A Promotive Effect of Low-Level Laser on Hair Cell Regeneration Following Gentamicin Induced Ototoxicity in Postnatal Organotypic Culture of Rat Utricles / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: In normal postnatal mammalian inner ear sensory epithelium, regeneration of hair cells is a very rare event, but there is hair cell regeneration with partial restoration of the vestibular sensory epithelium following ototoxic damage. In this study, the effects of low-level laser on hair cell regeneration following gentamicin exposure in postnatal organotypic culture of rat utricles were investigated. MATERIALS AND METHOD: A long term organotypic culture of 2 to 7 day old rat utricular maculae was established to study aminoglycoside-induced vestibular hair cell renewal. The utricles were exposed to 1 mM of gentamicin for 48 hr and allowed to recover in a culture medium only or in a medium with daily irradiation of low-level laser, whereas the control group was not exposed to gentamicin. Whole-mount utricles were stained with FM1-43, which are known to be an efficient marker, to identify live hair cells in cultured tissues. RESULTS: Loss of hair cells was nearly stopped from 2 days after exposure to gentamicin ; a peak of regeneration was reached after 18 days and sustained for two weeks in the medium with the irradiation of low-level laser. CONCLUSION: These results suggest that low-level laser promotes spontaneous hair cell regeneration following gentamicin damage in utricular explants.

Incidence of Actinomycosis in the Tonsils and Its Clinical Significance / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The relationship between actinomycosis and chronic tonsillar diseases, such as chronic recurrent tonsillitis or tonsillar hypertrophy, has been reported several times; but there seems to remain some controversy. The aim of this study was to find out the incidence of actinomycosis in the tonsil and its clinical significance. SUBJECTS AND METHOD: A histologic evaluation with tonsil specimen for actinomycosis was done for 300 patients who had undergone tonsillectomy from July 2005 to February 2006. Other clinical features such as age, sex, chief complaints, tonsil size, frequency of recurrent tonsillitis, and laboratory findings were also analyzed. RESULTS: The incidence of actinomycosis in tonsil was significantly high in adult group. There was no significantly statistical difference in the rate of actinomycosis according to sex, chief complaints, tonsil size, frequency of recurrent tonsillitis, number of leukocytes, and hemoglobin. CONCLUSION: Actinomycosis seems to have no causal role in recurrent tonsillitis or tonsillar hypertrophy. However, the possibility of actinomycosis should be considered in unusual tonsillar hypertrophy patients.

A Promotive Effect of Low Level Laser on Hair Cell Viability in Postnatal Organotypic Culture of Rat Utricles

BACKGROUND AND OBJECTIVES: To culture and maintain mammalian hair cells is still a big challenge. In this study, long-term organotypic culture of rat utricular maculae was established to study vestibular hair cell. The effects of low level laser on hair cell viability in postnatal organotypic culture of rat utricles were investigated. MATERIALS AND METHOD: Uticular explants were prepared from postnatal 2 to 7 rats and cultured. To improve hair cell survival, the utricles were irradiated daily with low level laser. Whole-mount utricles were stained with FM1-43 which is known to be an efficient marker to identify live hair cells in cultured tissues. Such cells visualized directly through tissue culture dish with cover glass bottom by Confocal laser scanning microscope at specific time points. RESULTS: The explanted utricular hair cells were cultured for up to 31 days in in vitro culture system. In low level laser irradiation group, utricular hair cells were more survived at 24 DIV and 31 DIV. CONCLUSION: These results suggest that low level laser promotes hair cell viability in utricular explants.

A Promotive Effect of Low Level Laser on Hair Cell Viability in Postnatal Organotypic Culture of Rat Utricles

BACKGROUND AND OBJECTIVES: To culture and maintain mammalian hair cells is still a big challenge. In this study, long-term organotypic culture of rat utricular maculae was established to study vestibular hair cell. The effects of low level laser on hair cell viability in postnatal organotypic culture of rat utricles were investigated. MATERIALS AND METHOD: Uticular explants were prepared from postnatal 2 to 7 rats and cultured. To improve hair cell survival, the utricles were irradiated daily with low level laser. Whole-mount utricles were stained with FM1-43 which is known to be an efficient marker to identify live hair cells in cultured tissues. Such cells visualized directly through tissue culture dish with cover glass bottom by Confocal laser scanning microscope at specific time points. RESULTS: The explanted utricular hair cells were cultured for up to 31 days in in vitro culture system. In low level laser irradiation group, utricular hair cells were more survived at 24 DIV and 31 DIV. CONCLUSION: These results suggest that low level laser promotes hair cell viability in utricular explants.

