1,348 research outputs found

    Metabolic myopathy presenting with polyarteritis nodosa: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>To the best of our knowledge, we describe for the first time a patient in whom an unusual metabolic myopathy was identified after failure to respond to curative therapy for a systemic vasculitis, polyarteritis nodosa. We hope this report will heighten awareness of common metabolic myopathies that may present later in life. It also speculates on the potential relationship between metabolic myopathy and systemic vasculitis.</p> <p>Case presentation</p> <p>A 78-year-old African-American woman with a two-year history of progressive fatigue and exercise intolerance presented to our facility with new skin lesions and profound muscle weakness. Skin and muscle biopsies demonstrated a medium-sized artery vasculitis consistent with polyarteritis nodosa. Biochemical studies of the muscle revealed diminished cytochrome C oxidase activity (0.78 μmol/minute/g tissue; normal range 1.03 to 3.83 μmol/minute/g tissue), elevated acid maltase activity (23.39 μmol/minute/g tissue; normal range 1.74 to 9.98 μmol/minute/g tissue) and elevated neutral maltase activity (35.89 μmol/minute/g tissue; normal range 4.35 to 16.03 μmol/minute/g tissue). Treatment for polyarteritis nodosa with prednisone and cyclophosphamide resulted in minimal symptomatic improvement. Additional management with a diet low in complex carbohydrates and ubiquinone, creatine, carnitine, folic acid, α-lipoic acid and ribose resulted in dramatic clinical improvement.</p> <p>Conclusions</p> <p>Our patient's initial symptoms of fatigue, exercise intolerance and progressive weakness were likely related to her complex metabolic myopathy involving both the mitochondrial respiratory chain and glycogen storage pathways. Management of our patient required treatment of both the polyarteritis nodosa as well as metabolic myopathy. Metabolic myopathies are common and should be considered in any patient with exercise intolerance. Metabolic myopathies may complicate the management of various disease states.</p

    The metastasis-associated protein S100A4 exists in several charged variants suggesting the presence of posttranslational modifications

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    <p>Abstract</p> <p>Background</p> <p>S100A4 is a metastasis-associated protein which has been linked to multiple cellular events, and has been identified extracellularly, in the cytoplasm and in the nucleus of tumor cells; however, the biological implications of subcellular location are unknown. Associations between a variety of posttranslational protein modifications and altered biological functions of proteins are becoming increasingly evident. Identification and characterization of posttranslationally modified S100A4 variants could thus contribute to elucidating the mechanisms for the many cellular functions that have been reported for this protein, and might eventually lead to the identification of novel drugable targets.</p> <p>Methods</p> <p>S100A4 was immuoprecipitated from a panel of <it>in vitro </it>and <it>in vivo </it>sources using a monoclonal antibody and the samples were separated by 2D-PAGE. Gels were analyzed by western blot and silver staining, and subsequently, several of the observed spots were identified as S100A4 by the use of MALDI-TOF and MALDI-TOF/TOF.</p> <p>Results</p> <p>A characteristic pattern of spots was observed when S100A4 was separated by 2D-PAGE suggesting the presence of at least three charge variants. These charge variants were verified as S100A4 both by western immunoblotting and mass spectrometry, and almost identical patterns were observed in samples from different tissues and subcellular compartments. Interestingly, recombinant S100A4 displayed a similar pattern on 2D-PAGE, but with different quantitative distribution between the observed spots.</p> <p>Conclusion</p> <p>Endogenously expressed S100A4 were shown to exist in several charge variants, which indicates the presence of posttranslational modifications altering the net charge of the protein. The different variants were present in all subcellular compartments and tissues/cell lines examined, suggesting that the described charge variants is a universal phenomenon, and cannot explain the localization of S100A4 in different subcellular compartments. However, the identity of the specific posttranslational modification and its potential contribution to the many reported biological events induced by S100A4, are subject to further studies.</p

