@article{FigueiredoKraussSteffanDewenteretal.2019,
  author    = {Figueiredo, Ludmilla and Krauss, Jochen and Steffan-Dewenter, Ingolf and Cabral, Juliano Sarmento},
  title     = {Understanding extinction debts: spatio-temporal scales, mechanisms and a roadmap for future research},
  series = {Ecography},
  volume    = {42},
  journal   = {Ecography},
  number    = {12},
  doi       = {10.1111/ecog.04740},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204859},
  pages     = {1973-1990},
  year      = {2019},
  abstract  = {Extinction debt refers to delayed species extinctions expected as a consequence of ecosystem perturbation. Quantifying such extinctions and investigating long-term consequences of perturbations has proven challenging, because perturbations are not isolated and occur across various spatial and temporal scales, from local habitat losses to global warming. Additionally, the relative importance of eco-evolutionary processes varies across scales, because levels of ecological organization, i.e. individuals, (meta)populations and (meta)communities, respond hierarchically to perturbations. To summarize our current knowledge of the scales and mechanisms influencing extinction debts, we reviewed recent empirical, theoretical and methodological studies addressing either the spatio-temporal scales of extinction debts or the eco-evolutionary mechanisms delaying extinctions. Extinction debts were detected across a range of ecosystems and taxonomic groups, with estimates ranging from 9 to 90\% of current species richness. The duration over which debts have been sustained varies from 5 to 570 yr, and projections of the total period required to settle a debt can extend to 1000 yr. Reported causes of delayed extinctions are 1) life-history traits that prolong individual survival, and 2) population and metapopulation dynamics that maintain populations under deteriorated conditions. Other potential factors that may extend survival time such as microevolutionary dynamics, or delayed extinctions of interaction partners, have rarely been analyzed. Therefore, we propose a roadmap for future research with three key avenues: 1) the microevolutionary dynamics of extinction processes, 2) the disjunctive loss of interacting species and 3) the impact of multiple regimes of perturbation on the payment of debts. For their ability to integrate processes occurring at different levels of ecological organization, we highlight mechanistic simulation models as tools to address these knowledge gaps and to deepen our understanding of extinction dynamics.},
  language  = {en}
}
@article{GrebinykPrylutskaBuchelnikovetal.2019,
  author    = {Grebinyk, Anna and Prylutska, Svitlana and Buchelnikov, Anatoliy and Tverdokhleb, Nina and Grebinyk, Sergii and Evstigneev, Maxim and Matyshevska, Olga and Cherepanov, Vsevolod and Prylutskyy, Yuriy and Yashchuk, Valeriy and Naumovets, Anton and Ritter, Uwe and Dandekar, Thomas and Frohme, Marcus},
  title     = {C60 fullerene as an effective nanoplatform of alkaloid Berberine delivery into leukemic cells},
  series = {Pharmaceutics},
  volume    = {11},
  journal   = {Pharmaceutics},
  number    = {11},
  issn      = {1999-4923},
  doi       = {10.3390/pharmaceutics11110586},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193216},
  pages     = {586},
  year      = {2019},
  abstract  = {A herbal alkaloid Berberine (Ber), used for centuries in Ayurvedic, Chinese, Middle-Eastern, and native American folk medicines, is nowadays proved to function as a safe anticancer agent. Yet, its poor water solubility, stability, and bioavailability hinder clinical application. In this study, we have explored a nanosized carbon nanoparticle—C60 fullerene (C60)—for optimized Ber delivery into leukemic cells. Water dispersions of noncovalent C60-Ber nanocomplexes in the 1:2, 1:1, and 2:1 molar ratios were prepared. UV-Vis spectroscopy, dynamic light scattering (DLS), and atomic force microscopy (AFM) evidenced a complexation of the Ber cation with the negatively charged C60 molecule. The computer simulation showed that π-stacking dominates in Ber and C\(_{60}\) binding in an aqueous solution. Complexation with C\(_{60}\) was found to promote Ber intracellular uptake. By increasing C\(_{60}\) concentration, the C\(_{60}\)-Ber nanocomplexes exhibited higher antiproliferative potential towards CCRF-CEM cells, in accordance with the following order: free Ber < 1:2 < 1:1 < 2:1 (the most toxic). The activation of caspase 3/7 and accumulation in the sub-G1 phase of CCRF-CEM cells treated with C\(_{60}\)-Ber nanocomplexes evidenced apoptosis induction. Thus, this study indicates that the fast and easy noncovalent complexation of alkaloid Ber with C\(_{60}\) improved its in vitro efficiency against cancer cells.},
