In this study, dynamic behavior of the basilar membrane and cochlear fluid caused by the vibration of the stapes was analyzed using a three-dimensional finite element model of the human cochlea. Numerical results and the measurement results were compared, and the validity of the model was verified. In addition, an influence of perilymphatic fistula on the vibration of the basilar membrane was analyzed. The leakage of the lymph from a perforation opened near the round window did not have the great influence on the vibration of the basilar membrane. In contrast, the amplitude of the basilar membrane decreased when the lymph flowed out through the perforation near the oval window. This result suggests that oval window perilymphatic fistula causes an increase of hearing threshold from the viewpoint of dynamics.

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Gentian violet (Pyoktanin) is known to have a potent antibacterial activity against Gram-positive bacteria including methicillin-resistantStaphylococcus aureus (MRSA).
From November 2000 to August 2006, we have treated 91 patients for intractable ear infected with MRSA by topical treatment with gentian violet. There were 99 infected ears: 44 chronic otitis media, 11 otitis media with effusion treated with tympanostomy tube, 10 repetitive suppurative otitis media, 10 otitis externa, 8 postoperative discharging mastoid cavity for cholesteatoma, 6 cholesteatoma, 4 eosinophilic otitis media, 3 acute otitis media, 3 myringitis. The pathogens detected in those ears during the treatment period were as follows: MRSA in 92 ears, MRSA andP. aeruginosa7 ears. Topical treatment with gentian violet was performed 7.5 times on average. In the 92 ears (92.9%), topical treatment was performed 5.4 times on average. Noteworthily, 23 ears required only one treatment and 16 ears required twice, and this fact was suggesting that frequent treatments were not necessary to control the pathogens sensitive to gentian violet. This high cure rate (92/99) of the ear infected with MRSA also suggested that this treatment was especially effective for the treatment of MRSA infected ears.

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We investigated health-related quality of life (HRQOL) in patients with Bell's palsy. HRQOL questionnaire, SF-36 Japanese version 2, was filled out by 32 patients with Bell's palsy at 3 weeks or later after the onset. The QOL scores were analysed twice in 15 patients within 7 days and about a month after the onset. No significant relation was observed between age and any of 8 subscales, however significant decrease was noted in 4 of 8 subscales in women, which were Role Physical (p=0.022), Bodily Pain (p=0.039), Mental Health (p=0.039), and Social Functioning (p=0.004). Patients with moderate and severe paralysis (score 8-32 on Yanagihara grading scale) tended to have lower scores in General Health (p=0.085), compared to the patients with mild paresis (score 34-40 on Yanagihara grading scale). Social Functioning significantly lowered about a month after the onset in comparison to those within 7 days from the onset (p=0.029). In conclusion, HRQOL in Bell's palsy patients obtained by using SF-36 was promising, and especially Social Functioning (SF) was thought to be the most effective subscale for evaluation of QOL in Bell's palsy.

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An 11-year-old boy with the right ear discharge showed a soft tissue density with extensive destruction of the middle cranial fossa bone on CT. At the first operation, cholesteatoma was found attached to the middle fossa dura causing cerebrospinal fluid leakage. The operation was completed after removal of most of the cholesteatoma matrix except for the dura area. At the second operation, however, there was no cholesteatoma in the middle cranial fossa and the bone defect was closed. We speculated that the rest of cholesteatoma was evacuated to the mastoid cavity because of reduction of volume at the first operation, and the regeneration of periosteum and bone occurred.

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私たちは音を聞いたり、重力の向きを感じたりすることができる。音は鼓膜を揺すりその結果、内耳の有毛細胞にある感覚毛が動毛の方向に倒れると何らかの機構でイオンチャネルが開いて、有毛細胞の膜が脱分極し、さらに神経伝達によって、信号が中枢神経系に伝わると考えられている。これらの機能を実現するのにイオンチャネルは不可欠である。
われわれが普通の生活で聴く音圧の音刺激を内耳の有毛細胞が受容する場合、細胞は極めて小さい力を感じる必要がある。音刺激が内耳に伝わると、感覚毛がたわみ二本の感覚毛の問にずれが生じて、その結果イオンチャネルが開くと考えられている。図1に音の受容のモデルを示す。二つの感覚毛はチップリンクと呼ばれるひも状の構造で結ばれている(その分子組成は最近明らかになった (Siemens, et al., 2004; Kazmierczak, et al., 2007))。このモデルではひも状の構造はチャネルの力感受部位に接続されている。またチャネル自身は細胞内骨格につながっている。細胞骨格はチャネルの移動を制限していて、チャネルに力が掛かったときにチャネルが膜上を移動しないようにしている。膜の上をチャネルが自由に移動できないので、力はチャネルに作用し、チャネルが開く。すなわち感覚毛がたわむと二つの感覚毛の問の距離が離れて、チップリンクを介して力がチャネルに伝わりチャネルが開くと考えられている。しかし、このモデルは仮説の段階で状況証拠があるのみである (Gillespie and Walker, 2001)。このように機械的な力によって開閉が制御されているチャネルを機械受容 (SA) チャネルと呼ぶ (Blount, et al, 2008)。
機械受容チャネルの開閉の制御機構についてはこれまで二つの仮説が知られている。一つはチャネルは細胞内骨格あるいは細胞外のマトリクスにつながっていて、これらの構造変化(歪み)がチャネルに伝わってチャネルが開くとするもの (図1a、bの有毛細胞のモデル)。他の説は、チャネルは細胞膜に発生する張力によって開くとするものである (図1cの大腸菌のチャネルのモデル)。大腸菌のチャネルの場合、チャネル蛋白質を精製して人工的に作られた膜にチャネルを再構成できる。そして、人工膜に張力を発生させるとチャネルが開くことが実験で確認されている (Sukharev, et al., 1999)。しかし、最初にのべてた細胞骨格を介してチャネルが活性化されるとする仮説については、真核生物の細胞における機械受容の仕組みとして想定されてきたが、実験的な証明はなされていない (Gillespie and Walker, 2001)。
われわれは最近、近接場光や光ピンセット法やパッチクランプ法などの研究方法を用いて細胞骨格によるチャネルの活性化を強く示す実験データを得ることができた (Hayakawa, et al., 2008)。その概要を報告する。

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