TY - GEN A1 - Kupka, Friedrich T1 - Improvements to the Short-Characteristics Method in 3D RHD Simulations and some Unsolved Problems in Spectral Line Shapes of A-type Stars KW - Convection KW - Radiative transfer KW - Methods: spectroscopy KW - Methods: numerical Y1 - ER - TY - GEN A1 - Kupka, Friedrich T1 - Improvements in Numerical and Analytical Modelling Techniques to Study the Solar Surface KW - Convection KW - Stars: Sun KW - Methods: numerical KW - Radiative transfer Y1 - ER - TY - GEN A1 - Kupka, Friedrich T1 - Advanced Convection Modelling in Asteroseismology and Stellar Evolution KW - Convection KW - Asteroseismology KW - Stars: evolution Y1 - ER - TY - JOUR A1 - Tomasch, Janine A1 - Maleiner, Babette A1 - Hromada, Carina A1 - Szwarc-Hofbauer, Dorota A1 - Teuschl-Woller, Andreas T1 - Cyclic Tensile Stress Induces Skeletal Muscle Hypertrophy and Myonuclear Accretion in a 3D Model JF - Tissue Eng. Part A. N2 - Skeletal muscle is highly adaptive to mechanical stress due to its resident stem cells and the pronounced level of myotube plasticity. Herein, we study the adaptation to mechanical stress and its underlying molecular mechanisms in a tissue-engineered skeletal muscle model. We subjected differentiated 3D skeletal muscle-like constructs to cyclic tensile stress using a custom-made bioreactor system, which resulted in immediate activation of stress-related signal transducers (Erk1/2, p38). Cell cycle re-entry, increased proliferation, and onset of myogenesis indicated subsequent myoblast activation. Furthermore, elevated focal adhesion kinase and β-catenin activity in mechanically stressed constructs suggested increased cell adhesion and migration. After 3 days of mechanical stress, gene expression of the fusogenic markers MyoMaker and MyoMixer, myotube diameter, myonuclear accretion, as well as S6 activation, were significantly increased. Our results highlight that we established a promising tool to study sustained adaptation to mechanical stress in healthy, hypertrophic, or regenerating skeletal muscle. KW - fibrin KW - tissue engineering KW - tensile stress KW - regeneration KW - hypertrophy Y1 - VL - 2023 IS - Mar SP - 257 EP - 268 ER - TY - JOUR A1 - Heinzel, Johannes Christoph A1 - Oberhauser, Viola A1 - Keibl, Claudia A1 - Schädl, Barbara A1 - Swiadek, Nicole V. A1 - Längle, Gregor A1 - Frick, Helen A1 - Slezak, Cyrill A1 - Prahm, Cosima A1 - Grillari, Johannes A1 - Kolbenschlag, Jonas A1 - Hercher, David T1 - ESWT Diminishes Axonal Regeneration following Repair of the Rat Median Nerve with Muscle-In-Vein Conduits but Not after Autologous Nerve Grafting JF - Biomedicines N2 - Investigations reporting positive effects of extracorporeal shockwave therapy (ESWT) on nerve regeneration are limited to the rat sciatic nerve model. The effects of ESWT on muscle-in-vein conduits (MVCs) have also not been investigated yet. This study aimed to evaluate the effects of ESWT after repair of the rat median nerve with either autografts (ANGs) or MVCs. In male Lewis rats, a 7 mm segment of the right median nerve was reconstructed either with an ANG or an MVC. For each reconstructive technique, one group of animals received one application of ESWT while the other rats served as controls. The animals were observed for 12 weeks, and nerve regeneration was assessed using computerized gait analysis, the grasping test, electrophysiological evaluations and histological quantification of axons, blood vessels and lymphatic vasculature. Here, we provide for the first time a comprehensive analysis of ESWT effects on nerve regeneration in a rat model of median nerve injury. Furthermore, this study is among the first reporting the quantification of lymphatic vessels following peripheral nerve injury and reconstruction in vivo. While we found no significant direct positive effects of ESWT on peripheral nerve regeneration, results following nerve repair with MVCs were significantly inferior to those after ANG repair. KW - Tissue Engineering KW - Muscle-In-Vein Conduits KW - Axonal Regeneration KW - Autologous Nerve Grafting Y1 - VL - 2022 IS - 10(8) SP - 1777 ER - TY - JOUR A1 - Lauer, Henrik A1 - Prahm, Cosima A1 - Thiel, Johannes Tobias A1 - Kolbenschlag, Jonas A1 - Daigeler, Adrien A1 - Hercher, David A1 - Heinzel, Johannes Christoph T1 - The Grasping Test Revisited: A Systematic Review of Functional Recovery in Rat Models of Median Nerve Injury JF - Biomedicines N2 - The rat median nerve model is a well-established and frequently used model for peripheral nerve injury and repair. The grasping test is the gold-standard to evaluate functional recovery in this model. However, no comprehensive review exists to summarize the course of functional recovery in regard to the lesion type. According to PRISMA-guidelines, research was performed, including the databases PubMed and Web of Science. Groups were: (1) crush injury, (2) transection with end-to-end or with (3) end-to-side coaptation and (4) isogenic or acellular allogenic grafting. Total and respective number, as well as rat strain, type of nerve defect, length of isogenic or acellular allogenic allografts, time at first signs of motor recovery (FSR) and maximal recovery grasping strength (MRGS), were evaluated. In total, 47 articles met the inclusion criteria. Group I showed earliest signs of motor recovery. Slow recovery was observable in group III and in graft length above 25 mm. Isografts recovered faster compared to other grafts. The onset and course of recovery is heavily dependent from the type of nerve injury. The grasping test should be used complementary in addition to other volitional and non-volitional tests. Repetitive examinations should be planned carefully to optimize assessment of valid and reliable data. KW - Tissue Engineering KW - Median Nerve Injury KW - Nerve Regeneration Y1 - VL - 2022 IS - 10(8) SP - 1878 ER - TY - GEN A1 - Kupka, Friedrich T1 - On the Potential of the Reynolds Stress Approach to Model Convective Overshooting in Grids of Stellar Evolution Models KW - Convection KW - Turbulence KW - Asteroseismology KW - Stars: evolution Y1 - U6 - http://dx.doi.org/https://doi.org/10.5281/zenodo.5572778 ER - TY - JOUR A1 - Ashmwe, Mohamed A1 - Posa, Katja A1 - Rührnößl, Alexander A1 - Heinzel, Johannes Christoph A1 - Heimel, Patrick A1 - Mock, Michael A1 - Schädl, Barbara A1 - Keibl, Claudia A1 - Couillard-Despres, Sebastien A1 - Redl, Heinz A1 - Mittermayr, Rainer A1 - Hercher, David T1 - Effects of Extracorporeal Shockwave Therapy on Functional Recovery and Circulating miR-375 and miR-382-5p after Subacute and Chronic Spinal Cord Contusion Injury in Rats JF - Biomedicines N2 - Extracorporeal shockwave therapy (ESWT) can stimulate processes to promote regeneration, including cell proliferation and modulation of inflammation. Specific miRNA expression panels have been established to define correlations with regulatory targets within these pathways. This study aims to investigate the influence of low-energy ESWT-applied within the subacute and chronic phase of SCI (spinal cord injury) on recovery in a rat spinal cord contusion model. Outcomes were evaluated by gait analysis, µCT and histological analysis of spinal cords. A panel of serum-derived miRNAs after SCI and after ESWT was investigated to identify injury-, regeneration- and treatment-associated expression patterns. Rats receiving ESWT showed significant improvement in motor function in both a subacute and a chronic experimental setting. This effect was not reflected in changes in morphology, µCT-parameters or histological markers after ESWT. Expression analysis of various miRNAs, however, revealed changes after SCI and ESWT, with increased miR-375, indicating a neuroprotective effect, and decreased miR-382-5p potentially improving neuroplasticity via its regulatory involvement with BDNF. We were able to demonstrate a functional improvement of ESWT-treated animals after SCI in a subacute and chronic setting. Furthermore, the identification of miR-375 and miR-382-5p could potentially provide new targets for therapeutic intervention in future studies. KW - Tissue Engineering KW - ESWT KW - Spinal Cord Injury Y1 - U6 - http://dx.doi.org/https://doi.org/10.3390/biomedicines10071630 VL - 2022 IS - 10(7) SP - 1630 ER -