2,602 research outputs found

    Fc receptors in mucosal immunology

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    Immunoglobulin A (IgA) is the most prevalent antibody class at mucosal surfaces. In addition to protecting mucosal surfaces by preventing invasion of pathogens, IgA can interact with multiple IgA receptors by binding to the Fc tail, carbohydrate side chains, or accessory molecules. The best characterized IgA Fc receptor is FcαRI (CD89), which acts as a regulator between anti- and proinflammatory responses of IgA. Furthermore, the Fcα/μR, polymeric Ig receptor, transferring receptor, and asialoglycoprotein receptor have been described, as well as IgA receptors on M cells, T cells, natural killer cells, and dendritic cells. However, the significance of several of these receptors is still unclear. The neonatal Fc receptor for IgG, furthermore, plays a role in transporting IgG across epithelial cells, whereas Fc receptors for IgE are involved in parasitic infections, allergies, and asthma. The focus of this chapter is therefore the role of Fc receptors in mucosal immunology.</p

    The Reproducibility of Lists of Differentially Expressed Genes in Microarray Studies

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    Reproducibility is a fundamental requirement in scientific experiments and clinical contexts. Recent publications raise concerns about the reliability of microarray technology because of the apparent lack of agreement between lists of differentially expressed genes (DEGs). In this study we demonstrate that (1) such discordance may stem from ranking and selecting DEGs solely by statistical significance (P) derived from widely used simple t-tests; (2) when fold change (FC) is used as the ranking criterion, the lists become much more reproducible, especially when fewer genes are selected; and (3) the instability of short DEG lists based on P cutoffs is an expected mathematical consequence of the high variability of the t-values. We recommend the use of FC ranking plus a non-stringent P cutoff as a baseline practice in order to generate more reproducible DEG lists. The FC criterion enhances reproducibility while the P criterion balances sensitivity and specificity

    Fc receptors

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    Fc receptors for immunoglobulin A (IgA) have been recognized functionally for many years. The myeloid receptor, FcαRI, is the most thoroughly characterized. It is structurally related to the FcγRs and Fce{open}RI and also associates with the FcR γ chain dimer. In recent years it has become increasingly apparent that another class of Fc receptor, FcRn, plays important roles in the transport of immunoglobulin G (IgG) across the epithelial layer at mucosal surfaces. FcRn shares only limited homology with other FcR and is distantly related to the major histocompatibility complex (MHC) class I family, dimerizing with β2-microglobulin, the obligate subunit of all class I molecules. The expression levels of FcαRI on a number of cell types can be upregulated or downregulated by certain cytokines or other stimuli. Increased expression can be observed on monocytes and macrophages on treatment with calcitriol, phorbol myristate acetate (PMA), tumor necrosis factorα (TNFα), interleukin 1β (IL-1β), granulocyte-macrophage colony stimulating factor (GM-CSF), and lipopolysaccharide (LPS), whereas decreased expression is reportedly driven by transforming growth factorβ (TGFβ), IFNγ, suramin, and polymeric IgA (pIgA).</p

    Le Corbeau et le Renard: 99 versions réinventées: Style d'exercices

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    This book represents a fascinating effort. At first I thought it was going to be a collection of various parodies of La Fontaine's FC. It is not that, but rather a creative presentation of some 97 different versions of La Fontaine created by the author. The first two versions are a French translation of the Greek prose of the most original FC text in the Aesopic manuscripts and then La Fontaine's verse. Thereafter the fun begins! The imagination and the execution of this project are both remarkable. Let me offer a sample of five approaches: (1) an acrostic, so that the opening letters of each verse spell "M Jean La Fontaine"; (2) a prose version after the manner of Balzac; (3) a scientific version needing more than a full page; (4) a tourist guide version; and (5) a rhyming version in English. T of C at the end. 136 pages. 5¼" x 8". Printed upon demand.Language note: FrenchNicolas Mille

    Role of CrkII in Fc gamma receptor-mediated phagocytosis

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    Phagocytosis of IgG-opsonized pathogens by Fc gamma receptors requires extensive remodeling of the actin cytoskeleton, a process regulated by the small GTPase Rac. Vav was thought to be the guanine nucleotide exchange factor responsible for the activation of Rac, but recent evidence indicates that Fc gamma receptor-mediated phagocytosis is unaffected in macrophages lacking all three isoforms of Vav. We therefore tested whether another GEF, DOCK180, participates in Fc gamma receptor-initiated phagocytosis. DOCK180 associates with the adaptor protein Crk, which mediates recruitment of the GEF to sites of tyrosine phosphorylation. CrkII and DOCK180 were found to accumulate at the phagocytic cup. Knockdown of Crk or DOCK180 in murine macrophages using small interfering RNA inhibited phagocytosis of IgG-opsonized particles. Moreover, transfection of dominant negative CrkII prevented both recruitment of DOCK180 and the activation of Rac at the phagocytic cup. This is the first report of a role for either Crk or DOCK180 in Fc gamma receptor-mediated phagocytosis. The Crk-DOCK180 complex is involved in the clearance of apoptotic cells, which unlike the ingestion of IgG-opsonized particles, is an anti-inflammatory process. The finding that CrkII-DOCK180 is also responsible, at least in part, for the effects of Fc gamma receptors implies that additional, parallel pathways must account for the associated pro-inflammatory effect

