thrombomodulin levels increase during pregnancy. Fibrinolytic capacity is diminished during pregnancy, mainly because of markedly increased levels of plasminogen activator inhibitor-1 (PAI-1) from endothelial cells and plasminogen activator inhibitor-2 (PAI-2) from the placenta. Thrombin-activated fibrinolysis inhibitor is reported to be unaffected. The total hemostatic balance has been studied by analyses of prothrombin fragment 1+2, thrombin-antithrombin complex, fibrinopeptide A, soluble fibrin, D-dimer, and plasmin-antiplasmin complex. There is activation of blood coagulation and a simultaneous increase in fibrinolysis without signs of organ dysfunction during normal pregnancy. These changes increase as pregnancy progresses. During delivery, there is consumption of platelets and blood coagulation factors, including fibrinogen. Fibrinolysis improves and increases fast following childbirth and expulsion of the placenta, resulting in increased D-dimer levels. These changes are self-limiting at normal delivery. The hemostatic changes, noted during pregnancy, normalize after delivery within 4 to 6 weeks. Platelet count and free protein S, however, can be abnormal longer. Hemostasis should not be tested earlier than 3 months following delivery and after terminating lactation to rule out influences of pregnancy. PAI-1 and PAI-2 levels decrease fast postpartum, but PAI 2 has been detected up to 8 weeks postpartum. alpha 2 -antiplasmin, urokinase, and kallikrein inhibitor levels have been reported to be increased 6 weeks postpartum.
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PMID:Hemostasis during normal pregnancy and puerperium. 1270 15

A randomized controlled multicenter study was undertaken to monitor the effects on hemostasis of two once-a-month injectable contraceptive preparations, Mesigyna (50 mg norethisterone enanthate and 5 mg estradiol valerate) and Cyclofem (25 mg medroxyprogesterone acetate and 5 mg estradiol cypionate) in comparison with a well-known oral contraceptive (OC) Ortho-Novum 1/35 (norethisterone 1 mg and ethinyl estradiol 35 microg). A total of 378 volunteers from four centers (Bangkok, Hangzhou, Santiago and Singapore) were monitored. Blood sampling took place in one pretreatment cycle, the third and ninth injection intervals and one posttreatment cycle. In each of the three treatment groups, a rise in hemoglobin, and increases in platelet count and in prothrombin time were observed. With treatment there was a significant increase in activated partial thromboplastin time among Mesigyna users, no change among Cyclofem users and a significant decrease among OC users. OC use led to increases in plasma levels of fibrinogen, factor VII, factor X, plasminogen, protein C and decreases in plasma levels of t-PAI and antithrombin. Use of combined injectables induced no change (Cyclofem) or decreases (Mesigyna) in plasma levels of fibrinogen, factor VII, factor X and antithrombin. Use of both combined injectables led to decreases in protein C, slight decreases in plasminogen and increases in plasminogen and fibrinogen. Overall, the injectable preparations may be more beneficial than the oral preparation in not enhancing a hypercoagulable state because of the reduced synthesis of fibrinogen, factors VII and X; however, decreases in antithrombin and protein C, which are potent coagulation inhibitors, may raise some concern. Whether these changes can lead to modifications in the risk of arterial or venous disease can only be ascertained by conducting epidemiological studies.
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PMID:Comparative study of the effects of two once-a-month injectable contraceptives (Cyclofem and Mesigyna) and one oral contraceptive (Ortho-Novum 1/35) on coagulation and fibrinolysis. 1456 36

