Objective To study the recovery of the outer hair cells in the bat cochlea after gentamicin exposure. Methods Bats were injected with a daily dose of gentamicin for 15 consecutive days and bromodeoxyuridine (BrdU) was...Objective To study the recovery of the outer hair cells in the bat cochlea after gentamicin exposure. Methods Bats were injected with a daily dose of gentamicin for 15 consecutive days and bromodeoxyuridine (BrdU) was given from day 16 to day 40 of this recovery phase. Hearing was assessed by overt acoustic behavior and auditory brainstem responses analysis, which was performed one day prior to the first injection and a day after the last injection (day 16). On day 40 animals were sacrificed for detection of cells that could take up BrdU. Results After 15 days of gentamicin treatment, all of the animals were proved to be deafened with significant increases of ABR thresholds, compared with control group. The findings in immunocytochemical stained samples and scanning electron microscopy revealed that BrdU labeled nuclei were observed in the cochlea in all of the deafened animals most commonly in the regions of the first-row and second-row Deiter’s cells (DCs) and occasionally in the regions of the third-row DCs. Conclusion We suggest that, under sufficient drug and enough time, the bat cochlear supporting cells can directly transdifferentiate into the outer hair cells after aminoglycoside exposure. This transdifferentation process is essential for repair of outer hair cells and recovery of normal function after gentamicin exposure.展开更多
Hereditary hearing loss is one of the most common neurosensory defects in humans. Approximately 70% of cases are nonsyndromic and could be inherited in autosomal domi- nant, autosomal recessive, mitochondrial, X-linke...Hereditary hearing loss is one of the most common neurosensory defects in humans. Approximately 70% of cases are nonsyndromic and could be inherited in autosomal domi- nant, autosomal recessive, mitochondrial, X-linked, and Y-linked manners （Wang et al., 2004; Alford, 2011）. The autosomal dominant type, comprising 15%-20% of non- syndromic hearing loss, is monogenic and genetically heterogeneous. Since the first dominant deafness locus （DFNA 1） was identified in 1992, a total of 64 DFNA loci have been mapped （DFNA1-DFNA64）,展开更多
Attic cholesteatoma with antral extension in tight sclerotic mastoid cavities is a common presentation that creates difficult decision-making intraoperatively.Drilling through a sclerotic and small mastoid cavity,keep...Attic cholesteatoma with antral extension in tight sclerotic mastoid cavities is a common presentation that creates difficult decision-making intraoperatively.Drilling through a sclerotic and small mastoid cavity,keeping the canal wall intactis often difficult and increases the risk of serious injury.Consequently,a canal-wall-down mastoidectomy is often performed.The endoscopic transcanal modified canal-wall-down mastoidectomy approach al lows the benefits of an open cavity for cholesteatoma resection and the benefits of a closed cavity for better long-term care and a more normal ear canal and middle ear reconstruction.展开更多
基金supported by the National Natural Science Foundation of China (No.39970785) International Collaborate Research Foundation of National Natural Science of China (No.322200462).
文摘Objective To study the recovery of the outer hair cells in the bat cochlea after gentamicin exposure. Methods Bats were injected with a daily dose of gentamicin for 15 consecutive days and bromodeoxyuridine (BrdU) was given from day 16 to day 40 of this recovery phase. Hearing was assessed by overt acoustic behavior and auditory brainstem responses analysis, which was performed one day prior to the first injection and a day after the last injection (day 16). On day 40 animals were sacrificed for detection of cells that could take up BrdU. Results After 15 days of gentamicin treatment, all of the animals were proved to be deafened with significant increases of ABR thresholds, compared with control group. The findings in immunocytochemical stained samples and scanning electron microscopy revealed that BrdU labeled nuclei were observed in the cochlea in all of the deafened animals most commonly in the regions of the first-row and second-row Deiter’s cells (DCs) and occasionally in the regions of the third-row DCs. Conclusion We suggest that, under sufficient drug and enough time, the bat cochlear supporting cells can directly transdifferentiate into the outer hair cells after aminoglycoside exposure. This transdifferentation process is essential for repair of outer hair cells and recovery of normal function after gentamicin exposure.
基金supported by the grants from the National Natural Science Foundation of China,key project(No.30830104) and major project(No.81120108009)
文摘Hereditary hearing loss is one of the most common neurosensory defects in humans. Approximately 70% of cases are nonsyndromic and could be inherited in autosomal domi- nant, autosomal recessive, mitochondrial, X-linked, and Y-linked manners （Wang et al., 2004; Alford, 2011）. The autosomal dominant type, comprising 15%-20% of non- syndromic hearing loss, is monogenic and genetically heterogeneous. Since the first dominant deafness locus （DFNA 1） was identified in 1992, a total of 64 DFNA loci have been mapped （DFNA1-DFNA64）,
文摘Attic cholesteatoma with antral extension in tight sclerotic mastoid cavities is a common presentation that creates difficult decision-making intraoperatively.Drilling through a sclerotic and small mastoid cavity,keeping the canal wall intactis often difficult and increases the risk of serious injury.Consequently,a canal-wall-down mastoidectomy is often performed.The endoscopic transcanal modified canal-wall-down mastoidectomy approach al lows the benefits of an open cavity for cholesteatoma resection and the benefits of a closed cavity for better long-term care and a more normal ear canal and middle ear reconstruction.
