Objective:To compare the changes in distortion product otoacoustic emission （DPOAE） test results in clinical patients with negative middle ear pressure after equalizing the pressure in the external canal and the middle ear cavity. This study aims to analyze the effect of negative middle ear pressure on otoacoustic emissions and investigate the correlation between the degree of negative middle ear pressure and the changes in amplitude and signal-to-noise ratio of DPOAE. Methods:Twenty-seven clinical patients were included, with 34 ears exhibiting negative middle ear pressure. Acoustic conductance tests, pure tone hearing threshold tests, and DPOAE tests were conducted under ambient pressure and peak pressure after equalizing the middle ear pressure for all tested ears. The amplitude and signal-to-noise ratio of DPOAE before and after compensating for middle ear pressure were recorded and statistically analyzed. Results:At 1.0 k Hz, 1.5 k Hz, and 8.0 k Hz, the DPOAE amplitude under ambient pressure was significantly higher than that under negative pressure （P<0.05）. A significant difference in the DPOAE signal-to-noise ratio was observed at 1.0 k Hz and 8.0 k Hz （P<0.05）. The difference in both amplitude and signal-to-noise ratio between these two test conditions was more pronounced at 1.0 k Hz （P<0.01）. There was no correlation between the negative pressure value from the tympanogram and the change in amplitude, with a weak negative correlation trend observed only at 0.75 k Hz （r=-0.328, P=0.054）. However, a significant negative correlation was found between the negative pressure value from the tympanogram and the change in signal-to-noise ratio at 0.75 k Hz （r=-0.366, P<0.05）. Conclusion:Compensating for middle ear pressure significantly improves the amplitude and signal-to-noise ratio of DPOAE in cases of negative middle ear pressure, particularly in the medium-frequency range. The smaller the degree of negative pressure in the middle ear, the weaker the effect of equalizing middle ear pressure is, especially in the low-frequency range.
Humans ; Ear, Middle/physiopathology* ; Male ; Female ; Adult ; Otoacoustic Emissions, Spontaneous ; Young Adult ; Middle Aged ; Pressure ; Adolescent ; Aged ; Signal-To-Noise Ratio

Objective To investigate the impact of daidzein(DAI)on the pyroptosis of renal tubular epithelial cells induced by high glucose by regulating NOD-like receptor protein 3(NLRP3)/caspase-1 signal pathway.Methods HK-2 cells were divided into control group(NC group)(5.5 mmol/L D-glucose),HG group(30 mmol/L D-glucose),DAI-L,DAI-M,DAI-H groups(HK-2 cells were incubated with 30 mmol/L D-glucose and 25,50,100 μmol/L DAI,respectively),and DAI-H+LPS group(HK-2 cells were incubated with 30 mmol/L D-glucose,100 μmol/L DAI and 1 μg/mL LPS).MTT assay was applied to detect the cytotoxicity and proliferation of HK-2 cells;the apoptosis of HK-2 cells was detected by flow cytometry.The level of interleukin-1β(IL-1β)and inter-leukin-18(IL-18)in HK-2 cells was detected by ELISA.The morphology of pyroptosis cells was ob-served by scanning electron microscope.Immunofluorescence staining was applied to detect pyroptosis related pro-teins.The expression of NLRP3,cleaved casase-1 and GSDMD-N was detected by Western blot.Results In NC group,the cells were spherical with regular boundaries,while in HG group,the cells swelled and became larger with irregular boundaries;the OD value(490 nm)of HK-2 cells in HG group was obviously lower than that in NC group(P＜0.05),the apoptosis rate,IL-1β,IL-18 contents,NLRP3,cleaved casase-1,GSDMD-N protein level of HK-2 cells were obviously higher(P＜0.05);After DAI treatment,the swelling of cells was alleviated,the A value(490 nm)of HK-2 cells increased significantly(P＜0.05),the apoptosis rate of HK-2 cells,IL-1 β,IL-18 content,NLRP3,cleaved-caspase-1 and GSDMD-N protein levels were significantly decreased(P＜0.05)and the therapeutic effect of DAI was dose-dependent;LPS eliminated the beneficial effect of DAI-H on high glucose in-duced apoptosis of renal tubular epithelial cells.Conclusions DAI may alleviate pyroptosis of renal tubular epithe-lial cells induced by high glucose through inhibition of NLRP3/caspase-1 signaling pathway.