Pre-eclampsia is an extremely severe condition. It is associated with vasospasm, activation of the coagulation system and abnormal haemostasis. In pre-eclamptic patients increased plasmatic concentrations of fibronectin, laminin, von Willebrand factor (VWF) and endothelin are observed. Experimental studies on rats have also shown that the doses of antithrombin III (AT) needed to mediate anti-inflammatory processes are much higher than those required to obtain the anti-coagulant effect. The study aimed to evaluate the clinical efficacy of treatment with high AT doses (HD) in comparison with standard doses (SD). The primary endpoint was the prolongation of pregnancy defined as time (in days) from enrollment to delivery and to assess the maternal bleeding at and after delivery. The secondary endpoint was to demonstrate a role for AT in controlling haemostasis at conventional doses, and the inflammatory state at higher doses. The biochemical parameters assessed were: AT activity (%), Fibronectin (Fn), Fibrinogen, D-dimer, Uricemia, Proteinuria 24h, Protein C Reactive (PCR), Granulocyte Elastase and Endothelin. This study included 23 pre-eclamptic women. Patients were randomly subdivided into two groups: 10 patients ("cases") were treated with high doses of AT (6 vials: 3000 units) once daily for 5 days, or until delivery, while 13 women ("controls") were treated with doses of AT sufficient to maintain at least 80% of the activity. High-dose therapy was associated with prolongation of pregnancy by 2.5 days more when compared with controls (p = 0.03; Mann-Whitney test). The incidence of clinical significant bleeding was lower in cases than in controls (mean 550 mL vs. 650 mL, respectively). Preventive- and conservative-type treatment of moderate-severe pre-eclampsia, based on the administration high doses of AT, allows a significant prolongation of pregnancy, and thus a better neonatal outcome, as well as less maternal intra- and post-operative bleeding. Fn, PCR and elastase levels (markers of inflammation) decrease in the HD group in comparison with SD group. In the HD group, the AT plasma levels were obviously higher both at the end of the treatment (p < 0.0001) and after delivery (p = 0.03), in comparison with SD group. The fibrinogen and D-dimer levels were above the reference interval in both groups. TPA and PAI 1 were found to be significantly raised in the course of pre-eclampsia. In conclusion, the bio-chemical findings support a role for AT in controlling the haemostasis at conventional doses, and the inflammatory state at higher doses.
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PMID:Efficacy of AT in pre-eclampsia: a case-control prospective trial. 1496 Nov 55

During the last few years, the availability of endothelial cell cultures isolated from different vascular regions contributed to a significant increase in understanding the complex pro- and antithrombotic mechanisms in our circulatory system. The most important key enzyme is thrombin. Due to its haemostatic properties this serin protease catalyzes fibrin formation, activation of factors V, VIII and XIII as well as irreversible platelet aggregation. These processes may occur even within the circulatory system in case of endothelial stimulation (e. g. by inflammation mediators) for expression of binding sites for factors IX, IXa, X, Xa, von Willebrand protein and PAF. Thus not only catalytically activated coagulatory cascades, but also enhanced cooperation of platelets and granulocytes will occur. Paradoxically, in low intravascular concentration, thrombin, in combination with a healthy endothelial layer, may be the critical factor for the inhibition of thromboses. Respective antithrombogenic properties will mainly affect pre-venous microvascular circulation. In detail, they include thrombin-induced endothelial formation of antiaggregatory autacoids from platelet release products, anticoagulatory activation of protein C and absorption of active coagulation factors at endothelial heparan/ATIII complexes as well as release of profibrinolytic plasminogen activator of endothelial origin. The understanding of these complex regulatory functions enables not only a critical evaluation of actually discussed haemostasiologic risk factors (enhanced platelet reactivity, high concentrations of factor VII, VIII, fibrinogen, PAI, ATIII), but also the development of new pharmacologic strategies for prevention of thrombosis.
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PMID:[Thrombin: antithrombotic properties and pharmacological consequences]. 1531 3

