@unpublished{Dandekar2008, author = {Dandekar, Thomas}, title = {Why are nature´s constants so fine-tuned? The case for an escalating complex universe}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34488}, year = {2008}, abstract = {Why is our universe so fine-tuned? In this preprint we discuss that this is not a strange accident but that fine-tuned universes can be considered to be exceedingly large if one counts the number of observable different states (i.e. one aspect of the more general preprint http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/3353/). Looking at parameter variation for the same set of physical laws simple and complex processes (including life) and worlds in a multiverse are compared in simple examples. Next the anthropocentric principle is extended as many conditions which are generally interpreted anthropocentric only ensure a large space of different system states. In particular, the observed over-tuning beyond the level for our existence is explainable by these system considerations. More formally, the state space for different systems becomes measurable and comparable looking at their output behaviour. We show that highly interacting processes are more complex then Chaitin complexity, the latter denotes processes not compressible by shorter descriptions (Kolomogorov complexity). The complexity considerations help to better study and compare different processes (programs, living cells, environments and worlds) including dynamic behaviour and can be used for model selection in theoretical physics. Moreover, the large size (in terms of different states) of a world allowing complex processes including life can in a model calculation be determined applying discrete histories from quantum spin-loop theory. Nevertheless there remains a lot to be done - hopefully the preprint stimulates further efforts in this area.}, subject = {Natur}, language = {en} } @phdthesis{Lechner2008, author = {Lechner, Melanie}, title = {Charakterisierung des Umweltkeims Bordetella petrii. Untersuchungen zur genomischen Variabilit{\"a}t und zum Bvg Regulon}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-34391}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Die 2001 beschriebene Art B. petrii stellt den ersten Umweltkeim der Gattung Bordetella dar, welcher aus einer anaeroben, dechlorinierenden Anreicherungskultur aus Flusssediment isoliert wurde. Phylogenetisch wird B. petrii an die Basis der Gattung Bordetella eingeordnet und ist in evolution{\"a}rer Hinsicht deshalb interessant, weil er sowohl f{\"u}r orthologe Gene bestimmter Virulenzfaktoren der pathogenen Bordetellen kodiert als auch typische Eigenschaften von Umweltkeimen aufweist und somit eine Art Bindeglied darstellt. Da B. petrii ein orthologes BvgAS-System besitzt (der Hauptregulator der Virulenzgenexpression in den pathogenen Bordetellen), wurde dessen Struktur im Rahmen dieser Arbeit mittels in silico Analysen untersucht. Dabei konnte gezeigt werden, dass eine Konservierung nur auf Aminos{\"a}ureebene deutlich zu erkennen ist und der Response Regulator BvgA von B. petrii die st{\"a}rkste Konservierung aufweist. Desweiteren besitzt B. petrii Gene f{\"u}r zwei Histidinkinasen, BvgS1 und BvgS2, sowie ein separates Gen, welches f{\"u}r eine Hpt-Dom{\"a}ne kodiert. Weitere putative Virulenzfaktoren von B. petrii geh{\"o}ren in die Gruppe der Adh{\"a}sionsfaktoren. Diese Faktoren spielen bei den „klassischen" Bordetellen im Infektionszyklus eine wichtige Rolle f{\"u}r die Anheftung z.B. an die Epithelzellen des Respirationstraktes. Um ein m{\"o}gliches pathogenes Potential von B. petrii absch{\"a}tzen zu k{\"o}nnen, wurden vergleichende Zellkulturstudien mit B. bronchiseptica durchgef{\"u}hrt. Dabei konnte gezeigt werden, dass B. petrii um den Faktor 7,5 weniger in Makrophagen aufgenommen wird. Hinweise auf die Funktionalit{\"a}t des BvgAS-Systems in B. petrii wurden durch Proteomstudien mit einer BvgA-Mutante erhalten, und deuten darauf hin, dass das BvgAS-System in B. petrii m{\"o}glicherweise eine Funktion in der Respirationskontrolle haben k{\"o}nnte. Im Rahmen der Genomsequenzierung wurden acht genomische Inseln beschrieben, die in dieser Arbeit hinsichtlich ihrer Struktur und ihrem Excisionsverhalten untersucht wurden. Es konnte gezeigt werden, dass die genomischen Inseln, mit Ausnahme der Insel GI0, in verschiedenen Kombinationen, als ringf{\"o}rmige Intermediate aus dem B. petrii Genom ausgeschnitten werden k{\"o}nnen. Vier der genomischen Inseln (GI1-GI3 und GI6) weisen strukturelle {\"A}hnlichkeiten zu