@article{BudichTrauzettel2013, author = {Budich, Jan Carl and Trauzettel, Bj{\"o}rn}, title = {Z(2) Green's function topology of Majorana wires}, series = {New Journal of Physics}, volume = {15}, journal = {New Journal of Physics}, number = {065006}, doi = {10.1088/1367-2630/15/6/065006}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129751}, year = {2013}, abstract = {We represent the Z2 topological invariant characterizing a one-dimensional topological superconductor using a Wess-Zumino-Witten dimensional extension. The invariant is formulated in terms of the single-particle Green's function which allows us to classify interacting systems. Employing a recently proposed generalized Berry curvature method, the topological invariant is represented independent of the extra dimension requiring only the single-particle Green's function at zero frequency of the interacting system. Furthermore, a modified twisted boundary conditions approach is used to rigorously define the topological invariant for disordered interacting systems.}, language = {en} } @article{HerbertSfaerleaBlumenthal2013, author = {Herbert, Cornelia and Sf{\"a}rlea, Anca and Blumenthal, Terry}, title = {Your emotion or mine: labeling feelings alters emotional face perception—an ERP study on automatic and intentional affect labeling}, series = {Frontiers in Human Neuroscience}, journal = {Frontiers in Human Neuroscience}, doi = {10.3389/fnhum.2013.00378}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97065}, year = {2013}, abstract = {Empirical evidence suggests that words are powerful regulators of emotion processing. Although a number of studies have used words as contextual cues for emotion processing, the role of what is being labeled by the words (i.e., one's own emotion as compared to the emotion expressed by the sender) is poorly understood. The present study reports results from two experiments which used ERP methodology to evaluate the impact of emotional faces and self- vs. sender-related emotional pronoun-noun pairs (e.g., my fear vs. his fear) as cues for emotional face processing. The influence of self- and sender-related cues on the processing of fearful, angry and happy faces was investigated in two contexts: an automatic (experiment 1) and intentional affect labeling task (experiment 2), along with control conditions of passive face processing. ERP patterns varied as a function of the label's reference (self vs. sender) and the intentionality of the labeling task (experiment 1 vs. experiment 2). In experiment 1, self-related labels increased the motivational relevance of the emotional faces in the time-window of the EPN component. Processing of sender-related labels improved emotion recognition specifically for fearful faces in the N170 time-window. Spontaneous processing of affective labels modulated later stages of face processing as well. Amplitudes of the late positive potential (LPP) were reduced for fearful, happy, and angry faces relative to the control condition of passive viewing. During intentional regulation (experiment 2) amplitudes of the LPP were enhanced for emotional faces when subjects used the self-related emotion labels to label their own emotion during face processing, and they rated the faces as higher in arousal than the emotional faces that had been presented in the "label sender's emotion" condition or the passive viewing condition. The present results argue in favor of a differentiated view of language-as-context for emotion processing.}, language = {en} } @article{SchwarzWieserGerdesetal.2013, author = {Schwarz, Katharina A. and Wieser, Matthias J. and Gerdes, Antje B. M. and M{\"u}hlberger, Andreas and Pauli, Paul}, title = {Why are you looking like that? How the context influences evaluation and processing of human faces}, series = {Social Cognitive and Affective Neuroscience}, volume = {8}, journal = {Social Cognitive and Affective Neuroscience}, number = {4}, doi = {10.1093/scan/nss013}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132126}, pages = {438-445}, year = {2013}, abstract = {Perception and evaluation of facial expressions are known to be heavily modulated by emotional features of contextual information. Such contextual effects, however, might also be driven by non-emotional aspects of contextual information, an interaction of emotional and non-emotional factors, and by the observers' inherent traits. Therefore, we sought to assess whether contextual information about self-reference in addition to information about valence influences the evaluation and neural processing of neutral faces. Furthermore, we investigated whether social anxiety moderates these effects. In the present functional magnetic resonance imaging (fMRI) study, participants viewed neutral facial expressions preceded by a contextual sentence conveying either positive or negative evaluations about the participant or about somebody else. Contextual influences were reflected in rating and fMRI measures, with strong effects of self-reference on brain activity in the medial prefrontal cortex and right fusiform gyrus. Additionally, social anxiety strongly affected the response to faces conveying negative, self-related evaluations as revealed by the participants' rating patterns and brain activity in cortical midline structures and regions of interest in the left and right middle frontal gyrus. These results suggest that face perception and processing are highly individual processes influenced by emotional and non-emotional aspects of contextual information and further modulated by individual personality traits.}, language = {en} } @article{GageikStrohmeierMontenegro2013, author = {Gageik, Nils and Strohmeier, Michael and Montenegro, Sergio}, title = {Waypoint flight parameter comparison of an autonomous UAV}, series = {International Journal of Artificial Intelligence \& Applications (IJAIA)}, journal = {International Journal of Artificial Intelligence \& Applications (IJAIA)}, doi = {10.5121/ijaia.2013.4304}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96833}, year = {2013}, abstract = {The present paper compares the effect of different waypoint parameters on the flight performance of a special autonomous indoor UAV (unmanned aerial vehicle) fusing ultrasonic, inertial, pressure and optical sensors for 3D positioning and controlling. The investigated parameters are the acceptance threshold for reaching a waypoint as well as the maximal waypoint step size or block size. The effect of these parameters on the flight time and accuracy of the flight path is investigated. Therefore the paper addresses how the acceptance threshold and step size influence the speed and accuracy of the autonomous flight and thus influence the performance of the presented autonomous quadrocopter under real indoor navigation circumstances. Furthermore the paper demonstrates a drawback of the standard potential field method for navigation of such autonomous quadrocopters and points to an improvement.}, language = {en} } @article{CamagoMolinaO'LearyPorodetal.2013, author = {Camago-Molina, J.E. and O'Leary, B. and Porod, W. and Staub, F.}, title = {Vevacious: a tool for finding the global minima of one-loop effective potentials with many scalars}, series = {European Physical Journal C}, volume = {73}, journal = {European Physical Journal C}, number = {2588}, doi = {10.1140/epjc/s10052-013-2588-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132110}, year = {2013}, abstract = {Several extensions of the Standard Model of particle physics contain additional scalars implying a more complex scalar potential compared to that of the Standard Model. In general these potentials allow for charge- and/or color-breaking minima besides the desired one with correctly broken SU(2) L ×U(1) Y . Even if one assumes that a metastable local minimum is realized, one has to ensure that its lifetime exceeds that of our universe. We introduce a new program called Vevacious which takes a generic expression for a one-loop effective potential energy function and finds all the tree-level extrema, which are then used as the starting points for gradient-based minimization of the one-loop effective potential. The tunneling time from a given input vacuum to the deepest minimum, if different from the input vacuum, can be calculated. The parameter points are given as files in the SLHA format (though is not restricted to supersymmetric models), and new model files can be easily generated automatically by the Mathematica package SARAH. This code uses HOM4PS2 to find all the minima of the tree-level potential, PyMinuit to follow gradients to the minima of the one-loop potential, and CosmoTransitions to calculate tunneling times.}, language = {en} } @article{MatlachFreibergGadeholtetal.2013, author = {Matlach, Juliane and Freiberg, Florentina J. and Gadeholt, Ottar and G{\"o}bel, Winfried}, title = {Vasculitis-like hemorrhagic retinal angiopathy in Wegener's granulomatosis}, series = {BMC Research Notes}, volume = {6}, journal = {BMC Research Notes}, number = {364}, doi = {10.1186/1756-0500-6-364}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128744}, year = {2013}, abstract = {Background: Granulomatosis with polyangiitis, also known as Wegener's granulomatosis, is a chronic systemic inflammatory disease that can also involve the eyes. We report a case of massive retinal and preretinal hemorrhages with perivascular changes as the initial signs in granulomatosis with polyangiitis (Wegener's granulomatosis). Case presentation: A 39-year-old Caucasian male presented with blurred vision in his right eye, myalgia and arthralgia, recurrent nose bleeds and anosmia. Fundus image of his right eye showed massive retinal hemorrhages and vasculitis-like angiopathy, although no fluorescein extravasation was present in fluorescein angiography. Laboratory investigations revealed an inflammation with increased C-reactive protein, elevated erythrocyte sedimentation rate and neutrophil count. Tests for antineutrophil cytoplasmic antibodies (ANCA) were positive for c-ANCA (cytoplasmatic ANCA) and PR3-ANCA (proteinase 3-ANCA). Renal biopsy demonstrated a focal segmental necrotizing glomerulonephritis. Granulomatosis with polyangiitis (Wegener's granulomatosis) was diagnosed and a combined systemic therapy of cyclophosphamide and corticosteroids was initiated. During 3 months of follow-up, complete resorption of retinal hemorrhages was seen and general complaints as well as visual acuity improved during therapy. Conclusion: Vasculitis-like retinal changes can occur in Wegener's granulomatosis. Despite massive retinal and preretinal hemorrhages that cause visual impairment, immunosuppressive therapy can improve ocular symptoms.}, language = {en} } @article{StrengGroteCarretal.2013, author = {Streng, Andrea and Grote, Veit and Carr, David and Hagemann, Christine and Liese, Johannes G.}, title = {Varicella routine vaccination and the effects on varicella epidemiology - results from the Bavarian Varicella Surveillance Project (BaVariPro), 2006-2011}, series = {BMC Infectious Diseases}, journal = {BMC Infectious Diseases}, doi = {10.1186/1471-2334-13-303}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96297}, year = {2013}, abstract = {Background In 2004, routine varicella vaccination was recommended in Germany for children 11-14 months of age with one dose, and since 2009, with a second dose at 15-23 months of age. The effects on varicella epidemiology were investigated. Methods Data on varicella vaccinations, cases and complications were collected from annual parent surveys (2006-2011), monthly paediatric practice surveillance (Oct 2006 - Sep 2011; five varicella seasons) and paediatric hospital databases (2005-2009) in the area of Munich (about 238,000 paediatric inhabitants); annual incidences of cases and hospitalisations were estimated. Results Varicella vaccination coverage (1st dose) in children 18-36 months of age increased in two steps (38\%, 51\%, 53\%, 53\%, 66\% and 68\%); second-dose coverage reached 59\% in the 2011 survey. A monthly mean of 82 (62\%) practices participated; they applied a total of 50,059 first-dose and 40,541 second-dose varicella vaccinations, with preferential use of combined MMR-varicella vaccine after recommendation of two doses, and reported a total of 16,054 varicella cases <17 years of age. The mean number of cases decreased by 67\% in two steps, from 6.6 (95\%CI 6.1-7.0) per 1,000 patient contacts in season 2006/07 to 4.2 (95\%CI 3.9-4.6) in 2007/08 and 4.0 (95\%CI 3.6-4.3) in 2008/09, and further to 2.3 (95\%CI 2.0-2.6) in 2009/10 and 2.2 (95\%CI 1.9-2.5) in 2010/11. The decrease occurred in all paediatric age groups, indicating herd protection effects. Incidence of varicella was estimated as 78/1,000 children <17 years of age in 2006/07, and 19/1,000 in 2010/11. Vaccinated cases increased from 0.3 (95\%0.2-0.3) per 1,000 patient contacts in 2006/07 to 0.4 (95\%CI 0.3-0.5) until 2008/09 and decreased to 0.2 (95\%CI 0.2-0.3) until 2010/11. The practices treated a total of 134 complicated cases, mainly with skin complications. The paediatric hospitals recorded a total of 178 varicella patients, including 40 (22.5\%) with neurological complications and one (0.6\%) fatality due to varicella pneumonia. Incidence of hospitalisations decreased from 7.6 per 100,000 children <17 years of age in 2005 to 4.3 in 2009, and from 21.0 to 4.7 in children <5 years of age. Conclusions Overall, the results show increasing acceptance and a strong impact of the varicella vaccination program, even with still suboptimal vaccination coverage.}, language = {en} } @phdthesis{Christ2013, author = {Christ, Thomas}, title = {Value-distribution of the Riemann zeta-function and related functions near the critical line}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97763}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {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 Lindel{\"o}f hypothesis deals with the growth behavior of the Riemann zeta-function on the critical line. Due to classical works by Hardy and Littlewood, the Lindel{\"o}f 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.}, subject = {Riemannsche Zetafunktion}, language = {en} } @phdthesis{Huang2013, author = {Huang, Ting}, title = {Vaccinia Virus-mediated Therapy of Solid Tumor Xenografts: Intra-tumoral Delivery of Therapeutic Antibodies}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-91327}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {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.}, subject = {Vaccinia-Virus}, language = {en} } @phdthesis{Hess2013, author = {Heß, Michael}, title = {Vaccinia virus-encoded bacterial beta-glucuronidase as a diagnostic biomarker for oncolytic virotherapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-86789}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {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.}, subject = {Vaccinia-Virus}, language = {en} } @article{GholamiChenBelinetal.2013, author = {Gholami, Sepideh and Chen, Chun-Hao and Belin, Laurence J. and Lou, Emil and Fujisawa, Sho and Antonacci, Caroline and Carew, Amanda and Chen, Nanhai G. and De Brot, Marina and Zanzonico, Pat B. and Szalay, Aladar A. and Fong, Yuman}, title = {Vaccinia virus GLV-1h153 is a novel agent for detection and effective local control of positive surgical margins for breast cancer}, series = {Breast Cancer Research}, volume = {15}, journal = {Breast Cancer Research}, number = {R26}, doi = {10.1186/bcr3404}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122140}, year = {2013}, abstract = {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.}, language = {en} } @article{DuggalGeissingerZhangetal.2013, author = {Duggal, Rohit and Geissinger, Ulrike and Zhang, Qian and Aguilar, Jason and Chen, Nanhai G. and Binda, Elena and Vescovi, Angelo L. and Szalay, Aladar A.}, title = {Vaccinia virus expressing bone morphogenetic protein-4 in novel glioblastoma orthotopic models facilitates enhanced tumor regression and long-term survival}, series = {Journal of Translational Medicine}, volume = {11}, journal = {Journal of Translational Medicine}, number = {155}, doi = {10.1186/1479-5876-11-155}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129626}, year = {2013}, abstract = {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.}, language = {en} } @article{Prelog2013, author = {Prelog, Martina}, title = {Vaccination in Patients with Rheumatoid Arthritis Receiving Immunotherapies}, series = {Clinical \& Cellular Immunology}, journal = {Clinical \& Cellular Immunology}, doi = {10.4172/2155-9899.S6-007}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96446}, year = {2013}, abstract = {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.}, language = {en} } @article{BarcenaUribarriTheinMaieretal.2013, author = {B{\´a}rcena-Uribarri, Iv{\´a}n and Thein, Marcus and Maier, Elke and Bonde, Mari and Bergstr{\"o}m, Sven and Benz, Roland}, title = {Use of Nonelectrolytes Reveals the Channel Size and Oligomeric Constitution of the Borrelia burgdorferi P66 Porin}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {11}, doi = {10.1371/journal.pone.0078272}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129965}, pages = {e78272}, year = {2013}, abstract = {In the Lyme disease spirochete Borrelia burgdorferi, the outer membrane protein P66 is capable of pore formation with an atypical high single-channel conductance of 11 nS in 1 M KCl, which suggested that it could have a larger diameter than 'normal' Gram-negative bacterial porins. We studied the diameter of the P66 channel by analyzing its single-channel conductance in black lipid bilayers in the presence of different nonelectrolytes with known hydrodynamic radii. We calculated the filling of the channel with these nonelectrolytes and the results suggested that nonelectrolytes (NEs) with hydrodynamic radii of 0.34 nm or smaller pass through the pore, whereas neutral molecules with greater radii only partially filled the channel or were not able to enter it at all. The diameter of the entrance of the P66 channel was determined to be \(\leq\)1.9 nm and the channel has a central constriction of about 0.8 nm. The size of the channel appeared to be symmetrical as judged from one-sidedness of addition of NEs. Furthermore, the P66-induced membrane conductance could be blocked by 80-90\% by the addition of the nonelectrolytes PEG 400, PEG 600 and maltohexaose to the aqueous phase in the low millimolar range. The analysis of the power density spectra of ion current through P66 after blockage with these NEs revealed no chemical reaction responsible for channel block. Interestingly, the blockage of the single-channel conductance of P66 by these NEs occurred in about eight subconductance states, indicating that the P66 channel could be an oligomer of about eight individual channels. The organization of P66 as a possible octamer was confirmed by Blue Native PAGE and immunoblot analysis, which both demonstrated that P66 forms a complex with a mass of approximately 460 kDa. Two dimension SDS PAGE revealed that P66 is the only polypeptide in the complex.}, language = {en} } @article{MayerRabindranathBoerneretal.2013, author = {Mayer, Matthias and Rabindranath, Raman and B{\"o}rner, Juliane and H{\"o}rner, Eva and Bentz, Alexander and Salgado, Josefina and Han, Hong and B{\"o}se, Holger and Probst, J{\"o}rn and Shamonin, Mikhail and Monkman, Gereth J. and Schlunck, G{\"u}nther}, title = {Ultra-Soft PDMS-Based Magnetoactive Elastomers as Dynamic Cell Culture Substrata}, series = {PLOS ONE}, volume = {8}, journal = {PLOS ONE}, number = {10}, issn = {1932-6203}, doi = {10.1371/journal.pone.0076196}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128246}, pages = {e76196}, year = {2013}, abstract = {Mechanical cues such as extracellular matrix stiffness and movement have a major impact on cell differentiation and function. To replicate these biological features in vitro, soft substrata with tunable elasticity and the possibility for controlled surface translocation are desirable. Here we report on the use of ultra-soft (Young's modulus <100 kPa) PDMS-based magnetoactive elastomers (MAE) as suitable cell culture substrata. Soft non-viscous PDMS (<18 kPa) is produced using a modified extended crosslinker. MAEs are generated by embedding magnetic microparticles into a soft PDMS matrix. Both substrata yield an elasticity-dependent (14 vs. 100 kPa) modulation of alpha-smooth muscle actin expression in primary human fibroblasts. To allow for static or dynamic control of MAE material properties, we devise low magnetic field (approximate to 40 mT) stimulation systems compatible with cell-culture environments. Magnetic field-instigated stiffening (14 to 200 kPa) of soft MAE enhances the spreading of primary human fibroblasts and decreases PAX-7 transcription in human mesenchymal stem cells. Pulsatile MAE movements are generated using oscillating magnetic fields and are well tolerated by adherent human fibroblasts. This MAE system provides spatial and temporal control of substratum material characteristics and permits novel designs when used as dynamic cell culture substrata or cell culture-coated actuator in tissue engineering applications or biomedical devices.}, language = {en} } @article{BodemSchromMoschalletal.2013, author = {Bodem, Jochen and Schrom, Eva-Maria and Moschall, Rebecca and Hartl, Maximilian J. and Weitner, Helena and Fecher, David and Langemeier, J{\"o}rg and W{\"o}hrl, Brigitta M.}, title = {U1snRNP-mediated suppression of polyadenylation in conjunction with the RNA structure controls poly (A) site selection in foamy viruses}, series = {Retrovirology}, journal = {Retrovirology}, doi = {10.1186/1742-4690-10-55}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96085}, year = {2013}, abstract = {Background During reverse transcription, retroviruses duplicate the long terminal repeats (LTRs). These identical LTRs carry both promoter regions and functional polyadenylation sites. To express full-length transcripts, retroviruses have to suppress polyadenylation in the 5′LTR and activate polyadenylation in the 3′LTR. Foamy viruses have a unique LTR structure with respect to the location of the major splice donor (MSD), which is located upstream of the polyadenylation signal. Results Here, we describe the mechanisms of foamy viruses regulating polyadenylation. We show that binding of the U1 small nuclear ribonucleoprotein (U1snRNP) to the MSD suppresses polyadenylation at the 5′LTR. In contrast, polyadenylation at the 3′LTR is achieved by adoption of a different RNA structure at the MSD region, which blocks U1snRNP binding and furthers RNA cleavage and subsequent polyadenylation. Conclusion Recently, it was shown that U1snRNP is able to suppress the usage of intronic cryptic polyadenylation sites in the cellular genome. Foamy viruses take advantage of this surveillance mechanism to suppress premature polyadenylation at the 5'end of their RNA. At the 3'end, Foamy viruses use a secondary structure to presumably block access of U1snRNP and thereby activate polyadenylation at the end of the genome. Our data reveal a contribution of U1snRNP to cellular polyadenylation site selection and to the regulation of gene expression.}, subject = {Polyadenylierung}, language = {en} } @article{EngelAlbertSchubert2013, author = {Engel, Volker and Albert, Julian and Schubert, Alexander}, title = {Two-dimensional vibronic spectroscopy of molecular predissociation}, series = {New Journal of Physics}, journal = {New Journal of Physics}, doi = {10.1088/1367-2630/15/2/025008}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96199}, year = {2013}, abstract = {We calculate two-dimensional (2D) spectra reflecting the time-dependent electronic predissociation of a diatomic molecule. The laser-excited electronic state is coupled non-adiabatically to a fragment channel, leading to the decay of the prepared quasi-bound states. This decay can be monitored by the three-pulse configuration employed in optical 2D spectroscopy. It is shown that in this way it is possible to state-selectively characterize the time-dependent population of resonance states with different lifetimes. A model of the NaI molecule serves as a numerical example.}, language = {en} } @article{ChopraLangSalzmannetal.2013, author = {Chopra, Martin and Lang, Isabell and Salzmann, Steffen and Pachel, Christina and Kraus, Sabrina and B{\"a}uerlein, Carina A. and Brede, Christian and Jord{\´a}n Garrote, Ana-Laura and Mattenheimer, Katharina and Ritz, Miriam and Schwinn, Stefanie and Graf, Carolin and Sch{\"a}fer, Viktoria and Frantz, Stefan and Einsele, Hermann and Wajant, Harald and Beilhack, Andreas}, title = {Tumor Necrosis Factor Induces Tumor Promoting and Anti-Tumoral Effects on Pancreatic Cancer via TNFR1}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075737}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97246}, year = {2013}, abstract = {Multiple activities are ascribed to the cytokine tumor necrosis factor (TNF) in health and disease. In particular, TNF was shown to affect carcinogenesis in multiple ways. This cytokine acts via the activation of two cell surface receptors, TNFR1, which is associated with inflammation, and TNFR2, which was shown to cause anti-inflammatory signaling. We assessed the effects of TNF and its two receptors on the progression of pancreatic cancer by in vivo bioluminescence imaging in a syngeneic orthotopic tumor mouse model with Panc02 cells. Mice deficient for TNFR1 were unable to spontaneously reject Panc02 tumors and furthermore displayed enhanced tumor progression. In contrast, a fraction of wild type (37.5\%), TNF deficient (12.5\%), and TNFR2 deficient mice (22.2\%) were able to fully reject the tumor within two weeks. Pancreatic tumors in TNFR1 deficient mice displayed increased vascular density, enhanced infiltration of CD4+ T cells and CD4+ forkhead box P3 (FoxP3)+ regulatory T cells (Treg) but reduced numbers of CD8+ T cells. These alterations were further accompanied by transcriptional upregulation of IL4. Thus, TNF and TNFR1 are required in pancreatic ductal carcinoma to ensure optimal CD8+ T cell-mediated immunosurveillance and tumor rejection. Exogenous systemic administration of human TNF, however, which only interacts with murine TNFR1, accelerated tumor progression. This suggests that TNFR1 has basically the capability in the Panc02 model to trigger pro-and anti-tumoral effects but the spatiotemporal availability of TNF seems to determine finally the overall outcome.}, language = {en} } @article{ShannonHein2013, author = {Shannon, Graver and Hein, Melanie}, title = {Tumor cell response to bevacizumab single agent therapy in vitro}, series = {Cancer Cell International}, journal = {Cancer Cell International}, doi = {10.1186/1475-2867-13-94}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97185}, year = {2013}, abstract = {Background Angiogenesis represents a highly multi-factorial and multi-cellular complex (patho-) physiologic event involving endothelial cells, tumor cells in malignant conditions, as well as bone marrow derived cells and stromal cells. One main driver is vascular endothelial growth factor (VEGFA), which is known to interact with endothelial cells as a survival and mitogenic signal. The role of VEGFA on tumor cells and /or tumor stromal cell interaction is less clear. Condition specific (e.g. hypoxia) or tumor specific expression of VEGFA, VEGF receptors and co-receptors on tumor cells has been reported, in addition to the expression on the endothelium. This suggests a potential paracrine/autocrine loop that could affect changes specific to tumor cells. Methods We used the monoclonal antibody against VEGFA, bevacizumab, in various in vitro experiments using cell lines derived from different tumor entities (non small cell lung cancer (NSCLC), colorectal cancer (CRC), breast cancer (BC) and renal cell carcinoma (RCC)) in order to determine if potential VEGFA signaling could be blocked in tumor cells. The experiments were done under hypoxia, a major inducer of VEGFA and angiogenesis, in an attempt to mimic the physiological tumor condition. Known VEGFA induced endothelial biological responses such as proliferation, migration, survival and gene expression changes were evaluated. Results Our study was able to demonstrate expression of VEGF receptors on tumor cells as well as hypoxia regulated angiogenic gene expression. In addition, there was a cell line specific effect in tumor cells by VEGFA blockade with bevacizumab in terms of proliferation; however overall, there was a limited measurable consequence of bevacizumab therapy detected by migration and survival. Conclusion The present study showed in a variety of in vitro experiments with several tumor cell lines from different tumor origins, that by blocking VEGFA with bevacizumab, there was a limited autocrine or cell-autonomous function of VEGFA signaling in tumor cells, when evaluating VEGFA induced downstream outputs known in endothelial cells.