10 research outputs found

    Acetarsol Suppositories: Effective Treatment for Refractory Proctitis in a Cohort of Patients with Inflammatory Bowel Disease.

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    BACKGROUND: Management of proctitis refractory to conventional therapies presents a common clinical problem. The use of acetarsol suppositories, which are derived from organic arsenic, was first described in 1965. Data concerning clinical efficacy and tolerability are very limited. AIM: To examine the efficacy of acetarsol suppositories for the treatment of refractory proctitis. METHODS: A retrospective analysis was performed on patients with inflammatory bowel disease treated with acetarsol suppositories between 2008 and 2014 at Addenbrooke's Hospital, Cambridge, United Kingdom. Clinical response was defined as resolution of symptoms back to baseline at the time of next clinic review. RESULTS: Thirty-nine patients were prescribed acetarsol suppositories between March 2008 and July 2014 (29 patients with ulcerative colitis, nine with Crohn's disease, and one with indeterminate colitis). Thirty-eight were included for analysis. The standard dose of acetarsol was 250 mg twice daily per rectum for 4 weeks. Clinical response was observed in 26 patients (68%). Of the 11 patients who had endoscopic assessment before and after treatment, nine (82%) showed endoscopic improvement and five (45%) were in complete remission (Wilcoxon signed-rank test p = 0.006). One patient developed a macular skin rash 1 week after commencing acetarsol, which resolved within 4 weeks of drug cessation. CONCLUSION: Acetarsol was effective for two out of every three patients with refractory proctitis. This cohort had failed a broad range of topical and systemic treatments, including anti-TNFα therapy. Clinical efficacy was reflected in significant endoscopic improvement. Adverse effects of acetarsol were rare

    ATG16L1 orchestrates interleukin-22 signaling in the intestinal epithelium via cGAS-STING.

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    A coding variant of the inflammatory bowel disease (IBD) risk gene ATG16L1 has been associated with defective autophagy and deregulation of endoplasmic reticulum (ER) function. IL-22 is a barrier protective cytokine by inducing regeneration and antimicrobial responses in the intestinal mucosa. We show that ATG16L1 critically orchestrates IL-22 signaling in the intestinal epithelium. IL-22 stimulation physiologically leads to transient ER stress and subsequent activation of STING-dependent type I interferon (IFN-I) signaling, which is augmented in Atg16l1 ΔIEC intestinal organoids. IFN-I signals amplify epithelial TNF production downstream of IL-22 and contribute to necroptotic cell death. In vivo, IL-22 treatment in Atg16l1 ΔIEC and Atg16l1 ΔIEC/Xbp1 ΔIEC mice potentiates endogenous ileal inflammation and causes widespread necroptotic epithelial cell death. Therapeutic blockade of IFN-I signaling ameliorates IL-22-induced ileal inflammation in Atg16l1 ΔIEC mice. Our data demonstrate an unexpected role of ATG16L1 in coordinating the outcome of IL-22 signaling in the intestinal epithelium

    Defective ATG16L1-mediated removal of IRE1α drives Crohn's disease-like ileitis.

