@article{JuergensBieniussaVoelkeretal.2020, author = {Juergens, Lukas and Bieniussa, Linda and Voelker, Johannes and Hagen, Rudolf and Rak, Kristen}, title = {Spatio-temporal distribution of tubulin-binding cofactors and posttranslational modifications of tubulin in the cochlea of mice}, series = {Histochemistry and Cell Biology}, volume = {154}, journal = {Histochemistry and Cell Biology}, issn = {0948-6143}, doi = {10.1007/s00418-020-01905-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234852}, pages = {671-681}, year = {2020}, abstract = {The five tubulin-binding cofactors (TBC) are involved in tubulin synthesis and the formation of microtubules. Their importance is highlighted by various diseases and syndromes caused by dysfunction or mutation of these proteins. Posttranslational modifications (PTMs) of tubulin promote different characteristics, including stability-creating subpopulations of tubulin. Cell- and time-specific distribution of PTMs has only been investigated in the organ of Corti in gerbils. The aim of the presented study was to investigate the cell type-specific and time-specific expression patterns of TBC proteins and PTMs for the first time in murine cochleae over several developmental stages. For this, murine cochleae were investigated at the postnatal (P) age P1, P7 and P14 by immunofluorescence analysis. The investigations revealed several profound interspecies differences in the distribution of PTMs between gerbil and mouse. Furthermore, this is the first study to describe the spatio-temporal distribution of TBCs in any tissue ever showing a volatile pattern of expression. The expression analysis of TBC proteins and PTMs of tubulin reveals that these proteins play a role in the physiological development of the cochlea and might be essential for hearing.}, language = {en} } @article{FriedrichSchneiderBuerkleinetal.2023, author = {Friedrich, Maximilian U. and Schneider, Erich and Buerklein, Miriam and Taeger, Johannes and Hartig, Johannes and Volkmann, Jens and Peach, Robert and Zeller, Daniel}, title = {Smartphone video nystagmography using convolutional neural networks: ConVNG}, series = {Journal of Neurology}, volume = {270}, journal = {Journal of Neurology}, number = {5}, doi = {10.1007/s00415-022-11493-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324526}, pages = {2518-2530}, year = {2023}, abstract = {Background Eye movement abnormalities are commonplace in neurological disorders. However, unaided eye movement assessments lack granularity. Although videooculography (VOG) improves diagnostic accuracy, resource intensiveness precludes its broad use. To bridge this care gap, we here validate a framework for smartphone video-based nystagmography capitalizing on recent computer vision advances. Methods A convolutional neural network was fine-tuned for pupil tracking using > 550 annotated frames: ConVNG. In a cross-sectional approach, slow-phase velocity of optokinetic nystagmus was calculated in 10 subjects using ConVNG and VOG. Equivalence of accuracy and precision was assessed using the "two one-sample t-test" (TOST) and Bayesian interval-null approaches. ConVNG was systematically compared to OpenFace and MediaPipe as computer vision (CV) benchmarks for gaze estimation. Results ConVNG tracking accuracy reached 9-15\% of an average pupil diameter. In a fully independent clinical video dataset, ConVNG robustly detected pupil keypoints (median prediction confidence 0.85). SPV measurement accuracy was equivalent to VOG (TOST p < 0.017; Bayes factors (BF) > 24). ConVNG, but not MediaPipe, achieved equivalence to VOG in all SPV calculations. Median precision was 0.30°/s for ConVNG, 0.7°/s for MediaPipe and 0.12°/s for VOG. ConVNG precision was significantly higher than MediaPipe in vertical planes, but both algorithms' precision was inferior to VOG. Conclusions ConVNG enables offline smartphone video nystagmography with an accuracy comparable to VOG and significantly higher precision than MediaPipe, a benchmark computer vision application for gaze estimation. This serves as a blueprint for highly accessible tools with potential to accelerate progress toward precise and personalized Medicine.}, language = {en} } @article{BahmerGupta2018, author = {Bahmer, Andreas and Gupta, Daya Shankar}, title = {Role of Oscillations in Auditory Temporal Processing: A General Model for Temporal Processing of Sensory Information in the Brain?