Influence of Incudomalleolar joint and Hearing in rats dosed with Ciprofloxacin / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Quinolone-induced arthropathy is an unusual toxic effect observed in juvenile animals of multiple species. Such toxic effects are usually found in joint cartilages. The reports of chondrotoxic potential of quinolones in juvenile animals were mainly performed in weight bearing joints such as hips and knees. The purpose of this study was to investigate the morphological changes in the incudomalleolar joint of immature rats dosed with ciprofloxacin, and to draw relationship between the incudomalleolar joint pathology and hearing. MATERIALS AND METHODS: An experimental group of 21-day-old rats were administrated intraperitoneally with 200 mg ciprofloxacin/kg for 10 days. The hearing threshs of the control and experimental animals were determined with auditory brainstem response (ABR). Their ossicles were obtained and fixed, and we observed them with light microscopy (LM) and transmission electron microscopy (TEM). RESULTS: The ABR threshs were increased in the ciprofloxacin administrated group, and the increased latency of the first waves were identified in the ciprofloxacin administrated group, but there were no differences in the interval of wave I-III. The LM findings of incudomalleolar joint in the ciprofloxacin administrated group showed cartilage lesions such as disrupted articilar surface, irregular cellularity of the chondrocytes, matrix swelling, cleft formation, decreased matrix staining. The TEM findings of the incudomalleolar joint cartilage in the ciprofloxacin administrated group showed decreased bundle-like matrix and cell process, condensed nucleus, and vacuolated cytoplasm. CONCLUSION: From the results of recent works and the present study, we suggest that ciprofloxacin may induce morphological changes in the incudomalleolar joint, and that such morphological changes may induce conductive hearing loss.

Histopathologic Changes of Cochlea and Hearing Threshold Changes according to Duration of Noise-Exposure in the Rat / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The degree of noise induced hearing loss was determined principally according to the level and duration of noise and patient's state. The purpose of this study was to investigate the cochlear histopathology and hearing threshold immediately after noise exposure according to duration of noise exposure, and finally to draw relationship between the cochlear pathology and hearing threshold. MATERIALS AND METHOD: Each group of animals (6 ears) has been exposed for 10 minutes, 1 hour, 2 hours, 3 hours, 4 hours, 24 hours and 48 hours to an octave band of noise with a center frequency of 4000 Hz and a sound pressure level of 110 dB. After noise exposure, the hearing thresholds of the subjects were determined with auditory brainstem response (ABR) and immediately their inner ear were fixed and observed with transmission electron microscopy (TEM). RESULTS: ABR thresholds were increased according to lengthening of duration of noise exposure. TEM findings of outer hair cells, Deiters' cells and ganglion cells showed more severe degeneration according to lengthening of duration of noise exposure. Damages of all kinds of cells appeared almost at the same time. CONCLUSION: Through the foregone study, cochlear pathology was proportioned to increased hearing threshold, and the damages of outer hair cells and ganglion cells appeared almost at the same time. It seems that not only damages of outer hair cells, but also damages of ganglion cells contribute to early hearing threshold shift during continuous intense noise exposure.

A Case of Craniocervical Necrotizing Fasciitis / 대한이비인후과학회지

Necrotizing fasciitis is a rapidly progressive invasive soft tissue infection that is rarely seen in craniocervical area. In the majority of cases described in the medical literature, there has been an identifiable initiating event such as instrumentation or other trauma to the skin. Because of the rapid progression of the infection, the key to a successful outcome is early recognition and rapid initiation of definitive surgical management. A case is presented in which necrotizing fasciitis was seen in a craniocervical area with instrumentation especially dental extraction.