A review about the research progress of the acoustical-electrical transducer for totally implantable cochlear implant / 中华耳鼻咽喉头颈外科杂志

Cochlear implantation has become a crucial approach for the treatment for patients with severe and profound sensorineural hearing loss. However, some patients would be embarrassed by the exterior components, which limited the patient′s social activities. The idea of totally implantable cochlear implant (TICI) was put forward to alleviate these inconveniences. The implantable acoustical-electrical transducer would be a breakthrough in the study of TICI. In this paper, a summary of all kinds of designs ideas was made.

The pathological change of synapses in cochlear inner hair cell of hidden hearing loss mice / 复旦学报（医学版）

Objective To investigate the synaptopathy of hidden hearing loss mice,and to observe the synapses of the cochlear inner hair cell after temporary threshold shift of noise exposure.Methods Mice were divided into normal control group and experiment group,the latter was exposed under noise of 98 dB SPL for 2 h to establish the model of temporary threshold shift.Mice cochleae of the two groups were dissected and prepared with whole mount and immunostaining.Cellular morphology was observed under confocal laser scanning microscope.Cochlear lengths were measured through cochlear frequency map to localize hair cells in different frequency regions.Then,3-D morphometry of synapses was constructed by Amira software to observe pre-synaptic ribbons,post-synaptic receptors and its pathological changes.Results In control group,each cochlear nerve fiber contacted a single inner hair cell by a single synapse,each inner hair cell had 5-30 synapses contacting cochlear nerve fibers.The larger ribbons patched smaller receptors located in the modiolar side,and the smaller ribbons patched larger receptors located in the pillar side.While in experiment group,noise overexposures caused moderate or completely reversible thresholds shift,i,e.,distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) thresholds increased 30-40 dB.Although returned to normal after 2 weeks,ABR wave Ⅰ amplitudes recovered to only 46.1 ％ of pre-exposure amplitudes.There was 41.3％ synapses loss of inner hair cell,but there was no loss of inner hair cells and spiral ganglion neurons.Conclusions Threshold test is not sensitive to degeneration and loss of synapse in mice inner hair cells,while super threshold test is sensitive to it.

Dynamic changes in hair cell ribbon synapse induced by loss of spiral ganglion neurons in mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies have suggested that primary degeneration of hair cells causes secondary degeneration of spiral ganglion neurons (SGNs), but the effect of SGN degeneration on hair cells has not been studied. In the adult mouse inner ear ouabain can selectively and permanently induce the degeneration of type 1 SGNs while leaving type 2 SGNs, efferent fibers, and sensory hair cells relatively intact. This study aimed to investigate the dynamic changes in hair cell ribbon synapse induced by loss of SGNs using ouabain application to the round window niche of adult mice.</p><p><b>METHODS</b>In the analysis, 24 CBA/CAJ mice aged 8-10 weeks, were used, of which 6 normal mice were used as the control group. After ouabain application in the round window niche 6 times in an hour, ABR threshold shifts at least 30 dB in the three experimental groups which had six mice for 1-week group, six for 1-month group, and six for 3-month group. All 24 animals underwent function test at 1 week and then immunostaining at 1 week, 1 month, and 3 months.</p><p><b>RESULTS</b>The loss of neurons was followed by degeneration of postsynaptic specializations at the afferent synapse with hair cells. One week after ouabain treatment, the nerve endings of type 1 SGNs and postsynaptic densities, as measured by Na/K ATPase and PSD-95, were affected but not entirely missing, but their partial loss had consequences for synaptic ribbons that form the presynaptic specialization at the synapse between hair cells and primary afferent neurons. Ribbon numbers in inner hair cells decreased (some of them broken and the ribbon number much decreased), and the arrangement of the synaptic ribbons had undergone a dynamic reorganization: ribbons with or without associated postsynaptic densities moved from their normal location in the basal membrane of the cell to a more apical location and the neural endings alone were also found at more apical locations without associated ribbons. After 1 month, when the neural postsynaptic densities had completed their degeneration, most ribbons were lost and the remaining ribbons had no contact with postsynaptic densities; after 3 months, the ribbon synapses were gone except for an occasional remnant of a CtBP2-positive vesicle. Hair cells were intact other than the loss of ribbons (based on immunohistochemistry and DPOAE).</p><p><b>CONCLUSION</b>These findings define the effect of SGN loss on the precise spatiotemporal size and location of ribbons and the time course of synaptic degeneration and provide a model for studying plasticity and regeneration.</p>

