To explore the mechanism of therapeutic effect of basic fibroblast growth factor (bFGF) in the treatment of blast-induced deafness, and to define its optimal clinical use, bFGF was infused into the guinea pig's cochlea, combined with intramuscular injection of bFGF after being exposed to explosion. The compound action potential (CAP) and auditory brainstem response (ABR) were measured in these animals. 125I labeled basic fibroblast growth factor ( 125I -bFGF) was injected intraperitoneal to the guinea pigs to observe whether it could pass through the blood-labyrinthine barrier. The results showed that bFGF infused to the cochlea might facilitate recovery of hearing loss following acoustic trauma. Basic fibroblast growth factor ( 125I -bFGF) intraperitoneally injected, could not pass through the blood-labyrinthine barrier. However intramuscular bFGF promoted the recovery of hearing, probably indirectly through the neuro-immunity network.

Objective To examine the age-related morphological changes in hair cell nuclei,and explore the death modes of cochlea hair cells in aged rats.Methods Thirty-two Wistar rats were used in present experiment.The animals were assigned to one of the two groups,rats in aged group(n=20)were 22-23 months of age,and those in young group(n=12)were 2-3 months of age.The auditory brainstem response(ABR)thresholds of both ears elicited with tone bursts at 4,10 and 20 kHz were measured in both young and aged Wistar rats.Upon completion of the auditory test,animals were decapitated and both left and right bullae were exposed.Following fixation,whole specimens comprising the basilar membrane with Corti's organ were separated from the modiolus.Propidium iodide(PI),a popular DNA intercalating fluorescent probe,was used to trace the morphological changes in cochlea hair cell nuclei in the aged rats.Each Corti's organ was thoroughly inspected from the apical to the basal turns of cochlea with fluorescence microscopy.According to the morphological changes in the nuclei,the death modes of cochlea hair cell were determined.Results There were significant differences on ABR thresholds(P=0.001)at all tested frequencies between the young and aged rats.Three types of cochlea hair cell pathology appeared in the aged rats,including karyopyknosis,nuclear swelling and denucleation.A large number of loss or degenerated hair cells were present in the apical and basal end of cochlea in aged rats.Conclusion The present study indicates that apoptosis and necrosis are the death modes of cochlea hair cells in aged Wistar rats.

BACKGROUND: The sensorineural deafness occurs as a result of loss of inner ear hair cells in the cochlea or of their primary afferent the spiral ganglion neurons. Stem cells to restore hearing following inner ear cell death has become a focus in recent years.OBJECTIVE: To summarize research progress in stem cells differentiating into inner ear cells in vitro and in vivo and to review the achievement in stem cells replacing inner ear cells in treating sensorineural deafness.METHODS: With "inner ear, stem cells" as key words, a computer-based online search of Pubmed and CNKI was performed for articles published from January 2000 to August 2009. RESULTS AND CONCLUSION: A total of 170 articles were collected, and experimental studies and review articles on stem cells in sensorineural deafness were included, while repetitive articles were excluded. Finally, 32 articles were summarized and analyzed. Different types of stem cells have the capacity to differentiate into inner ear cells. They can differentiate into neural cell types. Stem cells can live and migrate, differentiating into cell types of the sites of injury. It provides a therapy strategy to restore hearing following sensorineural deafness by he capacity of stem cells differentiating into inner ear cells. However, it remains further investigation how to function following cell differentiation and how to form the appropriate neural pathways by stem cell transplantation in sensorineural deafness.

This paper is to report the results of the experimental study on the effects of the explosion sound waves on the hearing power and the activities of succinic dehydrogenase (SDH) and malic dehydrogenase (MDH) of the cochlea tissues in guinea pigs. The alterations of the hearing power and the activities of the two enzymes were monitored with auditory physiological and histochemical methods respectively. The results of the experiment were as follows:The activities of both SDH and MDH decreased significantly (P

Objective To understand the structural characteristics and significance of the outer tunnel of corti's organ.Methods The structural characteristics of the outer tunnel were observed and analyzed with celloidin section and scanning electron microscope(SEM).Results The inner wall of outer tunnel consisted of the third row of outer hair cells(OHC) and the stalk of Deiter's cells in the basal and the first turn.Hensen's cells made up the outer wall of the outer tunnel.The stalks of Deiter's cells gradually moved to outer side to constitute the outer and top walls of outer tunnel from the basal turn to the top turn.The inner wall of outer tunnel consisted of the third OHC.The stalks of Deiter's cells moved to Hensen's cells to make the outer wall of the outer tunnel.The space of outer tunnel was gradually decreased.The outer tunnel was full of Deiter's cells in the third and fourth turn.The stalks of Deiter's cells tightly contacted with the Hensen's cells.Conclusion The structural characteristics of the outer tunnel play an important role in maintaining the stability of Corti's organ.