    FC Omniworld

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    Het maken van een stedenbouwkundig plan voor de locatie Almere Poort in Almere. Hierbij is het programma van de Gemeente, zoals gespecificeerd voor de locatie, overgenomen. De kern van het nieuwe plan is een centrale (groene) as waaraan alle centrumfuncties voor deze wijk worden gerealiseerd. Deze nieuwe as zorgt, door de combinatie van functies met verschillende gebruikstijden, voor een continue drukte op deze centrale as. Aan een van de eindes van de as ligt een verhoogd maaiveld. Dit maaiveld gaat over het spoortalud zodat men het spoor over kan steken zonder tunnel of spoorwegovergang. In dit talud worden diverse functies gehuisvest welke normaal dichte dozen zijn (zoals parkeren, expo ruimten en sportzalen). Deze functies met voornaleijk dichte gevels worden omkleed met kleinschalige functies om continue activiteit bij het verhoogde maaiveld te genereren en om interessante gevelbeelden te hebben (i.p.v. dichte wanden van grootschalige functies). In het verhoogde maaiveld ligt verdiept het nieuwe stadion voor FC Omniworld. Dit stadion wordt zo opgenomen in een natuurlijke en groene omgeving. De dakconstructie bestaat uit houten spanten en een semi-transparant doek om zo goed mogelijk aan te sluiten op het park bovenop het nieuwe maaiveld. Bezoekers komen ook via het park binnen. Op dit niveau kan men rondlopen om versnaperingen te kopen en vervolgens af te dalen naar de tribunes. Het stadion is in de toekomst uit te breiden door nieuwe tribunes te positioneren boven de promenade van het stadion en onder het dak. Hiervoor zijn geen aanpassingen vereist. Tevens is het stadion multifuntioneel te gebruiken door verplaatsbare tribunedelen.Architectur

    Plant expression of cocaine hydrolase-Fc fusion protein for treatment of cocaine abuse

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    BACKGROUND: A recently reported cocaine hydrolase (CocH3) fused with fragment crystallizable (Fc) region of human immunoglobulin G1, denoted as CocH3-Fc, is known as a promising therapeutic candidate for the treatment of cocaine overdose and addiction. A challenge for practical therapeutic use of this enzyme exists in the large-scale protein production and, therefore, it is interesting to identify a low-cost and feasible, sustainable source of CocH3-Fc production. RESULTS: CocH3-Fc was transiently expressed in plant Nicotiana benthamiana leaves. The plant-expressed protein, denoted as pCocH3-Fc, was as active as that expressed in mammalian cells both in vitro and in vivo. However, compared to the mammalian-cell expressed CocH3-Fc protein, pCocH3-Fc had a shorter biological half-life, probably due to the lack of protein sialylation in plant. Nevertheless, the in vivo half-life was significantly extended upon the PEGylation of pCocH3-Fc. The Fc fusion did not prolong the biological half-life of the plant-expressed enzyme pCocH3-Fc, but increased the yield of the enzyme expression in the plant under the same experimental conditions. CONCLUSIONS: It is feasible to express pCocH3-Fc in plants. Further studies on the pCocH3-Fc production in plants should focus on the development of vectors with additional genes/promoters for the complete protein sialylation and for a better yield

    Stable Foliage Cluster (FC), a Basic Unit of the Crown Structure of Tree Species and Its Application to Modeling of Tree and Forest Structure: Configuration of the FC Model

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    The "foliage cluster (FC) model" shows that the size (the amount of leaves, number of yearly shoots and total twig length), turnover time, and branching (i.e., forking) structure of a twig becomes stable in the top of the crown in an oak species by forming a "stable FC" [1]. A stable FC can be treated as a basic component of the crown structure and as an alternative to individual leaf or current-year shoot. The FC model is composed of several equations approximating the branching structure of twigs. Differences in size and branching morphology among twigs are represented by differences in values of the parameters of the equations. We described details of our analyses of data taken from real twigs and applied to the equations implemented in the FC model

    Financial analysis of FC SLOVAN Liberec

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    Thesis "Financial analysis of FC Slovan Liberec" focuses especially on reviewing financial position and efficiency of this football club in four year period. The first theoretical part is complemented with practical calculations in the second part. In the second part author focuses on horizontal analysis, vertical analysis and other models of financial analysis

    Contributing human and organizational factors to the collapse of the FC Twente stadium roof

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    In 2011 the city of Enschede was shocked by the collapse of the roof of an extension for the FC Twente stadium. The structure collapsed during construction and two fatalities and nine injuries were recorded. The cantilevering steel roof structure was covered with corrugated steel sheets and stabilized by bracings. Investigation showed that the structure was already loaded with the finishing structure before it was completed and stabilized. Contributing influencing human and organizational factors to the incident were the tight schedule resulting in a flawed construction sequence. Furthermore, there was too little attention to the way of execution during design, unjustified trust between parties resulting in inadequate coordination, checking and allocation of responsibilities.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Applied Mechanic
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