  language  = {en}
}
@article{LiLiLinketal.2019,
  author    = {Li, Shan and Li, Xin and Link, Roman and Li, Ren and Deng, Liping and Schuldt, Bernhard and Jiang, Xiaomei and Zhao, Rongjun and Zheng, Jingming and Li, Shuang and Yin, Yafang},
  title     = {Influence of cambial age and axial height on the spatial patterns of xylem traits in Catalpa bungei, a ring-porous tree species native to China},
  series = {Forests},
  volume    = {10},
  journal   = {Forests},
  number    = {8},
  issn      = {1999-4907},
  doi       = {10.3390/f10080662},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196297},
  year      = {2019},
  abstract  = {Studying how cambial age and axial height affects wood anatomical traits may improve our understanding of xylem hydraulics, heartwood formation and axial growth. Radial strips were collected from six different heights (0-11.3 m) along the main trunk of three Manchurian catalpa (Catalpa bungei) trees, yielding 88 samples. In total, thirteen wood anatomical vessel and fiber traits were observed usinglight microscopy (LM) and scanning electron microscopy (SEM), and linear models were used to analyse the combined effect of axial height, cambial age and their interaction. Vessel diameter differed by about one order of magnitude between early- and latewood, and increased significantly with both cambial age and axial height in latewood, while it was positively affected by cambial age and independent of height in earlywood. Vertical position further had a positive effect on earlywood vessel density, and negative effects on fibre wall thickness, wall thickness to diameter ratio and length. Cambial age had positive effects on the pit membrane diameter and vessel element length, while the annual diameter growth decreased with both cambial age and axial position. In contrast, early- and latewood fiber diameter were unaffected by both cambial age and axial height. We further observed an increasing amount of tyloses from sapwood to heartwood, accompanied by an increase of warty layers and amorphous deposits on cell walls, bordered pit membranes and pit apertures. This study highlights the significant effects of cambial age and vertical position on xylem anatomical traits, and confirms earlier work that cautions to take into account xylem spatial position when interpreting wood anatomical structures, and thus, xylem hydraulic functioning.},
  language  = {en}
}
@phdthesis{Sauer2019,
  author    = {Sauer, Mark},
  title     = {Die microRNA-26 Familie kontrolliert {\"u}ber den REST-Komplex ein f{\"u}r die Neurogenese essentielles regulatorisches RNA Netzwerk},
  doi       = {10.25972/OPUS-18400},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-184008},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {In einem sich entwickelnden multizellul{\"a}ren Organismus ist die r{\"a}umlich-zeitliche Regulation der Genexpression von entscheidender Bedeutung f{\"u}r die Bildung, Identit{\"a}t und Funktion von Zellen. Der REST (repressor element silencing transcription factor) Komplex spielt bei der neuronalen Differenzierung und bei der Aufrechterhaltung des neuronalen Status eine essentielle Rolle, indem er in nicht neuronalen Zellen und neuralen Vorl{\"a}ufern die Expression neuronaler Gene unterdr{\"u}ckt, in deren Promotorregion eine RE1 (repressor element 1) Erkennungssequenz vorhanden ist. W{\"a}hrend der neuronalen Differenzierung wird der REST-Komplex schrittweise inaktiviert, was zur Einleitung eines neuronalen Genexpression-Programms f{\"u}hrt. Es wird daher angenommen, dass die Inhibierung des REST-Komplexes ein essentieller Vorgang der Neurogenese ist. Wichtige Bestandteile f{\"u}r die transkriptionell repressive Funktion des REST-Komplexes sind kleine Phosphatasen (CTDSP = C-terminal domain small phosphatases), welche die Polymerase-II-Aktivit{\"a}t an Zielgenen inhibieren. Im Zebrafisch wurde gezeigt, dass ctdsp2 durch die miR-26b negativ reguliert wird. Alle miR-26 Familienmitglieder sind in Vertebraten evolution{\"a}r konserviert und in Introns von Ctdsp Genen kodiert. Sie sind in der Lage, die Expression ihres eigenen Wirtsgens mittels einer autoregulatorischen R{\"u}ckkopplungsschleife zu regulieren. Im Rahmen dieser Dissertation wurde als Modellsystem f{\"u}r die Neurogenese ein neurales Differenzierungssystem, welches auf murinen, embryonalen Stammzellen (ESCs) aufbaut, eingesetzt. Zur funktionellen Analyse der miR-26 Familie wurden mit Hilfe der CRISPR/Cas9-Methode verschiedene miR-26 Knockout (KO) ESC-Linien hergestellt. Hierbei wurden die Sequenzen der einzelnen Familienmitglieder und der gesamten miR-26 Familie im Genom von Wildtyp (Wt) ESCs deletiert. Diese miR-26-defizienten