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OBJECTIVE:The aim of this study was to obtain norm values for a young adult Turkish group and to investigate the differences between female and male subjects in terms of wideband tympanometry. MATERIALS and METHODS:One hundred ten young adult volunteers (mean±SD: 21.1±1.9 years) participated in this study. The measurements of wideband tympanometry were performed at octave frequencies between 226 Hz and 8000 Hz using Titan version 3.1. The stimulus level was set at 100 dB peSPL. RESULTS:A cross-sectional study design was used. In total, 218 ears were tested. A significant relationship was found between gender and absorbance values for the frequency band from 3100 Hz to 6900 Hz. The difference between the middle ear resonance frequency and ear canal volume (ECV) of the male and female subjects was also found to be significant. The difference in ECV may result from the difference in body size between the male and female subjects because there was a significant relationship among ECV and the height and weight. CONCLUSION:According to these results, it can be concluded that using separate norms for males and females may increase test specificity and sensitivity for the diagnosis of disorders, such as ossicular discontinuity and tympanic membrane perforations, affecting the high-frequency region.

Objective: We aimed to examine the effect of topical dexamethasone by otomicroscopic and histologic examinations for preventing myringosclerosis induced by myringotomy in rat tympanic membranes.Methods: Twenty-one Sprague Dawley rats (42 ears) were randomly divided into the following three groups after otomicroscopic examinations: experimental surgical group (5 rats), control group (8 rats), and study group (8 rats). The rats of all the groups underwent myringotomy in both tympanic membranes. Other than myringotomy, no additional procedure was performed for the rats in the experimental surgical group. In the control group, 0.9% NaCl was applied to the ears, whereas in the study groups, topical dexamethasone was applied to the ears. These applications in the control and study groups were repeated for nine days. On the 10th day of the study, the rat ears of all groups underwent otomicroscopic and histologic examinations. The prevalence and process of myringosclerosis were evaluated by otomicroscopic examination, whereas inflammation, membrane thickness, and myringosclerosis intensity were evaluated by histologic examination. Results:The growth of myringosclerosis with otomicroscopic examination was lesser in the study group in which topical dexamethasone was applied than the control and the experimental surgical groups. Moreover, it was observed that myringosclerosis effected fewer quadrants in the study group.Histologic examinations revealed that inflammation was significantly lesser in the study group than in the experimental surgical and control groups. The average membrane thickness values were significantly lesser in the study group than in the experimental surgical group. With respect to myringosclerosis growth, no statistically significant difference was observed among all groups, whereas with respect to myringosclerosis intensity, the rat ears in the study group were less severely affected.Conclusion: Thus, our study results suggest that applying topical dexamethasone after myringotomy has positive effects on limiting the intensity and prevalence of myringosclerosis.

Cochlear implants (CIs) are widely used to provide auditory rehabilitation to individuals having severe to profound sensorineural hearing loss (SNHL). However, insertion of electrode leads to inner trauma and activation of inflammatory and apoptotic signaling cascades resulting in loss of residual hearing in implanted individuals. Pharmaceutical interventions that can target these signaling cascades hold great potential for preserving residual hearing by preventing sensory cell damage. Bile salts have shown efficacy in various regions of the body as powerful antioxidants and anti-inflammatory agents. However, their efficacy against inner ear trauma has never been explored. The objective of this study was to determine whether taurodeoxycholic acid (TDCA), a bile salt derivative, can prevent sensory cell damage employing an in vitro model of electrode insertion trauma (EIT). The organ of Corti (OC) explants were dissected from postnatal day 3 (P-3) rats and placed in serum-free media. Explants were divided into control and experimental groups: (1) untreated controls; (2) EIT; (3) EIT+ TDCA (different concentrations). Hair cell (HC) density, analyses of apoptosis pathway (cleaved caspase 3), levels of reactive oxygen species (ROS) as well as inducible nitric oxide synthase (iNOS) activity and Mitochondrial Membrane Potential (MMP) were assayed. Treatment with TDCA provided significant otoprotection against HC loss in a dose-dependent manner. The molecular mechanisms underlying otoprotection involved decreasing oxidative stress, lowering levels of iNOS, and abrogating generation of cleaved caspase 3. The results of the present study suggest that TDCA provides efficient otoprotection against EIT, in vitro and should be explored for developing pharmaceutical interventions to preserve residual hearing post-cochlear implantation.

