Retraction: Expression of PLC-1 in Human Middle Ear Cholesteatoma / 대한이비인후과학회지

No abstract available.

Retraction: Mitotic Activity of Tympanic Membrane and External Auditory Canal Skin in Normal Mongolian Gerbil / 대한이비인후과학회지

No abstract available.

Retraction: Study for ReVersibility of Experimental Cholesteatoma Using Mongolian Gerbil / 대한이비인후과학회지

No abstract available.

Study for Reversibility of Experimental Cholesteatoma Using Mongolian Gerbil / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Epidermal characteristics of cholesteatoma such as invasion, migration, uncoordinated proliferation, and altered differentiation may arise as a result of defectiVe wound healing process, induction of preneoplastic transformation or genetic alteration. To date, a number of genes haVe been shown to be differentially regulated in cholesteatoma, which might be responsible for these clinical characteristics. HoweVer, it is still unclear whether these phenomena is only oVert when cholesteatoma is under specific conditions such as inflammation or infection. If these genetic alterations in the deVelopment of cholesteatoma are transient, the pathology of cholesteatoma may be reVersible. We hypothesized that once cholesteatoma is in the normal environment, the cellular or molecular pathology of cholesteatoma can return to normal epidermal characteristics. The aim of this study was to determine whether common molecular characteristics are reVersible or not after removal of inductive factors in aural cholesteatoma induced gerbils. MATERIALS AND METHODS: We induced canal ligation cholesteatoma using Mongolian gerbils. The treated group was untied and managed for 2 weeks. We examined differences between treated cholesteatoma and untreated cholesteatoma by using a TUNEL staining and immunohistochemical technique with proliferation markers (PCNA, cytokeratin 13/16). RESULTS: With PCNA and CK 13/16, untreated group showed positive staining in the suprabasal cells as well as in the basal cells, but the treated group showed weakly positive staining only in the basal cell layer. With TUNEL staining, positive cells increased more in the untreated group than in the treated group. CONCLUSION: These results encourage our belief that some cholesteatomas, especially cholesteatoma in early stages, might be managed with only minimal treatments such as control of inflammation and maintenance of adequate Ventilation.

The Significance of T2-Weighted, Fast-Spin Echo Magnetic Resonance Imaging Scan in a Screening Test for Patients with Acoustic Tumor / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES:Although auditory brainstem response(ABR) has been the screening test of choice, recent studies showed that ABR had only a 63% sensitivity and 64% specificity in detecting small acoustic tumor when compared with the magnetic resonance imaging(MRI) scan. Full MRI scans with gadolinium enhancement are highly accurate at detecting these lesions, but these are time consuming and expensive. The purpose of this study is to evaluate the effectiveness of T2-weighted, fast-spin echo(FSE) MRI scan as a screening test for acoustic tumor compared with full MRI scans with gadolinium enhancement. PATIENTS AND METHODS : From January 1995 through March 1999, 293 patients visiting to Department of otolaryngology underwent full MRI scans with gadolinium enhancement including T2-weighted FSE MRI to rule out the acoustic tumor. Pure tone audiogram was routinely performed in all the patients. One hundred fifty four of these patients received speech audiogram. Decreased speech discrimination score below 60% was considered abnormal. ABR was ordered to 65 patients. Interaural latency difference for wave V greater han 0.2 msec was considered abnormal. RESULTS: Eleven of 293 cases were detected as acoustic tumor on T2-weighted FSE MRI scan and gadolinium-enhanced MRI scan. The tumors less than 1.5 cm in diameter were 7 cases, and 3 cases of normal ABR was all less than 1 cm in diameter. T2-weighted FSE MRI scan had 100% sensitivity and 99.6% specificity, while ABR showed relatively low sensitivity(72.7%) and specificity(33.3%). CONCLUSION: T2-weighted FSE MRI scan is so sensitive to acoustic tumor that is comparable to full MRI scans with gadolinium enhancement. And it has rapid performance time and low cost. However, ABR has low sensitivity for acoustic tumor, especially for small tumor less than 1 cm in diameter. So, T2-weighted FSE MRI scan is considered as a cost-effective screening test for early detection of acoustic tumor.

