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purpose: The purpose of this study was to evaluate whether induction of temporary threshold shift (TTS) with aspirin prior to cisplatin exposure can prevent or minimize cisplatin detrimental effects on hearing.Methods: We randomly divided BALB mice into three groups: ]1[ cisplatin only, ]2[ aspirin only, and ]3[ combined aspirin/cisplatin. Cisplatin was administered as a single intraperitoneal injection of 14 mg/kg. Aspirin was administered for three weeks via intraperitoneal injection of 200 mg/kg sodium salicylate, twice daily. Air conduction thresholds were recorded using Auditory Brainstem Responses (ABR). Cochleae were harvested and cochlear hair cells were counted using a scanning electron microscope (SEM).Results: Aspirin-induced TTS have reached an average of 30.05±16.9 dB after two weeks. At 60 days, cisplatin-only treated mice experienced an average threshold shifts of 50.7 dB at 4 kHz, 35.16 dB at 8 kHz, 70dB at 16 kHz, 53.1 dB at 32 kHz. All threshold shifts were significantly worse than for cisplatin/aspirin treated mice with TTS of 11.85 dB at 4 kHz, 3.58 dB at 8 kHz, 16.58 dB at 16 kHz, 20.41dB at 32 kHz (pConclusion: Aspirin induced TTS can protect from cisplatin-induced ototoxicity. This beneficial effect was demonstrated by auditory thresholds as well as SEM. Larger pre-clinical and clinical studies are still needed to confirm these findings.

OBJECTIVES/HYPOTHESIS The effects of different electrocautery power settings on mucosal contraction and margin status in the oral cavity have not been well established. The aim of this study was to examine how different levels of electrocautery energy outputs affect oral mucosal tissue margins. STUDY DESIGN Animal model. METHODS A model of 23 adult rats was used (two specimens per rat). After anesthetizing the animals, a 6-mm biopsy punch marked the resection margin on the buccal mucosa (one per cheek). The specimens were excised by means of three energy levels, a cold knife, and monopolar diathermy that was set on either 20 W or 30 W cut modes. The specimens were evaluated for extent of contraction. RESULTS A total of 45 samples were obtained and measured, including 15 specimens in the cold-knife group, 15 specimens in the 20 W group, and 15 specimens in the 30 W group. The median diameters of the specimens after resection were 4.5 mm for the cold-knife group (interquartile range [IQR] = 4.0-5.0), 3.5 mm for the 20 W group (IQR = 3.5-4.0), and 2.8 mm for the 30 W group (IQR = 2.5-3.0). Specimen contraction was 25.0%, 41.7%, and 53.3%, respectively. The difference in shrinkage between each pair was statistically significant: cold knife versus 20 W, P = .001; cold knife versus 30 W, P

POU3F4 is a POU domain transcription factor that is required for hearing. In the ear, POU3F4 is essential for mesenchymal remodeling of the bony labyrinth and is the causative gene for DFNX2 human nonsyndromic deafness. Ear abnormalities underlie this form of deafness, characterized previously in multiple spontaneous, radiation-induced and transgenic mouse mutants. Here, we report three novel mutations in the POU3F4 gene that result in profound hearing loss in both humans and mice. A p.Gln79* mutation was identified in a child from an Israeli family, revealed by massively parallel sequencing (MPS). This strategy demonstrates the strength of MPS for diagnosis with only one affected individual. A second mutation, p.Ile285Argfs*43, was identified by Sanger sequencing. A p.Cys300* mutation was found in an ENU-induced mutant mouse, schwindel (sdl), by positional cloning. The mutation leads to a predicted truncated protein, similar to the human mutations, providing a relevant mouse model. The p.Ile285Argfs*43 and p.Cys300* mutations lead to a shift of Pou3f4 nuclear localization to the cytoplasm, demonstrated in cellular localization studies and in the inner ears of the mutant mice. The discovery of these mutations facilitates a deeper comprehension of the molecular basis of inner ear defects due to mutations in the POU3F4 transcription factor.

microRNAs (miRNAs) are regulators of differentiation and development of inner ear cells. Mutations in miRNAs lead to deafness in humans and mice. Among inner ear pathologies, inflammation may lead to structural and neuronal defects and eventually to hearing loss and vestibular dysfunction. While the genetic factors of these pathways have not been defined, autoimmunity participates in these processes. We report that inflammatory stimuli in the inner ear induce activation of the innate immune system via miR-224 and pentraxin 3 (Ptx3). miR-224 is a transcriptional target of nuclear factor κB, a key mediator of innate immunity. Ptx3 is a regulator of the immune response. It is released in response to inflammation and regulated by nuclear factor κB. We show that miR-224 and Ptx3 are expressed in the inner ear and we demonstrate that miR-224 targets Ptx3. As a model of the innate immune response, we injected lipopolysaccharide into the scala tympani of mouse inner ears. This resulted in changes in the levels of miR-224 and Ptx3, in addition to activation of the complement system, as measured by immune cell infiltration and activated C3. This suggests that while miR-224 regulates Ptx3 under normal conditions, upon inflammation, both are recruited to offer a front line of defense in acting as responders to inflammation in the inner ear. miR-224 diminishes the innate immune response by down-regulating Ptx3 expression, while Ptx3 stimulates the innate immune response. An understanding of the molecular components of the inflammatory pathway may help develop therapeutics for reducing inflammation associated with inner ear injury.

Hereditary hearing loss affects a significant proportion of the hearing impaired, with genetic mutations estimated to be responsible for its etiology in over 50% of this population. The methods for molecular diagnostics are changing as a result of the transition from linkage analysis to next generation sequencing to identify the genes responsible for hearing loss in affected families. In this review, we summarize the attitudes of the hearing impaired towards genetic testing, the latest techniques for identifying mutations, and provide a comprehensive list of the mutations found in the Israeli Jewish hearing-impaired population.

Hereditary hearing loss is extremely heterogeneous, represented by mutations in hundreds of genes. These include nuclear and mitochondrial genes, as well as microRNAs. The complexity of the auditory system is thus represented by a multitude of proteins encoded by these genes and regulatory pathways involved in many different functional pathways. A variety of techniques have been used over the years to identify the genes involved in hearing loss, which have evolved significantly with the sequencing of the human genome. Both the costs and the speed with which mutations can be found have changed, transforming the field. Further, the contribution of mouse models for the study of the human deafness genes has been unparalleled. The consequences of the genetic mutations have been elucidated in these mouse models, possible because of the similarity between the human and mouse inner ear structure and genes. More genes have yet to be discovered, which will help complete the knowledge of genotype–phenotype correlations between genetic mutation and type and characteristic of hearing loss. Finally, the genetic basis of deafness will help the discovery of the array of pathways involved in normal and impaired auditory and vestibular function.