Christopher Charon - Academia.edu (original) (raw)

Papers by Christopher Charon

Research paper thumbnail of Reduction of noise-induced hearing loss using L-NAC and salicylate in the chinchilla

Hearing Research, 2000

The effects of a combination of two antioxidant compounds were studied in a chinchilla model of n... more The effects of a combination of two antioxidant compounds were studied in a chinchilla model of noise-induced hearing loss. After obtaining baseline hearing thresholds using inferior colliculus evoked potentials, chinchillas were exposed for 6 h to octave band noise centered at 4 kHz (105 dB SPL). Post-noise thresholds were obtained 1 h after the noise exposure, and then animals received either saline or salicylate and N-L-acetylcysteine combination. Another group received antioxidant treatment 1 h prior to noise. Hearing was tested at 1, 2 and 3 weeks post-noise. Subsequently, the cochleae were harvested, and cytocochleograms were prepared. There was a 20^40 dB SPL threshold shift at 3 weeks for tested controls. Permanent threshold shifts (PTS) were significantly reduced (P 6 0.05) to approximately 10 dB for the pre-treatment group at week 3. The PTS for the post-treatment group at week 3 was similar to the pre-treatment group at 1 and 2 kHz (0^10 dB) but was intermediate between the control and pre-treatment groups at 4 and 8 kHz (23 dB). Animals pre-treated with antioxidant had a significant reduction in hair cell loss but those post-treated with antioxidant had no protection from hair cell loss. These findings demonstrate the feasibility of reduction of noise-induced hearing loss using clinically available antioxidant compounds.

Research paper thumbnail of Timing and use of antioxidants for prevention and rescue of noise‐induced hearing loss

Otolaryngology–Head and Neck Surgery, 1999

Volume 121 Number 2 Research ForummMonday P79 tional advantage of a closed system, thereby improv... more Volume 121 Number 2 Research ForummMonday P79 tional advantage of a closed system, thereby improving physician and patient safety. In comparison, the conventional CO 2 laser must be coupled to a microscope, is cumbersome, and is an open system with certain safety concerns. It has a much longer tissue dwell time, making patient cooperatio n and movement much more important. Spot size cannot be precisely predetermined. Conclusions: The introduction of new technology requires an in-depth understanding of the technological advantages of such a technology. This is particularly true if there is variation from an existing technology that is widely used and accepted by practitioners. Understanding flash scanner CO 20toScan technology will greatly help to understand its advantages for office-based laser-assisted myringotomy in children.

Research paper thumbnail of Giant juvenile xanthogranuloma of the tongue

American Journal of Otolaryngology, 1999

Juvenile xanthogranulomas (JXGs) are rare, benign, fibrohistiocytic lesions. They usually appear ... more Juvenile xanthogranulomas (JXGs) are rare, benign, fibrohistiocytic lesions. They usually appear as one or more cutaneous papules on the head, neck, or trunk in infants. Twelve cases of oral JXGs have been reported, four of which involved the tongue. We present a 6-year-old girl with a large tongue mass diagnosed as JXG after an excisional biopsy. Histological and immunohistochemical staining results are presented. This is the first reported case of a giant oral JXG. A review of the literature on these unusual lesions is presented, along with discussion of their differential diagnosis and key aspects of the patient's evaluation, management, and pathological diagnosis.

Research paper thumbnail of Reduction of noise-induced hearing loss using L-NAC and salicylate in the chinchilla

Hearing Research, 2000

The effects of a combination of two antioxidant compounds were studied in a chinchilla model of n... more The effects of a combination of two antioxidant compounds were studied in a chinchilla model of noise-induced hearing loss. After obtaining baseline hearing thresholds using inferior colliculus evoked potentials, chinchillas were exposed for 6 h to octave band noise centered at 4 kHz (105 dB SPL). Post-noise thresholds were obtained 1 h after the noise exposure, and then animals received either saline or salicylate and N-L-acetylcysteine combination. Another group received antioxidant treatment 1 h prior to noise. Hearing was tested at 1, 2 and 3 weeks post-noise. Subsequently, the cochleae were harvested, and cytocochleograms were prepared. There was a 20^40 dB SPL threshold shift at 3 weeks for tested controls. Permanent threshold shifts (PTS) were significantly reduced (P 6 0.05) to approximately 10 dB for the pre-treatment group at week 3. The PTS for the post-treatment group at week 3 was similar to the pre-treatment group at 1 and 2 kHz (0^10 dB) but was intermediate between the control and pre-treatment groups at 4 and 8 kHz (23 dB). Animals pre-treated with antioxidant had a significant reduction in hair cell loss but those post-treated with antioxidant had no protection from hair cell loss. These findings demonstrate the feasibility of reduction of noise-induced hearing loss using clinically available antioxidant compounds.

Research paper thumbnail of Timing and use of antioxidants for prevention and rescue of noise‐induced hearing loss

Otolaryngology–Head and Neck Surgery, 1999

Volume 121 Number 2 Research ForummMonday P79 tional advantage of a closed system, thereby improv... more Volume 121 Number 2 Research ForummMonday P79 tional advantage of a closed system, thereby improving physician and patient safety. In comparison, the conventional CO 2 laser must be coupled to a microscope, is cumbersome, and is an open system with certain safety concerns. It has a much longer tissue dwell time, making patient cooperatio n and movement much more important. Spot size cannot be precisely predetermined. Conclusions: The introduction of new technology requires an in-depth understanding of the technological advantages of such a technology. This is particularly true if there is variation from an existing technology that is widely used and accepted by practitioners. Understanding flash scanner CO 20toScan technology will greatly help to understand its advantages for office-based laser-assisted myringotomy in children.

Research paper thumbnail of Giant juvenile xanthogranuloma of the tongue

American Journal of Otolaryngology, 1999

Juvenile xanthogranulomas (JXGs) are rare, benign, fibrohistiocytic lesions. They usually appear ... more Juvenile xanthogranulomas (JXGs) are rare, benign, fibrohistiocytic lesions. They usually appear as one or more cutaneous papules on the head, neck, or trunk in infants. Twelve cases of oral JXGs have been reported, four of which involved the tongue. We present a 6-year-old girl with a large tongue mass diagnosed as JXG after an excisional biopsy. Histological and immunohistochemical staining results are presented. This is the first reported case of a giant oral JXG. A review of the literature on these unusual lesions is presented, along with discussion of their differential diagnosis and key aspects of the patient's evaluation, management, and pathological diagnosis.