}, language = {en} } @article{MuturiDreesenNilewskietal.2013, author = {Muturi, Harrison T. and Dreesen, Janine D. and Nilewski, Elena and Jastrow, Holger and Giebel, Bernd and Ergun, Suleyman and Singer, Berhard B.}, title = {Tumor and Endothelial Cell-Derived Microvesicles Carry Distinct CEACAMs and Influence T-Cell Behavior}, series = {PLOS ONE}, volume = {8}, journal = {PLOS ONE}, number = {9}, issn = {1932-6203}, doi = {10.1371/journal.pone.0074654}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128373}, pages = {e74654}, year = {2013}, abstract = {Normal and malignant cells release a variety of different vesicles into their extracellular environment. The most prominent vesicles are the microvesicles (MVs, 100-1 000 nm in diameter), which are shed of the plasma membrane, and the exosomes (70-120 nm in diameter), derivates of the endosomal system. MVs have been associated with intercellular communication processes and transport numerous proteins, lipids and RNAs. As essential component of immune-escape mechanisms tumor-derived MVs suppress immune responses. Additionally, tumor-derived MVs have been found to promote metastasis, tumor-stroma interactions and angiogenesis. Since members of the carcinoembryonic antigen related cell adhesion molecule (CEACAM)-family have been associated with similar processes, we studied the distribution and function of CEACAMs in MV fractions of different human epithelial tumor cells and of human and murine endothelial cells. Here we demonstrate that in association to their cell surface phenotype, MVs released from different human epithelial tumor cells contain CEACAM1, CEACAM5 and CEACAM6, while human and murine endothelial cells were positive for CEACAM1 only. Furthermore, MVs derived from CEACAM1 transfected CHO cells carried CEACAM1. In terms of their secretion kinetics, we show that MVs are permanently released in low doses, which are extensively increased upon cellular starvation stress. Although CEACAM1 did not transmit signals into MVs it served as ligand for CEACAM expressing cell types. We gained evidence that CEACAM1-positive MVs significantly increase the CD3 and CD3/CD28-induced T-cell proliferation. All together, our data demonstrate that MV-bound forms of CEACAMs play important roles in intercellular communication processes, which can modulate immune response, tumor progression, metastasis and angiogenesis.}, language = {en} } @article{SpitznagelDurigZimanowski2013, author = {Spitznagel, N. and Durig, T. and Zimanowski, B.}, title = {Trigger - and heat-transfer times measured during experimental molten-fuel-interactions}, series = {AIP Advances}, volume = {3}, journal = {AIP Advances}, number = {102126}, doi = {10.1063/1.4827023}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128625}, year = {2013}, abstract = {A modified setup featuring high speed high resolution data and video recording was developed to obtain detailed information on trigger and heat transfer times during explosive molten fuel-coolant-interaction (MFCI). MFCI occurs predominantly in configurations where water is entrapped by hot melt. The setup was modified to allow direct observation of the trigger and explosion onset. In addition the influences of experimental control and data acquisition can now be more clearly distinguished from the pure phenomena. More precise experimental studies will facilitate the description of MFCI thermodynamics.}, language = {en} } @article{SzalayWeibelHofmannetal.2013, author = {Szalay, Aladar A and Weibel, Stephanie and Hofmann, Elisabeth and Basse-Luesebrink, Thomas Christian and Donat, Ulrike and Seubert, Carolin and Adelfinger, Marion and Gnamlin, Prisca and Kober, Christina and Frentzen, Alexa and Gentschev, Ivaylo and Jakob, Peter Michael}, title = {Treatment of malignant effusion by oncolytic virotherapy in an experimental subcutaneous xenograft model of lung cancer}, series = {Journal of Translational Medicine}, journal = {Journal of Translational Medicine}, doi = {doi:10.1186/1479-5876-11-106}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96016}, year = {2013}, abstract = {Background Malignant pleural effusion (MPE) is associated with advanced stages of lung cancer and is mainly dependent on invasion of the pleura and expression of vascular endothelial growth factor (VEGF) by cancer cells. As MPE indicates an incurable disease with limited palliative treatment options and poor outcome, there is an urgent need for new and efficient treatment options. Methods In this study, we used subcutaneously generated PC14PE6 lung adenocarcinoma xenografts in athymic mice that developed subcutaneous malignant effusions (ME) which mimic pleural effusions of the orthotopic model. Using this approach monitoring of therapeutic intervention was facilitated by direct observation of subcutaneous ME formation without the need of sacrificing mice or special imaging equipment as in case of MPE. Further, we tested oncolytic virotherapy using Vaccinia virus as a novel treatment modality against ME in this subcutaneous PC14PE6 xenograft model of advanced lung adenocarcinoma. Results We demonstrated significant therapeutic efficacy of Vaccinia virus treatment of both advanced lung adenocarcinoma and tumor-associated ME. We attribute the efficacy to the virus-mediated reduction of tumor cell-derived VEGF levels in tumors, decreased invasion of tumor cells into the peritumoral tissue, and to viral infection of the blood vessel-invading tumor cells. Moreover, we showed that the use of oncolytic Vaccinia virus encoding for a single-chain antibody (scAb) against VEGF (GLAF-1) significantly enhanced mono-therapy of oncolytic treatment. Conclusions Here, we demonstrate for the first time that oncolytic virotherapy using tumor-specific Vaccinia virus represents a novel and promising treatment modality for therapy of ME associated with advanced lung cancer.}, subject = {Lungenkrebs}, language = {en} } @article{AblinFitzcharlesBuskilaetal.2013, author = {Ablin, Jacob and Fitzcharles, Mary-Ann and Buskila, Dan and Shir, Yoram and Sommer, Claudia and H{\"a}user, Winfried}, title = {Treatment of Fibromyalgia Syndrome: Recommendations of Recent Evidence-Based Interdisciplinary Guidelines with Special Emphasis on Complementary and Alternative Therapies}, series = {Evidence-Bayed Complementary and Alternative Medicine}, journal = {Evidence-Bayed Complementary and Alternative Medicine}, issn = {1741-427X}, doi = {10.1155/2013/485272}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122235}, pages = {485272}, year = {2013}, abstract = {Objective. Current evidence indicates that there is no single ideal treatment for fibromyalgia syndrome (FMS). First choice treatment options remain debatable, especially concerning the importance of complementary and alternative medicine (CAM) treatments. Methods. Three evidence-based interdisciplinary guidelines on FMS in Canada, Germany, and Israel were compared for their first choice and CAM-recommendations. Results. All three guidelines emphasized a patient-tailored approach according to the key symptoms. Aerobic exercise, cognitive behavioral therapy, and multicomponent therapy were first choice treatments. The guidelines differed in the grade of recommendation for drug treatment. Anticonvulsants (gabapentin, pregabalin) and serotonin noradrenaline reuptake inhibitors (duloxetine, milnacipran) were strongly recommended by the Canadian and the Israeli guidelines. These drugs received only a weak recommendation by the German guideline. In consideration of CAM-treatments, acupuncture, hypnosis/guided imagery, and Tai Chi were recommended by the German and Israeli guidelines. The Canadian guidelines did not recommend any CAM therapy. Discussion. Recent evidence-based interdisciplinary guidelines concur on the importance of treatment tailored to the individual patient and further emphasize the need of self-management strategies (exercise, and psychological techniques).}, language = {en} } @article{WalterReilichThieleetal.2013, author = {Walter, Maggie C. and Reilich, Peter and Thiele, Simone and Schessl, Joachim and Schreiber, Herbert and Reiners, Karlheinz and Kress, Wolfram and M{\"u}ller-Reible, Clemens and Vorgerd, Matthias and Urban, Peter and Schrank, Bertold and Deschauer, Marcus and Schlotter-Weigel, Beate and Kohnen, Ralf and Lochm{\"u}ller, Hans}, title = {Treatment of dysferlinopathy with deflazacort: a double-blind, placebo-controlled clinical trial}, series = {Orphanet Journal of Rare Diseases}, volume = {8}, journal = {Orphanet Journal of Rare Diseases}, number = {26}, issn = {1750-1172}, doi = {10.1186/1750-1172-8-26}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125663}, year = {2013}, abstract = {Background: Dysferlinopathies are autosomal recessive disorders caused by mutations in the dysferlin (DYSF) gene encoding the dysferlin protein. DYSF mutations lead to a wide range of muscular phenotypes, with the most prominent being Miyoshi myopathy (MM) and limb girdle muscular dystrophy type 2B (LGMD2B). Methods: We assessed the one-year-natural course of dysferlinopathy, and the safety and efficacy of deflazacort treatment in a double-blind, placebo-controlled cross-over trial. After one year of natural course without intervention, 25 patients with genetically defined dysferlinopathy were randomized to receive deflazacort and placebo for six months each (1 mg/kg/day in month one, 1 mg/kg every 2nd day during months two to six) in one of two treatment sequences. Results: During one year of natural course, muscle strength declined about 2\% as measured by CIDD (Clinical Investigation of Duchenne Dystrophy) score, and 76 Newton as measured by hand-held dynamometry. Deflazacort did not improve muscle strength. In contrast, there is a trend of worsening muscle strength under deflazacort treatment, which recovers after discontinuation of the study drug. During deflazacort treatment, patients showed a broad spectrum of steroid side effects. Conclusion: Deflazacort is not an effective therapy for dysferlinopathies, and off-label use is not warranted. This is an important finding, since steroid treatment should not be administered in patients with dysferlinopathy, who may be often misdiagnosed as polymyositis.}, language = {en} } @phdthesis{Regneri2013, author = {Regneri, Janine}, title = {Transcriptional regulation of cancer genes in the Xiphophorus melanoma system}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-82319}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {The Xiphophorus melanoma system is a useful animal model for the study of the genetic basis of tumor formation. The development of hereditary melanomas in interspecific hybrids of Xiphophorus is connected to pigment cell specific overexpression of the mutationally activated receptor tyrosine kinase Xmrk. In purebred fish the oncogenic function of xmrk is suppressed by the molecularly still unidentified locus R. The xmrk oncogene was generated by a gene duplication event from the Xiphophorus egfrb gene and thereby has acquired a new 5' regulatory sequence, which has probably altered the transcriptional control of the oncogene. So far, the xmrk promoter region was still poorly characterized and the molecular mechanism by which R controls xmrk-induced melanoma formation in Xiphophorus still remained to be elucidated. To test the hypothesis that R controls melanoma development in Xiphophorus on the transcriptional level, the first aim of the thesis was to gain a deeper insight into the transcriptional regulation of the xmrk oncogene. To this end, a quantitative analysis of xmrk transcript levels in different Xiphophorus genotypes carrying either the highly tumorigenic xmrkB or the non-tumorigenic xmrkA allele was performed. I was able to demonstrate that expression of the tumorigenic xmrkB allele is strongly increased in malignant melanomas of R-free backcross hybrids compared to benign lesions, macromelanophore spots, and healthy skin. The expression level of the non-tumorigenic xmrkA allele, in contrast, is not influenced by the presence or absence of R. These findings strongly indicate that differential transcriptional regulation of the xmrk promoter triggers the tumorigenic potential of these xmrk alleles. To functionally characterize the xmrk promoter region, I established a luciferase assay using BAC clones containing the genomic regions where xmrk and egfrb are located for generation of reporter constructs. This approach showed for the first time a melanoma cell specific transcriptional activation of xmrkB by its flanking regions, thereby providing the first functional evidence that the xmrk oncogene is controlled by a pigment cell specific promoter region. Subsequent analysis of different deletion constructs of the xmrkB BAC reporter construct strongly indicated that the regulatory elements responsible for the tumor-inducing overexpression of xmrkB in melanoma cells are located within 67 kb upstream of the xmrk oncogene. Taken together, these data indicate that melanoma formation in Xiphophorus is regulated by a tight transcriptional control of the xmrk oncogene and that the R locus acts through this mechanism. As the identification of the R-encoded gene(s) is necessary to fully understand how melanoma formation in Xiphophorus is regulated, I furthermore searched for alternative R candidate genes in this study. To this end, three genes, which are located in the genomic region where R has been mapped, were evaluated for their potential to be a crucial constituent of the regulator locus R. Among these genes, I identified pdcd4a, the ortholog of the human tumor suppressor gene PDCD4, as promising new candidate, because this gene showed the expression pattern expected from the crucial tumor suppressor gene encoded at the R locus.}, subject = {Melanom}, language = {en} } @phdthesis{Rudolf2013, author = {Rudolf, Ronald}, title = {Transcriptional Regulation of and by NFATc1 in Lymphocytes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83993}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {The transcription factor NFATc1 has been shown to regulate the activation and differentiation of T-cells and B-cells, of DCs and megakaryocytes. Dysregulation of NFAT signaling was shown to be associated with the generation of autoimmune diseases, malignant transformation and the development of cancer [71]. The primary goal of this work was to gain insights on Nfatc1 induction and regulation in lymphocytes and to find new direct NFATc1 target genes. Three new BAC -transgenic reporter mouse strains (tgNfatc1/Egfp, tgNfatc1/DE1 and tgNfatc1/DE2) were applied to analyze Nfatc1 induction and regulation in primary murine B- and T-cells. As a result, we were able to show the persistent requirement of immunoreceptor-signaling for constant Nfatc1 induction, particularly, for NFATc1/αA expression. Furthermore, we showed that NF-κB inducing agents, such as LPS, CpG or CD40 receptor engagement, in combination with primary receptor-signals, positively contributed to Nfact1 induction in B-cells [137]. We sought to establish a new system which could help to identify direct NFATc1 target genes by means of ChIP and NGS in genom-wide approaches. We were able to successfully generate a new BAC-transgene encoding a biotinylatable short isoform of NFATc1, which is currently injected into mice oocyte at the TFM in Mainz. In addition, in vivo biotinylatable NFATc1-isoforms were cloned and stably expressed in the murine B-cell lymphoma line WEHI-231. The successful use of these cells stably overexpressing either the short NFATc1/αA or the long NFATc1/βC isoform along with the bacterial BirA biotin ligase was confirmed by intracellular stainings, FACS analysis, confocal microscopy and protein IP. By NGS, we detected 2185 genes which are specifically controlled by NFATc1/αA, and 1306 genes which are exclusively controlled by NFATc1/βC. This shows that the Nfatc1 locus encodes "two genes" which exhibit alternate, in part opposite functions. Studies on the induction of apoptosis and cell-death revealed opposed roles for the highly inducible short isoform NFATc1/αA and the constantly expressed long isoform NFATc1/βC. These findings were confirmed by whole transcriptome-sequencing performed with cells overexpressing NFATc1/αA and NFATc1/βC. Several thousand genes were found to be significantly altered in their expression profile, preferentially genes involved in apoptosis and PCD for NFATc1/βC or genes involved in transcriptional regulation and cell-cycle processes for NFATc1/αA. In addition we were able to perform ChIP-seq for NFATc1/αA and NFATc1/βC in an ab-independent approach. We found potential new target-sites, but further studies will have to address this ambitious goal in the future. In individual ChIP assays, we showed direct binding of NFATc1/αA and NFATc1/βC to the Prdm1 and Aicda promoter regions which are individually controlled by the NFATc1 isoforms.}, subject = {Lymphozyt}, language = {en} } @phdthesis{Kullmann2013, author = {Kullmann, Martin Armin}, title = {Tracing Excited-State Photochemistry by Multidimensional Electronic Spectroscopy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-81276}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Light-induced excitation of matter proceeds within femtoseconds, resulting in excited states. Originating from these states chemical reaction mechanisms, like isomerization or bond formation, set in. Photophysical mechanisms like energy distribution and excitonic delocalization also occur. Thus, the reaction scheme has to be disentangled by assessing the importance of each process. Spectroscopic methods based on fs laser pulses have emerged as a versatile tool to study these reactions. Within this thesis time-resolved experiments with fs laser pulses on various molecular systems were performed. Novel photosystems, with possible applications ranging from ultrathin molecular wires to molecular switches, were extensively characterized. To resolve the complex kinetics of the investigated systems, time-resolved techniques had to be newly developed. By combining a visible excitation pulse pair with an additional pulse and a continuum probe electronic triggered-exchange two-dimensional spectroscopy (TE2D) was demonstrated for the first time. This goal was accomplished by combining a three-color transient-absorption setup with a pulse shaper. Hence, 2D spectroscopy with a continuum probe was also implemented. Using these methods two different molecular systems in solution were characterized in a comprehensive manner. (ZnTPP)2, a directly beta,beta'-linked Zn-metallated bisporphyrin, and a spiropyran-merocyanine photosystem, 6,8-dinitro BIPS, were characterized. (ZnTPP)2 is a homodimer, featuring strong excitonic effects. These manifest themselves in a twofold splitting of the Soret band (S2). 6,8-Dinitro BIPS exists in one of two possible conformations. The ring closed spiropyran absorbs only in the UV, while the ring open merocyanine also absorbs in the visible. For both molecular systems photodynamics upon illumination were monitored using transient-absorption. However, the obtained results were ambiguous, necessitating more complex methods. In the case of (ZnTPP)2 first the monomeric building block was characterized. There, population transfer from the S2 state into S1 within 2 ps was identified. Afterwards, intersystem crossing proceeds within 2 ns. For (ZnTPP)2 similar pathways were found, albeit the relaxation is faster. The intersystem crossing with 1.5 ns was not only indirectly deduced but directly measured by probing in the NIR spectral range. The excitonic influence of was investigated by coherent 2D spectroscopy in the Soret band. Population transfer within S2 was directly visualized on a time-scale of 100 fs. Calculation of the 2D spectra of a simple homodimer confirmed the results. After this analysis of the distinct excitonic character, this molecule may serve as a building block for larger porphyrin arrays with applications ranging from asymmetric catalysis over biomimicry of electron-transfer to organic optical devices. The second photosystem was the molecular switch 6,8-dinitro BIPS, existing in two conformations. Merocyanine is the more stable form in thermal equilibrium. Transient-absorption measurements uncovered that the sample consisted of a mixture of two merocyanine isomers, referred to as TTC and TTT. However, both isomers are capable of ring-closure forming spiropyran. The remaining excited molecules return to the ground state radiatively. Conducting 2D measurements utilizing a continuum probe the differing photochemistry of both isomers was examined in a single measurement. No isomerization between these conformations was detected. Therefore, 6,8-dinitro BIPS performs a concerted switching without long-living intermediates. This was confirmed by a pump-repump-probe scan. 6,8-DinitroBIPS can be closed by visible and opened by UV pulses using subsequent pulses and vice versa. These mechanisms via singlet pathways satisfy an important criterion for a unimolecular switching device. A second pump-repump-probe experiment showed that the sample is ionized, resulting in a merocyanine radical cation, when the first excited state is resonantly excited. Furthermore, by implementing TE2Dspectroscopy, it was elucidated that only TTC was ionized. Taking all this into account new techniques were developed and complex molecular systems were characterized within this thesis. Deeper insight into the photodynamics of (ZnTPP)2and 6,8-dinitro BIPS was gained by adapting transient absorption for the NIR spectral range, constructing a 2D setup in pump-probe geometry, and combining it with multipulse excitation to coherent TE2D. All techniques solved the questions for which they were constructed, but they are not limited to these cases. Especially TE2D opens new roads in photochemistry. By connecting reactant, product and the corresponding intermediates, a chemical reaction can be tracked through all stages, making unambiguous identification of the reactive states feasible. Thus, fundamental insight into the photochemistry of molecular compounds is gained.}, subject = {Femtosekundenspektroskopie}, language = {en} } @article{HolubyevBratengeierGaineyetal.2013, author = {Holubyev, Konstyantyn and Bratengeier, Klaus and Gainey, Mark and Polat, B{\"u}lent and Flentje, Michael}, title = {Towards automated on-line adaptation of 2-Step IMRT plans: QUASIMODO phantom and prostate cancer cases}, series = {Radiation Oncology}, journal = {Radiation Oncology}, doi = {10.1186/1748-717X-8-263}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96818}, year = {2013}, abstract = {Background The standard clinical protocol of image-guided IMRT for prostate carcinoma introduces isocenter relocation to restore the conformity of the multi-leaf collimator (MLC) segments to the target as seen in the cone-beam CT on the day of treatment. The large interfractional deformations of the clinical target volume (CTV) still require introduction of safety margins which leads to undesirably high rectum toxicity. Here we present further results from the 2-Step IMRT method which generates adaptable prostate IMRT plans using Beam Eye View (BEV) and 3D information. Methods Intermediate/high-risk prostate carcinoma cases are treated using Simultaneous Integrated Boost at the Universit{\"a}tsklinkum W{\"u}rzburg (UKW). Based on the planning CT a CTV is defined as the prostate and the base of seminal vesicles. The CTV is expanded by 10 mm resulting in the PTV; the posterior margin is limited to 7 mm. The Boost is obtained by expanding the CTV by 5 mm, overlap with rectum is not allowed. Prescription doses to PTV and Boost are 60.1 and 74 Gy respectively given in 33 fractions. We analyse the geometry of the structures of interest (SOIs): PTV, Boost, and rectum, and generate 2-Step IMRT plans to deliver three fluence steps: conformal to the target SOIs (S0), sparing the rectum (S1), and narrow segments compensating the underdosage in the target SOIs due to the rectum sparing (S2). The width of S2 segments is calculated for every MLC leaf pair based on the target and rectum geometry in the corresponding CT layer to have best target coverage. The resulting segments are then fed into the DMPO optimizer of the Pinnacle treatment planning system for weight optimization and fine-tuning of the form, prior to final dose calculation using the collapsed cone algorithm. We adapt 2-Step IMRT plans to changed geometry whilst simultaneously preserving the number of initially planned Monitor Units (MU). The adaptation adds three further steps to the previous isocenter relocation: 1) 2-Step generation for the geometry of the day using the relocated isocenter, MU transfer from the planning geometry; 2) Adaptation of the widths of S2 segments to the geometry of the day; 3) Imitation of DMPO fine-tuning for the geometry of the day. Results and conclusion We have performed automated 2-Step IMRT adaptation for ten prostate adaptation cases. The adapted plans show statistically significant improvement of the target coverage and of the rectum sparing compared to those plans in which only the isocenter is relocated. The 2-Step IMRT method may become a core of the automated adaptive radiation therapy system at our department.}, language = {en} } @article{AssaadBercxHohenadler2013, author = {Assaad, F. F. and Bercx, M. and Hohenadler, M.}, title = {Topological Invariant and Quantum Spin Models from Magnetic pi Fluxes in Correlated Topological Insulators}, series = {Physical Review X}, volume = {3}, journal = {Physical Review X}, number = {1}, doi = {10.1103/PhysRevX.3.011015}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129849}, year = {2013}, abstract = {The adiabatic insertion of a \(\pi\) flux into a quantum spin Hall insulator gives rise to localized spin and charge fluxon states. We demonstrate that \(\pi\) fluxes can be used in exact quantum Monte Carlo simulations to identify a correlated \(Z_2\) topological insulator using the example of the Kane-Mele-Hubbard model. In the presence of repulsive interactions, a \(\pi\) flux gives rise to a Kramers doublet of spin-fluxon states with a Curie-law signature in the magnetic susceptibility. Electronic correlations also provide a bosonic mode of magnetic excitons with tunable energy that act as exchange particles and mediate a dynamical interaction of adjustable range and strength between spin fluxons. \(\pi\) fluxes can therefore be used to build models of interacting spins. This idea is applied to a three-spin ring and to one-dimensional spin chains. Because of the freedom to create almost arbitrary spin lattices, correlated topological insulators with \(\pi\) fluxes represent a novel kind of quantum simulator, potentially useful for numerical simulations and experiments.