TY - JOUR A1 - Kuchler, Timon A1 - Günthner, Roman A1 - Ribeiro, Andrea A1 - Hausinger, Renate A1 - Streese, Lukas A1 - Wöhnl, Anna A1 - Kesseler, Veronika A1 - Negele, Johanna A1 - Assali, Tarek A1 - Carbajo-Lozoya, Javier A1 - Lech, Maciej A1 - Adorjan, Kristina A1 - Stubbe, Hans Christian A1 - Hanssen, Henner A1 - Kotliar, Konstantin A1 - Haller, Berhard A1 - Heemann, Uwe A1 - Schmaderer, Christoph T1 - Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation N2 - Background Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians. Methods In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204). Measurements and main results PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42% ± 1.77% vs. 4.64% ± 2.59%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5–190.2] vs. 189.1 [179.4–197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8–0.9] vs. 0.88 [0.8–0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = − 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters. Conclusion Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management. KW - Endothelial dysfunction KW - Long COVID KW - Post-COVID-19 syndrome KW - retinal microvasculature Y1 - 2023 U6 - http://dx.doi.org/10.1007/s10456-023-09885-6 N1 - Corresponding author: Christoph Schmaderer VL - 26 SP - 547 EP - 563 PB - Springer Nature CY - Dordrecht ER - TY - JOUR A1 - Waldvogel, Janice A1 - Freyler, Kathrin A1 - Helm, Michael A1 - Monti, Elena A1 - Stäudle, Benjamin A1 - Gollhofer, Albert A1 - Narici, Marco V. A1 - Ritzmann, Ramona A1 - Albracht, Kirsten T1 - Changes in gravity affect neuromuscular control, biomechanics, and muscle-tendon mechanics in energy storage and dissipation tasks JF - Journal of Applied Physiology N2 - This study evaluates neuromechanical control and muscle-tendon interaction during energy storage and dissipation tasks in hypergravity. During parabolic flights, while 17 subjects performed drop jumps (DJs) and drop landings (DLs), electromyography (EMG) of the lower limb muscles was combined with in vivo fascicle dynamics of the gastrocnemius medialis, two-dimensional (2D) kinematics, and kinetics to measure and analyze changes in energy management. Comparisons were made between movement modalities executed in hypergravity (1.8 G) and gravity on ground (1 G). In 1.8 G, ankle dorsiflexion, knee joint flexion, and vertical center of mass (COM) displacement are lower in DJs than in DLs; within each movement modality, joint flexion amplitudes and COM displacement demonstrate higher values in 1.8 G than in 1 G. Concomitantly, negative peak ankle joint power, vertical ground reaction forces, and leg stiffness are similar between both movement modalities (1.8 G). In DJs, EMG activity in 1.8 G is lower during the COM deceleration phase than in 1 G, thus impairing quasi-isometric fascicle behavior. In DLs, EMG activity before and during the COM deceleration phase is higher, and fascicles are stretched less in 1.8 G than in 1 G. Compared with the situation in 1 G, highly task-specific neuromuscular activity is diminished in 1.8 G, resulting in fascicle lengthening in both movement modalities. Specifically, in DJs, a high magnitude of neuromuscular activity is impaired, resulting in altered energy storage. In contrast, in DLs, linear stiffening of the system due to higher neuromuscular activity combined with lower fascicle stretch enhances the buffering function of the tendon, and thus the capacity to safely dissipate energy. KW - electromyography KW - locomotion KW - overload KW - stretch-shortening cycle KW - ultrasound Y1 - 2023 U6 - http://dx.doi.org/10.1152/japplphysiol.00279.2022 SN - 1522-1601 (Onlineausgabe) SN - 8750-7587 (Druckausgabe) VL - 134 IS - 1 SP - 190 EP - 202 PB - American Physiological Society CY - Bethesda, Md. ER - TY - CHAP A1 - Dachwald, Bernd A1 - Ulamec, Stephan A1 - Kowalski, Julia A1 - Boxberg, Marc S. A1 - Baader, Fabian A1 - Biele, Jens A1 - Kömle, Norbert ED - Badescu, Viorel ED - Zacny, Kris ED - Bar-Cohen, Yoseph T1 - Ice melting probes T2 - Handbook of Space Resources N2 - The exploration of icy environments in the solar system, such as the poles