}, series = {Frontiers in Neuroscience}, volume = {12}, journal = {Frontiers in Neuroscience}, number = {793}, issn = {1662-453X}, doi = {10.3389/fnins.2018.00793}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-196087}, year = {2018}, abstract = {We review the role of oscillations in the brain and in the auditory system showing that the ability of humans to distinguish changes in pitch can be explained as a precise analysis of temporal information in auditory signals by neural oscillations. The connections between auditory brain stem chopper neurons construct neural oscillators, which discharge spikes at various constant intervals that are integer multiples of 0.4 ms, contributing to the temporal processing of auditory cochlear output. This is subsequently spatially mapped in the inferior colliculus. Electrophysiological measurements of auditory chopper neurons in different species show oscillations with periods which are integer multiples of 0.4 ms. The constant intervals of 0.4 ms can be attributed to the smallest synaptic delay between interconnected simulated chopper neurons. We also note the patterns of similarities between microcircuits in the brain stem and other parts of the brain (e.g., the pallidum, reticular formation, locus coeruleus, oculomotor nuclei, limbic system, amygdala, hippocampus, basal ganglia and substantia nigra), dedicated to the processing of temporal information. Similarities in microcircuits across the brain reflect the importance of one of the key mechanisms in the information processing in the brain, namely the temporal coupling of different neural events via coincidence detection.}, language = {en} } @article{GreiserGreiserAhrensetal.2012, author = {Greiser, Eberhard M. and Greiser, Karin Halina and Ahrens, Wolfgang and Hagen, Rudolf and Lazszig, Roland and Maier, Heinz and Schick, Bernhard and Zenner, Hans Peter}, title = {Risk factors for nasal malignancies in German men: the South-German Nasal cancer study}, series = {BMC Cancer}, volume = {12}, journal = {BMC Cancer}, number = {506}, doi = {10.1186/1471-2407-12-506}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-133365}, year = {2012}, abstract = {Background: There are few studies of the effects of nasal snuff and environmental factors on the risk of nasal cancer. This study aimed to investigate the impact of using nasal snuff and of other risk factors on the risk of nasal cancer in German men. Methods: A population-based case-control study was conducted in the German Federal States of Bavaria and Baden-Wurttemberg. Tumor registries and ear, nose and throat departments provided access to patients born in 1926 or later. Results: Telephone interviews were conducted with 427 cases (mean age 62.1 years) and 2.401 population-based controls (mean age 60.8 years). Ever-use of nasal snuff was associated with an odds ratio (OR) for nasal cancer of 1.45 (95\% confidence interval [CI] 0.88-2.38) in the total study population, whereas OR in smokers was 2.01 (95\% CI 1.00-4.02) and in never smokers was 1.10 (95\% CI 0.43-2.80). The OR in ever-smokers vs. never-smokers was 1.60 (95\% CI 1.24-2.07), with an OR of 1.06 (95\% CI 1.05-1.07) per pack-year smoked, and the risk was significantly decreased after quitting smoking. Exposure to hardwood dust for at least 1 year resulted in an OR of 2.33 (95\% CI 1.40-3.91) in the total population, which was further increased in never-smokers (OR 4.89, 95\% CI 1.92-12.49) in analyses stratified by smoking status. The OR for nasal cancer after exposure to organic solvents for at least 1 year was 1.53 (1.17-2.01). Ever-use of nasal sprays/nasal lavage for at least 1 month rendered an OR of 1.59 (1.04-2.44). The OR after use of insecticides in homes was 1.48 (95\% CI 1.04-2.11). Conclusions: Smoking and exposure to hardwood dust were confirmed as risk factors for nasal carcinoma. There is evidence that exposure to organic solvents, and in-house use of insecticides could represent novel risk factors. Exposure to asbestos and use of nasal snuff were risk factors in smokers only.}, language = {en} } @article{GehrkeScherzadHagenetal.2019, author = {Gehrke, Thomas and Scherzad, Agmal and Hagen, Rudolf and Hackenberg, Stephan}, title = {Risk factors for children requiring adenotonsillectomy and their impact on postoperative complications: a retrospective analysis of 2000 patients}, series = {Anaesthesia}, volume = {74}, journal = {Anaesthesia}, number = {12}, doi = {10.1111/anae.14844}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204787}, pages = {1572-1579}, year = {2019}, abstract = {Adenotonsillectomies are commonly performed procedures and sleep-disordered breathing is becoming increasingly important as an indication for surgery. Because of the higher risks in patients with obstructive sleep apnoea, the required level of postoperative care for these patients is currently under discussion, and better identification of patients at risk may reduce unnecessary postoperative monitoring. To evaluate the influence of obstructive sleep apnoea, and other risk factors, on peri-operative complications in children requiring adenotonsillectomy, we performed a retrospective case-control study that included 1995 patients treated between January 2009 and June 2017. In our analysis, young age (OR 3.8, 95\%CI 2.1-7.1), low body weight (OR 2.6, 95\%CI 1.5-4.4), obstructive sleep apnoea (OR 2.4, 95\%CI 1.5-3.8), pre-existing craniofacial or syndromal disorders (OR 2.3, 95\%CI 1.4-3.8) and adenotonsillectomy, compared with adenoidectomy alone, (OR 7.9, 95\%CI 4.7-13.1) were identified as risk factors for complications during or after surgery, p < 0.001. All 13 patients suffering from complications more than 3 h postoperatively had obstructive sleep apnoea plus at least one more of these risk factors. Patients at risk of postoperative complications can therefore be identified by several criteria pre-operatively, and should be monitored postoperatively using pulse oximetry overnight. For all other patients, postoperative observation on a surgical ward without extra monitoring is sufficient. Admission to paediatric intensive care should be reserved for patients suffering serious intra-operative complications.