905 research outputs found

    Essays on Distributive Preferences

    Get PDF

    Influence of the Atrial Natriuretic Peptide on TNF- αα α -activated human endothelial cells

    Get PDF
    The present work deals with the inhibitory action of ANP on TNF- -induced expression of adhesion molecules (ICAM-1, VCAM-1, E-selectin), chemokines (MCP-1), and cytoskeleton changes in human endothelial cells. 5.1.1 Effect of ANP on TNF- α αα-induced CAM expression The following diagram shows a schematic outdraw of the summerized results of the first part of the present work. figure 1 summary: schematic diagram of the signal transduction pathways clarified by the first section of the present work It has been shown before that TNF- increases the expression of cell adhesion molecules E-selectin and ICAM-1 via activation of the transcription factor NF- B. We could show that ANP is able to inhibit the activation of NF- B via binding its guanylyl-cyclase-coupled NPR-A and -B receptor. We could further elucidate the molecular mechanism leading to the inhibition of NF- B activation by ANP. ANP was shown to transcriptionally activate the expression of I B isoforms. In consequence of the ANP mediated inhibition of NF- B DNA-binding activity we could demonstrate an attenuated surface expression of E-selectin and ICAM-1. E-selectin ICAM-1 NF- ÎșÎșB Îș B 5.1.2 Effect of ANP on TNF- αα α -induced cytoskeleton and perme- ability changes The following figure shows an outdraw of the summerized results of the second part of the present work. figure 2 summary: schematic diagram of the signal transduction pathways clarified by the second section of the present work TNF- has been shown to induce changes in cytoskeleton and macromolecule permeability of endothelial cells. We have shown here for the first time that ANP is able to abrogate both TNF- - induced effects via its guanylyl-cyclase-coupled NPR-A receptor. Moreover, ANP was shown to reduce TNF- -induced F-actin polymerization and stress fiber formation via the inhibition of p38 MAPK and its downstream target HSP27. Furthermore we could report here for the first time a decrease in TNF- -induced macromolecule permeability by ANP. The deactivation of p38 MAPK was demonstrated to be mediated via a significant transcriptional induction of the MKP-1 by ANP. intercellular gap5.1.3 Effect of ANP on TNF- α αα-induced MCP-1 expression The results of the third part of the present work are summerized in figure 3. figure 3 summary: schematic diagram of the signal transduction pathways clarified by the first and third section of the present work It is known that TNF- induces the release of MCP-1 during inflammatory processes via influencing the transcription factor NF- B and the p38 MAPK pathway. We could report here for the first time a decreased TNF- -induced MCP-1 expression by treatment of endothelial cells with ANP. The observed ANP effect was shown to be mediated via the particulate guanylyl-cyclase-coupled NPR. Furthermore we show that trancriptional induction of MKP-1 by ANP is essential for inhibition of TNF- - induced MCP-1 expression by ANP. In summary the data presented here provides evidence that ANP is able to preserve the structure and function of endothelial cells. These observations are of special importance because there is clear evidence that endothelial cell dysfunction is the cause for many acute and chronic vascular diseases (Biegelsen and Loscalzo 1999). The potency of an endogenous compound, i.e. ANP, to protect against such endothelial dysfunction points to an antiinflammatory and antiatherogenic potential of this cardiovascular hormone. This work has been supported by the DFG (Vo376/8-1). macromolecul

    The ICT Revolution and Preferences for Taxing Top Earners

    Get PDF
    How has the ICT-driven transformation of labour markets in recent decades affected redistributive preferences? We move beyond existing research by focusing on the ‘winners’ of the ICT revolution and on other-regarding preferences for taxing top earners. We carry out an interactive, online experiment with around 3,000 US respondents to test whether fairness perceptions and redistributive preferences differ when top incomes are gained through luck, routine work, or complex work. This set up aims to mirror the changing nature of tasks performed by high-earning workers in the US labour market as a result of the ICT revolution. We find that the desired tax rate on top earners is up to 5.3 percentage points lower for the complex work than the routine work treatment, and that high incomes from complex work are perceived as fairer and more deserved. A follow-up vignettes study then provides strong evidence that high earning jobs are perceived to be more complex. Taken together, our findings highlight an important and previously under-explored channel through which the ICT revolution may have dampened demand for progressive taxation in the advanced democracies