of Mars and the icy moons (a.k.a. ocean worlds), is a key aspect for understanding their astrobiological potential as well as for extraterrestrial resource inspection. On these worlds, ice melting probes are considered to be well suited for the robotic clean execution of such missions. In this chapter, we describe ice melting probes and their applications, the physics of ice melting and how the melting behavior can be modeled and simulated numerically, the challenges for ice melting, and the required key technologies to deal with those challenges. We also give an overview of existing ice melting probes and report some results and lessons learned from laboratory and field tests. KW - Ice melting probe KW - Ice penetration KW - Icy moons KW - Ocean worlds KW - Mars Y1 - 2023 SN - 978-3-030-97912-6 (Print) SN - 978-3-030-97913-3 (Online) U6 - http://dx.doi.org/10.1007/978-3-030-97913-3_29 SP - 955 EP - 996 PB - Springer CY - Cham ER - TY - JOUR A1 - Uysal, Karya A1 - Firat, Ipek Serat A1 - Creutz, Till A1 - Aydin, Inci Cansu A1 - Artmann, Gerhard A1 - Teusch, Nicole A1 - Temiz Artmann, Aysegül T1 - A novel in vitro wound healing assay using free-standing, ultra-thin PDMS membranes JF - membranes N2 - Advances in polymer science have significantly increased polymer applications in life sciences. We report the use of free-standing, ultra-thin polydimethylsiloxane (PDMS) membranes, called CellDrum, as cell culture substrates for an in vitro wound model. Dermal fibroblast monolayers from 28- and 88-year-old donors were cultured on CellDrums. By using stainless steel balls, circular cell-free areas were created in the cell layer (wounding). Sinusoidal strain of 1 Hz, 5% strain, was applied to membranes for 30 min in 4 sessions. The gap circumference and closure rate of un-stretched samples (controls) and stretched samples were monitored over 4 days to investigate the effects of donor age and mechanical strain on wound closure. A significant decrease in gap circumference and an increase in gap closure rate were observed in trained samples from younger donors and control samples from older donors. In contrast, a significant decrease in gap closure rate and an increase in wound circumference were observed in the trained samples from older donors. Through these results, we propose the model of a cell monolayer on stretchable CellDrums as a practical tool for wound healing research. The combination of biomechanical cell loading in conjunction with analyses such as gene/protein expression seems promising beyond the scope published here. Y1 - 2022 U6 - http://dx.doi.org/10.3390/membranes13010022 N1 - This article belongs to the Special Issue "Latest Scientific Discoveries in Polymer Membranes" VL - 2023 IS - 13(1) PB - MDPI CY - Basel ER - TY - JOUR A1 - Thiebes, Anja Lena A1 - Klein, Sarah A1 - Zingsheim, Jonas A1 - Möller, Georg H. A1 - Gürzing, Stefanie A1 - Reddemann, Manuel A. A1 - Behbahani, Mehdi A1 - Cornelissen, Christian G. T1 - Effervescent atomizer as novel cell spray technology to decrease the gas-to-liquid ratio JF - pharmaceutics N2 - Cell spraying has become a feasible application method for cell therapy and tissue engineering approaches. Different devices have been used with varying success. Often, twin-fluid atomizers are used, which require a high gas velocity for optimal aerosolization characteristics. To decrease the amount and velocity of required air, a custom-made atomizer was designed based on the effervescent principle. Different designs were evaluated regarding spray characteristics and their influence on human adipose-derived mesenchymal stromal cells. The arithmetic mean diameters of the droplets were 15.4–33.5 µm with decreasing diameters for increasing gas-to-liquid ratios. The survival rate was >90% of the control for the lowest gas-to-liquid ratio. For higher ratios, cell survival decreased to approximately 50%. Further experiments were performed with the design, which had shown the highest survival rates. After seven days, no significant differences in metabolic activity were observed. The apoptosis rates were not influenced by aerosolization, while high