Recent Development in Thrombin Receptor Antagonist as Novel Antithrombotic Agent

Significant progress was achieved in the search of a thrombin receptor antagonist as a novel antithrombotic treatment since the thrombin receptor (protease-activated receptor-1, PAR-1) was cloned 20 years ago. Previous works have shown that it is possible to develop potent thrombin receptor antagonists to compete effectively with the receptor’s internal “tethered” ligand to block platelet activation. Vorapaxar (SCH 530348) from Schering-Plough (now Merck) and atopaxar (E5555) from Eisai have been advanced to human clinical trials. Recently, the pivotal phase III clinical trial results for vorapaxar were published. In this article we review these results plus the phase II results from atopaxar. Several newly described thrombin receptor antagonists from the literature will also be discussed. The phase III results from vorapaxar demonstrated that a thrombin receptor antagonist can achieve efficacy in addition to current standard- of-care in treating atherothrombotic patients, especially those with previous myocardial infarction (MI). However, the increased moderate and severe bleeding, especially intracranial bleeding, point to the limitations of current thrombin receptor antagonists. Future thrombin receptor antagonists that can improve on the efficacy and bleeding profile of current ones should have a promising place in meeting the unmet medical need in treating atherothrombotic patients using current standard therapy.

Emergence of H5N8 avian influenza virus in domestic geese in a wild bird habitat,Yishui Lake,north central China

Dear Editor,China is located in the eastern part of the Eurasian continent,with a large north–south range,resulting in a large temperature difference.Wild birds migrate two times annually along with the north–south range,including eastern,central and western routes in China.Wild birds are reported to carry influenza viruses from multiple sources,causing the virus to spread across a wide range of regions,which present great challenges for the prevention and control of avian influenza viruses(AIVs)(He et al.,2021;Shi and Gao,2021).

Inside out:deep carbon linked to deep-time carbon cycle

The Ediacaran Shuram excursion(SE)is widely regarded as oneof the largest carbon isotope(δ^(13)C)negative excursions in Earthhistory,with carbonate δ^(13)C values down to ca.-12%e(VPDB)[1].This event has been reported in Ediacaran strata on a global scale,and is closely associated with the earliest emergence of macro-scopic animal life in fossil record[2].Numerous hypotheses havebeen proposed to account for this profound carbon cycle anomaly,including both primary[2-7]and diagenetic[8-11]origins.Amongall the published hypotheses,a common ground is the long-standing and fundamental assumption of a marine origin for thebedded carbonates that record the SE.