Objective To establish reliable tissue culture methods of organ of Corti in neonatal Wistar Rat.Methods The organ of corti was aquired from Wistar Rat with the method of microdissection.The tissues were cultured by two different methods.Results Twenty-four hours after the tissue cultivation,new epithelia cells and fibroblast were found around the tissue.Inner hair cell、outer hair cell and supporting cell grew well.The tissue was stained by Acridine orange and Prodium iodine.It became green,meaning the tissue had good activity.Conclusion The culture of organ of corti we introduced is an a ideal method for otology research.

Objective To investigate the effects of hydrogen peroxide on function and morphology of guinea pig cochlea in vivo.Methods Animals were divided into four groups and their cochleas were perfused with artificial perilymph(AP), 50 ?M H 2O 2, 100 ?M H 2O 2 and 200 ?M H 2O 2 resolved in AP separately. The compound action potential(AP) and cochlear microphonic(CM) were recorded after two-hours' perfusion. Then hydrogen peroxide-induced cell damage in the inner ear was investigated with morphologic method.Results In all H 2O 2 groups, CAP threshold shifts and CM amplitude shifts were significantly greater than that of APL group. The effect of H 2O 2 perfusion on cochlear function showed dose-dependence. OHCs were major targets of H 2O 2-induced cell death, while Hensen's cells did not show any signs of damage in the presence of H 2O 2. Conclusion Hydrogen peroxide, as an ubiquitous reactive oxygen species(ROS), can induce cochlea dysfunction and damage of cells in guinea pig inner ear. Hensen's cells maybe more resistant to the damage of ROS than hair cells.

Geographic information system (CIS) was applied to analyse the endemic situation of schistosomiasis and the distribution of snails in Dali City. Hie data of endemic situation of schistosomiasis in Dali City from 2002 to 2008 were collected and a CIS database was set up. The endemic situation and the distribution of snails and acute schistosomiasis cases were analyzed by ArcGIS 9. 2 software. The results showed that the schistosomiasis transmission areas included 11 towns, 91 villages, and 401 nature villages. The trend surface analysis suggested that snail distribution in 2008 had a trend to accumulate in the northwest, while the population infection had a trend of gathering to the southeast. All acute schistosomiasis cases distributed in 6 towns, 23 villages, which showed significant aggregation by space-time clustering analysis, and three endemic villages in Xizhou Town in 2002 were identified as the first stratum endemic areas. It is concluded that CIS as database and graphics management tools can describe the epidemic situation intuitively, imaginably and macrosopically.

Objective To investigate plasma pharmacokinetics profiles of compound betameth in guinea pig after postaurieal and systemic administrations,and to explore the possible pathway for postaurical injection. Methods 1 ml compound-betameth was injected postaurieally and intramuscularly into the guinea pig. Blood were samples obtained 0. 5,1,1.5,2,3,5,7 h and 1,2,4 w after the administration of contralateral sigmoid sinus blood and circulatory blood respectively. High performance liquid chromatography was used to dectet compound betameth in the samlowing postaurieal administration. The Cmax(peak concentration) in sigmoid sinus of postaurieal group was 2.56 and 3.03 higher than those in the contralateral and the systemic group. The AUC((area under the ct curve) was 2.41 postaurieal administration. The Cmax and AUC in postaurieal group were 0. 13 and 0. 32 higher than systemic group. Conclusion The postaurieal injection reached a higher concentration of drugs in the sigmoid sinus blood, and remained a lower concentration in circulatory blood.

Objective To study the correlation between dopamine and glutamate receptor NMDA NR_1 and NMDA NR_(2A),and to share the understanding of the mechanism of dopamine in the synaptic complex of inner hair cells.Methods Forty guinea pigs were divided randomly into four groups and the whole intacochlear perfusions were performed.The perfused cochleas were taken out as preparations 2 hours after perfusing,the contralateral cochleas were also taken out as the normal control group in the group perfused with artifical perilymph solutions.All the preparations were divided into 5 groups:①normal control cochleas;②perfused with artificial perilymph solutions;③perfused with artifical perilymph solutions containing 10 mmol/L dopamine；④perfused with artificial perilymph so lutions containing 30 mmol/L dopamine；⑤perfused with artifical perilymph solutions containing 50 mmol/L dopa mine.The semi-quantitive RT-PCR was used to observe the difference in the amount of glutamate receptor NMDA NR_1、NMDA NR_(2A).Results Dopamine inhibited the compound action potential(CAP),the increase of CAP threshold was observed and correlated with the contentration of dopamine in the perfusion solution.Regarding the amount of glutamate receptor NMDA NR_1 mRNA,there was no significant difference between group ① and group ② (P＞0.05).But a significant difference was observed the other 3 groups when compared to group ①(P＜0.05).No significant difference was detected among the 5 groups in the amount of glutamate receptor NMDA NR_(2A) (P＞0.05).Conclusion Dopamine may inhibit the cochlear auditory afferent nerve.The significant correlation between dopamine and glutamate receptor NMDA NR_1 was observed,the amount of glutamate receptor NMDA NR_1 decreased along with the increasing of the contentration of dopamine in the perfusion solution.And there was no significant correlation between dopamine and glutamate receptor NMDA NR_(2A).