Reinnervation of hair cells by neural stem cell-derived neurons / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Replacement of spiral ganglion neurons would be one prioritized step in an attempt to restore sensory neuronal hearing loss. However, the possibility that transplanted neurons could regenerate new synaptic connections to hair cells has not been explored. The objective of this study was to test whether neural stem cell (NSC)-derived neurons can form synaptic connections with hair cells in vitro.</p><p><b>METHODS</b>NSCs were mechanically separated from the hippocampus in SD rat embryos (E12-E14) and cultured in a serum-free medium containing basic fibroblast growth factor and epidermal growth factor. Rat NSCs were co-cultured with explants of cochlea sensory epithelia obtained from postnatal Day 3 rats under transway filter membrane.</p><p><b>RESULTS</b>At Day 3, the NSCs began to show chemotactic differentiation and grew toward cochlea sensory epithelia. After 9-day co-culture, neurites of NSC-derived neurons predominantly elongated toward hair cells. Immunohistochemical analyses revealed the fibers overlapped with synapsin and hair cells, indicating the formation of new synaptic connections. After 14-day culture, triple staining revealed the fibers overlapped with PSD95 (postsynaptic density) which is juxtaposed with CtBP2 (presynaptic vesicle), indicating the formation of new ribbon synapse.</p><p><b>CONCLUSIONS</b>NSC-derived neurons can make synaptic connections with hair cells and provide a model for studying synaptic plasticity and regeneration. Whether the newly forming synapse is functional merits further electrophysiological study.</p>

Clinical analysis of the diagnosis and treatment of benign paroxysmal positional vertigo by TRV-CRP / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the effective of the new mechanical assistant canalith repositioning procedure (TRV-CRP) to the diagnosis and treatment of the benign paroxysmal positional vertigo (BPPV).@*METHOD@#The data of the cases with suspected diagnosis of BPPV from April to June of 2012 checked and treated by TRV-CRP in our vestibular function checking room were collected and analyzed. All of the cases were followed up to one to three months.@*RESULT@#Total 504 cases of suspected diagnosis of BPPV were collected. Three cases were rejected for un completed procedure. All of the 501 completed procedure cases included 162 male and 339 female with age ranging from 10 years old to 86 years old (52. 8 +/- 14 years old). 169 cases (33.73%) were positive diagnosis and 332 cases were negative diagnosis (66.27%). 135 cases enrolled only one semicircular canal (SC) account for 79.89% of all the positive diagnosis that included 17 cases of left horizontal SC, 4 cases of left superior SC, 29 cases of left posterior SC, 23 cases of right horizontal SC, 4 cases of superior SC and 58 cases of right posterior SC. 25 cases enrolled more than two SC (14.80%). 9 cases of objective BPPV (5.33%) included 5 cases of right posterior SC, 3 cases of left posterior SC and one cases of right horizontal SC. Exception of 163 cases without classic BPPV history in the 332 negative diagnosis cases, 169 cases had classic BPPV history including 14 cases treated by manual canalith repositioning procedure and 33 cases which had released from the vertigo. The rate of treatment effective by TRV-CRP was 100%. There were 20 cases returned for retreatment because their unsatisfied about the release of their symptom but proved to be negative diagnosis again in 10 cases and positive diagnosis in 10 cases, however, only 4 cases proved to be the same SC disease were considered as relapse (2.37%) and others enrolled different SC. After retreated, all cases got release without relapse.@*CONCLUSION@#TRV-CRP could diagnosis 34% of the primary diagnosis cases of BPPV. TRV-CRP had high rate of effective and lower relapse which especially fitted to patients suffered from complex BPPV or difficult to finish the manual repositioning procedure. However, due to the expensive of TRV-CRP, it is reasonable to combine TRV-CRP and manual repositioning procedure in clinical.