Decision Analysis in Diagnosis of Small Acoustic Tumors / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: With great development that took place in the last 10 years in the imaging techniques such as MRI with gadolinium, small acoustic tumors can be detected before significant symptoms have developed. However, suspicion of acoustic neuroma is not easy at its earlier stage due to the lack of its characteristic symptoms. The detection rate of acoustic neuroma using traditional audiologic methods such as ABR and pure tone audiogram with speech discrimination score is relatively low contrary to expectation. Therefore, there is a need to develop other methods of diagnosis at an earlier stage. The aim of this study was to review symptomatology, diagnostic approach and the management of acoustic neuroma and to make a decision analysis tree of the diagnostic work-up. MATERIALS AND METHODS:From June 1994 through May 1998, eight patients with a small acoustic neuroma were treated at Ajou University Hospital. We analysed these 8 patients by age, sex, chief complaint, size of tumor, preoperative and postoperative audiologic studies, caloric test, treatment modalities and preoperative and postoperative imaging study. RESULTS: Acoustic neuroma had variable symptoms, with the most common initial symptom of our cases being sudden hearing loss. The sensitivity of ABR was relatively lower than we thought. Two out of three in the observation group showed an abrupt deterioration of hearing. CONCLUSION: When acoustic neuroma is suspected in patients with unilateral hearing loss, tinnitus and dizziness are very important symptoms to consider. We developed a decision analysis tree for diagnosis of small acoustic neuroma, which should be treated with earlier intervention of MRI.

Immunohistochemical Study for Differentiation of Human Middle Ear Cholesteatoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Human epidermis is a continuously dividing tissue, in which keratinocytes gradually differentiate and mature while moving from basal cells to suprabasal cell layers. Epidermal homeostasis is maintained by a delicate balance between proliferation and terminal differentiation. Cholesteatoma is characterized by the presence of a squamous epithelium invading the middle ear, which is believed to have hyperproliferative properties. The aim of this study is to determine whether the hyperproliferative character of cholesteatoma is associated with differentiation of basal cell or suprabasal cell layers. MATERIALS AND METHODS: Using immunohistochemical techniques, we investigated the reaction pattern of monoclonal antibody to involucrin and filaggrin as differentiation markers in the cholesteatoma matrices which were harvested during surgery. For the control, the same immunohistochemical study was also done in deep meatal skin and retroauricular skin during the same surgery. RESULTS: The immunostaining intensity of filaggrin at suprabasal cell layers was higher in cholesteatoma than in retroauricular skin and deep meatal skin. The immunostaining intensity of involucrin at suprabasal cell layers was higher in cholesteatoma and deep meatal skin than in retroauricular skin. CONCLUSION: This result represents that the epidermal cells in cholesteatoma at suprabasal layers actively differentiate more than the epidermal cells in retroauricular skin. So this study suggests that hyperkeratinization in cholesteatoma might be due to altered differentiation of suprabasal keratinocytes. Furthermore, this study reveals that the deep meatal skin has unusual hyperproliferative behavior in contrast to the retroauricular skin.

Clinical Appearances on the Extension of Attic Cholesteatoma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Attic cholesteatoma which develops from the papillary or retracted from progresses through various anatomic sites such as the mesotympanium, the mastoid process and the epitympanium. Although the most common site for attic cholesteatoma is the lateral attic space, it has also been found frequently in the medial attic space. We hoped to understand the pathogenesis of attic cholesteatoma through clinical analyses in order to contribute to the cholesteatoma treatment. MATERIALS AND METHODS: We chose 60 attic cholesteatoma patients showing attic retraction or perforation. These cases of attic cholesteatomas were classified into either the lateral or the medial types depedning on the main site of occurence. They were further classified into anterior, posterior and inferior types according to the direction of cholesteatomatic progression. CONCLUSION: The accurate assessment and clear understanding of the pathogenesis of different forms of cholesteatoma enabled a successful operation and helped to minimize the operative field.

