TY - THES A1 - Gnamlin, Prisca T1 - Use of Tumor Vasculature for Successful Treatment of Carcinomas by Oncolytic Vaccinia Virus T1 - Die Tumorvasulatur in der erfolgreichen Therapie von Carcinomen durch onkolytische Vaccinia Viren N2 - Tumor-induced angiogenesis is of major interest for oncology research. Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor characterized so far. VEGF blockade was shown to be sufficient for angiogenesis inhibition and subsequent tumor regression in several preclinical tumor models. Bevacizumab was the first treatment targeting specifically tumor-induced angiogenesis through VEGF blockade to be approved by the Food and Drugs Administration (FDA) for cancer treatment. However, after very promising results in preclinical evaluations, VEGF blockade did not show the expected success in patients. Some tumors became resistant to VEGF blockade. Several factors have been accounted responsible, the over-expression of other angiogenic factors, the noxious influence of VEFG blockade on normal tissues, the selection of hypoxia resistant neoplastic cells, the recruitment of hematopoietic progenitor cells and finally the transient nature of angiogenesis inhibition by VEGF blockade. The development of blocking agents against other angiogenic factors like placental growth factor (PlGF) and Angiopoietin-2 (Ang-2) allows the development of an anti-angiogenesis strategy adapted to the profile of the tumor. Oncolytic virotherapy uses the natural propensity of viruses to colonize tumors to treat cancer. The recombinant vaccinia virus GLV-1h68 was shown to infect, colonize and lyse several tumor types. Its descendant GLV-1h108, expressing an anti-VEGF antibody, was proved in previous studies to inhibit efficiently tumor induced angiogenesis. Additional VACVs expressing single chain antibodies (scAb) antibodies against PlGF and Ang-2 alone or in combination with anti VEGF scAb were designed. In this study, VACV-mediated anti-angiogenesis treatments have been evaluated in several preclinical tumor models. The efficiency of PlGF blockade, alone or in combination with VEGF, mediated by VACV has been established and confirmed. PlGF inhibition alone or with VEGF reduced tumor burden 5- and 2-folds more efficiently than the control virus, respectively. Ang-2 blockade efficiency for cancer treatment gave controversial results when tested in different laboratories. Here we demonstrated that unlike VEGF, the success of Ang-2 blockade is not only correlated to the strength of the blockade. A particular balance between Ang-2, VEGF and Ang-1 needs to be induced by the treatment to see a regression of the tumor and an improved survival. We saw that Ang-2 inhibition delayed tumor growth up to 3-folds compared to the control virus. These same viruses induced statistically significant tumor growth delays. This study unveiled the need to establish an angiogenic profile of the tumor to be treated as well as the necessity to better understand the synergic effects of VEGF and Ang-2. In addition angiogenesis inhibition by VACV-mediated PlGF and Ang-2 blockade was able to reduce the number of metastases and migrating tumor cells (even more efficiently than VEGF blockade). VACV colonization of tumor cells, in vitro, was limited by VEGF, when the use of the anti-VEGF VACV GLV-1h108 drastically improved the colonization efficiency up to 2-fold, 72 hours post-infection. These in vitro data were confirmed by in vivo analysis of tumors. Fourteen days post-treatment, the anti-VEGF virus GLV-1h108 was colonizing 78.8% of the tumors when GLV-1h68 colonization rate was 49.6%. These data confirmed the synergistic effect of VEGF blockade and VACV replication for tumor regression. Three of the tumor cell lines used to assess VACV-mediated angiogenesis inhibition were found, in certain conditions, to mimic either endothelial cell or pericyte functions, and participate directly to the vascular structure. The expression by these tumor cells of e-selectin, p-selectin, ICAM-1 and VCAM-1, normally expressed on activated endothelial cells, corroborates our findings. These proteins play an important role in immune cell recruitment, and there amount vary in presence of VEGF, PlGF and Ang-2, confirming the involvement of angiogenic factors in the immuno-modulatory abilities of tumors. In this study VACV-mediated angiogenesis blockade proved its potential as a therapeutic agent able to treat different tumor types and prevent resistance observed during bevacizumab treatment by acting on different factors. First, the expression of several antibodies by VACV would prevent another angiogenic factor to take over VEGF and stimulate angiogenesis. Then, the ability of VACV to infect tumor cells would prevent them to form blood vessel-like structures to sustain tumor growth, and the localized delivery of the antibody would decrease the risk of adverse effects. Next, the blockade of angiogenic factors would improve VACV replication and decrease the immune-modulatory effect of tumors. Finally the fact that angiogenesis blockade lasts until total regression of the tumor would prevent the recovery of the tumor-associated vasculature and the relapse of patients. N2 - Ein Hauptinteresse der onkologischen Forschung liegt auf dem Verständnis der Tumor-induzierten Angiogenese. Es wurde bereits festgestellt, dass die meisten Tumortypen eine abnorme Expression angiogener Faktoren zeigen. Der vascular endothelial growth factor (VEGF) wurde als der effektivste angiogene Faktor beschrieben. Es wurde gezeigt, dass die Hemmung des VEGF zur Inhibition der Angiogenese führt, das wiederum zu Tumorregression in vorklinischen Tumormodellen führte. Bevacizumab ist das erste FDA zugelassene Krebs-Therapeutikum, welches spezifisch auf die Tumor-induzierte Angiogenese durch VEGF-Inhibition abzielt. Der erwartete Erfolg durch VEGF-Hemmung konnte im Patienten allerdings nicht erzielt werden. Die Entwicklung von neuen Angiogenese hemmenden Stoffen wie gegen den placental growth factor (PIGF) oder Angiopoietin-2 (Ang-2), ermöglichen eine an das Tumor-Profil angepasste anti-angiogene Strategie. Die onkolytische Virustherapie die natürliche Eigenschaft der Viren Tumore zu kolonisieren. Das Vaccinia-Virus (VACV) gehört zur Familie der Poxviridae und wurde bereits lange Zeit als Vakzin zur Immunisierung gegen Pocken eingesetzt. Es konnte gezeigt werden, dass das rekombinante VACV GLV-1h68 effizient verschiedene Tumortypen infiziert, kolonisiert und lysiert. Das VACV GLV-1h108, welches auf der Basis des GLV-1h68 generiert wurde, kodiert einen anti-VEGF Antikörper. Dieses Virus ist in der Lage ist die Tumor-induzierte Angiogenese effizient zu inhibieren. Zusätzlich zu diesem VACV wurden weitere Konstrukte kloniert, welche für Antikörper gegen PIGF und Ang-2 kodieren. Zusätzlich wurden Virusstämme konstruiert, die gleichzeitig zwei Angiogenesefaktoren anzielen. Es wurde verschiedene VACV-vermittelte anti-Angiogenese Therapien in vorklinischen Tumormodellen wie Lungenadenokarzinome, KolonKarzinom, Melanom und Lungenadenokarzinome evaluiert. Die Effizienz der VACV-vermittelten Hemmung von PIGF und Ang-2, singulär oder in Kombination mit VEGF, wurde mit Tumor-Xenotransplantaten ermittelt. Die Inhibition von PlGF alleine oder in Kombination mit VEGF reduzierten die Tumorbelastung bis zu fünf, beziehungsweise zwei mal effizienter als GLV-1h68. Weiterhin wurde gezeigt, dass anders als VEGF, der Erfolg der Ang-2 Hemmung nicht nur mit der Stärke der Hemmung korreliert. Um Tumorregression sowie eine verbesserte Überlebensrate zu verursachen muss eine Balance zwischen Ang-2, VEGF und Ang-1 induziert werden. GLV-1h68 behandelte Tumore waren drei mal gröβer als Tumore, die mit den anti-Ang2 exprimierenden Viren behandelt wurden. Dieselben Virusstämme verursachten eine erhebliche Verspätung des Wachstums der Tumoren. Ausserdem hat diese Arbeit die Notwendigkeit enthüllt, ein angiogenes Profil des zu behandelnden Tumors zu etablieren sowie den Bedarf die synergistischen Effekte von VEGF und Ang-2 besser zu verstehen. Durch die Inhibition der Angiogenese durch VACV-verursachte PIGF und Ang-2 Hemmung wurde die Anzahl der Metastasen und der migrierenden Tumorzellen reduziert. Es wurde gezeigt, dass VEGF die VACV-Kolonisierung von Tumorzellen limitiert, da der Einsatz eines anti-VEGF VACV zu einer Verbesserung der Kolonisierung führt. In vivo Analysen bestätigten diese in vitro Daten. Nach vierzehn Tagen kolonisierte das anti-VEGF Virus 78,85% der Tumoren während die Kolonizationsquote des Kontrollviruses 49,64 % war. Dies resultierte in Tumorregression. Drei der getesteten Tumorzelllinien, in welchen die VACV-vermittelte Angiogenese-Inhibition untersucht wurde, waren in der Lage als Teil der Vaskulatur zu fungieren. Die Expression von Adhäsionsproteinen in diesen Tumorzellen untermauert die Ergebnisse. Weiterhin konnte ein unterschiedliches Expressionsmuster in Anwesenheit von VEGF, PIGF und Ang-2 festgestellt werden, wodurch die Beteiligung angiogener Faktoren bei den immunmodulatorischen Eigenschaften von Tumoren gezeigt werden konnte. In dieser Arbeit konnte gezeigt werden, dass eine VACV-vermittelte anti-angiogene Behandlung für verschiedene Tumorvarianten erfolgsversprechend ist. Die Möglichkeit verschiedene Antikörper gegen unterschiedliche angiogene Faktoren zu exprimieren würde verhindern, dass diese die Angiogenese stimulierende Wirkung des VEGF übernehmen. Die Eigenschaft von VACV Tumorzellen zu infizieren verhindert, dass diese Blutgefäß-ähnliche Strukturen bilden, welche das Tumorwachstum gewährleisten würde. Weiterhin würde die lokal begrenzte Antikörper-Freisetzung das Risiko von Nebenwirkungen senken. Die Inhibition angiogener Faktoren würde die VACV Replikationsrate steigern und den immunmodulatorischen Effekt der Tumore abschwächen. Letztlich würde die Hemmung der Angiogenese bis zur völligen Regression des Tumors aufrechterhalten, die Neubildung Tumor-assoziierter Vaskulatur verhindern und somit den Rückfall des Patienten. KW - Vaccinia-Virus KW - cancer KW - vaccinia virus KW - virotherapy KW - tumor vascularization KW - oncolytic virotherapy KW - Onkolyse KW - Angiogenese Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119019 ER - TY - JOUR A1 - Weidemann, Frank A1 - Maier, Sebastian K. G. A1 - Störk, Stefan A1 - Brunner, Thomas A1 - Liu, Dan A1 - Hu, Kai A1 - Seydelmann, Nora A1 - Schneider, Andreas A1 - Becher, Jan A1 - Canan-Kühl, Sima A1 - Blaschke, Daniela A1 - Bijnens, Bart A1 - Ertl, Georg A1 - Wanner, Christoph A1 - Nordbeck, Peter T1 - Usefulness of an implantable loop recorder to detect clinically relevant arrhythmias in patients with advanced fabry cardiomyopathy JF - The American Journal of Cardiology N2 - Patients with genetic cardiomyopathy that involves myocardial hypertrophy often develop clinically relevant arrhythmias that increase the risk of sudden death. Consequently, guidelines for medical device therapy were established for hypertrophic cardiomyopathy, but not for conditions with only anecdotal evidence of arrhythmias, like Fabry cardiomyopathy. Patients with Fabry cardiomyopathy progressively develop myocardial fibrosis, and sudden cardiac death occurs regularly. Because 24-hour Holier electrocardiograms (ECGs) might not detect clinically important arrhythmias, we tested an implanted loop recorder for continuous heart rhythm surveillance and determined its impact on therapy. This prospective study included 16 patients (12 men) with advanced Fabry cardiomyopathy, relevant hypertrophy, and replacement fibrosis in "loco typico." No patients previously exhibited clinically relevant arrhythmias on Holier ECGs. Patients received an implantable loop recorder and were prospectively followed with telemedicine for a median of 1.2 years (range 0.3 to 2.0 years). The primary end point was a clinically meaningful event, which required a therapy change, captured with the loop recorder. Patients submitted data regularly (14 +/- 11 times per month). During follow-up, 21 events were detected (including 4 asystole, i.e., ECG pauses >= 3 seconds) and 7 bradycardia events; 5 episodes of intermittent atrial fibrillation (>3 minutes) and 5 episodes of ventricular tachycardia (3 sustained and 2 nonsustained). Subsequently, as defined in the primary end point, 15 events leaded to a change of therapy. These patients required therapy with a pacemaker or cardioverter defibrillator implantation and/or anticoagulation therapy for atrial fibrillation. In conclusion, clinically relevant arrhythmias that require further device and/or medical therapy are often missed with Holier ECGs in patients with advanced stage Fabry cardiomyopathy, but they can be detected by telemonitoring with an implantable loop recorder. KW - Cardiovascular magnetic-resonance KW - Coronary artery disease KW - Ventricular-arrhythmias KW - Task force KW - Management KW - Enzyme replacement therapy KW - Hypertrophic cardiomyopathy KW - Myocardial fibrosis KW - Guidelines KW - Manifestation Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-188093 VL - 118 IS - 2 ER - TY - JOUR A1 - Hohm, Anna A1 - Happel, Oliver A1 - Hurtienne, Jörn A1 - Grundgeiger, Tobias T1 - User experience in safety–critical domains: a survey on motivational orientations and psychological need satisfaction in acute care JF - Cognition, Technology & Work N2 - The relevance of user experience in safety–critical domains has been questioned and lacks empirical investigation. Based on previous studies examining user experience in consumer technology, we conducted an online survey on positive experiences with interactive technology in acute care. The participants of the study consisted of anaesthesiologists, nurses, and paramedics (N = 55) from three German cities. We report qualitative and quantitative data examining (1) the relevance and notion of user experience, (2) motivational orientations and psychological need satisfaction, and (3) potential correlates of hedonic, eudaimonic, and extrinsic motivations such as affect or meaning. Our findings reveal that eudaimonia was the most salient aspect in these experiences and that the relevance of psychological needs is differently ranked than in experiences with interactive consumer technology. We conclude that user experience should be considered in safety–critical domains, but research needs to develop further tools and methods to address the domain-specific requirements. KW - user experience KW - healthcare KW - eudaimonia KW - hedonia KW - need satisfaction KW - meaning Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324486 SN - 1435-5558 VL - 24 IS - 2 ER - TY - JOUR A1 - Homberger, Christina A1 - Barquist, Lars A1 - Vogel, Jörg T1 - Ushering in a new era of single-cell transcriptomics in bacteria JF - microLife N2 - Transcriptome analysis of individual cells by single-cell RNA-seq (scRNA-seq) has become routine for eukaryotic tissues, even being applied to whole multicellular organisms. In contrast, developing methods to read the transcriptome of single bacterial cells has proven more challenging, despite a general perception of bacteria as much simpler than eukaryotes. Bacterial cells are harder to lyse, their RNA content is about two orders of magnitude lower than that of eukaryotic cells, and bacterial mRNAs are less stable than their eukaryotic counterparts. Most importantly, bacterial transcripts lack functional poly(A) tails, precluding simple adaptation of popular standard eukaryotic scRNA-seq protocols that come with the double advantage of specific mRNA amplification and concomitant depletion of rRNA. However, thanks to very recent breakthroughs in methodology, bacterial scRNA-seq is now feasible. This short review will discuss recently published bacterial scRNA-seq approaches (MATQ-seq, microSPLiT, and PETRI-seq) and a spatial transcriptomics approach based on multiplexed in situ hybridization (par-seqFISH). Together, these novel approaches will not only enable a new understanding of cell-to-cell variation in bacterial gene expression, they also promise a new microbiology by enabling high-resolution profiling of gene activity in complex microbial consortia such as the microbiome or pathogens as they invade, replicate, and persist in host tissue. KW - single-cell RNA-seq KW - heterogeneity KW - microSPLiT KW - PETRI-seq KW - MATQ-seq KW - par-seqFISH Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313292 VL - 3 ER - TY - JOUR A1 - Linz, Christian A1 - Faber, Julian A1 - Schmid, Reiner A1 - Kunz, Felix A1 - Böhm, Hartmut A1 - Hartmann, Stefan A1 - Schweitzer, Tilmann T1 - Using a 3D asymmetry index as a novel form for capturing complex three-dimensionality in positional plagiocephaly JF - Scientific Reports N2 - Positional plagiocephaly (PP) is the most common skull deformity in infants. Different classification systems exist for graduating the degree of PP, but all of these systems are based on two-dimensional (2D) parameters. This limitation leads to several problems stemming from the fact that 2D parameters are used to classify the three-dimensional (3D) shape of the head. We therefore evaluate existing measurement parameters and validate a newly developed 3D parameter for quantifying PP. Additionally, we present a new classification of PP based on a 3D parameter. 210 patients with PP and 50 patients without PP were included in this study. Existing parameters (2D and 3D) and newly developed volume parameters based on a 3D stereophotogrammetry scan were validated using ROC curves. Additionally, thresholds for the new 3D parameter of a 3D asymmetry index were assessed. The volume parameter 3D asymmetry index quantifies PP equally as well as the gold standard of 30° diagonal difference. Moreover, a 3D asymmetry index allows for a 3D-based classification of PP. The 3D asymmetry index can be used to define the degree of PP. It is easily applicable in stereophotogrammetric datasets and allows for comparability both intra- and inter-individually as well as for scientific analysis. KW - craniofacial orthodontics KW - physical examination KW - three-dimensional imaging Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-300427 VL - 12 ER - TY - JOUR A1 - Liman, Leon A1 - May, Bernd A1 - Fette, Georg A1 - Krebs, Jonathan A1 - Puppe, Frank T1 - Using a clinical data warehouse to calculate and present key metrics for the radiology department: implementation and performance evaluation JF - JMIR Medical Informatics N2 - Background: Due to the importance of radiologic examinations, such as X-rays or computed tomography scans, for many clinical diagnoses, the optimal use of the radiology department is 1 of the primary goals of many hospitals. Objective: This study aims to calculate the key metrics of this use by creating a radiology data warehouse solution, where data from radiology information systems (RISs) can be imported and then queried using a query language as well as a graphical user interface (GUI). Methods: Using a simple configuration file, the developed system allowed for the processing of radiology data exported from any kind of RIS into a Microsoft Excel, comma-separated value (CSV), or JavaScript Object Notation (JSON) file. These data were then imported into a clinical data warehouse. Additional values based on the radiology data were calculated during this import process by implementing 1 of several provided interfaces. Afterward, the query language and GUI of the data warehouse were used to configure and calculate reports on these data. For the most common types of requested reports, a web interface was created to view their numbers as graphics. Results: The tool was successfully tested with the data of 4 different German hospitals from 2018 to 2021, with a total of 1,436,111 examinations. The user feedback was good, since all their queries could be answered if the available data were sufficient. The initial processing of the radiology data for using them with the clinical data warehouse took (depending on the amount of data provided by each hospital) between 7 minutes and 1 hour 11 minutes. Calculating 3 reports of different complexities on the data of each hospital was possible in 1-3 seconds for reports with up to 200 individual calculations and in up to 1.5 minutes for reports with up to 8200 individual calculations. Conclusions: A system was developed with the main advantage of being generic concerning the export of different RISs as well as concerning the configuration of queries for various reports. The queries could be configured easily using the GUI of the data warehouse, and their results could be exported into the standard formats Excel and CSV for further processing. KW - data warehouse KW - eHealth KW - hospital data KW - electronic health records KW - radiology KW - statistics and numerical data KW - medical records Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-349411 SN - 2291-9694 VL - 11 ER - TY - JOUR A1 - Kunz, Tobias C. A1 - Götz, Ralph A1 - Gao, Shiqiang A1 - Sauer, Markus A1 - Kozjak-Pavlovic, Vera T1 - Using Expansion Microscopy to Visualize and Characterize the Morphology of Mitochondrial Cristae JF - Frontiers in Cell and Developmental Biology N2 - Mitochondria are double membrane bound organelles indispensable for biological processes such as apoptosis, cell signaling, and the production of many important metabolites, which includes ATP that is generated during the process known as oxidative phosphorylation (OXPHOS). The inner membrane contains folds called cristae, which increase the membrane surface and thus the amount of membrane-bound proteins necessary for the OXPHOS. These folds have been of great interest not only because