Advanced glycoxidation and lipoxidation end products (AGEs and ALEs): an overview of their mechanisms of formation

Advanced lipoxidation end products (ALEs) and advanced glycation end products (AGEs) have a pathogenetic role in the development and progression of different oxidative-based diseases including diabetes, atherosclerosis, and neurological disorders. AGEs and ALEs represent a quite complex class of compounds that are formed by different mechanisms, by heterogeneous precursors and that can be formed either exogenously or endogenously. There is a wide interest in AGEs and ALEs involving different aspects of research which are essentially focused on set-up and application of analytical strategies (1) to identify, characterize, and quantify AGEs and ALEs in different pathophysiological conditions ; (2) to elucidate the molecular basis of their biological effects ; and (3) to discover compounds able to inhibit AGEs/ALEs damaging effects not only as biological tools aimed at validating AGEs/ALEs as drug target, but also as promising drugs. All the above-mentioned research stages require a clear picture of the chemical formation of AGEs/ALEs but this is not simple, due to the complex and heterogeneous pathways, involving different precursors and mechanisms. In view of this intricate scenario, the aim of the present review is to group the main AGEs and ALEs and to describe, for each of them, the precursors and mechanisms of formation

Bleeding risk assessment using multiple electrode aggregometry in patients following coronary artery bypass surgery

Individual variability in the response to antiplatelet therapy (APT), frequently administered preoperatively, has been established by various platelet function assays and could reflect bleeding tendency after coronary artery bypass surgery (CABG). Our hypothesis is that multiple electrode whole-blood aggregometry (MEA) can identify patients at risk for excessive bleeding. We enrolled 211 patients (155 male and 56 female) undergoing isolated CABG in a prospective observational study. Patients were divided into four groups with respect to their preoperative APT management. MEA, using the ASPI and the ADP test, was performed prior to surgery. The primary endpoint was chest tube output (CTO) and the secondary endpoint was perioperative packed red blood cell concentrate (PRBC) administration. Patients were characterized as bleeders if their 24 h CTO exceeded the 75th percentile of distribution. 24 h CTO value of 11.33 ml/kg presented 75th percentile of distribution, thus cut-off value for "bleeder category". The proportion of patients characterized as bleeders was significantly different among the groups in regard to preoperative APT (p = 0.039). Significant differences in both ASPI (p < 0.001) and ADP (p = 0.038) tests were observed between different preoperative APT groups. Significant correlations between the ASPI test (r = -0.170, p = 0.014) and ADP test (r = -0.206, p = 0.003) with 24 h CTO were found. The receiver operating curve revealed an ASPI test value of <20 area under curve (AUC) units (AUC 0.603, p = 0.023) and an ADP test <73 AUC (AUC 0.611, p = 0.009) as a "bleeder" determinant. The proportion of patients transfused with PRBC did not significantly differ among the groups in regard to preoperative APT (p = 0.636). Comparison of the ASPI test values between patients with respect to PRBC administration revealed lower values in the ASPI test in a group of patients transfused with PRBC (mean, 27.88 vs. 40.32 AUC, p = 0.002). Our study showed that MEA is a useful method of predicting CABG patients with excessive postoperative bleeding