962 research outputs found

    Differential regulation of CCL-11/eotaxin-1 and CXCL-8/IL-8 by Gram-positive and Gram-negative bacteria in human airway smooth muscle cells

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    Background: Bacterial infections are a cause of exacerbation of airway disease. Airway smooth muscle cells (ASMC) are a source of inflammatory cytokines/chemokines that may propagate local airway inflammatory responses. We hypothesize that bacteria and bacterial products could induce cytokine/chemokine release from ASMC.Methods: Human ASMC were grown in culture and treated with whole bacteria or pathogen associated molecular patterns (PAMPs) for 24 or 48 h. The release of eotaxin-1, CXCL-8 or GMCSF was measured by ELISA.Results: Gram-negative E. coli or Gram-positive S. aureus increased the release of CXCL-8, as did IL-1β, LPS, FSL-1 and Pam3CSK4, whereas FK565, MODLys18 or Poly I:C did not. E. coli inhibited eotaxin-1 release under control conditions and after stimulation with IL-1β. S. aureus tended to inhibit eotaxin-1 release stimulated with IL-1β. E. coli or LPS, but not S. aureus, induced the release of GMCSF.Conclusion: Gram-positive or Gram-negative bacteria activate human ASMC to release CXCL-8. By contrast Gram-negative bacteria inhibited the release of eotaxin-1 from human ASMCs. E. coli, but not S. aureus induced GMCSF release from cells.Our findings that ASMC can respond directly to Gram-negative and Gram-positive bacteria by releasing the neutrophil selective chemokine, CXCL-8, is consistent with what we know about the role of neutrophil recruitment in bacterial infections in the lung. Our findings that bacteria inhibit the release of the eosinophil selective chemokine, eotaxin-1 may help to explain the mechanisms by which bacterial immunotherapy reduces allergic inflammation in the lung. © 2008 Issa et al; licensee BioMed Central Ltd

    Differential regulation of CCL-11/eotaxin-1 and CXCL-8/IL-8 by Gram-positive and Gram-negative bacteria in human airway smooth muscle cells.

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    Background: Bacterial infections are a cause of exacerbation of airway disease. Airway smooth muscle cells (ASMC) are a source of inflammatory cytokines/chemokines that may propagate local airway inflammatory responses. We hypothesize that bacteria and bacterial products could induce cytokine/chemokine release from ASMC. Methods: Human ASMC were grown in culture and treated with whole bacteria or pathogen associated molecular patterns (PAMPs) for 24 or 48 h. The release of eotaxin-I, CXCL-8 or GMCSF was measured by ELISA. Results: Gram-negative E. coli or Gram-positive S. aureus increased the release of CXCL-8, as did IL-1 beta, LPS, FSL-1 and Pam(3)CSK4, whereas FK565, MODLys18 or Poly I:C did not. E. coli inhibited eotaxin-I release under control conditions and after stimulation with IL-1 beta. S. aureus tended to inhibit eotaxin-I release stimulated with IL-1 beta. E. coli or LPS, but not S. aureus, induced the release of GMCSF. Conclusion: Gram-positive or Gram-negative bacteria activate human ASMC to release CXCL-8. By contrast Gram-negative bacteria inhibited the release of eotaxin-I from human ASMCs. E. coli, but not S. aureus induced GMCSF release from cells. Our findings that ASMC can respond directly to Gram-negative and Gram-positive bacteria by releasing the neutrophil selective chemokine, CXCL-8, is consistent with what we know about the role of neutrophil recruitment in bacterial infections in the lung. Our findings that bacteria inhibit the release of the eosinophil selective chemokine, eotaxin-I may help to explain the mechanisms by which bacterial immunotherapy reduces allergic inflammation in the lung

    Potentiality in Biology

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    We take the potentialities that are studied in the biological sciences (e.g., totipotency) to be an important subtype of biological dispositions. The goal of this paper is twofold: first, we want to provide a detailed understanding of what biological dispositions are. We claim that two features are essential for dispositions in biology: the importance of the manifestation process and the diversity of conditions that need to be satisfied for the disposition to be manifest. Second, we demonstrate that the concept of a disposition (or potentiality) is a very useful tool for the analysis of the explanatory practice in the biological sciences. On the one hand it allows an in-depth analysis of the nature and diversity of the conditions under which biological systems display specific behaviors. On the other hand the concept of a disposition may serve a unificatory role in the philosophy of the natural sciences since it captures not only the explanatory practice of biology, but of all natural sciences. Towards the end we will briefly come back to the notion of a potentiality in biology

    Investigating the effect of independent blinded digital image assessment on the STOP GAP trial

