135 research outputs found

    Untersuchung der Eindringtiefe von Micropartikeln durch Wasserstrahlapplikation in porciner Urethra

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    Therapieversuche mit mesenchymalen Stromazellen (MSC) versprechen auch zur Therapie der Inkontinenz großes Potenzial. Ersetzend fĂŒr mesenchymalen Stromazellen werden hier Mikropartikel, welche die gleiche GrĂ¶ĂŸe aufweisen, eingesetzt. Verglichen werden die unterschiedlichen Eindringtiefen der Mikropartikel in porciner Urethra, die mit verschiedenen DruckstĂ€rken mittels Wasserstrahl in das Kadavergewebe appliziert werden. Es werden insgesamt drei Injektionsprotokolle angewendet und der Effekt auf das Gewebe durch mikroskopische Auswertung gezeigt und diskutiert

    Analyse des molekularen Bindungsmechanismus zwischen BbCRASP-2 von Borrelia burgdorferi und den Komplementregulatoren Faktor H und FHL-1

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    Die Bindung von regulatorischen Proteinen an die ZelloberflĂ€che ist eine wirkungsvolle Strategie, die sich humanpathogene Bakterien, insbesondere B. burgdorferi, dem Erreger der Lyme-Borreliose, zu eigen gemacht haben, um der bakteriolytischen Wirkung von Komplement zu entgehen. Die Grundlage der Serumresistenz bei B. burgdorferi besteht vornehmlich in der Interaktion der Komplementregulatoren Faktor H und FHL-1 mit fĂŒnf verschiedenen Borrelienproteinen, die als Complement Regulator-Acquiring Surface Proteins bezeichnet werden. Bei der Genospezies B. burgdorferi s.s. nimmt das BbCRASP-2 Protein aufgrund seines spezifischen Bindungsverhaltens gegenĂŒber Faktor H und FHL-1 eine Sonderstellung ein. In frĂŒheren Untersuchungen konnten vier potenzielle Bindungsregionen von Faktor H und FHL-1 im BbCRASP-2 Protein lokalisiert werden. Das Ziel der vorliegenden Arbeit bestand in der detaillierten Charakterisierung der an der Bindung mit Faktor H und FHL-1 beteiligten AminosĂ€uren von BbCRASP-2 innerhalb der putativen Bindungsregionen 2, 3 und 4 sowie in einer Region, die eine coiled-coil Struktur aufweist. Dazu wurden selektiv AminosĂ€uren mittels gerichteter Mutagenese durch die neutrale AminosĂ€ure Alanin ausgetauscht und das Bindungsverhalten der mutierten BbCRASP-2 Proteine untersucht. Mittels LigandenaffinitĂ€tsblot-Analyse und ELISA konnten insgesamt 17 AminosĂ€uren – geladen, neutral polar, neutral unpolar - identifiziert werden, die nach Mutagenese eine erniedrigte BindungskapazitĂ€t oder keine Bindung gegenĂŒber Faktor H und FHL-1 in mindestens einem der beiden Testmethoden aufwiesen. Von diesen Mutanten zeigen 6 Proteine (BbCRASP-2S72A, BbCRASP-2D84A, BbCRASP-2F91A, BbCRASP-2R139A, BbCRASP-2Y207A, BbCRASP-2Y211A) in beiden Testsystemen ein deutlich verĂ€ndertes Bindungsverhalten. 12 weitere BbCRASP-2 Mutanten fielen im ELISA durch ihre reduzierte BindungskapazitĂ€t auf, verhielten sich jedoch im LigandenaffinitĂ€tsblot im Vergleich zu BbCRASP-2 in ihrer Bindungseigenschaft unverĂ€ndert. Die fĂŒr die Faktor H/FHL-1 Bindung relevanten AminosĂ€uren verteilten sich in allen der drei untersuchten Bindungsregionen, wobei Austausche in der C-terminal gelegenen Region 4 den grĂ¶ĂŸten Effekt auf die Bindung zeigten. Dies deutet darauf hin, dass dem C-Terminus eine essentielle Rolle bei der Interaktion zugeordnet werden kann. In Bezug auf die Ladungseigenschaften der identifizierten AminosĂ€uren ergab sich ebenfalls ein sehr heterogenes Bild. Da sowohl geladene als auch polare und unpolare AminosĂ€uren an der Bindung von Faktor H und FHL-1 partizipieren, ist davon auszugehen, dass gleichermaßen elektrostatische und hydrophobe Wechselwirkungen an der Bindung beteiligt sind. ZusĂ€tzlich konnte in der putativen coiled-coil Region eine AminosĂ€ure (Phe91) identifiziert werden, die direkt oder indirekt an der Bindung von BbCRASP-2 und Faktor H/FHL-1 beteiligt ist. FĂŒr die Hypothese einer an der Interaktion beteiligten coiled-coil Struktur spricht, dass AminosĂ€uresubstitutionen an drei weiteren Positionen (Leu-94, Ile-98 und Tyr-101) eine reduzierte Bindung bewirkten. Die rĂ€umlich weit auseinander liegenden Positionen der als bindungsrelevant identifizierten AminosĂ€uren deuten darauf hin, dass sich der Bindungsmechanismus von BbCRASP-2 an Faktor H und FHL-1 komplexer darstellt, als zunĂ€chst vermutet. Es ist