    Copper Inhibits NMDA Receptor-Independent LTP and Modulates the Paired-Pulse Ratio after LTP in Mouse Hippocampal Slices

    Get PDF
    Copper misregulation has been implicated in the pathological processes underlying deterioration of learning and memory in Alzheimer's disease and other neurodegenerative disorders. Supporting this, inhibition of long-term potentiation (LTP) by copper (II) has been well established, but the exact mechanism is poorly characterized. It is thought that an interaction between copper and postsynaptic NMDA receptors is a major part of the mechanism; however, in this study, we found that copper (II) inhibited NMDA receptor-independent LTP in the CA3 region of hippocampal slices. In addition, in the CA3 and CA1 regions, copper modulated the paired-pulse ratio (PPR) in an LTP-dependent manner. Combined, this suggests the involvement of a presynaptic mechanism in the modulation of synaptic plasticity by copper. Inhibition of the copper-dependent changes in the PPR with cyclothiazide suggested that this may involve an interaction with the presynaptic AMPA receptors that regulate neurotransmitter release

    Studien zur Regulation und Funktion der Phosphatase Cdc14 in S. cerevisiae

    Get PDF
    Die konservierte Phosphatase Cdc14, eine Vertreterin der Protein-Tyrosin-Phosphatasen-Superfamilie, spielt in der BĂ€ckerhefe Saccharomyces cerevisiae eine essentielle Rolle wĂ€hrend der Mitose und der Zytokinese. Die Phasen des Zellzyklus werden durch die oszillierende AktivitĂ€t der Zyklin-abhĂ€ngigen Kinase Cdk1 gesteuert. In der Mitose ist diese AktivitĂ€t im Vergleich zur Interphase hoch. FĂŒr den Austritt aus der Mitose muss die AktivitĂ€t der mitotischen Zyklin-Cdk-Komplexe herunterreguliert werden. Diese wird durch gezielte Dephosphorylierungen von Cdk1-Substraten in der Anaphase durch den Hauptantagonisten Cdc14 inhibiert. Die biologische AktivitĂ€t von Cdc14 wird durch ihre subzellulĂ€re Lokalisation kontrolliert: Bis zur Interphase wird Cdc14 im Nukleolus inaktiv gehalten. Diese Verankerung wird ĂŒber ihren Inhibitor Net1 vermittelt. Die Bindung an Net1 findet durch eine Proteinwechselwirkung mit der katalytischen DomĂ€ne von Cdc14 statt. In dieser Arbeit konnte anhand co-immunologischer Bindungsstudien, Wachstumstests und in vitro-Analysen gezeigt werden, dass zwischen Binde- und InhibitionsdomĂ€nen in N-terminalen Net1-Fragmenten differenziert werden kann. In der Anaphase wird Cdc14 aus dem Nukleolus in den Zellkern und das Zytoplasma freigesetzt, um dort Zielproteine fĂŒr den Austritt aus der Mitose zu dephosphorylieren. Diese Freisetzung von Net1 erfolgt ĂŒber die zwei regulatorischen Netzwerke FEAR und MEN. Cdc14 besteht aus einer N terminalen katalytischen DomĂ€ne und aus einer variablen DomĂ€ne im C-terminalen Anteil. Letztere enthĂ€lt eine Kernexportsequenz, eine kurze Tandem Repeat-Sequenz von bisher unbekannter Funktion, sowie eine Kernimportsequenz die durch MEN reguliert wird. Aufgrund der hohen Konservierung in höheren Eukaryoten wurde in der Literatur im Besonderen die N-terminale katalytische DomĂ€ne intensiv untersucht. ZusĂ€tzliche Regulationsmechanismen der Lokalisation von Cdc14 im Zellzyklus werden jedoch ĂŒber die variable DomĂ€ne erreicht. In dieser Arbeit kann gezeigt werden, dass die durch MEN kontrollierte Kernimportsequenz ĂŒberflĂŒssig fĂŒr die Lokalisation und die Funktion von Cdc14 ist. So wies ein N-terminales Derivat der Phosphatase in Abwesenheit der Kernimportsequenz ein vollkommen typisches Lokalisationsmuster auf. ErgĂ€nzend konnte in dieser Arbeit beschrieben werden, dass die variable DomĂ€ne zwar hinreichend ist, um den Kerntransport zu unterstĂŒtzen, jedoch weitere LokalisationsdomĂ€nen abseits der C terminalen DomĂ€ne vorliegen mĂŒssen. DarĂŒber hinaus konnte in dieser Arbeit erstmals gezeigt werden, dass Cdc14 ohne einen Teil der Tandem Repeat-Sequenz nicht mehr in der Lage ist, eine Deletion von CDC14 zu komplementieren, was auf eine essentielle Funktion dieses Motivs hinweist. Dieser Bereich in der C-terminalen DomĂ€ne konnte prĂ€zise eingegrenzt werden. In dieser Sequenz befinden sich ein Cdk1-Konsensusmotiv, sowie eine in anderen Hefen kurze konservierte Region. Zudem wurde festgestellt, dass diese Sequenz die Phosphatase-AktivitĂ€t in vitro unterstĂŒtzt. Dieser Bereich wurde durch Lokalisationsstudien anhand bekannter Substrate von Cdc14 nĂ€her analysiert, was eine verlĂ€ngerte Anaphasedauer und eine verminderte Phosphatasefunktion in vivo offenbarte. Die Identifizierung einer die Phosphatasefunktion unterstĂŒtzenden Sequenz in der variablen DomĂ€ne von Cdc14 könnte in Zukunft interessante Einblicke ĂŒber weitere regulatorische Mechanismen von Cdc14 in S. cerevisiae in der Mitose bieten

