Recreational noise exposure decreases olivocochlear efferent reflex strength in young adults.

OBJECTIVE: To investigate effects of recreational noise exposure on olivocochlear efferent function. METHODS: efferent suppression of DPOAEs and acoustic reflexes were tested in 32 young personal listening device users with normal hearing and compared with that of healthy, non-noise-exposed young adults. RESULTS: The results showed that the efferent suppression of DPOAEs was mainly at low frequencies (0.75 and 1.0 kHz) in both groups and the efferent suppression of DPOAEs and acoustic reflexes in the noise exposure group was slightly lower than that in the control group, with no significant differences. CONCLUSIONS: Our results revealed that there were no differences in DPOAE changes or medial olivocochlear bundle function between normal-hearing subjects exposed to recreational noise and controls and suggest that recreational noise has different effects on olivocochlear efferent reflex strength compared with occupational noise exposure.

[Study on cytotoxic activities on human leukemia cell line HL-60 by flavonoids extracts of Scurrula parasitica from four different host trees].

OBJECTIVE: To compare the anticancer effects of flavonoids extracts of Scurrula parasitica from different host trees in vitro. METHOD: 80% ethanol extracts of S. parasitica parasitizing on Nernium indicum, Morus alba, Opsmanthus fragrans, and Sapindus mulorossi were purified by polyamides column chromatography, and the eluates of 30%, 50%, 70% and 90% ethanol were mixed as flavonoids extracts. Human acute myeloid leukemia cell line HL-60 was used to evaluate the cytotoxicity induced by flavonoids extracts of S. parasitica L with MTT assay. Apoptosis was detected by AO/EB fluorescence staining and DNA fragmentation analysis, apoptosis rates and cell cycle distribution were detected by flow cytometry analysis. RESULT: Extract of S. parasitica parasitizing on N. indicum (NISPEX) was the most sensitive to HL-60 cells of the 4 different host trees, the IC50 value being 0.60 mg x L(-1); and extract of S. parasitica parasitizing on M. alba took the second place, the IC50 value, being 2.49 mg x L(-1); extract of S. parasitica parasitizing on O. fragrans had no effectiveness as high as 50 mg x L(-1) concentration. NISPEX induced HL-60 cell apoptosis and inhibited the cell proliferation in dose and time-dependent manner. Cell cycles were arrested at G0-G1 phase after treated with NISPEX. CONCLUSION: Anticancer effects of S. parasitica correlated with the host trees. Flavonoids extracts of S. parasitica parasitizing on N. indicum exhibited comparatively better anticancer activity in vitro among the host trees studied. NISPEX is found to be a good candidate for anticancer.