}, language = {en} } @article{KatoLuRapaportetal.2013, author = {Kato, Hiroki and Lu, Qiping and Rapaport, Doron and Kozjak-Pavlovic, Vera}, title = {Tom70 Is Essential for PINK1 Import into Mitochondria}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0058435}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131061}, pages = {e58435}, year = {2013}, abstract = {PTEN induced kinase 1 (PINK1) is a serine/threonine kinase in the outer membrane of mitochondria (OMM), and known as a responsible gene of Parkinson's disease (PD). The precursor of PINK1 is synthesized in the cytosol and then imported into the mitochondria via the translocase of the OMM (TOM) complex. However, a large part of PINK1 import mechanism remains unclear. In this study, we examined using cell-free system the mechanism by which PINK1 is targeted to and assembled into mitochondria. Surprisingly, the main component of the import channel, Tom40 was not necessary for PINK1 import. Furthermore, we revealed that the import receptor Tom70 is essential for PINK1 import. In addition, we observed that although PINK1 has predicted mitochondrial targeting signal, it was not processed by the mitochondrial processing peptidase. Thus, our results suggest that PINK1 is imported into mitochondria by a unique pathway that is independent of the TOM core complex but crucially depends on the import receptor Tom70.}, language = {en} } @article{MollReboredoSchwarzetal.2013, author = {Moll, Corinna and Reboredo, Jenny and Schwarz, Thomas and Appelt, Antje and Sch{\"u}rlein, Sebastian and Walles, Heike and Nietzer, Sarah}, title = {Tissue Engineering of a Human 3D in vitro Tumor Test System}, series = {Journal of Visualized Experiments}, volume = {78}, journal = {Journal of Visualized Experiments}, number = {e50460}, doi = {10.3791/50460}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132277}, year = {2013}, abstract = {Cancer is one of the leading causes of death worldwide. Current therapeutic strategies are predominantly developed in 2D culture systems, which inadequately reflect physiological conditions in vivo. Biological 3D matrices provide cells an environment in which cells can self-organize, allowing the study of tissue organization and cell differentiation. Such scaffolds can be seeded with a mixture of different cell types to study direct 3D cell-cell-interactions. To mimic the 3D complexity of cancer tumors, our group has developed a 3D in vitro tumor test system. Our 3D tissue test system models the in vivo situation of malignant peripheral nerve sheath tumors (MPNSTs), which we established with our decellularized porcine jejunal segment derived biological vascularized scaffold (BioVaSc). In our model, we reseeded a modified BioVaSc matrix with primary fibroblasts, microvascular endothelial cells (mvECs) and the S462 tumor cell line For static culture, the vascular structure of the BioVaSc is removed and the remaining scaffold is cut open on one side (Small Intestinal Submucosa SIS-Muc). The resulting matrix is then fixed between two metal rings (cell crowns). Another option is to culture the cell-seeded SIS-Muc in a flow bioreactor system that exposes the cells to shear stress. Here, the bioreactor is connected to a peristaltic pump in a self-constructed incubator. A computer regulates the arterial oxygen and nutrient supply via parameters such as blood pressure, temperature, and flow rate. This setup allows for a dynamic culture with either pressure-regulated pulsatile or constant flow. In this study, we could successfully establish both a static and dynamic 3D culture system for MPNSTs. The ability to model cancer tumors in a more natural 3D environment will enable the discovery, testing, and validation of future pharmaceuticals in a human-like model.}, language = {en} } @article{FalgeEngelGraefe2013, author = {Falge, M. and Engel, V. and Gr{\"a}fe, S.}, title = {Time-resolved photoelectron spectroscopy of coupled nuclear-electronic dynamics}, series = {EPJ Web of Conferences}, volume = {41}, journal = {EPJ Web of Conferences}, issn = {2100-014X}, doi = {10.1051/epjconf/20134102036}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121812}, pages = {02036}, year = {2013}, abstract = {We study the effect of nuclear-electron coupling on time-resolved photo-electron spectra, employing a model system which allows to directly comparing spectra resulting from the adiabatic approximation with those obtained within a non-Born-Oppenheimer description.}, language = {en} } @article{MeuleKueblerBlechert2013, author = {Meule, Adrian and K{\"u}bler, Andrea and Blechert, Jens}, title = {Time course of electrocortical food-cue responses during cognitive regulation of craving}, series = {Frontiers in Psychology}, volume = {4}, journal = {Frontiers in Psychology}, number = {669}, issn = {1664-1078}, doi = {10.3389/fpsyg.2013.00669}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122566}, year = {2013}, abstract = {In our current obesogenic environment, exposure to visual food-cues can easily lead to craving and overeating because short-term, pleasurable effects of food intake dominate over the anticipated long-term adverse effects such as weight gain and associated health problems. Here we contrasted these two conditions during food-cue presentation while acquiring event-related potentials (ERPs) and subjective craving ratings. Female participants (n = 25) were presented with either high-calorie (HC) or low-calorie (LC) food images under instructions to imagine either immediate (NOW) or long-term effects (LATER) of consumption. On subjective ratings for HC foods, the LATER perspective reduced cravings as compared to the NOW perspective. For LC foods, by contrast, craving increased under the LATER perspective. Early ERPs (occipital N1, 150-200 ms) were sensitive to food type but not to perspective. Late ERPs (late positive potential, LPP, 350-550 ms) were larger in the HC-LATER condition than in all other conditions, possibly indicating that a cognitive focus on negative long-term consequences induced negative arousal. This enhancement for HC-LATER attenuated to the level of the LC conditions during the later slow wave (550-3000 ms), but amplitude in the HC-NOW condition was larger than in all other conditions, possibly due to a delayed appetitive response. Across all conditions, LPP amplitudes were positively correlated with self-reported emotional eating. In sum, results reveal that regulation effects are secondary to an early attentional analysis of food type and dynamically evolve over time. Adopting a long-term perspective on eating might promote a healthier food choice across a range of food types.}, language = {en} } @article{LuxenhoferFetsch2013, author = {Luxenhofer, Robert and Fetsch, Corinna}, title = {Thermal Properties of Aliphatic Polypeptoids}, series = {Polymers}, journal = {Polymers}, doi = {10.3390/polym5010112}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96333}, year = {2013}, abstract = {A series of polypeptoid homopolymers bearing short (C1-C5) side chains of degrees of polymerization of 10-100 are studied with respect to thermal stability, glass transition and melting points. Thermogravimetric analysis of polypeptoids suggests stability to >200 °C. The study of the glass transition temperatures by differential scanning calorimetry revealed two dependencies. On the one hand an extension of the side chain by constant degree of polymerization decrease the glass transition temperatures (Tg) and on the other hand a raise of the degree of polymerization by constant side chain length leads to an increase of the Tg to a constant value. Melting points were observed for polypeptoids with a side chain comprising not less than three methyl carbon atoms. X-ray diffraction of polysarcosine and poly(N-ethylglycine) corroborates the observed lack of melting points and thus, their amorphous nature. Diffractograms of the other investigated polypeptoids imply that crystalline domains exist in the polymer powder.}, language = {en} } @article{GrossSamhita2013, author = {Gross, Hans J. and Samhita, Laasya}, title = {The "Clever Hans Phenomenon" revisited}, doi = {10.4161/cib.27122}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-112626}, year = {2013}, abstract = {In the first decade of the 20th century, a horse named Hans drew worldwide attention in Berlin as the first and most famous "speaking" and thinking animal. Hans solved calculations by tapping numbers or letters with his hoof in order to answer questions. Later on, it turned out that the horse was able to give the correct answer by reading the microscopic signals in the face of the questioning person. This observation caused a revolution and as a consequence, experimenters avoided strictly any face-to-face contact in studies about cognitive abilities of animals—a fundamental lesson that is still not applied rigorously.}, language = {en} } @article{MusselGoeritzHewig2013, author = {Mussel, Patrick and G{\"o}ritz, Anja S. and Hewig, Johannes}, title = {The value of a smile: Facial expression affects ultimatum-game responses}, series = {Judgment and Decision Making}, volume = {8}, journal = {Judgment and Decision Making}, number = {3}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129639}, pages = {381-385}, year = {2013}, abstract = {In social interaction, the facial expression of an opponent contains information that may influence the interaction. We asked whether facial expression affects decision-making in the ultimatum game. In this two-person game, the proposer divides a sum of money into two parts, one for each player, and then the responder decides whether to accept the offer or reject it. Rejection means that neither player gets any money. Results of a large-sample study support our hypothesis that offers from proposers with a smiling facial expression are more often accepted, compared to a neutral facial expression. Moreover, we found lower acceptance rates for offers from proposers with an angry facial expression.}, language = {en} } @phdthesis{Onyenali2013, author = {Onyenali, Rowland}, title = {The Trilogy of Parables in Mt 21:28-22:14 from a Matthean Perspective}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-74971}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {The parables of Jesus have undergone different transmutations in the long history of their transmission. The events surrounding his death and resurrection as well as the new situations his followers were confronted with after these events, led to the parables being given new accentuation according to the needs of the reflecting community. This is evident in Matthew's treatment of the parable trilogy of Mt 21:28-22:14. The work tries to show how Matthew has used the dominical parables and sayings found in his tradition to serve the needs of his community, especially in her struggles with the official Jewish leaders of his time. Through these parables, which he presented as a three-pronged attack against the Jewish leaders, he shows his community as the true Israel, called to produce the fruits of righteousness.}, subject = {Matth{\"a}usevangelium 21}, language = {en} } @phdthesis{Wetzel2013, author = {Wetzel, Andrea}, title = {The role of TrkB and NaV1.9 in activity-dependent axon growth in motoneurons}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-92877}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {W{\"a}hrend der Entwicklung des Nervensystems lassen sich bei Motoneuronen aktivit{\"a}tsabh{\"a}ngige Kalziumstr{\"o}me eobachten, die das Axonwachstum regulieren. Diese Form der neuronalen Spontanaktivit{\"a}t sowie das Auswachsen von Axonen sind bei Motoneuronen, die aus Tiermodellen der Spinalen Muskelatrophie isoliert werden, gest{\"o}rt. Experimente aus unserer Arbeitsgruppe haben gezeigt, dass spontane Erregbarkeit und aktivit{\"a}tsabh{\"a}ngiges Axonwachstum von kultivierten Motoneuronen auch unter Verwendung von Toxinen beeintr{\"a}chtigt sind, welche die Aktivit{\"a}t von spannungsabh{\"a}ngigen Natriumkan{\"a}len blockieren. In diesen Versuchen war die Wirkung von Saxitoxin effizienter als die Wirkung von Tetrodotoxin. Wir identifizierten den Saxitoxin-sensitiven/Tetrodotoxin-insensitiven spannungsabh{\"a}ngigen Natriumkanal NaV1.9 als Trigger f{\"u}r das {\"O}ffnen spannungsabh{\"a}ngiger Kalziumkan{\"a}le. Die Expression von NaV1.9 in Motoneuronen konnte {\"u}ber quantitative RT-PCR nachgewiesen werden und antik{\"o}rperf{\"a}rbungen offenbarten eine Anreicherung des Kanals im axonalen Wachstumskegel sowie an Ranvier'schen Schn{\"u}rringen von isolierten Nervenfasern wildtypischer M{\"a}use. Motoneurone von NaV1.9 knock-out M{\"a}usen zeigen reduzierte Spontanaktivit{\"a}t und eine Reduktion des Axonwachstums, welche durch NaV1.9 {\"U}berexpression normalisiert werden kann. In Motoneuronen von Smn-defizienten M{\"a}usen konnte keine Abweichung der NaV1.9 Proteinverteilung nachgewiesen werden. K{\"u}rzlich wurden Patienten identifiziert, die eine missense-Mutation im NaV1.9 kodierenden SCN11A Gen tragen. Diese Patienten k{\"o}nnen keinerlei Schmerz empfinden und leiden zudem an Muskelschw{\"a}che in Kombination mit einer verz{\"o}gerten motorischen Entwicklung. Im Rahmen dieser Doktorarbeit konnten molekularbiologische Untersuchungen an M{\"a}usen, welche die Mutation im orthologen Scn11a Gen tragen, zur Aufkl{\"a}rung des Krankheitsmechanismus beitragen. Die Kooperationsstudie zeigte, dass eine gesteigerte Funktion von NaV1.9 diese spezifische Kanalerkrankung ausl{\"o}st, was die Wichtigkeit von NaV1.9 in menschlichen Motoneuronen unterstreicht. Eine fr{\"u}here Studie beschrieb an hippocampalen Neuronen, dass die Rezeptortyrosinkinase tropomyosin receptor kinase B (TrkB) den NaV1.9 Kanal {\"o}ffnen kann. Im Wachstumskegel von Motoneuronen ist TrkB nachweisbar und folglich in r{\"a}umlicher N{\"a}he zu NaV1.9 zu finden. Um zu pr{\"u}fen, ob TrkB in die spontane Erregbarkeit von Motoneuronen involviert ist, wurden TrkB knock-out M{\"a}use untersucht. Isolierte Motoneurone von TrkB knock-out M{\"a}usen weisen eine Reduktion der Spontanaktivit{\"a}t und eine Verringerung des Axonwachstums auf. Ob TrkB und NaV1.9 hierbei funktionell gekoppelt sind, ist Gegenstand k{\"u}nftiger Forschung.}, subject = {Motoneuron}, language = {en} } @phdthesis{Link2013, author = {Link, Jana}, title = {The role of meiotic nuclear envelope components in chromosome dynamics and meiotic progression}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83540}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Meiosis is the specialised cell division which produces haploid germ cells, capable of developing into fertile gametes, from diploid progenitor cells. During meiosis, chromosomes undergo strictly regulated and strongly conserved dynamic processes, at the beginning of which the telomeres are actively tethered and intimately attached to the nuclear envelope (NE). The attached telomeres are then moved within the NE through cytoskeletal forces to cluster within a restricted region, forming the highly conserved bouquet stage. Subsequently, the bouquet is released simultaneously to the completion of the synaptonemal complex assembly tightly linking homologous chromosome pairs together. In combination these processes are essential for the successful completion of meiosis. Because the meiotic NE serves as a platform for telomere attachment and movement it can be assumed to be critically involved in these events crucial for fertility. However, the precise roles of many meiotic NE proteins in the attachment and movement of telomeres still remain elusive. Therefore, it was the aim of this thesis to investigate the functions of two mammalian meiotic NE components in telomere attachment and dynamics. The first part of this thesis is concerned with the meiosis-specific lamin C2. Lamin C2 is the only A-type lamin expressed during meiosis and has in previous studies shown to feature altered meiosis-specific properties, clearly distinguishing it from somatic lamins. Because lamin C2 is enriched at sites of telomere attachment, exhibits a high mobility within the nuclear lamina and influences NE integrity, it has been postulated that it may locally increase NE flexibility to allow efficient meiotic telomere movement. Therefore, possible functions of lamin C2 in the movement of attached telomeres were investigated in this thesis by studying the bouquet formation and release of pubertal mice specifically lacking lamin C2. This revealed that lamin C2 deficient mice show a delayed bouquet release, leading to severe defects in the synaptic pairing of homologous chromosomes, which in turn results in infertility of the males. Therefore, the efficient repositioning of attached meiotic telomeres, facilitated by lamin C2, seems essential for completing meiosis. The second part of this thesis focuses on the protein complex responsible for the attachment of meiotic telomeres to the NE and their coupling to the cytoskeleton. The so-called LINC complex is composed of SUN domain proteins in the inner nuclear membrane interacting with KASH domain proteins of the outer nuclear membrane. In previous studies it had been shown that SUN1, SUN2 and KASH5 localise to the attached meiotic telomeres. Regarding the meiotic role of SUN2, however, contradicting results have recently been discussed, showing the need for further investigations. Using an available SUN1 deficient mouse strain, this thesis was able to show that SUN2 is sufficient for telomere attachment per se although telomere attachment is impaired in SUN1 deficient mice leading to infertility. It is also demonstrated that SUN2 forms a functional LINC complex together with KASH5 to mediate this telomere attachment. This LINC complex in the absence of SUN1 is able to move attached telomeres into a bouquet-like cluster formation. Therefore, this demonstrates that SUN2 is involved in the functional attachment and movement of meiotic telomeres. In summary, this thesis has shown SUN2 and the meiotic nuclear lamina to be directly involved in or essential for the highly conserved attachment and movement of telomeres, making them critical for a successful meiosis. The meiotic NE is therefore in this thesis demonstrated to be a determinant of mammalian fertility.}, subject = {Meiose}, language = {en} } @phdthesis{KannenCardoso2013, author = {Kannen Cardoso, Vinicius}, title = {The role of Fluoxetine against preneoplastic lesions and tumors in colon tissue}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-77589}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Introduction: Colon cancer is one of the major human malignancies worldwide, and much effort has been applied to understand the process of colon carcinogenesis, as well as the role of potential treatments and co-therapeutical agents against it. A growing body of evidence suggests that the use of fluoxetine (FLX), an antidepressant belonging to the selective serotonin reuptake inhibitors (SSRIs), may be associated with a reduced colon cancer risk. However, controversial opinions have been published and an identification of the mechanisms of the activity of FLX on colon cells would help in the clarification of this controversy. Objectives: Using several in vitro and in vivo-based methods and analyses, we aimed to verify whether FLX has antioxidant, pro-oxidant or DNA-damaging potential in standard toxicological assays; to check whether and how FLX could prevent and reduce colon preneoplastic lesions; to ascertain whether FLX has any oncostatic potential against colon tumors; and, to investigate whether FLX activity could be comparable with a known and current applied chemotherapeutic agent against colon cancer. Results: FLX did not have any antioxidant potential in our experiments. Although it did not induce reactive oxygen species (ROS) generation or DNA-damage in fibroblast and colon tumor cell lines, FLX reduced dysplasia and proliferation in two different carcinogen models. Further, a significant decrease in colon stromal reactivity and angiogenesis was found in both carcinogen-induced preneoplasia models. In a xenograft model of colon cancer, FLX shrank tumors, reduced tumor proliferation, arrested cancer cells at the G0/G1 cell-cycle phase, and took ROS generation under control. Such effects were detected together with an intracellular acidification and loss of mitochondrial membrane potential in FLX-treated cells. Modulating mitochondrial respiratory chain, HIF-1 expression and Akt/mTOR signaling pathway, FLX was found to reduce colon tumors similar to the widely used chemotherapeutic agent 5-Fluoracil activity. Conclusion: Our collective data suggest that FLX is a remarkable chemopreventive and oncostatic agent against colon preneoplastic lesions and tumors, acting without DNA-damage or ROS generation.}, subject = {Fluoxetin}, language = {en} } @article{MeuleVoegele2013, author = {Meule, Adrian and V{\"o}gele, Claus}, title = {The psychology of eating}, series = {Frontiers in Psychology}, volume = {4}, journal = {Frontiers in Psychology}, issn = {1664-1078}, doi = {10.3389/fpsyg.2013.00215}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-190460}, year = {2013}, abstract = {No abstract available.}, language = {en} } @article{ChatterjeeAndrulisStuehmeretal.2013, author = {Chatterjee, Manik and Andrulis, Mindaugas and St{\"u}hmer, Thorsten and M{\"u}ller, Elisabeth and Hofmann, Claudia and Steinbrunn, Torsten and Heimberger, Tanja and Schraud, Heike and Kressmann, Stefanie and Einsele, Hermann and Bargou, Ralf C.}, title = {The PI3K/Akt signaling pathway regulates the expression of Hsp70, which critically contributes to Hsp90-chaperone function and tumor cell survival in multiple myeloma}, series = {Haematologica}, volume = {98}, journal = {Haematologica}, number = {7}, doi = {10.3324/haematol.2012.066175}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130574}, pages = {1132-1141}, year = {2013}, abstract = {Despite therapeutic advances multiple myeloma remains largely incurable, and novel therapeutic concepts are needed. The Hsp90-chaperone is a reasonable therapeutic target, because it maintains oncogenic signaling of multiple deregulated pathways. However, in contrast to promising pre-clinical results, only limited clinical efficacy has been achieved through pharmacological Hsp90 inhibition. Because Hsp70 has been described to interact functionally with the Hsp90-complex, we analyzed the suitability of Hsp72 and Hsp73 as potential additional target sites. Expression of Hsp72 and Hsp73 in myeloma cells was analyzed by immunohistochemical staining and western blotting. Short interfering RNA-mediated knockdown or pharmacological inhibition of Hsp72 and Hsp73 was performed to evaluate the role of these proteins in myeloma cell survival and for Hsp90-chaperone function. Furthermore, the role of PI3K-dependent signaling in constitutive and inducible Hsp70 expression was investigated using short interfering RNA-mediated and pharmacological PI3K inhibition. Hsp72 and Hsp73 were frequently overexpressed in multiple myeloma. Knockdown of Hsp72 and/or Hsp73 or treatment with VER-155008 induced apoptosis of myeloma cells. Hsp72/Hsp73 inhibition decreased protein levels of Hsp90-chaperone clients affecting multiple oncogenic signaling pathways, and acted synergistically with the Hsp90 inhibitor NVP-AUY922 in the induction of death of myeloma cells. Inhibition of the PI3K/Akt/GSK3b pathway with short interfering RNA or PI103 decreased expression of the heat shock transcription factor 1 and down-regulated constitutive and inducible Hsp70 expression. Treatment of myeloma cells with a combination of NVP-AUY922 and PI103 resulted in additive to synergistic cytotoxicity. In conclusion, Hsp72 and Hsp73 sustain Hsp90-haperone function and critically contribute to the survival of myeloma cells. Translation of Hsp70 inhibition into the clinic is therefore highly desirable. Treatment with PI3K inhibitors might represent an alternative therapeutic strategy to target Hsp70.}, language = {en} } @phdthesis{Dreykluft2013, author = {Dreykluft, Angela}, title = {The PD-1/B7-H1 Pathway in a Transgenic Mouse Model for Spontaneous Autoimmune Neuroinflammation: Immunological Studies on Devic B7-H1-/- Mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83288}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Multiple sclerosis is an autoimmune disease of the central nervous system characterized by inflammatory, demyelinating lesions and neuronal death. Formerly regarded as a variant of MS, neuromyelitis optica (NMO)/Devic's disease is now recognized as a distinct neurological disorder exhibiting characteristic inflammatory and demyelinated foci in the optic nerves and the spinal cord sparing the brain. With the introduction of the double-transgenic "Devic mouse" model featuring spontaneous, adjuvant-free incidence of autoimmune neuroinflammation due to the interaction of transgenic MOG-specific T and B cells, a promising tool was found for the analysis of factors triggering or preventing autoimmunity. The co-inhibitory molecule B7-H1 has been proposed to contribute to the maintenance of peripheral tolerance and to confine autoimmune inflammatory damage via the PD-1/B7-H1 pathway. Compared to Devic B7-H1+/+ mice, Devic B7-H1-/- mice developed clinical symptoms with a remarkably higher incidence rate and faster kinetics emphasized by deteriorated disease courses and a nearly quadrupled mortality rate. Remarkably enlarged immune-cell accumulation in the CNS of Devic B7-H1-/- mice, in particular of activated MOG-specific CD4+ T cells, correlated with the more severe clinical features. Our studies showed that the CNS not only was the major site of myelin-specific CD4+ T-cell activation but also that B7-H1 expression within the target organ significantly influenced T-cell activation and differentiation levels. Analysis at disease maximum revealed augmented accumulation of MOG-specific CD4+ T cells in the peripheral lymphoid organs of Devic B7-H1-/- mice partly due to increased T-cell proliferation rates. Transgenic MOG-specific B cells of Devic B7-H1-/- mice activated MOG-specific CD4+ T cells more efficiently than B cells of Devic B7-H1+/+ mice. This observation indicated a relevant immune-modulating role of B7-H1 on APCs (antigen-presenting cells) in this mouse model. We also assumed altered thymic selection processes to be involved in increased peripheral CD4+ T-cell numbers of Devic B7-H1-/- mice as we found more thymocytes expressing the transgenic MOG-specific T-cell receptor (TCR). Moreover, preliminary in vitro experiments hinted on an enhanced survival of TCRMOG-transgenic CD4+ T cells of Devic B7-H1-/- mice; a mechanism that might as well have led to higher peripheral T-cell accumulation. Elevated levels of MOG-specific CD4+ T cells in the periphery of Devic B7-H1-/- mice could have entailed the higher quantities in the CNS. However, mechanisms such as CNS-specific proliferation and/or apoptosis/survival could also have contributed. This should be addressed in future investigations. Judging from in vitro migration assays and adoptive transfer experiments on RAG-1-/- recipient mice, migratory behavior of MOG-specific CD4+ T cells of Devic B7-H1+/+ and Devic B7-H1-/- mice seemed not to differ. However, enhanced expression of the transmigration-relevant integrin LFA-1 on CD4+ T cells in young symptom-free Devic B7-H1-/- mice might hint on temporally differently pronounced transmigration capacities during the disease course. Moreover, we attributed the earlier conversion of CD4+ T cells into Th1 effector cells in Devic B7-H1-/- mice during the initiation phase to the lack of co-inhibitory signaling via PD-1/B7-H1 possibly leading to an accelerated disease onset. Full blown autoimmune inflammatory processes could have masked these slight effects of B7-H1 in the clinical phase. Accordingly, at peak of the disease, Th1 and Th17 effector functions of peripheral CD4+ T cells were comparable in both mouse groups. Moreover, judging from titers of MOG-specific IgG1 and IgM antibodies, alterations in humoral immunity were not detected. Therefore, clinical differences could not be explained by altered T-cell or B-cell effector functions at disease maximum. B7-H1 rather seemed to take inhibitory effect in the periphery during the initiation phase only and consistently within the target organ by parenchymal expression. Our observations indicate that B7-H1 plays a relevant role in the regulation of T-cell responses in this mouse model for spontaneous CNS autoimmunity. By exerting immune-modulating effects in the preclinical as well as the clinical phase of the disease, B7-H1 contributed to the confinement of the immunopathological tissue damage in Devic B7-H1+/+ mice mirrored by later disease onsets and lower disease scores. As a model for spontaneous autoimmunity featuring a close to 100 \% incidence rate, the Devic B7-H1-/- mouse may prove instrumental in clarifying disease-triggering and -limiting factors and in validating novel therapeutic approaches in the field of autoimmune neuroinflammation, in particular the human Devic's disease.