982 research outputs found

    Kann die 18F-FDG-PET/CT-Untersuchung die Panendoskopie zur Detektion von synchronen Zweitkarzinomen ersetzen?

    Full text link
    Ziel der Arbeit war es, die Wertigkeit der 18F-FDG-PET/ CT-Untersuchung bezüglich synchroner Zweitkarzinome im Vergleich mit der Panendoskopie beim initialen Staging zu untersuchen. 311 Patienten wurden mit beiden Untersuchungsmethoden abgeklärt. Als Referenz galt die zytologische, histologische und/oder klinische oder radiologische Untersuchung. Die Prävalenz für synchrone Zweitkarzinome betrug mit der Panendoskopie 4,5%, während die Prävalenz mittels PET/ CT-Untersuchung 6,1% betrug. Die Sensitivität für die Panendoskopie betrug 74%, die Spezifität 99,7%, der positiv prädiktive Wert 93% und der negativ prädiktive Wert 98%. Die Sensitivität für die PET/CT-Untersuchung betrug 100%, die Spezifität 95,7% der positiv prädiktive Wert 59% und der negativ prädiktive Wert 100%. Die PET/CT-Untersuchung scheint der Panendoskopie überlegen zu sein. Bei bezüglich synchroner Zweitkarzinome unauffälligem PET/CT kann die Panendoskopie auf die Endoskopie und Beurteilung des Primärtumors beschränkt werden kann. Aufgrund der hohen Kosten und der grossen Anzahl falsch positiver Resultate, welche durch das PET/CT generiert werden, empfehlen wir die Durchführung dieser Untersuchung nur bei fortgeschrittenen Tumoren mit der Frage nach Fernmetastasen. Die Panendoskopie bleibt weiterhin der Goldstandar

    Kinetic evidence for unique regulation of GLUT4 trafficking by insulin and AMP-activated protein kinase activators in L6 myotubes.

    Get PDF
    In L6 myotubes, redistribution of a hemagglutinin (HA) epitope-tagged GLUT4 (HA-GLUT4) to the cell surface occurs rapidly in response to insulin stimulation and AMP-activated protein kinase (AMPK) activation. We have examined whether these separate signaling pathways have a convergent mechanism that leads to GLUT4 mobilization and to changes in GLUT4 recycling. HA antibody uptake on GLUT4 in the basal steady state reached a final equilibrium level that was only 81% of the insulin-stimulated level. AMPK activators (5-aminoimidazole-4-carboxyamide ribonucleoside (AICAR) and A-769662) led to a similar level of antibody uptake to that found in insulin-stimulated cells. However, the combined responses to insulin stimulation and AMPK activation led to an antibody uptake level of approximately 20% above the insulin level. Increases in antibody uptake due to insulin, but not AICAR or A-769662, treatment were reduced by both wortmannin and Akt inhibitor. The GLUT4 internalization rate constant in the basal steady state was very rapid (0.43 min(-1)) and was decreased during the steady-state responses to insulin (0.18 min(-1)), AICAR (0.16 min(-1)), and A-769662 (0.24 min(-1)). This study has revealed a nonconvergent mobilization of GLUT4 in response to activation of Akt and AMPK signaling. Furthermore, GLUT4 trafficking in L6 muscle cells is very reliant on regulated endocytosis for control of cell surface GLUT4 levels

    Probing bacterial-fungal interactions at the single cell level.

    Get PDF
    Interactions between fungi and prokaryotes are abundant in many ecological systems. A wide variety of biomolecules regulate such interactions and many of them have found medicinal or biotechnological applications. However, studying a fungal-bacterial system at a cellular level is technically challenging. New microfluidic devices provided a platform for microscopic studies and for long-term, time-lapse experiments. Application of these novel tools revealed insights into the dynamic interactions between the basidiomycete Coprinopsis cinerea and the bacterium Bacillus subtilis. Direct contact was mediated by polar attachment of bacteria to only a subset of fungal hyphae suggesting a differential competence of fungal hyphae and thus differentiation of hyphae within a mycelium. The fungicidal activity of B. subtilis was monitored at a cellular level and showed a novel mode of action on fungal hyphae

    Social corrections act as a double-edged sword by reducing the perceived accuracy of false and real news in the UK, Germany, and Italy

