1994 Fiscal Year Final Research Report Summary
Middle Ear and Inner Ear Pathology in Otitis Media with Cholesteatoma.
| Project/Area Number |
05671438
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Otorhinolaryngology
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| Research Institution | Osaka City University |
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Principal Investigator |
OHASHI Yoshihiro Dept.Otolaryngology Osaka City University, 医学部, 助教授 (60160602)
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| Co-Investigator(Kenkyū-buntansha) |
MASUTANI Haruhiko Dept.Otolaryngology Osaka City University, 医学部, 講師 (10190357)
SAKASHITA Tetushi Dept.Otolaryngology Osaka City University, 医学部, 助手 (20205743)
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| Project Period (FY) |
1993 – 1994
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| Keywords | Cholesteatoma / cell cultare / mucociliary system / otitis media / hearing acuity. |
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| Research Abstract |
We have established the method for cholesteatoma cell culture from otitis media with cholesteatoma.Using the supernatant following cholesteatoma cell culture, we investigated whether cholesteatoma cells were able to induce inner ear pathology as well as mucociliary dysfunction of the middle in healthy guinea pigs.
Intratympanic injection of the supernatant following cholesteatoma culture resulted in (1) ciliary depression of the middle ear and the eustachian tube, (2) inflammatory cell accumulation in the tubotymapanum, (3) pathological mucus blanket in the tubotymapanum, (4) abnormal cilia formation, (5) sporadic appearance of ciliated cell sloughing, and (6) mild degeneration of stria vascularis in the inner ear. We also disclosed direct suppression of ciliary activity from healthy guinea pigs induced by the supernatant.These findings are clearly showing that cholesteatoma cells could produce some toxic factors to the middle ear as well as the inner ear.
Comparison of hearing acuity of patients with cholesteatoma and chronic simple otitis media demonstrated that hearing acuity of the high tones are significantly impaired in patients with cholesteatoma.This clinical feature may be attributed to the toxic factors to the inner ear developed from cholesteatoma cells following culture.
Otitis media with effusion is a major predisposing factor to otitis media with cholesteatoma.Therefore, our studies included the investigations on the pathogenesis, the recovery mechanism, and prossible medication resulting in prompt recovery as well as prevention of otitis media with effusion.These investigations concluded that mucociliary dysfunction is deeply involved in the pathogenesis and recovery process of otitis media with effusion and that otitis media with effusion could be prossibly preserved by some medication with ciliary accerelation, which might be also effective in preservation of otitis media with cholesteatoma.
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