}, language = {en} } @article{StelzigJacobMueller2011, author = {Stelzig, Yvonne and Jacob, Roland and Mueller, Joachim}, title = {Preliminary speech recognition results after cochlear implantation in patients with unilateral hearing loss: a case series}, series = {Journal of Medical Case Reports}, volume = {5}, journal = {Journal of Medical Case Reports}, number = {343}, doi = {10.1186/1752-1947-5-343}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-141722}, year = {2011}, abstract = {Introduction Cochlear implants known to provide support in individuals with bilateral hearing loss may also be of great benefit for individuals with unilateral hearing loss. This case report demonstrates the positive effects of cochlear implantation on speech understanding in noise conditions in patients with unilateral hearing loss and normal hearing on the contralateral side. To the best of our knowledge, the data presented here are from the first few cases to receive a cochlear implant for unilateral hearing loss. Case presentation Four Caucasian German men, two aged 48 and the others aged 51 and 57 years old, with post-lingual unilateral hearing loss and normal hearing on the contralateral side were implanted with a cochlear implant. All our patients were members of the German army. Before and after implantation, they were given a battery of speech tests in different hearing conditions to assess the effect of unilateral cochlear implantation on speech understanding in noise conditions. Test results showed that all patients benefited from unilateral cochlear implantation, particularly in terms of speech understanding in noise conditions. Conclusions Unilateral cochlear implantation might be a successful treatment method for patients with unilateral hearing loss not benefiting from alternative treatment options. The results of this case report open up the field of cochlear implantation for expanded criteria and new areas of research.}, language = {en} } @article{MeyerGerhardHartmannLodesetal.2021, author = {Meyer, Till Jasper and Gerhard-Hartmann, Elena and Lodes, Nina and Scherzad, Agmal and Hagen, Rudolf and Steinke, Maria and Hackenberg, Stephan}, title = {Pilot study on the value of Raman spectroscopy in the entity assignment of salivary gland tumors}, series = {PLoS One}, volume = {16}, journal = {PLoS One}, number = {9}, doi = {10.1371/journal.pone.0257470}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-264736}, year = {2021}, abstract = {Background The entity assignment of salivary gland tumors (SGT) based on histomorphology can be challenging. Raman spectroscopy has been applied to analyze differences in the molecular composition of tissues. The aim of this study was to evaluate the suitability of RS for entity assignment in SGT. Methods Raman data were collected in deparaffinized sections of pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC). Multivariate data and chemometric analysis were completed using the Unscrambler software. Results The Raman spectra detected in ACC samples were mostly assigned to nucleic acids, lipids, and amides. In a principal component-based linear discriminant analysis (LDA) 18 of 20 tumor samples were classified correctly. Conclusion In this proof of concept study, we show that a reliable SGT diagnosis based on LDA algorithm appears possible, despite variations in the entity-specific mean spectra. However, a standardized workflow for tissue sample preparation, measurement setup, and chemometric algorithms is essential to get reliable results.}, language = {en} } @article{PolatKaiserWohllebenetal.2017, author = {Polat, B{\"u}lent and Kaiser, Philipp and Wohlleben, Gisela and Gehrke, Thomas and Scherzad, Agmal and Scheich, Matthias and Malzahn, Uwe and Fischer, Thomas and Vordermark, Dirk and Flentje, Michael}, title = {Perioperative changes in osteopontin and TGFβ1 plasma levels and their prognostic impact for radiotherapy in head and neck cancer}, series = {BMC Cancer}, volume = {17}, journal = {BMC Cancer}, number = {6}, doi = {10.1186/s12885-016-3024-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157529}, year = {2017}, abstract = {Background: In head and neck cancer little is known about the kinetics of osteopontin (OPN) expression after tumor resection. In this study we evaluated the time course of OPN plasma levels before and after surgery. Methods: Between 2011 and 2013 41 consecutive head and neck cancer patients were enrolled in a prospective study (group A). At different time points plasma samples were collected: T0) before, T1) 1 day, T2) 1 week and T3) 4 weeks after surgery. Osteopontin and TGFβ1 plasma concentrations were measured with a commercial ELISA system. Data were compared to 131 head and neck cancer patients treated with primary (n = 42) or postoperative radiotherapy (n = 