761 research outputs found

    Lymphocytic colitis presenting as difficult diarrhoea in an African woman: a case report and review of the literature

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    <p>Abstract</p> <p>Introduction</p> <p>Lymphocytic colitis is an uncommon intestinal disorder that presents with chronic diarrhoea. It is treatable, but in the developing world, its diagnosis may often prove difficult. Data and reports of this condition in Africa are scarce because most medical centres lack a functional gastrointestinal endoscopy unit that would aid in the diagnosis.</p> <p>Case presentation</p> <p>We present the case of a 53-year-old Nigerian woman with pathogen-negative chronic diarrhoea and a family history of chronic diarrhoea. She responded well to treatment after colonoscopy and colonic biopsy successfully diagnosed her illness.</p> <p>Conclusion</p> <p>Referral of patients with pathogen-negative chronic diarrhoea to medical centres that have facilities for colonoscopy and biopsy is important in the developing world.</p

    Elabela/Toddler is an Endogenous Agonist of the Apelin APJ Receptor in the Adult Cardiovascular System, and Exogenous Administration of the Peptide Compensates for the Downregulation of its Expression in Pulmonary Arterial Hypertension

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    BACKGROUND: -Elabela/Toddler (ELA) is a critical cardiac developmental peptide that acts through the G protein-coupled apelin receptor, despite lack of sequence similarity to the established ligand apelin. Our aim was to investigate the receptor pharmacology, expression pattern and in vivo function of ELA peptides in the adult cardiovascular system, to seek evidence for alteration in pulmonary arterial hypertension (PAH) in which apelin signaling is down-regulated, and to demonstrate attenuation of PAH severity with exogenous administration of ELA in a rat model. METHODS: -In silico docking analysis, competition binding experiments and down-stream assays were used to characterize ELA receptor binding in human heart and signaling in cells expressing the apelin receptor. ELA expression in human cardiovascular tissues and plasma was determined using RT-qPCR, dual-labelling immunofluorescent staining and immunoassays. Acute cardiac effects of ELA-32 and [Pyr(1)]apelin-13 were assessed by magnet resonance imaging and cardiac catheterization in anesthetized rats. Cardiopulmonary human and rat tissues from PAH patients and monocrotaline (MCT) and Sugen/hypoxia exposed rats were used to show changes in ELA expression in PAH. The effect of ELA treatment on cardiopulmonary remodeling in PAH was investigated in the MCT rat model. RESULTS: -ELA competed for binding of apelin in human heart with overlap for the two peptides indicated by in silico modeling. ELA activated G protein- and Β-arrestin-dependent pathways. We detected ELA expression in human vascular endothelium and plasma. Comparable to apelin, ELA increased cardiac contractility, ejection fraction, cardiac output and elicited vasodilatation in rat in vivo ELA expression was reduced in cardiopulmonary tissues from PAH patients and PAH rat models, respectively. ELA treatment significantly attenuated elevation of right ventricular systolic pressure and right ventricular hypertrophy and pulmonary vascular remodeling in MCT exposed rats. CONCLUSIONS: -These results show ELA is an endogenous agonist of the human apelin receptor, exhibits a cardiovascular profile comparable to apelin, is down-regulated in human disease and rodent PAH models and exogenous peptide can reduce the severity of cardiopulmonary remodeling and function in PAH in rats. This study provides additional proof of principle that an apelin receptor agonist may be of therapeutic use in PAH in man.Supported by the Wellcome Trust 107715/Z/15/Z and Programme in Metabolic and Cardiovascular Disease 096822/Z/11/Z, Medical Research Council MC_PC_14116, British Heart Foundation PS/02/001, PG/05/127/19872, FS/14/59/31282 and in part by the National Institute for Health Research Cambridge Biomedical Research Centre and the Pulmonary Hypertension Association UK

    A persistent neutrophil-associated immune signature characterizes post-COVID-19 pulmonary sequelae.

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    Interstitial lung disease and associated fibrosis occur in a proportion of individuals who have recovered from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection through unknown mechanisms. We studied individuals with severe coronavirus disease 2019 (COVID-19) after recovery from acute illness. Individuals with evidence of interstitial lung changes at 3 to 6 months after recovery had an up-regulated neutrophil-associated immune signature including increased chemokines, proteases, and markers of neutrophil extracellular traps that were detectable in the blood. Similar pathways were enriched in the upper airway with a concomitant increase in antiviral type I interferon signaling. Interaction analysis of the peripheral phosphoproteome identified enriched kinases critical for neutrophil inflammatory pathways. Evaluation of these individuals at 12 months after recovery indicated that a subset of the individuals had not yet achieved full normalization of radiological and functional changes. These data provide insight into mechanisms driving development of pulmonary sequelae during and after COVID-19 and provide a rational basis for development of targeted approaches to prevent long-term complications

    The frequency of microscopic and focal active colitis in patients with irritable bowel syndrome