of their importance for energy conversion, but also because changes in morphology have been linked to a broad range of diseases from cancer, diabetes, neurodegenerative diseases, to aging and infection. With a distance between opposing cristae membranes often below 100 nm, conventional fluorescence imaging cannot provide a resolution sufficient for resolving these structures. For this reason, various highly specialized super-resolution methods including dSTORM, PALM, STED, and SIM have been applied for cristae visualization. Expansion Microscopy (ExM) offers the possibility to perform super-resolution microscopy on conventional confocal microscopes by embedding the sample into a swellable hydrogel that is isotropically expanded by a factor of 4–4.5, improving the resolution to 60–70 nm on conventional confocal microscopes, which can be further increased to ∼ 30 nm laterally using SIM. Here, we demonstrate that the expression of the mitochondrial creatine kinase MtCK linked to marker protein GFP (MtCK-GFP), which localizes to the space between the outer and the inner mitochondrial membrane, can be used as a cristae marker. Applying ExM on mitochondria labeled with this construct enables visualization of morphological changes of cristae and localization studies of mitochondrial proteins relative to cristae without the need for specialized setups. For the first time we present the combination of specific mitochondrial intermembrane space labeling and ExM as a tool for studying internal structure of mitochondria. KW - Expansion microscopy KW - mitochondria KW - cristae KW - structured illumination microscope KW - ultrastructure Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-208296 SN - 2296-634X VL - 8 ER - TY - JOUR A1 - Pook, Torsten A1 - Freudenthal, Jan A1 - Korte, Arthur A1 - Simianer, Henner T1 - Using Local Convolutional Neural Networks for Genomic Prediction JF - Frontiers in Genetics N2 - The prediction of breeding values and phenotypes is of central importance for both livestock and crop breeding. In this study, we analyze the use of artificial neural networks (ANN) and, in particular, local convolutional neural networks (LCNN) for genomic prediction, as a region-specific filter corresponds much better with our prior genetic knowledge on the genetic architecture of traits than traditional convolutional neural networks. Model performances are evaluated on a simulated maize data panel (n = 10,000; p = 34,595) and real Arabidopsis data (n = 2,039; p = 180,000) for a variety of traits based on their predictive ability. The baseline LCNN, containing one local convolutional layer (kernel size: 10) and two fully connected layers with 64 nodes each, is outperforming commonly proposed ANNs (multi layer perceptrons and convolutional neural networks) for basically all considered traits. For traits with high heritability and large training population as present in the simulated data, LCNN are even outperforming state-of-the-art methods like genomic best linear unbiased prediction (GBLUP), Bayesian models and extended GBLUP, indicated by an increase in predictive ability of up to 24%. However, for small training populations, these state-of-the-art methods outperform all considered ANNs. Nevertheless, the LCNN still outperforms all other considered ANNs by around 10%. Minor improvements to the tested baseline network architecture of the LCNN were obtained by increasing the kernel size and of reducing the stride, whereas the number of subsequent fully connected layers and their node sizes had neglectable impact. Although gains in predictive ability were obtained for large scale data sets by using LCNNs, the practical use of ANNs comes with additional problems, such as the need of genotyping all considered individuals, the lack of estimation of heritability and reliability. Furthermore, breeding values are additive by design, whereas ANN-based estimates are not. However, ANNs also comes with new opportunities, as networks can easily be extended to account for additional inputs (omics, weather etc.) and outputs (multi-trait models), and computing time increases linearly with the number of individuals. With advances in high-throughput phenotyping and cheaper genotyping, ANNs can become a valid alternative for genomic prediction. KW - phenotype prediction KW - Keras KW - genomic selection KW - selection KW - breeding KW - machine learning KW - deep learning Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-216436 VL - 11 ER - TY - INPR A1 - Nassourou, Mohamadou T1 - Using Machine Learning Algorithms for Categorizing Quranic Chaptersby Major Phases of Prophet Mohammad’s Messengership N2 - This paper discusses the categorization of Quranic chapters by major phases of Prophet Mohammad’s messengership using machine learning algorithms. First, the chapters were categorized by places of revelation using Support Vector Machine and naïve Bayesian classifiers separately, and their results were compared to each other, as well as to the existing traditional Islamic and western orientalists classifications. The chapters were categorized into Meccan (revealed in Mecca) and Medinan (revealed in Medina). After that, chapters of each category were clustered using a kind of fuzzy-single linkage clustering approach, in order to correspond to the major phases of Prophet Mohammad’s life. The major phases of the Prophet’s life were manually derived from the Quranic text, as well as from the secondary Islamic literature e.g hadiths, exegesis. Previous studies on computing the places of revelation of Quranic chapters relied heavily on features extracted from existing background knowledge of the chapters. For instance, it is known that Meccan chapters contain mostly verses about faith and related problems, while Medinan ones encompass verses dealing with social issues, battles…etc. These features are by themselves insufficient as a basis for assigning the chapters to their respective places of revelation. In fact, there are exceptions, since some chapters do contain both Meccan and Medinan features. In this study, features of each category were automatically created from very few chapters, whose places of revelation have been determined through identification of historical facts and events such as battles, migration to Medina…etc. Chapters having unanimously agreed places of revelation were used as the initial training set, while the remaining chapters formed the testing set. The classification process was made recursive by regularly augmenting the training set with correctly classified chapters, in order to classify the whole testing set. Each chapter was preprocessed by removing unimportant words, stemming, and representation with vector space model. The result of this study shows that, the two classifiers have produced useable results, with an outperformance of the support vector machine classifier. This study indicates that, the proposed methodology yields encouraging results for arranging Quranic chapters by phases of Prophet Mohammad’s messengership. KW - Koran KW - Maschinelles Lernen KW - Text categorization KW - Clustering KW - Support Vector Machine KW - Naïve Bayesian KW - Place of revelation KW - Stages of Prophet Mohammad’s messengership KW - Quran Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-66862 ER - TY - THES A1 - Beck, Sebastian T1 - Using optogenetics to influence the circadian clock of \(Drosophila\) \(melanogaster\) T1 - Die Verwendung der Optogenetik zur Beeinflussung der circadianen Uhr von \(Drosophila\) \(melanogaster\) N2 - Almost all life forms on earth have adapted to the most impactful and most predictable recurring change in environmental condition, the cycle of day and night, caused by the axial rotation of the planet. As a result many animals have evolved intricate endogenous clocks, which adapt and synchronize the organisms’ physiology, metabolism and behaviour to the daily change in environmental conditions. The scientific field researching these endogenous clocks is called chronobiology and has steadily grown in size, scope and relevance since the works of the earliest pioneers in the 1960s. The number one model organism for the research of circadian clocks is the fruit fly, Drosophila melanogaster, whose clock serves as the entry point to understanding the basic inner workings of such an intricately constructed endogenous timekeeping system. In this thesis it was attempted to combine the research on the circadian clock with the techniques of optogenetics, a fairly new scientific field, launched by the discovery of Channelrhodopsin 2 just over 15 years ago. Channelrhodopsin 2 is a light-gated ion channel found in the green alga Chlamydomonas reinhardtii. In optogenetics, researches use these light-gated ion channels like Channelrhodopsin 2 by heterologously expressing them in cells and tissues of other organisms, which can then be stimulated by the application of light. This is most useful when studying neurons, as these channels provide an almost non-invasive tool to depolarize the neuronal plasma membranes at will. The goal of this thesis was to develop an optogenetic tool, which would be able to influence and phase shift the circadian clock of Drosophila melanogaster upon illumination. A phase shift is the adaptive response of the circadian clock to an outside stimulus that signals a change in the environmental light cycle. An optogenetic tool, able to influence and phase shift the circadian clock predictably and reliably, would open up many new ways and methods of researching the neuronal network of the clock and which neurons communicate to what extent, ultimately synchronizing the network. The first optogenetic tool to be tested in the circadian clock of Drosophila melanogaster was ChR2-XXL, a channelrhodopsin variant with dramatically increased expression levels and photocurrents combined with a prolonged open state. The specific expression of ChR2-XXL and of later constructs was facilitated by deploying the three different clock-specific GAL4-driver lines, clk856-gal4, pdf-gal4 and mai179-gal4. Although ChR2-XXL was shown to be highly effective at depolarizing neurons, these stimulations proved to be unable to significantly phase shift the circadian clock of Drosophila. The second series of experiments was conducted with the conceptually novel optogenetic tools Olf-bPAC and SthK-bPAC, which respectively combine a cyclic nucleotide-gated ion channel (Olf and SthK) with the light-activated adenylyl-cyclase bPAC. These tools proved to be quite useful when expressed in the motor neurons of instar-3 larvae of Drosophila, paralyzing the larvae upon illumination, as well as affecting body length. This way, these new tools could be precisely characterized, spawning a successfully published research paper, centered around their electrophysiological characterization and their applicability in model organisms like Drosophila. In the circadian clock however, these tools caused substantial damage, producing severe arrhythmicity and anomalies in neuronal development. Using a temperature-sensitive GAL80-line to delay the expression until after the flies had eclosed, yielded no positive results either. The last series of experiments saw the use of another new series of optogenetic tools, modelled after the Olf-bPAC, with bPAC swapped out for CyclOp, a membrane-bound guanylyl-cyclase, coupled with less potent versions of the Olf. This final attempt however also ended up being unsuccessful. While these tools could efficiently depolarize neuronal membranes upon illumination, they were ultimately unable to stimulate the circadian clock in way that would cause it to phase shift. Taken together, these mostly negative results indicate that an optogenetic manipulation of the circadian clock of Drosophila melanogaster is an extremely challenging subject. As light already constitutes the most impactful environmental factor on the circadian clock, the combination of chronobiology with optogenetics demands the parameters of the conducted experiments to be tuned with an extremely high degree of precision, if one hopes to receive positive results from these types of experiments at all. N2 - Nahezu alle Lebewesen der Erde haben sich an den Tag-Nacht-Zyklus angepasst, die einflussreichste und verlässlichste wiederkehrende Veränderung der Umwelt-bedingungen, verursacht durch die axiale Rotation des Planeten. Daraus resultierend haben viele Tiere komplizierte innere Uhren entwickelt, welche ihre Physiologie, ihren Stoffwechsel und ihr Verhalten an die tägliche Veränderung der natürlichen Bedingungen anpassen. Das Wissenschaftsfeld, das sich der Erforschung dieser inneren Uhren widmet, wird Chronobiologie genannt und hat seit der Arbeit der ersten Pioniere ab 1960 stetig an Größe und Relevanz gewonnen. Der prominenteste Modellorganismus für die Erforschung der circadianen Uhr ist Drosophila melanogaster, deren Uhr als Ansatzpunkt dient, die grundlegenden Vorgänge eines derart komplexen, endogenen Taktsystems zu verstehen. In dieser Thesis wurde versucht die Forschung an der circadianen Uhr mit den Techniken der Optogenetik zu kombinieren, eines jungen Forschungsfeldes, welches durch die Entdeckung von Channelrhodpsin 2 vor über 15 Jahren eröffnet wurde. Channelrhodopsin 2 ist ein Licht-gesteuerter Ionenkanal, der in der Grünalge Chlamydomonas reinhardtii entdeckt wurde. In der Optogenetik nutzen Forscher diese Licht-gesteuerten Ionenkanäle, indem sie sie in den Zellen anderer Organismen exprimieren, welche dann durch Licht stimuliert werden können. Dies ist besonders nützlich bei der Untersuchung von Neuronen, da diese Kanäle ein nahezu nicht-invasives Werkzeug zur Depolarisation neuronaler Membranen bieten. Das Ziel dieser Thesis war es, ein optogenetisches Werkzeug zu entwickeln, welches die circadiane Uhr von Drosophila melanogaster durch Licht manipulieren und deren Phase verschieben kann. Eine Phasenverschiebung ist die adaptive Antwort der circadianen Uhr auf einen äußeren Reiz, welcher eine Veränderung des natürlichen Lichtzyklus signalisiert. Ein optogenetisches Werkzeug, das die Phase der inneren Uhr verlässlich verschieben kann, würde viele neue Möglichkeiten zur Erforschung des neuronalen Uhrnetzwerks eröffnen und wie die Neuronen miteinander kommunizieren um das Netzwerk zu synchronisieren. Das erste optogenetische Werkzeug das in der circadianen Uhr von Drosophila melanogaster getestet wurde war „ChR2-XXL“, eine Channelrhodopsin-Variante mit erhöhter Expression und Photoströmen, gepaart mit einem verlängerten geöffneten Zustand. Die spezifische Expression von ChR2-XXL und auch die späterer Konstrukte wurde durch die Verwendung der drei Uhr-spezifischen GAL4-Treiberlinien clk856-gal4, pdf-gal4 und mai179-gal4 bewerkstelligt. Obwohl bereits gezeigt wurde, dass ChR2-XXL höchst effektiv die Depolarisierung von Neuronen bewirkt, waren diese Stimulationen jedoch nicht in der Lage die Phase der circadianen Uhr von Drosophila signifikant zu verschieben. Die zweite Serie an Versuchen wurde mit den konzeptionell neuartigen optogenetischen Werkzeugen Olf-bPAC und SthK-bPAC durchgeführt, welche jeweils einen durch zyklische Nukleotide gesteuerten Ionenkanal (Olf und SthK) mit der Licht-gesteuerten Adenylatcyclase bPAC kombinieren. Diese Werkzeuge erwiesen sich als äußert nützlich, solange sie in den Motoneuronen von Drosophila-Larven im dritten Larvenstadium exprimiert wurden, wo sie bei Beleuchtung die Larven sowohl paralysierten, als auch deren Körperlänge beeinflussten. Auf diese Weise konnten diese neuen Werkzeuge präzise charakterisiert werden, was in der erfolgreichen Veröffentlichung eines Forschungsartikels mündete, welcher hauptsächlich von der elektrophysiologischen Charakterisierung der Werkzeuge handelte und von deren Anwendungsmöglichkeiten in Modellorganismen wie Drosophila. In der circadianen Uhr verursachten diese Werkzeuge jedoch substantielle Schäden und produzierten schwere Arrhythmie und Anomalien in der neuronalen Entwicklung. Die Verwendung einer temperatur-sensitiven GAL80-Linie um die Expression zu verzögern, erzeugte ebenfalls keinerlei positive Ergebnisse. Für die letzte Serie an Experimenten wurde eine weitere Reihe neuer optogenetischer Werkzeuge verwendet, orientiert an Olf-bPAC und SthK-bPAC, wobei bPAC durch die membrangebundene Guanylatcyclase „CyclOp“ ausgetauscht wurde, welche wiederrum mit weniger wirkstarken Olf-Varianten kombiniert wurde. Dieser letzte Ansatz scheiterte jedoch ebenfalls. Obwohl diese neuen Werkzeuge in der Lage waren die Neuronenmembran bei Beleuchtung effektiv zu depolarisieren, vermochten sie es letztendlich nicht eine Phasenverschiebung zu bewirken. Zusammengenommen zeigen diese überwiegend negativen Ergebnisse, dass die optogenetische Manipulation der circadianen Uhr von Drosophila melanogaster ein extrem anspruchsvolles Thema ist. Da Licht bereits ohnehin den einflussreichsten Umweltfaktor für die circadiane Uhr darstellt, verlangt die Kombination von Chronobiologie und Optogenetik eine extrem präzise Feinabstimmung der Versuchsparameter, um überhaupt darauf hoffen zu dürfen, positive Ergebnisse mit derlei Versuchen zu erzeugen. KW - Chronobiologie KW - Optogenetik KW - Taufliege KW - Optogenetics KW - Chronobiology KW - Channelrhodopsin KW - Drosophila melanogaster Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-184952 ER - TY - THES A1 - Schleier, Domenik T1 - Using Photoionization to Investigate Reactive Boron Species and the Kinetics of Hydrocarbon Radicals T1 - Die Untersuchung von Reaktiven Borspezies und die Kinetik von Kohlenwassterstoffradikalen mittels Photoionization N2 - This thesis highlights the importance of isomer-selective approaches for the complete analysis of chemical processes. The method of choice is photoelectron/photoion coincidence spectroscopy, which allows simultaneous detection of electrons and ions coming from a single ionization event. Ionization techniques are sensitive and can record multiple species simultaneously, rendering them ideal tools to probe molecular transformations. Coupling these setups to synchrotron radiation allows one to analyze complex mixtures with isomer selectivity, based on ionization energies and vibrational structure in the cation, without any prior separation steps. Only few setups exist that can be used to gather these data, although their impact and applicability is growing steadily in various fields. For closed-shell species an easier and more widely used method is gas-chromatography, but most open shell species would not survive the separation process. Due to the reactivity of radicals they have to be created by selectively converting stable precursor molecules. Depending on the radical generation method different properties can be investigated ranging from thermodynamic data, over concentrations in high temperature environments, to chemical kinetics. The first part of this thesis deals with the determination of bimolecular rate constants. Isomeric hydrocarbon radicals were generated by a high intense UV light pulses and their kinetics with oxygen was measured. The pressure dependence of different isomers in the falloff region was compared to theoretical models, and their reactivity could be explained. The second part deals with boron containing compounds in various electronic situations. The corresponding precursors were successfully synthesized or could be bought. They were subjected to fluorine atoms in chemical reactors or destroyed pyrolytically at high temperatures. Most investigated species exhibited vibronic effects that could be elucidated using high level computations. N2 - Die vorliegende Arbeit lässt sich in zwei Unterkategorien gliedern. Sie befasst sich zum einen mit der isomerenselektiven Identifikation von hochreaktiven anorganischen Verbindungen. Zum anderen werden Ratenkonstanten für die Reaktionen verschiedener Kohlenwasserstoffradikale mit Sauerstoff ermittelt. Beide Bereiche sind durch die Frage der Energiespeicherung und -gewinnung in der Zukunft unmittelbar miteinander verbunden. Die Herausforderung reaktive Moleküle zu untersuchen, liegt oft darin sie in einer inerten Atmosphäre erzeugen zu müssen. Nur unter diesen Bedingungen hat ihre Reaktivität kaum Möglichkeiten sich zu entfalten. Hierzu wurden stabile Vorläufermoleküle in die Gasphase überführt und in einer verdünnten Umgebung möglichst selektiv in die gewünschte Radikalspezies überführt. Sowohl deren isomereselektive Identifikation als auch die Bestimmung der Ratenkonstanten wurde mittels Schwellenphotoelektronenspektroskopie durchgeführt. Mit Hilfe eines Photoelektron/Photoion Koinzidenz (PEPICO) Aufbaus konnten massenselektive Signale detektiert werden. Diese Methode benötigt eine Lichtquelle, die eine hohe Repetitionsrate aufweist und im VUV-Bereich komplett spektral durchstimmbar ist. Diese Voraussetzungen sind an Synchrotron-Strahlungsquellen verfügbar, weshalb die Experimente in dieser Arbeit an den entsprechenden Strahllinien an der SwissLightSource oder am Synchrotron SOLEIL durchgeführt wurden. Zur Unterstützung der experimentellen Daten wurden durch quantenchemische Rechnungen und Simulationen durchgeführt, aus denen eine klare isomerenselektive Zuordnung des jeweiligen Signals erfolgt. Die gesuchten Ratenkonstanten konnten mittels geeigneter Programme aus den Kinetikdaten extrahiert werden, wobei auch die Ratenkonstanten der Seitenreaktionen berücksichtigt wurden. KW - Biradikal KW - Kinetics KW - Spectroscopy KW - Photolysis KW - Radicals KW - Biradicals KW - Fotoionisation KW - Fotolyse KW - Synchrotronstrahlung KW - Synchrotron Radiation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-242137 