Search

Summary Background: Direct thrombin inhibitors belong to a new class of antithrombotic drugs whose effects on blood coagulation in vivo in patients suffering from acute thrombotic conditions have not yet been fully explored. Methods and Results: One hundred and five patients with acute proximal deep-vein thrombosis were randomized to receive a continuous intravenous infusion of napsagatran, a novel synthetic thrombin inhibitor, at a fixed dose of 5 mg/h (n = 36) or 9 mg/h (n = 25) for five days, or APTT-adjusted unfractionated heparin (UFH, n = 44) for the same time. In these patients, thrombin activity and thrombin generation could be assessed by measuring thrombin-antithrombin III complexes (TAT) and prothrombin fragment 1+2 (F1+2), respectively, on three occasions. At baseline, TAT and F1+2 did not differ among the three groups. On Day 2 (steady state), TAT significantly decreased in all groups, and the decrease was significantly more pronounced in the patients given higher-dose napsagatran. F1+2 decreased significantly only in UFH-treated patients. Two hours after cessation of the infusion, the TAT levels increased in the two napsagatran groups but not in the UFH group, whilst F1+2 went back to the baseline levels in the napsagatran-treated patients but remained low in the UFH-treated patients. There was no rebound effect. Conclusions: The data presented suggest that direct thrombin inhibition with napsagatran at 9 mg/h is more potent than UFH in attenuating thrombin activity, but is less potent than UFH in inhibiting thrombin generation. The real significance of these findings will have to be substantiated in further trials with clinically relevant endpoints.

SummaryOne hundred and ten patients with acute proximal deep-vein thrombosis were randomized in a sequential dose-finding design, to receive continuous intravenous infusion of napsagatran, a novel synthetic thrombin-inhibitor, at a fixed dose of 5 mg/h (n = 37) or 9 mg/h (n = 26), or APTT-adjusted unfractionated heparin (n = 47). Oral anticoagulants were started on the 2nd day and the study drug was discontinued from the 5th treatment day, as soon as the International Normalized Ratio was above 2.Control venogram (97 venogram pairs evaluable) after 5-8 days of treatment showed improvement in 3 napsagatran-treated patients (versus none in heparin-treated patients) and worsening in 4 napsagatran- treated patients (versus 2 in heparin-treated patients). The venographic Marder’s score did not change among the treatment groups. New lung scan perfusion defects (99 scintigram pairs evaluable) occurred in 4 (11%), 4 (21%), and 4 (10%) patients in the napsagatran (5 mg/h) group, in the napsagatran (9 mg/h) group, and in the heparin control group, respectively. There was no statistically significant difference in any of these endpoints between the 3 groups. No major bleeding was observed and the rare minor bleedings occurred at a similar rate in the three treatment groups.In conclusion, the ADVENT trial has shown data that suggest comparable efficacy and safety of a synthetic, direct thrombin inhibitor (napsagatran) and conventional heparin therapy for treatment of proximal DVT. These results suggest that synthetic direct thrombin inhibitors are a promising class of antithrombotic agents which deserves further development in this field.

Background: Circos is a popular, highly flexible software package for the circular visualization of complex datasets. While especially popular in the field of genomic analysis, Circos enables interactive graphing of any analytical data, including alternative scientific domain data and non-scientific data. This high degree of flexibility also comes with a high degree of complexity, which may present an obstacle for researchers not trained in programming or the UNIX command line. The Galaxy platform provides a user-friendly browser-based graphical interface incorporating a broad range of "wrapped" command line tools to facilitate accessibility. Findings: We have developed a Galaxy wrapper for Circos, thus combining the power of Circos with the accessibility and ease of use of the Galaxy platform. The combination substantially simplifies the specification and configuration of Circos plots for end users while retaining the power to produce publication-quality visualizations of complex multidimensional datasets. Conclusions: Galactic Circos enables the creation of publication-ready Circos plots using only a web browser, via the Galaxy platform. Users may download the full set of Circos configuration files of their plots for further manual customization. This version of Circos is available as an open-source installable application from the Galaxy ToolShed, with its use clarified in a training manual hosted by the Galaxy Training Network.