ESCLinien behielten ihre Pluripotenz und zeigten keinen Ph{\"a}notyp hinsichtlich Proliferation, Morphologie und Identit{\"a}t der Zellen w{\"a}hrend der Differenzierung bis zum neuralen Vorl{\"a}uferzellstadium (NPCs, engl.: neural progenitor cells). Jedoch f{\"u}hrte die Deletion sowohl der gesamten miR-26 Familie als auch einzelner Mitglieder bei der terminalen Differenzierung zu einem spezifischen Entwicklungsstillstand im NPC Stadium und infolgedessen zu einer starken Reduktion der Anzahl von Neuronen und Astroglia. Die Transkriptom-Analyse der differenzierten miR-26-KO ESCs mittels RNA-Seq zeigte, dass die Expression von Genen die mit der Neurogenese und der neuronalen Differenzierung, aber auch der Gliogenese assoziert sind, herunterreguliert war. Die Abwesenheit der miR-26 Familie f{\"u}hrte außerdem zu einer selektiven Reduzierung bestimmter miRNAs (REST-miRs), die einerseits die Expression von REST-Komplex Komponenten unterdr{\"u}cken k{\"o}nnen, und andererseits selbst unter dessen transkriptioneller Kontrolle stehen. Zu diesem REST-miR Netzwerk geh{\"o}ren einige miRNAs (miR-9, miR-124, miR-132 und miR-218), die wichtige Funktionen bei verschiedenen Prozessen der neuronalen Entwicklung haben. Weiterhin f{\"u}hrte der miR-26-KO zu einer Derepression der Proteinlevel von REST und CTDSP2 w{\"a}hrend der terminalen Differenzierung. Funktionelle Analysen mit miRNA mimics zeigten, dass erh{\"o}hte miR-26 Level zu einer Hochregulation von REST-miRs f{\"u}hren. Weitere Experimente, die darauf zielten, die Hierarchie des REST-miR Netwerks aufzukl{\"a}ren zeigten, dass die miR-26 Familie stromaufw{\"a}rts die REST-miR Expression reguliert. Zusammengefasst weisen die in dieser Arbeit gezeigten Daten darauf hin, dass die miR-26 Familie als Initiator der schrittweisen Inaktivierung des REST-Komplexes eine zentrale Rolle bei der Differenzierung von neuralen Vorl{\"a}uferzellen zu postmitotischen Neuronen spielt.},
  language  = {de}
}
@unpublished{Dandekar2019,
  author    = {Dandekar, Thomas},
  title     = {Biological heuristics applied to cosmology suggests a condensation nucleus as start of our universe and inflation cosmology replaced by a period of rapid Weiss domain-like crystal growth},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-183945},
  pages     = {24},
  year      = {2019},
  abstract  = {Cosmology often uses intricate formulas and mathematics to derive new theories and concepts. We do something different in this paper: We look at biological processes and derive from these heuristics so that the revised cosmology agrees with astronomical observations but does also agree with standard biological observations. We show that we then have to replace any type of singularity at the start of the universe by a condensation nucleus and that the very early period of the universe usually assumed to be inflation has to be replaced by a period of rapid crystal growth as in Weiss magnetization domains. Impressively, these minor modifications agree well with astronomical observations including removing the strong inflation perturbations which were never observed in the recent BICEP2 experiments. Furthermore, looking at biological principles suggests that such a new theory with a condensation nucleus at start and a first rapid phase of magnetization-like growth of the ordered, physical laws obeying lattice we live in is in fact the only convincing theory of the early phases of our universe that also is compatible with current observations. We show in detail in the following that such a process of crystal creation, breaking of new crystal seeds and ultimate evaporation of the present crystal readily leads over several generations to an evolution and selection of better, more stable and more self-organizing crystals. Moreover, this explains the "fine-tuning" question why our universe is fine-tuned to favor life: Our Universe is so self-organizing to have enough offspring and the detailed physics involved is at the same time highly favorable for all self-organizing processes including life. This biological theory contrasts with current standard inflation cosmologies. The latter do not perform well in explaining any phenomena of sophisticated structure creation or self-organization. As proteins can only thermodynamically fold by increasing the entropy in the solution around them we suggest for cosmology a condensation nucleus for a universe can form only in a "chaotic ocean" of string-soup or quantum foam if the entropy outside of the nucleus rapidly increases. We derive an interaction potential for 1 to n-dimensional strings or quantum-foams and show that they allow only 1D, 2D, 4D or octonion interactions. The latter is the richest structure and agrees to the E8 symmetry