Die Evaluation von Seneszenzmarkern in der Kultur von dentalen Follikelvorläuferzellen

Für die moderne Zahnmedizin stellen adulte dentale Stammzellen wie dentale Follikelvorläuferzellen (DFVs) vielversprechende zukünftige Behandlungs-alternativen dar, beispielsweise für die Regeneration parodontalen Gewebes. Dafür werden große Mengen von Zellen benötigt, weshalb sie in vitro kultiviert werden müssen. Seneszenz ist dabei ein limitierender Faktor, da sie zu begrenzter Lebenserwartung, Einschränkung der Differenzierungsfähigkeit und verringertem Proliferationspotential führt. Bei DFVs sind Seneszenzmarker bisher noch nicht genau untersucht. Ziel der Arbeit war die Analyse von Seneszenzmarkern, um zu prüfen ob DFVs in hohen Passagen seneszent werden. Dazu wurden Zellmorphologie, Histologie, Telomerlänge, die Expression von Telomerase-assoziiertem TEP1 und osteogene Differenzierung untersucht. Die vorliegende Arbeit liefert neue Erkenntnisse zur Seneszenz von langzeit-kultivierten (bis Passage 18) dentalen Follikelvorläuferzellen. P14 scheint eine kritische Phase bei der Ausbildung seneszenter Tendenzen zu sein. So besitzen DFVs eine veränderte Zellmorphologie, exprimieren seneszenz-assoziierte β-Galaktosidase und zeigen vermindertes osteogenes Differenzierungspotential, sowie reduzierte Expression von TEP1. Telomerverkürzungen sind jedoch tendenziell. Weiterhin lässt sich nach Stammzellmarker-Analyse die Hypothese aufstellen, dass CD146 eine Rolle bei der Entstehung von seneszenten DFVs spielt. DFVs zeigen bis P18 keine stark ausgeprägte, zellzyklushemmende Seneszenz. Der Fokus zukünftiger Studien sollte daher auf Passagen größer 18 liegen. Ebenso sind weiterführende Studien nötig, welche die Bedeutung von CD146 für die Entstehung von Seneszenz untersuchen

Investigation of the fabrication suitability, structural performance, and sustainability of natural fibers in coreless filament winding

Coreless filament winding is an emerging fabrication technology in the field of building construction with the potential to significantly decrease construction material consumption, while being fully automatable. Therefore, this technology could offer a solution to the increasing worldwide demand for building floor space in the next decades by optimizing and reducing the material usage. Current research focuses mainly on the design and engineering aspects while using carbon and glass fibers with epoxy resin; however, in order to move towards more sustainable structures, other fiber and resin material systems should also be assessed. This study integrates a selection of potential alternative fibers into the coreless filament winding process by adapting the fabrication equipment and process. A bio-based epoxy resin was introduced and compared to a conventional petroleum-based one. Generic coreless wound components were created for evaluating the fabrication suitability of selected alternative fibers. Four-point bending tests were performed for assessing the structural performance in relation to the sustainability of twelve alternative fibers and two resins. In this study, embodied energy and global warming potential from the literature were used as life-cycle assessment indexes to compare the material systems. Among the investigated fibers, flax showed the highest potential while bio-based resins are advisable at low fiber volume ratios.Deutsche Forschungsgemeinschaft (DFG, German Research Foundation

Evaluation of patients with respiratory infections during the first pandemic wave in Germany: characteristics of COVID-19 versus non-COVID-19 patients

BACKGROUND Characteristics of COVID-19 patients have mainly been reported within confirmed COVID-19 cohorts. By analyzing patients with respiratory infections in the emergency department during the first pandemic wave, we aim to assess differences in the characteristics of COVID-19 vs. Non-COVID-19 patients. This is particularly important regarding the second COVID-19 wave and the approaching influenza season. METHODS We prospectively included 219 patients with suspected COVID-19 who received radiological imaging and RT-PCR for SARS-CoV-2. Demographic, clinical and laboratory parameters as well as RT-PCR results were used for subgroup analysis. Imaging data were reassessed using the following scoring system: 0 - not typical, 1 - possible, 2 - highly suspicious for COVID-19. RESULTS COVID-19 was diagnosed in 72 (32,9%) patients. In three of them (4,2%) the initial RT-PCR was negative while initial CT scan revealed pneumonic findings. 111 (50,7%) patients, 61 of them (55,0%) COVID-19 positive, had evidence of pneumonia. Patients with COVID-19 pneumonia showed higher body temperature (37,7~± 0,1 vs. 37,1~± 0,1 °C; p = 0.0001) and LDH values (386,3~± 27,1 vs. 310,4~± 17,5 U/l; p = 0.012) as well as lower leukocytes (7,6~± 0,5 vs. 10,1~± 0,6G/l; p = 0.0003) than patients with other pneumonia. Among abnormal CT findings in COVID-19 patients, 57 (93,4%) were evaluated as highly suspicious or possible for COVID-19. In patients with negative RT-PCR and pneumonia, another third was evaluated as highly suspicious or possible for COVID-19 (14 out of 50; 28,0%). The sensitivity in the detection of patients requiring isolation was higher with initial chest CT than with initial RT-PCR (90,4% vs. 79,5%). CONCLUSIONS COVID-19 patients show typical clinical, laboratory and imaging parameters which enable a sensitive detection of patients who demand isolation measures due to COVID-19

The induction of cellular senescence in dental follicle cells inhibits the osteogenic differentiation

