53 research outputs found

    Microbial ligand costimulation drives neutrophilic steroid-refractory asthma

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    Funding: The authors thank the Wellcome Trust (102705) and the Universities of Aberdeen and Cape Town for funding. This research was also supported, in part, by National Institutes of Health GM53522 and GM083016 to DLW. KF and BNL are funded by the Fonds Wetenschappelijk Onderzoek, BNL is the recipient of an European Research Commission consolidator grant and participates in the European Union FP7 programs EUBIOPRED and MedALL. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Recognition and control of neutrophil extracellular trap formation by MICL

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    Acknowledgements We thank the staff of the animal facilities at the University of Aberdeen and the University of Exeter for support and care for animals; C. Paterson from the University of Glasgow for assistance in establishing a Material Transfer Agreement; C. Parkin and D. Thompson for support with microscopy; and M. Stacey for valuable input. We acknowledge funding from the Wellcome Trust (102705 and 097377), Versus Arthritis (21164, 20775 and 21156), the US National Institutes of Health (R01DK121977 and R01AI163007), Versus Arthritis Centre of Excellence, Medical Research Council (MR/L020211/1) and the MRC Centre for Medical Mycology (MR/N006364/1). SLE tissue samples were provided by the Imperial College Healthcare Tissue Bank funded by the National Institute for Health Research (NIHR), Biomedical Research Centre based at the Imperial College Healthcare NHS Trust and Imperial College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.Peer reviewe

    Characterisation of Innate Fungal Recognition in the Lung

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    The innate recognition of fungi by leukocytes is mediated by pattern recognition receptors (PRR), such as Dectin-1, and is thought to occur at the cell surface triggering intracellular signalling cascades which lead to the induction of protective host responses. In the lung, this recognition is aided by surfactant which also serves to maintain the balance between inflammation and pulmonary function, although the underlying mechanisms are unknown. Here we have explored pulmonary innate recognition of a variety of fungal particles, including zymosan, Candida albicans and Aspergillus fumigatus, and demonstrate that opsonisation with surfactant components can limit inflammation by reducing host-cell fungal interactions. However, we found that this opsonisation does not contribute directly to innate fungal recognition and that this process is mediated through non-opsonic PRRs, including Dectin-1. Moreover, we found that pulmonary inflammatory responses to resting Aspergillus conidia were initiated by these PRRs in acidified phagolysosomes, following the uptake of fungal particles by leukocytes. Our data therefore provides crucial new insights into the mechanisms by which surfactant can maintain pulmonary function in the face of microbial challenge, and defines the phagolysosome as a novel intracellular compartment involved in the innate sensing of extracellular pathogens in the lung

    Group B <em>Streptococcus </em>engages an inhibitory siglec through sialic acid mimicry to blunt innate immune and inflammatory responses <em>in vivo</em>

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    Group B Streptococcus (GBS) is a common agent of bacterial sepsis and meningitis in newborns. The GBS surface capsule contains sialic acids (Sia) that engage Sia-binding immunoglobulin-like lectins (Siglecs) on leukocytes. Here we use mice lacking Siglec-E, an inhibitory Siglec of myelomonocytic cells, to study the significance of GBS Siglec engagement during in vivo infection. We found GBS bound to Siglec-E in a Sia-specific fashion to blunt NF-κB and MAPK activation. As a consequence, Siglec-E-deficient macrophages had enhanced pro-inflammatory cytokine secretion, phagocytosis and bactericidal activity against the pathogen. Following pulmonary or low-dose intravenous GBS challenge, Siglec-E KO mice produced more pro-inflammatory cytokines and exhibited reduced GBS invasion of the central nervous system. In contrast, upon high dose lethal challenges, cytokine storm in Siglec-E KO mice was associated with accelerated mortality. We conclude that GBS Sia mimicry influences host innate immune and inflammatory responses in vivo through engagement of an inhibitory Siglec, with the ultimate outcome of the host response varying depending upon the site, stage and magnitude of infection

    Untangling approaches to management and leadership across systems of medical education

