Effect of Quercetin on Recovery of Hearing Threshold in Noise-Induced HSP72 Model / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Heat shock proteins (HSPs) are a group of proteins that are preferentially expressed in many cell types when cells and organisms are exposed to various stresses. Their functions are not being fully clarified though HSPs are known to have a protective role against cellular injury. Quercetin, a bioflavonoid distributed widely in plants, has been reported to inhibit the stress response in heat-shocked cells. This study was undertaken to investigate the inhibitory effect of quercetin on HSP72 synthesis in rat cochlea and functional auditory threshold change after the intense noise overstimulation. MATERIALS AND METHOD: Sprague-Dawley rats treated with flavonoid were exposed to the intense broad band noise for three hours. Control animals were exposed to the same noise level. Immunocytochemistry of cochlear tissues was performed to detect HSP72 expression six hours after noise exposure. Also, auditory brainstem responses (ABRs) were recorded before and after noise exposure in each group. RESULTS: In animals exposed to noise for 3 hours without injection of quercetin, most of the outer hair cells (OHCs) of the cochlear second turn showed HSP72 immunoreactivity. However, animals exposed to noise for 3 hours with injection of quercetin revealed minimal HSP72 immunoreactivity in the OHCs. Results of ABRs of all groups showed about 40 dB threshold shifts immediately after the noise exposure. While control animals showed rapid recovery of the auditory threshold shifts after the ending of noise exposure and returned to the preexposure level by 24 hours, animals treated with quercetin showed delayed onset of recovery in the auditory threshold shifts after the ending of noise exposure and returned to the preexposure level by 48 hours. CONCLUSION: Quercetin may have an inhibitory effect on the HSP synthesis and expression of HSP72 and the outer hair cells may play a role in the protection of auditory function against acoustic trauma and rapid functional restoration of hearing.

Chondrosarcoma of the Temporal Bone / 대한이비인후과학회지

Chondrosarcoma of the temporal bone is a rare neoplasm constituting only 0.16% of intracranial tumors. Type of cranial nerve involvement in chondrosarcoma of the temporal bone is related to the specific anatomic location of the tumor. Clinically it has been confused with multiple sclerosis, glomus jugulare tumors, meningiomas, and chordomas. Ablative surgical treatment seems to be the procedure of choice and the value of irradiation or chemotherapy is still under debate and long term follow up is necessary. The authors experienced a case of chondrosarcoma of the temporal bone in a 27 year-old female with facial palsy. The patient underwent wide excision via transmastoid and suboccipital approach and then postoperative radiotherapy. She is free of local recurrence or metastasis for postoperative 18 months.

Role of Superoxide Dismutase in Eustachian Tube of Rat with Acute Otitis Media / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Superoxide dismutase (SOD) is an important protective enzyme against biochemical injury associated with inflammatory reaction. SOD are found in the epithelium of the normal middle ears and lesser amounts are found in infected ears. However, the localization of the SOD in the Eustachian tube in the normal and infected ear has been poorly studied. This study attempted to determine the distribution of SOD and how it changes from normal to infected. MATERIALS AND METHODS:We used fifty male Sprague-Dawley rats to observe the SOD expression and the change of its amount in the Eustachian tube using immunohistochemical method and western blotting. RESULTS: In normal rats, SOD was found in the epithelium of Eustachian tube and lower amounts were found in the connective tissue layers. In the streptococcus-infected ears, SOD was found in the similar pattern, but the infected tubal mucosa showed extensive submucosal edema and stained poorly with SOD, compared to the normal Eustachian tube mucosa. The amounts of SOD was 1.48+/-0.44ng/mg of protein in the normal mucosa and decreased markedly to 0.62+/-0.37ng/mg in the infected cosa. CONCLUSION: SOD was identified in the normal Eustachian tube; the amount decreased during the infected period. This finding suggests that SOD may have a protective role in the pathogenic state.

Expression of Ki-67 and Topoisomerase IIa in Human Middle Ear Cholesteatoma Epithelium / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Cholesteatoma is a destructive lesion of the middle ear or mastoid process. The development of human cholesteatoma is due to the altered control of cellular proliferation in part, which tilts the balance toward the aggressive, invasive growth of squamous epithelium within the middle ear. Many efforts were performed to prove overproliferative characteristics of cholesteatoma using various proliferation markers. Nonetheless, trigger site of overproliferation within the overgrowing epithelium of cholesteatoma is still ill defined. MATERIALS AND METHODS: In this study, we used the monoclonal antibody Ki-67 and Topoisomerase II, a marker of active proliferation, on frozen sections obtained from 12 cholesteatoma samples and observed expression of these markers in three different regions, from normal meatal skin, transitional zone and cholesteatoma sac. RESULTS: The results were interpreted on the basis of nuclear staining and percentage of positively stained cells (labeling index). We found that labeling indices of cholesteatoma and transitional zone were significantly increased compared with that of normal meatal skin. CONCLUSION: This result suggested that initiating of overproliliferation of cholesteatoma epithelium started from the transitional zone.

