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Volume 100, Issue 3
Displaying 1-9 of 9 articles from this issue
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Satoru Takebayashi, Yoshihiro Asai, Michihiko Nozue, Hiroyuki Mineta, ...1997 Volume 100 Issue 3 Pages 295-298
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSWe investigated 974 patients with sudden sensorineural hearing loss who consulted the otolaryngological service of Hamamatsu University Hospital and four affiliated hospitals from 1984 to 1992. Among them, we selected 569 new cases showing a pure tone average of 31 dB or more at 250 Hz, 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz on the affected side in the initial audiometry performed within 14 days after the onset of sudden sensorineural hearing loss. The 569 patients consisted of 13 with acoustic neuromas (SHLANs), 493 with idiopathic sudden sensorineural hearing loss (ISHLs) and 63 others. Ten of the 13 SHLANs and 40 of the 493 ISHLs showed the trough type audiogram on the initial examination. We defined the 10 cases as the Trough AN group and the 40 as the Trough ISHL group.
Statistical analysis of the difference in pure tone averages at 5 frequencies between the 2 groups demonstrated that the mean hearing losses at 125, 250 and 500 Hz of Trough AN were significantly less than those of Trough ISHL.
This study demonstrates that the trough type audiogram, especially a slight low tone loss, shown in patients with sudden sensorineural hearing loss was a significant finding suggesting the presence of acoustic neuroma.View full abstractDownload PDF (355K) -
Experimental Study of Hypoglossal-facial Anastomosis and Accessory-facial Anastomosis in Guinea PigsJoji Horiuchi1997 Volume 100 Issue 3 Pages 299-306
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSHypoglossal-facial nerve anastomosis (XII-VII anastmomsis) or accessory-facial anastomosis (XI-VII anastomosis) have been chosen for facial rehabilitation when the facial nerve is widely sacrificed and end-to-end anastomosis or nerve grafting is unavailable. However, no detailed study has been conducted to determine which donor nerve is better for the anastomosis procedure in view of regeneration of the facial nerve.
To compare and evaluate nerve regeneration after XII-VII anastomosis and XI-VII anastomosis, animal models of these anastomoses were made in guinea pigs by using a Y-shaped silicon tube. The proximal cut-ends of the hypoglossal nerve and accessory nerve were suspended in the paired inlet limbs of a Y-shaped silicone tube with a 9-0 nylon suture, and the distal cut-end of the facial nerve was suspended in the single outlet limb in a similar manner. After 4 and 8 weeks, histological studies were carried out. An electorophysiological study of conduction velocity and amplitude of evoked electromyography were measured at 8 weeks postoperation. The nerve fibers regenerated from the hypoglossal nerve were significantly more numerous than those from the accessory nerve at both 4 and 8 weeks after anastomosis. The amplitude of evoked electromyography elicited from the hypoglossal nerve was greater than that from the accessory nerve, even though there is no significant difference in conduction velocties between the two anastomoses.
The nerve regeneration by the cross-over procedure was influenced by many factors such as the number of nerve fibers in the donor nerve and the affinity between donor and recipient nerves. The number of nerve fibers in the hypoglossal nerve was significantly greater than that in the accessory nerve. However there was no significant difference in the ratios of regenerated nerve fibers to the preoperative nerve fibers. Accordingly, we concluded that the affinity of the hypoglossal or accessory nerve to the facial nerve is a minor factor if it exists, and the difference in the fiber count in these nerves is a major factor in the outcome of nerve regeneration.View full abstractDownload PDF (6344K) -
Comparison with Scanning Electron Microscopic FindingsHayato Tsuge, Hiromi Ueda, Makoto Kozuka, Kazuki Fujiura, Noriyuki Yan ...1997 Volume 100 Issue 3 Pages 307-315
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSTo investigate the mechanism of barotrauma to the inner ear, we used electrophysiologic methods to evaluate guinea pigs exposed to such trauma, and compared the findings with those observed by scanning electron microscopy (SEM).