einer Familie syntenischer genomischer Inseln auf, zu denen auch das clc-Element von Pseudomonas sp. Strain B13 z{\"a}hlt. Die gr{\"o}ßte {\"A}hnlichkeit zum clc-Element weist die Insel GI3 von B. petrii auf. Diese beiden Inseln haben ann{\"a}hernd die gleiche Gr{\"o}ße und besitzen Gene zu Abbau von 3-Chlorobenzoat (3-CBA). Die Untersuchung der Stabilit{\"a}t von GI3 ergab, dass nach 125-150 Generationen nur noch 1,5 \% der Bakterien die Insel GI3 enthielten. Desweiteren konnte die {\"U}bertragung der Insel GI3 von B. petrii auf B. bronchiseptica PS2 gezeigt und der Integrationsbereich bestimmt werden. Im Rahmen dieser Arbeit wurde auch ein neuer Stammbaum der Gattung Bordetella erstellt, in welchen eine Reihe k{\"u}rzlich neu beschriebener B. petrii Isolate mit aufgenommen wurden wodurch ein zu den pathogenen Bordetellen abgegrenztes Cluster gebildet wird.}, subject = {Mikrobiologie}, language = {de} } @article{KleinschmidtScheerDabauvalleetal.1983, author = {Kleinschmidt, J{\"u}rgen A. and Scheer, Ulrich and Dabauvalle, Marie-Christine and Bustin, Michael and Franke, Werner W.}, title = {High mobility group proteins of amphibian oocytes: a large storage pool of a soluble high mobility group-1-like protein and involvement in transcriptional events}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33250}, year = {1983}, abstract = {No abstract available}, language = {en} } @phdthesis{Steigerwald2008, author = {Steigerwald, Jutta}, title = {Der NK-Zellrezeptor NKG2D als Zielstruktur f{\"u}r eine Antik{\"o}rper-basierte therapeutische Immunmodulation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33446}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {Das NKG2D (Natural Killer Group 2 Member D)-Protein, ist ein aktivierender Rezeptor, der es NK- und CD8+ T-Zellen erm{\"o}glicht, infizierte oder transformierte k{\"o}rpereigene Zellen zu erkennen und zu eliminieren. Eine Fehlregulation dieses Rezeptors auf Immunzellen scheint jedoch auch zur Ausbildung von Autoimmunerkrankungen wie Typ I Diabetes, Z{\"o}liakie und RA zu f{\"u}hren. Im Rahmen dieser Arbeit wurde ein humaner Antik{\"o}rper gegen hNKG2D f{\"u}r einen m{\"o}glichen therapeutischen Einsatz bei Autoimmunerkrankungen generiert. Basierend auf den Sequenzen von schwerer (VH) und leichter Kette (VL) der murinen monoklonalen Antik{\"o}rper 6H7 und 6E5A7, welche hNKG2D spezifisch binden und die Interaktion zwischen Ligand und Rezeptor blockieren, wurden scFv-Phagenbibliotheken hergestellt. Diese wurden anschließend zur Selektion im Phagen-Display eingesetzt. Der Humanisierungsprozess erfolgte hierbei mit Hilfe des Guided Selection-Verfahrens. Dazu wurde in einem ersten Phagen-Display-Durchgang die VH-Dom{\"a}ne des parentalen scFv mit einem humanen VL-Repertoire kombiniert. Die beiden daraus resultierenden humanen VL-Ketten wurden im darauf folgenden Schritt mit einem Repertoire an humanen VH-Dom{\"a}nen verkn{\"u}pft. Da hierbei kein humaner rekombinanter scFv mit hNKG2D-Bindungsaktivit{\"a}t identifiziert werden konnte, musste eine schrittweise Humanisierung der Framework-Regionen (FR) der VH unter Beibehaltung der murinen CDR-Bereiche erfolgen. Diese f{\"u}hrte zur Generierung des humanen scFv E1VLV71KVH, welcher neben den murinen CDR-Regionen lediglich noch drei Aminos{\"a}uren murinen Ursprungs im FR-Bereich besaß. Dessen biologische Aktivit{\"a}t wurde nach Konvertierung in das IgG1/lambda-Format in verschiedenen in vitro-Systemen analysiert. Anhand der Ergebnisse aus diesen Versuchen konnte ein deutlicher Verlust der Affinit{\"a}t und inhibitorischen Aktivit{\"a}t nach der Humanisierung festgestellt werden. Die dadurch erforderliche Affinit{\"a}tsmaturierung des E1VLV71KVH Antik{\"o}rpers mittels sequentieller Randomisierung des CDR3-Bereichs von E1VL und V71KVH resultierte in f{\"u}nf unterschiedlichen, hoch-affinen Anti-hNKG2D scFv. Zwei dieser generierten Konstrukte, B1VLB6VH und E4VLG10VH, wurden nach ihrer Herstellung als vollst{\"a}ndige IgG1/lambda-Antik{\"o}rper in vitro hinsichtlich ihrer Aktivierungs- und Neutralisierungsaktivit{\"a}t, sowie ihrer Stabilit{\"a}t und Internalisierung durch NK-Zellen untersucht. Beide Antik{\"o}rper wiesen nach der Affinit{\"a}tsmaturierung mit einem IC50 von ca. 3,4x 10-2 µg/ml ein wesentlich h{\"o}heres Inhibitionspotential als der murine Ursprungsantik{\"o}rper (ca. 3,3 µg/ml) auf und zeigten gegen{\"u}ber Hitzeeinwirkung und Serumproteasen eine hohe Stabilit{\"a}t. Mit Hilfe fluoreszenzmikroskopischer Untersuchungen konnten Internalisierungsvorg{\"a}nge der Antik{\"o}rper in