Fibrosis in Atrial Fibrillation – Role of Reactive Species and MPO

Atrial fibrosis with enhanced turnover and deposition of matrix proteins leads to inhomogeneous atrial electrical conduction and gives rise to electrical reentry circuits resulting in atrial fibrillation. The multifactorial pathogenesis of atrial fibrosis involves resident cardiac cells as well as infiltrating leukocytes, both generating and sequestering matrix metalloproteinases (MMPs), a key enzyme family involved in fibrosis. A growing body of evidence points toward an important role of reactive oxygen species (ROS) in the release and activation of pro-MMPs and the stimulation of pro-fibrotic cascades. Myeloperoxidase (MPO), a bactericidal enzyme released from activated polymorphonuclear neutrophils (PMN) is not only associated with a variety of cardiovascular diseases, but has also been shown to be mechanistically linked to atrial fibrosis and fibrillation. MPO catalyzes the generation of reactive species like hypochlorous acid, which affect intracellular signaling cascades in various cells and advance activation of pro-MMPs and deposition of atrial collagen resulting in atrial arrhythmias. Thus, inflammatory mechanisms effectively promote atrial structural remodeling and importantly contribute to the initiation and perpetuation of atrial fibrillation

Measurements of light transfer through drift ice and landfast ice in the northern Baltic Sea

The aim of this study was to investigate the light transfer through sea ice with a focus on bio-optical substances both in fast ice and in the drift ice zones in the northern Baltic Sea. The measurements included snow and ice structure, spectral irradiance and photo-synthetically active radiation below the sea ice. We also measured the concentrations of the three main bio-optical substances which are chlorophyll-a, suspended particulate matter, and coloured dissolved organic matter (CDOM). These bio-optical substances were determined for melted ice samples and for the underlying sea water. The present study provides the first spectral light transfer data set for drift ice in the Baltic Sea. We found high CDOM absorption values typical to the Baltic Sea waters also within sea ice. Our results showed that the transmittance through bare ice was lower for the coastal fast ice than for the drift ice sites. Bio-optical substances, in particular CDOM, modified the spectral distribution of light penetrating through the ice cover. Differences in crystal structure and the amount of gas inclusions in the ice caused variation in the light transfer. Snow cover on ice was found to be the dominant factor influencing the light field under ice, confirming previous studies. In conclusion, snow cover dominated the amount of light under the ice, but did not modify its spectral composition. CDOM in the ice absorbs strongly in the short wavelengths. As pure water absorbs most in the long wavelengths, the light transfer through ice was highest in the green (549-585 nm). (C) 2020 Institute of Oceanology of Polish Academy of Sciences. Published by Elsevier B.V.Peer reviewe

Editorial: Media Education as a Key Discipline in a Mediatised World: Perspectives from Theory, Empirics and Practice