89; group B1 and B2). Results: A significant OPN increase was seen as early as 1 day after surgery (T0 to T1, p < 0.01). OPN levels decreased to base line 3-4 weeks after surgery. OPN values were correlated with postoperative TGFβ1 expression suggesting a relation to wound healing. Survival analysis showed a significant benefit for patients with lower OPN levels both in the primary and postoperative radiotherapy group (B1: 33 vs 11.5 months, p = 0.017, B2: median not reached vs 33.4, p = 0.031). TGFβ1 was also of prognostic significance in group B1 (33.0 vs 10.7 months, p = 0.003). Conclusions: Patients with head and neck cancer showed an increase in osteopontin plasma levels directly after surgery. Four weeks later OPN concentration decreased to pre-surgery levels. This long lasting increase was presumably associated to wound healing. Both pretherapeutic osteopontin and TGFβ1 had prognostic impact.}, language = {en} } @article{BieniussaKahramanSkornickaetal.2022, author = {Bieniussa, Linda and Kahraman, Baran and Skornicka, Johannes and Schulte, Annemarie and Voelker, Johannes and Jablonka, Sibylle and Hagen, Rudolf and Rak, Kristen}, title = {Pegylated insulin-like growth factor 1 attenuates hair cell loss and promotes presynaptic maintenance of medial olivocochlear cholinergic fibers in the cochlea of the progressive motor neuropathy mouse}, series = {Frontiers in Neurology}, volume = {13}, journal = {Frontiers in Neurology}, issn = {1664-2295}, doi = {10.3389/fneur.2022.885026}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276669}, year = {2022}, abstract = {The progressive motor neuropathy (PMN) mouse is a model of an inherited motor neuropathy disease with progressive neurodegeneration. Axon degeneration associates with homozygous mutations of the TBCE gene encoding the tubulin chaperone E protein. TBCE is responsible for the correct dimerization of alpha and beta-tubulin. Strikingly, the PMN mouse also develops a progressive hearing loss after normal hearing onset, characterized by degeneration of the auditory nerve and outer hair cell (OHC) loss. However, the development of this neuronal and cochlear pathology is not fully understood yet. Previous studies with pegylated insulin-like growth factor 1 (peg-IGF-1) treatment in this mouse model have been shown to expand lifespan, weight, muscle strength, and motor coordination. Accordingly, peg-IGF-1 was evaluated for an otoprotective effect. We investigated the effect of peg-IGF-1 on the auditory system by treatment starting at postnatal day 15 (p15). Histological analysis revealed positive effects on OHC synapses of medial olivocochlear (MOC) neuronal fibers and a short-term attenuation of OHC loss. Peg-IGF-1 was able to conditionally restore the disorganization of OHC synapses and maintain the provision of cholinergic acetyltransferase in presynapses. To assess auditory function, frequency-specific auditory brainstem responses and distortion product otoacoustic emissions were recorded in animals on p21 and p28. However, despite the positive effect on MOC fibers and OHC, no restoration of hearing could be achieved. The present work demonstrates that the synaptic pathology of efferent MOC fibers in PMN mice represents a particular form of "efferent auditory neuropathy." Peg-IGF-1 showed an otoprotective effect by preventing the degeneration of OHCs and efferent synapses. However, enhanced efforts are needed to optimize the treatment to obtain detectable improvements in hearing performances.}, language = {en} } @article{EngertSpahnBieniussaetal.2023, author = {Engert, Jonas and Spahn, Bjoern and Bieniussa, Linda and Hagen, Rudolf and Rak, Kristen and Voelker, Johannes}, title = {Neurogenic stem cell niche in the auditory Thalamus: in vitro evidence of neural stem cells in the rat medial geniculate body}, series = {Life}, volume = {13}, journal = {Life}, number = {5}, issn = {2075-1729}, doi = {10.3390/life13051188}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319387}, year = {2023}, abstract = {The medial geniculate body (MGB) is a nucleus of the diencephalon representing a relevant segment of the auditory pathway and is part of the metathalamus. It receives afferent information via the inferior brachium of the inferior colliculus and transmits efferent fibers via acoustic radiations to the auditory cortex. Neural stem cells (NSCs) have been detected in certain areas along the auditory pathway. They are of great importance as the induction of an adult stem cell niche might open a regenerative approach to a causal treatment of hearing disorders. Up to now, the existence of NSCs in the MGB has not been determined. Therefore, this study investigated whether the MGB has a neural stem cell potential. For this purpose, cells were extracted from the MGB of PND 8 Sprague-Dawley rats and cultured in a free-floating cell culture assay, which showed mitotic activity and positive staining for stem cell and progenitor markers. In differentiation assays, the markers β-III-tubulin, GFAP, and MBP demonstrated the capacity of single cells to differentiate into neuronal and glial cells. In conclusion, cells from the MGB exhibited the cardinal features of NSCs: self-renewal, the formation of progenitor cells, and differentiation into all neuronal lineage cells. These findings may contribute to a better understanding of the development of the auditory pathway.