433 research outputs found

    The effect of azithromycin in adults with stable neutrophilic COPD: A double blind randomised, placebo controlled trial

    Full text link
    Background: Chronic Obstructive Pulmonary Disease (COPD) is a progressive airway disease characterised by neutrophilic airway inflammation or bronchitis. Neutrophilic bronchitis is associated with both bacterial colonisation and lung function decline and is common in exacerbations of COPD. Despite current available therapies to control inflammation, neutrophilic bronchitis remains common. This study tested the hypothesis that azithromycin treatment, as an add-on to standard medication, would significantly reduce airway neutrophil and neutrophils chemokine (CXCL8) levels, as well as bacterial load. We conducted a randomised, double-blind, placebo-controlled study in COPD participants with stable neutrophilic bronchitis. Methods: Eligible participants (n = 30) were randomised to azithromycin 250 mg daily or placebo for 12 weeks in addition to their standard respiratory medications. Sputum was induced at screening, randomisation and monthly for a 12 week treatment period and processed for differential cell counts, CXCL8 and neutrophil elastase assessment. Quantitative bacteriology was assessed in sputum samples at randomisation and the end of treatment visit. Severe exacerbations where symptoms increased requiring unscheduled treatment were recorded during the 12 week treatment period and for 14 weeks following treatment. A sub-group of participants underwent chest computed tomography scans (n = 15). Results: Nine participants with neutrophilic bronchitis had a potentially pathogenic bacteria isolated and the median total bacterial load of all participants was 5.22×107 cfu/mL. Azithromycin treatment resulted in a non-significant reduction in sputum neutrophil proportion, CXCL8 levels and bacterial load. The mean severe exacerbation rate was 0.33 per person per 26 weeks in the azithromycin group compared to 0.93 exacerbations per person in the placebo group (incidence rate ratio (95%CI): 0.37 (0.11,1.21), p = 0.062). For participants who underwent chest CT scans, no alterations were observed. Conclusions: In stable COPD with neutrophilic bronchitis, add-on azithromycin therapy showed a trend to reduced severe exacerbations sputum neutrophils, CXCL8 levels and bacterial load. Future studies with a larger sample size are warranted. Trial Registration: Australian New Zealand Clinical Trials Registry ACTRN12609000259246. © 2014 Simpson et al

    PGF2α-F-prostanoid receptor signalling via ADAMTS1 modulates epithelial cell invasion and endothelial cell function in endometrial cancer

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>An increase in cancer cell invasion and microvascular density is associated with a poorer prognosis for patients with endometrial cancer. In endometrial adenocarcinoma F-prostanoid (FP) receptor expression is elevated, along with its ligand prostaglandin (PG)F<sub>2α</sub>, where it regulates expression and secretion of a host of growth factors and chemokines involved in tumorigenesis. This study investigates the expression, regulation and role of a disintegrin and metalloproteinase with thrombospondin repeat 1 (ADAMTS1) in endometrial adenocarcinoma cells by PGF<sub>2α </sub>via the FP receptor.</p> <p>Methods</p> <p>Human endometrium and adenocarcinoma tissues were obtained in accordance with Lothian Research Ethics Committee guidance with informed patient consent. Expression of ADAMTS1 mRNA and protein in tissues was determined by quantitative RT-PCR analysis and immunohistochemistry. Signal transduction pathways regulating ADAMTS1 expression in Ishikawa cells stably expressing the FP receptor to levels seen in endometrial cancer (FPS cells) were determined by quantitative RT-PCR analysis. In vitro invasion and proliferation assays were performed with FPS cells and human umbilical vein endothelial cells (HUVECs) using conditioned medium (CM) from PGF<sub>2α</sub>-treated FPS cells from which ADAMTS1 was immunoneutralised and/or recombinant ADAMTS1. The role of endothelial ADAMTS1 in endothelial cell proliferation was confirmed with RNA interference. The data in this study were analysed by T-test or ANOVA.</p> <p>Results</p> <p>ADAMTS1 mRNA and protein expression is elevated in endometrial adenocarcinoma tissues compared with normal proliferative phase endometrium and is localised to the glandular and vascular cells. Using FPS cells, we show that PGF2α-FP signalling upregulates ADAMTS1 expression via a calmodulin-NFAT-dependent pathway and this promotes epithelial cell invasion through ECM and inhibits endothelial cell proliferation. Furthermore, we show that CM from FPS cells regulates endothelial cell ADAMTS1 expression in a rapid biphasic manner. Using RNA interference we show that endothelial cell ADAMTS1 also negatively regulates cellular proliferation.</p> <p>Conclusions</p> <p>These data demonstrate elevated ADAMTS1 expression in endometrial adenocarcinoma. Furthermore we have highlighted a mechanism whereby FP receptor signalling regulates epithelial cell invasion and endothelial cell function via the PGF<sub>2α</sub>-FP receptor mediated induction of ADAMTS1.</p

