240 research outputs found

    Analysis of the Activities of the Inflammatory Cytokine Macrophage Migration Inhibitory Factor on Activation of Endoplasmic Reticulum Stress Responses

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    2018 dissertation for MRes. The inflammatory cytokine, Macrophage Migration Inhibitory Factor, was initially isolated in the 1970s as a chemokine involved with inhibition of random movement in Macrophages but has also been linked with many other components of the immune system and even foetal development. It is released almost-ubiquitously, during inflammation, with both pro-inflammatory and anti-inflammatory activities. One key regulator of inflammation is the Unfolded Protein Response. during which the Endoplasmic Reticulum within cells regulates protein flux within the ER lumen, especially when that load is beyond the capacity of the ER to successfully process. As part of the UPR response there is a stop in global translation, enhanced transcription and translation of chaperone proteins, increased ER size and capacity and eventually activation of the apoptosis pathways if the protein load does not reduce to a level within the ERā€™s capacity. The UPR is controlled via the transduction proteins, IRE1, PERK and ATF6. Because of the UPRā€™s effect on cellular health and known links to inflammation it was decided to investigate the effects of MIF on UPR activation within cells. Using two different reporter constructs (ATF4.EYFP-N1 or XBP-1.EeYFP-N1) which monitor activation IRE1 and PERK the effects of MIF on UPR activation in HeLa and SH-SY5Y cells was assessed. The observed results show that MIF exerts a marginal suppressive effect on both the IRE1 and PERK between with some variation in the effects of MIF on epithelial (HeLa) or neuronal (SH-SY5Y) origins. This data suggests that MIF may reduce the activation of apoptotic responses within these cells via activation UPR and the PERK pathway through suppression of JNK activity via the noncanonical MIF receptor JAB1. Modulation of UPR responses by MIF would have important downstream effects on the development of auto-inflammatory conditions and neuropathies include Alzheimerā€™s disease due to the suppressed UPRs inability to resolve the pathological protein load

    The Economic Value of Climate Information in Adaptation Decisions : Learning in the Sea-level Rise and Coastal Infrastructure Context

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    Traditional methods of investment appraisal have been criticized in the context of climate change adaptation. Economic assessment of adaptation options needs to explicitly incorporate the uncertainty of future climate conditions and should recognise that uncertainties may diminish over time as a result of improved understanding and learning. Real options analysis (ROA) is an appraisal tool developed to incorporate concepts of flexibility and learning that relies on probabilistic data to characterise uncertainties. It is also a relatively resource-intensive decision support tool. We test whether, and to what extent, learning can result from the use of successive generations of real life climate scenarios, and how non-probabilistic uncertainties can be handled through adapting the principles of ROA in coastal economic adaptation decisions. Using a relatively simple form of ROA on a vulnerable piece of coastal rail infrastructure in the United Kingdom, and two successive UK climate assessments, we estimate the values associated with utilising up-dated information on sea-level rise. The value of learning can be compared to the capital cost of adaptation investment, and may be used to illustrate the potential scale of the value of learning in coastal protection, and other adaptation contexts

    Candida auris undergoes adhesin-dependent and -independent cellular aggregation

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    Acknowledgments We are grateful to Rhys Farrer (MRC CMM, University of Exeter) and Sophie Shaw (CGEBM, University of Aberdeen) for guidance on bioinformatic analysis, to Louise Walker (University of Aberdeen) for advice on macrophage work, and to Neil A. R. Gow (MRC CMM, University of Exeter) and Dhara Malavia (MRC CMM, University of Exeter) for discussing their unpublished results. We thank Gillian Milne (Microscopy & Histology Facility, University of Aberdeen) for technical assistance with electron microscopy. Candida auris strains were kindly provided by Anuradha Chowdhary (Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India), Public Health England (PHE) (Bristol, UK), and the Mycotic Diseases Branch of the Centers for Disease Control and Prevention (CDC) (Atlanta, GA, USA). Funding This work was supported by a PhD studentship (MR/P501955/1) from the Medical Research Council (MRC) Centre for Medical Mycology at the University of Exeter, UK 694 (MR/N006364/2). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