die NK-Zelle beobachtet werden. F{\"u}r ein besseres Verst{\"a}ndnis NKG2D-abh{\"a}ngiger Regulationsvorg{\"a}nge und die Identifizierung NKG2D-spezifischer Zielgene wurde das Genexpressionsprofil von humanen NK-Zellen nach Interaktion mit dem NKG2D-Liganden ULBP-1Fc mittels Microarray untersucht. Infolge einer anschließenden Validierung der Ergebnisse auf RNA- und Proteinebene konnten mittels RT-qPCR, FACS, ELISA und CBA NKG2D-spezifische Biomarker wie CRTAM, TNFalpha, IFNgamma und GM-CSF etabliert werden. Erg{\"a}nzend zu 51Cr-Freisetzungs-Experimenten in zwei unterschiedlichen in vitro Zellkultursystemen erm{\"o}glichten diese Biomarker eine umfassende Charakterisierung neutralisierender und aktivierender Eigenschaften der beiden Antik{\"o}rper B1VLB6VH und E4VLG10VH. Anhand dieser Experimente konnte festgestellt werden, dass die humanen Anti-hNKG2D Antik{\"o}rper eine ambivalente Funktionalit{\"a}t aufweisen. In L{\"o}sung sind sie in der Lage, NKG2D-induzierte CRTAM-Expression, Zellyse und Zytokinfreisetzung zu inhibieren. Nach Kreuzvernetzung des NKG2D-Rezeptors {\"u}ber an Platten immobilisierte Anti-hNKG2D Antik{\"o}rper hingegen lassen sich aktivierende Eigenschaften wie Zellyse und Zytokinsekretion durch NK Zellen beobachten. Aufgrund ihrer ambivalenten Aktivit{\"a}t scheint ein therapeutischer Einsatz der beiden Antik{\"o}rper bei humanen Autoimmunerkrankungen zum jetzigen Zeitpunkt noch nicht m{\"o}glich. In der vorliegenden Arbeit wurden somit die Voraussetzungen geschaffen, um einen humanen, hoch affinen hNKG2D neutralisierenden Antik{\"o}rper in einem letzten Schritt in ein besser geeignetes Antik{\"o}rper-Format (scFv, Fab oder F(ab)2) zu konvertieren.}, subject = {Antik{\"o}rper}, language = {de} } @unpublished{Dandekar2007, author = {Dandekar, Thomas}, title = {Some general system properties of a living observer and the environment he explores}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-33537}, year = {2007}, abstract = {In a nice assay published in Nature in 1993 the physicist Richard God III started from a human observer and made a number of witty conclusions about our future prospects giving estimates for the existence of the Berlin Wall, the human race and all the rest of the universe. In the same spirit, we derive implications for "the meaning of life, the universe and all the rest" from few principles. Adams´ absurd answer "42" tells the lesson "garbage in / garbage out" - or suggests that the question is non calculable. We show that experience of "meaning" and to decide fundamental questions which can not be decided by formal systems imply central properties of life: Ever higher levels of internal representation of the world and an escalating tendency to become more complex. An observer, "collecting observations" and three measures for complexity are examined. A theory on living systems is derived focussing on their internal representation of information. Living systems are more complex than Kolmogorov complexity ("life is NOT simple") and overcome decision limits (G{\"o}del theorem) for formal systems as illustrated for cell cycle. Only a world with very fine tuned environments allows life. Such a world is itself rather complex and hence excessive large in its space of different states - a living observer has thus a high probability to reside in a complex and fine tuned universe.}, subject = {Komplex }, language = {en} } @article{GrafeSchmuckLinsenmair1992, author = {Grafe, T. Ulmar and Schmuck, Richard and Linsenmair, Karl Eduard}, title = {Reproductive energetics of the African Reed Frogs, Hyperolius viridiflavus and Hyperolius marmoratus}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31187}, year = {1992}, abstract = {No abstract available}, language = {en} } @article{Linsenmair1994, author = {Linsenmair, Karl Eduard}, title = {Biologische Vielfalt und {\"o}kologische Stabilit{\"a}t}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-31157}, year = {1994}, abstract = {No abstract available}, language = {en} } @article{KobeltLinsenmair1986, author = {Kobelt, Frank and Linsenmair, Karl Eduard}, title = {Adaptations of the reed frog Hyperolius viridiflavus to its arid environment. I. The skin of Hyperolius viridiflavus nitidulus in wet and dry season conditions.