    Get PDF
    This is the final version. Available from Nature Research via the DOI in this record. Data availability: All shareable data are found on the online OSF repository at https://osf.io/jhwfgCode availability: All the code including reproducible analyses are found on the online OSF repository at https://osf.io/4hjcf for data relating to the UK, https://osf.io/yvdj4 for Italy, and https:// osf.io/jhwfg Germany.Corrective or refutational posts from ordinary users on social media have the potential to improve the online information ecosystem. While initial evidence of these social corrections is promising, a better understanding of the effects across different topics, formats, and audiences is needed. In three pre-registered experiments (N = 1944 UK, N = 2467 Italy, N = 2210 Germany) where respondents completed a social media post assessment task with false and true news posts on various topics (e.g., health, climate change, technology), we find that social corrections reduce perceived accuracy of and engagement with false news posts. We also find that social corrections that flag true news as false decrease perceived accuracy of and engagement with true news posts. We did not find evidence to support moderation of these effects by correction strength, anti-expert sentiments, cognitive reflection capacities, or susceptibility to social influence. While social corrections can be effective for false news, they may also undermine belief in true news.British AcademyDavidson Colleg

    Mitochondrial oxidative stress causes insulin resistance without disrupting oxidative phosphorylation.

    Get PDF
    Mitochondrial oxidative stress, mitochondrial dysfunction, or both have been implicated in insulin resistance. However, disentangling the individual roles of these processes in insulin resistance has been difficult because they often occur in tandem, and tools that selectively increase oxidant production without impairing mitochondrial respiration have been lacking. Using the dimer/monomer status of peroxiredoxin isoforms as an indicator of compartmental hydrogen peroxide burden, we provide evidence that oxidative stress is localized to mitochondria in insulin-resistant 3T3-L1 adipocytes and adipose tissue from mice. To dissociate oxidative stress from impaired oxidative phosphorylation and study whether mitochondrial oxidative stress per se can cause insulin resistance, we used mitochondria-targeted paraquat (MitoPQ) to generate superoxide within mitochondria without directly disrupting the respiratory chain. At ≤10 μm, MitoPQ specifically increased mitochondrial superoxide and hydrogen peroxide without altering mitochondrial respiration in intact cells. Under these conditions, MitoPQ impaired insulin-stimulated glucose uptake and glucose transporter 4 (GLUT4) translocation to the plasma membrane in both adipocytes and myotubes. MitoPQ recapitulated many features of insulin resistance found in other experimental models, including increased oxidants in mitochondria but not cytosol; a more profound effect on glucose transport than on other insulin-regulated processes, such as protein synthesis and lipolysis; an absence of overt defects in insulin signaling; and defective insulin- but not AMP-activated protein kinase (AMPK)-regulated GLUT4 translocation. We conclude that elevated mitochondrial oxidants rapidly impair insulin-regulated GLUT4 translocation and significantly contribute to insulin resistance and that MitoPQ is an ideal tool for studying the link between mitochondrial oxidative stress and regulated GLUT4 trafficking

    Proteomic Analysis of GLUT4 Storage Vesicles Reveals Tumor Suppressor Candidate 5 (TUSC5) as a Novel Regulator of Insulin Action in Adipocytes.

    Get PDF
    Insulin signaling augments glucose transport by regulating glucose transporter 4 (GLUT4) trafficking from specialized intracellular compartments, termed GLUT4 storage vesicles (GSVs), to the plasma membrane. Proteomic analysis of GSVs by mass spectrometry revealed enrichment of 59 proteins in these vesicles. We measured reduced abundance of 23 of these proteins following insulin stimulation and assigned these as high confidence GSV proteins. These included established GSV proteins such as GLUT4 and insulin-responsive aminopeptidase, as well as six proteins not previously reported to be localized to GSVs. Tumor suppressor candidate 5 (TUSC5) was shown to be a novel GSV protein that underwent a 3.7-fold increase in abundance at the plasma membrane in response to insulin. siRNA-mediated knockdown of TUSC5 decreased insulin-stimulated glucose uptake, although overexpression of TUSC5 had the opposite effect, implicating TUSC5 as a positive regulator of insulin-stimulated glucose transport in adipocytes. Incubation of adipocytes with TNFα caused insulin resistance and a concomitant reduction in TUSC5. Consistent with previous studies, peroxisome proliferator-activated receptor (PPAR) γ agonism reversed TNFα-induced insulin resistance. TUSC5 expression was necessary but insufficient for PPARγ-mediated reversal of insulin resistance. These findings functionally link TUSC5 to GLUT4 trafficking, insulin action, insulin resistance, and PPARγ action in the adipocyte. Further studies are required to establish the exact role of TUSC5 in adipocytes

    Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

    Get PDF
    This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPEnsuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered

    Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

    Search for New Physics with Jets and Missing Transverse Momentum in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 inverse picobarns collected in proton--proton collisions at sqrt(s)=7 TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets
    corecore