Pattern of Ossicular Disruption after Head Trauma / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Mechanization and reliance on motorized transportation place everyone in our society at risk for head injury. Temporal bone trauma is usually the result of blunt head injury in patients suffering from multiple body injury. Hearing problems can be neglected initially, but many patients complain of hearing difficulties later after the head trauma. If hearing loss is conductive, there is the possibility of the ossicular disruption. The ossicular disruption after the head trauma can develop with or without the temporal bone fracture line. The aim of this study was to analyze the types of ossicular disruption and to review their pathophysiology. MATERIALS & METHODS: In the present study, we analyzed 23 cases of ossicular disruption following head trauma (mean age: 20.2 years, Male: female=14:9). The diagnosis was based on medical history, physical examination, findings of temporal bone CT and confirmed with operative findings. RESULTS: Among 6 types of ossicular disruption, we encounted 10 cases of complete incus dislocation, which was the most common type of ossicular disruption (43.5%). The most common cause of head injury was car accident. The fracture line of the temporal bone was found in 15 cases. In the 8 cases, we could not find any evidence of fracture. CONCLUSIONS: Incus dislocation is the most common type of ossicular disruption after head trauma and the I-S joint is the weakest point of ossicular chain because of its anatomical structure.

Clinical Values of HRCT for Diagnosis of Incus Dislocations / 대한이비인후과학회지

BACKGROUND: The quick and accurate radiologic evaluation is essential to minimize the sequelae of temporal bone trauma. High resolution computed tomography(HRCT) is regarded as a method of choice in the evaluation of the head trauma including temporal bone fractures. Although the diagnosis of ossicular dislocation with HRCT has been described, we could find only one report on the usefulness of coronal sections in the diagnosis of lateral displacement of the incus. OBJECTIVES: The purpose of this study is to evaluate the usefulness of a recently reported radiologic sign, named the "Y" sign, for the diagnosis of lateral dislocation of the incus on the coronal HRCT sections of the temporal bones. MATERIALS AND METHODS: We retrospectively reviewed the axial and coronal HRCT sections of 13 cases who the laterally dislocated incus was confirmed operatively. RESULTS: In the axial HRCT sections, abnormal ice cream cone was shown in only 3 cases, but normal ice cream cone was shown in 10 cases. In the coronal HRCT sections, the Y-sign was shown in 11 cases-open Y-sign: 3 cases, closed Y-sign: 8 cases, in contrast, only 2 cases did not shown Y-sign. CONCLUSION: The Y-sign in the coronal sections is more correlated with the dislocated incus than with abnormal ice cream cone configuration in the axial sections. So, the Y-sign seems to be very useful in the diagnosis of the dislocated incus.

The Management of Facial Nerve Schwannoma / 대한이비인후과학회지

Facial nerve schwannomas are uncommon tumors that involve the facial nerve. They are frequently misdiagnosed due to subtle and variable clinical presentations. The aim of management of facial nerve schwannoma is the complete removal of tumor, combined with preservation or restoration of facial nerve continuity. The site, size of the tumor, age, preoperative hearing level and facial nerve function are consider as decision making factors. But, it is management dilemma to decompress or resect the tumor. The purpose of this paper is to discuss to surgical management of complete removal of tumor and successful facial nerve reconstruction. Recently, we experienced three patients with facial nerve schwannoma with relatively good surgical result.