gas-to-liquid ratios caused increased necrosis levels. Tri-lineage differentiation potential into adipocytes, chondrocytes, and osteoblasts was not negatively influenced by aerosolization. Thus, the effervescent aerosolization principle was proven suitable for cell applications requiring reduced amounts of supplied air. This is the first time an effervescent atomizer was used for cell processing. KW - tri-lineage differentiation KW - survival KW - twin-fluid atomizer KW - adipose-derived stromal cells (ASCs) KW - cell atomization KW - cell aerosolization Y1 - 2022 U6 - http://dx.doi.org/10.3390/pharmaceutics14112421 N1 - This article belongs to the Special Issue "Stromal, Stem, Signaling Cells: The Multiple Roles and Applications of Mesenchymal Cells" VL - 14 IS - 11 PB - MDPI CY - Basel ER - TY - JOUR A1 - Akimbekov, N. Sh. A1 - Zhubanova, A. A. A1 - Mansurov, Z. A. A1 - Digel, Ilya A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Use of Carbonized Rise Shell for the local treatment of wounds JF - Eurasian ChemTech Journal N2 - On the model of musculocutaneous wound in rats, the effect of applicative sorption by carbonized rise shell (CRS) on the healing of festering wound was studied. It has been shown, that cytological changes end with rapid scar formation. The use of CRS at the period of severe purulent wound contributes to its favorable course, prevents the development of complications of the animals from sepsis. Y1 - 2010 U6 - http://dx.doi.org/10.18321/ectj35 SN - 2522-4867 VL - 12 IS - 2 SP - 133 EP - 138 PB - Institute of Combustion Problems CY - Almaty ER - TY - JOUR A1 - Aggeloussis, Nickos A1 - Giannakou, Erasmia A1 - Albracht, Kirsten A1 - Arampatzis, Adamantios T1 - Reproducibility of fascicle length and pennation angle of gastrocnemius medialis in human gait in vivo JF - Gait and Posture N2 - The purpose of the current study was to examine the reproducibility of fascicle length and pennation angle of gastrocnemius medialis while human walking. To the best of our knowledge, this is the first study of the reproducibility of fascicle length and pennation angle of gastrocnemius medialis in vivo during human gait. Twelve males performed 10 gait trials on a treadmill, in 2 separate days. B-mode ultrasonography, with the ultrasound probe firmly adjusted in the transverse and frontal planes using a special cast, was used to measure the fascicle length and the pennation angle of the gastrocnemius medialis (GM). A Vicon 624 system with three cameras operating at 120 Hz was also used to record the ankle and knee joint angles. The results showed that measurements of fascicle length and pennation angle showed high reproducibility during the gait cycle, both within the same day and between different days. Moreover, the root mean square differences between the repeated waveforms of both variables were very small, compared with their ranges (fascicle length: RMS = ∼3 mm, range: 38–63 mm; pennation angle: RMS = ∼1.5°, range: 22–32°). However, their reproducibility was lower compared to the joint angles. It was found that representative data have to be derived by a wide number of gait trials (fascicle length ∼six trials, pennation angle more than 10 trials), to assure the reliability of the fascicle length and pennation angle in human gait. Y1 - 2010 U6 - http://dx.doi.org/10.1016/j.gaitpost.2009.08.249 SN - 0966-6362 VL - 31 IS - 1 SP - 73 EP - 77 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Arampatzis, Adamantios A1 - Peper, Andreas A1 - Bierbaum, Stefanie A1 - Albracht, Kirsten T1 - Plasticity of human Achilles tendon mechanical and morphological properties in response to cyclic strain JF - Journal of Biomechanics N2 - The purpose of the current study in combination with our previous published data (Arampatzis et al., 2007) was to examine the effects of a controlled modulation of strain magnitude and strain frequency applied to the Achilles tendon on the plasticity of tendon mechanical and morphological properties. Eleven male adults (23.9±2.2 yr) participated in the study. The participants exercised one leg at low magnitude tendon strain (2.97±0.47%), and