Dental stem cells such as human dental follicle cells (DFCs) have opened new promising treatment alternatives for today's dental health issues such as periodontal tissue regeneration. However, cellular senescence represents a restricting factor to cultured stem cells, resulting in limited lifespan and reduced cell differentiation potential. Therefore, this study evaluated if and how DFCs exhibit features of cellular senescence after being expanded in cell culture. The cell proliferation of DFCs decreased, while the cell size increased during prolonged cell culture. Moreover, DFCs expressed the senescence-associated beta-galactosidase after a prolonged cell culture. The onset of senescence inhibited both the induction of osteoblast markers RUNX2 and osteopontin and the biomineralization of DFCs after stimulation of the osteogenic differentiation. In conclusion, we showed that a prolonged cell culture induces cellular senescence and inhibits the osteogenic differentiation in DFCs

Ganztagsschule und Integration von Migranten : Abschlussbericht

Das Projekt hat die Aufgabe zu klären, ob Heranwachsende mit Migrationshintergrund durch den Besuch einer Ganztagsschule im Vergleich zu Migrantenkindern an Halbtagsschulen hinsichtlich ihres Integrationsprozesses besonders unterstützt werden. Diese Leitfrage gliedert sich in spezifische Fragestellungen, die im Rahmen des Projekts empirisch zu beantworten sind. Als Vergleichsmaßstab für die Effekte des Ganztagsschulbesuchs wird der Besuch von Halbtagsschulen herangezogen. Primar-­ und Sekundarstufe werden berücksichtigt, um altersabhängige Möglichkeiten und Bedingungen der Integrationsförderung durch den Ganztagsschulbesuch untersuchen zu können. Das übergeordnete Ziel der Untersuchung ist die Identifikation von Bedingungen, unter denen Ganztagsschulen im Primar- und Sekundarbereich den Integrationsprozess von Kindern und Jugendlichen mit Migrationshintergrund in besonderem Maße fördern können. Das Projekt wurde im Zeitraum vom 01.07.2008 bis 30.06.2010 realisiert

Systematic use of cardiac magnetic resonance imaging in MINOCA led to a five-fold increase in the detection rate of myocarditis: a retrospective study

BACKGROUND Systematic work-up of patients with myocardial infarction and non-obstructive coronary artery disease (MINOCA) using cardiac magnetic resonance imaging (CMR) led to a more than six-fold increase in the detection rate of myocarditis. In this study, we expanded on our prior two-year analysis by including preceding and subsequent years. METHODS We performed a retrospective chart review of patients with angina-like symptoms and elevated high-sensitivity troponin T (TnT-hs ≥14 ng/l) but without significant coronary artery disease, from 2011 to 2017. Patients underwent CMR to test for myocarditis. From 2011 to 2015, only patients with elevated TnT-hs, no significant coronary artery disease and moderate to high clinical likelihood of suffering from myocarditis, underwent CMR. In 2016 and 2017, CMR images were obtained from all patients with MINOCA, independent of the clinical likelihood that patients were suffering from myocarditis. RESULTS A total of 556 patients who underwent CMR (70.5% male, 57 ± 17 years, with an average left ventricular ejection fraction of 51 ± 15%) qualified for inclusion in this study’s analysis. From 2011 to 2015, 240 CMR examinations were performed, with the number increasing to 316 between 2016 and 2017. In total, myocarditis was diagnosed in 76 out of the 556 patients (13.7%). Between 2011 and 2015, the detection rate of myocarditis was 12.7 per 100,000 hospitalisations and increased 4.9-fold (p <0.0001), to 62.5 per 100,000 hospitalisations, between 2016 and 2017. CONCLUSION A novel diagnostic algorithm led to an average 4.9-fold increase in the rate of myocarditis detection in our hospital over the two subsequent years. This highlights that myocarditis continues to be underdiagnosed when CMR is not systematically used in patients with MINOCA. &nbsp

Investigation of the Fabrication Suitability, Structural Performance, and Sustainability of Natural Fibers in Coreless Filament Winding

Coreless filament winding is an emerging fabrication technology in the field of building construction with the potential to significantly decrease construction material consumption, while being fully automatable. Therefore, this technology could offer a solution to the increasing worldwide demand for building floor space in the next decades by optimizing and reducing the material usage. Current research focuses mainly on the design and engineering aspects while using carbon and glass fibers with epoxy resin; however, in order to move towards more sustainable structures, other fiber and resin material systems should also be assessed. This study integrates a selection of potential alternative fibers into the coreless filament winding process by adapting the fabrication equipment and process. A bio-based epoxy resin was introduced and compared to a conventional petroleum-based one. Generic coreless wound components were created for evaluating the fabrication suitability of selected alternative fibers. Four-point bending tests were performed for assessing the structural performance in relation to the sustainability of twelve alternative fibers and two resins. In this study, embodied energy and global warming potential from the literature were used as life-cycle assessment indexes to compare the material systems. Among the investigated fibers, flax showed the highest potential while bio-based resins are advisable at low fiber volume ratios

Material Monitoring of a Composite Dome Pavilion Made by Robotic Coreless Filament Winding

A hemispherical research demonstration pavilion was presented to the public from April to October 2019. It was the first large-scale lightweight dome with a supporting roof structure primarily made of carbon- and glass-fiber-reinforced composites, fabricated by robotic coreless filament winding. We conducted monitoring to ascertain the sturdiness of the fiber composite material of the supporting structure over the course of 130 days. This paper presents the methods and results of on-site monitoring as well as laboratory inspections. The thermal behavior of the pavilion was characterized, the color change of the matrix was quantified, and the inner composition of the coreless wound structures was investigated. This validated the structural design and revealed that the surface temperatures of the carbon fibers do not exceed the guideline values of flat, black façades and that UV absorbers need to be improved for such applications