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Antithrombin Complex (antithrombin + complex)
Selected AbstractsCombined tissue factor pathway inhibitor and thrombomodulin deficiency produces an augmented hypercoagulable state with tissue-specific fibrin depositionJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2008S. A. MARONEY Summary.,Background and Objective:,Tissue factor pathway inhibitor (TFPI) and thrombomodulin (TM) are endothelial-associated anticoagulant proteins thought to control hemostasis in specific vascular beds. Here, we have examined the consequences of TFPI deficiency in the presence of a compounding procoagulant state caused by reduced TM function. Methods and results:,TFPI+/,/TMpro/pro mice are born at less than expected frequency in either TFPI+/,/TMpro/+ or TMpro/pro mothers but are born at near the expected frequency in TMpro/+ mothers. Adult TFPI+/,/TMpro/pro mice have elevated thrombin,antithrombin complex and increased thrombus volume in an electrical injury model of venous thrombosis. In striking contrast to mice with single deficiency of TFPI or TM, TFPI+/,/TMpro/pro mice exhibit augmented fibrin deposition not only in the liver, but also in the cerebral microvasculature. Conclusions:,TFPI+/,/TMpro/pro mice exhibit partial intrauterine lethality when carried by mothers with an underlying prothrombotic state, providing the first experimental evidence in an animal model that TFPI-dependent control of hemostasis in the vascular bed of the placenta fulfills a critical role for successful pregnancy outcome. In addition to the placenta, partial TFPI deficiency interacts with decreased TM function in an organ selective manner to produce fibrin deposition in other specific vascular beds, the liver and brain. [source] Thrombin activatable fibrinolysis inhibitor activity, thrombin-antithrombin complex and D-dimer levels in preterm neonates with early respiratory distress syndromeAMERICAN JOURNAL OF HEMATOLOGY, Issue 1 2008Tugba Gursoy Intraalveolar fibrin deposition found in neonates with respiratory distress syndrome (RDS) is explained by the activation of the coagulation system and inefficient fibrinolysis. However, thrombin activatable fibrinolysis inhibitor activity (TAFIa), an inhibitor of fibrinolysis, and the ratio of D-dimer to thrombin,antithrombin complex (D-dimer/TAT), an index of fibrinolytic activity, have not been reported previously in neonatal RDS. Aim of this study is to evaluate the influence of plasma TAFIa levels on the fibrinolytic state in neonatal RDS. The RDS group (Group 1) consisted of 29 neonates, and 18 neonates served as the control group (Group 2). Plasma TAFIa levels and D-dimer/TAT ratios were evaluated in all neonates in the first 6 hr of life. Neonates in the RDS group were further divided into two subgroups; Group 1a consisted of 12 neonates with evidence of mild asphyxia (Apgar score at 5 min <7 and cord pH <7.26), and Group 1b consisted of 17 nonasphyxiated neonates. No significant difference was found in TAFIa levels and D-dimer/TAT ratios between Groups 1 and 2 [214% (56.2,361%) and 124.3 (4.4,3,921) in Group 1 and 201% (60.3,381%) and 147 (5.9,1,426) in Group 2]. There were negative correlations between cord pH and TAFIa levels in both groups. Increased TAFIa levels and decreased D-dimer/TAT ratios and platelet counts were detected in mildly asphyxiated neonates when compared with nonasphyxiated ones. TAFIa is not responsible for the hypofibrinolytic state reported in RDS. However, asphyxia influences TAFIa levels and increased TAFIa levels depress fibrinolysis. Am. J. Hematol., 2008. © 2007 Wiley-Liss, Inc. [source] Tissue factor-dependent blood coagulation is enhanced following delivery irrespective of the mode of deliveryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 12 2007K. BOER Summary. Background:,The risk of thrombosis is clearly increased in the postpartum period. Mice with a targeted deletion of the transmembrane domain of tissue factor (TF) develop serious activation of blood coagulation and widespread thrombosis after delivery. Objective and methods:,We hypothesized that TF, abundantly present in placental tissue, is released during delivery, resulting in the activation of blood coagulation. We measured sensitive markers for TF-dependent activation of coagulation before and after induction of labor in two groups: a vaginal delivery (VAG) group and a cesarean section (CS) group.Results:,One hour after delivery, soluble TF (sTF) significantly increased in both groups [VAG group (mean ± SD) 226 ± 42 to 380 ± 42 pg mL,1 and CS group 193 ± 17 to 355 ± 44 pg mL,1]. The day after delivery, sTF was somewhat less increased. Both groups also showed an increase in factor VIIa, indicating activation of the TF pathway of coagulation. Indeed, after delivery, TF-dependent coagulation, as measured by the TF clotting time assay, was significantly enhanced. Increased plasma levels of prothrombin fragment 1 + 2 and thrombin,antithrombin complexes demonstrated thrombin generation following delivery. TF pathway-dependent activation of coagulation upon delivery was not blocked by TF pathway inhibitor and was not dependent on the mode of delivery.Conclusion:,The postdelivery increase in TF-dependent activation of coagulation is likely to be a natural mechanism to prevent excessive blood loss during and after delivery, and may also indicate a novel mechanism by which puerperal women have an increased risk of venous thromboembolism. [source] Dementia in subjects with atrial fibrillation: hemostatic function and the role of anticoagulationJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2004M. Barber Summary.,Background: Atrial fibrillation (AF) is associated with cognitive impairment and dementia, perhaps through encouraging a prothrombotic state and cardioembolism. Objectives: We wished to test the hypotheses that hemostatic function is altered in subjects with AF who develop dementia, and that long-term warfarin anticoagulation is protective against this complication. Patients and methods: Recruitment was from an observational cohort study of AF. Baseline assessment included measurement of plasma fibrinogen, fibrin D -dimer, prothrombin fragment 1+2 (F1+2), thrombin,antithrombin complexes (TAT), von Willebrand factor and tissue plasminogen activator. We assessed cognitive function after 3 years' follow-up using the 13-item modified Telephone Interview for Cognitive Status (TICSm) and the short form of the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Results: Of the 218 subjects assessed, 145 (66%) were prescribed warfarin. Forty-nine (22%) met TICSm/IQCODE criteria for dementia. D -dimer, F1+2 and TAT levels were higher in AF subjects with dementia compared with those without (medians 81 vs. 60 ng mL,1, P = 0.008; 0.76 vs. 0.49 nmol L,1, P = 0.006; and 1.78 vs. 1.44 µg L,1, P = 0.003, respectively). These associations became of borderline statistical significance following adjustment for age. Logistic regression showed a trend towards warfarin use being independently associated with reduced prevalence of dementia (odds ratio 0.52, P = 0.08). Conclusions: We found evidence of increased thrombin generation and fibrin turnover in subjects with AF and dementia compared with those without dementia. Long-term warfarin use may be protective against the development of dementia in subjects with AF. [source] | ||||||||||