The Point Prevalence of Otitis Media with Effusion among Kindergarten and Elementary School Children in Ansan Area / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Otitis media with effusion (OME) is most commonly found during the first two years of life, and becomes somewhat less prevalent thereafter. There are many reports about the prevalence rate of OME in preschool children, but there has been no large scale survey of its prevalence rate in school-age children. The point prevalence of OME among children of the above age in Ansan city were investigated. MATERIAL AND METHODS: Tympanometry and pneumatic otoscopic examination were performed on 2713 children aged 6-12 years, during the spring season of 1998. RESULTS: A total of 4.5% of the subjects had unilateral or bilateral OME. The prevalence rate of OME in 6 year-old children was 10.8%. The prevalence rate in 12 year-old children was decreased to 2.1%. The incidence of OME in girls was higher than in boys. Bilateral involvement was noted in 38.3%, and the remainder had unilateral involvement. The majority of the cases (88.5%) were free of subjective symptoms. CONCLUSION: More attention should be required to OME in children aged 9 years and younger because of its high prevalence.

Expression of Vascular Endothelial Growth Factor mRNA in Endotoxin Induced Otitis Media with Effusion of the Rat / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The vascular endothelial growth factor (VEGF), a heparin binding growth factor specific for endothelial cells, is both a potent enhancer of vascular permeability and an angiogenic growth factor. The purpose of this study was to investigate the semi-quantitative expression levels of multiple VEGF mRNA splicing variants in endotoxin-induced otitis media with effusion (OME) of rat. MATERIALS AND METHODS: We instilled endotoxin and saline as a control into the middle ear cavity of the rat, and middle ear mucosa were taken at 0 h, 1 h, 3 h, 6 h, 12 h, 1 d, 3 d, 7 d, and 14 d. The levels of splicing variants of VEGF transcripts were evaluated by semi-quantitative RT-PCR. RESULTS: Expression of VEGF164 mRNA and VEGF120 mRNA was first identified at 1 h after endotoxin instillation and was dramatically increased between 6 h and day 1 and then progressively decreased by day 7. Expression level of VEGF120 mRNA was 1.34+/-0.27 fold higher than that of VEGF164, and the expression level of VEGF164 was 3.89+/-0.97 fold higher than that of VEGF188. CONCLUSION: These results suggest that VEGF may be primarily responsible for the increased vascular permeability in OME and that it seems to play a significant role in the pathogenesis of OME.

Localization of Phosphoinositide Specific Phospholipase Cbeta Isozymes in Rat Cochlea / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Phosphoinositide specific phospholipase C (PLC) plays a pivotal role in the transmembrane signal transduction pathways by catalyzing the hydrolysis of phosphoinositide 4,5-bisphosphate (PIP2) to yield the intracellular second messengers, diacylglycerol (DG) and inositol 1,4,5-trisphosphate (IP3), in response to the interaction of various ligands with the cell surface receptors. The question arises as to the physiological roles of the phosphoinositide second messenger system in the inner ear. The purpose of this study was to determine whether PLCbeta isozymes are present at the cochlea and what portion of cochlea each PLCbeta isozymes are distributed in. MAERIALS AND METHODS: Two methods, an immunohistochemical staining and western blot for PLCbeta isozymes were used in the rat cochlea. Frozen section and surface preparation were prepared for immunohistochemical staining. The PLCbeta isozymes or proteolytic digests were separated by SDS-polyacrylamide gels and then electrophoretically transferred to nitrocellulose membranes. Rabbit polyclonal antibodies raised against four PLCbeta isozymes were used. RESULTS: Each PLCbeta isozymes showed differential expressions in the cochlea. PLCbeta1 immunoreactivity was observed in the inner and outer hair cells and the spiral ganglion cells; PLCbeta2 in the stria vascularis and PLCbeta3 mainly in the inner hair cells. PLCbeta4 was not observed in cochlea. In western blots of rat cochlea extracts, the PLCbeta isozymes stained several bands corresponding to the known molecular weight of PLCbeta monomers, which are probably proteolytic digests. CONCLUSION: These results suggest that differentially localized each PLCbeta isozymes in the cochlea may have specific roles in signal transduction pathway of auditory system.