the other leg at high tendon strain magnitude (4.72±1.08%) of similar frequency (0.5 Hz, 1 s loading, 1 s relaxation) and exercise volume (integral of the plantar flexion moment over time) for 14 weeks, 4 days per week, 5 sets per session. The exercise volume was similar to the intervention of our earlier study (0.17 Hz frequency; 3 s loading, 3 s relaxation) allowing a direct comparison of the results. Before and after the intervention ankle joint moment has been measured by a dynamometer, tendon–aponeurosis elongation by ultrasound and cross-sectional area of the Achilles tendon by magnet resonance images (MRI). We found a decrease in strain at a given tendon force, an increase in tendon–aponeurosis stiffness and tendon elastic modulus of the Achilles tendon only in the leg exercised at high strain magnitude. The cross-sectional area (CSA) of the Achilles tendon did not show any statistically significant (P>0.05) differences to the pre-exercise values in both legs. The results indicate a superior improvement in tendon properties (stiffness, elastic modulus and CSA) at the low frequency (0.17 Hz) compared to the high strain frequency (0.5 Hz) protocol. These findings provide evidence that the strain magnitude applied to the Achilles tendon should exceed the value, which occurs during habitual activities to trigger adaptational effects and that higher tendon strain duration per contraction leads to superior tendon adaptational responses. Y1 - 2010 U6 - http://dx.doi.org/10.1016/j.jbiomech.2010.08.014 SN - 0021-9290 VL - 43 IS - 16 SP - 3073 EP - 3079 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Heinzel, Alexander A1 - Schäfer, Ralf A1 - Müller, Hans-Wilhelm A1 - Schieffer, Andre A1 - Ingenhag, Ariane A1 - Eickhoff, Simon B. A1 - Northoff, Georg A1 - Franz, Matthias A1 - Hautzel, Hubertus T1 - Increased Activation of the Supragenual Anterior Cingulate Cortex during Visual Emotional Processing in Male Subjects with High Degrees of Alexithymia: An Event-Related fMRI Study JF - Psychotherapy and Psychosomatics N2 - Background: One of the most prominent neurobiological models of alexithymia assumes an altered function of the anterior cingulate cortex (ACC) as the crucial neural correlate of alexithymia. So far functional imaging studies have yielded inconclusive results. Therefore, we tested this hypothesis in healthy alexithymics and nonalexithymics in an event-related fMRI study. Methods: Thirty high- and 30 low-alexithymic right-handed male subjects (selected by the 20-item Toronto Alexithymia Scale, TAS-20) were investigated with event-related fMRI using a picture viewing paradigm. The stimuli consisted of happy, fearful and neutral facial expressions (Ekman-Friesen) as well as positive, negative and neutral pictures from the International Affective Picture System. Results: Contrasting the high-alexithymic with the low-alexithymic group we observed increased activation of the supragenual ACC for different emotional valences as well as for different emotional stimuli. Moreover, there was a positive correlation of the ACC with the individual TAS-20 scores but no correlations with the individual Beck Depression Inventory scores. Additionally, there was no difference in activity of the amygdala. Conclusions: We demonstrated that the supragenual ACC is constantly activated more strongly in alexithymic subjects and that this activation is related to the symptoms of alexithymia and not to associated symptoms such as depression. Therefore, our findings support the hypothesis of an altered function of the ACC in alexithymia. Y1 - 2010 U6 - http://dx.doi.org/10.1159/000320121 SN - 0033-3190 VL - 79 IS - 6 SP - 363 EP - 370 PB - Karger CY - Basel ER - TY - JOUR A1 - Turaliyeva, M. A1 - Yeshibaev, A. A1 - Saparbekova, A. A1 - Akynova, L. A1 - Abildayeva, R. A1 - Sadenova, M. A1 - Sartayeva, K. A1 - Schieffer, Andre A1 - Digel, Ilya T1 - Species composition and injuriousness of stranger xylophilous fauna affecting indigenous urban dendroflora of Central Asia JF - Asian journal of microbiology, biotechnology & environmental sciences : AJMBES N2 - At the present time, one of