}, subject = {Autoimmunit{\"a}t}, language = {en} } @article{PoppeBroeckerTrautmann2013, author = {Poppe, Lidia M. and Br{\"o}cker, Eva-Bettina and Trautmann, Axel}, title = {The One-nail Brown Band: Macro- and Micro-morphology}, series = {Acta Dermato-Venereologica}, volume = {93}, journal = {Acta Dermato-Venereologica}, number = {4}, doi = {10.2340/00015555-1505}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128566}, pages = {479-480}, year = {2013}, abstract = {No abstract available.}, language = {en} } @article{HohenauerBerkingSchmidtetal.2013, author = {Hohenauer, Tobias and Berking, Carola and Schmidt, Andreas and Haferkamp, Sebastian and Senft, Daniela and Kammerbauer, Claudia and Fraschka, Sabine and Graf, Saskia Anna and Irmler, Martin and Beckers, Johannes and Flaig, Michael and Aigner, Achim and H{\"o}bel, Sabrina and Hoffmann, Franziska and Hermeking, Heiko and Rothenfusser, Simon and Endres, Stefan and Ruzicka, Thomas and Besch, Robert}, title = {The neural crest transcription factor Brn3a is expressed in melanoma and required for cell cycle progression and survival}, series = {EMBO Molecular Medicine}, volume = {5}, journal = {EMBO Molecular Medicine}, issn = {1757-4676}, doi = {10.1002/emmm.201201862}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122193}, pages = {919-934}, year = {2013}, abstract = {Pigment cells and neuronal cells both are derived from the neural crest. Here, we describe the Pit-Oct-Unc (POU) domain transcription factor Brn3a, normally involved in neuronal development, to be frequently expressed in melanoma, but not in melanocytes and nevi. RNAi-mediated silencing of Brn3a strongly reduced the viability of melanoma cell lines and decreased tumour growth in vivo. In melanoma cell lines, inhibition of Brn3a caused DNA double-strand breaks as evidenced by Mre11/Rad50-containing nuclear foci. Activated DNA damage signalling caused stabilization of the tumour suppressor p53, which resulted in cell cycle arrest and apoptosis. When Brn3a was ectopically expressed in primary melanocytes and fibroblasts, anchorage-independent growth was increased. In tumourigenic melanocytes and fibroblasts, Brn3a accelerated tumour growth in vivo. Furthermore, Brn3a cooperated with proliferation pathways such as oncogenic BRAF, by reducing oncogene-induced senescence in non-malignant melanocytes. Together, these results identify Brn3a as a new factor in melanoma that is essential for melanoma cell survival and that promotes melanocytic transformation and tumourigenesis.}, language = {en} } @article{RascheDuellMorgneretal.2013, author = {Rasche, Leo and Duell, Johannes and Morgner, Charlotte and Chatterjee, Manik and Hensel, Frank and Rosenwald, Andreas and Einsele, Hermann and Topp, Max S. and Br{\"a}ndlein, Stephanie}, title = {The Natural Human IgM Antibody PAT-SM6 Induces Apoptosis in Primary Human Multiple Myeloma Cells by Targeting Heat Shock Protein GRP78}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {5}, doi = {10.1371/journal.pone.0063414}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130125}, pages = {e63414}, year = {2013}, abstract = {In contrast to other haematological malignancies, targeted immunotherapy has not entered standard treatment regimens for de novo or relapsed multiple myeloma (MM) yet. While a number of IgG-formatted monoclonal antibodies are currently being evaluated in clinical trials in MM, our study aimed to investigate whether the fully human IgM monoclonal antibody PAT-SM6 that targets a tumour-specific variant of the heat shock protein GRP78 might be an attractive candidate for future immunotherapeutic approaches. We here show that GRP78 is stably and consistently expressed on the surface on tumour cells from patients with de novo, but also relapsed MM and that binding of PAT-SM6 to MM cells can specifically exert cytotoxic effects on malignant plasma cells, whereas non-malignant cells are not targeted. We demonstrate that the induction of apoptosis and, to a lesser extent, complement dependent cytotoxicity is the main mode of action of PAT-SM6, whereas antibody dependent cellular cytotoxicity does not appear to contribute to the cytotoxic properties of this antibody. Given the favourable safety profile of PAT-SM6 in monkeys, but also in a recent phase I trial in patients with malignant melanoma, our results form the basis for a planned phase I study in patients with relapsed MM.}, language = {en} } @phdthesis{Ngwa2013, author = {Ngwa, Che Julius}, title = {The mosquito midgut-specific stages of the malaria parasite as targets for transmission blocking interventions}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-83594}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Die Tropenkrankheit Malaria, wird durch eine Infektion mit einzelligen Parasiten der Gattung Plasmodium verursacht und durch den Stich der weiblichen Anopheles-M{\"u}cke von Mensch zu Mensch verbreitet. Dabei kann eine erfolgreiche {\"U}bertragung des Parasiten auf den Menschen nur dann stattfinden, wenn der Parasit seine sexuelle Entwicklungsphase im Mitteldarm der M{\"u}cke erfolgreich durchl{\"a}uft. Ziel dieser Arbeit war es daher, die Wechselwirkungen des Malariaparasiten im Mitteldarm der M{\"u}cke in Hinblick auf die Identifizierung m{\"o}glicher neuer transmissionsblockierender Strategien zu untersuchen. Der Zweck von transmissionsblockierende Strategien ist es, der Verbreitung der Malaria durch die M{\"u}cke entgegenzuwirken, indem die Entwicklung des Parasiten in der M{\"u}cke unterbunden und dadurch der Lebenszyklus des Parasiten unterbrochen wird. Der Schwerpunkt der vorliegenden Arbeit lag auf insgesamt drei Aspekten. Der erste Aspekt der Arbeit befasste sich mit der Wechselwirkung zwischen dem Para-siten und der mikrobiellen Darmflora der M{\"u}cke. Dabei sollte der m{\"o}gliche Einfluss des Parasiten auf die Darmflora untersucht werden und weiterf{\"u}hrend die potentielle Verwendung von Darmbakterien als Vehikel f{\"u}r die Herstellung paratransgener M{\"u}cken erforscht werden. Vergleichende16S-rRNA- und DGGE-Analysen an der Darmflora des asiatischen Malariavektors Anopheles stephensi zeigten eine deutliche Reduktion der mikrobiellen Diversit{\"a}t w{\"a}hrend der Entwicklung vom Ei zur adulten M{\"u}cke. Zudem konnte das gram-negative Bakterium Elizabethkingia meningoseptica, das sich stadien- und generations{\"u}bergreifend verbreitet, als dominante Darmspezies bei im Labor aufgezogenen weiblichen und m{\"a}nnlichen An. stephensi festgestellt werden. Die Dominanz von E. meningoseptica wurde zudem nicht durch die Aufnahme von infiziertem Blut oder einer ver{\"a}nderten Nahrung beeinflusst. F{\"u}r die Studien wurde sowohl der humanpathogene Parasit P. falciparum als auch der Nagermalariaerreger P. berghei verwendet. Weiterf{\"u}hrende Versuche zeigten, dass Extrakte von E. meningoseptica antibakterielle, antifungale und antiplasmodiale Aktivit{\"a}ten aufwiesen, die ein m{\"o}glicher Grund f{\"u}r die Dominanz dieser Spezies im Mitteldarm des Vektors waren. Isolate von E. meningoseptica sind im Labor kultivierbar; dadurch stellt das Bakterium einen potentiellen Kandidaten zur Generierung von paratransgenen Anopheles-M{\"u}cken dar. Ein zweites Ziel dieser Arbeit war es, m{\"o}gliche Unterschiede in der Genexpression von P. falciparum darzustellen, die in den ersten 30 Minuten nach dessen {\"U}bertragung auf die M{\"u}cke erfolgen. Dies hatte zum einen zum Zweck, die durch den Wirtswechsel hervorgerufenen Genregulationen besser zu verstehen, und bot zum anderen die M{\"o}glichkeit, neue Proteine zu identifizieren, die als potentielle transmissionsblockierende Ziele genutzt werden k{\"o}nnen. Mittels supression substractive hybridization (SSH) konnten insgesamt 126 Gene identifiziert werden, deren Expression sich w{\"a}hrend der Gametogenese ver{\"a}ndert. Die identifizierten Gene konnten einer Vielzahl von putativen Funktionen wie zum Beispiel in der Signaltransduktion (17,5\%), im Zellzyklus (14,3\%) oder im Zytoskelett (8,7\%) zugeordnet werden. Des Weiteren wurden 7,9\% der Gene eine Funktion in der Proteastase und 6,4\% in metabolischen Prozessen zugeordnet. 12,7\% der Gene kodierten f{\"u}r zelloberfl{\"a}chenassoziierte Proteine. 11,9\% der Gene hatten anderen Funktionen, w{\"a}hrend 20\% der Gene keine putative Funktion zugeordnet werden konnte. Etwa 40\% der identifizierten Genprodukte waren bisher nicht in Proteomstudien nachgewiesen worden. In weiterf{\"u}hrenden Analysen wurden 34 Gene aus jeder ontologischen Gruppe ausgew{\"a}hlt und deren Expressionsver{\"a}nderung per quantitativer real time RT-PCR im Detail untersucht. F{\"u}r 29 Gene konnte dabei eine Transkriptexpression in Gametozyten nachgewiesen werden. Zudem wiesen 20 Gene eine erh{\"o}hte Expression in Gametozyten im Vergleich asexuellen Stadien auf. Insgesamt zeigten 8 Gene besonders hohe Transkriptlevel in aktivierten Gametozyten, was auf eine Funktion dieser Proteine w{\"a}hrend der {\"U}bertragung des Parasiten auf die M{\"u}cke hindeutet und diese somit potentielle Angriffspunkte f{\"u}r transmissionsblockierende Strategien darstellen k{\"o}nnten. Im letzten Teil dieser Arbeit stand die Untersuchung verschiedener antimikrobieller Substanzen in Bezug auf ihre transmissionsblockierenden Eigenschaften im Vordergrund. Die Substanzen waren entweder direkt aus der H{\"a}molymphe verschiedener Insekten isoliert oder rekombinant in transgenem Tabak exprimiert worden. Dabei wurden die rekombinanten Peptide so ausgew{\"a}hlt, dass sie entweder gegen die Mitteldarmstadien des Parasiten wirken oder m{\"u}ckenspezifische Rezeptoren blockieren, die der Parasit f{\"u}r seine weitere Entwicklung ben{\"o}tigt. Dabei konnte gezeigt werden, dass das antimikrobielle Molek{\"u}l Harmonin, ein Abwehrmolek{\"u}l aus der H{\"a}molymphe des asiatischen Marienk{\"a}fers Harmonia axyridis, antiplasmodiale als auch transmissions-blockierende Eigenschaften besitzt. Harmonin stellt daher eine potentielle Leitstruktur f{\"u}r die Entwicklung neuer Malariawirkstoffe dar}, subject = {Malariam{\"u}cke}, language = {en} } @phdthesis{Kuehn2013, author = {K{\"u}hn, Andrea}, title = {The molecular interplay of proteins expressed in the sexual stages and the induction of gamete formation in the malaria parasite Plasmodium falciparum}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-98028}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Transmission of the malaria parasite from man to the mosquito requires the formation of sexual parasite stages, the gametocytes. The gametocytes are the only parasite stage that is able to survive in the mosquito midgut and to undergo further development - gamete formation and fertilization. Numerous sexual stage-specific proteins have been discovered, some of which play crucial roles for parasite transmission. However, the functions of many sexual stage proteins remain elusive. Amongst the sexual stage-specific proteins are the proteins of the PfCCp proteins family, which exhibit numerous adhesion domains in their protein structures. For four members of the protein family, PfCCp1 to PfCCp4 gene-disruptant parasite lines had been already studied. Amongst these, PfCCp2 and PfCCp3 showed an important role for development of the parasites in the mosquito. In the present work the study of gene-disrupted parasites of the PfCCp Protein family was completed. PfCCp5-KO and PfFNPA-KO parasite lines were characterized to a great extent and many properties were similar to those of other PfCCp proteins. The co-dependent expression previously reported to be a phenomenon of PfCCp proteins was also observed in these two mutants, although to lesser extent. When either PfCCp5 or PfFNPA were absent, all other proteins were detected in reduced abundance only. Co-dependent expression manifests exclusively on the protein level. Transcript levels were not altered as RT-PCR showed. Amongst PfCCp proteins numerous proteinproteins interactions are taking place. The previously described multimeric protein complexes also include further sexual stage-specific proteins like Pfs230, Pfs48/45 and Pfs25. Recently, a new component of PfCCp-based multimeric protein complexes had been identified. The protein was named PfWLP1 (WD repeat protein-like protein 1) due to its possession of several WD40 repeats. In the present study expression of this uncharacterized protein was investigated via indirect IFA. It was expressed in asexual blood stages and gametocytes. Upon gamete formation and fertilization its expression ceased. Another sexual stage protein studied in this work was PfactinII. It was shown to be exclusively expressed in sexual stages. In gametocytes it co-localizes with Pfs230 and correct localization of PfactinII depends on presence of Pfs230. Transcript analysis by means of RT-PCR revealed the expression of several components of the IMC in gametocytes. Furthermore, five or six myosin genes encoded in the P. falciparum genome were detected in gametocytes. Gametocyte egress was studied on the ultrastructural level via transmission electron microscopy and an inside-out type of egress was observed. Firstly, the membrane of the parasitophorous vacuole (PVM) was lysed and only thereafter the membrane of the red blood cell (RBCM) ruptured. Furthermore, a new inductor of gametogenesis was identified: The K+/H+ ionophore nigericin induced gametocytes activation in the absence of xanthurenic acid (XA), which is responsible for gamtetocyte activation in the mosquito midgut. Selective permeabilization of RBCM and PVM by the mild detergent saponin, showed that in the absence of these membranes male gametocytes were still able to perceive both XA and the drop in temperature. Thus, the receptors for both factors signaling the parasite transmission to the mosquito, seem to be of parasitic origin. LC/MS/MS analysis confirmed the ability of RBCs to take up XA. With malaria eradication on the agenda of malaria research targeting the sexual stages becomes a crucial part of intervention strategies. The sexual stages are especially attractive target as they represent a population bottleneck. The here reported findings on P. falciparum gametocytes provide several potential candidate proteins for developing tools to interrupt transmission from man to mosquito. Such tools might include Transmission blocking vaccines and drugs.}, subject = {Malaria}, language = {en} } @article{AlsheimerLinkJahnetal.2013, author = {Alsheimer, Manfred and Link, Jana and Jahn, Daniel and Schmitt, Johannes and G{\"o}b, Eva and Baar, Johannes and Ortega, Sagrario and Benavente, Ricardo}, title = {The Meiotic Nuclear Lamina Regulates Chromosome Dynamics and Promotes Efficient Homologous Recombination in the Mouse}, series = {PLoS Genetics}, journal = {PLoS Genetics}, doi = {10.1371/journal.pgen.1003261}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96285}, year = {2013}, abstract = {The nuclear lamina is the structural scaffold of the nuclear envelope and is well known for its central role in nuclear organization and maintaining nuclear stability and shape. In the past, a number of severe human disorders have been identified to be associated with mutations in lamins. Extensive research on this topic has provided novel important clues about nuclear lamina function. These studies have contributed to the knowledge that the lamina constitutes a complex multifunctional platform combining both structural and regulatory functions. Here, we report that, in addition to the previously demonstrated significance for somatic cell differentiation and maintenance, the nuclear lamina is also an essential determinant for germ cell development. Both male and female mice lacking the short meiosis-specific A-type lamin C2 have a severely defective meiosis, which at least in the male results in infertility. Detailed analysis revealed that lamin C2 is required for telomere-driven dynamic repositioning of meiotic chromosomes. Loss of lamin C2 affects precise synapsis of the homologs and interferes with meiotic double-strand break repair. Taken together, our data explain how the nuclear lamina contributes to meiotic chromosome behaviour and accurate genome haploidization on a mechanistic level.}, language = {en} } @phdthesis{Reuss2013, author = {Reuß, Heiko}, title = {The interplay of unconscious processing and cognitive control}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-76950}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {The aim of this study was both to investigate the influence of cognitive control on unconscious processing, and to investigate the influence of unconscious processing on cognitive control. At first, different mechanisms and accounts to explain unconscious priming are presented. Here, perceptual and motor processes, as well as stimulus-response learning, semantic categorization, and the action trigger account as theories to explain motor priming are discussed. Then, the issue of the potential limits of unconscious processing is presented. Findings that indicate that active current intentions and expertise modulate unconscious processing are illustrated. Subsequently, results that imply an influence of unconsciously presented stimuli that goes beyond motor processes are discussed, with a special focus on inhibition processes, orienting of attention, task set activation, and conflict adaptation. Then I present the results of my own empirical work. Experiment 1 shows that the effective processing of unconsciously presented stimuli depends on expertise, even when potentially confounding difference between the expert and novice groups are controlled. The results of Experiments 2 and 3 indicate that the intention to use particular stimuli is a crucial factor for the effectiveness of these stimuli when they are presented unconsciously. Additionally, these findings show that shifts of attention can be triggered by centrally presented masked arrow cues. Experiments 4 and 5 broaden these results to cue stimuli that are not inherently associated with a spatial meaning. The finding corroborate that typically endogenously controlled shifts of attention can also be induced by unconscious stimuli. Experiments 6 and 7 demonstrate that even a central cognitive control process like task set activation is not contingent on conscious awareness, but can in contrast be triggered through unconscious stimulation. Finally, these results are integrated and I discuss how the concept of cognitive control and the limits of unconscious processing may have to be reconsidered. Furthermore, potential future research possibilities in this field are presented.}, subject = {Bewusstsein}, language = {en} } @article{BiehlEhlisMuelleretal.2013, author = {Biehl, Stefanie C. and Ehlis, Ann-Christine and M{\"u}ller, Laura D. and Niklaus, Andrea and Pauli, Paul and Herrmann, Martin J.}, title = {The impact of task relevance and degree of distraction on stimulus processing}, series = {BMC Neuroscience}, journal = {BMC Neuroscience}, doi = {10.1186/1471-2202-14-107}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97271}, year = {2013}, abstract = {Background The impact of task relevance on event-related potential amplitudes of early visual processing was previously demonstrated. Study designs, however, differ greatly, not allowing simultaneous investigation of how both degree of distraction and task relevance influence processing variations. In our study, we combined different features of previous tasks. We used a modified 1-back task in which task relevant and task irrelevant stimuli were alternately presented. The task irrelevant stimuli could be from the same or from a different category as the task relevant stimuli, thereby producing high and low distracting task irrelevant stimuli. In addition, the paradigm comprised a passive viewing condition. Thus, our paradigm enabled us to compare the processing of task relevant stimuli, task irrelevant stimuli with differing degrees of distraction, and passively viewed stimuli. EEG data from twenty participants was collected and mean P100 and N170 amplitudes were analyzed. Furthermore, a potential connection of stimulus processing and symptoms of attention deficit hyperactivity disorder (ADHD) was investigated. Results Our results show a modulation of peak N170 amplitudes by task relevance. N170 amplitudes to task relevant stimuli were significantly higher than to high distracting task irrelevant or passively viewed stimuli. In addition, amplitudes to low distracting task irrelevant stimuli were significantly higher than to high distracting stimuli. N170 amplitudes to passively viewed stimuli were not significantly different from either kind of task irrelevant stimuli. Participants with more symptoms of hyperactivity and impulsivity showed decreased N170 amplitudes across all task conditions. On a behavioral level, lower N170 enhancement efficiency was significantly correlated with false alarm responses. Conclusions Our results point to a processing enhancement of task relevant stimuli. Unlike P100 amplitudes, N170 amplitudes were strongly influenced by enhancement and enhancement efficiency seemed to have direct behavioral consequences. These findings have potential implications for models of clinical disorders affecting selective attention, especially ADHD.}, language = {en} } @article{PrelogZlamyKofleretal.2013, author = {Prelog, Martina and Zlamy, Manuela and Kofler, Sabine and Orth, Dorothea and W{\"u}rzner, Reinhard and Heinz-Erian, Peter and Streng, Andrea}, title = {The impact of Rotavirus mass vaccination on hospitalization rates, nosocomial Rotavirus gastroenteritis and secondary blood stream infections}, series = {BMC Infectious Diseases}, journal = {BMC Infectious Diseases}, doi = {10.1186/1471-2334-13-112}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96147}, year = {2013}, abstract = {Background The aim of the study was to evaluate the effects of universal mass vaccination (UMV) against rotavirus (RV) on the hospitalization rates, nosocomial RV infections and RV-gastroenteritis (GE)-associated secondary blood stream infections (BSI). Methods The retrospective evaluation (2002-2009) by chart analysis included all clinically diagnosed and microbiologically confirmed RV-GE cases in a large tertiary care hospital in Austria. The pre-vaccination period (2002-2005) was compared with the recommended and early funded (2006-2007) and the funded (2008-2009) vaccination periods. Primary outcomes were RV-GE-associated hospitalizations, secondary outcomes nosocomial RV disease, secondary BSI and direct hospitalization costs for children and their accompanying persons. Results In 1,532 children with RV-GE, a significant reduction by 73.9\% of hospitalized RV-GE cases per year could be observed between the pre-vaccination and the funded vaccination period, which was most pronounced in the age groups 0-11 months (by 87.8\%), 6-10 years (by 84.2\%) and 11-18 years (88.9\%). In the funded vaccination period, a reduction by 71.9\% of nosocomial RV-GE cases per year was found compared to the pre-vaccination period. Fatalities due to nosocomial RV-GE were only observed in the pre-vaccination period (3 cases). Direct costs of hospitalized, community-acquired RV-GE cases per year were reduced by 72.7\% in the funded vaccination period. The reduction of direct costs for patients (by 86.9\%) and accompanying persons (86.2\%) was most pronounced in the age group 0-11 months. Conclusions UMV may have contributed to the significant decrease of RV-GE-associated hospitalizations, to a reduction in nosocomial RV infections and RV-associated morbidity due to secondary BSI and reduced direct hospitalization costs. The reduction in nosocomial cases is an important aspect considering severe disease courses in hospitalized patients with co-morbidities and death due to nosocomial RV-GE.}, language = {en} } @article{RauertWunderlichSiegmundMaieretal.2013, author = {Rauert-Wunderlich, Hilka and Siegmund, Daniela and Maier, Eduard and Giner, Tina and Bargou, Ralf C. and Wajant, Harald and St{\"u}hmer, Thorsten}, title = {The IKK Inhibitor Bay 11-7082 Induces Cell Death Independent from Inhibition of Activation of NF kappa B Transcription Factors}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {3}, doi = {10.1371/journal.pone.0059292}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130140}, pages = {e59292}, year = {2013}, abstract = {Multiple myeloma (MM) displays an NFκB activity-related gene expression signature and about 20\% of primary MM samples harbor genetic alterations conducive to intrinsic NFκB signaling activation. The relevance of blocking the classical versus the alternative NFκB signaling pathway and the molecular execution mechanisms involved, however, are still poorly understood. Here, we comparatively tested NFκB activity abrogation through TPCA-1 (an IKK2 inhibitor), BAY 11-7082 (an IKK inhibitor poorly selective for IKK1 and IKK2), and MLN4924 (an NEDD8 activating enzyme (NAE)-inhibitor), and analyzed their anti-MM activity. Whereas TPCA-1 interfered selectively with activation of the classical NFκB pathway, the other two compounds inhibited classical and alternative NFκB signaling without significant discrimination. Noteworthy, whereas TPCA-1 and MLN4924 elicited rather mild anti-MM effects with slight to moderate cell death induction after 1 day BAY 11-7082 was uniformly highly toxic to MM cell lines and primary MM cells. Treatment with BAY 11-7082 induced rapid cell swelling and its initial effects were blocked by necrostatin-1 or the ROS scavenger BHA, but a lasting protective effect was not achieved even with additional blockade of caspases. Because MLN4924 inhibits the alternative NFκB pathway downstream of IKK1 at the level of p100 processing, the quite discordant effects between MLN4924 and BAY 11-7082 must thus be due to blockade of IKK1-mediated NFκB-independent necrosis-inhibitory functions or represent an off-target effect of BAY 11-7082. In accordance with the latter, we further observed that concomitant knockdown of IKK1 and IKK2 did not have any major short-term adverse effect on the viability of MM cells.}, language = {en} } @article{SchartlWalterShenetal.2013, author = {Schartl, Manfred and Walter, Ronald B. and Shen, Yingjia and Garcia, Tzintzuni and Catchen, Julian and Amores, Angel and Braasch, Ingo and Chalopin, Domitille and Volff, Jean-Nicolas and Lesch, Klaus-Peter and Bisazza, Angelo and Minx, Pat and Hillier, LaDeana and Wilson, Richard K. and F{\"u}rstenberg, Susan and Boore, Jeffrey and Searle, Steve and Postlethwait, John H. and Warren, Wesley C.}, title = {The genome of the platyfish, Xiphophorus maculatus, provides insights into evolutionary adaptation and several complex traits}, series = {Nature Genetics}, volume = {45}, journal = {Nature Genetics}, number = {5}, doi = {10.1038/ng.2604}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132152}, pages = {567-572}, year = {2013}, abstract = {Several attributes intuitively considered to be typical mammalian features, such as complex behavior, live birth and malignant disease such as cancer, also appeared several times independently in lower vertebrates. The genetic mechanisms underlying the evolution of these elaborate traits are poorly understood. The platyfish, X. maculatus, offers a unique model to better understand the molecular biology of such traits. We report here the sequencing of the platyfish genome. Integrating genome assembly with extensive genetic maps identified an unexpected evolutionary stability of chromosomes in fish, in contrast to in mammals. Genes associated with viviparity show signatures of positive selection, identifying new putative functional domains and rare cases of parallel evolution. We also find that genes implicated in cognition show an unexpectedly high rate of duplicate gene retention after the teleost genome duplication event, suggesting a hypothesis for the evolution of the behavioral complexity in fish, which exceeds that found in amphibians and reptiles.