We hypothesized that the thrombophilic G1691A factor V Leiden gene mutation was a common significant cause of sporadic first trimester miscarriage. We compared thrombophilia and hypofibrinolysis in 92 women (85 white, 5 black, 2 other) with 1 or more pregnancies and 1 miscarriage (143 live births, 92 miscarriages) (cases) and in 380 female controls (355 white, 21 black, 4 other) with 1 or more pregnancies and 0 miscarriages (964 live births). We used polymerase chain reaction techniques to characterize thrombophilic gene mutations (G1691A V Leiden [FV], G20210A prothrombin, C677T/A1298C MTHFR) and hypofibrinolytic gene mutations (plasminogen activator inhibitor [PAI-1] activity 4G4G). We carried out serologic measures of thrombophilia (homocysteine, anticardiolipin antibodies [ACLA] immunoglobulin G and immunoglobulin M, lupus anticoagulant, factor VIII, factor XI, protein C, total and free protein S, antithrombin III) and hypofibrinolysis (plasminogen activator inhibitor activity [PAI-Fx], lipoprotein[a]). Of the 380 controls, 6 (1.6%) had FV heterozygosity vs 12 heterozygous and 2 homozygous FV cases (15.2% [14/92]; P < .0001). Plasminogen activator inhibitor activity was high (> or =21.1 U/mL) in 21 (33%) of 63 cases vs 27 (18%) of 152 controls (P = .013). Factor VIII was high (>150%) in 15 (31%) of 48 cases vs 19 (18%) of 103 controls (P = .079). By logistic regression, with age and factor VIII (categorical [< or =150%, >150%]) as explanatory variables and group (cases, controls) as the dependent variable, after adjusting for age, high factor VIII was a significant predictor for miscarriage (odds ratio, 3.28; 95% confidence interval, 1.34-8.04; P = .01). There were no other group differences (P > .05) in measures of thrombophilia and hypofibrinolysis. After unexplained sporadic first trimester miscarriage, we suggest that measurements be done of the FV mutation, PAI-Fx, and factor VIII, etiologies for sporadic miscarriage.
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PMID:The factor V Leiden mutation, high factor VIII, and high plasminogen activator inhibitor activity: etiologies for sporadic miscarriage. 1615 34

We prospectively assessed whether thrombophilia and hypofibrinolysis, amplified by thrombophilic hormone replacement therapy (HRT), were associated with retinal vein occlusion (RVO). We studied 44 cases (18 men, 26 women), > or = 3 months after RVO, 42 with central RVO, 2 with branch RVO, in the consecutive order of their referral by 2 community-based ophthalmologists. PCR and serologic coagulation assays were compared to 83 and 40 healthy adult normal controls, respectively. The 4G allele frequency of the plasminogen activator inhibitor-1 (PAI-1) gene, associated with hypofibrinolysis, was 56 of 88 (64%) in cases vs 79 of 166 (48%) in controls, X(2) = 5.95, p = .015. The PAI-1 gene product, plasminogen activator inhibitor activity (PAI-Fx), was higher in cases than controls (age-race-sex- adjusted mean 12.2 U/mL vs 6.3, p = .013). By stepwise logistic regression, the PAI-1 gene 4G allele was associated with RVO, odds ratio 1.94, 95% CI 1.12-3.34, p = .018. Thrombophilic resistance to activated protein C (RAPC) was present in 6 of 32 (19%) of cases vs 0 of 40 (0%) controls, Fisher's p [p(f)] = .006. Thrombophilic high factor VIII (> 150%) was present in 3 of 30 (10%) cases vs 0 of 40 (0%) controls, p = .041, p(f) = .07. Comparing 23 RVO cases < or = age 55 and controls < or = age 55 (n = 44 for PCR, n = 40 for serologic measures), RAPC was present in 17% of cases vs 0% controls (p(f) = .026), high Factor VIII in 17% vs 0% (p(f) = .026), heterozygosity for the G1691A Factor V Leiden mutation in 13% vs 2% (p(f) = 0.11), and the 4G allele frequency of the PAI-1 gene 74% vs 39% (p = .0001). PAI-Fx was higher in cases than controls (age-race-sex adjusted mean 12.7 U/mL vs 6.7, p = .016). The case-control odds ratio for the PAI-1 4G allele was 5.54, 95% CI = 1.86-16.7, p = .002. Of the 26 women, 9 (35%) took HRT; 4 of the 9 had PAI-1 gene 4G4G homozygosity, 2 had thrombophilic high anticardiolipin antibody (IgG), 1 was heterozygous for the G1691A Factor V Leiden mutation, and 2 were heterozygous for the thrombophilic PL A1/A2 mutation of the platelet glycoprotein IIb/IIIa gene. Associations between heritable coagulation disorders and RVO, most marked in cases < or = age 55, and often amplified in women by thrombophilic HRT, are, speculatively, causal.
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PMID:Associations of thrombophilia, hypofibrinolysis, and retinal vein occlusion. 1624 63