ER - TY - THES A1 - Reissland, Michaela T1 - USP10 is a \(de\) \(novo\) tumour-specific regulator of β-Catenin and contributes to cancer stem cell maintenance and tumour progression T1 - USP10 ist ein \(de\) \(novo\) tumorspezifischer Regulator von ß-Catenin und trägt zur Erhaltung von Krebsstammzellen und zur Tumorprogression bei N2 - Colorectal Cancer (CRC) is the third most common cancer in the US. The majority of CRC cases are due to deregulated WNT-signalling pathway. These alterations are mainly caused by mutations in the tumour suppressor gene APC or in CTNNB1, encoding the key effector protein of this pathway, β-Catenin. In canonical WNT-signalling, β-Catenin activates the transcription of several target genes, encoding for proteins involved in proliferation, such as MYC, JUN and NOTCH. Being such a critical regulator of these proto-oncogenes, the stability of β-Catenin is tightly regulated by the Ubiquitin-Proteasome System. Several E3 ligases that ubiquitylate and degrade β-Catenin have been described in the past, but the antagonists, the deubiquitylases, are still unknown. By performing an unbiased siRNA screen, the deubiquitylase USP10 was identified as a de novo positive regulator of β-Catenin stability in CRC derived cells. USP10 has previously been shown in the literature to regulate both mutant and wild type TP53 stability, to deubiquitylate NOTCH1 in endothelial cells and to be involved in the regulation of AMPKα signalling. Overall, however, its role in colorectal tumorigenesis remains controversial. By analysing publicly available protein and gene expression data from colorectal cancer patients, we have shown that USP10 is strongly upregulated or amplified upon transformation and that its expression correlates positively with CTNNB1 expression. In contrast, basal USP10 levels were found in non-transformed tissues, but surprisingly USP10 is upregulated in intestinal stem cells. Endogenous interaction studies in CRC-derived cell lines, with different extend of APCtruncation, revealed an APC-dependent mode of action for both proteins. Furthermore, by utilising CRISPR/Cas9, shRNA-mediated knock-down and overexpression of USP10, we could demonstrate a regulation of β-Catenin stability by USP10 in CRC cell lines. It is widely excepted that 2D cell culture systems do not reflect complexity, architecture and heterogeneity and are therefore not suitable to answer complex biological questions. To overcome this, we established the isolation, cultivation and genetically modification of murine intestinal organoids and utilised this system to study Usp10s role ex vivo. By performing RNA sequencing, dependent on different Usp10 levels, we were able to recapitulate the previous findings and demonstrated Usp10 as important regulator of β-dependent regulation of stem cell homeostasis. Since genetic depletion of USP10 resulted in down-regulation of β-Catenin-dependent transcription, therapeutic intervention of USP10 in colorectal cancer was also investigated. Commercial and newly developed inhibitors were tested for their efficacy against USP10, but failed to significantly inhibit USP10 activity in colorectal cancer cells. To validate the findings from this work also in vivo, development of a novel mouse model for colorectal cancer has begun. By combining CRISPR/Cas9 and classical genetic engineering with viral injection strategies, WT and genetically modified mice could be transformed and, at least in some animals, intestinal lesions were detectable at the microscopic level. The inhibition of USP10, which we could describe as a de novo tumour-specific regulator of β-Catenin, could become a new therapeutic strategy for colorectal cancer patients. N2 - Darmkrebs ist die dritthäufigste Krebsart in den USA. Die Mehrheit der Darmkrebsfälle sind auf einen deregulierten WNT-Signalweg zurückzuführen. Diese Veränderungen wer- den hauptsächlich durch Mutationen im Tumorsuppressor-Gen APC oder in CTNNB1 verursacht, welches für das zentrale Protein dieses Signalwegs, β-Catenin, kodiert. Beim kanonischen WNT-Signalweg aktiviert β-Catenin die Transkription mehrerer Gene, die für, an der Proliferation beteiligte Proteine wie MYC, JUN und NOTCH, kodieren. Da β-Catenin ein kritischer Regulator dieser proto-Onkogene ist, wird die Stabilität von β-Catenin durch das Ubiquitin-Proteasom-System streng reguliert. In der Vergangen- heit wurden mehrere E3-Ligasen beschrieben, die β-Catenin ubiquitylieren und abbauen, aber die Deubiquitylasen, sind grö𐀀tenteils noch unbekannt. Mit Hilfe eines unvoreingenommenen siRNA-Screens wurde die Deubiquitylase USP10 als de novo Regulator der β-Catenin-Stabilität in Darmkrebs-Zellen identifiziert. In der Literatur wurde bereits gezeigt, dass USP10 sowohl die Stabilität von mutiertem als auch von wild typ TP53 reguliert, NOTCH1 in Endothelzellen deubiquityliert und an der Regulation des AMPKα Signalwegs beteiligt ist. Insgesamt bleibt seine Rolle in der kolorektalen Tumorgenese aber bisher umstritten. Anhand der Analyse öffentlich zugänglicher Protein- und Genexpressionsdaten haben wir gezeigt, dass USP10 bei der Transformation stark hochreguliert oder amplifiziert wird und dass seine Expression positiv mit der von CTNNB1 korreliert. Im Gegensatz dazu wurden in nicht transformiertem Gewebe basale USP10-Spiegel gefunden, aber überraschenderweise ist USP10 in intestinalen Stammzellen hochreguliert. Endogene Interaktionsstudien in Darmkrebs-Zelllinien mit unterschiedlichem Ausma𐀀 an APC-Trunkierung zeigten eine APC-abhängige Interaktion für beide Proteine. Darüber hinaus konnten wir mit Hilfe von CRISPR/Cas9, shRNA-vermitteltem Knock-down und Überexpression von USP10 eine Regulation der β-Catenin-Stabilität durch USP10 in Darmkrebs-Zelllinien nachweisen. Es ist allgemein bekannt, dass 2D-Zellkultursysteme die Komplexität, Architektur und Heterogenität nicht widerspiegeln und daher nicht geeignet sind, um komplexe biologische Fragen zu beantworten. Um dies zu überwinden, haben wir die Isolierung, Kultivierung und genetische Veränderung von murinen Dar- morganoiden etabliert und dieses System genutzt, um die Rolle von Usp10 ex vivo zu untersuchen. Durch die Durchführung von RNA-Sequenzierungen in Abhängigkeit von unterschiedlichen Usp10-Spiegeln konnten wir die bisherigen Ergebnisse rekapitulieren und Usp10 als wichtigen Regulator der β-Catenin-abhängigen Regulation der Stammzell- homöostase nachweisen. Da die genetische Depletion von USP10 zu einer Herunterregulierung der β-Catenin- abhängigen Transkription führte, wurde auch die therapeutische Intervention von USP10 in Darmkrebs untersucht. Kommerzielle und neu entwickelte Inhibitoren wurden auf ihre Wirksamkeit gegen USP10 getestet, konnten jedoch die Aktivität von USP10 in Darmkrebs- Zellen nicht hemmen. Um die Erkenntnisse aus dieser Arbeit auch in vivo zu validieren, wurde mit der Entwicklung eines neuartigen Mausmodells für Darmkrebs begonnen. Durch die Kombination von CRISPR/Cas9 und klassischer Gentechnik mit viralen Injektionsstrategien konnten WT- und gentechnisch veränderte Mäuse trans- formiert werden und zumindest bei einigen Tieren waren Darmläsionen auf mikroskopis- cher Ebene nachweisbar. Die Inhibtierung von USP10, als de novo tumorspezifischer Regulator von β-Catenin, könnte eine neue therapeutische Strategie für Darmkrebs-Patienten werden. KW - Biomedizin KW - Biomedicine Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-319579 ER - TY - JOUR A1 - Prieto-Garcia, Cristian A1 - Hartmann, Oliver A1 - Reissland, Michaela A1 - Braun, Fabian A1 - Bozkurt, Süleyman A1 - Pahor, Nikolett A1 - Fuss, Carmina A1 - Schirbel, Andreas A1 - Schülein-Völk, Christina A1 - Buchberger, Alexander A1 - Calzado Canale, Marco A. A1 - Rosenfeldt, Mathias A1 - Dikic, Ivan A1 - Münch, Christian A1 - Diefenbacher, Markus E. T1 - USP28 enables oncogenic transformation of respiratory cells, and its inhibition potentiates molecular therapy targeting mutant EGFR, BRAF and PI3K JF - Molecular Oncology N2 - Oncogenic transformation of lung epithelial cells is a multistep process, frequently starting with the inactivation of tumour suppressors and subsequent development of activating mutations in proto-oncogenes, such as members of the PI3K or MAPK families. Cells undergoing transformation have to adjust to changes, including altered metabolic requirements. This is achieved, in part, by modulating the protein abundance of transcription factors. Here, we report that the ubiquitin carboxyl-terminal hydrolase 28 (USP28) enables oncogenic reprogramming by regulating the protein abundance of proto-oncogenes such as c-JUN, c-MYC, NOTCH and ∆NP63 at early stages of malignant transformation. USP28 levels are increased in cancer compared with in normal cells due to a feed-forward loop, driven by increased amounts of oncogenic transcription factors such as c-MYC and c-JUN. Irrespective of oncogenic driver, interference with USP28 abundance or activity suppresses growth and survival of transformed lung cells. Furthermore, inhibition of USP28 via a small-molecule inhibitor resets the proteome of transformed cells towards a ‘premalignant’ state, and its inhibition synergizes with clinically established compounds used to target EGFR\(^{L858R}\)-, BRAF\(^{V600E}\)- or PI3K\(^{H1047R}\)-driven tumour cells. Targeting USP28 protein abundance at an early stage via inhibition of its activity is therefore a feasible strategy for the treatment of early-stage lung tumours, and the observed synergism with current standard-of-care inhibitors holds the potential for improved targeting of established tumours. KW - buparlisib KW - c-MYC KW - gefitinib KW - lung cancer KW - USP28 KW - vemurafenib Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312777 VL - 16 IS - 17 ER - TY - THES A1 - Prieto García, Cristian T1 - USP28 regulates Squamous cell oncogenesis and DNA repair via ΔNp63 deubiquitination T1 - USP28 reguliert Plattenepithelzell-Onkogenese und DNA-Reparatur über ΔNp63-Deubiquitinierung N2 - ∆Np63 is a master regulator of squamous cell identity and regulates several signaling pathways that crucially contribute to the development of squamous cell carcinoma (SCC) tumors. Its contribution to coordinating the expression of genes involved in oncogenesis, epithelial identity, DNA repair, and genome stability has been extensively studied and characterized. For SCC, the expression of ∆Np63 is an essential requirement to maintain the malignant phenotype. Additionally, ∆Np63 functionally contributes to the development of cancer resistance toward therapies inducing DNA damage. SCC patients are currently treated with the same conventional Cisplatin therapy as they would have been treated 30 years ago. In contrast to patients with other tumor entities, the survival of SCC patients is limited, and the efficacy of the current therapies is rather low. Considering the rising incidences of these tumor entities, the development of novel SCC therapies is urgently required. Targeting ∆Np63, the transcription factor, is a potential alternative to improve the therapeutic response and clinical outcomes of SCC patients. However, ∆Np63 is considered “undruggable.” As is commonly observed in transcription factors, ∆Np63 does not provide any suitable domains for the binding of small molecule inhibitors. ∆Np63 regulates a plethora of different pathways and cellular processes, making it difficult to counteract its function by targeting downstream effectors. As ∆Np63 is strongly regulated by the ubiquitin–proteasome system (UPS), the development of deubiquitinating enzyme inhibitors has emerged as a promising therapeutic strategy to target ∆Np63 in SCC treatment. This work involved identifying the first deubiquitinating enzyme that regulates ∆Np63 protein stability. Stateof-the-art SCC models were used to prove that USP28 deubiquitinates ∆Np63, regulates its protein stability, and affects squamous transcriptional profiles in vivo and ex vivo. Accordingly, SCC depends on USP28 to maintain essential levels of ∆Np63 protein abundance in tumor formation and maintenance. For the first time, ∆Np63, the transcription factor, was targeted in vivo using a small molecule inhibitor targeting the activity of USP28. The pharmacological inhibition of USP28 was sufficient to hinder the growth of SCC tumors in preclinical mouse models. Finally, this work demonstrated that the combination of Cisplatin with USP28 inhibitors as a novel therapeutic alternative could expand the limited available portfolio of SCC therapeutics. Collectively, the data presented within this dissertation demonstrates that the inhibition of USP28 in SCC decreases ∆Np63 protein abundance, thus downregulating the Fanconi anemia (FA) pathway and recombinational DNA repair. Accordingly, USP28 inhibition reduces the DNA damage response, thereby sensitizing SCC tumors to DNA damage therapies, such as Cisplatin. N2 - ∆Np63 ist ein Hauptregulator der Plattenepithelzellidentität und reguliert mehrere Signalwege, die entscheidend zur Entstehung von Plattenepithelkarzinomen (SCC) beitragen. Sein Beitrag zur Koordination der Expression von Genen, die an der Onkogenese, der epithelialen Identität, der DNA-Reparatur und der Genomstabilität beteiligt sind, wurde umfassend untersucht und charakterisiert. Für SCC ist die Expression von ∆Np63 eine wesentliche Voraussetzung, um den malignen Phänotyp zu erhalten. Darüber hinaus trägt ∆Np63 funktionell zur Entwicklung einer Krebsresistenz gegenüber Therapien bei, die DNA-Schäden induzieren. SCC-Patienten werden derzeit mit der gleichen konventionellen Cisplatin-Therapie behandelt, wie sie vor 30 Jahren behandelt worden wären. Im Gegensatz zu Patienten mit anderen Tumorentitäten ist das Überleben von SCC-Patienten begrenzt und die Wirksamkeit der aktuellen Therapien eher gering. Angesichts der steigenden Inzidenz dieser Tumorentitäten ist die Entwicklung neuer Therapien für das Plattenepithelkarzinom dringend erforderlich. Das Targeting von ∆Np63, dem Transkriptionsfaktor, ist eine potenzielle Alternative zur Verbesserung des therapeutischen Ansprechens und der klinischen Ergebnisse von SCC-Patienten. ∆Np63 gilt jedoch als „nicht medikamentös“. Wie bei Transkriptionsfaktoren häufig beobachtet, bietet ∆Np63 keine geeigneten Domänen für die Bindung von niedermolekularen Inhibitoren. ∆Np63 reguliert eine Vielzahl von verschiedenen Signalwegen und zellulären Prozessen, was es schwierig macht, seiner Funktion entgegenzuwirken, indem es nachgeschaltete Effektoren angreift. Da ∆Np63 stark durch das Ubiquitin-Proteasom-System (UPS) reguliert wird, hat sich die Entwicklung von deubiquitinierenden Enzyminhibitoren als vielversprechende therapeutische Strategie erwiesen, um ∆Np63 bei der Behandlung von Plattenepithelkarzinomen zu bekämpfen. Diese Arbeit beinhaltete die Identifizierung des ersten deubiquitinierenden Enzyms, das die Stabilität des ∆Np63-Proteins reguliert. Hochmoderne SCC-Modelle wurden verwendet, um zu beweisen, dass USP28 ∆Np63 deubiquitiniert, seine Proteinstabilität reguliert und Plattenepithel-Transkriptionsprofile in vivo und ex vivo beeinflusst. Dementsprechend hängt SCC von USP28 ab, um wesentliche Mengen des Np63-Proteinüberflusses bei der Tumorbildung und -erhaltung aufrechtzuerhalten. Zum ersten Mal wurde ∆Np63, der Transkriptionsfaktor, in vivo mit einem niedermolekularen Inhibitor gezielt, der auf die Aktivität von USP28 abzielt. Die pharmakologische Hemmung von USP28 war ausreichend, um das Wachstum von SCC-Tumoren in präklinischen Mausmodellen zu verhindern. Schließlich zeigte diese Arbeit, dass die Kombination von Cisplatin mit USP28-Inhibitoren als neuartige therapeutische Alternative das begrenzt verfügbare Portfolio an SCC-Therapeutika erweitern könnte. Zusammengefasst zeigen die in dieser Dissertation präsentierten Daten, dass die Hemmung von USP28 in SCC die Np63-Proteinhäufigkeit verringert, wodurch der Fanconi-Anämie (FA)-Signalweg und die rekombinatorische DNA-Reparatur herunterreguliert werden. Dementsprechend reduziert die Hemmung von USP28 die Reaktion auf DNA-Schäden und sensibilisiert dadurch SCC- Tumoren für DNA-Schädigungstherapien wie Cisplatin. KW - USP28 KW - Squamous cell carcinoma KW - ΔNp63 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-270332 ER - TY - JOUR A1 - Prieto-Garcia, Cristian A1 - Tomašković, Ines A1 - Shah, Varun Jayeshkumar A1 - Dikic, Ivan A1 - Diefenbacher, Markus T1 - USP28: oncogene or tumor suppressor? a unifying paradigm for squamous cell carcinoma JF - Cells N2 - Squamous cell carcinomas are therapeutically challenging tumor entities. Low response rates to radiotherapy and chemotherapy are commonly observed in squamous patients and, accordingly, the mortality rate is relatively high compared to other tumor entities. Recently, targeting USP28 has been emerged as a potential alternative to improve the therapeutic response and clinical outcomes of squamous patients. USP28 is a catalytically active deubiquitinase that governs a plethora of biological processes, including cellular proliferation, DNA damage repair, apoptosis and oncogenesis. In squamous cell carcinoma, USP28 is strongly expressed and stabilizes the essential squamous transcription factor ΔNp63, together with important oncogenic factors, such as NOTCH1, c-MYC and c-JUN. It is presumed that USP28 is an oncoprotein; however, recent data suggest that the deubiquitinase also has an antineoplastic effect regulating important tumor suppressor proteins, such as p53 and CHK2. In this review, we discuss: (1) The emerging role of USP28 in cancer. (2) The complexity and mutational landscape of squamous tumors. (3) The genetic alterations and cellular pathways that determine the function of USP28 in squamous cancer. (4) The development and current state of novel USP28 inhibitors. KW - USP28 KW - SCC KW - USP25 KW - FBXW7 KW - Tp63 KW - c-MYC KW - ΔNp63 KW - p53 KW - cancer KW - DUB inhibitor KW - squamous Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-248409 SN - 2073-4409 VL - 10 IS - 10 ER - TY - JOUR A1 - Engel, Katharina A1 - Rudelius, Martina A1 - Slawska, Jolanta A1 - Jacobs, Laura A1 - Abhari, Behnaz Ahangarian A1 - Altmann, Bettina A1 - Kurutz, Julia A1 - Rathakrishnan, Abirami A1 - Fernández-Sáiz, Vanesa A1 - Brunner, Andrä A1 - Targosz, Bianca-Sabrina A1 - Loewecke, Felicia A1 - Gloeckner, Christian Johannes A1 - Ueffing, Marius A1 - Fulda, Simone A1 - Pfreundschuh, Michael A1 - Trümper, Lorenz A1 - Klapper, Wolfram A1 - Keller, Ulrich A1 - Jost, Philipp J. A1 - Rosenwald, Andreas A1 - Peschel, Christian A1 - Bassermann, Florian T1 - USP9X stabilizes XIAP to regulate mitotic cell death and chemoresistance in aggressive B-cell lymphoma JF - EMBO Molecular Medicine N2 - The mitotic spindle assembly checkpoint (SAC) maintains genome stability and marks an important target for antineoplastic therapies. However, it has remained unclear how cells execute cell fate decisions under conditions of SAC‐induced mitotic arrest. Here, we identify USP9X as the mitotic deubiquitinase of the X‐linked inhibitor of apoptosis protein (XIAP) and demonstrate that deubiquitylation and stabilization of XIAP by USP9X lead to increased resistance toward mitotic spindle poisons. We find that primary human aggressive B‐cell lymphoma samples exhibit high USP9X expression that correlate with XIAP overexpression. We show that high USP9X/XIAP expression is associated with shorter event‐free survival in patients treated with spindle poison‐containing chemotherapy. Accordingly, aggressive B‐cell lymphoma lines with USP9X and associated XIAP overexpression exhibit increased chemoresistance, reversed by specific inhibition of either USP9X or XIAP. Moreover, knockdown of USP9X or XIAP significantly delays lymphoma development and increases sensitivity to spindle poisons in a murine Eμ‐Myc lymphoma model. Together, we specify the USP9X–XIAP axis as a regulator of the mitotic cell fate decision and propose that USP9X and XIAP are potential prognostic biomarkers and therapeutic targets in aggressive B‐cell lymphoma. KW - B‐cell lymphoma KW - mitosis KW - ubiquitin KW - USP9X KW - XIAP Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165016 VL - 8 ER - TY - JOUR A1 - Maas, Moritz A1 - Mischinger, Johannes A1 - Compérat, Eva A1 - Scharpf, Marcus A1 - Fend, Falko A1 - Todenhöfer, Timlan A1 - Stenzl, Arnulf A1 - Gakis, Georgios A1 - Rausch, Steffen T1 - Utility of pT3 substaging in lymph node-negative urothelial carcinoma of the bladder: do pathologic parameters add to prognostic sub-stratification? JF - World Journal of Urology N2 - Purpose The value of bladder cancer (BC) substaging into macroscopic (pT3b) and microscopic (pT3a) perivesical fat extension in lymph node (Ln)-negative patients is controversially discussed and limited evidence for prognostic relevance of additional histopathological factors in pT3 BC exists. We evaluated the prognostic value of pT3 substaging and established pathological and clinical parameters with focus on tumor invasive front (TIF) and tumor size. Methods Specimens of 52 patients treated with radical cystectomy (RC) for pT3 a/b muscle-invasive BC were reviewed and re-evaluated by a pathologist specialized in uropathology. Clinical variables and standard histopathologic characteristics were assessed including TIF and tumor size. Their value as prognosticators for overall survival (OS) and recurrence-free survival (RFS) was evaluated. Results Mean age of patients was 67.55 years. Tumors were staged pT3a in 28 patients (53.8%) and pT3b in 24 (46.8%). Median OS was 34.51 months. Median tumor size was 3.2 cm, median TIF was 11.0 mm. Differences in OS between pT3a and pT3b were not