Dysfunction of gap junctions (GJs) caused by mutations in connexin26 (Cx26) and Cx30 accounts for nearly half of all cases of hereditary nonsyndromic deafness cases. Although it is widely held that GJs connecting supporting cells in the organ of Corti mainly provide ionic pathways for rapid removal of K ؉ around the base of hair cells, the function of GJs in the cochlea remains unknown. Here we show that GJs were not assembled in the supporting cells of the organ of Corti until 3 days after birth in mice and then gradually matured to connect supporting cells before the onset of hearing. In organotypic cochlear cultures that were confirmed to express GJs, GJs mediated the propagation of intracellular Ca 2؉ concentration waves in supporting cells by allowing intercellular diffusion of inositol 1,4,5-trisphosphate. We found that a subset of structurally mild Cx26 mutations located at the second transmembrane region (V84L, V95M, and A88S) and a Cx30 mutation located at the first cytoplasmic segment (T5M) specifically affect the intercellular exchange of larger molecules but leave the ionic permeability intact. Our results indicated that Cx26 and Cx30 mutations that are linked to sensorineural deafness retained ionic coupling but were deficient in biochemical permeability. Therefore, GJ-mediated intercellular exchange of biochemically important molecules is required for normal cochlear functions.connexin ͉ deafness ͉ mutation
Main Outcome Measures: Age, sex, intervention, etiology, time from onset of UVFI to surgery, subjective success in improving voice, subjective duration of improvement, and complications.Results: Twenty-seven procedures were performed in 15 patients (mean age, 10.6 years). Nineteen injection laryngoplasties, 3 thyroplasties (1 bilateral), 2 ansa cervicalisrecurrent laryngeal nerve reinnervation procedures, 1 ad-duction arytenoidopexy, and 1 cricothyroid joint subluxation were performed. Causes of UVFI included thoracic surgery in 6 cases (40%), prolonged intubation in 4 (26%), central nervous system neoplasm in 3 (20%), unknown etiology in 1 (7%), and anoxic brain injury in 1 (7%). The mean duration from onset of symptoms to treatment was 47 months. There was 1 surgical complication (postoperative aspiration pneumonia following thyroplasty while the patient was under local anesthesia). Parents reported a satisfactory outcome in all cases.Conclusions: Injection laryngoplasty, thyroplasty, and nerve reinnervation can be performed in pediatric patients with good outcomes and an acceptable safety profile. This article describes the experiences of 2 institutions with phonosurgery for UVFI in children and provides insight into the advantages and disadvantages of each procedure. Prospective studies, with validated quality-of-life measurements, are needed to greater clarify the role of different types of phonosurgery in children with UVFI.
Portable video technology is a widely available new tool with potential to be used by pediatric otolaryngology practices for patient and family education. Podcasts are media broadcasts that employ this new technology. They can be accessed via the Internet and viewed either on a personal computer or on a handheld device, such as an iPod or an MP3 player. We wished to examine the feasibility of establishing a podcast-hosting Web site. We digitally recorded pediatric otologic procedures in the operating room and saved the digital files to DVDs. We then edited the DVDs at home with video-editing software on a personal computer. Next, spoken narrative was recorded with audio-recording software and combined with the edited video clips. The final products were converted into the M4V file format, and the final versions were uploaded onto our hospital's Web site. We then downloaded the podcasts onto a high-quality portable media player so that we could evaluate their quality. All of the podcasts are now on the hospital Web site, where they can be downloaded by patients and families at no cost. The site includes instructions on how to download the appropriate free software for viewing the podcasts on a portable media player or on a computer. Using this technology for patient education expands the audience and permits portability of information. We conclude that a home computer can be used to inexpensively create informative surgery demonstrations that can be accessed via a Web site and transferred to portable viewing devices with excellent quality.
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