    Plasma from Volunteers Breathing Helium Reduces Hypoxia-Induced Cell Damage in Human Endothelial Cells-Mechanisms of Remote Protection Against Hypoxia by Helium.

    Get PDF
    PurposeRemote ischemic preconditioning protects peripheral organs against prolonged ischemia/reperfusion injury via circulating protective factors. Preconditioning with helium protected healthy volunteers against postischemic endothelial dysfunction. We investigated whether plasma from helium-treated volunteers can protect human umbilical vein endothelial cells (HUVECs) against hypoxia in vitro through release of circulating of factors.MethodsHealthy male volunteers inhaled heliox (79% helium, 21% oxygen) or air for 30 min. Plasma was collected at baseline, directly after inhalation, 6 h and 24 h after start of the experiment. HUVECs were incubated with either 5% or 10% of the plasma for 1 or 2 h and subjected to enzymatically induced hypoxia. Cell damage was measured by LDH content. Furthermore, caveolin 1 (Cav-1), hypoxia-inducible factor (HIF1α), extracellular signal-regulated kinase (ERK)1/2, signal transducer and activator of transcription (STAT3) and endothelial nitric oxide synthase (eNOS) were determined.ResultsPrehypoxic exposure to 10% plasma obtained 6 h after helium inhalation decreased hypoxia-induced cell damage in HUVEC. Cav-1 knockdown in HUVEC abolished this effect.ConclusionsPlasma of healthy volunteers breathing helium protects HUVEC against hypoxic cell damage, possibly involving circulating Cav-1

    A school-based educational on-site vaccination intervention for adolescents in an urban area in Germany: feasibility and psychometric properties of instruments in a pilot study

    Get PDF
    Background: Vaccination rates for measles, mumps, and rubella (MMR) and diphtheria, tetanus, pertussis, and polio (Tdap-IPV) are not optimal among German adolescents. Education in combination with easy access to vaccination may be a promising approach to improve vaccination rates. The present paper describes a pilot study of a planned cluster randomized controlled trial (cRCT) in which we aim to improve MMR and Tdap-IPV vaccination rates together with knowledge and self-efficacy in a school setting. Methods: The study covered 863 students from 41 classes of four schools. The optimization and feasibility of access to schools, recruitment strategies, intervention, and assessment procedures were examined. The course and content of the educational unit were evaluated with a mixed-methods approach. A pre-post measurement design was tested for the vaccination rate in all schools. Additionally, at two schools, improvement in vaccination-related knowledge and perceived self-efficacy were measured by questionnaire pre-educational unit (n=287) and post-educational unit (n=293). The remaining two schools provided only postintervention data. Finally, we evaluated the psychometric properties (i.e., reliability, retest reliability, and change rates) of the questionnaire, applying Cronbach's alpha, factor analyses, generalized estimating equations and linear mixed models. Results: The findings of the pilot study indicated good feasibility. Of the total sample, 437 students (50.9%) brought their vaccination cards to school, 68 students received Tdap-IPV vaccinations, and 11 received MMR vaccinations. Out of six knowledge questions, on average, the students had M=2.84 (95% CI [2.69, 3.10]) correct answers before and M=4.45 (95% CI [4.26, 4.64]) after the class. Ranging from 1 to 4, the self-efficacy scale changed by 0.3 points (p <.001); Cronbach's alpha was 0.67 and 0.76 pre- and post-educational unit, respectively, and a one-factor solution was found. Content analysis of the five semistructured group interviews (n=12, 58.3% female) showed that all students found the length of the intervention to be appropriate. The teaching methods, including interactive and social media components, were perceived as very good. Conclusions: A school-based educational and on-site vaccination intervention appears to be feasible in terms of procedures and the adequacy of the instruments for the adolescent target group