significant (p = 0.45). Carcinoma in situ (CIS) and lymphovascular invasion (LVI) were significantly associated with pT3b tumors. Univariate analysis could not identify pathological prognosticators like TIF or tumor size for OS and RFS (p for all > 0.05). Conclusion No significant differences in OS or RFS were observed comparing Ln-negative pT3 BC following radical cystectomy. Additional pathologic variables like TIF could not be identified as prognosticator. Relevance of pT3 BC substaging needs reevaluation in larger prospective cohorts. KW - tumor invasion front KW - muscle-invasive bladder cancer KW - pathological staging KW - patient outcome KW - perivesical extension Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-266535 SN - 1433-8726 VL - 39 IS - 11 ER - TY - JOUR A1 - Seher, Axel A1 - Lagler, Charlotte A1 - Stühmer, Thorsten A1 - Müller-Richter, Urs Dietmar Achim A1 - Kübler, Alexander Christian A1 - Sebald, Walter A1 - Müller, Thomas Dieter A1 - Nickel, Joachim T1 - Utilizing BMP-2 muteins for treatment of multiple myeloma JF - PLoS ONE N2 - Multiple myeloma (MM) represents a haematological cancer characterized by the pathological hyper proliferation of antibody-producing B-lymphocytes. Patients typically suffer from kidney malfunction and skeletal disorders. In the context of MM, the transforming growth factor β (TGFβ) member Activin A was recently identified as a promoter of both accompanying symptoms. Because studies have shown that bone morphogenetic protein (BMP)-2-mediated activities are counteracted by Activin A, we analysed whether BMP2, which also binds to the Activin A receptors ActRII and ActRIIB but activates the alternative SMAD-1/5/8 pathway, can be used to antagonize Activin A activities, such as in the context of MM. Therefore three BMP2 derivatives were generated with modified binding activities for the type II (ActRIIB) and/or type I receptor (BMPRIA) showing either increased or decreased BMP2 activity. In the context of MM these BMP2 muteins show two functionalities since they act as a) an anti-proliferative/apoptotic agent against neoplastic B-cells, b) as a bone-formation promoting growth factor. The molecular basis of both activities was shown in two different cellular models to clearly rely on the properties of the investigated BMP2 muteins to compete for the binding of Activin A to the Activin type II receptors. The experimental outcome suggests new therapeutic strategies using BMP2 variants in the treatment of MM-related pathologies. KW - multiple myeloma KW - signaling KW - cell proliferation KW - cell binding KW - membrane receptor signaling KW - BMP KW - gene expression KW - B cell receptors KW - B cells Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158144 VL - 12 IS - 5 ER - TY - JOUR A1 - Kramer, Alexander A1 - Bangert, Philip A1 - Schilling, Klaus T1 - UWE-4: First Electric Propulsion on a 1U CubeSat — In-Orbit Experiments and Characterization JF - Aerospace N2 - The electric propulsion system NanoFEEP was integrated and tested in orbit on the UWE-4 satellite, which marks the first successful demonstration of an electric propulsion system on board a 1U CubeSat. In-orbit characterization measurements of the heating process of the propellant and the power consumption of the propulsion system at different thrust levels are presented. Furthermore, an analysis of the thrust vector direction based on its effect on the attitude of the spacecraft is described. The employed heater liquefies the propellant for a duration of 30 min per orbit and consumes 103 ± 4 mW. During this time, the respective thruster can be activated. The propulsion system including one thruster head, its corresponding heater, the neutralizer and the digital components of the power processing unit consume 8.5 ± 0.1 mW ⋅μ A\(^{−1}\) + 184 ± 8.5 mW and scales with the emitter current. The estimated thrust directions of two thruster heads are at angles of 15.7 ± 7.6∘ and 13.2 ± 5.5∘ relative to their mounting direction in the CubeSat structure. In light of the very limited power on a 1U CubeSat, the NanoFEEP propulsion system renders a very viable option. The heater of subsequent NanoFEEP thrusters was already improved, such that the system can be activated during the whole orbit period. KW - CubeSat KW - UWE-4 KW - electric propulsion KW - NanoFEEP KW - power consumption KW - thrust direction KW - characterization KW - in-orbit experiments Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236124 VL - 7 IS - 7 ER - TY - JOUR A1 - Prelog, Martina T1 - Vaccination in Patients with Rheumatoid Arthritis Receiving Immunotherapies JF - Clinical & Cellular Immunology N2 - Patients with rheumatoid arthritis (RA) are at higher risk to suffer from morbidity due to vaccine-preventable diseases and, thus, display an important target population to receive vaccines for protection from infectious complications. There have been only a few studies focusing on the administration of vaccines in RA patients with immunotherapy. Overall, antibody response rates against influenza or pneumococcal disease appeared to be only slightly lower than expected in healthy individuals. Crucial problems in the interpretation of data from studies in RA patients vaccinated against influenza and pneumococcal disease are the impaired comparability of studies due to different study designs and type of vaccines used, different health states among RA patients, heterogeneity in treatments including concomitant therapy with conventional DMARDs and glucocorticoids in addition to biological agents. Assessment of vaccination status should be performed in the initial work-up of patients with RA and should ideally be administered before initiation of immunotherapies or during stable disease. Due to differences in antibody responses and uncertainty regarding maintenance of protective antibodies, routine controls for antibody titers and specific strategies for earlier re-vaccination might be scheduled for patients with RA. KW - Immunotherapy KW - Anti-TNF-alpha agents KW - Rituximab KW - Tocilizumab KW - Abatacept KW - Pneumococcal vaccination KW - Influenza vaccination Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96446 ER - TY - JOUR A1 - Elias, Johannes A1 - Schouls, Leo M. A1 - van de Pol, Ingrid A1 - Keijzers, Wendy C. A1 - Martin, Diana R. A1 - Glennie, Anne A1 - Oster, Philipp A1 - Frosch, Matthias A1 - Vogel, Ulrich A1 - van der Ende, Arie T1 - Vaccine Preventability of Meningococcal Clone, Greater Aachen Region, Germany N2 - No abstract available KW - IMD Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68083 ER - TY - JOUR A1 - Duggal, Rohit A1 - Geissinger, Ulrike A1 - Zhang, Qian A1 - Aguilar, Jason A1 - Chen, Nanhai G. A1 - Binda, Elena A1 - Vescovi, Angelo L. A1 - Szalay, Aladar A. T1 - Vaccinia virus expressing bone morphogenetic protein-4 in novel glioblastoma orthotopic models facilitates enhanced tumor regression and long-term survival JF - Journal of Translational Medicine N2 - No abstract availableBackground: Glioblastoma multiforme (GBM) is one of the most aggressive forms of cancer with a high rate of recurrence. We propose a novel oncolytic vaccinia virus (VACV)-based therapy using expression of the bone morphogenetic protein (BMP)-4 for treating GBM and preventing recurrence. Methods: We have utilized clinically relevant, orthotopic xenograft models of GBM based on tumor-biopsy derived, primary cancer stem cell (CSC) lines. One of the cell lines, after being transduced with a cDNA encoding firefly luciferase, could be used for real time tumor imaging. A VACV that expresses BMP-4 was constructed and utilized for infecting several primary glioma cultures besides conventional serum-grown glioma cell lines. This virus was also delivered intracranially upon implantation of the GBM CSCs in mice to determine effects on tumor growth. Results: We found that the VACV that overexpresses BMP-4 demonstrated heightened replication and cytotoxic activity in GBM CSC cultures with a broad spectrum of activity across several different patient-biopsy cultures. Intracranial inoculation of mice with this virus resulted in a tumor size equal to or below that at the time of injection. This resulted in survival of 100% of the treated mice up to 84 days post inoculation, significantly superior to that of a VACV lacking BMP-4 expression. When mice with a higher tumor burden were injected with the VACV lacking BMP-4, 80% of the mice showed tumor recurrence. In contrast, no recurrence was seen when mice were injected with the VACV expressing BMP-4, possibly due to induction of differentiation in the CSC population and subsequently serving as a better host for VACV infection and oncolysis. This lack of recurrence resulted in superior survival in the BMP-4 VACV treated group. Conclusions: Based on these findings we propose a novel VACV therapy for treating GBM, which would allow tumor specific production of drugs in the future in combination with BMPs which would simultaneously control tumor maintenance and facilitate CSC differentiation, respectively, thereby causing sustained tumor regression without recurrence. KW - cancer stem cells (CSCs) and differentiation KW - glioblastoma multiforme (GBM) KW - vaccinia virus (VACV) KW - bone morphogenetic protein (BMP) Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-129626 VL - 11 IS - 155 ER - TY - JOUR A1 - Gholami, Sepideh A1 - Chen, Chun-Hao A1 - Belin, Laurence J. A1 - Lou, Emil A1 - Fujisawa, Sho A1 - Antonacci, Caroline A1 - Carew, Amanda A1 - Chen, Nanhai G. A1 - De Brot, Marina A1 - Zanzonico, Pat B. A1 - Szalay, Aladar A. A1 - Fong, Yuman T1 - Vaccinia virus GLV-1h153 is a novel agent for detection and effective local control of positive surgical margins for breast cancer JF - Breast Cancer Research N2 - Introduction: Surgery is currently the definitive treatment for early-stage breast cancer. However, the rate of positive surgical margins remains unacceptably high. The human sodium iodide symporter (hNIS) is a naturally occurring protein in human thyroid tissue, which enables cells to concentrate radionuclides. The hNIS has been exploited to image and treat thyroid cancer. We therefore investigated the potential of a novel oncolytic vaccinia virus GLV1h-153 engineered to express the hNIS gene for identifying positive surgical margins after tumor resection via positron emission tomography (PET). Furthermore, we studied its role as an adjuvant therapeutic agent in achieving local control of remaining tumors in an orthotopic breast cancer model. Methods: GLV-1h153, a replication-competent vaccinia virus, was tested against breast cancer cell lines at various multiplicities of infection (MOIs). Cytotoxicity and viral replication were determined. Mammary fat pad tumors were generated in athymic nude mice. To determine the utility of GLV-1h153 in identifying positive surgical margins, 90% of the mammary fat pad tumors were surgically resected and subsequently injected with GLV-1h153 or phosphate buffered saline (PBS) in the surgical wound. Serial Focus 120 microPET images were obtained six hours post-tail vein injection of approximately 600 mu Ci of I-124-iodide. Results: Viral infectivity, measured by green fluorescent protein (GFP) expression, was time-and concentrationdependent. All cell lines showed less than 10% of cell survival five days after treatment at an MOI of 5. GLV-1h153 replicated efficiently in all cell lines with a peak titer of 27 million viral plaque forming units (PFU) ( < 10,000-fold increase from the initial viral dose) by Day 4. Administration of GLV-1h153 into the surgical wound allowed positive surgical margins to be identified via PET scanning. In vivo, mean volume of infected surgically resected residual tumors four weeks after treatment was 14 mm(3) versus 168 mm(3) in untreated controls (P < 0.05). Conclusions: This is the first study to our knowledge to demonstrate a novel vaccinia virus carrying hNIS as an imaging tool in identifying positive surgical margins of breast cancers in an orthotopic murine model. Moreover, our results suggest that GLV-1h153 is a promising therapeutic agent in achieving local control for positive surgical margins in resected breast tumors. KW - conservation KW - carcinoma KW - mastectomy KW - metastases KW - stage-i KW - thyroid-cancer KW - radiation-therapy KW - conserving surgery KW - sodium-iodide symporter Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-122140 VL - 15 IS - R26 ER - TY - JOUR A1 - Cecil, Alexander A1 - Gentschev, Ivaylo A1 - Adelfinger, Marion A1 - Dandekar, Thomas A1 - Szalay, Aladar A. T1 - Vaccinia virus injected human tumors: oncolytic virus efficiency predicted by antigen profiling analysis fitted boolean models JF - Bioengineered N2 - Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a promising approach for cancer therapy. Recently, we showed that the oncolytic vaccinia virus GLV-1h68 has a therapeutic potential in treating human prostate and hepatocellular carcinomas in xenografted mice. In this study, we describe the use of dynamic boolean modeling for tumor growth prediction of vaccinia virus-injected human tumors. Antigen profiling data of vaccinia virus GLV-1h68-injected human xenografted mice were obtained, analyzed and used to calculate differences in the tumor growth signaling network by tumor type and gender. Our model combines networks for apoptosis, MAPK, p53, WNT, Hedgehog, the T-killer cell mediated cell death, Interferon and Interleukin signaling networks. The in silico findings conform very well with in vivo findings of tumor growth. Similar to a previously published analysis of vaccinia virus-injected canine tumors, we were able to confirm the suitability of our boolean modeling for prediction of human tumor growth after virus infection in the current study as well. In summary, these findings indicate that our boolean models could be a useful tool for testing of the efficacy of VACV-mediated cancer therapy already before its use in human patients. KW - boolean modeling KW - oncolytic virus KW - human xenografted mouse models KW - cancer therapy Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200507 VL - 10 IS - 1 ER - TY - THES A1 - Nguyen, Hoang Duong T1 - Vaccinia virus mediated expression of human erythropoietin in colonized human tumor xenografts results in faster tumor regression and increased red blood cell biogenesis in mice T1 - Expression von humanem Erythropietin in Vaccinia Virus-kolonisierten Tumorxenograftmodellen fördert die Tumorregression und die Biogenese roter Blutzellen N2 - Cancer-related anemia is prevalent in cancer patients. Anemia negatively affects normal mental and physical function capacity with common symptoms s like fatigue, headache, or depression. Human erythropoietin (hEPO), a glycoprotein hormone regulating red blood cell formation, is approved for the treatment of cancer-related anemia. It has shown benefits in correcting anemia, and subsequently improving health-related quality of life and/or enhancing radio-, and chemotherapy. Several recent clinical trials have suggested that recombinant hEPO (rhEPO) may promote tumor growth that raises the questions concerning the safety of using rhEPO for cancer treatment. However in others, such effects were not indicated. As of today, the direct functional effect of rhEPO in tumor models remains controversial and needs to be further analyzed. Based on the GLV-1h68 backbone, the hEPO-expressing recombinant VACV strains (EPO-VACVs) GLV-1h210, GLV-1h211, GLV-1h212 and GLV-1h213 were generated by replacing the lacZ expression cassette at the J2R locus with hEPO under the control of different vaccinia promoters p7.5, pSE, pSEL, pSL, respectively. Also, GLV-1h209 was generated, which is similar to GLV-1h210 but expresses a mutated non-functinal EPO (R103A). The EPO-VACV strains were characterized for their oncolytic efficacy in lung (A549) cancer cells in culture and tumor xenografts. Concomitantly, the effects of locally expressed hEPO in tumors on virus replication, host immune infiltration, tumor vascularization and tumor growth were also evaluated. As expected, EPO-VACVs enhanced red blood cell (RBC) formation in xenograft model. The number of RBCs and hemoglobin (Hb) levels were significantly increased in EPO-VACVs-treated mice compared to GLV-1h68-treated or untreated control mice. However, the mean size of RBC or Hb content per RBC remained normal. Furthermore, over-expression of hEPO did not significantly affect numbers of lymphocytes, monocytes, leucocytes or platelets in the peripheral blood stream. The expression of hEPO in colonized tumors of mice treated with EPO-VACVs was demonstrated by immunohistological staining. Interestingly, there were 9 - 10 hEPO isoforms detected either in tumors, cells, or supernatant, while 3-4 basic isoforms were missing in blood serum, where only six hEPO isoforms were found. Tumor-bearing mice after treatment with EPO-VACVs showed enhanced tumor regression compared to GLV-1h68. The virus titers in tumors in EPO-VACVs-treated mice were 3-4 fold higher compared to GLV-1h68-treated mice. Nevertheless, no significant difference in virus titers among EPO-VACVs was found. The blood vessels in tumors were significantly enlarged while the blood vessel density remained unchanged compared to the GLV-1h68 treated mice, indicating that hEPO did not affect endothelial cell proliferation in this model. Meanwhile, rhEPO (Epoetin alfa) alone or in combination with GLV-1h68 did not show any signs of enhanced tumor growth when compared to untreated controls and GLV-1h68 groups, while doses used were clinical relevant (500 U/kg). These findings suggested that hEPO did not promote angiogenesis or tumor growth in the A549 tumor xenograft model. Human EPO has been reported to function as an immune modulator. In this study, however, we did not find any involvement of hEPO in immune cytokine and chemokine expression or innate immune cell infiltration (leucocytes, B cells, macrophages and dendritic cells) into infected tumors. The degree of immune infiltration and cytokine expression was directly correlated to the number of virus particles. Increased virus replication, led to more recruited immune cells and secreted cytokines/chemokines. It was proposed that tumor regression was at least partially mediated through activation of innate immune mechanisms. In conclusion, the novel EPO-VACVs were shown to significantly increase the number of RBCs, Hb levels, and virus replication in tumors as well as to enhance tumor regression in the A549 tumor xenograft model. Moreover, locally expressed hEPO did not promote tumor angiogenesis, tumor growth, and immune infiltration but was shown to causing enlarged tumoral microvessels which facilitated virus spreading. It is conceivable that in a possible clinical application, anemic cancer patients could benefit from the EPO-VACVs, where they could serve as “wellness pills” to decrease anemic symptoms, while simultaneously destroying tumors. N2 - Blutarmut stellt eine häufige Begleiterscheinung in Krebspatienten dar. Anämie beeinträchtigt die normale mentale und körperliche Funktionsfähigkeit. Menschliches Erythropoetin (hEPO), welches die Bildung roter Blutzellen reguliert, ist klinisch zur Behandlung von Krebs-induzierter Blutarmut zugelassen. Wenn es zur Behandlung von Anämie benutzt wird, verbessert es den Gesundheitszustand sowie Bestrahlungs- und Chemotherapie. Verschiedene klinische zeigten, dass rekombinantes hEPO (rhEPO) das Tumorwachstum anregen kann, was die Frage nach Sicherheit der Anwendung von rhEPO aufbringt. In anderen Studien hingegen, gab es keine Anzeichen für eine Tumorwachstum anregenden Wirkung oder für ein Eingreifen in krebsspezifische Signalwege. Verschiedene hEPO exprimierende rekombinante VACV Stämme (EPO-VACV) wurden hergestellt, GLV-1h210, GLV-1h211 und GLV-1h213, in welchen die lacZ Expressionskassette im J2R Lokus durch das hEPO Gen unter der Kontrolle von verschiedenen Promotoren, p7.5, pSE und pSL, ersetzt wurde. Ebenfalls wurde GLV-1h209 hergestellt, welches ähnlich zu GLV-1h210 ist, jedoch ein mutiertes und nicht-funktionelles EPO Protein (R103A) exprimiert. Alle EPO-VACV Stämme wurden bezüglich ihrer onkolytischen Funktion in Zellkulturexperimenten sowie in in vivo Tumormodellen charakterisiert. Die Expression von zwei Markergene war in Zellkultur sowie in Tumorxenograften für alle EPO-VACV vergleichbar mit der des parentalen GLV-1h68 Virus. Unterschiede in hEPO Transkription und Translation der EPO-VACV war deutlich abhängig von der Promotorstärke und stieg an von p7.5, über pSE und pSL zu pSEL 12 h nach Infektion von Zellen. Darüberhinaus hatte die Insertion von hEPO in das virale Genom keinen Einfluss auf Replikation oder Zytotoxizität aller EPO-VACV in A549 oder NCI-H1299 Zelllinien, obwohl zu frühen Zeitpunkten (24-48 hpi) die Replikation der EPO-VACV etwas höher war, als die des GLV-1h68 Virus. Die A549 Zellen war zugänglicher für virale Infektion durch alle untersuchten Viren als die NCI-H1299 Zellen. Von besonderem Interesse ist, dass hypoxische Bedingungen (2% O2) die Replikation und damit Expression des Markergens gusA, sowie Zytotoxizität für alle untersuchten VACV unabhängig von hEPO Expression verlangsamte. Alle EPO-VACV erhöhen die Bildung von roten Blutzellen (RBC) in Mausmodellen. Anzahl und RBCs sowie Hämoglobin (Hb) Level waren signifikant erhöht im Vergleich zu unbehandelten oder GLV-1h68 behandelten Mäusen. Die Durchschnittsgröße einer RBC sowie der Hämoglobinanteil hingegen waren unverändert. Darüberhinaus hatte die Expression von hEPO keinen signifikanten Einfluss auf Lymphozyten, Monozyten, Leukozyten