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    <p>Abstract</p> <p>Background</p> <p>Irritable bowel syndrome (IBS) is a chronic functional bowel disorder. The frequency of microscopic colitis and focal active colitis in the colonic mucosa has been investigated in IBS patients.</p> <p>Methods</p> <p>Between June 2007 and September 2010, 378 patients (between 16 and 84 years) were recruited prospectively. Of these 378 patients, 226 patients were diagnosed with IBS using the Rome III criteria. 152 control patients were also enrolled who were undergoing colonoscopy for colorectal cancer screening or investigation of anemia. Histopathological abnormalities identified during colonoscopy were compared between the IBS and control groups.</p> <p>Results</p> <p>The average age of the IBS group was 46.13 ± 14.16 years and and the average age of the control group was 57.01 ± 13.07 years. The prevalence of microscopic colitis (MC) in the diarrhea predominant and the mixed subgroup of IBS patients was 4.32% (7/162) whereas in all IBS patients, the prevalence was 3.09% (7/226). MC was not found in the 152 control cases, (p = 0.045). Lymphocytic colitis was seen in 7 IBS patients, with 1 case in the mixed group and 6 cases in the diarrhea group and there was a significant difference in the frequency of lymphocytic colitis between the IBS subgroups (p < 0.01). Focal active colitis was found in 6.6% (15/226) of the IBS patients and in none of the controls (p < 0.01), and there was no differences between IBS subtypes.</p> <p>Conclusion</p> <p>Microscopic colitis was more often found in the diarrhea predominant/mixed subgroups of IBS patients and in patients who were older women. In patients who are older woman with non-constipated IBS, it may be reasonable to perform a biopsy to screen for microscopic colitis. Focal active colitis was significantly increased in patients with IBS compared to controls.</p

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Nicotine and smoking do not decrease basal gastric mucosal blood flow in anesthetized rats

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    The literature regarding the effect of nicotine and cigarette smoke on gastric blood flow is conflicting. The hydrogen gas clearance technique was used to measure the effects of nicotine and cigarette smoke on basal gastric mucosal blood flow in anesthetized rats. Blood flow was measured before, during, and after treatment with either intravenous nicotine (4 or 40 ÎŒg/kg/min) or inhaled cigarette smoke (nicotine or nicotine free). Neither intravenous nicotine nor cigarette smoke significantly altered gastric mucosal blood flow. On the other hand, hypotension produced by hemorrhage significantly decreased mucosal blood flow ( P <0.05). Thus the technique used could detect a decrease in blood flow. These findings indicate that in the anesthetized rats, hypotension but not intravenous nicotine or cigarette smoke, in the doses given, reduce gastric mucosal blood flow.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44399/1/10620_2005_Article_BF01320320.pd

    Rhamnolipids: diversity of structures, microbial origins and roles

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    Rhamnolipids are glycolipidic biosurfactants produced by various bacterial species. They were initially found as exoproducts of the opportunistic pathogen Pseudomonas aeruginosa and described as a mixture of four congeners: α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-ÎČ-hydroxydecanoyl-ÎČ-hydroxydecanoate (Rha-Rha-C10-C10), α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-ÎČ-hydroxydecanoate (Rha-Rha-C10), as well as their mono-rhamnolipid congeners Rha-C10-C10 and Rha-C10. The development of more sensitive analytical techniques has lead to the further discovery of a wide diversity of rhamnolipid congeners and homologues (about 60) that are produced at different concentrations by various Pseudomonas species and by bacteria belonging to other families, classes, or even phyla. For example, various Burkholderia species have been shown to produce rhamnolipids that have longer alkyl chains than those produced by P. aeruginosa. In P. aeruginosa, three genes, carried on two distinct operons, code for the enzymes responsible for the final steps of rhamnolipid synthesis: one operon carries the rhlAB genes and the other rhlC. Genes highly similar to rhlA, rhlB, and rhlC have also been found in various Burkholderia species but grouped within one putative operon, and they have been shown to be required for rhamnolipid production as well. The exact physiological function of these secondary metabolites is still unclear. Most identified activities are derived from the surface activity, wetting ability, detergency, and other amphipathic-related properties of these molecules. Indeed, rhamnolipids promote the uptake and biodegradation of poorly soluble substrates, act as immune modulators and virulence factors, have antimicrobial activities, and are involved in surface motility and in bacterial biofilm development

    Gaia data release 1, the photometric data

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    CONTEXT. This paper presents an overview of the photometric data that are part of the first Gaia data release. AIMS. The principles of the processing and the main characteristics of the Gaia photometric data are presented. METHODS. The calibration strategy is outlined briefly and the main properties of the resulting photometry are presented. RESULTS. Relations with other broadband photometric systems are provided. The overall precision for the Gaia photometry is shown to be at the milli-magnitude level and has a clear potential to improve further in future releases

    Dark Matter in the Milky Way's Dwarf Spheroidal Satellites

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    The Milky Way's dwarf spheroidal satellites include the nearest, smallest and least luminous galaxies known. They also exhibit the largest discrepancies between dynamical and luminous masses. This article reviews the development of empirical constraints on the structure and kinematics of dSph stellar populations and discusses how this phenomenology translates into constraints on the amount and distribution of dark matter within dSphs. Some implications for cosmology and the particle nature of dark matter are discussed, and some topics/questions for future study are identified.Comment: A version with full-resolution figures is available at http://www.cfa.harvard.edu/~mwalker/mwdsph_review.pdf; 70 pages, 22 figures; invited review article to be published in Vol. 5 of the book "Planets, Stars, and Stellar Systems", published by Springe
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