Morphological Study of the Eustachian Tube in Mongolian Gerbil / 대한이비인후과학회지

BACKGROUND: Many animals such as chinchilla, guinea pig, rat and rabbit have been used for study of the otitis media and their morphology of the eustachian tube are well known. However, it is not easy to use these animals in Korea. Therefore, active morphological study of the eustachian tube related to otitis media have not been performed. The Mongolian gerbil is an easily maintained rodent which has been useful for investigations of the ear canal cholesteatoma and inner ear. However, histologic study of the eustachian tube of Mongolian gerbil has not been established. OBJECTIVES: The purpose of this study was to describe the light microscopic morphology and the ultrastructure of the eustachian tube in Mongolian gerbil in order to prepare basic morphological data for the future animal study concerning pathogenesis of otitis media. MATERIALS & METHOD: Eight normal adult(90 to 120 days old) Mongolian gerbils(16 ears) were used for this study. Eustachian tube specimen was obtained after perfusion fixation and fixed. After 3 weeks of decalcification, paraffin block and EPON 812 block were made and sectioned. Those were observed under light microscope and transmission electron microscope. RESULTS: The cartilage and muscular structure(tensor veli palatini muscle, levator veli palatini muscle) of the eustachian tube of Mongolian gerbil were similar to those of other experimental animals. The total length of eustachian tube of Mongolian gerbil was relatively short and natural infection was rare.In the epithelium of the eustachian tube of Mongolian gerbil, four types of epithelial cells, ie ciliated, nonciliated, secretory cells and basal cells were identified like other experimental animals. On transmission electron microscopic findings, three types of secretory cells, ie, dark granulated, light granulated and mixed granulated cells were observed. The subepitheial glandular structure was observed along the whole length of eustachian tube. CONCLUSION: In this study, we found that the morphology of the eustachian tube of Mongolian gerbil was similar to those of other experimental animals such as chinchilla, guinea pig, rat and we recognized that Mongolian gerbil is possible to be used as a good experimental model of eustachian tube study for otitis media research.

An Experience of Early Surgical Intervention for Neurofibromatosis Type II / 대한이비인후과학회지

Neurofibromatosis type II(NF2) is clinically characterized by the presence of bilateral vestibular schwannomas. The exclusive goal in management of NF2 patients is hearing preservation. It has been controversial to determine whether to wait and see or to try early surgical management for hearing preservation. The authors experienced a case of vestibular schwannoma in association with NF2, which was partially removed and decompressed via middle fossa approach with hearing preservation. Based on our experience, we recommend a new strategy for hearing preservation on early surgical intervention of vestibular schwannoma. The criterias of the patient include (1) bilateral normal or serviceable hearing: (2) small sized tumorand: (3) young age. We suggest that the early surgical intervention including decompression may be considered for the hearing preservation especially on the favorable side to approach.

Hyperproliferative Characteristics in Human Deep Meatal Epidermis / 대한이비인후과학회지

In benign hyperproliferative epidermal diseases(eq. warts, psoriasis) and squamous carcinoma, some molecular markers of hyperproliferative keratinocyte such as cytokeratin 16 and PCNA were expressed predominantly. However, all healthy epidermis including the meatal epidermis are nonreactive to those molecular markers except some of thick skin. Recently, there are several reports which show unusal proliferative capacity around the annular region of the ear drum. Our study has concentrated on the characteristics of the differentiation in healthy deep meatal epidermis using immunohistochemistry with cytokeratins and PCNA. Our investigation has demonstrated that the deep meatal epidermis around the annular region in contrast to the other region of the meatus exhibited unusal proliferative capacity. This result suggests a pathology link such as invasion mechanism and hyperkeratinization between the cholesteatoma and deep meatal skin.

Mitotic Activity of Tympanic Membrane and External Auditory Canal Skin in Normal Mongolian Gerbil / 대한이비인후과학회지

BACKGROUND: Understanding the differentiation and migrating character of the tympanic membrane, external auditory canal as well as cholesteatoma pathogenesis needs knowledge about epithelial generation center. OBJECTIVE: We investigated the distribution of the epithelial generation center in the tympanic membrane and external auditory canal using 5-bromo-2-deoxyuridine(BrdU) immunohistochemistry. MATERIALS AND METHODS: BrdU was injected into peritoneum of 10 Mongolian gerbils and gerbil's temporal bones were obtained and serial section was done. Anti-BrdU antibody immunohistochemical stain was done. RESULTS: The labeling index was highest at posterosuperior quadrant of pars tensa, higher at malleus handle attached area and annulus region. On pars flaccida, labeling index was high at entire area. The labeling index of deep meatal skin was higher than that of lateral meatal skin, especially near annulus area. According to results, epithelial generation centers are thought to be on pars flaccida, posterosuperior quadrant of pars tensa, malleus handle attached area and annulus region. CONCLUSION: These findings are similar to those of human tympanic membrane and external auditory canal, and gerbils can be used as a animal model for study of normal human tymapnic membrane, external auditory canal and cholesteatomas.