oder Blutplättchen im peripheren Blut. Die Expression von hEPO in EPO-VACV kolonisierten Tumoren wurde durch immunohistologische Färbungen bestätigt. Interessanterweise konnten 9-10 EPO Isoformen in Tumoren, Zellen oder Zellüberständen gefunden werden, während im Blutserum 3-4 basische Isoformen fehlten und nur 6 Isoformen auftraten. Tumortragende Mäuse, die mit EPO-VACV behandelt wurden, wiesen im Vergleich zu GLV-1h68 behandelten Mäusen eine erhöhte Tumorregression auf. Ausserdem waren virale Titer in EPO-VACV behandleten Tumoren 3-4 fach höher also in denen, die mit GLV-1h68 behandelt wurden. Kein signifikanter Unterschied hingegen wurde zwischen viralen Titern der verschiedenen EPO-VACV in Tumoren gefunden. Tumorale Blutgefäße waren im Vergleich zu GLV-1h68 behandelten Mäusen deutlich vergrößert, wohingegen die Dichte an Blutgefäßen unverändert war, was andeuted, dass keine Proliferation von Endothelzellen angeregt wurde. Rekombinant hergestelltes Epoetin alfa in klinisch relevanten Dosen allein oder in Kombination mit GLV-1h68 hatte keinen Einfluss auf Verbesserung der Tumorregression verglichen mit unbehandelten oder GLV-1h68 behandelten Mäusen. Diese Ergbnisse legen nahe, dass weder Angiogenese noch Tumorwachstum durch hEPO im A549 Tumormodell angeregt wurde. In dieser Studie hingegen wurde kein Einfluss von hEPO im Bezug auf Zytokin- oder Chemokinexpression sowie Immunzellinfiltration in Tumore nachgewiesen. Das Ausmass an Immunzellinfiltratrion und Zytokinexpression konnte direkt mit der Anzahl an viralen Partikeln korreliert werden. Es wurde angenommen, dass Tumorregression zumindest teiweise durch eine Aktivierung des angeborenen Immunsystems bedingt ist. Zusammenfassend kann gesagt werden, dass durch die neuartigen EPO-VACV die Bildung von RBC, die Level an Hb und die virale Replikation signifikant angeregt wurden sowie eine erhöhte Tumorregression im Xenograftmodell auftrat. Darüberhinaus leitete lokal exprimiertes hEPO keine Tumorangiogenese oder Tumorwachstum ein, aber führte zu einer Vergrößerung von Tumorblutgefäßen, was die virale Ausbreitung erleichtern könnte. Es ist vorstellbar, dass anämische Patienten von einer möglichen klinischen Anwendung der EPO-Viren profitieren würden. KW - Erythropoietin KW - Lungenkrebs KW - Anämie KW - onkolytische Virotherapie KW - erythropoietin KW - lung cancer KW - anemia KW - oncolytic therapy KW - Onkolyse Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85383 ER - TY - THES A1 - Heß, Michael T1 - Vaccinia virus-encoded bacterial beta-glucuronidase as a diagnostic biomarker for oncolytic virotherapy T1 - Vaccinia Virus-codierte bakterielle Beta-Glucuronidase als diagnostischer Biomarker in der onkolytischen Virotherapie N2 - Oncolytic virotherapy represents a promising approach to revolutionize cancer therapy. Several preclinical and clinical trials display the safety of oncolytic viruses as wells as their efficiency against solid tumors. The development of complementary diagnosis and monitoring concepts as well as the optimization of anti-tumor activity are key points of current virotherapy research. Within the framework of this thesis, the diagnostic and therapeutic prospects of beta-glucuronidase expressed by the oncolytic vaccinia virus strain GLV-1h68 were evaluated. In this regard, a beta-glucuronidase-based, therapy-accompanying biomarker test was established which is currently under clinical validation. By using fluorescent substrates, the activity of virally expressed beta-glucuronidase could be detected and quantified. Thereby conclusions about the replication kinetics of oncolytic viruses in animal models and virus-induced cancer cell lysis could be drawn. These findings finally led to the elaboration and establishment of a versatile biomarker assay which allows statements regarding the replication of oncolytic viruses in mice based on serum samples. Besides the analysis of retrospective conditions, this test is able to serve as therapy-accompanying monitoring tool for virotherapy approaches with beta-glucuronidase-expressing viruses. The newly developed assay also served as complement to routinely used plaque assays as well as reference for virally expressed anti-angiogenic antibodies in additional preclinical studies. Further validation of this biomarker test is currently taking place in the context of clinical trials with GL-ONC1 (clinical grade GLV-1h68) and has already shown promising preliminary results. It was furthermore demonstrated that fluorogenic substrates in combination with beta-glucuronidase expressed by oncolytic viruses facilitated the optical detection of solid tumors in preclinical models. In addition to diagnostic purposes, virus-encoded enzymes could also be combined with prodrugs resulting in an improved therapeutic outcome of oncolytic virotherapy. In further studies, the visualization of virus-induced immune reactions as well as the establishment of innovative concepts to improve the therapeutic outcome of oncolytic virotherapy could be accomplished. In conclusion, the results of this thesis provide crucial findings about the influence of virally expressed beta-glucuronidase on various diagnostic concepts in the context of oncolytic virotherapy. In addition, innovative monitoring and therapeutic strategies could be established. Our preclinical findings have important clinical influence, particularly by the development of a therapy-associated biomarker assay which is currently used in different clinical trials. N2 - Onkolytische Viren stellen einen vielversprechenden Therapieansatz dar, der die Behandlung von Krebserkrankungen revolutionieren könnte. Intensive präklinische und klinische Studien zeigen sowohl die körperliche Verträglichkeit von onkolytischen Viren, als auch deren Wirksamkeit gegenüber soliden Tumoren. Die Entwicklung von therapiebegleitenden Diagnose- und Monitoringkonzepten sowie eine Optimierung der Antitumorwirkung onkolytischer Viren stellen Eckpunkte der aktuellen Forschung auf dem Gebiet der Virotherapie dar. Im Rahmen dieser Arbeit wurde untersucht, welche diagnostischen und therapeutischen Möglichkeiten die virale Expression von beta-Glucuronidase durch den onkolytischen Vaccinia-Virus-Stamm GLV-1h68 eröffnet. In diesem Zusammenhang wurde ein, auf beta-Glucuronidase basierender, therapiebegleitender Biomarkertest entwickelt, dessen klinische Validierung derzeit stattfindet. Mit Hilfe von fluorogenen Substraten konnte die Aktivität viral exprimierter beta-Glucuronidase detektiert und quantifiziert werden. Dies lies direkte Rückschlüsse auf das Replikationsverhalten von onkolytischen Viren im Tiermodell zu und ermöglichte zudem Aussagen über die Zelllyse Virus-infizierter Krebszellen. Diese Erkenntnisse führten letztendlich zur Ausarbeitung und Etablierung eines vielseitig anwendbaren Biomarker-Assays, der es ermöglicht anhand von Blutproben Aussagen über das Replikationsverhalten onkolytischer Viren in Mäusen zu machen. Neben retrospektiven Analysen erlaubt dieser Test auch ein therapiebegleitendes Monitoring der onkolytischen Virotherapie mit beta-Glucuronidase-exprimierenden Viren. In weiteren präklinischen Untersuchungen diente der entwickelte Assay zudem als Ergänzung zum viralen Plaque Assays sowie als Referenz für Virus-exprimierte anti-angiogene Antikörper. Eine fortführende Validierung dieses neuartigen Biomarkertests findet derzeit im Rahmen humaner Studien mit der klinischen Formulierung von GLV-1h68, GL-ONC1, statt und zeigte bereits erste positive Resultate. Weiterhin konnte im Rahmen dieser Arbeit gezeigt werden, dass die Expression von beta-Glucuronidase durch onkolytische Viren in Verbindung mit fluoreszierenden Substraten eine optische Detektion von Karzinomen im präklinischen Tiermodell ermöglicht. Neben diagnostischen Zwecken, konnten Virus-kodierte Enzyme in Kombination mit Prodrugs genutzt werden, um den Therapieerfolg der onkolytischen Virotherapie zu verbessern. In zusätzlichen Studien konnten zudem Methoden zur Visualisierung der Virus-induzierten Immunantwort sowie neuartige Konzepte zur Therapieverbesserung etabliert werden. Zusammenfassend liefern die Ergebnisse der vorliegenden Arbeit wichtige Erkenntnisse über den Einfluss Virus-exprimierter beta-Glucuronidase auf unterschiedliche Diagnosekonzepte im Rahmen der onkolytischen Virotherapie. Daneben konnten entscheidende Erkenntnisse über den möglichen Einsatz neuer Monitoring- und Therapieansätze erzielt werden. Insbesondere durch die Entwicklung eines therapiebegleitenden Biomarkertests haben diese Resultate erheblichen Einfluss auf die weitere klinische Anwendung von onkolytischen Vaccinia-Viren. KW - Vaccinia-Virus KW - Glucuronidase KW - Krebs KW - cancer KW - oncolytic virus KW - biomarker KW - beta-glucuronidase Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-86789 ER - TY - JOUR A1 - Schäfer, Simon A1 - Weibel, Stephanie A1 - Donat, Ulrike A1 - Zhang, Quian A1 - Aguilar, Richard J. A1 - Chen, Nanhai G. A1 - Szalay, Aladar A. T1 - Vaccinia virus-mediated intra-tumoral expression of matrix metalloproteinase 9 enhances oncolysis of PC-3 xenograft tumors JF - BMC Cancer N2 - Background Oncolytic viruses, including vaccinia virus (VACV), are a promising alternative to classical mono-cancer treatment methods such as surgery, chemo- or radiotherapy. However, combined therapeutic modalities may be more effective than mono-therapies. In this study, we enhanced the effectiveness of oncolytic virotherapy by matrix metalloproteinase (MMP-9)-mediated degradation of proteins of the tumoral extracellular matrix (ECM), leading to increased viral distribution within the tumors. Methods For this study, the oncolytic vaccinia virus GLV-1h255, containing the mmp-9 gene, was constructed and used to treat PC-3 tumor-bearing mice, achieving an intra-tumoral over-expression of MMP-9. The intra-tumoral MMP-9 content was quantified by immunohistochemistry in tumor sections. Therapeutic efficacy of GLV-1h255 was evaluated by monitoring tumor growth kinetics and intra-tumoral virus titers. Microenvironmental changes mediated by the intra-tumoral MMP-9 over-expression were investigated by microscopic quantification of the collagen IV content, the blood vessel density (BVD) and the analysis of lymph node metastasis formation. Results GLV-1h255-treatment of PC-3 tumors led to a significant over-expression of intra-tumoral MMP-9, accompanied by a marked decrease in collagen IV content in infected tumor areas, when compared to GLV-1h68-infected tumor areas. This led to considerably elevated virus titers in GLV-1h255 infected tumors, and to enhanced tumor regression. The analysis of the BVD, as well as the lumbar and renal lymph node volumes, revealed lower BVD and significantly smaller lymph nodes in both GLV-1h68- and GLV-1h255- injected mice compared to those injected with PBS, indicating that MMP-9 over-expression does not alter the metastasis-reducing effect of oncolytic VACV. Conclusions Taken together, these results indicate that a GLV-1h255-mediated intra-tumoral over-expression of MMP-9 leads to a degradation of collagen IV, facilitating intra-tumoral viral dissemination, and resulting in accelerated tumor regression. We propose that approaches which enhance the oncolytic effect by increasing the intra-tumoral viral load, may be an effective way to improve therapeutic outcome. KW - microenvironment KW - angiogenesis KW - therapy KW - cancer KW - breast-tumors KW - matrix metalloproteinases KW - adenovirus KW - carcinoma KW - prostate KW - mice Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-140800 VL - 12 IS - 366 ER - TY - JOUR A1 - Schäfer, Simon A1 - Weibel, Stephanie A1 - Donat, Ulrike A1 - Zhang, Qian A1 - Aguilar, Richard J. A1 - Chen, Nanhai G. A1 - Szalay, Aladar A. T1 - Vaccinia virus-mediated intra-tumoral expression of matrix metalloproteinase 9 enhances oncolysis of PC-3 xenograft tumors N2 - Background: Oncolytic viruses, including vaccinia virus (VACV), are a promising alternative to classical mono-cancer treatment methods such as surgery, chemo- or radiotherapy. However, combined therapeutic modalities may be more effective than mono-therapies. In this study, we enhanced the effectiveness of oncolytic virotherapy by matrix metalloproteinase (MMP-9)-mediated degradation of proteins of the tumoral extracellular matrix (ECM), leading to increased viral distribution within the tumors. Methods: For this study, the oncolytic vaccinia virus GLV-1h255, containing the mmp-9 gene, was constructed and used to treat PC-3 tumor-bearing mice, achieving an intra-tumoral over-expression of MMP-9. The intra-tumoral MMP-9 content was quantified by immunohistochemistry in tumor sections. Therapeutic efficacy of GLV-1h255 was evaluated by monitoring tumor growth kinetics and intra-tumoral virus titers. Microenvironmental changes mediated by the intra-tumoral MMP-9 over-expression were investigated by microscopic quantification of the collagen IV content, the blood vessel density (BVD) and the analysis of lymph node metastasis formation. Results: GLV-1h255-treatment of PC-3 tumors led to a significant over-expression of intra-tumoral MMP-9, accompanied by a marked decrease in collagen IV content in infected tumor areas, when compared to GLV-1h68-infected tumor areas. This led to considerably elevated virus titers in GLV-1h255 infected tumors, and to enhanced tumor regression. The analysis of the BVD, as well as the lumbar and renal lymph node volumes, revealed lower BVD and significantly smaller lymph nodes in both GLV-1h68- and GLV-1h255- injected mice compared to those injected with PBS, indicating that MMP-9 over-expression does not alter the metastasis-reducing effect of oncolytic VACV. Conclusions: Taken together, these results indicate that a GLV-1h255-mediated intra-tumoral over-expression of MMP-9 leads to a degradation of collagen IV, facilitating intra-tumoral viral dissemination, and resulting in accelerated tumor regression. We propose that approaches which enhance the oncolytic effect by increasing the intra-tumoral viral load, may be an effective way to improve therapeutic outcome. KW - Biochemie Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78220 ER - TY - THES A1 - Geissinger, Ulrike T1 - Vaccinia Virus-mediated MR Imaging of Tumors in Mice: Overexpression of Iron-binding Proteins in Colonized Xenografts T1 - Vaccinia Virus-vermittelte MR Bildgebung von Tumoren in Maeusen: Ueberexpression von Eisen-bindenden Proteinen in kolonisierten Heterotransplantaten N2 - Vaccinia virus plays an important role in human medicine and molecular biology ever since the 18th century after E. Jenner discovered its value as a vaccination virus against smallpox. After the successful eradication of smallpox, vaccinia virus, apart from its use as a vaccine carrier, is today mainly used as a viral vector in molecular biology and increasingly in cancer therapy. The capability to specifically target and destroy cancer cells makes it a perfect agent for oncolytic virotherapy. Furthermore, the virus can easily be modified by inserting genes encoding therapeutic or diagnostic proteins to be expressed within the tumor. The emphasis in this study was the diagnosis of tumors using different vaccinia virus strains. Viruses with metal-accumulating capabilities for tumor detection via MRI technology were generated and tested for their usefulness in cell culture and in vivo. The virus strains GLV-1h131, GLV-1h132, and GLV-1h133 carry the gene encoding the two subunits of the iron storage protein ferritin under the control of three different promoters. GLV-1h110, GLV-1h111, and GLV-1h112 encode the bacterial iron storage protein bacterioferritin, whereas GLV-1h113 encodes the codon-optimized version of bacterioferritin for more efficient expression in human cells. GLV-1h22 contains the transferrin receptor gene, which plays an important role in iron uptake, and GLV-1h114 and GLV-1h115 contain the murine transferrin receptor gene. For possibly better iron uptake the virus strains GLV-1h154, GLV-1h155, GLV-1h156, and GLV-1h157 were generated, each with a version of a ferritin gene and a transferrin receptor gene. GLV-1h154 carries the genes that encode bacterioferritin and human transferrin receptor, GLV-1h155 the human ferritin H-chain gene and the human transferrin receptor gene. GLV-1h156 and GLV-1h157 infected cells both express the mouse transferrin receptor and bacterioferritin or human ferritin H-chain, respectively. The virus strains GLV-1h186 and GLV-1h187 were generated to contain a mutated form of the ferritin light chain, which was shown to result in iron overload and the wildtype light chain gene, respectively. The gene encoding the Divalent Metal Transporter 1, which is a major protein in the uptake of iron, was inserted in the virus strain GLV-1h102. The virus strain GLV-1h184 contains the magA gene of the magnetotactic bacterium Magnetospirillum magnetotacticum, which produces magnetic nanoparticles for orientation in the earth’s magnetic field. Initially the infection and replication capability of all the virus strains were analyzed and compared to that of the parental virus strain GLV-1h68, revealing that all the viruses were able to infect cells of the human cancer cell lines A549 and GI-101A. All constructs exhibited a course of infection comparable to that of GLV-1h68. Next, to investigate the expression of the foreign proteins in GI-101A and A549 cells with protein analytical methods, SDS-gelelectrophoresis, Western blots and ELISAs were performed. The proteins, which were expressed under the control of the strong promoters, could be detected using these methods. To be able to successfully detect the protein expression of MagA and DMT1, which were expressed under the control of the weak promoter, the more sensitive method RT-PCR was used to at least confirm the transcription of the inserted genes. The determination of the iron content in infected GI-101A and A549 cells showed that infection with all used virus strains led to iron accumulation in comparison to uninfected cells, even infection with the parental virus strain GLV-1h68. The synthetic phytochelatin EC20 was also shown to enhance the accumulation of different heavy metals in bacterial cultures. In vivo experiments with A549 tumor-bearing athymic nude mice revealed that 24 days post infection virus particles were found mainly in the tumor. The virus-mediated expression of recombinant proteins in the tumors was detected successfully by Western blot. Iron accumulation in tumor lysates was investigated by using the ferrozine assay and led to the result that GLV-1h68-infected tumors had the highest iron content. Histological stainings confirmed the finding that iron accumulation was not a direct result of the insertion of genes encoding iron-accumulating proteins in the virus genome. Furthermore virus-injected tumorous mice were analyzed using MRI technology. Two different measurements were performed, the first scan being done with a seven Tesla small animal scanner seven days post infection whereas the second scan was performed using a three Tesla human scanner 21 days after virus injection. Tumors of mice injected with the virus strains GLV-1h113 and GLV-1h184 were shown to exhibit shortened T2 and T2* relaxation times, which indicates enhanced iron accumulation. In conclusion, the experiments in this study suggest that the bacterioferritin-encoding virus strain GLV-1h113 and the magA-encoding virus strain GLV-1h184 are promising candidates to be used for cancer imaging after further analyzation and optimization. N2 - Das Vaccinia Virus spielt in der Humanmedizin und Molekularbiologie eine wichtige Rolle seit E. Jenner im 18. Jahrhundert seinen Nutzen als Impfvirus entdeckt hat. Nach der erfolgreichen Ausrottung der Pocken, wird das Vaccinia Virus heutzutage neben der Anwendung als Impfstoffträger hauptsächlich als viraler Vektor in der Molekularbiologie und in zunehmendem Maße in der Krebstherapie verwendet. Die Fähigkeit Krebszellen gezielt zu zerstören, macht es zu einem perfekten Wirkstoff für die onkolytische Virotherapie. Des Weiteren kann das Virus durch das Inserieren von Genen, die für therapeutische oder diagnostische Proteine kodieren, und im Tumor exprimiert werden, modifiziert werden. Der Schwerpunkt dieser Arbeit war die Tumordiagnose mit Hilfe verschiedener Vaccinia Virusstämme. Viren mit der Fähigkeit, Metalle anzureichern wurden zur Tumordetektion mittels Kernspintomographie hergestellt und auf ihre Nutzbarkeit in Zellkultur und in vivo getestet. Die Virusstämme GLV-1h132, GLV-1h132 und GLV-1h133 tragen das Gen, welches für die zwei Untereinheiten des Eisenspeicherproteins Ferritin kodieren unter der Kontrolle von drei verschiedenen Promotoren. GLV-1h110, GLV-1h111, und GLV-1h112 tragen das Gen, welches für das bakterielle Eisenspeicherprotein Bacterioferritin kodiert, wohingegen das inserierte Gen in GLV-1h113 für die codon-optimierte Version dieses Proteins kodiert, die eine effizientere Expression in humanen Zellen ermöglichen soll. GLV-1h22 beinhaltet das Transferrin-Rezeptor-Gen, welches eine wichtige Rolle in der Eisenaufnahme spielt, und GLV-1h114 und GLV-1h115 beinhalten das murine Transferrin-Rezeptor-Gen. Für eine möglicherweise bessere Eisenaufnahme wurden die Virusstämme GLV-1h154, GLV-1h155, GLV-1h156 und GLV-1h157 mit je einer Version eines Ferritin-Gens und eines Transferrin-Rezeptor-Gens generiert. GLV-1h154 trägt die Gene, die für Bacterioferritin und den humanen Transferrin Rezeptor kodieren, GLV-1h155 trägt die Gene für die humane Ferritin H-Untereinheit und den humanen Transferrin Rezeptor. Zellen, die mit GLV-1h156 