fundamental to particle physics and also compatible with the ten dimensional string theory E8 which is part of the M-theory. Interestingly, any other interactions of other dimensionality can be ruled out using Hurwitz compositional theorem. Crystallization explains also extremely well why we have only one macroscopic reality and where the worldlines of alternative trajectories exist: They are in other planes of the crystal and for energy reasons they crystallize mostly at the same time, yielding a beautiful and stable crystal. This explains decoherence and allows to determine the size of Planck´s quantum h (very small as separation of crystal layers by energy is extremely strong). Ultimate dissolution of real crystals suggests an explanation for dark energy agreeing with estimates for the "big rip". The halo distribution of dark matter favoring galaxy formation is readily explained by a crystal seed starting with unit cells made of normal and dark matter. That we have only matter and not antimatter can be explained as there may be right handed mattercrystals and left-handed antimatter crystals. Similarly, real crystals are never perfect and we argue that exactly such irregularities allow formation of galaxies, clusters and superclusters. Finally, heuristics from genetics suggest to look for a systems perspective to derive correct vacuum and Higgs Boson energies.},
  language  = {en}
}
@article{BeerSchenkHelfrichFoersteretal.2019,
  author    = {Beer, Katharina and Schenk, Mariela and Helfrich-F{\"o}rster, Charlotte and Holzschuh, Andrea},
  title     = {The circadian clock uses different environmental time cues to synchronize emergence and locomotion of the solitary bee Osmia bicornis},
  series = {Scientific Reports},
  volume    = {9},
  journal   = {Scientific Reports},
  doi       = {10.1038/s41598-019-54111-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202721},
  pages     = {17748},
  year      = {2019},
  abstract  = {Life on earth adapted to the daily reoccurring changes in environment by evolving an endogenous circadian clock. Although the circadian clock has a crucial impact on survival and behavior of solitary bees, many aspects of solitary bee clock mechanisms remain unknown. Our study is the first to show that the circadian clock governs emergence in Osmia bicornis, a bee species which overwinters as adult inside its cocoon. Therefore, its eclosion from the pupal case is separated by an interjacent diapause from its emergence in spring. We show that this bee species synchronizes its emergence to the morning. The daily rhythms of emergence are triggered by temperature cycles but not by light cycles. In contrast to this, the bee's daily rhythms in locomotion are synchronized by light cycles. Thus, we show that the circadian clock of O. bicornis is set by either temperature or light, depending on what activity is timed. Light is a valuable cue for setting the circadian clock when bees have left the nest. However, for pre-emerged bees, temperature is the most important cue, which may represent an evolutionary adaptation of the circadian system to the cavity-nesting life style of O. bicornis.},
  language  = {en}
}
@phdthesis{Frank2019,
  author    = {Frank, Erik Thomas},
  title     = {Behavioral adaptations in the foraging behaviour of \(Megaponera\) \(analis\)},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156544},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {An efficient foraging strategy is one of the most important traits for the fitness of animals. The theory of optimal foraging tries to predict foraging behaviour through the overarching question: how animals should forage so as to minimize costs while maximizing profits? Social insects, having occupied nearly every natural niche through widely different strategies, offer themselves as an ideal group to study how well optimal foraging theory can explain their behaviour and success. Specialization often leads to unique adaptations in morphology and behaviour. I therefore decided to investigate the behaviour of Megaponera analis. This ponerine ant species is specialized on hunting only termites of the subfamily Macrotermitinae at their foraging sites. Their foraging behaviour is regulated by a handful of individual scouts (10-20) that search for termite foraging sites before returning to the nest to recruit a large number of nestmates (200-500 ants). These ants then follow the scout in a column formation to the termites and after the hunt return together to the nest, these raids occur two to five times per day. Predators of highly defensive prey likely develop cost reducing adaptations. The evolutionary arms race between termites and ants led to various defensive mechanisms in