@phdthesis{Schmithausen2019, author = {Schmithausen, Patrick Alexander Gerhard}, title = {Three-dimensional fluorescence image analysis of megakaryocytes and vascular structures in intact bone}, doi = {10.25972/OPUS-17854}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-178541}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {The thesis provides insights in reconstruction and analysis pipelines for processing of three-dimensional cell and vessel images of megakaryopoiesis in intact murine bone. The images were captured in a Light Sheet Fluorescence Microscope. The work presented here is part of Collaborative Research Centre (CRC) 688 (project B07) of the University of W{\"u}rzburg, performed at the Rudolf-Virchow Center. Despite ongoing research within the field of megakaryopoiesis, its spatio-temporal pattern of megakaryopoiesis is largely unknown. Deeper insight to this field is highly desirable to promote development of new therapeutic strategies for conditions related to thrombocytopathy as well as thrombocytopenia. The current concept of megakaryopoiesis is largely based on data from cryosectioning or in vitro studies indicating the existence of spatial niches within the bone marrow where specific stages of megakaryopoiesis take place. Since classic imaging of bone sections is typically limited to selective two-dimensional views and prone to cutting artefacts, imaging of intact murine bone is highly desired. However, this has its own challenges to meet, particularly in image reconstruction. Here, I worked on processing pipelines to account for irregular specimen staining or attenuation as well as the extreme heterogeneity of megakaryocyte morphology. Specific challenges for imaging and image reconstruction are tackled and solution strategies as well as remaining limitations are presented and discussed. Fortunately, modern image processing and segmentation strongly benefits from continuous advances in hardware as well as software-development. This thesis exemplifies how a combined effort in biomedicine, computer vision, data processing and image technology leads to deeper understanding of megakaryopoiesis. Tailored imaging pipelines significantly helped elucidating that the large megakaryocytes are broadly distributed throughout the bone marrow facing a surprisingly dense vessel network. No evidence was found for spatial niches in the bone marrow, eventually resulting in a revised model of megakaryopoiesis.}, subject = {Megakaryozytopoese}, language = {en} } @article{WeibelBasseLuesebrinkHessetal.2013, author = {Weibel, Stephanie and Basse-Luesebrink, Thomas Christian and Hess, Michael and Hofmann, Elisabeth and Seubert, Carolin and Langbein-Laugwitz, Johanna and Gentschev, Ivaylo and Sturm, Volker J{\"o}rg Friedrich and Ye, Yuxiang and Kampf, Thomas and Jakob, Peter Michael and Szalay, Aladar A.}, title = {Imaging of Intratumoral Inflammation during Oncolytic Virotherapy of Tumors by \(^{19}\)F-Magnetic Resonance Imaging (MRI)}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0056317}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130311}, pages = {e56317}, year = {2013}, abstract = {Background Oncolytic virotherapy of tumors is an up-coming, promising therapeutic modality of cancer therapy. Unfortunately, non-invasive techniques to evaluate the inflammatory host response to treatment are rare. Here, we evaluate \(^{19}\)F magnetic resonance imaging (MRI) which enables the non-invasive visualization of inflammatory processes in pathological conditions by the use of perfluorocarbon nanoemulsions (PFC) for monitoring of oncolytic virotherapy. Methodology/Principal Findings The Vaccinia virus strain GLV-1h68 was used as an oncolytic agent for the treatment of different tumor models. Systemic application of PFC emulsions followed by \(^1H\)/\(^{19}\)F MRI of mock-infected and GLV-1h68-infected tumor-bearing mice revealed a significant accumulation