und GLV-1h157 infiziert wurden, exprimierten den Maus-Transferrin-Rezeptor und Bacterioferritin beziehungsweise die humane Ferritin-H-Untereinheit. Die Virusstämme GLV-1h186 und GLV-1h187 wurden mit einer mutierten Form der leichten Untereinheit von Ferritin, für die eine Überladung mit Eisen gezeigt wurde, beziehungsweise mit der leichten Untereinheit des wildtypischen Gens ausgestattet. Das Gen, das für den Divalenten Metal Transporter 1 kodiert, welches ein bedeutendes Protein für die Aufnahme von Eisen darstellt, wurde in den Virusstamm GLV-1h102 inseriert. Der Virusstamm GLV-1h184 trägt das magA Gen des magnetotaktischen Bakteriums Magnetospirillum magnetotacticum, welches magnetische Nanopartikel zur Orientierung im Erdmagnetfeld produziert. Zunächst wurde die Infektions- und Replikationsfähigkeit aller Viren analysiert und mit der des Ausgangsstammes GLV-1h68 verglichen, was zeigte, dass alle Viren in der Lage waren humane Krebszellen der Zelllinien GI-101A und A549 zu infizieren. Alle Konstrukte zeigten einen vergleichbaren Infektionsverlauf zu GLV-1h68. Als nächstes, um die Expression der fremden Proteine in GI-101A und A549 Zellen zu untersuchen, wurden SDS-Gelelektrophorese, Western Blots und ELISAs durchgeführt. Die Proteine, welche unter der Kontrolle von starken Promotoren exprimiert wurden, konnten mit diesen Methoden detektiert werden. Um die Expression von MagA und DMT1 zu detektieren, welche unter der Kontrolle des schwachen Promotors exprimiert wurden, wurde die sensitivere Methode RT-PCR angewendet, mit der zumindest die Transkription der Gene nachgewiesen werden konnte. Die Bestimmung des Eisengehaltes in infizierten GI-101A und A549 Zellen zeigte, dass die Infektion mit allen Viren im Vergleich zu uninfizierten Zellen zu einer Eisenanreicherung führte, sogar die Infektion mit dem Ausgangsstamm GLV-1h68. Für das synthetische Phytochelatin EC20 wurde auch eine Anhäufung von verschiedenen Schwermetallen in Bakterienkulturen gezeigt. In vivo Experimente mit A549 tumor-tragenden athymischen Nacktmäusen ergaben, dass Viruspartikel 24 Tage nach der Infektion hauptsächlich im Tumor gefunden wurden. Die von den Viren vermittelte Expression der rekombinanten Proteine in den Tumoren wurde erfolgreich mit Hilfe von Western Blots detektiert. Die Eisenansammlung in Tumorlysaten wurde mit dem Ferrozine Assay untersucht und führte zu dem Ergebnis, dass Tumore, die mit GLV-1h68 infiziert wurden, den höchsten Eisengehalt vorwiesen. Histologische Färbungen bestätigten die Erkenntnis, dass die Eisenansammlung nicht ein direktes Resultat der Insertion von eisenansammelnden Genen in das Virusgenom war. Darüberhinaus wurden tumortragende Mäuse, denen Virus injiziert wurde, mittels Kernspintomographie analysiert. Zwei verschiedene Messungen wurden durchgeführt, wobei die erste Messung sieben Tage nach Virusinjektion mit einem sieben Tesla Kleintier-Scanner durchgeführt wurde und die zweite Messung mit einem humanen drei Tesla Scanner 21 Tage nach Virusinjektion. Tumore von Mäusen, die mit den Virusstämmen GLV-1h113 und GLV-1h184 injiziert wurden, zeigten verkürzte T2- und T2*-Relaxationszeiten, was auf eine verbesserte Eisenakkumulation hinweist. Zusammenfassend deuten die Experimente dieser Studie darauf hin, dass der Virusstamm GLV-1h113, welcher für Bacterioferritin kodiert, und der Virusstamm GLV-1h184, welcher für MagA kodiert, nach weiterer Untersuchung und Optimierung vielversprechende Kandidaten für die Krebs Bildgebung sind. KW - Vaccinia-Virus KW - NMR-Tomographie KW - Tumor KW - Krebsbildgebung KW - Tumordetektion KW - Vaccinia Virus KW - Tumor detection KW - MRI Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48099 ER - TY - THES A1 - Huang, Ting T1 - Vaccinia Virus-mediated Therapy of Solid Tumor Xenografts: Intra-tumoral Delivery of Therapeutic Antibodies T1 - Vaccini-Virus-vermittelte Therapie solider Tumoren: Intra-tumoraler Transport therapeutischer Antikörper N2 - Over the past 30 years, much effort and financial support have been invested in the fight against cancer, yet cancer still represents the leading cause of death in the world. Conventional therapies for treatment of cancer are predominantly directed against tumor cells. Recently however, new treatments options have paid more attention to exploiting the advantage of targeting the tumor stroma instead. Vaccinia virus (VACV) has played an important role in human medicine since the 18th century as a vaccination against smallpox. In our laboratory, the recombinant, replication-competent vaccinia virus, GLV-1h68, was shown to enter, colonize and destroy cancer cells both in cell culture, and in vivo, in xenograft models (Zhang, Yu et al. 2007). In addition, combined therapy of GLV-1h68 and anti-VEGF immunotherapy significantly enhanced antitumor therapy in vivo (Frentzen, Yu et al. 2009). In this study, we constructed several new recombinant VACVs carrying genes encoding different antibodies against fibroblast activation protein (FAP) in stroma (GLV-1h282), nanobody against the extracellular domain of epidermal growth factor receptor (EGFR, GLV-1h442) or antibodies targeting both vascular endothelial growth factor (VEGF) and EGFR (GLV-1h444) or targeting both VEGF and FAP (GLV-1h446). The expression of the recombinant proteins was first verified using protein analytical methods, SDS-gel electrophoresis, Western blot analysis, immunoprecipitation (IP) assays and ELISA assays. The proteins were detected after infection of the cells with the different VACVs and the recombinant proteins purified by affinity adsorption. The purified antibodies were shown to specifically bind to their respective antigens. Secondly, the infection and replication capability of all the virus strains was analyzed in cell culture using several human tumor cell lines (A549, FaDu or DU145), revealing that all the new recombinant VACVs were able to infect cancer cells with comparable efficiency to the parental viruses from which they were derived. Thirdly, the antitumor efficacy of the new recombinant VACVs was evaluated in vivo using several human cancer xenograft models in mice. In A549 and DU145 xenografts, the new recombinant VACVs exhibited an enhanced therapeutic efficacy compared to GLV-1h68 with no change in toxicity in mice. In the FaDu xenograft, treatment with GLV-1h282 (anti-FAP) significantly slowed down the speed of tumor growth compared to GLV-1h68. Additionally, treatment with the recombinant VACVs expressed the various antibodies achieved comparable or superior therapeutic effects compared to treatment with a combination of GLV-1h68 and the commercial therapeutic antibodies, Avastin, Erbitux or both. Next, the virus distribution in tumors and organs of treated mice was evaluated. For most of the viruses, the virus titer in tumors was not signficantly diffferent than GLV-1h68. However, for animals treated with GLV-1h282, the virus titer in tumors was significantly higher than with GLV-1h68. This may be the reason for enhanced antitumor efficacy of GLV-1h282 in vivo. Lastly, the underlying mechanisms of therapeutic antibody-enhanced antitumor effects were investigated by immunohistochemistry. Blood vessels density and cell proliferation in tumors were suppressed after treatment with the antibody-encoded VACVs. The results indicated that the suppression of angiogenesis or cell proliferation in tumors may cause the observed therapeutic effect. In conclusion, the results of the studies presented here support the hypothesis that the treatment of solid tumors with a combination of oncolytic virotherapy and immunotherapy has an additive effect over each treatment alone. Moreover, expression of the immunotherapeutic antibody by the oncolytic VACV locally in the tumor enhances the antitumor effect over systemic treatment with the same antibody. Combined, these results indicate that therapy with oncolytic VACVs expressing-therapeutic antibodies may be a promising approach for the treatment of cancer. N2 - In den letzten 30 Jahren wurde viel Aufwand und finanzielle Unterstützung in den Kampf gegen Krebs investiert, doch das Resultat ist limitiert, da Krebs immer noch die zweithöchste Todesursache in der Welt darstellt. Zusätzlich zu gegenwärtig verwendeten Therapien, die vorwiegend gegen Tumorzellen gerichtet sind, wird neuen Therapien mehr Aufmerksamkeit gewidmet, die stattdessen direkt auf das Tumorstroma zielen. Onkolytische Vaccinia Viren haben seit dem 18ten Jahrhundert als Impfstoff gegen Pocken in der Humanmedizin eine wichtige Rolle gespielt. In unserem Labor hat das rekombinante, replikationskompetente Vaccinia Virus GLV-1h68 gezeigt, dass es in Zellkultur und in Xenograft Modellen in Krebszellen eindringen sowie diese kolonisieren und zerstören kann (Zhang, Yu et al. 2007). Zusätzlich verbessert die kombinierte Therapie von GLV-1h68 und anti-VEGF Immunotherapy signifikant die Antitumortherapie in vivo (Frentzen, Yu et al. 2009). In dieser Studie haben wir mehrere neue rekombinante VACVs konstruiert, die die Gene für verschiedene Antikörper gegen das Fibroblasten Aktivierungs Protein (FAP) im Stroma (GLV-1h282) oder einen Nanobody gegen die extrazelluläre Domäne des Epidermalen Wachstumsfaktor (EGFR; GLV-1h442) kodieren. Ausserdem wurden Viren konstruiert, die eine Ko-Expression von Antikörpern gegen sowohl vaskulären Endothelwachstumsfaktor (VEGF) als auch EGFR (GLV-1h444) oder gegen sowohl VEGF als auch FAP (GLV-1h446) erlauben. Zunächst wurden SDS-Gelelektrophorese, Western Blot Analyse, Immunprezipitation (IP) und ELISA Assays durchgeführt, um die Expression der rekombinanten Proteine in Zellen mit proteinanalytischen Methoden zu untersuchen. Die Proteine waren nach Infektion der Zellen mit den verschiedenen VACVs nachweisbar und wurden mittles des FLAG Tags mit einem IP Kit aufgereinigt. Es konnte gezeigt werden, dass die aufgereinigten Antikörper spezifisch an ihr jeweiliges Antigen binden. Zweitens wurde die Infektion und Replikationsfähigkeit aller Virusstämme in Zellkultur untersucht (A549, FaDu oder DU145) und mit ihrem jeweiligen Ausgangsstamm GLV-1h68, GLV-1h164, GLV-1h282 oder GLV-1h442 verglichen. Die Ergebnisse zeigten, dass alle neuen rekombinanten VACVs Zellen mit vergleichbarer Effizienz infizieren konnten wie ihre Ausgangsstämme. Drittens, um die Antitumoreffizienz der neuen rekombinanten Stämme in vivo zu testen, wurden verschiedene humane Tumor Xenotransplantat-tragende Nacktmäuse mit verschiedenen VACVs behandelt. In A549 und DU145 Xenotransplantaten zeigten die neuen rekombinanten VACVs erhöhte therapeutische Effizienz verglichen mit dem Ausgangsstamm GLV-1h68, ohne Veränderung der Toxizität in Mäusen. Im FaDu Xenotransplantat verursachte die Behandlung mit GLV-1h68 keine Tumorregression, wohingegen die Behandlung mit GLV-1h282 (anti-FAP) die Geschwindigkeit des Tumorwachstums signifikant verlangsamte sowie das Überleben verlängerte. Zusätzlich haben wir herausgefunden, dass die Behandlung mit Antikörpern, die mittels Virus geliefert wurden, einen identischen oder sogar erhöhten inhibitorischen Effekt erzielen können, wie in einer Kombinationstherapie von GLV-1h68 und kommerziell erhältlichen Antikörpern, wie Avastin, Erbitux oder beidem. Um die virale Verteilung in vivo zu untersuchen, wurden Tumore und Organe von Mäusen seziert und homogenisiert, gefolgt von Titration der Virusmenge. Die Virus-Titer in Tumoren waren signifikant höher in Tieren, die mit GLV-1h282 behandelt wurden als solche, die mit GLV-1h68 behandelt wurden. Dies mag den Grund für die erhöhte Antitumoreffizienz von GLV-1h282 in vivo darstellen. Die Virus-Titer in allen anderen Gruppen zeigten keinen signifikanten Unterschied. Um den Mechanismus der durch therapeutische Antikörper erhöhten Antitumortherapie zu untersuchen, wurde Immunohistochemie durchgeführt. Nach Behandlung mit den Antikörper-kodierenden VACVs waren die Blutgefäβdichte und Zellproliferation in Tumoren reduziert, nachgewiesen durch die jeweilige CD31 and Ki67 Färbung. Die Resultate deuteten an, dass die Suppression der Angiogenese oder der Zellproliferation in Tumoren den beobachteten Effekt verursachen könnte. Zusammenfassend zeigen die hier präsentierten Daten dass die Kombination der Behandlung von onkolytischer Virotherapie mit Immunotherapie durch Virus-gelieferte Antikörper einen vielversprechenden Ansatz für Krebstherapie darstellt. KW - Vaccinia-Virus KW - therapeutic antibody KW - oncolytic virus KW - Krebs KW - Therapie KW - Antikörper KW - Tumor Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-91327 ER - TY - THES A1 - Camargo Molina, José Eliel T1 - Vacuum stability of models with many scalars T1 - Vakuumstabilität von Modellen mit vielen Skalaren N2 - One of the most popular extensions of the SM is Supersymmetry (SUSY). It is a symmetry relating fermions and bosons and also the only feasible extension to the symmetries of spacetime. With SUSY it is then possible to explain some of the open questions left by the SM while at the same time opening the possibility of gauge unification at a high scale. SUSY theories require the addition of new particles, in particular an extra Higgs doublet and at least as many new scalars as fermions in the SM. Much in the same way that the Higgs boson breaks SU (2)L symmetry, these new scalars can break any symmetry for which they carry a charge through spontaneous symmetry breaking. Let us assume there is a local minimum of the potential that reproduces the correct phenomenol- ogy for a parameter point of a given model. By exploring whether there are other deeper minima with VEVs that break symmetries we want to conserve, like SU (3)C or U (1)EM , it is possible to exclude regions of parameter space where that happens. The local minimum with the correct phenomenology might still be metastable, so it is also necessary to calculate the probability of tunneling between minima. In this work we propose and apply a framework to constrain the parameter space of models with many scalars through the minimization of the one-loop eff e potential and the calculation of tunneling times at zero and non zero temperature.After a brief discussion about the shortcomings of the SM and an introduction of the basics of SUSY, we introduce the theory and numerical methods needed for a successful vacuum stability analysis. We then present Vevacious, a public code where we have implemented our proposed framework. Afterwards we go on to analyze three interesting examples. For the constrained MSSM (CMSSM) we explore the existence of charge- and color- breaking (CCB) minima and see how it constraints the phenomenological relevant region of its parameter space at T = 0. We show that the regions reproducing the correct Higgs mass and the correct relic density for dark matter all overlap with regions suffering from deeper CCB minima. Inspired by the results for the CMSSM, we then consider the natural MSSM and check the region of parameter space consistent with the correct Higgs mass against CCB minima at T /= 0. We find that regions of parameter space with CCB minima overlap significantly with that reproducing the correct Higgs mass. When thermal eff are considered the majority of such points are then found to have a desired symmetry breaking minimum with very low survival probability. In both these studies we find that analytical conditions presented in the literature fail in dis- criminating regions of parameter space with CCB minima. We also present a way of adapting our framework so that it runs quickly enough for use with parameter fit studies. Lastly we show a different example of using vacuum stability in a phenomenological study. For the BLSSM we investigate the violation of R-parity through sneutrino VEVs and where in parameter space does this happen. We find that previous analyses in literature fail to identify regions with R-parity conservation by comparing their results to our full numerical analysis. N2 - Eine der populärsten Erweiterungen des SM ist die Supersymmetrie (SUSY). Dies ist eine Symmetrie, die Bosonen und Fermionen in Beziehung setzt und auch die einzige machbare Erweiterung der Raumzeitsymmetrien. SUSY kann einige offene Fragen des SM erklären und eröffnet die Möglichkeit einer Vereinheitlichung der Eichwechselwirkungen bei einer hohen Skala. Supersymmetrische Theorien erfordern das Hinzufügen neuer Teilchen, insbesondere eines zusätzlichen Higgs-Dubletts und zumindest eines Skalars für jedes Fermion im SM. So wie im SM das Higgs-Boson die SU (2)L-Symmetrie bricht, können diese neuen Skalare jede Symmetrie, deren Ladung sie tragen, spontan brechen. Angenommen, es gibt ein lokales Minimum des Potentials, das die korrekte Phänomenologie für einen Parameterraumpunkt eines Modells erzeugt: Durch die Suche nach anderen tieferen Minima mit Vakuumerwartungswerten, die gewünschte Symmetrien wie SU (3) oder U (1)EM brechen, ist es möglich Parameterraumpunkte, in denen dies passiert, auszuschliessen. Das lokale Minimum mit der korrekten Phänomenologie kann immernoch metastabil sein, weshalb es auch notwendig ist, die Tunnelwahrscheinlichkeit zwischen zwei Minima zu berechnen. In dieser Arbeit legen wir eine Prozedur vor und wenden sie an, um den Parameterraum von Modellen mit vielen Skalaren durch die Minimierung des effektiven Ein-Schleifen-Potentials und durch die Berechnung seiner Lebensdauer sowohl bei T = 0 und bei T /= 0 einzuschränken. Nach einer kurzen Diskussion der Unzulänglichkeiten des SM und Einführung der Grundlagen von SUSY erläutern wir die Theorie und die die nötigen numerischen Methoden für eine erfolgreiche Analyse der Vakuumstabilitaet. Danach präsentieren wir Vevacious, ein öffentliches Programmpaket, in das wir unsere Prozedur implementiert haben. Daraufhin analysieren wir drei interessante Beispiele. Für das Constrained MSSM (CMSSM) untersuchen wir die die Existenz von Minima, in denen die Farb- oder elektrische Ladung nicht erhalten ist (CCB-Minima), und wie dessen phänomenologisch relevante Region des Parameter- raums dadurch bei T = 0 eingeschränkt wird. Wir zeigen, dass die Regionen, die die korrekte Higgsmasse und die richtige Relikt-Dichte für die Dunkle Materie reproduzieren, mit Regionen, die tiefere CCB-Minima aufweisen, überlappen. Inspiriert durch die Ergebnisse für das CMSSM betrachten wir dann das Natural MSSM und prüfen die Parameterraumregion mit der korrekten Higgsmasse auf CCB-Minima bei T /= 0.Wir finden, dass die Region des Parameterraums mit CCB-Minima deutlich mit denen mit einer korrekten Higgsmasse überlappt. Bei Berücksichtigung von thermalen Effekten hat ein Großteil der bei T = 0 langlebigen Punkte ein gewünschtes symmetriebrechendes Minimum mit einer sehr geringen Überlebenswahrscheinlichkeit bei T /= 0. In beiden Studien finden wir, dass die analytischen Bedingungen, die bisher in der Literatur präsentiert wurden, nicht ausreichen, um Bereiche des Parameterraums mit CCB-Minima auszuweisen. Wir präsentieren einen Weg, unsere Prozedur für die Nutzung in Parameterraum-Fit-Studien zu beschleunigen. Zuletzt zeigen wir ein weiteres Beispiel. Für das BLSSM untersuchen wir die Verletzung der R-Parität durch Sneutrino- VEVs und in welchen Parameterraumbereichen dies geschieht. Wir stellen durch Vergleich mit unserer kompletten numerischen Analyse heraus, dass frühere Analysen in der Literatur darin fehlschlagen, diese Bereiche mit Erhaltung der R-Parität zu identifizieren. KW - Supersymmetry KW - Vacuum stability KW - Supersymmetry KW - Beyond Standard Model Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-112755 ER - TY - JOUR A1 - Iotzov, Vassil A1 - Weiß, Martin A1 - Windmann, Sabine A1 - Hein, Grit T1 - Valence framing induces cognitive bias JF - Current Psychology N2 - Valence framing effects refer to inconsistent choice preferences in response to positive versus negative formulation of mathematically equivalent outcomes. Here, we manipulate valence framing in a two-alternative forced choice dictator game using gains and losses as frames to investigate the cognitive mechanisms underlying valence framing. We applied a Drift-Diffusion Model (DDM) to examine whether gain (i.e., “take” money) and loss (i.e., “give” money) frames evoke a cognitive bias as previous research did not consistently reveal framing effects using reaction times and response frequency as dependent variables. DDMs allow decomposing the decision process into separate cognitive mechanisms, whereby a cognitive bias was repeatedly associated with a shift in the starting point of the model. Conducting both a laboratory (N = 62) and an online study (N = 109), female participants allocated money between themselves and another person in a prosocial or selfish way. In each study, one group was instructed to give money (give frame), the other to take money (take frame). Consistent with previous studies, no differences were found in response times and response frequencies. However, in both studies, substantial bias towards the selfish option was found in the take frame groups, captured by the starting point of the DDM. Thus, our results suggest that valence framing induces a cognitive bias in decision processing in women, even when no behavioral differences are present. KW - valence framing KW - cognitive bias KW - decision making KW - drift-diffusion modeling KW - laboratory and online studies Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324824 SN - 1046-1310 VL - 42 IS - 34 ER - TY - THES A1 - Lang, Melanie T1 - Valence Shell Photoionization of Soot Precursors with Synchrotron Radiation T1 - Valenzschalen-Photoionisation von Rußvorläufern mit Synchrotron-Strahlung N2 - A series of combustion relevant species like radicals, carbenes