termites, e.g. a caste specialized in fighting predators. As M. analis incurs high injury/mortality risks when preying on termites, some risk mitigating adaptations have evolved. I show that a unique rescue behaviour in M. analis, consisting of injured nestmates being carried back to the nest, reduces combat mortality. These injured ants "call for help" with pheromones present in their mandibular gland reservoirs. A model accounting for this rescue behaviour identifies the drivers favouring its evolution and estimates that rescuing allows for maintaining a 29\% larger colony size. Heavily injured ants that lost too many legs during the fight on the other hand are not helped. Interestingly, this was regulated not by the helper but by the uncooperativeness of the injured ant. I further observed treatment of the injury by nestmates inside the nest through intense allogrooming directly at the wound. Lack of treatment increased mortality from 10\% to 80\% within 24 hours, with the cause of death most likely being infections. Collective decision-making is one of the main mechanisms in social insects through which foraging is regulated. However, individual decision-making can also play an important role, depending on the type of foraging behaviour. In M. analis only a handful of individuals (the scouts) hold all the valuable information about foraging sites. I therefore looked at predictions made by optimal foraging theory to better understand the interplay between collective and individual decision-making in this obligate group-raiding predator. I found a clear positive relation between raid size and termite abundance at the foraging site. Furthermore, selectivity of the food source increased with distance. The confirmation of optimal foraging theory suggests that individual scouts must be the main driver behind raid size, choice and raiding behaviour. Therefore most central place foraging behaviours in M. analis were not achieved by collective decisions but rather by individual decisions of scout ants. Thus, 1\% of the colony (10-20 scouts) decided the fate and foraging efficiency of the remaining 99\%. Division of labour is one of the main reasons for the success of social insects. Worker polymorphism, age polyethism and work division in more primitive ants, like the ponerines, remain mostly unexplored though. Since M. analis specializes on a defensive prey, adaptations to reduce their foraging costs can be expected. I found that the work division, task allocation and column-formation during the hunt were much more sophisticated than was previously thought. The column-formation was remarkably stable, with the same ants resuming similar positions in subsequent raids and front ants even returning to their positions if displaced in the same raid. Most of the raid tasks were not executed by predetermined members of the raid but were filled out as need arose during the hunt, with a clear preference for larger ants to conduct most tasks. I show that specialization towards a highly defensive prey can lead to very unique adaptations in the foraging behaviour of a species. I explored experimentally the adaptive value of rescue behaviour focused on injured nestmates in social insects. This was not only limited to selective rescuing of lightly injured individuals by carrying them back (thus reducing predation risk) but moreover includes a differentiated treatment inside the nest. These observations will help to improve our understanding of the evolution of rescue behaviour in animals. I further show that most optimal foraging predictions are fulfilled and regulated by a handful of individuals in M. analis. Lastly, I propose that the continuous allometric size polymorphism in M. analis allows for greater flexibility in task allocation, necessary due to the unpredictability of task requirements in an irregular system such as hunting termites in groups. All of my observations help to further understand how a group-hunting predator should forage so as to minimize costs while maximizing profits.},
  subject      = {Stechameisen},
  language  = {en}
}
@phdthesis{Franke2019,
  author    = {Franke, Christian},
  title     = {Advancing Single-Molecule Localization Microscopy: Quantitative Analyses and Photometric Three-Dimensional Imaging},