Medienpädagogik als Schlüsseldisziplin?! Aufgrund der Digitalisierung unterliegen Lebenswelten inzwischen einer immer grösseren Dynamik. Bildungs- und Teilhabechancen in Schule und Ausbildung, Studium und Erwerbstätigkeit sowie auch im Freizeitalltag sind unter solchen Bedingungen des ständigen Wandels eng an die Fähigkeit geknüpft, medial vermittelte Informationen zu verstehen, gezielt auszuwählen, zu nutzen und – wiederum unter Einsatz geeigneter Medien – zu kommunizieren und weiterzuverarbeiten. Die Medienpädagogik als Reflexions- und Handlungswissenschaft ist zum einen gefordert, Mediatisierungsprozesse hinsichtlich bedingender Faktoren, aktueller Auswirkungen und sich abzeichnender künftiger Entwicklungen auf individueller wie gesellschaftlicher Ebene einzuschätzen und unter pädagogischen Gesichtspunkten zu diskutieren (Reflexionsaspekt). Zum anderen gilt es, pädagogisch relevante Strukturen und Prozesse im Zusammenhang mit Medien aktiv mitzugestalten (Handlungsaspekt) (vgl. Pietraß 2018, 12; DGfE Sektion Medienpädagogik Deutsche Gesellschaft für Erziehungswissenschaft 2017, 2). Der Medienpädagogik, so die leitende These des Bandes, kommt innerhalb einer zunehmend digitalisierten und mediatisierten Welt insofern die Rolle einer Schlüsseldisziplin zu. Anlass zur Publikation des Buches Das Sammelwerk entstand anlässlich des 60. Geburtstages von Prof. Dr. Dorothee M. Meister, die an der Universität Paderborn den Arbeitsbereich Medienpädagogik und empirische Medienforschung leitet. Ein zentrales Anliegen ihrer wissenschaftlichen Arbeit besteht darin, die Medienpädagogik sowohl durch Theorieentwicklung und empirische Forschung als auch durch die Weiterentwicklung medienpädagogischer Praxis voranzubringen. Zu diesem Zweck vereint sie in ihren Projekten und Publikationen bildungswissenschaftliche und speziell medienpädagogische Perspektiven mit jenen der Bildungspraxis und Bildungspolitik. Dorothee M. Meisters Engagement spiegelt sich in ihren umfangreichen Aktivitäten in Forschung und Lehre an all ihren Wirkungsstätten – Bielefeld, Halle a. d. Saale, Tübingen und Paderborn – wider. Stets griff und greift sie dabei höchstaktuelle Diskussionsfelder auf, um vor diesem Hintergrund neue medienpädagogisch relevante Fragestellungen zu entwickeln und zu bearbeiten. An dieser Stelle sei nur auf jüngste Beispiele, wie etwa die bildungspolitische Debatte um Geflüchtete (Meister 2017) und zuletzt die Diskussion um Distance Education im Zuge der Corona-Pandemie (Gerhardts u. a. 2020 in Begutachtung), verwiesen. Des Weiteren liegt Dorothee M. Meister die Professionalisierung der Medienpädagogik am Herzen: So macht sie immer wieder auf den besonderen Stellenwert medienpädagogischer Expertise aufmerksam und plädiert dafür, Medienpädagogik systematisch in Studiengängen sowie in der Aus- und Weiterbildung von pädagogischem Fachpersonal zu verankern (Meister 2018; Knaus, Meister, und Tulodziecki 2018; Kamin und Meister 2019). Ihre wissenschaftliche Arbeit wird zudem von umfangreichen berufspolitischen Tätigkeiten flankiert: etwa ihrem Wirken im Vorstand sowie als Vorsitzende der Gesellschaft für Medienpädagogik und Kommunikationskultur (GMK) e.V., ihrer Mitgliedschaft im Deutschen Kulturrat, ihrer Mitarbeit in der Initiative «Keine Bildung ohne Medien» sowie von ihrer Vorstandsarbeit innerhalb der Sektion Medienpädagogik der DGfE. Wichtige und nachhaltige Impulse für die Digitalisierung von Studium und Lehre entstanden durch ihr Wirken als Vizepräsidentin der Universität Paderborn sowie durch die Mitarbeit im Hochschulforum Digitalisierung. Die Beiträge dieses Buches spiegeln Dorothee M. Meisters Forschungs- und weitere Arbeitsschwerpunkte in ihrer Breite inhaltlich und methodisch wider. Die Herausgeberinnen sind Dorothee M. Meister seit langer Zeit und in ganz besonderer Weise verbunden: sei es durch ihre Betreuung im Rahmen von Dissertationsvorhaben, durch das Verfassen gemeinsamer Publikationen oder die Zusammenarbeit in Forschungsprojekten. Ihre Begleitung, Förderung, Unterstützung und Wertschätzung zeigt sie in diesen Kontexten in vielfältiger Weise. Dafür gilt Dorothee M. Meister an dieser Stelle unser herzlicher Dank

The Use of Placebo and Non-Specific Therapies and Their Relation to Basic Professional Attitudes and the Use of Complementary Therapies among German Physicians - A Cross-Sectional Survey

