ABSTRACT
Objective To investigate the role of β-catenin,the core protein of canonical Wnt/β-catenin signaling,in the inner-ear development and polarity regulation.Methods β-catenin was conditionally deleted from precursor cells of inner-ear sensory epithelium (Sox2-positive cells) in embryonic mice.Morphological changes of the inner ear were observed.Immunofluorescence staining was performed to basilar membranes,utricles and saccules to observe the hair-cell changes in arrangement and polarity.Results Compared with the control group,knock-out of β-catenin in Sox2-positive cells resulted in smaller otic vesicles,cochleas and vestibules,and fewer hair cells (HCs) in vestibular sensory epithelium (P＜0.01).Stereocilium showed misorientation and kinocillia had a change in location and quantity in the cochlea.Scattered misorented HCs were also observed in the vestibule.Conclusions β-catenin is crucial for the development of inner ear and polarity manipulation of HCs in mice.The canonical Wnt/β-catenin signaling may be involved in the regulation of cochlea extension and planar cell polarity (PCP) of inner ear,which is known to be controlled by non-canonical Wnt/PCP signaling.
ABSTRACT
<p><b>BACKGROUND</b>Otitis media with effusion is a highly concurrent disease in young children with adenoid hypertrophy. The aim of this study was to assess the middle ear effusion and audiological characteristics in children with adenoid hypertrophy and compare the various assessment methods.</p><p><b>METHODS</b>Two hundred and seven candidates who were to undergo adenoidectomy were analyzed using otoscopy, tympanometry, air-conduction auditory steady-state responses (AC-ASSR), and computerized tomography (CT) before adenoidectomy.</p><p><b>RESULTS</b>About 73.4% (304/414) of ears were confirmed to have middle ear effusion (MEE) by otoscopy; 75.4% (312/414) of ears revealed MEE by CT. CT scan correctly predicted all the myringotomy results, giving 100% accuracy on the diagnosis of MEE. Additionally, CT revealed two children with inner ear malformations. Type B tracing tympanogram provided a sensitivity of 91.7% and a specificity of 92.2%. Type C tympanogram with peak pressure < -200 daPa indicated effusion; type C tympanogram having acoustic stapedius reflex could exclude MEE. We excluded the AC-ASSR results of the 4 ears with malformation; 54.4% (223/410) of ears were confirmed of hearing loss. Furthermore, 5.2% (16/310) of the ears with MEE suffered from severe to profound hearing loss. The average threshold level in the 0.25 kHz frequency of children was found to have poorer hearing thresholds than those in the 0.5, 1, 2, and 4 kHz (P < 0.001) frequencies; 29.7% (92/310) of ears with MEE were regarded as normal hearing level. About 55.8% (173/310) of ears with MEE were classified as having slight-mild hearing loss.</p><p><b>CONCLUSIONS</b>The practitioners should pay much attention to the middle ear condition and be aware of a possible development of severe to profound hearing loss during the course of MEE in young children with adenoid hypertrophy. CT scan is good for the assessment of MEE before ventilation tube insertion.</p>