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-30551}, year = {1986}, abstract = {Hyperolius viridiflavus nitidulus inhabits parts of the seasonally very hot and dry West African savanna. During the long lasting dry season, the small frog is sitting unhidden on mostly dry plants and has to deal with high solar radiation load (SRL), evaporative water loss (EWL) and small energy reserves. It seems to be very badly equipped to survive such harsh climatic conditions (unfavorable surface to volume ratio, very limited capacity to st{\"o}re energy and water). Therefore, it must have developed extraordinary efficient mechanisms to solve the mentioned Problems. Some of these mechanisms are to be looked for within the skin of the animal (e.g. protection against fast desiccation, deleterious effects of UV radiation and over-heating). The morphology of the wet season skin is, in most aspects, that of a "normal" anuran skin. It differs in the Organization of the processes of the melanophores and in the arrangement of the chromatophores in the Stratum spongiosum, forming no "Dermal Chromatophore Unit". During the adaptation to dry season conditions the number of iridophores in dorsal and ventral skin is increased 4-6 times compared to wet season skin. This increase is accompanied by a very conspicuous change of the wet season color pattern. Now, at air temperatures below 35° C the color becomes brownish white or grey and changes to a brilliant white at air temperatures near and over 40° C. Thus, in dry season State the frog retains its ability for rapid color change. In wet season State the platelets of the iridophores are irregularly distributed. In dry season State many platelets become arranged almost parallel to the surface. These purine crystals probably act as quarter-wave-length interference reflectors, reducing SRL by reflecting a considerable amount of the radiated energy input. EWL is as low as that of much larger xeric reptilians. The impermeability of the skin seems to be the result of several mechanisms (ground substance, iridophores, lipids, mucus) supplementing each other. The light red skin at the pelvic region and inner sides of the limbs is specialized for rapid uptake of water allowing the frog to replenish the unavoidable EWL by using single drops of dew or rain, available for only very short periods.}, language = {en} } @article{ScheerTrendelenburgFranke1976, author = {Scheer, Ulrich and Trendelenburg, Michael F. and Franke, Werner W.}, title = {Regulation of transcription of genes of ribosomal RNA during amphibian oogenesis: a biochemical and morphological study}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32814}, year = {1976}, abstract = {Natural changes in the transcription of rRNA genes were studied in nucleoli from three oogenic stages of the newt Triturus alpestris with electron microscope, autoradiographic, and biochemical techniques. From determinations of the uridine triphosphate pool sizes and [3H]uridine uptake, phosphorylation, and incorporation into 28S and 18S rRNAs in vivo it was estimated that the rate of rRNA synthesis was about 0.01\% in previtellogenic oocytes and 13\% in mature oocytes when compared to midvitellogenesis. Spread preparations of nucleoli showed significant morphological changes in the transcriptional complexes. The total number of lateral fibrils, i.e., ribonucleoproteins containing the nascent rRNA precursor, were drastically decreased in stages of reduced synthetic activity. This indicates that rRNA synthesis is regulated primarily at the level of transcription. The resulting patterns of fibril coverage of the nucleolar chromatin axes revealed a marked heterogeneity. On the same nucleolar axis occurred matrix units that were completely devoid of lateral fibrils, matrix units that were almost fully covered with lateral fibrils, and various forms of matrix units with a range of lateral fibril densities intermediate between the two extremes. Granular particles that were tentatively identified as RNA polymerase molecules were not restricted to the transcription l complexes. They were observed, although less regularly and separated by greater distances, in untranscribed spacer regions as well as in untranscribed gene intercepts. The results show that the pattern of transcriptional control of rRNA genes differs widely in different genes, even in the same genetic unit.