OBJECTIVE To analyze 1000 Hz probe tone tympanometry of middle ear with different volume of fluid, and to evaluate the role of 1000 Hz probe tone tympanometry in the diagnosis of presence of fluid in tympanic cavity. METHODS Tympanometries with 1000 Hz or 226 Hz probe tone were obtained from all the guinea pigs with different volume of fluid in tympanic cavity using GSI33 analyzer and tympanometry curves were analyzed. RESULTS There was a significant difference of the peak pressure of 1000 Hz tympanometry among all test groups and control group. The peak pressure decreased with the increasing of fluid volume in tympanic cavity. CONCLUSION Tympanometry with 1000 Hz probe tone can be used in the diagnosis of fluid in tympanic cavity, and it can be an indicator of volume of fluid in tympanic cavity.

OBJECTIVE To investigate the protective effect and its frequency selection of dopamine on the inner cell in cochlea when exposed to white-noise;In order to offer an important step on understanding of negative protective modulation of dopamine in the cochlear auditory afferent nerve. METHODS Forty guinea pigs were randomly divided into 4 groups and whole intracochlear perfusions were performed. ① exposed to the 100dB white-noise; ② perfused with artificial perilymph solutions; ③exposed to the white-noise and perfused with artificial perilymph solutions; ④exposed to the white-noise and perfused with Artificial perilymph solutions containing 1mmol/L dopamine. Compound action potential(CAP)evoked by different frequencies tone pip, and cochlear mirophonics(CM)evoked by 4kHz tone burst were recorded from the round window of guinea pigs before and 2h after perfusion. RESULTS In the groups exposed to the white-noise, the CM amplitude and the linearity of input-output function both significantly decreased at 2h(P

The purpose of this study was to assess the diagnostic value of main frequency of transient evoked otoacoustic emissions for Meniere's disease. The click- evoked transient otoacoustic emissions(TEOAE) in normal subjects and in patients with Meniere' s disease were examined using ILO 88 otodynamic analyzer system to observe the main frequency distrbution. The main frequeencies ranged from 1.2 to 1.6 kHz in normal ears, and from 0.8 to 1. 1 kHz in Meniere' s ears. The main frequency range of normal ears was obviously higher than that in Meniere's ears. After application of glycerol, the main frequencies in some Meniere's ears were shifted from relative low frequency range to relative high frequency range. TEOAE appeared in some Meniere's ears in which TEOAEs could not be evoked before application of glycerol. The results suggest that the TEOAE can be used in the diagnosis of Meniere's disease.

Objective To observe the action of H_2O_2 on the hair cells in the organ of Corti of rats.Methods The culture technology of Corti in neonatal rat in vitro was used to establish the model of studying the injury of inner and outer hair cells caused by exogenous H_2O_2. 24 neonatal SD rats of 1～ 5 days were selected and divided into 4 groups with 6 in each group.There were 12 ears in each group:①serum-free medium;②0.05 mmol/L H_2O_2;③0.1 mmol/L H_2O_2;④0.5 mmol/L H_2O_2.Forty-eight hours after the tissues cultivation, the tissue was stained by AO and PI.The ratio of apoptotic cells in different groups was studied.Results Apoptosis cells were detected in groups of different concentration of H_2O_2.Outer hair cell were the main target attacked by H_2O_2.But not at apoptotic Sertoli cells.The loss of hair cells on the bottom,middle and parietal turn of basilar membranes varied as the injury to the bottom turn was more severe.The results suggest OFR could cause apoptosis of hair cells,and cochlea damage was dose-dependent in this way.Conclusion Under the conditions of this experiment,exogenous H_2O_2 can cause the apoptosis of hair cells of the organ of Corti in rats,but not related to apoptotic Sertoli cells.