Blood samples were obtained at 0 and 6 hours postdose for the measurement of serum bupropion (BU) and hydroxybupropion (HB) concentrations. Whole blood was obtained at baseline for CYP2B6 genotyping. To characterize the relationship between CYP2B6 activity and ethnicity, sex, and genotype when accounting for serum BU concentrations (dose-adjusted log(10)-transformed), Androgen Receptor Antagonist analysis of covariance model was fitted in which the dependent variable was CYP2B6 activity represented as the log(10)-transformed, metabolic ratio of HB to BU concentrations. Several CYP2B6 polymorphisms
were associated with CYP2B6 activity. Evidence of dependence of CYP2B6 activity on ethnicity or genotype-by-ethnicity interactions was not detected in women. These results suggest that CYP2B6 genotype is the most important patient variable for predicting the level of CYP2B6 activity in women, when measured by the metabolism of bupropion. The bupropion metabolic ratio appears to detect known differences in CYP2B6 activity associated with genetic polymorphism, across different ethnic groups. Prospective studies will be needed to validate the use of bupropion as a probe substrate for clinical use.”
“Since the start of cardiac surgery in the 1950s, multiple techniques have been used to protect the heart during the surgical requirement for elective global ischemia (and the still, relaxed, bloodless field that this provides the surgeon for repair
of the lesion). Most of these techniques have been discarded. The current gold standard, established click here over 30 years ago, is hyperkalemic (moderately increased extracellular potassium) cardioplegia; this technique revolutionized cardiac surgery, allowing significant surgical advancement with relative safety. Hyperkalemic QNZ ic50 cardioplegia induces a rapid depolarized arrest that is readily reversible. Recent patient demographic changes, with surgeons operating on older, sicker patients who have more severe and diffuse disease, potentially
requires a more prolonged elective ischemia: hence, an improved myocardial protection would be of benefit. Several areas of study have demonstrated that a new concept of myocardial protection ‘polarized’ arrest may provide this additional protection. Many pharmacological agents have been shown (in experimental studies), to have the ability to induce a polarized arrest and to provide improved protection. However, the often-overlooked requirements of effect reversibility and systemic safety have meant that these agents usually remain experimental in nature. This review attempts to highlight the cellular components that can be targeted, within the excitation-contraction coupling cascade, to induce cardiac arrest, and to provide an explanation for the mechanism of action of these agents. In this context, the agents are discussed in terms of their clinical potential for use during cardiac surgery, with particular reference to the safety aspects of the agents. (C) 2010 Elsevier Inc.