Expression of PLC- 1 in Human Middle Ear Cholesteatoma / 대한이비인후과학회지

BACKGROUND: EGF and TGF-gamma are believed to mediate their pleiotrophic actions by binding to and activating cell surface receptors with an intrinsic protein-tyrosine kinase. Protein-tyrosine kinase phosphorylation has been considered involved in intrinsic signal transduction, proliferation and transformation of the cells. Phospholipase C-gamma1 is well characterized substrate for tyrosine kinase. OBJECTIVE: The purpose of this study is to elucidate the distribution of PLC-gamma1 in normal meatal skin and cholesteatoma matrix. MATERIALS AND METHODS: 8 cholesteatoma specimens were obtained from operated patients for immunohistochemistry and western blot analysis. RESULTS: On immunohistochemistry, PLC-gamma1 was detected only in basal layer of the deep meatal skin, but was readily detectable in both the basal and suprabasal layer in cholesteatoma matrix. By western blot analysis, considerable higher levels of PLC-gamma1 protein were detectable in cholesteatoma matrix compared with the deep meatal skin. CONCLUSION: Overexpression of PLC-gamma1 in cholesteatoma suggests a possible derangement of enhanced growth signal transduction in keratinocytes.

A Study of Rotation Test in Patients with Unilateral Peripheral Vestibular Loss / 대한이비인후과학회지

BACKGROUND: In general, it is well known that dizzy patients show a remarkable ability to compensate for the loss of peripheral vestubular function. When the patient had decreased response to caloric stimulation and showed no symptoms of vestibular dysfunction, we thought that was a compensated state of unilateral peripheral vestibular loss. OBJECTIVES: The purpose of this study is to provide the basic data for analysis of findings of further rotatory chair test through analyzing the results of rotation test of unilateral peripheral vestibular loss patients. MATERIALS AND METHODS: We analysed the findings of rotatory chair test and clinical manifestations of 24 cases of unilateral vestublar loss which didn't show any symptoms of vestibular dysfunction and they were confirmed by bithermal caloric test and Kobrak's ice water test. RESULTS: We could find that phase lead, low gain and asymmetry could persist despite of chronic compensated state and these findings were relatively common in patients with nonspecific vestibular symptoms. CONCLUSION: Abnornal phase lead and decreased gain were observed in the compensated unilateral vestibular loss patients who showed nonspecific symptoms including oscillopsia, vague unsteadiness. We thought that their compensation was not completely perfect and SHA test was a good tool which detect the minor degree of vestibular dysfunction. We have to consider the past history and nonspecific symptoms of patients through precise history taking. Frequency of SHA test is slower than that of normal human movement and this status is not a real physiologic condition, so it would be advisable to consider the results of other vestibular function tests for precise evaluation the degree of compensation, and the serial check is also recommended.

Facial Translocation Approach for Nasopharyngeal Angiofibroma / 대한이비인후과학회지

Angiofibroma is a benign tumor that predominantly affects male adolescent and the most common benign tumor of nasopharynx. These tumors are highly vascular and usually with extension to the nose, paranasal sinus, pterygomaxillary fossa, infratemporal fossa, cranium, and the neck. There are many therapeutic approaches to huge sized angiofibroma with intracranial extension. Recently we experienced two cases of nasopharyngeal angiofibroma invading cranial base that was resected by facial translocation approach after superselective embolization and direct intratumoral embolization with good results. So, we report these with the review of literature.

Surgical treatment of nasopharyngeal carcinoma : Infratemporal fossa approach type C / 대한이비인후과학회지

No abstract available.

Effect of ebastine on perennial allergic rhinitis / 대한면역학회지

No abstract available.