  doi       = {10.25972/OPUS-15635},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156355},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Since its first experimental implementation in 2005, single-molecule localization microscopy (SMLM) emerged as a versatile and powerful imaging tool for biological structures with nanometer resolution. By now, SMLM has compiled an extensive track-record of novel insights in sub- and inter- cellular organization.\\ Moreover, since all SMLM techniques rely on the analysis of emission patterns from isolated fluorophores, they inherently allocate molecular information \$per\$ \$definitionem\$.\\ Consequently, SMLM transitioned from its origin as pure high-resolution imaging instrument towards quantitative microscopy, where the key information medium is no longer the highly resolved image itself, but the raw localization data set.\\ The work presented in this thesis is part of the ongoing effort to translate those \$per\$ \$se\$ molecular information gained by SMLM imaging to insights into the structural organization of the targeted protein or even beyond. Although largely consistent in their objectives, the general distinction between global or segmentation clustering approaches on one side and particle averaging or meta-analyses techniques on the other is usually made.\\ During the course of my thesis, I designed, implemented and employed numerous quantitative approaches with varying degrees of complexity and fields of application.\\ \\ In my first major project, I analyzed the localization distribution of the integral protein gp210 of the nuclear pore complex (NPC) with an iterative \textit{k}-means algorithm. Relating the distinct localization statistics of separated gp210 domains to isolated fluorescent signals led, among others, to the conclusion that the anchoring ring of the NPC consists of 8 homo-dimers of gp210.\\ This is of particular significance, both because it answered a decades long standing question about the nature of the gp210 ring and it showcased the possibility to gain structural information well beyond the resolution capabilities of SMLM by crafty quantification approaches.\\ \\ The second major project reported comprises an extensive study of the synaptonemal complex (SNC) and linked cohesin complexes. Here, I employed a multi-level meta-analysis of the localization sets of various SNC proteins to facilitate the compilation of a novel model of the molecular organization of the major SNC components with so far unmatched extend and detail with isotropic three-dimensional resolution.\\ In a second venture, the two murine cohesin components SMC3 and STAG3 connected to the SNC were analyzed. Applying an adapted algorithm, considering the disperse nature of cohesins, led to the realization that there is an apparent polarization of those cohesin complexes in the SNC, as well as a possible sub-structure of STAG3 beyond the resolution capabilities of SMLM.\\ \\ Other minor projects connected to localization quantification included the study of plasma membrane glycans regarding their overall localization distribution and particular homogeneity as well as the investigation of two flotillin proteins in the membrane of bacteria, forming clusters of distinct shapes and sizes.\\ \\ Finally, a novel approach to three-dimensional SMLM is presented, employing the precise quantification of single molecule emitter intensities. This method, named TRABI, relies on the principles of aperture photometry which were improved for SMLM.\\ With TRABI it was shown, that widely used Gaussian fitting based localization software underestimates photon counts significantly. This mismatch was utilized as a \$z\$-dependent parameter, enabling the conversion of 2D SMLM data to a virtual 3D space. Furthermore it was demonstrated, that TRABI can be combined beneficially with a multi-plane detection scheme, resulting in superior performance regarding axial localization precision and resolution.\\ Additionally, TRABI has been subsequently employed to photometrically characterize a novel dye for SMLM, revealing superior photo-physical properties at the single-molecule level.\\ Following the conclusion of this thesis, the TRABI method and its applications remains subject of diverse ongoing research.},
  subject      = {Einzelmolek{\"u}lmikroskopie},
  language  = {en}
}
@phdthesis{PompergebMueller2019,
  author    = {Pomper [geb. M{\"u}ller], Laura Dorothea},
  title     = {Unterschiede in Frontaler Kortex Oxygenierung in zweierlei Risikogruppen der Alzheimer Demenz},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156757},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Die verbesserte medizinische Versorgung f{\"u}hrt zu einer zunehmenden Lebenserwartung unserer Gesellschaft. Damit steigt auch die sozio{\"o}konomische Relevanz neurodegenerativer Erkrankungen kontinuierlich. F{\"u}r die Alzheimer Demenz (AD), die dabei die h{\"a}ufigste Ursache darstellt, stehen bisher keine krankheitsmodifizierenden Behandlungsoptionen zur Verf{\"u}gung. Die lange pr{\"a}klinische Phase der Erkrankung birgt jedoch großes Potential f{\"u}r die Entwicklung neuer Behandlungsoptionen. Das Untersuchen von