of the \(^{19}\)F signal in the tumor rim of virus-treated mice. Histological examination of tumors confirmed a similar spatial distribution of the \(^{19}\)F signal hot spots and \(CD68^+\)-macrophages. Thereby, the \(CD68^+\)-macrophages encapsulate the GFP-positive viral infection foci. In multiple tumor models, we specifically visualized early inflammatory cell recruitment in Vaccinia virus colonized tumors. Furthermore, we documented that the \(^{19}\)F signal correlated with the extent of viral spreading within tumors. Conclusions/Significance These results suggest \(^{19}\)F MRI as a non-invasive methodology to document the tumor-associated host immune response as well as the extent of intratumoral viral replication. Thus, \(^{19}\)F MRI represents a new platform to non-invasively investigate the role of the host immune response for therapeutic outcome of oncolytic virotherapy and individual patient response.}, language = {en} } @phdthesis{Blachutzik2012, author = {Blachutzik, J{\"o}rg O.}, title = {Visualisierung von Plasmamembran-Dom{\"a}nen in Arabidopsis thaliana}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-71925}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2012}, abstract = {Unter Verwendung fluoreszenzmarkierter Remorine der taxonomischen Gruppe 1b wurden Nanodom{\"a}nen in Arabidopsis Plasmamembranen (PM) unter Verwendung hoch aufl{\"o}sender Laser Scanning-Systeme sichtbar gemacht. In diesen kompartimentierten Membranbereichen lagerten sich Sterol-abh{\"a}ngige Remorine aus verschiedenen Pflanzen-familien zusammen und zeigten dort Kolokalisation. Dies wurde statistisch belegt durch hohe Pearson und Spearman Korrelationskoeffizienten. Remorine konnten schließlich als pflanzliche Markerproteine f{\"u}r kompartimentierte Membranbereiche etabliert werden. Die Nanodom{\"a}nen zeigten zu keinem Zeitpunkt laterale Bewegungen in der PM und scheinen sowohl von zytoskelett{\"a}ren Strukturen als auch von Komponenten der Zellwand stabilisiert zu werden. M{\"o}glicherweise spielen transmembrane Tetraspanine sowie GPI-verankerte SKU5-Proteine eine Rolle bei der stabilen Verankerung. F{\"u}r zwei native Arabidopsis Remorine wurden posttranslationale Modifikationsstellen aufgedeckt, die der Anheftung dieser hydrophilen Proteine an die PM dienen. Weiterhin scheinen gleichartige Remorine miteinander zu interagieren. Beispielsweise waren im Zytosol lokalisierte Remorin-Mutanten bei einer gleichzeitigen Expression der entsprechenden Voll{\"a}ngenproteine erneut an der PM zu finden. F{\"u}r die Remorine wurde postuliert, dass sie mit anderen Proteinen interagieren und dabei makromolekulare Strukturen ausbilden. Den Remorinen k{\"o}nnte daher eine Aufgabe bei der molekularen Organisation pflanzlicher Membrandom{\"a}nen zukommen, indem sie ein filamentartiges Netzwerk innerhalb distinkter Dom{\"a}nen ausbilden, das m{\"o}glicherweise zur Stabilit{\"a}t und Aufrechterhaltung dieser spezialisierten Bereiche beitr{\"a}gt. Unter Einbeziehung der STED-Mikroskopie wurde eine empirische Gr{\"o}ßenverteilung von 97±4nm Durchmesser f{\"u}r PM-st{\"a}ndige Dom{\"a}nen in Arabidopsis ermittelt. Hinsichtlich der physiologischen Relevanz konnte gezeigt werden, dass die Dom{\"a}nen eine Rolle bei der ABA-vermittelten, kalziumabh{\"a}ngigen Regulation des Anionenkanals SLAH3 einnehmen. SLAH3 wird durch kalziumabh{\"a}ngige Kinasen aus der CDPK-Familie aktiviert, im Speziellen durch CPK21 und CPK23. Beide Kinasen werden durch die ABA-sensitiven Phosphatasen ABI1 und ABI2 reguliert. Die spezifisch stattfindenden Interaktionen zwischen SLAH3 und CPK21, sowie zwischen CPK21 und ABI1 waren auf Nanodom{\"a}nen beschr{\"a}nkt und wurden durch die Methodik der bimolekularen Fluoreszenzkomplementation erstmals in planta nachgewiesen, mit Remorinen der taxonomischen Gruppe 1b als etablierte Markerproteine f{\"u}r Membrandom{\"a}nen.}, subject = {Plasmamembran}, language = {de} }