}, language = {en} } @article{DabauvalleLoosMerkertetal.1991, author = {Dabauvalle, Marie-Christine and Loos, Karin and Merkert, Hilde and Scheer, Ulrich}, title = {Spontaneous assembly of pore complex-containing membranes ("Annulate lamellae") in Xenopus egg extract in the absence of chromatin}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32797}, year = {1991}, abstract = {No abstract available}, language = {en} } @article{WilkenKossnerSenecaletal.1993, author = {Wilken, Norbert and Kossner, Ursula and Sen{\´e}cal, Jean-Luc and Scheer, Ulrich and Dabauvalle, Marie-Christine}, title = {Nup180, a novel nuclear pore complex protein localizing to the cytoplasmic ring and associated fibrils}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32049}, year = {1993}, abstract = {No abstract available}, language = {en} } @article{Scheer1970, author = {Scheer, Ulrich}, title = {The ultrastructure of the nuclear envelope of amphibian oocytes: a reinvestigation. III. Actinomycin D-induced decrease in central granules within the pores.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32110}, year = {1970}, abstract = {No abstract available}, language = {en} } @article{FrankeScheerFritsch1972, author = {Franke, Werner W. and Scheer, Ulrich and Fritsch, Hansj{\"o}rg}, title = {Intranuclear and cytoplasmic annulate lamellae in plant cells}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32148}, year = {1972}, abstract = {No abstract available}, language = {en} } @article{FrankeKartenbeckZentgrafetal.1971, author = {Franke, Werner W. and Kartenbeck, J{\"u}rgen and Zentgraf, Hanswalter and Scheer, Ulrich and Falk, Heinz}, title = {Membrane-to-membrane cross-bridges. A means to orientation and interaction of membrane faces}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32122}, year = {1971}, abstract = {No abstract available}, language = {en} } @article{ScheerFrankeTrendelenburg1975, author = {Scheer, Ulrich and Franke, Werner W. and Trendelenburg, Michael F.}, title = {Effects of actinomycin D on the association of newly formed ribonucleoproteins with the cistrons of ribosomal RNA in Triturus oocytes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32383}, year = {1975}, abstract = {No abstract available}, language = {en} } @article{FrankeSpringScheeretal.1975, author = {Franke, Werner W. and Spring, Herbert and Scheer, Ulrich and Zerban, Heide}, title = {Growth of the nuclear envelope in the vegetative phase of the green alga Acetabularia. Evidence for assembly from membrane components synthesized in the cytoplasm.}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32403}, year = {1975}, abstract = {No abstract available}, language = {en} } @phdthesis{Wuest2008, author = {W{\"u}st, Simone}, title = {Analyse des Wirkmechanismus von Kortikosteroiden bei der Therapie der Experimentellen Autoimmunen Enzephalomyelitis, einem Tiermodell f{\"u}r Multiple Sklerose}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32961}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {In der vorliegenden Arbeit wurden die Mechanismen der Hochdosis-GC-Pulstherapie im Zusammenhang mit akuten Sch{\"u}ben von MS-Patienten anhand des Tiermodells der MS, der Experimentellen Autoimmunen Enzephalomyelitis (EAE), untersucht. Die EAE wurde in C57Bl/6 M{\"a}usen und diversen GR-defizienten M{\"a}usen durch Immunisierung mit Myelinoligodendrozytenglykoprotein (MOG35-55) induziert. Es konnte gezeigt werden, dass die Gabe von Dexamethason (Dex) den Krankheitsverlauf dosisabh{\"a}ngig verbessert. Die Untersuchung heterozygoter GR Knock-out M{\"a}use und h{\"a}matopoetischer Stammzellchim{\"a}ren verdeutlichte, dass der zytosolische GR (cGR) f{\"u}r die Vermittlung therapeutischer GC-Effekte von sehr großer Bedeutung ist. Der Einsatz zelltyp-spezifischer GR-defizienter M{\"a}use zeigte auf zellul{\"a}rer Ebene, dass f{\"u}r die Vermittlung von GC-Wirkungen die Expression des GR vor allem in T-Zellen unabdingbar ist, wohingegen die GR-Expression in myeloiden Zellen in diesem Kontext keine Bedeutung hat. Durch die Analyse des molekularen Mechanismus konnte festgestellt werden, dass diese Effekte durch Apoptoseinduktion und Herunterregulieren von Adh{\"a}sionsmolek{\"u}len in peripheren, aber nicht ZNS-residenten T-Zellen erzielt wurden. {\"U}berdies wurde ersichtlich, dass Dex die T-Zellmigration in das ZNS verhinderte. Diese Beobachtung unterst{\"u}tzt die Hypothese, dass Dex durch Apoptoseinduktion und Immunmodulation haupts{\"a}chlich auf periphere T-Zellen wirkt und somit den st{\"a}ndigen Influx neuer Immunzellen in das ZNS verhindert. Ferner konnte in dieser Arbeit gezeigt werden, dass die therapeutische Gabe hochdosierten Methylprednisolons (MP) in diesem EAE-Modell ebenfalls zu einer dosisabh{\"a}ngigen Verbesserung der EAE f{\"u}hrte. Diese beruhte auf einer reduzierten Lymphozyteninfiltration in das ZNS, war allerdings im Vergleich zur Dex-Therapie aufgrund geringerer Wirkpotenz weniger stark ausgepr{\"a}gt. Im Gegensatz dazu f{\"u}hrte die pr{\"a}ventive