Thromb Haemostasis
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Comparative Study
Therapeutic action of tranexamic acid in hereditary haemorrhagic telangiectasia (HHT): regulation of ALK-1/endoglin pathway in endothelial cells.
Recurrent epistaxis is the most frequent clinical manifestation of hereditary haemorrhagic telangiectasia (HHT). Its treatment is difficult. Our objective was to assess the use of tranexamic acid (TA), an antifibrinolytic drug, for the treatment of epistaxis in HHT patients and to investigate in vitro the effects of TA over endoglin and ALK-1 expression and activity in endothelial cells. ⋯ Cultured endothelial cells incubated with TA exhibited increased levels of endoglin and ALK-1 at the protein and mRNA levels, enhanced TGF-beta signaling, and improved endothelial cell functions like tubulogenesis and migration. In summary, oral administration of TA proved beneficial for epistaxis treatment in selected patients with HHT. In addition to its already reported antifibrinolytic effects, TA stimulates the expression ofALK-1 and endoglin, as well as the activity of the ALK-1/endoglin pathway.
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Multicenter Study Comparative Study
Venous thromboembolism during pregnancy or postpartum: findings from the RIETE Registry.
Venous thromboembolism (VTE) occurs infrequently during pregnancy, and issues concerning its natural history, prevention and therapy remain unresolved. RIETE is an ongoing registry of consecutive patients with objectively confirmed, symptomatic acute VTE. In this analysis, we compared the clinical characteristics and outcome for all enrolled pregnant and postpartum women with acute VTE, and all non-pregnant women in the same age range. ⋯ However, after delivery one patient (1.4%) developed recurrent thrombosis, four (5.6%) had major bleeding. In conclusion, VTE developed during the first trimester in 40% of the pregnant women, thus suggesting that thromboprophylaxis, when indicated during pregnancy, should start in the first trimester. No patient showed recurrence or bled before delivery, but after delivery the risk of bleeding exceeded the risk of recurrences.
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Comparative Study
Accuracy of compression ultrasound in screening for deep venous thrombosis in acutely ill medical patients.
The value of vein ultrasonography for diagnosis of symptomatic deep vein thrombosis (DVT) is widely accepted. We are unaware of published data comparing ultrasonography with the "gold standard" of venography for DVT diagnosis in asymptomatic persons in the patient group of acutely ill medical patients. It was the objective of this study to evaluate sensitivity and specificity of compression ultrasound (CUS) examinations in the diagnosis of proximal and distal DVT in acutely ill medical patients [with congestive heart failure (NYHA class III and IV), exacerbations of respiratory disease, infectious disease, and inflammatory diseases] considered to be at moderate risk of venous thromboembolism (VTE). ⋯ In two of seven patients with venographically proven calf DVT, the diagnosis was confirmed by CUS (sensitivity 28.6%, 95%CI=[8%-64%]) and in two patients, CUS was false positive (specificity 98.6, 95%CI=[95%-99%]). PPV and NPV of CUS in diagnosis of distal DVT were 50% (95%CI=[15-85%]) and 96% (95% CI=[92%-98%]), respectively. In conclusion, CUS underestimates the incidence of proximal and distal DVT compared to contrast venography in acutely ill medical patients without thrombosis symptoms.
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Angiopoietin-2 (Ang2) is among the relevant growth factors induced by hypoxia and plays an important role in the initiation of retinal neovascularizations. Ang2 is also involved in incipient diabetic retinopathy, as it may cause pericyte loss. To investigate the impact of Ang2 on developmental and hypoxia-induced angiogenesis, we used a transgenic mouse line overexpressing human Ang2 in the mouse retina. ⋯ The total expression of Ang2 in transgenic mice was seven-fold, compared with wild type controls. Ang2 modulated expression of genes encoding VEGF (+65%) and Ang1 (+79%) in transgenic animals. These data suggest that Ang2 is involved in pericyte recruitment, and modulates intraretinal, and preretinal vessel formation in the eye under physiological and pathological conditions.
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Controlled Clinical Trial
Inhibition of clot formation process by treatment with the low-molecular-weight heparin nadroparin in patients with carotid artery disease undergoing angioplasty and stenting. A thromboelastography study on whole blood.
Low-molecular-weight heparins (LMWHs) have become the corner stone of antithrombotic treatment but their administration protocol needs to be optimized for certain groups of patients. In this paper, we studied the influence of nadroparin treatment on clot formation process assessed by thromboelastography in patients with carotid artery disease undergoing angioplasty and stenting. Standard thromboelastography assays (in-TEM and ex-TEM) and minimal TF-triggered thromboelastography assay in citrated whole blood were performed in normal volunteers (n = 20), in patients with carotid artery disease receiving only antiplatelet treatment (n = 30), and in patients undergoing angioplasty receiving nadroparin 5750 anti-Xa IU s.c. twice daily (n = 60). ⋯ There was no statistical correlation for any other parameter in all tests. In conclusion, the present study shows that nadroparin treatment in patients with carotid artery disease undergoing endovascular procedures induces significant modification of the thrombus kinetics assessed by minimal TF-triggered whole blood thromboelastography. The clinical relevance of these findings has to be evaluated in future studies.