    Topological Strata of Weighted Complex Networks

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    The statistical mechanical approach to complex networks is the dominant paradigm in describing natural and societal complex systems. The study of network properties, and their implications on dynamical processes, mostly focus on locally defined quantities of nodes and edges, such as node degrees, edge weights and --more recently-- correlations between neighboring nodes. However, statistical methods quickly become cumbersome when dealing with many-body properties and do not capture the precise mesoscopic structure of complex networks. Here we introduce a novel method, based on persistent homology, to detect particular non-local structures, akin to weighted holes within the link-weight network fabric, which are invisible to existing methods. Their properties divide weighted networks in two broad classes: one is characterized by small hierarchically nested holes, while the second displays larger and longer living inhomogeneities. These classes cannot be reduced to known local or quasilocal network properties, because of the intrinsic non-locality of homological properties, and thus yield a new classification built on high order coordination patterns. Our results show that topology can provide novel insights relevant for many-body interactions in social and spatial networks. Moreover, this new method creates the first bridge between network theory and algebraic topology, which will allow to import the toolset of algebraic methods to complex systems.Comment: 26 pages, 19 figures, 1 tabl

    The outcomes of Perthes' disease of the hip: a study protocol for the development of a core outcome set.

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    BACKGROUND: Perthes' disease is an idiopathic osteonecrosis of a developmental hip that is most frequent in Northern Europe. Currently, the absence of a common set of standardised outcomes makes comparisons between studies of different interventions challenging. This study aims to summarise the outcomes used in clinical research of interventions for Perthes' disease and define a set of core outcomes (COS) to ensure that the variables of primary importance are measured and reported in future research studies investigating Perthes' disease. METHODS: A systematic review of the current literature will be used to identify a list of outcomes reported in previous studies. Additional important outcomes will be sought by interviewing a group of children with Perthes' disease, adults who were treated with the disease in infancy and parents of children with the disease. This list will then be evaluated by experts in Perthes' disease using a Delphi survey divided into two rounds to ascertain the importance of each outcome. The final outcomes list obtained from the Delphi survey will be then discussed during a consensus meeting of representative key stakeholders in order to define the COS to be reported in future clinical trials related to Perthes' disease. DISCUSSION: The absence of high-quality research and clear guidelines concerning the management of Perthes' disease is, at least in part, due to the difficulties in the comparing the results from previous studies. The development of a COS seeks to standardise outcomes collected in future research studies to enable comparisons between studies to be made and to facilitate meta-analyses of results. TRIAL REGISTRATION: Core Outcome Measures in Effectiveness Trials Initiative (COMET), 1003 . Registered on 20 July 2017. Prospero International Prospective Register of Systematic Reviews, CRD 42017069742 . Registered on 10 July 2017

    A review of elliptical and disc galaxy structure, and modern scaling laws

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    A century ago, in 1911 and 1913, Plummer and then Reynolds introduced their models to describe the radial distribution of stars in `nebulae'. This article reviews the progress since then, providing both an historical perspective and a contemporary review of the stellar structure of bulges, discs and elliptical galaxies. The quantification of galaxy nuclei, such as central mass deficits and excess nuclear light, plus the structure of dark matter halos and cD galaxy envelopes, are discussed. Issues pertaining to spiral galaxies including dust, bulge-to-disc ratios, bulgeless galaxies, bars and the identification of pseudobulges are also reviewed. An array of modern scaling relations involving sizes, luminosities, surface brightnesses and stellar concentrations are presented, many of which are shown to be curved. These 'redshift zero' relations not only quantify the behavior and nature of galaxies in the Universe today, but are the modern benchmark for evolutionary studies of galaxies, whether based on observations, N-body-simulations or semi-analytical modelling. For example, it is shown that some of the recently discovered compact elliptical galaxies at 1.5 < z < 2.5 may be the bulges of modern disc galaxies.Comment: Condensed version (due to Contract) of an invited review article to appear in "Planets, Stars and Stellar Systems"(www.springer.com/astronomy/book/978-90-481-8818-5). 500+ references incl. many somewhat forgotten, pioneer papers. Original submission to Springer: 07-June-201

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

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    This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}andcorrespondtoanintegratedluminosityof and correspond to an integrated luminosity of 4.6\;{\rm f}{{{\rm b}}^{-1}}.ThemeasurementisperformedbyreconstructingtheboostedWorZbosonsinsinglejets.ThereconstructedjetmassisusedtoidentifytheWandZbosons,andajetsubstructuremethodbasedonenergyclusterinformationinthejetcentreofmassframeisusedtosuppressthelargemultijetbackground.ThecrosssectionforeventswithahadronicallydecayingWorZboson,withtransversemomentum. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum {{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}andpseudorapidity and pseudorapidity |\eta |\lt 1.9,ismeasuredtobe, is measured to be {{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

    Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

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    A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN
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