ferner zu erwarten, dass noch weitere AminosĂ€uren außerhalb der putativen Bindungsregionen die Interaktion von BbCRASP-2 mit den Regulatorproteine beeinflussen, da in dieser Studie gezeigt werden konnte, dass die Substitution von Phenylalanin an Position 91 einen deutlichen Einfluss auf die Bindung von Faktor H und FHL-1 aufwies, obwohl sie außerhalb der ermittelten Bindungsregionen lokalisiert ist. Mit großer Wahrscheinlichkeit stellt die genaue Topologie des BbCRASP-2 Proteins ebenfalls einen entscheidenden Faktor fĂŒr die Bindung dar. Deshalb sollte mit Kenntnis der dreidimensionalen Struktur des BbCRASP-2 MolekĂŒls eine genauere Beschreibung des molekularen Bindungsmechanismus möglich sein. Die vorliegenden Untersuchungen zum molekularen Mechanismus der Serumresistenz von B. burgdorferi tragen wesentlich zum VerstĂ€ndnis der komplexen Interaktion zwischen BbCRASP-2 mit Faktor H und FHL-1, den beiden Komplementregulatoren des alternativen Weges bei. Diese Erkenntnisse könnten langfristig gesehen fĂŒr die Entwicklung eines Impfstoffs genutzt werden.Binding of regulatory proteins to bacterial surfaces is a sophisticated escape strategy used by diverse human pathogenic bacteria in order to avoid complement-mediated bacteriolysis, in particular Borrelia burgdorferi, the etiologic agent of Lyme disease. Serum resistance of B. burgdorferi is mainly based on the interaction of complement regulators factor H and FHL-1 with up to five distinct bacterial molecules, collectively termed as CRASPs (Complement Regulator-Acquiring Surface Proteins). Due to its specific factor H/FHL-1 binding properties, BbCRASP-2 is a unique protein among CRASPs of B. burgdorferi sensu stricto. In a previous study, four potential binding regions within the BbCRASP-2 molecule have been identified. The aim of the present study was to identify amino acid residues within these putative binding regions that are responsible for the binding of factor H and FHL-1. A separate region that potentially forms a coiled-coil structure was also characterized in this study. This was done by systematical substitution of single amino acid residues by a neutral alanine using site-directed mutagenesis. The respective BbCRASP-2 mutants were analyzed for their ability to bind factor H and/or FHL-1. Applying ligand affinity blotting and ELISA, up to 18 amino acid residues (charged, neutral polar and neutral non-polar) have been identified that showed a reduced binding capacity or no binding at all to factor H and FHL-1. Six of the BbCRASP-2 mutants, BbCRASP-2S72A, BbCRASP-2D84A, BbCRASP-2F91A, BbCRASP-2R139A, BbCRASP-2Y207A, and BbCRASP-2Y211A, displayed an altered binding property in both test systems. In addition, a reduced binding capacity could be demonstrated for 12 mutants using ELISA while binding was unchanged when the ligand affinity blot was employed on the same mutated proteins. The identified binding-relevant amino acid residues were distributed within the three putative binding regions whereby substitutions within the C-terminal binding region 4 showed the strongest effect on binding. Hence, the C-terminus of BbCRASP-2 appears to play an essential role in this interaction. A heterogeneous picture concerning the charge properties of the identified amino acid residues was observed. As charged, polar, and non-polar amino acid residues participate in binding of factor H and FHL-1 it has been suggested that both, electrostatic and hydrophobic forces are involved in this protein-protein interaction. Furthermore, an additional amino acid residue, Phe-91, within the putative coiled-coil region was identified to be either directly or indirectly involved in binding of factor H and FHL-1. Substitutions at three distinct positions (Leu-94, Ile-98, and Tyr-101) within the studied coiled-coil region also affected binding of both complement regulators, thus, it cannot be completely ruled out that this region might have an impact on the interaction. Resolving the crystal structure of the BbCRASP-2-Protein will be necessary to fully understand the way of interaction with complement regulators of the alternative pathway

    Pathways to Greener Pastures: Research Opportunities to Integrate Life Cycle Assessment and Sustainable Business Process Management Based on a Systematic Tertiary Literature Review