Objective The prestin,a motor protein responsible for outer hair cell(OHC)electromotility,is expressed on the OHC surface.Previous experiments revealed that OHC electromotility and its associated nonlinear capacitance was mainly located at the OHC lateral wall and was absent at the apical cuticular plate and the basal nucleus pole.Immunofluorescent staining for prestin failed to demonstrate the prestin expression at the OHC basal ends in whole-mount preparation of the organ of Corti.The aim of this study is to investigate the distribution of prestin at OHC.Methods In this experiment,the localization of prestin protein in single dissociated OHCs from cochlea of normal mouse,rat and guinea pig,were examined by immunofluorescent staining and confocal microscopy.Results We found that prestin was uniformly expressed on the OHC basolateral surface,including its basal pole.No staining was observed on the cuticular plate and stereocilia.The OHC lateral wall had a trilaminate organization and was composed of the plasma membrane,cortical lattice,and subsurface cisternae.By with co-staining with a membrane marker di-8-ANEPPS,prestin-labeling was found locating at the outer layer of the OHC lateral wall.Further separating the plasma membrane from the underlying subsurface cisternae,using a hypotonic extracellular solution,prestin-labeling was shown locating at the plasma membrane instead of the subsurface cisternae.Conclusion The data revealed that prestin is expressed in the plasma membrane on the whole OHC basolateral surface.

Objective To observe the effects of the re-therapeutic on later stage of sudden deafness.Methods Patients who met the criteria for sudden deafness and showed poor response tO conventional therapy over two months were recruited and assigned randomly for re-therapy.The pure tone audiometry was conducted before and after re-treatment in 103 patients(112 ears).Sodium bicarbonate and dexamethasone were iniected by intravenous drip for two days and batroxobin 5 BU for 6 days.Statistics were made in the effecency of the re-treatment.Results The effective rate of re-treatment group was 46.43% and the difference was significant before and after retreatment(P<0.01).Conclusion Combined use of sodium bicarbonate dexamethasone and batroxobin is effective in re-treating later sudden deafness.

The interference of optokinetic nystagmus from vestibular nystagmus was evaluated in 10 patients with a pre-existing spontaneous peripheral vestibular nystagmus, and in 9 normal subjects, in whom vestibular nystagmus was induced with 10 times of 60?sec constant speed count-clockwise rotation. The examinees of both groups were all subjected to horizontal clockwise and counter-clockwise optokinetic stimulation(target speed 60?/sec, frequency 2 Hz).It was found that vestibular nystagmus exerted no significant modifying effect on the eye velocity of the slow phas? of optokinptic nystagmus and that no favourablp evid?cs was demonstrated to support the algebraic summation hypothesis.

OBJECTIVE To investigate the effect of Hath1 on epithelial ridge (GER) cells from postnatal rat cochlear. METHODS An experimental method was developed which allowed the isolation and culture of GER cells from P1 rat cochleae using a combinatorial approach of enzymatic digestion and mechanical separation. The dissociated GER cells were cultured in DMEM+10% FBS. The GER explants infected with ad-Hath1 for 3 hours were cultured for 10 days and observed under scanning electron microscope. RESULTS The GER cell cultures tended to attach to the substratum and grow in patches which assume a polygonal morphology similar to that of epithelial cells in medium containing 10% serum. Stereociliary bundle-like structures were observed in the boundary of GER cell patches forced to express Hath1. CONCLUSION That GER cells which are likely hair cell progenitors could be cultured in vitro and generate stereociliary bundle-like structure when forced to express Hath1 suggests that the misexpression of Hath1 probably can induce the predifferentiation of pure hair cell progenitors into hair cells in vitro.

OBJECTIVE: Assess and compare the clinical efficacy and safety of cochlear implantation in deaf patients with inner ear malformation and in the ones with normal inner ear structure, so that to clarify whether it is effective to restore hearing for the deaf patients with inner ear malformation. METHOD: The literature with relevant key words were retrieved in the databases including PubMed, YZ365. com, WANFANG data, CMJD, CHKD and CNKI with language limited to Chinese and English. Extracted data included author, year of publication, diagnosis, treatment, et al. The clinical efficacy of cochlear implantation was assessed by the complications, electrode impedance, behavior T-level, hearing abilities and speech discrimination. Meta-analysis was performed using random or fixed effects model according to the heterogeneity of data. RESULT: There were 11 randomized control studies involving 655 patients included in this study. There was no statistically significant difference among the deaf patients in mixed inner ear-malformation group, Mondini group and large vestibular aqueduct syndrome group in the aspects of postoperative complications, electrode impedance, behavior T-level, hearing abilities and speech discrimination. CONCLUSION Cochlear implantation could be the way of treatment and rehabilitation for deaf patients with inner ear malformation. Further controlled studies with longer follow-up periods and more multiracial cases included may help to evaluate the efficacy of cochlear implantation for deaf patients with inner ear malformation more reliably.
Cochlear Implantation ; Ear, Inner ; abnormalities ; Electric Impedance ; Electrodes ; Hearing ; Hearing Loss ; therapy ; Humans ; Postoperative Complications ; Randomized Controlled Trials as Topic ; Speech Perception