Calprotectin (S100A8/S100A9) and Myeloperoxidase: Co-Regulators of Formation of Reactive Oxygen Species

Inflammatory mediators trigger polymorphonuclear neutrophils (PMN) to produce reactive oxygen species (ROS: O2-, H2O2, ∙OH). Mediated by myeloperoxidase in PMN, HOCl is formed, detectable in a chemiluminescence (CL) assay. We have shown that the abundant cytosolic PMN protein calprotectin (S100A8/A9) similarly elicits CL in response to H2O2 in a cell-free system. Myeloperoxidase and calprotectin worked synergistically. Calprotectin-induced CL increased, whereas myeloperoxidase-triggered CL decreased with pH > 7.5. Myeloperoxidase needed NaCl for CL, calprotectin did not. 4-hydroxybenzoic acid, binding ∙OH, almost abrogated calprotectin CL, but moderately increased myeloperoxidase activity. The combination of native calprotectin, or recombinant S100A8/A9 proteins, with NaOCl markedly enhanced CL. NaOCl may be the synergistic link between myeloperoxidase and calprotectin. Surprisingly- and unexplained- at higher concentration of S100A9 the stimulation vanished, suggesting a switch from pro-oxidant to anti-oxidant function. We propose that the ∙OH is predominant in ROS production by calprotectin, a function not described before

Results from Testing of Aker Solutions Advanced Amine Solvents at CO2 Technology Centre Mongstad

AbstractThe overall objective of the test program at CO2 Technology Centre Mongstad (TCM DA) is to verify Aker Solutions’ Advanced Carbon CaptureTM process including two proprietary advanced amine solvents, ACCTM-solvents S21 and S26. Also a short benchmark campaign is conducted with 30% MEA solvent in order to establish a reference. Key performance results are presented for MEA, S21 and S26.Close to 10 000 hours of operation of the TCM DA amine plant was obtained in the three campaigns, with high availability, showing that there are no operational issues related to the S21 and S26 solvents.Optimum SRD for 30 wt% MEA was found to be 3.8 MJ/kg CO2 when capturing CO2 from CHP gas with CO2 concentration 3.4-4.0% and CO2 capture rate of 87%. SRD was found to be approximately 10% lower for ACCTM advanced solvents S21 and S26. SRD values down to 3.4 MJ/kg CO2 was obtained for CHP flue gas with CO2 concentrations below 4 vol% and 87% capture without heat integration or use of ACCTM Energy Saver.Emissions to atmosphere using ACCTM emission control system were shown to be very low for solvent amines and alkyl amines, with measured levels below 0.1 mg/Nm3 in total. Emission of nitrosamines and nitramines were all below analytical detection limits typically around 0.1μg/Nm3.Solvent amine losses have been quantified to approximately 2.6 kg amine/ton CO2 captured for MEA, 0.5-0.6 kg amine/ton CO2 captured for ACCTM advanced solvent S21, and 0.2-0.3 kg amine/ton CO2 captured for ACCTM advanced solvent S26.Successful reclaiming of ACCTM advanced solvents S21 and S26 was performed towards the end of the campaigns.Reclaiming was performed for validation purposes and not due to any indications of critical loss of solvent performance, high emissions, high viscosity or other operational problems that could be an indication of excessive degradation. No operational problems such as precipitation or fouling were encountered during reclaiming. HSS and most impurities and degradation products were removed from the solvent by more than 80%

Ondansetron reduces nausea and vomiting after paediatric adenotonsillectomy

The efficacy, safety and resource implications of a single intravenous dose of ondansetron (0.1 mg.kg-1, maximum 4 mg) were assessed in a multinational, multicentre, randomized, double-blind, placebo-controlled trial of 427 children aged 1-12 years, undergoing tonsillectomy with/without adenoidectomy. Emesis (retching and/or vomiting) and nausea were analysed separately. Significantly more ondansetron-treated children had no episodes of emesis (127/212 (60%) vs 100/215 (47%); P = 0.004) and experienced no postoperative nausea (135/211 (64%) vs 108/213 (51%); P = 0.004) in the first 24 h. Ondansetron also reduced the number of emetic episodes (P<0.001), the time to the first emetic episode (P<0.001) and overall nausea severity (P = 0.003). Significantly fewer ondansetron-treated children were rescued or withdrawn from the study (5% vs 10%; P = 0.042). Fewer ondansetron-treated patients required nursing intervention (34% vs 45%; P = 0.007) and the average intervention time was significantly shorter (4.6 vs 8.1 minutes; P = 0.001). Resources used to manage PONV were significantly reduced by ondansetron (43% vs 57%; P = 0.014).SCOPUS: ar.jinfo:eu-repo/semantics/publishe