178 research outputs found

    Accelerated Axonal Loss Following Acute CNS Demyelination in Mice Lacking Protein Tyrosine Phosphatase Receptor Type Z

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    Protein tyrosine phosphatase receptor type Z (Ptprz) is widely expressed in the mammalian central nervous system and has been suggested to regulate oligodendrocyte survival and differentiation. We investigated the role of Ptprz in oligodendrocyte remyelination after acute, toxin-induced demyelination in Ptprz null mice. We found neither obvious impairment in the recruitment of oligodendrocyte precursor cells, astrocytes, or reactive microglia/macrophage to lesions nor a failure for oligodendrocyte precursor cells to differentiate and remyelinate axons at the lesions. However, we observed an unexpected increase in the number of dystrophic axons by 3 days after demyelination, followed by prominent Wallerian degeneration by 21 days in the Ptprz-deficient mice. Moreover, quantitative gait analysis revealed a deficit of locomotor behavior in the mutant mice, suggesting increased vulnerability to axonal injury. We propose that Ptprz is necessary to maintain central nervous system axonal integrity in a demyelinating environment and may be an important target of axonal protection in inflammatory demyelinating diseases, such as multiple sclerosis and periventricular leukomalacia. (Am J Pathol 2012, 181:1518-1523; http://dx.doi.org/10.1016/j.ajpath.2012.07.011)UK Multiple Sclerosis SocietyMultiple Sclerosis International FederationUniv Cambridge, Dept Vet Med, Cambridge CB3 0ES, EnglandUniv Cambridge, Wellcome Trust & MRC Cambridge Stem Cell Inst, Cambridge CB3 0ES, EnglandUniversidade Federal de SΓ£o Paulo, Dept Biosci, Santos, BrazilMerck Serono Int, Geneva Res Ctr, Geneva, SwitzerlandUniversidade Federal de SΓ£o Paulo, Dept Biosci, Santos, BrazilWeb of Scienc

    Globally increased ultraconserved noncoding RNA expression in pancreatic adenocarcinoma

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    This is the final version of the article. Available from the publisher via the DOI in this record.Transcribed ultraconserved regions (T-UCRs) are a class of non-coding RNAs with 100% sequence conservation among human, rat and mouse genomes. T-UCRs are differentially expressed in several cancers, however their expression in pancreatic adenocarcinoma (PDAC) has not been studied. We used a qPCR array to profile all 481 T-UCRs in pancreatic cancer specimens, pancreatic cancer cell lines, during experimental pancreatic desmoplasia and in the pancreases of P48Cre/wt; KrasLSL-G12D/wt mice. Fourteen, 57 and 29% of the detectable T-UCRs were differentially expressed in the cell lines, human tumors and transgenic mouse pancreases, respectively. The vast majority of the differentially expressed T-UCRs had increased expression in the cancer. T-UCRs were monitored using an in vitro model of the desmoplastic reaction. Twenty-five % of the expressed T-UCRs were increased in the HPDE cells cultured on PANC-1 cellular matrix. UC.190, UC.233 and UC.270 were increased in all three human data sets. siRNA knockdown of each of these three T-UCRs reduced the proliferation of MIA PaCa-2 cells up to 60%. The expression pattern among many T-UCRs in the human and mouse pancreases closely correlated with one another, suggesting that groups of T-UCRs are co-activated in PDAC. Successful knockout of the transcription factor EGR1 in PANC-1 cells caused a reduction in the expression of a subset of T-UCRs suggesting that EGR1 may control T-UCR expression in PDAC. We report a global increase in expression of T-UCRs in both human and mouse PDAC. Commonalties in their expression pattern suggest a similar mechanism of transcriptional upregulation for T-UCRs in PDAC.Supported by grants R21/R33CA114304 and U01CA111294. G.A.C. is supported as a Fellow at The University of Texas MD Anderson Research Trust, as a University of Texas System Regents Research Scholar and by the CLL Global Research Foundation. Work in Dr. Calin’s laboratory is supported in part by a 2009 Seena Magowitz–Pancreatic Cancer Action Network AACR Pilot Grant, the Laura and John Arnold Foundation, the RGK Foundation and the Estate of C. G. Johnson, Jr. A.C.P.A.P. was supported by NIH fellowship 5F31CA142238

