Circulation research
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Since the late 1970s when many journals published articles warning about the misuse of statistical methods in the analysis of data, researchers have become more careful about statistical analysis, but errors including low statistical power and inadequate analysis of repeated-measurement studies are still prevalent. In this review, several statistical methods are introduced that are not always familiar to basic and clinical cardiologists but may be useful for revealing the correct answer from the data. ⋯ Researchers need not know how to calculate the statistics from the data but are required to select the correct method from the menu and interpret the statistical results accurately. With the choice of appropriate statistical programs, the issue is no longer how to do the test but when to do it.
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Circulation research · Oct 2002
Carbon monoxide dilates cerebral arterioles by enhancing the coupling of Ca2+ sparks to Ca2+-activated K+ channels.
Carbon monoxide (CO) is generated endogenously by the enzyme heme oxygenase. Although CO is a known vasodilator, cellular signaling mechanisms are poorly understood and are a source of controversy. The goal of the present study was to investigate mechanisms of CO dilation in porcine cerebral arterioles. ⋯ This signaling pathway for CO is physiologically relevant because ryanodine, a ryanodine-sensitive Ca2+ release channel blocker that inhibits Ca2+ sparks, abolished CO dilation of pial arterioles in vivo. Thus, CO dilates cerebral arterioles by priming K(Ca) channels for activation by Ca2+ sparks. This study presents a novel dilatory signaling pathway for CO in the cerebral circulation and appears to be the first demonstration [corrected] of a vasodilator that acts by increasing the effective coupling of Ca2+ sparks to K(Ca) channels.