Biomedical subjects

R J Wobig

Publications and source records attributed to R J Wobig.

3 recordsLinked to original sources

PubMed1999

Steroid-responsive cochlear dysfunction in the MRL/lpr autoimmune mouse.

Corticosteroids historically have been used to treat autoimmune sensorineural hearing loss, although little is known of how steroids restore normal inner ear function. Therefore, to identify a potential model for this field of research, this study examined the effects of prednisolone on auditory brain stem response thresholds in the MRL/lpr mouse model of autoimmune sensorineural hearing loss. Mice treated with prednisolone after auditory threshold elevations demonstrated significant improvement and stabilization of thresholds compared with untreated controls. MRL/lpr mice treated with steroids before the onset of autoimmune disease and cochlear dysfunction demonstrated decreased serum immune complexes, higher survival rates, and lower auditory thresholds compared with untreated controls. These positive results suggest the autoimmune mouse may be useful for studies of steroid-responsive mechanisms of the cochlea in autoimmune sensorineural hearing loss, as well as any hearing disorder in which steroid therapy is currently used.

Animals↗

PubMed1999

Steroid treatment improves cochlear function in the MRL.MpJ-Fas(lpr) autoimmune mouse.

Corticosteroid therapy is used to reverse autoimmune sensorineural hearing loss, although little is known of the mechanism by which this occurs. This has been due to the lack of a suitable animal model with spontaneous hearing loss that is steroid responsive. The present study examined the effects of prednisolone treatment on auditory thresholds in the MRL.MpJ-Fas(lpr) autoimmune mouse to determine its suitability as such a model. Autoimmune mice at 3.5-4. 5 months of age were evaluated by pure-tone auditory brainstem response (ABR) to establish threshold elevations due to the disease. The steroid treatment group was then given prednisolone in their drinking water for 2.5 months, while untreated controls were given tap water. Significantly more steroid treated mice survived to the time of post-treatment ABR evaluation. Half of the steroid treated ears demonstrated either improvement or no change in cochlear function compared to only 25% in the untreated controls. Overall, cochlear thresholds in the untreated controls increased by 14.7 dB, whereas no significant threshold increase was seen in the steroid treated group (4.3 dB) over the treatment period. No qualitative anatomical differences were seen in the ears of those mice surviving to the end of the study. These findings establish the autoimmune mouse as a model for studies of steroid responsive mechanisms within the ear. This could apply to autoimmune sensorineural hearing loss, as well as any hearing disorder for which steroid therapy is recommended.

Administration, Oral↗

PubMed1999

Steroid treatment in young MRL.MpJ-Fas(lpr) autoimmune mice prevents cochlear dysfunction.

Corticosteroid therapy reverses clinical autoimmune sensorineural hearing loss, although little is known of how steroids restore normal auditory function. If suppression of systemic autoimmune processes underlies hearing restoration, then preventing autoimmune symptoms from developing should prevent cochlear dysfunction. MRL. MpJ-Fas(lpr) autoimmune mice were used to test this potential mechanism by initiating oral prednisolone treatment at 6 weeks of age, prior to autoimmune disease and hearing loss onset. The steroid treatment group was given prednisolone in their drinking water, while untreated controls were given tap water. Treatment continued for 7 months with periodic evaluations of cochlear function with auditory brainstem response (ABR) audiometry. Autoimmune mice given the steroid lived longer and did not develop levels of serum immune complexes seen in their untreated controls. Also, their ABR thresholds remained near normal throughout the 7 months of treatment, while untreated controls showed progressive threshold elevations typical for autoimmune disease. This correlation of suppressed systemic autoimmune activity and maintenance of normal cochlear function identifies one potential mechanism for autoimmune hearing loss and hearing restoration with steroid therapy. The autoimmune mouse should serve as a valuable model for future studies of the cochlear mechanisms responsive to steroid treatment in autoimmune hearing loss.

Administration, Oral↗