}, language = {en} } @article{ZahnertLoewenheimBeutneretal.2016, author = {Zahnert, Thomas and L{\"o}wenheim, Hubert and Beutner, Dirk and Hagen, Rudolf and Ernst, Arneborg and Pau, Hans-Wilhelm and Zehlicke, Thorsten and K{\"u}hne, Hilke and Friese, Natascha and Tropitzsch, Anke and L{\"u}ers, Jan-Christoffer and Mlynski, Robert and Todt, Ingo and H{\"u}ttenbrink, Karl-Bernd}, title = {Multicenter Clinical Trial of Vibroplasty Couplers to Treat Mixed/Conductive Hearing Loss: First Results}, series = {Audiology and Neurotology}, volume = {21}, journal = {Audiology and Neurotology}, number = {4}, issn = {1420-3030}, doi = {10.1159/000444616}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-199129}, pages = {212-222}, year = {2016}, abstract = {Objective: To evaluate the safety and effectiveness of round window (RW), oval window (OW), CliP and Bell couplers for use with an active middle ear implant. Methods: This is a multicenter, long-term, prospective trial with consecutive enrollment, involving 6 university hospitals in Germany. Bone conduction, air conduction, implant-aided warble-tone thresholds and Freiburger monosyllable word recognition scores were compared with unaided preimplantation results in 28 moderate-to-profound hearing-impaired patients after 12 months of follow-up. All patients had previously undergone failed reconstruction surgeries (up to 5 or more). In a subset of patients, additional speech tests at 12 months postoperatively were used to compare the aided with the unaided condition after implantation with the processor switched off. An established quality-of-life questionnaire for hearing aids was used to determine patient satisfaction. Results: Postoperative bone conduction remained stable. Mean functional gain for all couplers was 37 dB HL (RW = 42 dB, OW = 35 dB, Bell = 38 dB, CliP = 27 dB). The mean postoperative Freiburger monosyllable score was 71\% at 65 dB SPL. The postimplantation mean SRT50 (speech reception in quiet for 50\% understanding of words in sentences) improved on average by 23 dB over unaided testing and signal-to-noise ratios also improved in all patients. The International Outcome Inventory for Hearing Aids (IOI-HA)quality-of-life questionnaire was scored very positively by all patients. Conclusion: A significant improvement was seen with all couplers, and patients were satisfied with the device at 12 months postoperatively. These results demonstrate that an active implant is an advantage in achieving good hearing benefit in patients with prior failed reconstruction surgery.}, language = {en} } @article{EngertDollVonaetal.2023, author = {Engert, Jonas and Doll, Julia and Vona, Barbara and Ehret Kasemo, Totta and Spahn, Bjoern and Hagen, Rudolf and Rak, Kristen and Voelker, Johannes}, title = {mRNA abundance of neurogenic factors correlates with hearing capacity in auditory brainstem nuclei of the rat}, series = {Life}, volume = {13}, journal = {Life}, number = {9}, issn = {2075-1729}, doi = {10.3390/life13091858}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357392}, year = {2023}, abstract = {Neural stem cells (NSCs) have previously been described up to the adult stage in the rat cochlear nucleus (CN). A decreasing neurogenic potential was observed with critical changes around hearing onset. A better understanding of molecular factors affecting NSCs and neurogenesis is of interest as they represent potential targets to treat the cause of neurologically based hearing disorders. The role of genes affecting NSC development and neurogenesis in CN over time on hearing capacity has remained unclear. This study investigated the mRNA abundance of genes influencing NSCs and neurogenesis in rats' CN over time. The CN of rats on postnatal days 6, 12, and 24 were examined. Real-time quantitative polymerase chain reaction arrays were used to compare mRNA levels of 84 genes relevant to NSCs and neurogenesis. Age- and hearing-specific patterns of changes in mRNA abundance of neurogenically relevant genes were detected in the rat CN. Additionally, crucial neurogenic factors with significant and relevant influence on neurogenesis were identified. The results of this work should contribute to a better understanding of the molecular mechanisms underlying the neurogenesis of the auditory pathway.