[Comprehensive literature review on the application of the otological-surgical planning software OTOPLAN® for cochlear implantation. German version]. / Umfassender Literaturüberblick über die Anwendung der otologisch-chirurgischen Planungssoftware OTOPLAN® bei der Cochleaimplantation.

BACKGROUND: The size of the human cochlear, measured by the diameter of the basal turn, varies between 7 and 11 mm. For hearing rehabilitation with cochlear implants (CI), the size of the cochlear influences the individual frequency map and the choice of electrode length. OTOPLAN® (CAScination AG [Bern, Switzerland] in cooperation with MED-EL [Innsbruck, Austria]) is a software tool with CE marking for clinical applications in CI treatment which allows for precise pre-planning based on cochlear size. This literature review aims to analyze all published data on the application of OTOPLAN®. MATERIALS AND METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were applied to identify relevant studies published in the PubMed search engine between January 2015 and February 2023 using the search terms "otoplan" [title/abstract] OR "anatomy-based fitting" [title/abstract] OR "otological software tool" [title/abstract] OR "computed tomography-based software AND cochlear" [title/abstract]. RESULTS: The systematic review of the literature identified 32 studies on clinical use of OTOPLAN® in CI treatment. Most studies were reported from Germany (7 out of 32), followed by Italy (5), Saudi Arabia (4), the USA (4), and Belgium (3); 2 studies each were from Austria and China, and 1 study from France, India, Norway, South Korea, and Switzerland. In the majority of studies (22), OTOPLAN® was used to assess cochlear size, followed by visualizing the electrode position using postoperative images (5), three-dimensional segmentation of temporal bone structures (4), planning the electrode insertion trajectory (3), creating a patient-specific frequency map (3), planning of a safe drilling path through the facial recess (3), and measuring of temporal bone structures (1). CONCLUSION: To date, OTOPLAN® is the only DICOM viewer with CE marking in the CI field that can process pre-, intra-, and postoperative images in the abovementioned applications.

Development of an algorithm for correct placement of the basal electrode contact in the context of anatomy based cochlear implantation: a proof of concept.

BACKGROUND: Correct individual tonotopic frequency stimulation of the cochlea plays an important role in the further development of anatomy based cochlear implantation. In this context frequency specific fitting of the basal electrode contact with a normal insertion depth can be difficult since it is often placed in a frequency range higher than 10 kHz and current audio processors only stimulate for frequencies up to 8.5 kHz due to microphone characteristics. This results in a mismatch of the high frequencies. Therefore, this study represents a proof of concept for a tonotopic correct insertion and aims to develop an algorithm for a placement of the basal electrode below 8.5 kHz in an experimental setting. METHODS: Pre- and postoperative flat-panel volume CT scans with secondary reconstructions were performed in 10 human temporal bone specimens. The desired frequency location for the most basal electrode contact was set at 8.25 kHz. The distance from the round window to the position where the basal electrode contact was intended to be located was calculated preoperatively using 3D-curved multiplanar reconstruction and a newly developed mathematical approach. A specially designed cochlear implant electrode array with customized markers imprinted on the silicone of the electrode array was inserted in all specimens based on the individually calculated insertion depths. All postoperative measurements were additionally validated using an otological planning software. RESULTS: Positioning of the basal electrode contact was reached with only a small mean deviation of 37 ± 399 Hz and 0.06 ± 0.37 mm from the planned frequency of 8.25 kHz. The mean rotation angle up to the basal electrode contact was 51 ± 5 °. In addition, the inserted electrode array adequately covered the apical regions of the cochleae. CONCLUSION: Using this algorithm, it was possible to position the basal electrode array contact in an area of the cochlea that could be correctly stimulated by the existing speech processors in the context of tonotopic correct fitting.

[Online training for hearing implant surgery : A new approach to otological training. German version]. / Online-Training für Hörimplantatchirurgie : Ein neuer Ansatz in der otologischen Ausbildung.