Correlation between Spontaneous Nystagmus and Vestibular Function Test Parameters according to Gender and Age in Vestibular Neuritis

BACKGROUND AND OBJECTIVES: There are caloric test, SCEP, DP in Step velocity and VOR asymmetry in SHA test as parameters for evaluation in unilateral peripheral vestibulopathy in parameter of vestibular function test. The aim of this study is to assess the correlation between these parameters and intensity of spontaneous nystagmus in vestibular neuritis. MATERIALS AND METHOD: We evaluated 75 patients who were diagnosed as vestibular neuritis with 3 degree spontaneous nystagmus at vestibular function test lab from January 2000 to July 2005 in Dankook university hospital. The correlations between direction and intensity of spontaneous nystagmus and monothermal caloric test, SCEP and DP in step velocity, VOR asymmetry (0.01, 0.04, 0.16 Hz) in SHA test were analysed. And correlations according to sex, age were also analysed. RESULTS: The correlation coefficient between intensity of spontaneous nystagmus and monothermal caloric test was 0.60. The correlation coefficient between intensity of spontaneous nystagmus and SCEP was 0.35. The correlation coefficient between intensity of spontaneous nystagmus and Tc DP was 0.36 and it showed no significant correlation. The correlation coefficient between intensity of spontaneous nystagmus and VOR asymmetry (0.01, 0.04, 0.16) was 0.57, 0.46, 0.51, respectively and there was higher correlation in man, age under 60. CONCLUSION: Intensity of spontaneous nystagmus showed close relations to monothermal caloric test, VOR asymmetry of SHA, Tc DP, SCEP DP in sequence. In addition, young male patients tends to be closely related to intensity of spontaneous nystagmus.

Effect of Low Power Laser Irradiation on Gentamicin-Damaged Vestibular System in Guinea Pigs

BACKGROUND AND OBJECTIVES: The purpose of this study was to investigate the characteristics of gentamicin-induced vestibulotoxicity of otolith organs and preventive effect of low power laser to vestibulotoxicity by assessing the result of earth vertical and the off vertical axis rotation tests. MATERIALS AND METHODS: Twenty guinea pigs were grouped into two groups, laser and no laser group. Vestibulotoxicity was induced by intratympanic injection of gentamicin. Prevention of the vestibulotoxicity was studied by irradiation of low power laser. Off vertical axis rotation tilted 30 degree relative to the earth vertical axis was applied to evaluate the otolithic function. Results and CONCLUSION: Gentamicin induced vestibulotoxicity was confirmed by gain decreasing in slow harmonic acceleration test and modulation decreasing in the off vertical axis rotation test. Prevention effect of low power laser to gentamicin induced vestibulotoxicity was confirmed by modulation maintaining in the off vertical axis rotation test and gain maintaining in the earth vertical axis rotation.

A Case of Low-grade Papillary Adenocarcinoma of the Nasopharynx / 대한이비인후과학회지

Low-grade nasopharyngeal papillary adenocarcinoma is a very rare nasopharyngeal, surface epithelium-derived malignant tumor characterized with adenocarcinomatous differentiation and an indolent biological behavior. We report a case of 36-year old female presenting a papillary adenocarcinoma of the nasopharynx. The tumor was of a 0.5 cm sized exophytic mass located on the nasopharyngeal mucosa near the posterior choanal septum. Because of the histologic similarities with thyroid papillary carcinoma, it was necessary to rule out metastasis from thyroid by immunohistochemical staining for thyroglobulin. Surgical excision was done via transpalatal approach; mass was removed with a clear resection margin.