    O gĂȘnero reportagem em veĂ­culo de assessoria de comunicação para o pĂșblico rural

    Get PDF
    This work aims to study the generic and lexical structure of news reports in a newspaper produced by an agricultural co-operative society in the state of Santa Catarina. The research corpus is constituted by three newspaper issues. The theoretical basis for the analysis was taken from Bakhtin (1992), Bazerman (2005) and Bonini (2003). The results indicate that the newspaper privileges the genre news report, which can be divided into seven thematic categories. Among them is the category “Life story”, whose rhetorical and lexical movements demonstrate that its configuration is connected to the context in which it is produced, as well as to the function it performs in the communicative process.Este trabajo relata un estudio de la estructura genĂ©rica y del lĂ©xico de reportajes transmitidos en un periĂłdico de una cooperativa agropecuaria del estado de Santa Catarina. El corpus de la investigaciĂłn se ha construido desde tres ejemplares del periĂłdico. Para su anĂĄlisis se ha utilizado como referencial teĂłrico a Bakhtin (1992), Bazerman (2005) e Bonini (2003). Los resultados señalan que el periĂłdico concede privilegio al gĂ©nero reportaje, que se puede dividir en siete categorĂ­as temĂĄticas. Entre ellas se encuentra la categorĂ­a “Historia de vida”, cuyos movimientos retĂłricos y lĂ©xicos ponen en evidencia que su conformaciĂłn estĂĄ vinculada al contexto en el que se produce y a la funciĂłn por este cumplida en el proceso comunicativo.Ce travail fait le rapport d’une Ă©tude de la structure gĂ©nĂ©rique et du lexique de reportages vĂ©hiculĂ©s dans un journal produit par une coopĂ©ratve agropĂ©cuaire de l’État de Santa Catarina. Le corpus de la recherche fut constituĂ© par trois exemplaires de ce journal. Pour son analyse, on s’est servi de Bakhtine (1992), Bazerman (2005) et Bonini (2003) comme fondements thĂ©oriques. Les rĂ©sultats dĂ©montrent que le journal considĂšre comme privilĂ©giĂ© le genre reportage, qui peut ĂȘtre partagĂ© en sept catĂ©gories thĂ©matiques. Parmi celles-ci, il y a la catĂ©gorie “Histoire de vie”, dont les mouvements rhĂ©toriques et lexicaux dĂ©montrent que sa configuration est attachĂ©e au contexte parmi lequel elle est produite et Ă  la fonction qu’il exerce dans le procĂšs communicatif.Este trabalho relata um estudo da estrutura genĂ©rica e do lĂ©xico de reportagens veiculadas em um jornal produzido por uma cooperativa agropecuĂĄria do estado de Santa Catarina. O corpus da pesquisa foi constituĂ­do de 3 exemplares do jornal. Para sua anĂĄlise, foi utilizado como referencial teĂłrico Bakhtin (1992), Bazerman (2005) e Bonini (2003). Os resultados indicam que o jornal privilegia o gĂȘnero reportagem, que pode ser dividido em 7 categorias temĂĄticas. Entre elas estĂĄ a categoria “HistĂłria de vida”, cujos movimentos retĂłricos e lĂ©xico demonstram que sua configuração estĂĄ atrelada ao contexto em que Ă© produzida e Ă  função que ele cumpre no processo comunicativo
    • 

    corecore