    A Probabilistic Framework for Security Scenarios with Dependent Actions

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    This work addresses the growing need of performing meaningful probabilistic analysis of security. We propose a framework that integrates the graphical security modeling technique of attack–defense trees with probabilistic information expressed in terms of Bayesian networks. This allows us to perform probabilistic evaluation of attack–defense scenarios involving dependent actions. To improve the efficiency of our computations, we make use of inference algorithms from Bayesian networks and encoding techniques from constraint reasoning. We discuss the algebraic theory underlying our framework and point out several generalizations which are possible thanks to the use of semiring theory

    An Algebraic Theory for Data Linkage

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    There are countless sources of data available to governments, companies, and citizens, which can be combined for good or evil. We analyse the concepts of combining data from common sources and linking data from different sources. We model the data and its information content to be found in a single source by an ordered partial monoid, and the transfer of information between sources by different types of morphisms. To capture the linkage between a family of sources, we use a form of Grothendieck construction to create an ordered partial monoid that brings together the global data of the family in a single structure. We apply our approach to database theory and axiomatic structures in approximate reasoning. Thus, ordered partial monoids provide a foundation for the algebraic study for information gathering in its most primitive form

    Coliform pyosalpinx as a rare complication of appendicectomy: a case report and review of the literature on best practice

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    <p>Abstract</p> <p>Introduction</p> <p>Coliform pyosalpinx is a rare entity. We report a case that occurred three months after appendicectomy for gangrenous appendicitis. There follows a literature review on best practice for the treatment of pyosalpinx.</p> <p>Case presentation</p> <p>A seventeen year old girl presented with an acute abdomen three months after an appendicectomy for gangrenous appendicitis. Intraoperative findings were bilateral pyosalpinx treated by aspiration, saline and Betadine irrigation and intravenous antibiotics.</p> <p>Conclusion</p> <p>Microbiological analysis of the pus revealed <it>Escherichia coli </it>and anaerobes. Chlamydia and Candida were not isolated. This is the first known reported case of Coliform Pyosalpinx following appendicectomy. The best treatment does not necessarily involve salpingectomy especially in women of reproductive age where fertility may become compromised.</p

    BMJ Open

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    INTRODUCTION: The prevalence of postnatal depression (PND) is significant: reaching up to 20% in the general population. In mechanistic terms, the risk of PND lies in an interaction between a maternal psychophysiological vulnerability and a chronic environmental context of stress. On the one hand, repetition of stressor during pregnancy mimics a chronic stress model that is relevant to the study of the allostatic load and the adaptive mechanisms. On the other hand, vulnerability factors reflect a psychological profile mirroring mindfulness functioning (psychological quality that involves bringing one's complete and non-judgemental attention to the present experience on a moment-to-moment basis). This psychological resource is linked to protective and resilient psychic functioning. Thus, PND appears to be a relevant model for studying the mechanisms of chronic stress and vulnerability to psychopathologies.In this article, we present the protocol of an ongoing study (started in May 2017). METHODS AND ANALYSIS: The study is being carried out in five maternities and will involve 260 women. We aim to determine the predictive psychobiological factors for PND emergence and to provide a better insight into the mechanisms involved in chronic stress during pregnancy. We use a multidisciplinary approach that encompasses psychological resources and biophysiological and genetic profiles in order to detect relevant vulnerability biomarkers for chronic stress and the development of PND. To do so, each woman will be involved in the study from her first trimester of pregnancy until 12 months postdelivery. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ile de France III Ethics Committee, France (2016-A00887-44). We aim to disseminate the findings through international conferences and international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03088319; Pre-results

    Ischemia-Reperfusion Injury and Pregnancy Initiate Time-Dependent and Robust Signs of Up-Regulation of Cardiac Progenitor Cells