}, language = {en} } @article{VainioValtonenHeberetal.2013, author = {Vainio, Rami and Valtonen, Eino and Heber, Bernd and Malandraki, Olga E. and Papaioannou, Athanasios and Klein, Karl-Ludwig and Afanasiev, Alexander and Agueda, Neus and Aurass, Henry and Battarbee, Markus and Braune, Stephan and Dr{\"o}ge, Wolfgang and Ganse, Urs and Hamadache, Clarisse and Heynderickx, Daniel and Huttunen-Heikinmaa, Kalle and Kiener, J{\"u}rgen and Kilian, Patrick and Kopp, Andreas and Kouloumvakos, Athanasios and Maisala, Sami and Mishev, Alexander and Miteva, Rosita and Nindos, Alexander and Oittinen, Tero and Raukunen, Osku and Riihonen, Esa and Rodriguez-Gasen, Rosa and Saloniemi, Oskari and Sanahuja, Blai and Scherer, Renate and Spanier, Felix and Tatischeff, Vincent and Tziotziou, Kostas and Usoskin, Ilya G. and Vilmer, Nicole}, title = {The first SEPServer event catalogue similar to ~68-MeV solar proton events observed at 1 AU in 1996-2010}, series = {Journal of Space Weather and Space Climate}, volume = {3}, journal = {Journal of Space Weather and Space Climate}, number = {A12}, issn = {2115-7251}, doi = {10.1051/swsc/2013030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122847}, year = {2013}, abstract = {SEPServer is a three-year collaborative project funded by the seventh framework programme (FP7-SPACE) of the European Union. The objective of the project is to provide access to state-of-the-art observations and analysis tools for the scientific community on solar energetic particle (SEP) events and related electromagnetic (EM) emissions. The project will eventually lead to better understanding of the particle acceleration and transport processes at the Sun and in the inner heliosphere. These processes lead to SEP events that form one of the key elements of space weather. In this paper we present the first results from the systematic analysis work performed on the following datasets: SOHO/ERNE, SOHO/EPHIN, ACE/EPAM, Wind/WAVES and GOES X-rays. A catalogue of SEP events at 1 AU, with complete coverage over solar cycle 23, based on high-energy (similar to 68-MeV) protons from SOHO/ERNE and electron recordings of the events by SOHO/EPHIN and ACE/EPAM are presented. A total of 115 energetic particle events have been identified and analysed using velocity dispersion analysis (VDA) for protons and time-shifting analysis (TSA) for electrons and protons in order to infer the SEP release times at the Sun. EM observations during the times of the SEP event onset have been gathered and compared to the release time estimates of particles. Data from those events that occurred during the European day-time, i.e., those that also have observations from ground-based observatories included in SEPServer, are listed and a preliminary analysis of their associations is presented. We find that VDA results for protons can be a useful tool for the analysis of proton release times, but if the derived proton path length is out of a range of 1 AU < s less than or similar to 3 AU, the result of the analysis may be compromised, as indicated by the anti-correlation of the derived path length and release time delay from the associated X-ray flare. The average path length derived from VDA is about 1.9 times the nominal length of the spiral magnetic field line. This implies that the path length of first-arriving MeV to deka-MeV protons is affected by interplanetary scattering. TSA of near-relativistic electrons results in a release time that shows significant scatter with respect to the EM emissions but with a trend of being delayed more with increasing distance between the flare and the nominal footpoint of the Earth-connected field line.}, language = {en} } @article{FischerPlessowKiesel2013, author = {Fischer, Rico and Plessow, Franziska and Kiesel, Andrea}, title = {The effects of alerting signals in masked priming}, series = {Frontiers in Psychology}, volume = {4}, journal = {Frontiers in Psychology}, number = {448}, issn = {1664-1078}, doi = {10.3389/fpsyg.2013.00448}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122581}, year = {2013}, abstract = {Alerting signals often serve to reduce temporal uncertainty by predicting the time of stimulus onset. The resulting response time benefits have often been explained by facilitated translation of stimulus codes into response codes on the basis of established stimulus-response (S-R) links. In paradigms of masked S-R priming alerting signals also modulate response activation processes triggered by subliminally presented prime stimuli. In the present study we tested whether facilitation of visuo-motor translation processes due to alerting signals critically depends on established S-R links. Alerting signals resulted in significantly enhanced masked priming effects for masked prime stimuli that included and that did not include established S-R links fi.e., target vs. novel primes). Yet, the alerting-priming interaction was more pronounced for target than for novel primes. These results suggest that effects of alerting signals on masked priming are especially evident when S-R links between prime and target exist. At the same time, an alerting-priming interaction also for novel primes suggests that alerting signals also facilitate stimulus-response translation processes when masked prime stimuli provide action-trigger conditions in terms of programmed S-R links.}, language = {en} } @article{KopfDreslerReichertsetal.2013, author = {Kopf, Juliane and Dresler, Thomas and Reicherts, Philipp and Herrmann, Martin J. and Reif, Andreas}, title = {The Effect of Emotional Content on Brain Activation and the Late Positive Potential in a Word n-back Task}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0075598}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96687}, year = {2013}, abstract = {Introduction There is mounting evidence for the influence of emotional content on working memory performance. This is particularly important in light of the emotion processing that needs to take place when emotional content interferes with executive functions. In this study, we used emotional words of different valence but with similar arousal levels in an n-back task. Methods We examined the effects on activation in the prefrontal cortex by means of functional near-infrared spectroscopy (fNIRS) and on the late positive potential (LPP). FNIRS and LPP data were examined in 30 healthy subjects. Results Behavioral results show an influence of valence on the error rate depending on the difficulty of the task: more errors were made when the valence was negative and the task difficult. Brain activation was dependent both on the difficulty of the task and on the valence: negative valence of a word diminished the increase in activation, whereas positive valence did not influence the increase in activation, while difficulty levels increased. The LPP also differentiated between the different valences, and in addition was influenced by the task difficulty, the more difficult the task, the less differentiation could be observed. Conclusions Summarized, this study shows the influence of valence on a verbal working memory task. When a word contained a negative valence, the emotional content seemed to take precedence in contrast to words containing a positive valence. Working memory and emotion processing sites seemed to overlap and compete for resources even when words are carriers of the emotional content.}, language = {en} } @article{NessBleySchmidtetal.2013, author = {Ness, Thomas and Bley, Thorsten A. and Schmidt, Wolfgang A. and Lamprecht, Peter}, title = {The Diagnosis and Treatment of Giant Cell Arteritis}, series = {Deutsches {\"A}rzteblatt International}, volume = {110}, journal = {Deutsches {\"A}rzteblatt International}, number = {21}, doi = {10.3238/arztebl.2013.0376}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131676}, pages = {376-86}, year = {2013}, abstract = {Background: Giant cell arteritis (GCA) is the most common systemic vasculitis in persons aged 50 and above (incidence, 3.5 per 100 000 per year). It affects cranial arteries, the aorta, and arteries elsewhere in the body, e.g., in the limbs. Methods: We selectively review the pertinent literature, including guidelines and recommendations from Germany and abroad. Results: The typical symptoms of new-onset GCA are bi-temporal headaches, jaw claudiacation, scalp tenderness, visual disturbances, systemic symptoms such as fever and weight loss, and polymyalgia. The diagnostic assessment comprises laboratory testing (erythrocyte sedimentation rate, C-reactive protein), imaging studies (duplex sonography, high-resolution magnetic resonance imaging, positron-emission tomography), and temporal artery biopsy. The standard treatment is with corticosteroids (adverse effects: diabetes mellitus, osteoporosis, cataract, arterial hypertension). A meta-analysis of three randomized controlled trials led to a recommendation for treatment with methotrexate to lower the recurrence rate and spare steroids. Patients for whom methotrexate is contraindicated or who cannot tolerate the drug can be treated with azathioprine instead. Conclusion: Giant cell arteritis, if untreated, progresses to involve the aorta and its collateral branches, leading to various complications. Late diagnosis and treatment can have serious consequences, including irreversible loss of visual function.}, language = {en} } @article{KuehnSchoenEdelmannetal.2013, author = {K{\"u}hn, Heike and Sch{\"o}n, Franz and Edelmann, Karola and Brill, Stefan and M{\"u}ller, Joachim}, title = {The Development of Lateralization Abilities in Children with Bilateral Cochlear Implants}, series = {ORL}, volume = {75}, journal = {ORL}, number = {2}, issn = {0301-1569}, doi = {10.1159/000347193}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196375}, pages = {55-67}, year = {2013}, abstract = {Objectives: The purpose of this study was to investigate the development of lateralization skills in children who received bilateral cochlear implants (CIs) in sequential operations. Methods: The lateralization skills of 9 children with a mean age of 4.1 years at the first surgery and 5.5 years at the second surgery were assessed at 3 time intervals. Children were assessed with a 3-loudspeaker setup (front, left and right) at 0.9 years (interval I) and 1.6 years (interval II) after the second implantation, and after 5.3 years of bilateral implant use (interval III) with a 9-loudspeaker setup in the frontal horizontal plane between -90° and 90° azimuth. Results: With bilateral implants, a significant decrease in lateralization error was noted between test interval I (45.0°) and II (23.3°), with a subsequent significant decrease at test interval III (4.7°). Unilateral performance with the CI did not improve significantly between the first 2 intervals; however, there was a bias of responses towards the unilateral side by test interval III. Conclusions: The lateralization abilities of children with bilateral CIs develop in a relatively short period of time (1-2 years) after the second implant. Children appear to be able to acquire binaural skills after bilateral cochlear implantation.}, language = {en} } @article{RittnerHackelPflueckeetal.2013, author = {Rittner, Heike Lydia and Hackel, Dagmar and Pfl{\"u}cke, Diana and Neumann, Annick and Viebahn, Johannes and Mousa, Shaaban and Wischmeyer, Erhard and Roewer, Norbert and Brack, Alexander}, title = {The Connection of Monocytes and Reactive Oxygen Species in Pain}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0063564}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96669}, year = {2013}, abstract = {The interplay of specific leukocyte subpopulations, resident cells and proalgesic mediators results in pain in inflammation. Proalgesic mediators like reactive oxygen species (ROS) and downstream products elicit pain by stimulation of transient receptor potential (TRP) channels. The contribution of leukocyte subpopulations however is less clear. Local injection of neutrophilic chemokines elicits neutrophil recruitment but no hyperalgesia in rats. In meta-analyses the monocytic chemoattractant, CCL2 (monocyte chemoattractant protein-1; MCP-1), was identified as an important factor in the pathophysiology of human and animal pain. In this study, intraplantar injection of CCL2 elicited thermal and mechanical pain in Wistar but not in Dark Agouti (DA) rats, which lack p47phox, a part of the NADPH oxidase complex. Inflammatory hyperalgesia after complete Freund's adjuvant (CFA) as well as capsaicin-induced hyperalgesia and capsaicin-induced current flow in dorsal root ganglion neurons in DA were comparable to Wistar rats. Macrophages from DA expressed lower levels of CCR2 and thereby migrated less towards CCL2 and formed limited amounts of ROS in vitro and 4-hydroxynonenal (4-HNE) in the tissue in response to CCL2 compared to Wistar rats. Local adoptive transfer of peritoneal macrophages from Wistar but not from DA rats reconstituted CCL2-triggered hyperalgesia in leukocyte-depleted DA and Wistar rats. A pharmacological stimulator of ROS production (phytol) restored CCL2-induced hyperalgesia in vivo in DA rats. In Wistar rats, CCL2-induced hyperalgesia was completely blocked by superoxide dismutase (SOD), catalase or tempol. Likewise, inhibition of NADPH oxidase by apocynin reduced CCL2-elicited hyperalgesia but not CFA-induced inflammatory hyperalgesia. In summary, we provide a link between CCL2, CCR2 expression on macrophages, NADPH oxidase, ROS and the development CCL2-triggered hyperalgesia, which is different from CFA-induced hyperalgesia. The study further supports the impact of CCL2 and ROS as potential targets in pain therapy.}, language = {en} } @article{MuellerFiebigWeidaueretal.2013, author = {Mueller, Thomas D. and Fiebig, Juliane E. and Weidauer, Stella E. and Qiu, Li-Yan and Bauer, Markus and Schmieder, Peter and Beerbaum, Monika and Zhang, Jin-Li and Oschkinat, Hartmut and Sebald, Walter}, title = {The Clip-Segment of the von Willebrand Domain 1 of the BMP Modulator Protein Crossveinless 2 Is Preformed}, series = {Molecules}, journal = {Molecules}, doi = {10.3390/molecules181011658}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97196}, year = {2013}, abstract = {Bone Morphogenetic Proteins (BMPs) are secreted protein hormones that act as morphogens and exert essential roles during embryonic development of tissues and organs. Signaling by BMPs occurs via hetero-oligomerization of two types of serine/threonine kinase transmembrane receptors. Due to the small number of available receptors for a large number of BMP ligands ligand-receptor promiscuity presents an evident problem requiring additional regulatory mechanisms for ligand-specific signaling. Such additional regulation is achieved through a plethora of extracellular antagonists, among them members of the Chordin superfamily, that modulate BMP signaling activity by binding. The key-element in Chordin-related antagonists for interacting with BMPs is the von Willebrand type C (VWC) module, which is a small domain of about 50 to 60 residues occurring in many different proteins. Although a structure of the VWC domain of the Chordin-member Crossveinless 2 (CV2) bound to BMP-2 has been determined by X-ray crystallography, the molecular mechanism by which the VWC domain binds BMPs has remained unclear. Here we present the NMR structure of the Danio rerio CV2 VWC1 domain in its unbound state showing that the key features for high affinity binding to BMP-2 is a pre-oriented peptide loop.}, language = {en} } @article{SzaboPapinZornetal.2013, author = {Szab{\´o}, {\´A}ron and Papin, Christian and Zorn, Daniela and Ponien, Prishila and Weber, Frank and Raabe, Thomas and Rouyer, Fran{\c{c}}ois}, title = {The CK2 Kinase Stabilizes CLOCK and Represses Its Activity in the Drosophila Circadian Oscillator}, series = {PLoS Biology}, volume = {11}, journal = {PLoS Biology}, number = {8}, issn = {1545-7885}, doi = {10.1371/journal.pbio.1001645}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127234}, pages = {e1001645}, year = {2013}, abstract = {Phosphorylation is a pivotal regulatory mechanism for protein stability and activity in circadian clocks regardless of their evolutionary origin. It determines the speed and strength of molecular oscillations by acting on transcriptional activators and their repressors, which form negative feedback loops. In Drosophila, the CK2 kinase phosphorylates and destabilizes the PERIOD (PER) and TIMELESS (TIM) proteins, which inhibit CLOCK (CLK) transcriptional activity. Here we show that CK2 also targets the CLK activator directly. Downregulating the activity of the catalytic alpha subunit of CK2 induces CLK degradation, even in the absence of PER and TIM. Unexpectedly, the regulatory beta subunit of the CK2 holoenzyme is not required for the regulation of CLK stability. In addition, downregulation of \(CK2\alpha\) activity decreases CLK phosphorylation and increases per and tim transcription. These results indicate that CK2 inhibits CLK degradation while reducing its activity. Since the CK1 kinase promotes CLK degradation, we suggest that CLK stability and transcriptional activity result from counteracting effects of CK1 and CK2.}, language = {en} } @article{BuchbergerBoehm2013, author = {Buchberger, Alexander and B{\"o}hm, Stephanie}, title = {The Budding Yeast Cdc48Shp1 Complex Promotes Cell Cycle Progression by Positive Regulation of Protein Phosphatase 1 (Glc7)}, series = {PLoS One}, journal = {PLoS One}, doi = {10.1371/journal.pone.0056486}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96073}, year = {2013}, abstract = {The conserved, ubiquitin-selective AAA ATPase Cdc48 regulates numerous cellular processes including protein quality control, DNA repair and the cell cycle. Cdc48 function is tightly controlled by a multitude of cofactors mediating substrate specificity and processing. The UBX domain protein Shp1 is a bona fide substrate-recruiting cofactor of Cdc48 in the budding yeast S. cerevisiae. Even though Shp1 has been proposed to be a positive regulator of Glc7, the catalytic subunit of protein phosphatase 1 in S. cerevisiae, its cellular functions in complex with Cdc48 remain largely unknown. Here we show that deletion of the SHP1 gene results in severe growth defects and a cell cycle delay at the metaphase to anaphase transition caused by reduced Glc7 activity. Using an engineered Cdc48 binding-deficient variant of Shp1, we establish the Cdc48Shp1 complex as a critical regulator of mitotic Glc7 activity. We demonstrate that shp1 mutants possess a perturbed balance of Glc7 phosphatase and Ipl1 (Aurora B) kinase activities and show that hyper-phosphorylation of the kinetochore protein Dam1, a key mitotic substrate of Glc7 and Ipl1, is a critical defect in shp1. We also show for the first time a physical interaction between Glc7 and Shp1 in vivo. Whereas loss of Shp1 does not significantly affect Glc7 protein levels or localization, it causes reduced binding of the activator protein Glc8 to Glc7. Our data suggest that the Cdc48Shp1 complex controls Glc7 activity by regulating its interaction with Glc8 and possibly further regulatory subunits.}, language = {en} } @article{SchultzTerhoeven2013, author = {Schultz, J{\"o}rg and Terhoeven, Niklas}, title = {The bilaterian roots of cordon-bleu}, series = {BMC Research Notes}, journal = {BMC Research Notes}, doi = {10.1186/1756-0500-6-393}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97161}, year = {2013}, abstract = {Background The actin cytoskeleton is essential for many physiological processes of eukaryotic cells. The emergence of new actin fibers is initiated by actin nucleators. Whereas most of them are evolutionary old, the cordon-bleu actin nucleator is classified as vertebrate specific. Findings Using sensitive methods for sequence similarity detection, we identified homologs of cordon-bleu not only in non-vertebrate chordates but also in arthropods, molluscs, annelids and platyhelminthes. These genes contain only a single WH2 domain and therefore resemble more the vertebrate cordon-bleu related 1 protein than the three WH2 domain containing cordon-bleu. Furthermore, we identified a homolog of the N-terminal, ubiquitin like, cobl domain of cordon-bleu in the cnidarian Nematostella vectensis. Conclusion Our results suggest that the ur-form of the cordon-bleu protein family evolved already with the emergence of the bilateria by the combination of existing cobl and WH2 domains. Following a vertebrate specific gene-duplication, one copy gained two additional WH2 domains leading to the actin nucleating cordon-bleu. The function of the ur-form of the cordon-bleu protein family is so far unknown. The identification of a homolog in the model organism Drosophila melanogaster could facilitate its experimental characterization.}, language = {en} } @article{LutzHeuerBehlichetal.2013, author = {Lutz, Manfred B. and Heuer, Marion and Behlich, Anna-Sophie and Lee, Ji-Sook and Ribechini, Eliana and Jo, Eun-Kyeong}, title = {The 30-kDa and 38-kDa antigens from Mycobacterium tuberculosis induce partial maturation of human dendritic cells shifting CD4+ T cell responses towards IL-4 production}, series = {BMC Immunology}, journal = {BMC Immunology}, doi = {10.1186/1471-2172-14-48}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96871}, year = {2013}, abstract = {Background Mycobacterium tuberculosis (Mtb) infections are still a major cause of death among all infectious diseases. Although 99\% of individuals infected with Mtb develop a CD4+ Th1 and CD8+ T cell mediated immunity as measured by tuberculin skin test, this results only in partial protection and Mtb vaccines are not effective. Deviation of immune responses by pathogens towards a Th2 profile is a common mechanism of immune evasion, typically leading to the persistence of the microbes. Results Here we tested the stimulatory capacity of selective Mtb antigens on human monocyte-derived dendritic cell (DC) maturation and cytokine production. DC maturation markers CD80, CD86 and CD83 were readily upregulated by H37Ra- and H37Rv-associated antigens, the 30-kDa (from Ag85 B complex) and 38-KDa Mtb antigens only partially induced these markers. All Mtb antigens induced variable levels of IL-6 and low levels of IL-10, there was no release of IL-12p70 detectable. Substantial IL-12p40 production was restricted to LPS or H37Ra and H37Rv preparations. Although the proliferation levels of primary T cell responses were comparable using all the differentially stimulated DC, the 30-kDa and 38-kDa antigens showed a bias towards IL-4 secretion of polarized CD4+ T cells after secondary stimulation as compared to H37Ra and H37Rv preparations. Conclusion Together our data indicate that 30-kDa and 38-kDa Mtb antigens induced only partial DC maturation shifting immune responses towards a Th2 profile.}, language = {en} } @article{HanKampikGrehnetal.2013, author = {Han, Hong and Kampik, Daniel and Grehn, Franz and Schlunck, G{\"u}nther}, title = {TGF-beta 2-Induced Invadosomes in Human Trabecular Meshwork Cells}, series = {PLoS ONE}, volume = {8}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0070595}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130074}, pages = {e70595}, year = {2013}, abstract = {Primary open-angle glaucoma (POAG) is a leading cause of blindness due to chronic degeneration of retinal ganglion cells and their optic nerve axons. It is associated with disturbed regulation of intraocular pressure, elevated intraocular levels of TGF-β2, aberrant extracellular matrix (ECM) deposition and increased outflow resistance in the trabecular meshwork (TM). The mechanisms underlying these changes are not fully understood. Cell-matrix interactions have a decisive role in TM maintenance and it has been suggested that TGF-β-induced inhibition of matrix metalloproteases may drive aberrant ECM deposition in POAG. Invadopodia and podosomes (invadosomes) are distinct sites of cell-matrix interaction and localized matrix-metalloprotease (MMP) activity. Here, we report on the effects of TGF-β2 on invadosomes in human trabecular meshwork cells. Human TM (HTM) cells were derived from donor tissue and pretreated with vehicle or TGF-β2 (2 ng/ml) for 3d. Invadosomes were studied in ECM degradation assays, protein expression and MMP-2 activity were assessed by western blot and zymography and ECM protein transcription was detected by RT-qPCR. HTM cells spontaneously formed podosomes and invadopodia as detected by colocalization of Grb2 or Nck1 to sites of gelatinolysis. Pretreatment with TGF-β2 enhanced invadosomal proteolysis and zymographic MMP-2 activity as well as MMP-2, TIMP-2 and PAI-1 levels in HTM cell culture supernatants. Rho-kinase inhibition by H1152 blocked the effects of TGF-β2. Concomitant transcription of fibronectin and collagens-1, -4 and -6 was increased by TGF-β2 and fibrillar fibronectin deposits were observed in areas of invadosomal ECM remodelling. In contrast to a current hypothesis, our data indicate that TGF-β2 induces an active ECM remodelling process in TM cells, characterized by concurrent increases in localized ECM digestion and ECM expression, rather than a mere buildup of material due to a lack of degradation. Invadosomal cell adhesion and signaling may thus have a role in POAG pathophysiology.}, language = {en} } @article{StotzMuellerZoelleretal.2013, author = {Stotz, Henrik U. and Mueller, Stefan and Zoeller, Maria and Mueller, Martin J. and Berger, Susanne}, title = {TGA transcription factors and jasmonate-independent COI1 signalling regulate specific plant responses to reactive oxylipins}, series = {Journal of Experimental Botany}, volume = {64}, journal = {Journal of Experimental Botany}, number = {4}, doi = {10.1093/jxb/ers389}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132318}, pages = {963-975}, year = {2013}, abstract = {Jasmonates and phytoprostanes are oxylipins that regulate stress responses and diverse physiological and developmental processes. 12-Oxo-phytodienoic acid (OPDA) and phytoprostanes are structurally related electrophilic cyclopentenones, which activate similar gene expression profiles that are for the most part different from the action of the cyclopentanone jasmonic acid (JA) and its biologically active amino acid conjugates. Whereas JA-isoleucine signals through binding to COI1, the bZIP transcription factors TGA2, TGA5, and TGA6 are involved in regulation of gene expression in response to phytoprostanes. Here root growth inhibition and target gene expression were compared after treatment with JA, OPDA, or phytoprostanes in mutants of the COI1/MYC2 pathway and in different TGA factor mutants. Inhibition of root growth by phytoprostanes was dependent on COI1 but independent of jasmonate biosynthesis. In contrast, phytoprostane-responsive gene expression was strongly dependent on TGA2, TGA5, and TGA6, but not dependent on COI1, MYC2, TGA1, and TGA4. Different mutant and overexpressing lines were used to determine individual contributions of TGA factors to cyclopentenone-responsive gene expression. Whereas OPDA-induced expression of the cytochrome P450 gene CYP81D11 was primarily regulated by TGA2 and TGA5, the glutathione S-transferase gene GST25 and the OPDA reductase gene OPR1 were regulated by TGA5 and TGA6, but less so by TGA2. These results support the model that phytoprostanes and OPDA regulate differently (i) growth responses, which are COI1 dependent but jasmonate independent; and (ii) lipid stress responses, which are strongly dependent on TGA2, TGA5, and TGA6. Identification of molecular components in cyclopentenone signalling provides an insight into novel oxylipin signal transduction pathways.