OBJECTIVE: Education in microsurgery of the ear includes staged training to allow for mastering of the complex microsurgical procedures, particularly in the context of middle ear reconstruction and cochlear implantation. Traditional surgical training includes temporal bone preparations by cadaver dissection and supervised operating room practice. As these on-site trainings are limited, there is a need to broaden education facilities in an on-line format. Therefore, a first basic on-line training for otosurgery was developed. MATERIALS AND METHODS: The system consists of an artificial temporal bone model together with a set of basic surgical instruments and implant dummies. As an essential part of the training kit, a high-resolution camera set is included that allows for connection to a video streaming platform and enables remote supervision of the trainees' surgical steps by experienced otological surgeons. In addition, a pre-learning platform covering temporal bone anatomy and instrumentation and pre-recorded lectures and instructional videos has been developed to allow trainees to review and reinforce their understanding before hands-on practice. RESULTS: Over the three courses held to date, 28 participants with varying levels of prior surgical experience took part in this otological surgical training program. The immediate feedback of the participants was evaluated by means of a questionnaire. On this basis, the high value of the program became apparent and specific areas could by identified where further refinements could lead to an even more robust training experience. CONCLUSION: The presented program of an otosurgical online training allows for basal education in practical exercises on a remote system. In this way, trainees who have no direct access to on-site instruction facilities in ear surgery now have the chance to start their otosurgical training in an educational setting adapted to modern technologies.

Adult Neurogenesis of the Medial Geniculate Body: In Vitro and Molecular Genetic Analyses Reflect the Neural Stem Cell Capacity of the Rat Auditory Thalamus over Time.

Neural stem cells (NSCs) have been recently identified in the neonatal rat medial geniculate body (MGB). NSCs are characterized by three cardinal features: mitotic self-renewal, formation of progenitors, and differentiation into all neuroectodermal cell lineages. NSCs and the molecular factors affecting them are particularly interesting, as they present a potential target for treating neurologically based hearing disorders. It is unclear whether an NSC niche exists in the rat MGB up to the adult stage and which neurogenic factors are essential during maturation. The rat MGB was examined on postnatal days 8, 12, and 16, and at the adult stadium. The cardinal features of NSCs were detected in MGB cells of all age groups examined by neurosphere, passage, and differentiation assays. In addition, real-time quantitative polymerase chain reaction arrays were used to compare the mRNA levels of 84 genes relevant to NSCs and neurogenesis. In summary, cells of the MGB display the cardinal features of NSCs up to the adult stage with a decreasing NSC potential over time. Neurogenic factors with high importance for MGB neurogenesis were identified on the mRNA level. These findings should contribute to a better understanding of MGB neurogenesis and its regenerative capacity.

[Initial assessment of ENT emergencies-a feasibility study]. / Ersteinschätzung HNO-spezifischer Notfälle ­ eine Machbarkeitsstudie.

In Germany, an increased volume of patient cases in the emergency department has been observed for several years, many of which do not represent hospital emergencies. To improve the triage and management of patient flows, the Structured Initial Medical Assessment (Strukturierte medizinische Ersteinschätzung in Deutschland, SmED) triage system was developed. This certified medical product is intended to assess both the urgency of everyday complaints and their adequate medical care in a targeted, faster, and safer manner. It supports medical professionals in triage by suggesting courses of action, whereby the ultimate responsibility remains with the professionals themselves. For otorhinolaryngology, a content review was carried out with regard to plausibility and patient safety in the head and neck region on the basis of nine specific emergencies. The cases were simulated by nine otorhinolaryngologists and triaged on the basis of the SmED by medical staff and medical students by assigning a care level and timepoint (urgency). The majority of cases were correctly assigned. The SmED initial assessment system is a good tool for assessing urgent clinical pictures in ear, nose, and throat (ENT) medicine. The long-term goal of the initial assessment is to relieve the capacities of outpatient departments. In order to achieve this and to shorten patient waiting times, it would be necessary to refer patients quickly to otorhinolaryngology. It is therefore necessary to ensure that patients are referred to an ENT on-call service via the online tool.

[Repetitio est mater studiorum-implementation of ENT cases in case-based e-learning]. / Repetitio est mater studiorum ­ Implementierung von HNO-Fällen in fallbasiertes E-Learning.