Clinical experience in facial nerve tumors: a review of 27 cases / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To analyze the clinical manifestations and the diagnosis of the facial nerve tumor according to the clinical information, and evaluate the different surgical approaches depending on tumor location.@*METHOD@#Twenty-seven cases of facial nerve tumors with general clinical informations available from 1999.9 to 2006.12 in the Shanghai EENT Hospital were reviewed retrospectively.@*RESULT@#Twenty (74.1%) schwannomas, 4 (14.8%) neurofibromas ,and 3 (11.1%) hemangiomas were identified with histopathology postoperatively. During the course of the disease, 23 patients (85.2%) suffered facial paralysis, both hearing loss and tinnitus affected 11 (40.7%) cases, 5 (18.5%) manifested infra-auricular mass and the others showed some of otalgia or vertigo or ear fullness or facial numbness/twitches. CT or/and MRI results in 24 cases indicated that the tumors originated from the facial nerve. Intra-operative findings showed that 24 (88.9%) cases involved no less than 2 segments of the facial nerve, of these 24 cases 87.5% (21/24) involved the mastoid portion, 70.8% (17/24) involved the tympanic portion, 62.5% (15/24) involved the geniculate ganglion, only 4.2% (1/24) involved the internal acoustic canal (IAC), and 3 cases (11.1%) had only one segments involved. In all of these 27 cases, the tumors were completely excised, of which 13 were resected followed by an immediate facial nerve reconstruction, including 11 sural nerve cable graft, 1 facial nerve end-to-end anastomosis and 1 hypoglossal-facial nerve end-to-end anastomosis. Tumors were removed with preservation of facial nerve continuity in 2 cases.@*CONCLUSION@#Facial nerve tumor is a rare and benign lesion, and has numerous clinical manifestations. CT and MRI can help surgeons to make a right diagnosis preoperatively. When and how to give the patients an operation depends on the patients individually.

Modified gavage methods for guinea pigs / 复旦学报（医学版）

Objective To modify the method of gavage administration in guinea pigs. Methods Fourty awake guinea pigs were kept rearing on the hind legs and leaning on a vertical fixture to avoid their escaping forward. A 1 mL injector was inserted into the mouth to the depth when the molar teeth were passed. Another fourty guinea pigs under general anesthesia were reversed at trendelenburg position and a children suction tube with an outer diameter of 2 mm was inserted into the stomach. Results All of the 80 guinea pigs were administered by modified gavage smoothly for seven consecutive days by one operator each time. None endured much pain or digestive tract injury, or died from air way perfusion by mistake. Conclusions We successfully modified the gavage method in guinea pigs, which would definitely take guinea pigs involved in intragastical pharmacal experiments besides the routine of rats and mice.