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    To explore how cardiac regeneration and cell turnover adapts to disease, different forms of stress were studied for their effects on the cardiac progenitor cell markers c-Kit and Isl1, the early cardiomyocyte marker Nkx2.5, and mast cells. Adult female rats were examined during pregnancy, after myocardial infarction and ischemia-reperfusion injury with/out insulin like growth factor-1(IGF-1) and hepatocyte growth factor (HGF). Different cardiac sub-domains were analyzed at one and two weeks post-intervention, both at the mRNA and protein levels. While pregnancy and myocardial infarction up-regulated Nkx2.5 and c-Kit (adjusted for mast cell activation), ischemia-reperfusion injury induced the strongest up-regulation which occurred globally throughout the entire heart and not just around the site of injury. This response seems to be partly mediated by increased endogenous production of IGF-1 and HGF. Contrary to c-Kit, Isl1 was not up-regulated by pregnancy or myocardial infarction while ischemia-reperfusion injury induced not a global but a focal up-regulation in the outflow tract and also in the peri-ischemic region, correlating with the up-regulation of endogenous IGF-1. The addition of IGF-1 and HGF did boost the endogenous expression of IGF and HGF correlating to focal up-regulation of Isl1. c-Kit expression was not further influenced by the exogenous growth factors. This indicates that there is a spatial mismatch between on one hand c-Kit and Nkx2.5 expression and on the other hand Isl1 expression. In conclusion, ischemia-reperfusion injury was the strongest stimulus with both global and focal cardiomyocyte progenitor cell marker up-regulations, correlating to the endogenous up-regulation of the growth factors IGF-1 and HGF. Also pregnancy induced a general up-regulation of c-Kit and early Nkx2.5+ cardiomyocytes throughout the heart. Utilization of these pathways could provide new strategies for the treatment of cardiac disease

    In Situ Dividing and Phagocytosing Retinal Microglia Express Nestin, Vimentin, and NG2 In Vivo

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    BACKGROUND: Following injury, microglia become activated with subsets expressing nestin as well as other neural markers. Moreover, cerebral microglia can give rise to neurons in vitro. In a previous study, we analysed the proliferation potential and nestin re-expression of retinal macroglial cells such as astrocytes and MΓΌller cells after optic nerve (ON) lesion. However, we were unable to identify the majority of proliferative nestin(+) cells. Thus, the present study evaluates expression of nestin and other neural markers in quiescent and proliferating microglia in naΓ―ve retina and following ON transection in adult rats in vivo. METHODOLOGY/PRINCIPAL FINDINGS: For analysis of cell proliferation and cells fates, rats received BrdU injections. Microglia in retinal sections or isolated cells were characterized using immunofluorescence labeling with markers for microglia (e.g., Iba1, CD11b), cell proliferation, and neural cells (e.g., nestin, vimentin, NG2, GFAP, Doublecortin etc.). Cellular analyses were performed using confocal laser scanning microscopy. In the naΓ―ve adult rat retina, about 60% of resting ramified microglia expressed nestin. After ON transection, numbers of nestin(+) microglia peaked to a maximum at 7 days, primarily due to in situ cell proliferation of exclusively nestin(+) microglia. After 8 weeks, microglia numbers re-attained control levels, but 20% were still BrdU(+) and nestin(+), although no further local cell proliferation occurred. In addition, nestin(+) microglia co-expressed vimentin and NG2, but not GFAP or neuronal markers. Fourteen days after injury and following retrograde labeling of retinal ganglion cells (RGCs) with Fluorogold (FG), nestin(+)NG2(+) microglia were positive for the dye indicating an active involvement of a proliferating cell population in phagocytosing apoptotic retinal neurons. CONCLUSIONS/SIGNIFICANCE: The current study provides evidence that in adult rat retina, a specific resident population of microglia expresses proteins of immature neural cells that are involved in injury-induced cell proliferation and phagocytosis while transdifferentiation was not observed
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