MP-Applikation zu einem verst{\"a}rkten EAE-Verlauf, der nach der Beeinflussung peripherer, h{\"a}matopoetischer Immunzellen auf eine verst{\"a}rkte Proliferation autoreaktiver T-Zellen zur{\"u}ckzuf{\"u}hren ist. Im weiteren Verlauf der vorliegenden Arbeit wurde als m{\"o}glicher Ersatz f{\"u}r die Hochdosis-GC-Pulstherapie eine nicht-steroidale, antiinflammatorische Substanz im chronischen EAE-Modell der C57Bl/6 Maus etabliert. Erste tierexperimentelle Untersuchungen mit Compound A (CpdA) offenbarten eine lediglich geringe therapeutische Breite dieser Substanz, wobei innerhalb pharmakologischer Dosierungen dennoch therapeutische Wirkungen vermittelt werden konnten. Anhand von in vitro Experimenten konnte eindeutig nachgewiesen werden, dass CpdA GR-unabh{\"a}ngig Apoptose induzierte, wobei Immunzellen und neuronale Zellen gegen{\"u}ber CpdA besonders empfindlich reagierten. Der Einsatz T-Zell-spezifischer GR-defizienter M{\"a}use konnte zeigen, dass CpdA f{\"u}r die Vermittlung therapeutischer Wirkungen den cGR ben{\"o}tigt. Ferner wurde offensichtlich, dass CpdA in Abwesenheit des cGR in T-Zellen eine signifikante Verschlechterung der EAE verursachte. Durch die Anwendung physikochemischer Analysenmethoden, wie der Massenspektrometrie und 1H-NMR-Spektroskopie, konnte festgestellt werden, dass CpdA in vitro in gepufferten Medien in eine zyklische, chemisch sehr reaktive Verbindung (Aziridin) metabolisiert wird. Diese kann sehr wahrscheinlich f{\"u}r die Apoptose-Induktion in Zellen und die in M{\"a}usen beobachteten neurotoxischen Ausfallerscheinungen verantwortlich gemacht werden. Durch chemische Analysen konnte in vitro in w{\"a}ssriger CpdA-L{\"o}sung ein weiterer Metabolit, das sympathomimetisch wirksame Synephrin, identifiziert werden. Um die Wirksamkeit adrenerger Substanzen in vivo zu testen, wurde das ß1/2-Sympathomimetikum Isoproterenol appliziert. Dieses verbesserte die EAE-Symptomatik, was sehr wahrscheinlich auf eine reduzierte Antigenpr{\"a}sentation und einer damit verbundenen verminderten T-Zellinfiltration in das ZNS zur{\"u}ckzuf{\"u}hren ist.}, subject = {Multiple Sklerose}, language = {de} } @phdthesis{Li2009, author = {Li, Naixin}, title = {Dorso-ventral Differentiation and Specification of the Mesencephalon in Early Chick Embryos}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32950}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {The chick midbrain is subdivided into functionally distinct ventral and dorsal domains, tegmentum and optic tectum. In the mature tectum, neurons are organized in layers, while they form discrete nuclei in the tegmentum. An interesting characteristic of the embryonic brain is the development of a large optic tectum, of which the growth becomes obvious at embryonic day 3 (E3). Dorsoventral (DV) specification of the early midbrain should thus play a crucial role for the organization of the neuronal circuitry in optic tectum and tegmentum. In the first part of my thesis, I investigated regional commitment and establishment of cellular differences along the midbrain DV axis. I examined the commitment of gene expression patterns in isolated ventral and dorsal tissue in vivo and in vitro, and studied their cell mixing properties. Explant cultures, and grafting of dorsal midbrain into a ventral environment or vice versa, revealed a gradual increase in the autonomy of region-specific gene regulation between, which was accompanied by a gradual increase in differential adhesive properties from E2 to E3, once the DV axis polarity was fixed. These events happened at a time-point when the majority of midbrain cells are not yet differentiated. Long-term transplantation (6 - 9 days) using quail cells from ventral midbrain as grafts showed the same result. Hence, the results suggest that progressive specification of the midbrain DV axis is accompanied by progressively reduced cell mixing between dorsal and ventral precursors, leading to a partial regionalization of midbrain tissue into autonomous units of precursor cell populations. In the second part I investigated the genes that might be involved in regulating the growth of the tectum. In particular, I focused on the role of Pax7 transcription factor, a paired domain protein. The results suggested that Pax7 was involved in regulating the medial-lateral extension of the tectum. Over expression of Pax7 in dorsal midbrain led to an enlarged tectum accompanied by a raise in cell division, while Pax7 knockdown by shrank caused a reduction in tectum. The overall pattern of neuronal differentiation was not