Background: Excess mucus production and hypersecretion characterize upper airway diseases. The primary mechanisms leading to mucus hypersecretion in chronic rhinosinus inflammation are not well understood. Mucus hypersecretion is commonly accompanied by goblet cell and submucosal gland cell hyperplasia. It is important to identify which mucin gene messenger RNAs (mRNAs) are expressed in the sinus mucosa. Objectives: To investigate the expression of MUC5AC and MUC5B mRNAs and localization of these proteins in human sinus mucosa and to compare the expression of MUC5AC and MUC5B mRNAs in normal and in chronic sinus mucosa. Design: Twenty chronic maxillary sinusitis mucosa samples and 20 normal maxillary sinus mucosa samples were obtained; RNAs were extracted from sinus mucosa, and semiquantitative reverse transcriptionpolymerase chain reaction was performed for MUC5AC and MUC5B. Localization of these proteins was sought by using immunohistochemical analysis. Results: The levels of MUC5AC and MUC5B mRNA in chronic rhinosinusitis were significantly increased compared with those in normal sinus mucosa (P=.02). In inflammed sinus mucosa, MUC5AC protein was expressed in the cytoplasm of the goblet cell in the surface epithelium, and MUC5B expression was restricted to mucous cells of the submucosal glands and to the epithelium of sinus mucosa. However, in the normal sinus mucosa, MUC5AC and MUC5B proteins were expressed at low levels in the sinus epithelium and submucosal glands, respectively. Conclusion: These results suggest that up-regulation of MUC5AC and MUC5B, which are major components of respiratory secretion in chronic rhinosinusitis, may play important roles in the pathogenesis of sinus hypersecretion in chronic rhinosinusitis.

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Hearing loss (HL) is one of the most frequent clinical manifestations of patients who suffer with multi-systemic genetic disorders. HL in association with other physical stigmata is referred to as a syndromic form of HL. LEOPARD syndrome (LS) is one of the disorders with syndromic HL and it is caused by a mutation in the PTPN11 or RAF1 gene. In general, 5 year old children who undergo cochlear implantation usually show a marked change in behavior regarding sound detection within the first 6 months of implant use, but word identification may not be exhibited for at least another 6-12 months of implant use. We herein report on a 5-year-old girl with LS. Her clinical manifestations including bilateral sensorineural HL, which indicated the diagnosis of LS. We confirmed the diagnosis by identifying a disease-causing mutation in the PTPN11 gene, which was a heterozygous missense mutation Ala461Thr (c.1381G>A). She underwent cochlear implantation (CI) without complications and she is currently on regular follow-up at postoperative 1 year. This is the first reported case of CI in a patient with LS in the medical literature.

ObjectivesCarboplatin, a platinum-containing anti-cancer drug used to treat a variety of cancers, induces ototoxicity. Since, reactive oxygen species (ROS) and nitric oxide (NO) seem to be responsible for this toxicity, the antioxidant, N-acetyl-L-cysteine (L-NAC), and NO synthetase inhibitor, N-nitro-L-arginine methyl ester (L-NAME) were predicted to have protective effects against carboplatin ototoxicity. The aim of this study was to test for the protective effects of L-NAC and L-NAME on cochlear hair cells and spiral ganglion neurons (SGNs).MethodsCochlear organotypic cultures and dissociated spiral ganglion neuron cultures, from mice postnatal day 5 cultures were used in this study. The cultures were treated with carboplatin alone or in combination with L-NAC or L-NAME, and carboplatin-induced damage was monitored.ResultsTreatment with carboplatin induced a significant loss of outer hair cells, while inner hair cells were preserved in the cochlear organotypic cultures. Addition of L-NAC or L-NAME reduced the amount of carboplatin-induced hair cell damage; the differences did not reach statistical significance. However, carboplatin significantly decreased the number of surviving SGNs in dissociated cultures. The toxic effects were significantly reduced by addition of L-NAC or L-NAME. In addition, carboplatin induced the loss of neurites from the SGN somata, and this was not blocked with L-NAC or L-NAME.ConclusionThe results of this study suggest that ROS and NO are involved in carboplatin-induced damage to hair cells and SGNs, and administration of L-NAC/L-NAME can be used to attenuate the toxicity.