}, language = {en} } @article{ScherzadMeyerKleinsasseretal.2017, author = {Scherzad, Agmal and Meyer, Till and Kleinsasser, Norbert and Hackenberg, Stephan}, title = {Molecular Mechanisms of Zinc Oxide Nanoparticle-Induced Genotoxicity Short Running Title: Genotoxicity of ZnO NPs}, series = {Materials}, volume = {10}, journal = {Materials}, number = {12}, doi = {10.3390/ma10121427}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169948}, pages = {1427}, year = {2017}, abstract = {Background: Zinc oxide nanoparticles (ZnO NPs) are among the most frequently applied nanomaterials in consumer products. Evidence exists regarding the cytotoxic effects of ZnO NPs in mammalian cells; however, knowledge about the potential genotoxicity of ZnO NPs is rare, and results presented in the current literature are inconsistent. Objectives: The aim of this review is to summarize the existing data regarding the DNA damage that ZnO NPs induce, and focus on the possible molecular mechanisms underlying genotoxic events. Methods: Electronic literature databases were systematically searched for studies that report on the genotoxicity of ZnO NPs. Results: Several methods and different endpoints demonstrate the genotoxic potential of ZnO NPs. Most publications describe in vitro assessments of the oxidative DNA damage triggered by dissoluted Zn2+ ions. Most genotoxicological investigations of ZnO NPs address acute exposure situations. Conclusion: Existing evidence indicates that ZnO NPs possibly have the potential to damage DNA. However, there is a lack of long-term exposure experiments that clarify the intracellular bioaccumulation of ZnO NPs and the possible mechanisms of DNA repair and cell survival.}, language = {en} } @article{TopsakalAgrawalAtlasetal.2022, author = {Topsakal, Vedat and Agrawal, Sumit and Atlas, Marcus and Baumgartner, Wolf-Dieter and Brown, Kevin and Bruce, Iain A. and Dazert, Stefan and Hagen, Rudolf and Lassaletta, Luis and Mlynski, Robert and Raine, Christopher H. and Rajan, Gunesh P. and Schmutzhard, Joachim and Sprinzl, Georg Mathias and Staecker, Hinrich and Usami, Shin-ichi and Van Rompaey, Vincent and Zernotti, Mario and Heyning, Paul van de}, title = {Minimally traumatic cochlear implant surgery: expert opinion in 2010 and 2020}, series = {Journal of Personalized Medicine}, volume = {12}, journal = {Journal of Personalized Medicine}, number = {10}, issn = {2075-4426}, doi = {10.3390/jpm12101551}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288196}, year = {2022}, abstract = {This study aimed to discover expert opinion on the surgical techniques and materials most likely to achieve maximum postoperative residual hearing preservation in cochlear implant (CI) surgery and to determine how these opinions have changed since 2010. A previously published questionnaire used in a study published in 2010 was adapted and expanded. The questionnaire was distributed to an international group of experienced CI surgeons. Present results were compared, via descriptive statistics, to those from the 2010 survey. Eighteen surgeons completed the questionnaire. Respondents clearly favored the following: round window insertion, slow array insertion, and the peri- and postoperative use of systematic antibiotics. Insertion depth was regarded as important, and electrode arrays less likely to induce trauma were preferred. The usefulness of dedicated soft-surgery training was also recognized. A lack of agreement was found on whether the middle ear cavity should be flushed with a non-aminoglycoside antibiotic solution or whether a sheath or insertion tube should be used to avoid contaminating the array with blood or bone dust. In conclusion, this paper demonstrates how beliefs about CI soft surgery have changed since 2010 and shows areas of current consensus and disagreement.}, language = {en} } @article{RadeloffRadeloffTiradoetal.2019, author = {Radeloff, Katrin and Radeloff, Andreas and Tirado, Mario Ramos and Scherzad, Agmal and Hagen, Rudolf and Kleinsasser, Norbert H. and Hackenberg, Stephan}, title = {Long-Term Impact of Zinc Oxide Nanoparticles on Differentiation and Cytokine Secretion of Human Adipose-Derived Stromal Cells}, series = {Materials}, volume = {12}, journal = {Materials}, number = {1823}, doi = {10.3390/ma12111823}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224779}, pages = {1-14}, year = {2019}, abstract = {Zinc oxide nanoparticles (ZnO-NPs) are widely utilized, for example in manufacturing paints and in the cosmetic industry. In addition, there is raising interest in the application of NPs in stem cell research. However, cytotoxic, genotoxic and pro-inflammatory effects were shown for NPs. The aim of this study was to evaluate the impact of ZnO-NPs on cytokine secretion and differentiation properties of human adipose tissue-derived stromal cells (ASCs). Human ASCs were exposed to the subtoxic concentration of 0.2 mu g/mL ZnO-NPs for 24 h. After four weeks of cultivation, adipogenic and osteogenic differentiation procedures were performed. The multi-differentiation potential was confirmed histologically and using polymerase chain reaction (PCR). In addition, the gene expression of IL-6, IL-8, vascular endothelial growth factor (VEGF) and caspase 3 was analyzed. Over the course of four weeks after ZnO-NPs exposure, no significant differences were detected in the gene expression of IL-6, IL-8, VEGF and caspase 3 compared to non-exposed cells. The differentiation was also not affected by the ZnO-NPs. These findings underline the fact, that functionality of ASCs is likely to be unaffected by ZnO-NPs, despite a long-term disposition of NPs in the cells, supposing that the starting concentration was safely in the non-toxic range. This might provide important information for single-use nanomedical applications of ZnO-NPs.