214 resultados para Héloïse, 1101-1164


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Rationale: Increasing epithelial repair and regeneration may hasten resolution of lung injury in patients with the Acute Respiratory Distress Syndrome (ARDS). In animal models of ARDS, Keratinocyte Growth Factor (KGF) reduces injury and increases epithelial proliferation and repair. The effect of KGF in the human alveolus is unknown.

Objectives: To test whether KGF can attenuate alveolar injury in a human model of ARDS.

Methods: Volunteers were randomized to intravenous KGF (60 μg/kg) or placebo for 3 days, before inhaling 50μg lipopolysaccharide. Six hours later, subjects underwent bronchoalveolar lavage (BAL) to quantify markers of alveolar inflammation and cell-specific injury.

Measurements and Main Results: KGF did not alter leukocyte infiltration or markers of permeability in response to LPS. KGF increased BAL concentrations of Surfactant Protein D (SP-D), MMP-9, IL-1Ra, GM-CSF and CRP. In vitro, BAL fluid from KGF-treated subjects (KGF BAL) inhibited pulmonary fibroblast proliferation, but increased alveolar epithelial proliferation. Active MMP-9 increased alveolar epithelial wound repair. Finally, BAL from the KGF pre-treated group enhanced macrophage phagocytic uptake of apoptotic epithelial cells and bacteria compared with BAL from the placebo-treated group. This effect was blocked by inhibiting activation of the GM-CSF receptor.

Conclusions: KGF treatment increases BAL SP-D, a marker of type II alveolar epithelial cell proliferation in a human model of ALI. Additionally KGF increases alveolar concentrations of the anti-inflammatory cytokine IL-1Ra, and mediators that drive epithelial repair (MMP-9) and enhance macrophage clearance of dead cells and bacteria (GM-CSF).

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Due to the high degree of international and economic integration across the globe, the 2007 global financial crisis quickly spread, causing recessions and widespread credit restrictions in advanced nations. During recessions, economic fluctuations cause dramatic changes to the market structure of industries, in particular, that of the construction sector. These structural changes can be further influenced by government strategies and policies; which if used incorrectly, can serve to fuel and exacerbate downturns. In contrasting form, during an economic recession, government strategies and policies can also be used to aid in exiting such economic turbulence. From an extensive review of literature it became apparent that very little research offered a comprehensive and systematic overview of Irish and UK construction related government policies and strategies adopted during recessions; hence the emergence of this topic. As part of an ongoing research PhD, the purpose of this paper is to collate and group Irish and UK Government strategies and policies adopted for the construction sector during the recession period 2007-2013; resulting in the establishment of a construction industry development framework and a taxonomic framework. The results reveal serious problems with the national strategic plan for the Irish construction industry, given that there is no overseeing body or target dates for implementation of the proposed actions. Furthermore, both countries failed to prioritize the proposed key actions within their strategic plans. The findings of this paper can be applied in the context of the construction sector to address shortcomings in the respective sub-sectors, while also aiding policy makers and company executives in mapping out future strategic milestones.

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A new pathway to (+)-inthomycin C is reported that exploits an O-directed free radical hydrostannation reaction on (−)-12 and a Stille cross-coupling as key steps. Significantly, the latter process was effected on 19 where a gauche-pentane repulsive interaction could interfere. Our stereochemical studies on the alkynol (−)-12 and the enyne (+)-7 confirm that Ryu and Hatakeyama’s (3S)-stereochemical revision of (+)-inthomycin C is invalid and that Zeeck and Taylor’s original (3R)-stereostructure for (+)-inthomycin C is correct.

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Rationale: Ex vivo, bronchial epithelial cells from people with asthma are more susceptible to rhinovirus infection caused by deficient induction of the antiviral protein, IFN-b. Exogenous IFN-b restores antiviral activity.

Objectives: To compare the efficacy and safety of inhaled IFN-b with placebo administered to people with asthma after onset of cold symptoms to prevent or attenuate asthma symptoms caused by respiratory viruses.

Methods: A total of 147 people with asthma on inhaled corticosteroids (British Thoracic Society Steps 2–5), with a history of virus-associated exacerbations, were randomized to 14-day treatment with inhaled IFN-b (n = 72) or placebo (n = 75) within 24 hours of developing cold symptoms and were assessed clinically, with relevant samples collected to assess virus infection and antiviral responses.

