Effectiveness of aldosterone antagonists for preventing atrial fibrillation after cardiac surgery in patients with systolic heart failure: a retrospective study

Postoperative atrial fibrillation (POAF) is the most common arrhythmia after cardiac surgery. There exist consistent experimental and clinical data suggesting that aldosterone antagonists (AAs) may exert beneficial effects regarding electrical and structural remodeling in failing myocardium. Recently, eplerenone (EPL) has been found to reduce the incidence of nonsurgical AF when added to guideline-recommended therapy in patients with systolic heart failure. Based on these findings, we primarily aimed to evaluate by retrospective analysis the impact of the two AAs, EPL and spironolactone (SPL), given at standard therapeutic doses in preventing new-onset POAF in patients the majority of which had a preoperative ejection fraction (EF) below 40 %. A total of 332 patients (298 men/34 women, mean age 64.3 +/- A 9 years) without history of AF were included in this analysis; 132 of these patients received long-term EPL or SPL in addition to beta-blockade/statins therapy and 200 patients received neither EPL nor SPL. All patients underwent on-pump coronary artery bypass graft (80 %) and/or valvular surgery (20 %). In the nonAA group (EF = 35.8 +/- A 6 %) 90/200 patients (45 %) had POAF, while in the AA group (EF = 36.2 +/- A 5 %) only 40/132 patients (30.3 %) developed POAF (P < 0.01, chi (2) test). Multivariate logistic regression analysis revealed that only AAs and left atrial diameter significantly affected the development of POAF even when adjusted for other clinical variables (P < 0.05). In conclusion, AAs significantly reduced the incidence of POAF when added to standard heart failure therapy in patients undergoing on-pump cardiac surgery

Functional differences in nucleoside and nucleobase transporters expressed on the rabbit corneal epithelial cell line (SIRC) and isolated rabbit cornea

The purpose of this study was to investigate the expression of nucleoside/nucleobase transporters on the Statens Seruminstitut rabbit corneal (SIRC) epithelial cell line and to evaluate SIRC as an in vitro screening tool for delineating the mechanism of corneal permeation of nucleoside analogs. SIRC cells (passages 410–425) were used to study uptake of [3H]thymidine, [3H]adenine, and [3H]ganciclovir. Transport of [3H]adenine and [3H]ganciclovir was studied across isolated rabbit cornea. Uptake and transport studies were performed for 2 minutes and 120 minutes, respectively, at 34°C. Thymidine uptake by SIRC displayed saturable kinetics (Km=595.9±80.4μM, and Vmax=289.5±17.2 pmol/min/mg protein). Uptake was inhibited by both purine and pyrimidine nucleosides but not by nucleobases. [3H]thymidine uptake was sodium and energy independent but was inhibited by nitrobenzylthioinosine at nanomolar concentrations. Adenine uptake by SIRC consisted of a saturable component (Km=14.4±2.3μM, Vmax=0.4±0.04 nmol/min/mg protein) and a nonsaturable component. Uptake of adenine was inhibited by purine nucleobases but not by the nucleosides or pyrimidine nucleobases and was independent of sodium, energy, and nitrobenzylthioinosine. [3H]ganciclovir uptake involved a carrier-mediated component and was inhibited by the purine nucleobases but not by the nucleosides or pyrimidine nucleobases. However, transport of [3H]adenine across the isolated rabbit cornea was not inhibited by unlabeled adenine. Further, corneal permeability of ganciclovir across a 100-fold concentration range remained constant, indicating that ganciclovir permeates the cornea primarily by passive diffusion. Nucleoside and nucleobase transporters on rabbit cornea and corneal epithelial cell line, SIRC, are functionally different, undermining the utility of the SIRC cell line as an in vitro screening tool for elucidating the corneal permeation mechanism of nucleoside analogs

Peer selection and socialization in adolescent depression: The role of school transitions

Item does not contain fulltextPrevious studies have indicated homophily in depressive symptoms among adolescent friends, resulting from both peer selection and socialization processes. However, developmental differences and the role of school transitions in these processes have not been elucidated. A sample of 367 (51% female) adolescents was followed from 6th to 11th grade to investigate prospective relationships between adolescents' and their friends' depressive symptoms in middle school and in high school. Results revealed that students selected friends with similar levels of depressive symptoms after each school transition. Additionally, friends appeared to socialize adolescents to become more similar in depressive affect in late middle school years. These findings suggest normative selection effects after school transitions, followed by socialization effects in middle school, but not high school