}, language = {en} } @phdthesis{Krauss2013, author = {Krauß, Martin Bernhard}, title = {Testing Models with Higher Dimensional Effective Interactions at the LHC and Dark Matter Experiments}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-94519}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Dark matter and non-zero neutrino masses are possible hints for new physics beyond the Standard Model of particle physics. Such potential consequences of new physics can be described by effective field theories in a model independent way. It is possible that the dominant contribution to low-energy effects of new physics is generated by operators of dimension d>5, e.g., due to an additional symmetry. Since these are more suppressed than the usually discussed lower dimensional operators, they can lead to extremly weak interactions even if new physics appears at comparatively low scales. Thus neutrino mass models can be connected to TeV scale physics, for instance. The possible existence of TeV scale particles is interesting, since they can be potentially observed at collider experiments, such as the Large Hadron Collider. Hence, we first recapitulate the generation of neutrino masses by higher dimensional effective operators in a supersymmetric framework. In addition, we discuss processes that can be used to test these models at the Large Hadron Collider. The introduction of new particles can affect the running of gauge couplings. Hence, we study the compatibilty of these models with Grand Unified Theories. The required extension of these models can imply the existence of new heavy quarks, which requires the consideration of cosmological constraints. Finally, higher dimensional effective operators can not only generate small neutrino masses. They also can be used to discuss the interactions relevant for dark matter detection experiments. Thus we apply the methods established for the study of neutrino mass models to the systematic discussion of higher dimensional effective operators generating dark matter interactions.}, subject = {Neutrino}, language = {en} } @article{LueckerathLapaSpahmannetal.2013, author = {L{\"u}ckerath, Katharina and Lapa, Constantin and Spahmann, Annika and J{\"o}rg, Gerhard and Samnick, Samuel and Rosenwald, Andreas and Einsele, Herrmann and Knop, Stefan and Buck, Andreas}, title = {Targeting Paraprotein Biosynthesis for Non-Invasive Characterization of Myeloma Biology}, doi = {10.1371/journal.pone.0084840}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-111319}, year = {2013}, abstract = {Purpose Multiple myeloma is a hematologic malignancy originating from clonal plasma cells. Despite effective therapies, outcomes are highly variable suggesting marked disease heterogeneity. The role of functional imaging for therapeutic management of myeloma, such as positron emission tomography with 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG-PET), remains to be determined. Although some studies already suggested a prognostic value of 18F-FDG-PET, more specific tracers addressing hallmarks of myeloma biology, e.g. paraprotein biosynthesis, are needed. This study evaluated the amino acid tracers L-methyl-[11C]-methionine (11C-MET) and [18F]-fluoroethyl-L-tyrosine (18F-Fet) for their potential to image myeloma and to characterize tumor heterogeneity. Experimental Design To study the utility of 11C-MET, 18F-Fet and 18F-FDG for myeloma imaging, time activity curves were compared in various human myeloma cell lines (INA-6, MM1.S, OPM-2) and correlated to cell-biological characteristics, such as marker gene expression and immunoglobulin levels. Likewise, patient-derived CD138+ plasma cells were characterized regarding uptake and biomedical features. Results Using myeloma cell lines and patient-derived CD138+ plasma cells, we found that the relative uptake of 11C-MET exceeds that of 18F-FDG 1.5- to 5-fold and that of 18F-Fet 7- to 20-fold. Importantly, 11C-MET uptake significantly differed between cell types associated with worse prognosis (e.g. t(4;14) in OPM-2 cells) and indolent ones and correlated with intracellular immunoglobulin light chain and cell surface CD138 and CXCR4 levels. Direct comparison of radiotracer uptake in primary samples further validated the superiority of 11C-MET. Conclusion These data suggest that 11C-MET might be a versatile biomarker for myeloma superior to routine functional imaging with 18F-FDG regarding diagnosis, risk stratification, prognosis and discrimination of tumor subtypes.}, language = {en} } @article{DiessnerBruttelBeckeretal.2013, author = {Diessner, Joachim and Bruttel, Valentin and Becker, Kathrin and Pawlik, Miriam and Stein, Roland and H{\"a}usler, Sebastian and Dietl, Johannes and Wischhusen, J{\"o}rg and H{\"o}nig, Arnd}, title = {Targeting breast cancer stem cells with HER2-specific antibodies and natural killer cells}, series = {American Journal of Cancer Research}, volume = {3}, journal = {American Journal of Cancer Research}, number = {2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128633}, pages = {221-220}, year = {2013}, abstract = {Breast cancer is the most common cancer among women worldwide. Every year, nearly 1.4 million new cases of breast cancer are diagnosed, and about 450.000 women die of the disease. Approximately 15-25\% of breast cancer cases exhibit increased quantities of the trans-membrane receptor tyrosine kinase human epidermal growth factor receptor 2 (HER2) on the tumor cell surface. Previous studies showed that blockade of this HER2 proto-oncogene with the antibody trastuzumab substantially improved the overall survival of patients with this aggressive type of breast cancer. Recruitment of natural killer (NK) cells and subsequent induction of antibody-dependent cell-mediated cytotoxicity (ADCC) contributed to this beneficial effect. We hypothesized that antibody binding to HER2-positive breast cancer cells and thus ADCC might be further improved by synergistically applying two different HER2-specific antibodies, trastuzumab and pertuzumab. We found that tumor cell killing via ADCC was increased when the combination of trastuzumab, pertuzumab, and NK cells was applied to HER2-positive breast cancer cells, as compared to the extent of ADCC induced by a single antibody. Furthermore, a subset of \(CD44^{high}CD24^{low}HER2^{low}\) cells, which possessed characteristics of cancer stem cells, could be targeted more efficiently by the combination of two HER2-specific antibodies compared to the efficiency of one antibody. These in vitro results demonstrated the immunotherapeutic benefit achieved by the combined application of trastuzumab and pertuzumab. These findings are consistent with the positive results of the clinical studies, CLEOPATRA and NEOSPHERE, conducted with patients that had HER2-positive breast cancer. Compared to a single antibody treatment, the combined application of trastuzumab and pertuzumab showed a stronger ADCC effect and improved the targeting of breast cancer stem cells.}, language = {en} } @article{MuellerWindhofMaximovetal.2013, author = {M{\"u}ller, Sara and Windhof, Indra M. and Maximov, Vladimir and Jurkowski, Tomasz and Jeltsch, Albert and F{\"o}rstner, Konrad U. and Sharma, Cynthia M. and Gr{\"a}f, Ralph and Nellen, Wolfgang}, title = {Target recognition, RNA methylation activity and transcriptional regulation of the Dictyostelium discoideum Dnmt2-homologue (DnmA)}, series = {Nucleic Acids Research}, volume = {41}, journal = {Nucleic Acids Research}, number = {18}, issn = {1362-4962}, doi = {10.1093/nar/gkt634}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-123149}, pages = {8615-8627}, year = {2013}, abstract = {Although the DNA methyltransferase 2 family is highly conserved during evolution and recent reports suggested a dual specificity with stronger activity on transfer RNA (tRNA) than DNA substrates, the biological function is still obscure. We show that the Dictyostelium discoideum Dnmt2-homologue DnmA is an active tRNA methyltransferase that modifies C38 in \(tRNA^{Asp(GUC)}\) in vitro and in vivo. By an ultraviolet-crosslinking and immunoprecipitation approach, we identified further DnmA targets. This revealed specific tRNA fragments bound by the enzyme and identified \(tRNA^{Glu(CUC/UUC)}\) and \(tRNA^{Gly(GCC)}\) as new but weaker substrates for both human Dnmt2 and DnmA in vitro but apparently not in vivo. Dnmt2 enzymes form transient covalent complexes with their substrates. The dynamics of complex formation and complex resolution reflect methylation efficiency in vitro. Quantitative PCR analyses revealed alterations in dnmA expression during development, cell cycle and in response to temperature stress. However, dnmA expression only partially correlated with tRNA methylation in vivo. Strikingly, dnmA expression in the laboratory strain AX2 was significantly lower than in the NC4 parent strain. As expression levels and binding of DnmA to a target in vivo are apparently not necessarily accompanied by methylation, we propose an additional biological function of DnmA apart from methylation.}, language = {en} } @article{SchwarzRemerNahrendorfetal.2013, author = {Schwarz, Tobias and Remer, Katharina A. and Nahrendorf, Wiebke and Masic, Anita and Siewe, Lisa and M{\"u}ller, Werner and Roers, Axel and Moll, Heidrun}, title = {T Cell-Derived IL-10 Determines Leishmaniasis Disease Outcome and Is Suppressed by a Dendritic Cell Based Vaccine}, series = {PLoS Pathogens}, volume = {9}, journal = {PLoS Pathogens}, number = {6}, doi = {10.1371/journal.ppat.1003476}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-130385}, pages = {e1003476}, year = {2013}, abstract = {Abstract In the murine model of Leishmania major infection, resistance or susceptibility to the parasite has been associated with the development of a Th1 or Th2 type of immune response. Recently, however, the immunosuppressive effects of IL-10 have been ascribed a crucial role in the development of the different clinical correlates of Leishmania infection in humans. Since T cells and professional APC are important cellular sources of IL-10, we compared leishmaniasis disease progression in T cell-specific, macrophage/neutrophil-specific and complete IL-10-deficient C57BL/6 as well as T cell-specific and complete IL-10-deficient BALB/c mice. As early as two weeks after infection of these mice with L. major, T cell-specific and complete IL-10-deficient animals showed significantly increased lesion development accompanied by a markedly elevated secretion of IFN-γ or IFN-γ and IL-4 in the lymph nodes draining the lesions of the C57BL/6 or BALB/c mutants, respectively. In contrast, macrophage/neutrophil-specific IL-10-deficient C57BL/6 mice did not show any altered phenotype. During the further course of disease, the T cell-specific as well as the complete IL-10-deficient BALB/c mice were able to control the infection. Furthermore, a dendritic cell-based vaccination against leishmaniasis efficiently suppresses the early secretion of IL-10, thus contributing to the control of parasite spread. Taken together, IL-10 secretion by T cells has an influence on immune activation early after infection and is sufficient to render BALB/c mice susceptible to an uncontrolled Leishmania major infection. Author Summary The clinical symptoms caused by infections with Leishmania parasites range from self-healing cutaneous to uncontrolled visceral disease and depend not only on the parasite species but also on the type of the host's immune response. It is estimated that 350 million people worldwide are at risk, with a global incidence of 1-1.5 million cases of cutaneous and 500,000 cases of visceral leishmaniasis. Murine leishmaniasis is the best-characterized model to elucidate the mechanisms underlying resistance or susceptibility to Leishmania major parasites in vivo. Using T cell-specific and macrophage-specific mutant mice, we demonstrate that abrogating the secretion of the immunosuppressive cytokine IL-10 by T cells is sufficient to render otherwise susceptible mice resistant to an infection with the pathogen. The healing phenotype is accompanied by an elevated specific inflammatory immune response very early after infection. We further show that dendritic cell-based vaccination against leishmaniasis suppresses the early secretion of IL-10 following challenge infection. Thus, our study unravels a molecular mechanism critical for host immune defense, aiding in the development of an effective vaccine against leishmaniasis.}, language = {en} } @article{BuderGesierichGelbrichetal.2013, author = {Buder, Kristina and Gesierich, Anja and Gelbrich, G{\"o}tz and Goebeler, Matthias}, title = {Systemic treatment of metastatic uveal melanoma: review of literature and future perspectives}, series = {Cancer Medicine}, volume = {2}, journal = {Cancer Medicine}, number = {5}, doi = {10.1002/cam4.133}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97175}, pages = {674-686}, year = {2013}, abstract = {Up to 50\% of patients with uveal melanoma develop metastatic disease with poor prognosis. Regional, mainly liver-directed, therapies may induce limited tumor responses but do not improve overall survival. Response rates of metastatic uveal melanoma (MUM) to systemic chemotherapy are poor. Insights into the molecular biology of MUM recently led to investigation of new drugs. In this study, to compare response rates of systemic treatment for MUM we searched Pubmed/Web of Knowledge databases and ASCO website (1980-2013) for "metastatic/uveal/melanoma" and "melanoma/eye." Forty studies (one case series, three phase I, five pilot, 22 nonrandomized, and two randomized phase II, one randomized phase III study, data of three expanded access programs, three retrospective studies) with 841 evaluable patients were included in the numeric outcome analysis. Complete or partial remissions were observed in 39/841 patients (overall response rate [ORR] 4.6\%; 95\% confidence intervals [CI] 3.3-6.3\%), no responses were observed in 22/40 studies. Progression-free survival ranged from 1.8 to 7.2, median overall survival from 5.2 to 19.0 months as reported in 21/40 and 26/40 studies, respectively. Best responses were seen for chemoimmunotherapy (ORR 10.3\%; 95\% CI 4.8-18.7\%) though mainly in first-line patients. Immunotherapy with ipilimumab, antiangiogenetic approaches, and kinase inhibitors have not yet proven to be superior to chemotherapy. MEK inhibitors are currently investigated in a phase II trial with promising preliminary data. Despite new insights into genetic and molecular background of MUM, satisfying systemic treatment approaches are currently lacking. Study results of innovative treatment strategies are urgently awaited.}, language = {en} } @article{OjhaForsterKumaretal.2013, author = {Ojha, Animesh K. and Forster, Stefan and Kumar, Sumeet and Vats, Siddharth and Negi, Sangeeta and Fischer, Ingo}, title = {Synthesis of well-dispersed silver nanorods of different aspect ratios and their antimicrobial properties against gram positive and negative bacterial strains}, series = {Journal of Nanobiotechnology}, volume = {11}, journal = {Journal of Nanobiotechnology}, number = {42}, doi = {10.1186/1477-3155-11-42}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-132222}, year = {2013}, abstract = {In the present contribution, we describe the synthesis of highly dispersed silver nanorods (NRs) of different aspect ratios using a chemical route. The shape and size of the synthesized NRs were characterized by Transmission Electron Microscopy (TEM) and UV-visible spectroscopy. Longitudinal and transverse absorptions bands confirm the rod type structure. The experimentally recorded UV-visible spectra of NRs solutions were fitted by using an expression of the extinction coefficient for rod like nano structures under the dipole approximation. Simulated and experimentally observed UV-visible spectra were compared to determine the aspect ratios (R) of NRs. The average values of R for NR1, NR2 and NR3 solutions are estimated to be 3.0 ± 0.1, 1.8 ± 0.1 and 1.2 ± 0.1, respectively. These values are in good agreement with those obtained by TEM micrographs. The silver NRs of known aspect ratios are used to study antimicrobial activities against B. subtilis (gram positive) and E. coli (gram negative) microbes. We observed that the NRs of intermediate aspect ratio (R = 1.8) have greater antimicrobial effect against both, B. subtilis (gram positive) and E. coli (gram negative). The NRs of aspect ratio, R = 3.0 has better antimicrobial activities against gram positive than on the gram negative.}, language = {en} } @article{OjhaForsterKumaretal.2013, author = {Ojha, Animesh K. and Forster, Stefan and Kumar, Sumeet and Vats, Siddharth and Negi, Segeeta and Fischer, Ingo}, title = {Synthesis of well-dispersed silver nanorods of different aspect ratios and their antimicrobial properties against gram positive and negative bacterial strains}, series = {Journal of Nanobiotechnology}, volume = {11}, journal = {Journal of Nanobiotechnology}, number = {42}, issn = {1477-3155}, doi = {10.1186/1477-3155-11-42}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122837}, year = {2013}, abstract = {In the present contribution, we describe the synthesis of highly dispersed silver nanorods (NRs) of different aspect ratios using a chemical route. The shape and size of the synthesized NRs were characterized by Transmission Electron Microscopy (TEM) and UV-visible spectroscopy. Longitudinal and transverse absorptions bands confirm the rod type structure. The experimentally recorded UV-visible spectra of NRs solutions were fitted by using an expression of the extinction coefficient for rod like nano structures under the dipole approximation. Simulated and experimentally observed UV-visible spectra were compared to determine the aspect ratios (R) of NRs. The average values of R for NR1, NR2 and NR3 solutions are estimated to be 3.0 +/- 0.1, 1.8 +/- 0.1 and 1.2 +/- 0.1, respectively. These values are in good agreement with those obtained by TEM micrographs. The silver NRs of known aspect ratios are used to study antimicrobial activities against B. subtilis (gram positive) and E. coli (gram negative) microbes. We observed that the NRs of intermediate aspect ratio (R = 1.8) have greater antimicrobial effect against both, B. subtilis (gram positive) and E. coli (gram negative). The NRs of aspect ratio, R = 3.0 has better antimicrobial activities against gram positive than on the gram negative.}, language = {en} } @phdthesis{Mandel2013, author = {Mandel, Karl}, title = {Synthesis and Characterisation of Superparamagnetic Nanocomposite Particles for Water Purification and Resources Recovery}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-81208}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Superparamagnetic nanocomposite microparticles, compromised of magnetite nanoparticles in a silica matrix, have been synthesised and surface-modified to act as adsorbers for substances (e.g. toxic heavy metals or valuable resources) dissolved in fluids like water. The particles can be used for a magnetic-extraction-assisted separation process of these target substances which thereby can be recovered from the fluid.}, subject = {Magnetisches Trennverfahren}, language = {en} } @article{ReichertSchmalzlPrageretal.2013, author = {Reichert, Johannes and Schmalzl, Jonas and Prager, Patrick and Gilbert, Fabian and Quent, Verena M. C. and Steinert, Andre F. and Rudert, Maximilian and N{\"o}th, Ulrich}, title = {Synergistic effect of Indian hedgehog and bone morphogenetic protein-2 gene transfer to increase the osteogenic potential of human mesenchymal stem cells}, series = {Stem Cell Research \& Therapy}, journal = {Stem Cell Research \& Therapy}, doi = {10.1186/scrt316}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-97010}, year = {2013}, abstract = {Introduction To stimulate healing of large bone defects research has concentrated on the application of mesenchymal stem cells (MSCs). Methods In the present study, we induced the overexpression of the growth factors bone morphogenetic protein 2 (BMP-2) and/or Indian hedgehog (IHH) in human MSCs by adenoviral transduction to increase their osteogenic potential. GFP and nontransduced MSCs served as controls. The influence of the respective genetic modification on cell metabolic activity, proliferation, alkaline phosphatase (ALP) activity, mineralization in cell culture, and osteogenic marker gene expression was investigated. Results Transduction had no negative influence on cell metabolic activity or proliferation. ALP activity showed a typical rise-and-fall pattern with a maximal activity at day 14 and 21 after osteogenic induction. Enzyme activity was significantly higher in groups cultured with osteogenic media. The overexpression of BMP-2 and especially IHH + BMP-2 resulted in a significantly higher mineralization after 28 days. This was in line with obtained quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analyses, which showed a significant increase in osteopontin and osteocalcin expression for osteogenically induced BMP-2 and IHH + BMP-2 transduced cells when compared with the other groups. Moreover, an increase in runx2 expression was observed in all osteogenic groups toward day 21. It was again more pronounced for BMP-2 and IHH + BMP-2 transduced cells cultured in osteogenic media. Conclusions In summary, viral transduction did not negatively influence cell metabolic activity and proliferation. The overexpression of BMP-2 in combination with or without IHH resulted in an increased deposition of mineralized extracellular matrix, and expression of osteogenic marker genes. Viral transduction therefore represents a promising means to increase the osteogenic potential of MSCs and the combination of different transgenes may result in synergistic effects.}, language = {en} } @phdthesis{EngelhardtgebChristiansen2013, author = {Engelhardt [geb. Christiansen], Frauke}, title = {Synaptic Connectivity in the Mushroom Body Calyx of Drosophila melanogaster}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85058}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Learning and memory is considered to require synaptic plasticity at presynaptic specializations of neurons. Kenyon cells are the intrinsic neurons of the primary olfactory learning center in the brain of arthropods - the mushroom body neuropils. An olfactory mushroom body memory trace is supposed to be located at the presynapses of Kenyon cells. In the calyx, a sub-compartment of the mushroom bodies, Kenyon cell dendrites receive olfactory input provided via projection neurons. Their output synapses, however, were thought to reside exclusively along their axonal projections outside the calyx, in the mushroom body lobes. By means of high-resolution imaging and with novel transgenic tools, we showed that the calyx of the fruit fly Drosophila melanogaster also comprised Kenyon cell presynapses. At these presynapses, synaptic vesicles were present, which were capable of neurotransmitter release upon stimulation. In addition, the newly identified Kenyon cell presynapses shared similarities with most other presynapses: their active zones, the sites of vesicle fusion, contained the proteins Bruchpilot and Syd-1. These proteins are part of the cytomatrix at the active zone, a scaffold controlling synaptic vesicle endo- and exocytosis. Kenyon cell presynapses were present in γ- and α/β-type KCs but not in α/β-type Kenyon cells. The newly identified Kenyon cell derived presynapses in the calyx are candidate sites for an olfactory associative memory trace. We hypothesize that, as in mammals, recurrent neuronal activity might operate for memory retrieval in the fly olfactory system. Moreover, we present evidence for structural synaptic plasticity in the mushroom body calyx. This is the first demonstration of synaptic plasticity in the central nervous system of Drosophila melanogaster. The volume of the mushroom body calyx can change according to changes in the environment. Also size and numbers of microglomeruli - sub-structures of the calyx, at which projection neurons contact Kenyon cells - can change. We investigated the synapses within the microglomeruli in detail by using new transgenic tools for visualizing presynaptic active zones and postsynaptic densities. Here, we could show, by disruption of the projection neuron - Kenyon cell circuit, that synapses of microglomeruli were subject to activity-dependent synaptic plasticity. Projection neurons that could not generate action potentials compensated their functional limitation by increasing the number of active zones per microglomerulus. Moreover, they built more and enlarged microglomeruli. Our data provide clear evidence for an activity-induced, structural synaptic plasticity as well as for the activity-induced reorganization of the olfactory circuitry in the mushroom body calyx.}, subject = {Taufliege}, language = {en} } @article{MuranyiMalkuschMuelleretal.2013, author = {Muranyi, Walter and Malkusch, Sebastian and M{\"u}ller, Barbara and Heilemann, Mike and Kr{\"a}usslich, Hans-Georg}, title = {Super-Resolution Microscopy Reveals Specific Recruitment of HIV-1 Envelope Proteins to Viral Assembly Sites Dependent on the Envelope C-Terminal Tail}, series = {PLoS Pathogens}, volume = {9}, journal = {PLoS Pathogens}, number = {2}, doi = {10.1371/journal.ppat.1003198}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131235}, pages = {e1003198}, year = {2013}, abstract = {The inner structural Gag proteins and the envelope (Env) glycoproteins of human immunodeficiency virus (HIV-1) traffic independently to the plasma membrane, where they assemble the nascent virion. HIV-1 carries a relatively low number of glycoproteins in its membrane, and the mechanism of Env recruitment and virus incorporation is incompletely understood. We employed dual-color super-resolution microscopy visualizing Gag assembly sites and HIV-1 Env proteins in virus-producing and in Env expressing cells. Distinctive HIV-1 Gag assembly sites were readily detected and were associated with Env clusters that always extended beyond the actual Gag assembly site and often showed enrichment at the periphery and surrounding the assembly site. Formation of these Env clusters depended on the presence of other HIV-1 proteins and on the long cytoplasmic tail (CT) of Env. CT deletion, a matrix mutation affecting Env incorporation or Env expression in the absence of other HIV-1 proteins led to much smaller Env clusters, which were not enriched at viral assembly sites. These results show that Env is recruited to HIV-1 assembly sites in a CT-dependent manner, while Env\((\Delta CT)\) appears to be randomly incorporated. The observed Env accumulation surrounding Gag assemblies, with a lower density on the actual bud, could facilitate viral spread in vivo. Keeping Env molecules on the nascent virus low may be important for escape from the humoral immune response, while cell-cell contacts mediated by surrounding Env molecules could promote HIV-1 transmission through the virological synapse.}, language = {en} } @article{DoerhoeferLammertKraneetal.2013, author = {D{\"o}rh{\"o}fer, Lena and Lammert, Alexander and Krane, Vera and Gorski, Mathias and Banas, Bernhard and Wanner, Christoph and Kr{\"a}mer, Bernhard K. and Heid, Iris M. and B{\"o}ger, Carsten A.}, title = {Study design of DIACORE (DIAbetes COhoRtE) - a cohort study of patients with diabetes mellitus type 2}, series = {BMC Medical Genetics}, volume = {14}, journal = {BMC Medical Genetics}, number = {25}, issn = {1471-2350}, doi = {10.1186/1471-2350-14-25}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-122040}, year = {2013}, abstract = {Background: Diabetes mellitus type 2 (DM2) is highly associated with increased risk for chronic kidney disease (CKD), end stage renal disease (ESRD) and cardiovascular morbidity. Epidemiological and genetic studies generate hypotheses for innovative strategies in DM2 management by unravelling novel mechanisms of diabetes complications, which is essential for future intervention trials. We have thus initiated the DIAbetes COhoRtE study (DIACORE). Methods: DIACORE is a prospective cohort study aiming to recruit 6000 patients of self-reported Caucasian ethnicity with prevalent DM2 for at least 10 years of follow-up. Study visits are performed in University-based recruiting clinics in Germany using standard operating procedures. All prevalent DM2 patients in outpatient clinics surrounding the recruiting centers are invited to participate. At baseline and at each 2-year follow-up examination, patients are subjected to a core phenotyping protocol. This includes a standardized online questionnaire and physical examination to determine incident micro-and macrovascular DM2 complications, malignancy and hospitalization, with a primary focus on renal events. Confirmatory outcome information is requested from patient records. Blood samples are obtained for a centrally analyzed standard laboratory panel and for biobanking of aliquots of serum, plasma, urine, mRNA and DNA for future scientific use. A subset of the cohort is subjected to extended phenotyping, e. g. sleep apnea screening, skin autofluorescence measurement, non-mydriatic retinal photography and non-invasive determination of arterial stiffness. Discussion: DIACORE will enable the prospective evaluation of factors involved in DM2 complication pathogenesis using high-throughput technologies in biosamples and genetic epidemiological studies.