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    ATG16L1T300A^{T300A}, a major risk polymorphism in Crohn's disease (CD), causes impaired autophagy, but it has remained unclear how this predisposes to CD. In this study, we report that mice with Atg16l1 deletion in intestinal epithelial cells (IECs) spontaneously develop transmural ileitis phenocopying ileal CD in an age-dependent manner, driven by the endoplasmic reticulum (ER) stress sensor IRE1α. IRE1α accumulates in Paneth cells of Atg16l1ΔIEC^{ΔIEC} mice, and humans homozygous for ATG16L1T300A^{T300A} exhibit a corresponding increase of IRE1α in intestinal epithelial crypts. In contrast to a protective role of the IRE1ÎČ isoform, hyperactivated IRE1α also drives a similar ileitis developing earlier in life in Atg16l1;Xbp1ΔIEC^{ΔIEC} mice, in which ER stress is induced by deletion of the unfolded protein response transcription factor XBP1. The selective autophagy receptor optineurin interacts with IRE1α, and optineurin deficiency amplifies IRE1α levels during ER stress. Furthermore, although dysbiosis of the ileal microbiota is present in Atg16l1;Xbp1ΔIEC^{ΔIEC} mice as predicted from impaired Paneth cell antimicrobial function, such structural alteration of the microbiota does not trigger ileitis but, rather, aggravates dextran sodium sulfate-induced colitis. Hence, we conclude that defective autophagy in IECs may predispose to CD ileitis via impaired clearance of IRE1α aggregates during ER stress at this site.This study was supported by the European Research Council under the European Community’s Seventh Framework Program (grant FP7/2007-2013)/ERC, agreement no. 260961 to A. Kaser and grant HORIZON2020/ERC, agreement no. 648889 to A. Kaser), the Wellcome Trust (Investigator Award 106260/Z/14/Z to A. Kaser and Principal Research Fellowship 2008/Z/16/Z to D. Ron), the Cambridge Biomedical Research Centre (A. Kaser), a Medical Research Council PhD for clinicians training fellowship (grant MR/N001893/1 to J. Bhattacharyya), fellowships from the European Crohn’s and Colitis Organization (M. Tschurtschenthaler and T.E. Adolph), the Research Training Group Genes, Environment, and Inflammation supported by the Deutsche Forschungsgemeinschaft (grant RTG 1743/1 to P. Rosenstiel), the SFB877 subproject B9 and CLVIII ExC 306 Inflammation at Interfaces (P. Rosenstiel), and the National Institutes of Health (grants DK044319, DK051362, DK053056, and DK088199 to the Harvard Digestive Diseases Center and grant DK0034854 to R.S. Blumberg)

    Monolithic cells for solar fuels

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    International audienceHybrid energy generation models based on a variety of alternative energy supply technologies are considered the best way to cope with the depletion of fossil energy resources and to limit global warming. One of the currently missing technologies is the mimic of natural photosynthesis to convert carbon dioxide and water into chemical fuel using sunlight. This idea has been around for decades, but artificial photosynthesis of organic molecules is still far away from providing real-world solutions. The scientific challenge is to perform in an efficient way the multi-electron transfer reactions of water oxidation and carbon dioxide reduction using holes and single electrons generated in an illuminated semiconductor. In this tutorial review the design of photoelectrochemical (PEC) cells that combine solar water oxidation and CO2 reduction is discussed. In such PEC cells simultaneous transport and efficient use of light, electrons, protons and molecules has to be managed. It is explained how efficiency can be gained by compartmentalisation of the water oxidation and CO2 reduction processes by proton exchange membranes, and monolithic concepts of artificial leaves and solar membranes are presented. Besides transferring protons from the anode to the cathode compartment the membrane serves as a molecular barrier material to prevent cross-over of oxygen and fuel molecules. Innovative nano-organized multimaterials will be needed to realise practical artificial photosynthesis devices. This review provides an overview of synthesis techniques which could be used to realise monolithic multifunctional membrane-electrode assemblies, such as Layer-by-Layer (LbL) deposition, Atomic Layer Deposition (ALD), and porous silicon (porSi) engineering. Advances in modelling approaches, electrochemical techniques and in situ spectroscopies to characterise overall PEC cell performance are discussed

    Potentiated Electron Transference in a-Ag2WO4 Microcrystals with Ag Nanofilaments as Microbial Agent

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    This study is a framework proposal for understanding the antimicrobacterial effect of both α-Ag2WO4 microcrystals (AWO) synthesized using a microwave hydrothermal (MH) method and α-Ag2WO4 microcrystals with Ag metallic nanofilaments (AWO:Ag) obtained by irradiation employing an electron beam to combat against planktonic cells of methicillin-resistant Staphylococcus aureus (MRSA). These samples were characterized by X-ray diffraction (XRD), FT-Raman spectroscopy, ultraviolet visible (UV–vis) measurements, field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and high resolution transmission electron microscopy (HRTEM). The results reveal that both AWO and AWO:Ag solutions have bacteriostatic and bactericidal effects, but the irradiated sample is more efficient; i.e., a 4-fold of the MRSA planktonic cells as compared to the nonirradiated sample was observed. In addition, first principles calculations were performed to obtain structural and electronic properties of AWO and metallic Ag, which provides strong quantitative support for an antimicrobacterial mechanism based on the enhancement of electron transfer processes between α-Ag2WO4 and Ag nanoparticles
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