Expression of Fos Protein in Brainstem Vestibular Nuclei of Rat-II. Sinusoidal Acceleration Stimulation- / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Fos, the protein product of c-fos gene, has been known to be rapidly expressed in neurons following various external and internal stimuli and this protein expression has been used as a neural activation marker in many fields. This experiment was performed to examine the afferent pathway of the lateral semicircular canals following sinusoidal acceleration. MATERIALS & METHODS: To stimulate the lateral semicircular canals, animals received rotary stimulation for 90 minutes with 2.0Hz sinusoidal acceleration. Thirty minutes after stimulation, the subjects were sacrificed and their brainstems were processed for immunohistochemistry to detect Fos expression. RESULTS: Fos proteins were strongly expressed in the superior, dorsal medial vestibular and inferior vestibular nuclei. However, there was no expression in the lateral and ventral portion of medial vestibular nuclei. CONCLUSION: This finding suggested that the afferent pathway from peripheral vestibular end-organ can be successfully mapped by detection of Fos expression and Fos is an useful neural activity marker in the vestibular system.

Clinical Experience of Acute Mastoiditis in Recent 10 Years / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Acute mastoiditis is an acute inflammatory disease of the mastoid process but it has declined dramatically in the postantibiotic era. However, contrary to the benefits of broad-spectrum antibiotics, resistant and unusual pathogens may cause this disease entity. Recently, in our hospital, antibiotic resistant and atypical pathogens such as Actinomyces, Mycobacterium tuberculosis were on the increase. In this paper we would like to discuss optimal diagnosis and treatment for acute mastoiditis. PATIENTS AND METHODS: Thirteen patients with mastoititis were treated in our hospital in the last 10 years. All of them were reviewedretrospectively. RESULTS: Eight patients recovered after treating with intravenous antibiotics with or without myringotomy and the rest were managed surgically. Among the 5 who received surgical treatments, one developed chronic otitis media and one developed cholesteatoma 3 years later. CONCLUSION: Surgical intervention was indicated for cases that accompanied complications. It would be important to be aware of any unusual pathogens in the management of acute mastoiditis which does not respond to empirical antibiotics therapy.

Noise Induced Expression of 72kD Heat Shock Protein in Rat Saccule / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Heat shock protein (HSP) is an intracellular protein, expressed for cell protection under stressful condition. Expression of HSP was found in cochlear after noise stimulation. The vestibular end organs, especially saccule, have been known to be damaged by loud sound because of its anatomical and embryological vicinity with the cochlea. In this study, we observed the function of HSP72 that it is indeed expressed in rat saccule following noise stimulation. MATERIALS AND METHODS: Experimental animals were exposed to noisy environment at 100, 110 and 120 dB SPL for 90 minutes. Noise stimulation was transferred through a tone hook of behind-the-ear type hearing aid. Saccule was dissected and stained immunohistochemically and examined for expression of HSP under light microscope. RESULTS: Strong immunoreactivities were observed at type I and II hair cells of rat saccule which received noise of 120 dB for 90 minutes. Stronger imm-unoreactivities were found along the marginal areas of the saccule. CONCLUSION: These findings suggest that HSP72 are expressed in rat saccule following overthreshold noise and it could be presumed that HSP72 may have a protective role against noise trauma.

Distribution of Calcitonin Gene-Related Peptide Immunoreactive Nerve Fibers in Rat Cochlea and Brainstem Auditory Nuclei / 대한이비인후과학회지

BACKGROUND: Calcitonin gene-related peptide(CGRP) is one of the neuronal elements of the inner ear. CGRP immunoreactive fibers are known to regulate auditory action potential and blood flow of cochlea. OBJECTIVES: This study was designed to localize the CGRP immunoreactive fibers in the cochlear tissue and auditory brainstem of normal rat. MATERIAL AND METHODS: Male Sprague-Dawley rats were perfused with 4% paraformaldehyde. Cochleae and brainstems were taken out and processed for surface preparations and frozen sections. Immunoperoxidase immunohistochemistry was carried out using anti-CGRP polyclonal antibody. RESULTS: Numerous CGRP immunoreactive fibers were located in the inner spiral bundle, intraganglionic nerve fibers, base of inner hair cells and lateral superior olivary nuclei in brainstems. CONCLUSION: CGRP is one of the neuropeptides in the olivocochlear effent system and may participate in the inhibitory effect on auditory action potential.