disturbed by an up or down regulation of Pax7. Pax7 also positively regulated Pax3, another pair-ruled gene expressed dorsally. These results suggest that Pax7 very likely together with Pax3 could facilitate or maintain neural cell proliferation in the midbrain at early stages and that a regulation of the size in that region does not influence the neuronal patterning of the developmental field. I further checked the expression and function of a GFPase Rab 23, that was suggested to be involved in the DV patterning in mouse neural tube as a negative regulator of Shh signaling. Overexpression of Rab23 indicated that it facilitated the expression of Pax7 and Pax3 in the neural tube and suppressed ventral genes like Nkx6.1 cell autonomously, however, it did not disturb neuronal patterning. Interestingly, a thorough expression study of Rab 23 during chick early development revealed that Rab23 is already expressed very early and asymmetrically during gastrulation, suggesting a possible role of Rab23 on the left-right determination of Hensen's node. In combination with the result that Rab23 is expressed in the notochord early in development, I assume that both Rab23 and Shh exist in all neural progenitor cells initially, and when their expression patterns separate gradually the neural cells adopt a ventral or dorsal fate according to their location along the dorsoventral axis. The avian embryo is a classic system used widely to investigate questions of vertebrate development. The easy and cheap accessibility of the embryo for in ovo or ex ovo experiments all around the year make it an ideal animal model to work with. The only recently developed method of over expressing genes in specific cells or regions in the chick embryo by electroporation enabled me to study different ways of gene suppression using this way of gene transfection. Thus, I compared the effect of long-hairpin and short hairpin dsRNA in different vectors and antisense morpholino oligonucleotides. The results revealed that all hairpin dsRNA constructs did reduce gene and protein expression often accompanied by morphological changes. Most efficiently were shRNAi constructs cloned into a siRNA-specific vector - pSilencer 1.0-U6. Gene silencing was already well observed 36 hours after transfection. In comparison antisense morpholino oligonucleotides did not show such big gene reduction as the shRNA in pSilencer. Taken together, this methodical research proposes that the shRNA in the pSilencer vector was a good and effective tool to reduce gene and protein expression locally.}, subject = {Differenzierung}, language = {en} } @article{ScheerFrankeTrendelenburgetal.1976, author = {Scheer, Ulrich and Franke, Werner W. and Trendelenburg, Michael F. and Spring, Herbert}, title = {Classification of loops of lampbrush chromosomes according to the arrangement of transcriptional complexes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32822}, year = {1976}, abstract = {The arrangement of transcriptional units in the loops of lampbrush chromosomes from oocyte nuclei of urodele amphibia and from primary nuclei of the green alga Acetabularia have been studied in the electron microscope using spread preparations. Loops with different patterns of arrangement of matrix units (i.e. to a first approximation, transcriptional units) can be distinguished: (i) loops consisting of one active transcriptional unit; (ii) loops containing one active transcriptional unit plus additional fibril-free, i.e. apparently untranscribed, intercepts that may include 'spacer' regions; (iii) loops containing two or more transcriptional units arranged in identical or changing polarities, with or without interspersed apparent spacer regions. Morphological details of the transcriptional complexes are described. The observations are not compatible with the concept that one loop reflects one and only one transcriptional unit but, rather, lead to a classification of loop types according to the arrangement of their transcriptional units. We propose that the lampbrush chromosome loop can represent a unit for the coordinate transcription of either one gene or a set of several (different) genes.