41 research outputs found
Aspirin-triggered resolvin D1 reduces pneumococcal lung infection and inflammation in a viral and bacterial coinfection pneumonia model
Formyl peptide receptor 2/lipoxin A4 (LXA4) receptor (Fpr2/ALX) co-ordinates the transition from inflammation to resolution during acute infection by binding to distinct ligands including serum amyloid A (SAA) and Resolvin D1 (RvD1). Here, we evaluated the proresolving actions of aspirin-triggered RvD1 (AT-RvD1) in an acute coinfection pneumonia model. Coinfection with Streptococcus pneumoniae and influenza A virus (IAV) markedly increased pneumococcal lung load and neutrophilic inflammation during the resolution phase. Fpr2/ALX transcript levels were increased in the lungs of coinfected mice, and immunohistochemistry identified prominent Fpr2/ALX immunoreactivity in bronchial epithelial cells and macrophages. Levels of circulating and lung SAA were also highly increased in coinfected mice. Therapeutic treatment with exogenous AT-RvD1 during the acute phase of infection (day 4–6 post-pneumococcal inoculation) significantly reduced the pneumococcal load. AT-RvD1 also significantly reduced neutrophil elastase (NE) activity and restored total antimicrobial activity in bronchoalveolar lavage (BAL) fluid (BALF) of coinfected mice. Pneumonia severity, as measured by quantitating parenchymal inflammation or alveolitis was significantly reduced with AT-RvD1 treatment, which also reduced the number of infiltrating lung neutrophils and monocytes/macrophages as assessed by flow cytometry. The reduction in distal lung inflammation in AT-RvD1-treated mice was not associated with a significant reduction in inflammatory and chemokine mediators. In summary, we demonstrate that in the coinfection setting, SAA levels were persistently increased and exogenous AT-RvD1 facilitated more rapid clearance of pneumococci in the lungs, while concurrently reducing the severity of pneumonia by limiting excessive leukocyte chemotaxis from the infected bronchioles to distal areas of the lungs
IL-17A and serum amyloid A are elevated in a cigarette smoke cessation model associated with the persistence of pigmented macrophages, neutrophils and activated NK cells
While global success in cessation advocacy has seen smoking rates fall in many developed countries, persistent lung inflammation in ex-smokers is an increasingly important clinical problem whose mechanistic basis remains poorly understood. In this study, candidate effector mechanisms were assessed in mice exposed to cigarette smoke (CS) for 4 months following cessation from long term CS exposure. BALF neutrophils, CD4+ and CD8+ T cells and lung innate NK cells remained significantly elevated following smoking cessation. Analysis of neutrophil mobilization markers showed a transition from acute mediators (MIP-2α, KC and G-CSF) to sustained drivers of neutrophil and macrophage recruitment and activation (IL-17A and Serum Amyoid A (SAA)). Follicle-like lymphoid aggregates formed with CS exposure and persisted with cessation, where they were in close anatomical proximity to pigmented macrophages, whose number actually increased 3-fold following CS cessation. This was associated with the elastolytic protease, MMP-12 (macrophage metallo-elastase) which remained significantly elevated post-cessation. Both GM-CSF and CSF-1 were significantly increased in the CS cessation group relative to the control group. In conclusion, we show that smoking cessation mediates a transition to accumulation of pigmented macrophages, which may contribute to the expanded macrophage population observed in COPD. These macrophages together with IL-17A, SAA and innate NK cells are identified here as candidate persistence determinants and, we suggest, may represent specific targets for therapies directed towards the amelioration of chronic airway inflammation
Multiresidue Method for the Simultaneous Analysis of Antibiotics and Mycotoxins in Feeds by Ultra-High Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry
Residues in animal feeds and foods of animal origin have been important safety issue concerning both human and animal health. A multiresidue method for determination of eight mycotoxins and ten antibiotics was developed and validated in animal feeds by using QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction followed by UHPLC-MS/MS. Optimisation of UHPLC-MS/MS parameters was performed to achieve good separation and resolution. The method was validated according to the European Commission Decision 2002/657/EC. Matrix matched calibration curves showed good r2 (≥0.995) values, and limit of quantification (LOQ) values varied between 1.2 and 5.2 mg kg1. Average recoveries ranged from 60 to 102% with relative standard deviations of 2.2 and 15.6% for all type of feed samples except for tetracyclines, lincomycin, tylosin, ochratoxin A, and fumonisin (B1 and B2)
