Perioperative management of dual anti-platelet therapy.

Dual anti-platelet therapy denotes a regimen of aspirin plus a P2Y12 receptor inhibitor, clopidogrel, prasugrel, or ticagrelor. Such therapy is a cornerstone of medical management following acute coronary syndromes and is imperative following percutaneous coronary interventions. While there is uncertainty about the optimal duration of dual antiplatelet therapy following percutaneous coronary intervention, the new 2016 American College of Cardiology/American Heart Association Guidelines suggest that for patients with stable ischemic heart disease at least six months of such therapy following a drug eluting stent and one month following a bare metal stent should be implemented. In patients with acute coronary syndrome including non-ST elevation and ST elevation myocardial infarction it is recommended to extend dual antiplatelet therapy treatment to one year in both drug eluting stent and bare metal stent groups. There may be latitude for earlier discontinuation in appropriately selected patients; extended dual antiplatelet therapy beyond one year may be beneficial in others. Herein, we describe current guidelines and evidence supporting if and when dual antiplatelet therapy should be interrupted for surgery for patients who have undergone percutaneous coronary intervention.

Deep genome-wide measurement of meiotic gene conversion using tetrad analysis in Arabidopsis thaliana.

Gene conversion, the non-reciprocal exchange of genetic information, is one of the potential products of meiotic recombination. It can shape genome structure by acting on repetitive DNA elements, influence allele frequencies at the population level, and is known to be implicated in human disease. But gene conversion is hard to detect directly except in organisms, like fungi, that group their gametes following meiosis. We have developed a novel visual assay that enables us to detect gene conversion events directly in the gametes of the flowering plant Arabidopsis thaliana. Using this assay we measured gene conversion events across the genome of more than one million meioses and determined that the genome-wide average frequency is 3.5×10(-4) conversions per locus per meiosis. We also detected significant locus-to-locus variation in conversion frequency but no intra-locus variation. Significantly, we found one locus on the short arm of chromosome 4 that experienced 3-fold to 6-fold more gene conversions than the other loci tested. Finally, we demonstrated that we could modulate conversion frequency by varying experimental conditions.