Sildenafil inhibits the ROS production by xanthine oxidase

Xanthine oxidase (XO) catalyzes the hydroxylation of a wide variety of substrates, including purines, pirimidines, pterins d aldehydes, to acids1. At relatively high oxygen pressure, it generates reactive oxygen species (ROS) as superoxides and hydroxyl radicals. The XO, detected in endothelial and epithelial cell outer surface, has been involved in ischemia/reperfusion injury1,2. Furthermore, XO-ROS production has been implicated in chronic hearth failure, inflammatory diseases, LDL oxidation, atherosclerosis, hypertension, cancer, aging1. Allopurinol, a hypoxanthine analogue developed as xanthine oxidase inhibitor 30 years ago, and oxypurinol, its oxidation product, have proved to be effe…

Analysis of N-terminal pro-B-type natriuretic peptide in patients with acute coronary syndromes

Background The N-terminal portion of brain natriuretic peptide (NT-proBNP) has been identified as an indicator of prognosis in different cardiovascular diseases. The objective of this study was to determine the utility of measuring plasma NT-proBNP levels in patients with acute coronary syndromes. Methods and results We studied 66 patients admitted in our division for acute coronary syndromes. Patients underwent a venous blood sample within 24 h from the admission to determine NT-proBNP levels. Increasing plasma levels of NT-proBNP (in tertiles) was associated with a greater history of hypertension and current smoking, whereas biochemical parameters were associated with higher level of crea…

The flaring afterglow of GRB 050730

We present a detailed spectral and temporal analysis of Swift and XMM-Newton observations of GRB 050730. The X-ray afterglow of GRB 050730 was found to decline with time with intense flaring activity superimposed. Evidence of flaring activity in the early UVOT optical afterglow, simultaneous with that observed in the X-ray band, was found. Strong spectral evolution in the X-ray energy band during the flaring activity was present.

Prevention of hospital-acquired infection in the Palermo Burns Center.

Sildenafil protects epithelial cell through the inhibition of xanthine oxidase and the impairment of ROS production

Recent reports suggest that xanthine oxidase (XO), a modified form of the native xanthine dehydrogenase enzyme, plays an important role in various forms of ischemic and vascular injuries, inflammatory diseases, and chronic heart failure. The XO inhibitors allopurinol and its oxidation product oxypurinol held considerable promises in the treatment of these conditions both in experimental animals and in human clinical trials. More recently, an endothelium-based protective effect of sildenafil, a well-known type-5 phosphodiesterase inhibitor, has been reported in preconditioning prior to ischemia/reperfusion in healthy human subjects. Based on the structural similarities between allopurinol an…