The ubiquitin-proteasome system is the major pathway for intracellular protein degradation in eukaryotic cells. Endothelial nitric oxide synthase (eNOS) is the key enzyme of vascular homeostasis involved in the pathophysiology of several cardiovascular diseases. The aim of our study was to investigate whether eNOS expression and activity are regulated by the proteasome. Bovine pulmonary artery endothelial cells (CPAE cells) were treated with the proteasome inhibitor MG132. MG132 (50-250 nmol/L) dose-dependently increased mRNA and protein levels of eNOS. Comparable results were obtained with other specific proteasome inhibitors, whereas the nonproteasomal calpain and cathepsin inhibitor ALLM had no effect. Efficacy of proteasome inhibition was evidenced by accumulation of poly-ubiquitinylated proteins and by measuring proteasomal activity in cell extracts. Cycloheximide prevented up-regulation of eNOS protein, indicating that post-translational stabilization of eNOS is not involved. eNOS activity was increased up to 2.8-fold (MG132 100 nmol/L, 48 h). Incubation of rat aortic rings with MG132 significantly enhanced endothelial-dependent vasorelaxation. Single MG132 treatment (100 nmol/L) induced long-term effects in CPAE cells, with increases of eNOS protein and activity for up to 10 days. Our results indicate that low-dose proteasome inhibition enhances eNOS expression and activity, and improves endothelial function.

As part of a comprehensive health care programme for people who use drugs in Nepal, HIV and viral hepatitis B and C status—including risk factors, HCV-genotypes and co-infections—as well as two IL28B Single-nucleotide polymorphisms (SNPs) were assessed for a random sample of 401 people who inject drugs in three regions of Nepal: mid-western Terrai (Nepalgunj), the eastern region (Dharan, Biratnagar) and the central region (Kathmandu, Lalitpur and Chitwan). Individuals were included who showed at least a minimum of health care seeking behaviour. This latter criterion was defined by being registered with any organisation offering health services. The average age of the participants was 30.5 yrs, and the average length of intravenous drug use was 8.5 yrs. The prevalence rates of HBsAg, anti-HIV antibodies and HCV-RNA were 3.5%, 13.8% and 41.9%, respectively. Spontaneous HCV clearance was evident in 16% of all of those who tested positive for anti-HCV antibodies. Independent risk factors for HCV-RNA positivity were age, gender, geographical region, duration of injecting drug use, history of imprisonment and HIV co-infection. In the age group ≤24 yrs, the rate of spontaneous HCV clearance was 43.5%. Overall, 59.8% of HCV infections were caused by HCV genotype 3 and 40.2% by HCV genotype 1. No other HCV genotypes were identified in this study. The IL28B SNP rs12979860 and rs8099917 were identified in 122 patients, and 75.4% of all participants had both favourable genotypes rs12979860 C/C and rs8099917 T/T.

No abstract

Background: There is evidence that the tea catechin epigallocatechin-3-gallate (EGCG) modulates myocardial contractility. However, the underlying mechanisms remain to be determined. Aims: To study potential signalling pathways involved in EGCG-induced contractile parameters. Methods and results: EGCG increased fractional shortening in rat cardiac myocytes and enhanced intracellular systolic Ca 2+ concentrations. In isolated rat hearts, perfusion with EGCG resulted in significant, dose-dependent increase in peak systolic left ventricular pressure, as well as in contraction and relaxation velocities. Heart rate did not change. Inhibition of the β 1 -receptor with metoprolol had no influence on the contractile effects of EGCG. Furthermore, levels of cAMP and phosphorylation of phospholamban did not change with EGCG, indicating that the beta-receptor pathway is not involved. The L-type Ca 2+ channel inhibitors, nifedipine and gallopamil, failed to modulate EGCGinduced increase in contractility. However, the myocardial effects and intracellular calcium transients stimulated by EGCG were significantly reduced by the antagonist of the Na + /H + exchanger (NHE) methyl-N-isobutyl amiloride (MIA), and by blocking of the reverse mode of the Na + /Ca 2+ exchanger (NCX) by KB-R7943. Conclusion: These results indicate that Ca 2+ -dependent positive inotropic and lusitropic effects of EGCG are mediated in part via activation of the Na + /H + exchanger and the reverse mode of the Na + /Ca 2+ exchanger in the rat myocardium.

No abstract

No abstract

Bei Untersuchungen über die Häufigkeit der chronischen Bronchitis ist von den zur Verfügung stehenden Tabellenwerken auszugehen.

No abstract