BACKGROUND: German university otorhinolaryngology has a need for digital teaching content. Case-based e­learning represents a digital teaching methodology. The data on student use of case-based e­learning in university teaching of ENT medicine are limited. OBJECTIVE: The aim of this work was to determine the extent to which voluntary case-based e­learning is used by otolaryngology students and what influence the quality of the e­learning has on motivation to use e­learning and on the interest in otolaryngology. MATERIALS AND METHODS: Fifteen voluntary e­learning cases were created based on the content of the ENT lecture in the winter semester 2022/2023. Subsequently, a descriptive evaluation of the usage statistics of the cases of 157 students was conducted. Likewise, an evaluation of the quality of the e­learning as well as the motivation to complete it and the interest in otorhinolaryngology was carried out using a voluntary questionnaire. RESULTS: Voluntary case-based e­learning was used to varying degrees by 66% of the students. The quality of e­learning correlated significantly with the motivation and the interest in otolaryngology. CONCLUSION: The teaching content of otorhinolaryngology can be implemented sufficiently in case-based e­learning and is characterized by satisfactory student acceptance. Integration should be accomplished in a high-quality manner to increase motivation and interest in otorhinolaryngology.

The Stapes Head Coupler-A Flexible and Safe Option for Vibroplasty.

OBJECTIVE: To investigate the surgical approach and the audiological outcome of a stapes head coupler in active middle ear implant surgery. STUDY DESIGN: Retrospective data analysis. SETTING: Tertiary referral center with a large active middle ear implant program. PATIENTS: Twelve patients with active middle ear implant surgery. INTERVENTIONS: Therapeutic surgical approach for hearing rehabilitation in human subjects. MAIN OUTCOME MEASURES: Auditory brainstem response, sound field thresholds, vibrogram, speech perception in the Freiburger monosyllabic word test. RESULTS: The stapes head was attached safely in different coupling situations. Audiological outcomes were similar to the audiological performance of established vibroplasty couplers presented in the literature. CONCLUSION: The stapes head coupler is a new and safe tool for vibroplasty with a good audiological outcome.

Computed tomographic 3D analysis of the cochlear aqueduct-potential and limitations of clinical imaging.

Background: The cochlear aqueduct (CA), which connects the scala tympani and the subarachnoid space, and its accompanying structures appear to have a significant relevance during cochlear implantation and an accurate visualization in clinical imaging is of great interest. Aims and Objective: This study aims to determine which potential and limitations clinically available imaging modalities have in the visualization of the CA. Methods: Micro-CT, flat-panel volume computed tomography with and without secondary reconstruction (fpVCT, fpVCTseco) and multislice computed tomography (MSCT) of 10 temporal bone specimen were used for 3D analysis of the CA. Results: FpVCTseco proved superior in visualizing the associated structures and lateral portions of the CA, which merge into the basal turn of the cochlea. All clinical imaging modalities proved equal in analyzing the length, total volume of the CA and its area of the medial orifice. Conclusion: The choice of the most accurate clinical imaging modality to evaluate the CA and its associated structures depends on the clinical or scientific question. Furthermore, this study should provide a basis for further investigations analyzing the CA.

mRNA Abundance of Neurogenic Factors Correlates with Hearing Capacity in Auditory Brainstem Nuclei of the Rat.

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.

Neurogenic Stem Cell Niche in the Auditory Thalamus: In Vitro Evidence of Neural Stem Cells in the Rat Medial Geniculate Body.

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 ß-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.

Accuracy of radiological prediction of electrode position with otological planning software and implications of high-resolution imaging.

OBJECTIVES: In cochlear implantation, preoperative prediction of electrode position has recently gained increasing attention. Currently, planning is usually done by multislice CT (MSCT). However, flat-panel volume CT (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for more precise visualization of the cochlea. Combined with a newly developed otological planning software, the position of every single contact can be effectively predicted. In this study it was investigated how accurately radiological prediction forecasts the postoperative electrode localization and whether higher image resolution is advantageous. METHODS: Utilizing otological planning software (OTOPLAN®) and different clinical imaging modalities (MSCT, fpVCT and fpVCTSECO) the electrode localization [angular insertion depth (AID)] and respective contact frequencies were predicted preoperatively and examined postoperatively. Furthermore, inter-electrode-distance (IED) and inter-electrode-frequency difference (IEFD) were evaluated postoperatively. RESULTS: Measurements revealed a preoperative overestimation of AID. Corresponding frequencies were also miscalculated. Determination of IED and IEFD revealed discrepancies at the transition from the basal to the middle turn and round window to the basal turn. All predictions and discrepancies were lowest when using fpVCTSECO. CONCLUSION: The postoperative electrode position can be predicted quite accurately using otological planning software. However, because of several potential misjudgments, high-resolution imaging, such as offered by fpVCTSECO, should be used pre- and postoperatively.