    Water-use dynamics of an alien-invaded riparian forest within the Mediterranean climate zone of the Western Cape, South Africa

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    In South Africa, the invasion of riparian forests by alien trees has the potential to affect the countryā€™s limited water resources. Tree water-use measurements have therefore become an important component of recent hydrological studies. It is difficult for South African government initiatives, such as the Working for Water (WfW) alien clearing program, to justify alien tree removal and implement rehabilitation unless hydrological benefits are known. Consequently, water use within a riparian forest along the Buffeljags River in the Western Cape of South Africa was monitored over a 3-year period. The site consisted of an indigenous stand of Western Cape afrotemperate forest adjacent to a large stand of introduced Acacia mearnsii. The heat ratio method of the heat pulse velocity sap flow technique was used to measure the sap flow of a selection of indigenous species in the indigenous stand, a selection of A. mearnsii trees in the alien stand and two clusters of indigenous species within the alien stand. The indigenous trees in the alien stand at Buffeljags River showed significant intraspecific differences in the daily sap flow rates varying from 15 to 32 L day 1 in summer (sap flow being directly proportional to tree size). In winter (June), this was reduced to only 7 L day 1 when limited energy was available to drive the transpiration process. The water use in the A. mearnsii trees showed peaks in transpiration during the months of March 2012, September 2012 and February 2013. These periods had high average temperatures, rainfall and high daily vapor pressure deficits (VPDs ā€“ average of 1.26 kPa). The average daily sap flow ranged from 25 to 35 L in summer and approximately 10 L in the winter. The combined accumulated daily sap flow per year for the three Vepris lanceolata and three A. mearnsii trees was 5700 and 9200 L, respectively, clearly demonstrating the higher water use of the introduced Acacia trees during the winter months. After spatially upscaling the findings, it was concluded that, annually, the alien stand used nearly 6 times more water per unit area than the indigenous stand (585mma 1 compared to 101mma 1/. This finding indicates that there would be a gain in groundwater recharge and/or streamflow if the alien species are removed from riparian forests and rehabilitated back to their natural state.The Water Research Commission (WRC) of South Africa and the Department of Economic Development, Tourism and Environmental Affairs (EDTEA).https://www.hydrology-and-earth-system-sciences.netam2017Plant Production and Soil Scienc

    The potential of using circulating tumour cells and their gene expression to predict docetaxel response in metastatic prostate cancer

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    BackgroundDocetaxel improves overall survival (OS) in castration-resistant prostate cancer (PCa) (CRPC) and metastatic hormone-sensitive PCa (mHSPC). However, not all patients respond due to inherent and/or acquired resistance. There remains an unmet clinical need for a robust predictive test to stratify patients for treatment. Liquid biopsy of circulating tumour cell (CTCs) is minimally invasive, can provide real-time information of the heterogeneous tumour and therefore may be a potentially ideal docetaxel response prediction biomarker.ObjectiveIn this study we investigate the potential of using CTCs and their gene expression to predict post-docetaxel tumour response, OS and progression free survival (PFS).MethodsPeripheral blood was sampled from 18 mCRPC and 43 mHSPC patients, pre-docetaxel treatment, for CTC investigation. CTCs were isolated using the epitope independent ParsortixĀ® system and gene expression was determined by multiplex RT-qPCR. We evaluated CTC measurements for post-docetaxel outcome prediction using receiver operating characteristics and Kaplan Meier analysis.ResultsDetection of CTCs pre-docetaxel was associated with poor patient outcome post-docetaxel treatment. Combining total-CTC number with PSA and ALP predicted lack of partial response (PR) with an AUC of 0.90, p= 0.037 in mCRPC. A significantly shorter median OS was seen in mCRPC patients with positive CTC-score (12.80 vs. 37.33 months, HR= 5.08, p= 0.0005), ā‰„3 total-CTCs/7.5mL (12.80 vs. 37.33 months, HR= 3.84, p= 0.0053), ā‰„1 epithelial-CTCs/7.5mL (14.30 vs. 37.33 months, HR= 3.89, p= 0.0041) or epithelial to mesenchymal transitioning (EMTing)-CTCs/7.5mL (11.32 vs. 32.37 months, HR= 6.73, p= 0.0001). Significantly shorter PFS was observed in patients with ā‰„2 epithelial-CTCs/7.5mL (7.52 vs. 18.83 months, HR= 3.93, p= 0.0058). mHSPC patients with ā‰„5 CTCs/7.5mL had significantly shorter median OS (24.57 vs undefined months, HR= 4.14, p= 0.0097). In mHSPC patients, expression of KLK2, KLK4, ADAMTS1, ZEB1 and SNAI1 was significantly associated with shorter OS and/or PFS. Importantly, combining CTC measurements with clinical biomarkers increased sensitivity and specificity for prediction of patient outcome.ConclusionWhile it is clear that CTC numbers and gene expression were prognostic for PCa post-docetaxel treatment, and CTC subtype analysis may have additional value, their potential predictive value for docetaxel chemotherapy response needs to be further investigated in large patient cohorts