}, language = {en} } @article{SchendzielorzFroelichRaketal.2016, author = {Schendzielorz, P. and Froelich, K. and Rak, K. and Gehrke, T. and Scherzad, A. and Hagen, R. and Radeloff, A.}, title = {Labeling Adipose-Derived Stem Cells with Hoechst 33342: Usability and Effects on Differentiation Potential and DNA Damage}, series = {Stem Cells International}, journal = {Stem Cells International}, doi = {10.1155/2016/6549347}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-181268}, year = {2016}, abstract = {Adipose-derived stem cells (ASCs) have been extensively studied in the field of stem cell research and possess numerous clinical applications. Cell labeling is an essential component of various experimental protocols and Hoechst 33342 (H33342) represents a cost-effective and easy methodology for live staining. The purpose of this study was to evaluate the labeling of rat ASCs with two different concentrations of H33342 (0.5 μg/mL and 5 μg/mL), with particular regard to usability, interference with cell properties, and potential DNA damage. Hoechst 33342 used at a low concentration of 0.5 μg/mL did not significantly affect cell proliferation, viability, or differentiation potential of the ASCs, nor did it cause any significant DNA damage as measured by the olive tail moment. High concentrations of 5 μg/mL H33342, however, impaired the proliferation and viability of the ASCs, and considerable DNA damage was observed. Undesirable colabeling of unlabeled cocultivated cells was seen in particular with higher concentrations of H33342, independent of varying washing procedures. Hence, H33342 labeling with lower concentrations represents a usable method, which does not affect the tested cell properties. However, the colabeling of adjacent cells is a drawback of the technique.}, language = {en} } @article{MoratinIckrathScherzadetal.2021, author = {Moratin, Helena and Ickrath, Pascal and Scherzad, Agmal and Meyer, Till Jasper and Naczenski, Sebastian and Hagen, Rudolf and Hackenberg, Stephan}, title = {Investigation of the immune modulatory potential of zinc oxide nanoparticles in human lymphocytes}, series = {Nanomaterials}, volume = {11}, journal = {Nanomaterials}, number = {3}, issn = {2079-4991}, doi = {10.3390/nano11030629}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234016}, year = {2021}, abstract = {Zinc oxide nanoparticles (ZnO-NP) are commonly used for a variety of applications in everyday life. In addition, due to its versatility, nanotechnology supports promising approaches in the medical sector. NP can act as drug-carriers in the context of targeted chemo- or immunotherapy, and might also exhibit autonomous immune-modulatory characteristics. Knowledge of potential immunosuppressive or stimulating effects of NP is indispensable for the safety of consumers as well as patients. In this study, primary human peripheral blood lymphocytes of 9 donors were treated with different sub-cytotoxic concentrations of ZnO-NP for the duration of 1, 2, or 3 days. Flow cytometry was performed to investigate changes in the activation profile and the proportion of T cell subpopulations. ZnO-NP applied in this study did not induce any significant alterations in the examined markers, indicating their lack of impairment in terms of immune modulation. However, physicochemical characteristics exert a major influence on NP-associated bioactivity. To allow a precise simulation of the complex molecular processes of immune modulation, a physiological model including the different components of an immune response is needed.}, language = {en} } @phdthesis{Moharam2020, author = {Moharam, Mona}, title = {Intraoperative monitoring of cochlear nerve function during acoustic neuroma surgery with transtemporal approach: Warning signs as predictors of postoperative hearing loss}, doi = {10.25972/OPUS-21136}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211365}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Objectives: The aim of this work is to define critical warning brainstem auditory evoked potential (BAEP) signs as a marker for the postoperative hearing outcome. Study design: Retrospective study Setting: Tertiary referral center Patients: 162 patients who underwent resection of acoustic neuroma via a transtemporal approach with intraoperative monitoring (IOM) at the Department of Otorhinolaryngology, Plastic, Esthetic and Reconstructive Head and Neck Surgery, from January 2011 to December 2017. Interventions: BAEP was performed in all patients; while intraoperative direct recording of the cochlear nerve function was done in 131 patients. Main Outcome Measure: postoperative hearing thresholds (Pure tone audiometry). Results: The most significant risk factor is the permanent loss of wave V as it increases the risk of postoperative hearing loss by 18 times; followed by three-steps increment of the stimulus intensity as it increases the risk by 5.75 times; and finally the response thresholds obtained during the intraoperative direct recording of cochlear nerve function. Each unite increment of the threshold increases the risk of postoperative hearing loss by 6.7\%. Conclusions: We believe that the intraoperative BAEP critical signs during IOM detected in this study can be used as a helpful tool to predict postoperative hearing loss in patients with acoustic neuroma.