[Idiopathic sudden deafness: the therapeutic evaluation of hyperbaric oxygen treatment].

OBJECTIVE: To further evaluate the therapeutic effect of hyperbaric oxygen (HBO) to idiopathic sudden deafness. METHOD: A total number of 236 medical records of inpatients with idiopathic sudden deafness during 1997-2004 were collected from the Wuhan Union Hospital. Single factor analysis was done to evaluate the therapeutic effect with ten factors with SPSS analysis software. We divided the cases into HBO group and non-HBO group. The logistic regression was used in multivariate analysis. RESULT: Single factor analysis indicated that sex, ear side, presence of tinnitus, inducement and period of treatment had no effect on the prognosis, while age, course, presence of vertigo, a sensorineural hearing loss history with the other ear, degree of deafness had some effect on the prognosis. Multivariate analysis indicated: the effective (hearing threshold has elevated above 15 dB) ratio of HBO group comparing to the control group (non-HBO group), the difference was significant (P<0.01). CONCLUSION: The first visit after 14 days, the presence of vertigo, a sensorineural hearing loss history with the other ear and complete deafness may imply poor prognosis. HBO is effective for sudden deafness.

[The patterns of cell proliferation in the chick basilar papilla following severe acoustic trauma].

OBJECTIVE: To investigate the characteristics of cell proliferation in chick basilar papilla (BP) following severe acoustic trauma, and the orgin of precursor cell that can generate into new hair cell. METHOD: Chicks were continuously exposed to a 1.5 kHz pure tone at 120 dB SPL for 48 h, and they were intraperitoneally injected with bromodeoxyuridine (BrdU) at 40 h, 48 h after the onset of exposure. Then, cochlea were immunocytochemically labeled to detect BrdU, and examined the cell proliferative activity in BP. RESULT: 1. Labeled cells presented in the mid-proximal region of BP where hair cells have been damaged and lost following noise overstimulation; 2. The most cells in S phase were detected at 48 h after the onset of exposure; and 3. Both labeled hair cells and supporting cells can be seen in BP; In addition, the supporting cells may act as precursor cells that can generate into new hair cells. CONCLUSION: These findings suggest that auditory epithelial cells can be regenerated in chick cochlea after acoustic trauma, even though ongoing production of hair cells don't occur in BP, and supporting cells may be a source of newly generated hair cells under pathological conditions.