    Specification and Verification of Synchronous Hardware using LOTOS

    Get PDF
    This paper investigates specification and verification of synchronous circuits using DILL (Digital Logic in LOTOS). After an overview of the DILL approach, the paper focuses on the characteristics of synchronous circuits. A more constrained model is presented for specifying digital components and verifying them. Two standard benchmark circuits are specified using this new model, and analysed by the CADP toolset (Cæsar/Aldébaran Development Package)

    Multiple ITS Copies Reveal Extensive Hybridization within Rheum (Polygonaceae), a Genus That Has Undergone Rapid Radiation

    Get PDF
    During adaptive radiation events, characters can arise multiple times due to parallel evolution, but transfer of traits through hybridization provides an alternative explanation for the same character appearing in apparently non-sister lineages. The signature of hybridization can be detected in incongruence between phylogenies derived from different markers, or from the presence of two divergent versions of a nuclear marker such as ITS within one individual.In this study, we cloned and sequenced ITS regions for 30 species of the genus Rheum, and compared them with a cpDNA phylogeny. Seven species contained two divergent copies of ITS that resolved in different clades from one another in each case, indicating hybridization events too recent for concerted evolution to have homogenised the ITS sequences. Hybridization was also indicated in at least two further species via incongruence in their position between ITS and cpDNA phylogenies. None of the ITS sequences present in these nine species matched those detected in any other species, which provides tentative evidence against recent introgression as an explanation. Rheum globulosum, previously indicated by cpDNA to represent an independent origin of decumbent habit, is indicated by ITS to be part of clade of decumbent species, which acquired cpDNA of another clade via hybridization. However decumbent and glasshouse morphology are confirmed to have arisen three and two times, respectively.These findings suggested that hybridization among QTP species of Rheum has been extensive, and that a role of hybridization in diversification of Rheum requires investigation

    Radio emission from Supernova Remnants

    Get PDF
    The explosion of a supernova releases almost instantaneously about 10^51 ergs of mechanic energy, changing irreversibly the physical and chemical properties of large regions in the galaxies. The stellar ejecta, the nebula resulting from the powerful shock waves, and sometimes a compact stellar remnant, constitute a supernova remnant (SNR). They can radiate their energy across the whole electromagnetic spectrum, but the great majority are radio sources. Almost 70 years after the first detection of radio emission coming from a SNR, great progress has been achieved in the comprehension of their physical characteristics and evolution. We review the present knowledge of different aspects of radio remnants, focusing on sources of the Milky Way and the Magellanic Clouds, where the SNRs can be spatially resolved. We present a brief overview of theoretical background, analyze morphology and polarization properties, and review and critical discuss different methods applied to determine the radio spectrum and distances. The consequences of the interaction between the SNR shocks and the surrounding medium are examined, including the question of whether SNRs can trigger the formation of new stars. Cases of multispectral comparison are presented. A section is devoted to reviewing recent results of radio SNRs in the Magellanic Clouds, with particular emphasis on the radio properties of SN 1987A, an ideal laboratory to investigate dynamical evolution of an SNR in near real time. The review concludes with a summary of issues on radio SNRs that deserve further study, and analyzing the prospects for future research with the latest generation radio telescopes.Comment: Revised version. 48 pages, 15 figure