Possibility of Reciprocal Infections of Methicillin-Resistant Staphylococcus Aureus between Medical Personnel and Patients after Performing Middle Ear Surgery / 대한이비인후과학회지

BACKGROUND: The cases of Methicillin-Resistant Staphylococcus aureus(MRSA) infection after middle ear surgery, most of which are thought to be hospital acquired infection, are increasing recently in our hospital. MRSA infection is apt to be long lasting and to bring many complications because MRSA is resistant to aminoglycosides and cephalosporin as well as methicillin. There are many reports that medical personnel have a role to transmit that organisms to other patients. OBJECTIVES: To find and eradicate infection source and transmission route are both essential because medical personnel who contact MRSA infected patients can be a continuing transmission route. MATERIALS AND METHODS: Bacterial cultures from the noses and hands of medical personnel working in the department of Otolaryngology of Korea University Hospital were done and ribotyping through Southern blot technique was used to compare and prove an identical strain of MRSA organism between medical personnel and patients. RESULTS: As a result of ribotyping with EcoRI and HindIII, one distinct subtype(type I) was identified to be shared between medical personnel and patients. Among 30 medical personnel, 10 were carriers of MRSA. Seven MRSA isolates from these 10 medical carriers and 18 from 30 isolates of otorrhea shared the same type I ribotype. CONCLUSION: This finding reveals that MRSA transmission could occur between medical personnel and patients. Medical personnel should be aware of their possible role as a relay-stay of transmission of pathogenic organisms and should give efforts to prevent it.

Noise Induced Changes of Glucocorticoid Receptors in Rat Cocohlea / 대한이비인후과학회지

It has been suggested that glucocorticoid receptors are present in inner ear tissues and may act in stress related mechanism of cochlea. The purpose of this study was to determine whether stress to auditory system could change glucocorticoid receptors(GR) in the cochlear tissues and to hypothesize the relationship between heat shock protein and glucococorticoid receptors which may involve in stress related mechanism of cochlea. Sprague-Dawley rats were exposed to intense broad band noise(110dB SPL) as a stressful condition to auditory system and immunohistochemical and western blot analyses were used to compare the expression patterns of glucocorticoid receptors between noise exposed and normal rat cochlea. In western blot analysis, immunoreactive bands of noise exposed cochlear tissues were weaker than those of normal non-noise exposed cochlear tissues. In immunohistochemistry, GR immunostaining was observed in spiral ligament, stria vascularis, and outer hair cells of both noise exposed and normal cochlear tissues. Density of immunoreactive staining was decreased after noise exposure. With these results was could hypothesize the relationship between glucocorticoid receptor and heat shock proteins under stressful condition in the cochlea. If the cochlea is exposed to stress such as noise trauma, glucocorticoid hormone would be released and enter the cell to bind to glucocorticoid receptors with dissociation of heat shock proteins from the DNA binding sites. Then the levels of glucocorticoid receptors in the cytoplasm would be decreased and resultant increased expression of heat shock proteins may occur. This study suggest that glucocorticoid receptors may participate in stress response of the cochlea alone or in conjunction with heat shock proteins.

Expression of Fos Protein in Brainstem Vestibular Nuclei of Rat - I. Off-axis Centripetal Acceleration - / 대한이비인후과학회지

Fos, the protein product of c-fos gene, has been known to be rapidly expressed in neurons following various external and internal stimuli. This experiment was performed to determine whether off-axis centripetal acceleration cause a proper stimulation to the otolith organ and the afferent neural pathway from the otolith organ can be mapped by detection of expressed Fos protein. Therefore we performed on-axis and off-axis centripetal acceleration stimulation to experimental animals and investigated Fos expression immunohistochemically. In results, there were no expression of Fos protein following on-axis centripetal acceleration, whereas in the medial, descending vestibular nuclei and y-group of the off-axially stimulated animal, we could find strong expression of Fos protein.

Statistical Estimate Formula Using Prognostic Factors for Predicting Hearing Recovery in Idiopathic Sudden Sensorineural Hearing Loss / 대한이비인후과학회지

Sudden deafness is not rare but its pathophysiology has not been fully determined and treatment is controversial at present. About concerning factors for the recovery of sudden deafness, various studies have been done, but there are still many unknown things. The probability of recovery from sudden deafness depends on many factors. To evaluate hearing recovery and prognostic factors we studied 65 patients treated with bed rest, steroid, vasodilator, plasma expander, vitamines from March 1988 to October 1995 at our department. Data were statistically examined and we present a model for calculating the probability of patient recovery based on the combined effects of risk factors determined for these variables. Interrelationships among the prognostic factors and their relative importance in predicting hearing recovery are discussed.

Clinical analysis of distant metastases in the squamous cell carcinoma of head and neck / 대한이비인후과학회지

No abstract available.

A clinical study of uvulopalatopharyngoplasty for sleep apneasyndrome / 대한이비인후과학회지

No abstract available.

Prognostic significance of the mastoid pneumatization in the childhood otitis media with effusion / 대한이비인후과학회지

No abstract available.