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    Sustainable Business Process Management (BPM) is a research field that aims to improve the sustainability performance of organizations’ operations. With its focus on business processes, it has the potential to bring sustainability considerations from external reporting to the core of organizations. We present a systematic tertiary literature study to provide a catalog of existing literature reviews and primary work and to give a consolidated overview of the state and research needs of the field. We find that Sustainable BPM research has focused on modeling approaches and most of the work so far is largely conceptual, with a limited sustainability perspective. Based on these findings, we propose an integration of BPM and Life Cycle Assessment (LCA), an established and rigorous method for sustainability analysis. We present research opportunities to show how both disciplines can synergize and leverage methods and techniques for business process automation and innovation to effectively improve the sustainability performance of organizations

    "Same same, but different" - Körperlichkeit und Moderation im virtuellen Raum

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    Interaktives interkulturelles Lernen ist auch im virtuellen Kontext möglich. Praxis und Evaluation an der UniversitĂ€t Göttingen zeigen, dass Videokonferenzen Potential dazu haben. Gleichzeitig ergeben sich Herausforderungen, die durch den virtuellen Raum, Sichtbarkeit und persönliche Trennung begrĂŒndet sind. Diese Herausforderungen sind verknĂŒpft mit dem Thema Körperlichkeit und dem Fehlen von physischer PrĂ€senz. Zur Sicherstellung einer hohen InteraktionsqualitĂ€t fordert dies von der Moderation neben einem proaktiven Umgang einen bewussten Fokus auf Initiieren und Erhalt von persönlichen Beziehungen innerhalb der Gruppe von Lernenden. DarĂŒber hinaus eröffnet die virtuelle Begegnung neue Möglichkeiten fĂŒr erfahrungsbezogenes Lernen, indem der virtuelle Kontext als gemeinsamer interkultureller Kontext verstanden und zum Lerngegenstand gemacht wird.Interactive intercultural learning is also possible in virtual space. Evaluation and experience at Goettingen University shows that video conferencing is a potential medium for intercultural communication and cooperation. In order to make full use of this, facilitators need a proactive approach to use methods which support understanding and maintaining relationships within a group of participants. This report points out the effects of the absence of physicality in virtual rooms through selected topics and suggests corresponding implications for facilitators. In the conclusion implementations for future intercultural trainings design are considered by discussing the virtual context as intercultural context itself and using it in order to develop new topics and methods for intercultural trainings

    „Same same, but different“ - Körperlichkeit und Moderation im virtuellen Raum

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    Interaktives interkulturelles Lernen ist auch im virtuellen Kontext möglich. Praxis und Evaluation an der UniversitĂ€t Göttingen zeigen, dass Videokonferenzen Potential dazu haben. Gleichzeitig ergeben sich Herausforderungen, die durch den virtuellen Raum, Sichtbarkeit und persönliche Trennung begrĂŒndet sind. Diese Herausforderungen sind verknĂŒpft mit dem Thema Körperlichkeit und dem Fehlen von physischer PrĂ€senz. Zur Sicherstellung einer hohen InteraktionsqualitĂ€t fordert dies von der Moderation neben einem proaktiven Umgang einen bewussten Fokus auf Initiieren und Erhalt von persönlichen Beziehungen innerhalb der Gruppe von Lernenden. DarĂŒber hinaus eröffnet die virtuelle Begegnung neue Möglichkeiten fĂŒr erfahrungsbezogenes Lernen, indem der virtuelle Kontext als gemeinsamer interkultureller Kontext verstanden und zum Lerngegenstand gemacht wird

    Psychometric properties of the Tinnitus Functional Index (TFI): assessment in a UK research volunteer population

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    Objectives Questionnaires are essential for measuring tinnitus severity and intervention-related change but there is no standard instrument used routinely in research settings. Most tinnitus questionnaires are optimised for measuring severity but not change. However, the Tinnitus Functional Index (TFI) claims to be optimised for both. It has not however been fully validated for research purposes. Here we evaluate the relevant psychometric properties of the TFI, specifically the questionnaire factor structure, reproducibility, validity and responsiveness guided by quality criteria for the measurement properties of health-related questionnaires. Methods The study involved a retrospective analysis of data collected for 294 members of the general public who participated in a randomised controlled trial of a novel tinnitus device (ClinicalTrials.gov Identifier: NCT01541969). Participants completed up to eight commonly used assessment questionnaires including the TFI, Tinnitus Handicap Inventory (THI), Tinnitus Handicap Questionnaire (THQ), a Visual Analogue Scale of loudness (VAS-Loudness), Percentage Annoyance question, the Beck's Depression Inventory (BDI), Beck's Anxiety Inventory (BAI), and the World Health Organisation Quality of Life-Bref (WHOQOL-BREF). A series of analyses assessed the study objectives. Forty four participants completed the TFI at a second visit (within 7–21 days and before receiving any intervention) providing data for reproducibility assessments. Results The 8-factor structure was not fully confirmed for this general (non-clinical) population. Whilst it was acceptable standalone subscale, the ‘auditory’ factor showed poor loading with the higher order factor ‘functional impact of tinnitus’. Reproducibility assessments for the overall TFI indicate high internal consistency (α = 0.80) and extremely high reliability (ICC: 0.91), whilst agreement was borderline acceptable (93%). Construct validity was demonstrated by high correlations between scores on the TFI and THI (r = 0.82) and THQ (r = 0.82), moderate correlations with VAS-L (r = 0.46), PR-A (r = 0.58), BDI (r = 0.57), BAI (r = 0.39) and WHOQOL (r = −0.48). Floor effects were observed for more than 50% of the items. A smallest detectable change score of 22.4 is proposed for the TFI global score. Conclusion Even though the proposed 8-factor structure was not fully confirmed for this population, the TFI appears to cover multiple symptom domains, and to measure the construct of tinnitus with an excellent reliability in distinguishing between patients. While the TFI may discriminate those whose tinnitus is not a problem, floor effects in many items means it is less appropriate as a measure of change in this subgroup. Further investigation is needed to determine whether these effects are relevant in other populations