}, language = {en} } @phdthesis{Hofmann2013, author = {Hofmann, Sebastian}, title = {Studies on the function and regulation of CD84, GPVI and Orai2 in genetically modified mice}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87949}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Platelet activation and aggregation at sites of vascular injury are essential processes to limit blood loss but they also contribute to arterial thrombosis, which can lead to myocardial infarction and stroke. Stable thrombus formation requires a series of events involving platelet receptors which contribute to adhesion, activation and aggregation of platelets. Regulation of receptor expression by (metallo-)proteinases has been described for several platelet receptors, but the molecular mechanisms are ill-defined. The signaling lymphocyte activation molecule (SLAM) family member CD84 is expressed in immune cells and platelets, however its role in platelet physiology was unclear. In this thesis, CD84 deficient mice were generated and analyzed. In well established in vitro and in vivo assays testing platelet function and thrombus formation, CD84 deficient mice displayed phenotypes indistinguishable from wild-type controls. It was concluded that CD84 in platelets does not function as modulator of thrombus formation, but rather has other functions. In line with this, in the second part of this thesis, a novel regulation mechanism for platelet CD84 was discovered and elucidated. Upon platelet activation, the N-terminus of CD84 was found to be cleaved exclusively by the a disintegrin and metalloproteinase 10 (ADAM10), whereas the intracellular part was cleaved by calpain. In addition, regulation of the platelet activating collagen receptor glycoprotein VI (GPVI) was studied and it was shown that GPVI is in contrast to CD84 differentially regulated by ADAM10 and ADAM17. A novel role of CD84 under pathophysiological conditions was revealed as CD84 deficient mice were protected from ischemic stroke in the model of transient middle cerebral artery occlusion and this protection was based on the lack of CD84 in T cells. Ca2+ is an essential second messenger that facilitates activation of platelets and diverse functions in different eukaryotic cell types. Store-operated Ca2+ entry (SOCE) represents the major mechanism leading to rise in intracellular Ca2+ concentration in non-excitable cells. The Ca2+ sensor STIM1 (stromal interaction molecule 1) and the SOC channel subunit protein Orai1 are established mediators of SOCE in platelets. STIM2 is the major STIM isoform in neurons, but the role of the SOC channel subunit protein Orai2 in platelets and neurons has remained elusive. In the third part of this thesis, Orai2 deficient mice were generated and analyzed. Orai2 was dispensable for platelet function, however, Orai2 deficient mice were protected from ischemic neurodegeneration and this phenotype was attributed to defective SOCE in neurons.}, subject = {Thrombozyt}, language = {en} } @phdthesis{Heydenreich2013, author = {Heydenreich, Nadine}, title = {Studies on the contact-kinin system and macrophage activation in experimental focal cerebral ischemia}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-94534}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Traditionally, ischemic stroke has been regarded as the mere consequence of cessation of cerebral blood flow, e.g. due to the thromboembolic occlusion of a major brain supplying vessel. However, the simple restoration of blood flow via thrombolysis and/or mechanical recanalization alone often does not guarantee a good functional outcome. It appears that secondary detrimental processes are triggered by hypoxia and reoxygenation, which are referred to as ischemia/reperfusion (I/R) injury. During recent years it became evident that, beside thrombosis inflammation and edema formation are key players in the pathophysiology of cerebral ischemia. The contact-kinin system represents an interface between thrombotic, inflammatory and edematous circuits. It connects the intrinsic coagulation pathway with the plasma kallikrein-kinin system (KKS) via coagulation factor FXII. The serine protease inhibitor C1-inhibitor (C1-INH) has a wide spectrum of inhibitory activities and counteracts activation of the contact-kinin system at multiple levels. The first part of the thesis aimed to multimodally interfere with infarct development by C1-INH and to analyze modes of actions of human plasma derived C1-INH Berinert® P in a murine model of focal cerebral ischemia. It was shown that C57BL/6 mice following early application of 15.0 units (U) C1-INH, but not 7.5 U developed reduced brain infarctions by ~60\% and less neurological deficits in the model of transient occlusion of the middle cerebral artery (tMCAO). This protective effect was preserved at more advanced stages of infarction (day 7), without increasing the risk of intracerebral bleeding or affecting normal hemostasis. Less neurological deficits could also be observed with delayed C1-INH treatment, whereas no improvement was achieved in the model of permanent MCAO (pMCAO). Blood-brain-barrier (BBB) damage, inflammation and thrombosis were significantly improved following 15.0 U C1-INH application early after onset of ischemia. Based on its strong antiedematous, antiinflammatory and antithrombotic properties C1-INH constitutes a multifaceted therapeutic compound that protects from ischemic neurodegeneration in 'clinically meaningful' settings. The second part of the thesis addresses the still elusive functional role of macrophages in the early phase of stroke, especially the role of the macrophage-specific adhesion molecule sialoadhesin (Sn). For the first time, sialoadhesin null (Sn-/-) mice, homozygous deficient for Sn on macrophages were subjected to tMCAO to assess the clinical outcome. Neurological and motor function was significantly improved in Sn-/- mice on day 1 after ischemic stroke compared with wildtype (Sn+/+) animals. These clinical improvements were clearly detectable even on day 3 following tMCAO. Infarctions on day 1 were roughly the same size as in Sn+/+ mice and did not grow until day 3. No intracerebral bleeding could be detected at any time point of data acquisition. Twenty four hours after ischemia a strong induction of Sn was detectable in Sn+/+ mice, which was previously observed only on perivascular macrophages in the normal brain. Deletion of Sn on macrophages resulted in less disturbance of the BBB and a reduced number of CD11b+ (specific marker for macrophages/microglia) cells, which, however, was not associated with altered expression levels of inflammatory cytokines. To further analyze the function of macrophages following stroke this thesis took advantage of LysM-Cre+/-/IKK2-/- mice bearing a nuclear factor (NF)-ϰB activation defect in the myeloid lineage, including macrophages. Consequently, macrophages were not able to synthesize inflammatory cytokines under the control of NF-ϰB. Surprisingly, infarct sizes and neurological deficits upon tMCAO were roughly the same in conditional knockout mice and respective wildtype littermates. These findings provide evidence that macrophages do not contribute to tissue damage and neurological deficits, at least, not by release of inflammatory cytokines in the early phase of cerebral ischemia. In contrast, Sn which is initially expressed on perivascular macrophages and upregulated on macrophages/microglia within the parenchyma following stroke, influenced functional outcome.}, subject = {Blut-Hirn-Schranke}, language = {en} } @article{BajdaWieckowskaHebdaetal.2013, author = {Bajda, Marek and Wieckowska, Anna and Hebda, Michalina and Guzior, Natalia and Sotriffer, Christoph A. and Malawska, Barbara}, title = {Structure-Based Search for New Inhibitors of Cholinesterases}, series = {International Journal of Molecular Sciences}, volume = {14}, journal = {International Journal of Molecular Sciences}, number = {3}, doi = {10.3390/ijms14035608}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129423}, pages = {5608-5632}, year = {2013}, abstract = {Cholinesterases are important biological targets responsible for regulation of cholinergic transmission, and their inhibitors are used for the treatment of Alzheimer's disease. To design new cholinesterase inhibitors, of different structure-based design strategies was followed, including the modification of compounds from a previously developed library and a fragment-based design approach. This led to the selection of heterodimeric structures as potential inhibitors. Synthesis and biological evaluation of selected candidates confirmed that the designed compounds were acetylcholinesterase inhibitors with \(IC_{50}\) values in the mid-nanomolar to low micromolar range, and some of them were also butyrylcholinesterase inhibitors.}, language = {en} } @phdthesis{Schiebel2013, author = {Schiebel, Johannes}, title = {Structure-Based Drug Design on Enzymes of the Fatty Acid Biosynthesis Pathway}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69239}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {W{\"a}hrend die Wirkung der meisten gebr{\"a}uchlichen Antibiotika auf einer Beeintr{\"a}chtigung wichtiger bakterieller Prozesse beruht, wirken manche Substanzen durch die St{\"o}rung der Zellmembran-Struktur. Da Fetts{\"a}uren ein essentieller Bestandteil von Membran-Phospholipiden sind, stellt die bakterielle Fetts{\"a}urebiosynthese II (FAS-II) einen relativ wenig erforschten, aber dennoch vielversprechenden Angriffspunkt f{\"u}r die Entwicklung neuer Antibiotika dar. Das wichtige Antituberkulotikum Isoniazid blockiert die mykobakterielle Fetts{\"a}urebiosynthese und ruft dadurch morphologische {\"A}nderungen sowie letztlich die Lyse des Bakteriums hervor. Eine wichtige Erkenntnis war, dass Isoniazid den letzten Schritt des FAS-II Elongationszyklus inhibiert, der durch die Enoyl-ACP Reduktase katalysiert wird. Darauf aufbauend wurden mehrere Programme ins Leben gerufen, die sich zum Ziel gesetzt hatten, neue Molek{\"u}le zu entwickeln, welche dieses Protein verschiedener Pathogene hemmen. Die S. aureus Enoyl-ACP Reduktase (saFabI) ist von besonders großem Interesse, da drei vielversprechende Inhibitoren dieses Proteins entwickelt werden konnten, die momentan in klinischen Studien eingehend untersucht werden. Trotz dieser Erfolgsaussichten waren zum Zeitpunkt, als die vorliegenden Arbeiten aufgenommen wurden, keine Kristallstrukturen von saFabI {\"o}ffentlich verf{\"u}gbar. Daher war es eines der Hauptziele dieser Doktorarbeit, auf der Basis von kristallographischen Experimenten atomar aufgel{\"o}ste Modelle f{\"u}r dieses wichtige Protein zu erzeugen. Durch die Entwicklung einer verl{\"a}sslichen Methode zur Kristallisation von saFabI im Komplex mit NADP+ und Diphenylether-Inhibitoren konnten Kristallstrukturen von 17 verschiedenen tern{\"a}ren Komplexen gel{\"o}st werden. Weitere kristallographische Experimente ergaben zwei apo-Strukturen sowie zwei Strukturen von saFabI im Komplex mit NADPH und 2-Pyridon-Inhibitoren. Basierend auf der nun bekannten saFabI-Struktur konnten Molekulardynamik-Simulationen durchgef{\"u}hrt werden, um zus{\"a}tzliche Erkenntnisse {\"u}ber die Flexibilit{\"a}t dieses Proteins zu erhalten. Die so gewonnenen Informationen {\"u}ber die Struktur und Beweglichkeit des Enzyms dienten in Folge als ideale Grundlage daf{\"u}r, den Erkennungsprozess von Substrat und Inhibitor zu verstehen. Besonders bemerkenswert dabei ist, dass die verschiedenen saFabI Kristallstrukturen Momentaufnahmen entlang der Reaktionskoordinate der Ligandenbindung und des Hydrid-Transfers repr{\"a}sentieren. Dabei verschließt der so genannte Substratbindungsloop das aktive Zentrum des Enzyms allm{\"a}hlich. Die außergew{\"o}hnlich hohe Mobilit{\"a}t von saFabI konnte durch molekulardynamische Simulationen best{\"a}tigt werden. Dies legt nahe, dass die beobachteten {\"A}nderungen der Konformation tats{\"a}chlich an der Aufnahme und Umsetzung des Substrates beteiligt sind. Eine Kette von Wassermolek{\"u}len zwischen dem aktiven Zentrum und einer wassergef{\"u}llten Kavit{\"a}t im Inneren des Tetramers scheint f{\"u}r die Beweglichkeit des Substratbindungsloops und somit f{\"u}r die katalysierte Reaktion von entscheidender Bedeutung zu sein. Außerdem wurde die erstaunliche Beobachtung gemacht, dass der adaptive Substratbindungsprozess mit einem Dimer-Tetramer {\"U}bergang gekoppelt ist, welcher die beobachtete positive Kooperativit{\"a}t der Ligandenbindung erkl{\"a}ren kann. Alles in allem weist saFabI im Vergleich zu FabI Proteinen aus anderen Organismen mehrere außergew{\"o}hnliche Eigenschaften auf, die f{\"u}r die Synthese von verzweigten Fetts{\"a}uren n{\"o}tig sein k{\"o}nnten, welche wiederum f{\"u}r die {\"U}berlebensf{\"a}higkeit von S. aureus im Wirt von Bedeutung sind. Diese Erkenntnis k{\"o}nnte erkl{\"a}ren, warum S. aureus selbst bei Anwesenheit von exogenen Fetts{\"a}uren von FAS-II Inhibitoren abget{\"o}tet werden kann. Somit k{\"o}nnen die gewonnenen atomaren saFabI Modelle einen entscheidenden Beitrag zur Entwicklung neuer Hemmstoffe dieses validierten Angriffszieles leisten. Tats{\"a}chlich konnten die neuen Strukturen genutzt werden, um die Bindungsst{\"a}rken sowie die Verweilzeiten verschiedener saFabI Inhibitoren molekular zu erkl{\"a}ren. Die Struktur von saFabI im Komplex mit dem 2-Pyridon Inhibitor CG400549 hingegen enth{\"u}llte spezifische Wechselwirkungen in der geweiteten Bindetasche des S. aureus Enzyms, welche das geringe Aktivit{\"a}tsspektrum dieses derzeit klinisch erprobten Inhibitors erkl{\"a}ren. Diese Studien schaffen somit eine ideale Voraussetzung f{\"u}r die Entwicklung neuer wirksamer saFabI Inhibitoren, was am Beispiel des 4-Pyridons PT166 belegt werden kann. Im Rahmen der vorliegenden Dissertation konnten außerdem die Strukturen des Enzyms KasA im Komplex mit mehreren Derivaten des Naturstoffs Thiolactomycin gel{\"o}st werden.}, subject = {Staphylococcus aureus}, language = {en} } @article{ScholzSauerWiessneretal.2013, author = {Scholz, M. and Sauer, C. and Wiessner, M. and Nguyen, N. and Scholl, A. and Reinert, F.}, title = {Structure formation in organic thin films observed in real time by energy dispersive near-edge x-ray absorption fine-structure spectroscopy}, series = {New Journal of Physics}, volume = {15}, journal = {New Journal of Physics}, number = {083052}, doi = {10.1088/1367-2630/15/8/083052}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129749}, year = {2013}, abstract = {We study the structure formation of 1,4,5,8-naphthalenetetracarboxylicacid- dianhydride (NTCDA) multilayer films on Ag(111) surfaces by energy dispersive near-edge x-ray absorption fine-structure spectroscopy (NEXAFS) and photoelectron spectroscopy. The time resolution of seconds of the method allows us to identify several sub-processes, which occur during the post-growth three-dimensional structural ordering, as well as their characteristic time scales. After deposition at low temperature the NTCDA molecules are preferentially flat lying and the films exhibit no long-range order. Upon annealing the molecules flip into an upright orientation followed by an aggregation in a transient phase which exists for several minutes. Finally, threedimensional islands are established with bulk-crystalline structure involving substantial mass transport on the surface and morphological roughening. By applying the Kolmogorov-Johnson-Mehl-Avrami model the activation energies of the temperature-driven sub-processes can be derived from the time evolution of the NEXAFS signal.}, language = {en} } @phdthesis{Bollmann2013, author = {Bollmann, Stefan}, title = {Structural Dynamics of Oligopeptides determined by Fluorescence Quenching of Organic Dyes}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-92191}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {For determination of structures and structural dynamics of proteins organic fluorophores are a standard instrument. Intra- and intermolecular contact of biomolecular structures are determined in time-resolved and stationary fluorescence microscopy experiments by quenching of organic fluorophores due to Photoinduced Electron Transfer (PET) and dimerization interactions. Using PET we show in this work that end-to-end contact dynamics of serine-glycine peptides are slowed down by glycosylation. This slow down is due to a change in reaction enthalpy for end-to-end contact and is partly compensated by entropic effects. In a second step we test how dimerization of MR121 fluorophore pairs reports on end-to-end contact dynamics. We show that in aqueous solutions containing strong denaturants MR121 dimerization reports advantageously on contact dynamics for glycine-serine oligopeptides compared to the previously used MR121/tryptophane PET reporters. Then we analyze dimer interactions and quenching properties of different commercially available fluorophores being standards in F{\"o}rster Resonance Energy Transfer (FRET) measurements. Distances in biomolecules are determinable using FRET, but for very flexible biomolecules the analysis of masurement data can be distorted if contact of the two FRET fluorophores is likely. We quantify how strong the quenching of fluorophore pairs with two different or two identical fluorophores is. Dimer spectra and association constants are quantified to estimate if fluophores are applicable in various applications, e.g. in FRET measurements with unstructured peptides and proteins.}, subject = {Fluorophore}, language = {en} } @phdthesis{Andlauer2013, author = {Andlauer, Till Felix Malte}, title = {Structural and Functional Diversity of Synapses in the Drosophila CNS}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85018}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Large-scale anatomical and functional analyses of the connectivity in both invertebrate and mammalian brains have gained intense attention in recent years. At the same time, the understanding of synapses on a molecular level still lacks behind. We have only begun to unravel the basic mechanisms of how the most important synaptic proteins regulate release and reception of neurotransmitter molecules, as well as changes of synaptic strength. Furthermore, little is known regarding the stoichiometry of presynaptic proteins at different synapses within an organism. An assessment of these characteristics would certainly promote our comprehension of the properties of different synapse types. Presynaptic proteins directly influence, for example, the probability of neurotransmitter release as well as mechanisms for short-term plasticity. We have examined the strength of expression of several presynaptic proteins at different synapse types in the central nervous system of Drosophila melanogaster using immunohistochemistry. Clear differences in the relative abundances of the proteins were obvious on different levels: variations in staining intensities appeared from the neuropil to the synaptic level. In order to quantify these differences, we have developed a ratiometric analysis of antibody stainings. By application of this ratiometric method, we could assign average ratios of presynaptic proteins to different synapse populations in two central relays of the olfactory pathway. In this manner, synapse types could be characterized by distinct fingerprints of presynaptic protein ratios. Subsequently, we used the method for the analysis of aberrant situations: we reduced levels of Bruchpilot, a major presynaptic protein, and ablated different synapse or cell types. Evoked changes of ratio fingerprints were proportional to the modifications we had induced in the system. Thus, such ratio signatures are well suited for the characterization of synapses. In order to contribute to our understanding of both the molecular composition and the function of synapses, we also characterized a novel synaptic protein. This protein, Drep-2, is a member of the Dff family of regulators of apoptosis. We generated drep-2 mutants, which did not show an obvious misregulation of apoptosis. By contrast, Drep-2 was found to be a neuronal protein, highly enriched for example at postsynaptic receptor fields of the input synapses of the major learning centre of insects, the mushroom bodies. Flies mutant for drep-2 were viable but lived shorter than wildtypes. Basic synaptic transmission at both peripheral and central synapses was in normal ranges. However, drep-2 mutants showed a number of deficiencies in adaptive behaviours: adult flies were locomotor hyperactive and hypersensitive towards ethanol-induced sedation. Moreover, the mutant animals were heavily impaired in associative learning. In aversive olfactory conditioning, drep-2 mutants formed neither short-term nor anaesthesia-sensitive memories. We could demonstrate that Drep-2 is required in mushroom body intrinsic neurons for normal olfactory learning. Furthermore, odour-evoked calcium transients in these neurons, a prerequisite for learning, were reduced in drep-2 mutants. The impairment of the mutants in olfactory learning could be fully rescued by pharmacological application of an agonist to metabotropic glutamate receptors (mGluRs). Quantitative mass spectrometry of Drep-2 complexes revealed that the protein is associated with a large number of translational repressors, among them the fragile X mental retardation protein FMRP. FMRP inhibits mGluR-mediated protein synthesis. Lack of this protein causes the fragile X syndrome, which constitutes the most frequent monogenic cause of autism. Examination of the performance of drep-2 mutants in courtship conditioning showed that the animals were deficient in both short- and long-term memory. Drep-2 mutants share these phenotypes with fmrp and mGluR mutants. Interestingly, drep-2; fmrp double mutants exhibited normal memory. Thus, we propose a model in which Drep-2 antagonizes FMRP in the regulation of mGluR-dependent protein synthesis. Our hypothesis is supported by the observation that impairments in synaptic plasticity can arise if mGluR signalling is imbalanced in either direction. We suggest that Drep-2 helps in establishing this balance.}, subject = {Taufliege}, language = {en} } @phdthesis{Mishra2013, author = {Mishra, Shambhavi}, title = {Structural and Functional Characterization of the Enzymes Involved in the Menaquinone Biosynthesis and Benzoate Degradation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-90848}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {The present work illustrates the structural and biochemical characterization of two diverse proteins, BadI and MenD from Rhodopseudomonas palustris and Staphylococcus aureus, respectively. BadI or 2-ketocyclohexanecarboxyl-CoA is one of the key enzymes involved in the anaerobic degradation of aromatic compounds. The degradation of aromatic compounds is a vital process for the maintenance of the biogeochemical carbon cycle and bioremediation of xenobiotic compounds, which if present at higher concentrations can cause potential hazards to humans. Due to the relatively inert nature of aromatic compounds, enzymes catalyzing their degradation are of special interest for industrial applications. BadI is one of the key enzymes involved in the anaerobic degradation of aromatic compounds into an aliphatic moiety. The major focus of this study was to provide mechanistic insights into the reaction catalyzed by BadI. BadI belongs to the crotonase superfamily and shares high sequence homology with the family members of MenB or dihydroxynaphthoate synthase. BadI is known to catalyze the cleavage of the cyclic ring of 2-ketocyclohexane carboxyl-CoA by hydrolyzing the C-C bond leading to the formation of the aliphatic compound pimelyl CoA. On the other hand MenB catalyzes the condensation reaction of o-succinylbenzoyl-CoA to dihydroxylnaphthoyl-CoA. A comprehensive amino acid sequence analysis between BadI and MenB showed that the active site residues of MenB from Mycobacterium tuberculosis (mtMenB) are conserved in BadI from Rhodopseudomonas palustris. MenB is involved in the menaquinone biosynthesis pathway and is a potential drug target against Mycobacterium tuberculosis as it has no known human homologs. Due to the high homology between MenB and BadI and the inability to obtain MenB-inhibitor complex structures we extended our interest to BadI to explore a potential substitute model for mtMenB as a drug target. In addition, BadI possesses some unique mechanistic characteristics. As mentioned before, it hydrolyzes the substrate via a retro Dieckmann's reaction contrasting its closest homolog MenB that catalyzes a ring closing reaction through a Dieckmann's reaction. Nevertheless the active site residues in both enzymes seem to be highly conserved. We therefore decided to pursue the structural characterization of BadI to shed light on the similarities and differences between BadI and MenB and thereby provide some insights how they accomplish the contrasting reactions described above. We determined the first structures of BadI, in its apo and a substrate mimic bound form. The crystal structures revealed that the overall fold of BadI is similar to other crotonase superfamily members. However, there is no indication of domain swapping in BadI as observed for MenB. The absence of domain swapping is quite remarkable because the domain swapped C-terminal helical domain in MenB provides a tyrosine that is imperative for catalysis and is also conserved in the BadI sequence. Comparison of the active sites revealed that the C-terminus of BadI folds onto its core in such a way that the conserved tyrosine is located in the same position as in MenB and can form interactions with the ligand molecule. The structure of BadI also confirms the role of a serine and an aspartate in ligand interaction, thus validating that the conserved active site triad participates in the enzymatic reaction. The structures also reveal a noteworthy movement of the active site aspartate that adopts two major conformations. Structural studies further illuminated close proximity of the active site serine to a water and chlorine molecule and to the carbon atom at which the carbonyl group of the true substrate would reside. Biochemical characterization of BadI using enzyme kinetics validated that the suggested active site residues are involved in substrate interaction. However, the role of these residues is very distinct, with the serine assuming a major role. Thus, the present work ascertain the participation of putative active site residues and demonstrates that the active site residues of BadI adopt very distinctive roles compared to their closest homolog MenB. The MenD protein also referred to as SEPHCHC (2-succinyl-5-enolpyruvyl-6- hydroxy-3-cyclohexene-1-carboxylic acid) synthase is one of the enzymes involved in menaquinone biosynthesis in Staphylococcous aureus. Though S. aureus is usually considered as a commensal it can act as a remarkable pathogen when it crosses the epithelium, causing a wide spectrum of disorders ranging from skin infection to life threatening diseases. Small colony variants (SCVs), a slow growing, small sized subpopulation of the bacteria has been associated with persistent, recurrent and antibiotic resistant infections. These variants show autotrophy for thiamine, menaquinone or hemin. Menaquinone is an essential component in the electron transport pathway in gram-positive organisms. Therefore, enzymes partaking in this pathway are attractive drug targets against pathogens such as Mycobacterium tuberculosis and Bacillus subtilis. MenD, an enzyme catalyzing the first irreversible step in the menaquinone biosynthetic pathway has been implicated in the SCV phenotype of S. aureus. In the present work we explored biochemical and structural properties of this important enzyme. Our structural analysis revealed that despite its low sequence identity of 28\%, the overall fold of staphylococcal MenD (saMenD) is similar to Escherichia coli MenD (ecMenD) albeit with some significant disparities. Major structural differences can be observed near the active site region of the protein and are profound in the C-terminal helix and a loop near the active site. The loop contains critical residues for cofactor binding and is well ordered only in the ecMenD-ThDP structure, while in the apo and substrate bound structures of ecMenD the loop is primarily disordered. In our saMenD structure the loop is for the first time completely ordered in the apo form and displays a novel conformation of the cofactor-binding loop. The loop adopts an unusual open conformation and the conserved residues, which are responsible for cofactor binding are located too far away to form a productive complex with the cofactor in this conformation. Additionally, biochemical studies in conjugation with the structural data aided in the identification of the substrate-binding pocket and delineated residues contributing to its binding and catalysis. Thus the present work successfully divulged the unique biochemical and structural characteristics of saMenD.