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.

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.

Implementation of secondary reconstructions of flat-panel volume computed tomography (fpVCT) and otological planning software for anatomically based cochlear implantation.

PURPOSE: For further improvements in cochlear implantation, the measurement of the cochlear duct length (CDL) and the determination of the electrode contact position (ECP) are increasingly in the focus of clinical research. Usually, these items were investigated by multislice computed tomography (MSCT). The determination of ECP was only possible by research programs so far. Flat-panel volume computed tomography (fpVCT) and its secondary reconstructions (fpVCTSECO) allow for high spatial resolution for the visualization of the temporal bone structures. Using a newly developed surgical planning software that enables the evaluation of CDL and the determination of postoperative ECP, this study aimed to investigate the combination of fpVCT and otological planning software to improve the implementation of an anatomically based cochlear implantation. METHODS: Cochlear measurements were performed utilizing surgical planning software in imaging data (MSCT, fpVCT and fpVCTSECO) of patients with and without implanted electrodes. RESULTS: Measurement of the CDL by the use of an otological planning software was highly reliable using fpVCTSECO with a lower variance between the respective measurements compared to MSCT. The determination of the inter-electrode-distance (IED) between the ECP was improved in fpVCTSECO compared to MSCT. CONCLUSION: The combination of fpVCTSECO and otological planning software permits a simplified and more reliable analysis of the cochlea in the pre- and postoperative setting. The combination of both systems will enable further progress in the development of an anatomically based cochlear implantation.

Spontaneous Calcium Oscillations through Differentiation: A Calcium Imaging Analysis of Rat Cochlear Nucleus Neural Stem Cells.

Causal therapies for the auditory-pathway and inner-ear diseases are still not yet available for clinical application. Regenerative medicine approaches are discussed and examined as possible therapy options. Neural stem cells could play a role in the regeneration of the auditory pathway. In recent years, neural stem and progenitor cells have been identified in the cochlear nucleus, the second nucleus of the auditory pathway. The current investigation aimed to analyze cell maturation concerning cellular calcium activity. Cochlear nuclei from PND9 CD rats were microscopically dissected and propagated as neurospheres in free-floating cultures in stem-cell medium (Neurobasal, B27, GlutaMAX, EGF, bFGF). After 30 days, the dissociation and plating of these cells took place under withdrawal of the growth factors and the addition of retinoic acid, which induces neural cell differentiation. Calcium imaging analysis with BAPTA-1/Oregon Green was carried out at different times during the differentiation phase. In addition, the influence of different voltage-dependent calcium channels was analyzed through the targeted application of inhibitors of the L-, N-, R- and T-type calcium channels. For this purpose, comparative examinations were performed on CN NSCs, and primary CN neurons. As the cells differentiated, a significant increase in spontaneous neuronal calcium activity was demonstrated. In the differentiation stage, specific frequencies of the spontaneous calcium oscillations were measured in different regions of the individual cells. Initially, the highest frequency of spontaneous calcium oscillations was ascertainable in the maturing somata. Over time, these were overtaken by calcium oscillations in the axons and dendrites. Additionally, in the area of the growth cones, an increasing activity was determined. By inhibiting voltage-dependent calcium channels, their expression and function in the differentiation process were confirmed. A comparable pattern of maturation of these channels was found in CN NSCs and primary CN neurons. The present results show that neural stem cells of the rat cochlear nucleus differentiated not only morphologically but also functionally. Spontaneous calcium activities are of great relevance in terms of neurogenesis and integration into existing neuronal structures. These functional aspects of neurogenesis within the auditory pathway could serve as future targets for the exogenous control of neuronal regeneration.

Different Neurogenic Potential in the Subnuclei of the Postnatal Rat Cochlear Nucleus.

