@article{BiermannHeilmannDidieetal.2012, author = {Biermann, Daniel and Heilmann, Andreas and Didi{\´e}, Michael and Schlossarek, Saskia and Wahab, Azadeh and Grimm, Michael and R{\"o}mer, Maria and Reichenspurner, Hermann and Sultan, Karim R. and Steenpass, Anna and Erg{\"u}n, S{\"u}leyman and Donzelli, Sonia and Carrier, Lucie and Ehmke, Heimo and Zimmermann, Wolfram H. and Hein, Lutz and B{\"o}ger, Rainer H. and Benndorf, Ralf A.}, title = {Impact of AT2 Receptor Deficiency on Postnatal Cardiovascular Development}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {10}, doi = {10.1371/journal.pone.0047916}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-134902}, pages = {e47916}, year = {2012}, abstract = {Background: The angiotensin II receptor subtype 2 (AT2 receptor) is ubiquitously and highly expressed in early postnatal life. However, its role in postnatal cardiac development remained unclear. Methodology/Principal Findings: Hearts from 1, 7, 14 and 56 days old wild-type (WT) and AT2 receptor-deficient (KO) mice were extracted for histomorphometrical analysis as well as analysis of cardiac signaling and gene expression. Furthermore, heart and body weights of examined animals were recorded and echocardiographic analysis of cardiac function as well as telemetric blood pressure measurements were performed. Moreover, gene expression, sarcomere shortening and calcium transients were examined in ventricular cardiomyocytes isolated from both genotypes. KO mice exhibited an accelerated body weight gain and a reduced heart to body weight ratio as compared to WT mice in the postnatal period. However, in adult KO mice the heart to body weight ratio was significantly increased most likely due to elevated systemic blood pressure. At postnatal day 7 ventricular capillarization index and the density of \(\alpha\)-smooth muscle cell actin-positive blood vessels were higher in KO mice as compared to WT mice but normalized during adolescence. Echocardiographic assessment of cardiac systolic function at postnatal day 7 revealed decreased contractility of KO hearts in response to beta-adrenergic stimulation. Moreover, cardiomyocytes from KO mice showed a decreased sarcomere shortening and an increased peak Ca\(^{2+}\) transient in response to isoprenaline when stimulated concomitantly with angiotensin II. Conclusion: The AT2 receptor affects postnatal cardiac growth possibly via reducing body weight gain and systemic blood pressure. Moreover, it moderately attenuates postnatal vascularization of the heart and modulates the beta adrenergic response of the neonatal heart. These AT2 receptor-mediated effects may be implicated in the physiological maturation process of the heart.}, language = {en} } @phdthesis{Grimm2005, author = {Grimm, Michael Werner}, title = {Untersuchung costimulatorischer Signalwege bei chronischer Transplantatabstoßung und Langzeit-Organakzeptanz nach allogener Nierentransplantation an einem experimentellen Hirntod-Spender-Transplantationsmodell}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-15217}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {Zusammenfassend zeigen die Untersuchungsergebnisse, dass eine Kombination aus niedrig dosiertem Sirolimus und CsA einen synergistischen immunsuppressiven Effekt nach Nierentransplantation aufweisen. rPSGL-Ig wirkt additiv und reduziert fr{\"u}he unspezifische oder auch Alloantigen-unabh{\"a}ngige hervorgerufene Sch{\"a}digung gegen{\"u}ber dem Transplantat.