Clinical experience in facial nerve tumors:A review of 27 cases / 临床耳鼻咽喉头颈外科杂志

Objective:To analyze the clinical manifestations and the diagnosis of the facial nerve tumor according to the clinical information, and evaluate the different surgical approaches depending on tumor location.Method:Twenty-seven cases of facial nerve tumors with general clinical informations available from 1999.9 to 2006.12 in the Shanghai EENT Hospital were reviewed retrospectively.Result:Twenty(74.1%) schwannomas,4 (14.8%)neuofibromas ,and 3(11.1%)hemangiomas were identified with histopathology postoperatively.During the course of the disease,23 patients(85.2%)suffered facial paralysis,both hearing loss and tinnitus affected 11 (40.7%)cases,5(18.5%)manifested infra-auricular mass and the others showed some of otalgia or vertigo or ear fullness or facial numbness/twitched. CT or/and MRI results in 24 cases indicated that the tumors originated from the facial nerve.Intra-operative findings showed that 24(88.9%)cases involved no less than 2 segments of the facial nerve,of these 24 cases 87.5%(21/24)involved the mastoid protion,70.8%(17/24)involved the tympanic protion, 62.5%(15/24)involved the geniculate ganglion, only 4.2%(1/24)involved the internal acoustic canal(IAC),and 3 cases (11.1%)had only one segments involved. In all of these 27 cases ,the tumors were completely excised,of which 13 were resected followed by an immediate facial nerve reconstruction,including 11 sural nerve cable graft,1 facial nerve end-to-end anastomosis and 1 hypoglossal-facial nerve end-to-end anastomosis.Tumors were removed with preservation of facial nerve continuity in 2 cases.Conclusion:Facial nerve tumor is a rare and benign lesion,and has numerous clinical manifestations.CT and MRI can help surgeons to make a right diagnosis preoperatively.When and how to give the patients an operation depends on the patients individually.

The character of superior semicircular canal dehiscence syndrome on multi-slice CT / 中华放射学杂志

Objective To better understand the MSCT characteristic of superior semicircular canal dehiscence syndrome (SSCDS). Methods A retrospective study was conducted on 8 patients who were diagnosed with SSCD syndrome in the otology and skull base surgery group of fudan university. All the patients CT features, the conventional axial and coronal images base on high-resolution MSCT and the images displayed the whole superior semicircular canal, which were reconstructed by using the technology of MPR, were reviewed. Results All the images that displayed the whole superior semicircular canal exhibited the dehiscence. Six patients' dehiscences occur in the middle of the roof over the superior semicircular (4 of 6 dehiscences also occur in the front of the roof), 2 patients dehiscences occur in the back of the roof over the superior semicircular. The range of the maximal diameter of the dehiscence was 0.8-4.2 mm, (median value: 2.4 mm). Conclusion The technology of MPR based on the high-resolution MSCT scan is very useful in diagnosis of the SSCDS.

Distributions of cells infected by AD5-EGFP infused in different ways in guinea pig's cochlear / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the distribution of cells infected by AD5-EGFP infused in different ways in the cochlea of guinea pig.@*METHOD@#AD5-EGFP was infused into the endolymphatic system through a hole on the lateral wall of the scala media or into the extralymphatic system through the round window membrane respectively. The infected cochlear cells confirmed by expression of EGFP were examined on the whole mount or cryostat sections.@*RESULT@#In the cochleae in which AD5-EGFP was infused into the extralymphatic system through the round window membrane, expression of EFGP could be found in the type I, IV and V fibrocyte of the stria vascularis, superlimbal cells of the spiral lip, cells in Ressenal membrane, spiral ganglion neurons in Rosenthal hole and cells lining the inner wall of scala vestibular and scala tympani, indicating that these cells were infected by adenovirus. None of the inner, outer hair or supporting cells was found to be infected in these cochleae. In the cochleae in which AD5-EGFP was infused into the endolymphatic system through a hole on the lateral wall of scala media, expression of EFGP could be found in supporting cells in the organ of Corti and lining cells of the scala media.@*CONCLUSION@#Adenovirus5 is a good and effective vector for delivering genes into cells in guinea pig's cochlea. The scope of infected cells will be very different when the vector is applied to the cochlea through different infusion ways. No cells in the endolymphatic system would be infected if the vector is infused into the extralymphatic system.