Risikogruppen ist f{\"u}r die Identifikation von Pr{\"a}diktoren einer sp{\"a}teren AD Manifestation von besonderem Interesse. In diesem Zusammenhang werden insbesondere das Vorliegen genetischer Risikokonstellationen, wie dem Apolipoprotein E (APOE) Ɛ4-Allel, sowie kognitiver Risikofaktoren, wie der „leichten kognitiven Beeintr{\"a}chtigung" (MCI), diskutiert. Die Identifikation pr{\"a}klinischer Aktivierungsunterschiede in relevanten Gehirnregionen von Risikogruppen kann als Basis f{\"u}r die Entwicklung neurofunktioneller Fr{\"u}herkennungs-Marker dienen. Der pr{\"a}frontale Kortex (PFC), welcher mit der Steuerung von Exekutivfunktionen assoziiert wird, hat sich in diesem Zusammenhang in bisherigen Studien als eine relevante Schl{\"u}sselregion manifestiert. Aufgrund der aufwendigen und kostenintensiven bildgebenden Untersuchungsmethoden, sind die genauen Prozesse jedoch noch unklar. Ziel der vorliegenden Arbeit war es daher, Unterschiede in der PFC Oxygenierung in zweierlei Risikogruppen der AD mit einer kosteng{\"u}nstigeren Bildgebungsmethode, der funktionellen Nahinfrarot Spektroskopie (fNIRS), zu untersuchen. Daf{\"u}r wurde in einem ersten Schritt, der Trailmaking Test (TMT), ein weitverbreiteter neuropsychologischer Test zur Erfassung exekutiver Funktionen, f{\"u}r fNIRS implementiert. Als Grundlage f{\"u}r die Untersuchung fr{\"u}hpathologischer Prozesse, wurden zun{\"a}chst gesunde Alterungsprozesse betrachtet. Der Vergleich von jungen und {\"a}lteren Probanden (n = 20 pro Gruppe) wies neben der Eignung der Testimplementierung f{\"u}r fNIRS auf eine spezifische bilaterale PFC Oxygenierung hin, welche bei jungen Probanden rechtshemisph{\"a}risch lateralisiert war. {\"A}ltere Probanden hingegen zeigten bei vergleichbaren Verhaltensdaten insgesamt mehr signifikante Kan{\"a}le sowie eine Abnahme der Lateralisierung. Dies kann als zus{\"a}tzlicher Bedarf an Ressourcen in gesunden Alterungsprozessen interpretiert werden. Im Rahmen der Hauptstudie wurden anschließend insgesamt 604 {\"a}ltere Probanden im Alter von 70 bis 76 Jahren untersucht. Zun{\"a}chst wurde die genetische Risikogruppe der Ɛ4-Allel-Tr{\"a}ger (n = 78) mit den neutralen Ɛ3-Allel-Tr{\"a}gern (n = 216) und den Tr{\"a}gern des als protektiv geltenden Ɛ2-Allels (n = 50) verglichen. Hierbei zeigte sich eine geringere Oxygenierung der Risikogruppe bei geringer Aufgabenschwierigkeit, w{\"a}hrend sich ein erh{\"o}hter Oxygenierungsanstieg im medialen PFC mit steigender Aufgabenschwierigkeit zeigte. Dies deutet auf einen erh{\"o}hten Bedarf an neuronalen Kontrollmechanismen der Risikogruppe zur Bew{\"a}ltigung der steigenden Aufgabenschwierigkeit hin. Die protektive Gruppe zeigte hingegen eine erh{\"o}hte Oxygenierung im ventralen PFC mit steigender Aufgabenschwierigkeit, was m{\"o}glicherweise auf einen pr{\"a}ventiven Effekt hindeuten k{\"o}nnte. Weiterf{\"u}hrend wurden MCI-Patienten mit gesunden Probanden (n = 57 pro Gruppe) hinsichtlich des kognitiven Risikofaktors verglichen. Hierbei zeigte sich ein punktuell reduzierter Oxygenierunganstieg der MCI Patienten mit steigender Aufgabenschwierigkeit vor allem im ventralen PFC bei ebenfalls stabiler Verhaltensleistung. Die gefundene Reduktion k{\"o}nnte ein Zeichen f{\"u}r eine aufgebrauchte kognitive Reserve sein, welche Einbußen auf Verhaltensebene voranzugehen scheint. Diese charakteristischen Unterschiede in den frontalen Oxygenierungsmustern von Risikogruppen (APOE, MCI) k{\"o}nnten als Biomarker zur Fr{\"u}herkennung von AD noch vor dem Auftreten kognitiver Einbußen dienen. Die fNIRS-Untersuchung w{\"a}hrend der Durchf{\"u}hrung des TMT hat sich in diesem Zusammenhang als potentielles Instrument zur Fr{\"u}hdiagnose der pr{\"a}klinischen Phase der AD als geeignet erwiesen. Die Ergebnisse werden unter Einbezug des wissenschaftlichen Kontexts interpretiert und Implikationen f{\"u}r weitere notwendige Studien sowie die klinische Anwendbarkeit diskutiert.},
  subject      = {Alzheimerkrankheit},
  language  = {de}
}
@phdthesis{Goettlich2019,
  author    = {G{\"o}ttlich, Claudia},
  title     = {Etablierung eines humanen 3D Lungentumor-Testsystems zur Analyse von Behandlungseffekten},
  doi       = {10.25972/OPUS-16413},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-164132},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2019},