}, subject = {Benzoate}, language = {en} } @phdthesis{Parragh2013, author = {Parragh, Nicolaus}, title = {Strongly Correlated Multi-Orbital Systems : A Continuous-Time Quantum Monte Carlo Analysis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85253}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {In this thesis I present results concerning realistic calculations of correlated fermionic many-body systems. One of the main objectives of this work was the implementation of a hybridization expansion continuous-time quantum Monte Carlo (CT-HYB) algorithm and of a flexible self-consistency loop based on the dynamical mean-field theory (DMFT). DMFT enables us to treat strongly correlated electron systems numerically. After the implementation and extensive testing of the program we investigated different problems to answer open questions concerning correlated systems and their numerical treatment.}, subject = {Monte-Carlo-Simulation}, language = {en} } @article{FrantzKlaiberBabaetal.2013, author = {Frantz, Stefan and Klaiber, Michael and Baba, Hideo A. and Oberwinkler, Heinz and V{\"o}lker, Katharina and Gaßner, Birgit and Bayer, Barbara and Abeßer, Marco and Schuh, Kai and Feil, Robert and Hofmann, Franz and Kuhn, Michaela}, title = {Stress-dependent dilated cardiomyopathy in mice with cardiomyocyte-restricted inactivation of cyclic GMP-dependent protein kinase I}, series = {European Heart Journal}, volume = {34}, journal = {European Heart Journal}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134693}, pages = {1233-1244}, year = {2013}, abstract = {Aims: Cardiac hypertrophy is a common and often lethal complication of arterial hypertension. Elevation of myocyte cyclic GMP levels by local actions of endogenous atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP) or by pharmacological inhibition of phosphodiesterase-5 was shown to counter-regulate pathological hypertrophy. It was suggested that cGMP-dependent protein kinase I (cGKI) mediates this protective effect, although the role in vivo is under debate. Here, we investigated whether cGKI modulates myocyte growth and/or function in the intact organism. Methods and results: To circumvent the systemic phenotype associated with germline ablation of cGKI, we inactivated the murine cGKI gene selectively in cardiomyocytes by Cre/loxP-mediated recombination. Mice with cardiomyocyte-restricted cGKI deletion exhibited unaltered cardiac morphology and function under resting conditions. Also, cardiac hypertrophic and contractile responses to β-adrenoreceptor stimulation by isoprenaline (at 40 mg/kg/day during 1 week) were unaltered. However, angiotensin II (Ang II, at 1000 ng/kg/min for 2 weeks) or transverse aortic constriction (for 3 weeks) provoked dilated cardiomyopathy with marked deterioration of cardiac function. This was accompanied by diminished expression of the \([Ca^{2+}]_i\)-regulating proteins SERCA2a and phospholamban (PLB) and a reduction in PLB phosphorylation at Ser16, the specific target site for cGKI, resulting in altered myocyte \(Ca^{2+}_i\) homeostasis. In isolated adult myocytes, CNP, but not ANP, stimulated PLB phosphorylation, \(Ca^{2+}_i\)-handling, and contractility via cGKI. Conclusion: These results indicate that the loss of cGKI in cardiac myocytes compromises the hypertrophic program to pathological stimulation, rendering the heart more susceptible to dysfunction. In particular, cGKI mediates stimulatory effects of CNP on myocyte \(Ca^{2+}_i\) handling and contractility.}, language = {en} } @article{MantelFlentjeGuckenberger2013, author = {Mantel, Frederick and Flentje, Michael and Guckenberger, Matthias}, title = {Stereotactic body radiation therapy in the re-irradiation situation - a review}, series = {Radiation Oncology}, journal = {Radiation Oncology}, doi = {10.1186/1748-717X-8-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96346}, year = {2013}, abstract = {Although locoregional relapse is frequent after definitive radiotherapy (RT) or multimodal treatments, re-irradiation is only performed in few patients even in palliative settings like e.g. vertebral metastasis. This is most due to concern about potentially severe complications, especially when large volumes are exposed to re-irradiation. With technological advancements in treatment planning the interest in re-irradiation as a local treatment approach has been reinforced. Recently, several studies reported re-irradiation for spinal metastases using SBRT with promising local and symptom control rates and simultaneously low rates of toxicity. These early data consistently indicate that SBRT is a safe and effective treatment modality in this clinical situation, where other treatment alternatives are rare. Similarly, good results have been shown for SBRT in the re-irradiation of head and neck tumors. Despite severe late adverse effects were reported in several studies, especially after single fraction doses >10 Gy, they appear less frequently compared to conventional radiotherapy. Few studies with small patient numbers have been published on SBRT re-irradiation for non-small cell lung cancer (NSCLC). Overall survival (OS) is limited by systemic progression and seems to depend particularly on patient selection. SBRT re-irradiation after primary SBRT should not be practiced in centrally located tumors due to high risk of severe toxicity. Only limited data is available for SBRT re-irradiation of pelvic tumors: feasibility and acceptable toxicity has been described, suggesting SBRT as a complementary treatment modality for local symptom control.}, language = {en} } @article{RodriguesPopovKayeetal.2013, author = {Rodrigues, L{\´e}nia and Popov, Nikita and Kaye, Kenneth M. and Simas, J. Pedro}, title = {Stabilization of Myc through Heterotypic Poly-Ubiquitination by mLANA Is Critical for \(\gamma\)-Herpesvirus Lymphoproliferation}, series = {PLoS PATHOGENS}, volume = {9}, journal = {PLoS PATHOGENS}, number = {8}, doi = {10.1371/journal.ppat.1003554}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131227}, pages = {e1003554}, year = {2013}, abstract = {Host colonization by lymphotropic \(\gamma\)-herpesviruses depends critically on expansion of viral genomes in germinal center (GC) B-cells. Myc is essential for the formation and maintenance of GCs. Yet, the role of Myc in the pathogenesis of \(\gamma\)-cherpesviruses is still largely unknown. In this study, Myc was shown to be essential for the lymphotropic \(\gamma\)-herpesvirus MuHV- 4 biology as infected cells exhibited increased expression of Myc signature genes and the virus was unable to expand in Myc defficient GC B- cells. We describe a novel strategy of a viral protein activating Myc through increased protein stability resulting in increased progression through the cell cycle. This is acomplished by modulating a physiological posttranslational regulatory pathway of Myc. The molecular mechanism involves Myc heterotypic poly- ubiquitination mediated via the viral E3 ubiquitin- ligase mLANA protein. \(EC_5S^{mLANA}\) modulates cellular control of Myc turnover by antagonizing \(SCF^{Fbw7}\) mediated proteasomal degradation of Myc, mimicking \(SCF^{\beta-TrCP}\). The findings here reported reveal that modulation of Myc is essential for \(\gamma\)-herpesvirus persistent infection, establishing a link between virus induced lymphoproliferation and disease.}, language = {en} } @misc{Proell2013, type = {Master Thesis}, author = {Pr{\"o}ll, Sebastian}, title = {Stability of Switched Epidemiological Models}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-108573}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {In this thesis it is shown how the spread of infectious diseases can be described via mathematical models that show the dynamic behavior of epidemics. Ordinary differential equations are used for the modeling process. SIR and SIRS models are distinguished, depending on whether a disease confers immunity to individuals after recovery or not. There are characteristic parameters for each disease like the infection rate or the recovery rate. These parameters indicate how aggressive a disease acts and how long it takes for an individual to recover, respectively. In general the parameters are time-varying and depend on population groups. For this reason, models with multiple subgroups are introduced, and switched systems are used to carry out time-variant parameters. When investigating such models, the so called disease-free equilibrium is of interest, where no infectives appear within the population. The question is whether there are conditions, under which this equilibrium is stable. Necessary mathematical tools for the stability analysis are presented. The theory of ordinary differential equations, including Lyapunov stability theory, is fundamental. Moreover, convex and nonsmooth analysis, positive systems and differential inclusions are introduced. With these tools, sufficient conditions are given for the disease-free equilibrium of SIS, SIR and SIRS systems to be asymptotically stable.}, subject = {Gew{\"o}hnliche Differentialgleichung}, language = {en} } @article{MoffetRoedelKellyetal.2013, author = {Moffet, R. C. and R{\"o}del, R. C. and Kelly, S. T. and Yu, X. Y. and Carroll, G. T. and Fast, J. and Zaveri, R. A. and Laskin, A. and Gilles, M. K.}, title = {Spectro-microscopic measurements of carbonaceous aerosol aging in Central California}, series = {Atmospheric Chemistry and Physics}, volume = {13}, journal = {Atmospheric Chemistry and Physics}, number = {20}, issn = {1680-7324}, doi = {10.5194/acp-13-10445-2013}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121827}, year = {2013}, abstract = {Carbonaceous aerosols are responsible for large uncertainties in climate models, degraded visibility, and adverse health effects. The Carbonaceous Aerosols and Radiative Effects Study (CARES) was designed to study carbonaceous aerosols in the natural environment of the Central Valley, California, and learn more about their atmospheric formation and aging. This paper presents results from spectro-microscopic measurements of carbonaceous particles collected during CARES at the time of a pollution accumulation event (27-29 June 2010), when in situ measurements indicated an increase in the organic carbon content of aerosols as the Sacramento urban plume aged. Computer-controlled scanning electron microscopy coupled with an energy dispersive X-ray detector (CCSEM/EDX) and scanning transmission X-ray microscopy coupled with near-edge X-ray absorption spectroscopy (STXM/NEXAFS) were used to probe the chemical composition and morphology of individual particles. It was found that the mass of organic carbon on individual particles increased through condensation of secondary organic aerosol. STXM/NEXAFS indicated that the number fraction of homogenous organic particles lacking inorganic inclusions (greater than similar to 50 nm equivalent circular diameter) increased with plume age, as did the organic mass per particle. Comparison of the CARES spectro-microscopic dataset with a similar dataset obtained in Mexico City during the MILAGRO campaign showed that fresh particles in Mexico City contained three times as much carbon as those sampled during CARES. The number fraction of soot particles at the Mexico City urban site (ranging from 16.6 to 47.3 \%) was larger than at the CARES urban site (13.4-15.7\%), and the most aged samples from CARES contained fewer carbon-carbon double bonds. Differences between carbonaceous particles in Mexico City and California result from different sources, photochemical conditions, gas phase reactants, and secondary organic aerosol precursors. The detailed results provided by these spectro-microscopic measurements will allow for a comprehensive evaluation of aerosol process models used in climate research.}, language = {en} } @phdthesis{Schul2013, author = {Schul, Daniela}, title = {Spatio-temporal investigation and quantitative analysis of the BMP signaling pathway}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-84224}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Bone Morphogenetic Proteins (BMPs) are key regulators for a lot of diverse cellular processes. During embryonic development these proteins act as morphogens and play a crucial role particularly in organogenesis. BMPs have a direct impact on distinct cellular fates by means of concentration-gradients in the developing embryos. Using the diverse signaling input information within the embryo due to the gradient, the cells transduce the varying extracellular information into distinct gene expression profiles and cell fate decisions. Furthermore, BMP proteins bear important functions in adult organisms like tissue homeostasis or regeneration. In contrast to TGF-ß signaling, currently only little is known about how cells decode and quantify incoming BMP signals. There is poor knowledge about the quantitative relationships between signal input, transducing molecules, their states and location, and finally their ability to incorporate graded systemic inputs and produce qualitative responses. A key requirement for efficient pathway modulation is the complete comprehension of this signaling network on a quantitative level as the BMP signaling pathway, just like many other signaling pathways, is a major target for medicative interference. I therefore at first studied the subcellular distribution of Smad1, which is the main signal transducing protein of the BMP signaling pathway, in a quantitative manner and in response to various types and levels of stimuli in murine c2c12 cells. Results indicate that the subcellular localization of Smad1 is not dependent on the initial BMP input. Surprisingly, only the phospho-Smad1 level is proportionally associated to ligand concentration. Furthermore, the activated transducer proteins were entirely located in the nucleus. Besides the subcellular localization of Smad1, I have analyzed the gene expression profile induced by BMP signaling. Therefore, I examined two endogenous immediate early BMP targets as well as the expression of the stably transgenic Gaussia Luciferase. Interestingly, the results of these independent experimental setups and read-outs suggest oscillating target gene expression. The amplitudes of the oscillations showed a precise concentration-dependence for continuous and transient stimulation. Additionally, even short-time stimulation of 15' activates oscillating gene-expression pulses that are detectable for at least 30h post-stimulation. Only treatment with a BMP type I receptor kinase inhibitor leads to the complete abolishment of the target gene expression. This indicated that target gene expression oscillations depend directly on BMP type I receptor kinase activity.}, subject = {Knochen-Morphogenese-Proteine}, language = {en} } @article{ShahabfarEitzinger2013, author = {Shahabfar, Alireza and Eitzinger, Josef}, title = {Spatio-Temporal Analysis of Droughts in Semi-Arid Regions by Using Meteorological Drought Indices}, series = {Atmosphere}, volume = {4}, journal = {Atmosphere}, number = {2}, doi = {10.3390/atmos4020094}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-128644}, pages = {94-112}, year = {2013}, abstract = {Six meteorological drought indices including percent of normal (PN), standardized precipitation index (SPI), China-Z index (CZI), modified CZI (MCZI), Z-Score (Z), the aridity index of E. de Martonne (I) are compared and evaluated for assessing spatio-temporal dynamics of droughts in six climatic regions in Iran. Results indicated that by consideration of the advantages and disadvantages of the mentioned drought predictors in Iran, the Z-Score, CZI and MCZI could be used as a good meteorological drought predictor. Depending on the month, the length of drought and climatic conditions of the region, they are an alternative to the SPI that has limitations both because of only a few available long term data series in Iran and its complex structure.}, language = {en} } @article{KoenigBaenningerGarciaetal.2013, author = {K{\"o}nig, Markus and Baenninger, Matthias and Garcia, Andrei G. F. and Harjee, Nahid and Pruitt, Beth L. and Ames, C. and Leubner, Philipp and Br{\"u}ne, Christoph and Buhmann, Hartmut and Molenkamp, Laurens W. and Goldhaber-Gordon, David}, title = {Spatially Resolved Study of Backscattering in the Quantum Spin Hall State}, series = {Physical Review X}, volume = {3}, journal = {Physical Review X}, number = {2}, issn = {2160-3308}, doi = {10.1103/PhysRevX.3.021003}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-127225}, pages = {21003}, year = {2013}, abstract = {The discovery of the quantum spin Hall (QSH) state, and topological insulators in general, has sparked strong experimental efforts. Transport studies of the quantum spin Hall state have confirmed the presence of edge states, showed ballistic edge transport in micron-sized samples, and demonstrated the spin polarization of the helical edge states. While these experiments have confirmed the broad theoretical model, the properties of the QSH edge states have not yet been investigated on a local scale. Using scanning gate microscopy to perturb the QSH edge states on a submicron scale, we identify well-localized scattering sites which likely limit the expected nondissipative transport in the helical edge channels. In the micron-sized regions between the scattering sites, the edge states appear to propagate unperturbed, as expected for an ideal QSH system, and are found to be robust against weak induced potential fluctuations.}, language = {en} } @phdthesis{Fritsch2013, author = {Fritsch, Sebastian}, title = {Spatial and temporal patterns of crop yield and marginal land in the Aral Sea Basin: derivation by combining multi-scale and multi-temporal remote sensing data with alight use efficiency model}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-87939}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Irrigated agriculture in the Khorezm region in the arid inner Aral Sea Basin faces enormous challenges due to a legacy of cotton monoculture and non-sustainable water use. Regional crop growth monitoring and yield estimation continuously gain in importance, especially with regard to climate change and food security issues. Remote sensing is the ideal tool for regional-scale analysis, especially in regions where ground-truth data collection is difficult and data availability is scarce. New satellite systems promise higher spatial and temporal resolutions. So-called light use efficiency (LUE) models are based on the fraction of photosynthetic active radiation absorbed by vegetation (FPAR), a biophysical parameter that can be derived from satellite measurements. The general objective of this thesis was to use satellite data, in conjunction with an adapted LUE model, for inferring crop yield of cotton and rice at field (6.5 m) and regional (250 m) scale for multiple years (2003-2009), in order to assess crop yield variations in the study area. Intensive field measurements of FPAR were conducted in the Khorezm region during the growing season 2009. RapidEye imagery was acquired approximately bi-weekly during this time. The normalized difference vegetation index (NDVI) was calculated for all images. Linear regression between image-based NDVI and field-based FPAR was conducted. The analyses resulted in high correlations, and the resulting regression equations were used to generate time series of FPAR at the RapidEye level. RapidEye-based FPAR was subsequently aggregated to the MODIS scale and used to validate the existing MODIS FPAR product. This step was carried out to evaluate the applicability of MODIS FPAR for regional vegetation monitoring. The validation revealed that the MODIS product generally overestimates RapidEye FPAR by about 6 to 15 \%. Mixture of crop types was found to be a problem at the 1 km scale, but less severe at the 250 m scale. Consequently, high resolution FPAR was used to calibrate 8-day, 250 m MODIS NDVI data, this time by linear regression of RapidEye-based FPAR against MODIS-based NDVI. The established FPAR datasets, for both RapidEye and MODIS, were subsequently assimilated into a LUE model as the driving variable. This model operated at both satellite scales, and both required an estimation of further parameters like the photosynthetic active radiation (PAR) or the actual light use efficiency (LUEact). The latter is influenced by crop stress factors like temperature or water stress, which were taken account of in the model. Water stress was especially important, and calculated via the ratio of the actual (ETact) to the potential, crop-specific evapotranspiration (ETc). Results showed that water stress typically occurred between the beginning of May and mid-September and beginning of May and end of July for cotton and rice crops, respectively. The mean water stress showed only minor differences between years. Exceptions occurred in 2008 and 2009, where the mean water stress was higher and lower, respectively. In 2008, this was likely caused by generally reduced water availability in the whole region. Model estimations were evaluated using field-based harvest information (RapidEye) and statistical information at district level (MODIS). The results showed that the model at both the RapidEye and the MODIS scale can estimate regional crop yield with acceptable accuracy. The RMSE for the RapidEye scale amounted to 29.1 \% for cotton and 30.4 \% for rice, respectively. At the MODIS scale, depending on the year and evaluated at Oblast level, the RMSE ranged from 10.5 \% to 23.8 \% for cotton and from -0.4 \% to -19.4 \% for rice. Altogether, the RapidEye scale model slightly underestimated cotton (bias = 0.22) and rice yield (bias = 0.11). The MODIS-scale model, on the other hand, also underestimated official rice yield (bias from 0.01 to 0.87), but overestimated official cotton yield (bias from -0.28 to -0.6). Evaluation of the MODIS scale revealed that predictions were very accurate for some districts, but less for others. The produced crop yield maps indicated that crop yield generally decreases with distance to the river. The lowest yields can be found in the southern districts, close to the desert. From a temporal point of view, there were areas characterized by low crop yields over the span of the seven years investigated. The study at hand showed that light use efficiency-based modeling, based on remote sensing data, is a viable way for regional crop yield prediction. The found accuracies were good within the boundaries of related research. From a methodological viewpoint, the work carried out made several improvements to the existing LUE models reported in the literature, e.g. the calibration of FPAR for the study region using in situ and high resolution RapidEye imagery and the incorporation of crop-specific water stress in the calculation.}, subject = {Fernerkundung}, language = {en} } @article{DandekarAhmedSamanetal.2013, author = {Dandekar, Thomas and Ahmed, Zeeshan and Saman, Zeeshan and Huber, Claudia and Hensel, Michael and Schomburg, Dietmar and M{\"u}nch, Richard and Eisenreich, Wolfgang}, title = {Software LS-MIDA for efficient mass isotopomer distribution analysis in metabolic modelling}, series = {BMC Bioinformatics}, journal = {BMC Bioinformatics}, doi = {10.1186/1471-2334-13-266}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-95882}, year = {2013}, abstract = {Background The knowledge of metabolic pathways and fluxes is important to understand the adaptation of organisms to their biotic and abiotic environment. The specific distribution of stable isotope labelled precursors into metabolic products can be taken as fingerprints of the metabolic events and dynamics through the metabolic networks. An open-source software is required that easily and rapidly calculates from mass spectra of labelled metabolites, derivatives and their fragments global isotope excess and isotopomer distribution. Results The open-source software "Least Square Mass Isotopomer Analyzer" (LS-MIDA) is presented that processes experimental mass spectrometry (MS) data on the basis of metabolite information such as the number of atoms in the compound, mass to charge ratio (m/e or m/z) values of the compounds and fragments under study, and the experimental relative MS intensities reflecting the enrichments of isotopomers in 13C- or 15 N-labelled compounds, in comparison to the natural abundances in the unlabelled molecules. The software uses Brauman's least square method of linear regression. As a result, global isotope enrichments of the metabolite or fragment under study and the molar abundances of each isotopomer are obtained and displayed. Conclusions The new software provides an open-source platform that easily and rapidly converts experimental MS patterns of labelled metabolites into isotopomer enrichments that are the basis for subsequent observation-driven analysis of pathways and fluxes, as well as for model-driven metabolic flux calculations.}, language = {en} } @article{DietzHasseFerrarisetal.2013, author = {Dietz, Mariana S. and Hasse, Daniel and Ferraris, Davide M. and G{\"o}hler, Antonia and Niemann, Hartmut H. and Heilemann, Mike}, title = {Single-molecule photobleaching reveals increased MET receptor dimerization upon ligand binding in intact cells}, series = {BMC Biophysics}, volume = {6}, journal = {BMC Biophysics}, number = {6}, issn = {2046-1682}, doi = {10.1186/2046-1682-6-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121835}, year = {2013}, abstract = {Background: The human receptor tyrosine kinase MET and its ligand hepatocyte growth factor/scatter factor are essential during embryonic development and play an important role during cancer metastasis and tissue regeneration. In addition, it was found that MET is also relevant for infectious diseases and is the target of different bacteria, amongst them Listeria monocytogenes that induces bacterial uptake through the surface protein internalin B. Binding of ligand to the MET receptor is proposed to lead to receptor dimerization. However, it is also discussed whether preformed MET dimers exist on the cell membrane. Results: To address these issues we used single-molecule fluorescence microscopy techniques. Our photobleaching experiments show that MET exists in dimers on the membrane of cells in the absence of ligand and that the proportion of MET dimers increases significantly upon ligand binding. Conclusions: Our results indicate that partially preformed MET dimers may play a role in ligand binding or MET signaling. The addition of the bacterial ligand internalin B leads to an increase of MET dimers which is in agreement with the model of ligand-induced dimerization of receptor tyrosine kinases.}, language = {en} }