    Testing the theory of immune selection in cancers that break the rules of transplantation

    Get PDF
    Modification of cancer cells likely to reduce their immunogenicity, including loss or down-regulation of MHC molecules, is now well documented and has become the main support for the concept of immune surveillance. The evidence that these modifications, in fact, result from selection by the immune system is less clear, since the possibility that they may result from reorganized metabolism associated with proliferation or from cell de-differentiation remains. Here, we (a) survey old and new transplantation experiments that test the possibility of selection and (b) survey how transmissible tumours of dogs and Tasmanian devils provide naturally evolved tests of immune surveillance

    Open Problems on Central Simple Algebras

    Full text link
    We provide a survey of past research and a list of open problems regarding central simple algebras and the Brauer group over a field, intended both for experts and for beginners.Comment: v2 has some small revisions to the text. Some items are re-numbered, compared to v

    Active inference, sensory attenuation and illusions.

    Get PDF
    Active inference provides a simple and neurobiologically plausible account of how action and perception are coupled in producing (Bayes) optimal behaviour. This can be seen most easily as minimising prediction error: we can either change our predictions to explain sensory input through perception. Alternatively, we can actively change sensory input to fulfil our predictions. In active inference, this action is mediated by classical reflex arcs that minimise proprioceptive prediction error created by descending proprioceptive predictions. However, this creates a conflict between action and perception; in that, self-generated movements require predictions to override the sensory evidence that one is not actually moving. However, ignoring sensory evidence means that externally generated sensations will not be perceived. Conversely, attending to (proprioceptive and somatosensory) sensations enables the detection of externally generated events but precludes generation of actions. This conflict can be resolved by attenuating the precision of sensory evidence during movement or, equivalently, attending away from the consequences of self-made acts. We propose that this Bayes optimal withdrawal of precise sensory evidence during movement is the cause of psychophysical sensory attenuation. Furthermore, it explains the force-matching illusion and reproduces empirical results almost exactly. Finally, if attenuation is removed, the force-matching illusion disappears and false (delusional) inferences about agency emerge. This is important, given the negative correlation between sensory attenuation and delusional beliefs in normal subjects--and the reduction in the magnitude of the illusion in schizophrenia. Active inference therefore links the neuromodulatory optimisation of precision to sensory attenuation and illusory phenomena during the attribution of agency in normal subjects. It also provides a functional account of deficits in syndromes characterised by false inference and impaired movement--like schizophrenia and Parkinsonism--syndromes that implicate abnormal modulatory neurotransmission

    Predictors of gallstone composition in 1025 symptomatic gallstones from Northern Germany

    Get PDF
    BACKGROUND: Gallstones represent a prevalent and costly health problem. The changing epidemiology and the emerging non-surgical interventions for gallstone disease necessitate the definition of target populations for future therapies. This study aimed to define patterns of gallstone composition and identify demographic predictors of gallstone composition in a large sample of symptomatic gallstones from Northern Germany. METHODS: One thousand and seventy-four post-cholecystectomy gallstone specimens were obtained. Demographic and clinical information was provided by questionnaire (N = 1025 independent individuals with complete information). Two samples from each gallstone were analyzed using Fourier transformed infrared spectrometry. RESULTS: The most prevalent substance was cholesterol, which was detected in 95.0% of gallstone specimens. Bilirubin and bilirubinate were present in 30.0% and calcium was detected in 10.0% of the spectra. Ninety-two percent of measurements from the same stone yielded the same "main" substances, indicating a homogenous stone composition in most cases. Female sex and higher body mass index (BMI) were associated with the presence of cholesterol as a main substance in the gallstones (p < 0.001). CONCLUSION: The changing epidemiology of gallstone disease is reflected by a marked shift in stone composition: Only two percent of stones in this study were pigment stones as compared to 91% percent of stones containing cholesterol as a main substance. Obese individuals from Germany with a BMI > 30 kg/m(2 )have in 95% cholesterol-dominant gallstones and represent a potential target population for non-surgical interventions for the prevention or treatment of cholesterol stones
    corecore