}, language = {en} } @phdthesis{Le2008, author = {Le, Thu Ha}, title = {Protein dynamics in responder and non-responder solid tumor xenografts during oncolytic viral therapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-32016}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2008}, abstract = {VACV GLV-1h68 was reported as a diagnostic/therapeutic vector which enters, replicates in, and reveals the locations of tumors in mice. Furthermore, the effect on tumor colonization, on tumor growth, regression and eradication by VACV GLV-1h68 without the need of any known genes with anti-tumoral activities was determined. To investigate differential protein expression between infected tumor cells and corresponding tumors, as well as between infected tumor cells, between infected tumors, proteomics is particularly used, possibly contributing to the understanding oncolytic ability on the protein level of VACV GLV-1h68. The given effects of VACV GLV-1h68 infection on cellular protein expression support tumor cell killing. In this study, differential protein expression was analyzed at different time points with two-dimensional gel electrophoresis (2DE) followed by MALDI-TOF/TOF identification. Comparative analysis of multiple 2-DE gels revealed that the majority of protein expression changes appeared at 48 hours post infection in cell cultivation and at 42 days post infection in tumors. Mass spectrometry identified 68, 75, 159 altered cellular proteins in the GI-101A, HT-29, PC-3 infected cells, respectively, including 30, 23, 49 up-regulated proteins and 38, 52, 110 down-regulated proteins 12 to 48 hours after infection. For xenografts, mass spectrometry identified 270, 101, 91 altered cellular proteins in the infected GI-101A, HT-29, PC-3 tumors, respectively, including 89, 70, 40 up-regulated proteins and 181, 31, 51 down-regulated proteins 7 to 42 days after infection. In general, in the cell lines, the proteins found to be differentially regulated are most often associated with metabolic processes, in particular with primary energy metabolism (glucose catabolism, TCA and lactate production). VAVC GLV 1h68 infection results in hijacking of the host translation apparatus, alteration of cytoskeleton networks, induce ubiqitin proteasome pathway (UPP) disorders. Particularly in tumors, the responses cover a much broader panel of cellular processes, including signalling (e.g., cell death), transport (in particular of iron ions) and migration. A common pathway to be up-regulated in both tumors and cell lines is the "unfolded protein response". Notably, VACV GLV-1h68 affected the anti-apoptosis pathways in GI-101A and PC-3 cancer cells but not in HT-29 xenografts. For example, GI-101A xenografts in mice appear 12 proteins associated with anti-apoptosis function. They were found down-regulated, including tumor protein-translationally-controlled (H-TPT1), rho-GDP-dissociation inhibitor alpha (H-GDIa), ywhaq protein (M-1433T), H-PRDX4, serine/threonine-protein phosphatase-2A-catalytic subunit beta isoform PP2A (M-Ppp2cb), eukaryotic translation initiation factor 2-subunit 1 alpha-35kDa (H-eIF2), H-actinin-\&\#945;1 (ACTN1 ), Annexin A1 (H-A1), annexin A5 (H-A5), Mouse albumin 1 (M-Alb1), dimethylarginine dimethylaminohydrolase 2 (H-DDAH2). In PC-3 xenografts, anti-apoptosis expression is lesser than those in GI-101A cells, however 3 anti-apoptosis associated proteins were down-regulated such as ARP3 actin-related protein-3-homolog (H-ARP3), Human FLNA protein, Rho GDP dissociation inhibitor (GDI) alpha (H-GDIa). In contrast, in HT-29 xenografts, there are several anti-apoptosis-associated proteins that show even to be up-regulated; they mostly belong to peroxiredoxin proteins. Lesson from HT-29 had been given what various means the HT-29 cells use to escape their apoptosis fate. This suggests that VAVC GLV1h68 infection may induce unbalance of unfolded protein response (UPR) but tending to anti-apoptosis-mediated proteins and promote the destructive elements of UPR, including caspase-12 cleavage and apoptosis. Taken together in this thesis research I have tried to compare protein profiles obtained from responder cell line and from regressing solid tumors colonized by VAVC GLV-1h68 with that of non-responding tumors. I also compared these data with PC-3 prostate cell line and tumor data on intermediate responder which alter mouse protein profiling in tumors similarly to the highly efficacious GI-101A breast tumor cell line. From these comparisons I have deduced exciting protein pattern signature characteristic for a responder or distinctly different from non-responder system. Combining these few crucial genes involved with the transcriptional test data obtained by fellow graduate student at NIH a novel national designed VACV GLV-1h68 strains with enhanced efficacy in many today non-responder cancer cell lines will be available to be tested into ongoing clinical trials.}, language = {en} }