Measurements and Main Results: A total of 91% of randomized patients developed a defined cold. In this modified intention-to-treat population, asthma symptoms did not get clinically significantly worse
(mean change in six-item Asthma Control Questionnaire ,0.5) and IFN-b treatment had no significant effect on this primary endpoint, although it enhanced morning peak expiratory flow recovery (P = 0.033), reduced the need for additional treatment, and boosted innate immunity as assessed by blood and sputum biomarkers. In an exploratory analysis of the subset ofmore difficult-to-treat, Step 4-5 peoplewith asthma (n = 27 IFN-b; n = 31 placebo), Asthma Control Questionnaire-6 increased significantly on placebo; this was prevented by IFN-b (P = 0.004).

Conclusions: Although the trial did not meet its primary endpoint, it suggests that inhaled IFN-b is a potential treatment for virus-induced deteriorations of asthma in difficult-to-treat people with asthma and supports the needforfurther, adequately powered, trialsin this population. Clinical trial registered with www.clinicaltrials.gov (NCT 01126177).

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Cathepsin S (CTSS) activity is increased in bronchoalveolar lavage (BAL) fluid from patients with cystic fibrosis (CF). This activity contributes to lung inflammation via degradation of antimicrobial proteins, such as lactoferrin and members of the β-defensin family.

Objectives:
In this study, we investigated the hypothesis that airway epithelial cells are a source of CTSS, and mechanisms underlying CTSS expression in the CF lung.

Methods:
Protease activity was determined using fluorogenic activity assays. Protein and mRNA expression were analyzed by ELISA, Western blotting, and reverse-transcriptase polymerase chain reaction.Measurements and Main Results: In contrast to neutrophil elastase, CTSS activity was detectable in 100% of CF BAL fluid samples from patients without Pseudomonas aeruginosa infection. In this study, we identified epithelial cells as a source of pulmonary CTSS activity with the demonstration that CF airway epithelial cells express and secrete significantly more CTSS than non-CF control cells in the absence of proinflammatory stimulation. Furthermore, levels of the transcription factor IRF-1 correlated with increased levels of its target gene CTSS. We discovered that miR-31, which is decreased in the CF airways, regulates IRF-1 in CF epithelial cells. Treating CF bronchial epithelial cells with a miR-31 mimic decreased IRF-1 protein levels with concomitant knockdown of CTSS expression and secretion.

Conclusions:
The miR-31/IRF-1/CTSS pathway may play a functional role in the pathogenesis of CF lung disease and may open up new avenues for exploration in the search for an effective therapeutic target.

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Background: Comparative effectiveness research (CER) is intended to inform decision making in clinical practice, and is central to patientcentered outcomes research (PCOR). Purpose: To summarize key aspects of CER definitions and provide examples highlighting the complementary nature of efficacy and CER studies in pulmonary, critical care, and sleep medicine. Methods: An ad hoc working group of the American Thoracic Society with experience in clinical trials, health services research, quality improvement, and behavioral sciences in pulmonary, critical care, and sleepmedicinewas convened. The group used an iterative consensus process, including a reviewbyAmerican Thoracic Society committees and assemblies. Results: The traditional efficacy paradigm relies on clinical trials with high internal validity to evaluate interventions in narrowly defined populations and in research settings. Efficacy studies address the question, "Can it work in optimal conditions?" The CER paradigm employs a wide range of study designs to understand the effects of interventions in clinical settings. CER studies address the question, "Does it work in practice?" The results of efficacy and CER studies may or may not agree. CER incorporates many attributes of outcomes research and health services research, while placing greater emphasis on meeting the expressed needs of nonresearcher stakeholders (e.g., patients, clinicians, and others). Conclusions: CER complements traditional efficacy research by placing greater emphasis on the effects of interventions in practice, and developing evidence to address the needs of the many stakeholders involved in health care decisions. Stakeholder engagement is an important component of CER. Copyright © 2013 by the American Thoracic Society.

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Cystic fibrosis (CF) lung disease is characterized by chronic bacterial infection and an unremitting inflammatory response, which are responsible for most of CF morbidity and mortality. The median expected survival has increased from <6 mo in 1940 to >38 yr now. This dramatic improvement, although not great enough, is due to the development of therapies directed at secondary disease pathologies, especially antibiotics. The importance of developing treatments directed against the vigorous inflammatory response was realized in the 1990s. New therapies directed toward the basic defect are now visible on the horizon. However, the impact of these drugs on downstream pathological consequences is unknown. It is likely that antibiotics and anti-inflammatory drugs will remain an important part of the maintenance regimen for CF in the foreseeable future. Current and future antibiotic and anti-inflammatory therapies for CF are reviewed. © 2013 Cold Spring Harbor Laboratory Press; all rights reserved.