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    Aims: How future doctors might be educated and trained in order to meet the population and system needs of countries is currently being debated. Incorporation of a broad range of capabilities, encompassed within categories of management and, increasingly, leadership, form part of this discussion. The purpose of this paper is to outline a framework by which countries’ progress in this area might be assessed and compared. Methods: Key databases and journals related to this area were reviewed. From relevant articles potential factors impacting on the incorporation of aspects of management and leadership within medical education and training were identified. These factors were tested via an online survey during 2013 with six members of a European Association of doctors who promote medical involvement in hospital management, including members from countries less represented in the health management literature. Results: A framework for analysing how management and leadership education is being approached within different systems of healthcare is developed and presented. Conclusions: More systematic work across a wider range of countries is needed if we are to have a better understanding of how countries within and beyond Europe are approaching and progressing the education of doctors in management and leadership. Keywords: Medical education, Management, Leadership, Competency framework

    INTERPRETATION, ETHICS, AND THE COMPLEX RELATIONSHIP BETWEEN A PROPHET AND AN ??????? ?????????

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    The ontological turn in hermeneutics made it increasingly clear that an interpreter’s “inner self” is not detached from the world in which s/he lives. This had a profound impact on not only how one conceives of the process of interpretation, in general, but also how one thinks of ethical evaluation and appropriation, in particular. In this regard, the narrative of Hosea’s marriage to Gomer (Hos. 1-3) presents an interesting test case for how an interpreter’s previously established moral framework influences his/her current understanding of the biblical text. To illuminate this matter, three prominent ethical theories (consequentialism, deontology, and virtue ethics) are used as interpretative frameworks. Finally, the author reiterates that pre-understanding plays an important role in biblical interpretation. This matter is often more complex than simply focussing on theological presuppositions in terms of dealing with different ethical questions and challenges

    Automating human thought processes for a UAV forced landing

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    This paper describes the current status of a program to develop an automated forced landing system for a fixed-wing Unmanned Aerial Vehicle (UAV). This automated system seeks to emulate human pilot thought processes when planning for and conducting an engine-off emergency landing. Firstly, a path planning algorithm that extends Dubins curves to 3D space is presented. This planning element is then combined with a nonlinear guidance and control logic, and simulated test results demonstrate the robustness of this approach to strong winds during a glided descent. The average path deviation errors incurred are comparable to or even better than that of manned, powered aircraft. Secondly, a study into suitable multi-criteria decision making approaches and the problems that confront the decision-maker is presented. From this study, it is believed that decision processes that utilize human expert knowledge and fuzzy logic reasoning are most suited to the problem at hand, and further investigations will be conducted to identify the particular technique/s to be implemented in simulations and field tests. The automated UAV forced landing approach presented in this paper is promising, and will allow the progression of this technology from the development and simulation stages through to a prototype syste

    Exploring source differences on diet-tissue discrimination factors in the analysis of stable isotope mixing models

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    Stable isotope mixing models are regularly used to provide probabilistic estimates of source contributions to dietary mixtures. Whilst Bayesian implementations of isotope mixing models have become prominent, the use of appropriate diet-tissue discrimination factors (DTDFs) remains as the least resolved aspect. The DTDFs are critical in providing accurate inferences from these models. Using both simulated and laboratory-based experimental data, this study provides conceptual and practical applications of isotope mixing models by exploring the role of DTDFs. The experimental study used Mozambique Tilapia Oreochromis mossambicus, a freshwater fish, to explore multi-tissue variations in isotopic incorporation patterns, and to evaluate isotope mixing model outputs based on the experiment- and literature-based DTDFs. Isotope incorporation patterns were variable for both muscle and on tissues among the consumer groups that fed diet sources with different stable isotope values. Application of literature-based DTDFs in isotope mixing models consistently underestimated the dietary proportions of all single-source consumer groups. In contrast, application of diet-specific DTDFs provided better dietary estimates for single-source consumer groups. Variations in the proportional contributions of the individual sources were, nevertheless, observed for the mixed-source consumer group, which suggests that isotope assimilation of the individual food sources may have been influenced by other underlying physiological processes. This study provides evidence that stable isotope values from different diet sources exhibit large variations as they become incorporated into consumer tissues. This suggests that the application of isotope mixing models requires consideration of several aspects such as diet type and the associated biological processes that may influence DTDFs
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