Total auricular reconstruction using nitinol shape memory alloy stent: Scanning electron microscope verification of surrounding tissue structure changes at 6 and 12 months after implantation / 中国组织工程研究

BACKGROUND: Plenty of materials have been used as stent in total auricular reconstruction with varying advantages and disadvantages. The in vitro prepared tissue engineered complex cartilage stent has been not applied in clinic.OBJECTIVE: To observe the ultrastructure changes of surrounding tissues following total auricular reconstruction with nickel-titanium (NiTi) shape memory alloy stent in vivo.DESIGN, TIME AND SETTING: The randomized, controlled, animal experiment was performed in the Central Laboratory of EENT Hospital of Fudan University, Anhui Provincial Hospital and Department of Nuclear Medicine, Huashan Hospital of Fudan University from April 2004 to October 2005.MATERIALS: A total of 12 New Zealand rabbits were randomized divided into the skin-expanded and unexpanded groups, with 6 animals in each group.METHODS: Each animal underwent subcutaneous implantation with a NiTi alloy stent like human auricle. In the skin-expanded group, the stent was implanted after skin expansion, while no treatment in the unexpanded group.MAIN OUTCOME MEASURES: The ultrastructure changes of surrounding tissues were detected by scanning electron microscope at months 6 and 12 after implantation.RESULTS: Structure of nickel-titanium alloy implant stent make fibrovascular ingrowth more easily. The surface of nickel-titanium alloy stent was smooth without corrosion. There was no evidence of infection in the host tissue. Microstructure of Ni-Ti stent wires showed no morphologic and functional changes after subcutaneously implanted in vivo, and the difference between 2 groups had no significance.CONCLUSION: NiTi shape memory alloy stent can smoothly pass the process of fibrovascularization with less complication.According to the examination by SEM, the nickel-titanium stent showed good biocompatibility.

The effects of small dose of intratympanic gentamicin injection on intractable Meniere's disease / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#To explore the efficacy of small dose of intratympanic gentamicin injection on intractable Meniere's disease.@*METHOD@#Retrospectively study the efficacy of gentamicin intratympanic injection on intractable Meniere's disease. The end-point of treatment was determined based on bedside tests (Spontaneous Nystagmus test, Head shaking test and Head Thrust test), hearing tests, or the improvement of patients symptoms.@*RESULT@#Nineteen patients with Meniere's disease were treated with intratympanic gentamicin injection. Vertigo control was achieved in 17 patients (89%). Of them, vertigo of 5 patients was successfully controlled after single injection. Eight patients need double injections and 4 patients need the third injections to control the vertigo. Endolymphatic sac shunt was performed to 1 patient because he could not tolerate the fullness of ear due to injection. The remainder 2 patients with double injections showed no improvement of vertigo and rejected further treatment. Hearing was improved in two patients after gentamicin injection. Three patients complained of hearing loss after intratympanic gentamicin injection. The hearing of the other patients did not change.@*CONCLUSION@#Three weeks after using small dose of gentamicin intratympanic injection to treat intractable Meniere's disease, it was determined whether more injections is required. The results showed that by using this approach, the vertigo could be effectively controlled and the risk of hearing loss following intratympanic gentamicin injection could be reduced.

Imaging of glomus tympanicum tumors / 中华放射学杂志

Objective To evaluate the imaging diagnosis value of glomus tympanicum tumors.Methods Images of 10 patients with surgically and pathologically confirmed glomus tympanicum tumors were reviewed.The image characteristics and diagnostic value were summarized.Results In 8 patients with high resolution CT scan and 2 patients with routine CT scan,soft tissue nodules within the tympanic cavity were identified on axial or coronal images in 7 of them.And in 3 patients with chronic tympanitis,glomus tympanicum tumors were not differentiated on CT images.Eight patients had undergone MR examination,on T2WI the tumors were moderate hyperintense(n=6)and hyperintense(n=2),and the tumors were enhanced obviously after contrast.In 3 patients with chronic tympanitis,moderate high signal of the tumor can be differentiated with the high signal of tympanitis on T2WI.On contrast MRI,the signal of enhanced tumor or unenhanced tympanitis was identified clearly.Conclusion On diagnosis of glomus tympanicum tumors,MRI is prior to CT,especially in patient with glomus tympanicum and tympanitis.