    Neurophysiological consequences of synapse loss in progressive supranuclear palsy

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    Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even in the absence of gross atrophy. Currently, for human disease there are few formal models to explain how cortical networks underlying cognition are affected by synaptic loss. We advocate that biophysical models of neurophysiology offer both a bridge from clinical to preclinical models of pathology, and quantitative assays for experimental medicine. Such biophysical models can also disclose hidden neuronal dynamics generating neurophysiological observations like electro- and magneto-encephalography. Here, we augment a biophysically informed mesoscale model of human cortical function by inclusion of synaptic density estimates as captured by [11C]UCB-J positron emission tomography, and provide insights into how regional synapse loss affects neurophysiology. We use the primary tauopathy of progressive supranuclear palsy (Richardson's syndrome) as an exemplar condition, with high clinicopathological correlations. Progressive supranuclear palsy causes a marked change in cortical neurophysiology in the presence of mild cortical atrophy and is associated with a decline in cognitive functions associated with the frontal lobe. Using parametric empirical Bayesian inversion of a conductance-based canonical microcircuit model of magnetoencephalography data, we show that the inclusion of regional synaptic density-as a subject-specific prior on laminar specific neuronal populations-markedly increases model evidence. Specifically, model comparison suggests that a reduction in synaptic density in inferior frontal cortex affects superficial and granular layer glutamatergic excitation. This predicted individual differences in behaviour, demonstrating the link between synaptic loss, neurophysiology, and cognitive deficits. The method we demonstrate is not restricted to progressive supranuclear palsy or the effects of synaptic loss: such pathology-enriched dynamic causal models can be used to assess the mechanisms of other neurological disorders, with diverse non-invasive measures of pathology, and is suitable to test the effects of experimental pharmacology

    The impact of islet mass, number of transplants, and time between transplants on graft function in a national islet transplant program

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    The UK islet allotransplant program is nationally funded to deliver one or two transplants over 12 months to individuals with type 1 diabetes and recurrent severe hypoglycemia. Analyses were undertaken 10 years after program inception to evaluate associations between transplanted mass; single versus two transplants; time between two transplants and graft survival (stimulated C-peptide >50 pmol/L) and function. In total, 84 islet transplant recipients were studied. Uninterrupted graft survival over 12 months was attained in 23 (68%) single and 47 (94%) (p =.002) two transplant recipients (separated by [median (IQR)] 6 (3ā€“8) months). 64% recipients of one or two transplants with uninterrupted function at 12 months sustained graft function at 6 years. Total transplanted mass was associated with Mixed Meal Tolerance Test stimulated C-peptide at 12 months (p <.01). Despite 1.9-fold greater transplanted mass in recipients of two versus one islet infusion (12 218 [9291ā€“15 417] vs. 6442 [5156ā€“7639] IEQ/kg; p <.0001), stimulated C-peptide was not significantly higher. Shorter time between transplants was associated with greater insulin dose reduction at 12 months (beta āˆ’0.35; p =.02). Graft survival over the first 12 months was greater in recipients of two versus one islet transplant in the UK program, although function at 1 and 6 years was comparable. Minimizing the interval between 2 islet infusions may maximize cumulative impact on graft function