In patients suffering from hearing loss, the reduced or absent neural input induces morphological changes in the cochlear nucleus (CN). Neural stem cells have recently been identified in this first auditory relay. Afferent nerve signals and their impact on the immanent neural stem and progenitor cells already impinge upon the survival of early postnatal cells within the CN. This auditory brainstem nucleus consists of three different subnuclei: the anteroventral cochlear nucleus (AVCN), the posteroventral cochlear nucleus (PVCN), and the dorsal cochlear nucleus (DCN). Since these subdivisions differ ontogenetically and physiologically, the question arose whether regional differences exist in the neurogenic niche. CN from postnatal day nine Sprague-Dawley rats were microscopically dissected into their subnuclei and cultivated in vitro as free-floating cell cultures and as whole-mount organ cultures. In addition to cell quantifications, immunocytological and immunohistological studies of the propagated cells and organ preparations were performed. The PVCN part showed the highest mitotic potential, while the AVCN and DCN had comparable activity. Specific stem cell markers and the ability to differentiate into cells of the neural lineage were detected in all three compartments. The present study shows that in all subnuclei of rat CN, there is a postnatal neural stem cell niche, which, however, differs significantly in its potential. The results can be explained by the origin from different regions in the rhombic lip, the species, and the various analysis techniques applied. In conclusion, the presented results provide further insight into the neurogenic potential of the CN, which may prove beneficial for the development of new regenerative strategies for hearing loss.

[Simultaneous implantation of epithesis anchors and Bonebridge to treat severe ear malformations]. / Simultane Implantation von Epithesenankern und Bonebridge zur Versorgung großer Ohrmissbildungen.

OBJECTIVE: Surgical treatment with bone conduction hearing implants and epitheses for ear malformations offer the right combination of hearing rehabilitation and cosmetic reconstruction. The surgical procedure is often performed in two-stage surgical steps. This project aimed to gain experience with a procedure in which the hearing implant and the epithesis anchors are inserted simultaneously. MATERIAL AND METHODS: Four ears of three patients (nf = 1, nm = 2) with severe ear malformations (type III, according to Weerda) received a Bonebridge and an epithesis anchor with three base posts in one operation each. Previously, the indication for the use of a bone conduction implant using the active middle ear implant (aMEI) score, according to Frenzel (2013), had been established. RESULTS: All patients scored 4 points each in the aMEI-score, indicating an unfavorable prognosis for successful implantation of an active middle ear implant. The treatment with a Bonebridge and an epithesis anchor was performed without complications. Postoperatively, the initial audiological fitting and the application of the magnetic abutment were performed after 4 weeks. Audiometry showed a functional gain of up to 30 dB and an improved speech comprehension. The epithesis was shaped like the contralateral ear. After treatment, patients were satisfied with the audiological and cosmetic results. CONCLUSIONS: The simultaneous surgical procedure with a bone conduction hearing implant and epithesis anchor is a good option for the treatment of ear malformations. The aMEI-score was a helpful instrument for the indication. The procedure reduced the surgical risk and the time and effort required for treatment.

Button batteries and typical swallowed foreign bodies can be differentiated in high-resolution X-Rays.

BACKGROUND: Button battery ingestions have emerged as an increasing medical issue in recent years, especially for children. The frequent use of these energy sources in small appliances and toys is responsible for their ubiquitous occurrence in households. In addition to other possible foreign bodies, button batteries are particularly dangerous as they can cause severe complications in the aerodigestive tract. OBJECTIVE: The study aimed for a detailed analysis of specific radiographic identifiers of button batteries and similarly configured potential esophageal foreign bodies in high-resolution X-ray scans. METHODS: A selection of potentially hazardous button batteries - in cases of ingestion (CR2032) or aspiration (LR44, LR1130) - was made. Other clinically relevant radio-opaque objects of similar size and shape have been selected accordingly. High-resolution X-ray scans (33.3 lp/mm) were made using an in vitro model in porcine esophageal preparations. A systematic, comparative analysis was carried out with the digital radiographic images. FINDINGS: In the study described, the selected foreign bodies were scanned at distinct angles in high image quality. Using button batteries, radiographically details of their internal structures were shown that have not yet been described. The known markers, as well as new detailed characteristics, were found in the experimental setting. The differentiation from other typical esophageal foreign bodies was possible by analyzing four relevant identification features: the edge properties, internal structures, the size, and differences in 0°/90° scans. CONCLUSIONS: The study results reveal that specific features of potential esophageal foreign bodies can be identified by improved radiographic resolution, contrast, and dynamics. Thus, the diagnostic reliability in distinguishing 'high-risk foreign bodies' from less dangerous ones could be increased. In the future, button batteries could be detected more reliably with intelligent digital image analysis and enhanced radiographic technology. This may further support clinical triage algorithms and help reduce medical complications in cases of foreign body ingestions.

