Explaining the mechanism of the cochlear active phonosensitive amplification has been a major problem in medicine.The basilar membrane(BM)is the key infrastructure.In 1960,Nobel Laureate von B′ek′esy first discovere...Explaining the mechanism of the cochlear active phonosensitive amplification has been a major problem in medicine.The basilar membrane(BM)is the key infrastructure.In 1960,Nobel Laureate von B′ek′esy first discovered BM's traveling wave motion.Since that time,BM's models only have considered the traveling wave but not the biological activity.Therefore,a new model considering changes of BM's stiffness in space and time is established based on the immersed boundary method to describe its biological activity.It not only reproduces the results of traveling wave motion but also explains the mechanization on the generation of traveling wave.An important discovery is that changes of BM's stiffness in space and time will cause the unstable global resonance,which will induce amplification of sounds in cochlea.An important inference is that biological activity shall be included in the application of mechanical principles to the analysis of life,which is the essential difference between biomechanics and general mechanics.展开更多
Objective The aim of this study is to investigate the effect of transfected hTERT gene on cell apoptosis of newborn rat cochlear basilar membrane cells (CBMCs). Methods CBMCs isolated from newborn rat cochlear were tr...Objective The aim of this study is to investigate the effect of transfected hTERT gene on cell apoptosis of newborn rat cochlear basilar membrane cells (CBMCs). Methods CBMCs isolated from newborn rat cochlear were transfected using a plasmid containing human telomerase reverase transcriptase gene (pCI-neo-hTERT) , and were screened using G418 to obtain stable transfected cell lines. Cell apoptosis rate was analyzed by flow cytometry. hTERT and apoptosis related genes expression were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results hTERT gene expression was detected 72 hours after gene transfection in transfected cells. The apoptotic rate of transfected CBMCs significantly reduced. Expression of apoptosis related genes correspondingly changed. Conclusion Transfection of hTERT gene leads to reduced apoptosis rate in newborn rat CBMCs.and lower expression of apaf1, Caspase3 and BCL2 in transfected cells as compared to that of normal CBMCs.展开更多
Normal mammalian ears not only detect but also generate sounds. The ear-generated sounds, i.e., otoacoustic emissions (OAEs), can be measured in the external ear canal using a tiny sensitive microphone. In spite of wi...Normal mammalian ears not only detect but also generate sounds. The ear-generated sounds, i.e., otoacoustic emissions (OAEs), can be measured in the external ear canal using a tiny sensitive microphone. In spite of wide applications of OAEs in diagnosis of hearing disorders and in studies of cochlear functions, the question of how the cochlea emits sounds remains unclear. The current dominating theory is that the OAE reaches the cochlear base through a backward traveling wave. However, recently published works, including experimental data on the spatial pattern of basilar membrane vibrations at the emission frequency, demonstrated only forward traveling waves and no signs of backward traveling waves. These new findings indicate that the cochlea emits sounds through cochlear fluids as compression waves rather than through the basilar membrane as backward traveling waves. This article reviews different mechanisms of the backward propagation of OAEs and summarizes recent experimental results.展开更多
基金Project supported by the Key Projects of National Natural Science Foundation of China(No.11932010)。
文摘Explaining the mechanism of the cochlear active phonosensitive amplification has been a major problem in medicine.The basilar membrane(BM)is the key infrastructure.In 1960,Nobel Laureate von B′ek′esy first discovered BM's traveling wave motion.Since that time,BM's models only have considered the traveling wave but not the biological activity.Therefore,a new model considering changes of BM's stiffness in space and time is established based on the immersed boundary method to describe its biological activity.It not only reproduces the results of traveling wave motion but also explains the mechanization on the generation of traveling wave.An important discovery is that changes of BM's stiffness in space and time will cause the unstable global resonance,which will induce amplification of sounds in cochlea.An important inference is that biological activity shall be included in the application of mechanical principles to the analysis of life,which is the essential difference between biomechanics and general mechanics.
文摘Objective The aim of this study is to investigate the effect of transfected hTERT gene on cell apoptosis of newborn rat cochlear basilar membrane cells (CBMCs). Methods CBMCs isolated from newborn rat cochlear were transfected using a plasmid containing human telomerase reverase transcriptase gene (pCI-neo-hTERT) , and were screened using G418 to obtain stable transfected cell lines. Cell apoptosis rate was analyzed by flow cytometry. hTERT and apoptosis related genes expression were detected by reverse transcriptase polymerase chain reaction (RT-PCR). Results hTERT gene expression was detected 72 hours after gene transfection in transfected cells. The apoptotic rate of transfected CBMCs significantly reduced. Expression of apoptosis related genes correspondingly changed. Conclusion Transfection of hTERT gene leads to reduced apoptosis rate in newborn rat CBMCs.and lower expression of apaf1, Caspase3 and BCL2 in transfected cells as compared to that of normal CBMCs.
文摘Normal mammalian ears not only detect but also generate sounds. The ear-generated sounds, i.e., otoacoustic emissions (OAEs), can be measured in the external ear canal using a tiny sensitive microphone. In spite of wide applications of OAEs in diagnosis of hearing disorders and in studies of cochlear functions, the question of how the cochlea emits sounds remains unclear. The current dominating theory is that the OAE reaches the cochlear base through a backward traveling wave. However, recently published works, including experimental data on the spatial pattern of basilar membrane vibrations at the emission frequency, demonstrated only forward traveling waves and no signs of backward traveling waves. These new findings indicate that the cochlea emits sounds through cochlear fluids as compression waves rather than through the basilar membrane as backward traveling waves. This article reviews different mechanisms of the backward propagation of OAEs and summarizes recent experimental results.