}, language = {en} } @article{WohllebenScherzadGuettleretal.2015, author = {Wohlleben, Gisela and Scherzad, Agmal and G{\"u}ttler, Antje and Vordermark, Dirk and Kuger, Sebastian and Flentje, Michael and Polat, Buelent}, title = {Influence of hypoxia and irradiation on osteopontin expression in head and neck cancer and glioblastoma cell lines}, series = {Radiation Oncology}, volume = {10}, journal = {Radiation Oncology}, number = {167}, doi = {10.1186/s13014-015-0473-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-125746}, year = {2015}, abstract = {Background Tumor hypoxia is a known risk factor for reduced response to radiotherapy. The evaluation of noninvasive methods for the detection of hypoxia is therefore of interest. Osteopontin (OPN) has been discussed as an endogenous hypoxia biomarker. It is overexpressed in many cancers and is involved in tumor progression and metastasis. Methods To examine the influence of hypoxia and irradiation on osteopontin expression we used different cell lines (head and neck cancer (Cal27 and FaDu) and glioblastoma multiforme (U251 and U87)). Cells were treated with hypoxia for 24 h and were then irradiated with doses of 2 and 8 Gy. Osteopontin expression was analyzed on mRNA level by quantitative real-time RT-PCR (qPCR) and on protein level by western blot. Cell culture supernatants were evaluated for secreted OPN by ELISA. Results Hypoxia caused an increase in osteopontin protein expression in all cell lines. In Cal27 a corresponding increase in OPN mRNA expression was observed. In contrast the other cell lines showed a reduced mRNA expression under hypoxic conditions. After irradiation OPN mRNA expression raised slightly in FaDu and U87 cells while it was reduced in U251 and stable in Cal27 cells under normoxia. The combined treatment (hypoxia and irradiation) led to a slight increase of OPN mRNA after 2 Gy in U251 (24 h) and in U87 (24 and 48 h) cell lines falling back to base line after 8 Gy. This effect was not seen in Cal27 or in FaDu cells. Secreted OPN was detected only in the two glioblastoma cell lines with reduced protein levels under hypoxic conditions. Again the combined treatment resulted in a minor increase in OPN secretion 48 hours after irradiation with 8 Gy. Conclusion Osteopontin expression is strongly modulated by hypoxia and only to a minor extent by irradiation. Intracellular OPN homeostasis seems to vary considerably between cell lines. This may explain the partly conflicting results concerning response prediction and prognosis in the clinical setting.}, language = {en} } @article{GinzkeyEickerMargetetal.2013, author = {Ginzkey, Christian and Eicker, Sven and Marget, Matthias and Krause, J{\"o}rg and Brecht, Stefan and Westphal, Manfred and Hugo, Heinz-Hermann and Mehdorn, Maximilian and Steinmann, J{\"o}rg and Hamel, Wolfgang}, title = {Incomplete tumour control following DNA vaccination against rat gliomas expressing a model antigen}, series = {Acta Neurochirurgica}, volume = {155}, journal = {Acta Neurochirurgica}, number = {1}, doi = {10.1007/s00701-012-1526-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-126775}, pages = {51-59}, year = {2013}, abstract = {Background Vaccination against tumour-associated antigens is one approach to elicit anti-tumour responses. We investigated the effect of polynucleotide (DNA) vaccination using a model antigen (E. coli lacZ) in a syngeneic gliosarcoma model (9L). Methods Fisher 344 rats were vaccinated thrice by intramuscular injection of a lacZ-encoding or a control plasmid in weekly intervals. One week after the last vaccination, lacZ-expressing 9L cells were implanted into the striatum. Results After 3 weeks, in lacZ-vaccinated animals the tumours were significantly smaller than in control-vaccinated animals. In cytotoxic T cell assays lysis rates of >50 \% could only be observed in a few of the lacZ-vaccinated animals. This response was directed against lacZ-expressing and parental 9L cells but not against syngeneic MADB 106 adenocarcinoma cells. In Elispot assays interferon-γ production was observed upon stimulation with 9LlacZ and 9L wild-type but not MADB 106 cells. This response was higher for lacZ-immunized animals. All animals revealed dense infiltrates with CD8+ lymphocytes and, to a lesser extent, with NK cells. CD25-staining indicated cells possibly associated with the maintenance of peripheral tolerance to self-antigens. All tumours were densely infiltrated by microglia consisting mostly of ramified cells. Only focal accumulation of macrophage-like cells expressing ED1, a marker for phagocytic activity, was observed. Conclusion Prophylactic DNA vaccination resulted in effective but incomplete suppression of brain tumour formation. Mechanisms other than cytotoxic T cell responses as measured in the generally used in vitro assays appear to play a role in tumour suppression.}, language = {en} }