}, language = {de} } @phdthesis{Grimm2005, author = {Grimm, Michael}, title = {Aufladungsexperimente an gespeicherten Nanopartikeln mit Synchrotronstrahlung}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-13188}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2005}, abstract = {Gegenstand dieser Arbeit ist die Untersuchung von gespeicherten Nanopartikeln mit weicher R{\"o}ntgenstrahlung. Daf{\"u}r wurde eine neue Apparatur aufgebaut. In dieser befindet sich ein dreidimensionaler elektrodynamischer Quadrupolspeicher, mit dem die positiv geladenen Nanopartikel ber{\"u}hrungsfrei und ortsfest gespeichert werden. Mit Hilfe eines Streulichtnachweises werden die Eigenbewegungen der Partikel gemessen und daraus das Ladungs- zu Masseverh{\"a}ltnis ermittelt. Durch gezielte Umladung k{\"o}nnen die absolute Ladung und die Masse der Partikel mit hoher Genauigkeit bestimmt werden. Die gespeicherten Partikel wurden mit Synchrotronstrahlung am Elektronenspeicherring BESSY II untersucht. Bei niedrig geladenen Partikeln wurden Aufladungsexperimente mit variabler Photonenenergie durchgef{\"u}hrt. Dabei kann die Emission von einzelnen Elektronen beobachtet werden. Die totale Sekund{\"a}relektronenausbeute wurde f{\"u}r verschiedene Photonenenergien ermittelt. Sie gleicht den Werten, die durch Messungen mit Elektronenbeschuss bekannt sind. Die Partikel wurden weiterhin bis zum maximal erreichbaren Ladungszustand aufgeladen. Dieser Gleichgewichtszustand liegt unterhalb der theoretischen Erwartungen. Bei den hochgeladenen Partikeln wurden nach Abschalten der Synchrotronstrahlung Entladevorg{\"a}nge beobachtet, die f{\"u}r das verminderte Ladungsgleichgewicht verantwortlich sind. Die Entladung wird als Ionen-Feldemission interpretiert, m{\"o}glicherweise hervorgerufen durch den elektrischen Durchschlag im Teilchenmaterial. Das Aufladungsverhalten der Partikel bei verschiedenen Ladungszust{\"a}nden wurde mit Hilfe von Messungen an der O 1s-Kante untersucht. Bei niedrigen Ladungszust{\"a}nden liefert der Ladestrom die bekannten R{\"o}ntgenabsorbtionsstrukturen von Siliziumdioxid. Stark geladene Partikel werden dagegen vor allem im Bereich der resonanten O 1s-Anregung durch schnelle Augerelektronen aufgeladen, w{\"a}hrend Photoelektronen aus dem O 1s-Kontinuum nicht mehr zur Aufladung beitragen. Deren kinetische Energie ist zu gering, um dem Coulombfeld des Partikels zu entkommen.}, subject = {Nanopartikel}, language = {de} } @article{ChaudryGrimmFriedbergeretal.2020, author = {Chaudry, Oliver and Grimm, Alexandra and Friedberger, Andreas and Kemmler, Wolfgang and Uder, Michael and Jakob, Franz and Quick, Harald H. and von Stengel, Simon and Engelke, Klaus}, title = {Magnetic Resonance Imaging and Bioelectrical Impedance Analysis to Assess Visceral and Abdominal Adipose Tissue}, series = {Obesity}, volume = {28}, journal = {Obesity}, number = {2}, doi = {10.1002/oby.22712}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-213591}, pages = {277 -- 283}, year = {2020}, abstract = {Objective This study aimed to compare a state-of-the-art bioelectrical impedance analysis (BIA) device with two-point Dixon magnetic resonance imaging (MRI) for the quantification of visceral adipose tissue (VAT) as a health-related risk factor. Methods A total of 63 male participants were measured using a 3-T MRI scanner and a segmental, multifrequency BIA device. MRI generated fat fraction (FF) maps, in which VAT volume, total abdominal adipose tissue volume, and FF of visceral and total abdominal compartments were quantified. BIA estimated body fat mass and VAT area. Results Coefficients of determination between abdominal (r\(^{2}\) = 0.75) and visceral compartments (r\(^{2}\) = 0.78) were similar for both groups, but slopes differed by a factor of two. The ratio of visceral to total abdominal FF was increased in older men compared with younger men. This difference was not detected with BIA. MRI and BIA measurements of the total abdominal volume correlated moderately (r\(^{2}\) = 0.31-0.56), and visceral measurements correlated poorly (r\(^{2}\) = 0.13-0.44). Conclusions Visceral BIA measurements agreed better with MRI measurements of the total abdomen than of the visceral compartment, indicating that BIA visceral fat area assessment cannot differentiate adipose tissue between visceral and abdominal compartments in young and older participants.