In the articles that appeared on page 317 of the February 2009 issue and page 576 of the March 2010 issue, an error was discovered in the units of measure for nitric oxide production. The correct units throughout these articles for nitric oxide production are picomoles per milligram protein.

Reference

Amour J, Brzezinska AK, Weihrauch D, Billstrom AR, Zielonka J, Krolikowski JG, Bienengraeber MW, Warltier DC, Pratt Jr PF, Kersten JR: Role of heat shock protein 90 and endothelial nitric oxide synthase during early anesthetic and ischemic preconditioning. Anesthesiology 2009; 110:317–25