the most serious environmental problems of Central Asia and South Kazakhstan is the ongoing large-scale deterioration of principal urban tree populations. Several major centers of massive spread of invasive plant pests have been found in urban dendroflora of this region. The degree of damage of seven most wide-spread aboriginal tree species was found to range from 21.4±1.1 to 85.4±1.8%. In particular, the integrity of the native communities of sycamore (Platanus spp.), willow (Salix spp.), poplar (Populus spp.) and elm (Ulmus spp.) is highly endangered. Our taxonomic analysis of the most dangerous tree pests of the region has revealed them as neobiontic xylophilous insects such as Cossus cossus L. (Order: Lepidoptera L.) Monochamus urussovi Fisch., Monochamus sutor L., Acanthocinus aedelis L. and Ñetonia aureate L. (Order: Coleoptera L.). We relate the origin of this threatening trend with the import of industrial wood in the mid 90’s of the last century that was associated with high degree of the constructional work in the region. Because of the absence of efficient natural predators of the pest species, the application of microbiological methods of the pest control and limitation is suggested. Y1 - 2016 SN - 0972-3005 VL - 18 IS - 2 SP - 359 EP - 366 PB - EM International ER - TY - JOUR A1 - Heinzel, Alexander A1 - Schäfer, Ralf A1 - Müller, Hans-Wilhelm A1 - Schieffer, Andre A1 - Ingenhag, Ariane A1 - Northoff, Georg A1 - Franz, Matthias A1 - Hautzel, Hubertus T1 - Differential modulation of valence and arousal in high-alexithymic and low-alexithymic individuals JF - Neuroreport N2 - High-alexithymic individuals are characterized by an impaired ability to identify and communicate emotions whereas low-alexithymic individuals have a wide-ranging ability to deal with emotions. This study examined the hypothesis that valence and arousal modifications of emotional stimuli differentially modulate cortical regions in high-alexithymic and low-alexithymic individuals. To this end, 28 high-alexithymic and 25 low-alexithymic individuals were investigated with event-related fMRI using visual emotional stimuli. We found differential neural activations in the dorsal anterior cingulate, the insula and the amygdala. We suggest that these differences may account for the impaired ability of high-alexithymic individuals to appropriately handle emotional stimuli. Y1 - 2010 U6 - http://dx.doi.org/10.1097/WNR.0b013e32833f38e0 SN - 1473-558X VL - 21 IS - 15 SP - 998 EP - 1002 PB - Lippincott Williams & Wilkins CY - London ER - TY - JOUR A1 - Kozhalakova, A. A. A1 - Zhubanova, Azhar A. A1 - Mansurov, Z. A. A1 - Digel, Ilya A1 - Tazhibayeva, S. M. A1 - Artmann, Gerhard A1 - Temiz Artmann, Aysegül T1 - Adsorption of bacterial lipopolysaccharides on carbonized rice shell JF - Science of Central Asia (2010) Y1 - 2010 SP - 50 EP - 54 ER - TY - JOUR A1 - Digel, Ilya T1 - In-situ biological decontamination of an ice melting probe Y1 - 2010 N1 - 38th COSPAR Scientific Assembly. Held 18-15 July 2010, in Bremen, Germany Abstract unter https://www.cospar-assembly.org/abstractcd/OLD/COSPAR-10/abstracts/data/pdf/abstracts/F36-0013-10.pdf ER - TY - JOUR A1 - Kurz, R. A1 - Linder, Peter A1 - Trzewik, Jürgen A1 - Rüffer, M. A1 - Artmann, Gerhard A1 - Digel, Ilya A1 - Rothermel, A. A1 - Robitzki, A. A1 - Temiz Artmann, Aysegül T1 - Contractile tension and beating rates of self-exciting monolayers and 3D-tissue constructs of neonatal rat cardiomyocytes JF - Medical and Biological Engineering and Computing N2 - The CellDrum technology (The term 'CellDrum technology' includes a couple of slightly different technological setups for measuring lateral mechanical tension in various types of cell monolayers or 3D-tissue constructs) was designed to quantify the contraction rate and mechanical tension of self-exciting cardiac myocytes. Cells were grown either within flexible, circular collagen gels or as monolayer on top of respective 1-mum thin silicone membranes. Membrane and cells were bulged outwards by air pressure. This biaxial strain distribution is rather similar the beating, blood-filled heart. The setup