Expresion of Collagenase-3 (Matrix Metalloproteinase-13) in human middle ear cholesteatoma and granulation / 대한이비인후과학회지

INTRODUCTION: Middle ear cholesteatoma is notorious for its capacity to absorb surrounding bone, but the exact mechanism of bone destruction is not fully understood until now. Recently, a group of matrix metalloproteinases (MMPs) were found to dissolve extracellular matrices. Among them, collagenase-3 (MMP-13), a newly found collagenase, is thought to be a strong enzyme to dissolve bone and cartilage. So we tried to find out whether Collagenase-3 is found in cholesteatoma and plays some role in bone destruction by cholesteatoma. MATERIALS AND METHOD: We performed immunohistochemical stains on 5 cholesteatomas, 5 middle ear granulations, 5 normal middle ear mucosa and 5 deep meatal skin specimens with anticollagenase-3 antibody and analysed the staining patterns. RESULTS: All the cholesteatomas showed strong immunoreactivity with collagenase-3. Two out of 5 granulations showed somewhat weaker and more disseminated patterns of immunoreactivity, but the rest 3 granulations showed no immunoreactivity. Normal middle ear mucosa and deep meatal skin specimens showed no immunoreactivity at all. CONCLUSIONS: Collagenase-3 may play an active role in the process of bone destruction by cholesteatoma; however, a further study using zymography or blotting method is needed to make this clear.

A case of Microcystic Adnexal Carcinoma in the External Auditory Canal / 대한이비인후과학회지

Microcystic adnexal carcinoma (MAC) is a rare malignant skin appendageal tumor first described as a specific entity in 1982. It predominantly affects the head and neck, particularly in the centrofacial region. MAC can have a benign appearance under the light microscope. Despite this bland histologic appearance, MAC can be locally aggressive with permeation of perineural spaces, perichondriums, skeletal muscles and so on. Therefore, this tumor is characterized by high morbidity and frequent recurrence in spite of aggressive treatment such as wide local excision, Mohs' microscopic surgery, or radiation therapy. Close observation for a long term is therefore mandatory even after a satisfactory excision with a wide resection margin. Recently, the authors have experienced a case of MAC in the external auditory canal which was treated by wide local excision and skin graft.

Incidence of presbycusis of Korean populations in Seoul, Kyunggi and Kangwon provinces

Presbycusis, a bilateral sensorineural hearing loss caused by changes in the inner ear, is related to multiple factors such as noise exposure and otologic disease. In institute-based studies, we tried to determine the incidence of presbycusis in Korean populations living in Seoul, Kyunggi and Kangwon provinces by gender and age groups. The subjects were people who had visited health promotion centers. Pure tone audiometry was done over 20 years on 6,028 subjects. In a community-based study, the subjects were elderly residents of Kanghwa-do area. There were no obvious factors that could cause hearing impairment in the subjects. For the pure tone audiometry, hearing threshold was obtained by using the six-dimension method. The incidence of presbycusis for subjects aged 65 years and older was 37.8% and 8.3% for > or = 27 dB HL criterion and > or = 41 dB HL criterion, respectively. The incidence increased with age. A statistically significant difference in the hearing threshold was found between men and women aged 65 years or older. No differences were found between the community-based study and the institute- based studies. There was a high incidence (about 40%) of presbycusis among Koreans aged 65 years or older (for > or = 27 dB HL criterion). With an aging population, we anticipate that this report could be used to provide a basic data for the study of presbycusis.