Guinea pigs with good Preyer's reflexes were studied. In those animals that showed a loss of or decrease in Preyer's reflexes and/or nystagmus following exposure to an increase and decrease in pressures in a high-pressure chamber, we measured compound action potentials (CAPs) and cochlear microphonics (CMs) 7-11 days after the exposure. The pressure was increased from 1 ATA to 2 ATA over 30 sec and maintained for 10 min, then pressure was decreased to 1 ATA over 30 sec. Specimens obtained from animals in which CAPs and CMs could be measured were prepared for SEM examination. CAPs and CMs were measured at decreasing 5 dB increments to the visual threshold level of detection with tone bursts at 1, 2, 4 and 8 kHz.
Based on the CAPs measured 7-11 days after exposure, guinea pigs were divided into two groups by CAP thresholds, those with severe damage and those with mild damage. None of the animals showed moderate damage. The group with high CAP thresholds showed severe damage to hair cells on SEM, while the group with low CAP thresholds showed no specific morphological abnormalities on SEM. It appeared that some guinea pigs with normal SEM findings following barotrauma to the inner ear did not achieve complete recovery of hearing. From these results, it was speculated that some animals had sustained reversible damage in the mild group and that these animals had recovered from moderate damage. The elevation of CMs was usually not high compared to that of CAPs in the high frequency area, and 4 animals showed CAP and CM separation above 30 dB at 8 kHz. These findings suggested that the group with severe damage exhibited multiple patterns of injury.View full abstractDownload PDF (3648K) -
Hideo Yasuta, Hidetaka Kanno1997 Volume 100 Issue 3 Pages 316-325
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSIt is thought that the integrity of the hair cell plays an important role in the production of the negative anoxic endcochlear potential EP, because the destruction of hair cells abolished the production of negative anoxic EP, However, the mechanism by which the negative anoxic EP is generated remains controversial although most investigators have regarded negative anoxic EP as diffusion potential across the organ of Corti. We hypothesized that negative anoxic EP was mainly produced by diffusion of ions through the outer hair cells from the scala media to the scala tympani or viceversa. The present study examined the negative anoxic EP and the reduction in the number of hair cells.
Kanamycin (300 or 500mg/kg) or gentamicin (100 or 150mg/kg) were administered to albino guinea pigs (200 to 300 g) IM for 10 or 15 days in order to induce varying degrees of hair cell loss in the animals. EP was recorded using the round window approach and then hair cells were counted by scanning electron microscopy.
The number of missing outer hair cells in the whole cochlea correlated well with the maximum negative EP value, which was defined as the lowest EP value during anoxia. The value of the correlation coefficient was 0.882. The EP value depends on the position at which the EP is recorded. Closer examination indicated that maximum negative EP was well correlated with the number of missing outer hair cells of upper turns, such as the second or third turn, rather than with that of the hook portion, although EP and negative EP was recorded at the hook portion. These results suggested that negative EP reflects the diffusion potential over the entire cochlea. The present results supported our hypothesis that some ions only pass through the outer hair cells in the organ of Corti.View full abstractDownload PDF (3953K) -
Yoshiyuki Tamura, Yoshihiro Kobayashi, Syuichi Watanabe, Keisuke Endou1997 Volume 100 Issue 3 Pages 326-331
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSWe investigated the relationship of pollen counts of Japanese cedar to 9 different weather factors including means of the highest, and lowest temperatures, variation in temperatures mean of the lowest humidity on a day, daily mean, maximum wind velocity and daily wind direction in 1991, 1992, 1993 and 1995 in Isehara City, Kanagawa Prefecture. The results were as follows: 1. In each year, the highest temperature and the mean humidity were statistically related to the maximum pollen counts of Japanese cedar in the air. 2. Mean pollen counts per day on the days that the wind from the southwest were much higher than on the days with wind from the south. 3. These wind directions coincided with the dense plantation areas of Japanese cedar trees around Isehara City. We concluded that in terms of accurate daily forecasting of pollen counts in the air in a certain area or city, it should be taken into consideration that the highest temperature, and mean humidity together with the wind direction from the area of dense population of Japanese cedar trees surrounding the area are closely related to the increased pollen count per day.View full abstractDownload PDF (595K) -
Mitsuru Fujiwara1997 Volume 100 Issue 3 Pages 332-341
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSA primary culture system of olfactory cells derived from newborn mouse was established by coculturing with a feeder layer of brain astrocytes. In this system, the whole lifespan of olfactory cells could be observed in vitro. Neurogenesis occurred from 5 days after plating and coexistence of immature and mature olfactory cells was observed until day 14. After day 15, immature cells were diminished and most of the culture cells appeared differentiated after day 20. The lifespan of differentiated cells was estimated to be 3 to 6 weeks. Cultured cells expressed growth associated protein 43 (GAP43), neurofilament protein (NFP), protein gene product 9.5 (PGP9.5) and olfactory marker protein (OMP). In addition, other round cells were cytokeratin-positive by immunostaining.