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    Background Blinding is the process of keeping treatment assignment hidden and is used to minimise the possibility of bias. Trials at high risk of bias have been shown to report larger treatment effects than low risk studies. In dermatology, one popular method of blinding is to have independent outcome assessors who are unaware of treatment allocation assessing the end point using digital photographs. However, this can be complex, expensive and time-consuming. The objective of this study was to compare the effect of blinded and unblinded outcome assessment on the results of the STOP GAP trial. Methods The STOP GAP trial compared prednisolone to ciclosporin in treating pyoderma gangrenosum. Participants’ lesions were measured at baseline and 6 weeks to calculate the primary outcome, speed of healing. Independent blinded assessors obtained measurements from digital photographs using specialist software. In addition, unblinded treating clinicians estimated lesion area by measuring length and width. The primary outcome was determined using blinded measurements where available, otherwise unblinded measurements were used (method referred to as trial measurements). In this study, agreement between the trial and unblinded measurements was determined using the intraclass correlation coefficient (ICC). The STOP GAP primary analysis was repeated using unblinded measurements only. We introduced differential and non-differential error in unblinded measurements and investigated the effect on the STOP GAP primary analysis. Results 86 (80%) of the 108 patients were assessed using digital images. Agreement between trial and unblinded measurements was excellent (ICC=0.92 at baseline; 0.83 at 6 weeks). There was no evidence that the results of the trial primary analysis differed according to how the primary outcome was assessed (p-value for homogeneity = 1.00). Conclusions Blinded digital image assessment in STOP GAP did not meaningfully alter trial conclusions compared with unblinded assessment. However, as the process brought added accuracy and credibility to the trial it was considered worthwhile. These findings question the usefulness of digital image assessment in a trial with an objective outcome and where bias is not expected to be excessive. Further research should investigate if there are alternative, less complex ways of incorporating blinding in clinical trials

    Physiotherapy, and speech and language therapy intervention for patients with refractory chronic cough: a multicentre randomised control trial.

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    BACKGROUND: Physiotherapy, and speech and language therapy are emerging non-pharmacological treatments for refractory chronic cough. We aimed to investigate the efficacy of a physiotherapy, and speech and language therapy intervention (PSALTI) to improve health-related quality of life (HRQoL) and to reduce cough frequency in patients with refractory chronic cough. METHODS: In this multicentre randomised controlled trial, patients with refractory chronic cough were randomised to four weekly 1:1 sessions of either PSALTI consisting of education, laryngeal hygiene and hydration, cough suppression techniques, breathing exercises and psychoeducational counselling or control intervention consisting of healthy lifestyle advice. We assessed the change in HRQoL at week 4 with the Leicester Cough Questionnaire (LCQ). Secondary efficacy outcomes included 24-hour objective cough frequency (Leicester Cough Monitor) and cough reflex sensitivity. The primary analysis used an analysis of covariance adjusted for baseline measurements with the intention-to-treat population. This study was registered at UK Clinical Research Network (UKCRN ID 10678). FINDINGS: Between December 2011 and April 2014, we randomly assigned 75 participants who underwent baseline assessment (34 PSALTI and 41 controls). In the observed case analysis, HRQoL (LCQ) improved on average by 1.53 (95% CI 0.21 to 2.85) points more in PSALTI group than with control (p=0.024). Cough frequency decreased by 41% (95% CI 36% to 95%) in PSALTI group relative to control (p=0.030). The improvements within the PSALTI group were sustained up to 3 months. There was no significant difference between groups in the concentration of capsaicin causing five or more coughs. INTERPRETATION: Greater improvements in HRQoL and cough frequency were observed with PSALTI intervention. Our findings support the use of PSALTI for patients with refractory chronic cough. TRIAL REGISTRATION NUMBER: UKCRN ID 10678 and ISRCTN 73039760; Results

    Coordinated Ionospheric Reconstruction CubeSat Experiment (CIRCE) mission overview

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    The Coordinated Ionospheric Reconstruction Cubesat Experiment (CIRCE) is a joint US/UK mission consisting of two 6U CubeSats actively maintaining a lead-follow configuration in the same low Earth orbit with a launch planned for the 2020 timeframe. These nanosatellites will each feature multiple space weather payloads. From the US, the Naval Research Laboratory will provide two 1U Triple Tiny Ionospheric Photometers (Tri-TIPs) on each satellite, observing the ultraviolet 135.6 nm emission of atomic oxygen at nighttime. The primary objective is to characterize the twodimensional distribution of electrons in the Equatorial Ionization Anomaly (EIA). The methodology used to reconstruct the nighttime ionosphere employs continuous UV photometry from four distinct viewing angles in combination with an additional data source, such as in situ plasma density measurements, with advanced image space reconstruction algorithm tomography techniques. From the UK, the Defence Science and Technology Laboratory (Dstl) is providing the In-situ and Remote Ionospheric Sensing suite consisting of an Ion/Neutral Mass Spectrometer, a triple-frequency GPS receiver for ionospheric sensing, and a radiation environment monitor. We present our mission concept, simulations illustrating the imaging capability of the Tri-TIP sensor suite, and a range of science questions addressable via these measurements

