http://hdl.handle.net/10564/2692 2013-11 2026-04-10T15:42:28Z http://hdl.handle.net/10564/2696 タイトル: Left-right difference in high frequency sensitivity : application for unilateral cochlear disorder evaluation. 著者: Uratani, Yuka; Nishimura, Tadashi; Ohara, Nari; Yamanaka, Toshiaki; Hosoi, Hiroshi 抄録: High-frequency audiometry has the potential to detect hearing impairment at its early stage. However, several problems prevent the clinical application of high-frequency audiometry. In this study, the dispersion and left-right difference in the high-frequency sensitivity were investigated in normal hearing volunteers. In our results, the difference between the left and right ears varied only slightly among individuals or age groups, while dispersion of hearing threshold values became marked with an increase in frequency. The results suggest that the measurement of left-right difference in high-frequency sensitivity may be useful for the evaluation of unilateral impairment. To investigate this usefulness, the left-right differences were measured in the patients complaining of unilateral cochlear symptom with normal hearing. Considering the results of normal hearing, we determined that abnormal left-right difference in high-frequency sensitivity was over 20 dB. In 12 patients with unilateral tinnitus, 7 showed left-right differences, and 6 had tinnitus in the ear with increased thresholds. Our results suggested a relationship between tinnitus with normal hearing and hearing impairment in the high-frequency range. 内容記述: 博士（医学）・乙1335号・平成26年3月17日 2013-11-29T15:00:00Z http://hdl.handle.net/10564/2695 タイトル: Abnormal distribution of aquaporin-5 and lymphoid infiltration in salivary glands of primary sjögren's syndrome. 著者: Kobayashi, Takehiko; Fujimoto, Takashi; Yane, Katsunari; Hosoi, Hiroshi 抄録: Objectives: Patients with Sjögren's syndrome (SS) suffer from impaired saliva secretion due to an autoimmune destruction of salivary glands. Based upon its abnormal distribution in SS salivary glands, a potential role for the water channel protein aquaporin-5 (AQP5) is proposed in the pathogenesis of SS. Methods: The immunohistochemical distribution of AQP5 was compared in minor salivary gland (MSG) biopsies obtained from primary SS with a variety of lymphoid cells infiltration in MSG, and healthy volunteers. Results: Biopsies from normal subjects revealed AQP5 primarily at the apical membrane of the salivary gland acinus. In contrast, biopsies from SS patients with both moderate and severe lymphoid infiltration revealed AQP5 expression diffusely at the cytoplasm of the acinus. Computer-assisted microscopy was performed to quantitatively evaluate AQP5 distribution in the acini. Biopsies of SS patients exhibited lower labeling indices (LI) at the apical membrane compared with biopsies from control subjects. The LI of the acini obtained from SS patients with both moderate and severe lymphoid infiltration showed no difference. Conclusions: Abnormal distribution of AQP5 in salivary gland acini could be responsible for a loss of saliva secretion, and this abnormal distribution is likely to develop during the stage of moderate lymphoid infiltration in salivary gland. 内容記述: 博士（医学）・乙1334号・平成26年3月17日 2013-11-29T15:00:00Z http://hdl.handle.net/10564/2694 タイトル: Auditory habituation is revented in the background sound of 4-kHz pure tone : A magnetoencephalography study. 著者: Koizumi, Toshizo; Nishimura, Tadashi; Nakagawa, Seiji; Hosoi, Hiroshi 抄録: Auditory evoked magnetic field (AEF) is gradually attenuated as the number of　presentation of auditory stimuli increases. The attenuation of AEF is auditory habituation, and is prevented in the condition where a noise exists in the background. In this study, we investigated whether the background sound of pure tone prevent the auditory habituation to repeating stimuli. Subjects were 17 normal hearing individuals. Auditory stimuli were 1-kHz tone bursts set at 30 dB SL with durations of 100 ms and inter-stimulus intervals of 1.9-2.l s. The background sounds were silent, 4-kHz pure tone presented set at 5 and 20 dB SL which were presented with 1-kHz tone bursts. N1m component of AEF induced by auditory stimuli was measured using 122-channel neuromagnetometer. As a result, N1m amplitudes induced by repeating auditory stimuli were gradually attenuated in the condition of silent background due to the auditory habituation. Meanwhile, the attenuation of N1m amplitude was small in the conditions of background sounds of 4-kHz pure tones at 5 and 20 dB SL, compared to the conditions of silent background. Moreover, the time course of N1m amplitudes was not different between the condition of background sound at 5 and 20 dB SL. These results suggested that the background sound of pure tone, independent of its intensity, drove the subject to unconsciously pay attention to repeating auditory stimuli without disturbing signal-to-noise ratio of them, or the neural process of the background pure tone continuously activated the auditory pathway and resulted in the prevention of auditory habituation. 内容記述: 博士（医学）・乙1333号・平成26年3月17日 2013-11-29T15:00:00Z http://hdl.handle.net/10564/2693 タイトル: 表紙、目次、投稿規定、奥付(Vol.64 No.4) 2013-11-29T15:00:00Z