We aimed to investigate the use of placebos ( e. g. saline injections) and non-specific treatments ( e. g. vitamin supplements in individuals without a relevant deficiency) among physicians working in private practices in Germany, and how such use is associated with the belief in and the use of complementary and alternative treatments, and basic professional attitudes. A four-page questionnaire was sent to nationwide random samples of general practitioners ( GP),internists and orthopaedists working in private practices. The response rate was 46% ( 935 of 2018). 24% of GPs, 44% of internists and 57% of orthopaedists had neither used pure placebos nor non-specific therapies in the previous 12 months. 11% percent of GPs, 12% of internists and 7% of orthopaedists had exclusively used pure placebos;30%,33% and 26%,respectively, had exclusively used non-specific therapies;35%,12% and 9% had used both. Age, sex and agreement to the statement that physicians should harness placebo effects were not significantly associated with any pattern of use. Exclusive use of pure placebos was associated with being a GP, being an internist, and having unorthodox professional views. In addition to these three factors, a lower use of CAM therapies and a wish for having more time was associated with the exclusive use of nonspecific therapies. Among physicians using both pure placebo and non-specific therapies, heterodox views were also somewhat more pronounced. However, associations were particularly strong for being a GP ( Odds ratio 11.6 ( 95%CI 6.41;21.3)) and having orthodox views ( Odds ratio 0.10 ( 95%CI 0.06;0.18)) among this group. In conclusion, the use of placebos and non-specific treatments varies strongly between medical specialties and is associated with basic professional attitudes. The findings support the view that the use of placebos and, in particular, of non-specific therapies is primarily a coping behaviour for difficult and uncertain situations

Use of Placebos and Nonspecific and Complementary Treatments by German Physicians - Rationale and Development of a Questionnaire for a Nationwide Survey

Background: We are performing a nationwide survey in a random sample ofGerman general practitioners (GPs), orthopedists, and internists on theuse of placebos and nonspecific as well as complementary treatments andtheir association with basic professional attitudes. In this article weexplain the theoretical considerations behind the study approach and thedevelopment of the questionnaire. Methods: Based on a systematic reviewof published surveys, own surveys on the topic, and on theoreticalconsiderations we developed a preliminary version of a 4-pagequestionnaire that was tested for feasibility in a convenience sample of80 participants of a general medical education event. We also performedcognitive interviews with 8 physicians to investigate whether thequestions were understood adequately. Results: The questions on typicalplacebos and complementary treatments were well understood and easy toanswer for participants. Discussions about the phrasing of questions onnonspecific treatments during interview reflected the vagueness of thisconcept; but this did not seem to create major problems when answeringthe related questions. The original questions regarding basicprofessional attitudes partly were not understood in the mannerintended. The relevant questions were modified but the interviewssuggest that these issues are difficult to grasp in a quantitativesurvey. Conclusion: Our testing procedures suggest that ourquestionnaire is well-suited to investigate our questions with somelimitations regarding the issue of basic professional attitudes

Proteomics of the epicardial fat secretome and its role in post-operative atrial fibrillation.

Aims: Post-operative atrial fibrillation (POAF) is a predictor of morbidity and mortality after cardiac surgery. Latent predisposing factors may reside in the epicardial adipose tissue (EAT) due to its anatomical position and high protein production rate. In order to explore a possible mechanistic link, we characterized proteins secreted by the EAT preceding the onset of POAF. Methods and results: Epicardial adipose tissue samples were collected from 76 consecutive patients with no history of AF undergoing coronary artery bypass surgery, 50 samples for proteomic analysis and 26 for gene expression studies, further divided according to development of POAF. Ten vs. 10 matched samples representing EAT secretome were analysed by two-dimensional difference in-gel electrophoresis (2D-DIGE) and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to identify differentially expressed proteins (P 1.2 fold). Findings were validated by Western blotting on EAT protein extracts and by gene expression studies via quantitative polymerase chain reaction (qPCR). Proteomics returned 35 differentially expressed proteins. Amongst those, gelsolin was down regulated in POAF. Western blot analysis confirmed a significant reduction in gelsolin in the AF group. Gene expression for gelsolin was significantly reduced in the AF group confirming the proteomics findings. Conclusion: For the first time we describe EAT secretome as a possible substrate for POAF. It contains various proteins differentially expressed in patients who later develop POAF. Amongst those gelsolin, involved in inflammation and ion channel regulation, was associated with maintenance of sinus rhythm. Understanding the role of EAT may offer novel insights into prevention and treatment of AF