    Cruciferous vegetable supplementation in a controlled diet study alters the serum peptidome in a GSTM1-genotype dependent manner

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    <p>Abstract</p> <p>Background</p> <p>Cruciferous vegetable intake is inversely associated with the risk of several cancers. Isothiocyanates (ITC) are hypothesized to be the major bioactive constituents contributing to these cancer-preventive effects. The polymorphic glutathione-<it>S</it>-transferase (GST) gene family encodes several enzymes which catalyze ITC degradation <it>in vivo</it>.</p> <p>Methods</p> <p>We utilized high throughput proteomics methods to examine how human serum peptides (the "peptidome") change in response to cruciferous vegetable feeding in individuals of different <it>GSTM1 </it>genotypes. In two randomized, crossover, controlled feeding studies (EAT and 2EAT) participants consumed a fruit- and vegetable-free basal diet and the basal diet supplemented with cruciferous vegetables. Serum samples collected at the end of the feeding period were fractionated and matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometry spectra were obtained. Peak identification/alignment computer algorithms and mixed effects models were used to analyze the data.</p> <p>Results</p> <p>After analysis of spectra from EAT participants, 24 distinct peaks showed statistically significant differences associated with cruciferous vegetable intake. Twenty of these peaks were driven by their <it>GSTM1 </it>genotype (i.e., <it>GSTM1+ </it>or <it>GSTM1- </it>null). When data from EAT and 2EAT participants were compared by joint processing of spectra to align a common set, 6 peaks showed consistent changes in both studies in a genotype-dependent manner. The peaks at 6700 <it>m/z </it>and 9565 <it>m/z </it>were identified as an isoform of transthyretin (TTR) and a fragment of zinc α2-glycoprotein (ZAG), respectively.</p> <p>Conclusions</p> <p>Cruciferous vegetable intake in <it>GSTM1+ </it>individuals led to changes in circulating levels of several peptides/proteins, including TTR and a fragment of ZAG. TTR is a known marker of nutritional status and ZAG is an adipokine that plays a role in lipid mobilization. The results of this study present evidence that the <it>GSTM1</it>-genotype modulates the physiological response to cruciferous vegetable intake.</p

    Models of <i>KPTN</i>-related disorder implicate mTOR signalling in cognitive and overgrowth phenotypes

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    KPTN-related disorder is an autosomal recessive disorder associated with germline variants in KPTN (previously known as kaptin), a component of the mTOR regulatory complex KICSTOR. To gain further insights into the pathogenesis of KPTN-related disorder, we analysed mouse knockout and human stem cell KPTN loss-of-function models. Kptn -/- mice display many of the key KPTN-related disorder phenotypes, including brain overgrowth, behavioural abnormalities, and cognitive deficits. By assessment of affected individuals, we have identified widespread cognitive deficits (n = 6) and postnatal onset of brain overgrowth (n = 19). By analysing head size data from their parents (n = 24), we have identified a previously unrecognized KPTN dosage-sensitivity, resulting in increased head circumference in heterozygous carriers of pathogenic KPTN variants. Molecular and structural analysis of Kptn-/- mice revealed pathological changes, including differences in brain size, shape and cell numbers primarily due to abnormal postnatal brain development. Both the mouse and differentiated induced pluripotent stem cell models of the disorder display transcriptional and biochemical evidence for altered mTOR pathway signalling, supporting the role of KPTN in regulating mTORC1. By treatment in our KPTN mouse model, we found that the increased mTOR signalling downstream of KPTN is rapamycin sensitive, highlighting possible therapeutic avenues with currently available mTOR inhibitors. These findings place KPTN-related disorder in the broader group of mTORC1-related disorders affecting brain structure, cognitive function and network integrity.</p
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