Photocatalytic efficiencies of alternate heterogeneous catalysts: Iron modified minerals and semiconductors for removal of an azo dye from solutions
Photocatalytic degradation of reactive dye solutions have been compared using two types of heterogeneous catalysts, i.e., semiconductors and iron modified clays. Decolorization and mineralization efficiencies of the catalysts were performed in a slurry batch reactor with UVA and UVC (365 and 254 nm, respectively) light sources using reactive azo dye solutions. Two natural minerals (zeolites and beidellites) modified with Fe3+, Fe2+and semiconductors (TiO2-P25 and ZnO) were used as photocatalysts. Iron modified minerals produced similar results compared to homogeneous photo-Fenton reactions under UVC radiation. Fe2+-beidellite and Fe3+-zeolite showed the best efficiency for dye removal with 98.5% at 75 min and 96.3% at 90 min, respectively, which is higher than the other iron modified minerals under UVA radiation. ZnO and TiO2 exhibited initial dye removal rates under UVA as 98.9% and 95.5% at 45 min, respectively. Mineralization efficiencies for TiO2, ZnO and Fe2+-beidellite, Fe3+ -zeolite under UVA were 86.2%, 74.5% and 76.9%, 67.8%, respectively. However mineral catalysts performed 99% dye removal rates within 15 min with respect to semiconductor catalyst values (over 97% within 45min) under UVC radiation. Mineral catalysts and TiO2 provided higher initial TOC removal rates as 92% in 60 min under UVC radiation
Kinetics of the Photocatalytic Decolorization of an Azo Reactive Dye in Aqueous ZnO Suspensions
ZnO Nanorods Grown on Flexible Polyurethane Foam Surfaces for Photocatalytic Azo Dye Treatment
A flexible photocatalyst hybrid structure made up of
aligned ZnO
nanorods and three-dimensional networks of polyurethane (PU) foam
struts was fabricated. The surfaces of the PU struts were first functionalized
by the two-step chemical solution treatment method. The functional
groups of the PU foam and the nanohybrid structure were characterized
using Fourier transmission infrared spectroscopy (FTIR). Their crystal
structures and morphologies were examined by using X-ray diffraction
(XRD) and scanning electron microscopy (SEM), respectively. The adequacy
of the chemical surface modification process was examined by analyzing
the differences in the −N C O and O–H
regions of the FTIR spectrum. The hybrid photocatalyst samples were
also tested in terms of their structural integrities under ultrasonic
irradiation. It was observed that the ZnO layers remained intact and
adherent on the surfaces even after 1 h of sonication. The optical
properties of the samples were also characterized by ultraviolet–visible
(UV–vis) and photoluminescence (PL) spectroscopies. Aqueous
Acid Red 88 (AR88) azo dye solutions were prepared and used to assess
both the color and the total organic carbon (TOC) removal efficiencies
of the samples utilizing the laboratory-scale photoreactor. The maximum
color removal of 97% was reached in 180 min under UVA light irradiation
as a consequence of simultaneous adsorption and photocatalysis mechanisms
Integrated process of fungal membrane bioreactor and photocatalytic membrane reactor for the treatment of industrial textile wastewater
WOS: 000367776500012In this study, fungal membrane bioreactor (FMBR) and semiconductor photocatalytic membrane reactor (PMR) were used in order to test the efficiency of integrated fungal biodegradation and photocatalytic degradation of textile wastewater from reactive washing processes. It was found that color removal and chemical oxygen demand (COD) reduction efficiencies were 88% and 53% for photocatalytic degradation, respectively. TiO2 and ZnO were tested as semiconductor catalysts in the PMR and TiO2 showed better efficiencies than ZnO for both color and COD removal. However, it was attained that color removal and COD reduction efficiencies were about 56% and 60% for fungal biodegradation using Phatterochaete chrysosporium, respectively. Moreover, integrated system in which photocatalytic degradation was employed as a post-treatment application after fungal biodegradation process achieved high removal efficiencies for color and COD removal as 93% and 99%, respectively. (C) 2015 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey (TUBITAK) [113Y334]This work was funded by The Scientific and Technological Research Council of Turkey (TUBITAK), Project No: 113Y334