TY - JOUR A1 - Zahnert, Thomas A1 - Löwenheim, Hubert A1 - Beutner, Dirk A1 - Hagen, Rudolf A1 - Ernst, Arneborg A1 - Pau, Hans-Wilhelm A1 - Zehlicke, Thorsten A1 - Kühne, Hilke A1 - Friese, Natascha A1 - Tropitzsch, Anke A1 - Lüers, Jan-Christoffer A1 - Mlynski, Robert A1 - Todt, Ingo A1 - Hüttenbrink, Karl-Bernd T1 - Multicenter Clinical Trial of Vibroplasty Couplers to Treat Mixed/Conductive Hearing Loss: First Results JF - Audiology and Neurotology N2 - 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. KW - conductive hearing loss KW - mixed hearing loss KW - vibroplasty KW - couplers KW - middle ear implant Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199129 SN - 1420-3030 SN - 1421-9700 N1 - This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively. VL - 21 IS - 4 ER - TY - JOUR A1 - Chumak, Tetyana A1 - Rüttiger, Lukas A1 - Lee, Sze Chim A1 - Campanelli, Dario A1 - Zuccotti, Annalisa A1 - Singer, Wibke A1 - Popelář, Jiří A1 - Gutsche, Katja A1 - Geisler, Hyun-Soon A1 - Schraven, Sebastian Philipp A1 - Jaumann, Mirko A1 - Panford-Walsh, Rama A1 - Hu, Jing A1 - Schimmang, Thomas A1 - Zimmermann, Ulrike A1 - Syka, Josef A1 - Knipper, Marlies T1 - BDNF in Lower Brain Parts Modifies Auditory Fiber Activity to Gain Fidelity but Increases the Risk for Generation of Central Noise After Injury JF - Molecular Neurobiology N2 - For all sensory organs, the establishment of spatial and temporal cortical resolution is assumed to be initiated by the first sensory experience and a BDNF-dependent increase in intracortical inhibition. To address the potential of cortical BDNF for sound processing, we used mice with a conditional deletion of BDNF in which Cre expression was under the control of the Pax2 or TrkC promoter. BDNF deletion profiles between these mice differ in the organ of Corti (BDNF \(^{Pax2}\) -KO) versus the auditory cortex and hippocampus (BDNF \(^{TrkC}\) -KO). We demonstrate that BDNF \(^{Pax2}\) -KO but not BDNF \(^{TrkC}\) -KO mice exhibit reduced sound-evoked suprathreshold ABR waves at the level of the auditory nerve (wave I) and inferior colliculus (IC) (wave IV), indicating that BDNF in lower brain regions but not in the auditory cortex improves sound sensitivity during hearing onset. Extracellular recording of IC neurons of BDNF \(^{Pax2}\) mutant mice revealed that the reduced sensitivity of auditory fibers in these mice went hand in hand with elevated thresholds, reduced dynamic range, prolonged latency, and increased inhibitory strength in IC neurons. Reduced parvalbumin-positive contacts were found in the ascending auditory circuit, including the auditory cortex and hippocampus of BDNF \(^{Pax2}\) -KO, but not of BDNF \(^{TrkC}\) -KO mice. Also, BDNF \(^{Pax2}\) -WT but not BDNF \(^{Pax2}\) -KO mice did lose basal inhibitory strength in IC neurons after acoustic trauma. These findings suggest that BDNF in the lower parts of the auditory system drives auditory fidelity along the entire ascending pathway up to the cortex by increasing inhibitory strength in behaviorally relevant frequency regions. Fidelity and inhibitory strength can be lost following auditory nerve injury leading to diminished sensory outcome and increased central noise. KW - Inner hair cell KW - Neurotropathic Factor KW - Hearing-loss KW - Alzheimers-disease KW - low-threshold fibers KW - cochlear nucleus neurons KW - Frequency-response areas KW - Inferior colliculus KW - Environmental enrichment KW - Synaptic plasticity KW - Cortical plasticity KW - BDNF KW - Central hyperactivity KW - High-spontaneous rate KW - Homeostatic plasticity KW - Sound detection threshold Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-187341 VL - 53 IS - 8 ER - TY - JOUR A1 - Schendzielorz, P. A1 - Froelich, K. A1 - Rak, K. A1 - Gehrke, T. A1 - Scherzad, A. A1 - Hagen, R. A1 - Radeloff, A. T1 - Labeling Adipose-Derived Stem Cells with Hoechst 33342: Usability and Effects on Differentiation Potential and DNA Damage JF - Stem Cells International N2 - 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. KW - cell labeling KW - adipose-derived stem cells KW - Hoechst 33342 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-181268 ER - TY - JOUR A1 - Kurabi, Arwa A1 - Pak, Kwang K. A1 - Bernhardt, Marlen A1 - Baird, Andrew A1 - Ryan, Allen F. T1 - Discovery of a Biological Mechanism of Active Transport through the Tympanic Membrane to the Middle Ear JF - Scientific Reports N2 - Otitis media (OM) is a common pediatric disease for which systemic antibiotics are often prescribed. While local treatment would avoid the systemic treatment side-effects, the tympanic membrane (TM) represents an impenetrable barrier unless surgically breached. We hypothesized that the TM might harbor innate biological mechanisms that could mediate trans-TM transport. We used two M13-bacteriophage display biopanning strategies to search for mediators of trans-TM transport. First, aliquots of linear phage library displaying 10\(^{10th}\) 12mer peptides were applied on the TM of rats with active bacterial OM. The middle ear (ME) contents were then harvested, amplified and the preparation re-applied for additional rounds. Second, the same naïve library was sequentially screened for phage exhibiting TM binding, internalization and then transit. Results revealed a novel set of peptides that transit across the TM to the ME in a time and temperature dependent manner. The peptides with highest transport capacities shared sequence similarities. Historically, the TM was viewed as an impermeable barrier. However, our studies reveal that it is possible to translocate peptide-linked small particles across the TM. This is the first comprehensive biopanning for the isolation of TM transiting peptidic ligands. The identified mechanism offers a new drug delivery platform into the ME. KW - biological mechanism KW - otitis media KW - tympanic membrane KW - active transport KW - middle ear Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167741 VL - 6 IS - 22663 ER -