RT-PCR of growth factor receptors on the coculture cells revealed the expressions of fibroblast growth factor receptor 2 (FGFR2) and FGFR3, both of which could not be detected in the feeder cell layer of astrocytes. FGFR1 and transforming growth factor β receptor (TGFβR) were detected both on the coculture and on feeder cells. FGFR4, insulin-like growth factor 2 receptor (IGF2R) and hepatocyte growth factor receptor (HGFR) could not be detected in both samples. Furthermore, basic FGF, a prototypic FGF, was also found in the coculture system and in feeder cells. The present study indicated FGF might affect regulation of proliferation and differentiation of olfactory cells.View full abstractDownload PDF (7409K) -
You Suzaki, Hiroshi Wada, Kenji Ohyama, Toshimitsu Kobayasi, Kouji Hou ...1997 Volume 100 Issue 3 Pages 342-350
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSThe dynamic behavior of the middle ear was studied in living guinea pigs by using a laser Doppler vibrometer coupled to a compound microscope. Placing glass microbeads 20μm in diameter on four points of the tympanic membrane and six points of the ossicles, their velocity amplitudes were measured under a constant stimulus of 65 dB SPL. Velocity responses of the four points on the tympanic membrane differed over the frequency range from 0.1kHz to 3kHz. At low frequencies, the malleus and incus rotated around an axis running from the malleus head to the incus short process. At middle frequencies, the whole ossicle had a piston-like motion. At high frequencies, the malleus and incus rotated around a vertical axis running through the ossicles, while the stapes had a hinge-like movement.View full abstractDownload PDF (756K) -
Akihiko Kato1997 Volume 100 Issue 3 Pages 351-356
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSSince erythromycin was shown to be effective in the treatment of patients with diffuse panbronchiolitits, newly discovered effects of macrolide antibiotics have attracted much attention. It was reported that erythromycin inhibits Cl secretion across cultured canine tracheal epithelial cells. Erythromycin may decrease the movement of water toward the lumen, thus reducing sputum volume. We tested the hypothesis that erythromycin and clarithromycin have a similar effect on the dissected canine tracheal epithelium, by measuring the short circuit current using Ussing chambers. Addition of erythromycin or clarithromycin did not change the short circuit current within 20 minutes when applied on either the mucosal side or the submucosal side. No changes in the short circuit current were observed after pretreatment of the epithelium with amiloride, an Na channel blocker, or bumetanide, a Cl transport inhibitor, and subsequent addition of the macrolide antibiotics. These data indicate that neither erythromycin nor clarithromycin has any short term effect on ion transport in the dissected canine tracheal epithelium.View full abstractDownload PDF (2354K) -
[in Japanese]1997 Volume 100 Issue 3 Pages 358-361
Published: March 20, 1997
Released on J-STAGE: October 22, 2010
JOURNAL FREE ACCESSDownload PDF (4558K)
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