allowed presetting the mechanical residual stress level externally by adjusting the centre deflection, thus, mimicking hypertension in vitro. Tension was measured as oscillating differential pressure change between chamber and environment. A 0.5-mm thick collagen-cardiac myocyte tissue construct induced after 2 days of culturing (initial cell density 2 x 10(4) cells/ml), a mechanical tension of 1.62 +/- 0.17 microN/mm(2). Mechanical load is an important growth regulator in the developing heart, and the orientation and alignment of cardiomyocytes is stress sensitive. Therefore, it was necessary to develop the CellDrum technology with its biaxial stress-strain distribution and defined mechanical boundary conditions. Cells were exposed to strain in two directions, radially and circumferentially, which is similar to biaxial loading in real heart tissues. Thus, from a biomechanical point of view, the system is preferable to previous setups based on uniaxial stretching. Y1 - 2010 U6 - http://dx.doi.org/10.1007/s11517-009-0552-y SN - 1741-0444 VL - 48 IS - 1 SP - 59 EP - 65 PB - Springer Nature CY - Cham ER - TY - JOUR A1 - Albanna, Walid A1 - Kotliar, Konstantin A1 - Lüke, Jan Niklas A1 - Alpdogan, Serdar A1 - Conzen, Catharina A1 - Lindauer, Ute A1 - Clusmann, Hans A1 - Hescheler, Jürgen A1 - Vilser, Walthard A1 - Schneider, Toni A1 - Schubert, Gerrit Alexander T1 - Non-invasive evaluation of neurovascular coupling in the murine retina by dynamic retinal vessel analysis JF - Plos one N2 - Background Impairment of neurovascular coupling (NVC) was recently reported in the context of subarachnoid hemorrhage and may correlate with disease severity and outcome. However, previous techniques to evaluate NVC required invasive procedures. Retinal vessels may represent an alternative option for non-invasive assessment of NVC. Methods A prototype of an adapted retinal vessel analyzer was used to assess retinal vessel diameter in mice. Dynamic vessel analysis (DVA) included an application of monochromatic flicker light impulses in predefined frequencies for evaluating NVC. All retinae were harvested after DVA and electroretinograms were performed. Results A total of 104 retinal scans were conducted in 21 male mice (90 scans). Quantitative arterial recordings were feasible only in a minority of animals, showing an emphasized reaction to flicker light impulses (8 mice; 14 scans). A characteristic venous response to flicker light, however, could observed in the majority of animals. Repeated measurements resulted in a significant decrease of baseline venous diameter (7 mice; 7 scans, p < 0.05). Ex-vivo electroretinograms, performed after in-vivo DVA, demonstrated a significant reduction of transretinal signaling in animals with repeated DVA (n = 6, p < 0.001). Conclusions To the best of our knowledge, this is the first non-invasive study assessing murine retinal vessel response to flicker light with characteristic changes in NVC. The imaging system can be used for basic research and enables the investigation of retinal vessel dimension and function in control mice and genetically modified animals. Y1 - 2018 U6 - http://dx.doi.org/10.1371/journal.pone.0204689 VL - 13 IS - 10 PB - PLOS CY - San Francisco ER - TY - JOUR A1 - Herssens, Nolan A1 - Cowburn, James A1 - Albracht, Kirsten A1 - Braunstein, Bjoern A1 - Cazzola, Dario A1 - Colyer, Steffi A1 - Minetti, Alberto E. A1 - Pavei, Gaspare A1 - Rittweger, Jörn A1 - Weber, Tobias A1 - Green, David A. ED - Cattaneo, Luigi T1 - Movement in low gravity environments (MoLo) programme – the MoLo-L.O.O.P. study protocol JF - PLOS ONE / Public Library of Science N2 - Exposure to prolonged periods in microgravity is associated with deconditioning of the musculoskeletal system due to chronic changes in mechanical stimulation. Given astronauts will operate on the Lunar surface for extended periods of time, it is critical to quantify both external (e.g., ground reaction forces) and internal (e.g., joint reaction forces) loads of relevant movements performed during Lunar missions. Such knowledge is key to predict musculoskeletal deconditioning and determine