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Postoperative outcomes of a third-generation porcine bioprosthesis for mitral valve replacement (MVR) have been poorly addressed. The objective of this study was to perform an independent, retrospective, multicenter study on outcomes of patients undergoing MVR with a Mosaic (Medtronic Inc, Minneapolis, MN) porcine bioprosthesis. From 1998 to 2011, 805 patients underwent MVR with a Mosaic porcine valve in 11 cardiac centers. There were 465 female patients (58%), and the overall mean age was 73.5 ± 7 years. Associated procedures included coronary artery bypass grafting (201 patients; 24.9%), aortic valve replacement (152 patients; 18.9%), tricuspid annuloplasty (187 patients; 22.3%), and other cardiac procedures (116 patients; 14.4%). Median follow-up was 44 months (interquartile range, 16 to 63), with a cumulative duration of 2.769 patient-years. Early mortality for isolated elective MVR was 3.8% (12 of 313), and overall early mortality was 7.8% (n = 63). The rate of late mortality was 3.4%/patient-year (95 late deaths). At 10 years, overall survival was 57.4% (95% confidence interval [CI], 48.8% to 67.5%), and cumulative rates of cardiac- and valve-related death were 7.4% (95% CI, 4.8% to 10.1%) and 1.1% (95% CI, 0.2% to 1.9%), respectively. The 10-year cumulative rates of thromboembolic and hemorrhagic events were 6.6% (95% CI, 1.4% to 11.8%) and 3.9% (95% CI, 0.1% to 8%), respectively, and the 10-year cumulative incidence of prosthetic valve endocarditis was 3% (95% CI, 1.2% to 4.9%). Finally, the 10-year cumulative incidences of structural valve degeneration and reoperations were 5.8% (95% CI, 0.2% to 11.5%) and 4.8% (95% CI, 0.7% to 10.3%), respectively. This independent, multicenter, retrospective study indicated that the Mosaic porcine bioprosthesis for MVR provides satisfactory results in terms of both early and long-term outcomes up to 14 years from its implantation. [ABSTRACT FROM AUTHOR]

Adolescents may be more sensitive to stress-induced alcohol drinking than adults, which would explain the higher prevalence of alcohol abuse and dependence in late adolescence than in adulthood. The present study analyzed the impact of restraint stress on the initiation of alcohol intake across 2 weeks of intermittent, two-bottle choice intake in male and female adolescent rats and adult female rats. Restraint stress significantly increased alcohol intake and preference in female adolescent rats but decreased alcohol intake and preference in male adolescent and female adult rats. The effects of restraint stress on alcohol intake were mitigated in adolescent females following administration of the κ opioid receptor antagonist norbinaltorphimine. Adolescent but not adult female rats that were subjected to restraint stress spent more time on the open arms of the elevated plus maze. Female adolescents exposed to stress also exhibited greater risk-taking behaviors in a concentric square field test compared with non-stressed controls. These results indicate age- and sex-related differences in the sensitivity to alcohol-stress interactions that may facilitate the initiation of alcohol use in female adolescents. The facilitatory effect of stress on alcohol intake was related to greater exploratory and risk-taking behaviors in young females after stress exposure. [ABSTRACT FROM AUTHOR]

Abstract: Background: Several lines of clinical and experimental evidence have demonstrated that reactive oxygen species and nitrogen species are generated in unregulated amounts during diverse cardiovascular disorders. It has been previously reported by our group and others that augmented expression of nitric oxide synthase isoforms is associated with human atherogenesis and that the activity of the enzymes in an atherosclerotic environment may promote the formation of peroxynitrite. Among the downstream mechanisms triggered by oxidants, poly(ADP-ribose) polymerase-1 activation has recently been implicated in the pathogenesis of acute and chronic myocardial dysfunction, diabetes, hypertension, aging, and various forms of shock. Methods: Based on these observations, we performed immunohistochemical and immunogold labeling analyses to evaluate the expression profile and the subcellular localization of inducible nitric oxide synthase and poly(ADP-ribose) polymerase-1 in healthy and atherosclerotic human aortae. Results: We have demonstrated that inducible nitric oxide synthase colocalizes with poly(ADP-ribose) polymerase-1 within vascular cells of atherosclerotic human aortae. We have reported for the first time, to our knowledge, the ultrastructural localization of poly(ADP-ribose) polymerase-1 within the nuclei of lesional smooth muscle cells. Finally, we have evidenced that poly(ADP-ribose) polymerase-1 induction within cells of the diseased aorta strongly correlates with alterations in mitochondrial morphology. Conclusions: Our data imply the possibility of a significant role for cross-talk between inducible nitric oxide synthase and poly(ADP-ribose) polymerase-1 in human atherosclerotic lesions. We conclude that the prooxidant milieu of the plaque might exert damaging effects on mitochondria via a poly(ADP-ribose) polymerase-1-mediated mechanism since the absence of the enzyme results in a corresponding lack of changes in mitochondrial morphology. The present report may open avenues for further researches that could have important therapeutic consequences for the treatment of atherosclerosis and its clinical sequelae. [Copyright &y& Elsevier]

Abstract: Background: Nitric oxide has been proven to play an important role in the maintenance of vascular tone and structure. Impairment of nitric oxide production is an early indicator of atherosclerosis, but not much is known about the real mechanisms underlying this phenomenon. Methods: In the present study, immunocytochemical methods have been used to analyze the patterns of expression of endothelial nitric oxide synthase and inducible nitric oxide synthase proteins in healthy and atherosclerotic human aortae using both confocal laser scanning microscopy and electron microscopy. Results: Induction of the expression of endothelial nitric oxide synthase and inducible nitric oxide synthase proteins was observed in smooth muscle cells of atherosclerotic human aortae. Altered nitric oxide synthase expression was reported in atheromatous plaques and in apparently normal vascular tissues adjacent to the lesions. Conclusions: Our data confirm and extend previous findings of a direct relationship between dysregulation of nitric oxide pathway and atherosclerosis, suggesting another possible mechanism by which nitric oxide synthase system abnormalities may promote vascular dysfunction during human atherogenesis. Changes in nitric oxide production might be the primary step in the development of atheroma. [Copyright &y& Elsevier]