and polycyclic aromatic hydrocarbons were characterized in the gas phase by vacuum UV synchrotron radiation and their ionization energies (IE) and further spectroscopic details of the respective cations were retrieved from threshold photoelectron spectra. The reactive intermediates were generated by flash vacuum pyrolysis from stable precursor molecules. Furthermore three polycyclic aromatic hydrocarbons were investigated by threshold photoelectron spectroscopy, too. The experiment was performed at the VUV beamline of the Swiss Light Source in Villigen/Switzerland and the iPEPICO (imaging photoelectron photoion coincidence) setup was applied to correlate ions and electrons from the same ionization event. From the threshold photoelectron spectra and from quantum chemical computations the vibrational structure of the molecule cations and the geometry changes upon ionization were assigned. The ionization energies of the two C4H5 isomers 2-butyn-1-yl and 1-butyn-3-yl were assigned to 7.94±0.02 eV and 7.97±0.02 eV, respectively. The isomerization between the two isomers was computed to have a barrier of 2.20 eV, so a rearrangement between the two radicals cannot be excluded. From the threshold photoelectron spectra of the two constitutional C4H7 isomers 1-methylallyl and 2-methylallyl the ionization energies were assigned to 7.48±0.02 eV and to 7.59±0.02 eV for 1-E-methylallyl and 1-Z-methylallyl, as well as to 7.88±0.01 eV for 2-methylallyl. The two radicals 9-fluorenyl, C13H9, and benzhydryl, C13H11, were observed to ionize at 7.01±0.02 eV and 6.7 eV. The threshold photoelectron spectrum of benzhydryl also incorporated the signal of the diphenylmethyl carbene, C13H10, which has an IE at 6.8 eV. In addition, the head-to-head dimers of 9-fluorenyl and benzhydryl were observed as products in the pyrolysis. C26H18 has an IE at 7.69±0.04 eV and C26H22 has an IE at 8.13±0.04 eV. The three polycyclic aromatic hydrocarbon DHP (C14H16) 1-PEN (C18H22) and THCT (C22H16) were investigated in an effusive beam. The ionization energies were determined to IE(DHP)= 7.38±0.02 eV, IE(1-PEN)=7.58±0.05 eV and IE(THCT)=6.40±0.02 eV. Furthermore the thermal decomposition and the dissociative photoionization of diazomeldrum’s acid was investigated. The pyrolysis products yielded beside several other products the two not yet (by photoelectron spectroscopy) characterized molecules E-formylketene, C3O2H2 and 2-diazoethenone, N2C2O. The dissociative photoionization showed the Wolff rearrangement to occur at higher internal energies. N2 - Die vorliegende Arbeit befasst sich mit VUV Valenz-Photoionisations-Experimenten, welche in der Gasphase an verschiedenen Kohlenwasserstoffradikalen und drei polyzyklischen aromatischen Kohlen- wasserstoffen (PAH) durchgeführt wurde. Des Weiteren wurden die Pyrolyseprodukte der Dia- zomeldrumsäure mit dem genannten Experiment untersucht. Die reaktiven Intermediate wurden im Vakuum mittels Flash-Pyrolyse aus stabilen Vorläufermolekülen erzeugt. Die meisten dieser waren kommerziell erhältlich, wobei auch einige Moleküle selbst im Würzburger Chemielabor synthetisiert wurden. Die erzeugten Radikale und Carbene wurden in einem kontinuierlichen Molekularstrahl ex- pandiert. Um den Vorläufer in die Gasphase zu überführen, wurden verschiedene Molekular-Quellen eingesetzt. Die Auswahl erfolgte dabei in Abhängigkeit des Dampfdrucks des Vorläufermoleküls. Die Polyzyklischen Aromaten (PAH) wurden in der Arbeitsgruppe von Prof. Dr. Anke Krüger im Insti- tut für Organische Chemie der Universität Würzburg synthetisiert. Die PAH wurden in einer Fest- stoffmolekularquelle geheizt und in einem effusiven Molekularstrahl expandiert. Die Ionisation aller Spezies erfolgte mit monochromatischem VUV-Synchrotronlicht, das an der Bending-Magnet Beam- line an der Swiss Light Source in Villigen/Schweiz erzeugt wird. Das Schwellenphotoelektronen- Photoionen-Koinzidenz (TPEPICO) Experiment wurde zur Detektion und Analyse der Ionisation- sprozesse angewendet. Dieses Experiment ermöglicht es massenselektierte Ionen und Schwellen- photoelektronen des selben Ionisationsereignisses zu korrelieren. Die Ionen wurden in einem Time- of-Flight Massenspektrometer detektiert. Durch Integration des Massensignals und anschließende Auswertung des zugeordneten Schwellenphotoelektronen-Signals erhält man das Schwellenphotoelek- tronen-Spektrum (TPES) des Moleküls bzw. Fragments. Aus den TPE-Spektren konnten Ion- isierungsenergien bestimmt werden und mit Hilfe von Franck-Condon-Simulationen sowohl die Schwin- gungsstruktur im Kation, als auch die Geometrieänderung, hervorgerufen durch die Ionisation, analysiert werden. Berechnete Ionisierungsenergien wurden zusätzlich mit den experimentellen Daten verglichen. Im Folgenden werden die einzelnen Ergebnisse aufgelistet. ... KW - Ultraviolett-Photoelektronenspektroskopie KW - photoelectron-photoion coincidence KW - Photoelektronen-Photoionen-Koinzidenz KW - reactive intermediates KW - pyrolysis KW - reaktive Intermediate KW - Pyrolyse KW - Fotoionisation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-117038 ER - TY - JOUR A1 - Wamser, Florian A1 - Seufert, Anika A1 - Hall, Andrew A1 - Wunderer, Stefan A1 - Hoßfeld, Tobias T1 - Valid statements by the crowd: statistical measures for precision in crowdsourced mobile measurements JF - Network N2 - Crowdsourced network measurements (CNMs) are becoming increasingly popular as they assess the performance of a mobile network from the end user's perspective on a large scale. Here, network measurements are performed directly on the end-users' devices, thus taking advantage of the real-world conditions end-users encounter. However, this type of uncontrolled measurement raises questions about its validity and reliability. The problem lies in the nature of this type of data collection. In CNMs, mobile network subscribers are involved to a large extent in the measurement process, and collect data themselves for the operator. The collection of data on user devices in arbitrary locations and at uncontrolled times requires means to ensure validity and reliability. To address this issue, our paper defines concepts and guidelines for analyzing the precision of CNMs; specifically, the number of measurements required to make valid statements. In addition to the formal definition of the aspect, we illustrate the problem and use an extensive sample data set to show possible assessment approaches. This data set consists of more than 20.4 million crowdsourced mobile measurements from across France, measured by a commercial data provider. KW - mobile networks KW - crowdsourced measurements KW - statistical validity Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-284154 SN - 2673-8732 VL - 1 IS - 2 SP - 215 EP - 232 ER - TY - JOUR A1 - Ruf, Katharina C. A1 - Fehn, Sonja A1 - Bachmann, Michèle A1 - Moeller, Alexander A1 - Roht, Kristina A1 - Kriemler, Susi A1 - Hebestreit, Helge T1 - Validation of activity questionnaires in patients with cystic fibrosis by accelerometry and cycle ergometry N2 - Background: The objective of this study was to validate physical activity questionnaires for cystic fibrosis (CF) against accelerometry and cycle ergometry. Methods: 41 patients with CF (12-42 years) completed the Habitual Activity Estimation Scale (HAES), the 7-Day Physical Activity Recall questionnaire (7D-PAR) and the Lipid Research Clinics questionnaire (LRC) and performed an incremental exercise test according to the Godfrey protocol up to volitional fatigue. Time spent in moderate and vigorous physical activity (MVPA) assessed objectively by accelerometry was related to the time spent in the respective activity categories by correlation analyses and calculating intraclass correlation coefficients (ICC). Furthermore, the results of the exercise test were correlated with the results of the questionnaires. Results: Time spent in the categories ‘hard’,’very hard’ and ‘hard & very hard’ of the 7D-PAR (0.41 < r < 0.56) and ‘active’ (r = 0.33) of the HAES correlated significantly with MVPA. The activity levels of the LRC were not related to objectively determined physical activity. Significant ICCs were only observed between the 7D-PAR activitiy categories and MVPA (ICC = 0.40-0.44). Only the LRC showed moderate correlations with the exercise test (Wmax: r = 0.46, p = 0.002; VO2peak: r = 0.32, p = 0.041). Conclusions: In conclusion, the activity categories ‘hard’ and ‘very hard’ of the 7D-PAR best reflected objectively measured MVPA. Since the association was at most moderate, the 7D-PAR may be selected to describe physical activity within a population. None of the evaluated questionnaires was able to generate valid physical activity data exercise performance data at the individual level. Neither did any of the questionnaires provide a valid assessment of aerobic fitness on an invidual level. KW - Medizin Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-75083 ER - TY - JOUR A1 - Reiners, Philipp A1 - Asam, Sarah A1 - Frey, Corinne A1 - Holzwarth, Stefanie A1 - Bachmann, Martin A1 - Sobrino, Jose A1 - Göttsche, Frank-M. A1 - Bendix, Jörg A1 - Kuenzer, Claudia T1 - Validation of AVHRR Land Surface Temperature with MODIS and in situ LST — a TIMELINE thematic processor JF - Remote Sensing N2 - Land Surface Temperature (LST) is an important parameter for tracing the impact of changing climatic conditions on our environment. Describing the interface between long- and shortwave radiation fluxes, as well as between turbulent heat fluxes and the ground heat flux, LST plays a crucial role in the global heat balance. Satellite-derived LST is an indispensable tool for monitoring these changes consistently over large areas and for long time periods. Data from the AVHRR (Advanced Very High-Resolution Radiometer) sensors have been available since the early 1980s. In the TIMELINE project, LST is derived for the entire operating period of AVHRR sensors over Europe at a 1 km spatial resolution. In this study, we present the validation results for the TIMELINE AVHRR daytime LST. The validation approach consists of an assessment of the temporal consistency of the AVHRR LST time series, an inter-comparison between AVHRR LST and in situ LST, and a comparison of the AVHRR LST product with concurrent MODIS (Moderate Resolution Imaging Spectroradiometer) LST. The results indicate the successful derivation of stable LST time series from multi-decadal AVHRR data. The validation results were investigated regarding different LST, TCWV and VA, as well as land cover classes. The comparisons between the TIMELINE LST product and the reference datasets show seasonal and land cover-related patterns. The LST level was found to be the most determinative factor of the error. On average, an absolute deviation of the AVHRR LST by 1.83 K from in situ LST, as well as a difference of 2.34 K from the MODIS product, was observed. KW - Land Surface Temperature KW - AVHRR KW - MODIS KW - time series KW - Europe KW - validation KW - TIMELINE Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246051 SN - 2072-4292 VL - 13 IS - 17 ER - TY - JOUR A1 - Mayr, Stefan A1 - Kuenzer, Claudia A1 - Gessner, Ursula A1 - Klein, Igor A1 - Rutzinger, Martin T1 - Validation of earth observation time-series: a review for large-area and temporally dense land surface products JF - Remote Sensing N2 - Large-area remote sensing time-series offer unique features for the extensive investigation of our environment. Since various error sources in the acquisition chain of datasets exist, only properly validated results can be of value for research and downstream decision processes. This review presents an overview of validation approaches concerning temporally dense time-series of land surface geo-information products that cover the continental to global scale. Categorization according to utilized validation data revealed that product intercomparisons and comparison to reference data are the conventional validation methods. The reviewed studies are mainly based on optical sensors and orientated towards global coverage, with vegetation-related variables as the focus. Trends indicate an increase in remote sensing-based studies that feature long-term datasets of land surface variables. The hereby corresponding validation efforts show only minor methodological diversification in the past two decades. To sustain comprehensive and standardized validation efforts, the provision of spatiotemporally dense validation data in order to estimate actual differences between measurement and the true state has to be maintained. The promotion of novel approaches can, on the other hand, prove beneficial for various downstream applications, although typically only theoretical uncertainties are provided. KW - accuracy KW - error estimation KW - global KW - intercomparison KW - remote sensing KW - uncertainty Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-193202 SN - 2072-4292 VL - 11 IS - 22 ER - TY - JOUR A1 - Matthes, Niels A1 - Diers, Johannes A1 - Schlegel, Nicolas A1 - Hankir, Mohammed A1 - Haubitz, Imme A1 - Germer, Christoph-Thomas A1 - Wiegering, Armin T1 - Validation of MTL30 as a quality indicator for colorectal surgery JF - PLoS One N2 - Background Valid indicators are required to measure surgical quality. These ideally should be sensitive and selective while being easy to understand and adjust. We propose here the MTL30 quality indicator which takes into account 30-day mortality, transfer within 30 days, and a length of stay of 30 days as composite markers of an uneventful operative/postoperative course. Methods Patients documented in the StuDoQ|Colon and StuDoQ|Rectal carcinoma register of the German Society for General and Visceral Surgery (DGAV) were analyzed with regard to the effects of patient and tumor-related risk factors as well as postoperative complications on the MTL30. Results In univariate analysis, the MTL30 correlated significantly with patient and tumor-related risk factors such as ASA score (p<0.001), age (p<0.001), or UICC stage (p<0.001). There was a high sensitivity for the postoperative occurrence of complications such as re-operations (p<0.001) or subsequent bleeding (p<0.001), as well as a significant correlation with the CDC classification (p<0.001). In multivariate analysis, patient-related risk factors and postoperative complications significantly increased the odds ratio for a positive MTL30. A negative MTL30 showed a high specify for an uneventful operative and postoperative course. Conclusion The MTL30 is a valid indicator of colorectal surgical quality. KW - surgical care KW - discharge definition KW - definition KW - mortality KW - pancreatectomy KW - complications KW - superior KW - capture Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230530 VL - 15 IS - 8 ER - TY - BOOK A1 - Wang, Wen T1 - Validation of shRNA clones for gene silencing in 293FT cells N2 - ... N2 - The goal of the project was to establish knock down of mRNA in human mesenchymal stem cells. Since these cells are difficult to transfect, a viral approach is needed to achieve sufficient expression of e. g. shRNA in a high percentage of cells to allow for an efficient silencing of corresponding mRNAs. For this purpose for every gene product of interest, a number of shRNA clones have to be tested to detect an individual shRNA with sufficient efficacy. Lentiviral systems for shRNA approaches have recently become available. The principal advantage of the lentiviral system is that it allows gene silencing in nondividing cells and therefore expands the usefulness of the RNAi-based gene silencing system. Lentivirus-delivered shRNAs are capable of specific, highly stable and functional silencing of gene expression in a variety of cell types. Since the viral transfection of MSCs is a time consuming process that involves transfection of 293 FT cells plus transduction of target cells, for this thesis the following approach was chosen: genes of interest were checked for expression in 293FT cells by RT-PCR. These gene products can be silenced in 293FT cells simply by transfection of shRNA clones and efficacy was subsequently tested by RT-PCR. Beyond this thesis then the project can proceed with effective clones to transduce primary MSCs with individual shRNA clones identified as effective silencing tool in this thesis. KW - shRNA KW - RNAi KW - .................................................................... KW - shRNA KW - RNAi Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-25955 N1 - Aus rechtlichen Gründen wurde der Zugriff auf den Volltext zu diesem Dokument gesperrt. ER - TY - JOUR A1 - Franke, Maximilian A1 - Bieber, Michael A1 - Stoll, Guido A1 - Schuhmann, Michael Klaus T1 - Validity and Efficacy of Methods to Define Blood Brain Barrier Integrity in Experimental Ischemic Strokes: A Comparison of Albumin Western Blot, IgG Western Blot and Albumin Immunofluorescence JF - Methods and Protocols N2 - The clinical and preclinical research of ischemic strokes (IS) is becoming increasingly comprehensive, especially with the emerging evidence of complex thrombotic and inflammatory interactions. Within these, the blood brain barrier (BBB) plays an important role in regulating the cellular interactions at the vascular interface and is therefore the object of many IS-related questions. Consequently, valid, economic and responsible methods to define BBB integrity are necessary. Therefore, we compared the three ex-vivo setups albumin Western blot (WB), IgG WB and albumin intensity measurement (AIM) with regard to validity as well as temporal and economic efficacy. While the informative value of the three methods correlated significantly, the efficacy of the IgG WB dominated. KW - IgG KW - albumin KW - immunohistochemistry KW - Western blot KW - stroke KW - tMCAO KW - blood brain barrier KW - neuroinflammation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-234214 SN - 2409-9279 VL - 4 IS - 1 ER - TY - JOUR A1 - Dreiner, Herbi K. A1 - Krauss, Manuel E. A1 - O'Leary, Ben A1 - Opferkuch, Toby A1 - Staub, Florian T1 - Validity of the CMSSM interpretation of the diphoton excess JF - Physical Review D N2 - It has been proposed that the observed diphoton excess at 750 GeV could be explained within the constrained minimal supersymmetric standard model via resonantly produced stop bound states. We reanalyze this scenario critically and extend previous work to include the constraints from the stability of the electroweak vacuum and from the decays of the stoponium into a pair of Higgs bosons. It is shown that the interesting regions of parameter space with a light stop and Higgs of the desired mass are ruled out by these constraints. This conclusion is not affected by the presence of the bound states because the binding energy is usually very small in the regions of parameter space which can explain the Higgs mass. Thus, this also leads to strong constraints on the diphoton production cross section which is in general too small. KW - Minimal supersymmetric model KW - 2-loop level KW - Bound-states KW - Higgs-boson KW - MSSM KW - Mass KW - Spheno KW - Sarah KW - Spectrum KW - Breaking Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187429 VL - 94 IS - 5 ER - TY - JOUR A1 - Suchotzki, Kristina A1 - Kakavand, Aileen A1 - Gamer, Matthias T1 - Validity of the reaction time concealed information test in a prison sample JF - Frontiers in Psychiatry N2 - Detecting whether a suspect possesses incriminating (e.g., crime-related) information can provide valuable decision aids in court. To this means, the Concealed Information Test (CIT) has been developed and is currently applied on a regular basis in Japan. But whereas research has revealed a high validity of the CIT in student and normal populations, research investigating its validity in forensic samples in scarce. This applies even more to the reaction time-based CIT (RT-CIT), where no such research is available so far. The current study tested the application of the RT-CIT for an imaginary mock crime scenario both in a sample of prisoners (n = 27) and a matched control group (n = 25). Results revealed a high validity of the RT-CIT for discriminating between crime-related and crime-unrelated information, visible in medium to very high effect sizes for error rates and reaction times. Interestingly, in accordance with theories that criminal offenders may have worse response inhibition capacities and that response inhibition plays a crucial role in the RT-CIT, CIT-effects in the error rates were even elevated in the prisoners compared to the control group. No support for this hypothesis could, however, be found in reaction time CIT-effects. Also, performance in a standard Stroop task, that was conducted to measure executive functioning, did not differ between both groups and no correlation was found between Stroop task performance and performance in the RT-CIT. Despite frequently raised concerns that the RT-CIT may not be applicable in non-student and forensic populations, our results thereby do suggest that such a use may be possible and that effects seem to be quite large. Future research should build up on these findings by increasing the realism of the crime and interrogation situation and by further investigating the replicability and the theoretical substantiation of increased effects in non-student and forensic samples. KW - concealed information test KW - deception KW - lying KW - reaction times KW - inmates KW - forensic sample Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-177714 VL - 9 IS - 745 ER - TY - THES A1 - Hain, Johannes T1 - Valuation Algorithms for Structural Models of Financial