The existence of an association between idiopathic intracranial hypertension (IIH) and coagulation disorders in men was assessed prospectively. Microthrombi, associated with thrombophilia-hypofibrinolysis, occlude arachnoid sinus villi, thus reducing resorption of cerebrospinal fluid, leading to IIH. Ten consecutively referred men with IIH, nine whites, one African American, median age 36 years, were 2 to 1 matched by age and race by healthy male controls. Polymerase chain reaction assays were done for four thrombophilic and one hypofibrinolytic gene mutations: G1691A factor V Leiden, G20210A prothrombin, C677T MTHFR, platelet glycoprotein IIb/IIIa (PL A1/A2), and 4G/5G polymorphism of the plasminogen activator inhibitor (PAI-1) gene promoter. Coagulation measures in plasma included dilute Russel's viper venom time (dRVVT), activated partial thromboplastin time (aPTT), the lupus anticoagulant, factor VIII, factor XI, plasminogen activator inhibitor activity (PAI-Fx), protein C antigenic, protein S total (antigenic), protein S free (antigenic), antithrombin III (functional), and resistance to activated protein C (RAPC). Tests performed on serum included anticardiolipin antibodies, homocysteine, and Lp(a). The body mass index was 40 kg/m(2) or greater (extremely obese) in two men, 30 to 40 kg/m(2) (obese) in three, and was 25 to 30 kg/m(2) in five (overweight). Cases differed from controls for inherited 4G4G homozygosity of the PAI-1 gene, four of 10 (40%) vs. one of 20 (5%), Fisher's p [p(f)]= .031, and for high levels (>21.1 U/mL) of the hypofibrinolytic PAI-1 gene product, PAI-Fx, 5 of 10 (50%) vs. one of 18 (6%), p(f) = .013. Thrombophilic factor VIII was high (> or = 150%) in three of 10 (30%) cases vs. zero of 16 (0%) controls, p(f)=. 046. The thrombophilic lupus anticoagulant was present in two of 10 (20%) cases vs. zero of 32 (0%) controls, p(f) = .052. Heritable hypofibrinolysis and heritable and acquired thrombophilia appear, speculatively, to be treatable etiologies of IIH in men. Understanding contributions of hypofibrinolysis and thrombophilia to the development of IIH should facilitate development of novel new approaches to treat this often-disabling neurologic disorder.
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PMID:Idiopathic intracranial hypertension: associations with thrombophilia and hypofibrinolysis in men. 1624 70

The diagnosis of many hemostatic defects in infancy and childhood depends on the establishment of normal levels of various hemostatic factors. In this study, measurements of the natural anticoagulants (proteins C, S, and antithrombin III), as well as the fibrinolytic factors (tPA and PAI) were undertaken in healthy neonates (cord blood; n = 56), as well as in healthy children, up to 12 years of age (n = 103). The results were compared to normal adult values obtained from blood donors (n = 49). Neonatal values were found to be 50% of those obtained in adults and their mean concentrations were as follows: ATIII antigen = 48.4%, ATIII activity = 61.6%, protein C antigen = 47.7%, protein C activity = 57.2%, total protein S = 41.8% and tPA = 1.9 ng/mL. PAI level (25.7 ng/mL) was similar to adult values. In the first three years of life, almost all the hemostatic factors, other than PAI, gained adults levels. The diminished concentrations of the natural anticoagulants, in addition to the hypofibrinolysis in neonates, shifts the hemostatic balance towards fibrin formation and safeguards effective hemostasis. The values obtained in this study may serve as local reference values.
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PMID:Normal levels of the natural anticoagulants (proteins C & S and antithrombin III) and the fibrinolytic factors (tPA and PAI) in Arab children. 1742 25


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