RESUMO
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<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.
Assuntos
Acetilcisteína/uso terapêutico , Perda Auditiva Provocada por Ruído/tratamento farmacológico , Salicilatos/uso terapêutico , Animais , Audiometria , Limiar Auditivo/efeitos dos fármacos , Contagem de Células , Chinchila , Combinação de Medicamentos , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/patologia , Perda Auditiva Provocada por Ruído/fisiopatologiaRESUMO
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.