    Attenuated sex steroid receptor expression in fallopian tube of women with ectopic pregnancy

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    CONTEXT: Sex steroid hormone receptor (SHR) dynamics are well-documented in human endometrium but have not been comprehensively studied in Fallopian tube (FT). OBJECTIVE: To compare expression patterns and hormonal regulation of SHR in FT with that described in endometrium, and determine whether SHR expression is altered in FT of women with ectopic pregnancy (EP). DESIGN: Tissue analysis and culture. PATIENTS OR OTHER PARTICIPANTS: Women undergoing surgery for benign gynaecological conditions (n=14) and EP (n=6). INTERVENTIONS: Q-RT-PCR and immunohistochemistry were used to determine SHR mRNA expression and protein localization, respectively. SHR levels were measured in tubal explant cultures stimulated with estrogen and progestogen. RESULTS: ERĪ± and ERĪ² mRNAs were constitutively expressed in FT during the menstrual cycle. PR-AB and PR-B mRNAs were decreased in mid-luteal compared to follicular phase. ERĪ±, PR-AB and PR-B mRNAs were downregulated in human FT in vitro by treatment with progestogen. ERĪ±, ERĪ²1, ERĪ²2, PR and AR proteins localised to cell nuclei of epithelium, stroma and smooth muscle of non-pregnant FT. In FT from women with EP, PR-B mRNA was decreased when compared to mid-luteal FT, and ERĪ± protein was not detected. CONCLUSIONS: SHR expression in FT is different from that observed in endometrium recovered at similar stages of the menstrual cycle and expression in FT from women with EP is also altered compared with normal FT. These data are an important benchmark for furthering understanding of normal human FT physiology, transcriptional changes in FT in response to progesterone, and disorders of FT function, such as EP

    Histo-MRI map study protocol: a prospective cohort study mapping MRI to histology for biomarker validation and prediction of prostate cancer

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    INTRODUCTION: Multiparametric MRI (mpMRI) is now widely used to risk stratify men with a suspicion of prostate cancer and identify suspicious regions for biopsy. However, the technique has modest specificity and a high false-positive rate, especially in men with mpMRI scored as indeterminate (3/5) or likely (4/5) to have clinically significant cancer (csPCa) (Gleason ā‰„3+4). Advanced MRI techniques have emerged which seek to improve this characterisation and could predict biopsy results non-invasively. Before these techniques are translated clinically, robust histological and clinical validation is required. METHODS AND ANALYSIS: This study aims to clinically validate two advanced MRI techniques in a prospectively recruited cohort of men suspected of prostate cancer. Histological analysis of men undergoing biopsy or prostatectomy will be used for biological validation of biomarkers derived from Vascular and Extracellular Restricted Diffusion for Cytometry in Tumours and Luminal Water imaging. In particular, prostatectomy specimens will be processed using three-dimension printed patient-specific moulds to allow for accurate MRI and histology mapping. The index tests will be compared with the histological reference standard to derive false positive rate and true positive rate for men with mpMRI scores which are indeterminate (3/5) or likely (4/5) to have clinically significant prostate cancer (csPCa). Histopathological validation from both biopsy and prostatectomy samples will provide the best ground truth in validating promising MRI techniques which could predict biopsy results and help avoid unnecessary biopsies in men suspected of prostate cancer. ETHICS AND DISSEMINATION: Ethical approval was granted by the London-Queen Square Research Ethics Committee (19/LO/1803) on 23 January 2020. Results from the study will be presented at conferences and submitted to peer-reviewed journals for publication. Results will also be available on ClinicalTrials.gov. TRIAL REGISTRATION NUMBER: NCT04792138
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