Junichi Kambayashi

The Effect of Transient Anoxia Upon the Cochlear Potentials

To contribute to the analysis of the electrocochleographical findings in humans, the reversibility of the cochlear potentials (the AP, CM, and SP) after transient anoxia was examined using 24 albino guinea pigs. The durations of anoxia ranged from 5 to 120 min, and the AP, CM and SP were examined one hour after restoration of the blood supply. The mildest form of cochlear damage after transient anoxia was the disappearance of the L-part of the AP and the severest was the complete abolition of these potentials. The severity of the damage closely correlated with the duration of anoxia. The AP was poorer in reversibility than the CM and the SP. These results were analysed and discussed in the light of literature on clinical and basic studies.

A Case of Carcinoid Tumor of the Middle Ear Producing Peptide Hormones

We report 6th case of carcinoid tumor of the middle ear in a 16-year-old man. The clinical, histologic, immunohistochemical and ultrastructural features are discussed. The tumor in the attic and the tympanic cavity was successfully excised by radical mastoidectomy. Microscopically, the argyrophilic property and neurosecretory granules which are characteristic of carcinoid tumor were found in the cytoplasm of tumor cells. Furthermore, peptide hormones were confirmed immunohistochemically in this case. This tumor should be considered in the differential diagnosis when biologically lowgrade tumor with glandular and trabecular architectures are encountered in the middle ear.

Generation Mechanism of the Negative Endocochlear Potential during Early Stage of Anoxia

To investigate the generation mechanism of the -EP in anoxic cochlea, the perilymphatic space was perfused with solution of various K+ concentrations in 38 guinea pigs when the -EP was maximally reduced by anoxia. Although the perfusion of scala tympani and vestibuli with Ringer-Locke solution or that of scala vestibuli with 154 mM K+ solution did not have any effect upon the -EP, the potential was elevated to 0 mV when the scala tympani was perfused with 154 mM K+ solution. Furthermore, the elevation of the potential was less remarkable when the K+ concentration in perfusate was reduced. The level of the potential during perfusion was closely related to K+ concentration in perfusates. The present results strongly suggest that the -EP is the result of the K+ diffusion potential and this diffusion mechanism is performed through the organ of Corti.

Middle ear inflation as a treatment for secretory otitis media in children

Clinical evaluations of middle ear inflation for secretory otitis media (SOM) were performed with special emphasis on the influence of seasonal and aging factors. One hundred and forty-nine children between the ages of 3 and 9 years (227 ears) were all diagnosed as SOM by pneumatic-otoscopic findings, and type B tympanogram (TG) at 3 weeks or more after the onset of acute SOM or the initial observation of SOM. Middle ears were inflated by Politzers method or by our modified method once or twice each week for 2 months. After inflation, TG displayed two different time sequences: one group changed to the A or C type immediately after inflating the ear one or more times, but usually returned gradually to the B type (TG-improved group): and the other group remained without any changes (TG-unchanged group) for the duration of this study. The healing rate in the TG-improved group was significantly higher than in the TG-unchanged group at the 2-month endpoint. The cure rate of SOM was significantly higher in spring than in autumn in the TG-unchanged group but not in the TG-improved group. There were almost no differences between the healing rates in the 3-5 and 6-9 year-old children. When a TG-unchanged ear is found in autumn during the 2-month inflation treatment, more careful and forcible treatments should be introduced later, especially to children between the ages of 3 and 9 years.

Sensation of Aural Fullness and its Treatment with an Autonomic Nerve Blocking Agent

One hundred and eighteen patients (143 ears) complaining of a full sensation in the ear without any evidence of other ear diseases were selected for treatment with an autonomic nerve blocking agent and were analysed clinically. Females were extremely predominant in number, 79% of the cases. Sixty-five of 143 ears (45.4%) showed normal hearing and 54 ears (37.8%) had sensorineural hearing loss in low tone. Four mg of butropium bromide, Coliopan, an anti-cholinergic routinely used as an antispastic agent, was injected intravenously. Subsequently, the aural fullness diminished or disappeared in 72.7% (104/143) and 33.5% (48/143) was dramatically relieved within 30 min after the injection. Sensorineural hearing loss in low tone which was recognized in 57 ears in this series also improved remarkably in 57.9% (33/57). These results suggest a close relationship between the autonomic nervous system, aural fullness and sensorineural hearing loss in low tone. According to this study, we recommend anti-cholinergics as the treatment for patients, especially for women, complaining chiefly of aural fullness but with normal otoscopic findings and normal tympanogram, and with or without sensorineural hearing loss in low tone.

Loop Diuretics and Saccular Endolymphatic Potential

21匹のモルモットからSEPを記録し, エタクリソ酸, フロセミド投与による変化を調べた.1) SEPの平均は2.6mV±4.5mVであった.2) エタクリン酸, フロセミド投与によりSEPは低下しその反応様式はCEPと大変良く類似していた.3) ループ利尿剤の場合CEPが約15%に減衰して球形嚢に伝わると考えるとよく一致する所見が得られた.4) 前回のアノキシアの実験と併せて考えると球形嚢への減衰率は10～15%位の幅があると考えるのが妥当のようである.