Recent advancements in stem cell therapy have led to an increased interest within the auditory community in exploring the potential of mesenchymal stem cells (MSCs) in the treatment of inner ear disorders. However, the biocompatibility of MSCs with the inner ear, especially when delivered non-surgically and in the immunocompetent cochlea, is not completely understood. In this study, we determined the effect of intratympanic administration of rodent bone marrow MSCs (BM-MSCs) on the inner ear in an immunocompetent rat model. The administration of MSCs did not lead to the generation of any oxidative stress in the rat inner ear. There was no significant production of proinflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and IL-12, due to BM-MSCs administration into the rat cochlea. BM-MSCs do not activate caspase 3 pathway, which plays a central role in sensory cell damage. Additionally, transferase dUTP nick end labeling (TUNEL) staining determined that there was no significant cell death associated with the administration of BM-MSCs. The results of the present study suggest that trans-tympanic administration of BM-MSCs does not result in oxidative stress or inflammatory response in the immunocompetent rat cochlea.

Background: Electrode insertion trauma (EIT) during cochlear implantation (CI) can cause loss of residual hearing. L-N-acetylcysteine (L-NAC) and dexamethasone (Dex) have been individually shown to provide otoprotection albeit at higher concentrations that may be associated with adverse effects. Objective/Aims: The aim of this study is to determine whether L-NAC and Dex could be combined to decrease their effective dosage. Materials and Methods: The organ of Corti (OC) explants were divided into various groups: 1) control; 2) EIT; 3) EIT treated with different concentrations of Dex; 4) EIT treated with different concentrations of L-NAC; 5) EIT treated with L-NAC and Dex in combination. Hair cell (HC) density, levels of oxidative stress, proinflammatory cytokines and nitric oxide (NO) was determined. Results: There was a significant loss of HCs in explants subjected to EIT compared to the control group. L-NAC and Dex in combination was able to provide significant otoprotection at lower concentrations compared to individual drugs. Conclusions and Significance: A combination containing L-NAC and Dex is effective in protecting sensory cells at lower protective doses than each compound separately. These compounds can be combined allowing a decrease of potential side effects of each compound and providing significant otoprotection for EIT.

Background Perception of acoustic details in the speech signal is important for speech sound development. The medial olivocochlear pathway, a part of the auditory efferent system, plays a role in stimulus-related control of the cochlea. One clinical tool to evaluate the medial olivocochlear activity, which is thought to improve speech perception in noise, is the suppression of otoacoustic emissions. Aims This study investigated the suppression of transient evoked otoacoustic emissions in children with phonological disorder in comparison with that in typically developing controls. Study Design Case-control study. Methods A total of 23 children with phonological disorder (aged 5–10 years) and 21 age- and sex-matched controls ( P > 0.05) participated in the study. Participants had pure-tone thresholds ≤ 15 dB hearing loss and normal middle ear functions. Transient evoked otoacoustic emissions with and without contralateral acoustic stimulation were measured. Results Although the mean transient evoked otoacoustic emissions suppressions were lower in the group with phonological disorder than in the controls, these differences were not statistically significant ( P > 0.05). No left/right ear asymmetry of transient evoked otoacoustic emissions suppression was detected in either of the groups ( P > 0.05). Conclusion Children with phonological disorder did not show alterations in medial olivocochlear functioning in the medial olivocochlear activity as measured by the contralateral suppression of transient evoked otoacoustic emissions.

Objective: To systematically appraise the implementation of cochlear implantation (CI) in Usher Syndrome (USH) Types 1, 2, and 3 patients, and analyze who would benefit from CI. Data Sources: A comprehensive search of PubMed, Embase, CINAHL, and Cochrane Library electronic databases from inception through June 2020 was performed. There were no language restrictions. Study Selection: The PRISMA strategy was followed. Included studies discuss USH patients who underwent CI regardless of age, nationality, or clinical subtype. All included studies report post-implantation functional, cognitive, or quality of life outcomes. Only reviews were excluded. Results: Fifteen studies met the inclusion criteria. USH patients experienced improvements in PTA and speech perception and expression outcomes after CI, as well as improvements in phonological memory and quality of life measures. Overall, patients implanted at younger ages outperformed older patients in audiological testing. Similarly, patients with prolonged auditory deprivation had relatively poor performance outcomes in sentence recognition and speech detection following CI. Conclusions: Most USH patients benefit from CI. USH patients who undergo CI at younger ages generally achieve better hearing, speech, and cognitive outcomes. CI at older ages can still prove beneficial if appropriate auditory amplification is started at the right time. Further research is warranted to fill the gap in understanding regarding the gene mutations underlying the pathophysiology of USH that have favorable CI outcomes as well as the optimal time to perform CI.