  abstract  = {Lungenkrebs ist weltweit f{\"u}r die meisten krebsassoziierten Tode verantwortlich. Ursache daf{\"u}r ist unter anderem, dass viele Medikamente in der klinischen Anwendung, aufgrund nicht {\"u}bertragbarer Ergebnisse aus der Pr{\"a}klinik, scheitern. Zur Entwicklung neuer Therapiestrategien werden deshalb Modelle ben{\"o}tigt, welche die in vivo Situation besser widerspiegeln. Besonders wichtig ist es dabei, zu zeigen, f{\"u}r welche Fragestellungen ein neues Testsystem valide Ergebnisse liefert. In dieser Arbeit ist es mit Hilfe des Tissue Engineering gelungen, ein humanes 3D in vitro Lungentumor-Testsystem weiter zu entwickeln und f{\"u}r verschiedene Fragestellungen zu validieren. Zudem konnten sowohl f{\"u}r die Herstellung als auch f{\"u}r die Behandlung der Tumormodelle SOPs etabliert werden. Hier wurde zun{\"a}chst beobachtet, dass die Auswerteparameter f{\"u}r die Beurteilung von Behandlungseffekten eine geringe Varianz aufweisen und das 3D Modell deshalb als Testsystem geeignet ist. Ein Vergleich der Morphologie, des EMT-Status und der Differenzierung der Tumorzelllinien im 3D Modell mit Tumorbiopsaten von Adenokarzinompatienten verdeutlichte, dass die 3D Modelle tumorrelevante Merkmale besitzen. So sind die Zelllinien auf der biologischen Matrix, verglichen mit der jeweiligen 2D Kultur, durch eine reduzierte Proliferationsrate gekennzeichnet, welche eher der in vivo Situation entspricht. F{\"u}r die Etablierung und Validierung des 3D Modells als Testsystem war es notwendig, klinisch relevante Therapien in dem Modell anzuwenden und die Ergebnisse der Behandlung in vitro mit denen im Patienten zu vergleichen. Dabei konnte zun{\"a}chst best{\"a}tigt werden, dass eine zielgerichtete Therapie gegen den EGFR in dem 3D System zu einer verst{\"a}rkten Induktion der Apoptose im Vergleich zu 2D f{\"u}hrt. Dies entspricht klinischen Beobachtungen, bei denen EGFR-mutierte Patienten gut auf eine Therapie mit Tyrosin-Kinase-Inhibitoren (TKI) ansprechen. Anschließend wurde in dieser Arbeit erstmals in vitro gezeigt, dass die Behandlung mit einem HSP90-Inhibitor bei KRAS-Mutation wie in behandelten Patienten keine eindeutigen Vorteile bringt, diese jedoch in Experimenten der 2D Zellkultur mit den entsprechenden Zelllinien vorhergesagt werden. Die Ergebnisse aus dem in vitro Modell spiegeln damit verschiedene klinische Studien wider und unterstreichen das Potenzial des 3D Lungentumor-Testsystems die Wirkung zielgerichteter Therapien vorherzusagen. Durch die Messung von Signalwegsaktivierungen {\"u}ber Phospho-Arrays und Western Blot konnten in dieser Arbeit Unterschiede zwischen 2D und 3D nach Behandlung gezeigt werden. Diese lieferten die Grundlage f{\"u}r bioinformatische Vorhersagen f{\"u}r Medikamente. Mit fortschreitender Erkrankung und dem Entstehen invasiver Tumore, die m{\"o}glicherweise Metastasen bilden, verschlechtert sich die Prognose von Krebspatienten. Zudem entwickeln Patienten, die zun{\"a}chst auf eine Therapie mit TKI ansprechen, bereits nach kurzer Zeit Resistenzen, die ebenfalls zur Progression des Tumorwachstums f{\"u}hren. Zur Wirkungsuntersuchung von Substanzen in solchen fortgeschrittenen Erkrankungsstadien wurde das bestehende Testsystem erweitert. Zum einen wurde mit Hilfe des Wachstumsfaktors TGF-β1 eine EMT ausgel{\"o}st. Hier konnte beobachtet werden, dass sich die Expression verschiedener EMT- und invasionsassoziierter Gene und Proteine ver{\"a}nderte und die Zellen vor allem in dynamischer Kultur verst{\"a}rkt die Basalmembran der Matrix {\"u}berquerten. Zum anderen wurde die Ausbildung von Resistenzen gegen{\"u}ber TKI durch die Generierung von resistenten Subpopulationen aus einer urspr{\"u}nglich sensitiven Zelllinie und anschließender Kultivierung auf der Matrix abgebildet. Dabei zeigte sich keine der klinisch bekannten Mutationen als urs{\"a}chlich f{\"u}r die Resistenz, sodass weitere Mechanismen untersucht wurden. Hier konnten Ver{\"a}nderungen in der Signaltransduktion sowie der Expression EMT-assoziierter Proteine festgestellt werden. Im letzten Teil der Arbeit wurde eine neuartige Behandlung im Bereich der Immuntherapie erfolgreich in dem 3D Modell angewendet. Daf{\"u}r wurden T-Zellen, die einen chim{\"a}ren Antigen-Rezeptor (CAR) gegen ROR1 tragen, in statischer und dynamischer Kultur zu den Tumorzellen gegeben und der Therapieeffekt mittels histologischer F{\"a}rbung und der Bestimmung der Apoptose evaluiert. Zus{\"a}tzlich konnten Eigenschaften der T-Zellen, wie deren Proliferation sowie Zytokinaussch{\"u}ttung quantifiziert und damit eine spezifische Wirkung der CAR transduzierten T-Zellen gegen{\"u}ber Kontroll-T-Zellen nachgewiesen werden. Zusammenfassend ist es in dieser Arbeit gelungen, ein humanes 3D Lungentumor-Testsystem f{\"u}r die Anwendung in der pr{\"a}klinischen Entwicklung von Krebsmedikamenten sowie der Grundlagenforschung im Bereich der Tumorbiologie zu etablieren. Dieses Testsystem ist in der Lage relevante Daten zu Biomarker-geleiteten Therapien, zur Behandlung fortgeschrittener Tumorstadien und zur Verbesserung neuartiger Therapiestrategien zu liefern.},
  subject      = {Tissue Engineering},
  language  = {de}
}