appropriate exercise countermeasures associated with extended exposure to hypogravity. Y1 - 2022 U6 - http://dx.doi.org/10.1371/journal.pone.0278051 SN - 1932-6203 VL - 17 IS - 11 PB - Plos CY - San Francisco ER - TY - JOUR A1 - Albanna, W. A1 - Conzen, C. A1 - Weiss, M. A1 - Clusmann, H. A1 - Fuest, M. A1 - Mueller, M. A1 - Brockmann, M.A. A1 - Vilser, W. A1 - Schmidt-Trucksäss, A. A1 - Hoellig, A. A1 - Seiz, M. A1 - Thomé, C. A1 - Kotliar, Konstantin A1 - Schubert, G.A. T1 - Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study JF - PLoS ONE N2 - Background Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH. Methods In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2–14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling. Results Image quality was satisfactory in the majority of cases (93.3%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion. Conclusion RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort. Y1 - 2016 U6 - http://dx.doi.org/10.1371/journal.pone.0158781 SN - 1932-6203 VL - 11 IS - 7 PB - PLOS CY - San Francisco ER - TY - JOUR A1 - Kolditz, Melanie A1 - Albin, Thivaharan A1 - Abel, Dirk A1 - Fasse, Alessandro A1 - Brüggemann, Gert-Peter A1 - Albracht, Kirsten T1 - Evaluation of foot position and orientation as manipulated variables to control external knee adduction moments in leg extension training JF - Computer methods and programs in biomedicine N2 - Background and Objective Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed. Methods Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position. Results Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector. Conclusions The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training. KW - External knee adduction moments KW - Manipulated variables KW - Inverse dynamic problem KW - Inverse kinematic problem KW - Musculoskeletal model Y1 - 2016 U6 - http://dx.doi.org/10.1016/j.cmpb.2016.09.005 SN - 0169-2607 N1 - Part of special issue: "SI: Personalised Models and System Identification" VL - 171 SP - 81 EP - 86 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Garhofer, Gerhard A1 - Bek, Toke A1 - Boehm, Andreas G. A1 - Gherghel, Doina A1 - Grundwald, Juan A1 - Jeppesen, Peter A1 - Kergoat, Hélène A1 - Kotliar, Konstantin A1 - Lanzl, Ines A1 - Lovasik, John V. A1 - Nagel, Edgar A1 - Vilser, Walthard A1 - Orgul, Selim A1 - Schmetterer, Leopold T1 - Use of the retinal vessel analyzer in ocular blood flow research JF - Acta Ophthalmol N2 - The present article describes a standard instrument for the continuous online determination of retinal vessel diameters, the commercially available retinal vessel analyzer. This report is intended to provide informed guidelines for measuring ocular blood flow with this system. The report describes the principles underlying the method and the instruments currently available, and discusses clinical protocol and the specific parameters measured by the system. Unresolved questions and the possible limitations of the technique are also discussed. Y1 - 2010 U6 - http://dx.doi.org/10.1111/j.1755-3768.2009.01587.x SN - 1755-3768 VL - 88 IS - 7 SP - 717 EP - 722 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Pressler, Axel A1 - Esefeld, Katrin A1 - Scherr, Johannes A1 - Ali, Mohammad A1 - Hanssen, Henner A1 - Kotliar, Konstantin A1 - Lanzl, Ines A1 - Halle, Martin A1 - Kaemmerer, Harald A1 - Schmidt-Trucksäss, Arno A1 - Hager, Alfred T1 - Structural alterations of retinal arterioles in adults late after repair of aortic isthmic coarctation JF - The American Journal of Cardiology N2 - Patients after coarctation repair still have an increased risk of cardiovascular or cerebrovascular events. This has been explained by the persisting hypertension and alterations in the peripheral vessels. However, involvement of the central vessels such as the retinal arteries is virtually unknown. A total of 34 patients after coarctation repair (22 men and 12 women; 23 to 58 years old, age range 0 to 32 years at surgical repair) and 34 nonhypertensive controls underwent structural and functional retinal vessel analysis. Using structural analysis, the vessel