Aim:This study aimed to demonstrate the feasibility of a novel high-resolution manometry (HRM) system, and to establish normal values of swallowing pressures along the velopharynx and upper esophagus. Methods:Thirty three asymptomatic adult Japanese controls were studied. A solid-state HRM assembly with 36 circumferential sensors spaced 1 cm apart was positioned to record pressures during swallowing from the velopharynx to the upper esophagus. The maximum values of the swallowing (dry and 5 ml of water) pressures at velo, mesohypopharynx, and at the upper esophageal sphincter (UES) were measured. The resting UES pressure, the length of the part in the cervical esophagus showing the resting UES pressure, and the distances from the nostril to the above-mentioned points of pressure measurement were also measured. Results:The maximum value of dry and water swallowing pressures at the velopharynx, meso-hypopharynx and UES, and the distances from the nasal vestibulum to each point in male were 141.1±73.5 (mmHg, mean ± standard deviation) and 162.7±94.9, 175.3±59.7 and 182.9±83.6, 172.7±73.8 and 236.1±78.9, and 10.0±1. Conclusion:The present study provides anatomical and physiological information about normal swallowing along the velopharynx and upper esophagus, which will be an aid to the future clinical and investigative studies.

The anti-diuretic hormone vasopressin (AVP) regulates water excretion from the kidney by increasing the water permeability of the collecting duct. AVP binds to V2-receptors and induces the translocation of aquaporin-2 water channels (AQP-2) into the apical plasma membrane of principal cells. By this mechanism AVP controls water reabsorption in the kidney. The effects of AVP on the endolymphatic sac (ES) of the inner ear, which is thought to mediate reabsorption of endolymph, were investigated. Both the V2-receptor and the AQP-2 water channel were found to be expressed in the ES epithelium. In the ES AVP binds to receptors most probably of the V2-subtype. Application of AVP to organotypically cultured ES inhibits membrane turnover in ribosomal-rich cells of the ES epithelia, which is thought to mediate translocation of AQP-2 into the surface membrane. This suggests that AVP has contrasting effects in the inner ear and kidney, which may be physiologically useful for maintaining endolymphatic pressure during severe hypovolemia. Animal experiments show that AVP causes endolymphatic hydrops after systemic application to guinea-pigs, which suggests a causal role for the increased AVP levels found in humans suffering from Ménière's disease.

Objective: To obtain clues on the anatomical features of the eustachian tube (ET) related to the susceptibility to otitis media with effusion (OME) in children. Methods:The angle and length of the ET in children with (54 ears, OME children) and without OME (50 ears, normal children), as well as those of normal adults were measured on the CT using the multiplanar reconstruction technique Results:The angles of ET in OME children group, normal children group, and normal adult group were 20.4±3.5 degree (°) and 21.2±4.8°, 19.9±3.4°and 20.0±3.6°, and 27.3±2.7° and 27.3±2.8° in the right and left sides, respectively. There was no significant difference between the right and left sides in any group (p=0.541, p=0.952, p=0.978). The lengths of the ET in the OME children group, normal children group, and normal adult group were 37.2±3.0 mm (mean±standard deviation) and 37.6±3.2 mm, 37.5±3.3 mm and 38.0±3.2 mm, and 42.5±2.8 mm and 42.9±2.9 mm in the right and the left side, respectively. There was no significant difference between in the right and left sides in any groups (p=0.670, p=0.597, and p=0.545).Both the angles and lengths were significantly greater in the normal adult group than in either the OME children group or normal children group (one-way ANOVA and Fisher's PLSD tests, p<0.05), but there was no significant difference either in the angle or length of the ET between the OME group and normal children group (p>0.05). In the OME and normal children groups, the angle was observed to constantly increase with age, and the values were found to be within the range of the adult size in all the cases older than 2737 days and 2818 days in the OME children group and in normal children group, respectively. In addition to the angle, the lengths were observed to constantly increase with age, but the increase appeared to be greater in younger age until around 1000 to 1500 days (3 to 4 year old) than in the older age, and the values were found to be within the range of the adult size in all the cases older than 2470 days and 2818 days in OME children group and in normal children group, respectively. Conclusion:The angle and length of ET are more horizontal and shorter in infants than in adults. However, there is no statistical difference between the angle and length of ET in infants with and without OME. These results suggest that short and horizontal ET may be one of the predisposing factors related to the high susceptibility of OME in infants and children rather than etiological factors.

Child implant users enjoy music more than adult implant users. Moreover, younger age at implantation increases children's engagement with music, which may enhance their progress in other auditory domains.