    A Bayesian explanation of the 'Uncanny Valley' effect and related psychological phenomena

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    There are a number of psychological phenomena in which dramatic emotional responses are evoked by seemingly innocuous perceptual stimuli. A well known example is the ‘uncanny valley’ effect whereby a near human-looking artifact can trigger feelings of eeriness and repulsion. Although such phenomena are reasonably well documented, there is no quantitative explanation for the findings and no mathematical model that is capable of predicting such behavior. Here I show (using a Bayesian model of categorical perception) that differential perceptual distortion arising from stimuli containing conflicting cues can give rise to a perceptual tension at category boundaries that could account for these phenomena. The model is not only the first quantitative explanation of the uncanny valley effect, but it may also provide a mathematical explanation for a range of social situations in which conflicting cues give rise to negative, fearful or even violent reactions

    Efficient Bayesian inference for COM-Poisson regression models

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    COM-Poisson regression is an increasingly popular model for count data. Its main advantage is that it permits to model separately the mean and the variance of the counts, thus allowing the same covariate to affect in different ways the average level and the variability of the response variable. A key limiting factor to the use of the COM-Poisson distribution is the calculation of the normalisation constant: its accurate evaluation can be time-consuming and is not always feasible. We circumvent this problem, in the context of estimating a Bayesian COM-Poisson regression, by resorting to the exchange algorithm, an MCMC method applicable to situations where the sampling model (likelihood) can only be computed up to a normalisation constant. The algorithm requires to draw from the sampling model, which in the case of the COM-Poisson distribution can be done efficiently using rejection sampling. We illustrate the method and the benefits of using a Bayesian COM-Poisson regression model, through a simulation and two real-world data sets with different levels of dispersion

    Walk well:a randomised controlled trial of a walking intervention for adults with intellectual disabilities: study protocol

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    Background - Walking interventions have been shown to have a positive impact on physical activity (PA) levels, health and wellbeing for adult and older adult populations. There has been very little work carried out to explore the effectiveness of walking interventions for adults with intellectual disabilities. This paper will provide details of the Walk Well intervention, designed for adults with intellectual disabilities, and a randomised controlled trial (RCT) to test its effectiveness. Methods/design - This study will adopt a RCT design, with participants allocated to the walking intervention group or a waiting list control group. The intervention consists of three PA consultations (baseline, six weeks and 12 weeks) and an individualised 12 week walking programme. A range of measures will be completed by participants at baseline, post intervention (three months from baseline) and at follow up (three months post intervention and six months from baseline). All outcome measures will be collected by a researcher who will be blinded to the study groups. The primary outcome will be steps walked per day, measured using accelerometers. Secondary outcome measures will include time spent in PA per day (across various intensity levels), time spent in sedentary behaviour per day, quality of life, self-efficacy and anthropometric measures to monitor weight change. Discussion - Since there are currently no published RCTs of walking interventions for adults with intellectual disabilities, this RCT will examine if a walking intervention can successfully increase PA, health and wellbeing of adults with intellectual disabilities

    Coordinated Ionospheric Reconstruction CubeSat Experiment (CIRCE), In situ and Remote Ionospheric Sensing (IRIS) suite

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    The UK’s Defence Science and Technology Laboratory (Dstl) is partnering with the US Naval Research Laboratory (NRL) on a joint mission to launch miniature sensors that will advance space weather measurement and modelling capabilities. The Coordinated Ionospheric Reconstruction Cubesat Experiment (CIRCE) comprises two 6U cube-satellites that will be launched into a near-polar low earth orbit (LEO), targeting 500 km altitude, in 2021. The UK contribution to CIRCE is the In situ and Remote Ionospheric Sensing (IRIS) suite, complementary to NRL sensors, and comprising three highly miniaturised payloads provided to Dstl by University College London (UCL), University of Bath, and University of Surrey/Surrey Satellite Technology Ltd (SSTL). One IRIS suite will be flown on each satellite, and incorporates an ion/neutral mass spectrometer, a tri-band global positioning system (GPS) receiver for ionospheric remote sensing, and a radiation environment monitor. From the US, NRL have provided two 1U Triple Tiny Ionospheric Photometers (Tri-TIPs) on each satellite (Nicholas et al., 2019), observing the ultraviolet 135.6 nm emission of atomic oxygen at night-time to characterize the two-dimensional distribution of electrons
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