| 1. |
- Iguchi, Hiroyoshi, et al.
(författare)
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Acute effects of semicircular canal destruction on the cochlea, with and without preceding Pseudomonas aeruginosa exotoxin A treatment
- 1998
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Ingår i: Acta Oto-Laryngologica. - 0001-6489 .- 1651-2251. ; 118:4, s. 511-8
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Tidskriftsartikel (refereegranskat)abstract
- Acute electrophysiological and morphological changes in the cochlea following destruction of the semicircular canals (SCCs) were investigated to elucidate differences in cochlear vulnerability to surgical procedure under two conditions: normal healthy condition and a pathological condition induced by Pseudomonas aeruginosa exotoxin A (PaExoA). Frequency-specific auditory brainstem response recording and examination by light microscopy (LM) and scanning electron microscopy (SEM) were performed in the acute stage, immediately following, and 2, 5, and 10 days after the intervention. All normal healthy rats showed noticeable hearing loss immediately after the operation, predominantly in lower frequency areas, followed by complete recovery within 5 days. LM revealed rupture and slight distension of Reissner's membrane. SEM revealed considerable disarray of the stereocilia, especially on the outer hair cells (OHCs) of the third row in the upper half-turns of the cochlea. By contrast, all rats under pathological conditions showed delayed and incomplete hearing recovery from postoperative hearing loss. LM revealed various kinds of cochlear reaction, such as distension of Reissner's membrane, infiltration of inflammatory cells into the cochlea, and severe inflammatory change. Damage both of inner hair cells in the basal turn and of OHCs in the upper half-turns was more noticeable, compared with that under normal conditions. These findings indicate that SCC destruction under pathological conditions induced by PaExoA is detrimental to postoperative hearing recovery, even if the preoperative hearing level had appeared electrophysiologically normal.
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| 2. |
- Iguchi, Hiroyoshi, et al.
(författare)
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Interleukin 8 can affect inner ear function
- 1998
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Ingår i: Journal for Oto-Rhino-Laryngology. - : S. Karger AG. - 0301-1569 .- 1423-0275. ; 60:4, s. 181-9
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Tidskriftsartikel (refereegranskat)abstract
- The chemokine interleukin 8 (IL-8) was instilled into the round window niche of rats through a small perforation in the tympanic membrane in order to study its effect on inner ear function by electrophysiological and morphological techniques. The frequency-specific auditory brainstem response (ABR) was recorded at the frequencies 4, 8, 10, 12, 16 and 20 kHz just before and 1, 2, 5 and 14 days after instilling IL-8 to ascertain the hearing level during each interval. Morphological examination by light microscopy was performed during the same interval following the instillation of IL-8. On day 1, the rise in ABR threshold was within 5 dB SPL (non-significant elevation). However, a significant threshold elevation (above 5 dB SPL) occurred in high-frequency areas (16 and 20 kHz) on day 2, and in middle frequency areas (10 and 12 kHz) on day 5 with sensorineural hearing loss type intensity-latency curves. By day 14, the elevated thresholds had returned to pre-instillation levels. In the lowest areas (4 and 8 kHz), no significant threshold elevation was detected at any time during the observation period. By light microscopy, on day 1, clusters of inflammatory cells (predominantly neutrophils) were observed just outside the round window membrane (RWM), while only a few neutrophils were detected in the cochlea. These cells were still present outside the RWM on day 2. The neutrophils had disappeared by day 5 and only macrophages were present on the middle ear side of the RWM. However, throughout the observation period, the organ of Corti and stria vascularis appeared to be intact. These results suggest that IL-8 in the middle ear cavity is able to influence inner ear function.
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| 3. |
- Takano, Sakurako, et al.
(författare)
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Blockage pattern of longitudinal flow in Meniere's disease
- 2013
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 133:7, s. 692-698
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Tidskriftsartikel (refereegranskat)abstract
- Conclusion: In the present study, classification of the patterns of 3D CT images of the ductus reuniens (reuniting duct) (RD), saccular duct (SD), and endolymphatic sinus (ES) gave more precise information for assessing the pathological condition of Meniere's disease (MD) than our previous study. Objective: This study attempted to provide more detailed information on MD by classifying the patterns of 3D CT images of the RD, SD, and ES in patients with MD. Methods: We examined the ears of 62 patients with definitely diagnosed unilateral MD based on the criteria of the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) using 3D CT. The 3D CT images of bony grooves of RD, SD, and ES (BRD, BSD, and BES) were classified into patterns according to aspects of their patency. Results: BRD could be classified into six types by assessing their patency defined using the criteria in this study. In the ears on the affected side of patients with MD, the BRD, BSD, and BES lost continuity in 3D CT images along their bony routes and were significantly different from normal healthy ears (p<0.01). There were no significant differences among each stage of MD in the distributions of BRD and BES except for BSD.
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| 4. |
- Yamane, Hideo, et al.
(författare)
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Assessment of Meniere's disease from a radiological aspect : saccular otoconia as a cause of Meniere's disease?
- 2012
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 0001-6489 .- 1651-2251. ; 132:10, s. 1054-1060
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Tidskriftsartikel (refereegranskat)abstract
- Conclusion:Significant reduced visualization of the reuniting duct (ductus reuniens; RD), saccular duct (SD) and endolymphatic sinus (ES) in Meniere's disease (MD) compared with normal control ears on three-dimensional (3D) CT imaging suggests the blockage of endolymphatic flow there with radiodense substances, which may be explained by dislodged otoconia from the saccule. These structures could be involved in the pathogenesis of MD.Objective:This study was designed to visualize and assess the RD, SD and ES in patients with MD using 3D CT.Methods:Sixty-two patients with a definite diagnose of unilateral MD, based on criteria proposed by the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS), were compared with contralateral ears and normal controls (26 ears) using 3D CT. The RD, SD and ES were scrutinized for patency on 3D CT images.Results:MD ears showed loss of continuity of the RD, SD and ES based on evaluation of 3D CT images, and differed significantly from normal healthy control ears (p < 0.01).
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| 5. |
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| 6. |
- Yamane, Hideo, et al.
(författare)
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Natural killer cell response in the inner ear
- 1995
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Ingår i: Acta Oto-Laryngologica. - 0001-6489 .- 1651-2251. ; 115:6, s. 738-741
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Tidskriftsartikel (refereegranskat)abstract
- Heterologous tumor cells (human chronic myelogenous leukemia K-562 cells) were injected into the perilymph and skin in guinea pigs in order to study the induction of NK cell activity in the inner ear. An in vitro transmission electron microscopic and immunohistochemical study showed that K-562 cells were attacked by guinea pig large granular lymphocytes. K-562 cells injected through the round window membrane were found to be targeted by NK cells emerging from surrounding venules after 7 to 9 days. During this time morhological changes occurred in the organ of Corti and stria vacularis. These findings suggest that the inner ear response to foreign cells induces activation and invasion of NK cells which occur relatively late compared with those in other organs such as skin.
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