Networks T1 - Algorithmen zur Bestimmung von Gleichgewichtslösungen in Finanzsystemen mit Kapitalverflechtung N2 - The thesis focuses on the valuation of firms in a system context where cross-holdings of the firms in liabilities and equities are allowed and, therefore, systemic risk can be modeled on a structural level. A main property of such models is that for the determination of the firm values a pricing equilibrium has to be found. While there exists a small but growing amount of research on the existence and the uniqueness of such price equilibria, the literature is still somewhat inconsistent. An example for this fact is that different authors define the underlying financial system on differing ways. Moreover, only few articles pay intense attention on procedures to find the pricing equilibria. In the existing publications, the provided algorithms mainly reflect the individual authors' particular approach to the problem. Additionally, all existing methods do have the drawback of potentially infinite runtime. For these reasons, the objects of this thesis are as follows. First, a definition of a financial system is introduced in its most general form in Chapter 2. It is shown that under a fairly mild regularity condition the financial system has a unique existing payment equilibrium. In Chapter 3, some extensions and differing definitions of financial systems that exist in literature are presented and it is shown how these models can be embedded into the general model from the proceeding chapter. Second, an overview of existing valuation algorithms to find the equilibrium is given in Chapter 4, where the existing methods are generalized and their corresponding mathematical properties are highlighted. Third, a complete new class of valuation algorithms is developed in Chapter 4 that includes the additional information whether a firm is in default or solvent under a current payment vector. This results in procedures that are able find the solution of the system in a finite number of iteration steps. In Chapter 5, the developed concepts of Chapter 4 are applied to more general financial systems where more than one seniority level of debt is present. Chapter 6 develops optimal starting vectors for non-finite algorithms and Chapter 7 compares the existing and the new developed algorithms concerning their efficiency in an extensive simulation study covering a wide range of possible settings for financial systems. N2 - Die vorliegende Dissertation hat die Unternehmensbewertung in Finanzsystemen mit Fremd- und Eigenkapitalverflechtung zum Thema. Die zentrale Eigenschaft dieser Modelle ist, dass zur Bestimmung der Firmenwerte eine Gleichgewichtslösung ermittelt werden muss. Die Zahl der Veröffentlichungen mit dem Schwerpunkt des Nachweises von Existenz- und Eindeutigkeitsaussagen der Gleichgewichte steigt zwar stetig an, allerdings ist die Fachliteratur in diesem Bereich teilweise noch sehr inkonsistent. Beispielsweise existieren je nach Autor unterschiedliche Vorgehensweisen, das zugrunde liegende Finanzsystem zu definieren. Darüber hinaus schenken nur wenige Fachartikel der Frage Beachtung, wie die Lösungsgleichgewichte genau bestimmt werden können. Zuletzt weisen die bereits entwickelten Verfahren den Nachteil auf, dass Sie womöglich unendlich viele Iterationsschritte benötigen bis die gesuchte Lösung exakt erreicht wird. Aus diesen Gründen beinhaltet die vorliegende Dissertation folgende Themen. Im ersten Schritt wird in Kapitel 2 eine möglichst allgemeine Definition eines Finanzsystems eingeführt. Es wird gezeigt dass unter nicht allzu strengen Voraussetzungen die Gleichgewichtslösung dieses Systems eindeutig bestimmt ist. In Kapitel 3 werden in der Fachliteratur zu diesem Thema zu findende Erweiterungen und abweichende Definitionen des Systems vorgestellt und wie diese in das allgemeine Modell aus dem vorherigen Kapitel eingebettet werden können. Danach wird in Kapitel 4 ein Überblick über bereits entwickelte Lösungsverfahren gegeben, wobei die existierenden Prozeduren in ihrem Vorgehen verallgemeinert und deren zugehörige mathematische Eigenschaften aufgezeigt werden. Des weiteren wird im gleichen Kapitel eine komplett neue Klasse von Lösungsverfahren entwickelt, die noch die zusätzliche Information verarbeiten, ob eine Firma für einen gegebenen Zahlungsvektor solvent oder insolvent ist. Als Folge dieses Ansatzes sind diese Algorithmen in der Lage, die exakte Gleichgewichtslösung des Systems in endlich vielen Schritten zu finden. In Kapitel 5 werden die entworfenen Konzepte dann für Finanzsysteme angewendet, in denen mehr als nur eine Schulden-Seniorität berücksichtigt wird. Kapitel 6 leitet optimale Startvektoren der nicht-endlichen Verfahren her und Kapitel 7 vergleicht die bereits existierenden und alle neu entwickelten Lösungsverfahren bezüglich ihrer Laufzeiteffizienz im Rahmen einer ausführlichen Simulationsstudie. KW - Risikomanagement KW - Finanzmathematik KW - Financial Networks KW - Counterparty Risk KW - Numerical Asset Valuation KW - Systemic Risk KW - Structrual Model KW - Unternehmensbewertung KW - Kapitalverflechtung KW - Finanzielle Netzwerke KW - Systemisches Risiko Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-128108 ER - TY - JOUR A1 - Engemann, R. A1 - Ulrichs, Karin A1 - Thiede, A. A1 - Müller-Ruchholtz, W. A1 - Hamelmann, H. T1 - Value of a physiological liver transplant model in rats. Induction of specific graft tolerance in a fully allogeneic strain combination N2 - No abstract available Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45622 ER - TY - JOUR A1 - Fekete, Stefanie A1 - Kulpok, Christine A1 - Taurines, Regina A1 - Egberts, Karin A1 - Geissler, Julia A1 - Gerlach, Manfred A1 - Malonga Makosi, Dorothée A1 - König, Jochem A1 - Urschitz, Michael S. A1 - Toni, Irmgard A1 - Neubert, Antje A1 - Romanos, Marcel T1 - Value of a web-based pediatric drug information system to prevent serious adverse drug reactions in child and adolescent psychiatry JF - Journal of Neural Transmission N2 - Psychotropic drugs are frequently prescribed ‘off-label’ to children and adolescents and carry the risk of serious adverse drug reactions (sADR). We examined the frequency of sADRs of psychotropic drugs in pediatric inpatients and explored their potential preventability through following the recommendations of a web-based pediatric drug information system (PDIS). The potential socio-economic impacts of using this online system is also addressed. Routine clinical data from all inpatients treated in a child and adolescent psychiatry department between January 2017 and December 2018 were retrospectively examined for the occurrence of sADRs as defined by the European Medicines Agency. The preventability of the sADRs was assessed based on the information of the PDIS. Furthermore, the expected prolongation of the hospital stay due to sADRs was calculated as well as the associated treatment costs. The study was supported by the Innovation Fund of the Joint Federal Committee, grant number 01NVF16021. In total, 1036 patients were screened of whom 658 (63.5%) received psychopharmacological treatment. In 53 (8.1%) of these patients 54 sADRs were documented, of which 37 sADRs were identified as potentially preventable through PDIS. Mitigating sADR through PDIS would likely have prevented prolonged hospital stays and conferred considerable savings for health insurance companies. PDIS provides systematic and evidence-based information about pediatric psychopharmacotherapy and helps to prevent prescribing errors. Therefore, PDIS is a useful tool to increase drug therapy safety in child and adolescent psychiatry. Further prospective studies are needed to confirm the results. KW - adverse effects KW - pharmacovigilance KW - drug safety KW - psychotropic drugs KW - mental health Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-324817 VL - 130 IS - 1 ER - TY - JOUR A1 - Kunze, Ekkehard A1 - Pham, Mirko A1 - Raslan, Furat A1 - Stetter, Christian A1 - Lee, Jin-Yul A1 - Solymosi, Laszlo A1 - Ernestus, Ralf-Ingo A1 - Hamilton Vince, Giles A1 - Westermaier, Thomas T1 - Value of Perfusion CT, Transcranial Doppler Sonography and Neurological Examination to detect delayed Vasospasm after aneurysmal Subarachnoid Hemorrhage [Research Article] N2 - Background If detected in time, delayed cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) may be treated by balloon angioplasty or chemical vasospasmolysis in order to enhance cerebral blood flow (CBF) and protect the brain from ischemic damage. This study was conceived to compare the diagnostic accuracy of detailed neurological examination, Transcranial Doppler Sonography (TCD), and Perfusion-CT (PCT) to detect angiographic vasospasm. Methods The sensitivity, specificity, positive and negative predictive values of delayed ischemic neurological deterioration (DIND), pathological findings on PCT- maps, and accelerations of the mean flow velocity (MVF) were calculated. Results The accuracy of DIND to predict angiographic vasospasm was 0.88. An acceleration of MFV in TCD (>140 cm/s) had an accuracy of 0.64, positive PCT-findings of 0.69 with a higher sensitivity, and negative predictive value than TCD. Interpretation Neurological assessment at close intervals is the most sensitive and specific parameter for cerebral vasospasm. PCT has a higher accuracy, sensitivity and negative predictive value than TCD. If detailed neurological evaluation is possible, it should be the leading parameter in the management and treatment decisions. If patients are not amenable to detailed neurological examination, PCT at regular intervals is a helpful tool to diagnose secondary vasospasm after aneurysmal SAH. KW - Medizin Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-76241 ER - TY - THES A1 - Koch, Julia Diana T1 - Value Ranges for Schlicht Functions T1 - Wertemengen schlichter Funktionen N2 - This thesis deals with value sets, i.e. the question of what the set of values that a set of functions can take in a prescribed point looks like. Interest in such problems has been around for a long time; a first answer was given by the Schwarz lemma in the 19th century, and soon various refinements were proven. Since the 1930s, a powerful method for solving such problems has been developed, namely Loewner theory. We make extensive use of this tool, as well as variation methods which go back to Schiffer to examine the following questions: We describe the set of values a schlicht normalised function on the unit disc with prescribed derivative at the origin can take by applying Pontryagin's maximum principle to the radial Loewner equation. We then determine the value ranges for the set of holomorphic, normalised, and bounded functions that have only real coefficients in their power series expansion around 0, and for the smaller set of functions which are additionally typically real. Furthermore, we describe the values a univalent self-mapping of the upper half-plane with hydrodynamical normalization which is symmetric with respect to the imaginary axis can take. Lastly, we give a necessary condition for a schlicht bounded function f on the unit disc to have extremal derivative in a point z where its value f(z) is fixed by using variation methods. N2 - Die vorliegende Dissertation beschäftigt sich mit Wertemengen, d.h. der Frage, welche Werte eine Menge von Funktionen in einem vorgegeben Punkt annehmen kann. Probleme dieser Art werden schon seit Langem behandelt; eine erste Antwort in Form des Lemmas von Schwarz wurde bereits im 19. Jahrhundert gegeben, und viele Verfeinerungen folgten. Seit den 30er Jahren des 20. Jahrhunderts steht ein mächtiges Instrument zur Lösung solcher Probleme in Form der Löwner-Theorie zur Verfügung. Wir benutzen diese sowie Variationsmethoden, die auf Schiffer-Variation zurückgehen, um die folgenden Fragestellungen zu klären: Wir beschreiben die Menge der Werte, die eine schlichte normalisierte Funktion mit fixierter Ableitung im Ursprung annehmen kann, durch Anwendung des Pontryagin-Maximumprinzip auf die radiale Löwner-Gleichung. Als Nächstes bestimmen wir die Wertemengen für holomorphe normalisierte beschränkte Funktionen, deren Taylor-Entwicklung um 0 nur reelle Koeffizienten hat, und für die kleinere Menge von Funktionen, die zusätzlich typisch reell sind. Außerdem beschreiben wir den Wertebereich schlichter Selbstabbildungen der oberen Halbebene mit hydrodynamischer Normalisierung, die symmetrisch bezüglich der imaginären Achse sind. Zuletzt geben wir mit Hilfe von Variationsmethoden eine notwenige Bedingung für schlichte beschränkte Funktionen auf dem Einheitskreis an, deren Ableitung in einem Punkt mit vorgegebenem Funktionswert extremal ist. KW - Value ranges KW - radial Loewner equation KW - chordal Loewner equation KW - Pontryagins's maximum principle KW - univalent functions KW - typically real functions KW - Pontrjagin-Maximumprinzip KW - Schlichte Funktion KW - Funktionentheorie Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-144978 ER - TY - JOUR A1 - Steuding, Jörn A1 - Suriajaya, Ade Irma T1 - Value-Distribution of the Riemann Zeta-Function Along Its Julia Lines JF - Computational Methods and Function Theory N2 - For an arbitrary complex number a≠0 we consider the distribution of values of the Riemann zeta-function ζ at the a-points of the function Δ which appears in the functional equation ζ(s)=Δ(s)ζ(1−s). These a-points δa are clustered around the critical line 1/2+i\(\mathbb {R}\) which happens to be a Julia line for the essential singularity of ζ at infinity. We observe a remarkable average behaviour for the sequence of values ζ(δ\(_a\)). KW - Riemann zeta-function KW - value-distribution KW - critical line KW - Julia line Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232621 SN - 1617-9447 VL - 20 ER - TY - THES A1 - Christ, Thomas T1 - Value-distribution of the Riemann zeta-function and related functions near the critical line T1 - Werteverteilung der Riemannschen Zetafunktion und verwandter Funktionen nahe der kritischen Geraden N2 - The Riemann zeta-function forms a central object in multiplicative number theory; its value-distribution encodes deep arithmetic properties of the prime numbers. Here, a crucial role is assigned to the analytic behavior of the zeta-function on the so called critical line. In this thesis we study the value-distribution of the Riemann zeta-function near and on the critical line. Amongst others we focus on the following. PART I: A modified concept of universality, a-points near the critical line and a denseness conjecture attributed to Ramachandra. The critical line is a natural boundary of the Voronin-type universality property of the Riemann zeta-function. We modify Voronin's concept by adding a scaling factor to the vertical shifts that appear in Voronin's universality theorem and investigate whether this modified concept is appropriate to keep up a certain universality property of the Riemann zeta-function near and on the critical line. It turns out that it is mainly the functional equation of the Riemann zeta-function that restricts the set of functions which can be approximated by this modified concept around the critical line. Levinson showed that almost all a-points of the Riemann zeta-function lie in a certain funnel-shaped region around the critical line. We complement Levinson's result: Relying on arguments of the theory of normal families and the notion of filling discs, we detect a-points in this region which are very close to the critical line. According to a folklore conjecture (often attributed to Ramachandra) one expects that the values of the Riemann zeta-function on the critical line lie dense in the complex numbers. We show that there are certain curves which approach the critical line asymptotically and have the property that the values of the zeta-function on these curves are dense in the complex numbers. Many of our results in part I are independent of the Euler product representation of the Riemann zeta-function and apply for meromorphic functions that satisfy a Riemann-type functional equation in general. PART II: Discrete and continuous moments. The Lindelöf hypothesis deals with the growth behavior of the Riemann zeta-function on the critical line. Due to classical works by Hardy and Littlewood, the Lindelöf hypothesis can be reformulated in terms of power moments to the right of the critical line. Tanaka showed recently that the expected asymptotic formulas for these power moments are true in a certain measure-theoretical sense; roughly speaking he omits a set of Banach density zero from the path of integration of these moments. We provide a discrete and integrated version of Tanaka's result and extend it to a large class of Dirichlet series connected to the Riemann zeta-function. N2 - Die Riemannsche Zetafunktion ist ein zentraler Gegenstand der multiplikativen Zahlentheorie; in ihrer Werteverteilung liegen wichtige arithmetische Eigenschaften der Primzahlen kodiert. Besondere Bedeutung kommt hierbei dem analytischen Verhalten der Zetafunktion auf der sog. kritischen Geraden zu. Wir untersuchen in dieser Arbeit die Werteverteilung der Riemannschen Zetafunktion auf und nahe der kritischen Geraden. Wir fokusieren wir uns dabei u.a. auf folgende Punkte. TEIL I: Ein modifiziertes Universalitätskonzept, a-Stellen nahe der kritischen Geraden und eine Dichtheitsvermutung nach Ramachandra. Die kritische Gerade fungiert als natürliche Grenze für die Voroninsche Universalitätseigenschaft der Riemannschen Zetafunktion. Wir modifizieren Voronins Universalitätskonzept dahingehend, dass wir die vertikalen Translationen aus Voronins Universalitätssatz mit einer zusätzlichen Skalierung versehen. Wir untersuchen, ob durch dieses modifizierte Konzept eine abgeschwächte Universalitätseigenschaft der Riemannschen Zetafunktion um die kritschen Gerade aufrecht erhalten werden kann. Es stellt sich heraus, dass die Gestalt der Funktionen, die sich auf diese Weise durch die Zetafunktion approximieren lassen, stark von der Funktionalgleichung und der Wahl des skalierenden Faktors abhängt. Nach einem Resultat von Levinson liegen fast alle a-Stellen der Riemannschen Zetafunktion in einem trichterförmigen Bereich um die kritische Gerade. Gewisse Normalitätsargumenten sowie das Konzept der 'filling discs' erlauben uns Levinsons Resultat zu ergänzen und a-Stellen in diesem trichterförmigen Bereich aufzuspüren, die sehr nahe an der kritischen Geraden liegen. Man vermutet, dass die Werte der Riemannschen Zetafunktion auf der kritischen Geraden dicht in den komplexen Zahlen liegen. Wir nähern uns dieser Vermutung (die man oft Ramachandra zuschreibt), indem wir die Existenz gewisser Kurven nachweisen, die sich asymptotisch an die kritische Gerade anschmiegen und die Eigenschaft besitzen, dass die Werte der Zetafunktion auf diesen Kurven dicht in den komplexen Zahlen liegen. Viele unserer Ergebnisse in Teil I sind unabhängig von der Eulerproduktdarstellung der Zetafunktion und gelten allgemein für beliebige meromorphe Funktionen, die einer Funktionalgleichung vom Riemann-Typ genügen. TEIL II: Diskrete und kontinuierliche Momente. Die Lindelöf Vermutung trifft eine Aussage über das Wachstumsverhalten der Zetafunktion auf der kritischen Geraden. Nach klassischen Arbeiten von Hardy und Littlewood lässt sie sich mittels Potenzmomente der Zetafunktion rechts von der kritischen Geraden umformulieren. Tanaka konnte kürzlich nachweisen, dass die asymptotischen Formeln, die man für diese Potenzmomente erwartet in einem gewissen maßtheoretischem Sinne Gülitgkeit besitzen: grob gesprochen wird heibei eine Menge mit Banachdichte null vom Integrationsweg der Potenzmomente ausgespart. Wir stellen eine diskrete und eine integrierte Version von Tanakas Resultat zur Verfügung. Zudem verallgemeinern wir Tanakas Ergebnis auf eine große Klasse von Dirichletreihen. KW - Riemannsche Zetafunktion KW - Riemann zeta-function KW - universality KW - a-point distribution Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-97763 ER - TY - JOUR A1 - Umstätter, Florian A1 - Domhan, Cornelius A1 - Hertlein, Tobias A1 - Ohlsen, Knut A1 - Mühlberg, Eric A1 - Kleist, Christian A1 - Zimmermann, Stefan A1 - Beijer, Barbro A1 - Klika, Karel D. A1 - Haberkorn, Uwe A1 - Mier, Walter A1 - Uhl, Philipp T1 - Vancomycin Resistance Is Overcome by Conjugation of Polycationic Peptides JF - Angewandte Chemie International Edition N2 - Multidrug‐resistant bacteria represent one of the biggest challenges facing modern medicine. The increasing prevalence of glycopeptide resistance compromises the efficacy of vancomycin, for a long time considered as the last resort for the treatment of resistant bacteria. To reestablish its activity, polycationic peptides were conjugated to vancomycin. By site‐specific conjugation, derivatives that bear the peptide moiety at four different sites of the antibiotic were synthesized. The most potent compounds exhibited an approximately 1000‐fold increased antimicrobial activity and were able to overcome the most important types of vancomycin resistance. Additional blocking experiments using d‐Ala‐d‐Ala revealed a mode of action beyond inhibition of cell‐wall formation. The antimicrobial potential of the lead candidate FU002 for bacterial infection treatments could be demonstrated in an in vivo study. Molecular imaging and biodistribution studies revealed that conjugation engenders superior pharmacokinetics. KW - antibiotics KW - bacterial resistance KW - glycopeptide antibiotics KW - peptide conjugates KW - vancomycin Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-215550 VL - 59 IS - 23 SP - 8823 EP - 8827 ER -