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RATIONALE: Anaerobic bacteria are present in large numbers in the airways of people with cystic fibrosis (PWCF). In the gut, anaerobes produce short-chain fatty acids (SCFAs) that modulate immune/inflammatory processes.

OBJECTIVES: To investigate the capacity of anaerobes to contribute to CF airway pathogenesis via SCFAs.

METHODS: Samples from 109 PWCF were processed using anaerobic microbiological culture with bacteria present identified by 16S RNA sequencing. SCFAs levels in anaerobe supernatants and bronchoalveolar lavage (BAL) were determined by gas chromatography. The mRNA and/or protein expression of SCFAs receptors, GPR41 and GPR43, in CF and non-CF bronchial brushings, and 16HBE14o- and CFBE41o- cells were evaluated using RT-PCR, western blot, laser scanning cytometry and confocal microscopy. SCFAs-induced IL-8 secretion was monitored by ELISA.

MEASUREMENTS AND MAIN RESULTS: Fifty seven of 109 (52.3%) PWCF were anaerobe-positive. Prevalence increased with age, from 33.3% to 57.7% in PWCF under (n=24) and over 6 years (n=85). All evaluated anaerobes produced millimolar concentrations of SCFAs, including acetic, propionic and butyric acid. SCFAs levels were higher in BAL samples from adults than children. GPR41 levels were elevated in; CFBE41o- versus 16HBE14o- cells; CF versus non-CF bronchial brushings; 16HBE14o- cells after treatment with CFTR inhibitor CFTR(inh)-172, CF BAL, or inducers of endoplasmic reticulum stress. SCFAs induced a dose-dependent and pertussis toxin-sensitive IL-8 response in bronchial epithelial cells with a higher production of IL-8 in CFBE41o- than 16HBE14o- cells.

CONCLUSIONS: This study illustrates that SCFAs contribute to excessive production of IL-8 in CF airways colonized with anaerobes via upregulated GPR41.

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Much interest now focuses on the use of the contingent valuation method (CVM) to assess non-use value of environmental goods. The paper reviews recent literature and highlights particular problems of information provision and respondent knowledge, comprehension and cognition. These must be dealt with by economists in designing CVM surveys for eliciting non-use values. Cognitive questionnaire design methods are presented which invoke concepts from psychology and tools from cognitive survey design (focus groups and verbal reports) to reduce a complex environmnetal good into a meaningful commodity that can be valued by respondents in a contingent market. This process is illustrated with examples from the authors' own research valuing alternative afforestation programmes. -Authors

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In Contingent Valuation studies, researchers often base their definition of the environmental good on scientific/expert consensus. However, respondents may not hold this same commodity definition prior to the transaction. This raises questions as to the potential for staging a satisfactory transaction, based on Fischoff and Furby's (1988) criteria. Some unresolved issues regarding the provision of information to respondents to facilitate such a transaction are highlighted. In this paper, we apply content analysis to focus group discussions and develop a set of rules which take account of the non-independence of group data to explore whether researcher and respondents' prior definitions are in any way similar. We use the results to guide information provision in a subsequent questionnaire.

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Rationale: IL-17A is purported to help drive early pathogenesis in acute respiratory distress syndrome (ARDS) by enhancing neutrophil recruitment. Whilst IL-17A is the archetypal cytokine of T helper (Th)17 cells, it is produced by a number of lymphocytes, the source during ARDS being unknown.

Objectives: To identify the cellular source and the role of IL17A in the early phase of lung injury

Methods: Lung injury was induced in WT (C57BL/6) and IL-17 KO mice with aerosolised LPS (100 µg) or Pseudomonas aeruginosa infection. Detailed phenotyping of the cells expressing RORγt, the transcriptional regulator of IL-17 production, in the mouse lung at 24 hours was carried out by flow cytometry.

Measurement and Main Results: A 100-fold reduction in neutrophil infiltration was observed in the lungs of the IL-17A KO compared to wild type (WT) mice. The majority of RORγt+ cells in the mouse lung were the recently identified type 3 innate lymphoid cells (ILC3). Detailed characterisation revealed these pulmonary ILC3s (pILC3s) to be discrete from those described in the gut. The critical role of these cells was verified by inducing injury in Rag2 KO mice which lack T cells but retain ILCs. No amelioration of pathology was observed in the Rag2 KO mice.

Conclusions: IL-17 is rapidly produced during lung injury and significantly contributes to early immunopathogenesis. This is orchestrated largely by a distinct population of pILC3 cells. Modulation of pILC3s’ activity may potentiate early control of the inflammatory dysregulation seen in ARDS, opening up new therapeutic targets.