Evaluation of the Neurogenic Potential in the Rat Inferior Colliculus from Early Postnatal Days Until Adulthood.

Neural stem cells (NSCs) have been recently identified in the inferior colliculus (IC). These cells are of particular interest, as no casual therapeutic options for impaired neural structures exist. This research project aims to evaluate the neurogenic potential in the rat IC from early postnatal days until adulthood. The IC of rats from postnatal day 6 up to 48 was examined by neurosphere assays and histological sections. In free-floating IC cell cultures, neurospheres formed from animals from early postnatal to adulthood. The amount of generated neurospheres decreased in older ages and increased with the number of cell line passages. Cells in the neurospheres and the histological sections stained positively with NSC markers (Doublecortin, Sox-2, Musashi-1, Nestin, and Atoh1). Dissociated single cells from the neurospheres differentiated and were stained positively for the neural lineage markers ß-III-tubulin, glial fibrillary acidic protein, and myelin basic protein. In addition, NSC markers (Doublecortin, Sox-2, CDK5R1, and Ascl-1) were investigated by qRT-PCR. In conclusion, a neurogenic potential in the rat IC was detected and evaluated from early postnatal days until adulthood. The identification of NSCs in the rat IC and their age-specific characteristics contribute to a better understanding of the development and the plasticity of the auditory pathway and might be activated for therapeutic use.

Severe tracheobronchial harm due to lithium button battery aspiration: An in vitro study of the pathomechanism and injury pattern.

BACKGROUND: Button battery incidents have become a rising medical issue in recent years, especially for infants. The increasing number of these cases can be explained by the expanding use of objects of everyday life and toys. As a result, button batteries in many households are ubiquitous in different states of charge. The extremely long shelf-life and the increasing energy densities of lithium button batteries boost the potential medical complications of accidental swallowing. OBJECTIVE: The study aimed to analyze the pathophysiology of damage to tracheobronchial structures by button batteries aspiration over time. METHODS: CR2032 and CR927 lithium button batteries (3.2/3.0 V) were exposed to porcine trachea preparations intraluminal at 37 °C in intervals up to 36 h. Measurements were made of the voltage curve, the discharge current, and the resulting pH values around the electrodes. The effects on tissue were examined using macroscopic time-lapse images and microscopic pictures of sections of the fixed specimens over time. FINDINGS: The examinations showed a tissue electrolysis reaction directly after the beginning of battery exposure, which led to an immediate coagulation impairment of the respiratory epithelium. Over time, a strongly alkaline environment was established around the batteries. The resulting tissue colliquation caused profound tissue damage beyond the basal membrane of the mucosa, affecting the tracheobronchial cartilage after only 4 h of exposure time. After 12 h, there was significant necrosis of the annular ligaments of the trachea and the peribronchial pulmonary tissue. After completion of the experimental exposure time of 36 h, there was still a sufficient residual voltage on all button batteries of the experiments. CONCLUSIONS: Besides accidental ingestion, the aspiration of button batteries is a life-threatening situation. The partial or complete acute airway obstruction in the trachea or the bronchi initially is the leading symptom, as with any foreign body aspiration. However, the results of the investigations show that even after a short exposure time, relevant tissue damage can be caused by the electrolysis reaction of the battery. After 12 h, a profound destruction of cartilage, connective tissue, and smooth muscles was observed in vitro, which may cause significant consequential damage in vivo. These findings reveal the need for rapid diagnosis and immediate foreign body removal after any battery ingestion. Moreover, the results show how relevant prevention of these accidents is, and that future safety modifications of these types of battery by the manufacturers would be appropriate.

Spatio-temporal distribution of tubulin-binding cofactors and posttranslational modifications of tubulin in the cochlea of mice.

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.