diameters were measured. Using functional analysis, the endothelium-dependent vessel dilation in response to flicker light stimulation was assessed. In the patients after coarctation repair, the retinal arteriolar diameter was significantly reduced compared to that of the controls (median 182 μm, first to third quartile 171 to 197; vs 197 μm, first to third quartile 193 to 206; p <0.001). These findings were independent of the peripheral blood pressure and age at intervention. No differences were found for venules. The functional analysis findings were not different between the patients and controls (maximum dilation 3.5%, first to third quartile 2.1% to 4.5% vs 3.6%, first to third quartile 2.2% to 4.3%; p = 0.81), indicating preserved autoregulative mechanisms. In conclusion, the retinal artery diameter is reduced in patients after coarctation repair, independent of their current blood pressure level and age at intervention. As a structural marker of chronic vessel damage associated with past, current, or future hypertension, retinal arteriolar narrowing has been linked to stroke incidence. These results indicate an involvement of cerebral microcirculation in aortic coarctation, despite timely repair, and might contribute to explain the increased rate of cerebrovascular events in such patients. Y1 - 2010 U6 - http://dx.doi.org/10.1016/j.amjcard.2009.10.070 SN - 0002-9149 VL - 105 IS - 5 SP - 740 EP - 744 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Wiescher, A. A1 - Kotliar, Konstantin A1 - Neuhann, T. A1 - Lanzl, Ines M. T1 - Rasch progrediente Visusminderung beider Augen bei einem jungen Patienten JF - Der Ophthalmologe N2 - Ein 34-jähriger männlicher Patient stellte sich zur Abklärung einer seit dem 9. Lebensjahr bestehenden und im letzten Jahr rasch progredienten Visusminderung beider Augen bei uns vor. Er beschrieb eine subjektiv zunehmende, im Spiegel für ihn selbst sichtbare, weißliche Trübung in der Pupille beidseits und eine starke Blendempfindlichkeit. Nebenbefundlich gab er rezidivierende Konjunktivitiden und morgens verklebte Lider an. Eine Allergie auf Gräserpollen und eine Unverträglichkeit auf Alkohol sowie mehrere Lebensmittel seien ebenfalls bekannt. Zusätzlich leidet der Patient an stark ausgeprägtem atopischem Ekzem. Dieses wurde nie systemisch, sondern nur bei Bedarf mit kortisonhaltiger Salbe therapiert. Y1 - 2010 U6 - http://dx.doi.org/10.1007/s00347-007-1586-x SN - 1433-0423 VL - 105 IS - 4 SP - 389 EP - 392 PB - Springer CY - Berlin ER - TY - JOUR A1 - Lanzl, Ines M. A1 - Seidova, Seid-Fatima A1 - Erben, A. A1 - Thürmel, K. A1 - Kotliar, Konstantin T1 - Diffuse stromale Hornhauttrübungen und Veränderungen der Hände JF - Der Ophthalmologe N2 - Bilaterale stromale Hornhauttrübungen sind für den Augenarzt eine differenzialdiagnostische Herausforderung. Im folgenden Beitrag werden 2 Patieninnen (30 und 36 Jahre) mit unterschiedlich stark ausgeprägter stromaler diffuser Hornhauttrübung vorgestellt. Patientin 1 war kleinwüchsig (114 cm) und Patientin 2 normal groß (172 cm). Beide Patientinnen wiesen veränderte Gelenkstrukturen an Hand und Fußgelenken sowie diffuse stromale Hornhauttrübungen auf. Des Weiteren lagen eine Mitral- und Aorteninsuffizienz (Patientin 1) bzw. eine Aorteninsuffizienz (Patientin 2) vor. Die stromalen diffusen Hornhauttrübungen ließen im Zusammenhang mit den Gelenkveränderungen ein Scheie-Syndrom vermuten. Therapeutisch ist bei Patienten mit Visusminderung eine (lamelläre) Keratoplastik sinnvoll. Y1 - 2010 U6 - http://dx.doi.org/10.1007/s00347-009-2066-2 SN - 1433-0423 VL - 107 IS - 4 SP - 363 EP - 365 PB - Springer CY - Berlin ER - TY - JOUR A1 - Kotliar, Konstantin A1 - Nagel, Edgar A1 - Vilser, Walthard A1 - Seidova, Seid-Fatima A1 - Lanzl, Ines T1 - Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension JF - Investigative Ophthalmology & Visual Science, IOVS N2 - Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530–600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation. Y1 - 2010 U6 - http://dx.doi.org/10.1167/iovs.09-3649 SN - 0146-0404 VL - 51 IS - 4 SP - 2165 EP - 2172 PB - ARVO CY - Rockville, Md. ER -