Objective To compare the relationship of acceptable noise level (ANL) between monaural and binaural hearing aid in patients with bilateral moderate-to-severe hearing loss, and to investigate the clinical significance of the ANL in binaural hearing aid fitting and the predictive role in the hearing aid effect assessment.Methods A total of 15 patients with bilateral moderate-to-severe hearing loss were selected, and the most comfortable levels (MCL), background noise level (BNL) and calculate ANL were tested, respectively, in 4 conditions: without hearing aids, fitted only left ears, fitted only right ears and binaural fitting.Results The ANL in 15 subjects measured at 4 conditions were 18.87±5.26, 12.60±2.47, 12.00±2.90, and 5.13±1.25 dB S/N, respectively.The MCLs were 80.40±9.28, 63.73±5.15, 62.27±5.36, and 61.80±6.05 dB HL, respectively.The BNLs were 61.67±6.14, 51.13±3.94, 50.27±4.50, and 56.67±5.16 dB HL.The ANL difference between the only left and right fitting groups was not statistically significant(P>0.05).The ANL difference between the monaural or the binaural hearing aid group and without hearing aids group were statistically significant (P<0.05), respectively.Compared with the monaural hearing aid group, the binaural hearing aid group had significantly lower ANL(P<0.05).Conclusion For people with bilateral hearing loss, hearing aids can improve their ability to manage the background noise, and binaural hearing aid fitting is better than monaural.

OBJECTIVE: To study the role of Nrf2/ARE signaling pathway in cypermethrin-induced oxidative stress and apoptosis of cerebral cortex neurons in C57BL/6 mice. METHODS: The cortical neurons of C57BL/6 mice were cultured and identified, and a cypermethrin-induced cell injury model was established by treating the cells with 0, 25, 50 and 100 μmol/L of cypermethrin for 48 h. CCK-8 assay was used to analyze the effects of cypermethrin on the cell viability, and the fluorescence probe DCFH-DA was used for detecting intracellular reactive oxygen species (ROS); flow cytometry was performed for determining the apoptosis rate of the cells. The mRNA and protein expression levels of Nrf2 and its downstream genes HO-1 and NQO1 were detected using qPCR and Western blotting. RESULTS: Exposure to cypermethrin at different doses inhibited the viability of the cultured cortical neurons. With the increase of cypermethrin dose, the viability of the neurons decreased progressively, the intracellular ROS and the cell apoptosis rate increased, and the neuronal injury worsened. At the dose of 50 and 100 μmol/L, cypermethrin significantly down-regulated the expressions of HO-1, NQO1 and Nrf2 at both the mRNA and protein levels in the cells ( < 0.01). CONCLUSIONS Cypermethrin exposure shows a dose-dependent neurotoxicity by inhibiting Nrf2/ARE signaling pathway, down-regulating the expression of Nrf2 and its downstream genes HO-1, NQO1 mRNA and protein, and inducing oxidative damage and apoptosis in primary mouse cortical neurons, .
Animals ; Carboxylic Ester Hydrolases ; Cerebral Cortex ; Mice ; Mice, Inbred C57BL ; NF-E2-Related Factor 2 ; Neurons ; Pyrethrins ; Signal Transduction