}, language = {en} } @article{BiereKranzMaturaetal.2020, author = {Biere, Silvia and Kranz, Thorsten M. and Matura, Silke and Petrova, Kristiyana and Streit, Fabian and Chiocchetti, Andreas G. and Grimm, Oliver and Brum, Murielle and Brunkhorst-Kanaan, Natalie and Oertel, Viola and Malyshau, Aliaksandr and Pfennig, Andrea and Bauer, Michael and Schulze, Thomas G. and Kittel-Schneider, Sarah and Reif, Andreas}, title = {Risk Stratification for Bipolar Disorder Using Polygenic Risk Scores Among Young High-Risk Adults}, series = {Frontiers in Psychiatry}, volume = {11}, journal = {Frontiers in Psychiatry}, doi = {10.3389/fpsyt.2020.552532}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-214976}, year = {2020}, abstract = {Objective: Identifying high-risk groups with an increased genetic liability for bipolar disorder (BD) will provide insights into the etiology of BD and contribute to early detection of BD. We used the BD polygenic risk score (PRS) derived from BD genome-wide association studies (GWAS) to explore how such genetic risk manifests in young, high-risk adults. We postulated that BD-PRS would be associated with risk factors for BD. Methods: A final sample of 185 young, high-risk German adults (aged 18-35 years) were grouped into three risk groups and compared to a healthy control group (n = 1,100). The risk groups comprised 117 cases with attention deficit hyperactivity disorder (ADHD), 45 with major depressive disorder (MDD), and 23 help-seeking adults with early recognition symptoms [ER: positive family history for BD, (sub)threshold affective symptomatology and/or mood swings, sleeping disorder]. BD-PRS was computed for each participant. Logistic regression models (controlling for sex, age, and the first five ancestry principal components) were used to assess associations of BD-PRS and the high-risk phenotypes. Results: We observed an association between BD-PRS and combined risk group status (OR = 1.48, p < 0.001), ADHD diagnosis (OR = 1.32, p = 0.009), MDD diagnosis (OR = 1.96, p < 0.001), and ER group status (OR = 1.7, p = 0.025; not significant after correction for multiple testing) compared to healthy controls. Conclusions: In the present study, increased genetic risk for BD was a significant predictor for MDD and ADHD status, but not for ER. These findings support an underlying shared risk for both MDD and BD as well as ADHD and BD. Improving our understanding of the underlying genetic architecture of these phenotypes may aid in early identification and risk stratification.}, language = {en} } @article{KrausGrimmSeibel2018, author = {Kraus, Michael and Grimm, Clemens and Seibel, J{\"u}rgen}, title = {Reversibility of a Point Mutation Induced Domain Shift: Expanding the Conformational Space of a Sucrose Phosphorylase}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, doi = {10.1038/s41598-018-28802-2}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224845}, year = {2018}, abstract = {Despite their popularity as enzyme engineering targets structural information about Sucrose Phosphorylases remains scarce. We recently clarified that the Q345F variant of Bifidobacterium adolescentis Sucrose Phosphorylase is able to accept large polyphenolic substrates like resveratrol via a domain shift. Here we present a crystal structure of this variant in a conformation suitable for the accommodation of the donor substrate sucrose in excellent agreement with the wild type structure. Remarkably, this conformation does not feature the previously observed domain shift which is therefore reversible and part of a dynamic process rather than a static phenomenon. This crystallographic snapshot completes our understanding of the catalytic cycle of this useful variant and will allow for a more rational design of further generations of Sucrose Phosphorylase variants.}, language = {en} }